bluuebunny/crossref_metadata_2025 huggingface dataset:
Uncertainty of PIV/PTV based Eulerian pressure estimation using velocity uncertainty
Authors: Zhang Jiacheng , Bhattacharya Sayantan , Vlachos Pavlos P
Published: February 2022

This work introduces a method to estimate the uncertainty of the pressure fields reconstructed from particle image velocimetry / particle tracking velocimetry (PIV/PTV) measurements by propagating the instantaneous velocity vector uncertainty through the pressure reconstruction. The uncertainty propagations through the calculation and integration of pressure gradients are modelled as linear transformations. The autocorrelation coefficient was modelled and incorporated in the uncertainty estimation to reproduce the effect of the autocorrelation of velocity errors on the reconstructed pressure’s accuracy. The method was first tested on synthetic velocity fields contaminated with varying levels of artificial noise correlated in space, time, or between components. The error analysis shows that the proposed method could predict the spatiotemporal variations of the pressure errors. The estimated pressure uncertainty also captures the effects of the velocity noise level, the autocorrelation, and the different pressure-gradient integration methods, with more than 80% accuracy in most test cases. The method was applied to an experimental vortex ring flow with planar PIV and a laminar pipe flow with volumetric PTV. The error analysis shows that the obtained pressure uncertainty possessed similar spatial and statistical distributions as the pressure errors. The results also indicate that the performance of the proposed uncertainty estimation method depends on the accuracy of the velocity uncertainty. The proposed uncertainty estimation method exhibits reliability in obtaining the local and instantaneous pressure uncertainty from the PIV/PTV measurements.
A high performance trench gate tunneling field effect transistor based on quasi-broken gap energy band alignment heterojunction
Authors: Chen Shupeng , Wang Shulong , Liu Hongxia , Han Tao , Zhang Hao
Published: February 2022

In this letter, a tunneling field effect transistor based on quasi-broken gap energy band alignment (QB-TFET) is proposed and investigated by simulation method. To offering high on-state current, InGaAs/GaAsSb heterojunction with quasi-broken gap energy band alignment is applied to QB-TFET to improve the band-to-band tunneling rate. Trench gate structure and InGaAs pocket layer are applied to further increase the tunneling efficiency. To suppress the leakage current caused by the off-state tunneling path from source to drain, an intrinsic InGaAs spacer is inserted between n+ InGaAs drain and p+ GaAsSb source. In order to further improve the control ability of gate voltage on channel, TiO2 is used as the gate dielectric of the proposed QB-TFET. Moreover, the effect of x and y fraction of In
x
Ga1–x
As and GaAs
y
Sb1–y
on quasi-broken gap tunneling junction are studied in this work. The electrical characteristic change of QB-TFET with different x and y fraction is analyzed. The proposed QB-TFET is compared with other works and shows an obvious advantage on performance. As a result, a large on-state current (I
on) of 921 μA μm−1 can be obtained. Moreover, steep average subthreshold swing (SSavg) of 4.9 mV/dec can be achieved when I
on = 1 μA μm−1.
Tuning the interfacial friction force and thermal conductance by altering phonon properties at contact interface
Authors: Dong Yun , Ding Yusong , Rui Zhiyuan , Lian Fangming , Hui Weibin , Wu Jie , Wu Zhiguo , Yan Pengxun
Published: February 2022

Controlling friction force and thermal conductance at solid/solid interface is of great importance but remains a significant challenge. In this work, we propose a method to control the matching degree of phonon spectra at the interface through modifying the atomic mass of contact materials, thereby regulating the interfacial friction force and thermal conductance. Results of Debye theory and molecular dynamics simulations show that the cutoff frequency of phonon spectrum decreases with increasing atomic mass. Thus, two contact surfaces with equal atomic mass have same vibrational characteristics, so that more phonons could pass through the interface. In these regards, the coupling strength of phonon modes on contact surfaces makes it possible to gain insight into the nonmonotonic variation of interfacial friction force and thermal conductance. Our investigations suggest that the overlap of phonon modes increases energy scattering channels and therefore phonon transmission at the interface, and finally, an enhanced energy dissipation in friction and heat transfer ability at interface.
SuPART: supervised projective adapted resonance theory for automatic quality assurance approval of radiotherapy treatment plans
Authors: Kamran Hootan , Aleman Dionne M , McIntosh Chris , Purdie Thomas G
Published: February 2022

Radiotherapy is a common treatment modality for the treatment of cancer, where treatments must be carefully designed to deliver appropriate dose to targets while avoiding healthy organs. The comprehensive multi-disciplinary quality assurance (QA) process in radiotherapy is designed to ensure safe and effective treatment plans are delivered to patients. However, the plan QA process is expensive, often time-intensive, and requires review of large quantities of complex data, potentially leading to human error in QA assessment. We therefore develop an automated machine learning algorithm to identify ‘acceptable’ plans (plans that are similar to historically approved plans) and ‘unacceptable’ plans (plans that are dissimilar to historically approved plans). This algorithm is a supervised extension of projective adaptive resonance theory, called SuPART, that learns a set of distinctive features, and considers deviations from them indications of unacceptable plans. We test SuPART on breast and prostate radiotherapy datasets from our institution, and find that SuPART outperforms common classification algorithms in several measures of accuracy. When no falsely approved plans are allowed, SuPART can correctly auto-approve 34% of the acceptable breast and 32% of the acceptable prostate plans, and can also correctly reject 53% of the unacceptable breast and 56% of the unacceptable prostate plans. Thus, usage of SuPART to aid in QA could potentially yield significant time savings.
Tri-stable stochastic resonance coupling system driven by dual-input signals and its application in bearing fault detection
Authors: Zhang Gang , Zeng Yujie , He Lifang
Published: February 2022

