1,720,971 research outputs found
Pembuatan dan Karakterisasi Bahan Superkonduktor Bi1.6Pb0.4Sr2Ca2-xMxCu3Oy(M= Na, Mg dan Ce) FASE 2223 dengan Metode Sol-Gel
No full textBahan superkonduktor BPSCCO non-dopan dan dopan Mx (M = Mg, Na, dan Ce dengan x = 5% dan 15%) dengan metode sol-gel berhasil dibuat. Namun setelah melalui uji Cryogenic Magnetic yang menghasilkan bahan superkonduktor dengan Tc-zero hanya BPSCCO non-dopan dan dopan Mg dan Ce. Dimana BPSCCO dengan dopan Mg 15% memiliki harga Tc-zero tertinggi yaitu pada suhu 77 K dengan fraksi volume 77.27% melalui uji XRD, sedangkan bahan superkonduktor yang memiliki harga Tc-zero terendah yaitu bahan superkonduktor dengan dopan Ce 15% pada suhu 72 K dan memiliki fraksi volume 52.62%. Bahan superkonduktor BPSCCO dengan dopan Na tidak berhasil mencapai Tc-zero (Nol resistansi), hanya mampu mencapai resistansi 3.77 x 10-2 Ohm pada suhu 69KThe BPSCCO non-dopant and dopant Mx superconducting materials (M = Mg, Na, and Ce with x = 5% and 15%) with the sol-gel method were successfully made. But after going through the Cryogenic Magnetic test which produces superconducting material with Tc-zero only BPSCCO is non-dopant and dopant Mg and Ce. Where BPSCCO with 15% Mg dopant has the highest Tc-zero price that is at 77 K with a volume fraction of 77.27% through XRD test, while superconducting material has the lowest Tc-zero price that is superconductor material with Ce 15% dopant at 72 K and has a volume fraction of 52.62%. BPSCCO superconductor material with dopant Na failed to achieve Tc-zero (Zero resistance), only able to achieve resistance 3.77 x 10-2 Ohm at 69K76 HalamanTesis Magiste
Analisis Superkonduktivitas Bi-2223 Dopan Carbon Nanoparticles dan Carbon Nanotube dengan Metode Sol-Gel dan Sintering Berulang
No full textPembuatan material superkonduktor BPSCCO dengan perhitungan stokiometri Bi:Pb:Sr:Ca:Cu = 1.6:0.4:2:2:3 telah dilakukan menggunakan metode sol-gel dan melalui proses sintering berulang pada temperatur 840 oC selama 30 jam serta penambahan dopan Carbon Nanoparticles (0.05 wt.% dan 0.1 wt.%) dan Carbon nanotube (0.05 wt.% dan 0.2 wt.%). Karakterisasi yang digunakan adalah karakterisasi XRD untuk menganalisis pembentukan fasa, karakterisasi SEM untuk menganalisis mikrostruktur dan karakterisasi resistivity untuk menganalisis temperatur kritis. Hasil pengkarakterisasian XRD dan SEM menunjukkan efek sintering berulang meningkatkan fasa Bi-2223 pada sampel, morfologi semakin rapat dan porositas menurun. Dari hasil pengkarakterisasian resistivitas, diperoleh niai temperatur kritis (Tc) optimum setelah proses sintering berulang sebesar 117,62 K. Kandidat terbaik didapatkan pada sampel BPSCCO dengan penambahan dopan CNT sebesar 0.2 wt.% terdapat fasa Bi-2223 semakin meningkat dengan fraksi volume superkonduktor 33,04 % dan morfologi yang terbentuk memiliki ukuran kristal yang kecil dengan kerapatan butir yang rendah dan sedikit porositas. Nilai Tconset sebesar 119,43 K dan Tczero sebesar 102,03 K dengan nilai p120ksebesar 2,1948×10-3 Ω.cm.The manufacture of BPSCCO superconducting material with stoichiometric at the nominal composition of Bi:Pb:Sr:Ca:Cu =1.6:0.4:2:2:3 has been carried out using the sol-gel method and through the two-step sintering at 840 oC for 30 hours and addition of dopant Carbon Nanoparticles (0.05 wt.% and 0.1 wt.%) and Carbon Nanotubes (0.05 wt.% and 0.2 wt.%). The characterization used is XRD to analyze phase formation, SEM characterization to analyze microstructure and resistivity characterization to analyze critical temperature. The results of XRD and SEM characterization showed the effect of two-step sintering increased the Bi-2223 phase in the sample, the morphology was tighter and the porosity decreased. From the results of resistivity characterization, the optimum critical temperature (Tc) value after two-step sintering process was 117.62 K. The best candidate was obtained in the BPSCCO sample with the addition of CNT dopants of 0.2 wt.% there was an increasing Bi-2223 phase with a volume fraction of superconductors 33,04 % and the morphology formed has a small crystal size with low grain density with a minimum of porosity. The value of Tconset is 119.43 K and Tczero is 102.03 K with a value of p120k is 2,1948×10-3 Ω.cm.138 HalamanTesis Magiste
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
EFEKTIVITAS PEMUTUSAN MULTIWALLED CARBON NANOTUBES (MWNT) DENGAN MENGGUNAKAN HIGH ENERGY MILLING DAN CONVENTIONAL BALL MILLING
No full textThe cutting efficiency of MWNTs was compared systematically between conventional ball milling and high-energy milling. The efficiency of both processes was evaluated in term of dispersion properties, aggregates size evolution, and degree of crystallinity. Two-hour high-energy milling produced a large portion of MWNTs smaller than 150 nm, while even 120-hour ball milling struggled to achieve smaller than 300 nm. It was revealed by the significantly viscosity value. Since the high-energy milling viscosity was much higher than ball milling, 2-hours high energy milling exhibited lower damage on the MWNTs thread than the 120-hours ball milling according to the I /I ratio and values of raman spectra were 3.63 and 2.81 for high energy milled and ball milled respectively.
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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