bluuebunny/crossref_metadata_2025_split huggingface dataset:
Vertical structure of raindrop size distribution over West Sumatera from global precipitation measurement (GPM) observation
Authors: Ramadhan R , Marzuki  , Harmadi  
Published: May 2021

Abstract
Vertical Structure of Raindrop Size Distribution (DSD) over West Sumatera (99.82 E – 100.82 E; 0.73 S – 0.27 N) was observed from Normal Scan (NS) of Global Precipitation Measurement (GPM) observation during December 2014 to June 2018. This observation was carried out for stratiform and convective rain. The vertical structure of DSD from GPM was described as two gamma distribution parameters, namely, mass-weighted mean diameter (Dm
) and total raindrop concentration (Nw
). In addition, the vertical structure of integral rainfall parameters was investigated from the vertical structure of radar reflectivity (Z). It was found that vertical structure of DSD from NS of GPM observation shown different value for both stratiform and convective rain, for the same rainfall intensity. The NS of GPM estimates larger (smaller) Dm
(Nw
) for convective than stratiform rain. It indicates convective has more large drops than stratiform rain with lower of total drops number for the same rainfall intensity. Furthermore, the gradient of vertically downward from Dm
and Nw
is slightly larger during convective rain than during stratiform rain for all classes intensity. This indicates a more significant growth of raindrop in rain column during convective rain than during stratiform rain over West Sumatera.
Development of technology vermicompost production for the coffee plant Industry
Authors: Zulhipri  , Erdawati  , Purwanto Agung 
Published: May 2021

Abstract
The aim of this study was to convert skin coffee (SC) amended with green waste (GW) and biochar(B) into vermicompost and evaluates their effects on the plant growth coffee. Biochar is a carbon rich product made from the rice husk pyrolysis process at 450°C, green waste eq branch cuttings and leaves from in the garden Universitas Negeri Jakarta and skin coffee from Cibulao coffee farm Bogor, Indonesia. Biochar was mixed with SC and GW in different proportion i.e., 6%,8% and 10% b along with control and allowed to pass through earthworm guts during two months. Vermicompost was characterization with SEM EDX and chemical content. The 8% biochar addition rate achieved maturity of vermicomposting and resulted in the highest quality vermicompost based on parameters such as organic C, C:N ratio, total N, P, K content and pH, were compared to a vermicompost as control. in the cultivation of plant growth, physiological parameters and morphology plant coffee growth such as number of leaf, heigh plant, steam diameter and shoot dried weight.
Deformation analysis for Padang earthquake using GPS data
Authors: Iqbal Rahmat , Syafriani  , Arisa D , Setiadi B 
Published: May 2021

Abstract
On September 30, 2009, an Mw 7.6 earthquake occurred off the coast of Sumatra. This earthquake caused deformation in the area around the center of the earthquake. Surface deformation in the area around the epicenter was Analyzed carried out using GPS data from the SuGAr (Sumatran GPS Array) network. The observed SuGAr stations were TIKU, PSKI, NGNG and MSAI. Data processing used GAMIT/GLOBK software. GPS data were observed for 100 days before and after the main earthquake occurrence. The measurement results indicate that the MSAI and NGNG stations in Mentawai deformed towards the south-weast direction, varies between 38 - 50 mm, and TIKU and PSKI stations on the mainland of Sumatra were deformed in north-west directions, varies from 5 - 12 mm. This indicates that this Earthquake deformed the area of Western Sumatra and nearby Mentawai regions, in Siberut Island.
Analysis of validity and practicality test of physics enrichment e-book based on CTL and enviromental factor
Authors: Asrizal  , Desnita  , Darvina Y 
Published: May 2021

