bluuebunny/crossref_metadata_2025_split huggingface dataset:
Experimental study of two organic phase change materials in cylindrical containers for battery module thermal management: a comparative analysis
Authors: Budiman A C , Kaleg S , Hidayat N A , Silalahi G N , Gani M N , Sudirja  , Amin  , Muharam A , Hapid A 
Published: October 2021

Abstract
Thermal runaway in battery Electric Vehicles (EV) is one of the most significant threats to their safety and overall performance. In this study, the use of saturated fatty acid and paraffin wax as phase change materials stored separately in a battery-like container, which acts as a thermal absorber for heat dissipation management, is analyzed. The melting characteristics between these two materials are relatively different, as shown from the Differential Scanning Calorimetry results. The fatty acid used in this study has a narrow melting point with its peak at 56°C, while the paraffin mixture has a wide range starting from as low as 37°C. The effect of such different profiles is translated to the difference in the measured temperature profiles. In passive thermal management based on PCM alone, the latent heat capacity is more important than having a melting range when the amount of PCM as heat absorber is strictly limited. However, when the PCM is evenly distributed, the paraffin tubes would have a better thermal profile than the fatty acid ones. Meanwhile, when the air blower is operated hence forming a hybrid thermal management system, there is almost no significant difference between the two PCM under investigation.
Study on Process Optimization and Performance of Low Formaldehyde Etherified 2D Resin
Authors: Liu Ma 
Published: October 2021

Abstract
With the improvement of people’s awareness of environmental protection and safety, formaldehyde emission from textiles is strictly restricted in many countries in the world. In this thesis, 2D resin was modified to prepare etherified 2D resin by a one-step process which is simple, time-saving, energy-saving, and quick reaction. The etherified 2D resin has low formaldehyde content, good handle and wrinkle resistance, and its comprehensive properties are superior to those of 2D resin.
Laboratory Evaluation on the Road Performance of Diatomite Modified Porous Asphalt Mixture
Authors: Liu H B , Liu H , Wei H B , Chai C , Zhu B 
Published: October 2021

Abstract
Porous asphalt mixture (PAM) is an indispensable pavement material for the construction of sponge city with low-cost and environment friendly characteristics, which conducive to replenishing urban groundwater and alleviating the heat island effect. The main purpose of this article is to explore the change of road performance and water permeability of PAM under different diatomite dosage, and determine the optimal amount of diatomite content. First, the volume characteristics of diatomite permeable asphalt mixture (D-PAM) were measured by Darcy’s law, the void of D-PAM decreased slightly according to the test results. Furthermore, based on the water damage Marshall test and freeze-thaw splitting test, the water stability of D-PAM increases significantly with the increase of diatomite content. At last, the low-temperature anti-cracking performance and ductility of D-PAM were carried out based on the acoustic emission (AE) detector and the Low temperature universal mechanics testing machine. According to the experimental results, it is recommended that the content of diatomite is 10%.
Longan Leaves biomass-derived renewable activated carbon materials for electrochemical energy storage
Authors: Taer Erman , Tampubolon Desy Kristin Harida , Apriwandi  , Farma Rakhmawati , Setiadi Rahmondia Nanda , Taslim Rika 
Published: October 2021

AbstractBiomass-based energy conversion and storage applications have proven to be the most effective technology for practical and sustainable applications. However, their further development was hindered by poor electrode performance. Naturally, abundant biomass is a green alternative carbon source with many desirable properties. This study presents a relatively easy approach for the synthesis of activated carbon-based electrode materials derived from natural biomass with an emphasis on supercapacitor applications. The selected biomass waste is Longan leaves. The precursor was converted into activated carbon through ZnCl2impregnation at three different concentrations in high-temperature pyrolysis. All activated carbon confirmed a good amorphous structure. Furthermore, oxidative compounds were also found to have an effect on their electrochemical properties. supercapacitor cells prepared in a two-electrode system exhibit high electro-capacitive properties with a specific capacitance of 169.83 F g−1at a constant current density of 1.0 A g−1in an aqueous electrolyte of 1 M H2SO4. Furthermore, the optimum energy density was found in LF0.5 samples as high as 19.04 Wh kg−1at a maximum power density of 124.37 W kg−1.
Coupling Backpropagation Neural Network and AdaBoost Algorithm for Quantitative Analysis of Nickel via Laser-Induced Breakdown Spectroscopy
Authors: Harefa Edward , Zhou Weidong 
Published: October 2021

