Table of contents

Proceeding

9^th International Conference of Physics and Its Applications (ICOPIA) 14 August 2018, Surakarta, Indonesia

Preface

International Conference of Physics and Its Applications (ICOPIA) is a biannual conference, started in 2001, for presenting and discussing current research in Physics and Its Applications. This year of 2018, this conference is the ninth one. Studies about material physics, optics, geophysics, instrumentation, magnetics and theoretical physics are presented orally. This conference is mainly supported by Department of Physics, Universitas Sebelas Maret, Indonesia.

The keynote presentations are provided to talk the current research in Physics. The keynote speaker Profesor Osamu Nakatsuka from Nagoya University presents the study of thin film growth and characterization of Group-IV alloy semiconductors for future nanoelectronic applications. The keynote from Universiti Kebangsaan Malaysia, Assoc. Prof. Dr. Mohd. Yusri Abd Rahman, presents about Dye-Sensitized Solar Cell Utilizing Titanium Dioxide-Strontium and Titanium Dioxide-Sulphur Composite Films Photoanode. The speech of analysis of groundwater level is also provided.

This proceeding contains the papers presented in ICOPIA 2018. The papers are divided into sections: Acoustic, Geophysics, Instrumentation Physics, Magnetism and Magnetic Material, Material Physics and Characterization, Optical, Theoretical and Computation Physics and Other Related to Physics magnetism and magnetic material, material physics and characterization, acoustics, theoretical physics, instrumentation physics, optics and geophysics. This structure is made so that readers are easier to find an article in this proceeding.

All papers published in this volume of Journal of Physics: Conference Series have been peer reviewed through processes administered by the proceedings Editors. Reviews were conducted by expert referees to the professional and scientific standards expected of a proceedings journal published by IOP Publishing.

Sound Power Level (SWL) is a measure to be used to describe a sound source regardless its surrounding and environment. In general, there are two different standardized methods to determine the Sound Power Level of a sound source, which are by using sound pressure and sound intensity. Other than that, there is a possibility to estimate Sound Power Level using an acoustic beamforming array or more popularly known as acoustic camera. This estimation is considered more time-efficient compared to the two methods and can be done when there are other sound sources during the measurement. However, this measurement is not yet standard compliant and therefore cannot be used for standardized reporting or legislative purposes.

The paper highlights the possibility to estimate Sound Power Level of a Reference Sound Source using an acoustic beamforming array, when another sound source is present at the time of measurement. Besides comparing to the Reference Sound Source's calibration chart, the measurement is compared with two ISO-compliant measurements which are ISO 3746 (Survey grade, sound pressure method) and ISO 9614-2 (survey grade, sound intensity method).

In the science of acoustics required two special rooms namely Reverberation Chamber and Anechoic Room. In Anechoic room is a free field from the reflection of sound so this room used to examine signals in audiosonics. one of which can be used to evaluate the noise of a machine and the analysis of acoustic materials. The calculation approach of Reverberation time is based on the semi-empirical formulation of Sabine and Eyring's theory. Measurement software used YMEC, can determine the time of buzzing EDT and T30. This research was conducted in semi-an echoic room department of physics ITS. From the measurement results obtained, cutoff frequency value of 23 Hz and critical frequency 200 Hz. The correlation of EDT and T30 results of Measurement of YMEC compared with the Reverberation time of Sabine and Eyring's Theory. Based on the measurement results obtained the corresponding reverberation time is EDT using Eyring theory approach method. Measurement T30 has almost the same value, but at 4000 Hz frequency experienced a significant increase. Reverberation time using the Sabine or Eyring theory has the same curve but for the value obtained Eyring theory is closer to the value of EDT.

In this study discussed the analysis of acoustic parameters of measurement and simulation of loudspeaker position at Cak Durasim Surabaya. Based on ISO-3382-1 acoustic parameters that need to be analyzed are SPL distribution, RT, C50, and C80. To get these parameters result, data retrieval using Impulse Response method was done. Measurements are made in a condition without audiences. Based on the measurement results, SPL distribution was less evenly with the maximum and minimum difference reached 14 dBA. In addition, the value of RT was 1.1 s which showed the impression of a sound was less "alive". From these measurements, it was necessary to add loudspeaker to improve the SPL distribution and the value of reverberation time. Based on the simulation, the result of the SPL distribution evenly with the maximum and minimum difference of 6 dBA, C50 of 4.5 dB, and C80 of 8.2 dB. For RT there were no significant change that were 0.68 s. It means the sound impression in the room was still less "alive". Problems in the simulation result can be solved by giving certain effects of the sound system so it doesn't need to change the material composing of the room.

Many of the building materials on the market in Indonesia are not included with material properties data. In acoustic books, quite a lot of acoustic data are listed, but these data do not match the material marketed in Indonesia. Bricks that are marketed in European countries or neighboring countries, have different nature with brick in Indonesia. so that materials from abroad do not reflect the acoustic properties of building materials in Indonesia. One important data is the value of material absorption coefficient. Calculating The value of the absorption coefficient is performed in a standardized Reverberation Chamber. In this study conducted an evaluation of Reverberation Chamber in Physics Laboratory Building Department of Physics FIA ITS. The method used in the study refers to ISO 354. From the measurement results have been obtained cut-off frequency of 20 Hz while the critical frequency is 150 Hz. The measured RT value is quite high and above the minimum RT value of ISO 354 in all frequency ranges as shown in figure.1. as shown in figure.1, at a frequency of 500 Hz, Reverberation Time reaches 7.35 s. Evaluation of this Reverebration Chamber is important to know if it can be done as a test chamber.

In the field of acoustic physics required a certain material to make a room to have better sound quality. One of the materials that can be used to manipulate sound resonator panel. In general, the panel used is made of wood and box-shaped, but in this study used resonator pipe which is a half-cylinder pipe. The panel variations used are 1.5'', 2'', and 2.5'' with pipe length 60 cm. While the variation in the number of pipes is 1, 3 and 5. The measurements are done in the semianechoic chamber at the acoustic physics laboratory, the physics department of FIA ITS based on the method written by C. Lagarrigue. In resonator measurement, resonance capability is measured. From the results of the measurements, the resonance frequency for the 1.5'' pipe size with the number of pipes 1, 3 and 5 all resonance at 40Hz, 80Hz and 400Hz for size 2'' pipe size is 40Hz, 80Hz. And the 2.5'' pipe has a resonance frequency at 40Hz only. From the measurement results it is seen that the addition of the number of pipes resulted in the decreasing some point of resonance frequency.

The quality of the performance is determined by the stage acoustic condition. The parameter will determine the harmonization of performances as well as communication media between musicians. There are some acoustic parameters that determine the stage acoustics, which are ST early, ST late, reverberation time and clarity of music (C₈₀). The study evaluated the stage acoustic parameters in Grha Sepuluh Nopember. The evaluation has done by measuring the impulse response to obtain some acoustic parameters such as the direct sound energy, the first reflection energy and the final reflection energy of the sound heard by each position of the musician. Based on the measurement and analysis, the value of reverberation time is ranged from 0.8-2.9s, ST early has a range of -10dB - 6dB at each frequency, ST late has a range of -8dB - 3dB at each frequency and C₈₀ has a range of -2dB - 7dB at each frequency. So, the stage of Grha Sepuluh November cannot be said to be good as music (space) room or concert hall, but it is more suitable to be used as speech room. Therefore, it should have some improvement in order to make it functioned as performance room or concert hall.

One of the important things in stage acoustic is how a performer can hear their own and their comrades' musical instrument. Stage acoustics condition for Indonesian traditional music will affect the quality and harmonization of the performance. Music on traditional dance performance has an important role in determining the dance movement. This paper discusses the stage acoustic parameters for a Javanese traditional dance performance on Cak Durasim Concert Hall Surabaya based on the optimum acoustics parameters of the Javanese gamelan as an accompanying music for Javanese traditional dance. Those parameters are loudness level, RT, BR, TR, C₈₀, D₅₀ and Support. Measurements were made with two variations of sound source position, which are on the corner in front of the stage and on the center in front of the stage. According to the measurement result and analysis, the optimum position for gamelans' player is on the corner in front of the stage, but with the loudness level distribution having a 4dB difference between the nearest and farthest positions from the source. This result is also supported on the aesthetic side of the layout of the show because its location does not affect the visual side that became the main focus of dance performances.

Voice classification is one of the deeper research of speech recognition. Classification analysis of gender based sound with wav format using Praat software is a clever system that distinguish male and female voice through the system. This article aims to look at the similarities and differences in the pitch and formant frequencies using voice record for 35 samples. Subject for speech beginner musical scale pronunciation taken from college student of Sepuluh Nopember Institute of Technology aged 18 to 23 years old. From this study, the results from 100-150 Hz for men as well as 200-250 Hz for women. In addition to the pronunciation has a value of F1 ranges from 650 - 950 Hz, Formant 2 ranges from 1300-1500 Hz and formant 3 is in the range 2500-4000 Hz. 100% of the pronunciation "La" and "Fa" has a complete composition of the fundamental frequency and frequency bands for each scale of musical. Different with "Do" and "Sol" that have 15% of formant 1.

As an alternative ingredient that is safe for health, the sonic crystal (SC) is expected to provide acoustic performance like other acoustic materials. Generally, SC is designed with certain forms and formations. This paper discusses the performance of SC made from a half the PVC pipe with diameter of pipe is 3,8 cm, 5.1 cm and 6.8 cm, with the direct angle of sound 90°. The parameters that measurement is the resonance frequency. Based on the measurement result, the resonance frequency value is 40 Hz, for a diameter 3,8 cm then 63 Hz for diameter 5.1 cm and 6.8 cm. Beside as a resonator, the sonic crystal was design able to absorb the sound.

Study about microtremor method has been done in Sukoharjo regency. This study aims to determine and mapping the earthquake-prone areas as mitigation efforts based on dominant frequency parameters, dominant periods, and amplification factors. Data acquisition is performed at 19 sites with intervals of each location 2 – 3 Km. P.A.S.I Seismograph 16S24-P is used to acquiring the data. The data acquisition is done with a duration of 20 minutes in three times repetitions. Microtremor data processing using the Geopsy software. Based on HVSR curve analysis, obtained the dominant frequency and amplification factor values. From the result of parameter analysis obtained is made of earthquake hazard map by reviewing the soil classification that has become the standard geological parameter of a region. The dominant period in type IV has a degree of vulnerability to earthquakes, as it has a dominant period of more than 0.75. Type IV is located on Parangjoro, Gadingan, Dukuh, and Jetis areas with the dominant period in 2.43 s until 2.63 s. Most of Sukoharjo areas have low amplification in the zone I with amplification between 1.11 and 2.92.

In this study we update the S wave velocity model near the Cimandiri fault zone obtained from the inversion of teleseismic receiver function by incorporating the contribution of complex structure. The research area is situated near the fault zone in which the calculation of receiver functions is heavily affected by the presence of the fault providing backazimuthal variation in the amplitude of receiver functions. In this situation the traditional inversion method may not provide satisfied models. Thus, in this study we employ Neighbourhood Algorithm method with an initial model containing the properties of shallow dipping fault and anisotropic mantle subducted slab in the inversion process. To speed the computation process, we use the crustal properties obtained from the previous studies and only make variation in the near surface layers (sediment and basement layers) and upper mantle properties. The inversion result shows very good fitting between our actual data and synthetic receiver functions. The result suggests that the orientation of dipping structure beneath the station is well resolved. The best velocity model reveals that the shallow dipping feature related to the fault is striking N74°E and dipping -30°. The structure properties obtained from our best model is consistent with the Cimandiri fault model resulted from other geological and geophysical studies.

Grabagan Village is located to the southwest of Bledug Kuwu, the famous mud volcano in Central Java Province. In this area, there are surface manifestations such as mudflow and saltwater explosion. Mud volcano is a product of mountains that emit mud or clay onto the earth's surface.The aim of this research is to know the dispersion of salty zones in Grabagan mud volcano using 3D model. This research was done by geoelectric method using Sclumberger configuration with stretch of approximately 300 meters at 8 measurement points. Based on the resistivity value distribution, the research area is dominated by salty zone with resistivity values of 0.0851- 8.22 Ωm and at depth of 0.75-129 meters. The salty zone leads to the northeast direction. Two vertical columns were identified in southeast and southwest of the measured area.

Horizontal to vertical spectral ratio (HVSR) method has been widely used for estimating site effects and soil properties beneath a station. Recent studies have shown that it is possible to extract Rayleigh wave ellipticity from the record of seismic noise or vibration. In this study, we applied HVSR method to obtain frequency resonance and site amplification beneath a seismic station in Tangerang, Indonesia. We applied time frequency analysis (HVTFA) using a continuous wavelet transform to extract Rayleigh ellipticity. We carried out inversion from the computed Rayleigh ellipticity to estimate shallow subsurface structure. We applied non linear inversion using two layers as initial model to obtain the best fit subsurface structure. We obtained that the layer boundary between two layer model is found at depth of about 100 m.

Identification of lithology properties of groundwater has been done in Nglengkeh and surrounding area, Pendoworejo Village, Girimulyo District, Kulon Progo, Special Region of Yogyakarta. There are 13 points survey (ST) with long of 80-250 meters spread across the surface. This measurement is done in Nanggulan Claystone and Old Andesit Intrusion which each have widh 71.8% and 6.3% of the total research area. Nanggulan Claystone consists of claystone, siltstone and sandstone while The Old Andesite Intrusion consists of andesites. The results of interpretation resistivity data indicate three lithology properties to groundwater are aquiclude, aquifer and aquifuge. This area are dominated by aquiclude that consist of siltstone with resistivity 12-25 Ωm and claystone 1-10 Ωm at depth 3 meters and 25 meters. Rocks, as aquifers, are sandstones and siltclay. The type of aquifer identified is unconfined aquifer of soil by the name of silt clay with resistivity 14-20 Ωm at a depth of about 23 meters. Sandstone as confined aquifer with resistivity 25-75 Ωm in depth of 25-45 meters. Aquifuge which consist of andesite intrusion has resistivity 380-1984 Ωm. It was found only in ST 11 at depth ± 35 meters and ST 12 at depth ± 80 meters. The variations lithology properties to groundwater and unconfirmity of a sedimentary layer in the reseach area are controlled by stratigraphic parameters and exogenic processes (weathering and erosion).

Meratus mountain, located in Borneo Island is interpreted as sincerity of Subduction Zone in Java. It is predicted that there was a microcontinent in research area. This research aimed to predict the age and reconstruction the subduction zione around Meratus mountain by using earthquake data around Java, Borneo and Celebes islands. The data is relocated using Geiger method to get better description of Subduction Zone. Furthermore, the angle of subduction and velocity modelling is calculated to give more information to reconstruction the Meratus mountain hystory. From the subduction model, Meratus mountain is affected by subdcution from Sumatera and Java, it is not affected by subduction from Celebes. From the subdcution too, it is known that there are two subduction under Borneo, it is improve that there was microcontinent that shifted the early subdcution and borned the new one.

In this study, Sea Level Anomaly based on the tide gauge and satellite altimetry measurements are used to analyze Sea Level Rise (SLR) and tidal component in Sunda Kelapa Waters for 9-years. The satellite altimetry data uses data from AVISO and Tide Gauge data is obtained from BIG (Geospatial Information Agency of Indonesia). This study uses the least square analysis method to know the value of SLR, and harmonic analysis method to know the type of tidal along with tidal components value in Sunda Kelapa Waters. SLR analytic result in Sunda Kelapa based on satellite altimetry Jason-2 show increase in 0.00342 meters / year. Sunda Kelapa Waters can be classified as having mixed single dominant tides on January - June and diurnal tides on July-December. Tidal component in Sunda Kelapa Waters with tide gauge observation resulted average value of Z0; 0.1501 m, M2; 0.0062 m, S2; 0.0086 m, N2; 0.0022 m, K2; 0.0045 m, K1; 0.0240 m, O1; 0.0093 m, P1; 0.0106 m, M4; 0.0011 m, and MS4; 0.0011 m.

The dynamics of a tsunami wave in a zone of propagation in the open ocean includes examination of time evolution of tsunami amplitude whilst propagating over a large distance. In this study, we used NOAA Center for Tsunami Research database from field measurements of vertical displacement of sea surface elevation referred here to tsunami maximum amplitudes for two trans-Pacific tsunamis, namely the 2011 Tohoku, Japan and 2014 Iquique, Chili events. The data were all recorded by DART buoys located at various geographical positions across the Pacific and were analyzed to examine tsunami energy decay in terms of tsunami amplitude decrease with increasing epicentral distance, defined here as tsunami travel distance measured from the epicenter. The results show that the amplitude decreases dramatically in a near-field region of observation and decreases gradually in distant propagation before advancing with relatively constant energy. Extracted from the amplitude decay curve, this finding suggests that different mechanisms of energy conversion and conservation are responsible for energy release in the propagation zone. This is of significance for the development of tsunami early warning as accurate prediction of tsunami run-up in a zone of mitigation requires knowledge of tsunami wave height when the wave approaches shorelines.

