bluuebunny/crossref_metadata_2025_split huggingface dataset:
Household behavior towards shallow groundwater saving in Pekanbaru City
Authors: Rafi F , Karuniasa M , Asseggaf A 
Published: April 2021

Abstract
Growth in household activities that increase water resource needs can be incompatible and their availability can be threatened. Limited water supply makes groundwater a primary need because it is easily exploited and practical. This paper attempts to understand the behavior of shallow groundwater saving by households and to observe the influence between knowledge, attitudes, and practice with their behavior. This research was conducted in the Bukit Raya Subdistrict in Pekanbaru City with 113 respondents, analyzed using a quantitative approach (SPSS). The results showed that knowledge, attitudes, and practice had a positive influence of 32.4% on shallow groundwater saving behavior. This research concludes that knowledge is the most influencing shallow groundwater saving behavior seen from the influence of attitude and practice.
How to learn oscillation and wave in SAMR framework?
Authors: Ayu H D , Jufriadi A , Mustika S E , Kurniawati M , Pratiwi H Y , Sundaygara C , Hudha M N 
Published: April 2021

Abstract
This study was to see how to optimize the application and laboratory software on Oscillation and Wave material. This study was conducted using computers and android equipped with Internet access in SAMR framework. SAMR is a framework that requires the use of technology in learning The design of this research is content analysis. The results show that the Olabs application is complete and the most capable of explaining the formula if it is reviewed mathematically and physis meaning. This application is also able to explain the oscillator and wave phenomena well. Based on this research, during the Covid-19 pandemic, students can do STEM (science, technology, engineering and mathematics) from home, one of which is with the help of the Olabs and PhET application.
Distribution and abundance of macroplastic at Musi estuary, South Sumatera, Indonesia
Authors: Almiza G , Patria M P 
Published: April 2021

Abstract
Musi River in the upstream and estuary is used for fisheries, transportation, industry, and settlement. These activities has potential to produce plastic waste with various types and sizes, one of them is macroplastic (2.5-100 cm). This study aims to determine the distribution and abundance of macroplastic in the upstream and estuary of the Musi River. This study used a purposive sampling method with 6 stations, 2 stations in the upstream and 4 stations in the estuary. Macroplastic sampling used transect quadrants then sample is cleaned and dried, counted, identified and weighed for each type. And for macroplastic coverage by taking photos of each transect quadrant, then calculate the percent of coverage using the Point Intercept Transect (PIT) method. The results of this study indicate that the macroplastic abundance in the upstream and estuary of the Musi River ranges from 5-32 items/m2 with an average weight of 27.82 – 126.89 gr/m2. Macroplastic types are dominated by plastics fragments, food wrappers, other jugs/containers, bags/films, and cups, while macroplastic coverage is dominated by bags/films.
Assessing two-dimensional collisions second-years students using PhET simulations on momentum and impulse concept
Authors: Adimayuda R , Sari L , Ismail A , Amalia I F , Gumilar S , Samsudin A 
Published: April 2021

Abstract
Assessment is an important component in education that always needed. To improve the quality of education can be done by improving assessment learning quality and system. This study aims to determine the performance of students of grade X SMA N in Bandung West Java Indonesia school with 34 participants on a two-dimensional collision concept. This research is descriptive research which is conducted to examine the condition and situation that is happening, so that gives a fact-based description found in the school in other to find information factually. Problem studies that analyzed are the student’s performance after using PhET simulations on two-dimensional collision concept. The instrument utilized in this study is a written test in the form of students’ worksheets of momentum and impulse. Student worksheets test shows the average percentage on student performance in understandings concept of two-dimensional collision concept is 67.14%. These data indicated that student learning performance in good category. Learning by using virtual laboratory can provide more meaningful learning especially in physics concept that cannot be presented and observed directly in daily life.
Ab-initio calculation of cubic and tetragonal phase of CsPbI3 perovskite
Authors: Shanaz H R , Nuryadin B W , Subkhi M N , Pitriana P , Aliah H 
Published: April 2021

