bluuebunny/crossref_metadata_2025_split huggingface dataset:
Resistive switching kinetics of parylene-based memristive devices with Cu active electrodes
Authors: Matsukatova A N , Minnekhanov A A , Rylkov V V , Demin V A , Emelyanov A V 
Published: February 2021

Abstract
The temporal characteristics of the resistive switching process in parylene-based memristive devices with Cu electrodes are studied. It was found that the switching time of the structures is hundreds of nanoseconds at switching voltages less than 2 V. The median value of the estimated energy consumption does not exceed 3 nJ. Thus, it was shown that parylene-based memristors are effective in neuromorphic computing systems, including those trained by bio-inspired rules such as memristive STDP. The possibility of further reduction of the switching energies down to picojoules when the size of the memristors is reduced to 50x50 µm2 (in crossbar architecture) is noted. Biocompatibility and scalability of the devices is also promising in the creation of energy-efficient wearable systems. The obtained results can be useful for further study of parylene-based memristors, in particular, for developing models of their performance.
Features of the research of the structure and assessment of the quality of composite materials by means of non-destructive testing techniques
Authors: Yu Rusakov D , Chernushin V A , Kuryatin A A 
Published: February 2021

Abstract
In the present paper, features and problems of non-destructive testing (NDT) of composite materials with big inside quantity of pores have been discussed. Solutions for issues of NDT of this materials have been proposed.
Numerical calculation of laser welds nanocomposite formation parameters for solders based on proteins and carbon nanotubes
Authors: Ryabkin D I , Taritsyna N A , Morozova E A , Yu Gerasimenko A 
Published: February 2021

Abstract
Laser welding is an alternative method of biological tissues joining. One of the actual tasks of laser welding of biological tissues is to determine the weld depth by a noninvasive method during surgery. The paper presents a model for calculating the duration of the formation of welds depending on the density of laser radiation power and the depth of the joint. The calculations were performed for the laser beam diameter d = 1.1 mm, power density in the range from 10 to 25 W cm1, weld formation depth l in the range from 0.2 to 1 mm and solders based on aqueous dispersions of bovine serum albumin, indocyanin green and single-walled carbon nanotubes.
Hybrid nanostructures superconductor-ferromagnet for superconducting spintronics
Authors: Sidorenko A S , Morari R A , Boian V , Prepelitsa A A , Antropov E I , Savva Yu B , Yu Fedotov A , Yu Sevryukhina O , Vakhrushev A V 
Published: February 2021

Abstract
The work is devoted to the study of the processes of formation of multilayer nanostructures, their vacuum deposition, and the manufacture of a novel functional element of spintronics - superconducting spin valve, which is a multilayer structure consisting of ferromagnetic cobalt nanolayers separated by superconductor niobium films. Multilayer nanostructures are fabricated by magnetron sputtering on (111) silicon substrates at a temperature of 300K. The prototypes of the superconducting spin valve are prepared from multilayer nanostructures by the method of sharp focus reactive ion etching (FIB). Modeling was carried out using molecular dynamics methods.
Green synthesis of zinc oxide nanoparticles using Moringa oleifera l. water extract and its photocatalytic evaluation
Authors: Adam F , Himawan A , Aswad M , Ilyas S , Heryanto  , Anugrah M A , Tahir D 
Published: February 2021

Abstract
Green synthesis of Zinc Oxide Nanoparticles (ZnO-NPs) using Moringa oleifera L extract is successfully carried out. ZnO-NPs is precipitated out with the help of Moringa oleifera L water extract and thermally treated at 300, 350, 400, 450, and 500°C prior characterization. The prepared ZnO-NPs were characterized using Fourier Transform Infrared (FTIR), X-ray diffraction (XRD), and The Ultraviolet-visible (UV-Vis). The photocatalytic activity was determined based on its ability to decompose methylene blue in solution. FTIR analysis result shows the absorption band at 422-497 cm−1 which associated with stretching of Zn-O, and the intensity of O-H bond (3417 cm−1) decreases with increasing calcination temperature. The XRD spectrum shows a significant increase in electron properties and bond formation as the temperature increase. Calcination at 500°C results in the achievement of methylene blue degradation as a pollutant model of 80% after 60 minutes of exposure. This study shows that Moringa oleifera L. water extract can be used as a green alternative in ZnO-NPs synthesis and calcination temperature affects the photocatalytic activity of the prepared nanoparticles.
High sensitivity and resolution sensor plastic optical fiber for determining compressive and tensile tensor concrete applications
Authors: Arifin A , Rusyam N I , Lebang A K , Abdullah B , Tahir D 
Published: February 2021

