The Experts below are selected from a list of 666 Experts worldwide ranked by ideXlab platform
Lucas, Carla De Souza - One of the best experts on this subject based on the ideXlab platform.
-
Medida de tamanho de poro em membrana polimérica de microfiltração utilizando técnica ultrassônica e redes neurais artificiais
2009Co-Authors: Lucas, Carla De SouzaAbstract:O presente trabalho propõe um estudo sobre a avaliação por ultrassom do tamanho de poro em membranas poliméricas de microfiltração, utilizadas na área nuclear para a filtração de rejeitos radioativos, no tratamento de águas residuais da indústria petroquímica, na indústria eletrônica para a produção de água ultrapura para a fabricação de condutores e para lavagem de microcircuitos e em muitos outros processos de separação. Existem diversos processos para medidas de tamanhos de poros em membranas, dentre estes, microscopia eletrônica, ponto de bolha e porosimetria por intrusão de mercúrio, porém a maioria destes utiliza técnicas destrutivas, de custo elevado ou de grande tempo de análise. A proposta deste trabalho é medir tamanho de poro utilizando técnica ultrassônica no domínio da frequência e redes neurais artificiais. Foi utilizado um gerador/receptor de pulsos ultrassônicos, um transdutor de 25 MHz, um tanque de imersão e membranas microporosas de tamanhos de poros 0,2 μm, 0,4 μm, 0,6 μm, 8 μm, 10 μm e 12 μm. Os sinais ultrassônicos após percorrerem a membrana, voltam ao transdutor (emissor/receptor) trazendo informações da interação do sinal com as membranas. Estes sinais foram utilizados para o treinamento de redes neurais, e estas forneceram a precisão necessária para a distinção dos mesmos. Logo após, foi feita a comparação desta técnica com a de microscopia eletrônica de varredura. O experimento mostrou resultados muito próximos aos resultados obtidos com o MEV, o que indicou que a técnica estudada pode medir tamanho de poro em membrana polimérica com boa precisão e repetibilidade. Por ser uma técnica não destrutiva poder ser usada em linha de produção.This work presents a study of the pore size in microfiltration polymeric membranes, used in the nuclear area for the filtration of radioactive liquid effluent, in the residual Water treatment of the petrochemical industry, in the electronic industry for the Ultrapure Water Production for the manufacture of conductors and laudering of microcircuits and in many other processes of separation. Diverse processes for measures of pores sizes in membranes exist, amongst these, electronic microscopy, of bubble point and mercury intrusion porosimetry, however the majority of these uses destructive techniques, of high cost or great time of analysis. The proposal of this work is to measure so great of pore being used ultrasonic technique in the time domain of the frequency and artificial neural networks. A receiving/generator of ultrasonic pulses, a immersion transducer of 25 MHz was used, a tank of immersion and microporous membranes of pores sizes of 0,2 μm, 0,4 μm, 0,6 μm, 8 μm, 10 μm and 12 μm. The ultrasonic signals after to cover the membrane, come back to the transducer (emitting/receiving) bringing information of the interaction of the signal with the membranes. These signals had been used for the training of neural networks, and these had supplied the necessary precision the distinction of the same ones. Soon after, technique with the one of electronic microscopy of sweepings was made the comparison of this. The experiment showed very resulted next to the results gotten with the MEV, what it indicated that the studied technique is ideal for measure of pore size in membranes for being not destructive and of this form to be able to be used also on-line of Production
-
Medida de tamanho de poro em membrana polimérica de microfiltração utilizando técnica ultrassônica e redes neurais artificiais
2009Co-Authors: Lucas, Carla De SouzaAbstract:Submitted by Almir Azevedo (barbio1313@gmail.com) on 2014-01-08T16:18:28Z No. of bitstreams: 1 dissertacao_mestrado_ien_2009_08.pdf: 2286938 bytes, checksum: 63793f4c54b047550efb82703458c9ef (MD5)Made available in DSpace on 2014-01-08T16:18:28Z (GMT). No. of bitstreams: 1 dissertacao_mestrado_ien_2009_08.pdf: 2286938 bytes, checksum: 63793f4c54b047550efb82703458c9ef (MD5) Previous issue date: 2009O presente trabalho propõe um estudo sobre a avaliação por ultrassom do tamanho de poro em membranas poliméricas de microfiltração, utilizadas na área nuclear para a filtração de rejeitos radioativos, no tratamento de águas residuais da indústria petroquímica, na indústria eletrônica para a produção de água ultrapura para a fabricação de condutores e para lavagem de microcircuitos e em muitos outros processos de separação. Existem diversos processos para medidas de tamanhos de poros em membranas, dentre estes, microscopia eletrônica, ponto de bolha e porosimetria por intrusão de mercúrio, porém a maioria destes utiliza técnicas destrutivas, de custo elevado ou de grande tempo de análise. A proposta deste trabalho é medir tamanho de poro utilizando técnica ultrassônica no domínio da frequência e redes neurais artificiais. Foi utilizado um gerador/receptor de pulsos ultrassônicos, um transdutor de 25 MHz, um tanque de imersão e membranas microporosas de tamanhos de poros 0,2 μm, 0,4 μm, 0,6 μm, 8 μm, 10 μm e 12 μm. Os sinais ultrassônicos após percorrerem a membrana, voltam ao transdutor (emissor/receptor) trazendo informações da interação do sinal com as membranas. Estes sinais foram utilizados