bluuebunny/crossref_metadata_2025_split huggingface dataset:
Textronics Interdigitate Electrodes for Staphylococcus Aureus bacteria detecting
Authors: Korzeniewska E , Szczesny A , Lipinski P , Dróżdż T , Kiełbasa P , Miernik A , Politowski K 
Published: March 2021

Abstract
The aim of the paper is to investigate the changes in electrical parameters of the interdigitated electrodes (IDEs) due to the development of Staphylococcus aureus. More precisely, the article presents the results of electrode’s resistance, capacitance and inductance changes in the function of bacteria density. The electrodes are made in the process of physical vacuum deposition on composite textile substrates. This allows to apply them in textronic applications. Changes in the electrical parameters of the produced IDEs were observed during microbial cell culture growing. The results of the research have demonstrated that the bacteria density influences the electrical parameters of the electrode. The greatest changes in these parameters are observed at the frequencies of 100 and 120 Hz after the day of inoculating staphylococcal cells into the medium, where the measuring electrodes were placed.
System construction based on a wire-mesh sensor for flow analysis
Authors: Szumowski J , Rymarczyk T , Rymarczyk P , Adamkiewicz P , Kowalski M , Bednarczuk P 
Published: March 2021

Abstract
Wire-mesh sensor (WMS, mesh sensor) is a device for invasive imaging of vertical and horizontal flows of liquids and gases. Visualisation of the measurement results does not require any complicated software reconstruction. The device consists of two parts: the wire-mesh acquisition module and the wire-mesh sensor. The device allows for testing of multiphase flows as well as air bubbles in air-lift reactors. The sensors are also suitable for testing various types of surface flows and the movement of bulk materials along the bottom of a pipeline. This paper describes the goals and results of construction of the system for flow analysis based on a wire-mesh sensor.
The effect of scientific inquiry learning model and scientific attitude on students’ science process skills
Authors: Pulungan Mailita Sari , Nasution Derlina , Rahmatsyah  
Published: March 2021

Abstract
This study aims to analyze how science process skills use scientific inquiry, to analyze how science process skills with high scientific attitude and low scientific attitude, to analyze the interaction between scientific inquiry and scientific attitude. This type of research is a quasi experiment with a pretest-posttest control group design. Data analysis was performed using descriptive analysis which aims to be able to explain and predict the symptoms that apply on the basis of data obtained in the field. Based on the results of the study it was found that the science process skills using scientific inquiry on the temperature and heat material experienced a significant increase, the skills that had a high scientific attitude were better than the science process skills which had a low scientific attitude, and there was an interaction between scientific inquiry and scientific attitude.
Analysis of linear motion kinematics on student’s critical thinking skillsbased on scientific inquiry
Authors: Pulungan Nurul Hidayah , Sirait Makmur , Ginting Eva M 
Published: March 2021

AbstractThis purpose of this studywas to analyze students’ critical thinking skills on linear motion kinematics material using the Scientific Inquiry model. This type of research is a quasi-experimental. The data analysis was carried out through 7 critical thinking skills test in essay form. Before the test instruments are tested on students, expert validation tests were carried outfirst. The critical thinking skill test indicators used consist of elementary indicators of clarification, basic support, inference, advanced clarification and indicators of strategies and tactics. The results of the study showed that the average value of students’ critical thinking skills on linear motion material was 60.02 and included in the sufficient category.
Model of quality control station allocation with consider work in process, and defect probability of final product
Authors: Regent Montororing Yuri Delano , Nurprihatin Filscha 
Published: March 2021