AbstractA wide area of cropland or soil might well be contaminated with heavy metals, contaminating agricultural goods and posing a risk to human health. As a result, it is required to evaluate the concentration of heavy metals in soil. The combination between laser-induced breakdown spectroscopy (LIBS) and multivariate chemometrics methods was employed to determine heavy metal Ni concentration in twelve soil samples. The comparison between univariate calibration curve, traditional backpropagation neural network (BPNN), and hybrid BPNN-AdaBoost was presented. The result revealed that BPNN-AdaBoost outperformed other models with the coefficient determination calibration(RG2), coefficient determination prediction(RP2), root mean square error calibration (RMSEC), root mean square error prediction (RMSEP) are 0.985, 0.977, 2.04, 3.18, respectively. This study indicates that BPNN-AdaBoost can be adopted as a reliable chemometric technique to enhance the quantitative analysis of heavy metals based on LIBS.
Less Expensive and Eco-Friendly Preparation of Activated Carbon Derived from Coffee Leaf as an Supercapacitors Electrode
Authors: Taer E , Gultom E S , Agustino  , Taslim R , Febriani W 
Published: October 2021

AbstractIn this paper, less expensive and eco-friendly biomass-based activated carbon from coffee leaf (CL) was prepared as electrode materials for supercapacitor applications using KOH activation, carbonization, and physical activation in a CO2atmosphere. Using cyclic voltammetry and galvanostatic charge/discharge techniques, the CL sample was tested in a two-electrode configuration operating in 1 M H2SO4. After physical activation, the percentage reduction of the mass, diameter, thickness, and diameter are 76.47%, 29.38%, 28.57%, and 38.04%, respectively. The CL sample exhibits specific capacitance, energy and power densities of 210 F/g, 29.17 Wh/kg, and 39.99 W/kg at constant current 1 A, respectively. Therefore, the CL sample obtained through KOH activation, carbonization, and physical activation using CO2atmosphere has a promising future applied as an electrode material for supercapacitor applications.
Matoa Fruit peel-based Activated Carbon and its Application as an Electrode Materials in Supercapacitor Devices
Authors: Taer Erman , Agustino  , Taslim Rika 
Published: October 2021

Abstract
The use of matoa fruit peel waste-based activated carbon as electrode materials for supercapacitor devices is described in this paper. The chemical and CO2 activation were used to prepared the activated carbon. In the chemical activation process, zinc chloride 0.1 M was used as a chemical reagent. Cyclic voltammetry (CV) and galvanostatic charge-discharge (GCD) measurements are used to assess the electrochemical performance of as-prepared electrode materials. After CO2 activation process, the density of the MFP samples have been decreased. From the CV and GCD data, the MFP-0.1 sample has optimum specific capacitance are 158 F g−1 and 187 F g−1, respectively. The electrochemical results demonstrated that the MFP sample is a potential choice for supercapacitor electrode materials.
The Effect of Support on the Catalytic Efficiency of MnO2/Activated Carbon for degradation of Methylene blue
Authors: Yanti Aurora SD , Sophia Halida , Anggraini Riska , Siregar Siti Saidah , Awaluddin Amir 
Published: October 2021