Stochastic resonance is of great significance for extracting fault signals of bearings. A novel tri-stable stochastic resonance coupling system driven by dual-input signals(DTDTSR) is proposed in this paper, which significantly improve Spectral Amplification(SA) and amplitude of traditional two-dimensional tri-stable stochastic resonance system(TDTSR). Firstly, under the condition of adiabatic approximation theory, the Steady-state Probability Density(SPD), Mean First Pass Time(MFPT) and SA are derived, and the system parameters’ influence on them are analyzed. Then, using SA as the measurement index, numerical simulations are carried out and system parameters are optimized by adaptive genetic algorithm to achieve optimal performance. So DTDTSR, TDTSR and classical tri-stable stochastic resonance system(CTSR) are applied to weak periodic signals detection and compared with each other. The experimental results show that DTDTSR has a large SA and amplitude, which proves that the synergistic effect of coupled system and dual input signal drive can better promote the generation of stochastic resonance. Finally, the three systems and wavelet transform method are applied in two kinds of engineering bearing fault detection, and adaptive genetic algorithm is also used to optimize the system parameters. The experiments reveal are similar to the previous one, proving that DTDTSR is indeed optimal among the three systems. This system is therefore very adaptable and advanced in practical engineering applications.
Solving time-dependent Schrödinger equation in momentum space with application to strong-field problems
Authors: Jheng Shih-Da , Jiang Tsin-Fu
Published: February 2022

We present a numerical method to solve the time-dependent Schrödinger equation (TDSE) in momentum representation (p-space). We show that the method is practically useful and easier than the coordinate space (r-space) method when continuous states are involved. For a single-active electron (SAE) atom, the numerically complete eigenset can be accurately constructed in p-space by quadrature method which bypasses the singularities in the Coulombic kernel. Although there is an ingenious Lande subtraction for dealing with the singularity but is not straightforward. We formulate the time marching algorithms for an SAE atom in linearly polarized (LP) laser pulse and in circularly polarized (CP) pulse, respectively. We show calibrations to literature results to justify the formulations. Argon in a resonant and a nonresonant CP pulse are investigated and show distinct properties from the case of tunneling regime. Together with the currently available powerful graphics processing unit (GPU) for massively parallel computing, the p-space method could provide a useful alternative tool for some problems such as atoms in intense light pulses.
Inflation with 0 ≤ c
s ≤ 1
Authors: Gorji Mohammad Ali , Motohashi Hayato , Mukohyama Shinji
Published: February 2022

We investigate a novel single field inflationary scenario which allows
a transition between a slow-roll k-inflation with c
s of order unity
and a ghost inflation with c
s ≃ 0, where c
s is the sound
speed for the curvature perturbations. We unify the two phases
smoothly by appropriately taking into account a higher derivative
scordatura term, which is always there from the effective field theory
point of view but which becomes important only in the c
s ≃ 0
regime. The model achieves the whole range of 0 ≤ c
s ≤ 1
avoiding strong coupling and gradient instability, and allows us to
access the c
s ≃ 0 regime in a self-consistent manner. We also
discuss implications to the formation of primordial black holes.
Design of RFSoC-based Digital Phased Array Feed (PAF) and Hybrid Architecture Beamforming System
Authors: Pei Xin , Wang Na , Werthimer Dan , Duan Xue-Feng , Li Jian , Ergesh Toktonur , Liu Qi , Cai Ming-Hui
Published: February 2022

As the number of array elements and bandwidth increase, the design challenges of the Phased Array Feed (PAF) front-end and its signal processing system increase. Aiming at the ng-PAF of the 110 m radio telescope, this article introduces the concept of fully digital receivers and attempts to use Radio Frequency System-on-Chip (RFSoC) technology to digitize close to the feed array, reduce the complexity and analog components of the front-end, and improve the fidelity of the signals. The article discusses the digital beamforming topology and designs a PAF signal processing experimental system based on RFSoC+GPU hybrid architecture. The system adopts a ZCU111 board to design RF-direct digitization and preprocessing front-end, which can sample eight signals up to 2.048 GSPS, 12 bit, channelize the signals into 1024 chunks, then reorder into four data streams and select one of the 256 MHz frequency bands to output through four 10 Gb links. A GPU server is equipped with four RTX 3090 GPUs running four HRBF_HASHPIPE instances, each receiving a 64 MHz bandwidth signal for high-throughput real-time beamforming. The experimental system uses a signal generator to emulate Sa-like signals and propagates through rod antennas, which verifies the effectiveness of the beamforming algorithm. Performance tests show that after algorithm optimization, the average processing time for a given 4 ms data is less than 3 ms in the four-GPU parallel processing mode. The RFSoC integrated design shows significant advantages in power consumption and electromagnetic radiation compared with discrete circuits according to the measurement results.
Topology Identification of the Hindmarsh-Rose Model via Deterministic Learning
Authors: Chen Danfeng , Li Junsheng , Cai Yuping
Published: February 2022

