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Volcanic ash is danger for aviation because it harms the flight engine. This study presented the simulation of volcanic ash dispersion with the PUFF-Langarangian methods. The data was conducted from the Tangkuban Perahu volcano, which was erupted on 26 July 2019 in West Java, Indonesia. The results simulated volcanic ash dispersion based on the ash concentration and altitude at 105 minutes after the eruption. Simulation results were then compared with the satellite image of volcanic ash dispersion from The Indonesian Meteorological, Climatological, And Geophysical Agency or BMKG. With correction factor −14.75°, then the α = 0.50717°, AR = 0.99138, the simulation was fit with the satellite image. The simulation results showed that the combination of PUFF and Lagrangian methods gave a better volcanic ash dispersion map. [ABSTRACT FROM AUTHOR]

We briefly discuss the spiral ground state in face-centered cubic (FCC) iron implementing the generalized Bloch theorem which combines a linear combination of pseudo-atomic orbital basis sets. The generalized Bloch theorem aims to make the calculation much more efficient than using the supercell method. We use a magnetic iron atom in the primitive unit cell with a magnetic moment direction of 90o as the initial ferromagnetic state. We observe the different positions of spiral ground states for several lattice constants. For small lattice constants, the low-spin states appear, while high spin states appear in higher lattice constants. This achievement means that the spiral ground state and the spin state depend on the lattice constant. [ABSTRACT FROM AUTHOR]

Alfirsa Sekar Tanmala Putri 010002-3 REVIEWER Coordinator: Riser Fahdiran, M.Si (Universitas Negeri Jakarta) Members: Prof. Dr. Mangasi Alion Marpaung, M.Si Prof. Dr. Agus Setyo Budi, M.Sc Prof. Dr. Yusaku Fujii Prof. Dr. Sunaryo, M.Si Prof. Dr. Yetti Supriyati, M.Pd. 9 th National Physics Seminar Strengthening the Freedom of Learning through Innovative Physics and Physics Education Proceedings of the National Physics Seminar 2020 Jakarta, Indonesia 20 June 2020 Editors: Hadi Nasbey (hadinasbey@unj.ac.id) Riser Fahdiran (riser-fahdiran@unj.ac.id) Widyaningrum Indrasari (widyaningrum-indrasari@unj.ac.id) Esmar Budi (esmarbudi@unj.ac.id) Fauzi Bakri (fauzi-bakri@unj.ac.id) Teguh Budi Prayitno (teguh-budi@unj.ac.id) Dewi Muliyati (dmuliyati@unj.ac.id) Department of Physics Department of Physics Education Universitas Negeri Jakarta Rawamangun, East Jakarta, 13220 Indonesia The 9th National Physics Seminar 2020 AIP Conf. Proc. [Extracted from the article]

The preparation of Metal Matrix Composite (MMCs) Al/SiCp and Al-Cu/SiCp with the addition of silicon carbide powder (SiCp) and mixing with the hot sterring method has been done successfully. Material Al and Al-Cu melted in the temperature of 900°C then added SiC with variations (1, 2, 3, 4) weight % with the method of hot sterring. Microstructural observation with SEM shows both Al/SiCp and Al-Cu/SiCp grain boundaries are not obvious. Testing tensile test showed that the addition of Cu make Yield Stress tends to increase. While the corrosion rate of Al-Cu/SiCp is smaller when compared to Al/SiCp. Meaning Al/SiCp tends to be more corrosive when compared to Al-Cu/SiCp. [ABSTRACT FROM AUTHOR]

After the COVID-19 pandemic ended, the Ministry of Education, Culture, Research, and Technology launched a new learning curriculum called the Merdeka Curriculum that requires teachers to use various kinds of learning media. However, a few of the technology-illiterate teachers keep using the same learning media monotonously, which makes the students bored to study. The goal of this research is to develop a learning media called Physicatz learning application for topics impulse and momentum that is feasible to be used in physics learning. The model that has been used in this research is the ADDIE model with steps: (1) Analytic, (2) Design, (3) Development, (4) Implementation, (5) Evaluation. This research obtained a percentage score of 81% from material experts, 90% from media experts, and 92% from learning experts. This application is also being tested on physics teachers with a percentage score of 95% and 74% score from 39 second-graded SMAN 30 East Jakarta science students. The slightly lower score compared to other validations came from the student's point of view due to limitations of their access to the internet. [ABSTRACT FROM AUTHOR]

We briefly considered the effect of electric field on magnon dispersion in zigzag graphene nanoribbons via density functional theory. We implemented the generalized Bloch theorem combined with the constraint scheme approach to calculate the magnon energies over the first Brillouin zone. By observing the magnon dispersion, we found the small increases of spin stiffness and critical temperature up to a certain value, but then remain constant. We conclude that the magnetism in zigzag graphene nanoribbons disappears below room temperature. [ABSTRACT FROM AUTHOR]

This seminar was organized by the Department of Physics and Physics Education, Faculty of Mathematics and Natural Sciences, Universitas Negeri Jakarta. The theme of the seminar is "Strengthening the Freedom of Learning through Innovative Physics and Physics Education". PREFACE: The 9 th National Physics Seminar 2020 The 9 th National Physics Seminar 2020 was held online via webinar on June 20, 2020 due to the pandemic condition. [Extracted from the article]

An analysis on the structure and mechanical properties of the electrodeposition of Ni-Si3N4 composite coatings has been carried out. The composite coatings were deposited at the Si3N4 concentration variations of 10 gr/L, 20 gr/L, and 30 gr/L. The samples were characterized by X-Ray Diffraction (XRD) and Vickers hardness test. The XRD data obtained was used to calculate the crystallite size, lattice strain, residual stress, and its relation to the mechanical properties of the coating are presented. The results showed that Ni crystal growth was resisted by increasing Si3N4 concentration due to the increase of Si3N4 crystal size followed by the decrease of lattice strain, internal stress and residual stress. From the hardness test result, it showed that the high hardness of composite at high Si3N4 concentration indicate the contribution of crystal refinement rather than coating stress. [ABSTRACT FROM AUTHOR]

