bluuebunny/crossref_metadata_2025 huggingface dataset:
Using PhET simulation to learning the concept of acid-base
Authors: Nuraida O , Akbar G S , Farida I , Rahmatullah S
Published: April 2021

This study aims to analyze student outcomes after learning the acid-base concept supported by PhET Simulation. The PhET simulation is used to help visualize sub-microscopic representation of the acid base solution. The method used is one group pre-test and post-test design with the subject this study consists of thirty high school students in the Bandung area. The research instrument used was a test that measured the ability to distinguish the strength of acid-base at the level of sub-microscopic representation, calculate the degree of ionization, the relationship of Ka to concentration, and analyze the pH of the solution. The result of this study it can be concluded that the PhET simulation can improve student learning outcomes to the level sub-microscopic representation.
Neuroscience update on minimally invasive decompression for surgical treatment of neural compression in lumbar spinal stenosis
Authors: Wibawa B , Wibawa G A , Syakdiyah H
Published: April 2021

Neuroscience is a neural science that studies the nervous system, especially studying neurons and nerve cells with a multidisciplinary approach. The scope of the study of neuroscience includes molecular cellular, nervous system, behavioral neuroscience, and social neuroscience. Spinal stenosis occurs when the space around the spinal veins narrows, burdening the spinal cord and nerve roots. A minimally invasive approach to lumbar spine decompression is treatment for patients with spinal stenosis and spondylolisthesis This article was written to carry out a theoretical update of neuroscience with the aim of analyzing what is meant by lumbar spinal stenosis, what are the trends and minimally invasive surgical approaches for the spine and its management? Minimally invasive surgery, may provide the opportunity for a less invasive surgical intervention. It is an approach that bridges the gap between invasive surgery and more conservative treatment for lumbar spinal stenosis.
A new D-Loop mitochondrial nucleotide variation from individual at Naga and Kuta traditional village
Authors: Rosahdi T D , Satiyarti R B , Nurbaeti D D , Miharja D
Published: April 2021

The D-Loop region of human mitochondrial DNA (mtDNA) has a higher level of polymorphism compared to nuclear DNA. Therefore, the mtDNA D-Loop area can determine a particular individual or ethnic identity. This study aims to determine the variation of the D-Loop region nucleotide sequence, namely the Hipervariable I (HV1) region in normal tribal individuals in Kampung Naga and Kampung Kuta. The sample used is the hair root. In determining the variation of nucleotides has been carried out a series of stages of research, namely the isolation of mitochondrial DNA from hair root samples using buffer lysis, mtDNA sample amplification using PCR techniques with M1 primers and HV2R primers, detection of D-Loop region mtDNA fragments by agarose gel electrophoresis, and sequencing of PCR products by the Sanger Dideoxy method and nucleotide sequence analysis of the sequencing results. The results of DNA amplification by PCR showed a band in the area of 1.0 kb. Homology analysis was carried out by comparing the nucleotide sequences of samples with the Cambridge nucleotide sequence, which shows that there are 10 variations. The new variation (morph) is determined by comparing the results of the variations of the two samples with variations from Homo Sapiens Indonesia including Baduy, Sundanese, Javanese (Sangiran), and Madura. Homology results showed 4 new variations, namely c(16184)A, t(16209)C, a(16272)G, t(16519)C. Sapiens Kuta village and Sundanese (general) have a close genetic relationship. The ancestors of the two Homo Sapiens were closely related to Homo Sapiens Naga, Homo Sapiens Naga are closely related to the Homo Sapiens of the Baduy. The ancestors of Homo sapiens, Kuta, Sundanese, Naga and Baduy, are closely related to Homo sapiens Sangiran (Java). Homo Sapiens Madura is most likely the oldest Homo sapiens seen from phylogenetic trees. The results of this study are expected to be able to add Indonesia’s normal human database.
Ethanol and methanol levels of red dragon fruit wine (Hylocereus costaricensis) with the treatment of sugar and fermentation time
Authors: Sudiarta I W , Saputra I W R , Singapurwa N M A S , Candra I P , Semariyani A A M
Published: April 2021

Red dragon fruit (Hylocereus costaricensis) contains anthocyanin which is a polyphenol compound that is rich in pigments, determining the formation of red, purple and blue colors of various fruits and vegetables. Wine fermentation is the process of breaking down sugar into alcohol and CO2 gas due to enzymes produced by yeast cells. Factors that influence the fermentation process are the type of yeast, sugar content, nutrition, temperature, aeration, and pH. The fermentation time in making fruit wine is very important to know to produce wine with good characteristics. This study aims to determine the effect of sugar levels and the best fermentation time on the characteristics of red dragon fruit wine (Hylocereus costaricensis). This research was conducted at the Food Processing Laboratory of the Faculty of Agriculture, University of Warmadewa. Research with a Completely Randomized Design (CRD) consisting of 2 (two) factors and two replications, the first factor is sugar content, which consists of four levels: 10%, 15%, 20%, 25%. The second factor is the fermentation time, which consists of three levels: 10 days, 15 days, 20 days. Variables observed in dragon fruit wine include objective observations: levels of methanol and levels of ethanol. From the results of the study obtained 10.42% ethanol content, and the wine produced does not contain methanol.
Development of mobile learning integration with scientific approaches on electrolyte solution and redox reaction
Authors: Cahyana U , Fitriani E , Utari W
Published: April 2021

