The Experts below are selected from a list of 10602 Experts worldwide ranked by ideXlab platform
Hector D Mansilla - One of the best experts on this subject based on the ideXlab platform.
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orange ii photocatalysis on immobilised tio2 effect of the ph and h2o2
Applied Catalysis B-environmental, 2004Co-Authors: J Fernandez, J Kiwi, Jaime Baeza, Juanita Freer, C Lizama, Hector D MansillaAbstract:The discoloration and mineralisation of the azo-dye Orange II in a photoreactor using TiO2-coated glass rings as immobilised photocatalyst is reported. The variation of pH and the H2O2 addition effect were systematically investigated. The use of the response surface methodology allowed to fit the optimal values of the parameters leading to Orange II abatement. Also, a single Polynomial Expression modelling the reaction was obtained. The photocatalytic degradation of Orange II was followed by spectrophotometric analysis and total organic carbon (TOC) measurements.
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factorial experimental design of orange ii photocatalytic discolouration
Journal of Photochemistry and Photobiology A-chemistry, 2002Co-Authors: J Fernandez, J Kiwi, Jaime Baeza, Juanita Freer, C Lizama, Hector D MansillaAbstract:Abstract Photo-discolouration of Orange II solutions at different concentrations was carried out in a 1 l concentric reactor irradiated with a 254 nm mercury lamp (125 W) in the presence of Degussa TiO2 P-25 dispersions. Experimentation involving discolouration of Orange II has been carried out using factorial design methodology for the simulation of the three critical variables affecting the dye discolouration: concentration of Orange II, pH and concentration of TiO2. A single Polynomial function corresponding to optical absorbance of Orange II (Y) was constructed for the treatment of the experimental data obtained in the immersion photo-reactor. The function (Y) allowed the prediction of the residual discolouration after 20 min photo-treatment. By following this model, a minimum of well-chosen experiments was performed to optimise Orange II photo-discolouration. The modelling takes into account that in the chemical system one reaction parameter determines the setting of another and vice-versa (interactive effects). The correlation factor between the experimental and predicted values by the Polynomial Expression for the discolouration of Orange II was better than 95%. In a typical photo-reactor run at pH 3, the concentration of TiO2 could be decreased to values
J Fernandez - One of the best experts on this subject based on the ideXlab platform.
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orange ii photocatalysis on immobilised tio2 effect of the ph and h2o2
Applied Catalysis B-environmental, 2004Co-Authors: J Fernandez, J Kiwi, Jaime Baeza, Juanita Freer, C Lizama, Hector D MansillaAbstract:The discoloration and mineralisation of the azo-dye Orange II in a photoreactor using TiO2-coated glass rings as immobilised photocatalyst is reported. The variation of pH and the H2O2 addition effect were systematically investigated. The use of the response surface methodology allowed to fit the optimal values of the parameters leading to Orange II abatement. Also, a single Polynomial Expression modelling the reaction was obtained. The photocatalytic degradation of Orange II was followed by spectrophotometric analysis and total organic carbon (TOC) measurements.
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factorial experimental design of orange ii photocatalytic discolouration
Journal of Photochemistry and Photobiology A-chemistry, 2002Co-Authors: J Fernandez, J Kiwi, Jaime Baeza, Juanita Freer, C Lizama, Hector D MansillaAbstract:Abstract Photo-discolouration of Orange II solutions at different concentrations was carried out in a 1 l concentric reactor irradiated with a 254 nm mercury lamp (125 W) in the presence of Degussa TiO2 P-25 dispersions. Experimentation involving discolouration of Orange II has been carried out using factorial design methodology for the simulation of the three critical variables affecting the dye discolouration: concentration of Orange II, pH and concentration of TiO2. A single Polynomial function corresponding to optical absorbance of Orange II (Y) was constructed for the treatment of the experimental data obtained in the immersion photo-reactor. The function (Y) allowed the prediction of the residual discolouration after 20 min photo-treatment. By following this model, a minimum of well-chosen experiments was performed to optimise Orange II photo-discolouration. The modelling takes into account that in the chemical system one reaction parameter determines the setting of another and vice-versa (interactive effects). The correlation factor between the experimental and predicted values by the Polynomial Expression for the discolouration of Orange II was better than 95%. In a typical photo-reactor run at pH 3, the concentration of TiO2 could be decreased to values
T A Albanis - One of the best experts on this subject based on the ideXlab platform.
