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Preface: The International Conference on Condensed Matters and Advanced Materials (IC2MAM) 2018.

The International Conference on Condensed Matters and Advanced Materials (IC2MAM) 2018 was held on 5 September 2018 at the prestigious Graha Cakrawala Hall Universitas Negeri Malang, Indonesia. This conference was financially supported by Universitas Negeri Malang. This conference was organized by the Department of Physics, Faculty of Mathematics and Natural Sciences, Universitas Negeri Malang (UM), in collaboration with Consortium of Materials Science & Technology (KOSATEM), Institut Teknologi Bandung (ITB), Universitas Gajah Mada (UGM), Universitas Brawijaya (UB), Institut Teknologi Sepuluh Nopember (ITS), Universitas Negeri Surabaya (UNESA), Universitas Negeri Makasar (UNM), Universitas Negeri Semarang (UNNES), Universitas Sebelas Maret (UNS), and Universitas Diponegoro (UNDIP).

The IC2MAM 2018 means for sharing new ideas and indulging in interactive discussion amongs the researchers, academicians, and industry experts from research areas of condensed matters and advanced materials; from the theoretical perspectives to the technological applications. To be explicit, the conference involves the rapidly expanding fields like theoretical and analysis in materials, computational material science, strong correlated systems, topological order, synthesis and characterization approaches, material science related instrumentations, nanoscience and technology, functional materials, natural-based minerals and complex materials, geomaterials, metal-organic materials, intermetallic compounds, and low dimensional systems.

IC2MAM 2018 finally accepted 106 papers from no less than 200 papers after a peer review process by two reviewers. In this conference, 10 parallel sessions were held in order to contribute to specific research field. Finally, extraordinary thanks to all keynote and invited speakers, reviewers, participants, delegates, for contributing and supplying the input for supporting the IC2MAM 2018.

Chief Editors

Nandang Mufti, MT. Ph.D

Conference Logo available in this PDF.

List of Committee and Editorial Boards (Science Section) are available in this PDF.

List of Participant IC2MAM 2018 are available in this PDF.

List of Photographs of IC2MAM 2018 are available in this PDF.

All papers published in this volume of IOP Conference Series: Materials Science and Engineering 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.

Magnetic switches working in solid states are of recent interest for applications to sensor, memory, etc. The author and co-workers have developed various unconventional spin transition/crossover materials. The first example is a supramolecular chemistry consisting of genuine organic nitroxide biradicals with a triplet ground state. Each nitroxide group is located close to each other to form weak covalent bonds in an intermolecular fashion. Biradicals are polymerized/depolymerized stepwise. The second example belongs to 3d-2p heterospin systems where the nitroxide oxygen atom is directly bonded to a nickel(II) or copper(II) ion. The planar/nonplanar chelate structure changes, accompanied by high-/low-spin transition due to a 3d-2p exchange-coupling switch. A novel entropy-driven spin crossover scenario has been established. The third example is a 3d iron(II) spin crossover material carrying a stearyl (C₁₈) group. An order-disorder-type structural transition appears with respect to the alkyl conformation. As these examples show, single-crystal-to-single-crystal structural transitions are often observed. It is because the spin entropy term regulates the atomic dislocation enthalpy, and the entropy change due to the spin multiplicity is basically small. These molecular motions clarified by means of detailed crystallography afford one of the most convincing evidence for the spin transition phenomenon.

The development of renewable energy devices has seen the application of several methods to improve the efficiency of DSSC. One of the methods is to reduce the electron recombination effect from TiO₂ to the oxidized dye by introducing copper nanopowder (CuNW) as an electron recombination barrier into the TiO₂ layer. The phthaloyl chitosan (PhCh)-based gel polymer electrolytes (GPEs) containing tetrapropylammonium iodide (TPAI) salt, 1-butyl-3-methylimidazolium iodide (BMII) ionic liquid (IL), 4-tert-butylpyridine (TBP), Guanidinium thiocyanate (GuSCN) as additives and (I⁻/I₃⁻) redox couple have been used as an ion conducting medium in the DSSCs. The DSSCs were characterized by incident photon-to-current conversion efficiency (IPCE) measurements. The DSSC containing 3 wt% of CuNW showed the highest IPCE of 53.7% at 535 nm. Under the irradiation of 1000 W m⁻² (AM 1.5), 3 wt% of CuNW exhibited the highest cell efficiency, η of 7.19%, J_sc = 0.0133 A cm^-2, V_oc = 0.76 V, and FF = 0.71.

A carbon hydrochar material (BG-230) has successfully been prepared by conversion of sugarcane bagasse through low-temperature hydrothermal carbonization (HTC) at 230 °C. BG-230 was subsequently subjected to further thermal treatment at 400 °C for 1 hour under air (BG-230/400). Both resulting materials were characterized using specific surface area analysis (BET), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), elemental analysis (C, H, N, O) and X-ray photoelectron spectroscopy (XPS). The characterization results showed that BG-230 possesses a higher number of acidic-oxygen functionalities than BG-230/400, indicating that the thermal treatment at 400 °C under air removed those functionalities. The adsorption properties were evaluated by the removal of methylene blue (MB) from aqueous solutions. The adsorption capacity of MB was found to be higher for BG-230 (∼100 mg g^-1) than that for BG-230/400 (∼25 mg g^-1). The investigation into the adsorption performance of both prepared adsorbents suggests that the oxygen functional groups on the prepared carbon materials are responsible for the adsorption mechanism.

This work aimed at investigating the crystal evolution, crystallite phase, morphology, and particle size of the magnetite ferrofluids as the effects of heating temperature. The iron sand was used to prepare magnetite ferrofluids by employing a simple chemical method. The high-resolution transmission microscopy characterization presented that the particle size and morphology were expanded from small to bigger size in nanometric size with aggregation. The electron and X-ray diffractions patterns exhibited that the magnetite particles in the fluids evolved from Fe₃O₄ (cubic structure) structure to α-Fe₂O₃ (rhombohedral structure) as the effect of heating treatment. At a temperature of 500 °C, the magnetite particles had a mixed crystallite phases consisting of α-Fe₂O₃ and Fe₃O₄ structures. Interestingly, at the temperature of 600 °C or higher, the magnetite particles in the fluids changed to the pure α-Fe₂O₃ structure. Such evolution phenomenon gives significant information in designing new sophisticated application of the magnetite ferrofluids, especially for the temperature sensor.

Garlic (Allium sativum) is one of the plants traditionally used for food supplement, natural medicine, and a food flavoring. Garlic has been proven to exhibit many important pharmacological activities that bring benefits for human health such as antioxidant, antimicrobial, antithrombotic, antihypertensive, cancer prevention, and lipid-lowering effects. However, the organosulfur compounds that contribute the previously mentioned activities have a high rate of degradability. In this paper, composite fibers of garlic extract encapsulated in polyvinylpyrrolidone (PVP) fibers are reported. The fibers were synthesized using the rotary forcespinning technique to protect organosulfur compounds from degradation and to maintain their antioxidant properties. The precursor solution was prepared by mixing 15% PVP in 50% ethanol (w/w) with garlic extract (GAE) in the ratio of 10:1, 10:3, and 10:5 (w/w). Microscopy images showed that the average diameter of fibers increases with increasing viscosity, which was the result of the higher polymer-to-extract ratio. All the fibers had smooth surfaces with no beads. The coefficient of variance (CV) of each fibers distribution was lower than 0.3, which marks the uniformity of the fibers formed. Analyses of the Fourier Transform Infrared (FT-IR) spectra proved some peak differences between the PVP fibers and the PVP fibers loaded with GAE, one of them is the peak at wavenumber 1034 cm^-1 indicating the presence of sulfoxide functional groups.

Photo-supercapacitor is a combination of solar cells and supercapacitor which intensively being developed. Photo-supercapacitor performance is influenced by the efficiency of solar cells and storing and releasing capacity of supercapacitors. Any types of either solar section or supercapacitor sections could be used. In the DSSC solar cell, one of the influential variables is the performance of the photoanode. The photoanode with semiconducting metal oxides play a role in charges mobility and light absorption process, which are influenced by crystal morphology and structures. The common metal oxides used are ZnO and TiO₂ which show high electron mobility, wide band gap, and good optical properties. This work is designed to investigate the effect of annealing temperature of the composite layer of ZnO and mesoporous TiO₂ on structure, morphology, optical absorption, and photo-supercapacitor performance. The ZnO compact layer was deposited onto the FTO substrate by a spin coating method with various annealing temperature. The mesoporous TiO₂ layer was deposited on top of the ZnO compact layer by means of screen printing method. The construction of photo-supercapacitor model comprises DSSC and BaTiO₃-PVDF symmetric supercapacitor which integrated by using aluminum substrate. Characterization was done using XRD, SEM, UV-Vis, and I-V solar simulators for the performance of photo-supercapacitor.

Perovskite Solar Cell (PSC) CH₃NH₃PbI₃ has attracted interest due to a high potential for cheap and high-efficiency solar cell. The PSC mainly consists of three components that are an electron transporting material (ETM), perovskite layer, and hole transport material (HTM). The ETM layer quality plays an important role for electron transport, acts as a selective collection of electron and hole blocking layers that have an important influence on photovoltaic performance. TiO₂ and ZnO are the most common materials used in ETM. TiO₂ has a good photo activity, high stability, and non-toxicity. Meanwhile, ZnO has good anti-reflecting properties that make electron more easy to transfer from valence band to conduction band. In this research, the formation of TiO₂ and ZnO was composited as ETM to combine the advantages of both with the variations of TiO₂/ZnO mass ratio. The ETM films were synthesized by screen printing methods, whereas the perovskite layer and HTM of Cu₂O were coated by spin coating and chemical bath deposition (CBD) respectively. The samples were characterized by XRD and UVVis spectrometer. The photosensitivity and solar cell performance were measured by electrometer and solar simulators. The TiO₂/ZnO composition of ETM showed a different efficiency and photosensitivity. The sample with higher TiO₂ indicated stable photosensitivity but less in the solar cell efficiency and vice versa.

Mn_0.25Fe_2.75O₄-PEG nanoparticles based on local iron sand were synthesized using the coprecipitation method. The characterization of sample was conducted using the X-ray Diffraction (XRD) instrument, Fourier Transform Infrared (FTIR), Small Angle X-Ray Scattering (SAXS), and Magneto-thermal each has a purpose to find out the formed phase structure, the adsorption pattern of sample functional group, nanoparticle distribution, and thermal effect of the sample. The results of characterization using XRD showing that the formed sample phase was in the form of the magnetite spinel structure. Through Rietica analysis and calculation using Debye-Scherrer, the sizes of nanoparticle samples were 7.9, 6.4, and 5.3 nm respectively with the addition of PEG concentration of 1000, 2000, and 4000. The adsorption of nanoparticle functional group was confirmed well with the appearance of Fe-O and Mn-O bound adsorption, at the wavenumbers of 430 cm^-1 and 482 cm^-1 respectively which were the representations of Mn_0.25Fe_2.75O₄ material. Furthermore, the SAXS data analysis using the two lognormal method showed that the primary size of the particle sample was around 3 nm. Meanwhile, the secondary sizes of the sample were 8.5, 7.1, and 5.9 nm with the addition of PEG concentration of 1000, 2000, and 4000. Interestingly, Mn_0.25Fe_2.75O₄-PEG nanoparticles of 1000, 2000, and 4000 characterized using the Magneto thermal instrument have the value of 1.079, 1.082, and 1.105 W/g respectively and was able to improve the temperature of 37 °C up to 38°C. These characteristics showed that the Mn_0.25Fe_2.75O₄-PEG nanoparticles have potentials to become a unique material which can function as the material for hyperthermia therapy.

Data analyses of XRD and XANES using Fe as absorber have been conducted which were aimed for phase identification, Fe oxidation state determination, absorption edge value (E₀) calculation, and valence electron determination of LiFe_xCu_1-xPO₄ (x = 3%, 4%, and 5%) powders. The powders were prepared by a dissolution method with the source of Fe was local ironstone from South Kalimantan, Indonesia. Analyses of the x-ray diffraction data of the powders were done using the Rietveld method. The XANES data were acquired using Fe K-edge spectral techniques at Synchrotron Light Research Institute (SLRI), Nakhon Ratchasima, Thailand. Results showed that olivine was the only identified phase in the LiFe_1-xCu_xPO₄ powders. Further analyses gave the crystallite size of 188, 193, and 205 nm and cell volume of 278.96, 279.12, and 280.52 ų, for the x = 3, 4, and 5% samples, respectively. Qualitative analysis of the XANES data acquired for all samples showed the oxidation state of Fe²⁺, and the absorption edge values (E₀) were 7121.56, 7121.71 and 7121.75 eV for the samples.

In this study, gel polymer electrolytes (GPEs) have been prepared using PMMA, lithium bis(oxalato)borate, (LiBOB) and tetraethylene glycol dimethyl ether, (TEGDME) as polymer host, ion source and solvent, respectively. PMMA-LiBOB-TEGDME GPEs were using electrical impedance spectroscopy, Fourier-transform infrared spectroscopy, linear sweep voltammetry, transference number and also charge-discharge measurement. The highest conductivity is achieved by the 15 wt.% LiBOB- 32.69 wt. % PMMA-52.31 wt. %TEGDME GPE with the conductivity value of 1.71 mS cm^-1. From the FTIR deconvolution of selected GPE, the highest ionic conductivity of GPE is contributed by the 64% of the free ion. The Li-ion transference number for the highest conducting GPE is 0.38. The GPEs are stable up to 4.2 V (vs.Li/Li⁺) suggesting suitability for the application in the lithium-oxygen battery. The capacity is 447 mAh g^-1 at the first discharge cycle.

