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Top venting of low and high viscosity fluids during vessel depressurisationBell, Keith Ian January 1994 (has links)
No description available.
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The venting of a runaway esterification reaction on both the laboratory and pilot scalesHare, John Andrew January 1997 (has links)
No description available.
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Extratos padronizados para o tratamento de doenças crônicas: Arrabidaea sppRocha, Claudia Quintino da [UNESP] 12 September 2013 (has links) (PDF)
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000747346_20300901.pdf: 406543 bytes, checksum: e275af55cdc15d69f159528500e479c5 (MD5) / O projeto teve como objetivo padronizar extratos para tratar doenças crônicas mais prevalentes na população brasileira. A espécie investigada foi Arrabidaea brachypoda (Bignoniaceae), gênero do qual são relatadas várias atividades farmacológicas. Folhas e cascas das raízes foram secas em estufa. Os pós obtidos de cada parte foram percolados com etanol 70% v/v, a mistura foi filtrada e concentrada em rotaevaporador. Os extratos obtidos foram submetidos a clean-up em cartuchos Sep-Pak de fase reversa e analisados por HPLC-PDA. Os perfis cromatográficos mostraram que ambos são ricos em substâncias fenólicas. Fracionamento do extrato das raízes forneceu 7 substâncias inéditos dentre eles 6 flavonóides diméricos raros, sendo um deles majoritário no extrato. Esta substância serviu de marcador para padronização do extrato. Fracionamento cromatográfico do extrato das folhas forneceu 13 substâncias, 10 delas relatatas aqui pela primeira vez na espécie. A rutina é majoritária nesse extrato e foi usada como marcador para padronização do mesmo. Ensaios biológicos demonstraram que os extratos e substâncias de A.brachypoda possuem atividade anti-inflamatória, anti-úlceras gástricas e anti-protozoários. Este projeto resultou em dois pedidos de patentes internacionais. / The project aimed to standardize extracts to treat most prevalent chronic diseases in our population. The specie investigated was Arrabidaea brachypoda (Bignoniaceae), genus of which are reported various pharmacological activities. Leaves and barks of the roots were dried in an oven. The obtained powders were percolated each part with 70% ethanol v / v, the mixture was filtered and concentrated on rotaevaporator. The extracts were subjected to clean-up cartridges Sep-Pak reverse phase and analyzed by HPLC-PDA. The chromatographic profiles showed that both are rich in phenolic substances. Fractionation of the extract of the roots provided novel compounds 7, 6 of them rare dimeric flavonoids, being a majority of them in the extract. This substance served as a marker for standardization of the extract. Fractionation of leaf extract provided 13 substances, 10 of them reported here for the first time in this species. Rutin is a majority in this extract and was used as a marker for standardization of the same. Biological assays showed that extracts and compounds of A.brachypoda possess anti-inflammatory activity, anti-gastric ulcer and anti-protozoa. This project resulted in two international patent applications.
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Extratos padronizados para o tratamento de doenças crônicas: Arrabidaea spp. /Rocha, Claudia Quintino da. January 2013 (has links)
Orientador: Wagner Vilegas / Banca: Humberto Marcio Santos Milagre / Banca: Nivaldo Boralle / Banca: Veridiana Vera de Rosso / Banca: Danielle Ferreira Dias / Resumo: O projeto teve como objetivo padronizar extratos para tratar doenças crônicas mais prevalentes na população brasileira. A espécie investigada foi Arrabidaea brachypoda (Bignoniaceae), gênero do qual são relatadas várias atividades farmacológicas. Folhas e cascas das raízes foram secas em estufa. Os pós obtidos de cada parte foram percolados com etanol 70% v/v, a mistura foi filtrada e concentrada em rotaevaporador. Os extratos obtidos foram submetidos a clean-up em cartuchos Sep-Pak de fase reversa e analisados por HPLC-PDA. Os perfis cromatográficos mostraram que ambos são ricos em substâncias fenólicas. Fracionamento do extrato das raízes forneceu 7 substâncias inéditos dentre eles 6 flavonóides diméricos raros, sendo um deles majoritário no extrato. Esta substância serviu de marcador para padronização do extrato. Fracionamento cromatográfico do extrato das folhas forneceu 13 substâncias, 10 delas relatatas aqui pela primeira vez na espécie. A rutina é majoritária nesse extrato e foi usada como marcador para padronização do mesmo. Ensaios biológicos demonstraram que os extratos e substâncias de A.brachypoda possuem atividade anti-inflamatória, anti-úlceras gástricas e anti-protozoários. Este projeto resultou em dois pedidos de patentes internacionais. / Abstract: The project aimed to standardize extracts to treat most prevalent chronic diseases in our population. The specie investigated was Arrabidaea brachypoda (Bignoniaceae), genus of which are reported various pharmacological activities. Leaves and barks of the roots were dried in an oven. The obtained powders were percolated each part with 70% ethanol v / v, the mixture was filtered and concentrated on rotaevaporator. The extracts were subjected to clean-up cartridges Sep-Pak reverse phase and analyzed by HPLC-PDA. The chromatographic profiles showed that both are rich in phenolic substances. Fractionation of the extract of the roots provided novel compounds 7, 6 of them rare dimeric flavonoids, being a majority of them in the extract. This substance served as a marker for standardization of the extract. Fractionation of leaf extract provided 13 substances, 10 of them reported here for the first time in this species. Rutin is a majority in this extract and was used as a marker for standardization of the same. Biological assays showed that extracts and compounds of A.brachypoda possess anti-inflammatory activity, anti-gastric ulcer and anti-protozoa. This project resulted in two international patent applications. / Doutor