Abstract
Teaching in the 21st century should have context, use multiple learning resources, and use ICT. This teaching will support the attention, involvement, and motivation of students. However, learning resources for physics enrichment and the use of ICT in physics teaching were still limited. The solution to this problem is to develop a physics enrichment e-book. The research objective was to determine the validity and practicality of the physics enrichment ebook on the theme of motion. This research method can be categorized into research and development. The development model in this research was included in the ADDIE model. The research instrument consisted of two parts, namely the validity assessment questionnaire sheet from the experts and the practicality assessment questionnaire sheet from the physics teachers and students. The research data were analyzed using descriptive statistics. From the results of data analysis, it can be stated that two results from this research. First, the validity of the physics enrichment e-book can be classified into a very good category in the aspects of learning material, presentation, language, graphics, and e-book criteria. Second, the practicality of using physics enrichment e-books based on CTL and environmental factor can be included in the very good category according to both physics teachers and students in the aspects of usability, easy of use, appealing, and clarity. Therefore, physics enrichment e-book based on CTL and environmental factor has met the high generic quality criteria of intervention in the components of validity and practicality.
The analysis of depth high school physics material in terms of standars for the development of earthquake theme physics e-books
Authors: Perwita D P , Fauzi A 
Published: May 2021

Abstract
The aim of this study was to determine the current level of depth of the material compared to standard books, if the physics material was superficial, it will be added with standard material. So, before developing an earthquake-themed physics e-book, it was necessary to conduct a depth analysis of high school physics material in terms of standard material. The population of this study was a high school physics book and a physics standard book, with a sample of two high school physics material books class X semester 1 based on the 2013 curriculum and two physics standard books. This study was descriptive qualitative in nature, using a sheet instrument of physics material depth analysis in terms of standard material. The data collection techniques were used documentation and content analysis. Based on the analysis, it was found that the physics material for class X semester 1 was still in the deep enough category. This was evidenced from the results of the depth analysis of physics material in terms of standard material that basic competence (BC) 3.1, 3.2, 3.3, 3.4, 3.5 and 3.6 with the percentage of depth respectively 20%, 87%, 47%, 60%, 60%, and 53%. Therefore, shallowness in physics material will be complemented by standard material, thereby improving the quality and having a high level of depth in the high school physics e-book in the development of earthquake physics e-book. So, the next study to be carried out is to develop an earthquake-themed high school physics e-book.
Analysis of learning media based electronic for developing of physics e-book with earthquake theme
Authors: Yanti Y , Fauzi A 
Published: May 2021

Abstract
Education always tries to take advantage of technology in the learning process according to the needs of students and teachers. Teachers and students need learning media based electronic to minimize the limitations of space and time, and prepare students mentally in the face of natural disasters. This study aims to analyze learning media based electronic as a preliminary study for the developing of physics e-books with earthquake theme used in physics learning. This research uses a quantitative descriptive methods with the population being all students of class X at SMAN 2 Ranah Pesisir and the sample selected using a purposive sampling technique. The instrument used was a questionnaire about learning media the distributed to students that included thirty five statement. The results showed that the quality of technical, content and purpose were in good category with values of 73.09%, the quality of learning were in good category with values of 74.30% and learning media based electronic were in simply category with values of 68.97%. These results indicate that the learning media based electronic need to be further improved. So, further research needs is the developing of physics e-book with earthquake theme for students.
The validity of the science edupark E-Book with a scientific approach based on Padang Beach tourism destinations
Authors: Elvisa Gita Oktia , Rifai Hamdi 
Published: May 2021

Abstract
Learning science by utilizing tourist destinations can observe objects and phenomena in a more real way. Tourist destinations as a source of learning in the form of educational tours are called edupark. This research aims to produce a valid science edupark e-book. Validity is needed to test a study. The validity tested in product development is a material substance, appearance feasibility, presentation feasibility, and language. The edupark e-book validation was carried out by three experts. The research conducted was Design Research with the type of Development Studies using the Plomp model with the steps of Preliminary Research, self-evaluation, expert review. The research instruments were the validity instrument sheet and the edupark e-book validation sheet. Analysis of the data from the results of the validation by the validator shows that each aspect of validity has met the valid category. This shows that the edupark e-book developed meets validity aspects, namely aspects of material substance, feasibility of appearance, feasibility of presentation, and language. Thus, the edupark e-book developed is valid for use in learning.
Identification of students’ misconception about light using a four-tier instrument
Authors: Maison  , Asrial  , Susanti N , Effrita A , Tanti  
Published: May 2021

