bluuebunny/crossref_metadata_2025 huggingface dataset:
Energy dissipation and enstrophy production/destruction at very low Reynolds numbers in the final stage of the transition period of decay in grid turbulence
Authors: Zheng Y. , Nagata K. , Watanabe T.
Published: March 2021

Decay characteristics of turbulent kinetic energy and enstrophy in grid turbulence have been investigated in the far downstream region (x/M∼103: x is the downstream distance from the grid, M is the mesh size of the grid) through wind tunnel experiments using hot-wire anemometry, with the lowest turbulent Reynolds number Reλ≈5. The non-dimensional dissipation rate Cε increases rapidly toward the final stage of the transition period of decay and the profile agrees well with previous direct numerical simulation [W. D. McComb et al., “Taylor's (1935) dissipation surrogate reinterpreted,” Phys. Fluids 22, 061704 (2010)] and theoretical estimation [D. Lohse, “Crossover from high to low Reynolds number turbulence,” Phys. Rev. Lett. 73, 3223 (1994)] at very low Reλ in decaying and stationary isotropic turbulence. The present result of Cε is an update on the experimental data in grid turbulence toward a very low Reλ, where measurements have been absent. The energy spectrum in the dissipation range at very low Reλ deviates from a universal form observed at high Reynolds numbers. The decay rate of enstrophy is proportional to S+2G/Reλ (S is the skewness of the longitudinal velocity derivative and G is the destruction coefficient). It is shown that G and S+2G/Reλ increase rapidly with decreasing Reλ at very low Reλ, indicating that the effect of enstrophy destruction is dominant in the final stage of the transition period of decay. The profiles of S+2G/Reλ against Reλ is well fitted by a power-law function even in the final stage of the transition period of decay.
Damped (linear) response theory within the resolution-of-identity coupled cluster singles and approximate doubles (RI-CC2) method
Authors: Fedotov Daniil A. , Coriani Sonia , Hättig Christof
Published: March 2021

An implementation of a complex solver for the solution of the linear equations required to compute the complex response functions of damped response theory is presented for the resolution-of-identity (RI) coupled cluster singles and approximate doubles (CC2) method. The implementation uses a partitioned formulation that avoids the storage of double excitation amplitudes to make it applicable to large molecules. The solver is the keystone element for the development of the damped coupled cluster response formalism for linear and nonlinear effects in resonant frequency regions at the RI-CC2 level of theory. Illustrative results are reported for the one-photon absorption cross section of C60, the electronic circular dichroism of n-helicenes (n = 5, 6, 7), and the C6 dispersion coefficients of a set of selected organic molecules and fullerenes.
Transmission and reduction of aerosols in classrooms using air purifier systems
Authors: Burgmann Sebastian , Janoske Uwe
Published: March 2021

SARS-CoV-2 (COVID-19) as an airborne respiratory disease led to a bunch of open questions: how teaching in classrooms is possible and how the risk of infection can be reduced, e.g., by the use of air purifier systems. In this study, the transmission of aerosols in a classroom is analyzed numerically and experimentally. The aerosol concentration in a classroom equipped with an air purifier system was measured with an aerosol spectrometer (optical particle sizer, TSI Incorporated) at different locations. The transient reduction of the aerosol concentration, which was artificially generated by an aerosol generator (di-ethyl hexyl sebacate-atomizer, detected particle size ranging from 0.3 to 10 μm), was monitored. The experimental results were used to validate a numerical simulation model of the classroom using the Open Source Computational Fluid Dynamics code OpenFOAM® (version 6). With the numerical simulation model, different scenarios with infected persons in the room have been analyzed, showing that the air purifier system leads to a significant reduction of airborne particles in the room dependent on the location of the infected person. The system can support additional ventilation strategies with fresh air, especially in cold seasons.
Assessment of Reynolds-averaged Navier–Stokes method for modeling the startup regime of a Darrieus rotor
Authors: Ramírez J. M. , Saravia Martín
Published: March 2021

In this article, the suitability of the Reynolds-averaged Navier–Stokes (RANS) to predict the dynamic response in the startup process of small-scale Darrieus vertical-axis wind turbines (VAWT) was investigated. Using OpenFOAM, numerical simulations have been run to evaluate the regions of the rotor revolution where the prediction of the aerodynamic coefficients is expected to give unreliable results. The qualitative aspects of the prediction of the self-starting of the VAWT for tip speed ratio (λ) ranging from 0 to 3 have been evaluated and to model a more realistic condition, resistive forces acting on the rotor have been implemented. These resistive forces, which are the mechanical friction and the magnetic forces of the generator, were implemented numerically through a viscous damping model and, therefore, a new OpenFOAM library was developed adopting the object-oriented programming methodology as well as the C++ language. From the results, it has been observed that for a λ equal to 0.4 (starting speed), the aerodynamic forces are overestimated for a portion of 82% of the full revolution of the rotor. For a λ equal to 2.70 (steady state), this portion is reduced to 52%. This means that the aerodynamic forces and also the power output are overestimated by a large percentage in a full revolution of the rotor. Therefore, such results allow us to conjecture that RANS modeling may not seem to be an adequate approach to accurately assess the aerodynamic response of VAWTs.
Zero absolute vorticity state in thermal equilibrium as a hydrodynamic analog of the quantum harmonic oscillator ground state
Authors: Heifetz E. , Maas L. R. M.
Published: March 2021

