1,720,956 research outputs found
Optimasi Condensat Extration Plan di Lapangan X
Get PDFKondisi krisis harga minyak dunia yang terjadi sejak akhir tahun 2014 memberikan dampak yang signifikan terhadap kebijakan perusahaan minyak dan gas bumi dalam mengembangkan lapangan. Lapangan X memiliki reservoir dengan kandungan Gas Oil Ratio (GOR) yang tinggi. Hal ini mengindikasikan terdapat potensi kondensat untuk dapat diekstraksi dari gas alam sebelum gas dijual menuju konsumen. Condensate Extraction Plant dikembangkan di Lapangan X sejak tahun 2011 dengan kapasitas handling total sebesar 27,5 mmscfd. Seiring dengan penurunan produksi minyak dan gas bumi secara alamiah, diperlukan penyesuaian mode operasi sehingga aset yang dimiliki oleh Lapangan X dapat memberikan efisiensi yang lebih baik dibandingkan kondisi sebelumnya. Simulasi proses modifikasi plant dilakukan dengan 5 alternatif skenario proses yaitu Metode Mechanical Refrigeration Mode Operasi Seri dengan Media Pendingin Chilled Water, Metode Mechanical Refrigeration Mode Operasi Pararel dengan Media Pendingin Propana, Metode Mechanical Refrigeration Mode Operasi Seri dengan Media Pendingin Propana, Metode JT-Valves, dan Metode Turbo Expander. Evaluasi teknis dilakukan dengan simulasi menggunakan perangkat lunak Unisim, sedangkan analisa keekonomian dilakukan dengan metode levelized cost. Selain itu, dilakukan juga analisis sensitivitas keekonomian terhadap komponen harga gas, harga kondensat, CAPEX, dan OPEX. Berdasarkan hasil simulasi proses dan perhitungan keekonomian, empat alternatif proses skenario secara teknis dan ekonomis dapat dipilih untuk meningkatkan produksi kondensat. Alternatif proses skenario yang paling optimum adalah metode Mechanical Refrigeration dengan Media Pendingin Chilled Water. Berdasarkan perhitungan sensitivitas NPV dan IRR, parameter yang berpengaruh paling besar terhadap NPV dan IRR skenario proses tersebut adalah harga gas, OPEX dan harga kondensat sedangkan CAPEX memberikan pengaruh terkecil
Pemanfaatan Energi Biogas untuk Pembangkit Listrik di Desa Tuwang Kecamatan Karanganyar Kabupaten Demak
Get PDFThe Increase of energy demand in Indonesia causes the need for alternative energy to replace fossil energy. One of alternative energy is renewable energy that obtained from nature freely. Tuwang Village in Karanganyar District, Demak Regency has the potential for renewable energy from methane gas produced by cow dung on farms. Cow dung is tested in the laboratory to take the methane gas content. Two chambers biodigester from fiberglass are used to ferment and hold biogas which is then used as fuel on the stove. From 171 kg of cow manure that mixed with water in a ratio of 1:3, the ideal digestification time with the highest energy production of 689 kJ is 22 days. The average of CH4 composition is around 50% from the total of biogas content. The total energy obtained during the water heating process is 4.32 MJ, smaller than the theoretical energy calculation (20,52 MJ). Based on the results of experiments, it can be estimated that biogas energy generated from Tuwang Village each day is 40,42 MJ. Biogas energy power plant can use a genset or stirling engine with 468 Watt of power. This power can be used for neighborhood association lighting needs. 
OPTIMASI KONSENTRASI ETHYLENE GLYCOL FLUIDA KERJA PADA PERANCANGAN PARABOLIC TROUGH CONCENTRATOR DENGAN REPLEKTOR
Get PDFAn excellence innovation for reducing greenhouse gases are done by developing a new water heater model for household applications. The application of the new model water heater by utilizing Parabolic Trough Concentrator with an indirect heating system uses heat transfer fluid able to improve the reliability of water heater compared to the thermosyphon model. Optimization for the new model is done by enhancing the reflector material and also heat transfer fluid. The experiment is done by applying the same standard measurement in order to set an adequate data for each model. The optimal reflector for the system to concentrating the solar power is polymer substrate as the fluid heated faster. The water-based solution with ethylene glycol 50:50 (v/v) for heat transfer fluid shows the best performance by achieving 98,2 oC for the 10th minute, and after one hour, the final temperature is 100,5 oC. By using a polymer substrate as a reflector for the Parabolic Trough Concentrator and using heat transfer fluid based on ethylene glycol water-based solution by concentrator 50:50 (v/v) shows the best performance among all sample with the fastest heating rate and the highest final temperature after the one-hour experiment. It shows this model has advantages to improve the system reliability by increasing the heating rate of the heat transfer fluid, which able to heat the water on the system faster
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
- …
