1,720,971 research outputs found
Evaluation and Optimization for Extraction Parameters of Allium sativum Extract using Microwave Hydrodistillation (MHD)
Full text linkAllium sativum L extraction using microwave hydrodistillation (MHD) was chosen as one of the techniques for becoming a safer and greener technology. The yield of garlic oil obtained by MHD using water as solvent. The optimization was designed by response surface methodology (RSM) to evaluate and analyze the effect parameters of raw material mass, microwave power, and extraction time. The highest yield was found in 100 g, 450 W, and 90 min of 0.1392% based on experimental data. In addition, RSM using the quadratic model predicted that optimal condition at 88.09 g, 474.94 W, and 99.53 min was 0.1430%, respectively. An ANOVA analysis resulted in a p-value of less than 0.05 with a high determination coefficient (R2 = 0.9971). It indicates that this model gives a significant response and has good accuracy. Furthermore, the error rates between experimental data and the predicted model were less than 5%. The model obtained from optimization is close to the reability runs and could be explained for correlating the yield of garlic oil with parameter conditions using optimization
Stabilitas Zeolit HY Hidrofobik terhadap Uji Hot Liquid Water (HLW)
Full text linkInitially, zeolite catalysts cannot be used for reactions involving hot liquid water, so it is necessary to modify the zeolite to be stable under these conditions. The synthesis of HY and hydrophobic zeolites aimed to determine the stability of zeolite in hot liquid water (HLW). The stability of zeolite in HLW is related to zeolite hydrophobicity. In this study, the main raw materials for the synthesis of HY zeolite were sodium aluminate (NaAlO2) and Ludox HS-40 by calcining the product at 350 oC for 1 hour. Furthermore, increasing the hydrophobicity of HY zeolite was carried out by modifying the external zeolite surface using organosilanes (aminopropyltriethoxysilane). The stability of two zeolites in HLW was set at 200 oC. Zeolite analysis used physical test and Fourier Transform-Infra Red (FTIR) Spectrometer. The results of the zeolite distribution in two phases confirmed that HY zeolite was completely dispersed in the water phase, while the zeolite one was dispersed in the organic phase. Moreover, the IR spectra of HY zeolite showed that the wide peak detection at wave number 720 cm-1 for beginning to disappear. This means that the HLW condition could be damaged to the d6r unit. Another result was shown by hydrophobic zeolite spectra with a stable peak for 72 hours. This indicates that the hydrophobic zeolite has thermal stability in HLW so that it can be used in chemical reaction catalytic applications that use on phase
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
Studi Efektivitas Ekstraksi (Capsaicin) dari Cabai (Capsicum) Dengan Metode MASE (Microwave Assisted Soxhlet Extraction)
Full text linkCabai merupakan salah satu jenis komoditi holtikultura yang penting dan digemari oleh masyarakat dalam kehidupan sehari-hari. Cabai dapat digunakan untuk bumbu masak sehari-hari, Industri makanan dan obat-obatan. Namun masalah yang terjadi adalah ketika adanya fluktuasi harga yang sangat merugikan petani cabai. Terlebih apabila hasil panen sedang meningkat sehingga ketersediaan komoditas ini semakin banyak, tentu hal ini dibarengi dengan turunnya harga yang membuat hasil penjualan petani tidak mampu menutup biaya produksi yang digunakan. Oleh karena itu, melalui serangkaian proses penelitian ini diharapkan mampu menghasilkan proses ekstraksi cabai yang digunakan sekelompok petani cabai untuk mengekstraksi produk cabai yang melimpah pada saat musimnya sehingga bisa diubah menjadi produk yang memiliki nilai jual tinggi.
Pada penelitian ini akan dilakukan beberapa tahap yaitu meliputi tahap persiapan berupa studi literatur dan observasi laboratorium; perancangan alat dimana alat yang akan digunakan adalah MASE ( Microwave Assisted Soxhlet Extraction). Untuk treatment bahan baku diambil sampel cabai rawit segar dilanjutkan dengan proses ekstraksi yaitu dengan menggunakan metode MASE dan tahap analisa dengan variabel-variabel massa cabai dengan jenis bahan baku Cabai Rawit segar yaitu massa cabai rawit (0,04; 0,08; 0,12; 0,16; dan 0,2 gram). Daya microwave (400 W, 600 W, dan 800 W). Siklus proses di microwave ( 2; 4; 6; 8; dan 10 cycle). Kemudian uji kadar ekstrak cabai dengan secara kuantitatif; dan menghitung yield yang dihasilkan sehingga dapat diketahui kondisi yang paling tinggi.
Hasil Penelitian menghasilkan yield ekstrak cabai rawit segar dengan metode Microwave Assisted Soxhlet Extraction (MASE) adalah 400 W dengan 8 extraction cycle, massa cabai rawit 20 gram menghasilkan yield sebesar 8,4824%. Hasil Uji High Performance Liquid Chromatography (HPLC) mengandung capsaicin sebesar (0,453±0,004) %b/b atau sebesar (45.3±0,4) ppm.