Research on materials classified into strongly-correlated systems has become a crucial subject due to the strong interactions among the material constituents yielding various exotic physical properties and phenomena. There have been many computational methods developed to address the properties of such systems accurately within the Hubbard model, but most of them require a lot of computational costs to expect good results. In this research, we proposed a new approach within the Dynamical Mean Field Theory (DMFT) framework that requires a simpler and potentially less numerical-cost algorithm. We implemented this algorithm by constructing the local self-energy matrix elements that depend on the occupancy fluctuations. We integrated them over all possible occupancy configurations to obtain the fully interacting Green functions. The resulted Green function matrix was then used to compute the density of states (DOS) and other quantities. We investigated the case of quarter filling. Our computation results showed that pseudogap appeared when the onsite Coulomb repulsion was sufficiently high and tended to diminish as temperature increased. The system preserved its paramagnetic metallic character for all circumstances we studied.

The ruin of energy and environmental pollution has led to the pursuit of novel technologies for green energy productions. For hydrogen energy itself, the search for the photocatalytic-based nanostructured β-SiC is one of the main research focus during the last few years. Herein, we reported the successful magnesiothermic reduction at low temperature, i.e., 700 °C, using an argon gas tubular furnace to fabricate β-SiC with a particle size below 10 nm. The X-ray diffraction (XRD) data collection and Rietveld refinement showed the single phase of moissanite β-SiC formation having cubic structure with lattice constants of a = b = c = 4.3523(50) Å and α = β = γ = 90°. The formation of the nanostructured β-SiC was well confirmed by the high-resolution transmission microscopy (HRTEM) image. The equivalent crystallite size produced by the XRD profile analysis was 4.2(8) nm, and extracted from the HRTEM image was about 6 nm. The d-spacing for (111) plane met a reliable agreement between the XRD and HR-TEM data. The energy dispersive X-ray spectroscopy in scanning transmission electron microscopy (STEM-EDS) also brought a good capture for the nearly 50:50 concentration of Si:C in our sample. Furthermore, in-situ heating experiments via HR-TEM were also conducted. In brief, carbon nanolayers were initiated on the surface of the nanostructured β-SiC. All these fine-tuned crystallographic properties assigned the as synthesized β-SiC to be the promising candidate for photocatalytic hydrogen production.

This study reported the potency of 'biologically synthesized silver nanoparticles using Andrographis paniculata extract' (S-AgNp) as an antibacterial agent and its minimum inhibitory concentration (MIC). The antibacterial test was conducted to pathogenic bacteria of S. aureus and E. coli by using a diffusion-well method. The media used were Nutrient Agar (NA) and Nutrient Broth (NB). The tests were carried out in two steps. The first step was determining the potency of S-AgNp as an antibacterial agent. This step used S-AgNp with the concentration of 100%, Andrographis paniculata extract and AgNO₃ solution as a positive control, and distilled water as negative control. It was found that S-AgNp were able to inhibit the growth of both bacteria. The second step was finding out the MIC of S-AgNp to both bacteria. In this step, the concentration of S-AgNp tested from 70% to 10% and amoxicillin of 5% was used as the positive control. It was found that the antibacterial activity on both bacteria increased as increasing the concentration of S-AgNp tested. The growth inhibition of S. aureus was greater than that of E. coli (p < 0.05). The MIC value of both bacteria was 0.0005 g/mL. Based on this result, it is concluded that S-AgNp has a potency to be used as an antibacterial agent, especially for S. aureus.

Investigation of hydrogenation catalytic application has become an interesting subject area by many experts, especially in nanoscience and nanotechnology. In general, metal-based SiO₂ and ZrO₂ composites become one of the promising materials to be applied as a hydrogenation support catalyst. In this work, we report the synthesis of Ni/SiO₂/ZrO₂ nanocomposites by using impregnation route. The characterization was done by means of XRD, XRF and SEM to investigate the structural, elemental compositional and morphological behaviors of the samples. Based on the data analysis, it showed that the presence of ZrO₂ during synthesis causes the crystallinity change of the SiO₂ from crystallite to amorphous phase. The addition of Ni loading altered the XRD pattern originating from amorphous SiO₂ and crystallite growth of the samples. Meanwhile, the elemental analysis exhibited that the change of metal composition in concomitant with the addition of Ni and Zr. Furthermore, the microscopy analysis showed that the samples have agglomerated shape in nanometric size. Therefore, the prepared Ni/ZrO₂/SiO₂ in this work opens the potential to be applied as hydrogenation catalyst.

Monitoring of environmental pollution can be carried out in the leaching process to determine the quality of sediment. This study modified the Tessier method leaching process using an optimized microwave. This study reported the effect of radiation contact time and microwave power in the microwave Tessier method based on their level of accuracy and precision to the analysis of Fe in sediment. After optimizing the microwave Tessier method, we continued using this optimization to determine pollution status using the Contamination Factor (CF) values. The results showed the time of contact of the radiation and microwave power gave an influence in the optimized Tessier analysis of Fe in sediment. The optimized conditions were in the fraction 1 (power radiation: 10%; time: 2 minutes), fraction 2 (power radiation: 30%; time: 3 minutes), fraction 3 (power radiation: 50%; time: 2 minutes), fraction 4 (power radiation: 50%; time: 3 minutes). The microwave Tessier method produced the recovery percentage of 94.11%. Fe concentration in sediments showed in the non-resistant fraction had a range between 537.6 mg/kg - 575.9 mg/kg, whereas Fe concentrations in the resistant fraction ranged from 3161.6 mg/kg - 10067.2 mg/kg. The results of CF values were obtained at 1.933-1.961, indicating the moderate contamination status in the Gulf of Prigi.

Dye-sensitized solar cells (DSSC) made of TiO₂ have received considerable attention from many researchers for the last three decades. Rapid theoretical and experimental studies have been conducted to improve the performance of DSSC. To understand the DSSC internal parameters, we need to fine-tune each component and identify the suitable conditions in optimizing the performance of assembled devices. In this work, we analyzed and calculated of several parameters the DSSC photoanode, e.g. electron diffusion and photon absorption coefficients. The experimental I-V data from solar simulator measurements were fitted base on electron diffusion model using Microcal Origin software. We compared the photon absorption coefficient values from this calculation method with the result of UV-Vis measurement and compared the electron diffusion coefficient values with the result of the SEM image data fitting calculation method. It was apparent that the results of I-V data fitting calculation method were comparable with the results of two other techniques.

The research objectives were phase characterization and magnetic properties of Fe₃O₄/SiO₂ nanocomposite (NCs) prepared by a wet-mixing process so that Fe₃O₄ magnetite nanoparticles coated amorphous silica SiO2; Polyethylene glycol is used as a binding medium. The Fe₃O₄ magnetic material was prepared from the iron sand with a co-precipitation method and silica (SiO₂) nanoparticles from quartz sand with a continuous method (hydrothermal-coprecipitation). The samples were characterized using X-ray diffraction (XRD), Fourier transformed infrared spectroscopy (FTIR), and vibrating sample magnetometers (VSM). The data analysis of the XRD and FTIR data presented that theFe₃O₄ and SiO₂ crystals were obtained which respectively act as the Fe₃O₄/SiO₂ NCs; signified by the existence of silanol (Si-O; O-Si-O) and Fe⁺² (Fe-O) functional groups. The VSM profile exhibited the superparamagnetic/soft-magnetic properties at room temperature. The presence of the silica shell is able to decrease the magnetization from 29 emu/g to 5 emu/g.

In this work, the surface treatment of stainless steel 304 was conducted using nitrogen an ion implantation route performing at 90 KeV and 100 μA with a dose variation of 0.7 × 10¹⁷, 1 × 10¹⁷, 1.3 × 10¹⁷, and 1.6 × 10¹⁷ atoms/cm². The stainless steel used was a thin plate with a thickness of 2 mm and a diameter of 14 mm. The data analysis showed the sample density increased with the increase of nitrogen ions. The samples had hardness value up to 143.32 HVN at an optimum dose of 1 × 10¹⁷ ions/cm². Such an increase is predicted due to the formation of a new nitride layer on the surface. Furthermore, the corrosion properties showed that the best corrosion resistance was of 0.71 mm/year. The microscope electron investigation presented the addition of nitrogen ions.

We study morphology and optical properties of graphene. A graphene on Si (100) substrate has been successfully prepared by the simple-spray method. The heat treatment of 150°C was performed during the deposition to assist the distribution of graphene on Si (100) substrate. We revealed that the graphene was well distributed with an island structure was observed. The real part and imaginary part of the refractive index of the graphene island were presented. Furthermore, the optical analysis revealed that the UV absorption was observed in our system. The results shown here would provide a good understanding of the graphene island properties, which potential for the optoelectronic-based application. In any case, our proposed method would reduce the complexity of the production of graphene with the inexpensive and simple procedure.

In recent years, hydroxyapatite nanoparticles have exhibited excellent characters especially related to biomedical applications. Therefore, it is important to conduct the synthesis route development in simple and inexpensive ways. This work aimed to study the structural and optical characters of the hydroxyapatite nanoparticles prepared by precipitation route from natural limestone. The characterization results presented that the sample formed a pure hydroxyapatite with the hexagonal structure and sized in nanometric scale with the respective primary and secondary particles of 5 nm and 29 nm. The vibrational investigation exhibited that the prepared sample had functional groups of the hydroxyapatite originating from phosphate, carbonate, and hydroxyl. Furthermore, the hydroxyapatite had an optical bandgap of 3.38 eV.

The cassava as a starch source has a great potential as biocomposite matrix in a packaging material technology. The addition of nanoclay as biocomposite reinforcement into matrix will increase the biocomposite properties but it is difficult to homogenize a nanoclay particle into the biocomposite matrix. Accordingly, the research aimed at showing the effect of ultrasonic wave treatment on the strength of starch-based biocomposite with nanoclay as reinforcement. The research was conducted by applying a casting technique to synthesize the biocomposite. The ultrasonic wave treatment was conducted during biocomposite synthetic process with 5% (wt/wt) nanoclay with various homogenizing time and subsequently pour it into the mold. Biocomposite strength was determined by a tensile tester. The fracture morphology was observed using SEM and the functional group was analyzed using FTIR methods. The results show that the ultrasonic wave treatment affects the mechanical properties of nanoclay reinforced starch biocomposite. This result shows that the duration time of the ultrasonic wave treatment 15, 30, 45, and 60 min. increase strength and elongation of 11.79 MPa, 14.77 MPa, 20.52 MPa, 28.01 MPa, and 12.08%, 16.08%, 26.12%, 27.90%, respectively. It shows that the duration time of the ultrasonic wave treatment ≥ 45 minutes resulted in better mechanical properties of biocomposite.

The effect of doping Ag on the oxygen content of Y_0.90La_0.05Eu_0.05Ba₂Cu₃O_7-d (YLEBCO) superconductor has been carried out. YLEBCO superconductor was synthesized by the addition of Ag with the variations of 0.010, 0.025, and 0.050 of molar ratio. The synthesis process was made using a wet-mixing method with calcination at 600 °C for 3 hours and sintering at 900 °C for 5 hours. The samples were characterized by means of X-ray diffraction (XRD), Fourier Transform Infrared (FTIR), and Micro-Oxygen. The results of XRD analyses showed the domination of YLEBCO-123 phase with a volume fraction of between 85-92%, while the impurity phase Y-113 was also detected with a volume fraction between 8-15%. The increase in Ag (0.010-0.050) gave rise to enlarge the Meanwhile, the smaller change on b (3.891971-3.884080 Å) was observed with the increase in Ag content. Orthorhombic strain decreased (1.593%-1.126%) with the increase in doping Ag. The addition of Ag doping caused YLEBCO oxygen content decreased (6.938-6.674 Å).

Solar energy can be converted into hydrogen fuel using photoelectrochemical (PEC) cell through split water molecules. Among semiconductor metal oxide materials, ZnO material has shown promising potential as PEC cells due to the large band gap value (3.37 eV), high excitation energy (60 meV), abundant material, and non-toxic. ZnO in the form of nanorods (NRs) can increase the conversion efficiency of the PEC performance because of the large surface area. In this research, we investigated the influence of zinc nitrate concentrations on the morphology of ZnO NRs on the stainless steel substrate and its PEC performance. Stainless steel was chosen as a substrate because of high conductivity, excellent corrosion resistance, and inexpensive. ZnO NRs are synthesized by the hydrothermal method. The structure and morphology of ZnO NRs were characterized by XRD and SEM. While PEC performances were studied using two probe method. The graph of current versus times was fitted by an exponential equation to determine time response and time decay of ZnO NRs. We found that ZnO NRs has good photoresponse but the current value is low.

The trend of nanoparticles technology has been so advanced in several years; for instance, the bio-applications of polymer gel composites that involve micro/nanoparticles to be embedded in polymer gel have been many observed. This complex material composition can express a specific property and low toxicity so it can be used in various domain uses. Besides, the polymers material must possess certain properties to be utilized in the biomedical application (magnetic hyperthermia, cancer therapy, and food industry) such as flexible, biocompatibility, and water swallowability. Magnetite is nanoparticle with a unique property that can be utilized as a filler. The low toxicity of magnetite under the superparamagnetic condition is very useful in biomedical application. This research was succeeded to synthesize PVA/PVP polymer-based hydrogel magnetic with PEG-coated magnetite with Manganese doping filler, which has good biocompatibility and stable particle. An advanced characterization using XRD has shown the crystallite size about 9-11 nm with the magnetite phase confirmed from the sample. The SAXS analysis using two-lognormal functions exhibited primary and secondary particles around 2.40 and 9.74 nm that was well proven by TEM image analysis that showed a close value of the average particles size about 9.78 nm. From the SAXS and TEM analysis, it could be observed that the samples formed clusters from primary and secondary particles.