The primary aim of this study is to estimate earthquake duration magnitude M_d from local magnitude M_l for a set of seismo-tectonic events in North Sulawesi, Central Sulawesi, and West Sulawesi during 2008-2015 years. The data were collected from Webdc3, comprising datasets of magnitudes in the three regions of interest. The data were firstly used to develop corresponding local magnitudes, after which these magnitudes were analyzed to parameterize duration magnitude. Using a simple parametric equation (adopted from relevant work) directly linked M_d to M_l, M_d = 1.05M_l - 0.17 + c where c represented a correction factor, we found that the equation is applicable to moderate events considered with no significant difference in the calculated values whether or not c was used. For completeness, we compared the M_d values in the three provinces with M_w scales provided by the Global CMT catalogue as the reference. The results show that the obtained values of M_d are in good agreement with the magnitude reference of M_w within ± 0.2 units in magnitude. The results suggest that empirical relations between M_d and M_l used here are appropriate for rapid and accurate magnitude determination to improve seismic hazard assessment in the three provinces.

Identification of the distribution of andesite rocks have been conducted in Kalirejo village, Kokap district, Kulon Progo regency, Special Region of Yogyakarta based on geoelectrical tomography data. Kulon Progo is a mountain area that occupies one of the mountains in South Serayu area. The mountain area of Kulon Progo consists of formation, constituting one is Old Andesite Formation. Resistivity data taken using Resistivitymeter OYO model 2119C McOHM-EL, while the configuration is dipole-dipole. The result obtained from this study, there is an andesite rocks in the northen part of the site and the volume is 3.88 x 10⁶ m³. The andesite is covered by clay and sand with thickness of 6.84 m.

A study has been conducted to measure the depth of the Mohorovicic (Moho) discontinuity and the Indo-Australian Plate subduction zone in Central Java. Both of these structures have high density contrast and thus are very sensitive to gravity methods. This study uses satellite image gravity data derived from satellite Geodetic Satellite (GEOSAT) and European Remote-Sensing 1 (ERS-1). Satellite data obtained in the form of free air anomaly which then corrected Bouguer using the average density of the Parasnis method of 2.64 g/cm³ so obtained Complete Bouguer Anomaly (CBA). The identification of Moho layers and subduction zones was done using the Energy Spectrum Analysis - the Multi Window Test (ESA-MWT) method with 19 lines of South-North. ESA-MWT results get 9 layers with depths that can reach more than 100 km. The Moho layer is identified as the 4^th layer at varying depths from 28 to 63 km. The subduction zone is also identified by ESA-MWT with a depth of about 60 km and deeper to the North. The dip of slab looks sloped down at 40° at the South of Central Java. The dip of slab in the middle of mainland Central Java seen sharply sloped down into the North with a dip of about 75°. All these results are well confirmed by the seismic data of the earthquake in Central Java.

This research is about the distribution of earthquake in subduction zone and calculation of subduction angle in the central Sumatera period 1967-2016. The data used in this research is earthquake data period January 1, 1967 until December 31, 2016 associated with the subduction zone. Research region consist of West Sumatera, Riau and North Sumatera. This region is made by following the slope of the subduction zone using GMT 5. Graphic of the relation between distance and depth every earthquake event is processed using polynomial method to be able to know the trend of subduction zone in this region. While, to find out the subduction angle in this region, calculation with the first derivative of the parabolic equation have been do. The results show that the subduction trend within 50 years is calculated in 10 years interval, the displacement that occurs is not too visible. But, it shows that the longer, the more subdued. While the angle of subduction at 50 km, 100 km, 150 km and 200 km respectively is 22.68°, 35.73°, 42.89° and 47.72°. This shows that the deeper, the larger subduction angle is formed.

This study was conducted to make Multi Electrode Resistivity Meter with simple and low-cost circuit design. The instrument that has been made use switching mode boost converter for increasing the voltage with Arduino Nano as a source of PWM signal connected to the boost converter circuit, and cascode current mirror circuit is used for constant current source. The sensor on this resistivity meter using the voltage divider circuit for voltage sensor, and non-inverting OPAMP circuit for current sensor. Multi electrode circuit using relay module connected with IC74HC595 and controlled by Arduino MEGA 2560. This instrument is integrated with GUI that serves as controller and data display. There are several measurements for this instrument that is maximum resistance on each constant current generated from the circuit, repeatability and reproducibility measurement, sensor calibration measurement, and ERT measurement with three configuration i.e wenner configuration, wenner-schlumberger configuration, and dipole-dipole configuration on soil samples.

The dominant frequency and amplification factor are the parameter used to determine the value of seismic vulnerability index of an area. This research aims to determine the f₀ and A₀ in the southern area of Klaten regency. Besides, in this research a value range of K_g in the southern area of Klaten regency is obtained.This research was done in the southern area of Klaten regency by using P.A.S.I Seismograph Mod. 16S24-P, 3D Borehole Geophone Model GFA 60/100. The data acquisition was done in 12 different locations with the interval being about 5 km. In each location, the measurement needed 20 minutes and was done with three times repetition. The microtremor data obtained were processed by using the Geopsy software so that HVSR curve was obtained. From the HVSR curve, the f₀ and A₀ value can be determined which then were used to determine the value of K_g. After that, the value range of f₀, Ao, and K_g obtained was made into a contour map by using Software Surfer.The result of the research shows that the value of f₀ in the southern areas of Klaten regency is in the range of 4.104 Hz to 9.300 Hz, the value of A₀ is in the range of 1.326 to 2.328, and the value of Kg is in the range of 4.259 × 10-5 s2/cm to 59.873 × 10-5 s2/cm. The microzonation result with the minimum K_g value of 3.00 × 10-1 s2/cm is located in Pedan Subdistrict and the maximum K_g value of 15.704 × 10-1 s2/cm is spread in Prambanan Subdistrict.

A research of the potential hazard of earthquakes has been conducted in Kartasura, Sukoharjo regency, Central Java province, Indonesia. The research aims to know the local land response as an attempt of earthquake disaster mitigation. The method used in this research is the microtremor method through analyzing HVSR (Horizontal to Vertical Spectral Ratio) curves. PASI Seismograph 16S24-P and 3D Borehole Geophone Model GFA 60/100 are used for data acquisition at 14 locations with interval spacing between locations of 1-3 km. Based on HVSR curves, parameters have been obtained in the forms of (A₀) amplitude value and dominant period (T₀). The largest amplitude (A₀) in location Gumpang with the value of 2,14 and the largest period (T₀) in location Ngadirejo with the value of 0,43 second.

Early detection of forest fires is important to reducing the problem of forest land abatement by 2% each year. The use of sensors for monitoring is still very low so that it is very necessary to reduce the existence of forest fires. The method is done by measuring the temperature and gas content (CO, CO2) which is then divided into four levels, which are Normal, Level 1, Level 2 and Level 3, based on sensor readings value. Using temperature sensor and gas sensors which are both integrated with microcontroller and GSM module to send a massage GSM alert than can be viewed by users with the level of conditions read by the device. This tool will be placed around the hiking trail of Lawu Mountain.

Jember Regency has many relics of historical objects spread in some sub-districts, one of which is Beteng Site located in Sidomekar Village, Semboro Sub district - Jember. Beteng site is one of the relics of the Majapahit period, with an area of 93,5 m x 40,5 m. Inside of the site, there is red brick which is the vestige of the castle's foundation, a small part exposed on the surface and most still buried beneath the soil surface. The real condition of the Beteng Site with its limitations interesting to further investigated about its relevance to the history of the Majapahit Kingdom and the reconstruction of the fortress design and its function based on the mapping of the foundation of the building. The result of laboratory measurement of exposed red brick resistivity value is 17,5 Ωm. The used values as a reference for analysing the field measurement results with 2D geo-electrical resistivity methods using Wenner-Schlumberger configuration. The measurement result using the geo-electrical resistivity method shows that the resistivity value of 22.1 Ωm - 25,0 Ωhm in every line with depth 1 m - 2 m. This is quite close to the results of laboratory measurements, so it is presumed to be a red brick layer. Based on the distribution result of resistivity value in every line and real condition in the form of an exposed red brick, distribution of artifacts can be mapped to estimate the design of the foundation building of the castle's vestige.

Bouguer anomaly is separated by moving average method with MATLAB 13. In moving average method there is spectrum analysis process to get optimal window length. The window length value used is 5. The depth of the regional anomaly boundary area is 1871.75 m, while the depth of the residual anomaly boundary area is 359.33 m. After anomaly separation, 2.5D modeling was made with Oasis Montaj 6.4.2. The gravity anomaly data used to construct the model is the residual gravity anomaly. The result of 2.5D modeling is seen 4 formations of rock, among others Batilembu Formation with density 2.4 gr / cc, Batumadi Formation with density 2.37 gr / cc, Tangustabun Formation 2.42 gr / cc, and Molu Complex with density 2.7 gr / cc.

Recently, Love wave applications on geological and geophysical problems have been frequently reported by numerous authors. Unlike Rayleigh wave, Love wave modelling has a simpler algorithm since depends only on three earth properties: SH-wave velocity, density, and thickness of layers. The fewer the parameters more stable the inversion result. There are several tasks, however, that have not been reported related to the modelling and inversion of Love wave data. The tasks are to give answer to several following questions: (a) can Love wave propagate in an inversely dispersive medium of the earth? (b) what is the method recommended to use for explaining appropriate Love wave dispersion curve for the inversely dispersive medium? (c) is that possible to have 'effective' Love wave dispersion curve for the inversely dispersive medium and to utilize it in the inversion process? Numerical simulations show that modal matrix method cannot prepare appropriate Love wave dispersion for such a medium. The resulting Love wave dispersion curve still shows high phase velocities at low frequencies, which is not as desired. Full SH-waveform method, in the other hand, successful simulates appropriate Love wave dispersion for such a medium. By this method, an effective Love wave dispersion curve is also introduced. Inversion of the effective dispersion curve can excellently estimate the shear-wave velocity.

In this part we discussed field example of SH wave data recorded using horizontal component of the three-component geophone that might represent characteristic of the inversely dispersive medium. Extraction of the SH wavefield data, both for north- and south-source impact, using tau-pi transform showed increasing phase-velocity dispersion with the frequencies. Such patterns of "effective" dispersion curves illustrated the nature of the inversely dispersive medium. Inversions of the dispersion curves were carried out by utilizing a series of Love wave inversion approaches. These approaches included forward modelling of Love wave dispersion curve by full SH-wavefield method and partial derivatives of the Love wave phase velocity. The inversion procedures utilized a linearized inversion of Occam's algorithm. Inversions of the Love wave real data, both for north- and south-source impact, confirm the presence of an inversely dispersive medium.

Through this article, we would like to propose the method of urgent information notification or an early warning about the dangers that occur in the college environment by utilizing smartphone devices. Early warning notification media currently still has many shortcomings, a little passive, not directly to the parties who need the information. The media we mean is like a notice board or website portal owned by a college. In other words, the given early warning information may be targeted or otherwise. Therefore, here we try to provide a solution to this problem, which is by utilizing smartphone device to convey information of early warning that is happening or will occur in a campus environment. This information notification system or the early warning system is called e-Announcement.

Some experimental problems challenge the users when using a GC equipped with FID or PDHID detector in the context of trace level impurity analysis in ultra high purity bulk gases. In this study, a comparative evaluation of GC-FID and GC-PDHID is conducted based on both author's experiment and literature review in terms of two technical aspects i.e., imitation and capability. Findings shows that both GC-FID and GC-PDHID reflect capability aspect through a pretty detection sensitivity and quantification at trace level of the impurity compounds. Regarding detectability range of compounds, the GC-FID has relatively lower than the GC-FID since the FID responds to only hydrocarbon-type impurity compound, while PDHID can detect almost any compound, except neon. In case of limitation aspect for these two instruments, detectable range of target compounds and operating cost are remarkable. In addition, in context of operating cost and maintenance, however, the FID is relatively inexpensive in comparison to that of PDHID. Besides aforementioned technical aspects, other capabilities and limitations of both FID and PDHID are also evaluated and compared.

Chest and abdomen Radiographic are most commonly performed and contribute to doses. For this reason, the examination needs to be controlled to obtain image quality with a safe radiation level. This study aims to obtain standardized radiographic exposure index (EI) in Computed Radiography (CR) which is capable of displaying the image quality optimally and to obtain lower radiation dose based on techniques and EI standardized radiographic exposure without reducing the quality of the image information.

This research is a quantitative study with descriptive analysis. Data collected by random sampling technique. The total sample was 61 image editors that have been done by selecting Look Preference Editor (LPE) predetermined. Visual Grading Analysis (VGA) used to analyze quality assessment of the image viewer.

The results showed for the chest's VGA image quality is best viewed directly on the monitor CR with EI value 1430/220.99, whereas to the abdomen by using CR directly, with the best image has EI 1725/496.7. Good criteria image, with low dose estimation and optimal image quality, both chest and abdominal remain below the required range of Bapeten, which chest with 0.003 mGy and abdomen 0.0069 mGy.

Pulse discharge helium ionization detector (PDHID) is developed to respond the need of many applications in the area of chromatographic quantitative analysis. The PDHID is a general type of detector with very high detectability property covering a wide range of chemical compounds. Based on ISO/IEC 17025, a reliable and accurate of measurement result can be obtained by applying a validated method. This paper reports a validation study with regard to the application of GC-PDHID for trace impurity analysis in bulk gases. An optimized operating condition of GC was used to evaluate the method performance with parameters including precision (repeatability and reproducibility), linearity, limit of detection (LoD), and limit of quantification (LoQ). In this study, six trace compounds (CO₂, H₂, Ar, O₂, CH₄, and CO) in bulk gas were analyzed. The results show that the validated of the GC-PDHID method was repeatable and reproducible for the analysis of trace impurities in bulk gas. The %RSD of repeatability and reproducibility were found to be < 3.00% and < 10.50%, respectively. Good linearity of the validated method was obtained with the correlation coefficient (R²) higher than 0.99 for all six trace compounds. In addition, the calculated LOD and LOQ of the GC-PDHID were found to be < 0.60 and < 2.00 μmol mol⁻¹ respectively. In conclusion, validated method of the GC-PDHID for the measurement of the six trace compounds in bulk gas is reliable and fit for its purpose, implying that the validated method can be used in daily measurement in the testing laboratory.

In this paper, a landslide monitoring system was built to detect the movement and humidity of the soil that generally causes landslides. The soil movement sensors utilizes a sliding potentiometer that converts distances into stresses and a humidity sensors. Data from sensors processed using a 10 bit Analog to Digital Converter (ADC) on the ATmega8535 microcontroller. The value of soil movement and humidity then sent digitally via serial USB communication protocol. The soil movement and humidity is displayed through the website interface in the form of graphic data and can be downloaded in the form of excel files. The results obtained through the simulation that the system is able to measure the movement of soil, soil moisture, and provide early warning through sirens. The system has a 1 mm resolution specification with a range of motion measurements with a linear correlation of 0.998. The system can also recognize sudden ground movements as an indication of landslides.

Trace measurement for gas impurities plays an important role in the quality determination of pure-gases. High purity gases will certainly have a higher economic value than gases with lower purity, especially for the ultra-high purity gases used in the preparation of standard gas mixtures. These types of gases shall have a maximum limit for their impurities, which should be verified by a validated method. In this study, an experiment was conducted to determine the impurities in three cylinders of ultra-high purity nitrogen (UHP N₂) gases using a validated gas chromatography equipped with pulse dicharge helium ionization detector (GC-PDHID) method. The impurities detected by the GC-PDHID in the aforementioned UHP N₂ samples consist of argon (Ar), oxygen (O₂), methane (CH₄), and carbon monoxide (CO). Meanwhile, hydrogen (H₂) and carbon dioxide (CO₂) cannot be seen on the chromatogram, then assumed to be lower than the PDHID's detection limit. Concentrations of the impurities, along with their uncertainties, were found to be 0.987 ± 0.104; 5.818 ± 0.807; 3.163 ± 0.449; and 1.289 ± 0.158 μmol/mol for Ar, O₂, CH₄, and CO, respectively for the first N₂ cylinder. H₂and CO₂ were estimated to be half of the limit of detection, and H₂O component was quoted from the UHP N2 manufacturer's certificate of analysis. The other two N₂ cylinders showed almost similar amounts of impurities. Based on the results, the actual purity for each of the three N₂ gases can be estimated as 99.9987% mol/mol; 99.9987% mol/mol; and 99.9988% mol/mol. It is expected that the results of this study could useful as reference for both pure-gas manufacturers and consumers to properly determine the quality of their products.