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Chili is one type of horticultural commodity that is important and favored by society in everyday life. Chili can be used for everyday cooking spices, Food industry and medicine. But the problem that occurs is when the price fluctuations are very detrimental to chili farmers. Especially if the yield for increasing so the availability of this commodity, of course this is coupled with the decline in prices that make the sale of farmers unable to cover the cost of production was used. Therefore, through a series of research process is expected to produce a process of chili extraction used a group of chili farmers to extract chili products in abundance during the season so it can be converted into products that have high for selling value.
In this research will be done several stages that include preparation phase in the form of literature study and laboratory observation; Design tools where the tool to be used is MASE (Microwave Assisted Soxhlet Extraction). For treatment of raw material was taken sample of fresh cayenne pepper is followed by extraction process that is by using method of MASE and analysis phase with variables of mass of chili with type raw material of fresh chili Rawit is mass of cayenne pepper (0,04,0,0; 0,12 ; 0.16; and 0.2 gram). Microwave power (400 W, 600 W, and 800 W). Process cycles in microwave (2; 4; 6; 8; and 10 cycle). Then test the content of chili extract with a quantitative; And calculate for resulting in yield so it can know the highest condition.
The result of this research yield yield of fresh chilli extract with Microwave Assisted Soxhlet Extraction (MASE) method is 400 W with 8 extraction cycle, mass of 20 gram of cayenne pepper yield yield of 8,4824%. High Performance Liquid Chromatography (HPLC) test results was contained capsaicin (0.453 ± 0.004)% w / w or (45.3 ± 0.4) ppm
Inovasi teknologi alat pemurnian garam dari impuritiesnya menghasilkan high sodium chloride melalui metode rekristalisasi dengan penambahan koagulan PAC
Full text linkGaram merupakan salah satu kebutuhan yang merupakan pelengkap dari kebutuhan pangan dan merupakan sumber elektrolit bagi tubuh manusia. Walaupun Indonesia termasuk negara maritim, namun usaha meningkatkan produksi garam belum diminati, termasuk dalam usaha meningkatkan kualitasnya.
Proses pemurnian ini secara garis besar dilakukan dengan tiga tahap: tahap pertama (koagulasi), yaitu dengan menambahkan ion dengan muatan yamg berlawanan agar menimbulkan destabilisasi partikel koloid sehingga lapisan difusi akan mengecil dan memungkinkan bekerjanya gaya tarik menarik antar partikel. Koagulannya adalah PAC dan penambahan NaOH dan Na2CO3 yang ditambahkan ke dalam larutan garam dan dilakukan pengadukan. Na2CO3 ditambahkan terlebih dahulu sebelum NaOH.Tahap kedua (flokulasi), dengan penambahan flokulan untuk membentuk flok-flok yang lebih besar dan lebih berat, akibatnya densitas padatan yang terbentuk menjadi lebih besar dan laju pengendapan menjadi naik. Flokulasi dilakukan dengan pengadukan lambat untuk mencegah pecahnya flok tersebut. Tahap ketiga (sedimentasi), semua flok-flok yang terbentuk akan turun ke dasar wadah memisahkan diri dari larutan dengan percepatan maksimum padatan sesuai konsentrasinya Tahap keempat (Filtrasi), yaitu dengan melewatkan fluida yang telah terpisah dari endapannya pada medium penyaringan.
Kadar NaCl terbaik pada garam hasil rekristalisasi adalah penambahan koagulan PAC 15 ppm. Kadar ini telah memenuhi SNI 06-0303-1989 sebesar (98,5% d.b) untuk kualitas garam industri soda elektrolisis.
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Salt is one requirement that is complementary to the needs of food and a source of electrolytes to the human body. Although Indonesia is a maritime country, but the effort to increase the production of salt is not desirable, including in an effort to improve its quality.
This purification process is broadly done in three phases: the first phase (coagulation), by adding ion with a charge opposite yamg that cause destabilization of colloidal particles so that the diffusion layer will shrink and allow the operation of attractive forces between the particles. Koagulannya is PAC and the addition of NaOH and Na2CO3 were added to the saline solution and stirring. Na2CO3 was added prior to the second NaOH. Part of (flocculation), with the addition of flocculant to form a floc-floc larger and heavier, consequently density solids that formed became larger and the deposition rate to be increased. Flocculation carried out with slow stirring to prevent the outbreak of the floc. The third stage (sedimentation), all formed floc-floc will drop to the bottom of the container broke away from the solution with maximum acceleration corresponding solids concentration fourth stage (Filtration), namely by passing the fluid that has been separated from the sediment at the filtering medium.
From the experiment result are obtained as follows, the highest mass result PAC coagulant addition of 15 ppm. These levels have fulfilled SNI 06-0303-1989 of (98.5% db) to the quality of industrial salt soda electrolysi
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
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