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Barrera-arellano D. - One of the best experts on this subject based on the ideXlab platform.

  • Optimisation Of The Acidulation Process Of Soapstock From The Neutralisation Of Rice Bran Oil [optimización Del Proceso De Acidulación De La Borra De Neutralización De Aceite De Salvado De Arroz]
    2015
    Co-Authors: Scavariello E.m.s., Barrera-arellano D.
    Abstract:

    Soapstock from the neutralisation of rice bran oil was characterised through the most important parameters with direct influence on the acidulation process. A central composite rotational experimental design of two levels was used. The responses of the trials were γ-oryzanol concentration in the acid oil and process time necessary for total hydrolysis of the soaps present. The optimal process conditions were determined using the response surface methodology. Adjustments were made to second order mathematical models and validity was verified by analysis of variance using the STATISTICA program. The process variables studied were: molar ratio - sulphuric acid/soaps (0.55-0.95) and process temperature (70-100°C). The results indicated that the process temperature does not significantly interfere in the concentration of γ-oryzanol of the acid oil, but it does affect process time. In the different concentrations of sulphuric acid added, represented by the molar ratio of sulphuric acid/soaps, the concentration of γ-oryzanol varied between 3.13 and 3.74%. Through the superposition of the areas of the response surface contour curves the optimal process parameters were determined: process temperature of 95°C and molar ratio of sulphuric acid/soaps of 0.74, resulting in a γ-oryzanol concentration of 3.64% and a process time of 90 minutes.552155159(1996) "Official Methods and Recommended Practices of the American Oil Chemists Society", 3. Ed., , ChampaignBarros-Neto, B., Scarminio, I.S., Bruns, R.E., (1996) Planejamento e Otimização de Experimentos. 2a Ed., , Editora da UNICAMP, Campinas, SP, BrasilBox, G.E.P., Hunter, W.G., Hunter, J.S., (1978) Statistics for Experiments - An Introduction to Design, Data Analysis and Model Building, , Wiley & Sons, New YorkDown, M.K., Gas chromatographic characterization of soapstocks from vegetable oil refining (1998) J. Chromatography, 816, pp. 185-193Kano, T., Shibayama, Y., Tamura, N., (1995), Stabilization of aqueous γ-oryzanol solutions". Patent JP 07258165Kato, Y., Samura, K., Kawamura, M., Osawa, S., (1996), Compositions containing γ-oryzanol and/or soybean unsaponified products". Patent JP 08295627Khuri, A.I., Cornell, J.A., (1987) Response Surface-designs and Analyses, , Marcel Dekker, Inc., New YorkOrthoefer, F.T., Rice bran oil: Healthy lipid source (1996) Food Technol., 50, pp. 62-64Rogers, E.J., Rice, S.M., Nicolosi, R.J., Carpenter, D.R., Mc Clelland, C.A., Romanczyk, L.J., Identification and quantitation of γ-oryzanol components and simultaneous assessment of tocols in rice bran oil (1993) J. Am. Oil Chem. Soc., 70, pp. 301-307Swern, D., Refining and bleaching (1982) Bailey's Industrial Oil and Fat Products, p. 4. , D.Swern (Ed). J. Wiley & Sons, New York(1995) γ-oryzanol, a Naturally Derived Food Antioxidant, p. 8. , Wakayama, JapanWatson, K.S., Hoefer, M., Use or disposal of by-products and spent material from the vegetable oil processing industry in the U.S. (1976) J. Am. Oil Chem. Soc., 53, pp. 437-442Woerfel, J.B., Processing and utilization of by -products from soy oil processing (1981) J. Am. Oil Chem. Soc., 58, pp. 188-191Woerfel, J.B., Alternatives for processing of soapstock (1983) J. Am. Oil Chem. Soc., 60, pp. 262A-265AWoerfel, J.B., Soybean oil processing byproducts and their utilization (1995) Practical Handbook of Soybean Processing and Utilization, , D.R. Erickson (Ed). AOCS Press, Champaig

  • Optimization Of Chemical Esterification Process Of Saponificated And Acidulated Soybean Oil Deodorizer Distillate [optimización Del Proceso De Esterificación Química Del Destilado De Desodorización Del Aceite De Soja Previamente Saponificado Y Acidulado]
    2015
    Co-Authors: Facioli N.l., Barrera-arellano D.
    Abstract:

    In this research work, it was optimized the reaction conditions for the chemistry esterification of unsaponifiable matter in soybean oil deodorizer distillate. The process involves (i) alkaline hydrolysis of saponifiable matter; (ii) acidulation of soaps and (iii) acid catalyzed esterification of resulting total fatty acid. To determine the best process conditions to get the higher conversion rates of total fatty acids to ethylic esters, preserving the tocopherols, it was used, to analyze the results, the response surface methodology in a 2nd order factorial planning. In the step (i) saponification of soybean oil deodorizer distillate saponifiable matter using NaOH:total fatty acids molar ratio = 2:1, temperature = 80°0 and reaction time of 40 min. In the step (ii) the resulting soaps were rapidly and stoichiometricatiy converted in free fatty acids with sulfuric acid (23%), using an acid molar excess of 50%, at 80°0, for 40 min and under atmospheric pressure. In the step (iii) the optima conditions for the esterification reaction of soybean oil deodorizer distillate were: ethanol:total fatty acids molar ratio from 8.4 to 11.2:1, H2SO4 concentration from 0.9 to 1.5% and reaction time from 1.3 to 2.8 h, with ethyl esters conversion rates up to 98%. The mathematical model obtained is predictive and statistically significant (p<0.05). The total tocopherol losses during the process were less than 10.5%.532218225Firestone, D., (1997) Official Methods and Recommended Practices of the American Oil Chemists' Society, 1-2. , 4th Ed., AOCS Press, Champaign, ILBalazs, I.L., Refining and use of byproducts from various fats and oils (1987) J. Am. Oil Chem. Soc., 64, pp. 1126-1128Barros, N.B., Scarminio, I.S., Bruns, R.E., (1996) Planejamento e Otimização de Experimentos, pp. 61-186. , Editora Unicamp, Campinas, São PauloBox, G.E.P., Hunter, W.G., Hunter, J.S., (1978) Statistics goes Experiments. An Introduction to Design, Data Analysis and Model Building, , Wiley & Sounds Ed., New YorkBrokaw, W., Smith, F.E., Process for Separating Tocopherols and Sterols from Deodorizer Sludge and the like, , Patent U.S. No 3.153.055 (13.10.64)Diplock, A.T., Antioxidant and disease prevention (1994) Mol Aspects of the Medicine, 15, pp. 293-376Dobarganes, M.C., Márquez-Ruiz, G., Size exclusion chromatography in the analysis of lipids (1993) Advances in Lipids Methodology, pp. 113-137. , The Oil Press Ltd, ScotlandFormo, M.W., Ester reactions of fatty materials (1954) J. Am. Oil Chem. Soc., 31, pp. 548-559Hartman, L., Lago, R.C.A., Rapid preparation of fatty acid methyl esters from lipids (1973) Laboratory Practice, 22, pp. 475-476Holen, B., Rapid separation of free sterols by reversed-phase high performance liquid chromatography (1985) J. Am. Oil Chem. Soc., 62, pp. 1344-1346Hauman, B.F., Antioxidants: Firms seeking products they can label as natural (1990) Inform, 1, pp. 1002-1009Khuri, A.I., Cornell, J.A., Response surfaces (1987) Design and Analyses, , Marcel Dekker Ed., New YorkLing, W.H., Jones, P.J.H., Enhanced efficacy of sitostanol-containing versus sitostanol-free phytosterol mistures in altering lipoprotein cholesterol levels and synthesis in rats (1995) Atherosclerosis, 118, pp. 319-331Morrison, R.T., Boyd, R., Carboxylic acids (1992) Organic Chemistry, pp. 713-752. , cap.19, 6a. Ed. Prentice Hall International Inc., LondonPryde, E.H., Composition of soybean oil (1980) Handbook of Soy Oil Processing and Utifization, pp. 13-33. , Ed. WING-AOCS, Champaign, ILRamamurthi, S., Bhirud, P.R., McCurdy, A.R., Enzymatic methylation of canola oil deodorizer distillate (1991) J. Am. Oil Chem. Soc., 68, pp. 970-975Smith, F.E., (1967) Separation of tocopherols and sterols from deodorizer sludge and the like, , Patent U.S. No 3.335.154 (08.08.67)Winters, R.L., Basic principles and modern practices (1989) Proceedings World Conference Edible Fats and Oils Processing, pp. 186-238. , Erickson D.R., AOCS Press, Champaign, I

Stig E Friberg - One of the best experts on this subject based on the ideXlab platform.

