Table of contents

Distinguished guests and participants,

Assalamualaikum Warahmatullahi Wabarakatuh.

Good Morning Ladies and Gentlemen.

Welcome to Medan, a fascinating city, and welcome to USU.

On behalf of the Organizing Committees, we would like to express a warm welcome to all delegates and participants to the TALENTA-International Conference on Science and Technology (TALENTA-ICST) 2019. It is a great honor for all faculties and departments at Universitas Sumatera Utara (USU) to support the conference.

I believe that this conference is an important forum for exchange of information and research results among us, who come from different countries, different educational and research institutes, and different research interest. But we are one in the same room today for all of us have a same target to achieve our goals, i.e. to support our competitive advantage TALENTA. As we know USU has a competitive advantage named TALENTA, namely Tropical Science and Medicine, Agroindustry, Local Wisdom, Energy (sustainable), Natural Resources (biodiversity, forest, marine, mine, tourism), Technology (appropriate) dan Arts (ethnic). Thus, I hope that the contacts established during the conference may bind us in one vision. A vision is achieving better tomorrow together. Wish that we may strengthen close relationship among TALENTA-ICST members, develop more join research project, and very importantly we have a strong commitment to support the TALENTA-ICST events.

In closing, I would like to thank the Rector of USU and also the Ministry of Research, Technology and Higher Education of the Republic of Indonesia, for supporting the research climate at USU. I would also like to thank all contributors for your good cooperation. Special thanks for TALENTA-ICST Organizing Committee members for their hard work and patience.

Your Sincerely,

Prof. Dr. Tulus, Vor.Dipl.Math., M.Si

Chair of the Talenta-ICST 2019

List of Honorary Board, International Board, Scientific Committee, Organizing Committee, Local Committe, Publication, Venue Map and Program Schedule are available in this pdf.

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

The Halal supply chain is one of the most important factors for Muslim because the product to be consumed must be halal, from the source to the end consumers. This research was conducted at several feedlots (fattening cattle), slaughterhouses (RPH), and traditional markets in the city of Medan and surrounding areas. In this study identified all activities in the slaughterhouse, activity mapping, determination of risk events, risk agents, and Aggregate Risk Potential (ARP) calculations in the red meat supply chain with the adoption of the SCOR model namely plan, source, make, deliver, and return and HOR (House of Risk). The results showed that there were 19 activities (sub-processes), 28 risk events and 28 risk agents. The selected risk agents based on the five highest ARP values are less cleaned floor after slaughtering (Ag17), the accumulation of blood into clots (Ag20), lack of machine maintenance management (Ag2), too many cattle to be slaughtered (Ag3), and increased consumer demand (Ag1). Knowing the risks and causes of risks will facilitate handling so that supply chain performance can be improved. It is necessary to study appropriate risk mitigation actions so that risk events can be reduced.

The objective of this research is utilization of cassava by-products as complete ration on physical and chemical meat quality of weaning male of crossbred Landrace pigs. This research was conducted at Desa Rumah Mbacang Pancur Batu from April to June 2019. The research used completely randomized design (CRD) with 4 treatments and 2 replications. The treatments compose of P0 (without cassava by-products), P1 (with 20% cassava by-products), P2 (with 40% cassava by-products) and P3 (with 60% cassava by-products). The variables were observed consist of physical quality (pH value, water holding capacity, cooking loss and color) and chemical quality (water content, fat content and protein content). The results showed that the best pH value on P1 (5.00), the best water holding capacity on P1 (51.32%), best cooking loss on P1 (44.99%), the best color on P1 (1.50), the best water content on P1 (78.11%), the best fat content on P1 (3.84%) and the best protein content on P1 (21.72%). It was concluded that the use of cassava by-products in complete feed for pigs should not exceed 20%.

A good distribution can be used to achieve various goals ranging from supply chain gain low cost until it gets a response to high customer satisfaction. In addition to the above issues, transport routes is a constraint that cannot be allowed. Without a good transportation system, logistics could not bring the full benefit for the company. In addition, a good transportation system in logistics activities could provide logistical efficiency, reduce operating costs, and improve service quality by using Distribution Requirement Planning Method.

Sustainable Manufacturing is becoming a hot issue among companies in Indonesia. Sustainable Manufacturing itself has the meaning of an effort to develop the concept of a sustainable Manufacturing Industry. This concept is considered very necessary to be developed in order to maintain the sustainability of natural resources on earth. The concept of Sustainable Manufacturing has three important aspects, namely economic aspects, social aspects and environmental aspects. The economic aspect is the company's efforts to keep developing and continue to generate commercial profits, while the social aspect is the company's effort to provide reciprocity to the local residents. The last aspect is the most important aspect, which is the environment. In protecting the environment, some parameters in manufacturing company such as efficiency material, minimization waste, efficiency resource must be as a priority awareness.

In shipping goods, companies must have a basis for scheduling and determining routes correctly, thus speeding up product delivery times and saving product shipping costs. There are so many routes that companies can choose in distributing their products, and require different costs, for that the company need a method that can analyze product distribution in order to minimize the time, distance and cost. Transportation provides geographical benefits to logistics systems by connecting facilities with markets.

Candlenut seed contains a minimum of 60% of oil. Candlenut oil in the seeds can be used to turn it into oleochemicals such as paint, varnish, soap, medicines, cosmetics, and fuel. This study aims to produce fatty acids directly from the Candlenut by activating the lipase enzyme found in Candlenut. This study is done by varying the immersion time, the addition of water and stirring. The method of this research is by manually breaking the Candlenut, then blended with water and soaked with a certain time variation at temperatures of 30 °C and 35 °C. During the immersion, a pH test is carried out to determine the reaction pH. The Candlenut oil produced is tested for free fatty acid content according to AOCS Official Method Ca 5a-40, and then the composition of fatty acid is determined by using gas chromatography. From this study, it can be concluded that the lipase enzyme in candlenut can be activated directly to produce fatty acids. The highest fatty acid content in this study is 9.5%, achieved at a reaction time of 24 hours by stirring and adding 40% of water.

This study aims to make and analysis a tube group type evaporator design alternately with crossing flow as a result of modification of split PK 1 evaporator AC and to evaporate the working fluid, namely R-22, to environmental so that it also simultaneously cools the room. The evaporator designed has a length of 26 cm, a width of 16 cm and a height of 84.2 cm, with a tube diameter of 6.35 mm, a tube length of 58 cm and as many as 25 passes, consisting of 5 rows and 5 columns with alternating positions, distance between tubes 15 mm vertically and horizontally. With this design, the evaporator reduce the temperature air inlet of 0.08.

Mechanical ventilation is the highest respiratory support in critical condition. The study showed that 64% children need mechanical ventilation at least 24 hours. Prolonged mechanical ventilation can increase mortality and morbidity rate. The most common complication that happened from prolonged mechanical ventilation is ventilator-associated lung injury and ventilator-associated pneumonia. To lessened the risk of complications, one of the solutions was decreased the duration of mechanical ventilation. Factors that have been proposed to correlate with the duration of mechanical ventilation was a fluid balance. Study shows that positive fluid balance correlates with decreased oxygenation, prolonged mechanical ventilation, longer hospital length of stay and mortality of children. This is a prospective observational study in children 1 month to 18 years old who admitted to PICU Haji Adam Malik General Hospital Medan, Sumatera Utara, Indonesia. We conducted this study to show the profile of fluid balance and duration of mechanical ventilation in the pediatric intensive care unit. Fluid balance is a routine procedure in PICU, so it is expected that information on fluid balance and duration of mechanical ventilation can be used for further adjustment to improve the outcome in the intensive care unit.