This study aimed to investigate the potential of brown algae (Padina sp.). The investigation focused on surface morphology of the brown algae as preparation for making sodium alginate-based impression materials to obtain standardized impression materials. The sample was a natural sodium alginate type Padina sp. taken from South Sulawesi, Indonesia. The extraction process was conducted to attain the sodium alginate extract. Subsequently, an irreversible hydrocolloid impression material was fabricated by mixing some of the impression material composition and sodium alginate from Padina sp. The test of physical characteristic was conducted by describing the surface morphology of impression materials using scanning electron microscope (SEM). The data analysis of the SEM images showed that there was a difference in the surface morphology structure of the impression materials of the brown algae of the type of Padina sp. and standard impression materials showing a rough surface. Furthermore, the particles had no binding with other particles for all samples.

The Fe_3-xZn_xO₄-PEG/Carboxymethyl Cellulose/Polyvinyl Alcohol (Fe_3-xZn_xO_4-PEG/CMC/PVA) magnetic hydrogel has been successfully synthesized through the freezing-thawing process. The filler of Fe_3-xZn_xO₄ nanoparticles has been successfully fabricated using the coprecipitation method. The investigation of nanostructural characteristic of Fe_3-xZn_xO_4-PEG/CMC/PVA magnetic hydrogel was conducted using X-Ray Diffractometer (XRD), TEM, and Small Angle X-ray Scattering (SAXS) spectrometer to analyse the structure of crystal, morphology of Fe_3-xZn_xO₄-PEG/CMC/PVA nanoparticles, and nanostructural behaviour of Fe_3-xZn_xO₄ distribution in the Fe_3-xZn_xO₄-PEG/CMC/PVA magnetic hydrogel The addition of Zn doping into Fe_3-xZn_xO₄ nanoparticles with the variation of compositions of x = 0.65, 0.75, and 0.85 has been done and caused the shifting of the peak of diffraction angle to the smaller diffraction angle as the addition of x composition. Through the X-ray analysis, it can be found that the sizes of Fe_3-xZn_xO₄ nanoparticles crystal in the Fe_3-xZn_xO₄-PEG/CMC/PVA magnetic hydrogel were around 10 - 12 nm. These data were in line with the data analysis using SAXS, especially the value of secondary particles from the Fe_3-xZn_xO₄ magnetic filler with the values of about ∼ 9 nm. Meanwhile, the values of Fe_3-xZn_xO₄ primary particles were about ∼ 2 nm. The data of the distribution of Fe_3-xZn_xO₄-PEG magnetic nanoparticles in the Fe_3-xZn_xO_4-PEG/CMC/PVA magnetic hydrogel were also supported by the characterization of the nanoparticles filler morphology using TEM showing the number of about 9 - 11 nm. The tissue of PEG/CMC/PVA polymer was effective enough in inhibiting the aggregation of Fe_3-xZn_xO₄ filler nanoparticles so that they could be equally distributed in the Fe_3-xZn_xO₄-PEG/CMC/PVA magnetic hydrogel.

The oxidation behaviour of ZrO₂ nanoparticles added to Fe-18Al alloy has been studied. Isothermal oxidation behaviour with various temperatures and times was investigated and the results of microstructure showed the presence of Fe₃Al intermetallic phases in grey color, Al₂O₃ oxide in white color, and the porosity indicated by dark color. The results of XRD and SEM-EDS analysis also confirmed the presence of the ZrO₂ nanoparticles in addition to Fe3Al intermetallic phases and Al₂O₃ oxide phases. The addition of ZrO₂ nanoparticles tended to decrease oxidation rate by promoting Al₂O₃ layers.

Al-Si alloy was synthesized of combining aluminum and silicon (Al-Si). The addition of 15% silicon was aimed to improve the ductility and hardness of aluminum up to 525 MPa. It was also intended for reducing defects from gas porosity. However, the use of more than 15% silicon would make the alloy more brittle drastically which microscopically representing by the formation of crystalline silica granules. This study involved eggshell nanopowders as reinforcing material in enhancing hardness and ductility of Al-Si alloy. The casting process began with synthesizing eggshells into nanopowders. We added a certain amount of eggshell nanopowders (ESNPs) (0.05%, 0.1%, or 0.2%) into the Al-Si molten and subsequently mixed using a stirrer for 1 minute. The resulting mixture was poured into a permanent mold. It was shown that the Al-Si casting reinforced with 0.1% ESNPs had the highest tensile strength of 20.38 kg/mm² and the highest hardness of 137.9 HV. Further analysis revealed that the microstructure homogeneity of the samples is strongly affected its hardness.

This research aimed at identifying the structure and potentials of Fe₃O₄ coated with a double surfactant system as an antifungal material. The double surfactant was maintained by exploring dimethyl sulfoxide (DMSO) and oleic acid (OA). The samples were varied with temperature treatments at room temperature until 200 °C. Based on the results of XRD data analysis, it was found that the sample phase was Fe₃O₄ overall with the highest peak at 35.59° and the particle size of approximately 10 nm. Based on the SEM-EDS characterization, the morphology of the samples and the constituent element of Fe₃O₄ could be identified; they were Fe and O with the mass percentage of each sample was 78.7% and 21.3% respectively. FTIR was used to identify the sample functional group and was able to detect the existence of constituent component of Ferrofluid which was Fe₃O₄ at wavenumbers of 596 and 713 cm^-1, then the stretching bonds of oleic acid were at the wavenumbers of 1312, 1376, 1464, 2856, and 2920 cm^-1, DMSO at the wavenumbers of 954 and 1018 cm^-1, and the stretching bonds of olive oil at the wavenumbers of 1089, 1169, 1233, 1599, 1742, 2856, 2920, and 3008 cm^-1. The antifungal potential was tested using a diffusion method and the best result was obtained for the sample treated at room temperature with the fungal zone of inhibition was around 13 mm and potentially recommended for an antifungal material.

Billion tons of chicken feathers are being generated every year from the poultry industry. Ironically, although egg white is one important source of proteins for a human, it only contains 57% of protein, while chicken feathers contains about 980% of protein. However, due to its complex structure, chicken feathers are not consumable by the human. This makes chicken feathers are classified as biowaste material which causes environmental problems. The huge amount of this biomaterial offers a potential raw material for polypeptide and amino acids source. Chicken feathers contains a highly fibrous protein called keratin. X-ray diffraction model of keratin architecture showed supercoiled of helical proteins. The structure is also strengthened by disulphide bonds which make keratin insoluble in water and an organic solvent. Many attempts have been tried to break down the chemical bonds and convert chicken feathers into simple structural materials for sustainable uses. Currently, hydrothermal degradation is a preferable technique to concert chicken feathers into keratin powder because it is cheap for industrial purposes. Enzymatic degradation offers a greener process. We have successfully isolated a Gram-positive bacterium named Bacillus sp. MD24 which is capable of producing keratinase, an enzyme that degrades chicken feathers. In this paper, we described fibrous keratin powder as a by-product of keratinase fermentation by Bacillus sp. MD24 under solid-state fermentation (SSF). Scanning electron micrograph showed a tremendous reduction in the size of keratin after fermentation.

The composite of cement base matrix filled with LDPE/PET/Styrofoam plastic waste as aggregates has been successfully synthesized through a conventional mixing process. The highest density and lowest water absorbability of the composite are 2.06 g/cm3 and 6.02% respectively. SEM results show the distribution of sand aggregates were distributed evenly within the matrix. The PET has shown the tendency to form a spherical morphology. It is probably caused by the high adhesiveness of PET that induces the surface tension between PET and LDPE. The highest compressive strength value of the composite is 18.8 MPa.

An alternative method of amalgamation to extract gold in small-scale industries was investigated by means of chloride-ion-based solution leaching. In this study, the addition of NaCl and optimization of chloride-ion-based leaching of gold was analyzed by using the Taguchi Method. Indonesia gold ore processed from artisanal mining was utilized in this study. The solutions of HCl (11.6 mol/L)-H₂O₂ (1 vol%) were used as lixiviants. The effects of temperature, pulp ratio, leaching time, and NaCl addition were examined. The optimum leaching condition was predicted using a signal to noise ratio and the influences of given input parameters were studied through the analysis of variance. More than 78% extraction of gold was achieved after 3 hours using pulp ratio of 0.5, a temperature of 75 °C, and the addition of 0.05 M of NaCl.

The higher incidence of hypertension strongly and significantly associated with unhealthy lifestyle and lack of physical exercise. This study aimed to investigate the fundamental correlation between musical tempo and physiological response particularly on vascular tension and cardiorespiratory activity in the nonathletes. This pre-posttest randomized design study involving non-athletes with age ranged from 19-21 years old, resting cardiac 60-80 beat/minute, maximal oxygen consumption (VO₂ max) 37- 49 ml/KgBW, average body mass index (BMI) and hemoglobin level (Hb), and without smoking history. The experimental data were collected from 60 participants that divided into four criteria. The placebo was treated with high exercise in the acute model while another group was exposed by moderate exercise with fast and slow musical tempo during treatment for 20 minutes. The monitoring of vascular tension and cardiovascular performance were done by using standardized clinical test. Importantly, the slow tempo of musical beat and acute moderate exercise model significantly decreased the vascular tension in cardiovascular activity without significant alteration in the lung activity. The pre-treatment with slow beat of musical tempo strongly correlated to vascular wall pressure. The systolic and diastolic pressure was significantly different among the group (P < 0.05). Moreover, the combination treatment in our study improved the primary effect of musical tempo and muscular stretch on heart rate and cardiovascular performance. Our preliminary study suggests that co-treatment of slow beat musical and acute moderate exercise can reduce the progression of hypertension in the trained non-athletes.

A synthesis of nano-hydroxyapatite:polylactide acid (n-HA:PLA) composites based on natural materials has been performed. The synthesis was performed using sonication method, with a variation of n-HA:PLA ratio of 90:10, 80:20, 70:30, 60:40, 50:50 in %wt. The crystal structure and morphology of the sample were characterized by using X-ray diffractometer (XRD) and scanning electron microscopy (SEM). The bioactivity and biodegradable tests were performed in vitro using Krebs solution. Meanwhile, the biocompatibility test was performed by a separate bath organ method. The results show that for all compositions of n-HA:PLA exhibit a biocompatible characteristic. The sample with a ratio of 90:10 %wt shows higher bioactivity and biodegradability properties than other compositions. Our result would give a good understanding of the synthesis and biocompatibility, bioactivity, and biodegradability of n-HA:PLA composite, which is crucial for bone regeneration.

Mn_0.25Fe_2.75O₄@PANI material has been successfully synthesized using in-situ polymerization method. Meanwhile, Mn_0.25Fe_2.75O₄ nanoparticles based on local sand was synthesized using the coprecipitation method. The Mn_0.25Fe_2.75O₄@PANI sample was characterized using the instrument of X-Ray Diffraction (XRD), Fourier Transform Infrared (FTIR), Transmission Electron Microscopy (TEM), and Magneto-Thermal Test to know the structure of the material, functional group of the material, size morphology of the material, and the specific absorption rate (SAR) value. The XRD pattern of Mn_0.25Fe_2.75O₄@PANI material was dominated by an amorphous structural pattern. The domination of PANI polymer in the Mn_0.25Fe_2.75O₄@PANI material implicated to the decrease in the intensity of Mn_0.25Fe_2.75O₄ nanoparticle peak. The existence of PANI polymer also impacted on the amount of aggregation of the Mn_0.25Fe_2.75O₄ nanoparticles so that the size of the Mn_0.25Fe_2.75O₄ particles increased from 8.4 nm (without PANI) to 30.4 nm (with PANI). Moreover, the test result using magneto-thermal instrument showed that the bigger the frequency of the alternating magnetic field, the obtained SAR value of the Mn_0.25Fe_2.75O₄@PANI material would be bigger as well. For the frequency of 483 and 553 Hz, the SAR values of Mn_0.25Fe_2.75O₄@PANI material was 0.81 and 3.65 W/g, respectively. Based on the SAR results, the Mn_0.25Fe_2.75O₄@PANI material has the potential to be the media of drug delivery for cancer therapy.

The purpose of this study was to synthesize NaY zeolite by utilizing local sand as a source of silica which was carried out at various crystallization temperatures. The synthesis of NaY zeolite is carried out using silica resulted from the purification of local sand while NaOH and Al₂O₃ are pure analysis (pa) quality. Crystallization temperature was carried out at various temperatures of 80, 100, and 150 °C. The synthesis results were characterized by physical properties, XRF, FTIR, XRD, SEM, surface area. NaY zeolite was successfully synthesized supported by FTIR data by the presence of functional groups such as Si-O, O-Al-O, Si-OH, and O-H from Si-OH, and SEM data which showed the formation of cube-shaped crystals. The formation of NaY zeolite is also strengthened by the appearance of peaks with a sharp intensity from XRD diffractogram that this zeolite is NaY and as well as data molar ratio of Si/Al is in the range of 2.027 to 2.045 respectively at various crystallization temperature. The crystallization temperature of 80 °C produces NaY zeolite better than that of crystallization temperatures of 100 and 150 °C. The synthesized NaY zeolites using local sand have a good surface area that is 658 m²/g. The crystallization temperature affects the success of NaY zeolite synthesis.

