bluuebunny/crossref_metadata_2025 huggingface dataset:
Application of geothermal physics to support geotourism development in Maluku Province
Authors: Souisa M , Sapulete S M
Published: March 2021

This investigation aims to determine the hydrophysical gradient and the distribution of shallow surface geothermal manifestations. Geothermal manifestation data acquisition using the hydrophysical method. The manifestation of surface geothermal at the research location is only used by the local community as a place for bathing, and there is no accurate data regarding the potential of geothermal so that it can be used as a development of tourist objects (geotourism). The results showed the distribution of temperature and conductivity of surface hot springs based on hot springs around geothermal energy, consisting of two locations, namely the locations of Tulehu Village, Salahutu Subdistrict, and Nalahia Village, Nusalaut Subdistrict. The Tulehu Village location consists of two loci that are the Hatuasa locus with surface temperature values ranging from (60.1 - 80.9) °C and conductivity values ranging from (0.69 - 0.95) W/m. °C, and Talanghaha locus locations surface temperature values range from (65.5 - 67.5) °C, and conductivity values ranging from (0.68 - 0.78) W/m.°C. Whereas the location of Nalahia Village consists of the Bantang locus which has a surface temperature value of (50.1 - 61.9) °C, and the conductivity value is (0.51 - 0.71) W/m.°C. For this reason, the hydrothermal conditions of geothermal manifestations in the two research sites can be developed into geothermal hot water and maximum therapy to improve the economy of the local community and the development of the geotourism sector in Maluku Province.
Improving of students’ critical thinking ability through learning based on CCM-CCA assisted virtual experiments on optical materials
Authors: Makhrus M , Ayub S , Wahyudi  , Verawati N N P S , Busyairi A
Published: March 2021

This study aims to improve students’ critical thinking skills of optical material through the application of CCM-CCA assisted by virtual experiments. The study was conducted using a mixed-method that is using the exploratory design. The subjects of this study were 30 students in the physics education study program. Students’ critical thinking skills are obtained through critical thinking tests. The results showed that the CCM-CCA assisted by virtual experiment was feasible to use for an optical material. Students’ critical thinking skills have increased in 5 indicators of critical thinking, namely basic clarification, basic decisions, inference, further explanation, reasoning. Learning instructions based CCM-CCA assisted with virtual experiments on optical materials are valid and can be used in learning. Students’ critical thinking skills have improved after learning with CCM CCA with the help of virtual experiments. The inference indicator experienced the highest increase among other indicators.
Development of digital handout on particle wave dualism material
Authors: Akhsan H , Rianti S , Muslim M , Ariska M
Published: March 2021

A valid and practical digital handout on particle wave dualism material was produced in this study. The adaptation of Rowntree product development model and Tessmer formative evaluation was used as the method on the Physics Education Study Program, FKIP, Sriwijaya University. The walkthrough and questionnaire techniques was used to collect data. The result showed the mean score for the validity of the digital handout was 4,53 for the design, content, and linguistic aspects with a highly valid category. The practicality average score in the one-to-one evaluation stage was 79,08% (practical) and in the small group evaluation stage was 84,59% (practical). The product can be used as an additional material in modern physics learning to improve students’ technological literacy.
Mechanical properties of composite board based on coconut coir and terminalia catappa fruit fibers with Polyvinyl Acetate (PVAc) Matrix
Authors: Susilawati  , Doyan A , Muliyadi L
Published: March 2021

The synthesis of composite board made from a mixture of coconut coir and Terminalia catappa fruit fibers using Polyvinyl Acetate (PVAc) matrix has been successfully carried out. The synthesis aims to determine the effect of a mixture of coconut coir and Terminalia catappa fruit fibers with PVAc matrix on the mechanical properties of the composite board. The samples were made with variations in the composition of the volume fraction of coir fiber and Terminalia catappa fruit fibers, namely (30:70), (40:60), (50:50), (60:40), and (70:30)%. The ratio of the volume fraction of the mixture of natural fibers and the PVAc) matrix made was (70:30)%. The sample production begins with taking the coconut coir and Terminalia catappa fruit, drying and cutting, then mixing the coconut coir and Terminalia catappa fruit fibers with a PVAc matrix, printing the composite with printing tools and drying. The finished sample was then mechanically tested using the UTM tool AnD, model R3010. The results showed that the value of the maximum tensile stress and the modulus of elasticity increased with the increase in the concentration of coir fibers used. The value added in length and strain decreased with the decrease in the concentration of coco fiber used. Overall, the composite sample has met the SNI 03-02105-2006 criteria where the maximum tensile stress value ranges from 8.21 MPa to 18.81 MPa and the modulus of elasticity ranges from 829.71 MPa to 1620.67 MPa.
Analysis of susceptible disaster region based on the peak ground acceleration and earthquake intensity in Mamasa 2018
Authors: Anugrayanti A , Arsyad M , Tiwow V A
Published: March 2021