A square-wave deposition technique synthesized platinum (Pt) nanoparticles as electrocatalysts for the ethanol electrooxidation reaction. The electrodeposition was conducted in a solution with different concentrations of H2SO4 as a supporting electrolyte. Structural analysis using an X-ray diffractometer shows that a face-centered cubic of Pt nanoparticles was successfully deposited on the substrate. At a supporting electrolyte concentration of 0.5 M, the granular particles with rough surface nanoparticles were formed. The delicate spikes, which became thicker by increasing the supporting electrolyte concentration, were found to grow on the surface of the particles. The cyclic voltammogram showed that the highest anodic current from the ethanol electrooxidation reaction was obtained by Pt0.5M, which was found to exhibit a low charge transfer resistance measured by an electrochemical impedance spectroscopy technique. [ABSTRACT FROM AUTHOR]

We review the derivation as well as the free particle solution of nonlinear master Schrödinger equation. Even though this equation is founded by the Hamilton-Jacobi and continuity equations, the plane-wave solution does still exist for the free particle case. In addition, we will also formulate the gauge invariance form, which describes the electromagnetic interaction. In this case, the Hamilton-Jacobi equation should be modified while the continuity equation remains unchanged. [ABSTRACT FROM AUTHOR]

This study aimed to simulate the gamma-ray energy spectrum of Ga-67 with the Monte Carlo methods. The simulation was conducted one million photons as the samples. The probability of gamma-ray interaction (photoelectric effect Pfe, the Compton effect Pce, and pair production Ppp) was generated from a random number from 0 to (Pfe + Pce + Ppp = 1). The ratio of undetected and incident photon in the detector were set 1:9, 2:8, 3:7, 4:6, and 5:5, respectively. The simulation results were then compared with the data measurement of Ga-67 spectrum energy from the spectrometer. The simulation results showed that the ratio of 2:8 gave the best result. Therefore, the Monte Carlo method attained build the simulation of Ga-67 energy spectrum. [ABSTRACT FROM AUTHOR]

The patterns of climate change and El Nino were studied to obtain the characteristics of rainfall variability in Kalimantan. The pattern of climate change is analyzed in ten-year periods (decades of 1986-1995, 1996-2005, and 2006-2015). The analyses carried out include climatology averages, the amount of annual rainfall, climatological patterns of high rainfall (Percentile 95), shifts to the lowest monthly rainfall, and shifting to the dry season. The frequency of rainfall that occurred in the Below Normal (BN) category was calculated using the average method and standard deviation. Annual variability analysis was correlated with El Nino by calculating the average composite frequency of BN category occurrences in El Nino intensity (weak, medium, and strong). The analysis was undertaken between the correlation of rainfall and the Nino Index of 3.4 to obtain the relationship of sea surface temperatures in the central Pacific and rainfall in Kalimantan. The results showed that the Kalimantan region's atmosphere got wetter in the last three decades in the annual rainfall patterned area and drier in the annual rainfall patterned area. This is indicated by the average climatological rainfall, which experienced an increase in rainfall in the third decade, a decrease in the frequency of occurrence BN rainfall, increased rainfall (95th percentile) in areas with annual rainfall patterns and vice versa (semi-annual). The lowest and foremost rainfall shifts occur in semi-annual rainfall patterns compared to normal and do not occur in annual rainfall patterns. The influence of El Nino has a weak to medium effect in annual and semi-annual rainfall patterns. The correlation between rainfall and the Nino index is 3.4 with r (0.33-0.66). The nature of rainfall is BN at weak, moderate, and strong intensity with a frequency of BN events between low (<33%) to medium (33-66%). [ABSTRACT FROM AUTHOR]

Much research and development have been performed to investigate the high-temperature oxidation resistance of nickel-/nitride composite coatings. It is an important study since the high oxidation problem caused to reduce the coating performance, product quality, and coating lifetime, as well as high cost, consume in industrial applications. The high-temperature oxidation of composite coating might be received during mechanical applications such as in high-speed machining. It shows that the coating performance depends on its properties, such as hardness and microstructure. This paper presents a brief discussion based on a literature study and previous investigation results. [ABSTRACT FROM AUTHOR]

One limitation of solar panels as a high potential renewable energy is the efficiency decrease due to surface temperature increase of solar panels during the day. To overcome these problems a hybrid solar panel was developed, using a combination of photovoltaic (PV) and thermoelectric generator (TEG) modules. The developed prototype composed of 17cm x 11cm of solar panel, a SP1848-27145 Thermoelectric generator (TEG), heatsink, INA219 sensor, two units of DS18B20 temperature sensor, and Arduino Uno R3 microcontroller as a control system. Through sensor characterizations are obtained, that maximum relative error of voltage, current, and temperatures are 2.48%, 2.52%, 2.85%, and 2.75%, respectively. Whereas TEG has a power increasing rate of 1,015 mW/0C. Data acquisition of prototype was carried out in South Tangerang. The highest power produced by the hybrid solar panel of 847,26 mW is obtained at 12:15. The TEG's additional increase the output power of hybrid solar panels by 5,45%. [ABSTRACT FROM AUTHOR]

A close system consisted of 2500 agents is simulated to observe the spread of disease that can only be transmitted through contact between two agents. This agent-based model (ABM) is accompanied by a partial differential model known as the SIR (Susceptible-Infected-Recovered) model, which requires the rate of infection and rate of recovery as parameters, wherefrom these two other parameters known as basic reproduction number can be obtained. For homogeneous agents, ABM will give similar results with the SIR model, but for an inhomogeneous agents' average of ABM with the different initial condition can approximate the results of the SIR model. Besides the inhomogeneous agents, a spatial barrier that prevents agents from moving freely in the two-dimensional space can also introduce inhomogeneity in the system. Both models must have an initial infected agent or individual to begin the infection. [ABSTRACT FROM AUTHOR]

