1,721,006 research outputs found
Determination Of The Solubility Of Extracts From Vegetable Raw Material In Pressurized Co2: A Pseudo-ternary Mixture Formed By Cellulosic Structure + Solute + Solvent
No full textThis paper discusses the application of the dynamic method to measure the solubility in pseudo-ternary systems formed by vegetable raw materials (cellulosic structure + solute) and CO2. For aromatic, medicinal, and spice plants, the soluble portion of the solid is formed of essential oils, oleoresins, pigments, and various substances from several other classes of organic compounds. The experimental data were measured in two independent laboratories, using three experimental set-ups, and three vegetable species: clove buds, eucalyptus, and ginger. The solubility for the system clove buds/CO2 varied from 0.220 to 0.277 kg-extract/kg-CO2 for the isotherm of 288.15 K. The ginger extract solubility varied from 2.01 × 10-3 to 7.20 × 10-3 kg-extract/kg-CO2 for pressures of 100-300 bar, and temperatures of 298.15-313.15 K. The eucalyptus solubility for the isobar of 66.7 bar varied from 3.95 × 10-3 to 4.07 × 10-3 kg-extract/kg-CO2. © 2002 Elsevier Science B.V. All rights reserved.2212136Brunner, G., (1994) Gas Extraction: An Introduction to Fundamentals of Supercritical Fluids and the Application to Separation Processes, , Springer, New York, USAMcHugh, M.A., Krukonis, V.J., (1994) Supercritical Fluid Extraction: Principles and Practice, , Butterworth-Heinemann, Newton, USAVernin, G., Verinin, E., Metzger, J., Pujol, L., Parkanyi, C., GC/MS analysis of clove essential oils (1994) Spices, Herbs and Edible Fungi, p. 483. , George Charalambous (Ed.), Elsevier Science, Amsterdam, HollandCraveiro, A.A., Queiroz, D.C., Óleos essenciais e química fina (1993) Química Nova, 16, p. 224Matos, F.J.A., (1998) Farmácias Vivas, , Edições da Universidade Federal do Ceará, Fortaleza, BrazilBartley, J.P., Foley, P., Supercritical fluid extraction of Australian-grown ginger (Zingiber officinale) (1994) Journal of the Science of Food and Agriculture, 66, p. 365Monteiro, A.R., Meireles, M.A.A., Marques, M.O.M., Ginger (Zingiber officinale) essential oil and oleoresin extraction with pressurized CO2: An evaluation of pretreatment and process variables in oil composition (1998) Proceedings of the 5th Meeting on Supercritical Fluids: Natural Products and Materials, 2, p. 515. , M. Perrut (ed.), Nice, FranceBrod, F.D., Oliveira, R., Park, K.J., Estudo de um secador convectivo de fluxo perpendicular e paralelo (2000) Proceedings of the 29th Congresso Brasileiro de Engenharia Agricola - CONBEA 2000, , Fortaleza, CE, CD RomGomide, R., Manual de Operações Unitárias, , Cenpro (Ed.), São Paulo, BrazilJacobs, M.B., (1973) The Chemical Analysis of Food and Products, , Robert Krieger Publishing Co., New York, USARodrigues, V.M., Meireles, M.A.A., Marques, M.O.M., (2000) Determination of the solubility of clove essential oil in CO2: A standardization of the dynamic method, Proceedings of the 5th International Symposium on Supercritical Fluids, , Westin Atlanta, Georgia, USA, CD-RomFerreira, S.R.S., Meireles, M.A.A., Cabral, F.A., Extraction of essential oil of black pepper with liquid carbon dioxide (1993) Journal of Food Engineering, 20, p. 121Sousa, E.M.B.D., Chiavone-Filho, O., Moreno, M.T., Oliveira, H.N., Meireles, M.A.A., Experimental results for the extraction of essential oil from the species Lippia Sidoides in pressurized carbon dioxide (2001) Proceedings of the 2nd International Meeting on High Pressure Chemical Engineering, , TUHH, Hamburg, Germany, CD-RomFrança, L.F., Meireles, M.A.A., Modeling the extraction of carotene and lipids from pressed palm oil (Elaes guineensis) fibers using supercritical CO2 (2000) Journal of Supercritical Fluids, 18, p. 35Monteiro, A.R., Meireles, M.A.A., Marques, M.O.M., Petenate, A.J., Extraction of the soluble material from the shells of the bacuri fruit (Platonia insignis Mart) with pressurized CO2 and other solvents (1997) Journal of Supercritical Fluids, 11, p. 