In this paper, the complex dynamic behavior of the Hindmarsh-Rose (HR) model which characterizes the neuron cell is analyzed numerically. And the unknown topology of the system in dynamic environment is locally accurately identified based on the deterministic learning (DL) algorithm. Firstly, the influence of different parameters on the dynamic behavior of the HR model are investigated. Then, the nonlinear dynamics of the HR model under unknown dynamic environment is locally accurately identified. In addition, the identified system dynamics can be stored in the form of constant neural network. The achievement of this work can provide more incentives and possibilities for the application of HR model in clinic and other related researches. Simulation studies are included to demonstrate the effectiveness.
3D-RPP: a novel 3D vision-based Pose Perception Approach for Industrial Robots
Authors: Li Mo , Niu Jianwei , Dou Yuanbo , Ren Tao , Li Qingfeng , Yu Xiaolong
Published: February 2022

Enhanced by artificial intelligence, industrial robots are becoming more powerful, gaining a large variety of applications in intelligent factories. Pose perception, the aim of which is to obtain the joint coordinates of the robot in the camera coordinate system, has been proposed as a promising technology for multi-robot intelligent interaction. A large number of efforts have been made on studying robot pose perception. However, most of existing studies estimate the position of robot joints in 3D space by just using 2D color images, and perform pose perception by estimating the position of joint key points in the image, which could become infeasible in scenarios with various camera views and background environments. To address the issue, considering the information about the robot itself as a prior knowledge, we propose a novel approach for robot pose perception, named 3D-RPP. We adopt a 3D visual point cloud to estimate the rigid transformation of the camera coordinate system with respect to the robot base coordinate system, which effectively improves the accuracy of the obtained robot joint position in the camera coordinate system. We conduct extensive experiments on ROKAE xMate3 robot to investigate the performance of 3D-RPP, and the experimental results show that 3D-RPP could solve the pose perception problem well.
Techno-economic assessment of a hybrid solar PV/syngas/battery power system for off-grid application: Long Pahangai-Indonesia case study
Authors: Aditya I A , Simaremare A
Published: February 2022

This paper presents the design of the hybrid renewable energy system (HRES) composed of photovoltaic, batteries, biomass gasifiers, and diesel generators to determine the optimal configuration of the system located in Long Pahangai, Indonesia. Long pahangai is one of the remote villages in Indonesia that has not enjoyed 24-hour electricity. This paper presents optimal modeling of the Hybrid Optimization Model for Electric Renewable (HOMER) to find the most cost-effective configurations for electricity requirement of 1.219,1 kWh/day primary load. The results suggest that a PV-Diesel-Gasifier-Battery system is the best optimal design for Long Pahangai in terms of cost of energy (COE) and Total Net Present Cost (TNPC). The sensitivity analysis also identifies the influence of diesel price, biomass price, biomass gasification ratio, substitution ratio, and minimum fossil fraction.
Fuel spray and flame characteristic of biodiesel blend for CFB coal-fired steam power plant start-up process
Authors: Sitanggang Ruly Bayu , Hapsari Tiva Winahyu Dwi , Alif Hamdan Hartono , Cahyo Nur
Published: February 2022

This study aims to obtain the spray and flame characteristics of biodiesel blend fuel used in the ignition system of a Circulating Fluidized Bed (CFB) coal-fired steam power plant. Characterization of the chemical composition, physics of fuel, handling of biodiesel in handling system to the burner, and the characterization of combustion in the burner simulator are studied. The primary data in this study is the data from the combustion trial results in the burner simulator, while the secondary data is in the form of operation data and power plant design data. Biodiesel has properties close to diesel oil and allows use in blending to a specific ratio. The result shows that the spraying angle of biodiesel and blends are narrower than the B0 condition, and the distance of flame become shorter along with the increase in biodiesel content. These phenomena can cause the burner difficult to ignite, which can be overcome by adjusting the igniter position into the fuel spray distribution zone. Because biodiesel is easily oxidized, it is necessary to maintain the fuel lines kept clean, primarily when the system is not operating for a long time. Biodiesel has a higher viscosity and density than petroleum diesel which can cause problems with the injection start-up burner. The use of biodiesel fuel requires more stringent handling, adding filters, isolating fuel oil tanks from rainwater and humid air, and replacing materials that are not compatible with biodiesel in pipe fittings and gasket.
Analysis of control rod effect on the safety operation parameter of the RSG-GAS Core
Authors: Kuntoro Iman , Pinem Surian , Surbakti Tukiran
Published: February 2022