This paper aims to investigate the effects of sodium chloride (NaCl) and glucose on a single strain of yeast Saccharomyces cerevisiae during the respiration period. A Biochip-C sensor was used to measure the oxygen consumption rate and calibrated with PbS solution of pH 7.3 and 2.3 M before the experiment, which has a reference voltage of 1840 mV. A 150 µL of S.cerevisiae solution with a density of 5•107 cells/ml was immobilized into the Biochip-C chamber and left for 600 s at the initial experiment. An amount of 100 µL sodium chloride and glucose with concentrations of 0.1 M, 0.2 M, and 0.3 M were added into the yeast solution and measured until the stationary phase. For every single oxygen consumption, the models were then simulated to predict their stationary phase. The results show the addition of glucose causes an increase in the sensor potential level by a maximum of 3.9 % from the reference represented a higher oxygen consumption, while salt decreases 2.39 % lower, which is shows an inhibit fermentation process and reaches the stationary phase at 1200 s. This work comprises a model study of respiration for the fermentation phase of yeast, especially food screening applications, and to detect the amount of sugar in food. [ABSTRACT FROM AUTHOR]

The practicum device of beat frequency has been developed. The device composes of the AD9833 module as an artificial sound frequency source, Arduino Uno as a control system, and application as the output's display. The module produces an adjustable frequency of sound in real-time. Then, these frequency sources are connected to an adjustable speaker stereo as the sound's output. The instrument available produces frequencies from 0.1 Hz to 2500 Hz with a stepping frequency of 0.1 Hz. Frequency calibration was carried out using a frequency audio counter in the frequency range of 300 Hz - 500 Hz. The maximum relative error of the first frequency source and the second frequency source is 0.01% and 0.008%, respectively. The beat frequency was observed using an audacity application in the 10 s and 15 s intervals. The smallest frequency that can be observed is 0.1 Hz. Validation by a media expert is carried out to determine the feasibility of the developed device. The assessment results were 95% of all aspects. [ABSTRACT FROM AUTHOR]

Puri Bunga Nirwana Regency is one of the regencies with the densest regency in Jember. The factor of the number of occupants is followed by the high usage of vehicles, so that it has the potential to cause large exhaust emissions. Lack of concern for regency developers for the impact of exhaust emissions poses a health hazard for the population. This research aims is design green open space (RTH) based on vehicle exhaust emissions. This design is based on the results of the analysis of vehicle exhaust emissions in Puri Bunga Nirwana Regency. Kinds of plants used in this design are based on the ability of plants to absorb carbon dioxide gas (CO2). The method used in this study is a field survey by counting the number of vehicles passing 200 m from the gate of the Menteng Cluster Puri Bunga Nirwana Regency. The results of vehicle exhaust emissions in Puri Bunga Nirwana Regency are 1030.2 kg / year. Based on the analysis of emissions results, the CO2 absorption of tree was 1559 kg / ha. day so that the number of trees needed was one trees / ha. While the CO2 absorption of soursop trees was 75.29 kg / tree / year, so that 13 soursop trees were needed and the CO2 absorption of kecik sapodilla was 36.19 kg / tree / year, so that 28 kecik sapodilla trees were needed. [ABSTRACT FROM AUTHOR]

Observations that the differentiation of stem cell into other cells, e.g. bone cell, blood cell, epithelial cell, muscle cell, nervous cell, are well known. In the recent years experiment of deposition of stem cell on a surface with nanopattern has been succesfully showing the difference of produced cells. The patterns can be in the form of nanopillar, nanowells, or other form in between. The order of magnitude of the nanostructure compared to the cell size plays also importance role, in which scale that the pattern can influence the cell, e.g. internally, externally, or until the shape of the cell colony. Single cell based on granular model is simulated using molecular dynamics (MD) method, where the content of the cell is approximated using agent-based model (ABM) to assure that the cell volume is kept constant. Due to cell shape change induced by the nanopartern, interaction between cell inner particles, performed by agents, has also changed. In this article we are reporting the development stage of an in-house simulator. [ABSTRACT FROM AUTHOR]

The depletion of the fossil fuel supply, provoking a lot of research focused on alternative or renewable energies. A hybrid power plant system (a combination of wind and solar energy) as an alternative energy to Faculty of Mathematics and Natural Sciences Universitas Negeri Jakarta is developed. The advantages of a hybrid power generation system are to combine the advantages of each power source so that each one fills the weaknesses of the other under certain conditions, so that the overall system can operate more economically and more efficient. In this research, ESM50W is used as a source of solar electricity and the 24VDC generator is used as a power plant from wind turbines. The solar power plant has an optimal voltage of 17.2 volts and an optimal current of 2.91 A. Based on the results of the measurement of the efficiency of solar power plants approximately to 14.4%. The tachometer is used to measure the speed of the wind passing through the wind turbine. The cut in speed of the wind turbine used is approximately 3 m/s. The voltage generated at a speed of 3 m/s is approximately 49.3 mV with a turbine rotation speed of 17.4 rpm. [ABSTRACT FROM AUTHOR]

We formulated some gauge transformations of the three-dimensional Gross-Pitaevskii equation coupled by a time-dependent potential. To do that, we determined explicitly all the related functions to keep the invariance of the Gross-Pitaevskii equation adopted from the gauge transformation in the classical electrodynamics. This work can be done since the present Gross-Pitaevskii equation can remain invariant after transforming the wave function through the local phase transformation. In this case, we only discussed its mathematical aspects and ignored the physical interpretation to open all the possibilities. However, we still imposed the condition that all the lengths of vectors should be real and found that only two cases can be explored since it is impossible to obtain the appropriate transformations, except we set the potential vector to be zero and the phase to be an arbitrary function of time. Thus, it may yield the different physical interpretations using this method. [ABSTRACT FROM AUTHOR]