91McLaferty, F.W., Stauffer, D.B., (1989) The Wiley/NBS Registry of Mass Spectral Data, 1-2. , John Wiley and Sons, New York, USAAdams, R.P., (1995) Identification of Essential Oil Components by Gas Chromatography/Mass Spectroscopy, , Allured Publishing Corporation, Illinois, USACollins, C.H., Braga, G.L., Bonato, P.S., (1995) Introdução a Métodos Cromatográficos, , Editora da Unicamp, Campinas, BrazilMatos, F.J.A., (1997) Introdução à Fitoquímica Experimental, , Editora da Universidade Federal do Ceará, Fortaleza, CE, BrazilFreund, R.J., Littell, R.C., (1995) SAS System for Regression - SAS Series in Statistical Applications, , SAS Institute Inc., NC, USASovová, H., Rate of the vegetable oil extraction with supercritical CO2-I. Modeling of extraction curves (1994) Chemical Engineering Science, 49, p. 409Santacesaria, E., Morbidelli, M., Servida, A., Storti, G., Carrà, S., Separation of xylenes on Y zeolites. 2. Breakthrough curves and their interpretation (1982) Ind. Eng. Chem. Proc Esso Des. Dev., 21, p. 446Cathpole, O.J., Berning, R., King, M.B., Measurement and correlation of Packed-Bed axial dispersion coefficients in supercritical carbon dioxide (1996) Ind. Eng. Chem. Res., 35, p. 824Tan, C.-S., Liou, D.-C., Axial dispersion of supercritical carbon dioxide in packed beds (1989) Ind. Eng. Res., 28, p. 1246Monteiro, A.R., (1999) Extração do Óleo Essencial/Oleoresina de Gengibre (Zingiber officinale Roscoe) com CO2 Supercrítico: uma avaliação do pré-tratamento e das variáveis de processo, , Doctoral thesis, FEA - Universidade Estadual de Campinas (Unicamp), Campinas, São Paulo, BrazilZancan, K.C., Marques, M.O.M., Meireles, M.A.A., Petenate, A.J., (2001), TUHH, Hamburg, Germany, CD-RomPovh, N.P., Meireles, M.A.A., Marques, M.O.M., (2001) Supercritical CO2 extraction of essential oil and oleoresin from chamomile (Matricaria recutita [L.] Rauschert), , TUHH, Hamburg, Germany, CD-RomRodrigues, V.M., Marques, M.O.M., Meireles, M.A.A., (2001) Supercritical extraction of essential oil from anise seed (Pimpinella anisum, L) using CO2: Kinetics and equilibrium data, , TUHH, Hamburg, Germany, CD-RomGovidarajan, V.S., (1982) CRC Critical Reviews in Food Science and Nutrition, 17, p. 1. , CRC Press Inc., Florid
Supercritical Fluid Extraction From Stevia Rebaudiana Bertoni Using Co2 And Co2 + Water: Extraction Kinetics And Identification Of Extracted Components
No full textStevia rebaudiana Bertoni contains glycosides, which are insoluble in carbon dioxide and soluble in mixtures of carbon dioxide and a polar solvent. The purpose of this work was to study the supercritical fluid extraction of these glycosides from stevia leaves using a two-step process: (i) CO2 extraction at 200 bar and 30 °C, and (ii) CO2+water extraction. The chemical compositions of the extracts were analyzed by GC-FID, GC-MS, TLC and HPLC. The overall extraction curves for the system stevia+CO2 had the typical shape and were successfully described by the Sovová's model. Approximately 72% of the CO2-soluble compounds were recovered and the major compound was austroinulin. The system stevia+CO2+water behaved as expected at 10 and 16 °C and 120 and 250 bar but its behavior was unusual at 30 °C and 250 bar. The process removed approximately 50% of the original stevioside and about 72% of the rebaudioside A. © 2002 Elsevier Science Ltd. All rights reserved.572125134Adams, R.P., (1995) Identification of essential oil components by gas chromatography/mass spectroscopy, pp. 1-468. , Illinois: Allured Publishing CoAngus, S., Armstrong, B., De Reuck, K.M., (1976) International thermodynamics tables of the fluid state - Carbon dioxide, pp. 156-161. , Oxford: Pergamon PressBolhmann, F., Zdera, C., Grenz, M., Weitere Inhaltsstoffe aus Vertretern der Eupatorium-Grupe (1977) Chemische Berichte, 110, pp. 1034-1041Brandle, J.E., Rosa, N., Heritability for yield, leaf stem ratio and stevioside from landrace cultivar of Stevia rebaudiana (1992) Canadian Journal of Plant Science, 72, pp. 1263-1266Brandle, J.E., Starrat, A.N., Guzen, M., (2002) Stevia rebaudiana - Its biological chemical and agricultural properties, , http://res2.agr.ca/london/pmrc/english/faq/stevia_rev.html, 14 MayBudzikiewicz, H., Djerassi, C., Williams, D.H., (1964) Structure elucidation of natural products by mass spectrometry, 2, pp. 121-139. , San Francisco, London, Amsterdam: Holden-dayBudzikiewicz, H., Wilson, J.M., Djerassi, C., Mass spectrometry in structural and stereochemical problems. XXXII. pentacyclic triterpenes (1963) Journal of the American Chemical Society, 83, pp. 3688-3699Chan, P., Xu, D.