The operation cycle of the RSG-GAS reactor is regulated by control rod positions from the lowest to uppest positions. It is of necessary to know the effect of this control rods positions to the safety operation parameter a long the cycle. The objective of this research is to confince that the changes of safety operation parameter still meet the its safety limits. The neutronics and thermalhydraulics parameter to be observed are power peaking factor, kinetic and steady state parameters. Calculations are conducted by a combination code of WIMSD/5 and MTRDYN. The main results of maximum axial power peaking factor is 1.84 at control rod position of 20 cm. The maximum temperature of cooling, cladding and fuel are consecutively 67.18 °C, 122.26 °C, and 123.24 °C. These results lay far under safety limits of maximum temperature of coolant and fuel of 100 °C dan 200 °C at steady state operation of the RSG-GAS reactor which means that the reactor operation is safe as long as the cicle operation.
Synthesis and characterization of gadolinium nanoparticles using polyol method as a candidate for MRI Contrast Agent
Authors: Setiawan H , Triyatna F , Nurmanjaya A , Subechi M , Sarwono D A , Billah A A , Rindiyantono F
Published: February 2022

This research is related to the preparation and initial characterization of gadolinium nanoparticles as a Magnetic Resonance Imaging (MRI) contrast agent. Nanomaterial-based contrast agents aim to improve clearer imaging, longer examination retention times with lower toxicity than gadolinium ion-based contrast agents, and evaluate the potential use of MRI contrast agents for early detection of cancer. Gadolinium nanoparticles were synthesized using polyol method with stabilizer and chemical reaction process at high temperature. The stabilizers used are diethylene glycol (DEG) and triethylene glycol (TEG). The reaction process was carried out at 180°C for 4 hours to obtain gadolinium nanoparticles with uniform size and shape. The results of hydrodynamic and visual measurements using DLS and HRTEM instruments on the gadolinium nanoparticles produced were 50 nm and 18 nm, respectively. The results of the characterization of the crystal structure obtained the X-ray diffraction pattern in the crystal plane (222), which is a typical for the Gd2O3 crystal phase. Characterization of chemical bonds using FTIR showed absorption at 1438-1627 cm−1, 1000-1138 cm−1 and 450-795 cm−1 indicated the presence of Gd-O bond vibrations, while absorption at 1310-1466 cm−1 indicated the presence of Gd-O-Gd bonds. This is evidenced by the similarity with the absorption peak of commercial Gd2O3. The content of free Gd3+ ions found in the synthesized products detected was only about 0.99% of the Gd3+ precursors used.
Salt Farmer measurement performance system facing Covid-19 pandemic used interval type-2 FAHP Method
Authors: Kustiyahningsih Y , Rahmanita E , Purbandini  , Kholifah N
Published: February 2022

Indonesia is an archipelagic country with a coastline of about 81,000 km and has a variety of very large biological and non-biological resources. Position as an archipelagic country with a very wide sea causes each region to have the potential to produce salt. The Covid-19 pandemic has resulted in various negative impacts on several fields such as the economy, social, SMEs and community services. Covid-19 has also resulted in a decrease in salt production and farmers also have difficulty marketing it. The research problem is the large number of salt farmers and number of indicators in providing assistance so that a model for measuring performance of salt farmers is needed. This performance measurement model is guided by several indicators, namely land area (K1), production result (K2), business capital (K3), and marketing system (K4). The method used Interval type-2 Fuzzy Analytic Hierarchy Process (IVFAHP). IVFAHP is used to determine indicators that most influence measurement of salt farmers. This study aims to build a model for measuring performance of salt farmers to increase economic productivity and ability of human resources to deal with COVID-19 pandemic. The contribution is a group-based decision by developing the fuzzy interval type-2 method with triangular fuzzy number (TFN) one midpoints. The findings from study are that the most influential indicators in dealing with COVID-19 pandemic are business capital and salt marketing. This research also produces recommendations for improvement salt farmers in an effort to increase salt production.
Hybrid FAHP and TOPSIS to determine recommendation for improving SMEs facing Covid-19 pandemic
Authors: Kustiyahningsih Y , Rahmanita E , Anamisa D. R.
Published: February 2022

The Covid-19 pandemic has had an impact on domestic economy, such as a decrease in people’s consumption and purchasing power, a decline in company performance, as well as SMEs. This situation, SMEs sector controls 99.99% of all existing businesses, employs 97.16% of private sector workforce, and contributes 57.5% to Indonesia’s gross product. Various government program efforts in helping Batik SMEs players face Covid-19 pandemic so that they are right on target. The large number of SMEs in Bangkalan is around 166,768, causing department to find it difficult to determine recommendations for improvement for each MSME. Based on these problems, a cooperative model for the SMEs industry is needed so that official work program runs smoothly on target. The method used is FAHP and TOPSIS integration method, FAHP method is used to determine weighting and TOPSIS method is used for ranking and recommendations for improvement. The advantage of FAHP is consistency index to control error rate of decision. TOPSIS method is capable of making multi-criteria decisions based on alternative SMEs industry mapping process. The purpose is make a recommendation model for improvement using hybrid method of FAHP and TOPSIS with balanced scorecard indicators for learning and growth perspective. The research contribution is to make decisions based on group recommendations and consistency ratio (CR) is less than 0.1. The findings research, that the influential indicators are batik business ownership and variations of batik motifs. The recommendations for improvement, the average MSME still does not have branding.
Scaled-up production of 131I radioisotope using dry distilation method for radiopharmaceutical application
Authors: Chaidir P. , Daya A.S. , Indra S. , Fany T. , Ahid N. , Fernanto R. , Herlan S. , Anung P.
Published: February 2022