Here, we point out on an intriguing mapping between the quantum harmonic oscillator ground state and the zero absolute vorticity plane Couette flow of a Boltzmann-like density distributed ideal gas in thermal equilibrium. The mapping is obtained when the gas is embedded in a rotating frame whose rotation rate is equal to half of the frequency of the quantum harmonic oscillator.
The canid pest ejector challenge: controlling urban foxes while keeping domestic dogs safe
Authors: Gil-Fernández Margarita , Harcourt Robert , Towerton Alison , Newsome Thomas , Milner Hayley A. , Sriram Sanjana , Gray Natalie , Escobar-Lasso Sergio , González-Cardoso Victor Hugo , Carthey Alexandra
Published: March 2021

Abstract Context It is widely recognised that red foxes (Vulpes vulpes) are abundant within urban areas; however, it is difficult to apply lethal control measures using poison baits in cities because of concerns about the safety of domestic pets, particularly dogs (Canis familiaris). Aims We tested canid pest ejectors (CPEs) as a potential method of fox control by measuring visitation and activation behaviour of foxes and other wildlife while assessing non-target risk to domestic dogs. Methods We compared eight urban and eight peri-urban sites in Sydney, with half of the sites having restricted access for domestic dogs. We allocated five camera traps and ejectors per site. Through generalised linear mixed models, we compared the probability of ejector activation between foxes and dogs. We also assessed the relationship between dog visitation and distance to habitation and dog restrictions as measures of dog safety. Key results Both species of canids were equally likely to pull the ejector (P = 0.26). As expected, dog visitation was significantly lower in sites with dog restrictions (P < 0.001). However, it was not related to distance from habitation. Only two non-canid species were recorded pulling the ejector, suggesting high target-specificity for canids. Conclusions In sites with dog restrictions, the risk of dog casualties from CPEs is minimal. However, distance from habitation does not increase dog safety, at least within 250 m. The ejector is highly specific for canids. Implications We provide specific recommendations for the design of a potential fox control program using CPEs in urban and peri-urban areas. The ejector may be a safe method for fox control in cities when deployed at places without domestic dogs.
Ecological variation and institutionalized inequality in hunter-gatherer societies
Authors: Smith Eric Alden , Codding Brian F.
Published: March 2021

Significance

Persistent differences in wealth and power are pervasive in contemporary societies, yet were absent or muted for most of human history. To help explain how and why institutionalized hierarchy can arise in egalitarian systems, we examine a sample of Native American hunting and gathering societies that vary in the degree of inequality. Systematic evaluation of alternative hypotheses identifies the presence of defensible clumped resources that can be monopolized as a likely determinant of institutionalized hierarchy. When such resources are present, societies in our study exhibit substantial inequality, including slavery. Other possible predictors, such as population pressure and warfare, do not show this effect. These results suggest general factors likely facilitate the initial emergence of inequality in human societies.
miRNA-independent function of long noncoding pri-miRNA loci
Authors: He Daniel , Wu David , Muller Soren , Wang Lin , Saha Parna , Ahanger Sajad Hamid , Liu Siyuan John , Cui Miao , Hong Sung Jun , Jain Miten , Olson Hugh E. , Akeson Mark , Costello Joseph F. , Diaz Aaron , Lim Daniel A.
Published: March 2021

Significance

The human genome contains many thousands of genes that produce a large diversity of long noncoding RNAs (lncRNAs). Some lncRNA genes produce microRNAs (miRNAs), which are regulators of protein expression. It has been unclear whether lncRNA genes that produce miRNAs, termed lnc-pri-miRNAs, have important function independent of their miRNAs. We find multiple lnc-pri-miRNA genes that regulate cell proliferation even when miRNA production machinery is knocked down. lnc-pri-miRNA
LOC646329
produces miR-29a/b1, and the function of
LOC646329
in cell proliferation can be genetically and phenotypically separated from its cognate miRNAs. The miRNA-independent function of
LOC646329
and other lnc-pri-miRNAs relates to their activation of genes in physical proximity. These results shed light on the function and intermingled complexity of the noncoding genome.
A new liquid density measurement method based on elastic spring stretching
Authors: Kovačević Milan S , Milošević Marko M , Cimbaljević Željko M
Published: March 2021

A simple method is described for measuring liquid density based on stretching of the spring and equilibrium of weight and elastic force. The method involves placing a container with liquid under test on the spring causing a stretch of the spring that is directly proportional to the weight of the liquid. With this technique, the liquid density can be determined without measuring its mass and volume, and it should help students comprehend the concept of density more easily. The design of the measuring setup in this study is made using tools and materials that are simple and easy to obtain, such as spring, ruler, and small plastic or metallic container (tube). Two liquids used to test the measuring method were ethanol and glycerol. A test showed that the density of the test liquids at room temperature could be measured with the relative uncertainty of 3%, hence the reliability of the described method was confirmed.
Don't cross the streams: caustics from fuzzy dark matter
Authors: Dalal Neal , Bovy Jo , Hui Lam , Li Xinyu
Published: March 2021