para o treinamento de redes neurais, e estas forneceram a precisão necessária para a distinção dos mesmos. Logo após, foi feita a comparação desta técnica com a de microscopia eletrônica de varredura. O experimento mostrou resultados muito próximos aos resultados obtidos com o MEV, o que indicou que a técnica estudada pode medir tamanho de poro em membrana polimérica com boa precisão e repetibilidade. Por ser uma técnica não destrutiva poder ser usada em linha de produção.This work presents a study of the pore size in microfiltration polymeric membranes, used in the nuclear area for the filtration of radioactive liquid effluent, in the residual Water treatment of the petrochemical industry, in the electronic industry for the Ultrapure Water Production for the manufacture of conductors and laudering of microcircuits and in many other processes of separation. Diverse processes for measures of pores sizes in membranes exist, amongst these, electronic microscopy, of bubble point and mercury intrusion porosimetry, however the majority of these uses destructive techniques, of high cost or great time of analysis. The proposal of this work is to measure so great of pore being used ultrasonic technique in the time domain of the frequency and artificial neural networks. A receiving/generator of ultrasonic pulses, a immersion transducer of 25 MHz was used, a tank of immersion and microporous membranes of pores sizes of 0,2 μm, 0,4 μm, 0,6 μm, 8 μm, 10 μm and 12 μm. The ultrasonic signals after to cover the membrane, come back to the transducer (emitting/receiving) bringing information of the interaction of the signal with the membranes. These signals had been used for the training of neural networks, and these had supplied the necessary precision the distinction of the same ones. Soon after, technique with the one of electronic microscopy of sweepings was made the comparison of this. The experiment showed very resulted next to the results gotten with the MEV, what it indicated that the studied technique is ideal for measure of pore size in membranes for being not destructive and of this form to be able to be used also on-line of Production
Seungkwan Hong - One of the best experts on this subject based on the ideXlab platform.
-
applications of capacitive deionization desalination softening selective removal and energy efficiency
Desalination, 2019Co-Authors: Jongmoon Choi, Pema Dorji, Ho Kyong Shon, Seungkwan HongAbstract:Abstract Capacitive deionization (CDI) has attracted a great attention as a promising desalination technology, and studies on CDI have increased significantly in the last ten years. However, there have been no guidelines for developing strategies involving CDI technology for specific applications. Therefore, our work presents a critical review of the recent advances in CDI to meet the technical requirements of various applicable areas, with an emphasis on hybrid systems. This paper first summarizes the major developments made on novel electrode materials for CDI for brackish Water desalination. Then, CDI and reverse osmosis (RO) integrated systems are critically reviewed for both Ultrapure Water Production and wasteWater treatment. Additionally, the applicability of CDI on various industrial processes is discussed, covering two distinct topics: (1) Water softening and (2) selective removal of valuable heavy metals and nutrients (nitrate/phosphate). Lastly, recent improvements on the energy efficiency of CDI processes are delineated, specifically focusing on energy recovery and hybridization with energy producing technology, such as reverse electrodialysis (RED) and microbial fuel cells (MFC). This review paper is expected to share the practical experience of CDI applications as well as to provide guidelines for electrode material development for each specific application.
Jongmoon Choi - One of the best experts on this subject based on the ideXlab platform.
-
applications of capacitive deionization desalination softening selective removal and energy efficiency
Desalination, 2019Co-Authors: Jongmoon Choi, Pema Dorji, Ho Kyong Shon, Seungkwan HongAbstract:Abstract Capacitive deionization (CDI) has attracted a great attention as a promising desalination technology, and studies on CDI have increased significantly in the last ten years. However, there have been no guidelines for developing strategies involving CDI technology for specific applications. Therefore, our work presents a critical review of the recent advances in CDI to meet the technical requirements of various applicable areas, with an emphasis on hybrid systems. This paper first summarizes the major developments made on novel electrode materials for CDI for brackish Water desalination. Then, CDI and reverse osmosis (RO) integrated systems are critically reviewed for both Ultrapure Water Production and wasteWater treatment. Additionally, the applicability of CDI on various industrial processes is discussed, covering two distinct topics: (1) Water softening and (2) selective removal of valuable heavy metals and nutrients (nitrate/phosphate). Lastly, recent improvements on the energy efficiency of CDI processes are delineated, specifically focusing on energy recovery and hybridization with energy producing technology, such as reverse electrodialysis (RED) and microbial fuel cells (MFC). This review paper is expected to share the practical experience of CDI applications as well as to provide guidelines for electrode material development for each specific application.