This study aims to develop innovative learning media that is mobile learning through scientific approaches on Electrolyte and Redox and to find out the feasibility of media produced. This research was conducted at SMAN 39 Jakarta and SMAN 98 Jakarta from January to May 2019. The research method used is Research and Development (Borg and Gall) by modifying five stages, namely: needs analysis, product development, validation, and product test. The resulting mobile learning media is called “Electrolyte and Redox.apk” that is compatible with Android devices and provides a summary, videos, simulations, quizzes, and educational games. Feasibility test by topic and language expert acquired 83%-100% with 0.808 of reliability. Feasibility tests by media experts acquired 91%-100% with 0.812 of reliability. Media trials by chemistry teachers acquired 88% -100% with “very good” criteria. Media trials by small scale students received 88%, and a large scale gained 92% with “very good” standards. Based on the results, it can be concluded that mobile learning media through the scientific approach in Electrolyte and Redox topic proper to use as a learning media and suitable for students and teachers needed.
Development of mobile learning integration with scientific approach in stoichiometry
Authors: Cahyana U , Hadinugrahaningsih T , Luthfianisa R I
Published: April 2021

This study aims to develop mobile learning on stoichiometry based on the scientific approach. Mobile Learning was tested in two different high schools. Research and Development method by Borg and Gall used by modifying stages of need analysis, development, validation, and product test. The result of need analysis indicated necessary media, which provide a summary, exercise, practical video, animation video, and educational games as learning based on scientific support in stoichiometry. 74% of respondents liked mobile learning. At the development phase, designed mobile learning media and storyboard along with software chosen to make mobile learning. The feasibility test of the media produced 88% with a reliability of 0.77. Feasibility test for topic and language feasibility test produced 88% with a reliability of 0.9. Chemistry teacher’s test acquired 92% as the best criteria. Small-scale student tests acquired 81%, and big-scale student tests acquired 83% considered as the best criteria. According to this, the study concluded that mobile learning media based on scientific in stoichiometry topic is proper to use and suitable for students and teachers needed.
Utilization of fermented cassava skin ration on carcass weight and percentage of broiler carcass
Authors: Mori M B , R Astiti N M A G , Mardewi N K
Published: April 2021

The purpose of this study was to determine the effect of fermented cassava peel flour on carcass weights and parts of broiler carcasses. This study used 45 CP-707 broiler strains. The design used was a randomized design complete with 3 replications. This study uses fermented cassava peels mixed in ration with 5 level administration, namely: without fermented cassava skin flour (P0), fermented cassava skin flour 3% (P1), fermented cassava skin flour 6% (P2), fermented cassava skin flour 9 % (P3), and 12% fermented cassava peel flour (P4). The application of fermented cassava peel at 9% level in the 6-week broiler ration did not significantly affect all observed variables, but application at 6% level tended to increase carcass weight, breast weight, thigh weight, and wing weight. The fermentation of cassava peel flour at 12% in the ration had a significant effect in reducing carcass weights and weight of broilers at 6 weeks. The results showed that fermentation of cassava peel flour in rations up to 6% tended to increase carcass weight, chest weight, thigh weight, and swing weight, whereas at 12% had a significant effect in reducing carcass weight and weight of broilers at 6 weeks.
Integration dilemmas stories in STEAM project of colloid
Authors: Natalya E , Rahmawati Y , Erdawati E
Published: April 2021

The study aimed is to develop students’ chemical literacy through dilemmas stories and STEAM project in chemistry learning in colloid topic. The dilemmas stories of environmental pollution were explored to engage students in contextual problems. The STEAM project of smoke absorbance was used as the problem solutions in dilemmas stories. The learning approach consists of several steps such as value reflection, problem solving, project development, project monitoring and evaluation, and transformation. The research employed qualitative approach with data collection of students’ interviews, reflective journals, observations, and chemical literacy tests. Chemical literacy consists of several dimension such as scientific ideas, chemical characteristics, chemistry in context, high-level learning skills, and affective aspects. The results showed that the average chemical literacy ability of students were 85,29% in the good category. The teacher faced the challenges in developing dilemmas stories to be relevant to chemistry concepts and curricula. Students need to shift their paradigms within active learning approach. The results of this study can be concluded that the integration of dilemmas stories in the STEAM project provides opportunity to develop students’ chemical literacy.
Molecular docking study of inclusion complex between aromatic amine and Calixarene analogs
Authors: Ivansyah A L
Published: April 2021

