bluuebunny/crossref_metadata_2025_split huggingface dataset:
Study on the compressive behavior of Miura origami column structure
Authors: Permana I G R , Rismalia M , Hidajat S C , Nandiyanto A B , Triawan F 
Published: December 2019

Abstract
Miura-origami pattern has taken interest of many engineers and mathematicians due to its unique foldability and wide range of engineering applications. However, its mechanical behavior is yet to be fully explored, especially when it is made by additive manufacturing (3D printing) method. In this paper, the compressive behavior of 3D printed column structure using the Miura-origami pattern is investigated. Polylactic Acid (PLA) material was used to make the specimen with various printing parameters, i.e. infill pattern and density. Moreover, six kind of origami patterns with different folding angle and wall thicknesses were tested. Finally, the elastic and plastic deformation behavior under compressive load is examined. The result is useful to develop a finite element model which can be utilized to comprehensively explore the mechanical behavior under complicated loading condition. In addition, this study is expected to give impact on developing an innovative engineering design by the use of Miura-Ori pattern, for example is on designing an energy absorption device such as prosthetic leg and automotive crash box.
Re-design tony kart mitox gokart model (Re-design analysis of chain-drive components)
Authors: Mubarak I 
Published: December 2019

Abstract
The purpose of this study was to determine the type of chain suitable for use on karts, besides that this study aimed to determine the safety factors of chain hinges and sprocket gears used in redesigned karts. The method used in this study uses descriptive analysis method, namely by describing the data about the chain wheel on karts, after describing the data, the data are analyzed theoretically about the forces that occur in the chain wheel and the safety of the use of chain wheels used in redesigned kart After analysing the data, it was found that the chain wheels on the redesigned karts were safe to use. This is indicated by the acquisition of a hinge safety factor value of 4.02. The results of this study have an impact on the use of chain wheels on the redesigned karts in the safe category to be used for kart racing purposes.
An experimental investigation on the effects of mineral oil flow rate on CPU immersion cooling
Authors: Kristian S N , Wibowo K M , Pambudi N A , Harjanto B , Bugis H , Biddinika M K , Kuncoro I W , Hijriawan M 
Published: December 2019

Abstract
The aim of this research is to analyze the effect of using immersion cooling with different flow rate and fan rotation on decreasing the temperature on CPU. The study used three variables of flow rate: 0.5, 1 and 1.5lpm. in addition, three other variables of fan rotation, 400, 600, and 800 rpm, were used as well. Data collection was by means of benchmark software to load the CPU to work maximum and the logging software to record the temperature. The results show that the immersion cooling could potentially be utilized as the new and more effective cooling system. The most optimum variable to decrease the temperature was 1, 5 lpm with fan rotation at 800 rpm. It decreased the maximum temperature from 60 °C to 47 °C, a deviation of 13 °C lower compared to the conventional fan cooling system with air as a medium. The study established that the higher the flow rate and the fan rotation, the higher temperature can be decrease. Therefore, immersion cooling can be the solution to decrease the consumption of energy on IT sector on a bigger scale.
Public knowledge in changes of fossil fuel become biofuel on the transportation sector
Authors: Untari R , Pambudi N A , Biddinika M K , Harjanto B 
Published: December 2019

Abstract
The government of Indonesia through vision energy 25/25 saves energy by saving fossil fuels. One sector that consume the largest fossil fuel is transportation. Through the vision, this sector has a great opportunity to make savings by converting fossil fuels into biofuels as stipulated in the mandatory B20 policy. The success of the implementation of the policies depends on providing socialization to the public. Therefore, the objective of this study is to collect the information about the level of knowledge of the community in receiving information about the use of biofuels in the transportation sector. This is a quantitative study using a questionnaire in data collection, finding that people’s understanding of biofuels, including the perception and information of biofuels, still needs to be improved. The results of the study can be used to assist in the planning, implementation and evaluation of policies made by the government in the use of biofuels in the transportation sector in Indonesia. The implications of this study are as a material consideration for increasing the dissemination of information to the public about biofuels, so that the use of biofuels can increase.
Structural, optical, and room temperature dielectric properties of La1-xAxFeO3 (A = Mg, Sr, and Ba) perovskite nanomaterials
Authors: Masta N , Rafsanjani R A , Triyono D 
Published: December 2019