The superconductor of Y-124, Y259, and Y-358 phases has been successfully synthesized using the wet-mixing method. The compounds of Yttrium Oxide, Barium Carbonate, Cuprum Oxide, and Nitric Acid as a digesting agent have been used. The sample was prepared by calcination at 600 °C for 3 hours and subsequently sintering at 850 °C for 5 hours. The synthesis of Y-124, Y-259, and Y-358 phases were processed using a wet-mixing method. The phases were assumed to have the same initial temperature of crystalline growth around 800 °C. The a and b-axis lattice parameters decreased by the increase in Y atoms. On the other hand, the c-axis lattice parameter increased by adding Cu atoms. The volume of unit cells increased with the addition of Ba and Cu atoms. It was also found that LIBS was very effective in detecting the atoms contained in the sample and predicted in the percentage of the atoms in the sample.

Half-metal is a class of the metallic ferromagnet having a 100% spin polarization. The conduction electrons of half-metals can only carry electrons with a particular spin orientation. Because of this, the current generation of half-metal is expected to be governed only by the particular conducting spin. However, the contribution of the opposite spin, on which the half-metal acts as an insulator, is often neglected. Here we theoretically study the contribution of this insulating spin on the spin transport in the half-metal, in comparison with the conducting spin. We found that the collective dynamic of the insulating spin is responsible for magnonic transport that in turns influence the spin current generation in the half-metal.

Styrofoam fibers have been fabricated using a rotary forcespinning route. The fibers were produced by utilizing the centrifugal force derived from the high-speed motor. Styrofoam was dissolved in d-limonene at the concentration of 10, 15, 20, 25, and 30 wt%, then the solution was subjected to the rotary forcespinning at a rotational speed of 12,000 rpm. The effect of concentration on fibers' morphology was studied. SEM images showed that the fibers produced had a straight and smooth surface with no beads. The diameter of the fibers ranged from 600 nm to 3 μm. The solution concentration parameter is important in fiber formation. An increase in the concentration of the solution increased the diameter of the fibers. The analysis of FTIR spectra suggested that FTIR peaks of styrofoam fibers had the same peaks like those in the styrofoam bulk and there was no peak of d-limonene detected in the samples, which indicates the solvent has evaporated. XRD analysis showed that the styrofoam fibers had an amorphous structure. The use of rotary forcespinning to produce the fibers has shown a good quality fiber, a high production rate, and relatively inexpensive for mass-scale production.

Catalytic partial oxidation of methane into syngas has been investigated over a series of La_1-xSr_xCo_0.8Fe_0.2O_{3 ± δ} perovskite powder (x = 0.0; 0.1; 0.2; 0.3; 0.4) in a continuous flow reactor. Characterization studies of this powder by XRD showed that the incorporation of more Sr (x) increased the lattice parameter and transformed broad to single, sharp peak of La_1-xSr_xCo_0.8Fe_0.2O₃. The performance of syngas formation from methane without the presence of molecular oxygen was determined by the ratio of H₂/CO in the range of 750-950 °C. The performance correlated with thermogravimetric analysis. At a low temperature (750 °C), the CH₄ conversions over La_1-xSr_xCo_0.8Fe_0.2O_{3 ± δ} were affected by the crystallite size, whereas at a high temperature (950 °C), it was influenced by the mobility of oxygen ions coming from bulk. The weight loss in the range of 455-1100 °C due to the reduction of Fe³⁺ to Fe⁰ had a reverse effect on H₂/CO ratio. Among all of the powder catalysts tested at 950 °C, LaCo_0.8Fe_0.2O_{3 ± δ} had the largest Fe³⁺ reduction to Fe⁰ and the lowest ratio of H₂/CO.

Carbon rods of battery were utilized as a target in a plasma sputtering deposition of a carbon thin film. The rods were taken from unused battery waste containing some impurities. This study was intended to investigate the effect of the impurities on the resulted thin film. Furthermore, this work aimed to study the utilization of an unconventional sputtering technique to deposit the carbon film on glass substrates. A low-frequency plasma generator of 40 kHz was used to power the sputtering reactor. The plasma was generated from an Argon gas in a medium vacuum pressure. Two deposition parameters studied in this work were plasma power varied from 220 watts to 360 watts and substrate temperature varied from 25 °C to 202 °C. The carbon target in this research was also functioned as an electrode in the sputtering system. The deposition process was carried out for 1 hour to produce a reasonably thick carbon thin film. The resulted films were characterized using a Fourier Transform Infrared (FTIR) spectroscopy. The FTIR spectra showed a distinct peak around 1200 cm^-1 and 1600-1700cm^-1 related to the C-C and C = C vibration respectively. The relatively broad peak consisted of a doublet indicating a complex structure of the carbon film, presumably an amorphous carbon film. It was proven that impure carbon could be used as the target and successfully deposited on the glass substrate.

The purpose of this research was to synthesize the methyl ester of crude palm oil off grade using a K₂O/Al₂O₃ catalyst and its potential as a biodiesel. The procedure of this study was refining CPO off grade using active natural zeolite, CPO off grade of esterification, transesterification of CPO off grade using a K₂O/Al₂O₃ catalyst by varying the concentrations of 2–4% (w/w) catalyst. The results showed that the activation of natural zeolite HCl 2% (w/w) could be used for refining CPO off grade; the methyl ester could be synthesized from CPO off grade through transesterification of K₂O/Al₂O₃ catalyst that obtained the highest yield of 85.58% (w/w) at the catalyst concentration of 4% (w/w). The results of catalyst characterization of methyl ester with 4% (w/w) of methyl esters obtained a density of 0.86 g/mL, a viscosity of 4.33 cSt, a refractive index of 1.45, and the acid number of 0.49 mg/g methyl ester thus fulfilling SNI biodiesel; the major components of the building blocks of the methyl ester transesterification catalyst results of K₂O/Al₂O₃ were methyl palmitate, methyl linoleate, methyl oleate, and methyl stearate.

Lithium-ion batteries are currently the most promising storage device. An electronic conductivity is a key factor that affects the performance of Lithium-ion batteries (LiB). In this work, LiNiSi_xP_1-xO₄/C, (x = 0.00, 0.05, 0.10, 0.15, and 0.20) as cathode materials were effectively synthesized by a solid-state reaction technique. To enhance the ionic conductivity of Lithium-Ion Battery application, we used sucrose as a carbon source and Si ion as a dopant in LiNiPO₄ cathode material. The effect of Si dopant on its crystal structure, composition, and functional groups existing in cathode material LiNiSi_xP_1-xO₄/C are investigated analytically. The samples were characterized by using the X-ray Diffractometer (XRD), X-Ray fluorescence (XRF), and Fourier Transform Infrared Spectroscopy (FTIR). The different amount of Si dopant promotes the structural modification and important role to improve the rate performance of LiB.

The aim of this study was to identify the steroid hormone compound in the urine of male tiger grouper, and the role of steroid hormone suspected as pheromone of the male fish to induce gonad maturity of female tiger grouper. The methods employed in this study included broodstock maintenance, the collection of male urine samples, pheromone analysis of male urine, and application test of urine for gonad maturity of female tiger grouper. The analysis of pheromone content in urine was performed by using LC-MS / MS and FTIR methods. Urine was applied for several females placed in concrete tanks with a volume of 12 tons, 4 females for each tank. The parameters tested were male urine dose: 1 ml, 2 ml, and 3 ml. The results of pheromone analysis using LC-MS / MS method in urine and sperm of male tiger grouper indicated a peak of ion percussion of 255 ms and 273 ms, while the ion products showed 159 F and 255F. Based on the result of FTIR test, it could be seen that the resulted bands were infrared absorption which had certain character patterns, in which urine had six infrared spectrums; this steroid was classified in alcohol group β-sitosterol. The role of urine as a pheromone carrier administered to female was observed through the concentrations of estradiol-17β hormone and testosterone in blood plasma. The results showed that the concentration of estradiol-17β was much higher when compared with testosterone, either before or after treatment. The high concentration of estradiol was related to the stages of egg development in the female before the spawning season. From the results of this study, it could be concluded that male urine of tiger grouper was a pheromone that could increase the stimulation and gonad maturity of female broodstock.

The increasing demand for materials for manufacturing products needs to be met with the development of new materials. This research aimed at developing a composite of Hibiscus cannabinus L. fiber, corn silk, and polyester resin. In the first stage of this research, a composite of a variety of mass fractions and fiber length was made. The mass fraction used in the Hibiscus cannabinus L. fiber: corn silk was (10%: 10%), (12.5%: 7.5%), and (15%: 5%). The fiber lengths of Hibiscus cannabinus L. fiber and corn silk were 30, 60, and 90 mm. The method used to make composite materials was the hand lay-up method using molds. In the second stage, the composite material was tested with a tensile test. The standard used was ASTM D 638M-84 M-1. The third stage was to optimize tensile test results by using the Response Surface Methodology (RSM). The result of RSM optimization was Hibiscus cannabinus L. fiber: corn silk composition (16%: 4%) with the fiber length of 102.4 mm, having a tensile strength of 3.65 Kg/mm².

To develop a new coolant for nuclear and non-nuclear applications, nanoparticles of Al₂O₃ for nanofluids have been successfully synthesized using a self-combustion method from Al(OH)₃ precursor extracted from local bauxite. A sol was prepared by dissolving the Al(OH)₃ powder in water and adding an amount of PEG 1000 into the solution. The solution was stirred to form a sol and then was heated at 150 °C until forming a gel. The gel was then self-combusted at 450 °C and heated at 600 °C. The combusted and heated material was calcined at 1200 °C for 1 hour to get Al₂O₃ nanoparticles. The preparation of nanofluids was done by dispersing the Al₂O₃ nanoparticles into an amount of water as the base fluid. The Al₂O₃ nanoparticles were crystallized in a theta phase with a crystallite size of 15.7 nm as confirmed by the XRD analyses. According to TEM data, it was known that the particle size of the nanoparticles was 35 nm. The nanofluid with the concentration of 0.025 vol % and pH of 10 possessed zeta potential of -42 mV indicating a stable suspension. This nanofluid had a CHF enhancement of 73% compared to water as the base fluid.

In the last years, CoFe₂O₄ (cobalt ferrite) nanoparticles become remarkable material due to their performance in various sophisticated applications. In this study, the cobalt ferrite both in powder and ferrofluid phases was successfully synthesized from natural sand. Investigation of the structural properties of the cobalt ferrite was performed using an X-ray diffractometer (XRD) and a small angle X-ray scattering (SAXS) spectrometer to study the crystal structure in the powder and liquid states. The results of the SAXS data analysis using lognormal model revealed that the primary particle size of the cobalt ferrite in powder and ferrofluid had the similar size for the primary particle and fractal dimension, but varied in the secondary particle size. The data analysis using the Rietveld method from XRD data showed that the cobalt ferrite had an inverse spinel cubic structure, respectively. Such data was also confirmed by the data from Fourier transform infrared (FTIR) spectroscopy experiment. Moreover, the data analysis obtained from the ultra-violet visible (UV-Vis) spectroscopy showed that the cobalt ferrite had a semiconductor characteristic with direct band gaps of about 2.27 eV.

Dye is a photosensitizer which is one of the key elements in developing high performance dye-sensitized solar cells (DSSC). However, the use of natural dyes as photosensitizers in DSSC, until now still produces much lower device efficiency compared to those from complex metal dyes or organic synthesis dyes. Therefore, research is still needed to find the efficiency of DSSC using the best variety of natural dyes. In this research, the characteristics of the dye-sensitized solar cell (DSSC) has been simulated using MATLAB based on TiO₂ by modifying the internal parameters (Φ, τ, α, m, Τ), external, and previous DSSC research data. The simulation has been performed to determine the performance of natural dye made locally (coffee, turmeric, cocktail (coffee and turmeric), phyllanthus reticulatus poir, piper crocatum, and melaleuca leucadendra), in terms of the change due to the intensity of solar radiation and temperature by displaying the I-V and P-V curve characteristics. The simulation has produced the highest DSSC performance by using natural dye from melaleuca leucadendra with a maximum voltage, current density, and power of 0.7882 Volt, 0.0032 A/cm², and 0.0015 W, respectively, using a cell area of 1.5 cm x 1.5 cm. The DSSC performance also produced a higher performance when measured at 12.00 o'clock in the afternoon with a maximum power of 0.0013 W. Therefore, some of these natural dyes have indicated the high potential of becoming low-cost photosensitizer, which is available abundantly and environmentally friendly.

In general, about 10-15% of the dyes used in the colouring process in the textile industries are wasted into the waters. Though the dye waste is generally resistant, it is difficult to decompose, and toxic. One effort to process the waste before being discharged into the environment is the adsorption process. The process requires superior adsorbents of which main requirement is to have a large specific surface area, chemically and thermally stable, and also easily isolated from the system. One of the adsorbents that meet these requirements is zinc ferrite nanoparticles (ZnFe₂O₄), which is a magnetic nanometer-scale material that is thermally and chemically stable. Various methods of synthesis of ZnFe₂O₄ nanoparticles have been developed, one of which is coprecipitation. This method is a simple method but often produces polydisperse particles. The use of templates in the synthesis process is expected to overcome this problem. For this reason, the purpose of this study was to synthesize the ZnFe₂O₄ nanoparticles by coprecipitation using a PEG 6000 as a template. It was followed by the performance test of these materials as adsorbents for malachite green which is one of the dyestuffs often used in industry. The data analysis showed that PEG increased the crystallinity, specific surface area and monodispersity of ZnFe₂O₄. The results of VSM analysis showed that ZnFe₂O₄ without PEG had a magnetic value greater than ZnFe₂O₄ with a PEG template. In the malachite green adsorption test, the adsorption capacity of ZnFe₂O₄ with PEG was higher than the bar one that was equal to 16.7 mg/g.