This study aims to analyze the proximate composition and color of the rabbit feed. This research method uses a kinetic method that starts with drying, mixing ingredients and pelleting. The next step is to analyze rabbit feed in combination (0:0; 0:15; 5:10; 10: 5; 15: 0)% moringa leaves flour and guava leaves flour. The research parameters observed included: the determination of protein, crude fiber, crude fat, water, ash, calcium, and phosphorus. This research uses a completely randomized design. The results showed that the combination of moringa leaves flour and guava leaves flour affected the proximate composition and color of rabbit pellets. The combination (5:10)% of moringa leaves flour and guava leaves flour has the best proximate composition and dark chocolate colour.

It has been made of porous ceramics made of clay with a mixture of candlenut shell activated charcoal through conventional techniques of printing and presses the clay composition variation: activated charcoal shell candlenut 100: 0, 90:10, 80:20, 70:30, 60:40, 50: 50 grams. Clay and activated charcoal candlenut shells sifted with a particle size of 100 mesh. Clay and activated charcoal powder candlenut shells which have been mixed printed by the dry pressing method with the pressure of 5 tons was detained for 10 minutes. Then the beam-shaped sample was burned with a combustion temperature of 900°C and held for 3 hours. Each sample is characterized that include: physical properties (porosity, water absorption, and surface morphology), mechanical properties (hardness, compressive strength, and XRD) and thermal properties (DTA). The results showed that variations in the composition of clay: candlenut shell activated charcoal optimum at 50: 50-gram composition with 66.20% porosity; water absorption value of 69.42%; 298.19 Mpa hardness values; 6,75Mpa value of the compressive strength and optimum pore diameter 1.0785 μm with oxygen element content of 51.76%. The XRD results showed the addition of activated charcoal on a pecan shell does not form a porous ceramic crystallinity, and from the graph shows that the dominant crystal structure is monoclinic. DTA testing results 70°C and temperature endothermic temperature eksoterm450°C. The XRD results showed the addition of activated charcoal on a pecan shell does not form a porous ceramic crystallinity, and from the graph shows that the dominant crystal structure is monoclinic. DTA testing results 70°C and temperature endothermic temperature eksoterm450°C. The XRD results showed the addition of activated charcoal on a pecan shell does not form a porous ceramic crystallinity, and from the graph shows that the dominant crystal structure is monoclinic. DTA testing results in endothermic temperature 70°C and exotherm temperature 450°C.

Forest damage has had a real impact in increasing the level of disaster risk, especially landslides. The real impact of landslides, especially in the Dairi District, North Sumatera Province, is physical, social, economic, and environmental losses that are felt directly by the community near the disaster location. This study was conducted to determine the spatial distribution of landslide-prone areas in the Dairi District. The determination of the distribution of landslide-vulnerability level areas used spatial modeling with the Storie Index method with several variables, which were rainfall, slope, soil type, and land cover type. The distribution of landslide-prone areas was mostly at very low - low levels with the percentage of the area reaching almost 60% of the area of the Dairi District. The areas that occupy high - very high landslide-vulnerable levels with the largest area were in three sub-districts, which were Tanah Pinem, Sumbul, and Parbuluan. The landslide areas were generally located on shrubs and grassland and on steep slopes. Various parties need to improve unmanaged land to productive land by land rehabilitation and agroforestry system.

Superabsorbent polymers (CMC-Al-BSM) were synthesized from aqueous solutions of sodium carboxymethyl cellulose (CMC), aluminum sulfateoctadecahydrate (Al) and oxidized bread fruit starch (BSM). BSM is obtained by oxidizing the starch (BS) with2% hydrogen peroxide solution. CMC-Al-BSM was preparedby mixing 100 mL of 2% Na-CMC solution and 50 mL of 2% BSM solution, stirring with a magnetic stirrer for 60 minutes at 80⁰C and then adding 0.01 g of aluminum sulphate and stirring for 30 minutes. The mixture formed is poured onto Teflon and dried at 70 ° C until the film is formed and then the film formed is made as a powder. The same experiment was carried out with variations in the weight of aluminum sulfate 0.03 and 0.06 g. BS and BSM are characterized by measuring the carboxyl group content, recording the FTIR spectrum and morphological analysis with SEM. CMC-Al-BSM is characterized by measuring WAC by tea bag method, surface morphology with SEM and Tg with DSC. Based on the calculation, the carboxyl group content of BSM that obtained is 0,09 % and SEM Photograph shows that the BSM particle size is smaller than the BS particle size. The optimum water absorption capacity of SAP is obtained at CMC-Al3-BSM which reaches 8330% (in 1.0 g dry weight of CMC-Al3-BSM can absorb 83.3 g of water). SEM photograph also shows that the surface morphology of CMC-Al3-BSM is more homogeneous and smooth than other SAP compositions and from DSC analysis it can be concluded that CMC-Al3-BSM is a miscible mixture

The use of starch is currently very widespread in the food and non-food industries, but this is not supported by the natural starches which have weaknesses in their application so that modification of natural starch is needed. Dual modification of starch by hydroxypropylation and crosslingking is expected to be a solution to overcome the weaknesses of the nature starches, especially in foof sectore. Dual modification starch is synthesized by reacting breadfruit stach with the addition of 12% propylene oxide and STMP : STPP (1:4; 2:5; and 3:6). From the results of tests that have been carried out on IR spectroscopy testing are marked POC vibrations appear in the region of the wave number 1050-995 cm⁻¹and vibration P=O or P-O bonding in the area of 1149-1157 cm⁻¹. The degree of substitutions obtained ranged 0.18 – 0.30. Dual modification starch has a gelatinization temperature (81.16 – 82.32°C), peak viscosity (4750 – 8000cP), setback viscosity (1090 – 2583cP), and breakdown viscosity (620 – 1090cP). The result dual modification of breadfruit starch has stable properties when heating and stirring.

Mangrove plants are known to produce secondary metabolites including isoprenoid and long chain polyisoprenoid. SonneratiaalbaandS. caseolaris, are true mangroves that contain alkane (C₂₅-C₃₃), triterpenoid, phytosterol, dolichol, polyprenol, and polyprenyl acetone. Here we reported new compounds of probably epoxy polyprenol and epoxy dolichol from S. albaandS. caseolarisold leaves using two-dimensional thin layer chromatography (2D-TLC). In the S. albaold leaves, having the occurrence of polyprenol, dolichol, epoxy polyprenol, and epoxy dolichol with a dominating pattern of polyprenol. A similar result obtained in the S. caseolarisold leaves, displaying the presence of polyprenol, dolichol, epoxy polyprenol, and epoxy dolichol with a dominating carbon chain length of dolichol. By contrast, no epoxy polyprenol or epoxy dolichol were detected in S. alba, and S. caseolarisleaves. The present study indicated a new type of polyisoprenoid distribution and further investigation is needed to clarify the chemical structure of this newcompound.