Abstract
Planning is needed in quality control for the target output produced is good. Quality control in the production line is carried out based on the inspection with acceptance of products that meet the requirements. This quality control method is carried out by allocating the quality control station flexibly to separate the rework products to be reworked and scrap to dispose of. The number of acceptable product proportions will depend on the ability of the production line to produce the product expressed in the probability of the product defect. The probability of a production line defect product will be affected to the probability at each work station, where the proportion of product defects that occur will also determine the allocation of the number of quality control stations. Research that discusses the allocation of quality control stations by considering the probability of the final product on the production line and the proportion of work in process does not yet exist, therefore researchers intend to do so. The development of this model is done by developing an objective function to minimize the total production cost. The total cost consists of processing costs, inspection costs, waiting costs, quality control station assignation costs, rework costs, and scrap costs. The aim is to find the configuration of the quality control station allocation in the production line at a minimum cost. From the results of the study obtained a quality control station allocation model that can minimize assembly costs and be flexible to changes in demand parameters, costs, defect probability of final product.
Investigation of chaos behaviour on damped and driven nonlinear simple pendulum motion simulated by mathematica
Authors: Rahayu Siti Utari , Tamba Takdir , Tarigan Kerista 
Published: March 2021

Abstract
This study aimed to investigate the chaos behavior resulted from damped driven nonlinear simple pendulum motion, which was simulated by using Mathematica. The method used to solve the equation of the pendulum was the 4th order of Runge-Kutta. The solution was obtained by setting some parameters to be determined at a certain value (dimensionless), namely the gravitational acceleration (g) was 9.8; the length of rope (l) was 9.8, the dumpling coefficient (q) was 0.4; the initial conditions (θ

0
and ω

0
) were 0.8 for both; the frequency of driving force (Ω

D
) was 0.6; and the mass of pendulum (m) was 1. Due to these settings, the natural frequency of the pendulum (Ω

2
) was calculated to be 1. Still, the driving force (a) was varied in order to analyze the chaos clearly. The solution was then plotted as θ vs t graphs, phase space, and Poincaré section. The results showed that the chaotic motion occurs when the driving force was in the range of 1.36-3.0, in which 3.0 was the maximum value in this simulation. In this range, the slight change in the initial condition resulted in significant differences of θ vs t graph, implying sensitivity to initial conditions. The phase space depicted a chaotic attractor, while the Poincaré section resulted in many dots forming stretching and folding patterns. Based on these results, it can be said that the chaos behavior could arise from damped and driven nonlinear simple pendulum motion by varying parameters, such as driving force.
Identification of mother plant for in vitro propagation of sumatra benzoin as a strategy to improve non-timber forest product
Authors: Nurwahyuni Isnaini , Situmorang Manihar , Sinaga Riyanto 
Published: March 2021

Abstract
Efforts to increase non-timber forest products need to be made to prevent illegal logging. One of the strategy is increasing the production of frankincense sap, which has high economic value as a raw material for medicine and cosmetics. This study aims to choose the best Sumatra Benzoin (Styrax benzoin Dryander) mother plant that qualifies as a source of explants for in vitro propagation, in an effort to provide seeds for forest conservation and at the same time to increase non-timber products. The research was conducted in the forest area of Pakpak Bharat Regency, North Sumatra, Indonesia. The research stages included surveying the Sumatran Benzoin plants in forest areas, identifying plant quality phenotically, and determining the best plants based on the production of incense sap. The production of incense sap at each harvest period is determined based on the quantity and quality of the sap produced by using traditional tapping techniques. The best parent plants was chosen as the source of explants for in vitro propagation. The mature and productive Sumatra Benzoin trees had been identified and marked as good quality plants that met the criteria as mother plants for in vitro propagation. The traditional technique used by the farmers to extract frankincense sap from mature trees is described in this study which guarantees the production of gum in large quantities and with very good quality of sap. The best quality mother plant has been selected, namely plant of Styrax benzoin Dryander that is phenotically very fertile, dense, bearing fruit, relatively resistant to various forest plant diseases, and productive produce lagrge quantity accompany with very good quality incense sap. This mother plant has been determined as the source of explantsin the in vitro propagation of Sumatra Benzoin.
The Development of Physics Objective Tests Based on PISA for Sound Wave Topics in High School
Authors: Sari Bestrica Kurnia , Sahyar  , Sani Ridwan Abdullah 
Published: March 2021