Abstract
The research objective is to make a valid and reliable identification of junior high school students’ misconceptions about light. The four-tier light instrument (FTLI) was administered to 456 students from two junior high schools in Jambi, Indonesia. Data were analyzed to obtain the percentage of students who have scientific concepts and misconceptions. The results indicated that only 7.7% understood the concept well, and 12.1% had misconceptions about light. The remaining students were categorized as experiencing false positives, false negatives, and lack of knowledge. There are 12 types of misconceptions about the light that can be identified. Some of them are: (1) Light cannot reach faraway places, but distant observers can see the light source; (3) The distance traveled by the candles during the day is shorter than at night; and (3) The color vision of an object is not determined by the color of the light hitting the object.
Implementation of constructivism approach in physics learning on students’ critical thinking ability of junior high school students
Authors: Nurpatri Y , Muliani D , Indrawati E S 
Published: May 2021

Abstract
The background of this study is the problem of education in pandemic of Covid 19 where the students should study from home. The students are tended to extra learn and they are asked to understand and comprehend the material deeply by themselves. One of learning approach that can solve their problem is by implementing constructivism approach, especially in physics learning. This study aims to analyze previous studies related to implementing constructivism approach in improving students’ critical thinking ability and to obtain sources to develop physics learning module about constructivism approach for grade VIII. This research method is a meta-analysis with a sample of 10 articles in national and international journals. The data collection is done by collecting and classifying similar scientific articles and then analyzing them. The result of study shows that there are 8 out of articles used experimental research, and others used field research and classroom action research. Furthermore, there are 40% of articles show the effectiveness of constructivist approach to improve students’ critical thinking ability in physics learning such as students can express their ideas by discussing with others students, they can make a conclusion after doing experiment activity, and they train to express their mind by debating. In conclusion, constructivism approach can improve students’ critical thinking ability and it is needed developing beneficial physics module to get more improvement and to be a source in physics learning.
Development of online learning tools based on problem solving on circular motion materials
Authors: Serevina V , Khofiya N 
Published: May 2021

Abstract
Online learning device is a device used in the online learning process. During the Covid-19 pandemic, teachers are required to change the learning system directly into online learning. This research aims to developing online learning tool based on problem solving in effective circular motion material in the midst of the covid-19 pandemic. This learning tool was made online in order to facilitate teachers and students to conduct teaching and learning activities on physics subject matter by using problem solving learning models. Learning tools were validated by three experts, namely media experts, material experts, learning experts and one physics teacher, and tested on students. The trial subjects were carried out in class X SMA as many as 25 students. Data collection instruments use a questionnaire guide through Google’s forms. The development of this research includes ADDIE research with the stages of development: 1. Analysis, 2. Design, 3. Develop, 4. Implement, 5. Evaluate. From the results of research on the development of problem solving based online learning tools on circular motion material obtained learning devices (learning implementation plan, student activity sheet and online media) have been tested for eligibility by experts and field trials with good criteria and are suitable for use.
Validity of student worksheet inquiry based learning model with multi-representation approach integrated scientific literacy for grade XI physics learning on 21st century
Authors: Septiani T , Yulkifli  
Published: May 2021