This study aims to know the susceptible disaster region based on peak ground acceleration and earthquake intensity on earthquake study cases in Mamasa 2018. Data that is used in this research is data on earthquake cases in Mamasa 2018 that is gained from the Indonesian Agency for Meteorology, Climatology, and Geophysics (BMKG) district IV Makassar, it included data of the time when the earthquake happened, latitude, longitudinal (, depth (< 60 km) and magnitude (≥ 5) SR. The calculation of on peak ground acceleration was conducted by using Donovan and Mc.Guirre methods, whereas to calculate the value of intensity, it is using the Wald method (1999). The result from the calculation of on peak ground acceleration by Donovan is 95.903 gal to 377.094 gals with the intensity VI to VIII MMI. Whereas the calculation result of on peak ground acceleration by Mc.Guirre method is 58.981 gal to 227.39 gals with the intensity V to VII MMI. MMI intensity of the Wald method is obtained by using the PGA value conversation Mc.Guirre method that is closer to the intensity of the result of the macroseismic survey in Mamasa District and relates with the damage that happened on location. The mapping of earthquake intensity based on PGA Mc.Guirre method shows that 3 (three) sub-districts that have an intensity of VII MMI, namely Tawalian Sub-district, Mamasa Sub-district, and Sesean Padang Sub-district. The area is the most vulnerable. Mamasa has low-risk level from the earthquake, although sometimes an earthquake happened until now. This result is supported by a geological map in the Mamasa regions that showed source rock in that area is a type of hard rock that consis of granitic materials.
Students’ misconceptions on rotational and rolling motions
Authors: Rafika R , Syuhendri S
Published: March 2021

This study aimed to analyze the misconceptions experienced by senior high school students on rotational and rolling motion topics. The sample consisted of 35 students of a state senior high school in Palembang, Indonesia, in grade 11 in a science class. The data was collected using the Rotational and Rolling Motion Conceptual Survey (RRMCS), and were analyzed using modified Certainty of Response Index (mCRI) with a scale of 0 to 5. The result showed that the distribution of students’ conceptual understandings were in four categories, i.e. understanding the concepts 1.70%, understanding the concepts but not sure 1.90%, holding misconceptions 58.30%, and not understanding the concepts 38.10%. It can be identified that the students experienced misconceptions in all the concepts involved, namely 54.30% in the moment of inertia, 57.10% in rotational kinetic energy, 60.0% in angular velocity, 62.90% in angular acceleration, 58.90% in the moment of inertia, 51.40% in rolling motion (relative motion), 65.70% in rolling motion (the role of friction and other parameters), and 55.70% in the sliding cube on an inclined plane. Therefore, teachers should consider these misconceptions experienced by students in choosing appropriate strategies to overcome them.
Optical and structural studies on bio-synthesized ZnO using Citrullus lanatus peel extract
Authors: Fadillah R , Rati Y , Dewi R , Farma R , Rini A S
Published: March 2021

Bio-fabrication of ZnO films using plants, enzymes, and microorganisms has been recognized as an environmentally friendly procedure as an alternative to physical and chemical methods. In this research, the optical and structural properties of ZnO thin film have been investigated using UV-Vis spectrophotometer, X-ray diffraction (XRD), and Scanning Electron Microscopy (SEM), respectively. The ZnO films was prepared by spin-coating the mixed solution of Zn(NO3)2 and watermelon (Citrullus lanatus) peel extract on glass substrate. The ZnO films were then annealed at 400°C for 3h. The UV-Vis absorbance spectra show the strong absorption peaks occurs over a range of wavelengths of 220-380nm, and 190-235 nm for pre-annealed and annealed samples, respectively. The optical band gap of the samples was influenced by the heat treatment. The as-prepared samples synthesized at pH 8 is 3.73 eV and increased up to 5.4 eV after annealed at 400 °C for 3 h. This result suggested that pre-annealed sample has better photocatalytic activity compared to the annealed samples. The XRD pattern of the ZnO films exhibits the ZnO diffraction peaks that correspond to the hkl of hexagonal wurtzite structure. SEM image shows that the morphology of ZnO samples are spherical and rod-like microstructure.
Deflection light in strong field from global monopole in Eddington-inspired Born-Infeld gravity
Authors: Huda I N , Ramadhan H S
Published: March 2021

We examine the deflection of light due to the gravitational field of global monopole in Eddington-inspired Born-Infeld theory using strong field approach, which accurately explains light deflection when the impact parameter is small. In this paper, we will discuss the deflection angle and the radius of the photon sphere. We discover that the global monopole will increase the deflection angle and the radius of the photon sphere (compared to Schwarzschild), while EiBI parameter will decrease the radius of the photon sphere and the decreasing of deflection angle is shown clearly with small impact parameter.
The linear regression method of the RC circuit for electrical impedance characterization
Authors: Ain K , Purwanti E , Rulaningtyas R , Hairiyah N A
Published: March 2021

An impedance bode plot modelling simulation has been conducted with the regression method to determine the RC model. The aim of the research is to determine the RC model and determine the resistance and capacitance of the equivalent circuit. The study uses nine RC models which are modelled into a linear regression equation and the equivalent model is determined based on the smallest error. Gradient and regression constants are used to determine the resistance and capacitance of the equivalent model. The results in the RC series show that the equivalent model is the first model with a resistance 998.580? and a capacitance 9.253 pF with an error 2.4%. While the program implementation of the RC parallel produces a resistance 999.809? and a capacitance 9.995 pF with an error 0.042%.
Temperature and water level control system in water thermal mixing process using adaptive fuzzy PID controller
Authors: Tunjung D , Prajitno P , Handoko D
Published: March 2021