To find out the level of carbon monoxide gas emission in motor vehicles, we need a tool that can measure these conditions. So in this study made a measuring tool for carbon monoxide gas emission levels in motor vehicles. This measurement tool uses the TGS 2442 sensor. While Arduino Uno as a microcontroller and signal processor, and Android smartphone as a data viewer. Based on the sensor testing obtained, the graphs obtained linear equations when measuring carbon monoxide levels in BK 6776 PAN cars y_reg = 38.436-0.0641x with standard deviation values (δ) = 10.816, uncertainty values of measurement results (UA_1) = 6.245 and uncertainty values regression approach UA_2 = 1.02 and on vehicles with BK 6281 AAG y_reg = -3371 + 1.03x with a standard deviation value (δ) = 157.25, the uncertainty value of the measurement results (UA_1) = 90.788 and the uncertainty value of the UA_2 regression approach = 28185.05 and on vehicles BK 3181 MAM y_reg = -24.48 + 0.001x with a standard deviation value (δ) = 99.168, the uncertainty value of the measurement results (UA_1) = 57.255 and the uncertainty value of the regression approach UA_2 = 3824.05. Retrieval of data on the measuring instrument that the standard deviation value at 10 seconds is 2375.32, at 12 seconds is 3318.42, and at 15 seconds is 2639,813. The measurement uncertainty value at 10 seconds is 1371.39, at 12 seconds is 1915.89 and at 15 seconds is 1524.1

The antioxidant properties of Ocimumsanctum extract were characterized. The extract was prepared by extraction using ultrasonic bath at 50 °C for 30 minutes. The characterization was performed using FT-IR analysis.The phytochemical assays were carried out using various reagents. The results confirmed the presence of phenolics, flavanones, flavonoids, steroids and terpenoids in the extract. The DPPH assay also showed the antioxidant radical scavenging activity by percentage of inhibition of 57.95%.

The choice of impeller type is an important factor in maximizing the performance of a stirred tank reactor in saponification process. This study aims to determine the type of impeller that can produce the highest reaction rate by taking into account changes in alkali concentration in saponification reactions so as to obtain a shorter residence time. The saponification process was carried out by reacting 30% oil with alkali (KOH) at operating conditions 70°C, stirring speed of 400 rpm for 45 minutes using 4 types of impellers namely paddle-2 blades, pitch blade turbine 45°-2 blades, paddle-4 blades, pitch blade turbine 45°-4 blades. Testing of alkali concentration was carried out every 5 minutes until the reaction was complete. Alkali concentration was obtained at the end of the reaction using a paddle-2 bladesimpeller of 0.182 M with a conversion of 97.35%, a pitch blade turbine 45°-2 bladesof 0.142 M with a conversion of 97.93%, paddle-2 bladesof 0.106 M with conversion of 98.46%, pitch blade turbine 45°-4 blades of 0.100 M with conversion of 98.54%.

Baung Suat fish (Hemibagrus caveatus) become the newest species in North Sumatera. H. caveatus were collected in Batangtoru downstream. This species has a special mark, specifically a horizontal and vertical strip both on the left and right of the body of this species. The research has been done at Batangtoru downstream, North Sumatera in July 2019. The total amount of this captured fish was53 fish with 170 mm to 394 mm in total length (TL). The value of constant b obtained from the relationship length weight of H. caveatus fish was 3.09 which makes H. caveatus are positive allometric. Condition Factor values obtained based on the relation of body length and weight about 0,8098 – 1,3527. Sex ratio between male and female are 1,41. The male of H. caveatus are at the Gonado Maturity Level (GML) I, II, III, and IV, while the female at GML III and IV. Gonado Maturity Index (GMI) of H. caveatus at 2,46 – 13,07 %. The first size maturity of gonad begins to appear in 291,27 mm length for the male and 303,32 mm length for the female.

In steel construction, some stages demand a learning process first to understand the functions and procedures that will occur. The erection process in steel construction is a process of assembling steel components so that it becomes a unity that will be carried out in the field. When carrying out steel as part of erection activities, there are huge potential risks to employees, subcontractors, or other personnel within the construction area, therefore it requires intensive training before real work done. Various methods can be done to facilitate the teaching of the erection process in steel construction; one of them is by using a simulator. A simulator system that uses hand gesture readings and haptic feedback is the best choices of learning methods to help the learning process of erection in steel construction. Virtual reality is an option to be applied the desired simulator system. With virtual reality, users can utilize cognitive and motor skills to interact with the system. The cognitive and motor skills are increasingly driven by control devices like senso gloves that can read and display the motion at the system interface in the same time. In addition, the addition of haptic feedback in the form of vibrations at each fingertip of the glove makes the simulation closer to reality. The purpose of this study is to design the use of motion control Senso Glove as a tool in developing simulator for the erection process learning in steel construction within a virtual reality environment.

One key element in that development is concrete. The basic ingredients of concrete is a mixture of cement, water, fine aggregate and coarse aggregate, while the concrete using steel reinforcement called reinforced concrete. The times in the era of rapid globalization have resulted in increasing number of second-hand goods / waste can be a problem for the existence of life, one of which is the existence of waste steel slag. To that end, much has been done in order to recycle in order to overcome the problem of the existence of this waste. One way is to capitalize upon such waste for purposes that could be used. In this study, the steel slag is used as a substitute or substitutes in normal concrete mix. Variations addition of steel slag at normal concrete to determine the compressive strength and flexural strength better and is expected to improve the quality of the concrete form of the compressive strength and strong bending. The variation of the addition of steel slag used was 0%, 15%, 25%, and the testing was done by the compressive strength and flexural strength. From the test results obtained by the resulting increase in the value of the slump, the increase in the compressive strength and increased compressive strength lentur. The increase in the capacity of steel slag respectively 11.91% and 20.35%, of normal concrete. Whereas the increase in the flexural strength of steel slag substitution respectively 16.62% and 31.18% of normal concrete. Therefore, if conducted further research it is better grades of steel slag enlarged variation of more than 25% in order to be used as a substitute. Continued research for high quality concrete can be done by mixing a solution that can increase the holding capacity of steel slag with other concrete constituent materials.

In order to utilize durian seeds waste, production of wood adhesive made from them was carried out. Method of dextrinization was applied and characterizations of the adhesive's properties were evaluated, namely specific gravity, viscosity, gel time, pH, clarity, color, and microscopic description including the particle's size of the adhesives. The properties were compared to other starch based adhesives, such as sago and tapioca. For further utilization as wood adhesive, application for particleboard binder was investigated. Parameter of internal bonding of the board then was evaluated. Result of this work showed fundamental properties of dextrin adhesive made of durian seed were similar with sago and tapioca's dextrin excluding the colour. Values of internal bonding of particleboard were varied that indicated many factors affected the quality of particleboard for instance the distribution of the adhesive.

Scaphium macropodum or malvanut or locally known as Kembang semangkok was member of Sterculiacease those well adapted under closed canopy stratum. The species was targeted for illegal logger due to its valuable seed that has many benefits for medicinal purposes and the wood for building and construction. This extraction causing Kembang semangkok classified at least concern according to IUCN redlist. Lack information on the existence and morphology on Kembang semangkok in North Sumatra, causing confusing identification in the field. Therefore, our research was conducted to identify leaf morphology and assumed ontogeny of Kembang semangkok originated from Gunung Leuser National Park. The research was conducted through survey method on 9 (nine) plot of Kembang semangkok. Observation and measurement for morphology were carry out on leaf organ those were leaf shape, leaf arrangement, leaf composition, leaf margin, leaf base, leaf blade and leaf apex. Our research showed that ontogenic change was found in Kembang semangkok due to their respond to survival and plant growth. The changes can be identified by leaf shape from entire (under 50 cm height) into palmed-parted leaf (taller than 50 cm) and returned onto entire after 12 m height.