Abstract
Student worksheet is a learning resource that guides student during investigations or problem solving. Learning activities will be successful if they are carried out with the right learning model and learning approach as well as supporting literacy skills. Based on the analysis of the needs and characteristics of student, and the limitation of previous validation studies, student worksheet based on the inquiry-based learning model with an integrated multi-representation approach to scientific literacy can be a problem solution. The purpose of this study was to produce a worksheet based on an inquiry based learning model with an integrated multi-representation approach to scientific literacy in valid category. This research method uses descriptive statistics. The instrument was used a validation sheet filled out by experts. The validity of student worksheet obtains on the feasibility of content, presentation, language and graphic components. The average of the four components of student worksheet validation was 0.81 by development experts. In this way, it can be said that student worksheet inquiry-based learning model with an integrated multi-representation approach of scientific literacy is in valid category.
Hand-arm vibration transmissibility measurement from the petrol driven motorboat engine
Authors: Isa M S M , Mazlan A Z A 
Published: May 2021

Abstract
Petrol driven motorboat engine consisted of direct handle-engine mounting mechanism which exposed the operators to the high level of vibration and can lead to the Hand-arm Vibration syndrome (HAVs). The transmitted vibration from the engine to the handle with natural frequency excitation making the transmitted vibration worsen. This study is focusing on the vibration analysis of the 3.3 HP motorboat engine and the transmitted vibration to the operator handle in specific directions and frequency ranges. A lab-scale experimental rig with motorboat engine is set-up to represent the actual operation of the motorboat engine. Experimental Modal Analysis (EMA) is conducted at the motorboat handle to obtain the natural frequencies in y and z axis directions. Two levels of engine speed (Speed 1: Low and Speed 2: High) are taken into consideration for the vibration measurement of both engine and handle in x, y and z axis directions. From this study, the natural frequencies of the handle are determined within 75 – 80 Hz. For the vibration spectral measurement, the engine has produced high vibration in x and y axis directions, whereby the transmitted vibration to the handle is worst in y axis direction. At Speed 1, the engine excited the vibration within frequency range of 45 – 50 Hz while by increasing the engine to Speed 2, the vibration peak shifted to 95 – 100 Hz with higher vibration amplitude. In overall, the vibration transmissibility at the handle are significant between the frequency range of 0 – 100 Hz (above 1) which can result the HAVs among the operators if no necessary action been taken.
Acoustical periodic test of sound level meter based on smartphone application using free-field method
Authors: Dwisetyo B , Hermawanto D , Putri C C , Rusjadi D , Palupi M R , Utomo F B , Prasasti N R 
Published: May 2021

Abstract
The number of smartphone-based application software for noise measurement has been increasing recently. Some application software has complete features of the sound level meter such as frequency weighting and time averaging. They have been used for field noise measurement. However, the reliability of the smartphone-based sound level meter as a measurement instrument has not known yet. In this paper, we tested the smartphone-based sound level meter application software according to the international standard for sound level meter calibration IEC 61672. The parameter of self-generating noise, frequency weighting, and long-term stability in a fully anechoic chamber was measured. We evaluated the class of the smartphone-based sound level meter from the deviation of the measured parameter with the tolerance value described in the standard. The practical implementation of the calibration method is also discussed.
Design of ECG Front End Amplifier Based on CMOS OTA
Authors: Zhang Zekun , Meng Fanxiang , Fan Luyuan 
Published: May 2021

Abstract
The low-noise and low-power amplifier, an important part of ECG recordings, remains a vital challenge in the biomedical instrumentation amplifier field. This paper describe a method of using the capacitive feedback structure and the MOS-bipolar pseudo-resistor to reject the DC offset and amplify signals down to the milli-hertz range. This study used the noise efficiency factor (NEF) to quantify the tradeoff between power and noise. Fabricated in a 180 nm CMOS process, the amplifier consumes 1.44 µW, and achieves the input referred noise of 3.89 µVrms The calculated NEF is 18.07, while the corresponding to common-mode rejection ratio (CMRR) is 87.72 dB. The device achieves low-noise, low-power and appropriate CMRR, which provides a reference for the design of biomedical instrumentation amplifier.
Modeling and Simulation of Lithium-ion Battery Considering the Effect of Charge-Discharge State
Authors: Jin Yin , Zhao Wenchun , Li Zhixin , Liu Baolong , Liu Liu 
Published: May 2021

