1,720,953 research outputs found
Efek Substitusi Al (Aluminium) dan Mn (Mangan) pada Material Magnetik Barium Heksaferit terhadap Kemampuan Serapan Gelombang Elektromagnetik
Full text linkABSTRAK
JUWANDA FERNANDO, 2024. Efek Substitusi Al (Aluminium) dan Mn (Mangan) pada Material Magnetik Barium Heksaferit terhadap Kemampuan Serapan Gelombang Elektromagnetik, Program Studi Fisika, Fakultas Matematika dan Ilmu Pengetahuan Alam, Universitas Negeri Jakarta. Juli 2024. Barium heksaferit merupakan suatu jenis ferit yang memiliki struktur kristal heksagonal. Penelitian tentang efek substitusi Al dan Mn pada material magnetik Barium Heksaferit terhadap kemampuan serapan gelombang elektromagnetik telah dilakukan. Berdasarkan sintesis material magnetik BaFe12-2xAlxMnxO19 yang dilakukan dengan menggunakan metode reaksi zat padat. Pada sintesis yang
dilakukan diperoleh hasil yang akan dikarakterisasi berupa pellet hasil dari kompaksi . Hasil analisis optik pada sampel perbesaran 500 kali terlihat tercampur rata, perbesaran 1300 kali terlihat semakin tinggi nilai variasi penambahan Al dan Mn maka, pada sampel terlihat partikel yang bewarna putih yang semakin meningkat. Dikarenakan komposisi material Al2O3 yang berwarna putih meningkat.
Sifat kemagnetan material magnetik BaFe12-2xAlxMnxO19 menunjukan penurunan magnetisasi remanensi (Mr) dan nilai medan koersivitas (Hc) serta peningkatan magnetisasi saturasi (Ms) seiring meningkatnya penambahan massa Al dan Mn.Berdasarkan nilai Hc yang diperoleh menunjukan material magnetik BaFe12-2xAlxMnxO19 merupakan hard magnetic. Sifat penyerapan gelombang mikro rentang milliwave dengan frekuensi 26.5 – 40 GHz pada material magnetik BaFe12-
2xAlxMnxO19 yang optimal ketika x = 0.75. Hal ini dikarenakan pada variasi x = 0.75 memiliki nilai Reflection Loss (RL) minimum sebesar -10.031 dB , dengan bandwith (< -5 dB) sebesar 11.722 GHz, bandwith ( < -10 dB) sebesar 9.624 GHz. Presentase absorption material + transmission maksimum (gelombang yang tidak dipantulkan kembali) sebesar 90.070 %.
Kata Kunci : Barium heksaferit, substitusi, reaksi zat padat, BaFe12-2xAlxMnxO19 , gelombang mikro (milliwave).
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ABSTRACT
JUWANDA FERNANDO, 2024. Effects of Al (Aluminum) and Mn (Manganese) Substitution in Barium Hexaferite Magnetic Material on Electromagnetic Wave Absorption Ability, Physics Study Program, Faculty of Mathematics and Natural
Sciences, Universitas Negeri Jakarta. July 2024. Barium hexaferite is a type of ferrite that has a hexagonal crystal structure. Research on the effect of Al and Mn substitution in Barium Hexaferite magnetic material on the ability of electromagnetic wave absorption has been conducted. Based on the synthesis of BaFe12-2xAlxMnxO19 magnetic material carried out using the solid state reaction method. In the synthesis carried out, the results obtained will be
characterized in the form of pellets resulting from compaction. The results of optical analysis on the sample magnification of 500 times look evenly mixed, 1300 times
magnification looks the higher the value of the variation of the addition of Al and Mn then, in the sample visible white particles that are increasing. Due to the composition of white Al2O3 material increases. Due to the composition of white Al2O3 material increases. The magnetic properties of BaFe12-2xAlxMnxO19 magnetic material show a decrease in remanence magnetization (Mr) and coercivity field
value (Hc) and an increase in saturation magnetization (Ms) as the mass addition of Al and Mn increases. Based on the Hc value obtained, it shows that BaFe12-2xAlxMnxO19 magnetic material is hard magnetic. The microwave absorption
properties of the milliwave range with a frequency of 26.5 - 40 GHz in the BaFe12-2xAlxMnxO19 magnetic material are optimal when x = 0.75. This is because the x = 0.75 variation has a minimum Reflection Loss (RL) value of -10.031 dB, with a bandwidth (< -5 dB) of 11.722 GHz, a bandwidth (< -10 dB) of 9.624 GHz. The percentage of material absorption + maximum transmission (non-reflected waves) is 90.070%.
Keywords: Barium hexapherite, substitution, solid state reaction, BaFe12-2xAlxMnxO19, microwave (milliwave)
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
Author Under Sail The Imagination of Jack London, 1893-1902
No full textIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Intro -- Title Page -- Copyright Page -- Dedication -- Contents -- Acknowledgments -- Introduction -- 1. Spirit Truth -- 2. From Absorption to Theatricality and Back Again -- 3. "I Will Build a New Present" -- 4. Sons as Authors -- 5. Fathers as Publishers -- 6. The Daughter as Author -- 7. Lovers as Authors -- 8. At Sea with the Family -- 9. Yellow News, Yellow Stories -- 10. The Return Home -- Notes -- Bibliography -- Index -- About Jay WilliamsIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Description based on publisher supplied metadata and other sources.Electronic reproduction. Ann Arbor, Michigan : ProQuest Ebook Central, YYYY. Available via World Wide Web. Access may be limited to ProQuest Ebook Central affiliated libraries
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