bluuebunny/crossref_metadata_2025_split huggingface dataset:
The effect of sampling technique training using UNPAD statistical analysis series on sampling technique ability
Authors: Jatnika R , Haffas M , Agustiani H 
Published: March 2020

Abstract
UNPAD SAS (Statistical Analysis Series) is a software for analysing Statistical data. UNPAD SAS can be used to analyse descriptive statistics, nonparametric analysis, correlation analysis, and sample size determination. This research is an experimental study to determine the effect of sampling technique training using UNPAD SAS on sampling technique ability. The research design used one group pretest-posttest design. The independent variable in this study was the provision of sampling technique training using UNPAD SAS. The dependent variable was the ability of the sampling technique. The participants in this study were 32 students at the Faculty of Psychology, Universitas Padjadjaran. The ability of sampling techniques was measured using a questionnaire consisting of 28 items. The results of the data analysis showed a significant increase in the ability of the sampling technique after training compared to before taking the training (t = -13.145, p = 0.000).
Capability analysis of student mathematical representation viewed from self-regulated learning
Authors: Hidayati N , Usodo B , Subanti S 
Published: March 2020

Abstract
This study aims to analyze the ability of students’ mathematical representation in terms of Self-regulated Learning. This study focuses on the ability of visual representation, symbolic representation, and verbal representation. This study used a qualitative approach with test data collection techniques, questionnaires, and interviews. The data analysis technique used is the analysis technique according to Miles and Huberman through the phase of data reduction, data representation, and conclusion drawing. Students with SRL who are high in representation have lower grades than medium and low SRL The ability of verbal and symbolic representation of high SRL students has superior value from medium and low SRL. Indicators of mathematical representation can be achieved maximally by high SRL students. Students who have SRL are currently, the ability of visual representation is superior to high SRL students, symbol representation has a lower value than low SRL. So it can be concluded that SRL students are having difficulties in writing mathematical symbols. Low SRL students have advantages in visual representation. Indicators that can be achieved by SRL students are low only at the drawing stage. Low SRL students still have difficulty in expressing their abstract ideas in the form of mathematical representations.
Mathematical problem solving in students with disability based on prior mathematics ability
Authors: Muhafidin I , Nurlaelah E , Hasanah A 
Published: March 2020

Abstract
This research aims to understand the ability of deaf students to solve mathematical problem solving based on prior mathematical abilities. This research was conducted by using descriptive qualitative methods. Data collection techniques consists of tests, questionnaires, and interviews. The research subjects were deaf students in one of special schools in Bandung, Indonesia. The result of this study is problem solving abilities of 5 deaf students based on Prior Mathematics Ability. The result indicates one student has problem solving skills in a good category, three students are sufficient and the other one is in the low category. However, it does not mean that students who have Prior Mathematics Ability in a good category indicate that they also have good problem solving skills.
Enhancing concept mastery of students through STEM-project in scientific inquiry learning
Authors: Rachmayati D A , Kaniawati I , Hernani H 
Published: March 2020

Abstract
This study aims to examine the effect of STEM project in scientific inquiry learning towards enhancing concept mastery of students. The research method used was a quasi-experiment with the one group pretest-posttest design. Quantitative data was obtained through instrument of concept mastery test using a two-tier multiple choice instrument and then analyzed using dependent t-test. Based on the result of dependent t-test was found that there was significance difference between the pretest and posttest scores of students with sig = 0.000 (p<0.05). The enhancing between pretest and posttest score was obtained from N-gain analysis, the value of gain index is 0.64 showed that the enhancing of students’ concept mastery is in medium category. Based on the results obtained from this study, it showed that STEM project in scientific inquiry learning had positive impact on concept mastery of students, therefore it can be used as an alternative learning model in science learning that integrates technology.
Analysis of student needs for mathematics teaching materials
Authors: Annisah S , Zulela Z , Boeriswati E 
Published: March 2020