A molecular docking was performed in this research by using ArgusLab version 4.0.1. It was used to explore the capability of Calixarene analogs for aromatic amine extraction. There are 6 Calixarene analogs used in this research, i.e. Calixpyrrole, Calixpyridine, Thiacalixarene, Heterocalixaromatic, Calixcarbazole and Calixnaphtalene; and the aromatic amine used in this research are Aniline, 4-Chloroaniline, Toluene-2,4-diamine, 2-Naphtylamine, 4,4’-Metylenbis(2-chloroaniline), 4,4’-Metylendianiline, N-Nitrosodiphenylamine, Benzidine, 2-Aminobiphenyl, 2-Amino-1-methyl-6-phenylimidazo [4,5-b] Pyridine, 3-Trifluoromethylaniline, p-Phenylendiamine, o-Toluidin, 4-Chloro-o-toluidin. In this molecular docking simulation, the guest molecule of aromatic amine compounds were treated as ligand and host molecule of calixarene and its analogs were treated as binding site. This molecular docking simulation used AScore scoring function, binding sitebox size for host molecule with grid size of 0.4 Å, GA docking engine with flexible ligand, 50 population sizes, 1000 max generations, 5 elitisms, 0.2 mutation rate, and 0.8 crossover rate. Calixcarbazole and Calixnaphthelene is the best host molecule for aromatic amines extraction because the inclusion complexes formed between them have negative value of binding energy.
Detection of metal elements within Inductively Couple Plasma Emission Jambi batik waste and views as Muslim education
Authors: Deliza D , Syukri A , Wulanda M N , Sartika D
Published: April 2021

Batik in Jambi is located along the Batanghari river, making it easier for craftsmen to throw waste into the river. Batik waste containing heavy metals used is organic and inorganic dyes that are difficult to degrade naturally in the environment. The use of this dye by the batik craftsman industry has a negative impact on aquatic life, this study aims to detect the content of heavy metals and the views of Muslim intellectual. Detection of heavy metals using ICP (Inductively Couple Plasma) and proven to contain inorganic compounds that contain heavy metals Cd, Co, Cr, Cu, Fe: 1,335; 1,287; 1,325; 0.877; 1,022 mg/L. As a Muslim intellectual this is a challenge that must be resolved because it is his duty and together look after and find solutions to what has happened, all the inhabitants of the earth are responsible for the care of the earth. Earth is a place where we can do good and worship in a clean, friendly place with the earth, then friendly with its contents, we associate the environment with science and religion (greendeen).
Autonomous car using CNN deep learning algorithm
Authors: Sonata I , Heryadi Y , Lukas L , Wibowo A
Published: April 2021

Autonomous cars have become an interesting discussion in recent years. Several major automotive industries such as Tesla, GM and Nissan are trying to become pioneers in autonomous car technology. Giant technology companies such as Google Waymo, Baidu and Aptiv also developing autonomous car technology. Several technological approaches are carried out in implementing autonomous cars for recognizing surrounding situations, such as radar, lidar, sonar, GPS, and odometry. An automatic control system is used to control navigation based on the data obtained from these sensors. This paper will discuss the use of CNN deep learning algorithm for recognizing the surrounding environment in creating the automatic navigation required by autonomous cars. The system designed will create and learn the data set that will be taken in advance and the learning outcomes will be implemented in an open simulation system. This simulation shows high accuracy in learning to navigate the autonomous car by observing the surrounding environment.
An empirical study of regression testing techniques
Authors: Rahmani A , Min J L , Maspupah A
Published: April 2021

Regression testing is a testing process for established software and developed ones. Adding features to the software should not cause errors in the previous software version. There are several methods for implementing regression testing. The most straightforward is to do retest-all, but this technique is costly and protracted because it has to execute all test cases in the test suite. This situation is the nature of regression testing research, i.e. determining how to execute only a few test cases to shorten the time, and the faults can be found as much as possible. Recently there are various algorithms for regression testing process. This paper explains an empirical study of several regression testing methods. In the empirical evaluation, we used open-source SUTs, and several are implemented ourselves. On the other side, we utilize an MTS tool from the software artefact repository (SIR) and other open-source tools to automatic testing execution. The empirical study shows that each technique has a specific characteristic, and also has effectiveness significantly to reduce execution time testing process. So that in the regression testing implementation, it is crucial to determining the techniques considering each of them has consequences.
Effective preprocessed thin blood smear images to improve malaria parasite detection using deep learning
Authors: Swastika W , Kristianti G M , Widodo R B
Published: April 2021

Malaria can be difficult to detect from thin blood smears. Image recognition methods such as convolutional neural network can be used to detect malaria, but the training process takes a long time. Previous research created a new architecture and compares it to several other architectures such as VGG-16 and ResNet. The effect of preprocessing is analyzed in this research. VGG-16, ResNet, and the custom architecture created by the previous research are being used in this study. The preprocessing methods being analyzed in this research include gray-world normalization and comprehensive normalization. The highest accuracy improvement per epoch (0.5256% using ResNet-50 and 0.0352% using custom architecture) is achieved through gray-world normalization, that also improves final accuracy (90.1% using ResNet-50 and 93.1% using custom architecture) when compared to other methods with the same epochs for ResNet and custom architecture.
Comparative study of regression testing tools feature on unit testing
Authors: Maspupah A , Rahmani A , Min J L
Published: April 2021

