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Engine performance and emission of biodiesel from waste cooking oil using jackfruit peel waste derived catalyst / Andi Mulkan
No full textNowadays, the amount of waste cooking oil (WCO) continues to increase. Unfortunately, much of this waste is improperly disposed of, harming the environment. Utilizing WCO as biodiesel feedstock offers a solution to reduce the impact of this waste on the environment, creating a more cost-effective and environmentally friendly fuel. Moreover, the catalyst plays a crucial role in facilitating the biodiesel production reaction. In order to decrease the costs associated with catalysts in biodiesel production, one potential approach is to utilize heterogeneous or solid catalysts derived from easily accessible waste biomass products, such as fruit peel waste. By utilizing waste-derived biomass materials for catalyst development, the process becomes more cost-effective and sustainable. The utilization of fruit peel wastes for catalyst development has gained popularity in recent times due to the abundance of waste resources and the desire to mitigate disposal challenges. In the present study, jackfruit (Artocarpus heterophyllus) peel waste (JPW) has been chosen and developed as a heterogeneous catalyst for biodiesel synthesis. The prepared catalyst has been characterized and it is showed the presence of significant components such as potassium (K), calcium (Ca), and magnesium (Mg) in the catalyst, which play a significant role in the synthesis of biodiesel. Furthermore, response surface methodology (RSM) with a centered composite design type has been applied to examine the best conditions of the transesterification process. The optimization process shows the optimum conditions were achieved for biodiesel synthesis with an oil-tomethanol molar ratio of 1:9, a catalyst weight of 12 % (w/w), a reaction time of 105 minutes, and a constant reaction temperature of 65 °C, yielding a methyl ester content of 98.88%. Additionally, reusability studies were conducted to assess the stability of the prepared catalysts. The results indicated that the JPW catalyst can be utilized for up to three cycles, with the highest yield observed at 93.33%. Moreover, the fuel properties of the waste cooking oil (WCO) biodiesel were investigated, and it was found that the physicochemical properties of the WCO biodiesel comply with the requirements outlined in ASTM D 6751. Moreover, an experimental study of tested fuels using a single-cylinder direct injection diesel engine has been conducted, to evaluate engine performance and exhaust emissions. The BSFC demonstrated an average decrease of 16.67-22.69% with the rise in engine speed. Conversely, BTE exhibited an average increase of 16.67% as engine speed increased. Moreover, engine torque experienced a slight decrease initially, followed by a significant decrease at high speeds. In contrast, BP exhibited a proportional increase with the rise in engine speed. Meanwhile, it was observed that CO emissions exhibited a significant reduction, averaging 6.11-48.63% across all speeds, when compared to pure diesel. Conversely, CO2 and NO emissions showed an overall increase, although some reductions were noted for certain fuel samples. Additionally, as engine speed increased, a downward trend in HC emissions was observed. While an increase in smoke opacity was generally observed in this study, a slight decrease was noted for certain fuel samples within the engine speed range of 1800 to 2400 rpm
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
Analisis Pemanfaatan Energi Angin Sebagai Sumber Pembangkit Energi Listrik
Full text linkTujuan dari studi penelitian ini adalah untuk mengetahui potensi energi angin di Kota Banda Aceh serta merencanakan spesifikasi turbin angin yang sesuai berdasarkan hasil perhitungan.Permintaan akan energi khususnya energi listrik di Indonesia semakin tinggi dan menjadi bagian tak terpisahkan dari kebutuhan hidup masyarakat maupun sektor industri. Bahan bakar fosil yang digunakan sebagai bahan utama untuk menghasilkan listrik, ketersediannya semakin terbatas, belum lagi polusi yang dihasilkan oleh proses konversi dari bahan bakar fosil tersebut. Pengembangan sumber energi alternatif makin digalakkan melalui kebijakan pemerintah untuk mendorong dan menfasilitasi pemanfaatan sumber-sumber energi tersebut misalnya hydro, matahari, panas bumi, biomassa dan juga angin. Dari latar belakang dan rumusan masalah diatas maka dilakukan studi penelitian yang difokuskan kepada sumber energi angin.Hasil perhitungan didapat untuk diameter rotor 8 meter, daya output yang paling besar terlihat pada Bulan Agustus yaitu 18,71 kW dan yang terendah pada Bulan Februari yaitu 0,95 kW. Daya output rata-rata adalah 7,18 kW. Dari hasil perhitungan jelas terlihat bahwa daya output sangat tergantung pada kecepatan angin dan luas area sapuan rotor (rotor swept area). Spesifikasi turbin yang direncanakan adalah turbin angin sumbu horizontal dengan jumlah sudu 3 dan daya output 10 kW. Koefisien rotor adalah 0,42 dengan diameter rotor 8 meter.
 
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
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