1,720,959 research outputs found
ANALISA PROSES PENGOPERASIAN ALAT PENGHANCURAN DAN PENGAYAKAN YELLOW CAKE PADA SEKSI 100 DI INSTALASI PEMURNIAN DAN KONVERSI (PCP)
No full textABSTRAKInstalasi Pemurnian dan Konversi (Pilot Convertion Plant / PCP) adalah instalasi proses pembuatan yellow cake menjadi serbuk UO2. Pada awal proses instalasi pemurnian dan konversi, bahan baku yellow cake yang digunakan masih berupa batuan padat yang berasal dari hasil tambang. Untuk dapat di proses menjadi serbuk UO2, maka batuan yellow cake harus dihancurkan (crushing) dan diayak (sieving) sampai halus hingga terbentuk serbuk yellow cake dengan ukuran ≤ 5 mm. Penghancuran dan pengayakan batuan yellow cake ini di proses di seksi 100 pada Instalasi Pemurnian dan Konversi (PCP). Proses yang dilakukan semuanya berada didalam Glove Box (GB-101) agar tidak terjadi kontaminasi di ruang kerja. Didalam Glove Box 101 telah diatur tekanannya sesuai batas kondisi operasi (BKO) sebesar -5 mmH2O sampai dengan -15 mmH2O menggunakan pressure switch pneumatic. Penghancuran (crushing) yellow cake pada seksi 100 menggunakan Jaw Crusher (FC-101) dan pengayakan (sieving) menggunakan Vibrosieve (V-101). Hasil dari proses ini adalah sebuk yelow cake berukuran ≤ 5 mm sehingga siap dikirim seksi 300 untuk dilakukan pelarutan menggunakan asam nitrat pekat. Dari analisa proses pengoperasian alat penghancuran dan pengayakan yellow cake, bahwa ada beberapa faktor yang mempengaruhi jumlah produk yang dihasilkan, salah satunya adalah pelannya putaran rotary valve yang menyebabkan pengumpanan yellow cake menjadi sedikit.Kata kunci : crushing, sieving, yellow cakeAbstrackThe Pilot Conversion Plant (PCP) is the installation productions of UO2 powder from yellow cake powder. At the beginning of the process of the refinery and conversion installation of yellow cake, raw material used is still a solid rock that comes from the mine. To be processed until can produce UO2 powder, so yellow cake rock needs to go through crushing and sieving until its powder particle has a size ≤ 5 mm .This yellow cake will be crushing and sieving in section 100 on refinery Installation and conversion (PCP). The all process is done in the Glove box (GB-101) to prevent areal contamination. The pressure inside the glove box is maintained at the level of between -5 mmH2O to -15 mmH2O of used pressure switch pneumatic to fulfil safety requirement suitable at limit of operating conditions (BKO). The crushing of yellow cake at section 100 uses Jaw Crusher (FC-101) and sieving uses vibrosieve (V-101). The resulting fine this process is yellow cake powder with size until ≤ 5 mm and ready to be dissolved with concentrated nitric acid in section 300. An observation on the operation process of yellow cake crushing and sieving tools, that there are several factors that influence the amount of product produced, one of which is the rotary valve rotation too slow that causes yellow cake feeding to be less. Keywords: crushing, sieving, yellow cak
ANALISIS KESELAMATAN SISTEM KENDALI TUNGKU MUFFLE FURNACE ME-11 PADA PROSES REDUKSI GAGALAN PELET UO2
Full text linkABSTRAK - Proses reduksi di tungku Muffle Furnace ME-11 adalah proses pengolahan gagalan pelet UO2 menjadi serbuk UO2 yang menggunakan gas hidrogen sebagai pereduksi pada suhu± 800oC. Sistem Kendali logik pada tungku ini sangat diperlukan dengan titik berat faktorkeselamatan (safety) selama proses reduksi berlangsung, mengingat potensi bahaya gas hidrogen bersifat dapat mudah meledak pada kondisi tertentu. Sistem Kendali logik yang adapada sistem tungku Muffle furnace ME-11 terdiri dari sistem vacum, sistem pengaliran gas N2dan H2, sistem pembakar gas H2, sistem UPS (Uniterruptible Power Supply) dan alarm. Analisis keselamatan sistem kendali tungku Muffle Furnace ME-11 dilakukan untuk mengurangi kegagalan proses reduksi yang dilakukan dengan simulasi beberapa kondisi kegagalan, antara lain Supplai listrik utama (PLN) padam, api pembakar gas H2 menggunakan LPG padam, dan tekanan gas dalam tungku dibuat lebih tinggi atau rendah. Hasil analisis yang telah dilakukan pada sistem kendali logik terhadap kegagalan proses reduksi adalah sebagai berikut : apabila Supplai listrik utama padam maka alarm lampu indikator Power akan hidup, selanjutnya valve input H2 menutup, valve H2 output tetap membuka dan api pembakar gas H2 tetap menyala dengan supplai listrik oleh UPS. Apabila api pembakar gas LPG padam maka alarm dan lampu indikator Pilot Flame