Regression testing is one of the essential activities in software development. Regression testing ensures that the software is still working properly and new software modifications do not cause unexpected defects. Most of the software industry carries out regression testing on the system under test (SUT) by utilizing tools automatically rather than being done manually which requires a long time estimation and ineffective process. Currently, there are many regression testing tools and variations that make software practitioners need additional time and money to analyze the capabilities of the tools. This paper is a comparative study of the capabilities of tools in carrying out the regression testing process in the java programming language. Each tool has experimented with user input data in the form of a SUT program and a test case that has the same characteristics. Furthermore, the tool’s performance is observed based on the feature evaluation criteria. The criteria used are support platform and technology, test case selection, and functionality. The results showed the similarities and differences in the features of the selected testing tool in performing regression testing. Thus it can help users to choose regression testing tools that suit their needs.
Design and implementation software for mining association rules (market basket analysis) to design product layout desicions
Authors: Listiawan T , Hudha M N
Published: April 2021

A provided data from a transactional database, has supported technical development which can automatically find product association or items saved in the database. This finding association rules between saved product in database known as mining association rules. There are so many theories and algorithm developed for conducting mining association rules. One of algorithm developed is Apriori algorithm. This method, has a main goal to find the maximum frequent itemset. Next, this frequent itemset will be generated into associative rules which are not shown before in the database, become valuable information for considering materials in the decision process. Apriori algorithm is a interpretation technique of mining association rules, will be implemented into a web based software. On the software test which use in some different data, it’s concluded that time for mining association rules depends on the presence of every item in every transaction, total of transaction, minimum support and minimum confidence. For smaller value of minimum support and minimum confidence that entered, program will generate more association rules, vice versa.
Some properties of Max-Plus Algebra and generalized inverses on 2x2 matrices integers modulo 3
Authors: Hadi I , Mahatma Y , Sulistyaningrum A
Published: April 2021

The properties of Max Plus Algebra can be applied to the matrix. Furthermore, the generalized inverses in a matrix can also be related to this algebra. This paper discusses some properties of these concepts on 2 x 2 matrices integers modulo 3. Here, we derive the properties of matrices in this algebra. Then, the generalized inverses in these matrices is formed. We conclude that there is some relation between the matrices and its generalized inverses. Some examples of matrices are given to illustrate the properties.
Quantifying ENSO and IOD impact to hotspot in Indonesia based on Heterogeneous Correlation Map (HCM)
Authors: Dafri M , Nurdiati S , Sopaheluwakan A
Published: April 2021

Land and forest fires in Indonesia have a long history. Several major land and forest fires in Indonesia such as in 2002, 2006, 2009, 2015, and 2019 were associated impacts of the ENSO and IOD phenomena. This research aims to find out how much ENSO and IOD impact to land and forest fires in Indonesia. This research used Sea Surface Temperature (SST) anomalies in the Nino 3.4 index region and DMI region as indicators for ENSO and IOD, while hotspot was used as an indicator of land and forest fires in Indonesia. Heterogeneous Correlation Map (HCM) was used to describe the correlation of hotspots with ENSO variance and IOD variance on spatial patterns. The HCM obtained from Singular Value Decomposition (SVD) analysis used to identify the variances. The result showed that anomalies SST in Nino 3.4 index region had greater correlation with hotspot in Provinces of South Kalimantan, East Kalimantan, and Central Kalimantan than those of other regions in Indonesia. Anomalies SST in DMI region had greater correlation with hotspot in Provinces of Lampung, South Sumatera, West Kalimantan, South Kalimantan and Central Kalimantan, than those of other regions in Indonesia. Temporal analysis showed that the largest variance of hotspot in Indonesia mostly in the mid of the year.
Analysis skill of critical thinking on Newton Law Topics using Argument Based Science Inquiry (ABSI) model
Authors: Pratiwi H Y , Sundaygara C , Setyowati T , Ayu H D , Hudha M N , Ika Y , Sujito S
Published: April 2021

Analysis of students’ critical thinking skills is the focus of this study. The material used in this research is Newton’s law. This research was conducted in one of the senior high schools in Malang City. The research was carried out using the critical thinking test method to measure students’ critical thinking skills, with the collection taken was class X IPA with a sample of sixty-four students who were divided into experimental and control classes. The experimental class was applied the ABSI model while the control class was applied to the conventional model. The learning process in the classroom, especially in physics lessons, has not used a learning model that can improve students’ critical thinking skills, namely still using discussion, question and answer and lecture models, this also causes less open opportunities for students to participate in learning and low student curiosity so that impact on students’ critical thinking skills. By using the ABSI model and tests of critical thinking skills in seeing students ‘critical thinking skills in Newton’s law material, the result is that in the class with ABSI model learning, students’ critical thinking abilities are higher than those with conventional models.
The relativistic mass accretion rate for accretion disk in the equatorial of rapidly rotating neutron stars
Authors: Yasrina A , Widianingrum N , Risdianto N S , Andra D , Pramono N A , Fajrin A
Published: April 2021