Abstract
This paper investigated the variation of structure, optical and electrical properties of LMFO, LSFO, and LBFO. All samples were synthesized by sol gel method. For this present research study, the structure of the material was investigated by X-Ray Diffraction (XRD). Nevertheless, the electrical properties of this materials were investigated by using RLC Meter. The optical band gap energy was obtained by using UV-Vis Spectroscopy. The optical gap energy evaluated by Kubelka Munk method are 1,58 eV, 1,32 eV and 1,38 eV for LMFO, LSFO and LBFO respectively. Therefore, this small gap energy impacted sensitivity of the material towards its optical properties. To sum up, this what makes all samples are the suitable candidates for alcohol gas sensor.
Analysis of Uranyl Nitrate Hexahydrate composition for optimum neutron multiplication factor of SAMOP
Authors: Wahyono P I , Syarip S 
Published: December 2019

Abstract
Subcritical Assembly for Molybdenum Production (SAMOP) is a concept of nuclear reactor where the neutron multiplication factor (keff) less than one (keff ∼ 0.99). Therefore, SAMOP reactor need an external neutron source for its operation. Uranyl Nitrate Hexahydrate, UO2(NO3)2 or UN is used as fuel as well as target material for 99Mo production. The 99Mo isotope is used to generate 99mTc which is the most widely used radioisotopes for diagnostic in nuclear medical fields. The composition of Uranyl Nitrate Hexahydrate (UNH) should be analyzed to achieve the required subcritical level in the SAMOP core i.e. k-eff ∼ 0.99. Methodology for this analysis is an elemental composition calculation of UNH, with enrichment of uranium of 19.75% and 2.81 gr/cc of density. The analysis result shows that the elemental composition of 235U, 238U, N, O, and H, are 4.9715%, 20.2009%, 5.3448%, 37.4138%, and 32.069% respectively, and therefore, the composition of U and N-O-H are 25.1724%, and 74.8276% respectively. The composition is then used as input for the neutronic analysis using the WIMS-D/4 computer code for keff calculation of SAMOP. The result shows that the optimum keff of 0.99 is achieved with the above elemental compositions.
Microstructural and electrical properties of human blood
Authors: Handoko E , Budi S , Fahdiran R , Saptari S A , Humairrah A , Mutmainnah Z , Puspitaningrum R , Alaydrus M 
Published: December 2019

Abstract
Human blood has been prepared from healthy human body. Structure, and electrical properties of human blood are studied. Scanning electron microscope (SEM) image exhibits a uniform size distribution of thrombocyte of human blood with an average size less than 15 μm. Electrical analysis of the blood sample was measured by linear sweep voltammetry in the potential range between -1 and 1 V with scan rate 50 mV/s to 200 mV/s at room temperature.. At scan rate of 250 mV/s, a peak was clearly observed from 300 mV to 750 mV. The peak should be attributed to an oxidation process of occurred to blood sample.
Complex permittivity, complex permeability and microwave absorption properties of human blood
Authors: Handoko E , Fahdiran R , Budi S , Saptari S A , Humairrah A , Alaydrus M , Mutmainnah Z , Puspitaningrum R 
Published: December 2019

Abstract
This paper reports a method for measuring for the complex permittivity, permeability and microwave absorption properties of human blood of healthy human body. The proposed measurement method can be a useful technique for microwave absorption properties of human blood. The measurement using a waveguide in the microwave band. In order to measure the s-parameter of human blood, a sample should completely fill in the waveguide end and the samples holder using the vector network analyzer (VNA). The complex permittivity and permeability of human blood are resulted in the frequency range from 7 to 13 GHz. Their complex permeability and permittivity, microwave absorption properties values were calculated. The blood sample has the magnetic loss and magnetic energy dissipation. The reflection loss (RL) of blood sample has different absorption with its minimum value of -3.53 dB at 9.36 GHz.
The profile of critical thinking skills students on science learning
Authors: Hidayati Y , Sinaga P 
Published: December 2019