Soil is the most important thing required for farming activities. High-quality soil is needed for plants to grow well. Some of the parameters that indicate quality soil are the loose structure, pH 6.5-7.5, and salinity tolerance of 0-8000 µS/cm. The decline in soil quality in Indonesia due to pollution is one of the reasons that measurement soil quality device need to be developed. This study aims to characterize the soil pH sensor and conductivity sensor used in measuring soil quality parameters. The soil pH sensor is used as a pH detector, while the conductivity sensor is used as a salinity detector, as a control system the Arduino Uno is used. The results of sensor characterization show that the pH sensor has a sensitivity of -20,114 mV / pH and a maximum relative error of 2.16%, whereas, the conductivity sensor has a sensitivity of 0.0431 mVcm / µS and a maximum relative error of 6.78%. The results of measuring soil parameters of the five different soil samples, proves that the quality of the rice field's land and garden soil samples used in this research is still suitable for agricultural land. [ABSTRACT FROM AUTHOR]

In nowadays scenario, many accident cases of two-wheeler are occurred on road causing death. Such accidents cause intensive head injuries in spite of availability of helmet anywhere, individuals are not using them for shelter. The system of smart helmet is utilized to avoid motor bikes accidents and to recognize them at real time in order to maintain safety of human being. The IoT based-technology of smart helmet is a crucial issue, which improves safety of two-wheeler driving than, exist one. For time being, this technology is fruitful that and producing an assortment of items with excellent quality components in different industrial branches. All through the long time since its beginning, a number of advances to the smart helmet were developed and utilized around the world. The most point of this paper is to classify the currently utilized smart helmet technologies and show a comprehensive survey of these advances. [ABSTRACT FROM AUTHOR]

Physical properties of biomaterials are usually assessed mechanically as modulus elasticity or firmness through compression, tensile or shear test. This assessment is destructive which leads to handicap for online application in agroindustry automation for fresh products. In this study an acoustic method together with a computer software was employed to determine natural frequencies of three horticultural products, i.e. durian (Durio zibethinus), mango (Mangifera indica) and "sawo" (Arachaszapota). The results the durian and mango produced two types of natural frequency, single peak and double peaks whereas the sawo generated only single peak of natural frequency. The natural frequencies of single peak fruits and the first peak natural frequencies of double peaks fruits decreased exponentially during fruit ripening with high coefficients of determination. In the case of mango and sawo fruits, the natural frequencies were also highly correlated with the firmness indices assessed by compressive and penetrometric tests. This finding suggests that the natural frequencies may be utilized as a mean of a non destructive sorting and quality evaluation of these fruits. [ABSTRACT FROM AUTHOR]

A viscometer is an instrument used to measure the viscosity of industrial products in the form of liquid substances. There are three kinds of the viscometer that are often used to measure of liquid viscosity, one of them is a falling ball viscometer. In Physics Laboratory, a falling ball viscometer is used for physics experiment, but the equipment is still manual. Determination of liquid viscosity using falling ball viscometer manually is very susceptible to human error making it less accurate. To overcome this problem, this research has successfully developed a digital falling ball viscometer using an Arduino micro controller to measure the viscosity of the liquid. This digital viscometer consists of a measuring tube, photo diode sensor, laser (light-emitting), Arduino micro controller, stative, and iron ball. The liquid samples whose viscosities measured are placed in a measuring tube. At the body of the measuring tube mounted two pairs of photo diode- laser sensors separated by a certain distance. The first sensor pair detects the start time and the second sensor pair detects the final time of the falling ball in the liquid sample. The falling time of the iron ball when moving in the liquid sample is calculated by automatically and it displayed on the LCD. The system test shows that the digital viscometer is functioning well with a standard deviation is 0.036. Based on measurements using this equipment, the coefficient viscosity of cooking oil is 0.032 Pa.s and the engine oil is 0.024 Pa.s. It is hoped that the digital viscometer can help users in physics experiment with accurate measurement to reduce human error in measuring the viscosity of the liquid. [ABSTRACT FROM AUTHOR]

University of Bengkulu (UNIB) is an area that is located geologically close to the beach, causing aquifers located around campus is still influenced by seawater. This is indicated by several wells containing brackish water. The objective of this research is to map the thickness of the aquifer layer suspected of being intruded by seawater using Geoelectric VES 1D with Schlumberger configuration method at University of Bengkulu. This study was measured by using Geoelectric Resistivity and IP M MAE X612-EM with the VES (Vertical Electrical Sounding) method, which was carried out on 20 tracks, that were 10 tracks around the well bore and 10 other trails scattered inside campus area with length of 200 m. 1D data were processed by using Progress 3.0 software and 3D models processed by Voxler 4. Based on the results, this study indicated that the thickness of the brackish water layer reaches 10 m to 27 m, at the western part of University of Bengkulu the depth is located at 55 m to 82 m below the surface, and the eastern part of University of Bengkulu the depth is located at 20 m to 82 m below the surface with the resistivity from 1.38 Ωm – 4.90 Ωm caused by swamps around the campus. The unconfined aquifer layer is located at a depth of 5 m to 32 m and the confined aquifer layer is located from a depth of 43 m. Type of aquifer layer in the form of groundwater with resistivity ranging from 5.20 Ωm – 98.87 Ωm. [ABSTRACT FROM AUTHOR]

The sun has an important role in the lives of all beings on earth. Monitoring of solar irradiance is important because the data correlates with many disciplines. This research aimed to develop an irradiance monitoring instrument that has the ability to monitor the using a photovoltaic panel as the sensor. The principle of this instrument is that the photovoltaic panel produces electricity if it is exposed to direct sunlight and its output is proportional to the irradiance. The output is read by a microcontroller and it is calculated using an algorithm to estimate the irradiance value. This study is started by designing the hardware both the electronic parts including a microcontroller, radio transceiver, data logger, and the mechanical parts including the pole and the active solar tracker. The software is designed and developed using the Arduino IDE. Generally, the result shows that the photovoltaic panels can be used as a sensor to measure the irradiance. The maximum irradiance in Bengkulu during the test is 988.41 W/m2. The root mean square errors (RMSE) of the measurement compared to the standard instrument is about 14.06 which is acceptable. However, from this study, it is suggested to use good quality materials as it is an outdoor instrument that needs to be tough and durable. [ABSTRACT FROM AUTHOR]