Tapian Nauli Bay is along the coast of Sibolga Bay starting from the border of Sibolga City towards Barus, Tapanuli Tengah. In the Tapian Nauli Bay area there are plenty of fish biological resources and coral reef ecosystems. It is known that the reef fish community is a biotic component of the coral reef ecosystem that can be utilized as marine biological resources.This study aims to examine the diversity of reef fish. The method used in monitoring reef fish is a method Underwater Visual Census (UVC).The reef fishes observed were then grouped into 3 groups of fish, namely: target species, indicator species, and major species, then the structure of the reef fish community was calculated. The results showed that the composition of reef fish species in Sitardas Beach and Bakar island was dominated by major fish (97%), then followed by target fish (2%) and indicator fish (1%).And, overall the diversity of reef fish species in the Sitardas Beach and Bakar island waters shows a low level and shows a relatively unstable uniformity level.

The Rivest-Shamir-Adleman (RSA) public key cryptosystem has been extensively used to secure digital communication since more than forty years. The security of RSA relies on the hardness of factoring a big integer into its two big prime factors: the bigger the integer, the securer the cryptosystem. However, the RSA cryptosystem is proven to be not semantically secure. Some variants of Dependent RSA encryption schemes have been introduced by Pointcheval to overcome this problem. This study shows how the first variant of Dependent RSA (DRSA-1) encryption scheme is used to secure text. All algorithms have been implemented in the Python programming language version 2.7.15.

As one of the renewable energy that can be utilized in various fields, solar energy is a potential energy source considering that Indonesia has a tropical climate. One of the uses of solar energy is in agriculture. Various agricultural commodities need to be dried before further processing. Also in coffee commodities that are being favored by many people nowadays. For this reason, as a solution to the problem of long drying times with weather changes issue, a room is made as a drying medium. By sucking hot air from a 2.576 m2 solar collector using the exhaust, it is expected that heat will be maintained in the space that has been isolated. The 2.4 m2 dryer rack design is made in three trays to make the most of the space. The results of the room that have been made is able to keep the lowest temperature at night at 26.6 °C and the highest temperature at 60.7 °C during the day. The highest average temperature in the room is on the bottom shelf near the hot air source.

The availability of control devices that use hand and finger movements in virtual reality systems has an essential role in increasing the level of interaction in the virtual reality system. Hand and finger movements in a virtual reality system can be displayed either in the form of a controller that resembles its original shape or in the form of a virtual hand. The translation motion and rotation of the virtual reality controller can be used as input to the system. In addition, the virtual reality controllers allow the use of buttons or gestures as triggers on the system. Input in the form of translational and rotational movements on the virtual reality controller and its triggers can be applied to anatomical learning systems in a virtual reality environment. Virtual reality controller has a role as a system control tools. Different virtual reality controllers have different levels of feasibility to the system, similarity when used, and ease of learning. Therefore a comparison was performed on three virtual reality controllers that have different usage methods and features. The three tools chosen in this study are the VIVE Controller, Leap Motion Controller, and Senso Glove. These three tools have different ways of using and feature, including differences in touching the user or not, triggers in the form of buttons or gestures, and whether or not haptic feedback is available. The analysis of the use and its comparison between these three virtual reality controllers are the outcome of this study.

In reducing the pollutant load contained in laundry wastewater such as COD and phosphate levels can be processed through anaerobic process and will be followed by phytoremediation methods. The purpose of this study is to reduce levels of COD and phosphate in laundry wastewater. This research was conducted in a laboratory scale with variations in plant mass. One type of aquatic plants that has the potential in phytoremediation waste management is algae (Hydrillaverticillata). The initial step in this research was carried out the seeding stage in anaerobic reactors with the aim of breeding bacteria with a suspended culture method which was marked by a decrease in COD with +10% fluctuations. Followed by the running stage in the anaerobic reactor until the reduction in COD ≥60% then, the stage of neutralization and acclimatization of plants with the aim of removing impurities in plants and adaptation of plants with microorganisms in wastewater. The last stage is the running stage of the phytoremediation process which is carried out by observing the value of COD and Phosphate in wastewater with variations in plant mass of 50, 100, 150, 200 and 250 grams in each reactor with contact time treatment for 7 days. Based on the analysis of COD parameters for each plant after anaerobic and phytoremediation processes on the last day the average efficiency of COD removal at 50 grams of plant mass is 86.34%, 100 gram plant mass of 81.81%, plant mass of 150 grams of 85.21%, 200 gram plant mass of 90.87% and 250 gram plant mass of 87.47% while the results of the analysis of Phosphate COD parameters for each plant the average removal efficiency of Phosphate in 50 gram plant mass is -25 %, 100 gram plant mass of -298.81%, 150 gram plant mass of -417.86%, 200 gram plant mass of -501.19% and 250 gram plant mass of -462.5%.

Incense is a type of sap produced from kemenyan tree (Styrax spp.) by tapping the wood bark. Incense is one of the vegetative non-timber forests product which categorized to resins group that can be processed and utilized for various uses. The purpose of this study was to determine the marketing strategy of incense by the community around the protected area in PT. Toba Pulp Lestari concession. A SWOT analysis was applied to find the best strategy scenario. The analysis result recommends Strength-Opportunity (SO) is the best marketing strategy to be adopted.

Kepayang also called Picung or Pangium Edule is a spice used to make dishes in Indonesia. Kapayang fruit seeds have a variety of benefits including being used as a natural preservative to replace the use of formaldehyde in fish preservation. Kapayang fruit seeds are also inhibitors of microbial growth and activity so that food stays for have a long shelf life The purpose of this study was to determine the effect of the addition level of kepayang fruit extract on organoleptic characteristics, drip loss and meat rot at different shelf life. This research uses a completely randomized factorial design method with 3 replications. The material used was male lamb meat, kapayang fruit seeds extracted. Lamb meat was marinated in kapayang seed extraction with P0 as a control, P1 (3%), P2 (6%) and P3 (9%) were drained and the meat was stored for T1 (12 hours), T2 (24 hours) and T3 (36 hour) at room temperature. The results showed that kepayang fruit extract did not significantly affect water content and meat rot and drip loss. It was concluded that the use of Kepayang seed extract 3% to 9% is recommended because it can inhibit spoilage for 36 hours and reduce the characteristic odor of lamb meat.

Kepok banana peel is a waste product from the processing of kepok banana which can be used as an alternative in animal feed. Low crude protein and high crude fiber become the main problems in the utilization of kepok's peels. One way to improve its quality is by fermentation. The starter of fermentation used is EM4. The purpose of this research was to determine the effect of dose and length of fermentation against nutritional content of kepok's peels. This research was designed using completely randomized design factorial with 3 replications and continued using the duncan test. The kepok's peel were given EM4 at doses of 1, 3, and 5% and then fermented for 3, 5, and 7 days. The results of this research showed that the dose of 5% and 5 day fermentation time were optimal and efficient to increase water and crude protein content and reduce levels of dry matter and crude fiber of banana peel. There was no interaction between dosage and fermentation time for each research parameter.