Abstract
Critical thinking skills are an important and necessary skill to confront the challenges in the 21st century. Critical thinking define as basic skills that should be owned by someone to be able to develop thinking skills at a more complex level. This research is aimed to determine junior high school students’ critical thinking skills in science learning. This research is descriptive qualitative research using instruments developed based on aspects of critical thinking skills according Ennis which include elementary clarification, basic support, inference, advanced clarification and strategies and tactics. The subjects in this research were 30 students in grade eight of a junior high school in Bandung which was chosen using purposive sampling technique. The results of the study show that the average percentage of the five aspects of critical skills received by students is 45 and falls into a very low category. The conclusion from this skill of the students still was in a low category, so that needed a way to enhance on indicators of students’ critical thinking skills.
Phase transition in one-dimensional hydrogen chain: A dependence on basis orbitals, cut off radius, and doping
Authors: Prayitno T B , Fahdiran R 
Published: December 2019

Abstract
We demonstrated the dependence of the phase transition in the one-dimensional hydrogen chain on the basis orbitals, the cut off radius, and the doping. For reducing the computational cost, we employed the so-called generalized Bloch theorem, where a hydrogen atom was used in the unit cell. For the non-doped case, we showed a strong dependence of the phase transition on the basis orbitals and the cut off radius, which yields either the antiferromagnetic ground state or the ferromagnetic ground state. When the doping was considered, the spiral ground state appeared between the antiferromagnetic state and the ferromagnetic state. Therefore, we showed that the doping induced the spiral ground state.
Controlling band gap of monolayer MnCl2 with LDA+U
Authors: Prayitno T B , Fahdiran R 
Published: December 2019

Abstract
We performed the noncollinear first-principles calculations to control the band gap of 1T monolayer MnCl2 using LDA+U. It was shown that the increase of the band gap is proportional to the increase of the effective Coulomb energy U, as long as the magnetic moments of the atoms do not reduce. The reduction of the magnetic moment leads to the so-called low spin state, in which the magnetic moment is almost half of the magnetic moment of the high spin state. It seems that the monolayer MnCl2 can be a promising candidate for the spintronics applications.
Implications of higher order tensor in Einstein field equations on vacuum condition
Authors: Prayitno T B , Fahdiran R 
Published: December 2019

Abstract
We investigated the implications of introducing the higher order tensor in the Einstein field equations for the Schwarzschild metric on the vacuum condition and non de Sitter. Since the components of this tensor contain the fourth-order derivative, the solution of the Einstein field equations was solved by using the Frobenius method. To see the implications, we tested two cases, i.e., the deviation of light and the time delay of light. We found that the deviation of light has no correction while the time delay of light needs a correction.
Analysis characteristics of viscosity coefficient using viscometer stromer
Authors: Malik A , Hakiki M A , Imiyati N , Kurnia P , Zakwandi R , Setya W , Chusni M M 
Published: December 2019

Abstract
This research aims to develop methods of measuring the coefficient of viscosity using viscometer stromer are analyzed using Newtons law of 1. The viscometer stormer came from the simple equipment modifications in the form of a hollow cylinder, laver, a pulley, a ruler, a stopwatch, burdens, taps, boards, iron rods, and rope. The trial results do indicate fairly accurate results with the reference. Furthermore, the equipment used, reaching a level of precision that is good at the moment in the trial to the school community. According to the trial results obtained the relationship between viscosity coefficients against time is inversely proportional. The resulting coefficient of viscosity is greater when the mass of the given object is getting bigger. Thus, the viscometer stomer can describe the relationship between the value of the viscosity coefficient, the time and mass of several types of liquid.
[RAV] current meter: Manufacture a measuring instrument of water current using a spring balance
Authors: Malik A , Zakwandi R , Agustina R D , Anjani R , Syamsudin N R , Rochman C , Nasrudin D 
Published: December 2019