Abstract
Methylene blue (MB) is a blue cationic thiazine dye which is widely used in cotton fiber, wood and textile industries, but has an adverse effect to environment and living organism. It is urgent to find an alternative and effective solution for this recalcitrant compound. The Fenton process-based advanced oxidation process is considered as an effective method for the degradation of organic contaminants such as dyes. In this study, the composite α-MnO2/activated carbon (AC) was first synthesized by a facile, one-pot synthesis using sol-gel method and characterized by X-ray diffraction (XRD) and BET surface areas. The XRD results indicated that the tunnel cryptomelane-type manganese oxide (α-MnO2) was successfully synthesized as the minor phase in the activated carbon support. The composite α-MnO2/AC has higher specific surface area than the single α-MnO2. The catalytic studies indicated that the α-MnO2/AC has a much higher catalytic efficiency over single α-MnO2 for degradation of MB. The presence of the support and the increase in surface area of α-MnO2/AC could be responsible for its higher catalytic efficiency compared to single α-MnO2. In the optimum condition, the α-MnO2/AC was able to degrade 98.48 % and 99.2 % of MB within 10 and 120 minute of reaction time, respectively.
Constructivism-Based Magnetic KIT Design as a Science Learning Media
Authors: Ridho Muhammad , Rahmad M. , Wulandari Sri 
Published: October 2021

Abstract
Some students still feel foreign to hear about electrical material because the material that is passed by some considers it to be still abstract. So that the concept of electric magnetism is still a lot of misconceptions. Based on the research, there are also some teachers who make assignments to students for experiment at their respective homes which makes students not do experiment but imitate the existing theory. The research aims to design a magnetic KIT that can be used for practicum at school. This study uses a 4D development model which is limited to the media development stage. The development of KIT magnets designed with four experiments with precision values in each of experiment have a very high range from 0.93 to 0.99 which it can be categorized high and the highest precision. So that from very high precision the error percentage of the magnetic KIT experiments are the lowest ranging a the lowest precentage 1.8%-9.7% which is categorized as a very low percentage of the magnetic KIT device. So the accuracy of the magnetic KIT device can be said to be very high. For the first and second experiments the results obtained are not much different from the existing theory. The percentage of errors for the first and second experiments ranged from 1.8%-8.6% while the third and fourth experiments were carried out repeatedly but the results were not much different or almost the same.
A preliminary study of a landfill as a raw material for RDF: a case study in Medan City
Authors: Rhoshenia D A , Utami R , Khair H 
Published: October 2021

Abstract
The increase in population is directly proportional to the use of goods/materials, resulting in the volume of waste produced. If it is not processed, an increase in the volume of waste will lead to the emergence of piles of waste and the need for landfill land to accommodate waste is higher. One solution to solve the waste problem is to convert waste into fuel through Refuse Derived Fuel (RDF). This research aimed to study the characteristics of the landfill and its potential as an RDF raw material. The research was conducted at the Terjun Landfill in Medan. This study found that the water content of the waste ranged from 12.88 percent to 38.35 percent, the ash content from 0.625 percent to 1.575 percent, and the calorific value from 12,13 MJ/Kg to 36,58 MJ/Kg. According to the findings, inorganic combustible fraction waste can be used as a raw material for RDF and a substitute for coal.
Using Hawgent Mathematics Software to Help Primary School Students to Read Clocks
Authors: Pereira Jerito , Jianlan Tang , Wijaya Tommy Tanu , Purnama Aditya , Hermita Neni , Tamur Maximus 
Published: October 2021

AbstractClock reading is a very important skill for students however there are still students that finds clock reading difficult to understand. Technology can help students to understand mathematics concepts. This research developed a learning media using the research and development method and the ADDIE framework. The sample of this research are 87 students from Bandung, Indonesia. The learning media is made based on the analysis of teachers’ and students’ difficulties on clock reading. The result of this research shows that Hawgent dynamic mathematics software can help students to understand clock reading. The learning media also received a positive response from the students. During the teaching and learning process, students were more active in answering the teachers’ questions and were able to follow the instruction given. This research proved that technology can help students in various aspects that includes getting students’ attention so that they more focused in learning mathematics. The use of technology can be used for various topics in various grades.
A Comparison of Bagging and Boosting on Classification Data: Case Study on Rainfall Data in Sultan Syarif Kasim II Meteorological Station in Pekanbaru
Authors: Adnan A , Yolanda A M , Natasya F 
Published: October 2021

