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Journal of Earth Energy Engineering, Volume 9, pp 66-79; doi:10.25299/jeee.2020.4102
A heated swimming pool has long been known as a tourist destination, sports, to stress therapy. Warm water is obtained from burning fuels such as fossil fuel that is not environmentally friendly. Then technologies based on an alternative energy source is needed to be an optimal solution to the heating of a swimming pool, which can be very expensive in terms of energy demand and environment conservation. Due to the sizeable geothermal potential owned by Indonesia and only 3% of the total potential that has been successfully used for electricity generation (PLTP), therefore a design of a heated swimming pool heated by geothermal fluid was made to utilize clean and environmentally friendly energy sources in the Lembang region, West Java. The pool, which is designed to have an area of 10 x 10 m2, has a temperature of 26-30 oC and is heated by a geothermal fluid at a rate of 12.7 l/s and a temperature of 110 oC. The total heat energy utilized is 170 to 330 W/m2. Economic analysis shows an NPV of more than one and an IRR of 17% for a 10-year economic life. Hence, this warm swimming pool deserves to be developed.
Journal of Earth Energy Engineering, Volume 9, pp 102-111; doi:10.25299/jeee.2020.3922
Wax paraffin deposition is a problem faced in the pipeline for petroleum industries that they blockage the partial or full inside the pipe, which will decrease the production rate. One of the treatments is to use the preventive methods called wax inhibitors which are expected to inhibit the crystallization of paraffin wax, and bio-solvent is included. Hydrolysis and fermentation technique are used to produced bio-solvent. Hydrolysis aims to break lignin and hemicellulose, damage the crystal structure, and increase the porosity of the material. At the same time, the occurrence of pentose changes and some glucose into ethanol is present in the fermentation process. Then, purified by the distillation process to obtain bio solvent products that are applied with waxy crude oil can reduce the pour point value of crude oil. From the hydrolysis process with five variations of acid percentage, the amount of reducing sugars increase. By increasing temperature from 50 ° C to 100 ° C, the reducing sugars continues to increase until it reaches the optimal point of 18.2 ° Brix. The amount of inoculant also affects the level of bio-solvent where the optimum results using inoculants are 0.015 g/mL, which produces 6% levels of bioethanol. The high ethanol content of 2% had a density value of 0.979 g/mL. The best °API at 5% is 13.901, and the average value is about 13.0945, where the best viscosity values for ethanol content of 6% are 0.814. Bioethanol testing using waxy crude oil is carried out with the bioethanol content of 6%. The addition of the ethanol contents only decreased the pour point 2-3℃. At sample, #LGK19 experienced a 3°C drop in pour point from 45°C to 42°C. Therefore, it can be concluded that bioethanol used as a solvent can potentially inhibit paraffin deposition.
Journal of Earth Energy Engineering, Volume 9, pp 59-65; doi:10.25299/jeee.2020.5529
The source rock maturity and the hydrocarbon generation history are evaluated in the deepwater Phu Khanh Basin. The average values of heat flow, paleo water depth, and surface-water interface temperatures range from 50.80–61.69 mW/m2, 150-3,500 m, and 2.30-250C, respectively. The Oligocene and Lower–Middle Miocene source rocks are presented. The Oligocene source rock is derived from the lacustrine environment; it is mature to overmature in the Southwest part of the Phu Yen Depression. The main oil phase started in the Early Miocene, and the amount of wet gas occurred only at the bottom part. The Lower-Middle Miocene source rock has been immature in both the Southwest and Northeast part of the Phu Yen Depression. Based on the geochemical analysis, these source rocks were predominantly a mixture of type II and type III kerogens. The total organic carbon and the hydrogen index values range from 1.8-2.5 % and 250-320 mg/g, respectively. The results can help define reservoir locations for future field development planning in the Phu Khanh Basin.
Journal of Earth Energy Engineering, Volume 9, pp 88-101; doi:10.25299/jeee.2020.5264
This paper discusses a transient model of the intermittent gas lift technique in an oil well. The model is developed in the gas line, in the tubing-casing annulus, and the tubing. The line-pack and line-drafting phenomena in the gas line are considered in the model. A numerical approach will be used to solve the mathematical model that represents fluid flow during intermittent gas lift injection. The dynamics of important variables in the intermittent gas lift are investigated and analyzed to determine the best production strategy for intermittent gas lift. The variables are film thickness and velocity, slug height and velocity, and gas height and velocity. The relationships between surface injection control parameters (gas injection pressure and gas injection rate) and the velocity and height of film, gas, and liquid are shown in one cycle of the gas lift intermittent process. The higher the gas injection pressure, the faster the gas injection velocity, and the thinner the film thickness in the tubing. In order to obtain clean tubing from film thickness, the gas injection pressure needs to be optimized, which will lead to maintaining compressor discharge pressure availability. Detailed observation of the dynamic performance inside the tubing production well will give the optimum oil production rate for oil wells under a gas lift intermittent production strategy for field application.
Journal of Earth Energy Engineering, Volume 9, pp 80-87; doi:10.25299/jeee.2020.4659
Steam injection can be success in increasing oil recovery by determining the steam chamber growth. It will impact on the steam distribution and steam performance in covering hot areas in the reservoir. An injection plan and a proper cyclic steam stimulation (CSS) schedule are critical in predicting how steam chamber can grow and cover the heat area. A reservoir simulation model will be used to understand how CSS really impact in steam chamber generation and affect the oil recovery. This paper generates numerous scenarios to see how steam working in heavy oil system particularly in unconsolidated sand reservoir. Combine the CSS method and steam injection continue investigate in this research. We will validate the scenarios based on the how fast steam chest can grow and get maximum oil recovery. Reservoir simulation resulted how steam chest behavior in unconsolidated sand to improve oil recovery; It concluded that by combining CSS and Steam Injection, we may get a faster steam chest growth and higher oil recovery by 61.5% of heavy oil system.