In general, seashells can contain calcium up to 97.19%. Therefore, it is potentially as a calcium source for nano-HA production. In this work, nano-HA was produced by sonochemical method with a period of sonication for 2 hours. Furthermore, nano-HA was composited with chitosan by a sonochemical method with a period of sonication for 2 hrs. Some fundamental characterizations were conducted to reveal the crystal structure, particle size, lattice parameters, microstructural morphology, and particle size by means of XRD, SEM, and EDX, respectively. Our results clearly showed that this desired crystalline of the composites had been successfully formed. Nano-hydroxyapatite with particle size 25.03 nm and Ca/P ratio 1.65 have been formed. The SEM result showed that the morphology was uniform and the composite had particles with the needle-like shape. The result from the synthesis of nano-HA/chitosan is recommended for biomedical application as bone filler.

Rice husk is an agricultural waste that potentially produces high-purity amorphous silica as the source of the precursor of mesoporous silica MCM-41. To obtain pure silica, acid leaching was applied to the rice husk followed by heating treatment in the furnace and synthesized by a sol-gel technique to produce amorphous silica. In this research, mesoporous silica MCM-41 were synthesized by a sol-gel technique assisted by CTAB as a template, then titrated with acetic acid and hydrothermal in the teflon line-autoclave. Various CTAB concentrations were applied as the research variable parameters. X-ray diffraction pattern shows that silica has an amorphous-like curve. FTIR data showed the presence of Si-O-Si function groups in the sample. SEM results showed coral reefs-microstructure with the particle sizes about 243 - 482 nm. TEM image showed the porous structure on the silica surface and formed a hexagonal structure mcm-41. The diameter of the shaft was 3.13 - 3.58 nm, hence the resulted silica material is classified as mesoporous material.

We report the role of ultrasonic procedure on the recovery of Platinum (Pt) from spent removing catalyst of Pt/Al₂O₃. In this study, the Pt was extracted by combining acid leaching of aqua regia and ultrasonic cleaning procedure. The frequency-dependent ultrasonic (low and high-frequency modes) showed a significant change in the Pt content on the Al₂O₃ ball. The morphological analysis showed that the higher frequency of the ultrasonic led the larger number of Pt recovery due to the higher agitation from the ultrasonic wave. This study gives a detail characteristic and modification of the Pt during the recovery, which is the key role on optimization of recovery of the Pt from spent removing the catalyst of Pt/Al₂O₃.

Bacterial cellulose (BC) is a natural material with attractive physical properties produced by Acetobacter xylinum. Commonly, BC is subjected to a chemical treatment prior to use. Therefore, this study aimed to investigate the effect of chemical treatment using alkali (NaOH) with the various concentrations on the mechanical strength of the resulting BC films. The research method included BC film production using a pineapple peel extract as the main culture material. The resultant BC film was treated with NaOH solution with concentrations of 0%, 1%, 5%, and 10% and then dried in the oven. The mechanical strength of each sample was evaluated by a tensile test, and the film morphology was observed by scanning electron microscopy (SEM). The results showed that the tensile strength of the BC film before the treatment was 208 MPa and decreased to 165 MPa after the treatment with the highest concentration of NaOH because some BC component was dissolved in NaOH solution causing bulk fractured layers. The NaOH concentrations of 1%, 5%, and 10% resulted in the strains of BC films by 2.96%, 3.64%, and 3.00%, respectively. The chemical treatment of NaOH caused BC films to swell and damage to the network and layers in BC film.

The presence of specific and unique chemical structure of a protein with their bioavailability properties provide a hallmark of the essential contribution of the biomaterials. Protein-based biomaterials become a novel trend in the biomedical field, particularly on clinical management and biomarker development. Blinding proteins and other materials in an advanced technological approach is crucial to generating protein-based biomaterials for biomedical. Recently, liver-derived protein, betatrophin/lipasin/ANGPTL-8 showed a potential property as the future biomaterial marker for early detection of gastrointestinal cancer related metabolic syndrome. The betatrophin expression is significantly correlated with cancer incidence and lipid metabolism disorder in a subject with obesity, type 2 diabetes, and insulin resistance. This clinical study aimed to develop betatrophin as the potential protein-based biomaterial marker in colorectal cancer (CRC) and metabolic syndrome, especially among Indonesian subjects. Our preliminary study focuses on Java ethnic as the dominant population with a higher incidence of CRC. The general anthropometric data were collected from CRC patients with different stages and metastasis status. The expression of betatrophin and metastasis related genes were quantified by real-time quantitative PCR (RT-qPCR). Interestingly, the basic profile of betatrophin and genes linked to cancer metastasis showed significant expression in our baseline data. Betatrophin/lipasin/ANGPTL-8 activity correlated to another gene that involved in the progression of cell migration and malignant cell invasion. Thus, we suggested that the alteration of betatrophin and its related genes expression may associate with the progression of CRC incidence in a subject with onset metabolic syndrome. Betatrophin could be proposed as the novel protein-based biomaterial marker in an individual with early stages of colorectal cancer. Therefore, the future expanded clinical study is necessary to well establish the biomaterial property of this liver protein in CRC diagnosis and prognosis.

Plasmons, which are conventionally known as quanta of electron plasma oscillations in a metal, were discovered unconventionally in an experiment of Strontium Niobate Oxide with oxygen enrichment (SrNbO_3,4). Plasmons that revealed in this experiment arose in the visible-ultraviolet range due to a confinement created by additional oxygens forming nanometer-spaced planes. This experimental background motivated us to study the formation of unconventional plasmons in the material by modeling a hypothetical system described by 5-sites linear chain Hubbard model around a quarter filling. The model was then solved by exact diagonalization (ED) method, from which we constructed the corresponding retarded Green function via Lehmann representation. Our interest was to calculate the optical response functions using Kubo formula of the linear response theory. Our results showed that the conventional plasmonic signals got modified by the presence of on-site Coulomb interactions. In addition, we observed that unconventional plasmons, behaving similarly to those found in the experiment, arose when the Coulomb intersite interaction was applied to the calculation.

Greywater represents wastewater type which generated from kitchen, laundries, and bathroom. Disposal of untreated greywater into the water bodies can cause water contamination as greywater contains numerous substances such as a surfactant, oil, grease, organic material, solids particle, and pathogen organisms. This study is aimed to investigate the performance of the vertical sub-surface flow constructed wetland (VSSFCWs) in removing BOD and TSS from greywater which produced from a student dormitory at the State University of Malang, Indonesia. There were two of VSSFCWs lab scale as a control and a planted which have the same dimension of 0.9 × 0.4 × 0.5 m. Ipomoea Aquatica used as a plant in the planted VSSFCWs. Gravel with a size of ± 10-30 mm used as media in VSSFCWs both for control and planted VVSFCWs. The experiment was conducted in five weeks and collected triplicate sample in every three days. The average of raw greywater concentration was 48 mg/L and 99.3 mg/L for BOD and TSS respectively. While the treated greywater produced 13.4 mg/L of BOD and 8.6 mg/L of TSS for the control, 4.45 mg/L of BOD and 5.63 mg/L of TSS for the planted test. The VSSFCWs shows high removal performance of 91% BOD and 94% TSS. The quality of the treated greywater has met the standard of Ministry of Health regulation of Republic of Indonesia No. 82/2001 which suitable for toilet flushing, gardening, and groundwater recharging.

Titanium dioxide/magnetite nanocomposites become important materials due to their sophisticated potential applications regarding their significant roles in medical science. In this work, we reported the preparation of the titanium dioxide/magnetite nanocomposites prepared using a sol-gel method. The natural sand was explored as an important raw material to prepare the sample. Based on the structural characterizations, the sample size in nanometric ranged of 7.8 nm with amorphous and crystalline phases for titanium dioxide and magnetite, respectively. The vibrational characters of the samples were overlapped originating from Fe-O and Ti-O on the wavenumber ranged between 500-700 cm^-1. Microscopy investigation showed that the sample agglomerated in a 3-dimensional fractal dimension as a spherical shape with the size of 34.8 nm. Interestingly, the samples had the optical band gap value of 2.1 eV and presented an excellent character with a low toxicity.

DSSC is a natural dye-based organic solar cell composed of layers of semiconductor (photoanode), dye, electrolyte, and the counter electrode. The photoanode layer on DSSC acts as a dye binder and can pass on excited electrons to the electrode counter. This component is one of the keys to improve the DSSC performance. The TiO₂ material has been used widely as a photoanode due to its high stability to light so that at its optimum thickness it can pass well the sunlight energy on the surface of the DSSC. When the sunlight energy impinges to DSSC for relatively long time, it can increase the working temperature. Theoretically, the increase in the working temperature of the DSSC causes an increase in the electron diffusion coefficient in the DSSC, thus affecting its performance. Therefore, the interpretation of an increase in the electron diffusion coefficient due to an increase in the thickness and working temperature in DSSC is essential to be studied. In this article, a simulation of the determination of the optimum thickness of TiO₂ photoanode was carried out. We studied the effect of electron diffusion coefficient on the DSSC open voltage at the optimum thickness. The highest electron diffusion coefficient in this simulation was 9.65x10^-3 cm²/s with current density of 0.0145 A/cm², voltage of 0.3411 V, power of 0.0020 V·A/cm², and efficiency of 2.000%. We found that the higher the electron diffusion coefficient, the open voltage of DSSC increased so that its performance also increased.

Polymer hybrid latex poly-(St-co-BA-co-MMA) with organo-montmorillonite (OMMT) as a filler were synthesized through a mini-emulsion polymerization technique. To change the nature hydrophilic to organophilic of montmorillonite (MMT), surface modification with cationic surfactant alkylammonium MTAB, CTAB, and OTAB were done through ion exchange process. The results were characterized by X-ray Diffraction (XRD) and Fourier Transform Infrared (FTIR). Interlayer layer spacing of OMMT was extended from 1.21 nm to 2.03 nm, and 2θ decreased from 7.2° to 4.2° resulting in pseudotrilyer structure, FTIR confirmed the XRD results where the amine group from cationic surfactant inserting into MMT interlayer and the surface wettability of MMT changes from hydrophilicity to organophilicity. Mini-emulsion polymerization with 4.0 wt% level of OMMT addition showed the role of SDS surfactant in the mini-emulsion polymerization technique with variation in particle size distributions of hybrid latex, surface tension, and monomer conversion rate. Water-soluble surfactant SDS with the added level from 2.0 to 4.0 wt% contributed to monomer conversion rate (> 99%) with a particle size diameter 80 to 102 nm.

The k-space spin textures in the first Brillouin zone plays an essential role in determining how spin-polarized currents can be manipulated for spin-orbitronics based devices. Here, achieving unidirectional spin textures called as a persistent spin helix is important to induce very long spin lifetime, which is useful for controlling spin-polarized currents. Using density functional theory (DFT) with fully relativistic calculations, we show that the unidirectional spin textures are achieved in the k-space of bulk SF₃PbI₃ oriented on [110]-direction. We found that the Rashba parameter strength of the spin-orbit induced spin splitting is sizable, indicating that this material is promising for energy saving spintronics.

A plasma treatment of polymeric materials has become one of the most important methods to enhance the surface wettability without affecting the bulk material features. Oxygen plasma treatment of polystyrene surfaces deposited on a QCM sensor was evaluated by relating the plasma parameters, surface roughness, and the wettability. The internal plasma parameters investigated in this work were the electron temperature (T_e) and the electron density (n_e). The oxygen plasma was generated using an RF power generator. The power was varied by applying a voltage from 60 volts to 100 volts. An Optical Emission Spectroscopy (OES) was used to determine the plasma species, the T_e and the n_e during the plasma oxygen process. The dominant species in the plasma was excited atomic oxygen or activated oxygen (OI) which was detected from the 774 nm and 842 nm emissions. The higher applied RF voltage resulted in the higher T_e and n_e. The effect of the T_e and n_e on the polystyrene surface was observed on the change of the surface roughness. The surface roughness significantly related to the surface wettability observed with a contact angle measurement. Furthermore, the plasma treatment greatly changed the surface from hydrophobic to hydrophilic via reactive processes by the excited atomic oxygen species. This was confirmed by the increase in C = C and C = O functional groups observed using a Fourier transform infrared (FTIR) spectroscopy. The T_e and n_e may also affected the character of the plasma in terms of its reactivity.

Filter cake (or Blotong) is a dirt sugarcane sediment (DSS) obtained from refining sugarcane. Organic Supercapacitors is a new technology combined battery and capacitor for advanced energy storage. The elements and compound containing in the DSS have potential be used as an electrode for supercapacitor. Firstly we prepared three different samples, i.e., heating at 100 °C for an hour, and addition method with H₂SO₄, and carbonation method at high temperatures. To control the specific capacitance, BaTiO₃ nanoparticles fraction was added. It has been successfully fabricated with a structure of DSS/BaTiO3/aluminum films. This supercapacitor produces an average grain size of 31.81 ± 0.29 nm and porosity of 0.63. The capacitance and specific capacitance respectively reaches to 2.44 × 10⁶ pF and 1100 × 10⁶ pF/g.