-Y., Liu, J.-C., Chen, Y.-J., Tomlinson, B., Huang, W.-P., Cheng, J.-T., The effect of stevioside on blood pressure and plasma catecholamines in spontaneously hypertensive rats (1998) Life Sciences, 63, pp. 1679-1684Dev, S., Misra, R., Diterpenes (1985) Handbook of Terpenoides, 2, pp. 13-31. , Florida: CRC Press IncDonalisio, M.G.R., Duarte, F.R., Pinto, J.D., Sousa, C.J., (1982) Stevia rebaudiana. Agronômico, 34, pp. 65-68Ferreira, S.R.S., Meireles, M., Modeling the supercritical fluid extraction of black pepper (Piper nigrum L.) Essential oil (2002) Journal of Food Engineering, 54 (4), pp. 981-983Freund, R.J., Littell, R.C., Fitting splines with unknown knots (1995) SAS system for regression - SAS series in statistical applications, pp. 180-185. , North Caroline: SAS Institute IncGoenadi, D.H., Water tension and fertilization of Stevia rebaudiana Bertoni on Oxic Tropudalf (English abstr) (1983) Menara Perkebunan, 51, pp. 85-90Gomide, R., Operações com sistemas sólidos granulares (1983) Operações Unitárias, 1, pp. 27-30. , Gomide R. São Paulo: Edição do AutorGonzález, A.G., Arteaga, J.M., Breton, J.L., Fraga, B.M., Five new labdane oxides from Eupatorium jhanni (1977) Pytochemistry, 16, pp. 107-110Goto, A., (1997) Estudo da influência do rebaudiosídeo A na solubilidade do esteviosídeo e análise sensorial dos produtos obtidos, p. 83. , MS Thesis (Chemistry). Maringá, Brazil: Centro de Ciências Exatas, Universidade Estadual de MaringáHenkel, J., Sugar substitutes: American opt for sweetness and lite (1999) FDA Consumer: The magazine of the US Food and Drug Administration, 33 (6). , http://www.fda.gov/fdac/699_toc.htmlJacobs, M.B., (1973) The chemical analysis of foods and products, 3rd ed., pp. 21-31. , New York: Robert Krieger Publishing CoKinghorn, A.D., Soejarto, D.D., Current status of stevioside as a sweetening agent for human use (1985) Economic and Medicinal Plant Research, pp. 1-52. , H. Wagner, H. Hikino, & N.R. Farnsworth. London: Academic Press. (Chapter 1)Kinghorn, A.D., Soejarto, D.D., Stevioside (1991) Alternative Sweeteners, pp. 157-171. , L.O. Nabors, & R.C. Gelardi. New York: Marcel Dekker IncLiu, J., Ong, C.P., Li, S.F.Y., Subcritical fluid extraction of stevia sweeteners from Stevia rebaudiana (1997) Journal of Chromatographic Science, 35 (9), pp. 446-450. , AbstractMcLafferty, M.S., Stauffer, D.B., (1989) The Wiley/NBS registry of mass spectral data, 1-7. , New York: WileyMelis, M.S., Effects of chronic administration of Stevia rebaudiana on fertility in rats (1999) Journal of Ethnopharmacology, 167, pp. 157-161Montgomery, D.C., (2001) Design and analysis of experiments 5th ed., p. 247. , New York: John Wiley & Sons IncMooijer-van den Heuvel, M.M., Peters, C.J., Gas hydrate phase equilibria of methane, propane, carbon dioxide and nitrogen in the presence of pressure reducing agents: New challenges for storage and transportation of energy and for applications in chemical engineering (2001) Proceedings of the 4th Brazilian Meeting on Supercritical Fluids, , Salvador, BA, BrazilPasquel, A., (1999) Extração dos glicosídeos da estévia com fluidos pressurizados, , Ph.D. dissertation. SP, Brazil: Universidade Estadual de CampinasPasquel, A., Marques, M.O.M., Meireles, M.A.A., Stevia (Stevia rebaudiana Bertoni) leaves pre-treatment with pressurized CO2: An evaluation of the extract composition (1999) Proceedings of the 6th Meeting on Supercritical Fluids, Chemistry and Materials, , ISASF, NottinghamPasquel, A., Meireles, M.A.A., Marques, M.O.M., Petenate, A.J., Extraction