In this study, we identified the most important physiologic parameters determining the variability of the organ at risk and tumor absorbed doses (ADs) in Peptide-receptor radionuclide therapy (PRRT). Therefore, a global sensitivity analysis (GSA) with Sobol method and a physiologically-based pharmacokinetic (PBPK) model were used. A whole-body PBPK model that has been developed for treatment planning in PRRT therapy for meningioma and neuroendocrine patients was used. The physiologic parameters of interest for the GSA analysis were the parameters that have been previously estimated from the biokinetic data and were reported in the literature, i.e. the organ receptor densities Rd, organ flows f, organ release rates, and peptide binding rate. GSA with Sobol method was chosen based on its accuracy for sensitivity studies. A widely used GSA MATLAB-based toolbox (https://www.safetoolbox.info/) and an in-house program based on MATLAB software (version R2018b) were used for the analysis. The sampling method with a log-normal distribution was used to avoid any negative values of the sampled parameters. The main effects Si and total effects STi were calculated and analyzed using the GSA program and the PBPK model to identify the importance of each model parameter i for the individualization of the ADs in PRRT. To warrant the convergence of the calculated Si and STi, various numbers of model simulations up to 15000 samples were used. The inter-individual variability of tumor ADs (coefficients of variation CV up to 97.05%) was higher than that in the organ at risk (e.g. kidneys CV around 31.59%). Receptor density was identified as the most important parameters determined the ADs of tumors, e.g. [RdTU2]: Si = 0.856, STi = 0.951. The same results was found for the organ at risk where the receptor density had the highest main effect and total effect values, e.g. [RdK]: Si = 0.802, STi = 0.963. We have shown the first implementation of the GSA with the Sobol method to identify the most important parameters for the individualization of the calculated ADs in PRRT. Our results suggested an accurate measurement of the receptor densities for an accurate determination of the tumor and organ at risk ADs. [ABSTRACT FROM AUTHOR]

In a recent paper by Carballo-Rubio [Phys. Rev. Lett. 120, 061102 (2018)], the author proposed an ultra-compact object model, i.e., a combination of black stars and gravastars, from semi-classical gravity to obtain a generalized Tolman- Oppenheimer-Volkoff (TOV) equation with a new coupling constant lp. The resulting TOV equations have two different forms differentiated by the sign in metric function equation dgtt/dr. In the limit lp → 0, the second (respectively, the first) form of the equations from the negative (positive) sign is (is not) going back to the TOV equation. By defining a suitably new constant parameter λ, the author has found a solution from the first form of obeying boundary conditions. In this work, we investigate the model in a vacuum to obtain exterior solutions for the model. We calculate its exterior solutions using the perturbation method by a small parameter α=lp/rs where rs=2GM is the Schwarzschild radius and obtain the Schwarzschild metric as its leading terms. We also investigate its geodesic equations, whose effective potential from our exterior solutions has similar qualitative features as the geodesic of the Schwarzschild metric, i.e., it contains stable and unstable circular orbits. [ABSTRACT FROM AUTHOR]

One of the interesting aspects in the interaction between two cities or among cities is the commuter, people that do commuting every day. It is similar to a sharing of the population between two areas that bind together. A covalent bond might be the analogy in the chemical world. Usually, there is one city as the center of a commuting system, where the others are considered as a satellite city. The commuters are represented as agents in the simulation, where they commute between their home and workplace. This approach is known as an agent-based model. The average movement from point i to point j in a day will be the component mij in the origin-destination matrix (ODM), which is usually obtained from survey or observation. In this work, we would like to show that using ABM the ODM can be derived. [ABSTRACT FROM AUTHOR]

Conventional bricks are manufactured from clay with high firing temperatures. However, this method results in the depletion of clay and an increase in energy consumption. In addition, biomass lignocellulosic waste such as corn also increased along with population growth. Some studies reported the utilization of corn lignocellulosic waste to protect the environment in the biomass refinery. Therefore, this study aimed to examine the potential of corn lignocellulosic waste addition in the fired clay bricks production. The mixing of clay/corn lignocellulosic waste (500 µm size) with a ratio of 2.5% of the total weight of bricks was used in the manufacturing of fired brick. The raw bricks were then burned by using a temperature of 600 °C. Then, the influences of corn lignocellulosic waste impregnation fired clay brick was examined in terms of density, porosity, and compressive strength. The density of the mixture of clay/corn lignocellulosic waste brick was lower than clay brick, 1.437 gram/cm3 versus 1.521 gram/cm3, respectively. The porosity of the mixture of clay/corn lignocellulosic waste brick was lower than clay brick, 27.3% versus 35.79% respectively. However, the compressive strength of the mixture of clay/corn lignocellulosic waste brick was higher than clay brick, 6.81 MPa versus 4.15 MPa, respectively. This study showed that corn lignocellulosic waste has the potential as partial replacement of conventional raw bricks that the standard requirements were applied. [ABSTRACT FROM AUTHOR]

The pandemic of Covid-19 detected for the first time in early March in Indonesia has been making people stay at home. It affects almost every sector, including higher education. Lecturer, staff, and students have been pushed to work and study from home. There are many approaches from the government, and the ultimate method is a full and partial lockdown. During March to May, with these techniques, it is not only can be temporary slow-down the case but also improved the quality of air. We have two fixed stations at Telkom University (-6.970, 107.629), with an altitude of around 650 and 670 m above sea level, respectively. Those locations were influenced by residential and industrial pollution under not so much open green spaces. Low-cost PM2.5 and CO2 sensors were deployed as well as monitoring meteorological parameters through cheap detectors. The system was equipped by an Internet of Things (IoT)-based modem for data transferring via the internet every 2-min. Results showed that PM2.5 mass concentrations were lower than usual cased in that location. Meanwhile, no significant evidence that the level concentration of CO2 is decreased. The decreasing mobility of people working and studying from home have been making less dirty air. It means that fewer aerosols can be identified in the air. The complex behavior between those polluted air and meteorological conditions have been tried to analyze, but no direct evidence that better air quality makes the outbreak is slowing down. [ABSTRACT FROM AUTHOR]