The development of nuclear medicine is increasing every year, including the need for diagnostic or therapeutic radioisotope sources. Iodine-131 (131I) radioisotope is used for diagnostic and therapeutic purposes in patients with thyroid cancer or neuroblastoma. Research and Technology Center for Radioisotope and Radiopharmaceutical - National Research and Innovation Agency (RTCRR-NRIA) has been able to produce 131I radioisotope with radioactivity up to 18.5 – 29.6 Gbq/month. This study aims to scale-up the production capacity of 131I radioisotope by using dry distillation method and to determine the radionuclide and radiochemical purity of the 131I radioisotope. The scaled-up production of 131I radioisotope was carried out in a hot cell facility of Radioisotope and Radiopharmaceutical Laboratory (RRL). 50 grams of TeO2 was used as target material. The TeO2 was irradiated at the Central Irradiation Position (CIP) facility at G.A Siwabessy multipurpose reactor. The post-irradiation target was heated up to 800° C for ± 5 hours under a vacuum condition in the distillation system of -2 incHg to -3 incHg. In this study, the 131I radioisotope was produced with radioactivity of 192 – 344 Gbq/month, radionuclide purity of 99%, and radiochemical purity of 95%. The scaled-up production 131I radioisotope has been successfully carried out with an increase of more than 12 times the initial capacity. In the future, the production of 131I radioisotope will be used for domestic needs in the oral dosage form.
Influence of heating and cooling rates on thermodynamic properties of aluminum thin film from 300 to 1100 K
Authors: Fahdiran Riser , Sugihartono Iwan , Delina Mutia , Prayitno Teguh Budi , Sunaryo  , Budi Esmar
Published: February 2022

Temperature and pressure evolution due to heating and cooling in the range of 300 to 1100 K of Aluminum thin film with thickness 10 nm were investigated based on Molecular Dynamics (MD) simulation. Pressure evolution shows that heating and cooling rates with comparison of 3:2:1 provides significant contribution on melting and recrystallization of the system. The oscillation of the pressure is the strongest at the highest heating rate which indicate that the system collapses stronger than the lower rate. It is responsible for the destruction of the structure correlated to the elevation of the temperature. While for recrystallization, the analysis on pressure oscillations confirmed the influence of the rates. Analysis based on local crystal structure indicated that at T = 1100 K, all the systems are melted.
Thermodynamic and structure properties of aluminum nanoparticle due to heat treatment: a molecular dynamics study
Authors: Susila Anggara Budi , Handoko Erfan , Budi Agus Setyo , Nasbey Hadi
Published: February 2022

Thermodynamic and structure evolution of Aluminum nanoparticle with diameter of 10 nm are investigated due to heat treatment by means of stepping heat and compared it to sudden heat. Molecular Dynamics (MD) simulation is employed to track the trajectories of each atom and its surrounding to define thermodynamic properties, e.g., temperature and pressure. The temperature evolution gives clear different profile for both cases, while pressure profile strongly evident different mechanism of melting. From thermodynamics point of view, the nanoparticle suffered different final state for both heating methods. Structure analysis later confirmed that for stepping heat the nanoparticle is melted while for sudden heat it is only partially melted.
Mitigation of soil resistivity using composition of zeolite, NaCl, and charcoal
Authors: Hardi Surya , Kristian Alberto , Hasibuan Arnawan , Nasution Azwar , Alfhisyari Milli
Published: February 2022

The grounding resistance value is directly proportional to soil resistivity. The resistance value is better as low as possible for the equipment body grounding. The purpose is to provide a path of the short circuit current flows to the ground as protection and safety personal and also the equipment. The soil resistivity great is influenced by moisture and substance content in the soil. The highland soil and rocky soil commonly are poor the soil resistivity. Transmission line towers can be not avoided through the highland region. To reduce the soil resistivity value can widely be carried out by addition low material resistance (LMR) or LMR composite other materials. This research, to mitigate the value of the soil resistivity can be carried out by addition low material resistance (LMR) Zeolite composite with NaCl, Charcoal, and Soil. Various compositions of the LMR, NaCl, and Charcoal were used to find the lowest grounding resistance at certain depth. The three-point method was used to measure the grounding resistance value. The research result gives information that best composition is 90% Zeolite, 5% NaCL and 5% charcoal for the rod depth of 1.2m, the resistance decrease from 94.3Ω down to 5.3Ω (94.4%). The LMR Zeolite is dominant influence to reduce the grounding resistance.
Antibacterial textiles which impregnated silver nanoparticles prepared via green synthesis by Fusarium oxysporum BNT-02
Authors: Rohaeti Eli , Nanda Annisa Amalia Sultan , Yunita Isti , Suwardi
Published: February 2022