Abstract
This research discusses sensors based on plastic optical fiber (POF) for concrete compressive tests and concrete tensile tests. Sensors are made of plastic optical fibers without coat attached to concrete surfaces or planted in concrete with straight, one bending, and two bending configurations. Sensors are attached to concrete with four configurations to find the best sensitivity and resolution values. The pressure on the sensor is related to the loss of power. The best sensor characteristic based on plastic optical fiber for concrete compressive test and the concrete tensile test is the sensor with two bending configurations that are planted in concrete. The sensitivity and resolution values in the concrete compressive strength test were 0.085 volts/kN and 0.047 kN. While the value of sensitivity and resolution of the concrete tensile test obtained is 0.082 volts/kN, and 0.048 kN. Sensor-based on plastic optical fiber has the advantage that is low cost and simple in measurement method that can be applied for monitoring the condition of the building structure.
Implemented preconditioning conjugate gradient algorithm on electrical resistance tomography to modelling structural geology
Authors: Kusmiaran A , Sanny T A , Nurrahmi S , Yanti F , Minarti  
Published: February 2021

Abstract
The development of a method to enhance resolution in imaging subsurface structural geology has continuously developed. The method of tomography field is electrical resistance tomography that is a powerful method for imaging subsurface structural geology. The electrical resistance tomography method is divided into two parts that are forward modelling and inverse modelling. The principle of forwarding modelling is to solve elliptic differential equation second order by finite volume method. The result of this part is the subsurface resistivity magnitude where it is used to model structural geology. For modelling inverse, the algorithm that has used to the model of subsurface structural geology is the Gauss-Newton method with an updated model that is preconditioning conjugate gradient. The ability of the electrical resistance tomography has tested to models of subsurface structural geology such us layering, and fault model. The results have revealed that this method able to model the subsurface of the structural geology, delineate the edge of the layer, and enhance the resolution of the model.
Production of protein hydrolysate from tofu dregs using the crude extract of bromelain from pineapple core (Ananas comosus l)
Authors: Bahri S , Hadati K S , Satrimafitrah P 
Published: February 2021

AbstractTofu dregs are one of the waste products from making tofu that still has the potential to be processed, because the protein content is relatively high, namely 23.62%. This waste has not been optimally utilized by the community unless it is used as animal feed. One alternative to utilizing tofu waste is processing it into specific products, namely producing protein hydrolysate using bromelain. The purpose of this study was to determine the best concentration of crude bromelain enzyme extract and hydrolysis time to obtain the degree of hydrolysis (DH) of protein hydrolysate in tofu dregs. DH of protein hydrolysate was determined with various concentrations of bromelain (8, 9, 10, 11, and 12%) (v/v) and variations in the hydrolysis time (120, 180, 240, and 300 minutes). The best degree of hydrolysis was 22.82% using 11% crude bromelain extract with a hydrolysis time of 120 minutes.
Satellite data receiving antenna system for pleiades neo observation satellite
Authors: Hestrio Y F , Soleh M , Hidayat A , Afida H , Gunawan H , Maryanto A 
Published: February 2021