Abstract
A frequent way for classification data is using a machine learning algorithm alongside ensemble methods like bagging and boosting. In earlier studies, these two algorithms have shown to be very accurate. The aim of this research is to discover performance of bagging and boosting to classify rainfall data obtained at the Sultan Syarif Kasim II Meteorological Station in Pekanbaru from 1 January 2018 until 31 July 2021. Rainfall data are classified into two categories: rainy and non-rainy. The parameters are average temperature, average humidity, sunshine duration, wind direction at maximum speed, and average wind speed. For comparison, this study developed Stochastic Gradient Boosting with Gradient Boosting Modelling and C5.0 from boosting, as well as Bagged Classification and Regression Tree (CART) and Random Forest from bagging. In order to generate reliable conclusions, each algorithm is run 30 times with repeated cross validation. The result demonstrates that Stochastic Gradient Boosting with Gradient Boosting Modelling is the best algorithm based on average accuracy.
Item Analysis of Heat Transfer Concept Using Rasch Model in Elementary School
Authors: Hermita N , Sakinah S , Wijaya T T , Vebrianto R , Alim J A , Putra Z H , Fauza N , Dipuja D A , Pereira J , Jihe C 
Published: October 2021

Abstract
This study aims to analyze test items of heat transfer instructional materials using the Rasch model to obtain information on the Wright map, item measure, item fit, and item reliability. This study applied a quantitative-descriptive research design. The subjects in this study were 75 fifth graders of State Elementary School 192 of Pekanbaru. The students were asked to do 11 essay items. Students' responses on the essay items were collected through Google Form. The collected data were then analyzed using the Rasch model on the Winstep® application version 3.73. Based on the data analysis, item 2 and 3 were the most difficult items, and item 10 was the easiest item. All items are at a moderate difficulty level. There was an invalid item of 11 items. The item reliability value was 0.75 which meant sufficient. In conclusion, the 10 test items (1 is invalid) are selected for inclusion in the achievement test to measure the students' understanding of heat transfer instructional materials.
The Groundwater Analysis using Geoelectric Method Wenner Rules in Rejosari Village, Tenayan Raya Pekanbaru
Authors: Juandi M , Ginting E N 
Published: October 2021

Abstract
The interpretation of groundwater in Rejosari Village, Tenayan Raya, Pekanbaru City has been carried out using geochemical and geoelectrical methods using Wenner-Schlumberger rules. This study aims to identify aquifer layers, determine flow patterns, and groundwater quality. Measurements were made on two tracks with a length of 68 m and 100 m respectively. Based on the results of data processing, it is known that the groundwater aquifer layer is at a depth of up to 5–15 m below the surface with a resistivity value 9.4-160.40 m. The pattern of groundwater flow in the study area tends to spread and is located at a certain depth. In track one, the aquifer layer is on the upper surface, while for track 2 the distribution is to a depth of 18 meters. The lithology of the subsurface layer in this study area is a layer of peat with a resistivity value 138.9–170.8 m, gravel with a resistivity value 117.4–160.4 m, and sandstone with a resistivity value 117.4–170.8 m.
Dynamic Simulation of Bioethanol Production from Banana Rejected using Flocculating Yeast
Authors: Contreras J , Haro Y , Gelves G 
Published: October 2021

Abstract
A dynamic model is presented to simulate a fermentation process for bioethanol production from banana rejected using a batch system. The critical model feature is using an inhibition function to relate substrate concentration and specific growth rate. Kinetic parameters were calculated based on previous experimental data, and the optimal substrate concentration is investigated. The Andrews kinetic model was adapted to the concentration profiles, indicating that it could describe the existence of substrate and product inhibition. Different initial substrate concentrations were evaluated (90-400 g/L), and simulated results suggest 200 g/L of rejected banana as a starting point to reach a high and efficient bioethanol production since a maximal ethanol production is reached with a value of 150 g/L. However, when using a higher banana, rejected concentration inhibition occurs, and therefore bioethanol production decreases to reach levels lower than 100 g/L. Based on results found, kinetic models allow obtaining important observations on microbial metabolic processes and facilitating a good approximation for further large-scale stages.
Cellulase Production from Trichoderma harzianum: a Framework Modeling for Evaluating Different Operating Mode Strategies
Authors: Mora D , Carrillo F , Gelves G 
Published: October 2021