Abstract
The purpose of this study is to determine the mathematics teaching materials needed by students to improve problem-solving skills. This research is a qualitative descriptive study. The subjects of this study were PGMI students in the Metro city, province of Lampung. Data collection uses a non-test method that uses a questionnaire. The questionnaire consisted of 16 questions, which included eight questions about the analysis of learning resources (teaching materials) and 8 questions about determining learning resources (teaching materials). The results of this study are 1) mathematics teaching materials that are used effectively help students understand mathematical material, but are not effective in helping students develop problem-solving skills, 2) students need mathematics teaching materials based on contextual approaches to improve problem-solving skills. Based on the results of this study, it is necessary to develop mathematics teaching materials based on a contextual approach to improve problem-solving skills.
Experimental study of hydrocarbon refrigerant (R-1270) to replace R-32 in residential air conditioning system
Authors: Sumardi K , Nahadi N , Mutaufiq M 
Published: March 2020

Abstract
The purpose of this study was to test the performance of hydrocarbon refrigerant (R-1270) to replace R-32 refrigerant. The refrigerant R1270 is a propylene-base refrigerant (C3H6), while R32 is a synthetic refrigerant. Both refrigerants were tested on residential air conditioning systems with similar specifications. At pressure of 100 psig and external air temperature of 25 °C, the Coefficient of Performance (CoP) and Energy Efficiency Ratio (EER) of R32 were better than those of R32. The electrical power consumption of R1270 was 12.5 % more efficient than R32. In terms of volume used, R1270 required was 53.5 % lower than that of R32. The air temperature coming out of the evaporator of R1270 was 1 °C lower than that of R-32. This research showed that R-1270 could be used to replace R-32 effectively.
Effect of quenching on the electrical and optical properties of MoTe2
Authors: Marchenkov V V , Domozhirova A N , Parulin R A , Naumov S V , Makhnev A A , Shreder E I , Patrakov E I , Chistyakov V V , Ivanov A D , Huang J C A 
Published: March 2020

Abstract
The effect of quenching on the electrical resistivity and optical properties of MoTe2 compound was studied. Significant changes were detected in the behaviour and value of the electrical resistivity, indicating an increase in the metallic (conductive) properties of the compound, which is in good agreement with the data of optical measurements.
Influence of technological conditions on photoluminescent properties of halide perovskite nanocrystals
Authors: Belorus A O , Pleshanov I M , Doru-Tovt N V 
Published: March 2020

Abstract
We report on the technique for the synthesis of chlorine-free methylammonium lead bromide organic-inorganic perovskite nanocrystals with tunable green-blue photoluminescence. The synthesis was performed under ambient conditions at room temperature. Absorbance and photoluminescence characteristics were measured.
Peculiarities of the structural properties of InxGa1-xN polytype nanostructures grown by molecular-beam epitaxy
Authors: Gridchin V O , Kotlyar K P , Reznik R R , Shevchuk D S , Kirilenko D A , Bert N A , Soshnikov I P , Cirlin G E 
Published: March 2020

Abstract
In the article, the study of the morphology, crystal structure and chemical composition of InxGa1-xN nanostructures is presented. Scanning electron microscopy measurements show that the sample has a structure consisting of nanotubes, on top of which an array of nanocrystals (so-called “nanoflowers”) is formed. The results of transmission electron microscopy show that the nanotubes have a wurtzite crystal structure, whereas the “nanoflowers” exhibit both wurtzite and zinc blende one. The indium composition in wurtzite and zinc blende segments is about 20 % and 10 %, respectively.
Scanning tunneling microscopy of the tetraphenylporphyrin thin films on a graphite single-crystal substrate
Authors: Arias Muñoz J , Elistratova M A , Zakharova I B , Rykov S A 
Published: March 2020

Abstract
Features of the surface topography of a tetraphenylporphyrin film on a graphite single crystal (HOPG) substrate and the local current-voltage characteristics were studied using a scanning tunneling microscope under ambient conditions. STM images of surface were acquired on a scale from a few nanometers to 4 micrometers. Local tunnelling current-voltage characteristics in different ranges of bias voltage and in different directions of voltage scanning can have hysteresis due to the hopping electron conductivity in porphyrin.
Structure and surface morphology of GeSn/Si(001) layers grown by HW CVD with co-evaporation of Sn
Authors: Zaitsev A V , Kuz’min M Yu , Denisov S A , Shengurov V G , Chalkov V Yu , Kudrin A V , Ved’ M V , Filatov D O 
Published: March 2020

