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PENGARUH PENGGUNAAN KOMBINASI ABU AMPAS TEBU DAN ABU SEKAM PADI SEBAGAI SUBSTITUSI SEMEN PADA BETON MUTU TINGGI TERHADAP KUAT TEKAN BETON PADA LINGKUNGAN BERBEDA
No full textPenggunaan material semen dalam industri konstruksi terus meningkat dari tahun ke tahun dan peningkatan ini berakibat pada meningkatnya produksi gas buangan CO2 dialam yang berakibat pada pembentukan efek rumah kaca. Abu ampas tebu dan abu sekam padi mengandung unsur silika (SiO2) yang juga terdapat pada kandungan semen. Pada penelitian ini digunakan kombinasi abu ampas tebu dan abu sekam padi sebagai substitusi semen. Tujuan penelitian ini untuk mengetahui pengaruh penggunaan bahan substitusi semen dengan kombinasi 75% abu sekam padi dan 25% abu ampas tebu sebagai substitusi semen pada lingkungan yang berbeda terhadap kuat tekan beton mutu tinggi. Penelitian ini menggunakan kombinasi abu ampas tebu dan abu sekam padi dengan variasi 0%, 1%, 2% dan 3% dari volume semen dengan nilai FAS 0,3. Benda uji yang digunakan yaitu berbentuk silinder dengan diameter 10 cm dan tinggi 20 cm dengan masing-masing 3 benda uji setiap variasi. Perawatan dilakukan dengan cara perendaman selama 28 hari dan setelah perawatan benda uji diletakkan di lingkungan yang berbeda yaitu pada kondisi lingkungan yang terlindung, tidak terlindung dan tertimbun selama 7 hari dan 28 hari, sehingga total benda uji sebanyak 72 buah. Hasil yang didapatkan menunjukkan nilai kuat tekan optimum didapatkan pada beton mutu tinggi dengan substitusi persentase 1%. Variasi persentase yang berbeda memberi pengaruh pada kuat tekan beton mutu tinggi. Nilai kuat tekan beton pada perawatan 7 hari yaitu di lingkungan terlindung, tidak terlindung dan tertimbun sebesar 44,79 MPa, 52,67 MPa dan 52,01 MPa, sedangkan pada perawatan 28 hari kuat tekan optimum sebesar 67,06 MPa, 69,10 MPa dan 70,16 MPa. Pada umur 28 hari di masing-masing kondisi lingkungan yaitu terlindung, tidak terlindung dan tertimbun mengalami kenaikan kuat tekan pada persentase 1% yaitu sebesar 35,94%, 50,78% dan 30,79% dari beton mutu tinggi tanpa substitusi
STUDI EKOLOGI VEGETASI DASAR DAN INVASIF DI CAGAR ALAM BATANG PALUPUAH KABUPATEN AGAM SUMATERA BARAT
Get PDFCagar Alam Batang Palupuah merupakan kawasan hutan konservasi yang termasuk formasi hutan hujan tropis. Bertambahnya populasi penduduk diiringi peningkatan aktivitas manusia di sekitar cagar alam berupa kunjungan wisatawan, secara tidak langsung dapat memberi dampak terhadap komunitas vegetasi alami di kawasan cagar alam ini. Dampak yang ditimbulkan terhadap kawasan konservasi tersebut salah satunya berupa masuknya spesies tumbuhan invasif yang organ dispersalnya dibawa oleh manusia. Spesies tumbuhan invasif dapat mempengaruhi biodiversitas suatu ekosistem alami. Penelitian ini memiliki tujuan yaitu untuk mengetahui komposisi dan struktur komunitas vegetasi dasar invasif di Kawasan cagar alam Batang Palupuah, Nagari Koto Tangah, Kecamatan Tilatang Kamang, Kabupaten Agam Sumatera Barat. Penelitian dilaksanakan pada April 2017 sampai Juli 2017 di kawasan Cagar Alam Batang Palupuah. Identifikasi spesies dan pengolahan data dilakukan di Herbarium ANDA dan Laboratorium Ekologi Tumbuhan Universitas Andalas. Penelitian ini dilakukan dengan survei lapangan dengan peletakan plot secara systematic sampling sebanyak 45 plot dengan ukuran 2x2 m dari kawasan tepi sampai kedalam Cagar Alam Batang Palupuah. Hasil yang didapatkan bahwa komposisi komunitas vegetasi dasar di Kawasan Cagar Alam Batang Palupuah terdiri dari 31 famili, 54 spesies dan 1062 individu yang di dalamnya terdapat 4 famili, 4 spesies dan 14 individu spesies invasif dengan indeks keanekaragaman keseluruhan adalah 0,83. Spesies dengan INP tertinggi adalah Coffea robusta (79,18). Spesies invasif dengan INP tertinggi adalah Colubrina asiatica(1.97).
Kata kunci: Cagar Alam, INP, Tanaman invasif, Vegetasi dasa
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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