Fly ash/natural kaolin-based geopolymer with a low concentration of NaOH has been studied. The fly ash was taken from coal combustion waste of Asam-asam power plant, meanwhile the kaolin clay was taken from Tatakan, South Kalimantan, Indonesia. The kaolin powder was calcined at 750 °C for 3 hours to form pozzolanic metakaolin (Al₂O_3.2SiO₂). The silicon content from the X-ray fluorescence (XRF) test of the fly ash and the natural kaolin was respectively 44.58% and 72.98%. The aluminium weight percentage contained in the natural kaolin was roughly three times higher than that in the fly ash. Both starting materials together with the alkali solution (NaOH/Na₂SiO₃) were wisely mixed to produce geopolymers with Si/Al ratio of 4. The molarities of NaOH were controlled from 2M to 5M. The mixture was then heated at a curing temperature of 60 °C for 12 hours and dried at setting time of 14 to 28 days. The finest compressive strength, i.e. 91.6 MPa, was shown by the sample with 5M NaOH and 28 days setting time. This sample had a density of 2.04 g/ml and porosity of 5.88%. To the best of our knowledge, there is a prospective feature of using fly ash/natural kaolin-based geopolymer prepared by the low NaOH molarity in infrastructural industries.

In this study, we report the properties of current-voltage (I-V) of Ch/AgNP (chitosan/silver nanoparticles) composite membranes with emphasis on the effect of the content of AgNP. Composite membranes were made by a casting method using chitosan as matrix, 1% acetic acid as solvent and AgNP as filler. The content of AgNP added was 10, 100, 250, 500, 750 and 1000 μg. The I-V measurements were conducted using a two-compartment cell, which contains two working electrodes and two Ag/AgCl reference electrodes. The electrolyte solutions used were KCl and CaCl₂ with a concentration of 0.025 M. All measurements were done at room temperature of ± 28 °C. Also, it has been conducted FTIR analysis. The results showed that the absorbance peak of the -OH group in composite membranes are sharper compared with Ch membrane and also it has been observed peaks of Ag-O metal oxide at around 671 and 507 cm^-1. The I-V curve of the composite membranes in the range 0.66-0.98 mA is ohmic. The conductance of the composite membranes is smaller than that of Ch membranes, it decreased as increased the content of AgNP added, and it is greater in the KCl solution than in CaCl₂ solution.

Many studies have been conducted to produce ZnO including in the form of powder and film. This paper reports the characteristics of structures, optics, and magnetics of Zn_1-xMn_xO nanoparticles synthesized by coprecipitation method. The range of x value was maintained in the range of 0 to 0.03. The X-RD data analysis showed that all samples formed in nanosized. The lattice parameters sifted for all x values indicating the Mn ion was inserted into ZnO replacing Zn ion. The optical properties presented that the increase of Mn ion decreased the gap energy nanoparticles. Furthermore, the addition of Mn ion in the samples resulted in different magnetic properties.

The synthesis of Y-359 superconducting phase with a certain amount of Y-211 green phase compound has been carried out. The samples were synthesized by means of sintering method which were prepared by a wet-mixing route using Y₂O₃ (99.99%), BaCO₃ (99.99%), and CuO (99.99%) as raw materials. The purpose of this study was to find the microscopic properties of the Y-359 superconductor in terms of the changes on lattice parameters and morphology. This study consists of three steps. The first step was the formation of the Y-211 compound; the second is the formation of the Y-359 superconductor, the third is the formation of the Y-359 superconductor doped Y-211 compound. The wet-mixing method consists of mixing raw materials with HNO₃ and stirred using a magnetic stirrer. The processes were followed by calcination at 600 °C for 3 hours and subsequently followed by sintering at 900 °C for 5 hours. The characterizations of the samples were performed using X-ray diffractometer (XRD), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS). The addition of Y-211 causes the intensity, the volume fraction, orthorhombic strain and density of Y-359 superconductor increase. Also, the addition of Y-211 causes the lattice parameters of a and b is decreasing from 3.833434 to 3.830971 Å and from 3.890728 to 3.888263 Å respectively. On the other hand, the lattice parameter of c increased from 31.048117 to 31.052530 Å. Furthermore, we found that the particle size of the samples ranged between 500 to 750 nm.

Dynamics of vortex-antivortex (VAV) annihilation due to a defect in the side of material has been successfully studied using TDGL Equation. This study was to find out how is the potential curve (V-t) when VAV annihilation occurs. Type II superconductor with κ = 1.3 and size of L_x × L_y = 50ξ₀ × 50ξ₀ was used here. This study was based on a numerical solution of the TDGL Equation by means of finite difference method with FTCS (Forward Time Centered Space) Scheme. The external current density J_e = J_ei was applied to the material without applying external magnetic field H_e. That is the way to bring up antivortex on the bottom of material and vortex on the upper of material. The defects were prepared with the size of 0.3ξ₀ × 1ξ₀. The defect on the material gives effect to the presence of vortex and antivortex. VAVs can only enter the material through the defect and not enter through another side. This is showing that the defect on the material provides the force which causes VAV more easily enter the material at the defect than another side. VAVs will enter continuously until they will meet each other and the annihilation of VAV occurs in the middle of the material. The sharp pulses (the high peak pulse) appeared during the vortex and antivortex annihilating each other. Besides, the small pulses raised the vortex and antivortex when they entered the material. When annihilation occurred, the potential curve produced the very high potential value for a moment and returned to its normal potential state. The presence of the defect on the material can increase superconductivity of material as well.

A standard recovery of platinum (Pt) in a spent removing catalyst of Pt/Al₂O₃ was performed by acid leaching of aqua regia. The time-dependent extraction of Pt from Pt/Al₂O₃ showed that the percentage of the Pt in Pt/Al₂O₃ decreased by increasing the extraction time, which indicated an increase of the Pt in the leachate. Furthermore, a time-dependent ultrasonic-assisted extraction of Pt from Pt/Al₂O₃ was also performed. A small number of Pt content in the Pt/Al₂O₃ obtaining ultrasonic method revealed that the ultrasonic effectively enhanced the Pt extraction compared with standard extraction due to the agitation of high-frequency pressure (sound) waves. The further morphological analysis was also performed to study the morphological modification of Pt/Al₂O₃. Our results provide a good understanding of the recovery of Pt from spent removing catalyst of Pt/Al₂O₃ and give an alternative method to increase the Pt extraction.

Thermogenesis is an essential physiological mechanism in both bodies thermal and energy balance. Thermal balance is significantly associated with body heat homeostasis linked thermogenesis-caloric regulation. The caloric or energy balance was reported under facultative thermogenesis within skeletal muscle stimulated by exercise. Importantly, decreased energy expenditure, imbalance energy intake, and loss of energy was developed for types of obesity. Recently, music tempo and frequency are proposed as the new raw model of exercise treatment against the progression of overweight in the population. Thus, our preliminary pre-post test randomized study aimed to investigate the physical-physiological connection between thermogenesis, caloric regulation, acute- maximal and submaximal intensity exercise model and musical frequency/tempo on the body thermal homeostasis and physiological performance in the younger athlete. This study involved 45 participants with homogeneity in age, height, weight, heartbeat, and physical fitness. Interestingly, co-treatment high intensity, moderate intensity exercise and moderate intensity exercise with middle musical tempo/frequency decreased body temperature without relevant alteration on caloric production. Furthermore, this exercise model significantly induced caloric production and energy expenditure in a similar pattern with the placebo. Also, musical-moderate intensity exercise exposure enhanced muscle thermogenesis without effect to overheat condition during the treatment. The circulating level of physiological-physical stress marker (cortisol) significantly decreased post musical exposure. Hence, the development of physical combination therapy for individual onset obesity progress to metabolic syndrome can contribute to the prevention of metabolic disease. This combination model may offer an alternative solution to combating overweight and obesity through musical-exercise co-treatment. However, further studies are emerging to widely establish this model for global communities.

Physical and chemical characterizations of water hyacinth (Eichhornia crassipes) plants as an alternative energy source have been conducted. The samples were originated from Sengguruh, Kepanjen, and Selorejo Dams, Ngantang, district of Malang, East Java, Indonesia. The Scanning Electron Microscopy-Energy Dispersive X-ray (SEM-EDX) test was performed for the chemical element content analysis of water hyacinth biomass and the proximate test was performed for physical characteristics investigation. The results indicated that chemical elements of water hyacinth are C, O, Na, Mg, Al, Zr, Cl, K, Ca, Si, Ti, and Fe revealing dominant elements, i.e., oxygen and carbon for 49.50% and 14.46%, respectively. The proximate analysis revealed that its moisture, volatile matter, fixed carbon, and ash content were 4.9, 61.2, 13.8, 20.1 (wt.%), respectively. This biomass has gross calorific value (GCV) that tested with an adiabatic bomb calorimeter of 14.46 MJ/kg. Since the water hyacinth biomass has a relatively high volatile content and a low heating value, it is reasonable that water hyacinth might suitably for co-combustion with coal to increase the coal's reactivity during the combustion process.

Materials classified as strongly-correlated systems often exhibit complex and fascinating properties due to interactions among electrons as well as between electrons and other constituents of the material. A common model to describe electronic system with strong on-site Coulomb interaction is Hubbard model. One very powerful approximation method for solving Hubbard model having been widely used over the last few decades is dynamical mean-field theory (DMFT). This method maps the original lattice problem into an impurity problem embedded in a self-consistent bath. Apart from the many variants of implementation of DMFT, it relies on using an impurity solver as part of its algorithm. In this work, rather than solving a Hubbard model, we propose to explore the impurity solver itself for solving a problem of metallic host doped with correlated elements, commonly referred to as Anderson impurity model (AIM). We solve the model using the distributional exact diagonalisation method. Our particular aim is to show how the metal-insulator transition (MIT) occurs in the system and how the phenomenon reflects in its optical conductivity for various model parameters.

Shielded Metal Arc Welding (SMAW) process is widely used in the industrial world for metal welding processes. The use of SMAW with the types of electrodes and an incorrect number of passes will produce a geometric shape that has a low precision and high surface roughness in the process of making workpieces. The movement and types of welding electrodes can affect the welding characteristics. Wrong welding work can result in damage to the fatal welding results in terms of both safety and economics. This research was conducted to determine the effect of electrodes and the number of passes on the hardness of the welding and microstructure results in the welding process of Shielded Metal Arc Welding. The plate used in this study was a rectangular plate with a thickness of 10 mm, a length of 30 mm and a width of 15 mm. The specimens were welded using E6013 and E7016 electrodes with the number of 3 pass 3 pass and the number of 3 pass 6 pass. In welding using E6013 electrode with the number of passes of 3 layers 6 pass gave effect on escalating violence in the HAZ area. This happens because if the layer increases, the heat input generated decreases. If the heat input is small, the hardness of the welded joint will be large. Therefore, the number of pass 3 and 6 had different hardness.

We study the effect of stirring duration on the synthesis of polyethylene glycolhydroxyapatite (PEG/HA) nanocomposites and their hardness and antibacterial characteristics. The HA was used from natural deposit calcite rock from Druju-Malang. In this study, PEG/HA composite with a composition ratio of 20:80 in %Wt was obtained through co-precipitation method with various stirring duration of 1, 2, 4, and 6 hrs. The results indicate that the variation of stirring duration of the PEG/HA composite promotes a change of functional bonds, grain size, and hardness value. The optimum hardness was achieved by stirring duration of 2 hrs. Furthermore, the PEG/HA composite exhibited a relatively consistent value of antibacterial zone in a variation of stirring duration, but it still showed an antibacterial performance. Our study would give a good understanding of the technique to improve mechanical and antibacterial properties in HA-based biomedical applications for bone regeneration.

The effect of paint thickness based on Ba_0.6Sr_0.4Fe₁₀MnTiO₁₉ nanoparticles as a microwave absorber has been investigated. Nanoparticle powder Ba_0.6Sr_0.4Fe₁₀MnTiO₁₉ was made using a solid-state reaction method milled with seven hundred rpm for fifty hours then characterized first. Qualitative and quantitative analysis of structure and phase was measured by using X-ray diffraction (XRD). The sample has a hexagonal structure with a space group P6₃/mmc, and no other phase is detected. Meanwhile, scanning electron microscopy (SEM) was used for surface morphology analysis. Homogeneous sample granules with an almost round shape with a nanometer scale between seventy to one hundred nanometers. Loop hysteresis obtained from the measurement of vibrating sample magnetometer has a maximum magnetic value of Ms = 50 emu/g, magnetic remanent (Mr) of 32.0 emu/g and coercivity (Hc) of 0.34 T. Next step the nanoparticles were mixed with paint with a weight ratio composition of 30: 70. The mixture was then sprayed with several variations of paint thickness on the iron metal plate. After that, the reflection loss characteristic was measured by using vector network analyzer on a painted plate and resulted that the best performance of microwaves absorption resulted in the sample with two sprays. It was concluded that the paint thickness could affect the ability of reflection loss, but the thicker the paint does not mean that the loss of reflection is getting better.