Thermal Mixing Process, which is important in various industries, is a multiple-input multiple-output process (MIMO). It works by regulating hot-water and cold-water flows to control the temperature and level of the mixture. The Adaptive Fuzzy PID Control (AFPIDC) algorithm is a combination of two types of controller, has a simple PID basis with added Fuzzy aspects to speed up control. The AFPIDC algorithm is applied to the simulation of water thermal mixing process and is done with MATLAB/SIMULINK program. The fuzzy algorithm uses two inputs (errors & changes of errors) and has three outputs (changes of PID constants). The system is tested by simulating setpoint changes and adding disturbance. The testing result shows that AFPIDC controllers performs better than PID in controlling temperature and level. In temperature control, the PID settling time is 830 seconds, AFPIDC is 328 seconds and the PID overshoot is 6,3% and AFPIDC is 0%. In level control, the settling time of PID is 3221 seconds, while AFPIDC is 235 seconds, with PID overshoot is 10,5%, while AFPIDC 0%. From testing the system with leakage disturbance, the temperature controller needs time to regain stability at PID 780 seconds, AFPIDC 250 seconds. Meanwhile the level controlling stabilizes at PID 4510 seconds, and AFPIDC at 225 seconds.
New approach allowing detection of Cl using a pulsedcarbon dioxide (CO2) laser-induced breakdown spectroscopy (LIBS)
Authors: Sari A M , Lahna K , Ramli M , Miura A , Kurihara K , Marwan  , Idris N
Published: March 2021

A new approach to allow detection of Cl emission using atransversely excited atmosphere (TEA) carbon dioxide (CO2) laser-induced breakdown spectroscopy (LIBS), namely utilization of a metal sub-target, was introduced. The Cl sample was prepared from pure chemical powder in the form of a solutiondeposited on the metal sub-target. A zinc selenium lens was used to focus the CO2 laser beam (10.6Mm, 2.5 J, 10 Hz, 200 ns) onto the deposited sample under the surrounding gas of helium (pressure of 1 atm) for generated luminous plasma. An optical multichannel analyzer (OMA) system was used for collecting plasma and acquiring the emission spectrum. It was found that luminous plasma can be produced upon focusing the laser irradiation onto the deposited layer of the sample on the subtarget metal while leaving no ablation from the sub-target metal. Many ionic emission lines from Cl can be detected in the visible region.The ionic emission lines occur withfavorable spectrochemical features, namely strong emission intensity and low background level. Thus, this new approach is promising for conducting Cl analysis using a CO2 LIBS.
Elemental analysis and the impact of Sr substitution on magnetic properties of Nd(1-x)Sr(x)MnO3 (x = 0; 0.5 and 1) perovskite manganite
Authors: Dharmayanti A M R , Munazat D R , Razaq D S , Kurniawan B , Mustaghfiroh Q , Nanto D , Handoko D
Published: March 2021

The series sample of Nd(1-x)Sr(x)MnO3 (x = 0; 0.5 and 0.1) has been prepared with sol-gel method. The elemental compound or chemical characterization of Nd(1-x)Sr(x)MnO3 (x = 0; 0.5 and 0.1) were obtain using Energy Dispersive X-Ray Spectroscopy (EDS). The EDS results show that the elements were all presents in the sample, which also verified that the sample has successfully synthesized. The Vibrating Sample Magnetometer (VSM) was used to measure the magnetic properties of the sample under room temperature. The results show that the material is all soft magnetic with the magnetization decrease as the temperature decrease.
Development of holmium oxide glass calibration system measured using mathematical modelling
Authors: Prihhapso Y , Achmadi A , Suryani D , Farhania W , Nelfyenny  , Zaini H
Published: March 2021

Holmium oxide glass filter has known to exhibit persistence absorption lines across the visible region. Due to these properties, a holmium oxide glass filter is used as a reference standard to calibrate the wavelength accuracy of a spectrophotometer. In this research, a system consists of a double-monochromator and a photomultiplier tube will be evaluated. Mathematical modelling is used to calculate the true value of the absorption lines of the holmium glass filter to compensate for the low optical resolution of the double-monochromator system. Measurement results are validated by comparison with the single-monochromator-order shorting filter system which has higher optical resolving power. Wavelength differences between double-monochromator and single-monochromator systems are better than 0.1% and within the expanded uncertainty of 0.32 nm. Therefore, the double-monochromator system is suitable to provide measurement traceability for the calibration of holmium oxide glass filters.
The strategy of student-worksheet design with a causalitic-learning model to improve creative-thinking ability
Authors: Warodiah Y N , Rokhmat J , Zuhdi M , Kosim  , Ayub S
Published: March 2021