of stevia glycosides with CO2+water, CO2+ethanol, and CO2+water+ethanol (2000) Brazilian Journal of Chemical Engineering, 17 (3), pp. 271-282Philips, K.C., Stevia steps in developing a new sweetener (1987) Developments in sweeteners, 3, pp. 1-43. , T.H. Grenby. New York: ElsevierPovh, N.P., Marques, M.A.M., Meireles, M.A.A., Supercritical CO2 extraction of essential oil and oleoresin from chamomile (Chamomilla recutita [L.] Rauschert) (2001) Journal of Supercritical Fluids, 21 (3), pp. 245-256Robinson, B.L., (1930) Contributions from the Gray herbarium of Harvard University, , Cambridge: The Gray Herbarium of Harvard UniversityRodrigues, V.M., Marques, M.O.M., Meireles, M.A.A., Supercritical extraction of essential oil from anise seed (Pimpinella anisum, L) using CO2: Kinetics and equilibrium data (2001) Proceedings of the Second International Meeting on High Pressure Chemical Engineering, , Hamburg, GermanyRodrigues, V.M., Sousa, E.M.B.D., Monteiro, A.R., Chiavone-Filho, O., Marques, M.O.M., Meireles, M.A.A., Determination of the solubility of extracts from vegetable raw material in pressurized CO2 a pseudo-ternary mixture formed by cellulosic structure+solute+solvent (2002) Journal of Supercritical Fluids, 22 (1), pp. 21-36Rosa, P.T.V., Meireles, M.A.A., Influence of operating time on the costs of manufacturing extracts from natural substratum by SFE (2001) Proceedings of the 4th Brazilian Meeting on Supercritical Fluids, , Salvador, BA, BrazilSardzhveladze, G.P., Sardzhveladze, K.P., Ddzhugeli, R.Ya., Kharebava, L.G., Kalandiya, A.G., Improved taste in dried Stevia rebaudiana leaves (1995) Trends in Food Science and Technology, 6, p. 98Shock, C. C. (1982). Experimental cultivation of Rebaudi's stevia in California. University of California Progress Report No. 122Sholichin, M., Yamasaki, K., Miyama, R., Yahara, S., Tanaka, O., Labdane-type diterpenes from Stevia rebaudiana (1980) Pytochemistry, 19, pp. 326-327Soejarto, D.D., Compadre, C.M., Medon, P.J., Kamath, S.K., Kinghorn, A.D., Potential sweetening agents of plant origin. II. Field search for sweet-tasting Stevia species (1983) Economic Botany, 37, pp. 71-79Soejarto, D.D., Kinghorn, A.D., Farnsworth, N.R., Potential sweetening agents of plant origin. III. Organoleptic evaluation of stevia leaf herbarium samples for sweetness (1982) Journal of Natural Products, 45, pp. 590-599Sovová, H., Rate of the vegetable oil extraction with supercritical CO2: I. - Modeling of extraction curves (1994) Chemical Engineering Science, 49 (3), pp. 409-414Takahashi, M., Matsuda, M., Ohahi, K., Taniguchi, K., Nakogomi, O., Abe, Y., Mori, S., Shigeta, S., Analysis of anti-rotavirus activity of extract from Stevia rebaudiana (2001) Antiviral Research, 49, pp. 15-24Toyoda, K., Matsui, H., Shoda, T., Uneyama, C., Takada, K., Takahashi, M., Assessment of the carcinogenicity of stevioside in F344 rats (1997) Food and Chemical Toxicology, 35, pp. 597-603Yoda, S.K., Marques, M.O.M., Petenate, A.J., Meireles, M.A.A., Kinetics of SFE extraction of glycosides from Stevia rebaudiana Bertoni using CO2+H2O (2001) Proceedings of the 4th Brazilian Meeting on Supercritical Fluids, , Salvador, BA, BrazilYoo, K.-P., Choi, Y.H., Kim, J., SFE of Natural pharmaceuticals and nutraceuticals with emphasis on commercialization (2001) Tenth International Symposium & Exhibit on Supercritical Fluid Chromatography, Extraction, and Processing, , Myrtle Beach, USAZancan, K.C., Marques, M.O.M., Petenate, A.J., Meireles, M.A.A., Extraction of ginger (Zingiber officinale Roscoe) oleoresin with CO2 and Co-solvents: A study of the antioxidant action of the extracts (2001) Proceedings of the Second International Meeting on High Pressure Chemical Engineering, , Hamburg, GermanyZhang, S.Q., Kumar, A., Kutowy, O., Membrane-based separation scheme for processing sweeteners from stevia leaves (2000) Food Research International, 33, pp. 617-62
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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