Abstract
A Study of The CsPbI3 Two-Phase Electronic Structure Has Been Made Through Calculations Using the Density Functional Theory Method. Perovskite metal halide is used as a light-absorbing material on solar cells. This material has a high level of stability and an easy fabrication process. Also, the conversion efficiency has reached 10.1%. The two crystalline phases used are the cubic phase and the tetragonal phase. The electronic structure discussed includes the ribbon electronic curve, as well as the DOS (Density of States) curve, PDOS (Projected Density of States) curve. To find out the electronic structure, and optimization calculation is performed, namely variations in lattice constants, k-points, and cut-off energy. This optimization is done to get the structure with a minimum total energy so that its stability can be achieved. It is known that the bandgap energy value of the CsPbI3 cubic is 1.44eV on the electronic and DOS curve curves. Whereas the band gap energy value of tetragonal CsPbI3 is 0.6 eV on the electronic band curve and DOS as well. This shows that CsPbI3 can be used for the perovskite semiconductor material.
Analysis of solid oxygen distribution in kakap river, kubu raya district west kalimantan
Authors: Oktaliana R , Ahmad  , Rintayati P 
Published: April 2021

Abstract
The people of the Kakap River area live and open businesses along the river while they directly dispose of waste into the river. The people also use the river as a source of clean water to meet their daily needs. The purpose of this study was to determine the condition of the Kakap River water quality against dissolved oxygen with BOD, COD, pH, and DO parameters. This research used purposive sampling, starting from determining the sample point to be selected. The sample points used were three locations along the Kakap River. The results of the water quality analysis of the Kakap River from the first location in the estuary: COD parameter is 5.0 mg/L, the BOD parameter is <1 mg/L, DO parameter is 5.6 mg/L and pH parameter is 6.65. The second point of Pal 9 location: COD is 41 mg/L, the BOD parameter is 13 mg/L, the DO parameter is 4.9 mg/L, and the pH parameter is 7.17. The third location at Punggur Kecil: COD parameter is 210 mg/L, the BOD parameter is 137 mg/L, the DO parameter is 3.9 mg/L, and the pH parameter is 4.86 in the low tide conditions. These results will meet the water quality standards for class IV according to PP RI No. 82 of 2001, in which it can only be utilized for irrigating crops and other uses that require the same water quality. Apart from that, the results indicate that the water quality condition of the Kakap River has been polluted so it is not appropriate for the people to use the river as a clean water source.
Establishment of student characters as citarum river pollution solution program
Authors: Supriyono  , Sartika R , Kurniawaty I 
Published: April 2021

Abstract
The role of universities in fostering student character can be integrated within the scope of curricular, co-curricular and extracurricular activities. Thematic Real Work Lecture activity based The Pentahelix is a curricular program in the University Pendidikan Indonesia and supposed to be a forum for student character formation. The purpose of this study is how to shape the character of students who can support the Citarum River pollution solution program. This study uses an approach that is combining the two types of methods namely qualitative and quantitative. This method is called the RnD method or research and development. The results of this study are the presence of the character of students as supporters of the Citarum River pollution prevention program.
Community perception of flood relocation efforts in pacitan subdistrict, pacitan regency
Authors: Pradikka R A , Yusup Y , Nurhadi  
Published: April 2021