Silver nanoparticles can be prepared by using a microorganism. The objectives of the study were to determine the ability of Fusarium oxysporum BNT-02 in reducing silver nitrate solution to silver nanoparticles, to evaluate the effect of variations in treatment of textile materials toward antibacterial activity of textile materials impregnated with silver nanoparticles on Staphylococcus aureus ATCC 25924 and Escherichia coli ATCC 35218. In this study, silver nanoparticle were obtained by reducing the AgNO3 solution by F.oxysporum BNT-02. Coating of silver nanoparticles on textile materials was carried out by inserting sterile textile material into silver nanoparticle and shaking then drying. The textile material modified with silver nanoparticles was characterized for antibacterial activity against S.aureus ATCC 25924 and E.coli ATCC 35218. The inhibition zone to determine antibacterial activity was observed every 6 hours for 48 hours of incubation time. The inhibition zone data was analyzed using ANCOVA and t-test. The results showed that F.oxysporum BNT-02 can be used as a reducing agent for producing silver nanoparticles. The textile material coated with silver nanoparticles had antibacterial properties against S. aureus ATCC 25924 and E. coli ATCC 35218. Antibacterial activity of textile materials coated with silver nanoparticles on S.aureus ATCC 25924 showed a larger inhibition zone than E.coli ATCC 35218.
Mitigation of voltage sags in distribution line system using static VAR compensator and static synchronous compensator
Authors: Hardi Surya , Marpaung V. , Hariadi I. Nisja , Rohana  , Nisja I.
Published: February 2022

Voltage sag is one of the power quality disturbances most frequently by customers because it can cause economic loss for the customers especially industries and commercial customers. The main source of voltage sags are faults in transmission and distribution beside two others namely motor large starting and transformer energizing, both the voltage sags have less effect on the equipment. Voltage sags can cause degradation performance of the equipment, and it depends on the magnitude and the duration. The voltage sags that occur in the power system can be compensated with installed Static VAR compensator (SVC) and Static synchronous compensator (STATCOM) in the distribution system bus. The purpose of the study is to compare both types of the device used to mitigate voltage sags in simulation using Alternative transient program (ATP) software. The voltage sag results from the short circuit faults. The method proposes the installation of the two compensator devices alternatively at one of the IEEE thirteen busses systems. The result shows the STATCOM is better than the SVC to handle mitigation of voltage sags compared with the SVC.
Synthesis of silica particles through conventional sol-gel and sonochemistry methods and the effect of catalyst, water concentration and sample environment to the particle size
Authors: Kamila R , Ridwan  , Akhir M P M , Patriati A , Insani A
Published: February 2022

Various methods have been carried out in an effort to obtain SiO2(Silica) particles with relatively the same grain size distribution and a uniform shape. This fine Silica particle size will be useful in the formation of SiC in the next stage. In this works, Silica particles has been synthesized through two different methods: conventional sol-gel and sonochemistry (using ultrasonic probe). Silica was synthesized by mixing TEOS, ethanol, ammonia, and D.I water with the molar ratio of 1 : 75.9 : x : y respectively. In sol-gel method, x was varied with 2.85, 5.7, and 8.54 M while y was fixed at 61.6 M. In sonochemistry method, y was varied with 6.69, 12.3, and 75.9M while x was fixed at 2.85 M Additional variation of sample environment including with and without ice has also been done in sonochemistry method. Amorphous phase was found in all samples from the XRD profiles. FT-IR results showed that the IR spectral peaks of all samples match the FT-IR spectrum of SiO2with symmetric and asymmetric stretching mode of Si-O functional groups at 802 – 810 cm−1and 1093 – 1103 cm−1wavenumber. SEM images indicated that the average of SiO2particle size tends to increase with the higher amount of ammonia concentration used and lesser concentration of water used results in smaller particle size. The influence of sample environment in sonochemistry method showed an interesting phenomenon where a lot of small particles sticked with bigger particles.
Evaluation and development of wireless monitoring systems for an autonomous sailboat
Authors: Setiawan J D , Ihsan M S , Saputro R , Munadi M , Paryanto P , Alimi S
Published: February 2022

In this study, the performance of the Long-Range (LoRa) communication and 3DR Radio Telemetry modules was evaluated. The suitability of these two communication options was assessed for the application on an autonomous sailboat prototype. The communication range and power consumption of each module are the primary factors for selection. The test results found that LoRa technology can send data stably with a range of up to 10.5 km, while the 3DR Radio Telemetry module can only send data stably up to 300 m. The LoRa technology consumes 9.56 Wh of electrical energy per day for the autonomous sailboat application, while the 3DR Radio Telemetry consumes 11.07 Wh of electrical energy per day. It was decided that LoRA technology would be implemented on the autonomous sailboat.
Mechanical properties of polyethylene matrix composites with areca fruit peel powder filler (Areca catechu) and sugar cane fiber (Saccharum officinarum L)
Authors: Nurfajriani  , Herlinawati H. , Yusuf M. , Siregar M.I. , Yunus M. , Derlina
Published: February 2022