White dwarf (WD) is the final evolutionary state of the main sequence star with an initial mass of up to 8.5-10.6 M⊙. WD is different from neutron stars, it is relatively less compact, but the equation of state (EoS) of WD is relatively more certain. "General relativity" (GR) from Einstein is the standard theory of gravity. Recently, the study of modified theories of gravity has attracted many researchers' attention because compact stars like WD and neutron stars can be observed for modifications from GR. Compared to neutron stars, studies related to gravity modification for WD are relatively rare. Even though WD is currently observed with a larger mass than the Chandrasekar mass, which cannot be explained based on GR. In this work, we investigated the equilibrium configurations of white dwarfs based on modified gravity theory, namely f(R, T) gravity, R for the Ricci scalar and T for the trace of the energy-momentum tensor, where the theory f (R, T) = R + 2λT with λ being constant. Besides that, we also used realistic EoS proposed by Salpeter. The properties of WD to be investigated, including mass, radius, pressure, and energy density, as well as the dependence of these characteristics on the λ parameter. The results were compared with the other results of observations. [ABSTRACT FROM AUTHOR]

Neutronic analysis of thorium nitride (Th-233U)N and thorium-plutonium nitride (Th-Pu-233U)N fuel for 200 MWth long-life pressurized water reactors has been done. PWR is the most dominantly used reactor in the world and one of three types of light water reactor. In this study, we compared the neutronic analysis of two fuel type i.e., thorium nitride (Th-233U)N and thorium-plutonium nitride (Th-Pu-233U)N. The neutronic calculation performed using the SRAC code system based on library SRACLIB-JENDL 4.0. The calculations performed in this study shows that thorium-plutonium nitride fuel has greater initial excess reactivity than thorium nitride fuel. Thorium nitride fuel can be operated for more than 20 years, while thorium-plutonium nitride fuel can be operated for 17 years. The utilization of heterogeneous core configuration at the PWR system makes energy distribution become relatively flattered compared to homogeneous fuel configuration. [ABSTRACT FROM AUTHOR]

Biogas is one of alternative energy for tackling the energy crisis the longer fossil-fired on the wane. Besides, biogas can cope with the problem of air pollution, such as methane gas. Pollution from methane gas can be utilized by biogas as fuel. This study discusses a brief analysis of the effect of the internal gas pressure of an anaerobic digester on biogas production. The substrate used in this research as producing biogas is a mixture of cow dung/tofu liquid waste ratio of 2 (v/v). Therefore, the two identical biogases reactor with different treatments were developed, with (controlled) and without (uncontrolled) internal gas pressure treatment. The parameters such as temperature and methane gas amount were evaluated for nine days; moreover, the biogas production was monitored daily using a calibrated methane gas sensor. The uncontrolled biogas reactor produced methane gas lower than the controlled biogas reactor, 92074 ppm versus 254451 ppm, respectively, after nine days of reaction time. The uncontrolled biogas reactor's internal gas pressure was higher than the internal gas pressure of the controlled biogas reactor, 89.29 kPa versus 29.84 kPa, respectively, after nine days reaction time. The retention time of uncontrolled biogas production was longer than the retention time of biogas production of controlled biogas reactor, six days versus five days, respectively. The obtained results can be used to design an efficient anaerobic digester for treating, processing, and effectively utilizing organic waste. [ABSTRACT FROM AUTHOR]

This paper discusses the study on the development of potential energy in flat flow rivers using Vortex turbines and a techno-economic study. At this time, a small and medium scale hydroelectric power plant is developing by utilizing a very low head river. The type of turbine that can be applied to the very low head type is Vortex turbines. The Vortex turbine is a turbine that utilizes a whirlpool as an intermediary for energy. The results of the study revealed that the Vortex turbine is quite potential to be developed because Indonesia has many rivers with a flat flow pattern so that it fits with the Vortex turbine. Technical studies are conducted to determine the potential power generated, the types of components used, and the investment cost per kW. The technology analysis results show that the power generated by the MHPP Vortex turbine system is around 1.5 kW. The results of the economic analysis show that the total investment cost value of IDR 175,560,000 with a project NPV value is negative, and IRR is less than 10%, so the project is less commercially viable. Recommendations for project development can be funded through grant funding/government funds. [ABSTRACT FROM AUTHOR]

The new Indonesian national regulation for medical device evaluation necessitates the modification of current best practices for solution development. This article describes our current protocol for medical device development and evaluation. We have combined best practices from Simplified Pressman Standard and Indonesian Technology Readiness Level and Clinical Trial Regulation as a base for our medical device development and evaluation methods. Settings. This protocol is currently evaluated by "Konsorsium Riset Alat Ukur Haemoglobin, Kadar Gula (Glukosa dan HbA1c) Non- Invasive" between IPB University, Agency for the Assessment and Application of Technology, and PT Tesena Inovindo. This article is a preposition article developed from literature research and currently evaluated in three years of research in the consortium. We have developed a three-phase protocol, consist of technology, product, and market phase. This article describes in detail for each point for this protocol, using our current non-invasive blood glucose and Haemoglobin level medical device as an example. The technology phase includes primary literature and lab review for technological units for the non-invasive medical device. The product phase describes best practices for laboratory examination for medical device development in the research stage. The market phase describes best practices for medical device development for consumer usage. We are currently evaluating our protocol. and shall report the evaluation within three years. [ABSTRACT FROM AUTHOR]