We study how tidal streams from globular clusters may be
used to constrain the mass of ultra-light dark matter particles,
called `fuzzy' dark matter (FDM). A general feature of FDM models
is the presence of ubiquitous density fluctuations in bound,
virialized dark matter structures, on the scale of the de Broglie
wavelength, arising from wave interference in the evolving dark
matter distribution. These time-varying fluctuations can disturb
the motions of stars, leading to potentially observable signatures
in cold thin tidal streams in our own Galaxy. The study of this
effect has been hindered by the difficulty in simulating the FDM
wavefunction in Milky Way-sized systems. We present a simple method
to evolve realistic wavefunctions in nearly static potentials, that
should provide an accurate estimate of this granulation effect. We
quantify the impact of FDM perturbations on tidal streams, and show
that initially, while stream perturbations are small in amplitude,
their power spectra exhibit a sharp cutoff corresponding to the de
Broglie wavelength of the FDM potential fluctuations. Eventually,
when stream perturbations become nonlinear, fold caustics
generically arise that lead to density fluctuations with universal
behavior. This erases the signature of the de Broglie wavelength in
the stream density power spectrum, but we show that it will still be
possible to determine the FDM mass in this regime, by considering
the fluctuations in quantities like angular momenta or actions.
Self-tuning kinetic gravity braiding: cosmological dynamics, shift symmetry, and the tadpole
Authors: Bernardo Reginald Christian
Published: March 2021

We study the self-tuning subclass of kinetic gravity
braiding and obtain robust predictions on self-tuning and dynamics
in the tadpole-free shift symmetric sector of the theory. In
particular, we show inevitability of cosmic acceleration, prove the
dynamical stability of this late-time asymptotic state, and derive
ghost and gradient stability constraints on the self-tuning
vacuum. We discuss the results concretely in the context of
generalized cubic covariant Galileon theory and an exponential
kinetic gravity braiding.
Generation of super strong longitudinal electric field via vector superposition of linearly polarized laser beams
Authors: Zhang Jun , Wu Zhenhai , Long Jiao , Xiong Qian , Zheng Jiangang , Zhao Junpu , Zhang Xiongjun , Zheng Kuixing , Wei Xiaofeng
Published: March 2021

Radially polarized laser beams, which could generate longitudinal electric fields (LEF) in the far field after being focused have drawn increasing interest in wide fields. However, it is difficult to boost a radially polarized laser pulse to high peak power due to its spatially inhomogeneous polarization distribution. Here, we propose a vector superposition approach, firstly partition a linearly polarized beam into two parts in the near field, secondly modulate their polarization direction separately using the electro-optical effect and finally focus them using a high numerical aperture lens, thereby generating the LEF in the far field owing to vector superposition. This approach can amplify a laser pulse to the required peak power by using traditional schemes of the linearly polarized seed-pulse generation and multi-pass amplification, thereby efficiently scaling the LEF to the required magnitude. The simulation results support the theory in concluding that the approach would be a competent way to achieve super strong LEF in the far field of a laser beam.
GPR geophysical method as a remediation tool to determine zones of high penetration resistance of soil
Authors: Akinsunmade A , Tomecka-Suchoń S , Kiełbasa P , Juliszewski T , Pysz P , Karczewski J , Zagórda M
Published: March 2021

In this study, we demonstrated application of ground penetrating radar towards assessing zones of high penetration resistance (PR) within soil horizons with a view to characterize the subsurface media. Soil attributes changes both in time and space can be difficult to understand. This may be largely due to concealing nature of subsurface media and convectional methods of soil investigations that are usually restricted to observation at the surface and discrete points. Thus making interpolations, inferences and conclusions from such methods inadequate and less reliable. However, ground penetrating radar (GPR) – a geophysical method of investigation was used in this study in lieu of the traditional methods. Soil variability measured in its PR (strength) is related to its compactness-function of bulk density. GPR utilizes electromagnetic (EM) energy in the range of 10 MHz to 3GHz that propagates through the investigative materials. Analysis of the two-way travel time of EM wave gives information about the velocity of the travelling wave. Data were acquired on a loamy silty soil at a farmland in Krakow as a test site simulated with compaction by tractor passes to induce densification of the subsurface layers. Results of the test depicted distinguishing feature of the compacted zones which is reduction in (EM) waveform amplitude and rapid decay of the EM frequency spectra. The research outcome shows swift, cheap and less cumbersome method of soil investigation.
Incorrect problem analyzing in the Finite Element Method
Authors: Firych-Nowacka A , Smolka K
Published: March 2021