Abstract
Pleiades Neo Satellite is a future optical remote sensing satellite designed for launch in 2020 with a very high spatial resolution of up to 30 cm and consists of 4 constellation satellites to continuing Pleiades-1A/1B constellation. Pleiades Neo capable of producing high temporal resolution (revisit time) in one day to collecting imagery at the same location and its performance claimed will increase up to three times when compared to the Pleiades-1A/1B constellation. LAPAN, as the main official provider in high-resolution optical satellite data in Indonesia, has planned to receive the Pleiades Neo data. This paper discusses the antenna system for receiving Pleiades Neo data by LAPAN’s remote sensing ground station with analyzing the main antenna parameter requirements if Pleiades Neo will be received on Zodiac or Viasat antenna. By calculating the Carrier to Noise Ratio (C/N) value both of antenna system and compared with Airbus Defense and Space minimum C/N requirement about 13.8 dB at 5-degree elevation. The simulation result is obtained C/N value 14 dB and 6.5 dB on Zodiac and Viasat antenna, respectively. Based on the result analysis, it is found that the Zodiac antenna system is recommended for the Pleiades Neo data reception system.
Effect of additive polarity on the stability of organic-inorganic hybrid CH3NH3PbI3 perovskite thin film
Authors: Firmansyah  , Kartini I , Sutarno  , Ruslan  
Published: February 2021

Abstract
Synthesis of organic-inorganic hybrid CH3NH3PbI3 perovskite thin film from Pb(NO3)2 precursor was carried out by using alcohol with various polarity (isopropanol, 1-butanol and 1-propanol) as the additive. Preparation of CH3NH3PbI3 perovskite thin film was conducted by firstly forming Pb(NO3)2 thin film as the film’s precursor using spin coating method at 2500 rpm for 30 s with DMSO as the main solvent and isopropanol, 1-butanol or 1-propanol as the solvent additives. Pb(NO3)2 thin film was immersed in methyl ammonium iodide solution for 30 min to produce CH3NH3PbI3 perovskite thin film. The effect of solvent additive polarity on the grain size of perovskite film was studied using electron microscope method. Stability of CH3NH3PbI3 perovskite thin film was studied by using XRD and SEM. The result showed that increasing polarity of the solvent additives resulted in decreasing on the crystallinity of Pb(NO3)2 thin film. Pb(NO3)2 thin film with low crystallinity yielded high purity of CH3NH3PbI3 perovskite thin film with grain size up to 2.45 μm and have good stability with 43.09% degradation percentage for 24 h.
Geoelectrical Method for Detecting the Limit of Liquid Waste Flowing Below the Surface at Piyungan Landfill
Authors: Jayadi H , Muin M R , Sabhan  , Meidji I U 
Published: February 2021

Abstract
Increasingly limited residential land in urban areas results in residents looking for and making settlements around landfills. This affects people’s lives in fulfilling their daily needs, clean water. To meet the demand for clean water, some residents use well water as the primary drinking water source. Judging from the condition of the residential areas located in the landfill area, there may be an effect of waste, especially liquid waste, on well water sources. For this reason, research is carried out using the geoelectric method by combining two configurations, namely Schlumberger and dipole-dipole. So that it can provide an overview of the boundaries of liquid waste contaminants in the soil, which are associated with conductive fluids that affect the quality of clean water from residential areas around the landfill. In this study, it was found that the fluid flow associated with liquid waste has a lateral movement to the right with a depth of 24.5 meters.
Analysis of sea level changes in Balikpapan Bay as basic data for strategic planning the new capital city of Republic of Indonesia
Authors: Putri M R , Sari T , Anwar I P , Mandang I , Setiawan A , Tatipatta W M 
Published: February 2021

AbstractStudies from various sectors are needed regarding the plan to move the capital city of the Republic of Indonesia from Jakarta to Penajam Paser Utara. The aquatic ecosystem that needs attention is Balikpapan Bay which is located in the vicinity of these activities. One of the factors that influence this is global warming. Therefore, it is necessary to analyze the variability and trend of sea level rise in front of Balikpapan Bay. The first mode of Empirical Orthogonal Function (EOF) shows that sea level around Balikpapan Bay has a strong correlation with the Multivariate ENSO Index (MEI). This indicates that the sea level in the area is predominantly influenced by ENSO. A strong correlation between the first principal component and MEI was found to be around -0.85 in Balikpapan Bay (significance level> 95%). Based on sea level anomaly data for the last 20 years, sea level in Balikpapan has increased with a linear trend of 5.4 mm/year, with a decreasing trend due to El Niño and an increasing trend due to La Niña.
Classification of rainfall data using support vector machine
Authors: Sain H , Kuswanto H , Purnami S W , Rahayu S P 
Published: February 2021