Abstract
The purpose of this study is to develop a PISA-based physics objective test instrument for sound wave material in high school according to good test qualification standards in terms of index validity, reliability, discrimination, level of difficulty, and distractor effectiveness. This study is a type of research and development (R&D). The model used is Analysis, Design, Development, Implement and Evaluation (ADDIE). The analysis stage resulted in minimal variation in the assessment and students still lacking PISA-based physics questions, especially on sound wave material. The material for developed physics problems includes the magnitude of sound waves, reflection and refraction, resonance, sound intensity, and the Doppler effect. The design stage resulted in 45 items based on the PISA scientific literacy competency which were classified into three competency standards, namely: explaining scientific phenomena; evaluate and design scientific research; interpret scientific data and evidence. The development stage obtained 44 items in the very valid category based on content validation by 5 experts, both in terms of material, construct, and language. The results of the implementation and evaluation stages show that of the 45 questions developed, 38 questions have met the criteria for good test quality, based on index validity, reliability, discrimination, difficulty level, and distractor effectiveness in small group trials and large group trials.
Study development of digital teaching materials support online learning during Covid-19
Authors: Lubis Fitriani , Yudhi Achmad 
Published: March 2021

Abstract
The implementation of education activity policy conducted at home by applying work from home (WFH) demand all of the each education institutions to perform the online learning by using any platforms provided in internet web. For college education, it is hoped to develop the information system of online learning based on learning management system. This research is intended to find out the information about the college students responds related to the online learning activity conducted in the Study Program of Language and Literature of Bahasa Indonesia Unimed since March 2020 until June 2020. The data obtained by answering the questionnaire submitted to the college students randomly. The results showed that 81.6% was in the very positive category related to the college students’ responses to the implementation of online learning. Besides that, there are some obstacles in the implementation of online learning as well, they are a small proportion of instructors and the college students who have not mastered the use of IT in the online learning process. The college students highly hope that the instructors can transform the teaching materials into digital form based on the applications so that it makes easier for them to understand the materials and can save any costs as complained by the college students when the online learning is carried out.
Performance test of an aerosol concentration measurement system based on quartz crystal microbalance
Authors: Budianto A , Wardoyo A Y P , Masruroh  , Dharmawan H A , Nurhuda M 
Published: March 2021

Abstract
QCM or quartz crystal microbalance is a well-known sensor technology that generates cycles of oscillation related to mass change on the crystal’s surface. This crystal works well when it has a frequency counter and an oscillator to drive the crystal and count the oscillation, and a good airflow regulator. This study developed a measurement system for aerosol concentrations with a diameter of less than 2.5 micrometers. The system consists of QCM sensors, an oscillator, a frequency counter, and an airflow regulator. The system was tested inside an exposure chamber with a constant emission source for the different velocity speeds, namely v

1
, v

2
, v

3
, v

4
, and v

5
. The test was conducted every10seconds due to the saturated time of the QCM related to the mass loading effect of aerosol. The results show that the system can drive the QCM sensor with a frequency of 5MHz. The measurement system works well to measure aerosol concentrationafter the preload duration often seconds and every sixty seconds in which the durations are related to the optimum QCM’s response at v

1
and v

2
. The optimum performance was found to be in the laminar regime, with the sample rate of 0.6 m/s to 1.0 m/s.
Evaluating the stock volatility of service companies in the rise of COVID-19 using ARMAX-GARCHX
Authors: Setiarno Putera Muhammad Luthfi 
Published: March 2021

Abstract
This study evaluates the impact of Covid-19 variables which has attracted huge attention from whole countries. The service companies listed in IDX are being the main issue while many are struggling amidst the economy slowdown due to pandemy. By comparing the time series regression (TSR) - GARCHX and ARMAX - GARCHX of stock return of 4 companies listed in service sub-sector since early March 2020, proposed GARCHX models are able to assess the volatility of stock return. As a proxy of the volatility, Value-at-Risk (VAR) is analyzed at 1% and 5% quantiles. It is found that ARMAX-GARCHX is more accurate than TSR-GARCHX in evaluating the volatility in lower risk, particularly that of medical service stock. Through ARMAX-GARCHX model, it is indicated that JCI return and lagged Covid-19 daily death cases have significant impact to the stock volatility, particularly that of transportation and medical service companies.
Synthesis and characterization of natural zeolite-clay as resistive humidity detection
Authors: Susilawati  , Balyan Muhammad 
Published: March 2021