Nowadays, numerical methods are widely used in the field analysis of many electromagnetic devices, MEMS and more. Incorrect problem analysis using the Finite Element Method often leads to incorrect results and drawing wrong conclusions. Therefore, the role of the engineer who describes the model in the pre-processing stage cannot be forgotten. This paper presents an example of developing a computer model of a flat capacitor in FEMM program, using the 2-dimensional Finite Element Method. It has been shown, how simple can disturb the result after wrong input data implementing.
Soldered joints of Ag electrode to ultra-thin metallic Au layer on ceramic substrate
Authors: Lebioda M , Pawlak R , Rymaszewski J
Published: March 2021

Among various methods of microjoining applied to electronic equipment soldering technologies are of great importance. In the construction of sensors a technique of a reflow soldering, common for microelectronic devices assembly, is rather not applicable because of the unique design of the sensor. Connecting external leads to thin metal layer of contact pads is a particular challenge. Special requirements are placed on devices and joints operating at cryogenic temperatures. The joints operating in cryo-temperatures should be characterized by good and stable electrical conductivity, tightness and the required mechanical strength. In the paper the new method of soldering of Ag leads to thin Au layer on ceramic substrate is presented. A special feature of the new soldering method is the very short time (2-3 seconds) in which the solder (In) is in the liquid state. The manufactured joints are characterized by a very low resistance as well as a linear and continuous current-voltage characteristic in the temperature range of 15 to 300 K.
Assessment of the degree of secondary luminescence generated by industrial hemp seeds
Authors: Miernik A , Kiełbasa P , Korenko M , Zając M
Published: March 2021

The trial was undertaken to measure the amount of different types of seeds industrial hemp. Photonic analysis was used to make measurements which bases on counting the amount of emitted photons from standardized sample within estimated time interval. Photon emission tests were carried out in the Laboratory of Experimental Research Techniques of Raw Materials and Biological Products with PCA accreditation in the subject measurement procedure.
Modelling short-circuit current of a 21 MVA HTS superconducting transformer
Authors: Surdacki P , Jaroszyński L , Woźniak Ł
Published: March 2021

The paper presents a computer model of an HTS 21 MVA 70/10.5 kV two-winding superconducting transformer. The model takes into account the influence of temperature and current intensity on electrical and thermal properties of windings made of two types of second generation superconducting tape differing in the presence of copper stabilizer. Rhyner’s power law was used to describe the transition to the resistive state of the YBCO superconductor layer. A model of the non-linear magnetic core of the transformer was developed by using modified Jiles-Atherton equations. The proposed model allows numerical determination of current, resistance and winding temperature waveforms during an operating short circuit of a 21 MVA superconducting transformer.
Numerical Thermomechanical Viscous 2D Material Rheology Modelling Enhanced by Marker-in-Cell (MIC) Technique
Authors: Irwandi I. , Umar Muksin , Khaizal  , Sudarmaji
Published: March 2021

The rheology of a material especially related to mechanical behaviour is an important characteristic. Rheology has wide applications for example in nanomaterials, engineering design, biology, and in a large scale case in geodynamics study. Rheology relies on several physical equations such as continuity equation, momentum equation, gravity potential, state equation, heat transfer, and advection equation. The equations seem to be simple, however, the application of those equations to a real case is not easy and causes many numerical problems. Marker-in-Cell (MIC) is a technique to solve a numerical rheology modelling problem especially diffusion of sharp gradients during the advection process. The technique successfully simulates the advection process for thermomechanical viscous material for a 2-dimensional case study. The model was initially set up two parts with laterally contrast difference of material characteristics. The lateral density difference of material induced gravitational force and generated circular movement of material. After the simulation was run for the 20-time step, the whole material moved more clockwise circulation. The model started to be stable when all denser material at the lower layer and lower density material at the upper part. The model was fully stable and become at a stationary state at a time more than 100-time steps. The final simulation result showed that the MIC algorithm successfully simulated the conversion process involving the thermomechanical mechanism with diffusion error control and without breaking the contrast density of the material.
An analysis of 4c skill on heat in facing the industrial revolution era 4.0
Authors: Daulay Nora Hawari , Sani Ridwan Abdullah , Rahmatsyah
Published: March 2021

The purpose of writing this article is to find out how to build human character to face the industrial era 4.0, so that they have an understanding of digital literal dimensions and can increase the graduates’ competence who have 4Cs skills (critical thinking, creativity, collaboration, and communication) by using collaborative inquiry, especially on temperature and heat material. This type of research is a quasi experiment with a pretest-posttest control group design. The result of this research is that students 4Css skills using collaborative inquiry learning model are better than students4Cs skills using conventional learning at SMA Negeri 14 Medan. Then, it is hoped that they will be able to produce humans who are in accordance with the demands of the industrial era 4.0. With 4Cs skills, they can gain and increase cooperation in a group to solve certain problems, increase their tolerance for peer opinions, try to think critically and creatively to solve problems related to something.
Analysis of critical and creative thinking skills on the topic of static fluid physics with guided inquiry learning assisted by computer simulation
Authors: Ratna Salwa Dwi , Simanjuntak Mariati P. , Sahyar
Published: March 2021