Abstract
This paper presents the results of the investigation of Ge1-xSnx epitaxial layers grown by the hot wire chemical vapor deposition (HW CVD) method with simultaneous evaporation of Sn from a standard effusion cell. The Ge1-xSnx with a Sn molar fraction of 7.2% and a full width at half maximum (FWHM) of the rocking curve of 7.6` demonstrated intense photoluminescence at room temperature. The peaks in the energy bands 0.70 – 0.73 eV and 0.63 – 0.65 eV have been observed in the photoluminescence spectra. These peaks were related to the direct and indirect interband radiative optical transitions in GeSn, respectively.
Study of current-voltage characteristics of InAsSb-based LED heterostructures in 4.2 - 300 K temperature range
Authors: Kuzmenko E V , Semakova A A , Bazhenov N L , Kizhaev S S , Chernyaev A V , Stoyanov N N , Mynbaev K D 
Published: March 2020

Abstract
Current-voltage characteristics of light-emitting diode heterostructures based on InAsSb epitaxial films and a multi quantum-well structure were studied in the temperature range T = 4.2–300 K. It is shown that transport through the heterostructures is governed by the diffusion and recombination mechanisms at temperatures close to 300 K. The tunnelling effect appears in the temperature range 4.2–77 K. The presence of quantum wells in the active layer results in increased diode leakage currents due to tunnelling.
Impact of shell material on the nonlinear properties of colloidal CdSe nanoplatelets
Authors: Golinskaya A D , Smirnov A M , Zharkova E V , Kozlova M V , Saidzhonov B M , Vasiliev R B , Dneprovskii V S 
Published: March 2020

Abstract
The nonlinear change in the absorption of colloidal CdSe nanoplatelets capped with a CdS-shell and a ZnS-shell was investigated in the case of the steady-state excitation regime. It was revealed that the nonlinear optical response of planar heretostructured nanocrystals is strongly influenced by the crystal structure of the core and shell material.
Model for nucleation of catalyst-free III-V nanowires on patterned substrates
Authors: Berdnikov Y , Sokolovskii A S , Sibirev N V 
Published: March 2020

Abstract
Catalyst-free growth of III-V nanowires enables different optoelectronic applications though usually requires substrate patterning to control the size and position of nanowires. However, the impact of substrate modification on the nanowire nucleation is not well-understood yet. The theoretical approach of this work studies the effect of substrate boundaries and adatom diffusion on the nucleation rate of catalyst-free III-V NWs on substrates with circularly symmetric patterning. In the model results, we distinguish and demonstrate four different scenarios of nanowire nucleation, depending on the properties of the patterned and unpatterned surfaces.
All-optical comparator based on linear chain of silicon nanoparticles
Authors: Sapegin A A , Barabanenkov M Yu , Italyantsev A G 
Published: March 2020

Abstract
A simultaneous excitation of two last particles of a finite linear chain of particles by two electromagnetic wave beams with arbitrary amplitudes of the electric field is considered. Using the example of a Si nanosphere chain, that does not support the resonant long-range electromagnetic energy transfer in the visible spectral range, it has been theoretically shown that self-consisted currents excited in a chain composed of a few Si mutually wave interacting nanospheres are related to the amplitude ratio of two incident beams. This technique provides a new way of comparing two optical signals in integrated microphotonic circuits.
Solar cells based on GaAs and carbon nanotubes
Authors: Mitin D M , Mozharov A M , Raudik S A , Fedorov V V , Neplokh V V , Rajanna P M , Nasibulin A G , Mukhin I S 
Published: March 2020

Abstract
This work is devoted to fabrication and characterization of a GaAs solar cell with a CNT top contact. The characteristics of a conventional solar cell with a metal contact grid and a solar cell with a CNT electrode were compared to demonstrate the benefits of a CNT based approach. The photoelectric properties of the solar cells were studied by measuring the IV characteristics and external quantum efficiency. The fabricated CNT solar cell showed better performance due to improved photocurrent collection efficiency. The demonstrated technology for the fabrication of CNT electrodes can be applied to a wide range of semiconductor photovoltaic devices, including flexible thin-film solar cells and solar cells based on nanowires.
Subcontact layers of p-InGaAs with minimal resistance for photodetectors of high-power laser radiation
Authors: Epoletov V S , Marichev A E , Popova T B , Pushnyi B V , Levin R V 
Published: March 2020