akan hidup, sistem pemantik menyala dan operator segera mengatur aliran gas LPG. Apabila tekanan di dalam tungku terlalu tinggi atau rendah saat beroperasi maka alarm dan lampu indikator tekanan akan hidup, pressure switch akan memerintahkan valve gas H2 menutup, selanjutnya operator mengatur tekanan melalui flowmeter gas H2. Hasil analisis sistem keselamatan kendali logik ini menunjukkan sistem kendali logik dapat berfungsi dengan baik, sehingga dapat menjamin keselamatan operasi proses reduksi dan kegagalan proses dapat dieliminasi saat operasi berlangsung.Kata kunci – Proses reduksi, Muffle Furnace, kendali logik ABSTRACT- The reduction process in the ME-11 Muffle Furnace furnace is the process of processing a UO2 pellet failure into UO2 powder using hydrogen gas as a reducing agent at ±800oC. Logic control system in this furnace is very much needed with the safety factoremphasizing during the reduction process, considering the potential danger of hydrogen gas can be explosive under certain conditions. The logical control system in the ME-11 Muffle furnace system consists of a vacuum system, an N2 and H2 gas flow system, an H2 gas burner system, a UPS and alarm system. Safety analysis of the Muffle Furnace ME-11 furnace control system was carried out to reduce the failure of the reduction process which was carried out by simulating several failure conditions, including the main electricity supply (PLN) outages, H2 gas burners using extinguished LPG, and the gas pressure in the furnace was made higher or low. The results of the analysis that have been carried out on the logical control system for the failure of the reduction process are as follows: if the main power supply goes out then the alarm indicator lights Power will turn on, then the H2 input valve closes, the H2 output valve remains open and the H2 gas burner flame stays on with the supply electricity by UPS. If the LPG gas burner extinguishes, the Pilot Flame alarm and indicator lights will on, the lighter system is on and the operator immediately regulates the LPG gas flow. If the pressure inside the furnace is too high or low when operating then the alarm and the pressure indicator lights on, the pressure switch will order the H2 gas valve to close, then the operator regulates the pressure through the H2 gas flowmeter. The results of the logic control system safety analysis shows that the logical control system can function properly, so as to ensure the safety of the reduction process operations and process failures can be eliminated during operations.Keywords - Reduction process, Muffle Furnace, logical contro
ANALISIS KERUSAKAN DAN PERBAIKAN MESIN LAS TITIK ME-25
Full text linkANALISIS KERUSAKAN DAN PERBAIKAN MESIN LAS TITIK ME-25. Mesin las ME-25 adalah jenis Resistance Spot Welding (RSW) yang digunakan untuk perakitan kelongsong bahan bakar nuklir PLTN di Pusat Teknologi Bahan Bakar Nuklir (PTBBN) – BATAN. Mesin las titik ( ME-25 ) berfungsi untuk pengelasan end plate dari pin menjadi bundle elemen bakar nuklir. Mesin las ME-25 telah mengalami kerusakan akibat kondisi ruangan dan suplai udara tekan yang banyak mengandung air. Analisis kerusakan dilakukan pada tiga sistem, antara lain: Sistem Elektrik Power Suplai, Sistem Elektro Pneumatik, dan Sistem Kontrol Elektronik. Metode yang digunakan dalam melakukan analisis kerusakan adalah dengan cara melakukan pengukuran langsung pada bagian input dan output komponen. Setelah dilakukan pengukuran maka dapat diketahui bahwa kerusakan suplai daya listrik terdapat pada sistem emergensinya dan kerusakan pada Sistem Elektro Pneumatik. Setelah dilakukan perbaikan pada sistem emergensi dan penggantian unit elektro pneumatik, mesin las tetap tidak dapat bekerja. Kemudian dilakukan pemeriksaan pada modul kontrol arus pengelasan, ternyata modul kontrol arus mengalami kerusakan. Perbaikan dilakukan dengan cara modifikasi pada modul kontrol arus pengelasan. Setelah dimodifikasi kemudian dilakukan uji fungsi dan proses pengelasan dapat bekerja dengan baik, akan tetapi perlu dilakukan pengujian arus pengelasan pada sistem kontrol elektronik untuk mendapatkan parameter pengelasan yang baik
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Full text link“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
Full text linkWe 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
Full text linkWe 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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