The non-invasive glucose biomarker device is developing to compensate for the epidemiology of sufferers of metabolic syndrome in the world from increase dramatically. Additionally, to eliminate all risks arising from the invasive measurement. The percentage of population sufferers of glucose metabolic syndrome evenly occurs in each developing and developed country. All individual activities and behaviors are the main causes. The device was conducted at the Electronic and Material Physics Laboratory, IPB University. This study used Assayed Chemistry Clinical Control as a sample, UV-cuvettes as a simulation tool, and a probe from a silk-polylactic acid filament. The incident light source biomarker uses near-infrared (NIR) LED 1200 nm, LED 1300 nm, and FDG03-Ge as a photodetector. Data analysis derived from reflectance values in the form of intensities expanded using Discrete Fourier Transform (DFT). The output analysis of both LEDs was 0.99 pearson, 100% clinical accuracy, and the accuracy of measurement was 8.09 mg/dL on the 1200 nm LED, 10.57 mg/dL on the 1300 nm LED. Then the sensitivity value of both LEDs is 1.00, and the specificity of 1200 nm LED is 0.80, LED 1300 nm is 0.70. Refers to the results of this analysis and the gold standard ISO 15197, LED 1200 nm is an ideal candidate for the incident light source biomarker non-invasive reflectance method. Future research expected to do device testing in-vivo. [ABSTRACT FROM AUTHOR]

A non-invasive system based on the optical scanning method can be used to measure hemoglobin blood level because hemoglobin has a characteristic of being able to absorb optimally at wavelength 660nm for oxyhemoglobin and 940nm for deoxyhemoglobin. This hemoglobin level measuring system uses the reflectance principle. The sensor probe was designed to be used on patients' fingers, so the sensor reading results were obtained for the reflection of light, which was reflected from patients' fingers. The used sensor was FD100 that could read wavelength at 350nm until 1100nm. The LEDs used were LEDs with each wavelength 600nm and 940nm. Raspberry Pi 3 microprocessor was used as the brain of this device; this microprocessor functions to regulate the light intensity, sensor reading, data processing, visualization, and data storage. The visual result of hemoglobin value (g/dl) is obtained. The equation searching was done by comparing the hemoglobin value to the High-Performance Liquid Chromatography method and sensor reading value. This equation was implemented inside the device, and the test was done to find out the accuracy of the device. Non-invasive blood hemoglobin measuring device that has been developed has an accuracy rate of 94.2% with a standard deviation of 4.7. [ABSTRACT FROM AUTHOR]

We have analyzed the body attitude from a hockey player and considers three conditions, i.e., initial, pushing, and passing the hockey ball. A (165±0.1) cm-hockey player from Sports Faculty at Universitas Negeri Jakarta has demonstrated these three-body attitudes. We started analyzing by first observing and drawing all the force possibilities on the body hockey player and the stick. Then, we project the force possibilities into cartesian coordinates. Finally, we derived the physics law of the dynamic by calculating all the parameters as a function of the physics variable based on Newton's law. The results confirmed that some quantities such as force (F), torque (τ), the distance from the right hand to the axis (R), ball elasticity, and friction (μ) influence the hockey ball motion. Hence, instead of the player skill, we recommend that the coach and a hockey player can consider some physics quantities to improve their performance. [ABSTRACT FROM AUTHOR]

The distinction and characterization of noise have been carried out in the current mirror (CM) circuit as a part of a biosensor system with some main components of MOSFET type BS250 and two resistors at the input (Rref) and output (RL) of the circuit. This evaluation is important since the biosensor module has very high impedance due to the low conductivity sample measured and the high loading resistance for current to voltage conversion. This high impedance leads to the rise of high noise due to thermal noise which is proportional to the resistance, in addition, the type and the specifications of the MOSFET determine the noise due to semiconductor properties. Therefore, this evaluation can be used to reduce the resulted noise to obtain high Signal to Noise Ratio (SNR). The experiment was performed by applying Rref and RL with some values of 1 kν, 100 kν and 1 Mν while maintaining the voltage source at 1 V, which causes the input current to vary accordingly. This experiment was adjusted to meet the range of current in the biosensor application, which is relatively very small. The measurement is acquired by a DAQ card PCI-6221 that has been integrated with a LabVIEW program based on Fast Fourier Transform (FFT). The noise response analysis is performed within a bandwidth of 0.1 Hz to 100 kHz and a frequency resolution of 0.1 Hz. This bandwidth is sufficient to describe the noise in the CM circuit applied to the biosensor device. The results show that the noise characteristics vary with the applied resistance. Thus, it can be considered to determine an appropriate loading resistance, which could be used to build a high SNR current mirror circuit for the biosensor system. [ABSTRACT FROM AUTHOR]

Viscosity is one of the most important properties in determining fluid dynamics for many applications. This research is aimed to develop a viscometer apparatus for physics experiments based on the rotation method. A ATmega328-microcontroller and FC-33-5V phototransistor sensor were used to detect the angular motion of the blades. The rotation of 2-blades stirrer of 40 mm long and 30 mm wide stainless steel plate was measured to determine the viscosity value, while the data measurement is processed using a microcontroller and LCD screen for displaying the result. Calibration of the apparatus is carried out using a tachometer based on the rotation measurement resulted in an error of 0.17 %. The viscometer was tested using samples of distilled water, Turalik-52 oil, engine oil STP 15W40, and Yamalube 10W40 that give an error of 1.62 %, 6.75 %, 6.22 %, and 8.23 %, respectively. Based on these results, the rotation-based viscometer can be used as a simple apparatus for education learning tools in understanding the concept of viscosity. [ABSTRACT FROM AUTHOR]

An algae-based biosensor is investigated using dissolved oxygen levels producing from photosynthesis mechanism and from photoperiodism response time which describes the plant's reaction to light. This paper presents the sensitivity factor in the form of dissolved oxygen rate production level and response time of green algae-based biosensor, which is stimulated using artificial light of LEDs blue (480 nm) and red (650 nm). An amperometric electrode with two green algae as bioreceptors Chlorella kessleri and Chlorella sp. were tested in the biochip C chamber. A sample of 150µL algae with a density of 5−105 cells/ml was illuminated by the artificial light of blue and red spectrum altered for 1000 seconds of the dark-light cycle. The results showed a significant difference in the sensitivity of the algae chlorella sp. in producing dissolved oxygen which is 6.3 and 12.9 times higher than the chlorella kessleri for the blue and red light. While the photoperiodism response of Chlorella sp. has a time constant of 49.8 % for red and 37.5 % for blue smaller than Chlorella kessleri respectively. This result shows the algae chlorella sp. possesses good response characteristics to the red light, but less for photoperiodism response. [ABSTRACT FROM AUTHOR]