Industry 4.0 is marked with technological advancements that change the way of interactions between human and machines, suppliers and producers, as well as customers and distributors. Digitalization, internet of things, big data and cloud computing are example of technologies used in Industry 4.0. Readiness assessment is needed to evaluate the existing condition of organizations. The information from this assessment is used to design strategy in adopting industry 4.0. This adoption requires modifications in all aspects of organizations including vision, culture, people (social aspects) as well as technology, process and infrastructure (technical aspects). Modifications in selected aspects only, for example, modification in technology and infrastructure aspects only, might lead to failure in adopting industry 4.0. To overcome this, systemic approach is needed to assess the readiness of organizations to adopt industry 4.0. This paper uses socio-technical framework and composite indicators to assess the readiness of organizations to adopt industry 4.0.

Deli watershed is one of three most critical watershed in North Sumatera. Sei Petani Sub Watershed is upstream area of Deli Watershed which must be paid attention in Deli watershed management. There are some indicators in watershed management that have given attention such as hydrology, erosion, and sedimentation. This study aims to assess Sei Petani Sub watershed health on hydrology indicators (spesific maximum discharge, spesific minimum discharge, river regime coefficient, runoof coefficient and water yield). The result of this study shown that spesific maximum discharge value is 0.234 m³/s/km², spesific minimum discharge value is 0.095 m³/s/km², river regim coefficient is 2.34, and coefficient runoff is 0.142 whereas discharge value and water yield is shown by the time series data. The result shown that Sei Petani Sub Watershed categorized in a good condition.

Complete feed fermented cassava peel is a feed ingredient that is considered potential to support the performance of Male Kacang Goat. This research was conducted in Sihopuk Baru Village, Halongonan Timur District, Padang Lawas Utara Regency. Maintenance was carried out for three months, from April to June 2019. The research method was Completely Randomized Design (CRD) with 4 treatments and 3 replications so that there were 12 male goats maintained. P0: Complete feed 75% fermented cassava dried+ 0% cassava peel, P1: complete feed 55% fermented cassava dried + 20% cassava peel, P2: complete feed fermentation 35% cassava dried + 40% cassava peel, P3: complete feed 15% fermented cassava dried + 60% cassava peel. The research parameters are Feed Consumption, Weight gain, and Feed Conversion. The average feed consumption of Kacang goat is P0 of 274.67; P1 of 277.64; P2 of 277.63; and P3 of 279.33. The average weight gain kacang goat is P0 of 12.70 g / head / day; P1 of 18.33 g / head / day; P2 of 34.66 g / head / day; and, P3 of 27.33 g / head / day. The average conversion of kacang goat feed is P0 of 21.98; P1 of 15.43; P2 of 8.38; and P3 of 10.23. P2 is a formula complete feed fermented cassava peel which is best for supporting the performance of kacang goats.

The finite element method is one method used in the structural and nonstructural analysis. This paper aims to the simulated of the finite element method on nonstructural problems namely heat transfer. The media used has been a motorcycle exhaust system modeled with COMSOL Multiphysics 5.4 software by combining annealed stainless steel 405 with 35% chrome stainless steel, Beta-21S Titanium, and Carbon II type as a large tube on the exhaust model. The results of computing simulation obtained are that the lowest heat transfer value in Carbon II material type with a heat transfer rate of 325 K.

Non-timber forest product (NTFPs) that provide species are a substantial component of the agroforestry system in southern Tapanuli and contribute to local livelihoods. The aim of our study was to measure the annual economic contribution of NTFPs to local livelihoods. NTFPs such as Theobroma cacao L. Areca catechu, Archidendron pauciflorum, Aleurites moluccana (candlenut), Hevea braziliensis, Arenga pinnata, Cinnamomum sp are mostly collected from natural habit.The study site has contribution value for the utilization of non-timber forest products is 53.04% and provided a moderate increase in income to the people of Marancar Godang Village. The total contribution of NTFPs to annual household income was 2,441,416,000.00 IDR/year/households.

This research was conducted to overcome the problem of lack of sediment data in a watershed in North Sumatra due to the lack of sediment measurements recording which is caused by the amount of cost required, relatively long time, and the risk of obtaining such data. The purpose of this study was to obtain the equation of sediment curved line. Sediment curved line is an equation that connects the river discharge with the sediment discharge. The river discharge data could be used to obtain the sediment discharge. This research used descriptive methods in the form of primary data (debit data and sediment concentration) and secondary data (climate data). Results obtained sedimentary curved lines Qs = 18.995Qw1.9923 and R2 = 0.7451. The obtained sediment discharge has exceeded the limits set by the Ministry of Forestry regarding to the criteria for watershed determination.

Poncan Gadang Island used by people for marine tourism, underwater and fisheries activities. These activities make the island's area as a ship transportation route and feared the condition of the coral reef ecosystem will be damaged. This research aims to find out the condition of coral reef (life coral), the abundance of reef fish and the corellation between those two variables in Poncan Gadang Island. This research was conducted in June 2018 using Underwater Photo Transect (UPT) and Underwater Visual Cencus (UVC) methods. From the results of this research were found 14 species of reef fish that consists of 5 families and 161 individual fish with 23.96 % coral reef lifeform percentage (damaged category). The corellation between coral reef lifeform and abundance of reef fish is 29.5%, which means showing sufficient or moderate corellation.

The distribution of goods from distributors to several distribution agents is very important to be studied in order to minimize the total transportation costs and the availability of goods at each agent. The model generally developed in this problem is based on the shortest road distance. Basically, road distance is not the only factor considered but also the travel time and road quality that will be traversed. The travel time is uncertain, it really depends on the time and the density of the vehicles. Likewise, road quality is uncertain. Travel time and road quality are fuzzy. This research developed an algorithm to determine the route of distribution of goods by considering the distance, travel time, and road quality which are fuzzy. The optimal distribution route of the goods is a combination of three fuzzy criteria.

The Benaloh public key cryptosystem is an asymmetric cryptosystem with the property of homomorphic encryption scheme. This study explains how to use Benaloh public key cryptosystem to encrypt a simple text. To increase the clarity of the computation, some intermediate variables which are not available in the original Benaloh cryptosystem have been used. The Benaloh algorithm has been implemented in Python programming language version 2.7.15.

Most of The Pane Island Coastal communities are not yet aware of the potential of Sargassum in their coastal area even though its benefits as a foodstuff is quite high, for this reason, it is necessary to have scientific information about the importance of the nutritional content of Sargassum sp. such as proximate chemical composition and crude fibers as a components of functional food product. The proximate chemical composition and crude fibers of Sargassum were studied to understand the nutritional profile. The results show that physical-chemical parameters of waters play an essential role in the nutrients composition of Sargassum. Among the two seaweeds, S. cristaefolium contained highest protein and carbohydrates content (8.54% and 7.25%, respectively) and S. crassifolium possessed highest ash, fat and crude fiber (41.52%, 0.30%, and 24.54%, respectively). Nutrient content and crude fiber in Sargassum cristaefolium and Sargassum crassifolium can be used as components of functional foods.

Successive ionic layer adsorption and reaction (SILAR) method is a modified version of chemical bath deposition (CDB) that serves as a low-cost and convenient on the production of ternary metal chalcogenides. This research reported the utilization of SILAR method on the fabrication of Cu₃BiS₃ semiconductor-sensitized solar cells. The concentration of bismuth and copper precursor were varied, namely 0.03 M and 0.1 M, whereas the precursor of sulfide was varied in the concentration of 0.02 M and 0.05 M. The variation of SILAR cycles was employed to investigate the most appropriate cycle numbers in producing Cu₃BiS₃, in particular 3-9 cycles, 5-15 cycles, and 6-6 cycle with the immersing time of 20 s for each. The results show that there were only two suitable peaks appeared for 3-9 cycles and 6-6 cycles, while 5-15 cycles provide the more preferable XRD patterns with the power conversion efficiency of 0.02% (Jsc of 1.75 mA/cm²; Voc of 0.04 V; FF of 29.65%). It can be said that SILAR method with higher number of cycles can be employed to fabricate Cu₃BiS₃; however, smaller PCE came from inappropriate structure alignment between Cu₃BiS₃ and metal oxide layer.