This study aims to identify preparation strategies a causalitic model of student-worksheet (SW) to improve students’ creative thinking ability (CTA). This type of research is a Research and Development with a 4-D model. The research procedure refers to the stages in the 4-D model, namely the stages of defining, designing, developing, and disseminating. The instrument used was the SW validation questionnaire with a Likert scale of 1 to 4. The data were obtained from the SW validation by a validator consisting of 2 expert lecturers and 3 high school physics teachers. The validation result is 86% with very valid criteria. Based on the values and validation criteria, the causal model SW to improve the creative thinking ability of students is suitable for use in learning. The SW preparation strategy includes curriculum analysis, making needs maps, determining the SW title, basic competencies and indicators of competency achievement, central themes, and assessment tools, as well as compiling materials, and paying attention to the SW structure of the eight sets of strategies, there are three are uniques, namely the second, sixth, and eighth steps.
Implementation of causalitic-learning devices to improve creative thinking ability and problem-solving of students in physics
Authors: Rezeki H , Rokhmat J , Gunawan  , Makhrus M , Wahyudi
Published: March 2021

This study aims to test the effectiveness of the causalitic model learning device to improve students’ creative thinking ability and problem-solving. The design of this study was a one group pre-test and post-test design with a purposive sampling technique so that 15 students were obtained. The research instruments used were lesson plans, preliminary assignments, student worksheets, with data collection tools in the form of tests of creative thinking ability and problem-solving. Data were analyzed using calculation of N-Gain.Thus, the implementation of causal learning tools to improve creative thinking skills and physics problem-solving students is effectively used in learning.For further researchers, it is necessary to increase the frequency or duration of learning so that students can better understand learning.
The effectiveness of experiential learning – STEM model with formative assessment in building students’ mastery on fluid dynamics
Authors: Parno  , Mufti N , Widuri K A , Ali M
Published: March 2021

Fluid dynamics is related to science, technology, and daily lives, but students’ understanding of the topic is considered not optimal yet. This study aims to investigate the effectiveness of experiential learning (EL) – STEM model with formative assessment (FA) in building the mastery of fluid dynamics and explore students’ difficulties. This is a mixed-methods research with an embedded experimental design with 34 grade XI students of high school in Malang, Indonesia, as subjects, which were chosen with purposive sampling. This research used dynamics mastering test instrument in the form of 18 reasoned multiple-choice question items with a reliability of 0.65. The data were analyzed with Wilcoxon Signed Ranks test, N-gain, and the description of students’ answers. The result showed that EL-STEM with FA is effective to build the mastery of fluid dynamics with the effectiveness of the subtopic of Bernoulli’s law is higher than the subtopic of Continuity. Before learning, students had difficulties to understand almost all material of fluid dynamics. However, after learning, students only had difficulties to understand certain things, which are the relationship between physical quantities in Bernoulli’s law, the distance between the water reservoir and the water jet, the speed of air under or above the wing of an aeroplane, and the shape of aeroplane’s wing design.
Development of temperature monitoring and prediction system for urban heat island (UHI) based on the internet of things
Authors: Hidayat D J , Soekirno S
Published: March 2021

The population increase in urban areas is one of the primary reasons for changing the local climate, and there is a high impact on the surrounding areas. Due to rapid urbanization, natural land surfaces are being replaced by an artificial land cover which negatively impacts the ecosystem resulting in Urban Heat Island (UHI) effect. It has a detrimental impact on residential environments and implications for human health. Accurate UHI intensity information can be very helpful to take effective urban planning strategies. This research contributes to developing a temperature monitoring system based on the Internet of Things to support UHI information. The system is designed using a DS18b20 temperature sensor. Data from the sensor is processed by the data logger and sent to the server using the ESP8266. The system will process data from sensors into urban and rural temperature information and the UHI index. Besides, an Artificial Neural Network approach presented in this study for predicting temperature to anticipate the impact of increasing the UHI index. As a result, the system could be implemented to provide real-time information about temperature and UHI on the website. Sensor calibrated has a correlation coefficient R2 about 0.99996 and 0.99997 and data sent percentage 100% and temperature prediction using ANN were successfully made with acceptable accuracy of 85.1%.
Effect of annealing hold time on thickness and optical properties of barium titanate solar cell material
Authors: Cahyono Y , Ramadhanti S , Rasmianti  , Dewi Y N K , Asrori M Z
Published: March 2021

The development of perovskite-based solar cells has recently attracted the attention of many researchers because the efficiency value increases rapidly in a short span of time. Third generation solar cells have the potential to achieve Shockley-Queisser Limit of 31% for single energy bandgap solar cells. Besides that, this solar cell technology is economically very promising because the manufacturing costs are cheaper. The main drawback of this solar cell is its low stability (lifetime), which is caused by degradation over its lifetime. In addition, most of the high efficiency perovskite-based solar cells still use lead (Pb), so they are not environmentally friendly. Another alternative perovskite material is required. One promising material is Barium Titanate (BaTiO3). As a material for solar cells, not much research has been done. BaTiO3 film has been successfully made, which is then given annealing treatment at temperature of 500 °C, with annealing time of 30 minutes, 60 minutes, 90 minutes, and 120 minutes. In general, increasing the annealing time increases absorbance, decreases film thickness, decreases energy bandgap, and tends to reduce grain size of film. Energy bandgap tends to decrease with the increasing grain size. The grain size of film decreases with the decreasing thickness. More in-depth characterization and analysis are needed, especially those related to microstructure analysis.
First-Principles study of thermoelectric properties of Half-Metallic Non-Magnetic Half-Heusler alloy Mn2Ge
Authors: Azhar A , Majidi M A
Published: March 2021