Abstract
The flood disaster that hit Pacitan Subdistrict, Pacitan Regency has caused casualties and damage in the housing, infrastructure, and educational facilities. This disaster brought several consequences in the form of settling relocation policy. This study aims to analyze community perceptions of relocation efforts and factors that influence people’s perceptions of settlement relocation efforts. Data collection techniques through interviews, observation, and documentation of respondents in Pacitan District. Data analysis using qualitative descriptive. The results showed that some people 1) refused the existence of relocation and preferred repairs to embankments, and agreed with government efforts provided they were carefully prepared, (2) Factors influencing perceptions were physical and environmental factors in the form of embankment conditions, economic factors in the form of loss of land assets and livelihood, organizational factors in the form of delivering aspirations through various activities, and socio-cultural factors in the form of education, social relations and health.
Development of socioeconomic indicators for measuring the population wellbeing in lembah klang-langat extended metropolitan region, malaysia
Authors: Saleh Y , Mahat H , Hashim M , Nayan N , Norkhaidi S B , Mohd Zanuddin I H 
Published: April 2021

Abstract
This paper aims to develop a socioeconomic indicators to measure the wellbeing of the people in Lembah Klang-Langat Extended Metropolitan Region (EMR). A total of 400 respondents comprised heads of household in 15 settlement centres in Lembah Klang-Langat Extended Metropolitan Region (EMR) were selected as study sample. Quantitative approaches using SPSS and AMOS software were in this study. The data were analysed using factor analysis, namely exploratory factor analysis (EFA) and confirmatory factor analysis (CFA). The results showed that after EFA and CFA had been applied, only two sub-constructs of socioeconomic construct which were i) social, and ii) economy, and six items of B7_3, B7_4, B7_5, B7_7, B7_10 and B7_11 presented high validity values of CR exceeding 0.6. The analysis found that the measurement model met the measurement criteria for measuring suburban wellbeing. The study findings also showed that the similarity index value was equal to p=0.000, chi-square relative value of 3.553, 0.991 for GFI value, 0.983 for CFI value, 0.968 for TLI and RMSEA value of 0.051. Therefore, the findings of this study have successfully prepared a set of socioeconomic indicators that can be used by future researchers for analysing the wellbeing of socioeconomic aspect of metropolitan region’s extended area.
Geological Controls on Thermal Manifestation Occurences in Batu Gede and Batu Kapur, Subang Regency: A Preliminary Result
Authors: Sibarani Betseba br , Sianipar Juni Yesy , Daniel Danny , Apriani Lestari , Danakusumah Grandy , Suryantini  
Published: April 2021

Abstract
Batu Gede and Batu Kapur are administratively located in Subang Regency, West Java, precisely in the northern part of Tangkuban Perahu Geothermal Working Area. Characteristics of the manifestations in Batu Gede and Batu Kapur are generally bicarbonate neutral pH warm springs and their location exposed in the foot of Tangkuban Perahu Volcano. Despite the similar chemical characteristic of those two manifestations, there is a significant characteristic difference between them. Spring with low pH with the pungent smell emerges in the Batu Gede not far from neutral pH bicarbonate warm spring. The aim of this research is to determine control of the occurrence and relationship of manifestation in both areas by conducting geological mapping. Surface manifestations are controlled by a geological process associated with primary and secondary permeability. Both manifestations emerge dominantly in the control of fault as a secondary permeability. Primary permeability also controls the occurrence of manifestations but not significant. Batu Gede manifestations are dominantly controlled by overstepping structure, while Batu Kapur are dominantly controlled by intersections between structures. Based on high content of SO4
−2, acid pH, and the presence of sulfur, the acid manifestation might be correlated with magmatic activity beneath Batu Gede’s manifestation.
A System Design of a Solar and Geothermal Hybrid Power Plant for Flores Island
Authors: Berian Zagy Yakana , Riyanto Hendi 
Published: April 2021