In this study, we implemented for the first time the Population and Covariate Model (POPCOV) to simplify the Individual Treatment Planning (ITP) process in PRRT with minimal Physiologically based Pharmacokinetic (mPBPK) model. POPCOV method was used to predict the unknown parameters of the PBPK model using the individual covariates. Stepwise selection procedures (forward selection and backward elimination) were used for the covariate selection and the derivation of the final model. The performance of the final model was tested by comparing the predicted time-integrated activity coefficient (TIACs) from the Fixed-Dose Treatment Planning (FDP) i.e., mPBPK with mean parameters, and conventional ITP method, i.e., mPBPK with individual estimated parameters. Based on the POPCOV analysis, GFR was identified as the best covariate for the receptor density in the kidneys [Rk]. The final covariate model of receptor density in the kidney was: [Rk] (10-15mol/l)=6.32x106*(GFR/0.09)(0.67). These results indicated that the performance of POPCOV for ITP was around 12% better than the FDP and around 26% worse than the conventional ITP method for the kidneys. The results showed that the POPCOV method could be used as an alternative method in PRRT to predict kidneys TIACs in a case where the individual biokinetic data is unavailable. [ABSTRACT FROM AUTHOR]

It has successfully conducted a routine practicum with the theme of thermistor characteristics as a temperature sensor on the Sensor Unit (SU-6803) and OP Amp Unit (OU-6801) in the Sensor and Transducer Laboratory of the Department of Physics, FMIPA IPB Bogor. The installed specifications of the Sensor Unit (SU-6803) include: (i) Detection Circuit: Wheatstone Bridge; (ii) Temperature Source: Heater and cooler by fan; (iii) Sense Resistance: 50Ω∼5kΩ; (iv) Heater Control Input: H-Level (DC 5∼15V); (v) Cooler (Fan) Control Input: H-Level (DC 5∼15V); (vi) Sensor Device: Thermistor; (vii) Input Voltage: DC±15V, 1A. Specifications installed Sensor Unit (SU-6803) aided by OP Amp Unit (OU-6801). Temperature measurement uses a thermistor as a temperature sensor under two conditions, namely (i) Heater condition and (ii) cooler condition, with measurement time for 18 minutes with a 3 minutes step and with 12 replications. The measurement results show that the higher the measurement time, the higher the measurement temperature (for Heater conditions), and the higher the measurement time, the lower the measurement temperature (for Cooler conditions). The relationship between Temperature with electrical energy follows a quadratic function. This shows that the thermistor used is working well. [ABSTRACT FROM AUTHOR]

This paper reports optimization of an LVDT output signal using phase synchronization adjustment. The output signal of an LVDT that incorporates its sign or displacement direction are usually obtained by using a synchronization between the excitation and secondary output signal using a phase-sensitive rectifier. However, the phase of the excitation signal might not be perfectly matched with the phase of the second output signal of LVDT. This causes the rectifier to pass a small portion of the opposite polarity signal beyond the zero lines. Consequently, the total output signal after integration to a dc signal could be reduced, which yields a reduced sensitivity. The implementations of the phase synchronization adjustment methods could improve the performance of the output of the LVDT. The adjustment removes the signal beyond the zero line; thus, the dominant signal is not subtracted due to the leaked opposite sign signal. The adjustment of the phase synchronization to a certain phase angle provide the optimum sensitivity of the output of the LVDT and increase the sensitivity to 15% higher than the sensitivity without adjustment or zero phase shift. [ABSTRACT FROM AUTHOR]

Automatic doors that are developed and marketed today, generally use Arduino microcontrollers as controllers. Innovations were made to obtain new components for automatic door controllers. The research was conducted to address the issue of whether British Broadcasting Corporation (BBC) micro: bits can be used as controllers to make automatic doors or not. The research objective is to obtain a new control system for automatic doors. The research method used was the design method, including designing the programming code, designing, and making automatic doors. This study's output is a prototype automatic thrust open system using a BBC micro: bit controller. The sensor used can detect objects (humans) at a distance of 0.5 - 2.5 m and height of objects ≥ 1 m. The servo motor used can turn the gears 180° to open the door. The door will open when the sensor detects an object and closes again after 2 seconds the sensor no longer detects the object. This corresponds to the programmed lag time. Based on the test results concluded, Micro: bit BBC microcontroller can be used as an automatic door controller. [ABSTRACT FROM AUTHOR]

Has succeeded in conducting a Routine practicum with the theme of the characteristics of Photo-transistor and CdS as Photo sensor on the Photo Sensor Unit (SU-6804) and OP Amp Unit (OU-6801) in the Sensor and Transducer Laboratory of the Department of Physics, FMIPA IPB University. The installed specifications of the Photo Sensor Unit (SU-6804) include: Photo Bias Level: DC 0∼30mA, AC Bias Frequency: 100Hz∼10kHz (with Digital Counter), photo Sensing Range: 0∼200mm variable distance, photo Coupling Speed: 0∼1000 pulse / sec, sensor devices: LED, Photo- transistor, CdS, and input Voltage: DC±15V, 1A. The OP Amp Unit aids the installed specifications of the photosensor unit (SU-6804) (OU-6801). Measurement of light using CdS and Photo-transistor as photosensor with measurement distance ranges from 5 mm to 55 mm with a stage of 5 mm and 6 replications. The measurement results show that the farther the measurement distance of the light from the light source, the lower the electrical voltage. Based on the analyzed graphs and table, Photo-transistor is the most accurate to be used as a photosensor. [ABSTRACT FROM AUTHOR]