Energy is an element of a very important need and can not be separated from human life, especially electrical energy, electrical energy is energy that is widely used and can not be separated from everyday life. In this technological era, the need for electrical energy continues to grow with the development of technology. The energy source for power generation in Indonesia is largely supplied from fossil energy (combustion energy), but these energy sources will be exhausted within about 20 years. Various studies have now led to the development of alternative energy sources such as nuclear energy, solar energy (solar energy), water energy, wind energy, biomass energy, geothermal energy and wave energy. The use of engine coolant in this era has widened where refrigeration is not only applied to household needs, but can also be applied to the needs of industry such as the pharmaceutical industry and the fishing industry as fishermen at sea takes time from weeks to months. The cold storage's performance analysis aims to determine the best condition of the cooling engine with a variation of 5 photovoltaic units with 250 WP per unit. From the test results obtained daily average performance at 3:32 with testing carried out for 9 hours.

These studies relate to Red chili dryers sourced from solar energy, the main objective of these experiements to analyses the effectiveness of desiccant CaCl2 at nighttime, so that they can be received by the community. The parameters that are used in this experiment are, Temperature and Relative humidity, temperature and humidity can be maintained. The initial weight of 0.61 kg in drying chamber 1 and 0.60 kg drying chamber 2, then placed in a different drying chamber, and the final result where a 0.61 kg with desiccant and 0.64 kg without desiccant. The result of these experiment with desiccant CaCl2 the weight can be maintained with constantly and drying chamber without dessicant can be reached 0.05 kg.

The research on analyzing of phase change on binary alloy Pt1-X Mn_x (x=17.5 at. %) system had been performed by diffraction and resistivity measurements. The purpose of this experiment is to investigate the change of order-disorder phase transition and its critical temperatures. The polycrystal samples of nominal concentrations of 17.5 were prepared from 99.999 % of pure platinium and 99.99 % of pure manganese. This sample was heat-treated separately at 1150°C for 2 days to remove strains. Then, the sample was quenched by dropping quickly into iced water to get a disordered state. X-ray diffractometer experimental results shows that samples contained 17.5 at. % Mn and heat-treated at the temperature of 1150°C for 2 days were in the disorder state. Meanwhile, ordered state was seen on the sample of 17.5 at. % Mn, heat-treated at 800°C for 10 days.

The Isolation and purification of flavonoid compounds from the leaves of Bauhinia kockiana Lour had been done. Concentrated methanol extract was hydrolyzed with HCl 6%, partitioned with chloroform and it was separated by column chromatography using n-hexane: ethyl acetate (60:40 v/v). Pure yellow-crystalline amorphous compound; mass = 33.8 mg, m.p = 155 °C and Rf = 0.29, was then characterized by spectroscopy UV-Visible, FT-IR and ¹H-NMR. Interpretation of Spectrofotometer of compound compared with data standard showed the compound is flavonoid Flavonol. The antibacterial activity test toward methanol, hexane and ethyl acetate extracts respectively was conducted using diffusion method which inoculated bacteria were dipped into Mueller Hinton Agar. Results showed that inhibitory effect of bacterial growth was better with effective inhibition zone againsts Escherichia coli at concentration 500 mg/ml with diameter zone 17.8 mm

Soap is the product of saponification of fats with a base, which is used as a body cleanser, in the form of solid, foamy, with or addition of other ingredients and do not cause skin irritation. Clay (kaolin) is used as an active ingredient in cosmetics because of the high level of adsorption of substances such as oil, toxins, and others. The use of clay also been considered as a potential tanning agent in halal industrial applications. This study aimed to search for the effect of temperature reaction and addition of kaolin to the solid soap produced. The saponification reactions was carried out for 10 minutes in a reaction flask at a temperature that varied from 50ºC - 80ºC. The beginning stage was to heat the coconut oil to the reaction temperature and then mixed it with kaolin (10%, 12.5%, 15%, 17.5%, 20% wt.), followed by adding 35% NaOH. The reaction mixture was stirred at 250 rpm. The results of this study showed that all soap products met the Indonesia standard SNI.

Charcoal was produced from rambutan rods. The charcoal was then used as adsorbent to adsorb copper ion 70 ppm dissolved in solution. The charcoal rambutan has ability to adsorb the copper ion (%R) 62,068 or about 43,456 ppm. SEM EDX was used to confirm the ability of the charcoal to adsorb the metal ion. The ability to adsorb is 0,15 % of weight. The advantage the study is to give information that the rambutan rods charcoal has potential to use as adsorbent to clean of water contaminated by metal ions.

Soil compaction can occur due to repeated tractor trajectories in the tillage process. Changes in soil physical and mechanical properties that occur can be seen with changes in soil bulk density, soil porosity, ground pressure and soil penetration resistance. Soil compaction can cause disruption of plant root growth that will reduce crop production. The purpose of this study was to evaluate changes in soil physical and mechanical properties due to soil compaction caused by repeated tractor trajectories. The study was carried out at 20.05% moisture content, bulk density 1.06 gr / cm³ porosity 53.9% and an average penetration resistance of 1.32 kgf/cm² (0.13 MPa) with an average tractor ground pressure value of 0.88 kg/cm² crossing the ground as much as 1-8 times the track. The results showed that the number of tractor trajectories affected the value of bulk density, soil porosity and soil penetration resistance. The increasing number of trajectories, causing an increase in the level of soil density which can be seen by increasing the bulk density value by 1.31gr / cm3, decreasing porosity value by 26.63% while the average penetration resistance increases by 6.88 kgf/cm² (0.67 MPa).

It is well known that crude palm oil (CPO) is obtained from the milling process of raw bunch, called fresh fruit bunch (FFB). The process usually flows through a series of stages producing and consuming intermediate products. It is assumed that the CPO industry considered in this paper does not own oil palm plantation, in such a way that the FFB are supplied by several public plantations. Due to the availability of FFB, it is then necessary to select from which plantations should be appropriate. This paper describes a mixed integer linear programming model to tackle the supply chain integrated problem, along with waste problem. The mathematical optimization model is solved using generalized reduced gradient search approach.

Ball mill is an operating unit used to grind various types of solid materials into finer particle sizes. The purpose of this study was to determine the best variation of operating conditions of mung bean milling in a ball mill by varying the grinding time, weight of raw materials and the number of balls used. In this study, the raw material used is mung bean. After grinding, the beans are then sifted through sieves 70, 140 and 200 mesh where the fraction of green beans that passes each sieve was obtained. From the studies, it can be concluded that the best operating conditions of mung bean milling in the ball mill are at 60 minutes grinding time, the weight of the raw material is 45 grams and the number of balls size is 8 medium balls and 6 small balls.