Electricity capacity in Indonesia is about 89% produced from fossil fuels and the remaining renewable energy. These reasons encourage the government to accelerate the fulfilled of electricity needs with the use of energy mix with the ratio of the use of renewable energy by 25% to meet the 100% electrification ratio in 2025. This study discusses the prediction of electrical energy generated by solar cells combined based on the weather in Solo and surrounding areas as part to encourage the realization renewable energy use. The Prediction system using Artificial Neural Network (ANN) with multi layer neural network based on maximum temperature, minimum temperature, precipitation, wind speed, relativity humidity and solar energy. The result of system is electrical power generated 1 solar cell. The soalr cell with 0.35 m x 0.49 m of area generate electrical power 4.2865 x 10^–2 watt.

One method that can produce nanoparticle material is the spray pyrolysis method, but the use of a spray system requires a high temperature heating or pyrolisis system therefore a furnace is needed which can reach high temperatures. The built furnace has a vertical elongated turbular type with dimensions measuring 60 cm × 50 cm × 150 cm. For this furnace used nickell type windings which are loosely shaped, and given type R thermocouples that are able to measure up to 1600 °C, using a PID control system. The design scheme of the furnace is divided into 3 blocks, with heaters arranged in series to obtain the best efficiency when using electric power. The results obtained are that the furnace is able to reach a maximum temperature of 1000 °C with high accuracy in all three blocks, but the achievement time of the maximum temperature in each block is only the best block 2 compared to other blocks, this is due to the heat induction arising from blocks 1 and 2.

Through this study, we want to provide an alternative method to broadcast academic notification messages in a college using hubs as a transmitter. The academic notification provides information about the academic-related subject such as assessment, lecture schedule or reschedule, and information about the lecturer. The use of notification system on the smartphone so far it is very helpful. However, how effective is the current academic notification system, still doubts. The use of hubs as media to transmit can decrease the time and number of operators needed to broadcast the academic notification messages. So the use of hubs as transmitters can be an appropriate choice for admin of academic notification systems in a College.

In this article, we present QRS-complex peak detection using moving average and thresholding process. In the QRS-complex detection, electrocardiogram (ECG) signal is detrended to remove the baseline shift of the signal. Detrended ECG signal is passed through band pass filter that consist of low pass and high pass filter to remove various noises that present in the signal. The output of ECG signal from filtering process is differentiated to provide the slope of QRS-complex. To make all ECG data point positive, derived ECG signal is processed by squaring process. The final process to detect QRS-complex is passing the ECG signal to moving average and thresholding process. We use ECG data that taken directly from patient with AD8232. The signal that is obtained from AD8232 is processed in Arduino UNO. Processed signal is sent to Android Smartphone and recorded in this device. The accuracy, positive predictive, and sensitivity of QRS-complex detection are 98.28%, 99.01%, and 99.26%, respectively.

In this paper, a simple and low-cost wireless sensor module has been developed for structural health monitoring (SHM) purposes. The module can be divided into three main parts: sensing unit, data acquisition (DAQ) unit, and data communication (DC) unit. The sensing unit is three-axis vibration and tilt sensor. It is composed using single MEMS accelerometer e.g. MMA7361L, and signal conditioning circuit for both tilt and vibration parameters. The DAQ unit function for A/D converter and data formatting, built based on a microcontroller PIC16F873. Whereas DC unit is radio (RF) transceiver, it is used to communicate with the control module (monitoring room) wirelessly. In here, we use RF-transceiver YS-C20K. In the control room, vibrations and tilts data are analysed using the developed software to get information about dynamics condition of structural building being monitored. Results of experiment and evaluation show the tilt sensor is capable to detect up to ± 30 degrees dynamic range with resolution of about 0.05 degrees, while the vibration sensor can achieved up to sensitivity of (80 V/g) with noise compensation. To get portability and easiness in field installation, the sensor system was packaged into one module.

A simple and low-cost instrumentation system in this research for Electrical Impedance Tomography (EIT) experiments has been developed and committed to educational purposes. The developed EIT system mainly consist of two parts, e.g. chamber or phantom for placing measured sample and electronics device as measuring and controlling system. In the surface of phantom are placed as much as 16-electrodes circularly, the function is to inject current and measure spatial voltage across the object. AC current of 50 kHz is injected to the phantom boundary, then the surface potentials are measured using neighboring method. The developed data acquisition system has ability to record 16 channels simultaneously, thus does not require multiplexing technique which is can lead the delays that impact to the case of errors on the measurement results. For image reconstruction, an open source software, EIDORS, was used. Finite element modelling is a method used to simulate the reconstruction of the image process by imaging spheroidal phantoms in the circular of 16-electrodes array. As a comparison on the image reconstruction results, measurement data is presented in graphical using a Boundary Data Simulation (BDS). The experiment result shows the reconstructed images of a conductor and isolator, presenting the first step towards impedance imaging of other material sample.

The polymer coating on a Quartz Crystal Microbalance can be done using spin coating, dipping, spray coating (airbrush) and ultrasonic spray coating. Film thickness and surface morphology of the coating depend on the coating method. Using spray coating, one can control the film thickness and also the morphology by controlling the speed, polymer-solvent particle size, concentration and duration of the deposition process. This paper presents a method for monitoring the deposition of polystyrene onto the QCM sensor by using an ultrasonic atomizer system. The atomizer was working using an ultrasonic generator at 55 kHz. Theoretically, the atomizer was able to produce a mist of solvent and polymer with a diameter of around 28 microns. The system was equipped with a frequency counter which able to monitor the resonance frequency of the sensor being coated in every second with a resolution of 1 Hz. The frequency change was related to the amount of the deposited polymer and solvent on the sensor surface; it means that the deposited polymer can be measured and monitored during the coating process. The deposited polystyrene and its solvent were monitored directly by observing the frequency change of the sensor is coated. For 10 MHz sensor, the resolution was equaled to a deposited mass of 4.2ng. It means that the amount of the coating material to be deposited on the sensor surface can be controlled with high resolution. The evaporation of the solvent after coating process was also able to be monitored directly. The benefit offered by this system besides controlled mass deposited is also the simplicity of the system.

Atrial fibrillation (AF) is one of the most common arrhythmia which can cause a serious problem. Nevertheless, well treated AF might not lead to any further complication. Early detection of AF could be an important preventative step that have to be conducted. In this article, we aim to make an automatic detection of atrial fibrillation. Seven descriptive statistic features have been utilized to detect AF. The features obtained could differ between two condition: normal and AF. Later, we use Adaptive Neuro-Fuzzy Inference System (ANFIS) as a classification method. Sugeno-type fuzzy inference system along with Gaussian type of fuzzy are utilized to classify the condition. The proposed method is applied on MIT-BIH Atrial Fibrillation database. The performance obtained from this proposed method might be considered for a medical application.

Quartz Crystal Microbalance sensor responds to the mass change on the sensor surface as well as liquid viscosity and density which is in contact with the sensor surface. When the sensor surface was contacted with a liquid, the resonance frequency will decrease together with an increase of the series impedance of the sensor. Higher viscosity and density resulted in a decreased of the resonance frequency and increased the minimum impedance of the sensor. This paper showed that the surface hydrophobicity of the sensor surface also affected the change of the sensor resonance frequency as well as the sensor impedance. Surface hydrophobicity of the polystyrene coating was altered using UV irradiation. A variation of liquid viscosity was prepared by mixing water and glycerol. By varying the liquid viscosity from 1 to 2.6 cPs, the frequency and impedance change of the sensor was linearly related to the liquid viscosity. It was also observed that frequency and impedance change was also increase caused by a more hydrophilic surface. This result showed that lowering the hydrophobicity of the surface results in a better coupling between the sensor and the liquid. Those resulted in a higher energy transfer from the sensor to the liquid occurred and increased the sensor impedance.

This short review paper is organized the following: a material with high magnetoimpedance effect, a various of the patterned in magneto-impedance sensor and bio-magneto impedance application. Various of the magnetic material is presented such as a wire magnetic, ribbon, a magnetic thin films as well as multilayers structure. A pattern of the magneto impedance sensor is also presented in this paper. Finally, recently progress of the bio-magneto-impedance sensing biomagnetic fields of human are reviewed.

This article presents a technique for detecting atrial fibrillation (AF). The technique employs electrocardiographic interbeat interval (IBI) alteration. The IBI is the time interval between individual beats of electrocardiogram. Two statistical, mean and standard deviation of IBI are examined. For the classification a support vector machine (SVM) with RBF function is applied. We have examined this technique using clinical electrocardiogram of patients with AF. The examination shows that the detection which utilizes mean and standard deviation of two consecutive segments provide the performance of 95.17%.

Drowsiness is one of the main cause of road accidents. Recently, drowsiness detection of driver based on biosignal like electrocardiogram is being studied. Alterations during drowsiness, fatigue, and stress of the driver can be obtained from heart rate variability (HRV). HRV is derived from interval of RR in electrocardiogram. In this article, we present drowsiness detection using HRV analysis based on microcontroller unit. Electrocardiogram signal is obtained by AD8232 module and processed in microcontroller unit. Electrocardiogram is recorded during the subject using driving simulator. We extract features from HRV and use radial basis function neural network to classify between drowsy and normal.

Disease of the heart is one of the death main cause in the world. Special attention to prevent more deaths from the heart disease is needed; one of them is early diagnose for heart disease with electrocardiogram (ECG). ECG represent electrical activity of the heart. The heart's electrical activity can be recorded using some electrodes that is placed on certain body's surface. ECG records can be used to determine abnormalities of the heart. We design a ECG monitoring system based on android smartphone and microcontroller unit. The ECG signal is obtained directly from patient using AD8232 module. Then, ECG signal is processed in microcontroller unit. Furthermore, the ECG signal is sent to Android smartphone and displayed in this device. We analyse the abnormalities of the heart using the heart rate from ECG signal. Heart rate is obtained from RR-interval in the ECG which represent the time interval between two detected R peak. We use modified Pan-Tompkins algorithm to detect the peak of R wave. The device that we design give good performance to detect and analyse abnormalities of the heart using heart rate.

Drowsiness detection is important since its strong relation with traffic accident. A study for drowsiness level detection using Artificial Neural Network (ANN) method has been conducted. It utilizes electrocardigraphic RR interval statistical features and Radial Basis Function Artificial Neural Network or RBF Network as classifier. Drowsiness levels are defined by Karonlinska Sleep Scale (KSS) which simplified into two classes, alert and drowsy classes. The main parameter of the RBFN are centers and width which are tuned using k-means clustering. A gradient descent is utilized to determine the output weight. The classifier is evaluated by using DROZY database which are collected from 14 subjects; each of them in different drowsiness levels. Feature extraction stage is conducted by segmenting the 10-min data into 30-seconds and it get the RR interval statistical feature. This study is conducted by varying the number of features as the input of RBFN. The method has been evaluated using 5fold cross validation with best performance 81.96%, 84.77%, 76.90% of accuracy, sensitivity, and specifity respectively.

Atrial Fibrillation (AF) is the most common arrhythmia. AF has increased peoples health and financial burdens. Patients with AF should be stratified according to a predictive stroke-risk score. According to the complication, risk factor and data of epidemiology, AF is always interesting to be multidisciplinary research topic, one of which is the developing algorithms for auto-detect software. In this study we use analogue recorded of electrocardiography (ECG) data who converted to digital data. Before detecting the presences of AF, we detect R-Peaks of that ECG wave using differential operating method (DOM). Then we analyse the presence of AF by determining irregularities of RR-interval. To detect the occurrence of AF we use two methods, finding anomalies beat around the mean (FAM) and comparison of each other's beat (CEO). Both of methods are optimized using Particle Swarm Optimization (PSO).The principle of FAM is to look for intervals that have a big margin compared to mean of intervals in a segment. While CEO's principle is to compared all of intervals in the segment each other, then it find the big different to declare the presence of AF. The role of PSO is to optimize their performance by initializing and evaluating their parameters to create the threshold between normal and AF. We have used this method to test the patient's data from MIT-BIH. The performance of FAM is presented in accuracy, sensitivity, and specificity of 90.46%, 95.81, and 84.84% respectively. The performance of CEO is presented in accuracy, sensitivity, and specificity of 85.30%, 94.46%, and 77.19% respectively.

The aim of this paper is study the effect of PWM regulation on electric boost converter. The converter was used for electric driver in electrolysis injection system in order to modified the gas flow production. Electric driver will result the modified gas flow that injected into the combustion engine. The proposed scheme was expected to rose the combustion process and reduce the CO emission. The PMW regulation on this paper was developed using fuzzy logic controller that obtained feedback signal from CO gas sensor measurement. The experimental result showed that CO concentration measured about 330 PPM and its reduced until 253 PPM after the implementation of PWM variation.

This research uses basic compound of BaTiO₃ (BTO) and single phase multiferroic material BiFeO₃ (BFO) with weight ratio of BTO: BFO = 2: 1 to produce multiferoic ceramic. The purpose of this research is to know magnetic properties of the ceramic which consists of BFO multiferroic material combined with BTO electrical material. Changes in magnetic properties will affect the quality of multiferroic materials. The process used sol-gel method using temperature and time of calcination of 350°C and 4 hours, then sintered at 700,750 and 800°C for 2, 4 and 6 hours respectively. The sample was characterized by XRD test with diffraction angle of 20°-100° and the machine was made in Phillips type of PW 1835. This test is to know types of phases. To know magnetic properties of sample, it was used Permagraph test. To know particle size, it was used Particle Size Measurement from Nano Instrument of Beckman Coulter DelsaTM. The results show that new phase is formed which is the dominant phase, Barium Bismuth Iron (III) Oxide (BaBiFe₂O₅) with the largest percentage (98,79%) obtained at sintering process with temperature of 750°C for 6 hours. Increasing the percentage of dominant phases is linier by increasing of magnetic properties of the sample. The highest value of magnetic properties among other coercivity of 247.1 kA / m, remanent of 0.275 Tesla and Saturation of 0.41 Tesla belongs to ceramic with condition of sintering temperature and time of 750°C and 6 hours . The smallest particle size is also obtained under the same conditions equal to the particle size of 54-57 nm.

This paper considers about the nano fluid flow through porous sphere under the influence of mixed convection problem. Dimensional equations are further constructed by the continuity, momentum, and energy equations. The dimensional equations that have been obtained is further converted into non-dimensional equations by using non-dimensional variables. These non-dimensional equations are transformed into similarity equation by using stream function. These similarity equations further resolved numerically by using the KellerBox Scheme to analyze the effect of both mixed convection and magnetic toward velocity and its temperature profiles. We obtain that the velocity distribution and the temperature decrease when the magnetic parameter's value increases, and the velocity distributions and the temperature increase when the mixed convection's value increase.

This paper presents a performance comparison of BaFe, Pt/MnSb, and CoFeAl for HAMR applications regarding the impact of cooling time on the magnitude of the writing field using Micromagnetic Simulator. The materials were selected for study because they possess high magnetic anisotropy and thus have the potential to be used as HDD medium with high-density HAMR technology. However, this material has different characteristics. The magnetic parameters used in this study represent the characteristics of BaFe, Pt/MnSb, and CoFeAl with each Gilbert damping was set to 0.3. The materials were modelled in the form of a parallel-pipe which its dimension was 50 × 50 × 20 nm³. The simulation scheme used double pulses that are field pulses and thermal pulses. Field pulses were applied to drive the magnetic polarization of the nano-dot while the thermal pulse was used to heat the nano-dot up to close the Curie temperature and then freeze it to room temperature with a variety of cooling time in the range 100 - 2000 ps. As a result, BaFe and Pt/MnSb have an advantage regarding writing field consumption which is relatively lower than CoFeAl. The magnetization behavior of CoFeAl is different compared to others where the domain wall is formed from the beginning without going through random magnetization phases.