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lmprovement of Convergence in the Simulation of Complex Chemical PlantsLord, Stephen 09 1900 (has links)
<p> The various criteria and methods suggested in the literature for choosing the optimum sequence of calculation are compared. They are then analysed using the results of runs on three different simulations. Two techniques of convergence are used, and it is found that Geometric Convergence Promotion will improve the rate of convergence compared to Direct Substitution for any feasible sequence. It is also shown that the optimal sequences of calculation are different for the two techniques. </p> <p> It is concluded that the Minimum Cut Streams criterion is the best to use for Direct Substitution, but that the use of the feasible Set criterion and Convergence Promotion will yield better convergence. The iterative improvement of convergence is discussed, and it is concluded that the available time is best spent on improving the starting point and the Convergence Promotion technique rather than on changing the sequence of calculation. </p> / Thesis / Master of Engineering (MEngr)
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Vliv postřiku insekticidy na diverzitu střevlíků (\kur{Carabidae}) na poli ozimé řepky / Impact of the application of the insecticides on the diversity of ground beetles (Carabidae) in a winter rape standKEPL, Lukáš January 2013 (has links)
This thesis deals with the determination of the direct impact of spraying on soil invertebrates by comparing the treated and untreated surfaces by spraying with plant protection products. The experiment took place in crop of winter oilseed rape in the western part of South Bohemia in spring 2012. As bio-indicators were used ground beetles beetles (Carabidae). Trapping was conducted using pitfall traps. In this work we compared the difference in the occurrence of ground beetles in treated and untreated crop of winter oilseed rape and subsequent tree alley. Only 15% of beetles was recorded sprayed areas, 69% in untreated areas and and 16% in the alley. This suggests the direct impact of spraying on non-target organisms. That's followed by a second experiment, which aim was to determine the long-term effects of intensive farming on ground beetle populations in habitats related to reporting rape field. The selected habitats were meadow, pasture, alley, ruderals and riparian vegetation. The results indicated the inportance of the biotops consequent to field as tthe refugium and the center of spreading of groujd beetles to the field where they provide ecosystem service of biological control.
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Optimal synthesis of storageless batch plants using the process intermediate storage operational policyPattinson, Thomas 27 August 2008 (has links)
A novel operational policy, the Process Intermediate Storage (PIS) operational policy, is introduced and used to synthesize, schedule and design multipurpose batch plants. The model is based on the State Sequence Network (SSN) and non-uniform discretization of the time horizon of interest model developed by Majozi&Zhu (2001). Two cases are studied to determine the effectiveness of the operational policy. A plant without dedicated intermediate storage is considered in the first case. In this case the throughput is maximized with and without the use of the PIS operational policy. The use of the PIS operational policy results in a 50% improvement in the throughout. The second case is used to determine the minimum amount of intermediate storage while maintaining the throughput achieved with infinite intermediate storage. This resulted in a 33% reduction in the amount of dedicated intermediate storage. The models developed for both cases are MILP models. A design model is then developed to exploit the attributes of the PIS operational policy. The design model is a MINLP due to the capital cost objective function. This model is applied to a literature example and an industrial case study and in both cases results in improved flowsheets and reduced capital cost. / Dissertation (MEng)--University of Pretoria, 2008. / Chemical Engineering / unrestricted
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Dynamic Simulation of a Multiproduct Chemical PlantLozada, Alejandro 08 1900 (has links)
This report deals with the use of the "Modular Approach", in the simulation of change-over operations, for a continuous multiproduct chemical plant. A dynamic model of the continuous fat hydrolysis process was built, with the DYNSYS framework, with the purpose of evaluating the usefulness of this programme in simulating different change-over operation policies. Operator's activities were simulated making use of an interactive version of DYNSYS, demonstrating its value for studying alternate changeover policies and possible as a training device. Supervisory control was implemented in order to automate the change-over operations, simulating the functions of a small computer controlling the process. Improved operating policies for change-over are proposed and the validity of the simulation is discussed from both a practical and a theoretical point of view. / Thesis / Master of Engineering (ME)
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Comparison of Scheduling Algorithms for a Multi-Product Batch-Chemical Plant with a Generalized Serial NetworkTra, Niem-Trung L. 03 February 2000 (has links)
Despite recent advances in computer power and the development of better algorithms, theoretical scheduling methodologies developed for batch-chemical production are seldom applied in industry (Musier & Evans 1989 and Grossmann et al. 1992). Scheduling decisions may have significant impact on overall company profitability by defining how capital is utilized, the operating costs required, and the ability to meet due dates. The purpose of this research is to compare different production scheduling methods by applying them to a real-world multi-stage, multi-product, batch-chemical production line. This research addresses the problem that the theoretical algorithms are seldom applied in industry and allows for performance analysis of several theoretical algorithms.