Cotylelobium melanoxylon or locally known as raru is one of the endemic species in North Sumatra. The species was disjunct distributed in Central Tapanuli Regency, North Sumatra. The purpose of this study was to analyze the wood durability of C. melanoxylon against termites' attack by using the graveyard test method. Wood samples were made measuring 3 cm by 3 cm by 20 cm. The test sample was dried using an oven at 103 ± 2°C for 24 hours before and after the test. The graveyard test was carried out for 3 months (90 days). The test parameter observed was a weight loss of the sample. The results showed that C. melanoxylon wood was classified into durable class II and included in a resistant category with weight loss values ranging from 0.89 to 2.79% for axial direction and 1.81 to 2.22% for lateral direction.

The entrepreneurial spirit that gives birth to an interest in entrepreneurship is very important to be recognized. In-depth analysis of the characteristics of entrepreneurs will make it easier to find the teaching patterns needed to give birth to young entrepreneurs who continue farming. Thus, this study wants to analyze the factors of entrepreneurship that affect the interests of the children of farmers who are studying in agricultural colleges to continue farming owned by their parents. This study is a survey study using quantitative data. The location of the study was conducted in Indonesia. The study sample is expected to reach 200 respondents. Data analysis uses logistic regression. The risk taking, organizing, leading and hard work variables significantly influence the decision to engage in or not interested in continuing farming. The other three variables are exploiting opportunity, patient and influencing other found not to significantly influence the decision to be interested or not in continuing farming.

Characteristics of chitosan-ZnO-modified screen-printed copper electrodes showed good sensitivity as a sensor which characterized by using cyclic voltammetry. The copper electrode was prepared for the sensitivity testing before being used as a sensor substrate material, the tests carried out in sodium phosphate buffer solution (BSP), the use of BSP as a standard test in this study.

The heart is a very vital organ. There are two main states in the heartbeat cycle, systole and diastole. The heartbeat system studied in this paper was taken from a study of Thanom and Loh in 2011. This paper is aimed to analyze the stability of the heartbeat system using Lyapunov's Direct Method. This method requires a Lyapunov function. To construct the Lyapunov function, the Gradient Variable Method will be used. In this research, the Lyapunov function constructed $V(x)={x}_{1}^{2}+{x}_{2}^{2},\dot{V}(x)\gt 0$ is obtained. This means $\dot{V}(x)$ is said to be a positive definite and the equilibrium point (0,0) of the heartbeat system is unstable.

This study aims to assess effectiveness of indirect solar dryer for drying red chilli. The quality parameters were moisture content and colour (L*,a*,b*) values. The results showed the maximum temperature on sunny hours of the day within drying box varied from 52.4°C to 62.6 °C on 3 days drying period with lower final moisture content and better colour of dried chilli powder using Indirect solar drying than dried in the open sun.

This study reports the turmeric of drying operation. Variables that have been compared are size or surface area of the sample, drying air rate and drying temperature. In this case it was found that the effect of increasing surface area would be able to increase the amount of water evaporated from the sample. The effect of drying air flow rate at the same temperature decreases the ability to evaporate air in turmeric samples. This is due to the reduced time of interaction of the drying air with the sample surface. Relatively small temperature variations do not show significant differences. The optimal drying rate is achieved by using drying air temperature at 39°C with drying flow of 4,5 m/s and the turmeric sample with surface area of 0,00525 m². The effect of this drying variable obtained significantly on the size of the dried turmeric.

In this work, we introduce the modular sequence space T(Λ, (φ_n)) defined by infinite matrix Λ and a sequence of φ-functions (φ_n) and study the structure of the sequence space ℓ₁ of all sequence associated with absolutely convergent series in this space.

Water plays an essential part in human life. In our daily activities, water is something we must consume for our survival. As one of the largest seawater resources country in the world does not guarantee Indonesian citizens of having pure water to consume. Since, most of the water is already polluted by factories, industries and households. The needs of pure water are increasingly needed as the human population gradually increased. One of the technology to produce pure water is solar distillation. This research aims to find out the water productivity results and the efficiency of glass cover cooling by flowing water over the glass cover on passive double slope solar still. The results showed that the actual and theoretical water productivity calculation for this method are 4,36 liters and 7,57 liters. The efficiency for actual and theoretical of the system 52,32% and 90,88% respectively.

In this paper, we introduce some new modular vector valued sequence spaces defined by φ-function and give some basic result of this space.

The recovery status of mangroves at west coast of Aceh until 7 years post the Indian Ocean tsunami (IOT) was examined. The field researches were conducted during January 2005 to December 2011 in more than 20 km (1) to record flora species that were resistant to the paroxysm of tsunami swells, and (2) to record and observe the appearance of several existing and new plant species caused by tsunami. The main result shows that (1) mangrove beaches may not recover at all to their original state because the topography has changed greatly and the hydrological and sediment condition differ from their previous conditions, (2) most of mangrove trees dead due to change in habitat environments, (3) some mangrove species in land subsidence coasts were found migrating landward through seed recruitment, naturally, (4) several species of mangroves appear to flourish in the natural stands with mother trees survived against tsunami, (5) new species, for example, Typha angustifolia greatly colonize along the intertidal areas, and (6) Acrostichum aureum (mangrove fern) population occupies an bare lands left by mangrove vegetation communities or abandoned brackish pond. Because mangroves provide bio-shields or natural belts, more lives can possibly be survived during the natural hazard, including tsunamis. Unluckily, due to high market of brackish pond products, severe damage to mangroves was not managed. Therefore, degraded mangroves must be restored and preserved very well in the future.

Deforestation and forest degradation are the main contributors to climate change. Changes in the structure and composition of forests affect the value of biomass and carbon storages. Bukit Lawang's tropical rainforest of Gunung Leuser National Park which has great potential is not only a habitat for key species, namely the Sumatran orangutan (Pongo abelii) but also has other biodiversity values. This study aimed to determine the vegetation structure and to estimate the value of standing carbon storage of the forest. The vegetation structure was analyzed by the line transect method and the estimation of biomass and carbon storage values was carried out using an allometric model. Distribution of diameter classes is dominated by trees in the 30-50 cm diameter class, with B strata dominated by Aglaia tomentosa tree species. The value of standing biomass is 523.2-562.2 t/ha, carbon storage is 261.6-281.1 t C/ha and the amount of CO₂ gas absorbed is 960.0-1,031.6 t CO₂/ha. The results indicate that it is necessary to do better forest management ecosystems in Bukit Lawang to improve and maintain the ecological and economic functions of these ecosystems in order to support the implementation of REDD + in efforts to mitigate climate change in Indonesia.

Before influence of the western nations, the Minangkabau society already had their own systems related to natural protection and conservation. One of the systems is "Rimbo Larangan" or forbidden forest. In this case, prohibition law is determined by the State Council. The forbidden forest is a prohibition area, disallow to cut all plants. Rivers within the forbidden forest cannot be disturbed. All animals within the forbidden forest cannot be hunted. The conservation system was profitable to the local communities and to persist and sustain for the future. However after the Indonesian independence, especially in the period 1945 to 2000, many forbidden forests are damaged and destroyed. This is due to many forbidden forests are changed to production forests by the national government. It should be noted that the forbidden forest system should be re-applied and maintained now, in order to prevent the destruction of forests, loss of biodiversity, particularly due to the global warming. If forests are healthy, the water and air qualities are guarantee. Due to the social conditions, institutions and many rules have changed. Therefore, many future researches are required.