Research about Heusler alloys have been massively conducted through experimental and theoretical studies due to their fascinating properties. Most of Heusler alloy compounds exhibit half-metallic behavior, in which one of the spin channels of such a material behaves as a metal and the other behaves as an insulator because there is an open energy gap at the Fermi level. On the other hand, the thermoelectric properties of the materials usually work well in the insulator or semiconductor phase rather than in the metal phase. Motivated by such interesting phenomena, we conduct first-principles study to explore the thermoelectric properties of Mn2Ge, one of Heusler compounds that exhibits half-metallic behavior. Our calculation results show that Mn2Ge of the spin-down channel has a high Seebeck coefficient and ZT value (electron part) at room temperature around 892 MV/K and 0.97, respectively. The positive sign of the Seebeck coefficient on spin-up and spin down indicate that the majority charge carrier in Mn2Ge are positive charges (holes).
Development of multithread acquisition system for high quality EEG signal measurement
Authors: Apriadi W , Gani H S , Prayitno P , Ibrahim N , Wijaya S K
Published: March 2021

This work was concerned on development of the EEG acquisition and EEG signal processing by adding active electrodes and implementing multithread techniques. By using active electrodes, mounting them on the scalp surface would be easier to capture low signals of less than 1µV. The active electrodes were used to reduce noise when transfer signals from the electrode to the acquisition systems which equipped 20 gain. The verification was performed by comparing the active and passive electrodes using NETECH MiniSIM EEG Simulator 330. The advantage of this research was to reduce time delay for EEG signal computation on 32 channels. The acquisition system was based on Raspberry Pi and ADS1299 with multithread signal treatment. Signal filtering was performed into different threads and put all the EEG features into the database. A PC was used to process signal calculation such as processing FFT, signal feature extractions, and signal analysis. These calculations were divided into several functionally independent computations. The signals of each channel were calculated into different threads. The results of this work showed the effectiveness of the multithreaded method for processing large amounts of data (32 channels of 24 bits EEG signal) with low noise levels on the active electrodes.
The influence of Think-Pair-Share (TPS) cooperative learning methods on the results of studying physics assessed from student attention
Authors: Saraswati D L , Sari T A , Kameswari D , Solihatun S , Sirait E D , Apriyani D D , Alfi Z R , Nazelliana D , Ardy V , Rahmawati N D
Published: March 2021

The purpose of this study was to see the effect of the TPS Cooperative learning method on physics learning outcomes in terms of student attention. The research method used was an experimental method. One group was used as the experiment group, namely the physics treatment with the TPS model, While the other group as a control group treated with a model of learning physics discussion. From each group then divided into groups that have high activity and low activity. Based on the results of the analysis, it can be ignored that there is no significant interaction effect between the TPS cooperative learning method and attention to physics learning outcomes. This can be proven where F_count < Ftable (3.289 <4.11) at a very significant level of 5%. which means that there is no significant effect between the Think-Pair-Share cooperative learning method with student attention. So that the Think-Pair-Share cooperative learning method is not appropriate to use to assess the level of student attention.
Video analysis of basketball throws for parabolic motion learning materials
Authors: Azhar T A N , Mulyaningsih N N , Saraswati D L , Nurhayati N , Marliani N , Nursa’adah F P , Sari N I , Lestari I , Nurjanah N
Published: March 2021

The material of parabolic motion is one of the materials considered difficult by most high school students. Therefore, this study aims to analyze the parabolic motion with a contextual approach to throwing a basketball. The research method used was descriptive experimental, namely recording a video of throwing a basketball at a variation of the distance of 2 m, 3 m and 5 m from the thrower’s foot to the hoof. The video was analyzed using tracker software and the parameters measured were time of the ball to fly in the air, the farthest distance, maximum height and total velocity. The results obtained show that distance is directly proportional to time. The thrower was at a distance of 5 m from the foot of the basketball hoop represents more perfect parabolic motion. The conclusion is that basketball games can be used as a contextual approach to the parabolic motion material.
The relation between total column ozone with UV radiation and CO2 concentration on the island of Kalimantan during the Covid-19 Pandemic
Authors: Adriat R , Nurhasanah  , Perdhana R
Published: March 2021

The concentration of ozone in the ozone layer is minimal, but it means a lot to live. The total amount of column ozone varies, mainly influenced by solar radiation and anthropogenic activity. In this study, the total column ozone during the Covid-19 pandemic, and the effect of UV radiation and CO2 concentration on Kalimantan’s island was reviewed. Based on the research results, it can be seen that on Borneo’s island in September and October 2019, the total column ozone reached 0.0056 J/m2. From November 2019 to March 2020, the total amount of column ozone decreased to 0.005 J/m2. The total amount of column ozone increased in April 2020 but declined in May 2020, and from June to September 2020, it increased to reach 0.006 J/m2. The numbers are related but not significant with UV radiation (correlation 0.25) and CO2 concentration (correlation -0.40). It can be concluded that UV radiation and anthropogenic activity affect the total column ozone.
CT scan image segmentation based on hounsfield unit values using Otsu thresholding method
Authors: Katherine  , Rulaningtyas R , Ain K
Published: March 2021