Abstract
This research aims to build physics tools of measurement of river flow is current. The tool was developed with the balance spring as a means of collecting the data. data measurement results then analysed mathematically. It is designed using chloride polyvinyl (PVC) which is waterproof. The result of the test tool shows the average error value of 0.3342% and the value of the standard deviation of 0.1893. So, it can be stated that RAV current meter has a level of accuracy and the level of accuracy that is high enough. This equipment still needs to be optimized by performing test audiences to see the ease of the user. In addition. the size of the adjustment to the attention of the research further.
Selection method to identify the dominant elements that contribute to magnetic susceptibility in sediment
Authors: Iswanto B H , Zulaikah S 
Published: December 2019

Abstract
Measurements of magnetic susceptibility (χ) and chemical elements have been carried out on soils or sediments in various depositional environments for various purposes. Theoretically, the magnetic mineral content in nature is generally ferromagnetic which is characterized by the presence of a dominant element of Fe and is positively correlated with the value of χ and can be used as an indicator of environmental conditions. However, the presence of measured Fe elements does not always have a positive correlation with χ and if it has a positive correlation, often the correlation coefficient is very low. In this study, we offer simple steps to find out the dominant elements that correlate significantly with χ. First, a correlation analysis between χ and each measured element is carried out; Second, the elements that have a positive correlation coefficient are chosen; Third, summed all elements that have a positive correlation with χ and carried out a correlation test to χ (R). This step has been tested on sediments in various depositional environments and yields conclusions, if there is a positive correlation value between Fe and χ, even though the low value of r ∼ 0.3, a very significant correlation value will be obtained between total elements having positive r and χ, which is R approximately 0.9. The discovery of a dominant element that contributes to χ, then it will facilitate the determination of the minerals carrying magnetic properties.
TUMPULS teaching aids as an alternative media for physics learning
Authors: Mulhayatiah D , Ningsih R F , Suhendi H Y , Nasrudin D , Yuningsih E K 
Published: December 2019

Abstract
Development of learning media needs to increase students’ interest in learning and stimulate teacher creativity in creating an interactive learning atmosphere. This study aims to develop teaching aids as an alternative to physics learning media in momentum material. The method used in this study is research and development with the stages of analysis, design, development, implementation and evaluation. The stage described in this study is the development stage in the laboratory test section. The laboratory test results for momentum props found that the relative error of the data obtained for the initial momentum was 0.1% and the final momentum ranged from 9%. The momentum props developed were able to present data and show momentum calculations through equations.
Waste to Energy (WtE) as the basis for developing physics learning materials
Authors: Nasrudin D , Rachmadanti F E , Rochman C , Mulhayatiah D , Millah M F , Malik A 
Published: December 2019

Abstract
Many social and environmental issues that the world of education can respond to. One of them is learning physics. One issue that is still a problem is urban waste. This paper aims to describe the development of physics teaching materials by using the waste to energy issue as a learning context. The method used is Research and Development with ADDIE design. This study shows that: (1) student literacy about waste to energy is still low so it needs to be improved (2) The design of physics teaching materials must contain four literacy domains namely content, process, context and attitude (3) Physics teaching materials in the context of waste to energy is declared feasible to use (4) The results of limited implementation in several schools show positive results and (5) Further development is needed to get teaching materials that are simpler, flexible, easy to learn, easy to understand and easy to study. This study concludes that we can present many social topics as the application of the main principles of physics, one of which is Waste to Energy by integrating it in physics learning. Integrated physics teaching materials are proven to improve student literacy on the issue of waste to energy.
Learning materials of natural science of characters-based problems on light and optical concept
Authors: Tirmayasari T , Jufri A W , Harjono A 
Published: December 2019