Abstract
Establishing an accurate battery equivalent model is an important link in the development of battery management system (BMS). The second-order RC equivalent circuit model can accurately describe the dynamic characteristics of the battery. Considering the influence of state of charge (SOC) and battery charging and discharging state on the model parameters, the battery model parameters in charging state and discharging state are identified separately through battery performance test experiments. The equivalent circuit model of lithium ion battery with variable parameters is established by Simscape language, and simulation analysis is carried out. The results show that, considering the influence of battery charge and discharge state, the error of the model is small and the accuracy of the model is improved.
Luminescence Properties of Lu3+ doped Nd: YAG Transparent Ceramics
Authors: Jia Wentao , Wei Qinlei , Zhang Hongbo , Su Chunhui , Ren Guozhong , Zhao Mengjie 
Published: May 2021

Abstract
Lu2O3 doped Nd: YAG transparent ceramics were prepared by solid-state reaction and vacuum sintering. Ionic size compensation was investigated by comparing the X-ray diffraction patterns (XRD) and Raman spectroscopy (Raman) of (Nd0.06LuxY2.94-x)3Al5O12 ceramics. The micrographs and element mappings of ceramics samples sintered at 1750°C for 50 h were analyzed by scanning electron microscope (SEM) and X-ray energy dispersive spectroscopy (EDS), respectively. The emission peak intensity of 1064 nm is the largest, which corresponds to the 4F3/2→4I11/2 transition of Nd3+. Fluorescence spectra and decay curves show that the fluorescence intensity was the highest when the concentration of Lu2O3 was 0.02, and the fluorescence lifetime was 193.92 µs. The elimination of lattice distortion is beneficial to the improvement of fluorescence properties, which can be attributed to ionic size compensation of Lu3+.
Effect of NBTI on the Electrical Characteristics and Trap States of Low Temperature Poly-silicon Thin Film Transistor
Authors: Wang Si , Zhu Hui , Li Rui , Liu Jie , Liu Zheng , Li Dong , Zhang Zhirang 
Published: May 2021

Abstract
Polysilicon thin film transistors have broad application prospects in high-performance flat panel displays and flexible wearable devices due to their high carrier mobility and good stability. However, due to process conditions and other reasons, there are traps inside, and under some electrical stress conditions, its electrical properties will degrade. Here we report the changes in electrical characteristics of p-type polysilicon thin film transistors with stress time at a negative gate voltage of -20V and a temperature of 60°C. It is obtained that the transfer characteristics of the p-type polysilicon thin film transistor move in the negative direction with the increase of Negative Bias Temperature Instability time, and with the increase of SS degradation, and the total trap state inside it is calculated by SS, which provides a theoretical basis for improving the reliability of the device.
Preparation and Luminescent Properties of Tb4O7: CaWO4 Glass Ceramics
Authors: Wei Qinlei , Ma Chaoyu , zhang Cong , Zhao Mengjie , Zhang Zhongxing , Su Chunhui 
Published: May 2021

Abstract
Tb4O7: CaWO4 glass ceramics with CaWO4 (41–1431) as the main crystalline phase were prepared by the melt crystallization method. The effects of holding time on the crystal phase, transmittance, and fluorescence intensity of glass ceramics were studied. As the increase of holding time, the crystal phase does not change, the transmittance decreases gradually, and the fluorescence intensity first increases and then fade. The optimum heat treatment conditions were determined: heat treatment at 750°C for 70 min. Tb4O7: CaWO4 glass ceramics exhibit blue, green, and red light under the excitation of 245 nm light, and the green light emission at 545 nm is the strongest, which is attributed to the 5D4 →7F5 transition of Tb3+. Under the same heat treatment conditions, the emission spectra of Tb4O7 with different doping concentrations were studied, and the optimum doping concentration was determined as 0.6 mol%.