The use of medical images in diagnosing and analyzing various cases in the medical field is commonly used. In certain cases, the image used is not limited to two-dimensional images, but sometimes requires the use of three-dimensional images. CT scan image is an image that has several image slices that can be reconstructed into a three-dimensional image. In the reconstruction process, segmentation plays an important role to get a good reconstruction result and reduce the resulting noise. This study aims to develop a method used in CT scan image segmentation, with the hope that it can simplify the diagnosis process performed by doctors using two-dimensional images or those that have been constructed into three-dimensional images. The main method developed is the Otsu Thresholding method based on the threshold value, which is combined with the Hounsfield unit (HU) value which will be the input for the segmentation process. The image used is a thorax CT scan image with the final goal to get the results of heart segmentation. The results obtained based on the calculation of balanced accuracy for the 30 data tested had an average of 72.54%. The highest result of balanced accuracy for heart segmentation was obtained by data 4 of 77.43%, while the lowest result was obtained by data 29 of 69.1%.
Porosity and compressive strength of PLA-based scaffold coated with hydroxyapatite-gelatin to reconstruct mandibula: a literature review
Authors: Reina S A , Tito B J E , Malini M H , Iqrimatien F G , Sa’diyah E , Aminatun
Published: March 2021

Ameloblastoma is one of odontogenic tumours that is classified as benign, aggressive, and destructive. Mandibular tumours potentially cause bone disruption or damage, so it is necessary to do a resection to remove the infected part. Treatment done by resection may cause defects starting from the gap in the alveolar bone to the discontinuity of the mandible. Thus, it is necessary to reconstruct the mandible using a scaffold. Scaffold is made by using the PLA 3D-printing with the Fused Deposition Modelling (FDM) method. PLA is non-bioactive and hydrophobic, so the surface needs to be modified by coating PLA with hydroxyapatite (HA) and gelatine. This article aims to examine the effect of PLA surface modification using HA-Gelatine through a review article. The searching strategy for articles is by using databases of internationally reputable journals with certain keywords. From the search, journals were obtained (with status Q3, Q2 and Q1) as reference journals in this review. Literature review shows that the addition of hydroxyapatite can improve the bioactive properties of PLA, while the addition of gelatine can increase its hydrophilicity properties. Therefore, HA-Gelatin coating on 3D PLA has the potential to be used as a scaffold for mandibular reconstruction.
Development of an integrated augmented reality experiment module on the topic of motion kinematics on student learning motivation
Authors: Aththibby A R , Kuswanto H , Mundilarto
Published: March 2021

This study was designed to increase student learning motivation by developing a basic physics practicum module on the topic of integrated augmented reality kinematics. This study uses the Analysis, Design, Development, Implementation, and Evaluation (ADDIE) development model. The subjects tested in this study were students of the physics education study program, at one of the universities in Lampung in academic year 2019/2020. The data collection instrument was in the form of a student learning motivation questionnaire. The data obtained were analyzed quantitatively. The results showed that the developed module was suitable for use in learning and practical activities and was also able to increase student learning motivation.
Preliminary spectral investigation on Betel Nut (“Pinang”) using Laser Induced Breakdown Spectroscopy (LIBS)
Authors: Lahna K , Ilyas S , Bakri T K , Ramli M , Nufus H , Idris N
Published: March 2021

Preliminary optical spectroscopy studies have been carried out on betel nut samples using a new analytical tool, LIBS. The LIBS system consists of an neodymium -doped yttrium aluminium garnet (Nd YAG) laser as an excitation source, laser beam conditioning equipment, and an optical multichannel analyzer system (OMA system). Betel nut samples were collected from Aceh, Indonesia. The experiment was carried out under ambient air with a pressure of 760 Torr. It was found that strong luminous plasma could be generated directly from fresh betel nut samples, which resulted in strong emission spectrum. The emission spectrum obtained should have been dominated by host organic matter (C-H-O-N), but not as imagined because the organic host elements did not appear predominantly in the spectrum. Different treatments need to be carried out in further research so that the host organic matter appears. However, some salts, namely Mg, Fe, Na, Ca, Si, Al and K can be detected clearly. These initial investigations hold the promise of LIBS for spectral studies of betel nuts.
Characterization of indicator electrodes using the potentiometric biosensor method as urea sensor with XRD, SEM-EDS, UV-Vis and FTIR
Authors: A Hakim S , Sembiring T , Sebayang K , Situmorang M , Tarigan K , Sembiring K , Mihardi S , Waruwu E N
Published: March 2021

The purpose of this study is the characteristics of the indicator electrode which has been coated with a membrane with XRD, SEM-EDS, UV-Vis and FTIR. Research has been carried out using XRD, SEM-EDS, UV-Vis and FTIR tests on immobilized indicator electrodes 0.0350 g PVA-Enzyme coated with PVC-KTpClPB 0.0120 g and 0.0500 g. The method used was the biosensor potentiometric method with the urease enzyme immobilization technique in PVA coated with PVC-KTpClPB. To see the difference in the absorbance spectrum pattern of each PVA-Enzyme composition coated with PVC-KTpClPB against wavelength with UV-Vis, PVA-Enzim solution as a reference and PVC-KTpClPB solution as the first analysis 0.0120 g and as the second analysis 0,0500 g. To see the PVA-enzyme membrane coated with PVC-KTpClPB in the two compositions above was characterized by FTIR and SEM-EDS. To see the indicator electrode that had been immobilized by PVA-enzyme coated with PVC-KTpClPB in the two compositions above, it was characterized by XRD. It was concluded that the best results were found on the immobilization indicator electrode of 0.0350 g PVA-Enzyme coated with 0.0350 g PVC-0.0500 g KTpClPB.
Synthesis and characterization of TiO2 from Lampung’s ilmenite using leaching method with variation of time duration
Authors: Marjunus R , Handayani Y N , Stevani A , Febriyanti N , Firdaus I , Manurung P
Published: March 2021