Abstract
Classification problems can be based on cross-section or time-series data. In general, some of the characteristics found in time series data are data that are very susceptible to containing noise and outliers. In this paper, time series data-based classification was carried out using the support vector machine (SVM) method. The SVM method is the most popular binary classification technique in machine learning. The advantage of this method is that it can find a global optimum solution and always achieve the same solution for every running. Another advantage is that it can solve the over-fitting problem by minimizing the upper limit of generalization errors. SVM classification model performance can be seen from classification accuracy and sensitivity and specificity tests. The results showed that based on the level of classification accuracy used the SVM method resulted in an accuracy rate of the prediction results with training data of 96,3% and the accuracy of the prediction results with testing data of 90,08%. Therefore, the classification of rainfall data using the SVM method has a very good performance.
Synthesis of silver nanoparticles using bioreductors from clove leaf extract (Syzygium aromaticum) and test of its antibacterial activity
Authors: Kasim S , Dali S , Rahmah M 
Published: February 2021

Abstract
Synthesis of silver nanoparticles using clove leaf extract (Syzygium aromaticum) bioreductor and its antibacterial activity has been studied. Silver nanoparticles were synthesized using the green synthesis method with clove leaf extract (Syzygium aromaticum) as a bioreductor. Nanoparticles were analyzed and characterized by a spectrophotometer by UV-Vis, FTIR, SEM, XRD, and antibacterial activity. Antibacterial activity testing was carried out against Pseudomonas Aeruginosa and Bacillus Subtilis using the disc paper method. Silver nanoparticles were successfully synthesized by a reduction method using clove leaf extract (Syzygium aromaticum). The resulting nanoparticles have varying wavelengths in the range 420-435 nm and have non-uniform shapes with the resulting particle crystal size diameter based on the Debye-Scherer formula is 36.57 nm. FT-IR spectrum comparison of clove leaf extract and silver nanoparticles shows the contribution of the OH functional group in reducing silver ions which is indicated by its presence decrease in absorbance intensity in the area of wave number 3400 cm−1 after the formation of nanoparticles silver. Antibacterial activity of silver nanoparticles against Pseudomonas Aeruginosa and Bacillus Subtilis which showed that the inhibition zone diameter was 11 mm and 9 mm.
The investigation of self-absorption effect in cylindrical Ni-63/4H-SiC betavoltaic
Authors: Rahastama S , Agani I , Salim R , Teluma YC , Waris A 
Published: February 2021

Abstract
The limiting efficiency of betavoltaic battery can be affected by the self-absorption of radioisotope source. Moreover, this effect can be more detrimental for a low energy beta emitter such as Ni-63. The cylindrical design is known to have a benefit over rectangular one in response to the self-absorption effect. In this study, the model of betavoltaic was built under MCNPX which also capable to do many particle simulation based on Monte Carlo method. The interaction of beta particle and its average energy deposition in 4H-SiC semiconductor as the radiation-electricity converter was calculated, along with photonic emission due to the bremsstrahlung event. Basically, the average energy deposition shows a deterioration along with the addition of source mass thickness. However, an optimum peak was observed at about 0.1424 mg/cm2 source mass thickness in the N+ substrate average beta energy deposition. The cylindrical surface magnification also give a positive influence to the energy deposition. In addition, the absorbed dose in each layers of semiconductor was also investigated, and the results were consistent to the semi-empirical equation of self-absorption theory.
Batik Context as PISA-like Problem to Assess Students’ Mathematical Literacy
Authors: Machromah Isnaeni Umi , Sari Christina Kartika , Zakiyyah  
Published: February 2021

