1,720,955 research outputs found
Transesterifikasi In situ Produksi Biodiesel Dengan Variasi Massa Bahan Baku Terhadap Karakteristik Biodiesel
Get PDFBiodiesel is one of the promising alternative fuels, environmentally friendly, and has no adverse effects on health. In this study, biodiesel production was carried out using the in situ transesterification method. The raw material used was mahogany seeds with variations in raw material mass of 10 grams and 20 grams. The catalyst used was KOH with methanol as the solvent and n-hexane as the co-solvent. In situ transesterification was performed at a reaction temperature of 65°C, stirring speed of 400 rpm, and a reaction time of 40 minutes. The research results show that the mass of the raw material affects the biodiesel yield. At a raw material mass of 10 grams, a yield of 70.09% was obtained, while for a raw material mass of 20 grams, the yield was 82.00%. The biodiesel analysis results show that the density values for the 10-gram raw material mass variation are 0.8512, and for the 20-gram raw material mass variation, it is 0.8556. The water content is 1.46%, and the free fatty acid (FFA) content is 0.76 mg KOH/gram for the 10-gram raw material mass variation and 0.675 mg KOH/gram for the 20-gram raw material mass variation. The results of the biodiesel characteristic tests meet the SNI 7182:2015 standard
Prarancangan pabrik asam akrilat dari propilen dan udara dengan kapasitas 35000 ton/tahun
Get PDFPrarancangan pabrik asam akrilat dengan proses oksidasi propilen kapasitas
34. 000 ton per tahun ditunjukkan untuk memenuhi kebutuhan asam akrilat dalam
negeri karena semakin meningkatnya kebutuhan akan asam akrilat. Pabrik ini
direncanakan didirikan di kawasan industri Cilegon, Banten dengan bahan baku
propilena yang diambil dari PT. Candra Asri Petrochemical. Proses produksi asam
akrilat menggunakan prinsip reaksi oksidasi senyawa propilen oleh oksigen dalam
udara dilakukan melalui dua tahap oksidasi yaitu oksidasi propilena menjadi produk
Intermediete akrolein dan oksidasi akrolein menjadi produk utama asam akrilat.
Reaksi berlangsung dalam reaktor jenis multitubular fixed bed dengan bantuan
katalis Molybdenum Oxides Reaksi berlangsung dalam fase gas dengan suhu dan
tekanan 350 ℃ dengan tekanan 4,9 atm pada reaktor pertama R-01. Unit pendukung
proses sebagian diperoleh dari kawasan industri Cilegon seperti unit pengolahan
limbah dan pengadaan listrik, namun unit pengadaan air steam dan udara tekan
direncanakan akan dikelola sendiri oleh pabrik. Sumber air diperoleh dari sungai
waduk Krakatau Steel Cilegon untuk kebutuhan boiler feed water, dan cooling
water. Air sumur atau air tanah digunakan untuk sanitasi dari keberjalanan proses
dihasilkan limbah cair dan limbah gas yang akan dikelola terlebih dahulu sebelum
dialirkan ke unit pengolahan limbah. Bentuk badan usaha pabrik asam akrilat
adalah perseroan terbatas atau PT terbuka dengan sistem organisasi line and staff.
Jumlah karyawan yang dibutuhkan sebanyak 298 orang dengan pengoperasian
selama 330 hari kerja dan full time 24 jam. Dari hasil analisa ekonomi diperoleh
pos ROI (Return On Investment) sebesar 42,49% . Jika dilihat POT (Pay Out Time)
untuk pendirian pabrik ini selama 2 tahun 7 bulan dengan nilai BEP (Break Even
Point) dan SDP (Shutdown Point) berturut-turut sebesar 46,64% dan 30,40%
disimpulkan pabrik layak untuk didirikan dan menguntungkan bagi investor untuk
menanam sahamnya dalam pendirian pabrik ini.
Kata Kunci : Propilen, Asam Akrilat, Molybdenum Oxide
Transesterifikasi In situ Produksi Biodiesel Dengan Variasi Massa Bahan Baku Terhadap Karakteristik Biodiesel
Get PDFBiodiesel is one of the promising alternative fuels, environmentally friendly, and has no adverse effects on health. In this study, biodiesel production was carried out using the in situ transesterification method. The raw material used was mahogany seeds with variations in raw material mass of 10 grams and 20 grams. The catalyst used was KOH with methanol as the solvent and n-hexane as the co-solvent. In situ transesterification was performed at a reaction temperature of 65°C, stirring speed of 400 rpm, and a reaction time of 40 minutes. The research results show that the mass of the raw material affects the biodiesel yield. At a raw material mass of 10 grams, a yield of 70.09% was obtained, while for a raw material mass of 20 grams, the yield was 82.00%. The biodiesel analysis results show that the density values for the 10-gram raw material mass variation are 0.8512, and for the 20-gram raw material mass variation, it is 0.8556. The water content is 1.46%, and the free fatty acid (FFA) content is 0.76 mg KOH/gram for the 10-gram raw material mass variation and 0.675 mg KOH/gram for the 20-gram raw material mass variation. The results of the biodiesel characteristic tests meet the SNI 7182:2015 standard. 
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
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