Abstract
Solar and geothermal hybrid system will be promising in the upcoming years, Flores has both energies potential. The use of diesel electric power plant (PLTD) may harmed the environment, the hybrid system with storage energy can be an alternative solution to substitute PLTD. Hence, there is an opportunity to design and implement a hybrid geothermal and solar power plant for Flores Island. Based on existing geothermal fluid characteristics in Flores Island, a hybrid power plant is designed to comprising of a single flash geothermal power generation, a solar collector system with parabolic trough collectors (PTC) either in an East-West (E–W) or a North-South (N–S) alignment, and a thermal energy storage (TES) system with synthetic oil for heat transfer fluid (HTF) and a mixture of salts for storing thermal energy. The hybrid power plant’s operation is designed based on the result of the electricity load study for Flores Island. Solar energy potential for Flores Island is predicted by combining clear sky model empirical formulas and 2017–2019 sunshine duration data from local wheather station. Steady mass and energy balance analyses via Aspen HYSYS were performed to obtain electric power generation capacity for each standalone geothermal power plant and hybrid power plant. Besides, a comparison of carbon dioxide emission from the same capacity of a diesel-electric power plant, a standalone geothermal power plant, and a hybrid power plant is presented. The hybrid power plant is designed to have a solar collector system with a N–S alignment PTC system in which daily average solar irradiation is predicted to be 5.5 kWh/m2/day and a TES volume of 3,000 m3. The land area to be cleared for the solar collector system is estimated as 3.0 hectares (7.5 acres). For a steam turbine inlet pressure of 10 bar, a condenser pressure of 0.08 bar, and 1,215 operation hours per year, the hybrid power plant can produce 5,450 MWh/year of electric energy. The carbon dioxide emission reduction for standalone operation and a hybrid operation are 86% and 93%, respectively, compared to that of a PLTD.
Study of The Heat Loss Effect in Geothermal Steam Production Well
Authors: Wardana Andrian Putra , Saptadji Nenny Miryani , Maulana Dimas Taha 
Published: April 2021

Abstract
Well casing and cement temperature can change during geothermal production operation. The change of temperature occurs because of the heat transfer from the geothermal fluid to the formation. The heat transfer occurs because of the temperature difference in geothermal fluid and formation. The heat of fluid moves to the casing, cement, and formation through convection and conduction. This research aims to develop the heat transfer model in the steam production well, predict the steam heat loss and its effect on every 100 m well increment, and predict the well casing and cement temperature distribution and their effect on every well segment. The heat transfer model is an analytical calculation model developed to be the base of the calculation of heat loss and a temperature drop of well casing and cement. This model was developed for the calculation of heat loss in steam production well. The model was compared with a simulator to test the suitability. The fluid flow pressure drop and well lithology were considered in this model. The heat loss was very low during the steam production. The heat loss could be higher, along with the formation temperature drop. The material thermal conductivity and the well segment’s layer thickness could affect the steam heat transfer in the production well.
A Modified Non- Isothermal Lumped Parameter Model in Porous Media for Geothermal Reservoirs
Authors: Firanda Eric , Pasaribu Fernando , Sutopo  , Pratama Heru Berian 
Published: April 2021

Abstract
This paper presents a method to predict geothermal performance along production life using a lumped parameter model that has considered mass balance, heat changes, and porous media flow in geothermal reservoirs. Furthermore, the lumped model provides more information on the characteristics of geothermal reservoirs. This paper focuses on developed and combined Satman’s model on mass balance and Schilthuis’s model on material balance for oil reservoirs. This paper can calculate heat and mass balance for the non-isothermal condition with pressure and temperature changes, unlike previously published papers. Besides, this paper also includes Darcy’s equation to change the “tank” concept of lumped to be porous media as an actual reservoir condition. Thus the production mass rate can be calculated. The model developed can be used for performing history matching, “quick count’ of numerical simulation due to there is calculation well by well, if those combined, can determine an entire reservoir with a simple calculation. On the other hand, this method reduces the complexity of numerical calculation. Therefore, new lumped is expected to be an alternative for application in geothermal reservoirs.
Incremental Development Strategy of Geothermal Field Using Wellhead Unit Technology: Case Study Ulumbu Geothermal Field
Authors: Idianto Onny , Saptadji Nenny Miryani , Ashat Ali , Pratama Heru Berian , Nusiaputra Yodha Yudhistra 
Published: April 2021

