1,720,956 research outputs found
Liquid-liquid Equilibrium Of The Water + Citric Acid + Short Chain Alcohol + Tricaprylin System At 298.15 K
No full textIn the past few years, new processes for citric acid recovery have been studied. Among these processes, liquid-liquid extraction has had special attention. The extraction process is attractive due to the fact that, if a good solvent is used, it presents high selectivity and efficiency, it does not affect the thermal stability of products, and it requires low energy consumption. In this work, experimental data for the liquid-liquid equilibria of water-citric acid-solvent systems were obtained. The following solvents were tested: 2-butanol, 1-butanol, and mixed solvents containing those alcohols and tricaprylin. The parameters for the NRTL and UNIQUAC models were obtained by fitting the thermodynamic models to the experimental data.463546550Lintomen, L., (1999) Evaluation of the Liquid-Liquid Extraction for Recovery and Purification of Citric Acid (In Portuguese), , M.Sc. Thesis, Chemical Engineering Faculty, State University of CampinasMitchell, R.J., Arrowsmith, A., Ashton, N., Mixed solvent systems for recovery of ethanol from dilute aqueous solution by liquid- liquid extraction (1987) Biotechnol. Bioeng., 30, pp. 348-351Kertes, A.S., King, C.J., Extraction chemistry of fermentation product carboxylic acids (1986) Biotechnol. Bioeng., 28, pp. 269-282Welsh, F.W., Willians, R.E., The use of vegetable oils to recover compounds from aqueous solutions (1989) J. Chem. Technol. Biotechnol., 46, pp. 169-178Chumpitaz, L.D.A., Coutinho, L.F., Meirelles, A.J.A., Surface tension of fatty acids and triglycerides (1999) J. Am. Oil Chem. Soc., 76, pp. 1-4Silva, L.H.M., Coimbra, J.S., Meirelles, A.J.A., Equilibrium phase behavior of poly(ethylene glycol) + potassium phosphate + water two-phase systems at various ph and temperatures (1997) J. Chem. Eng. Data, 42, pp. 398-401Tiwari, R.D., Sharma, J.P., (1970) The Determination of Carboxylic Functional Groups, , Pergamon Press: New YorkLintomen, L., Pinto, R.T.P., Batista, E., Meirelles, A.J.A., MacIel, M.R.W., Liquid-liquid equilibrium of the water + citric acid + 2-butanol + sodium chloride system at 298.15 K (2000) J. Chem. Eng. Data, 45, pp. 1211-1214Batista, E., Monnerat, S., Kato, K., Stragevitch, L., Meirelles, A.J.A., Liquid-liquid equilibrium for systems of canola oil, oleic acid and short-chain alcohols (1999) J. Chem. Eng. Data, 44, pp. 1360-1364Magnussem, T., Rasmussen, P., Fredenslund, A., Unifac parameter table for prediction of liquid-liquid equilibria (1981) Ind. Eng. Chem. Process Des. Dev., 20, pp. 331-339MacEdo, E.A., Skovborg, P., Rasmussen, P., Calculation of phase equilibria for solutions of strong electrolytes in solvent-water mixtures (1990) Chem. Eng. Sci., 45, pp. 875-882Stragevitch, L., D'Avila, S.G., Application of a generalised maximum likelihood method in the reduction of multicomponent liquid-liquid equilibrium data (1997) Braz. J. Chem. Eng., 14, pp. 41-52Grinberg, A., Povimonski, D., Apelblat, A., Liquid-liquid distribution in the ternary system: Citric acid - 2-butanol - water at 298.15 K (1991) Solvent Extr. Ion Exch., 9, pp. 127-13
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
Liquid-liquid Equilibrium Of The Water+citric Acid+2-butanol+sodium Chloride System At 298.15 K