Abstract
Problem-based learning (PBL) is one of the recommended teaching materials model in the 2013 curriculum. The purpose of this research was to develop learning materials of natural science of characters-based problems on light and optical concept in junior high School four east Praya. Research and development study refering to Dick & Carey model. Validaton by three experts (media, content, and language). The results of the first validation obtained an average of 3.6 and second validation obtained an average of 4.1, this indicates that learning materials are feasible and relevant to be used as learning resources for class VIII. The results of the reading level by Kincaid readability showed that out of 76 pages there were 40 pages of text that corresponded to the junior high school class VIII with a percentage of 52.6%, while the non-compliant text contained 36 pages with a percentage of 47%. The results of a limited trial showed that responses from students by 28% with categories quite interesting, 36% interesting, and 36% very interesting. In conclusion, learning materials of natural science of characters-based problems on light and optical concept was feasible to be applied in science learning processes.
Development of tools problems-based learning model assisted by virtual experiment to increase students’ generic science skills
Authors: Jiniarti B E , Harjono A , Makhrus M 
Published: December 2019

Abstract
Type of research is research and development (R &D). This development research aims to produce physics learning tools using qualified problem based learning model assisted by virtual experiment has a valid, practical, and effective which to increase students generic science skills in subject of optical instruments. In this study, the generic skills that discussed on the science field, called generic science skills. The development model had used a four-D model consisting of define, design, develop and dessiminate phases. Trial of product conducted in students of eleventh grade of the state senior high school 1 east Praya in second semester the academic year 2018/2019and the method used was pre experiment. Generic science skills (GSS) was measured using student worksheet when the learning process was descriptively analyzed based on descriptors appeared on the observational sheet. Based on GSS observation data, that students were in the category “skilled” and “highly skilled”.
A systematic effect of clay volume on porosity – p-wave velocity relationship
Authors: Prakoso S , Burhannudinnur M , Yasmaniar G , Rahmawan S , Irham S 
Published: December 2019

Abstract
It has been believed that P-wave velocity is strongly influenced by complexity of pore arrangement. In Sandstones, the pore complexity is influenced by the constituent material of rock including clay volume. Rocks with a certain clay volume will have a certain pore geometry and pore structure and also, they have certain qualities. This research is intended to study the effect of clay volume on rock quality and its effect on the relationship of porosity with P-wave velocity. This research used 3 sandstone data sets from the North West Java basin, Kutai basin and Southern Sumatra basin. The mineralogy of each rock sample is dominated by quartz and kaolinite. The three data sets show the relationship of porosity and P-wave velocity can be clearly separated by clay volume. Each of these rock groups indicates different qualities called rock types. It can be concluded that the variation of P-wave velocity is influenced by rock type. The lower rock quality is denoted by the larger rock type number and is indicated by the increase in clay volume.
Coating of TiO2 nanoparticles in the surface of transparent plastic grains and its aplication for photocatalyst under solar irraidation
Authors: Amalia I F , Gumilar S , Ismail A , Amalia L , Abdullah M 
Published: December 2019

Abstract
A cylinder milling has been modified by adding a heating controller for coating TiO2 photocatalyst on the surface of polymer at constant temperature. By testing the polystyrene, polypropylene, and linear-low-density polyethylene polymer density before and after coating, it is obtained that polypropylene polymer is suitable for polymer-coated TiO2 because the surface is transparent and can remain floating on the surface of water although it has been coated with TiO2 catalyst. Coating process of TiO2 nanoparticles on the surface of the polypropylene is performed through three stages, that is stirring while heating in the cylinder milling, washing, and drying. The coating temperature is 1100C for 90 minutes. Photocatalytic activity was observed by testing the photodegradation of methylene blue dissolved in water using a container with a surface area 750 cm2 and illuminated by sunlight for 12 days. The experiment was done at 6 containers with similar volume and area and variable amount of catalyst, which is without catalyst (0 g) to 5 layer of catalyst (550 g). From the colour, turbidity, and UV-Vis characterization, the methylene blue decomposition effectively occurred with amount of 220 g catalyst (2layer of catalyst).