The Landau-Lifshift-Gilbert equation had been employed to study the effect of Gilbert damping on the dynamics of nano-Barium-Ferrite magnetization. This damping factor is necessary to investigate because of its impact on the dynamics of magnetization switching. In this study, Barium-Ferrite was chosen for study because it has large magnetic anisotropy, excellent chemical stability, and corrosion-free, potentially to be used as a magnetic storage medium with high-density. The nano-Barium-Ferrite magnetic parameters used were the anisotropy constants 3.0 × 10⁶ erg/cm³, 4800 G saturation magnetization, 6.3 × 10⁻⁷ erg/cm exchange field, and Gilbert damping factor which varied from 0.4 to 0.9. By using the Micro-magnetic Simulator software, Nano-Barium-Ferrite was simulated as a dot with surface-sized 50 × 50 nm² and 20 nm of the thickness. The simulation was conducted using Reduced Barrier Writing (RBW) scheme in which the sample was conditioned at room temperature of 298 K while induced by an external magnetic field. The magnetic field intensity linearly enlarged from 0 to 2 Tesla in 2.5 ns. As a result, the magnetization rate rises exponentially to the increase of Gilbert damping values at room temperature. Furthermore, the magnitude of Gilbert damping gives an impact on the propagation direction of the domain wall.

We have succeeded to synthesize the octahedral micro shape of MnFe₂O₄ through the co-precipation process followed by a ceramic processing method. At the beginning, the Mn₃O₄ and Fe₂O₃ nanoparticles were separately synthesized by the co-precipitation method from the low grade manganese ore and iron sand, respectively. Here, effect of the weight ratio of Fe₂O₃ and Mn₃O₄ to the crystal and microstructure of MnFe₂O₄ were investigated. Four cases of weight ratio i.e. 60:40, 70:30, 80:20, and 90:10 were considered. After mixing and compaction process in the cylindrical mould shape, the samples were sintered at 1000 °C and for 6 hours. XRD data showed that a high quality crystal phase of MnFe₂O₄ can be obtained for both mass ratio of 60:40 and 70:30, while in the case of 80:20 and 90:10 the MnFe₂O₄ appear together with impurity of α-Fe₂O₃. The particle shapes are almost octahedral in the micrometer size in the range of 1.2 to 1.5 m. The magnetic property shows a soft-magnetic type with a 27.5 emu/g of saturated magnetization. This will be potential for applications as the electrode materials and the magnetic core.

The XRD and FTIR analysis of the bismuth subtituted cobalt ferrite (CoFe_2-xBi_xO₄) nanoparticles are presented. The samples are produced by co-precipitation method. The bismuth content of the x is selected to be 0.1 for the whole experimental. The result of the x-ray diffraction pattern show that the single phase face center cubic inverse-spinel sample are obtained. It is indicated that the bismuth ion substituted into the cobalt ferrite stucture. The crystallite size change from 33.76 nm to 44.58 nm while the crystalline strain decrease 0.0336 to 0.0255. Finally, the presence of the bismuth ions modifies the resonance of the FTIR absorption curve at octahedral and tetrahedral sites.

Magnetic nano particles, Mn_xMg_1-xFe₂O₄ (x = 0.25, 0.5 and 0.75) with natural iron sand as raw material were successfully synthesized by co-precipitation method. The obtained samples were characterized by the x-ray diffractometer (XRD) and the vibrating sample magnetometer (VSM). The XRD result showed that the magnetic nano particles have a single phase of inverse-spinel face cubic center (fcc) structure. Furthermore, the lattice parameter constant, crystallite sizes and unit cell volume decrease with the increase of the x content. Contrary the dislocation density and lattice strain increase with increasing the x content. The VSM result showed that the saturated magnetization magnitude were getting high and the coercive field became low when the x were increased.

This study deals with magnetohydrodynamics mixed convection flow past a magnetic sphere. The governing equations consist of continuity, momentum and energy equation. All of the equations are analysed by using boundary layer concept. Stream function and similarity variable are used to transform these equations. Finite different method implicit scheme is used to solved the equations numerically. The velocity and temperature profiles are determined for various non-dimensional parameters such as Prandtl number, magnetic parameter and mixed convection parameter.

The manganese-natural ferrite anisotropy magnets were prepared via the solid state reaction method with various sintering temperature of 900, 1000 and 1100 °C for 3 hours. This process were performed by doping MnO₂ on fe₂O₃ natural ferrite. XRD, VSM and VNA Characterizations were carried out to investigate the effects of sintering temperature on structure, magnetic properties and microwave absorption capability. The characterization results showed that sintering temperature affect on microstructure, particle size and crystalline phase. Furthermore, the magnetic properties including the saturation magnetization value (M_s), and the remanent magnetization (M_r) increase, while the coercivity field value (H_c) decreases with the rise of sintering temperature. In addition, Manganese ferrites sintered at 1000 °C exhibit magnificent microwave absorption capability with an average value of reflection loss - 10.98 dB at 10.78 GHz. These superior materials is believed to be promising materials for microwave application in GHz range.

The research of fluid flows is growing. The physical research requires a high cost. So, it is needed science studies that can solve the problem. One of them is mathematical modeling. This research considers magnetic field effect in unsteady magnetohydrodynamics of micropolar fluid through a magnetic porous sphere with forced convection. Governing equations are derived from continuity, momentum, angular momentum, and energy equations. The form of these equations are two dimensional partial differential equations. Dimensional equations are transformed to non-dimensional equations and then, it will be converted to similarity equations. The similarity equations are solved numerically using Keller-Box scheme. It could be concluded that velocity curve decreases when magnetic, porosity and micropolar parameters increase. Microrotation curve increases with the increasing of magnetic, porosity, and micropolar parameters.

This paper considers the effect of mixed convection and magnetic field sphere in the unsteady magnetohydrodynamic micropolar fluid. For solving this problem, we develop dimensional governing equations from mass conservation law, energy conservation law, and Second Newton Law for momentum and angular momentum. We further convert them into non dimensional equations by using non dimensional variables. These non dimensional equations are further transformed into similarity equations using stream functions. Similarity equations are further solved numerically by implementing numerical method with euler implicit scheme. The result shows that the velocity and temperature will increase when parameter magnetic and mixed convection decrease. The higher magnetic parameter leads to higher microrotation of micropolar fluid particle. Whereas microrotation profile decrease with increasing mixed convection parameter.

The study of the magnetoconductance effect in the natural chlorophyllthin films has been presented. The natural chlorophyll films is deposited on a CuPCB substrate with a spin coating method. The results show that discrete-island type of the surface morphological was observed with Atomic Force Microscope.The measurement of the current as a function of magnetic field show that the a typical symmetrical curve of the magnetoconductance effect was obtained for the natural chlorophyllthin films sample. The rasio of the magnetoconductance effect decrease with the increase of the bias voltage. It is suggested that the recombination of the carrierschargeoccur in the present of the magnetic field.

Lead-free functional oxides can be dedicated to numerous applications. Here a part of a complete study on ST and SCT ceramics dedicated to high-Q capacitors is presented, as well as some results on W and WO₃ thin films dedicated to semiconductor gas sensors.

The well-ordered mesoporous silicate (SBA-15) was synthesized via soft-templating route using block copolymer P-123 as directing agent and tetraethoxysilane as the silica source. The ordered mesoporous carbon (CMK-3) was synthesized via a hard casting route using SBA- 15 as nano-template and sucrose as carbon source. The character of mesoporous structure of the samples was investigated by scanning electron microscopy, FTIR and element analysis. The loading release performance using SBA-15 and CMK-3 was investigated by ibuprofen molecule as the drug model. The results illustrated a unique trend of impregnation phenomenon from both of SBA-15 and CMK-3 which was closely related to the mesoporous structure of the materials. When the mesoporous carbon SBA-15 and CMK-3 were loaded by ibuprofen molecule, the agglomeration of ibuprofen did not appear on the outer surface of carbon with the increase of ibuprofen concentration. Our results indicated that mesoporous structure could influence the phase transformation behavior of ibuprofen, which can effectively decrease the drug release time of drug in delivery system.

In this paper, molecular sieve silica SBA-15-encapsulated iron nanoparticles (Fe/SBA-15) have been synthesized by arc discharge method. Molecular sieve silica SBA-15 prepared by self-assembly route using block copolymer P123 as structure directing agent and tetraethoxysilane as the source of silica under acidic condition. The transformation of texture dan structure of Fe/SBA-15 sample after heat-treatment at 900 °C was investigated by X-ray diffraction, scanning electron microscopy and nitrogen adsorption-desorption techniques, FTIR and VSM. The result shows that magnetic properties in Fe/SBA-15 sample have been observed by VSM as the impact of encapsulation process. The adsorption performance using Fe/SBA-15 sample was investigated by ibuprofen molecule as the drug model. The ibuprofen adsorption trend using reach the optimum equilibrium condition at 60 min which was closely related to the mesoporous structure of the materials. The most important of all, magnetic character of Fe/SBA-15 sample make detection of ibuprofen easier than mesoporous silica without magnetic character. It is can make Fe/SBA-15 sample be the new generation carrier material in drug delivery system in the future.

In this work, Polyaniline (PANI) was synthesized through emulsion polymerization assisted by sodium dodecyl sulfate (SDS) surfactant to investigate effects of surfactant to the electrical conductivity. The amount of SDS used has mol to the total quantity ratio of respectively 0.25%, 0.67%, 1.00%, and 2%. The emulsion aniline polymer obtained from the reaction was confirmed by FTIR. The addition of SDS surfactant as an additional component in the reaction solution, led to the chemical reaction run with a relatively slow rate. It indicated by a relatively long reaction time for an increase in the temperature of reaction solution. The viscosity of the emulsion aniline polymer increased with the addition of SDS. The higher amount of SDS is added, the higher the initial viscosity value of the emulsion. Electrical conductivity value evaluated by Four Point Probe (FPP) showed that the emulsion polymers of aniline doped with 80 ml Perchloric Acid (HQO₄) have an ohmic relationship between current and voltage from which the conductivity was derived. It was found that the electrical conductivity value of doped PANI assisted by surfactant reached two times higher than that of surfactant-free synthesized PANI. The highest electrical conductivity value obtained is 3.97 S/cm.

Nanofluids have big potential to replace conventional coolant such as water. Nanoparticles of Al₂O₃ for nanofluids has been successfully synthesized using self combustion method using sugar as fuel. Al(OH)₃ was used as precursor. It was extracted from local bauxite. The combustion was performed at 450°C. The combusted material was calcined at 1200°C for 1 hour to get Al₂O₃ nanoparticles. The Al₂O₃ nanoparticles were dispersed into an amount of water as base fluid to form nanofluids. XRD analysis revealed that the Al₂O₃ nanoparticles crystallized in theta phase with crystallite size of 15.5 nm. According to TEM analyses, the particle size was 30 nm. The nanofluid with concentration of 0.025 vol % and pH 10 possessed zeta potential of -45 mV indicating a stable suspension. Compared to water as base fluid, the nanofluid prepared in this study had a CHF enhancement of 70% making the nanofluids are potential for cooling fluids of metal machining, quenching, Reactor Vessel Cooling System (RVCS), and Emergency Core Cooling System (ECCS).

Synthesis of Zinc nanoparticles (ZnNPs) has been carried out using pulse laser ablation method. In this method neodymium-doped yttrium aluminum garnet (Nd:YAG) laser pulse are used. Effect of laser repetition rate pulse was examined to produced ZnNPs. Spherical shapes of ZnNPs was produced when pulse laser beam (1064 nm, 7 ns) was bombarded onto a high purity (99.95%) zinc plate surface. The averaged diameters of ZnNPs produced in this research were 12.1 nm with standard deviation 4.4 nm for the laser repetition rate 10 Hz, the diameter of ZnNPs was 5.6 with standard deviation 4.7 nm.The spectrum of ZnNPs was obtained by ultraviolet visible (UV-Vis) spectroscopy shows that the surface plasma resonance (SPR) at the center of 300 nm wavelength, which certifies that te ZnNPs produced has the spherical shape.

ZnO nanoparticles and nanorods were synthesized using a simple co-precipitation method. X-ray diffractometry was used to investigate the purity and nanocrystallinity of the final powders. Rietveld refinements for x-ray diffraction data of the nanopowders have been done using Rietica and MAUD softwares. The study was to compare the adjusted parameters in the models where Voigt and pseudo-Voigt functions, respectively, are used as profiles adopted in the softwares. Refinements using Rietica gives Lorentzian and Gaussian peak broadening components and preferred orientation parameter. The peak broadening components can be used to estimate crystallite size and non-uniform microstrain. MAUD can directly give crystallite size and its distribution parameter, microstrain and preferred orientation value. Further study and investigation using scanning electron microscopy (SEM) are required to confirm the accuracy of the diffraction size results.

Perovskites La_1-xBi_xFeO₃ (x = 0.1, 0.3, and 0.5) were prepared by sol-gel method. Structural characterization was performed by X-Ray diffraction (XRD) and X-Ray Fluorescence (XRF). Based on refinement results of XRD analysis, the samples shown the single phase orthorhombic structure with Pnma space group. The dielectric constant and loss factor of the bulk samples were investigated by using LCR-Meter in the frequency range of 100 Hz-1 MHz at room temperature. Increasing Bi content caused decreasing dielectric constant. It may be correlated with decreasing the density of sample with Bi-doped.

The perovskite-type oxide La_o.9Sr_o.1Fe_1-xMo_xO₃ (LSFMO) with x = 0.1, 0.2, and 0.3 were successfully prepared by sol-gel method. The synthesized perovskite has been characterized by Fourier transformed infrared spectroscopy (FTIR) and UV-Vis spectroscopy for further studies. FTIR spectra confirm the presence of Fe/Mo—O stretching and Fe/Mo—O— Fe/Mo bending vibrations in lattice. UV-Vis analysis displayed the optical band gap increase with increasing of Mo-content.

The comparison of two pre-treatment methods, such as mechanical polishing and chemical polishing, prior to anodization of titanium surface in the ethylene glycol based electrolyte containing H₂O₂, were carried out to investigate their effects on photo-electrochemical property of produced highly ordered TiO₂ nanotube arrays (HOTNAs). The Ti-chemical polishing was conducted in electrolyte containing H₂O₂ (0.6% H₂O₂/1.4% H₂O). The prepared HOTNAs were characterized by FT-IR, UV-Vis DRS and SEM. The obtained FTIR spectrum, showed vibration band at 1100 and 425 cm⁻¹, give strong indication on the existent of a -Ti-O-Ti-network. While from UV-Vis DRS spectra, the band gap of the fabricated HOTNAs were found in the range of 3.10-3.22 eV, which are characteristics for anatase phase. In addition, obtained SEM image indicates the existence of quite good ordered nanotube arrays morphology. Linear sweep voltammetry (LSV) measurement showed that the steady state photocurrent density of HOTNAs fabricated by Ti-chemical polishing were greater than that of prepared by Ti-mechanical polishing. The increasing of H₂O₂ content in electrolyte (1.5% H₂O₂/3.5% H₂O) affected to the enhancement of steady state photocurrent density of HOTNAs. Thus pre-treatment of the Ti foils using chemical polish method does enhance its photo-electrochemical property.

The synthesis of LiNi_0.8Mn_0.1Co_0.1O₂ (LNMC) material had been performed via hydrothermal method. LNMC materials as Li-ion battery cathode is chosen because it has many advantages, such as the availability of abundant materials, low cost, high capacity and superior performance of the battery. In this research, hydrothermal method is chosen because it can increase the size of crystallite with good structure hence the crystal quality is improved which is advantageous to improve battery capacity and cycle performance. The novelty of this study is the use of nickel sulfate, manganese sulfate and cobalt sulfate as the transitional metal source of LNMC. The hydrothermal temperature was varied between 160°C - 190°C. Based on X-ray Diffraction test (XRD), LNMC material has crystallite size in the range 45.37 - 46.74 nm. While based on the chargedischarge test, the resulting LNMC cathode battery has a capacity value in the range 0.0453 - 1.199 mAh/g. The highest capacity was obtained on batteries using LNMC cathode electrodes synthesized at 190° C hydrothermal (LNMC H-190 samples). This could be caused by large crystallite size of the sample. As the size of the crystal increases, the Li⁺ ion intercalation pathways will be wider hence the storage capacity is also greater.