The accretion process occurs when neutron stars are in a binary system. The hypothesis says that accretion reduces the magnetic field in a neutron star. The correlation between accretion and decrease in the magnetic field is indicated by the magnitude of the magnetic field dynamics and the mass accretion rate. The purpose of this research is to formulate the mass rate of accretion in rapidly rotating neutron stars. The accretion disc is assumed to be at the equator. The method used is theoretical-mathematical analysis. The quantities to be summarized are the Killing vector, 4-vector velocity, the angular velocity, and the Lorentz gamma factor derived from the metric. The metric used is a rapidly rotating neutron star. The rate of mass accretion is calculated from these quantities and the equation for mass sustainability. The equation of mass accretion rate is derived from these variables and the mass conservation equation. The equation of mass accretion rate is affected by the radial velocity of accretion flows and distance between matter and center of a neutron star. The result obtained is covariant with the equation of mass accretion rate for Kerr black holes. The results obtained can provide a dynamic equation for the magnetic field to produce an equation for the decrease in the magnetic field in a rapidly rotating neutron star.
The development of scientific literacy-based physics learning module on direct current circuit material
Authors: Susdarwati S , Dimas A , Hannum F
Published: April 2021

This research and development aim to describe the characteristics, determine the feasibility, and determine the Scientific Literacy-based physics learning module’s effectiveness on direct current circuit material. The development procedure uses the Research and Development model by Thiagarajan with 4-D stages (define, design, develop, and disseminate). The subjects of this study were students of class XII at SMA Negeri 1 Jogorogo Ngawi. Data collection techniques using observation, interviews, and questionnaires. Data analysis was carried out quantitatively and descriptively qualitatively. The results of the research and development concluded that 1) a physics learning module based on Scientific Literacy on direct current circuit material was developed based on the Scientific Literacy component, namely a) the scientific process includes explaining scientific phenomena, using scientific evidence, identifying scientific questions, b) scientific content includes understanding phenomena, and c) the context of science includes solving problems in everyday life; 2) the Module is feasible to use in physics learning in an excellent category, the average percentage of validation results is a) material components: 91.46% b) media components 92.99% c) scientific literacy components 93.75%; and 3) a useful module for improving critical thinking skills including Interpretation, analysis, evaluation, inference, explanation, and self-regulation with an increase of 17.56%.
Developing temperature and wind speed monitoring devices as a way to introduce IoT to students
Authors: Nasrudin D , Sanjaya M R , Setya W , Rochman C , Helsy I , Mulhayatiah D , Suhendi H Y
Published: April 2021

Although the Internet of Things (IoT) application is already widely used by students, understanding the working principle of the device is not easy. This paper aims to describe the way to introduce IoT to students through the development of learning media based on Arduino Uno built-in Wifi on temperature and wind speed monitoring devices. The method used is Research and Development. The results showed a flow chart and design of tool development. After the product is made, an expert’s view of the visibility and function of the device as a physics learning medium is needed before the invention is applied for its effectiveness to be known.
An optical instrument worksheet in physics class
Authors: Nurzaman R F R , Yuningsih E K , Agustina R D , Zakwandi R , Dirgantara Y , Kuntadi D
Published: April 2021

Optical instruments are one of the basic subjects in physics. The use of a very wide range of optical instruments in life creates a demanding environment so that students have adequate skills. This research aims to develop worksheets that can support student skills. The worksheet prepared in the form of a learning tutorial is expected to improve higher-order thinking skills. This study uses a 4D development model (Define, Design, Development, Dissemination) with the stages of implementation to Development. The results showed that there was a significant increase in students” higher-order thinking skills. The student also stated that the worksheets developed had an attraction with a percentage of 79.6% for the implementation aspect, 74.2% for the language aspect, 82.1% for the design aspect, and 75.3% for the acceptance aspect.
The effectiveness of breakwater shape: Fluid particle behavior simulation
Authors: Muliyati D , Sumardani D , Siswoyo S , Bakri F , Handoko E , Permana H
Published: April 2021

The simulation of physical phenomena between fluid and its boundary is a fascinating study because of its application in various fields of engineering. In this simulation, we analyze how fluids are arranged as granular particles with certain conditions interacting with the wall. The walls are varied as the characters that represent the shape of the breakwater building. This simulation compares the effectiveness of commonly used wave barriers. Wave barriers are used to hold the waves from reaching the land. In this, the simulation used two types of wave holders in the form of tetrapod and cubic, which are placed on a sloping surface. Next, an analysis of the farthest distances from the variations in the speed of the waves and the types of waves holds. Simulation results show that tetrapods are able to withstand wave speeds better than cubic.
Electric-field-induced lowest state in bilayer zigzag graphene nanoribbon
Authors: Sanjaya L A , Prayitno T B , Budi E
Published: April 2021

We investigated the lowest state in the bilayer zigzag graphene nanoribbon by taking the electric field into account. In this calculation, we considered five collinear configurations of magnetic moment of carbon atoms at the four edges. We found that the lowest state changes as the electric field is applied. We also showed that at the high electric field, those five configurations almost become degenerate. This suggests that the lowest state is not robust to the electric field so that the electric field can control the lowest state in the bilayer zigzag graphene nanoribbon.
An analytical Generalized Reciprocal Method (GRM) for near-surface seismic refraction investigations
Authors: Sari L , Srigutomo W , Adimayuda R , Andriyani D , Gumilar S , Amalia I F
Published: April 2021