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chemometric assessment and investigation of mechanism involved in photo fenton and tio2 photocatalytic degradation of the artificial sweetener sucralose in aqueous media
Applied Catalysis B-environmental, 2013Co-Authors: Paola Calza, Vasilios A Sakkas, Claudio Medana, A D Vlachou, Dal F Bello, T A AlbanisAbstract:Abstract Chemometric optimization tools were employed, such as experimental design and response surface methodology (RSM) to assess the efficiency of two advanced oxidation processes (AOPs): homogeneous Fenton (Fe II /H 2 O 2 ) and heterogeneous (TiO 2 ) photocatalysis for the degradation of the artificial sweetener sucralose. The aqueous samples were irradiated under a variety of experimental conditions (pH, light intensity) and with different amounts of H 2 O 2 , Fe(II), TiO 2 . The use of RSM allowed fitting the optimal values of the parameters leading to the degradation of the contaminant. Also, a single Polynomial Expression modeling the reaction was obtained for both AOPs. The intermediates formed during the photocatalytic and photo-Fenton process were investigated and characterized by means of HPLC/HRMS. The photocatalysed transformation of sucralose proceeds through the formation of few (eight) products, involving four different pathways: hydroxylation of the molecule, oxidation of the alcohol function, dechlorination and the cleavage of glycoside bond. All the identified intermediates were easily degraded and within four hours of irradiation complete mineralization was achieved. A comparison with Photo-Fenton reaction was also reported. In addition Microtox bioassay ( Vibrio fischeri ) was employed in evaluating the ecotoxicity of solutions treated by heterogeneous photocatalysis. Results clearly demonstrate the efficiency of the photocatalytic process in the detoxification of the irradiated solutions.
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photocatalytic degradation study of diclofenac over aqueous tio2 suspensions
Applied Catalysis B-environmental, 2006Co-Authors: Paola Calza, Claudio Medana, V A Sakkas, Claudio Baiocchi, Aikaterini Dimou, Ezio Pelizzetti, T A AlbanisAbstract:Abstract Diclofenac (2-[2′,6′-(dichlorophenyl)amino]phenylacetic acid) is a non-steroidal anti-inflammatory drug used to treat inflammatory and painful diseases of rheumatic and non-rheumatic origin. The present work deals with the photocatalytic transformation of diclofenac, under simulated solar irradiation using titania suspensions as catalyst, to assess the decomposition of the pharmaceutical compound, to identify intermediates, as well as to elucidate some mechanistic details of the degradation. The variation of TiO2 amount and initial diclofenac concentration on the reaction rate, were systematically investigated. The use of the response surface methodology allowed to fit the optimal values of the parameters leading to the degradation of the pollutant. Also, a single Polynomial Expression modeling the reaction was obtained. Photomineralization of the substrate in terms of chlorine ions release was rather a quick process (within 1 h), while the amino moiety is mainly transformed into NH4+ and in a lesser extend into NO3− ions. Evolution of CO2 (loss of TOC) was found to occur within 2 h of irradiation. LC/MS was brought to bear in assessing the temporal course of the photocatalyzed process. Based on our findings a tentative degradation pathway is proposed for the photocatalytic degradation of diclofenac based on the formation of hydroxy-derivatives before the complete mineralization of the starting molecule. In addition Microtox bioassay (Vibrio fischeri) was employed in evaluating the ecotoxicity of solutions treated by photocatalysis. Results clearly demonstrate the efficiency of the photocatalytic process in the detoxification of the irradiated solution.