This study aims to analyze student’s critical thinking skills and creative thinking skills on the topic of static fluid physics using guided inquiry learning assisted by computer simulations. This type of research is a quasi experiment with the design of three groups pretest-posttest. The sampling technique uses cluster random sampling. Analysis of research data using multivariate analysis of variance (Manova). The results showed that student’s critical thinking skills and creative thinking skills on the topic of static fluid physics using guided inquiry learning assisted by computer simulations were better than using guided inquiry learning without assisted by computer simulation or conventional learning.
Setting the natural gas selling price through pipeline network optimization and project feasibility study
Authors: Nurprihatin Filscha , Andry Johanes Fernandes , Tannady Hendy
Published: March 2021

Natural gas will play an important role in the energy revolution, but its construction is still costly. Natural gas transport pipeline network shoulders the task of gas supply, which plays a significant role in improving the overall socio-economic benefits for the region. Pipeline network optimization design is a complex problem, involving many variables. In this study, the location of the Distribution Center is considered and was obtained from the previous study. This study also considers the distance between locations of households. The Minimum Spanning Tree (MST) is applied to obtain the pipeline network length. Then, the calculation is proceeded through the Benefit-cost Ratio in determining whether this project is feasible or not. Although the MST result shows the pipeline is longer than the previous work, studies have shown that the project is still feasible to run. The study also explains that the government can still sell gas at a lower price in the break-even condition.
Contribution of observing indicators to temperature and heat experiments in improving science process skills
Authors: Purba Nita Ariany , Derlina  , Siregar Alkhafi Maas
Published: March 2021

This study aims to determine whether there are significant differences in the science process skills of students who are taught using the 5E learning cycle model with students who are taught using conventional learning and what indicators play a role in increasing students’ science process skills. This research is a quasi-experimental study with two group pretest-posttest designs. The population of this study was students of class XI of SMA Negeri 4 Pematang Siantar consisting of 8 classes. The sample in this study was taken by cluster random sampling technique, namely as many as two classes, where class XI MIPA 7 as an experimental class taught with learning cycle model 5E and class XI MIPA 8 as a control class taught with conventional learning. The instrument used was a non-test instrument for science process skills in the form of student worksheets. Data will be analyzed using the SPSS program. The results of the study concluded that there were significant differences in the science process skills of students who were taught using the 5E learning cycle model with students who were taught using conventional learning and observing indicators had a significant contribution in improving students’ science process skills.
Phythochemical and Toxicity of Ethanol extract Sijukkot Leaves (Lactuca IndicaL)
Authors: Riris Ida Duma , Silalahi Albinus , Juwitaningsih Tita , Damanik Marini , Susanti Nora
Published: March 2021

Phytochemical screening on Sijukkot which determined as Lactuca indica L, the plants from an area in the village of Parsaora Sibisa Ajibata, Toba Samosir, North Sumatera has been done. Test was carried out to determine the composition of secondary metabolites contained in these plants. It was started by extracting plant leaves using 96% ethanol. Phytochemical test was used to identify compounds from the ethanol extract of sijukkot leaves. The identification results obtained compounds as Flavonoids, tannins, saponins, steroids and triterpenoids. Furthermore, the toxicity test was carried out using the BSLT method and the results showed LC50: 11.644 ppm, thus the ethanol extract of the leaves had a strong toxicity.
Household electricity consumption in rural area: An occupant’s behavior analysis to increase energy saving
Authors: Akil Yusri Syam , Wardi  , Muslimin Zaenab , Taufik Imran
Published: March 2021

This research investigates electricity consumption and typical occupants’ behaviors for rural households in Indonesia. A questionnaire is composed to get important information from respondents through direct survey located in several rural areas in Bone, South Sulawesi province as a case study. The information included such as owned household appliances, occupants’ behaviors regarding appliances usage, factors barriers in buying energy saving appliances (ESA), and general barriers in electricity saving. To get more information, regression analysis is also applied to identify relationship between perception and consumption habits. Results of this study show lamp, washing machine, and television are low watt appliances which majority owned by users with installed electricity at home is between 450 VA to 1,300 VA. A main barrier to have ESA is price, and lack information to support practising electricity saving. Next from regression results, perception variable is found affected usage behavior and also daily habit of occupants. Output of this study gives more insight in understanding characteristics of electricity consumption for rural households. They can be used as a basis in making effective energy saving program to dealing with issue related to growth load in power systems.
Analysis of land use changes for green open space (gos) in tebingtinggi city
Authors: Lubis Darwin Parlaungan , Nurwihastuti Dwi Wahyuni , Sintong Mahara
Published: March 2021