The objectives of this study are to investigate the effectiveness of activated zeolite with and without impregnated Ag on the conversion of glycerol to ethanol. Zeolite catalyst used in this study was synthesized zeolite from silica extracted from local sand and glycerol conversion using zeolite with and without impregnated Ag done at various temperatures of sonication. Product conversion analyzed using Gas Chromatography. The results showed that the impregnation of g on the activated zeolite catalyst increase the acidity from 0.0774 to 3.6253 mmol/g. The surface area slightly decreases from 1339 becomes 1279 m²/g. The process of converting glycerol to ethanol, the use of ultrasonic waves increases the effectiveness of glycerol conversion. The higher the sonication temperature, the greater ethanol produced. The highest ethanol product with a yield of 13.6% was obtained at a sonication temperature of 60 °C when the active Ag/zeolite catalyst was used. The use of Ag/zeolite catalyst makes glycerol conversion can be carried out at relatively low temperatures and ambient pressures so that it has more promising future prospects.

Magnetite/zinc oxide nanocomposites were synthesized by a co-precipitation method. The mass compositions of the nanocomposites (ratio of magnetite: zinc oxide) were 1.5:0, 1:0.5, 0.75:0.75, 0.5:1, and 0:1.5. The ratios were given the respective codes of NC1, NC2, NC3, NC4, NC5. The data analysis of the x-ray diffraction data showed that the magnetite had a spinel configuration and sized 11 nm. Meanwhile, the zinc oxide had a particle size of 40 nm. However, the zinc oxide constructed any impurities. In this work, all samples formed agglomerations in nanometric size with various shapes. The functional groups of the magnetite and zinc oxide were detected in the respective wavenumber of about 470 cm^-1 and 575 cm^-1.

We performed a study to obtain the effect of duration of light irradiation on the performance of photo supercapacitor system based on TiO₂-ZnO and TiO₂/BaTiO₃/PVDF materials. Dye-Sensitized Solar Cells (DSSC) based on the TiO₂ material are potential because of several advantages such as high photostability, high thermal stability and are very effective for dye absorption. However, TiO₂ has limitations regarding electron mobility. It needs to be composited with other materials for electron mobility. The material preferred is ZnO. ZnO also has similar band gap range as TiO₂. In this process, TiO₂-ZnO composite system becomes more potential used as DSSC electrodes. In the Photo-Supercapacitor with the presence of a high electrical energy source from the DSSC, a supercapacitor unit with sufficient capacitance is needed. In this case, selection of capacitor electrodes is a crucial exercise. In this study, electrodes based on PVDF/BaTiO₃ composite systems were used. PVDF polymer-based electrodes have advantages regarding their flexible nature, high thermal stability, and easy in synthesis. However, the polymer material-based supercapacitor electrodes have limitations such as low dielectric constant. This problem is to overcome with ceramic-polymer composite systems. Among ceramic materials, the BaTiO₃ is the best choice because it has the highest dielectric constant compared to other ceramic materials. Thus, PVDF-BaTiO₃ composite system can function well because of dielectric constants and excellent mechanical properties. As a result, this composite system has the potential to be used as a supercapacitor electrode.

Dynamical Mean-Field Theory (DMFT) is among the most widely used techniques in computational condensed-matter physics, especially in addressing electron-electron interactions. In this regard, Quantum Monte Carlo may be considered as the most accurate DMFT impurity solver, but it usually requires a high numerical cost. On the contrary, lower numerical-cost technique, such as mean-field theory, often gives inaccurate results due to complete suppression of quantum fluctuations. In this study, we propose a new potentially low numerical-cost impurity solver taking a full account of fluctuation effects. Applying this new algorithm on Hubbard model, we formulate local self-energy that depends on the occupancy fluctuations. These fluctuations act as the semi-classical degree of freedom that needs to be integrated to obtain the averaged fully interacting Green functions. We test our algorithm by addressing temperature dependence of the density of states that reveals metal-insulator transition.

The search for finding effective ways to produce high quality of nanostructured materials have always been the never-ending work of many scientists and engineers from time to time. Important issues to address are reducing fabrication expense and lowering energy utilization to complete the synthesis. A specific circumstance is an investigation of using relatively low temperature to fabricate pure silicon carbide (SiC), one of the most notable materials due to its excellent properties, from naturally appearing minerals. In this current study, silicon carbide was prepared by means of magnesiothermic approach at some adjusting temperatures using argon gas furnace. The source of silicon and carbon were respectively initiated from naturally purified silica and sucrose. The X-ray diffraction (XRD) assessment clearly uncovered the pure moissanite-3c phase of silicon carbide, having a cubic crystal structure. The disappearing of magnesium, otherwise in the form of magnesium oxide, was also validated by the X-ray fluorescence (XRF) test. Furthermore, the chemical functional groups were clarified by Fourier-transform infrared (FTIR) spectroscopy, and the silicon-carbide interaction was evidently detected from the FTIR spectrum. Besides, the SiC products exhibited high Vickers hardness values, nearly 150 MPa for the sample with temperature synthesis of 800 °C.

Reduction of particle size of Polyaniline (PANI) evaluated after anionic surfactant assisted polymerization reaction was observed during synthesis. The use of Sodium Dodecyl Sulfate (SDS) during the reaction has reduced the particle size of PANI to the smallest 212 nm from original size 713 nm obtained from a synthesis of SDS free. The single compound of SDS has specific fingerprint at wavenumbers of 1247 and 1216 cm^-1 indicating an asymmetric stretching, vibration and a symmetric stretching vibration of SO₂ molecule at 1080 cm^-1. After SDS assisted polymerization reaction completely, the fingerprint specifically appears in the range of 950 - 1000 cm^-1 wavenumber for SO₂ molecule peaks. It indicates that there was SO₂ molecule bonded into PANI molecule. It was obtained that the higher SO₂ content in PANI of a high SDS concentration shows a wider of spectra and higher absorbency. In addition, there was no pH effect during the polymerization reaction under various SDS concentrations. It is concluded that the particles of PANI were reduced with the addition of SDS during polymerization reaction. The smallest average particle size obtained through the emulsion polymerization technique containing 0.67 % SDS was 212 nm.

This paper reports the nanostructural and magnetic behaviors of nano-sized magnetite/polyvinyl alcohol prepared by electrospinning route. The composition of the magnetite nanoparticles and polyvinyl alcohol were prepared from natural iron sand. The samples were maintained for pure magnetite without fibers, 0.075 g and 0.175 g for the mass compositions of magnetite in the fibers. The experimental data presented that the mass variation of the magnetite decreased the diameter of the fibers. Moreover, the higher composition of the magnetite has led to an increase in the saturation magnetization of the fibers. Such results were confirmed by the increasing content of the Fe atoms originating from magnetite particles. Morphologically, the magnetite/polyvinyl alcohol fibers were formed in continuous fibers with the diameter of 300 nm for optimum voltage of 20 kV.

Synthetic optimization of methyl ester has been extracted from low-quality crude palm oil using heterogeneous catalyst. Quantitatively, the crude palm oil with low-quality is in abundance. To prepare the raw material to be used for biodiesel, it requires to be refined beforehand. By using heterogeneous catalysts, the synthetic biodiesel would become more affordable and environmentally friendly. This study aimed to synthesize methyl esters from low-quality crude palm oil using CaO-ZnO catalyst and determine its potential as biodiesel. This research was carried out through several stages, namely refining low-quality crude palm oil, determining the levels of low-quality refined crude palm oil free fatty acids, esterification, synthesis of methyl esters from low-quality crude palm oil with CaO-ZnO catalyst through transesterification, identification of the components composition of the mixture of synthesized methyl ester by GC-MS, and the characterization of the synthesized methyl esters. The results showed that methyl esters could be synthesized from low-quality crude palm oil through a transesterification reaction using CaO-ZnO catalyst. The highest yield was obtained from the use of catalyst 4% w/w of oil with a yield of 84.74%. The components of the constituent compounds of the mixture of synthesized methyl ester were methyl myristate (2.72%), methyl palmitate (54.87%), methyl linoleic (5.78), methyl oleate (26.83%), and methyl stearate (2.55%). The results of the characterization of the synthesized methyl ester showed a density 0.876 g/mL, a viscosity 3.60 cSt, a refractive index 1.448, and an acid number of 0.39 mg KOH/g of methyl ester, resulting in the potential methyl ester as biodiesel.

Rice husk ash and nata de coco are used as the sources of silica and cellulose, both materials can be combined to form a silica-cellulose hybrid. This material can be used as the adsorbent for natural pigment or metals also for any bigger molecule like enzyme. Curcumin and chlorophyll were chosen as the probe adsorbate. This research aimed to know the characteristic of the silica-cellulose hybrid and the adsorption behavior of chlorophyll and curcumin pigments via the batch method and also as a stationary phase in TLC. FT-IR and UV-Vis analysis were involved. The research was an experimental laboratory and divided into 4 steps (1) preparation and produce silica-cellulose hybrid, (2) characterization of silica-cellulose hybrid, (3) application of the material to chlorophyll, curcumin and the mixtures, (4) analysis of surface interaction using spectrophotometer FT IR and UV-Vis. The results of this research showed the role of cellulose in changing the surface properties towards molecular interaction from both batch and thin layer experiments.

Today, solar cells have become one of the promising renewable energy alternatives to provide a clean and environmentally friendly. One of the solar cell technologies, which has been widely developed and studied intensively, is dye-sensitized solar cells (DSSC). DSSC optimization component is performed to produce a high conversion efficiency. One part of DSSC which plays an essential role in energy conversion is photoanode, and TiO₂ nanocrystals have been proven to be high-efficiency DSSC photoanode components. The metal oxide TiO₂ exhibits a high mesoporous surface area which can be used for dye absorption. The most widely developed organic material in DSSC is PANI. It is a conducting polymer that has a wide range of absorbance, porous morphology, excellent electrical properties, and ease of bond with metal ions. The PANI-TiO₂ composite system forms a bilayer structure that is expected to improve the efficiency of DSSC conversion. So far, no comprehensive study of DSSC-based PANI/TiO₂/FTO-Glass bilayer thin film structure as a photoanode component has been done. In this works, we report the effect of photoanode thickness represented by spin rotation on the optoelectronic properties is needed.

In this paper, we report the synthesis of Fe₃O₄ nanoparticles modifying polyethylene glycol/PEG-4000 by co-precipitation route. The structural and antibacterial features of the samples were studied by means of XRD, SEM, FTIR, and antibacterial test. The results of XRD data showed that Fe₃O₄/PEG was in a spinel cubic structure. The sample presented the combined composition of the Fe₃O₄/PEG-4000 in the nanometric scale in agglomerated form. Interestingly, the Fe₃O₄/PEG-4000 exhibited an excellent performance as an antibacterial agent with the average inhibitory diameter for each Escherichia Coli and Staphylococcus Aureus bacteria are 1.67 mm and 1.97 mm respectively.

Floating blade water wheel turbine is a development design of goose leg turbine which has been studied in the previous year. This water turbine has a specialty on its blade ability that can open and close like a goose leg. This study employed the Taguchi method to obtain the optimum design parameters on the floating blade water wheel turbine. There were 3 factors used, they are water flow rate with 4 levels (35; 40; 45; 50 l/min), number of buckets with 2 levels (4 and 6 units), and the shape of the blade with 2 levels (concave and flat) which was predicted to affect the turbine performance. The response or dependent variable used was the turbine efficiency. According to factors and levels that have been determined, orthogonal array used in this study is L16. Orthogonal Array is a matrix that used in Taguchi method to determine the minimum number of experiments that can provide information about factors which affect the parameter response. According to ANOVA results, they indicated the factors affecting the optimum quality characteristics of the turbine performance are the number of buckets with the contribution of 68.13%, the blade shape with the contribution of 23.28%, water flow rate with the contribution of 7.35%, and the 1, 25% is the other factors. According to Taguchi method, the optimum parameter design was a turbine with 6 blades, convex blade shape, and water flow rate at 50 l/m that yielded turbine efficiency as much as 3.999%.

In this paper, we report the experimental observation of temperature influence on optical properties of ferrofluids comprising of chromium ferrite nanoparticles by a 1 mW He-Ne laser beam. An external thermal field was maintained perpendicular to the beam. In this research, the thermal response of chromium ferrite ferrofluids prepared by coprecipitation-sonochemical technique was studied. The preliminary investigation showed that the chromium ferrite ferrofluids have an excellent property as a candidate for a temperature sensor application showing a good response on the temperature treatment. Interestingly, we found a hysteresis phenomenon in one cycle in transmission light originating by varying temperature.

Magnesium alloys are lightweight materials that have a great potential to be developed because the alloy can reduce the energy consumption and total weight. The alloy is made of magnesium metal as a primary component characterized by a soft and mechanically low-strength. The addition of aluminium in Mg-Al system will form Mg₁₇Al₁₂ particles causing grain refining the effect of the α-Mg matrix. Similarly, the addition of Zn in Mg-Zn system increases the strength and hardness of the alloy. Hence, the combined addition of Al and Zn in Mg-Al-Zn system would be interesting for automotive component applications. In this study, we have carried out the casting process for Mg-9Al-1Zn (wt. %) through a gravity of the metal mold with air cooling method. The cast alloy designated as Mg9Al1Zn alloy received a solution treatment at temperature of 415 °C for 2 hours. The microstructure observation for the cast alloy showed the presence of α-Mg as a matrix with the largest fraction and β-Mg₁₇Al₁₂ phase as a precipitate. The microstructure also showed the presence of pores indicated by black colour. We have also undertaken microanalysis to each phase present in the sample by EDS that detected all elements. The result of Hardness evaluation confirmed that the solution treated as-cast alloys possessed the hardness value of 65.21. The VHN significantly enhanced when compared with that of original cast-alloy which was only 73.02 VHN. The enhancement of the hardness is discussed in relation with processing method and microstructure development after a solution treatment.