Perez, Giulia Pieta - One of the best experts on this subject based on the ideXlab platform.
-
Evaluate of reduction urea dissolved in Water by oxidation from hypobromite
Faculdade de Engenharia, 2016Co-Authors: Perez, Giulia PietaAbstract:Submitted by Setor de Tratamento da Informa??o - BC/PUCRS (tede2@pucrs.br) on 2016-05-17T12:27:44Z No. of bitstreams: 1 DIS_GIULIA_PIETA_PEREZ_COMPLETO.pdf: 2021457 bytes, checksum: 522d4e2075aed41c7efa9ad1ee873a31 (MD5)Made available in DSpace on 2016-05-17T12:27:44Z (GMT). No. of bitstreams: 1 DIS_GIULIA_PIETA_PEREZ_COMPLETO.pdf: 2021457 bytes, checksum: 522d4e2075aed41c7efa9ad1ee873a31 (MD5) Previous issue date: 2016-03-28Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPESUrea is an organic contaminant on Ultrapure Water Production for semiconductors, remove it is hard due to its molecular characteristics of non-volatile, tough oxidation, non-ionic, high soluble and low molecular weight. This paper had been studied the dissolved urea oxidation by hypobromite, formed in situ from reaction between sodium bromide and sodium hypochlorite. The experimental tests evaluated the hypobromite formation through the time of hypobromite formation, the urea removal was quantified by TOC data (total organic carbon), on this case were performed different conditions of hypobomite concentrations, pH of solution containing urea, time of urea oxidation and bromate concentration. Either the pH, as the time of hypobromite formation do not affect the amount of urea reduced. Otherwise, the hypobromite concentration and bromide sodium concentration interfered its results. The hypobromite is capable to reduce main part of urea dissolved in Water when in absence of others NOM (natural organic matter). The best results on this study were achieved with Ultrapure Water used as solvent, hypobromite concentration of 3 mgL-1.A ureia ? um contaminante org?nico na produ??o de ?gua ultrapura para semicondutores, sua remo??o ? dif?cil devido as suas caracter?sticas de n?ovolatilidade, dif?cil oxida??o, car?ter n?o i?nico, altamente sol?vel em ?gua e baixa massa molar. Nesse trabalho foi estudada a remo??o da ureia dissolvida em ?gua atrav?s da oxida??o do ?on hipobromito, formado in situ pela rea??o de brometo de s?dio e hipoclorito de s?dio. Na parte experimental foi avaliada a forma??o do ?on hipobromito atrav?s da varia??o do tempo de forma??o do mesmo, e analisada a remo??o de ureia atrav?s dos valores de COT (carbono org?nico total), neste caso foram alterados os valores de concentra??o de hipobromito, concentra??o de brometo final, tempo de oxida??o com a ureia e pH da rea??o. Foram observadas que, tanto o pH como o tempo de forma??o de hipobromito n?o interferem na efici?ncia de remo??o da ureia, ao contr?rio da concentra??o de hipobromito e concentra??o de brometo utilizado. Verificou-se que hipobromito ? capaz de remover quase completamente a ureia presente em ?gua quando em aus?ncia de NOM (material org?nico de ocorr?ncia natural). Os melhores resultados obtidos foram com ?gua ultrapura e concentra??o de 3 mgL-1 de hipobromito
Cho Jaeweon - One of the best experts on this subject based on the ideXlab platform.
-
An Autopsy Study of a Fouled Reverse Osmosis Membrane Used for Ultrapure Water Production
'MDPI AG', 2019Co-Authors: Rho Hojung, Chon Kangmin, Cho JaeweonAbstract:This study investigated the fouling and cleaning behaviors of reverse osmosis (RO) membranes in a lab-scale Ultrapure Water (UPW) Production system via membrane autopsies and characterization of dissolved organic matter (DOM) and membrane foulants. Most of DOM were effectively removed by the MFC filter, with the exception of the peak at 150 Da. The RO membranes were effective in reducing conductivity, DOM, total nitrogen (TN), and ultraviolet A (UVA(254nm)) concentration; the polishing stage using IER filter resulted in ultra-trace levels of all these parameters required for semiconductor manufacturing (> 18.2 Omega M). The quantity of the desorbed RO membrane foulants, in terms of dissolved organic carbon (DOC), varied considerably depending on the type of desorbing agents: 0.1 N NaCl (65.12 mgC m(-2)) > 0.1 N NaOH (46.14 mgC m(-2)) > deionized Water (25.39 mgC m(-2)) > 0.1 N HCl (15.95 mgC m(-2)). The high cleaning efficiency of the salt solution (0.1 N NaCl) was attributed to the efficient desorption of hydrophilic DOM foulants from the RO membrane surfaces. These results demonstrate that the salt cleaning may provide a promising option to recover the performance of the RO membranes fouled primarily by hydrophilic DOM fractions