This study aimed to 1) Analyze land use change that has occurred in each sub-district in Tebing Tinggi City for 6 years (2014 - 2020), 2) Analyze the factors influencing the dynamics of changes in the use of green open space into a built-up area in the Tebing Tinggi City. The method used in this research was a survey method. The research design was performed in 3stages; (1) Literature study, (2) Data collection, (3) Discussing the processed data. The results showed that 1)Tebing Tinggi City had experienced very dynamic land use change. The biggest land use change was the built-up area, including a residential area, which increased by 370.95 hectares, the industrial area increased by 14.8 hectares, and the service area increased by 7.5 hectares. Meanwhile, vegetated land, such as rice fields decreased to 137,7 Ha. The mixed plantation land area decreased to 255.54 Ha. 2) The factors influencing land use change indicate that residential land has a significant effect on changes in GOS with a p-level value of less than 0.05 and is positive. It shows that each addition of residential land in a sub-district reduced the area GOS change to the built-up area of 0.016 Ha.
The influence of gasoline fuel additive on the motorcycle PM0.1 emission factor
Authors: Wardoyo A Y P , Majid I , Budianto A , Adi E T P
Published: March 2021

Fuel additive has been known to improve vehicle performance by raising the octane number or cleaning the combustion system. The performance enhancement might affect vehicle emission. In this research, we aim to investigate the impact of fuel additives on the PM0.1 emission. The commercial additives were evaluated based on the factory’s recommended concentration for the mixture fuel. The additive effect on the PM0.1 emission was investigated by measuring the PM0.1 concentration emitted by the motor engine operated using fuel with and without additives. The PM0.1 concentrations were measured using a TSI P-TrakTM Ultrafine Particle Counter Model 8525. The exhaust emission was injected into the chamber for 100 seconds for the PM0,1 concentration measurement. The emission factor was calculated by the total PM0.1concentration per the volume of the burned fuels. The result shows that fuel additives reduce the PM0.1 emission factor depending on the type of the additive. additives reduce the PM0.1 emission factor depending on the type of the additive.
NodeMCU-Based Automatic Motorcycle Tire Pump Monitored by Android Smartphone
Authors: Rahayu Siti Utari , Mulia Rajagukguk Tri Marta
Published: March 2021

This study aimed to design a motorcycle tire pump that uses an Android smartphone as a display of the pressure read during the pumping process, besides LCD. The motorcycle tire pump in this study is based on the NodeMCU so that the read data can be connected directly to the Android smartphone via WIFI (ESP 8266), which is already available on the microcontroller. The pressure sensor used is the MPX5700AP; the data read from the device during the pumping process can be monitored by using Blynk app that is available on the Google Play Store. The output accuracy of this sensor can be directly compared or verified with a standard pump pressure gauge, which is connected to the pump. Based on the test results, once the device is connected to the power source via adaptor, the pump works and the device provides data readings, which are displayed on the Blynk app. The defined threshold pressure is 28 psi, so the relay will switch off the pump automatically if the pressure is equal to or more than 28 psi. After testing the device for four times, the average accuracy was 0.75 %. This result indicates that the device can work quite accurately and can be used to pump the motorcycle with the appropriate pressure.
Prototype development of National Cattle Identification and Database System based on information technology
Authors: Purnama Diki Gita , Seminar KudangBoro , Nuraini Henny , Hariyadi Purwiyatno
Published: March 2021

The population of cattle in Indonesia reaches 17 million in 2018, but until now Indonesia does not yet have an integrated identification and recording system for cattle between farmers and / or farmer groups and the government, in this case the Livestock Service Office. The objective of this research is to build a prototype of national cattle identification and database system based on information technology. The prototype development system uses a prototyping method, preceded by surveys and interviews with farmers in several locations, namely Kupang Regency, Kupang Municipality, Tuban, Bogor and Bojonegoro. The result of this research is a prototype of a national cattle identification and database system that can be accessed using computers and smartphones by actors in the livestock industry. Cattle will obtain an identity in the form of a code written into the RFID tag issued by the district or municipal Animal Husbandry Service and recorded in a database. The identity is unique, that no cattle will have the same identity and it is valid for life. Farmers, farmer groups and companies engaged in livestock farming will also be recorded in the database so that it will facilitate national cattle management. The resulting prototype will be a model of a livestock database system in Indonesia.
Synthesis and characterization of polymer concrete withpumice aggregate and singkut leaf fiber as filler
Authors: Susilawati  , Husna Asma Ul , Ferdiansyah Bonar
Published: March 2021

Polymer concretehave been made based sand, pumice, epoxy resin, and singkut leaf fiber as fillers. The manufacture of polymer concrete uses block-shaped molds with a size of 100 mm x 20 mm x 10 mm with the press molding method using a hotpress. Variations in the composition polymer concrete of sand, pumice stone, singkut leaf fiber, and epoxy resin, namely 60:20:0:20 g, 60:18:2:20 g, 60:16:4:20 g, 60:14:6:20 g, 60:12:8:20 g, and 60:10:10:20 g. The variation in the composition was made into 2 groups of variations based on the concentration of NaOH used to singkut the leaves, namely the leaves with immersion of 5% NaOH and 13% NaOH. The polymer concrete then characterizes its physical properties (density and water absorption), mechanical properties (flexural strength, compressive strength, tensile strength), and SEM-EDX. The results of characterization carried out on concrete samples, show that the best composition is (60:18:2:20) g (5% NaOH content) with a density value of 1.74 g/cm3, water absorption of 0.34%, flexural strength. amounted to 37.07 MPa, compressive strength of 60.18 MPa, tensile strength of 8.33 MPa. The results of microstructure testing showed that the polymer concrete samples with a mixture of sand, pumice, epoxy resin, and singkut leaf fiber were mostly dominated by the element C (carbon).
3 Dimensional Visualization for Adaptive Building Construction Masterplan in University of Darussalam Gontor Area
Authors: Pradhana Faisal Reza , Taufiqurrahman  , Aziz Basyaruddin Inqi Azhar
Published: March 2021