Boglaev Igor - One of the best experts on this subject based on the ideXlab platform.

  • Monotone alternating direction implicit method for nonlinear integro-parabolic equations
    Australian Mathematical Society, 2018
    Co-Authors: Boglaev Igor
    Abstract:

    The paper deals with numerical solving nonlinear integro-parabolic problems based on an alternating direction implicit (ADI) scheme. A monotone iterative ADI method is constructed. An analysis of convergence of the monotone iterative ADI method is given. References I. Boglaev, Monotone alternating direction implicit scheme for nonlinear parabolic problems. BIT Numerical Mathematics, 55, 2015, 647-676. doi:10.1007/s10543-014-0529-6 J. Douglas, H. H. Rachford, On the numerical solution of heat condition problems in two and three variables. Trans. Amer. Math. Soc., 82, 1956, 421–439. G. I. Marchuk, Splitting and alternating direction methods, Handbook of Numerical Analysis, 1, 197–462. (Eds P. Ciarlet, J. Lions). North-Holland, Amsterdam, 1990. R. McLachlan, G. Quispel, Splittings methods. Acta Numer., 11, 2002, 341–434. doi:10.1017/S0962492902000053 C. V. Pao, Nonlinear Parabolic and Elliptic Equations. Plenum Press, New York, 1992. A. Samarskii, The Theory of Difference Schemes. Marcel Dekker, New York–Basel, 2001. I. H. Sloan, V. Thomee, Time distretization of an integro-differential equation of parabolic type. SIAM J. Numer. Anal., 23, 1986, 1052–1061. doi:10.1137/0723073 A. H. Stroud, Approximate Calculation of Multiple Integrals. Prentice–Hall, Englewood Cliffs, NJ, 1971

  • Monotone iterates for systems of nonlinear integro-elliptic equations
    Australian Mathematical Society, 2017
    Co-Authors: Boglaev Igor
    Abstract:

    This paper deals with numerically solving systems of nonlinear integro-elliptic equations. We give a monotone iterative method, based on the method of upper and lower solutions. The construction of the initial upper and lower solution is discussed, and numerical experiments are presented. References I. Boglaev, Numerical solving systems of nonlinear integro-parabolic equations of Volterra type. J. Integral Equ. Appl., 28(3):309–342, 2016. doi:10.1216/JIE-2016-28-3-1 C. V. Pao, Nonlinear Parabolic and Elliptic Equations. Plenum Press, New York, 1992. C. V. Pao, Monotone iterative methods for numerical solutions of nonlinear integro-elliptic boundary problems. Appl. Math. Comput., 186:1624–1642, 2007. doi:10.1016/j.amc.2006.08.074 A. Samarskii, The Theory of Difference Schemes. Marcel Dekker, New York, 2001. A. H. Stroud, Approximate Calculation of Multiple Integrals. Prentice–Hall, Englewood Cliffs, New Jersey, 1971

Atvars T.d.z. - One of the best experts on this subject based on the ideXlab platform.

  • Glassy State On The Undergraduate Course In Chemistry (physical Chemistry) [o Estado Vítreo Dentro Da Perspectiva Do Curso De Graduação Em Química (físico-química)]
    2015
    Co-Authors: Yamaki S.b., Pedroso A.g., Atvars T.d.z.
    Abstract:

    We consider the relevance of the study of the glassy state properties and the glass transition as important topics of the physical chemistry for undergraduate courses of Chemistry. Two of the most important theoretical approaches for the description of the glassy state, the thermodynamic and the kinetic models, are summarized with emphasis on the physical chemistry aspects. Examples illustrating the glass transition of some materials are also presented.252330334Moore, W.J., (1976) Físico-Química, tradução da 4a ed. americana, , Editora Edgar Blucher Ltda.: São PauloAtkins, P.W., (1994) Physical Chemistry, 5th ed., , Oxford University Press: OxfordLevine, I.N., (1983) Physical Chemistry, 2nd ed., , McGraw Hill Book Co: New YorkBarrow, G.M., (1976) Química Fisica, 3th ed., , Editorial Reverté S.A.: BarcelonaCastellan, G.W., (1975) Fisico-Química, 1a ed., , Livros Técnicos e Científicos Ed. S.A.: Rio de JaneiroEhrenfest, P., Atkins, P.W., (1994) Physical Chemistry5th ed., p. 200. , Oxford University Press: OxfordWunderlich, B., Turi, E.A., (1981) Thermal Characterization of Polymeric Materials, 1, p. 380. , 2nd ed., Academic Press: San DiegoSperling, L.H., Manson, J.A., (1976) Polymer Blends and Composites, , Plennun Press: New YorkKauzmann, W., (1948) Chem. Rev., 43, p. 219Rabeck, J.F., (1980) Experimental Methods of Polymer Chemistry - Physical Principles and Applications, , John Willey & Sons: New YorkSilva, M.A., De Paoli, M.A., Felisberti, M.I., (1998) Polymer, 39, p. 2551Gibbs, J.H., Di Marzio, E.A., (1958) J. Chem. Phys., 28, p. 373McKenna, G.B., (1989) Comprehensive Polymer Science, 2, p. 311. , Allen, G.Bevington, J.C., eds, Pergamon Press: Oxford, e referências contidas neste artigoNelson, E.W., Newton, R.F., (1941) J. Am. Chem. Soc., 63, p. 2178Prigogine, I., Defay, R., (1950) Thermodynamique Chimie, , edition Desoer, Liège: Belgium, citado em 13Flory, P.J., (1953) Principles of Polymer Chemistry, , Cornell University Press: Ithaca NY, citado em 13Doolittle, A.K., (1951) J. Appl. Phys., 22, p. 1031Williams, M.L., Landel, R.F., Ferry, J.D., (1955) J. Am. Chem. Soc., 77, p. 3701Nielsen, L.E., (1974) Mechanical Properties of Polymers and Composites, 1. , Marcel Dekker: New YorkMandelkern, L., (1990) Acc. Chem. Res., 23, p. 380Talhavini, M., Atvars, T.D.Z., Cui, C., Weiss, R.G., (1996) Polymer, 37, p. 436

  • Density Functional Theory Applied To Thermochemical Calculations For Phenol Reactions
    'Elsevier BV', 2015
    Co-Authors: Reis R.m., Atvars T.d.z., De Oliveira H.p.m., Mascolo L.f.s., Wolf-maciel M.r.
    Abstract:

    Phenol recovery from wastewaters is a crucial task in the chemical process area, for both economical and environmental reasons, since phenol is a high added value product but, also, highly toxic. Reactive distillation is being proposed as an alternative process for eliminating phenol from water. However, before studying the process, it is necessary to derive a suitable phenol reaction and, also, to calculate its equilibrium constants, since no such values are reported in the open literature. In this work, Benson's method and molecular modeling are applied to calculate thermochemical values for phenol reactions with acetic acid (phenol acylation) and with acetic anhydride (phenol esterification). However, Benson's method presented limitation for calculation of the thermochemical values for the proposed reactions, because some of the additivity groups are not found in published tables. Using molecular modeling, calculations were carried out at several temperatures. Results from density functional theory (DFT) indicate that the equilibrium constant for phenol esterification is greater than the one for phenol acylation and, thus, the former reaction is more suitable in terms of consumption of phenol. Moreover, it was observed that the acylation reaction reaches high conversions only at high temperatures. © 2004 Elsevier B.V. All rights reserved.228-229459464Manahan, S.E., (2000) Environmental Chemistry, , 7th ed. CRC PressHennion, M.C., Pichon, V., Barcelo, D., (1994) Trends Anal. Chem., 13, pp. 361-372Jiang, H., Tang, Y., Guo, Q.X., (2003) Sep. Sci. Technol., 38, pp. 2579-2596Long, R.B., (1995) Separation Processes in Waste Water Minimization, , Marcel Dekker New YorkGupta, T., Pradhan, N.C., Adhikari, B., (2003) J. Membr. Sci., 217, pp. 43-53Citro, F., Lee, J.W., (2004) Ind. Eng. Chem. Res., 43, pp. 375-383Malone, M.F., Huss, R.S., (2003) Environ. Sci. Technol., 37, pp. 5325-5329Benson, S.W., Cruicksh, F.R., Golden, D.M., Haugen, G.R., Oneal, H.E., Rodgers, A.S., Shaw, R., Walsh, R., (1969) Chem. Rev., 69, pp. 279-324Sandler, S.I., (2003) Fluid Phase Equilibria, 210, pp. 147-160Stein, S.E., Brown, R.L., (2003) Structures and Properties Group Additivity Model in NIST Chemistry WebBook, NIST Standard Reference Database Number 69, p. 20899. , P.J. Linstrom W.G. Mallard National Institute of Standards and Technology Gaithersburg, MDReid, C.R., Prausnitz, J.M., Sherwood, T.K., (1977) The Properties of Gases and Liquids, , McGraw-HillSobrinho, E.V., Cardoso, D., Souza-Aguiar, E.F., (1998) J. Brazil. Chem. Soc., 9, pp. 225-230Stull, D.R., Westrum, E.F., Sinke, G.C., (1969) The Chemical Thermodynamics of Organic Compounds, , Wiley New YorkForesman, J.B., Frisch, A., (1996) Exploring Chemistry with Electronic Structure Methods, , Gaussian Inc. Pittsburgh, PA, USAAfonso, A.P., (2004), D.Sc. Thesis, Laboratory of Separation Process Development (LDPS), State University of Campinas, School of Chemical Engineering, UNICAMP, Brazi