Seismic refraction is one of the active seismic methods that work based on seismic waves that are refracted following the layers of the earth beneath the surface. Seismic refraction surveying is an important tool for determining the geometries and elastic wave propagation velocities of near-surface layer for oil bearing structures. Based on the data acquisition sketch obtained, the acquisition is carried out using the In-Line technique. There are two sources of vibration chosen, namely at the forward and reverse points, the distance between the 5-meter geophone and the distance between the source of the vibration and the geophone of 5 meters. The seismic data processing technique used in this study is the Generalized Reciprocal Method (GRM). This method determines the value of analysis, XY Optimum distance, time-depth analysis value, and depth. In interpreting seismic data, the calculation results that have been made are validated for accuracy using Software. From the research that has been done, it can be known as modeling subsurface structure. There are three layers, the first layer is 6 m-10m deep, while the second layer is 18m-22m deep. In the range of about 0m-20m, the first layer has a velocity of 507.74 m/s, the second layer has a velocity of 1420.43 m/s and the third layer has a velocity of 2522.30 m/s. In the range of about 20m-80m the first layer has a velocity of 550.12 m/s, the second layer has a velocity of 1575.11 m/s and the third layer has a velocity of 2607.45 m/s. In the range of about 80m-100m, the first layer has a velocity of 482.34 m/s, the second layer has a velocity of 1301.09 m/s and the third layer has a velocity of 2400.86 m/s.
Accelerating permafrost collapse on the eastern Tibetan Plateau
Authors: Gao Tanguang , Zhang Yulan , Kang Shichang , Abbott Benjamin W , Wang Xiaoming , Zhang Tingjun , Yi Shuhua , Gustafsson Örjan
Published: April 2021

Permafrost collapse can rapidly change regional soil-thermal and hydrological conditions, potentially stimulating production of climate-warming gases. Here, we report on rate and extent of permafrost collapse on the extensive Tibetan Plateau, also known as the Asian Water Tower and the Third Pole. Combined data from in situ measurements, unmanned aerial vehicles (UAV), manned aerial photographs, and satellite images suggest that permafrost collapse was accelerating across the Eastern Tibetan Plateau. From 1969 to 2017, the area of collapsed permafrost has increased by approximately a factor of 40, with 70% of the collapsed area forming since 2004. These widespread perturbations to the Tibetan Plateau permafrost could trigger changes in local ecosystem state and amplify large-scale permafrost climate feedbacks.
Reduce aviation’s greenhouse gas emissions through immediately feasible and affordable gate electrification
Authors: Greer Fiona , Rakas Jasenka , Horvath Arpad
Published: April 2021

Aircraft at airport gates require power and air conditioning, provided by fossil fuel-combusting equipment, to maintain functionality and thermal comfort. We estimate the life-cycle greenhouse gas (GHG) emissions and economic implications from electrifying gate operations for 2354 commercial-traffic airports in the world. Here we show that complete electrification could yield GHG reductions of 63%–97% per gate operation relative to current practice, with greater reductions correlated with low-carbon electricity. Economic payback periods average just 1–2 years. Shifting to complete gate electrification could save a high-traffic airport an average of $5–6 million in annual climate economic damages relative to estimates of current practice. 10–12 million metric tons of annual GHG emissions are potentially saved if most airports in the world electrified gate operations, costing the 24 busiest global airports on average $25–30, U.S. airports $60–70, and non-U.S. airports $80–90 per metric ton of CO2 mitigated, in some cases comparable to carbon-market prices. Environmental benefits depend primarily upon electricity sources and operational parameters such as aircraft fleet composition.
Scientific thinking skills in solving global warming problems
Authors: A Suryansyah S , Kastolani W , Somantri L
Published: April 2021

Scientific thinking skills are higher-order thinking skills that must be had by students in facing the era of global competition to overcome various problems. This study aims to examine students’ scientific thinking skills covering aspects of logical thinking, analysis, systematic, inductive and deductive in solving problems that include defining, identifying, formulating alternative solutions and determining the best solutions in solving global warming problems. This research uses a quantitative approach as outlined in the form of a description. The subjects of the study were high school students, Bandung City, with a total of 196 people spread across nine schools. Data obtained through questionnaires, observation, literature study, and study of documentation. Data analysis techniques using data reduction, data display, and percentage. The results showed that the students’ scientific thinking skills in the analysis and logical aspects were good criteria. Whereas systematic, inductive, and deductive were sufficient criteria. The development of the issue of global warming has not been implemented well. The researchers recommend that schools and teachers integrate the problem of global warming with learning, train students in studying various global warming phenomena through higher order thinking problems and problem-solving to have scientific thinking skills.
Students’ environmental awareness and pro-environmental behaviour: preliminary study of geography students at state university of malang.
Authors: Handoyo B , Astina I K , Mkumbachi R L
Published: April 2021