The third generation of solar cells that found by Gratzel in 1991 was called Dye Sensitized Solar Cell (DSSC). DSSC is composed of five parts namely Indium Tin Oxide (ITO) as a substrate; TiO₂ and SnO₂ nanoparticles as semiconductor materials; natural dyes (chlorophyll alfalfa) as an electron donor; gel electrolyte as electron transfer; active carbon as a catalyst which can convert light energy into electrical energy. The layer of two semiconductors was deposited on top of an substrat by doctor-blade method. Characterization of DSSC photoanoda materials that will be carried out in this research are: electrical characterization using Keithley I-V meter, optical characteristic characterization and bandgap analysis using UV-Vis Spectrophotometer, DSSC efficiency using TiO₂ as a semiconductor highest than DSSC using SnO₂ as a semiconductor. Characterization of photoanoda layer with X-Ray Diffraction (XRD). From the research, DSSC with a TiO₂ photoanoda capable of producing a higher efficiency than with SnO₂ photoanoda. The results shows 0, 05% for DSSC using TiO₂ photoanoda and 0,022% for DSSC using SnO₂ photoanoda.

The briquettes made of activated charcoal of corncob (Zea mays,L) have been produced and characterized. The charcoal powder was firstly sieved by a 80-mesh strainer for grain homogenization. Then, it was activated at two different temperatures i.e. 550°C for 30 minutes, and 650°C for 20 minutes by using the electric furnace. The activated charcoals powder were mixed with sago powder as an adhesive agent with mass ratio of 9:1 and under stirring condition using the hot water. In other to investigate effect of compaction pressure, then it was transferred into a cylindrical mould with diameter of 4 cm and pressed at different pressure: 70.33 kg/cm², 94.22 kg/cm², and 117.78 kg/cm². After drying process at temperature of 60°C for 48 hours, the characteristic of the briquettes were investigated. The average density are ranging from 0.40 to 0.64 g/cm³, the moisture content 3.75% to 0.53%, and the ash content 5.03% to 6.97%. The volatile matter varies from 10.06% and 17.37%, consequently the fixed carbon changes from 74.81% to 82.21%. The highest caloric energy produced by the briquette is at the level of 6784.82 cal/gr were achieved at processing temperature of 550°C, and pressure of 117.78 kg/cm². This quality is appropriate for industrial standard of processing briquette.

This paper reports our studies on the synthesis of nanoscale zero-valent iron (nZVI) for lead ions (Pb(II)) adsorbent. The nZVI was prepared using clove (Syzygium aromaticum) extracts as an environmentally-friendly reducing agent. Fourier transform infra-red spectroscopy (FTIR) studies indicate that eugenol is the main fraction found in the extracts used in this work. Dynamic light scattering (DLS) measurements show that relatively small particles with narrow size distribution were obtained by dropping the reducing agent gradually into the iron sulphate solution. The batch experiments showed that the as-prepared nZVI exhibits very high removal efficiency of Pb(II). The optimum adsorption time was reached differently for the adsorbent with different size distribution. The highest value is 96%, which was achieved at the adsorption time of 30 minutes by using CT-nZVI.

Well water treatment with aeration-filtration method using the spray aerator and rapid sand filter in decreasing levels of iron (Fe) and manganese (Mn) has been carried out. This study aims to determine the effectiveness of Moramo beach sand in decreased levels of Fe and Mn after aeration-filtration processing. Characterization of Moramo beach sand minerals using XRF showed that SiO2 content of 98.68%, which means that it is qualified as silica sand. Measurement of concentration of Fe and Mn by using Atomic Absorption Spectroscopy (AAS) method. After the aertion-filtration processing, levels of Fe and Mn can be decreased to be 0.072 mg/L and 0.012 mg/L respectively. The results indicated that the concentrations of Fe and Mn have been under the threshold level of the Health Minister Regulation No. 492/Menkes/IV/2010 of ≥ 0.3 mg/L of Fe and ≥ 0.4 mg/L for Mn. In this case, the effectiveness of treatment in reduce of Fe and Mn ions could be 92.46 % and 98.82% respectively. It implied that Moramo beach sand is potential to be used as a filter media to reduce Fe and Mn concentration in dug well water.

Nanomaterials TiO₂ have been synthesized by the co-precipitation method using T1CI3 precursor and obtained TiO₂ powder with the crystal morphology of nanoparticles and nanorods. TiO₂/PMMA bilayer film has been prepared by a spin-coating method, with the first layer used PMMA layer for anti-reflection function and microscope slide glass (MSG) is used as a substrate. The optical properties of TiO₂ layers are measured on a single layer with the variation of the spin rate of the spin coater by measuring the absorption as a function of wavelength with used the spectrometers UV-Vis. The TiO₂ layer is deposited from a TiO₂ solution prepared by mixing TiO₂ powder, a binder of ethyl cellulose, and solvent of terpineol with a mass ratio of 1: 1: 28. The antireflection coating properties of TiO₂/PMMA bilayer have been investigated by using transmittance measurement.

The performance of dye sensitized solar cell (DSSC) is mainly based on the dye as sensitizer. Natural dyes become one of the most commonly used because of its low cost and abundance in supply of raw materials. However, the efficiency of DSSC with natural dyes is low because of low conductivity. In this research, modification of natural dye has been studied by doping Magnesium (Mg) to anthocyanin from Hylocereus costaricensis peel extracted with methanol, aquades, and acetic acid. Mg metal was obtained from MgSO₄.7H₂O salt at various concentration. This research resulted that the conversion efficiency of DSSC was increase and the optimum efficiency was obtained at 0,0924% when using Mg doped dye with MgSO₄.7H₂O salt concentration of 0.01 M. Fourier Transform Infra Red Spectrophotometer analysis showed that anthocyanin dye with 0.01 M doping has lowest transmittance. This suggested that 0,01 M doping has greatest dipole moment change, so it become the most polar molecule and has good conducting electrical current.

A research on the effect of the calcination temperature on the hydroxyapatite phase and its crystallinity formed has been done. The synthesis method uses sol-gel, for the reason that it can precisely control the composition, the process using low temperature, can produce high purity and homogeneity.The material used is coral from Banyuwangi, East Java. To optimize the forming process, the coral powder was made of 54.84 nm using mechanical high energy milling (HEM-3D) method. Sol-gel methods include hydrolysis, condensation, aging, and drying. The calcination process was then carried out with temperature variations of 450°C, 550°C, 650°C, 700°C, 750°C, 80 °C, 850°C and 900°C. The result of XRD observation shows that the temperature of 550°C gives the optimum hydroxyapatite phase which is 90.8%. In addition, at temperatures below 550°C formed Tricalcium phosphate (TCP), whereas above the temperature formed tetrakalsium phosphate (TTCP). The lower the calcination temperature, the larger the TCP. Conversely, the greater the calcination temperature the greater the TTCP phase. Both phases, both TCP and TTCP are unstable calcium phosphate compounds. The observation results also show that the increase of calcination temperature can increase the degree of crystallinity. The degree of crystallinity of the sample at 900°C is 77.28%, twice the degree of crystallinity of 450°C. In addition, an increase in calcination temperature increases the size of the crystal as well, although the increase is not consistent as the degree of crystallinityIn this study a magnetization reversal dynamics observed in the heat assisted.

We report the optical properties of monoclinic Hf_0.5Zr_0.5O₂ system calculated using the plane-wave method within the generalized gradient approximation. We also calculated the properties of monoclinic ZrO₂ and HfO₂ systems as the references. As a result, the systems show the significant optical dichroism between xy plane and z-axis indicated by the significant differences between the real-part optical conductivities along both directions. Additionally, the increase of dielectric constant is proportional with the absorption edge decrease for each axis, which verifies the Penn model. This work shows that the doping treatment significantly tunes the optical properties of Hf_1−xZr_xO₂ system. This report presents the essential properties for novel functional device applications.

The problem encountered in solid biofuels is their low quality, especially in terms of heating value. One treatment can improve this quality by employing a hydrothermal process. This study aims to determine the effect of a hydrothermal treatment of Terminalia catappa peels waste on the heating value and chemical composition. The experiment was conducted using temperature variations of 160°C and 220°C with holding times of 30 and 60 minutes. The water to biomass ratio used is 1:4. Furthermore, a heating value analysis and a proximate analysis was also conducted. The highest heating value is generated at a temperature variation of 220°C with a holding time of 60 minutes by 4,675.25 cal/gram. This value meets the Austrian solid fuel heating value standard (ONORM M 7135) i.e. ≥4,299.5 cal/gram. In the proximate analysis composition, the product showed a decrease in moisture content, ash content, and volatile matter, and an increase in fixed carbon along with an increasing temperature variation and its holding time. In this variation, the moisture content had reached 6.41%, with a volatile matter of 51.8%, an ash content of 2.2%, and a fixed carbon level of 39.59%. These results indicate a significant improvement in the quality of solid fuel. Therefore, hydrothermal treatment is able to answer the alternative fuels' needs in regards to environmental friendliness.

Characterization of soda-lime has been done with aluminum doping on soda-lime glass using an electric-field-assisted solid-state ion exchange method (EFASSiE) to produce an aluminum coating on the glass. EFASSIE is an ion-exchange method that enables the doping of glass surfaces with aluminum ions. The variations used in ion exchange are temperature and electric fields. Variations of temperature start from 400°C until 500°C, increased temperature will cause the ions inside the glass to vibrate and forming a gap, allowed aluminum ions to penetrate into the glass structure. Variations of electric field start from 300-500 V/mm. Electric field that been exposed to the soda lime glass will accelerate the penetration process of the aluminum ion and pushes the smallest ion out of the glass. The results of the soda-lime glass characterization test shows that the greater the value of temperature and electric field used, refractive index of the soda lime after the ion exchange will increase. Otherwise, glass transmittance after ion exchange process has a relatively small compared to the glass before the process. Soda-lime glass Microstructure after the ion exchange process are known from SEM-EDX test, the result proved that alumunium ion penetrate into the soda-lime glass.

The handling of baby diapers is a significant concern. This study aims to determine the effectiveness of infant absorption powder based coconut powder from the soil of Java, Kalimantan, and Papua. The image quality of coconut fiber absorption from these three islands provides an illustration of the differences in soil culture, the intensity of sunlight, and the type of coconut produced. This research uses a quantitative method of an experimental type. Each coconut husk powder sample used in this study was 200 mg wrapped in filter paper. Water used in the form of mineral water as much as 200 mL. A large amount of residual water from filtration shows the quality of the coconut husk's absorbency. The data collected from the three islands is analyzed to determine the effectiveness of its absorptive capacity. That was found this coconut coir powder has a good quality of absorption and is characterized by each soil culture as a distinct planting medium on these three islands. This research was expected that was deepened with the manufacture of baby diaper products made from coconut coir powder.

Determination of the ozone concentration produced by a reactor is very important. The titration method is an analytical chemical method with high accuracy still in use. Research on titration for measurement of ozone concentration generated by a generator at a given flow rate has been done. Ozone is produced by a dielectric barrier discharge plasma reactor. The reactor is formed with a cylindrical-cylindrical electrode configuration made of stainless steel wire mesh. Evaluation of ozone concentration of titration method was done by varying air flow rate between 4-15 liter/min. The titration time is varied between 3-12 minutes. Voltage source was used a high-voltage AC with variation between 6 - 11 kV. The greater the air flow rate the resulting ozone concentration will decrease. The concentration of ozone obtained is smaller with a large tear time at the same voltage and flow rate. From the results of this study, the time of titration in determining the concentration of ozone is not required larger, at 3 minutes has given the best results. The long of titration time probably the ozone dissolve and saturated in the titrant (KI) and released into the air again.

This study discusses the reduction of ammonia using plasma technology. Ammonia is one of the waste produced from farms, especially poultry farms that have many negative impacts such as foul odors and very irritating properties for the body. Plasma is ionized gas caused by high energy discharge and can be categorized into the fourth state of matter after solid, liquid and gas. The plasma technology used is generated by DBD reactor (dielectric barrier discharges) cylinder-cylinder configuration. The inner and outer electrodes use 20 cm long stainless mesh material and a glass barrier with length of 22 cm. The reactor is tuned on by an AC voltage source ranging from the smallest voltage 3 kV to a voltage 9 kV with flow rate of 0.82 L / min, 1.06 L / min, 1.18 L / min, 1.41 L / min and 1.64 L / min. From the measurement using ammonia MQ-135 sensor obtained value of ammonia concentration after treatment. The highest percentage reduction of ammonia gas concentration is at 9 kV with flow rate 1.64 L / minute that is 61.98% while the lowest reduction value at 3 kV with flow rate 0.82 L / minute is 21.69%. This study prove that plasma technology can reduce the ammonia.

Research on ozone generator performance technology of dielectric barrier discharge plasma (DBDP) has been conducted. The study was carried out by using two models of reactor configuration. The first model uses a wire mesh - aluminum foil configuration. The second model uses the wire mesh electrode configuration - wire mesh wrapped in aluminum foil. Ozone was generated using AC high Voltage. Oxygen that source of ozone has been taken from the water. The ozone was produced by DBDP reactor with voltage variation from 0.5 to 14 kV and a fixed air flow rate of 10 L / min. The first models of the reactor was Be Able to produce ozone of 138 ppm at a voltage of 14.3 kV with a maximum temperature of the inner reactor at 49 ° C. The second model of ozone produced with concentration of 163 ppm at a voltage of 14.2 kV and a maximum temperature of the inner reactor of 52 ° C. We found that reactor with wire mesh electrode configuration - wire mesh wrapped in aluminum foil can produce more high ozone concentration with the same voltage.

The development of the reactor for a lower concentration of ozone need to be done. The tipe of reactor can be used for the application of medical ozone therapy. Medical ozone therapy can be produced by using double DBD plasma reactor with oxygen as source and variation of voltage. The influence of flowrate to ozone capacity was investigated using double DBD plasma reactor with cylinder-cylinder configuration. The high AC voltage was applied in the range of 0-2000 Volts and the frequency of 50 Hz. The pure oxygen inserted into the reactor with several variations in flow rate, i.e. 2 to 10 L/min. The results showed that the ozone concentration decreased with increasing gas flow rate. I-V characteristic shows that reactor has two regime current as function of voltage. This characteristic is difference with single dielectric DBD Plasma reactor. The suitable dose of ozone therapy for medical other than useful in numerous pathological conditions could be a powerful therapeutic resource to prevent the damages of aging and to improve many functions in human bodies without deleterious effects.

In the present study, the water vapour and grease resistance properties of paper coating based starch – bentonite clay has been investigated. The clay concentration was 0%, 10%, 15%, 23%, 30%, 40% dan 50% w/w. The composites were prepared by solution casting and coated on the surface of the paper, and analysed using Payne cup method (water vapour transmitter rate-WVTR), grease resistance test and X-Ray diffraction (XRD).

The WVTR results showed that the addition of clay improved water vapour barrier properties and the most optimal improvement was obtained at clay concentration in the range of 10 - 23 wt %. However, the opposite trend was observed for grease resistance properties which showed that the grease resistance decreased with increasing clay concentration. XRD results showed that starch entered clay gallery and formed intercalated bilayer structure both at clay concentration of 10 and 23 wt % wt. The clay/starch composite (23 wt%) was more ordered and higher amount of starch chains entered gallery than than those of clay/starch (10 wt%) supporting better water barrier properties at high clay concentration.

In the present report, effect of different type of clay on water barrier properties of starch composite has been investigated. The starch was from cassava, and the clays of 23 % (w/w) were cloisite Na, cloisite 15A, nanofil 116 and PGV. Clay and starch composites were prepared by using solution casting by mixture at 80 °C, stirred for 60 minutes, then put in the oven for 12 hours at 40 °C. The films were characterized by payne cup analysisis (water vapour transmission rate - WVTR), X-ray diffraction (XRD) and Fourier Transform Infra Red (FTIR). The WVTR values showed that the best water barrier properties improvement of the composites when Cloisite-Na was added to starch. The XRD showed that intercalated nanocomposites were formed in the Cloisite-Na/starch, while microcomposites were formed when Cloisite 15A, PGV, and Nanofill clay were added to starch. Strong interaction between starch and Cloisite was also shown by FTIR.

The preparation and properties of paper coating based bilayer of starch and shellac composites has been investigated in the present report. The bilayer coating were prepared by coating the surface of the paper using starch as first layer then shellac was coated on the surface of the starch layer. Composition of the bilayer composites of starch/shellac was 20:80, 30:70, 40:60, 50:50; 60:40; 70:30; 80:20; % w/w. The Payne Cup Analysis showed that the water vapour barrier properties of starch/shellac increased with the increased of shellac concentration, and very significant improvement was achieved when shellac concentration was above 50 wt%. The grease resistance of the sample was better than that of conventional paper coating. The Diffuse Reflectance UV showed that the transparency of the samples did not change by the presence of the bilayer composites. XRD indicatedd that the stability of shellac was improved by the presence of starch.

