1,720,962 research outputs found
Intermolecular Force Pada Perubahan Sudut Kontak Droplet Minyak Nabati Akibat Pendinginan
Full text linkMasalah cleanability pada permukaan menjadi bahan diskusi para ahi beberapa tahun terakhir ini. Cleanability dapat dilakukan dengan cara kimia, atau dengan cara fisika. Selama ini penelitian cleanability banyak dilakukan pada material berupa penutup berupa material yag besar, tetapi pada material penutup berupa droplet masih jarang dilakukan.
Penelitian ini bertujuan meningkatkan cleanability dengan meningkatkan sudut kontak droplet melalui perubahan temperatur. Perubahan temperature akan mempengaruhi intermolecularforce pada droplet sehingga mengubah sudut kontak droplet.
Perubahan temperatur akan mengubah gaya London antar molekul. Penurunan temperature meningkatkan gaya London antar molekul pada permukaan droplet. Peningkatan gaya London akan meningkatkan tegangan permukaan. Kenaikan tegangan permukaan akan meningkatkan sudut kontak.
Untuk membuktikan konsep di atas, penelitian menggunakan 3 jenis droplet minyak nabati, yaitu minyak jarak, minyak kelapa, dan minyak bunga matahari.
Hasil penelitian menunjukkan bahwa pada minyak jarak : sudut kontak awalnya sekitar 20.660 pada 25,02oC. Kemudian sudut kontak meningkat hingga 24,380 pada 13,96oC. Kemudian menurun hingga 14,180 pada 6,72oC. Selanjutnya naik hingga 17,650 pada 4,28oC. Kemudian menurun lagi hingga 15,570 pada 2,510C.
Pada minyak bunga matahari penelitian menunjukkan bahwa: sudut kontak awalnya sekitar 18.920 pada 24,60oC. Kemudian sudut kontak meningkat hingga 22,140 pada 19,19oC. Kemudian menurun hingga 14,020 pada 7,69oC. Selanjutnya naik hingga 16,700 pada 6,12oC. Kemudian menurun lagi hingga 12,950 pada 3,250C
Pada minyak kelapa penelitian menunjukkan bahwa: Dari tabel di atas menunjukkan bahwa sudut kontak awalnya sekitar 9.070 pada 23,91oC. Kemudian sudut kontak meningkat hingga 12,70 pada 22,44oC. Kemudian menurun hingga 6,890 pada13,31oC. Selanjutnya naik hingga 9,280 pada 6,12oC. Kemudian menurun lagi hingga 4,470 pada 5,780C.
Kesimpulan penelitian ialah: Perubahan sudut kontak akibat perubahan suhu pada droplet minyak nabati dipengaruhi oleh intermolekuler force dari konstituen minyak tersebut. Gaya London mempengaruhi pembentukan sudut kontak saat terjadi perubahan temperatur. Sifat hidrofilik mempengaruhi gerakan uap air menempel di permukaan droplet dan mempengaruhi sudut kontak. Ikatan hidrogen mengikat uap air dan mempengaruhi sudut konta
Pengaruh orientasi arah serat dan waktu curing terhadap kekuatan tarik komposit serat sabut kelapa dengan resin epoxy.
Full text linkPerkembangan teknologi komposit yang semakin maju menyebabkan kebutuhan material. komposit semakin meningkat di bidang perindustrian, Salah satu jenis komposit yang banyak dikembangkan saat ini adalah komposit serat alam. Keuntungan yang dimiliki oleh serat alam (Natural Fiber) adalah jumlahnya berlimpah, proses pembuatan yang mudah dan aman, biaya yang terjangkau, dan tidak mencemari lingkungan. Salah satu serat alam yang akan dijadikan penelitian adalah serat sabut kelapa. Penelitian ini bertujuan untuk
menyelidiki dan mengetahui variasi arah serat dan variasi lama waktu curing dari komposit sabut kelapa terhadap kekuatan tarik. Bahan yang digunakan dalam pembuatan komposit adalah resin epoxy dan serat sabut kelapa. Pembuatan komposit dilakukan dengan metode hand lay-up. Spesimen uji
komposit berpenguat serat sabut kelapa dipotong sesuai standar ASTM D3039 untuk specimen uji tarik. Variabel penelitian ini adalah Orientasi arah serat dan variasi lama waktu yang berbeda. Orientasi arah serat yang digunakan adalah serat searah dan serat acak lalu parameter yang kedua adalah variasi lama waktu curing yang berbeda yaitu 0 menit, 10 menit, 30 menit, dan 50 menit dengan temperature yang sama yaitu 100C, dengan cara spesimen dipanaskan meggunakan oven listrik, kemudian dilakukan uji tarik dengan Universal Testing Machine
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
- …