Abstract
PISA is an international assessment of mathematics and science achievement that concern for the mathematical literacy. Students’ mathematical literacy, however, was still low in Indonesia. This study aims to develop PISA-like problem that valid, practical and has potential effect to assess mathematical literacy. This study was research and development that consisting of preliminary, development, and assessment stages. The subject of this research was students on grade 7th. The data was collected by observation, questionnaire, and test. This research result PISA-like problem involves three questions with Batik theme in quantity content. This PISAlike problem was declared valid, practical, and had a potential effect to assess mathematical literacy. This problem is valid based on judgment from experts concerning on the content, construct, and language aspects. This problem is practical based on the results of the test to small groups of students. Besides, this problem has potential effect on assessing students’ mathematical literacy.
Pattern Generalization Strategy From Concrete Operational Students
Authors: Fadiana Mu’jizatin , Amin S M , Lukito A , Yuliastuti R , Apriono D 
Published: February 2021

Abstract
Pattern generalization played an important role in the introduction of early algebra which became a bridge between arithmetic and algebra. However, there are still many students who have difficulty in generalizing patterns. The difficulty of students in generalizing patterns lies in the steps of producing general formulas. Students find it difficult to represent generalizations in the form of variables-n. In addition, students also find it difficult to justify the resulting generalization. This difficulty is experienced by concrete operational students. For this reason, this research aims to study students’ concrete operational thinking processes in generalizing patterns. The results of this study provide effective learning strategy solutions for concrete operational students in generalizing patterns. This research is a qualitative research with a case study approach to junior high school students. The results indicated that concrete operational students looked patterns represented in the form of geometric drawings globally without looking the structure of the images. Concrete operational students use two strategies in generalizing patterns, namely the guess and check strategy and the explicit visual strategy
Reflective thinking ability of junior high school students in relations and function problems
Authors: Hidayat Nurul , Usodo B , Saputro D R S 
Published: February 2021

Abstract
Reflective thinking is the ability of a person to select the knowledge he has to solve the problem at hand, starting from analyzing the problem, evaluating, to concluding. This study aims to describe the reflective thinking skills of students of class VIII C SMP N 1 Pundong in solving mathematical problems in the subject matter of relations and functions. This type of research is descriptive qualitative. The subjects of this study were 26 students taken using the purposive sampling method. The results of this study indicate that the percentage of achievement in the first indicator of reflective thinking describes a case based on mathematical concepts of 72.11%. The second indicator of reflective thinking to identify mathematical concepts or formulas involved in mathematical problems is 54.81%. The third indicator of reflective thinking draws an analogy from two similar cases of 24.04%. The fourth indicator of reflective thinking evaluates based on mathematical concepts was 38.46%. And the fifth indicator of reflective thinking makes conclusions using mathematical concepts by 42.31%. So that the average reflective thinking ability of students in class VIII C is 46.35% in the medium category.
Context-based tasks in mathematics textbooks for vocational high school students
Authors: Rejeki Sri , Meidina Rista Alfi , Hapsari Meytia Puspita , Setyaningsih Rini , Azura Raja Noor Farah 
Published: February 2021

Abstract
This study analyzes the context-based tasks in mathematics textbooks for grade ten and eleven vocational high school students in Indonesia. A vertical analysis was done based on the types of context, types of information, and cognitive demand types. This study is a descriptive qualitative study involving an external coder to ensure its validity and reliability. The data collection was conducted through text analysis and literature study. Whereas the data analysis used is content analysis. Based on the data analysis, it can be concluded that there are still little tasks with the relevant and essential context in the mathematics textbooks (10% for grade ten and 30% for grade eleven). Regarding vocational high school expertise, the tasks are relevant to vocational high school’s specific expertise. Regarding the types of information, tasks with matching categorized are dominant: 54% in grade ten and 88% in grade eleven. For the types of cognitive demand, grade ten is dominated with reproduction (54%), and grade eleven is dominated with connection (46%). Cohen’s Kappa coefficient on the types of context, types of information, and cognitive demand types in both mathematics books for vocational high school students grades ten and eleven are in a good or excellent category.