There was increasing evidence that the properties of polymer in thin polymer films differ to their bulk properties. This was represented by the discovery of substantial thickness dependent changes in mobility. In the present study, crystal morphology occurring during in the crystallisation of polyethelene therethalate (PET) film has been investigated. It was found that the lamellar width was temperature and thickness dependence, and the structure having a diffusion-controlled nature grew in very thin regions (∼20 Å in height) and at a very low temperature (65 °C) prepared from heating process but was not observed in thin films prepared from quenching process.

We report the synthesis and electrochemical properties of anode material based on Fe Oxide-Carbon Nano fibre (CNF)/Poly (Ethylene Terephthalate) Nano composite. Fe oxide-CNF was synthesized by liquid phase absorption method. XRD data shows that α-F₂O₃-CNFs was completely formed as indicated in 2θ of 24.31°, 34.04°, 36.59°, 40.09°, 57.5°, and 64.46°, corresponding to miller index of (012), (104), (110), (113), (122), and (300). The working anode that consist of 4 layers of Fe oxide-CNF was prepared by the deep coating method and followed by hot pressing at temperature of 72°C. The cyclic voltammetry measurement was performed using H2SO4 1 M as an electrolyte. The scan rate of 1 V/s was being considered as the best condition with the oxidation peak of 0,447 μV and -0,751 μV as the reduction peak voltage. Specific capacity after 25 cycles is 1,632 μAh/g. This was an initial try for development of the flexible lithium-ion batteries.

Dye-sensitized Solar Cells (DSSC) is a type of solar cell that uses dye to absorb the photon. The extracted purple sweet potato skin was used as anthocyanin dye which acted as a sensitizer in DSSC. This paper discusses how the influence of the platinum (Pt) counter electrode deposition methods on the performance of DSSC. Pt layer was deposited on fluorine-doped tin oxide (FTO) substrates by using the drop and the brush methods. The brush method produced Pt layer almost twenty times in thickness compare to Pt layer which is produced by the drop method. When the Pt layer was applied in DSSC, its efficiency was 0.022% for the brush method while it was 0.008% for the drop method. It is considered that electrons are easier diffuse toward the electrolyte in the Pt layer of the brush method than those of the drop method. This result was supported by the SEM images that the Pt layer of the brush method was flatter than those of the drop method. It is well known that electrons are easy to diffuse in the flat material.

DSSC consisted of FTO glass / TiO₂ / dye / electrolyte / platinum / FTO glass. The aims of the research are to obtain the optical properties (spectrum absorbance) and electrical properties (I-V Characterization) from DSSC based using chlorophyll dye doped metal of Iron (III) Sulphate / Fe₂(SO₄)₃ with various concentration. Variation of Fe₂(SO₄)₃ concentration which doped to the chlorophyll dye were 10⁻¹M, 10⁻²M, 10⁻³M and 10⁻⁴M. The I-V characterization was measured using Keithley Type 2602A with irradiation halogen lamp and the optical properties was tested using Spectrophotometer UV-Visible Lambda 25. The result showed that absorbance spectrum for all various dye at wavelength of 400-500 nm and 640-700 nm. I-V characteristic by DSSC without Fe2(SO4)3 doping obtained V_oc of 2,7 x 10⁻¹ V, I_sc = 8,9 x 10⁻⁵ A FF = 4,7 x 10¹ and η_ef was about 1,1 x 10⁻² %. After doped by Fe₂(SO₄)₃ with largest concentration of 10⁻¹M obtained V_oc of 5,0 x 10⁻¹ V, I_sc = 2,0 x 10⁻⁴ A, FF = 9,5 x 10⁻¹ and η_ef was about 9,7 x 10⁻² %.

DSSC is a solar cell that utilizes a dye to absorb light [1]. One of the components affecting DSSC performance is dye. Dye serves to absorb the energy of sunlight that produces electrons. Dye has a characteristic absorption area. Only solar radiation of a certain wavelength is converted into electrical energy [2]. The red color obtained from Hibiscus extract has an efficiency of 0.0341%. The blue color obtained from Telang flower extract has an efficiency of 0.0183%. The green color obtained from pteridophyta extract has an efficiency of 0.0513%. The yellow color obtained from chrysanthemum extract has an efficiency of 0.0414%. Then the image of Universitas Sebelas Maret logo will be made on the surface of DSSC so it can add aesthetic value.

TiO₂ semiconductor materials as working electrodes are commonly used in DSSC fabrication. One type of TiO₂ used in DSSC fabrication is a paste form. In this study aims to determine the effect of the viscosity level of TiO₂ paste. The deposition of a TiO₂ transparent thin film using spin coating method with 450 °C heating temperature. Preparation of TiO₂ paste was done by mixing TiO₂ and ethanol by comparison (1:1, 1:3, 1:5). DSSC fabrication is characterized by an I-V test to determine the efficiency value. Sweet potato dyes used from the anthocyanin type. Preparation of sweet potato dye by mixing the sweet potato into a mixture of solution between methanol, distilled water, and acetic acid with the ratio of solution (1:3:5). UV-Vis spectrophotometer characterized the results of sweet potato extraction. In the test results I-V the most significant efficiency value is obtained at a 1: 1 ratio with an efficiency value of 1.92 x 10⁻² and the absorbance peak obtained at 532 nm wavelength.

A spectrophotometer is an apparatus that can be used to identify the constituent elements of a material. Spectrophotometer uses the principle of interaction between the light spectrum that has a certain frequency with the material so that it can be measured the transmittance or absorbance of the sample as a function of concentration. The purpose of this research is to design a simple spectrophotometer using LDR sensor to convert the scale of light intensity into an electric scale, 28BYJ stepper motor and ULN 2003 driver motor controlled by Arduino Uno microcontroller for light spectrum selection, Op-Amp system as a signal amplifier and LCD 20x4 to display the output intensity value. The test results on Copper (II) Sulfate or CuSO4.5H2O samples with the concentration of 0.15 M, 0.25 M, 0.4 M, 0.5 M, 0.7 M and 1 M gave the absorbance value of 0.12, 0.32, 0.51, 0.66, 0.79, and 1.07 respectively in the red spectrum. The other solutions used to test the spectrophotometer system are two types of food dye solutions. This study provides a linear relationship between absorbance and concentration.

CO₂ laser cutting machine can provide convenience on making various souvenirs and decorations and billboards. CO₂ Laser cutting machines are widely used for cutting and grafting in some materials such as polymer, glass, paper, fabric and some non metallic materials. In this study using CO₂ laser cutting to create a directional coupler channel. In the process of making the canal done with engraving on acrylic substrate with 4.2 mW laser power and speed 10 mm/seconds and then repeated three times. Directional coupler fabrication is done variation of interaction length 20 mm, 25 mm, 30 mm, 35 mm and 40 mm. The result of directional coupler fabrication resulted in a coupling ratio of 49.8: 50.2 at 25 mm interaction length with input A2. Directional coupler fabrication with CO₂ laser cutting machine provides easy interaction length setting as it can be made with the engine and the results are in accordance with the desired design.

New devised metal subtarget technique has been developed for specific applications of liquid analysis. Experimentally, liquid material was homogeneously poured on a surface of metal plate, which functions as a metal subtarget. The metal surface was then dried using drying machine. When a pulse CO₂ laser (10.64 μm) was irradiated on a metal subtarget, a large-volume plasma was induced. During laser irradiation, a material target was vaporized and moved into the plasma region to be dissociated and excited. The technique was successfully used to identify major elements such as Ca and Mg in cement and to identify light elements such as C and H in gasoline liquid. Finally, the technique was also successfully employed to detect impurity element of Ca in human blood. This method is very potential to be applied for the analysis of liquid without tedious sample pretreatment.

We study the solution of the Proca equation for the modified Posch Teller potential. Proca equation is a relativistic wave equation for a massive spin-1 particle. Proca equation also describes the imaginary mass of photons. Vector fields are used to describe spin-1 mesons. The hypergeometric method was used to solve the Proca equation to obtain the relativistic energy and wave function of the particle. This work is limited to radial part of the spherical coordinate system. Using the improved approximation scheme to deal with the centrifugal term, we solve approximately the Proca equation for the modified Posch Teller potential. The relativistic energy eigenvalue and radial wave function equations are obtained.

Neutronic analysis has been performed on SAMOP with Monte Carlo method using MCNP6 software. This research used SAMOP design developed by PSTA BATAN. Fuel used in the form of UO₂(NO₃)₂ with enrichment of 19.75% and a concentration of 300 g U / L. The purpose of this study was to calculate the spectrum of γ and neutron around SAMOP by varying the water level at reactor pond tank and distance measurements and yields of fissionable nuclides by burning for 6 days. The number of simulated particles as many as 100000 with 150 cycles and the elimination of the first 50 cycles. From the results of this measurement obtained the average price and number of wells at a depth of 1500 cm with a height of air in the tank of 400 cm. The gamma spectrum is distributed at an intensity with a range of 10⁻⁸ while the neutron spectrum is distributed in the range 10⁻¹¹ so it can be concluded that the gamma penetrating power is higher than the neutron.

The purpose of this research is to study of replacing the type of cylinder fuel in the TRIGA 2000 reactor into the type of plate. We modeled the core of the TRIGA 2000 reactor geometry equiped with a moderator,a graphite reflector, AgInCd as control rods, and a reactor tank without changing the dimension of the reactor core. The composition of the fuel was U₃Si₂Al with a 19.75% enrichment and 2.96 gU/cm³ density. Criticality study was carried out on a 5x5 core configuration, consist of 16 fuel assemblies and 4 control fuel assemblies. Simulation has been done using the MCNPX. It has been found that the k_eff value when all of the neutron absorbers withdrawn was 1.07100± 0.00017.

Criticality Analysis of the Kartini Reactor as an external neutron source for the test facility of the Subcritical Assembly Molybdenum-99 Production (SAMOP) connected via its radial beamport is presented using The Monte Carlo N-Particle Six Version (MCNP6) software. The reactor was simulated at 100 kW operating power and the fuel of the SAMOP was a solution of uranyl nitrate with a concentration of 300 gU/L. The criticality values obtained from this research was 1.00749 ± 0.00045 and 0.99 ± 0,00041 for the Kartini and SAMOP respectively . When the both reactors were connected, criticality value was 1.01536 ± 0.00009. It could be concluded that the Kartini reactor remains critical although it was used as the neutron source for the SAMOP facility.

With increasing rates of cancer cases globally, scientists and technologists have proposed cancer diagnosis using radioisotope-labelled chemical compounds. In this paper, using the TALYS 2017 codes we calculated excitation functions of several (p,n), (p,α), (p, 2n) and (p,3n) nuclear reactions. The TALYS-calculated results indicated that a few radionuclides such as ¹⁸F, ¹¹C, ⁶⁴Cu, ^I24I could be produced at relatively low threshold energies ranging from as low as 2.7 MeV to 4 MeV, whereas other radionuclides such as ¹²³I, ²⁰¹Tl, ¹¹¹In and ⁶⁷Ga could only be generated with protons of over 10 MeV. While ¹⁸F, ¹⁵O, ⁶⁴Cu and ¹²⁴I radionuclides could be produced via (p,n) nuclear reactions, other radionuclides including ^99mTc, ¹²³I, ¹¹¹In and ⁶⁷Ga could be produced through (p,2n) nuclear reactions . In addition, (p,α) nuclear reaction was found to suit ¹¹C and ¹³N radionuclide production, whereas (p,3n) fit ²⁰¹Tl production. In general, most radionuclides used for Single Photon Computed Tomography (SPECT) modality requires higher proton incident energies compared to those for Positron Emission Tomography (PET) modality in nuclear medicine.

The air conditioner is used not only for indoor temperature control but also as a particulate filtering system. However, bad maintenance of the air conditioner would lead to the damage of the filtering system. The result is a bad indoor air quality due to particulate matters depositing from outdoor. By the fact that a room with an air conditioner system is isolated, the risk of the human to be exposed is high. In this research, we built a model to simulate the particulate dispersion from air conditioner without active filtering system to find the effective range of the exposure. The research is purposely to model particulate matters, especially for PM_2.5 and PM_0.1. The model was built in the Navier-Stokes equation for incompressible fluids by using a Lagrangian approach in the grid system. The model simulated the dispersion of particulate matters in an 8 × 8 × 3 m room with a single air conditioner. The temperature of the room was settled at 24°C without any external particulate source. The speed of the airflow was set at 3 m/s while the concentration of the PM was set by change the air conditioner temperature setting. In the simulation, we found the increase of the effective range of particulate matters in the function of time. In the initial condition, the particulate matters are dispersed into the ceiling with the highest concentration. In the less than 5 minutes, our simulation shows the particulates dispersing in the whole room in the varied concentration. In the minute 50^th, the concentration is similar to the air conditioner exposure. Our measurement in real condition showed a similar condition by a maximum different of 15% than the simulation both in the dispersion time and 2.5% in the concentration. These results were achieved after we compared the simulation in t time concentration with the real particulate dispersion in the identical room dimension with the simulation. In conclusion, the model can be performed to simulate an indoor PM dispersion from non-filtering air conditioner well.

Hypergeometric method can be used to solve D-dimensional Klein-Gordon equation with q-deformed of radial momentum for Kratzer potential. By substituting q-deformed of radial momentum variable, the D-dimensional and the potential parameters to obtain the second order of D-dimensional Klein-Gordon equation which is used to determine the energy and wave function equations. The analytical result of energy can be founded with D-dimension and q-deformed of radial momentum variations. As a result, the rise of D-dimension values cause the rise of energy values, while the rice of q deformation values causes the decline of energy values.

This study was conducted to determine the intensity distribution of X-ray energy spectrum of that produced by Linear Accelerator (Linac) with tungsten target (W). The x-ray spectra on the space behind of target is calculated through the simulation method using Monte Carlo N-Particle eXtended version software (MCNPX). Linac is simulated with acceleration voltage 6 MV up to 15 MV using tungsten metal target (W). Based on the simulation of electron source accelerated, X-rays generated mostly (40-75) % are X-rays with energy of 1 MeV to 2 MeV, whereas the intensity of X-rays with energies fit the energies of the shooter's electrons is very small (0.03 -0.340)%. It was indicated that the energy spectra dominated in the 1 MeV to 2 MeV than maximum energy in the x-ray spectrum range along the energy variation of Linac radiotherapy simulation. In addition, also found electrons about 2.24% to 5.67% compared to the intensity of X-rays, so as to increase the equivalent dose in the patient's tissue later. This information can be used for the manufacture of low energy range filter design that dominate the spectrum and consideration of radiation protection efforts.

The spacetime metric of cosmic string has been used to get the new form of Laplacian in Schrodinger equation for doubled ring-shaped Coulomb oscillator (DRSCO) potential. We use separation variable method to get three of one dimensional Schrodinger equations. Radial form is the main idea of this problem, so we just point out the solution of one dimensional Schrodinger equation for the radial part. Supersymmetric quantum mechanic method is used to get the energy spectrum and the wave function and we have used the approximation in the calculation of superpartner potential to get the same variable function as sextic-like potential in the radial form.

PRTF RSG-GAS is an irradiation facility that used especially for testing fuel pin element of nuclear power plant reactor. Before, during and after the testing, reactor shall remain in critical and steady state condition. In this research, we determine the PRTF readiness before testing. Pre-experimental analysis was performed using Monte Carlo method by MCNP- 6 software. K_eff value of RSG-GAS obtained in this study is 1,10234±0.00011 at power operation (15 MW). The total power was obtained 13.6 MW with difference of 9.3% to the actual operating power at RSG GAS. The maximum power released by one fuel and the average rod power at operating power reach 2.4 × 10⁻² MW and 9.5 × 10⁻³MW. The total neutron flux of PRTF at J7 and K7 grid position respectively are 0.64 × 10¹⁴ n.cm⁻² s⁻¹(70.80% thermal neutron flux and 29.20% fast neutron flux); and 0.26 × 10¹⁴ n.cm⁻² s⁻¹(84.89% thermal neutron flux and 15.11% fast neutron flux). Both testing location show that neutron profile dominated by thermal neutron. This condition enables to use irradiated fuel elements. However, if the neutron flux present in PRTF is generate to excessive fission reactions, it will adversely affect to the fuel element which testing and the reactor. Therefore, the existence of thermal neutrons and their changes when the irradiation proccess take place becomes an interesting topic to do.