No full textLiquid-liquid equilibrium of an aqueous solution containing different concentrations of water, citric acid, 2-butanol and sodium chloride were determined. It was observed that there was large increase in the heterogeneous region and on the selectivity, while there was not significant decrease of the citric acid distribution coefficient. The description of the liquid-liquid phase equilibrium presented mean deviations lower than 1.4%.45612111214Al-Sahhaf, T.A., Kapetanovic, E., Salt effects of lithium chloride, sodium bromide, or potassium iodide on liquid-liquid equilibrium in the systems water + 1-butanol (1997) J. Chem. Eng. Data, 42, pp. 74-77Shah, D.J., Tiwari, K.K., Effect of salt on the distribution of acetic acid between water and organic solvent (1981) J. Chem. Eng. Data, 26, pp. 375-379Solimo, H.N., Bonatti, C.M., Zurita, J.L., Gramajo, M.B., Liquid-liquid equilibria for the system water + propionic acid + 1-butanol at 303.2K. Effect of addition of sodium chloride (1997) Fluid Phase Equilib., 137, pp. 163-172Kertes, A.S., King, C.J., Extraction chemistry of fermentation product carboxylic acids (1986) Biotechnol. Bioeng., 28, pp. 269-282Grinberg, A., Povimonski, D., Apelblat, A., Liquid-liquid distribution in the ternary system: Citric acid-2-butanol-water at 298.15 k (1991) Solvent Extr. Ion Exch., 9, pp. 127-135Marcilla, A., Ruiz, F., Olaya, M.M., Liquid-liquid-solid equilibria of quaternary system water-ethanol-1-butanol-sodium choride at 25 °C (1995) Fluid Phase Equilib., 105, pp. 71-91Saravanan, G., Srinivasan, D., Liquid-liquid equilibria for the system ethyl acetate-acetic acid-water in the presence of dissolved inorganic salts (1985) J. Chem. Eng. Data, 30, pp. 166-171Silva, L.H.M., Coimbra, J.S., Meirelles, A.J.A., Equilibrium phase behavior of poly(ethylene glycol) + potassium phosphate + water two phase systems at various pH and temperatures (1997) J. Chem. Eng. Data, 42, pp. 398-401Tiwari, R.D., Sharma, J.P., (1970) The Determination of Carboxylic Functional Groups, , Pergamon Press: New YorkLintomen, L., Pinto, R.T.P., Batista, E., Meirelles, A.J.A., Maciel, M.R.W., New Solvent Alternatives for Citric Acid Recovery by Liquid-liquid Extraction. XIII Congresso Brasileiro de Engenharia Química, , in pressBatista, E., Monnerat, S., Kato, K., Stragevitch, L., Meirelles, A.J.A., Liquid-liquid equilibrium for systems of canola oil, oleic acid and short-chain alcohols (1999) J. Chem. Eng. Data, 44, pp. 1360-1364Magnussen, T., Rasmussen, P., Fredenslund, A., Unifac parameter table for prediction of liquid-liquid equilibria (1981) Ind. Eng. Chem. Process Des. Dev., 20, pp. 331-339Macedo, E.A., Skovborg, P., Rasmussen, P., Calculation of phase equilibria for solutions of strong electrolytes in solvent-water mixtures (1990) Chem. Eng. Sci., 45, pp. 875-882Stragevitch, L., D'Avila, S.G., Application of a generalised maximum likelihood method in the reduction of multicomponent liquid-liquid equilibrium data (1997) Braz. J. Chem. Eng., 14, pp. 41-52Shaw, J.M., De Loos, Th.W., Swaan Arons, J., Prediction of unusual retrograde condensation in model reservoir fluids (1993) Fluid Phase Equilib., 84, pp. 251-266Wennersten, R., The extraction of citric acid from fermentation broth using a solution of a ternary amine (1983) J. Chem. Technol. Biotechnol., 33 B, pp. 85-94Escudero, I., Cabezas, J.L., Coca, J., Liquid-liquid equilibria in (2,3-butanediol + 2-butoxyethanol + water + potassium chloride) at 70 °C (1996) J. Chem. Eng. Data, 41, pp. 1383-138
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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