Abstract
The cellulase enzyme has been used in essential applications in the textile industry and the formulation of some medicines. Therefore, a mathematical model based on previous reports is proposed for cellulase enzyme enhancement. First, the kinetic constants were taken from the literature. Then, two operating strategies were carried out to maximize cellulase production using 10g/L of cellulose and 0.4g/L of cells as a first strategy using a batch mode. Alternatively, a second operating mode is simulated using continuous cellulose feeding. Finally, a comparative analysis was made for determining the best operating mode related to maximal cellulase production. Interestingly, the continuous mode shows a high cellulase concentration lasting a shorter time than the batch mode to avoid inhibiting enzyme production. One of the most important findings of this work focuses on increasing cellulase production with values of 1800 FPT/L simulating the continuous mode. The latter suggests that cellulase production could be double the concentration obtained with the traditional batch mode (800FPU/L). Results obtained in this research may be promising for the enzyme production industry. Using simulation techniques, it is possible to determine an enhancement without requiring excessive experimentation and resources.
Efforts to Prevent Land Fires through the Use of Potential Peatlands in Coastal Areas
Authors: Syahza Almasdi , Nasrul Besri , Suwondo  , Irianti Mitri , Meiwanda Geovani 
Published: October 2021

Abstract
The development of the agricultural sector for coastal communities, especially on peatland plays an important role in the structure of the regional economy. In Riau province, there are potential peatlands of approximately 64% of the total land area, that support the local people's lives, especially for agriculture. These peatlands also have various ecological functions such as flood and global climate controls. Therefore, this study aims to determine efforts to prevent land fires through the development of superior commodities in potential peatlands. This study was carried out through a survey using the developmental research method and the data were collected with a participatory rural appraisal (PRA) approach. The food crops cultivated on the peatland were rice, corn, and cassava, and were carried out for the first 2-3 years. Furthermore, long-term crops such as rubber, sago, and coffee were also planted. The results showed that the use of peatland with an economic value has a positive impact on its management. Therefore, this effort is capable of preventing the occurrence of land fires.
Numerical Analysis of Filtering Circuit for Partial Discharges
Authors: Liew H F , Ariefbillah A B , Syed Akhmal J , Junaidah A M J , Norhanisa K , Muhammad Izuan R F 
Published: October 2021

Abstract
Partial Discharge (PD) is a small electrical spark that happens within the insulation of medium and high voltage electrical assets. It is important to note that the discharge will erode the insulation and eventually result in disastrous insulation failure. Thus, PD detection is a crucial issue in high voltage insulation area. However, the on-site field PD tests, the high frequency PD signals detected by sensors, are vulnerable to interferences and background noises. This has a negative effect on high voltage apparatus fault diagnosis and localization accuracy. For that reason, noise suppression has become an urgent and vital issue for field high frequency PD signal testing. Thus, this research aims to model a filtering circuit to suppress the noise along with PD in high frequency measurement. A filtering circuit was analysed by using Proteus software to filter out the noise along with PD with decent accuracy and efficiency. Then, performance investigation of active high pass and passive high pass was conducted and studies to filter out PD noise suppression in high frequency were successfully developed. The active filter was focusing on the first order stage until fourth order stage. The passive filter only concentrated on two types of order stage; first order stage and second order stage. The result demonstrated that active high pass filter presented the best performance with low decibel frequency response (-20 dB), and was suitable for this research purpose compared to passive high pass filter. Besides, 700 Vrms has been selected to check the response at high voltages and the frequency values set at 50 Hz for low frequency and 8 kHz for high frequency. This specification design values have been selected because it is suitable for situations in high-tension power line. This type of filtering circuit is suitable to be used for academic and lab experimentation.