University of Darussalam Gontor (UNIDA Gontor) is one of the universities that has been developing quite significantly in Ponorogo area since 2014, especially in terms of facilities and infrastructure. Until now, UNIDA Gontor has a development master plan in physical form in the form of paper. However, there are several drawbacks to the physical prototype. First, physical documents are vulnerable to damage and loss. Second, with the condition of the campus that continues to develop, it is difficult to update the prototype in physical form. Third, physical documents cannot provide a visual representation of the buildings that have been and will be built. To overcome some of these weaknesses, it is necessary to have a solution with technology that is adaptive to needs. The purpose of this research is the design of 3-dimensional modeling of buildings in UNIDA Gontor area that can be accessed easily and dynamically. The project design is based on the steps of the waterfall model with the following stages: (1) Requirements, (2) Design (3) Implementation, (4) Verification, and (5) Maintenance. Testing is done by testing a 3-dimensional display with a 3D image viewer which shows a success rate of 90% working as expected. The test is also carried out by measuring the level of color suitability, layout and comparison of the size of the 3D media with the actual building size, implemented through distributing questionnaires to relevant parties at the university and the public gets 88% according to their wishes. The resulting media is a adaptive building asset based on 3D modeling that can be accessed easily anytime and anywhere. With various existing features, it is hoped that the resulting media can facilitate access for the community and the development activities carried out at UNIDA Gontor. The long-term benefits of this research are taken into account in the framework of the university’s development plan and its infrastructure.
Use of Adobe Premiere Pro Software to Make Virtual Choir Video on Solfeggio Choir State University of Medan
Authors: Sihombing Lamhot Basani , Napitupulu Efendi , Hamid Abdul
Published: March 2021

This study aims to create a virtual video choir using Adobe Premier pro software media. The use of Adobe Premier Pro software is very important, because it is useful as a video processing software for solfeggio choirs. The method used is Action Research. The methods used to collect data were interviews, observations, and questionnaires distributed to 30 respondents consisting of 3 computer / multimedia experts, 3 design experts and 24 potential users / consumers. The results showed that the use of Adobe Premiere Pro software in the Solfeggio Choir choir in the aspect of content feasibility was categorized as good, the feasibility aspect of the category display was very good, the category presentation aspect was very good, the graphic aspect was good.
The Effects of the Concentration of Red and Yellow Gambier Fruit Dyes on the Short-Circuit Photocurrent in Dye-Sensitised Solar Cells
Authors: Nasyori A , Noor F A
Published: March 2021

Natural dyes still have low efficiency, although there are good opportunities to apply them in dye-sensitised solar cells (DSSCs). In this research, the working-electrode was prepared from indium tin oxide (ITO) and titanium oxide (TiO2), using the doctor blade method for doping TiO2 on ITO glass. Then, the working-electrode was soaked in gambier extract for 24 hours. The counter-electrode and electrolyte were made from burning a candle and mixing KI + I2, respectively. UV-vis and FTIR spectra have been made to investigate the effect of the concentration of red and yellow gambier prepared by maceration and evaporation from methanol. They were used to analyse absorbances and compounds in gambier, respectively. From UV-vis and FTIR spectra results, we obtained that the organic dyes from the red and yellow gambier fruits could have a high potential to be used as a sensitiser to absorb photons in DSSCs. From the I–V measurement, we found that the efficiency tends to increase as the concentration increases. It indicates that the concentration of natural dyes could increase the performance of DSSC. Furthermore, an efficiency of 3.248% was found to be achievable for DSSCs from a 70% concentration of yellow gambier fruit dye.
Minimizing capacity of Electric Vehicle Battery using Bottleneck Traveling Salesman Problem
Authors: Aurachman Rio , Saraswari Dyah Putri
Published: March 2021

Electrical vehicle technology has now developed. Various public transportation can start using electric power sources. However, there are battery capacity constraints. When the distance is too far, the battery capacity is not sufficient to provide the required power. In this paper, we will explain how the bottleneck travel salesman problem is applied to minimize battery capacity requirements. So that vehicles can choose the right route by minimizing the maximum distance between destinations. The optimization process is carried out with the Brute Force algorithm and python programming language.
Development of Dynamic Fluid props with ADDIE design at SMA
Authors: Rahmayani  , Rahmatsyah  , Sani Ridwan Abdullah
Published: March 2021