Ilmenite is one of the natural materials that are abundant in Lampung province. This research was conducted to determine the content of TiO2 from ilmenite Lampung by the leaching method. Previously, iron sand was mixed with sodium hydrogen carbonate (NaHCO3) and roasted at 700ºC for an hour. In this research, five samples were used to determine the TiO2 content of ilmenite Lampung, with variations in leaching time of 2, 3, 4, 5, and 6 hours at 110ºC. The acid leaching process was carried out using 12 M HCl with a ratio of 1: 4. Then the water leaching process was carried out using 50 ml distilled water. Furthermore, all samples were characterized using XRD and XRF to determine the content in Lampung ilmenite sand. In general, XRD analysis results have succeeded in increasing the rutile phase which is influenced by the heating temperature. The highest TiO2 content of Lampung ilmenite sand was obtained in samples with a leaching time variation of 2 hours at a temperature of 110ºC i.e. 60.701%.
The effect of inquiry learning model based on laboratory and achievement motivation toward students’ physics learning outcomes
Authors: Ernita N , Muin A , Verawati N N S P , Prayogi S
Published: March 2021

This study aims to explore the effect of the inquiry learning model based on laboratory and achievement motivation toward students’ physics learning outcomes. This study is experimental research with a factorial design. The research sample used 2 class groups in one high school in the city of Mataram. The first experimental group used inquiry learning model based on real laboratory and the second experimental group used inquiry learning model based on virtual laboratory. Virtual laboratory using PhET simulation. The questionnaire of achievement motivation scale was used to measure the students’ achievement motivation, and a test was used to measure students’ learning outcomes focusing on cognitive aspects. The analysis of motivation scores and learning outcomes was carried out descriptively. Furthermore, the hypothesis testing use the Anova test where the prerequisite test in the form of normality and homogeneity test is conducted. The research results show that; a) there is no significant difference between the students’ learning outcomes who learn using the inquiry learning model based real laboratory and virtual laboratory; b) there is no significant difference between the students’ learning outcomes who have the high achievement motivation and low achievement motivation; and c) there is no interaction between inquiry learning model based real laboratory and virtual laboratory with the achievement motivation (high and low) on the students’ learning outcomes.
Structural, morphological, optical, and electrical properties of TiO2/ZnO rods multilayer films as photoanode on dye-sensitized solar cells
Authors: Himmah S W , Diantoro M , Astarini N A , Tiana S K G , Nasikhudin  , Hidayat A , Taufiq A
Published: March 2021

TiO2 nanoparticles have been widely studied as photoanode materials in DSSC due to the high surface area. Still, TiO2 nanoparticles exhibit weak light scattering which limiting red light absorption. On the other hand, one-dimensional structures such as rods demonstrate an increase in the light scattering. ZnO has undergone many structural modifications and exhibits higher mobility than TiO2. The combining characteristics of TiO2 nanoparticles and ZnO rods can improve photoanode performance. Therefore, the efficiency of DSSC can be increased. The TiO2/ZnO rods photoanodes were fabricated in the following steps. First, TiO2 nanoparticles were deposited on the conductive surface of ITO-Glass to form a double layer using the spin-coating method. Meanwhile, we prepare ZnO rods grown on the TiO2 nanoparticles layer using the hydrothermal method by varying Zinc Nitrate Tetrahydrate precursors (20; 30; 50; and 100 mM). Several physical characterizations have been carried out, including XRD, SEM, FTIR, UV-VIS, and Keithley SourceMeter 2400 equipped with a solar simulator 100 mW/cm2. Based on the results, the increasing concentration of Zinc Nitrate Tetrahydrate precursor affects the structural, morphological, optical, and electrical properties of TiO2/ZnO rods multilayer photoanode and reaches the optimum point at 50 mM.
Design of controlled temperature test in biochar production furnace automation
Authors: Nurhidayah  , Peslinof M , Afrianto M F , Deswardani F , Restianingsih T , Pebralia J
Published: March 2021

This study aims to test the temperature sensor that will be used in the biochar production furnace. Temperature testing is carried out to determine the ability of the sensor to respond to temperature changes that will be applied to the furnace. The sensors used in this system are the K-type thermocouple and the MAX6675 module. Testing is done by forming a control system. The system will be installed in the furnace by providing heating with fire in the furnace. The result of the maximum temperature was 574.25 °C at 575 seconds of heating for 1110 seconds. The test of corelation between the sensor output voltage to temperature when the temperature is raised from the beginning to the maximum, the sensor sensitivity is obtained at 5.1762 mV / °C and the slope of the graph is close to 1. Testing the relationship of the sensor output voltage to temperature when the temperature is lowered from the maximum point, the sensor sensitivity is obtained at 4.878 mV / °C and an offset voltage of 25 mV. The voltage-to-time correlation of the two tests is close to the value of 1, which means that the sensor linearity is very good so that it can be used as a temperature measurement tool.
Identification of the constraints of physical properties on fluid flow rate (as a preliminary study for analysis of changes in subsurface conditions in the KEK Mandalika Lombok)
Authors: Alaydrus A T , Susilo A , Naba A , Minardi S
Published: March 2021