Numerical study of superconductor has been done by using Time Dependent Ginsburg-Landau (TDGL) to analyze the effect of variation on size of superconductor in the first critical field (H_c1) and the surface critical field values (H_c3) within the proximity effect. The object of this study is rectangular type-II superconductor with its variation on size of extrapolation length values are 3 and 10. The calculation of order parameter in this model used TDGL equation which finished by using ψυ method and proximity effect limit equation at the edge of superconductor. Results shown values of \ψ'\² — H_ext for every grid size variation. It also could be used to calculate H_c1 dan H_c3 by variation on size. We also concluded that the bigger size of superconductor made decreasing of H_c1 dan H_c3 values into a certain value until constant.

A braneworld model is a model of (1+3+N)-dimensional space-time, called the bulk, with N extra dimensions where standard model particles are assumed to be localized on a (1+3)-dimensional "surface", the so-called brane, embedded in the bulk. Gravitational fields, on the other hand, may propagate in the full space, the bulk. Some of the models could explain the weakness of the gravitational force relative to the other fundamental forces of nature. Among various models, the Randall-Sundrum (RS) model, an N = 1 braneworld model, has attracted much attention. Unfortunately, the assumption that standard model particles are trapped on the RS brane is not fully fulfilled. Accordingly, one of us with other colleagues proposed a modified RS model. The new model is conformally flat space-time and has much better localization properties. However, it is still not a perfect braneworld model since matter fields in some configurations are not localizable. This paper will elaborate localization properties of the model and discussed possible further modification to have a perfect model in terms of localization properties.

Numerical studies have been done on the effect of size on critical field of superconductor with Ginzburg-Landau parameter (κ) is equal to 3. The object is a Type-II rectangular superconductor wich was assumed to be in a vacuum and subjected to an external magnetic field as a function of time. The TDGL equation and boundary conditions are used to solve the problem numerically by using ψυ method. The results show the data in the form of 〈|ψ'|²〉 –H'_ext graphic for each size variation. The 〈|ψ'|²〉 –H'_ext graphs are used to find the values of H_c1 and H_c3 against of each size variations. From the results of the study, it can be seen that the larger size of superconductor will make the smaller prices of H_c1 and H_c3, until the value tend to be constant.

This paper present the extension of the Direct Meshless Petrov-Galerkin (DMLPG) for solving mixed convection heat transfer in a square cavity for the flow up to Reynolds number up to Re 400 and Grashof number Gr = 100. The semi algebraic forms of the governing equations are solved using fractional step method. The numerical results of the DMLPG method are in good agreement with the conventional numerical results in the literature. Based on the numerical results it is shown that The DMLPG is very promising in dealing with the fluid flow and heat transfer problem.

Inquiry-based learning is one of the pedagogical approaches to motivate students to solve problems. Laboratory activities are important for inquiry-based learning, but traditional laboratory activities have a disadvantage because they need high costs associated with the procurement of equipment, space, and maintenance staff. The virtual lab is an alternative to solve the problem. The purpose of this study was to test the effectiveness of inquiry models that aligned with the virtual laboratory in improving students' understanding of the heat problem. This study included quasi-experimental with pretest and posttest control group design. The subjects were divided into two groups, the experimental group and the control group. Research data were analyzed by N-gain test. The results showed that the achievement of conceptual understanding of the experimental group was better than the control group. It can be concluded that the guided inquiry model with virtual laboratories is effective in improving students' understanding of the concept of heat. In general, the increase in the experimental group is higher than the control group, in both the cognitive aspect and sub-concept of heat.

We have developed an interactive e-book on the rotational dynamics concepts. An ebook contains contents such as printed textbooks, with the images, animation, and video. The ebook has been validated by a team of matter experts, media, and practitioners with a right decision as teaching materials on physics. This study includes a quasi-experimental method with one group pre-test and post-test design. Data collected by the verbal and figural creativity test. The improvement of students' creative thinking skills has been measured using N-gain score. Fluency aspects have increased with a high category in one group, while other aspects are in the medium category. The results of this study have proven that interactive e-book is effective in improving students' creative thinking skills in learning the concept of rotational dynamics. The increased creative thinking skills related to the design and characteristic of the e-book.

This research aims to: 1) Identification of activity steps in project learning that can be recorded by video to facilitate formative assessment, and 2) Design a Self-Regulated Project Based Learning (SRPjBL) model to improve competences of Indonesian physics teacher candidates. The research method is done through two phases: 1) Study of literatures on video recording advantages in PjBL, and 2) Propose SRPjBL model to improve competences of physics teacher candidates through video recording based evaluation. The results show that the main phase of project learning is the inquiry activities to create new products. The activities are as follows: Problems challenging, preparing, planning, performing, and Evaluating. The process in each activity is integrated with self-regulation to improve competences of teacher candidates. Competencies are as follows: professional, pedagogic, personal, and social. Assessment of activities and products is easier by video documentation. In the future, this model can be used to explore competences of professional, pedagogy, and social of physics teacher candidates.

Resistor is an important component in electronics which function as the electrical resistance or resistor of electric current. In this experiment used 3 identical resistors, that means is having an equal resistance value which is 1000 Ω. From 3 resistors be made into 2 circuits. They are 3 resistors on the series and parallel circuit. The dynamic electrical experiment in an electric circuit used 3 resistors and voltage 3 V. The characteristics of resistance and electric current on the series circuit of 3 resistor is (3000 ± 250) Ω and (100 ± 2.5) 10⁻⁵ A and on the parallel circuit is (350 ± 25) Ω and (850 ± 25) 10⁻⁵ A. The application of learning is in daily life is a lamp for lighting a room. Has been characterized and analyzed the value of voltage and current for the circuit of 3 identical lamps series and parallel with Ohm's law. By using voltage 1.5 V, the electrical current in the circuit of series and parallel is (3 ± 2.5) 10⁻¹ A and (9 ± 2.5) 10⁻¹ A. The intensity of the light on the series of lights is dimmer than the parallel. This experimental testing is done directly by students on the learning process, so that learning can be effective especially on scientific attitude and knowledge transfer. Average Scores of pre-test is 4.5 and post-test is 10.1. Value of N-gain is 0.4, gives information that student learning by experiment method can improve cognitive learning outcomes is in medium criteria on the topics "dynamic electrical and Ohm's law".

This study aims to analyze the ability of students in the skills to represent a data on the subject of material elasticity properties. Samples were taken randomly, consist of 10 students of X-DPIB-C SMK N 2 Wonogiri academic year 2017/2018. This study used descriptive qualitative method. Data were collected using questionnaires and reports on student experimental results. Students conducted Hooke's experiments to find the spring constant value of 5 experiments. At the conclusion of the experimental results, 9 of 10 students rewrote the average value of spring constant constants without describing the data. Based on the results of the study, 90% of students have difficulty in describing an information from quantitative data.

Saccharin additives addition as a substitute for natural sweeteners is done to reduce production costs. This paper will discuss the effect of sweetener on the electric impedance of apple cider. The electrical impedance spectroscopy method was applied to the sample using four electrodes. Electrical impedance measurements made by injecting 100 μA currents in samples within the chamber in the frequency up to 1 MHz. The results showed that the electrical impedance value of apple cider manalagi is 1721.166 Ω to 41.870 Ω. The effect of sugar cane s mass composition and saccharin mass added to apple cider can be observed well in low frequency up to 10 kHz. The electric impedance characteristic of the apple cider manalagi increases with the addition of sugar canes mass, whereas the electric impedance value of the apple juice manalagi decreases with the addition of saccharin mass.

Science literacy shows that students should be familiar with the most basic principles of science, one of which is Newton's Law. The purpose of this research is to determine the ability of high school students in Newton's Law of science literacy using a test based on Nature Of Science (NOS). The NOS-based instrument consists of 25 multiple-choice test items with 4 alternative options modified by Nature of Science Literacy Test (NOSLiT) and is specifically developed on Newton's Law. The subjects of this study are 110 high school students of the IPA program. Data collection techniques were performed using tests based on NOS-based instruments and interviews using questionnaires. The method of his research used descriptive qualitative. The results show that the average percentage of students who answered correctly was 38.73% of 110 students. The highest average percentage was shown in the scientific disposition framework is 53.33% of students answered correctly, and the lowest in the major misconception about science framework is 23.93%. Based on the results of the study can be concluded that students who can't answer correctly about the NOS are the students who are less able to understand the language of the questions presented in the instrument NOS. Other factors that influence student performance in answering questions on the NOS are knowledge of science that is still less widespread, low student understanding and still many misconceptions on Newton's law. It can be said that the student has a low literacy ability in science.

Sound is an example of a mechanical waves, especially longitudinal wave. Using simple experiments involving musical instrument of Gamelan family and Oscope apps in a couple of smartphones, it is useful and possible for students to "see" characteristics of sound waves. This study aimed to: (1) illustrate the nodes-antinodes of standing acoustic waves in musical instrument of the Gamelan; (2) see the forms of sound waves for each Gamelan's instrument; (3) explain relationship between frequency and length; and (4) know about student's response after that learning. This study used experimental method. From this study can be concluded that: (1) the nodes-antinodes standing acoustic waves in musical instrument of the Gamelan can be drawn based on the results of video recording; (2) the form of sound waves for each Gamelan's instrument can be see using the Oscope apps; (3) relationship between frequency and length is inversely proportional; and (4) very good student's response with that learning.

Synthesis of copoly-(eugenol-stearyl acrylate)/Eg-co-SA was carried out through cationic copolymerization. Copolymerization was conducted using H₂SO₄ initiator, at room temperature (28-30 °C) and under nitrogen atmosphere. Structure of Eg-co-SA was identified by FTIR and ¹H-NMR spectroscopy. Average molecular weight (M_v) of Eg-co-SA was measured by Ostwald Viscometer at constant temperature 28 °C. Morphology and thermal properties of Eg-co-SA was characterized using SEM and DSC. Analysis of EG-CO-SA structure by using FTIR showed disappear of characteristics absorption of the vinyl group (-CH=CH₂) in 16381634 cm⁻¹ and 998-977 cm⁻¹ wave number. The success of synthesis was supported by the disappear of the ¹H-NMR vinyl proton signal at 5.7-6.39 ppm and the appearance of new proton signal of single bond carbon (C-C) at 1-2.6 ppm. The increasing the weight of SA in Eg-co-SA synthesis gives changes in average molecular weight (Mv) and Degree of Polymerization (DP). The results of determining the average molecular weight of Eg-co-SA 2%, 4% and 5% were obtained 49812.10, 67709.25 and 75283.59 g/mol, respectively. Meanwhile, the degree of polymerization were 102, 139 and 154 for 2%, 4%, and 5% Eg-co-SA, respectively. Morphology of Eg-co-SA showed that increasing of SA weight resulted spongy surfaces with 0.35-10.46 μm diameter. Thermal analysis of Eg-co-SA showed that increasing of SA weight influenced thermal stability from 399 °C to 386 °C, when the SA content increase from 2% to 4%.

The aim of this paper is to optimize of kerf (gap of width) and surface roughness in wire cut EDM of AISI O1 using Taguchi fuzzy method. The quality characteristics of gap of width and surface roughness are lower the better. The machining process variables is considered on time, wire feed, servo voltage, and arc on time. The machining variables studied has three levels and the experiment design used L₉ orthogonal array with two replications. Taguchi fuzzy is used to investigate the performance characteristic in wire cut EDM AISI O1. The results of this experiments confirm that fuzzy logic based Taguchi increase significantly the performance characteristics of quality in wire cut EDM. The experiment results shows that on time of 2 μs, wire feed of 8 mm/sec, servo voltage of 55 Volt and arc on time of 5 A are the optimum value for wire cut EDM of AISI O1.

The purpose of this study is to analyze student critical thinking skill in solving fluid static concept based on metacognition level. This research used the descriptive method. The subject of this research is 99 students of grade XI in SMA Batik 2 Surakarta. Data collection methods used are test methods which its instruments based on the indicator of critical thinking skill and metacognition level. Data analysis techniques use quantitative descriptive analysis. The results showed that student critical thinking skill is low which percentage of average student critical thinking skill for indicator assessment, inference and strategy in solving fluid static concept only reaches 20%. This is due to almost student occupy in low metacognition level that is 30% students in tacit use level, 54% students in aware use level, and only a few students occupy in high metacognition level that is 16% students in strategic use level and 0% student in reflective use level.

In Indonesia, many bamboo trees are found, including Petung bamboo (Dendrocalamus Asper). Bamboo has a high tensile strength enough, especialy on skin of bambu, so it has the opportunity to replace for steel reinforcing bars in reinforced concrete construction elements. This study will report the results of the use of Petung bamboo strips notched U shape as a reinforcement in concrete beams structural element. The bamboo strips notched U shape is expected to increase the bonding effects between bamboo reinforcement and concrete. Experimental studies were carried out in the laboratory. Distance between the notches are 5, 10, 15 cm with a high of notch size of 0.5 cm and width size of 1 cm and 2 cm. The specimens size test of the reinforced concrete beams is 11x15x170 cm. Based on test results, the bamboo strips notched U shape as reinforcing bars in concrete beams can improve the flexural capacity.

Self-compacting concrete (SCC) is a very special concrete that have inherent characteristics like a flowability, self comparability, segregation resistance and improved performance. The objective of this study is to investigate the effect of specimen size on the stress strain of SCC incorporating with High Volume Fly Ash (HVFA) compared to normal concrete for different sizes of height to diameter (h/d) ratio, with the fixed diameter (d) cylinder parameter. The experimental results show that the magnitude of stresses HVFA-SCC concrete and normal concrete will decrease on higher specimen size. The maximum strain and ductility factor of HVFA-SCC concrete is greater than normal concrete.

Students' problem-solving ability is important to be improved in physics learning because it can assist students to solve problems in everyday life. Some problems found in this study were the students do not have good problem-solving skill and students have limited learning resources that can guide students' self-learning. Therefore, learning resources that make students able to think and act in solving problems need to be developed. Creative problem solving is a learning model that focuses on teaching and problem-solving skill, followed by strengthening of creativity. The purpose of this study is to know the opinions of teachers and students on the physics module based on creative problem solving that will be developed. The research was conducted using 4-D models and was limited to define a phase, namely teachers' and students' requirements analysis. Data for this research was obtained from the questionnaire. This research used descriptive analysis method. The results of the questionnaire showed that the average requirement of students were 94.59% and the average requirement of teachers were 100%. Thus, it can be concluded that teachers and students need a module based on creative problem-solving method to improve students' problem-solving ability.

The rapid development of Science and technology challenges our education to be able to prepare literate community and workforce in the fields of Science, Technology, Engineering, and Mathematics (STEM) in order to survive in global competition. Contents and media of Science learning must continuously develop following the evolving era in order to remain concrete for students. This research aimed to develop STEM-based Science learning media for heat-transfer topic using solar-cookers. It consisted of 3 main stages of the Four-D development model. The developed learning media was validated by Science learning experts using a Likert-scale questionnaire. A field-test with 32 seventh-grade students in one-group was conducted to measure their responses to solar-cookers as a media in studying heat-transfer. The questionnaire was also given to 3 Science teachers to find out the responses from their perspectives. The collected data were tabulated and analyzed descriptive-qualitatively. The developed learning media (solar-cookers) was considered as feasible to be STEM-based learning media in heat-transfer topic with the feasibility level of 84.7%. The participants, both students, and teachers, also showed positive responses to solar-cookers as a learning media of heat-transfer topic in middle school level.

Mitigation of peatland fires and haze Disaster is done by restoration, namely rewetting, revegetation and revitalization of community livelihood. This study is conducted in Riau province which has the largest Peatland Hydrological Unit (PHU) area in Indonesia, with case studies in Pelalawan district. This study aims to develop the alternative livelihood to support peatland restoration through rewetting program by applying action research. We also examine the community participation of this livelihood revitalization program. The Merbau and Krumutan district are selected to represent of mainland malay and coastal malay community respectively. We stimulate the community to diversify economic activities by developing potential local processed food industry such as cassava, pineapple, and peatland fish. The results show that the participation of mainland Malay community is met at point 3.3, higher than that of coastal Malay community at 3.2. It is indicated that community participation and involvement of mainland Malay community in empowerment activities are highly rated and open for new activities (consultative), while in coastal Malay community is still growing. We need to encourage them toward consultative participation through modification of individualistic and instructive participation. It is highly possible that mitigation of peatland fires and haze disaster can be attempted through livelihood revitalization by strengthening empowerment, participation and market certainty.