The CH₃NH₃PbI₃ perovskite has great interest due to good candidate for low cost solar cell and photodetector. The research of this report is to investigate the effect of growth time to the morphology of ZnO NRs and its performance of solar cell and photoresponse. The ZnO NRs were grown at growth time of three and four hours on the ZnO seed layer using hydrothermal method. While perovskite CH₃NH₃PbI₃ were synthesized by one-step spin coating. The CH₃NH₃PbI₃/ZnO NRs samples was characterized by x-ray diffraction for structural properties analysis and scanning electron microscopy for morphological properties. The The CH₃NH₃PbI₃/ZnO NRs samples performance was measured by solar simulator under light illumination. The XRD results show that PSC has ZnO and CH₃NH₃PbI₃ phases with small impurities of PbI₂. The growth time increases the length of ZnO NRs and in combination with CH₃NH₃PbI₃ can enhance performance of solar cell and photoresponse.

Twisting forces in disc brakes and friction forces between disc brakes and bearings produce heat on the disc brakes. The compression force produced by the brake piston pushes the brake pads to produce heat and deformation in the disc brakes. For the development of vehicle braking systems, wrought iron is used to make disks. However, a failure still occurs during a crack testing. The results of the analysis using the finite element method showed that the highest total deformation was 4,411 x 105 mm. The highest maximum equivalent stress (represented by the red area) is 715.48 MPa. The maximum value of SIFS (K1) around the disc brake hole is -0.9030 MPa.mm^0.5, while at the edge of the disc is 5.385 MPa.mm^0.5.

BCR methods are known for leaching of heavy metals in sediment material. However, there is no optimization of modification BCR using a microwave in Fe in the Gulf of Prigi sediment. Thus in this paper, we attempted to use the variation of modified microwave power (10%, 25%, 50% watt) followed with contact time ranges (from 1 to 3 minutes). The results showed the fast method of BCR for leached Fe using a microwave with an optimized condition in the fraction 1 and fraction 2 with 50% watt at 2 minutes, fraction 3 (10% watt at 2 minutes) and fraction 4 (temperature used at 185 degrees Celsius at 10 minutes) in sediment materials. These investigated were also supported by characterization using SEM EDAX and AAS measurements of Fe in the filtrate sediment.

In this paper, we report the experimental observation of electro-optics effect in the ferrofluids comprising of Fe₃O₄ nanoparticles by a 1 mW He-Ne laser beam. An external electric field was applied perpendicular to the beam. Ferrite ferrofluid was prepared by using a coprecipitation-sonochemical technique. The effect of the electric field on the optical properties of ferrofluid was still too weak as we had expected. One possibility that can be suspected as the cause is that the electric field applied to ferrofluid is still too weak.

Adding defect on type II superconductor can influence to vortex dynamic. It declares vortex movement, so speed of vortex is more stable. In this research, we applied lattice defect. In case to study dynamics of the vortex in type II superconductor material, this study was based on numerical solution of the Time-Dependent Ginzburg Landau (TDGL) equations by means of finite difference method with Forward Time Centred Space (FTCS) scheme. Applied external current density Je and external magnetic field He to superconductor material generate a vortex flow from higher magnetic field to lower magnetic field. Furthermore, applied external current density Je without external magnetic field He generates vortex flow between lattice defects.

This computational material-based study aimed to provide a comprehensive data with the molecular interaction between betatrophin and its target as the confirmation of the primary role of betatrophin on serological lipid profile alteration and metabolic syndrome progression. We analyzed the binding behavior of betatrophin and LPL using docking model. The underlying molecular interaction between betatrophin and lipoprotein lipase (LPL) binding site results in the inhibitory activity of betatrophin on LPL. Our in Silico data showed that betatrophin could regulate that essential enzyme and suggested indirectly to restrict TG level during the circadian cycle in the human circulation. To sum up, betatrophin or RIFL shows as a promising future early biomarker for obesity and cancer linked metabolic syndrome. Hence, this preliminary computational material analysis data provided a hallmark for the future development of betatrophin as the clinical biomaterial marker in metabolic syndrome and gastrointestinal cancer.

In this present study, we report the fabrication of biphasic calcium phosphate (hydroxyapatite-tricalcium phosphate), abbreviated as BCP. The BCP was composited with alumina by grinding process and continuously sintering at 1200 °C for 2 hours. The sintering triggered the partial changes of crystalline phase from hydroxyapatite to tricalcium phosphate. Some fundamental characterizations were conducted to reveal the crystal structure, microstructural morphology, and mechanical strength, by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), and Vickers hardness test, respectively. Our results clearly showed that the desired crystalline phases of the composites have been successfully formed. The SEM data captured compact ceramic composites of BCP/alumina. On top of that, introducing of alumina into BCP leads to enhancing the mechanical strength of the composites, having maximum Vickers hardness of nearly 0.38 GPa. Therefore, the composites meet the criteria for load-bearing application in human dentin.

Peppermint oil is an essential oil that can provide fresh sensation but their fresh sensation will disappear in a short time. This research was designed to overcome that problem through encapsulating menthol oil in a term sensitive release microcapsule with carboxymethyl kappa carrageenan (CMKC) -gelatine-chitosan and crosslinking agent, lutensol, as microcapsule wall. Encapsulation of peppermint oil in a microcapsule is a chemical modification method for controlling the release of the component of peppermint oil to the environment. Microencapsulation of peppermint oil has been done by conservation method. Morphology of peppermint oil microcapsule was analyzed by Scanning Electron Microscope (SEM) image. The effect of temperature on the changes of microcapsule morphology was analyzed by optical microscope image. The effect of microcapsule heating temperature on the release of menthol oil component was analyzed by Gas Chromatography (GC) spectrum profile. Based on the observation of microcapsule morphology, without heating, the form of the microcapsule was round; after heated, the microcapsule became broken. There was a difference in the peppermint oil components releasing the power of microcapsule with different heating temperature; the quantity of each component of peppermint oil released when the microcapsule had been heating on 39 °C was higher than on 36 °C.

A supercapacitor is a new device of energy storage which shares similar properties with conventional capacitors and batteries. To optimize the energy storage as well as energy release cycling, we should observe in detail the one face electrode before use in the manufacture as a supercapacitor. An interesting materials' properties from various studies of supercapacitor are graphene, Mn₂O₃, and ZnO. It could be more intriguing when those materials deposited on nickel foam substrate. The manganese oxide Mn₂O₃ exhibits remarkable potential as a supercapacitor electrode because it has low cost, abundant and high specific theoretical capacitances. So far, many carbon-based materials have been studied as supercapacitor material electrodes, but still, show a low volumetric capacity and hamper several physical limitations. More practical and long-term use of high-performance supercapacitors is hard to find in the literature on ZnO, G, Mn₂O₃ system supercapacitors. The Mn₂O₃ nanoparticle has been synthesized using chemical co-precipitation methods. The film of supercapacitor ZnO-G-Mn₂O₃/Ni foam system was characterized using SEM-EDX, XRD, and LCR meter. It was found that the increase of manganese oxide gives rise to increase the capacitance, specific capacitance as well as dielectric constant. The behavior of its dielectric constant as a function of temperature is not a simple relationship.

Previous studies have shown that papaya seed contained flavonoids, tannins, and saponins Those compounds are potential as an inhibitor for pancreatic lipase, an enzyme that plays an important role for lipid absorption into the body. The aims of this study are to produce 'coffee' powder of papaya seeds for drinks; to test the organoleptic properties and the activity as a pancreatic lipase inhibitor. The seed was made into a powder by washing, sun drying, roasting, and then grinding. An organoleptic test was performed at 50 respondents and one trained respondent. Inhibitor activity for pancreatic lipase was measured relative to anti-obesity drugs of Orlistat (Xenical), using titrimetric method. The results showed that every 1.42 grams of papaya seeds powder have an inhibitory activity equivalent to 1 tablet (120 mg) of Orlistat. Most of the respondents like with the texture, color, and flavor of the drinks.

The addition of organoclay to Aluminium Matrix Composite (AMC) with heat treatment and setting process variables was able to change the microstructure affecting its mechanical properties. The method used in this study was a hot press. The pressure used was of 137.8951458634 MPa, and the temperature varies from 490-600 °C with a holding time of 3 hours. Characterization was carried out using XRD, optical microscope, hardness tester, and ultrasonic tester. The data analysis showed that the hardness increased from 126 to 197 HVN. Furthermore, the mass density also increased, and reached an optimal value with the addition of 1% wt of organoclay at a temperature of 550 °C. The microstructure exhibited that AMC was formed and increased the hardness and density. XRD results indicated that aluminium phase was successfully detected. From the results of several characterizations, it can be concluded that the optimal material has the composition by adding 1% wt of organoclay with a heating temperature of 550 °C, a pressure of 13.7859558534 MPa and a long press time of 3 hours. In this study, we construct a relationship between process variables based on experimental, computational design and use the Inference Adaptive Neuro-Fuzzy inference (ANFIS) method. Furthermore, the prediction accuracy made by the model was investigated based on the test case. The results showed that the hot press method had a relationship with the attraction properties having the same conclusion using experiments and ANFIS.

Besides lithium-ion battery (LIB), potassium-ion battery is also potentially developed as an alternative battery with cheaper and more secure battery. The synthesize of complex compounds of KCu[Fe(SCN)₆] was conducted using a direct reaction method. The characterization of complex compounds was conducted through melting point, SEMEDX and FTIR instrumentation, electrical conductivity, and cyclic voltammetry. The complex of K₃[Fe(SCN)₆] has melting point 92-95 °C, electrical conductivity f 714 µS, and indicated an ionic compound. The characterization with SEM-EDX and FT-IR instruments showed the empirical formula of complex compounds was KCu[Fe(SCN)₆]. The cyclic voltammetry analysis shows the complex as potassium-ion battery cathode material.

Gear is an essential element in motor vehicles. Bending stress and gear surface strength are two factors contributing to a gear failure. Therefore, calculating precisely the bending stress and total deformation of the gear tooth is profoundly important for the development of modern gear design industry. This study aimed to investigate the strength, deformation, and crack in gears. The Finite Element Method (FEM) was used in the ANSYS simulation. The simulation was performed on three gear materials, i.e. alloy steel, structural steel, and carbon steel. The results showed that among the three materials, the highest strength with the equivalent stress of 921.63 MPa was structural steel, with the maximum principal stress of 407.33 MPa and maximum shear stress of 407.33 MPa.

Biomaterials and the making is one of the emerging topics in the field of material science since most are porous medium and their surfaces have so much ability to be utilized. Active sites on the surface can hold desired materials which range from small ions, molecules up to bigger biomolecules. However, method development for analyzing this ability is always needed depending on the purposes. Spectroscopic methods are useful to describe the material as well as surface activity or molecules mobility in the adsorbed phase. Interaction governing dynamics in the interface can be accessed indirectly. In this brief review paper, various spectroscopy methods are employed to characterize the biomaterials from silica/silica cellulose, as well as to test the applications in the field of the purpose. UV-Visible and infrared spectroscopy as well as SEM/TEM analysis are used, GC/MS analysis can also detect the volatiles from the surface, more insight from other methods would be presented to make good an assessment of this type of biomaterials in a certain application area.

The potentials of corn silk in terms of its physicochemical properties and its heating value have been investigated. The sample was originated from Badas village, district of Kediri, East Java, Indonesia. The original material underwent a drying process in the oven at 100 °C for 90 minutes. The dry materials were continuously pulverized and filtered to reach the mesh size of 60. Subsequently, the sample was tested according to the proximate standard to specify its physical properties, while its elemental composition was investigated under the energydispersive X-ray (EDX) spectrometry procedure. The results showed that corn silk contains the moisture, volatile matter, fixed carbon, and ash in respective value, i.e., 8.6 (wt%, as received), 72.2, 22.4, and 5.4 (wt%, dry basis). The EDX test showed that C and O present as the dominant element. The gross calorific value assessed by using adiabatic bomb calorimeter was 19.50 MJ/kg.

This study proposed to investigate the synthesis and characterization of eggshell nanopowders. The phase and morphological characterization of eggshell nanopowders for reducing their grain size from micro to nano involved ball milling with the variations of duration (1, 5, and 10 hours) and sintering temperature at 1100 ºC for 1 hour. XRD test presented the phase characterization of eggshell nanopowder which ball-milled for 5 hours, obtained the smallesr crystalite size at 46.37nm. The one subjected to 1-hour sintering and 1-hour ball milling had the highest degree of crystallinity. Based on the SEM analysis, the eggshell nanopowders experienced morphological changes in grain size and shape from chunks, triangular grains, and irregular grains in micro size to Nano-sized with spherical grains. The EDX test presented the highest and the lowest compound in eggshell which non-sintered and ball-milled for 5 hours, the result showed that C compound was the lowest level, and C and O level were the highest level9f.

The electronics structure of monochalcogenide materials buckled square lattice is investigated by computation based on Density Functional Theory (DFT). The investigation shows that there is spin splitting on xy-plane at Γ point and M point as a Rashba effect. Perturbation theory k.p and symmetry group C_2v used to calculate the originates of the spin splitting. The results show that there are strong Rashba splitting for materials with center atom Pb (with Rashba parameter 5∼ eVÅ). Spin orientation displayed by spin-texture and show that there is time reversal symmetry between upper band and lower band. This condition explains that monochalcogenide materials buckled square lattice as potential candidates for spintronics devices.