Utilization of betel nut peel waste and sugarcane fiber has not been maximized so that the purpose of this study was to determine the characteristics of the mechanical properties, tensile strength and bending strength of the polyethylene matrix composite with betel nut peel powder and sugarcane fiber filler. In this study, the variation of the ratio of the volume of fiber used is: (0%: 10%), (10%: 0%), (5%: 5%). The fibers used previously were modified with 2% NaOH treatment for each fiber. The results for the tensile test were the variation of 10% sugarcane fiber was 34.876 MPa, 10% variation of areca nut husk powder was 28.109 MPa, 5% variation of areca nut peel powder and 5% sugarcane fiber was 12.104 MPa.
Pineapple leaf fiber (PALF) waste as an alternative fiber in making concrete
Authors: Karolina Rahmi , Tandika William , Hasibuan Azhari , Agung Putra M. , Fahreza Devi
Published: February 2022

Indonesia is the 9th largest pineapple producer in the world with a production of 1.39 million tons per year. this makes the pineapple leaf fiber (PALF) waste available abundantly in Indonesia. Palf waste has not been widely used in Indonesia. palf is usually used as fabric for textiles or yarn to be used as clothes and as handicrafts. palf has excellent mechanical properties and is environmentally friendly. in this study palf is used as a material for construction. Adding fiber to the concrete mixture is one way to minimize cracks in the concrete. This study aims to increase the compressive strength, tensile strength of concrete and utilize palf potential as construction material. This study compares the compressive strength and tensile strength of normal concrete against compressive strength and tensile strength of concrete with the addition of pineapple fiber with variations of 0%, 0.5 %, 1%, 1.5% to the weight of cement. The specimen used was a cylinder with a diameter of 15cm and a height of 30cm. The test is carried out on specimens with the age of 28 days. Experimental results show that inclusion of Palf improves the split tensile strength and compressive strenghth of concrete.
Synthesis and optical properties of Sb-doped ZnO thin film by sol-gel spin coating method
Authors: Siregar Nurdin , Sirait Makmur , Motlan
Published: February 2022

Sb-doped ZnO thin films had been successfully synthesized by the sol-gel spin coating method. The results of XRD analysis of ZnO and Sb-ZnO thin films showed a hexagonal wurtize crystal structure with crystal sizes of 21,251 nm and 11.265 nm, respectively. The results of SEM analysis showed that the grain size distribution of the crystallites was round and uniform, compactly covering the substrate and almost no porosity. The percentage of Sb concentration based on EDS analysis was 3.02%. UV-Vis analysis results showed the absorbance and transmittance values of Sb-ZnO thin films were higher than the transmittance values of ZnO thin films. The energy band gaps for ZnO and ZnO:Sb thin films were 3.20 eV and 3.30 eV, respectively.
The development of android-based mathematics learning application
Authors: Sinambela Pardomuan Nauli Josip Mario , Simanjorang Mangaratua Marianus , Manurung Nurliani , Simanullang Michael Christian
Published: February 2022

The purpose of this research was to produce an android based mathematics learning application. This research was motivated by the Indonesian government’s policy during the covid-19 pandemic. The government asked people to do all their activity from home. The government’s policy changed all the system including the learning activity system. Based on that, it was necessary to develop a learning application, which would enable students to learn from home. In this research, the learning application that would be developed was an Android based mathematics learning application. The research method used for this purpose was the development research developed by Dick and Carey. The quality standard used for the Product developed in this research were validity, practical, and effective, which was checked based on expert validation and trial results.
Development of science experiment media kits for elementary school students
Authors: Koswojo Jane , Wirjawan Johannes V.D. , Herwinarso
Published: February 2022

The essence of the current science curriculum (aka curriculum 2013) nationally applied in all elementary schools is scientific approach to improve the students’ skills and knowledge. Based on our need analysis we found that Mechanical experiment series are highly needed. The main goal of this study is to produce media kit for science experiment activities for elementary school students. The media kit consists of experimental tools kit and their experimental guide modules. We applied the 4-D model to achieve the goal. This study is on-going process; this article reports the progress status of the study.
Solar photovoltaic application for electric vehicle battery charging
Authors: Sinuraya Arwadi , Sinaga Denny Haryanto , Simamora Yoakim , Wahyudi Ridho
Published: February 2022

Increasing fuel consumption and limited fossil fuel reserves make us need energy sources that come from Renewable Energy Sources (RES). Solar Energy Resources (Photovoltaic systems) are very strategic to be used in supplying energy to Electric Vehicles (EVs) which generally use BLDC electric motors as wheel propulsion. Photovoltaic cells are components in solar panels that convert solar energy into electricity. The solar panels mounted on the roof of the vehicle work best during the daytime. When at night, electric vehicles will work using electrical energy that has been stored in the battery. This study aims to design a battery charging system using photovoltaic technology which is used to supply power to drive BLDC electric motor in electric vehicles.
Phytochemical screening and secondary metabolites toxicity test from toba frankincense leaf (STYRAX paralleoncomud PERK)
Authors: Sitorus Marham , Silaban Ramlan , Susanti Nora , Manurung Ruth Natalia
Published: February 2022