Abstract
Zeolite-clay was successfully employed in as resistance type humidity sensor. Zeolite-clay humidity sensor was synthesized by crushing into powder and soaked into 6% H2SO4while stirred for two hours using a magnetic stirrer. The solution was filtered, washed using aquadest and dried at 100°C for 5 hours with the mixture process of zeolite and clay were varied into 10%:0%, 9.5%:0.5%, 9%:1%, 8.5%:1.5%, and 8%:2%. The result pressed with a size of 3x3x1 cm3 using a hydraulic under 3 tons pressure for 10 minutes and heated at temperatures of 800°C.Zeolite-clay was placed in a testing chamber equipped with the electrode that connected to an electrical supply of 3 Volt. The electrical resistance was recorded using Multimeter Hydra Series III Fluke when exposed with humidity in range of 18.5-99% RH. Zeolite 8%-clay 2% sensor exhibits the highest sensitivity properties, which indicate saturated resistance value at 99% RH.Meanwhile, Zeolite 8.5 gr-clay 1.5 gr revealed the highest response value at 54.3 Mega Ohm. Based on SEM and EDX characterization, the ratio of Si/Al and microstructure surface have an effect towards humidity detection process. The results indicate enhancement than previous research on zeolite as a sensor, and therefore Zeolite-Clay has proved the capability to detect humidity.
An introduction of scada-based based back pressure vessel (BPV) at palm oil factory with biomass energy
Authors: Ulum Zahrul , Hasan Syafrudin , Sinulingga Emerson P. , Latifah Siti , Fachrudin Khaira Amalia 
Published: March 2021

Abstract
Empty bunches, shells and fibers are waste biomass for renewable energy in steam power plants. The automatic control system provides many advantages for industrial use. Apart from speeding up time, work productivity is also able to reduce human error. The SCADA system includes a number of RTUs (Remote Terminal Units), Main Station / RCC (Area Control Center) and a data telecommunication network between the RTU and the Main Station. Application of scada, BPV can be controlled easily. This study introduces the application of scada to the BPV regulation in the biomass power plant at the Gunung Melayu palm oil mill
The Toxicity of n-Hexane, Ethyl Acetate and Ethanol Extracts of SarangBanua (Clerodendrumfragrans Vent Willd) Leaves by Brine Shrimp Lethality Test (BSLT) Method
Authors: Simorangkir Murniaty , Nainggolan Bajoka , Juwitaningsih Tita , Silaban Saronom 
Published: March 2021

Abstract
Sarangbanua traditional medicinal plant is found in Simalungunand NorthTapanuli Regencies, Sumatera, Indonesia. The result of plant determination, sarangbanuais Clerodendrumfragrans Vent Willd, including the Verbenaceae family. This study aims to determine the toxicity of the three types of leaf extracts of C. fragrans Vent Will. The Brine Shrimp Lethality Test (BSLT) method was used to determine the toxicity of the extracts. The mortality data were then analyzed by Probit SAS to obtain LC50 values. The results showed that the three types of C. fragrans leaf extracts had LC50 values below 1000 µg/mL, so they were classified as toxic and potentially bioactive. The LC50 values of each of the ethanol, ethyl acetate and ethanol extracts were 26.25; 37.50 and 41.97 µg/mL
Ring-opening Polymerization Reaction Mechanism of ε-Caprolactone Catalyzed by Bis(dibenzoylmethanato) zirconium(IV) Using PM3 Semi-Empirical Method
Authors: Yusuf Muhammad , Pulungan Ahmad Nasir , Irmala Sari Rizki Dwi , Fitri Amne Dinda Prihatini , Siregar Rahmayani , Rahmah Mawaddatur 
Published: March 2021