In today’s world the environmental problems call for the serious solutions before they reach the point of no return. University students as scholars must be well informed about the current pressing environmental problems through formal education and informal education and become role models and champions of protecting the environment. The aim of this study was to evaluate the level of environmental awareness and pro-environmental behaviour among undergraduate Geography students at State University of Malang. This study used descriptive qualitative research design using survey method. To collect data, questionnaire was distributed among 100 respondents selected using simple random sampling method. Results on environmental awareness indicated that, most of the students were well informed and possessed higher understanding of environmental problems. However, the findings on self-reported environmentally responsible behaviour indicated otherwise that only few students practiced pro-environmental behaviour. There was a mismatch between students’ awareness on environmental problems and their actions towards environmentally responsible behaviour. That means being environmentally awareness does not necessarily translate directly into environmentally responsible behaviour. There is need to increase rising awareness and enhance university students’ engagement to sustainability activities to establishing sustainable initiatives both on campus and beyond.
Structural Geology and Volcanism in Hululais Geothermal Area, Bengkulu, Indonesia
Authors: Nurseto Sapto Trianggo , Arifin Muhammad Tajul , Pratama Graniko Reza , Nusantara Vivi Dewi , Thamrin Mochamad Husni , Suryantini
Published: April 2021

Hululais Prospect in Rejang Lebong, Bengkulu is one of the geothermal fields developed by Pertamina Geothermal Energy. The field is situated within the Bukit Barisan Mountain Range, an NW-SE volcanic arc of Sumatra, and located 8 km western from Musi Segment of Sumatra Fault Zone Zone. Based on field data from geological mapping, remote sensing analyses and borehole data these regional structures influence the occurrence of the NW-SE volcanic axis in Hululais Volcanic Complex (HVC). The Hululais Volcanic Complex (HVC) itself is a Quaternary volcanic complex which comprised of six crown units namely: (Bukit Resam, Suban Agung, Bukit Beriti, Bukit Gedang, Bukit Lumut and Bukit Pabuar) with its associated Hummocks and primary/secondary deposits. These NW-SE distributed of Subang Agung, Bukit Beriti and Bukit Gedang volcanic crowns can be grouped as Hululais Brigade. The manifestations distribution in Hululais also depict the influence of the NW-SE geological structure and its volcanic activity. This is validated by the presence of geothermal manifestation such as fumarole in the central of Hululais Volcanic Complex and hot spring in the medial – distal part of the field.
Integrated Geoscience Data to Identify Heat Source Beneath Umeh Volcanic Complex in Tompaso Geothermal Field
Authors: Suryanto Sigit , Tofan Sastranegara R.M. , Untoro Antonius Rishang , Affif Nanda Najih H. , Effendi Ristio , Raharjo Imam B. , Suryantini
Published: April 2021

Integrated geoscience data evaluation is needed to determine the location of the heat source in the Tompaso Geothermal Field. The location of the heat source in the Tompaso Geothermal Field should be known to update the conceptual model. The updated conceptual model can be used as a reference in development plans of Tompaso Geothermal Field. Therefore, through integrated geoscience data evaluation such as geological settings, remote sensing data, resistivity and gravity data, fluid chemistry data, and temperature measurements data from wells are expected to determine the presence of the heat sources, especially beneath Umeh Volcanic Complex (UVC) in the Tompaso Geothermal Field. Based on geological and remote sensing data, the location of heat sources of Tompaso Geothermal Field are predicted beneath Sempu Volcanic Complex (SVC) and Umeh Volcanic Complex (UVC). SVC is related to recent volcanic activity while UVC is related to “monogenetic” volcanism. The gravity data beneath SVC showed high gravity anomaly contrasts than its surrounding areas, while high gravity anomaly beneath UVC has lower contrast than SVC. However, chemical fluid analysis from thermal manifestations and temperature from the wells indicated the presence of heat source beneath UVC.
Study of catalyst support utilization on ZnO-based solid catalyst to its activity at transesterification of Kesambi (Schleichera oleosa) oil
Authors: Asri Nyoman Puspa , Saraswati Rahaju , Hindarso Herman , Suprapto  , Mirzayanti Yustia Wulandari , Yogaswara Rachmad Ramadhan
Published: April 2021

ZnO-based solid catalyst was successfully synthesized with two types of catalyst support that is gamma alumina and multi walled carbon nanotubes (MWCNTs). Those catalyst would be used to produce biodiesel from Kesambi (Schleichera oleosa) oil via transesterification reaction. The aims of this study are to compare the performance of catalyst support that are gamma alumina and multi walled carbon nanotubes (MWCNTs) for transesterification of Kesambi (Schleichera oleosa) oil. The two kinds of catalyst are gamma alumina supported zinc oxide – copper oxide (ZnO-CuO/γ-Al2O3) and multi-walled carbon nanotubes supported zinc oxide (ZnO/MWCNTs). All of the catalysts were prepared by a combination of precipitation, impregnation, and gel process that familiarly called by Stober process. All of the catalysts, then were analysed by X-ray diffraction (XRD), N2 adsorption-desorption followed by Brunauer-Emmett-Teller (BET) calculation and Scanning electron microscopy (SEM). The yield of biodiesel product has significantly different value which is ZnO-CuO/γ-Al2O3 catalyst can accelerate the reaction more effective than ZnO/MWCNTs catalyst. The yield of biodiesel reached above 80% while using ZnO-CuO/γ-Al2O3 catalyst. Contrarily, ZnO/MWCNTs catalyst only give biodiesel yield below 15% after 3 hours reaction.
Analysis of composite raft mount for vibration reduction of a centrifugal pump
Authors: Kumar G.Vijay , Prasanthi P.Phani
Published: April 2021

