1,720,956 research outputs found
Pengolahan limbah cair industri pelapisan logam dengan proses elektrokoagulasi secara kontinyu
Get PDFLimbah cair industri pelapisan logam berasal dari hasil pembilasan pada proses pelapisan dengan Chrome, masih banyak terkandung zat berbahaya apabila langsung dibuang kelingkungan. Untuk itu perlu dilakukan pengolahan lebih lanjut dengan menggunakan elektrokoagulasi. Metode ini memiliki potensi penjernihan limbah cair pelapisan logam dan penurunan kandungan logam yang terkandung tanpa adanya penambahan koagulan. Tujuan dari penelitian ini untuk mengetahui penerapan metoda elektrokoagulasi untuk menetralkan pH, serta menurunkan kadar TSS dan Cr pada limbah dan untuk mengetahui pengaruh perubahan laju alir dan kuat arus untuk menetralkan pH, serta menurunkan kadar TSS dan Cr pada limbah. Parameter yang diuji meliputi pH, TSS (Total Suspended Solid), dan Cr. Proses elektrokoagulasi menggunakan listrik searah melalui elektroda. Reaktor elektrokoagulasi yang dipasangkan kabel ke power suplay kemudian disambungkan ke arus listrik dengan variasi kuat arus (1,2 ; 1,6 ; dan 2 A) dan variasi laju alir (0,78 ; 1,32 ; 2,7 L/menit). Hasil penelitian didapat kondisi optimum pada kuat arus 2 A dan laju alir 0,78 L/menit dengan kenaikan pH dari 4,5 menjadi 6,6, penurunan TSS dari 3,2 menjadi 1,2 mg/L, penurunan Cr sebesar 82,4 % dari 1,5 mg/L menjadi 0,263 mg/L
Termodinamika Campuran Polipropilen/Karet Alam yang Ditambahkan Kompatibilizer Maleated Polypropylene
Get PDFKajian terhadap aspek termodinamika suatu sistem campuran polimer-polimer diperlukan untuk mendapatkan informasi mengenai kemampuan pencampuran maksimal dan pemisahan fasa dari sistem campuran tersebut. Penelitian ini bertujuan untuk memperkirakan kemampuan pencampuran sistem karet alam (natural rubber, NR) dan polipropilen (PP) yang ditambahkan kompatibilizer Maleated Polypropylene (MAPP), dimana fasa NR tervulkanisasi dinamik dalam matrik PP dengan cross-link agent sulfur. Estimasi kemampuan pencampuran didasarkan pada energi bebas pencampuran yang dihitung dengan persamaan Flory-Huggins. Entalpi pencampuran dan volume molar masing-masing dihitung dengan persamaan van Krevelen dan metode Group Contribution Volume (GCVol). Parameter kelarutan juga dihitung menggunakan metode van Krevelen. Energi bebas pencampuran dihitung pada komposisi NR antara 0 sampai dengan 100% dan suhu 30oC. Proses vulkanisasi fasa NR dianggap menghasilkan jumlah molekul yang berikatan silang sebanyak 1113 dan terjadi secara monosulfidik. Komposisi MAPP divariasikan antara 0 sampai 10% massa, sedangkan jumlah gugus anhydrate (MA) dalam molekul MAPP berkisar antara 1 sampai 5% mol. Hasil perhitungan menunjukkan bahwa penambahan MAPP pada sistem campuran NR/PP dengan fasa NR tervulkanisasi dinamik hanya dapat menurunkan nilai energi bebas pencampuran, namun tidak mengubah sifat ketidakmampuan campurnya. Kadar MA dalam MAPP relatif tidak mempengaruhi kemampuan pencampuran sistem campuran tersebut
Anti-microbic food packaging innovation from waste banana skin and durian seeds
Get PDFEdible film is a packaging that has the advantage of being easily degraded so that it does not cause environmental problems such as plastic waste which can pollute the environment. Edible film is considered to have good prospects for application in food ingredients, one of which is meat, because meat has a limited shelf life. The addition of antimicrobial ingredients to the edible film in the form of essential oil of basil leaves is useful for reducing microbial growth. The purpose of this study was to make edible films to extend the shelf life of frozen meat, utilize banana peels and durian seeds as the main ingredients for making edible films and use basil essential oil as an antimicrobial agent. The stages of activities carried out in this study included the preparation of raw materials for waste banana peels, durian seeds, and basil leaves. This stage includes the extraction process of each ingredient that produces pectin from banana peels, starch from durian seeds, and essential oil from basil leaves. Furthermore, the making of edible films from these raw materials varied the ratio between the mass of pectin and starch. The formed edible films were analyzed using FTIR, attractiveness test, and microbial growth testing by comparing meat coated with edible film and meat not coated with edible film. The characteristics of the edible film produced are 0.1 mm thick with a tensile strength value of 64.65 MPa - 75.34 MPa and a percent elongation value of 0.318% - 0.36%. The best edible film was produced at a ratio of 4: 1 (pectin: starch) with the addition of antimicrobials which had a film thickness of 0.1 mm with a tensile strength value of 75.34 MPa and 0.35% elongation percent
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
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