Abstract
Geothermal development in Indonesia is still dominated by the utilization of conventional geothermal power plants with large capacities. Generally, it requires a long time development phase and often experiences delays before an operation. This study aims to provide alternative field development options with an incremental development strategy. This study was conducted to show how a wellhead unit’s effective incremental development strategy compared to conventional power plants by applying the probability approach for the Ulumbu geothermal field’s case study in East Nusa Tenggara. Besides, this study also provides a comprehensive economic condition of the obtained revenue and project investment costs. Therefore, geothermal power plant development could be more feasible and minimize the barriers in the investment. The methods used in this study is a technical and economic approach, from total project investment cost and the financial return achieved for each development strategy. The technical analysis compares the power plant’s specific steam consumption (SSC) and the generated capacity. The total investment is determined for different development strategies of 40 MW (conventional) scenario 2×20 MW, 40 MW (incremental) scenario 8×5 MW, and 40 MW (incremental) scenario 16×2.5 MW using condensing power plant. The economic analysis shows P50 for the investment cost in millions of US$/MW is 5.84, 5.58, and 5.60, respectively. Regarding the tariff-based, which is 80% under Average Cost of Electricity Generation (BPP) of the relevant local grid, P50 for the Rate of Return is 16.85%, 17.33% 17.21%, respectively. Evaluation done by comparing investment cost, economic parameters, tariff variation, and risk assessment, for incremental development scenarios of 8×5 MW and 16×25 MW is feasible as development alternative scenario of Ulumbu field.
Numerical Study of Temperature Profiles of Transient Flow in the Geothermal Oilfield
Authors: Hendrarsakti J , Rahma M 
Published: April 2021

Abstract
Some petroleum wells that are no longer productive still have heat in their formation rocks. Those heat can be extracted and utilized by injecting working fluid into the wellbore. The current study’s objective was to create a 2D numerical calculation program for transient flow temperatures inside the well then it was used to calculate the temperature distribution in oil and gas fields in the Arun field and BK Area. The injected fluids were modeled as a double-pipe heat exchanger. Heat transfer processes inside the wellbore were convection in the inner pipe and the annulus and conduction in the pipe walls and rock formations. The computational calculation used a finite difference method. The computation results were then compared with calculations from the literature. After being validated, the program was used to calculate the Arun field and BK Area temperature distributions. This study found that compared with the reference literature, the current results had a similar optimum temperature range of 130°C-160°C but had different profiles shape with an average deviation of 12%. In the Arun fields, simulation results indicated that the field could reach temperatures between 90°C-120°C and was classified as a medium-temperature geothermal source. BK Area could reach optimum temperatures between 50°C-80°C and be classified as the low-temperature geothermal.
An experimental evaluation on revamping the productivity of solar PV panel using wind tunnel as an optimizer
Authors: Rajasekar R , Ramkumar R , Prasannaa P 
Published: April 2021

Abstract
At high working temperatures, the performance of the solar photovoltaic (PV) cells will be affected. With the increase in temperature of the PV cells, the conversion of solar radiation into electrical output will be decreased. The operating temperature of the PV cells is one of the prime factors for determining its electrical conversion efficiency. In order to get the maximum electrical output from the solar PV cells, the temperature should be maintained properly. In this experimental study, the temperature of the solar PV cells was maintained by cooling both sides of the PV panel simultaneously. The front surface of the PV panel is sprayed with a thin film of pot water and the rear side is attached with a fabricated duct that was connected into a wind tunnel blower. The mass flow rate of the moist air from the wind tunnel to the rear side of the PV is ranged between 0.1m/s to 0.5m/s. The performance characteristics of both the commercially available PV panel and the experimental PV panel (PVT Clay pipe panel) were compared. The results show that the PVT clay pipe panel has an electrical efficiency of about 11.72%, whereas the commercially available PV panel has only 9.77%. Also, the overall efficiency of the experimental PVT panel is 65.55% respectively.