The research presented in this thesis focuses on the development and comparison of several scheduling algorithms. The two objectives of this research are to:
1. modify different heuristic production scheduling algorithms to minimize tardiness for a multi-product batch plant involving multiple processing stages with several out-of-phase parallel machines in each stage; and
2. compare the robustness and performance of these production schedules using a stochastic discrete event simulation of a real-world production line.
The following three scheduling algorithms are compared:
1. a modified Musier and Evans scheduling algorithm (1989);
2. a modified Ku and Karimi Sequence Building Algorithm (1991); and
3. a greedy heuristic based on an earliest-due-date (EDD) policy.
Musier and Evans' heuristic improvement method (1989) is applied to the three algorithms. The computation times to determine the total tardiness of each schedule are compared. Finally, all the schedules are tested for robustness and performance in a stochastic setting with the use of a discrete event simulation (DES) model. Mignon, Honkomp, and Reklaitis' evaluation techniques (1995) and Multiple Comparison of the Best are used to help determine the best algorithm. / Master of Science
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\"O estudo da utilização do gás natural como insumo para a indústria química e petroquímica: modelagem de uma planta gás-química\" / The study of the use of natural gas as a feedstock for the chemical and petrochemical industry: the modeling of a gas-chemical plant.Gerosa, Tatiana Magalhães 26 February 2007 (has links)
Este trabalho tem como objetivo apresentar, através da modelagem de uma planta gásquímica e da identificação das tecnologias disponíveis, a versatilidade do uso do gás natural como insumo para a indústria química, visando à produção de metanol, amônia e hidrogênio, a partir da fração metano, bem como na indústria petroquímica a obtenção do eteno através da fração etano. Baseado nas pesquisas de mercado, determinou-se que dentre os produtos a serem obtidos a partir do metano, o metanol é o que apresenta o cenário interno mais crítico. Esta situação é refletida através do contínuo aumento da importação, sem que haja nenhuma sinalização deste déficit ser sanado, através da construção de novas unidades industriais. Por outro lado, o cenário da amônia se mostra estável e, ainda que haja um déficit na produção nacional, a situação atual não se mostra tão crítica, mesmo quando realizada a projeção da demanda até 2030. Analisando-se o cenário petroquímico, em poucos anos a produção de eteno atingirá o seu gargalo, e o maior entrave diagnosticado, para a expansão das centrais produtoras, está relacionado à disponibilidade do insumo. Dentro da abordagem técnica proposta, a modelagem da planta gás-química aponta ser viável concentrar a produção de amônia, metanol e hidrogênio no mesmo pólo e que, para estes produtos, a tecnologia atual encontra-se madura e em estágio avançado. Já a produção de eteno, a partir do etano, não deve estar diretamente vinculada, a princípio, à obtenção dos demais produtos, pelo alto volume de gás natural necessário para liberar a fração de etano ideal para a sustentabilidade do projeto. / This work has as objective to present, through the modeling of a gas-chemical plant and also, through the identification of the current available technologies, the versatility of the use of natural gas as a raw material for the chemical industry, aiming the production of methanol, ammonia and hydrogen, from the fraction methane, as well as in the petrochemical industry, the attainment of ethene from the ethane fraction. Based in a market research, it was determined that amongst the products to be obtained from methane, methanol is the product that presents the most critical internal scenario. This situation is reflected through the continuous increase of the importation; without it there is no signaling that this deficit can be overcome, unless new industrials units are constructed. On the other hand, the ammonia scenario is steady and, despite presenting a deficit in the national production, the current situation does not reveal to very so critical, carried through the projection of the demand up to 2030. Analyzing the petrochemical scene, in a few years the ethene production will reach its pass and the biggest diagnosed impediment is related to the availability of the feedstock. Considering the technique proposal, the modeling of the gas-chemical plant shows the viability of concentrating the production of ammonia, methanol and hydrogen in the same site and that, for these products, the current technologies are mature and very well developed. Already the ethene production, from ethane, does not have to be directly entailed, in principle, to the attainment of the other products, considering the high volume of natural gas necessary to liberate the necessary amount of ethane for the sustainable of the project.
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