Abstract
It is necessary to minimize the resistance of electrical contacts to reduce heat losses in photovoltaic converters of laser radiation. The paper describes ways to reduce the resistance of electrical contacts for p-InP by choosing the composition of the subcontact layer based on p-InGaAs. For this purpose, layers of p-InGaAs with different compositions and bandgaps were grown by the MOCVD method. AgMn/Ni/Au contact metallization was deposited on samples to compare the characteristics of electrical contacts. The minimum specific contact resistance was 7• 10−5 Ω-cm2 for the layer with Eg
= 0.51 eV.
Source forensics of n-alkanes and n-fatty acids in urban aerosols using compound specific radiocarbon/stable carbon isotopic composition
Authors: Ren Lujie , Wang Yiyun , Kawamura Kimitaka , Bikkina Srinivas , Haghipour Negar , Wacker Lukas , Pavuluri Chandra Mouli , Zhang Zhimin , Yue Siyao , Sun Yele , Wang Zifa , Zhang Yanli , Feng Xiaojuan , Liu Cong-Qiang , Eglinton Timothy I , Fu Pingqing 
Published: March 2020

Abstract

n-Alkanes and fatty acids are important molecular markers for the source apportionment of organic matter in the atmosphere. Traditional approaches to date have mostly relied upon the source-specific differences in their molecular distributions and carbon preference index. Alternatively, we demonstrate here the use of stable carbon and radiocarbon isotopic composition (δ
13C and Δ14C, respectively) of n-alkanes and n-fatty acids in aerosols from two urban receptor sites (Beijing and Tianjin) in Northeast China to assess their sources in autumn. The Δ14C
n

-alkanes of C19–C24 and C26–C32 even-carbon homologs (−851 to −708‰) indicate their dominance from fossil fuel combustion. In contrast, the Δ14C of most abundant palmitic acid (C16:0) and stearic acid (C18:0) suggest a larger contribution from nonfossil sources (∼91%–94%), mainly due to inputs from cooking, biomass burning and microorganisms. Compared with lower Δ14C of C27 and C31
n-alkanes (−449‰), C29
n-alkane (−241‰) and C20–C30
n-fatty acids (−263‰) showed more contemporary likely due to significant contribution from plant litter and biomass burning that contain more fresh biogenic material. Fossil character of C27–C31
n-alkanes (40%) and C20–C30
n-fatty acids (30%) could be from soil resuspension and/or loess deposits in upwind regions through long-range atmospheric transport.
Dynamic supplier selection strategy towards negotiation process in beef industry using K-means clustering
Authors: Paduloh  , Djatna T , Sukardi  , Muslich  
Published: March 2020

Abstract
Dynamic supplier selection strategy is the actual condition to get the best supplier and selecting supplier based on company condition, in conditions of uncertain demand for beef. The key criteria when choosing suppliers include the Term of Payment, price and quality factor; these criteria are used by the company during the negotiation process. The purpose of this research is to get the most appropriate and profitable supplier, then obtain proof that K-means clustering can be used as a strategy to simplify the negotiation process in supplier selection. The method used for clustering is K-means. From the analysis, the company gets the right cluster supplier to facilitate the process of selecting suppliers and negotiate the price and time offered. The clustering process using K-means shows which supplier is the most profitable with characteristics that are almost the same as the specified centroid. Dynamic demand changes can be solved by changing the number of clusters to make it easier for companies and still earn profitable suppliers. Companies can negotiate with suppliers in clusters; thus, the suppliers can meet the standards given by the company. Further research is suggested to do clustering with more variety of attributes such as lead time of delivery, service, and capital owned by suppliers.
The changes of moisture content, total phenolic content and pasting profile caused by parboiling process of black rice
Authors: Widyasaputra R , Syamsir E , Budijanto S 
Published: March 2020

Abstract
Parboiling process of black rice could reduce cooking time and improve texture. However, parboiling process involving heat had the potency to affect moisture content, total phenolic content (TPC), and pasting profile. The aim of this research was to find the effect of parboiling process in the moisture content, TPC and pasting profile of black rice. There were three kinds of black rice. That was parboiled black rice A (3.8% concentration of sodium citrate, 5-minute steaming time, and 3.8 times freezing-thawing cycles), parboiled black rice B (5% concentration of sodium citrate, 15-minute steaming time, and 4 times freezing-thawing cycles) and normal black rice. Analysis of variance (α=5%) showed that there was a significant difference in moisture content and TPC parameter. The changes of black rice moisture content and total phenolic content caused by parboiling process A were bigger than B. Measurement of pasting profile explained that parboiled black rice A and B had lower pasting profile than normal black rice.
Effect of corn silk powder extracts using in vivo to lipid profile and liver fat
Authors: Haslina  , Wahjuningsih S B 
Published: March 2020