The secondary metabolites of Toba frankincense leaf (STYRAX paralleoncomud PERK) have been isolated by maceration with n-Hexane, Ethyl acetate and Ethanol as solvents. The results of phytochemical screening of secondary metabolites in n-hexane extract were high amounts of flavonoids and steoids and low amounts of saponins and tannins, ethyl acetate extract were steroids and tannins in large amounts, moderate amounts of flavonoids and small amounts of saponins and extracts. ethanol, saponins and tannins in large quantities and small amounts of flavonoids. Alkaloids and terpenoids (essential oils) were not detected in the three extracts. It was concluded that the secondary metabolites in incense leaves were: flavonoids, saponins, steroids and tannins. Toxicity test of the three extracts was carried out using the Brine Shrimp Letality Test (BSLT) method with Arthemia salia Lech as a bioindicator with concentration variations: 10, 100, 500 and 1000 ppm. The test was carried out with three repetitions with 40 larvae of Arthemia salia Lech each. Toxicity test results obtained Inhibition Concentration ( IC50 ) of n-hexane extract was 1350.95 mg/L (non-toxic), ethyl acetate extract 18.98 mg/L (very toxic) and ethanol fraction 41.20 mg/L (moderate toxicity). Thus the secondary metabolites in the ethyl acetate extract are very potential as drug candidates, while the metabolites in the ethanol extract are quite potential.
Community constraints analysis in the use of solar power plants in Indonesia
Authors: Mendoza M D , Hutajulu O Y , Salman R
Published: February 2022

The Solar power plant is one of the alternative sources of electrical energy that is part of Indonesians national energy mix plan in Indonesia. The use of rooftop solar power plants became one of the programs proposed by the government to fulfill the plan. The problems found from this research are many that encourage factors to make prospective rooftop solar power plant users in Indonesia use this power generation. Because as we know, these systems are high costs and skill is needed to calculate the capacity. Data collection will be carried out by surveying the solar panel enthusiast community and potential solar power plant users then the data obtained will be processed using a path method to see what encourage factors that have a high effect on user decision to use rooftop solar power system for their household electrification. The data obtained from these results will be used as a reference to support the implementation of the government program to run smoothly. The result shows that competence and benevolence are two driving factors that have high effect on people decision to use solar panel systems. Therefore, the government can take advantage of these two factors to increase public enthusiasm for using solar power system to achieve the target.
The implementation of plyometrics circuit model to increase jump power
Authors: Marpaung Deni Rahman , Sari Rima Mediyana
Published: February 2022

The purpose of this study was to determine the difference in the effect of plyometrics circuit model based on the analysis of vertical jump movement on the increasing of jump power. This study used an experimental method consisting of two variables, namely the manipulative independent variable (exercise model) and the dependent variable (jump power). The research design was one group pre-test and post-test design. The sample used in this study was 10 students of the third semester of sports majoring in Health, Physical Education, and Recreation (HPER). The sample was taken by using purposive random sampling. Jump power data was measured by vertical jump test. The data analysis technique used Paired Samples Test. The prerequisite test used the sample normality test (Kolmogorov-Smirnov Test with α = 0.05) and the homogeneity of variance test (Levene Test with α = 0.05). Based on the results of the study, it showed that there was a significant difference between the pre-test and post-test of plyometrics circuit training model to increase jump power, Tscore = 12.31 > Ttable = 1.83 (p<0.05).
Characterization of sarulla natural zeolite activated with various acid concentration and loaded with Ni and Ni-Mo metals as bifunctional catalysts
Authors: Sihombing J L , Ginting E , Amdayani S , Pulungan A N , Tanjung V , Sandy A A , Rahayu R
Published: February 2022

Metal loading on zeolite to produce bifunctional catalysts is reported to increased the characteristics of zeolites which synergistically increase their catalytic activity. Sarulla natural zeolite (SNZ) from North Sumatera has the potential as a catalyst because of its excellent chemical properties including acidity, thermal stability, and large pores. On the other hand, natural zeolite contains a lot of impurities and lower acidity density so that it needs to be processed before use. In this research, modification of the acidity density of zeolite and metal loading were expected to improve the characteristics of SNZ as a catalyst. To achieved this goal, the research methods carried out include preparation, activation process with mineral acid with various concentrations of 3M, 5M, and 7M, then calcination with N2 gas flow. Ni and NiMo loading by wet impregnation method followed by oxidation and reduction with O2 and H2 gas flow, respectively. Some important properties of the catalyst were characterized by XRD, SEM, and determination of surface area by BET method. Ni/SNZ-7 catalyst showed the largest spesific surface area (92 m2/g), the least impurities (3%), and the most homogeneous surface morphology compared to other catalysts. The deposition of two metals in the zeolite generally causes an increase in the pore diameter and crystallinity degree, while decreasing in the pore volume of catalyst.