Singkil Swamp Wildlife Reserve (SSWR) is remaining tropical coastal forested wetland in west coast of Sumatra. The conservation area is also facing habitat loss and destruction due to illegal activities, such as logging and land conversion. However, there is no data available on land cover change of important habitat of great ape critically endangered, Sumatran orangutan (Pongo abelii). This study aimed to determine the rate of change in land cover of the SSRW and to analyze the factors causing these changes in the last 20 years using landsat image. Land cover classification was carried out using supervised classification with maximum likelihood approach. The result showed that primary swamp forest area of the SSWR continued to experience a significant decline every year during the period 1998-2018 that around 24% of primary swamp forest was lost in the period due to deforestation and degradation. Therefore, degraded forests of SSWR should immediately be rehabilitated to restore ecological functions and to increase their productivity as well as education program to increase awareness coupled with forest monitoring and law enforcement to reduce illegal activities. Finally, appropriate management should be applied with co-management between government and local communities in conserving the important conservation areas.

Mangrove forests are important for the productivity of estuary ecosystems, including diversity and population of coastal biota because of their contribution through the fall of litter so that mangroves as the first chain of tropical chains on the coast. Most of marine biota species are thought to be highly dependent on mangrove areas from west to east tropical region. About 70% of fish caught were only found in mangrove forests that were still good. The fish population and species in healthy mangroves were 159-234% and 116-129% greater than mangrove forests that have been degraded, respectively. The loss and degradations of mangroves also causes fishermen income to decrease. Therefore, the healthy mangrove should be maintained with properly management as well as the degraded mangrove should be restored based on scientific basis. Conserving and restoring mangroves are becoming a very productive investment, not only for the present generation, but also for future generations.

Thermal Manikin is a human model designed for research and development in outdoor and indoor, military, and clothing environmental experiments. This research aimed to analyze the skin temperature distribution from Thermal Manikin. This study used Thermal Manikin which functions as a representative of the human body where the surface temperature of the body Thermal Manikin is made close to the surface temperature of the human body. The temperature of the Manikin Thermal skin was made constant at 34°C ± 1°C under stable room temperature conditions. Experiment was carried out with various air temperature conditions from 26°C to 32°C. Skin temperature measurements carried out on 24 body parts of Thermal Manikin for 90 minutes at 1-minute intervals. The measurement results obtained was then compared and analyzed at various air temperature conditions. The results of the analysis showed that the temperature of the skin in each part of the body's thermal Manikin was evenly distributed in each part of the body and the temperature of the body's skin thermal Manikin increases with the increasing air temperature around thermal Manikin.

In this paper, a computerized modelling of a simple single-stage vapour compression refrigeration cycle has been carried out. The aim is to find a cycle performance that is suitable for fish preservation applications. The simulation was completed using the CoolPack software on two different refrigerants and analysed at various condensation temperatures. As a fixed variable, a specific compressor power has been chosen for all cases in meeting the evaporation temperature designed. The results of this study inform the comparison of cycle performance including heat rejection rate, cooling capacity, COP, and pressure-enthalpy diagram. The main conclusion is that both types of refrigerant that are simulated can produce high COP which is useful for handling the cooling load that is later available. The report on this study will be used further to design a fish-storage box.

Mangroves are a particular form of brackish plants, estuaries, and deltas which distributed in tropical and sub-tropical areas. Mangrove has various functions including the ecological functions of mangrove forests such as nesting places, spawning, and enlargement of various types of fish, shrimp, crabs, birds, and other fauna. This study was aimed to determine the mangrove ecosystems service to produce tiger shrimp (Penaeus monodon) in silvofishery ponds that are consisting domination of trees and saplings. Survival of shrimp at trees domination was 0.21% with a total of 125 individual, yielded as much as 1.2 kg. Shrimp survival at saplings domination was 0.31% with a total of 186 individuals, yielded of 1.8 kg. To further increase production results in silvofishery ponds, it is necessary to regulate the techniques of preventing predatory animals that enter the pond when the floodgates are opened, namely by placing a smooth net and repairing the fort.

The effects of impregnation ratio on characteristics of activated carbon from bagasse and banana stem were analyzed. The precursors were impregnated using phosphoric acid (H₃PO₄) solution as the activator at a ratio of the activator to the precursor (w/w) of 1:1, 2:1 and 3:1. Pyrolisis was conducted at 400 °C for 15 minutes. The results showed that activated carbon from bagasse has better yield, surface area and total pore volume compared to activated carbon from banana stem. The increased of impregnation ratio decreased the yield and surface area, but increased the total pore volume and pore radius. The highest yield of activated carbon from bagasse and banana stem were 61.87% and 45.53%, respectively. Whereas the highest surface area of activated carbon from bagasse and banana stem were 1,070 m²/g and 915 m²/g, respectively. The activated carbon produced from both precursors contained both micropores and mesopores structures.

Numerical study of three types of collectors. There is 0°, 20°, 30° of angled two collectors. This simulation finds out which collector will be the most optimum tilt angled solar collector while every collector got same sun's radiation. The boundary condition is The simulation will be at 3.33° North and 98.39° East (Mechanical Engineering Magister Program, University of North Sumatra, Medan) and The simulation will be on 23 April at 12.30 Measurement point in this simulation are the inlet temperature, the outlet temperature, absorber plate. The most efficient collector is 30°

Generally yogurt drinks are made from cow's milk, whereas buffalo milk has a higher nutrition value than cow's milk. The objective of this study was to produce yoghurt drinks from buffalo milk and determine proximate composition and sensory quality of the product based on starter concentration and fermentation time. The experiment was carried out using a completely randomized design of factorial patterns consisting two factors, i.e. starter concentration (3, 5 and 10%) and fermentation time (8 and 12 hours). The results of proximate analysis obtained showed starter concentration had significant effect on moisture, fat, protein and carbohydrate contents. While fermentation time had significant effect on fat and protein contents. The sensory evaluation result showed significant differences among the yoghurt drink samples. Sample F (10% starter concentration and 12 hours fermentation time) had the highest scoore in sensory atributes.

Research is the duty of universities in addition to education. Meanwhile, the community service is a different task, but it becomes a bridge is to downstream both of them. This paper intends to describe the relationship between research and community service, which implies that prior to servicing the community, a necessity of its implementation requires research, to ensure that community service fulfils the achievement targets.

Research is a part of every activity of human life, and the tri dharma of higher education only reaffirms that task for each academician. Research is not just a coincidence like that, but it is a possibility and opportunity, or not incidentally, for life itself. Because, however, every interest will urge to become the human needs, research becomes a solution so as not to contribute negatively to social and personal well-being. This is stated as research serendipity, which ontologically states that a research will supported by another research and will also give birth to another research.

The productivity of oil palm plants is determined by the success of pollination. Some factors that influence are the planting material, rainfall conditions and the adequacy of pollinating weevil, namely Elaeidobius kamerunicus (EK). Producers of planting materials produce crosses of Dura X Pisifera hybrids with their spesific characters. This research aim was to determine the effect of planting material on flowering characteristics and EK population.The research was conducted in Adolina (DxP Simalungun) and Dolok Ilir (DxP La Me) in January 2018 - October 2018 with a descriptive method. The research results showed that the character of oil palm planting material affected the number and character of male flowers as a source of pollen.In planting material with a large number of male flower spikelet, the DxP Simalungun has a positive effect on the population of Elaedobius kamerunicus. The efforts to increase the EK can be achieved by applying the Hatch and Carry technique which can increase EK populations by 32-45%.