This study aims to determine the relationship between character education and students critical thinking skills as the basis for success in the 21st century. The test instrument used is a critical thinking skill test using 4 items from the national exam, a character education questionnaire and Focus Group Discussion (FGD). The sample used is 99 students from all students in SMA Batik 2 Surakarta. The data obtained were analyzed using Bivariate Person to determine the content validity and Cronbach alpha to find out the reliability of the instrument. The test used to determine the relationship of character education with critical thinking skills using the Mann-Whitney U test. The analyzed result obtained content validity (Rbis> 0,05) and instrument reliability is good enough with Alpha value 0,794 (> 0,70). Test results show that there is a relationship between character education and critical thinking skills with Asymp Sig. 2-tailed by 0.011 (<0.05).

To know the level of light pollution due to human activities, we performed sky brightness measurements at Bosscha Observatory, Indonesia (107°36E; 6°49'S, 1300 m above the sea level) during years 2011-2012 by using a portable photometer at zenith direction. From 400 records of night, we obtained that average and maximum sky brightness were 17.75±0.86 mag/arcsec sq. and 19.14±0.79 mag/arcsec sq., respectively. Cities around the Observatory, that are Bandung and Lembang, clearly give a strong contribution to light pollution. The patches of Milky Way galaxy are disappearing from the sky. Higher maximum sky brightness occurred after midnight. Brightness values before midnight were 17.83±0.83 mag/arcsec sq. on average and 18.98±0.78 mag/arcsec sq. at maximum, with average temperature of 18.8±1.3 C. The average and maximum magnitudes after midnight were 17.67±0.88 mag/arcsec sq. and 19.41±1.24 mag/arcsec sq. with average temperature of 17.1±1.6 C. Sky brightness depends on Moon age and monthly seasonal variations, but it has no relation with Earth eccentricity.

Based on high resolution images obtained from Helioseismic and Magnetic Imager (HMI) instrument onboard Solar Dynamic Observatory (SDO) satellite at visual wavelength, we traced several individual umbral sunspots to find drift motion during flare occurrences within Active Region (AR) 11429 (N17, E15) at 00:00 to 05:00 UT on March 7, 2012. AR11429 was a large sunspot group with 1270 millionth solar hemisphere in area and complex magnetic morphology with beta-gamma-delta class. We measured relative motion of 22 umbral sunspots positions during eruptive and post-flare phases for about 5 hours. Some sunspots showed faster motion during eruptive phase at about 10% than decay phase and they moved nearly along the magnetic field polarity inversion line that showed shear motion. Flare outburst which is occurred in corona layer affected sunspot motion and area, as seen for their changing configuration and morphology, before and after peaked X-ray intensity. This result indicates that there is a strong connection between X-ray solar flare at corona layer and its foot points motion at photosphere.

It has been studied green synthesis of silver-chitosan nanocomposite using chitosan as a reducing agent as well as a stabilizing agent and NaOH accelerator. This research develops a new strategy for preparation silver-chitosan nanocomposite through gel phase. The silver-chitosan nanocomposite gel is transformed into colloidal by dissolving into chitosan solution. Localized surface plasmon resonance (LSPR) phenomenon of the colloidal silver nanoparticles were investigated using a UV-Vis spectrophotometer. The shape and size of the nanoparticle silver were analyzed using Transmission Electron Microscopy (TEM). Antibacterial activity test of silver-chitosan nanocomposite against E. coli and S. aureus bacteria by disc diffusion method. The formation of silver nanoparticles in the synthesis of silver nanocomposite-chitosan chitosan through the gel phase is characterized by the appearance of LSPRabsorption peak at 402.4 - 414.5 nm. The optimum conditions of silver-chitosan nanocomposite formation were the use of chitosan (1%) of 60 mL, AgNO3 0.07 mmol, NaOH 7 mmol within 18 hours. Based on TEM image of spherical particles with dominated at particle size between 5 - 11 nm. The antibacterial activity of silver-chitosan nanocomposite is high enough that it is potentially used as an antibacterial material for medical applications.

In this study is an analysis of three representations in problem-solving on additional relativistic velocities. This research method is descriptive quantitative. Purposive sampling is a technique to get sampling in this research. The sample in this study are students who have studied relativistic speed on three different islands, namely Java Island, Kalimantan, and Papua. The students can be problem-solving in three forms of representation: Verbal (V), Diagrams (D), and Mathematics (M). Three representation skills take some description about representation skills student of physics education. It found that students had difficulty 73% in problem-solving in the form of representation V, 86% difficulties in problem-solving in the form of representation D, and 7% difficulty in problem-solving in the form of representation M. This study should also be implemented on different materials and colleges.

This study aims to improve the performance of HAWT's wind turbines in low wind speeds condition. There are two possible approaches: developing low-speed rotor technology and improving the turbine's blades. In this research, we improve the turbine's blades by determining the type of airfoil, material and pitch angle. The airfoil used as its blade is NACA 4412 with teak wood material. Variations of pitch angles are at 0 ° 2 ° 4 ° 6 ° 8 ° 10 ° and 12 °. Testing is realized by making an artificial wind in the wind tunnel. The imitation speed are of 2 m/s, 2.5 m/s, 3 m/s, 3.5 m/s, 4 m/s, 4.5 m/s and 5 m/s. The result shows that at 4° is the best pitch angle that produces the maximum power output and rpm. The 4° pitch angle has a cut in of 2m/s wind speed and generates a power output of 9.71 Watt at an average Rpm of 505.6. The increasing pitch angle decreases the power output and RPM generator.

Heat exchanger (HX) is a device that provides heat exchange between two fluids that have temperature difference. Heat exchanger is widely applied to industrial process, power plant, transportation, air conditioning and refrigeration. In this study, the heat transfer coefficient between single tube and multi tube with the same heat transfer surface area are compared. The dimension of single tube heat exchanger is 40 cm length with 9.5 cm diameters. On the other hand, the multi tubes heat exchanger consists of ten tubes with 0.95 diameters and 40 cm length. These heat exchangers are submerged in low temperature water and the ambient air is streamed by fan with 0.0032 kg/s, 0.0026 kg/s, and 0.002 kg/s of mass flow rate. The experiment is performed for two hours. The temperature of ambient, outlet air, and water are recorded using T-type thermocouple. The heat transfer coefficient are then analyzed. The result shows that heat transfer coefficient of multi-tubes heat exchanger are 26.6% higher than single tube heat exchanger.

Solar energy is one of the most important sources of renewable energy. One of the technologies used for converting solar energy is Parabolic Trough Collector (PTC). The PTC is used to focus the heat of solar radiation. This study discusses the analysis of the PTC heat transfer with an alteration of the pipe absorber system. The goal of the research is to know the design of efficiency absorber pipe system for PTC. The research method used is an experimental research by testing the system in sunny weather conditions. The pipe absorber system is designed with two variations: PTC1 and PTC2. PTC1 uses an open loop system while PTC2 uses a closed loop system. When the experiment was conducted, the pool water temperature, the intensity of the sun, and the temperature of the fluid in the pipe absorber were measured. The results obtained showed that the highest pool water's temperature fro m PTC1 is 39.3°C at an intensity of 806.59W/m². Meanwhile, at PTC2 the highest pool water's temperature is 36.2°C at an intensity of 828.71W/m². Based on the findings, PTC1 with an open loop pipe system has a better efficiency than the PTC2 with a closed loop pipe system.

Worldwide energy usage continues to increase along with the depletion of fossil fuel reserves. This condition encourages society to develop renewable energy. Wind is one of the form of renewable energy which has low utilization. Furthermore, the available wind turbine has low efficiency especially in low wind speed condition. One way to improve a wind turbine's performance in a low wind speed is the use of pitch angles. This study aims to determine the effect of pitch angle on SG-6043 wind turbine, the pitch angle variations used are 0°, 2°, 4°, 6°, 8°, 10°, 12° and 14°. The data were collected using an experimental wind tunnel. The test results show that the pitch angle of 10° produces the most optimal power when compared to other angles, which is 6.82 watts, whereas the angles 0°, 2°, 4°, 6°, 8°, 12° and 14° produces power of 0; 0; 0; 0; 6.50; 6.55; 6.30 watts respectively.

Candida sp. is the most common of yeasts causes fungal infections in human. One virulence factor of Candida sp. is the Secreted Aspartyl Proteinase (SAP) 5. However, the molecular and immunological characteristics of the Candida Secreted Aspartyl Proteinase 5 is still limited known. To study the molecular and immunological characteristics of the Candida Secreted Aspartyl Proteinase 5, all complete coding sequences of Candida Secreted Aspartyl Proteinase 5 deposited in GenBank were retrieved and subjected to bioinformatic analysis. The sequences alignment was used to predict the evolutionary relationships among various Candida sp. based on the Secreted Aspartyl Proteinase 5 gene and to find out any possible genomic and proteomic variations. The molecular weight (Mw), signal peptide, protein charge, antigenicity, hydrophobicity, estimated half-life, and secondary structure of the predicted proteins also had been discussed. The results from this study would contribute information of molecular and immunological characteristics of the Candida Secreted Aspartyl Proteinase 5.

Textile wastewater with high concentration of dye caused by coloring and finishing process has been polluting the environment. Plasma is one of wastewater treatment required to degrade the dyes. In this study, plasma corona discharge was used to degrade the batik wastewater. Plasma corona discharge is generated by an AC voltage of 11.5 kV through one or two pair stainless steel electrode with diameter of 2±0.05 mm. The electrodes are placed 3 mm above the batik wastewater. The result show a decrease absorbance at wavelength of 400-500 nm. The treatment time of one pair electrode is 2 hours and 3.5 hours. While for two pairs electrode treated in 1 hour and 1.5 hour to get approximatelly same result with one pair. The percentage degradation of dye for one and two pairs of electrodes are 39.08; 50.85; 39.08; and 42.83%, respectively.

Critical thinking skills have not been optimally trained to students in the learning activity. This research aims to develop Tambora erupts in 1815 as a learning material to train the critical thinking skills especially on the aspects of interpretation and inference on the subject of energy learning in the living system. This research was conducted on 32 junior high school students through the learning material from the real event of the eruption of Mount Tambora. The responses to the students' critical thinking on the aspects of interpretation and inference were analyzed by the students' worksheet integrated with critical thinking skills. The critical thinking skills on the aspect of interpretation show that 80% of the students in the total amount are able to make question appropriately according to their knowledge. On the aspect of inference, it shows that 75% of the students in the total amount are able to make hypotheses of the questions that they have made. The result shows that the learning material can be used to train the critical thinking skills. However, this learning material does not train critical thinking skills in the aspects of self-regulation, explanation, evaluation, and analysis. Therefore, the future researchers need to develop the subject of energy learning in the living system that can be used to train those skills.

Neonatal jaundice is the yellowish condition due to high level bilirubin in new born baby. This condition must be treated if the bilirubin level above 12 mg/dL. One of the common treatment is by using blue light phototherapy to convert bilirubin become more soluble in the water then easily excreted from the body. The wavelength of light is 460-490 nm with minimum intensity of 30 μW/cm2. In this study, the phototherapy device is designed and tested. The blue light source is high power LED consisted six chips of CREE EZ900. Heat sink and fan are employed for LED package cooling system. Solar power meter and spectrometer are used to analyse the intensity and wave length produced by the LED. The device results 30 μW/cm 2 and 460 nm of wavelength.

The success of students in the achievement of learning if students have a concept of understanding and able to represent the concept it understands through various representation. This study aims to analyzing differences in understanding the concept of students between the three islands (Java, Kalimantan, Papua) through multiple representation approach on Time Dilation Material. Dilatation of time enters into part of the discussion of special relativity theories that require High Order Thinking and complex Abstraction reasoning in understanding the concept. This research method is Quantitative with Comparative Hypothesis. The sample of this research is Physics Education students in Java, Kalimantan, and Papua. Sampling technique is Purposive Sampling. This research instrument is in the form of a description test that is completed in the form of Verbal (V), Diagram (D), Graph (G), and Mathematical (M) representations. Data processing is done by linking three aspects of conceptual understanding and four forms of representation in three different study samples. The results of this study indicate significant differences that occur in several variable opportunities with different scopes of research areas. This research is expected to be studied more deeply and sustainably.

We present the spectroscopic variations of 14 program Be stars observed within 2008 – 2009 at the Bosscha Observatory, Lembang, Indonesia, using Zeiss Double Refractor equipped with Bosscha Compact Spectrograph. The Be stars show spectroscopic profiles as Be and Beshell, and sometimes as B-normal. These profiles originate from the disk-like envelope or rings surrounded the star's equatorial plane. Our program stars are: 5 as Be single-peaked, 2 as Be double-peak, and 7 as B-normal stars. We also measure the Ip/Ic ratio from the line profiles.

The magnetic field direction is one of the concepts in physics that need good representation ability to understand. This article presents an application of multiple representation models to help the student understand this concept. The sample that was taken using a purposive random sampling technique consisted of 62 high school students from 3 senior high schools in Purworejo. The analysis focused on the effectiveness of multiple representation models to enhance student understands in magnetic field direction concepts and level of students' understanding. We used drawing representation (magnetic force lines and magnetic pole) and mathematics representation. Based on the analysis it can be concluded that learning by using multiple representation models effectively to enhance students' understanding. By CRI scale also found that students did not understand the concept more than misconception.

This study aims to: 1) obtain the appropriate product of physics Worksheet based on POE, 2) determine the students' performance using POE-based Worksheet to improve the scientific process skill. This research is Research and Development (R & D). The development conducted by referring to the 4-D model (Define, Design, Develop and Disseminate). The subject of this study is the students of SMA Muhammadiyah Imogiri Yogyakarta. The total number of students is 42, 10 students belong to the small group test, 32 students belong to field test. The instruments of the research a questionnaire, test (post-test), and the distribution of student responses on the Worksheet. The results of this study were 1) the development results of physics POE-based Worksheet was feasible by the experts validation based on the content, language, presentation, and good validity graphic; 2) the percentage of learners' success in implementing the skills of the scientific process in the formulating hypotheses (83.1%), choose tools and materials (83.1%), writing experimental data (68.8%), analysing data (72.1%), interpreting data (77.1%) and make conclusions (91.4%). Based on the percentage of students achievement, the result on pre-test 36.5% (not good) and post-test 72.0% (quite good), the results able to be calculated the improvement of students' achievement competencies using N -Gain technique 0.6 which included in the middle category. Based on this result, the developed Worksheet had a decent usage.

The aim of this paper is to design a simple and low cost prototype apparatus for automatic control engineering education. The activities were arranged in order to support the development of student skill, particularly in control design for water level system. The system was developed from many parts such as coupled water tank, water level sensor, flow actuator and microcontroller. The integrated system characteristic was observed in order to understand the dynamics response and design the proper control law. The open loop system was approximated as first order system and has time constant τ about 7.59 second. The control scheme was designed using the conventional proportional and integral (PI) strategy. The proportional gain and integral gain were derived from dynamic characteristic, resulting 1.96 and 0.25 respectively. The experimental result showed rise time (Tr) 0.06 second, settling time (Ts) 0.17 second and steady state error around 8.55% relative to set point value.

Students' understanding is the students' ability to representing the concept correctly. Understanding and illustrating the direction of friction is very important in solving dynamic motion problems. The general idea that the direction of friction force is opposite to the direction of objects motion. This research aim was to describe students' understanding level of friction force direction on rolling object without slipping in the horizontal plane. This research used survey method by using descriptive qualitative. The sample used consists of 28 students who were selected bypurposive sampling in the academic year 2017/2018 of Physics Education, Universitas PGRI Madiun. Data collected from three-tier diagnostic test about the direction of friction force. A test was given to 28 students who had obtained the friction force topic in the lecture. The result is 10.7% students can understand and explain the friction force direction on the spool caused by the external force. 3.57% of the students can explain the friction force direction on the sphere with the external force at the center and the edge of the sphere and 3.57% can explain the friction force direction on each bicycle wheel. The friction force direction is not always opposed to the object's motion. The friction force direction acting on the rolling object can be pointed in the opposite direction or in the same direction of an external force. This research in further can be used to improve the learning process of friction force.

Understanding the concepts of simple harmonic motion will influence students' understanding of other physical phenomena such as the movement of disturbed objects from their equilibrium positions, macroscopic wave phenomena, and quantum phenomena. The aims of this study were to analyze students' answers about the concept of SHM and determine the problems experienced by students in pure harmonic motion material. . The sample of this research is 27 physics students on 2^nd semester year 2017/2018 in Universitas Sebelas Maret who has received basic physics course. This research using a descriptive method. The data collected by giving 12 multiple choices with reason. The questions are about the concept of simple harmonic motion. The result shows that most of the students only understand a partial concept. 57,10% students can answer the question correctly and the rest still have difficulty in understanding the concept. The most difficult concept is about the relationship among displacement, velocity, and acceleration.