AbstractPolycaprolactone (PCL) is a semi-crystalline polymer and belongs to a biodegradable plastic. PCL also can naturally degraded, has a high degree of adjustment with other polymer, and has great mechanical and thermal properties. By using the Lewis acid catalyst, PCL can be yielded through the ring opening polymerization (ROP) of caprolactone (ε-CL). The objective of this study was to explore the most likely reaction mechanism of the ROP of ε-CL using bis(dibenzoylmethanato) zirconium(IV) chloride as a catalyst. Here, the Hyper Chem 8.0 program was performed to compute the monomer molecule, intermediate molecules, and polymer molecule. The program can be launch on the Windows 07 systems. The method used was the PM3 semi-empirical method. This program also used to show the results of optimized structures. The calculation results show that to generate PCL required bis(dibenzoylmethanato) zirconium (IV) catalyst. The ROP reaction mechanism of ε-CL can be occurs through direct coordination ε-CL on the Zr complex. After that, deprotonation and insertion monomer. Last step was chain propagation of the χ–CL.
Development of Chemistry Practicum Guidelines with the Support of STEM (Science, Technology, Engineering, and Mathematics) Integrating Character Education
Authors: Sinaga Mahniar , Silaban Ramlan , Jahro Iis Siti 
Published: March 2021

Abstract
The implementation of the STEM-based learning approach is able to shape student character. One of them is using a chemistry lab guide based on the STEM approach. The purpose of this study was to determine the feasibility level of a chemistry lab guide based on the integrated STEM approach to character education based on the criteria of the National Education Standards Agency (BSNP) and the character level of students after using a validated practicum guide. This type of research uses the Research and Development (R & D) method with the ADDIE model development stages (Analysis, Design, Development, Implementation, and Evaluation). The data collection instrument consisted of a practicum guide validation sheet based on BSNP criteria and student character observation sheets. The data source in this study was 40 students of class XII SMA N 1 Tanjungbalai academic year 2020/2021 using purposive sampling technique of collecting samples. The results showed that the validation test for chemistry lab guides by expert validators stated that the chemistry practicum guidance based on the integrated STEM approach to character education was valid with an average value of 3.53 from a maximum scale of 4 which means it is feasible and does not need to be revised. Furthermore, the results of observations of the character level of students using a practical guide based on the STEM integrated approach to character education are very good with an average of 85.8%. Based on the results of character validation and observation, it shows that chemistry practicum speakers based on the STEM integrated approach to character education are feasible to be implemented in schools.
The Quality of Learning System by Using Online Learning Technology based on SIPDA during Covid-19 Pandemic
Authors: Atmojo Wahyu Tri , Adisaputera Abdurahman , Masitowarni  , Marice  
Published: March 2021

Abstract
One impact of the Covid 19 Pandemic on the education is the implementation of online learning policy. All the educational institutions are encouraged to develop any online learning platforms and continue to socialize the use of the online learning system to all the academic community. This research aims to assess the quality of online learning conducted by the instructors and college students at the Language and Arts Faculty. The data were obtained through a response questionnaire that distributed to the college students. There are 3294 respondents who took part in this research that consist of the college students who are from the study program of Bahasa Indonesia, Indonesian literature, English literature, Educations of English language, German language, French language, arts, dance, music and performing arts. The research results showed that the implementation of the online learning has a good quality based on the results of the college students’ responses. However, there are several weaknesses in the implementation of the online learning process, such as there are still a small proportion of the instructors (15 percent) who have not been able to use the Unimed online learning information system (SIPDA), and the low feedback provided by the instructors to the college students. The findings of this research then become an input for the head of the Language and Arts Faculty to arrange the online learning policy which will later become a standard guideline for the online learning at the Faculty of Language and Arts, Universitas Negeri Medan.