S.s.e. Lam - One of the best experts on this subject based on the ideXlab platform.
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Finite strip analysis of laminated plates with general initial imperfection under end shortening
Engineering Structures, 2001Co-Authors: Th H. Lui, S.s.e. LamAbstract:Abstract Description of a finite strip method is given for predicting the post-buckling response of rectangular laminated plates when subjected to progressive end shortening. Initial imperfection in very general shape is also included. Polynomial Expression is used to simulate the actual imperfection along each nodal line while the deformations are represented by trigonometric series. The analysis, under the assumption that thin plates are used, is based on the classical plate theory. Geometric non-linearity is introduced in the strain-displacement equations in the manner of the von Karman assumptions. The Newton–Raphson method is used to solve the non-linear equilibrium equations. A number of applications involving both isotropic and laminated plates are described to investigate the effects of initial imperfection.
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post buckling analysis of a strut with general initial imperfection
International Journal for Numerical Methods in Engineering, 1998Co-Authors: S.s.e. LamAbstract:Computational procedure has been presented for the post-buckling analysis of a strut with initial imperfection when subjected to progressive end shortening. Polynomial Expression in very general form is used to simulate the actual initial imperfection, while the deformations are expressed by suitable trigonometric series. Geometric non-linearity is introduced into the strain–displacement relations in a manner that is consistent with the von Karman assumptions. Non-linear equilibrium equations are solved by a Newton–Raphson procedure. Results are presented for cases with symmetric and non-symmetric initial imperfection. Good comparison with other solutions and experimental results is obtained in all applications. © 1998 John Wiley & Sons, Ltd.
J Kiwi - One of the best experts on this subject based on the ideXlab platform.
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orange ii photocatalysis on immobilised tio2 effect of the ph and h2o2
Applied Catalysis B-environmental, 2004Co-Authors: J Fernandez, J Kiwi, Jaime Baeza, Juanita Freer, C Lizama, Hector D MansillaAbstract:The discoloration and mineralisation of the azo-dye Orange II in a photoreactor using TiO2-coated glass rings as immobilised photocatalyst is reported. The variation of pH and the H2O2 addition effect were systematically investigated. The use of the response surface methodology allowed to fit the optimal values of the parameters leading to Orange II abatement. Also, a single Polynomial Expression modelling the reaction was obtained. The photocatalytic degradation of Orange II was followed by spectrophotometric analysis and total organic carbon (TOC) measurements.
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factorial experimental design of orange ii photocatalytic discolouration
Journal of Photochemistry and Photobiology A-chemistry, 2002Co-Authors: J Fernandez, J Kiwi, Jaime Baeza, Juanita Freer, C Lizama, Hector D MansillaAbstract:Abstract Photo-discolouration of Orange II solutions at different concentrations was carried out in a 1 l concentric reactor irradiated with a 254 nm mercury lamp (125 W) in the presence of Degussa TiO2 P-25 dispersions. Experimentation involving discolouration of Orange II has been carried out using factorial design methodology for the simulation of the three critical variables affecting the dye discolouration: concentration of Orange II, pH and concentration of TiO2. A single Polynomial function corresponding to optical absorbance of Orange II (Y) was constructed for the treatment of the experimental data obtained in the immersion photo-reactor. The function (Y) allowed the prediction of the residual discolouration after 20 min photo-treatment. By following this model, a minimum of well-chosen experiments was performed to optimise Orange II photo-discolouration. The modelling takes into account that in the chemical system one reaction parameter determines the setting of another and vice-versa (interactive effects). The correlation factor between the experimental and predicted values by the Polynomial Expression for the discolouration of Orange II was better than 95%. In a typical photo-reactor run at pH 3, the concentration of TiO2 could be decreased to values