The KEK Mandalika area, the southern coast of Lombok Island, is an area that is growing up in the tourism sector. The main need for tourist areas is the availability of clean water. The problem that occurs in coastal areas is seawater intrusion. The seawater intrusion can cause the changes in subsurface conditions, especially in groundwater. These changes have an impact on changes in subsurface physical properties, which can be detected by geophysical measurements and modeling based on geoelectric and gravity data. In monitoring the changes of subsurface conditions, it is necessary to observe the constraints based on the value of conductivity, density, viscosity, and fluid flow rate so that physical modeling can be carried out. The method used was an experiment with 11 mixed solutions of groundwater and seawater with different concentrations. The results show that the salinity, conductivity and density have a proportional relationship with viscosity. The higher the viscosity, the lower the groundwater flow rate, and vice versa. Based on these results, the value of the constraints for each variable is obtained, which is conductivity (1.930- 38) mS; density (0.995-1.021) kgm−3
; salinity (1.06-25.1) ppt; viscosity (0.835-0.876) x10−3
kgm−1s−1
; fluid flow rate (1292-1388) ms−1
.
Development of a set of props for collision based on Arduino Uno Microcontroller
Authors: Indrasari W , Budi A S , Fadilla D P
Published: March 2021

This research aims to produce physics teaching props for senior high school in the collision topic. The props developed to consist of Arduino as the central controller, photodiode sensor, and infrared sensor as a ball motion detector attached to the tube’s side as high as 100 cm. In its use, this teaching prop is also accompanied by student worksheets. The research design uses the Research and Development (R&D) method by using the 4D model, which includes: (1) define, (2) design, (3) develop, and (4) disseminate. Based on the media expert’s validation results, the score was 80% for concept suitability, 81% for design suitability, and 83% for effectiveness and efficiency. Therefore, the product worthy of use as a learning media.
Optimization of the Database Function Transactions by using the Fireworks Algorithm
Authors: Faisal Ammar , Hassan Rehab
Published: March 2021

Inspired by the fireworks flare-up at night, the old algorithm of fireworks (FWA) developed during 2010. Since then there have been some changes or unfinished programs intended to enhance FWAS affectivity. The conventional fireworks algorithm is a forward summary and reviewed in this article, or is presented below three elevated fireworks algorithms. By swapping the methods for numbers measured and instead of the amplitudes of the sparks between the Outbreak of fireworks, the high FWA algorithms turn out to be more lifelike or explainable. The multi-purpose fireworks algorithm, although the image processing (GPU) designed fireworks algorithm is provided as well, the GPU mostly based the algorithm of fireworks is capable of speeding up the optimization. Large experiments on thirteen benchmark services show that the sum of the 3 algorithms multiplied by fireworks dramatically increases the propriety of found solutions but strongly decreases the walking time. Lastly, the fireworks algorithm’s limited capabilities are concisely defined, while its inadequacies are acknowledged, then future lookup advices.
Seismic Images Interpretation to Discover Salt Domes Using Deep Fully Convolutional Network
Authors: Al-Duri Shms Aldeen S. , Abbas Amel H.
Published: March 2021

Interpretation of seismic data of seismic information available in the seismic image is an important process for oil exploration. By using computer vision and semantic segmentation techniques, defined the goal to extract salt domes, Which is a trap created due to the penetration of rock layers from below by the inelastic boulders of salt. The steps of this research explain the proposed model based on the semantic segmentation technique using the Fully Convolution Network as a U-net, one of the deep learning techniques. To discover salt domes to assist geophysicists in interpretation and detect oil in seismic sections. This model is designed to interact with the TGS dataset. Presented the research steps using the Python programming language. From the proposed U-net Model, we got a value of 97.50 as a result of training accuracy and 94.80 as a result of testing accuracy. The testing accuracy result of the proposed method was compared with other methods in the field of computer vision techniques used in interpreting seismic data, and the comparison result showed that the proposed U-net Model gives better results.
Structural Characterization of NiO Nanoparticles Prepared by Green Chemistry Synthesis Using Arundo donaxi Leaves Extract
Authors: Jawad N. A. , Hassan K. H.
Published: March 2021

The present work includes nickel oxide nanoparticles (NiO) synthesis via a green route using its salt and Arundo donaxi leaves extracts solution. Thus prepared particles were characterized by X-ray diffraction (XRD), spectrum of Fourier transform infrared, (FTIR) and then atomic force microscope (AFM) techniques. XRD data indicated that the particle size was in a nanoscale region and around 30 nm which seem to be agreed well with the one estimated from AFM. The surface of the nanoparticles studies using AFM demonstrated that the average particle size is 41.13 nm and also indicated that 10%, 50% and 90% of the prepared samples have a particle size being less than 34 nm, 44 nm and 48 nm respectively.