bluuebunny/crossref_metadata_2025_split huggingface dataset:
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

AbstractLand 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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

AbstractScientific 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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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.