Poppi R.j. - One of the best experts on this subject based on the ideXlab platform.

  • Teaching Experiment Of Chemometrics For Multivariate Calibration In Determination Of Paracetamol In Commercial Tablets Using Near-infrared Spectroscopy: A Tutorial, Part Ii [experimento Didático De Quimiometria Para Calibração Multivariada Na Determinação De Paracetamol Em Comprimidos Comerciais Utilizando Espectroscopia No Infravermelho Próximo: Um Tutorial, Parte Ii]
    2015
    Co-Authors: De Souza A.m., Breitkreitz M.c., Filgueiras P.r., Rohwedder J.j.r., Poppi R.j.
    Abstract:

    The aim of this manuscript was to show the basic concepts and practical application of Partial Least Squares (PLS) as a tutorial, using the Matlab computing environment for beginners, undergraduate and graduate students. As a practical example, the determination of the drug paracetamol in commercial tablets using Near-Infrared (NIR) spectroscopy and Partial Least Squares (PLS) regression was shown, an experiment that has been successfully carried out at the Chemical Institute of Campinas State University for chemistry undergraduate course students to introduce the basic concepts of multivariate calibration in a practical way.36710571065Souza, A.M., Poppi, R.J., (2012) Quim. Nova, 35, p. 223Ciurczak, E.W., (2001) Handbook of Near-Infrared Analysis, , Burns, D. A.Ciurczak E. W., eds. Marcel Dekker, INC.: New York, chap 2Williams, P., Norris, K.H., (1987) Near Infrared Technology in the Agricultural and Food Industries, , Amer. Assoc. of Cereal Chemists: St. PaulWorkman, J.J., Weyer, L., (2008) Practical Guide to Interpretative Near- Infrared Spectroscopy, , Taylor & Francis: Boca RatonMcClure, W.F., (1994) Anal. Chem, 66, pp. 43ABosco, G., (2010) TrAC, Trends Anal. Chem, 29, p. 197Pasquini, C., (2003) J. Braz. Chem. Soc, 14, p. 198Brereton, R.G., (2000) Analyst, 125, p. 2125Rinnan, A., Van Den Berg, F., Engelsen, S.B., (2009) TrAC, Trends Anal. Chem, 28, p. 1201Martens, H., Naes, T., (1993) Multivariate Calibration, , 2nd ed., John Wiley & Sons: ChichesterBeebe, K.R., Pell, R.J., Seasholtz, M.B., (1998) Chemometrics: A Practical Guide, , John Wiley & Sons: New YorkGeladi, P., Kowalski, B.R., (1986) Anal. Chim. Acta, 185, p. 1Lorber, A., Wangen, L.E., Kowalski, B.R., (1987) J. Chemom, 1, p. 19Andersson, M., (2009) J. Chemom, 23, p. 518(2005) Standard Practices for Infrared Multivariate Quantitative Analysis, , ASTM - American Society For Testing And Materials ASTM E 1655Roggo, I., Chalus, P., Maurer, L., Lema-Martinez, C., Edmond, A., Jent, N., (2007) J. Pharm. Biomed. Anal, 44, p. 683De Bleye, C., Chavez, P.F., Mantanus, J., Hubert, P., Rozet, E., Ziemons, E., (2012) J. Pharm. Biomed. Anal, 69, p. 125Yappert, M.C., (1999) J. Chem. Educ, 76, p. 315Ferreira, M.M.C., Antunes, A.M., Melgo, M.S., Volpe, P.L.O., (1999) Quim. Nova, 22, p. 724http://www.anvisa.gov.br/hotsite/cd_farmacopeia/pdf/volume2.pdf, acessado em Dezembro 201