The noise induced by centrifugal pump is one of the main concerns in the design and optimization of onboard equipment for ships and submarines. In this work, an attempt has been made to estimate the natural frequency of centrifugal pump with an ordinary conventional steel material foundation. Later, the conventional foundation is replaced with composite material with carbon reinforcement. The vibration studies are accomplished by using FE software ANSYS 18.1. The natural frequencies of centrifugal pump with steel foundation are compared with natural frequencies of centrifugal pump with composite raft foundation. It is observed that the natural frequencies are enhanced by providing composite material foundation.
Investigation of Electro-chemical performance of AZ31 Magnesium alloy – CaSiO3 Metal Matrix Composites in different environments
Authors: Babu Penugonda Suresh , Reddy Y. Pratapa , Narayana K. L , Mallik M. Kedar
Published: April 2021

The electrochemical behaviour of AZ31 magnesium alloy as matrix made as metal matrix composites (MMC) by adding the reinforcement with various weight percentages of Calcium Silicate (CaSiO3) powder was investigated under the influence of 3.5 percent Sodium Chloride (NaCl) and Simulated Body Fluid (SBF) environments using electrochemical workstation. After experimentation, the results exhibit that the pure magnesium alloy sample with 0% calcium silicate exhibits the corrosion rate higher value (40.562mmpy) compared to the other samples when 4 % of calcium silicate is added as additive which exhibits the lower corrosion rate (25.510mmpy). Similarly, the polarisation resistance is also calculated for the samples and the average value of polarisation resistance for the pure magnesium sample is 153.813mA and the other for other samples it lies in between 140.5 mA to 185.72mA respectively. By experimentation it concludes that addition of reinforcement with various weight percentages plays a significant role in the reduction of corrosion rate of AZ31 magnesium alloy rather than using it in a pure form.
Optimization of dry sliding wear parameters of Al4Mg system reinforced with high strength alloy particulate (HSAp)
Authors: Reddy Ch. Kishore , Krishna M. Gopi , Rahul  , Ramana V.S.N. Venkata , Vikas K. Sri Ram
Published: April 2021

The dry sliding wear behaviour of Al4Mg binary alloy and Al4Mg reinforced with Al20Cu20Mg composites was examined using pin on disc apparatus. The composites were synthesized by the reinforcement of different weight % (5, 10 and 15) of the high strength alloy particulate (HSAp) in the base binary alloy Al4Mg using stir casting technique followed by hot extrusion. In this way, composites were prepared with metal particulate reinforcement which are termed as metal-metal composites which is a novel idea instead of reinforcement of ceramic particulate. These extrudates of non-reinforced base alloy and composites were characterized to optimise dry sliding wear parameters, wear resistance and coefficient of friction under the load conditions of 0.5, 1 and 1.5 kgf at the sliding velocities is of 100, 120 and 140 metre per second and sliding times of 15, 30 and 45 seconds respectively. The wear parameters were optimised using Grey relational analysis (GRA) and ANOVA techniques and obtained the optimal combination of input parameters.
Six Sigma Approach for Material Handling System for a Tobacco Threshing Plant
Authors: Farokhi MD.Khaja Moinuddin , Chalapathi P V , Somasekhar K.V.L. , Vinitha M. , Srinivas P Naga
Published: April 2021

The prevailing global market which is competitive and fierce demands superior quality and high flexibility of production with shorter lead times. In order to stay competitive in the market, companies need to attain both customer satisfaction and cost reductions in production operations. Material Handling Systems (MHS) is the place to accomplish this goal, since they have direct impact on production. Material handling and its storage are features of all the companies although they are unexplored areas. Significant contribution made in the material handling area will go a long way in reducing the cost of production and improving profitability and rate of return. Therefore, the aim of this paper is to analyze how an in house MHS that could be efficient for the production it serves. With this intention, a case study has been conducted in A.S.KRISHNA&COMPANY PVT.LTD. Guntur. During the information is gathered through various sources, interviews, observations and measurements. Gathered data is further evaluated according to theoretical framework. By analyzing the findings from literature review and study, first problems and challenges related to present MHS’s are identified. Thereafter, possible features that the system should possess are drawn out and a design is built out of selected features with a compatible plant layout.
Multi-objective optimization using TOPSIS in turning of Al 6351 alloy
Authors: Rao S R , Jeelani S A K , Swamulu V
Published: April 2021

Surface finish and machining rate are the important machining criteria in turning process and plays a vital role in manufacturing environment. This work focused on the parametric optimization of cutting velocity, feed and depth of cut in turning of AA 6351 alloy with carbide tool for maximization of machining rate and minimization of surface roughness simultaneously using technique for order Preference by similarity to ideal solution (TOPSIS) method. Contribution of every machining parameter on multi objectives is spotted by employing analysis of variance (ANOVA). Finally results are validated with a confirmation experiment. Significant improvement within the responses is observed using the TOPSIS method.