Perspektif Pendidikan dan Keguruan, Volume 11, pp 43-50; doi:10.25299/perspektif.2020.vol11(2).5593
This study aims to determine the relationship between the character of discipline and students 'thinking skills in economic learning activities at SMAN 2 Singingi which is motivated by the students' low ability to think in economic learning activities at SMAN 2 Singingi. This type of research is quantitative research. Subjects in the study of the relationship of character education with thinking skills of students in economic learning activities. Data collection techniques in this study used questionnaires, documentation and tests. The data analysis technique used is the correlation test using the Produck moment correlation formula. Based on the corelation test results obtained by Person Corelation value of 0.727 this means that there is a strong relationship between the character of discipline with students' thinking ability on economic subjects at SMAN 2 Singingi. this is also done by comparing r Count with r Table where (1% 0.727> 0.232), (5% 0.727> 0.275). Then it can be concluded that Ha is accepted and Ho is rejected and from the results of the hypothesis test above it can be concluded that there is a significant relationship between the character of discipline and students' thinking ability on economic subjects at SMAN 2 Singingi.
Perspektif Pendidikan dan Keguruan, Volume 11, pp 51-65; doi:10.25299/perspektif.2020.vol11(2).5654
Studi ini berupaya mengungkapkan implementasi Garis-garis Besar Program Pengajaran (GBPP) Mata Pelajaran Bahasa Indonesia, Kurikulum 1994, Sekolah Lanjutan Tingkat Pertama (SLTP) dalam kegiatan belajar mengajar (KBM) di kelas. Tujuan studi ini untuk: (1) mengetahui apakah guru memenuhi prosedur pengajaran yang "wajar", (2) menyusun perencanaan dan melaksanakan pengajaran di kelas sesuai dengan waktu yang dialokasikan, serta (3) penggunaan metode dengan tepat. Hasil observasi kelas dan wawancara terhadap 18 guru Bahasa Indonesia kelas II SLTP di berbagai wilayah menunjukkan bahwa alokasi waktu yang disediakan dalam GBPP bahasa Indonesia dinilai sudah memadai namun, beberapa guru belum memanfaatkan waktu tersebut secara efisien dan efektif. Guru umumnya belum memiliki kemampuan yang baik dalam perencanaan dan pelaksanaan KBM. Buku paket diandalkan sebagai acuan mengajar ketimbang acuan perencanaan yang semestinya mereka susun. Tujuan pengajaran bahasa agar siswa mampu membaca, menyimak, menulis, dan mendengarkan, belum memperoleh perhatian yang proporsional
Perspektif Pendidikan dan Keguruan, Volume 11, pp 17-22; doi:10.25299/perspektif.2020.vol11(2).5393
Student learning outcomes in learning is very important to be used as a reference for indicate of successful in learning. The observation result at grade X TITL SMKN 1 Pariaman identified that there are several problems that influence student learning outcomes, such as communication in learning process just one - way, the students did not master the contents, students tend to be afraid to ask the question, the students out of the classroom and talk with their seatmate. Consequently most of student learning outcomes were under KKM that seen from the pretest. To overcome this problem, research is conducted which seeks to see an increase in student learning outcomes in subjects " Using the Measurement Results " in Learning Model Cooperative Script at grade X TITL SMKN 1 Pariaman. Type of this research was quasi experiment with one group pretest – posttest design. Subjects were students at grade X TITL SMKN 1 Pariaman for 2014/2015 academic year that consists of 40 students. Data were collected through the test of pretest - posttest results, 40 objective questions for the pretest and 34 objective questions for the posttest. Improving student learning outcomes calculated by the formula Gain Score of pretest - posttest. This research indicated that there is an increase in student learning outcomes in subjects “Using Measurement Results” in Learning Model Cooperative Script at grade X TITL SMKN 1 Pariaman.
Perspektif Pendidikan dan Keguruan, Volume 11, pp 39-42; doi:10.25299/perspektif.2020.vol11(2).5585
Vocabulary is part of language teaching and learning. Sufficient words usage ease students cope with academic assignments. This study tries to find out vocabulary level of freshman at English department State Polytechnic of Bengkalis. The method of the research is descriptive. Instruments used in gathered the data is set of vocabulary level test designed by Nation (1983) and developed by Schmitt, N., D. Schmitt, and C. Clapham. 2001. The population of the study is 16 freshman of Diploma program. The result of the test showed that most of the students are below 1000 vocabulary level. The finding revealed that the learners have limited vocabulary. It also brings two implications to the teaching. First, Lecturers should provide ekstra vocabulary training in lessons. Then, instruction language used should be adjusted between target language and mother tongue.
Perspektif Pendidikan dan Keguruan, Volume 11, pp 11-16; doi:10.25299/perspektif.2020.vol11(2).5301
Static achievement of Indonesian students in TIMSS, of course requires improvement efforts. One of the improvement efforts can be done by conducting further studies related to the results of Indonesia's achievements in TIMSS. The aim of this study to describe the chemistry content and the of science learning in junior high school based on K-13. This research is a descriptive study with content analysis method. Content analysis was carried out on documents related to K-13 specifically the content standards, the learning process, syllabus and science textbooks of junior high school. The results showed that there are chemistry contents in science learning of junior high school. The chemistry contents contained in science learning of junior high school is divided into 6 main subjects and 5 demands of cognitive abilities, namely C1, C2, C3, C4 and C6, while the demands of cognitive ability C5 (evaluating) are not contained in the Chemistry content in science learning of junior high school . Key words: chemistry content, cognitive demands abilities, K-13, science learning