Abstract
This study aimed to determine the effect of corn silk powder extracts using in vivo to lipid profile and liver fat (a liver weight and adipose fat). The used experimental animals were 30 Sprague Dawley mice with 200-250 g mice weight divided into 6 groups. Each group of 5 mice was randomly determined, then the mice were caged individually. At the time of intervention for 21 days, group I received standard food, group II got hypercholesterolemia induction, group III received high-fat food induction and simvastatin drug, group IV induced hypercholesterolemia and corn silk extract dose 2.25ml, group V induced hypercholesterolemia and extract corn silk dose 4.5 ml, and group VI got hypercholesterolemia induction of corn silk extract dose 6.75 ml. The provision of corn silk extracts is based on recommendations for consumption of vegetables per day in humans from the Food and Drug Administration (FDA) which is 30-40 g/day. Corn silk extracts were given as much as 125 ml; 250 ml; and 375 ml. The dose was then converted to mice (0.018) to obtain 2.25 ml; 4.5 ml; and 6.75 ml. Corn silk powder extracts significantly affected (p<0.05) on lipid profile and liver fat (a liver weight and adipose fat). The best corn silk powder extract was at a dose of 2.25 ml with lipid profile (total cholesterol of 24.4% from 120.29±2.23 ml/dl to 90.87 ±2.01 ml/dl, HDL cholesterol of 30.35% from 56.60 ±2.81 ml/dl to 81.26±1.88 ml/dl, LDL cholesterol of 53.84% from 57.47±0.82 ml/dl to 26.53±0.77 ml/dl, triglycerides of 29.14% from 98.15±1.92 ml/dl to 69.54±6.78 ml/dl), and liver fat content in P3 treatment dose 6.75 ml with a liver weight of 7.09 g and adipose fat of 6.99 g.
Evaluation of biogas potential from empty fruit oil palm bunches
Authors: Suhartini S , Hidayat N , Nurika I 
Published: March 2020

Abstract
Indonesia experiences an increasing demand for energy, triggering the development of renewable energy, particularly from biomass resources. Empty fruit oil palm bunches (EFOB) residue is one of the potential lignocellulosic biomass highly abundant for further application in bioenergy generation such as biogas. This study was aimed to investigate and evaluate the potential of EFOB for biogas production using anaerobic digestion (AD) route. The biogas production in AD of EFOB was investigated in a batch experiment operated at an inoculum to substrate ratio (RI/S) of 6:1 for 30 days under the temperature of 37 °C. The results showed that the specific methane potential (SMP) of EFOB (without any pre-treatment) was 0.110 m3/kgVSadded. Using the anaerobic digestion scenario modeling, it was indicated that EFOB is a potential feedstock for biogas production using AD technology, either for electricity or biomethane production. The model also indicated that biogas and methane generation from AD of EFOB can contribute to enhancing the GHG emissions savings from replacing the use of fossil fuels or other non-renewable energy sources. Yet, the problem of high lignin content in EFOB has hindered the optimal biogas production. Therefore, the next stage of this study was to integrate biological pre-treatment to improve the efficacy of AD process.
Study of process innovation on African catfish (Clarias gariepinus) gluten-free product
Authors: Hasnelly  , Fitria A , Haswidya  , Cahyadi W 
Published: March 2020

Abstract
Ground dendeng was used as one of the innovations of African catfish gluten-free products in this research. The research aims of the study were to determine the effect of drying temperature and the addition of seaweed on characteristics of African catfish ground dendeng. Randomized block design (RBD) was carried out. The first stage of this research was aimed to determine the best formula for the product and analyzing protein, water, and fat content of African catfish meat. This research consisted of 2 factors (drying temperature and amount of seaweed). Characteristics of chemical, physical, organoleptical, and microbiological responses were analyzed. Results of this research showed that water content and taste attribute of African catfish ground dendeng was not affected by the temperature of drying and additional of seaweed. Meanwhile, the aroma, color, and texture attribute, also carbohydrate, protein, and fat content of African catfish ground dendeng were affected.