This study aims to develop physical teaching aids on dynamic fluid material. This research is a research development (Research & Development) using the ADDIE design with the stages of analysis (analysis), design (design), development (development), and evaluation (evaluation). This research was conducted at MAS Darul Qur’an with sample of 37 students. The development stage was carried out with a validation test with four expert validators, which were divided into two expert validators and two material expert validators. The results of the validation of the props are based on the validation of material experts with a percentage of 97,5% and the percentage of validation of media experts is 87,5% with the very feasible category. The effectiveness of the developed teaching aids in understanding dynamic fluid material based on the results of the teacher’s assessment of the effectiveness test of dynamic fluid teaching aids, it was found that the teaching aids developed were effective for use in classroom learning activities with a total percentage of 90% in very good categories. The practicality of the props developed in understanding dynamic fluid material is 93.80% in the very practical category.
Preparation and Characterization of Bacterial Cellulose From Culturation of Acetobacter Xylinum In Coconut Water Media
Authors: Nurfajriani N. , Pulungan A. N. , Yusuf M. , Bukit N.
Published: March 2021

This study aims to analyze bacterial cellulose obtained from culturing Acetobacterxylinum in coconut water media. Coconut water media is obtained from coconut water waste in existing traditional markets. The resulting nata de coco purified with a 1% (w / v) solution of sodium hydroxide (NaOH) and 1% (v / v) acetic acid (CH3COOH). The preparation process, bacterial cellulose in the form of thin sheets, is dried under the sun or in an oven at 60 ° C; after drying, it is mashed in a blender until a solid powder is obtained. The resulting bacterial cellulose then characterized using Fourier Transform Infrared (FTIR), Thermo Gravimetric Analysis (TGA), and Scanning Electron Microscopy (SEM). The results of FTIR analysis showed that the cellulose obtained derived from microorganism activity; TGA analysis showed that the weight loss was 9.2%; this indicates the hydrophilic nature of cellulose. SEM analysis shows that bacterial cellulose’s surface morphology looks very dense and dense; this shows the characteristic properties of bacterial cellulose.
The Direction of Developing Green Building Criteria in Indonesia
Authors: Sahid  , Sumiyati Y , Purisari R
Published: March 2021

Until 2020, one province and two cities in Indonesia have local regulations governing green buildings’ implementation. Besides, there is also a ministerial regulation governing green building implementation, which serves as the primary reference for various cities or provinces that do not have local green buildings regulations. Three of the four laws are more than four years old. The implementation of these regulations has resulted in various achievements and findings and multiple obstacles. It is time to review these criteria so that the green building concept’s performance is broader and more weighty. This study aims to review these regulations’ requirements, particularly the requirements related to passive strategies, and propose further development directions. We were researching by dissecting the criteria contained in the rules, analyzing the potential impacts generated, and then comparing them with the opinions of building stakeholders. In the future, the green building regulation criteria need to prioritize measures that can significantly impact the environment and energy, and people as the three essential factors of the green building concept.
Interactive Animation Media of Sea Biota Design for Young Learners
Authors: Fitriasari N S , Suzanti L , Widjayatri R R D , Putri K A , Fakhrurrazi M , Zamil A C , Rahayu G
Published: March 2021

Interactive animation media could provide children good experience and imagination, which serve as important aspects in their intelligence development. However such media that incorporate children’s multiple intelligences and specifically focus on marine biota are relatively limited in number. To have such media is particularly relevant for Indonesia to build awareness among children towards marine environment preservation. Within that framework, the current study attempts to develop interactive animation media on marine lives through waterfall System Development Life Cycle (SDLC). Although the study is still in its analyzing and designing stages, to this point it has shown that the architectural design of the media might benefits classroom activities related to sea biota.
Gender Mainstreaming in Drought Disaster Risk Reduction
Authors: Retno Susilorini Rr M I , Lika Rusnianti Rambu , Sriyana  , Angghita Lintang Jata , Sinaga Julio Ignatius
Published: March 2021

Climate change has affected the whole world and caused disasters, include drought. Since Tana Mbanas village in Central Sumba District is the driest remote area in eastern region of Indonesia, gender inequality has affected in daily life of people in the village instead of other social and environmental problems. This research aimed to evaluate how gender mainstreaming implemented in drought disaster risk reduction in Tana Mbanas village in Central Sumba Regency, East Nusa Tenggara Province. The result of the research is expected to become a mirror that reflects Sumba island gender and development issues. The research took place in Tana Mbanas village in Central Sumba Regency, East Nusa Tenggara Province, and conducted by qualitative method with purposive data sampling. The steps taken in the research were observation, data collecting by questionnaire and in-depth interview to respondents, and literature review. It was reported that Tana Mbanas village people has given water management assistance by village fund, conducting water management counselling, saving water, and harvesting rain systems in every household. This research meets conclusions that: (1) Several programs and planned actions in water supply system and infrastructure development have become initiatives of government agencies of village authorities, BPBD and Public Work Agency of Central Sumba Regency; (2) People demonstrated vulnerability to drought as well as lack of water supply and also water resources; (3) Strong efforts should be conducted to educate people and increase women capacity in coping issues of poverty, drought, and lack of water supply; and (4) Government agencies and other private institutions have to build women capacity as their participation in enhancing gender equality and mainstreaming gender.