Dissertation (Ph. D.)--University of Akron, Dept. of Civil Engineering, 2009. / "August, 2009." Title from electronic dissertation title page (viewed 9/30/2009) Advisor, Christopher M. Miller; Committee members, William Brian Arbuckle, George G. Chase, Annabelle M. Foos, William H. Schneider IV; Department Chair, Wieslaw Binienda; Dean of the College, George K. Haritos; Dean of the Graduate School, George R. Newkome. Includes bibliographical references.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1963. / Typescript. Includes: Thermodynamic properties of ions at high temperatures / John W. Green, Duncan E. Poland, John L. Margrave. (Wright-Patterson Air Force Base, Ohio : Aeronautical Research Laboratory, Office of Aerospace Research, United States Air Force, 1961) -- Ideal gas thermodynamic functions of some selected elements / D.E. Poland, J.W. Green and J.L. Margrave. Reprinted from Journal of chemical & engineering data, v. 7, no. 3 (July 1962), p. 389-390 -- Corrected optical pyrometer readings / D.E. Poland, J.W. Green and J.L. Margrave. National Bureau of Standards monograph ; 30 (Washington, 1961), 74 p. -- Absorption spectrum of chlorine in the vacuum ultraviolet / Raymond P. Iczkowski, Raymond P., John L. Margrave and John W. Green. Reprinted from Journal of chemical physics, v. 33, no. 4 (Oct. 1960), p. 1261-1262. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1969. / Vita. Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (Ph. D.)--Earth and Atmospheric Sciences, Georgia Institute of Technology, 2007. / Robert Dickinson, Committee Member ; Athanasios Nenes, Committee Member ; David Tan, Committee Member ; Armistead Russell, Committee Member ; Yuhang Wang, Committee Chair.

Submitted by Johnny Rodrigues (johnnyrodrigues@ufcg.edu.br) on 2018-03-23T21:46:49Z No. of bitstreams: 1 FELIPE VIEIRA SANTOS - DISSERTAÇÃO PPGEQ 2015..pdf: 2547099 bytes, checksum: 7ba6e13e6f00650d6050d29d5473f708 (MD5) / Made available in DSpace on 2018-03-23T21:46:49Z (GMT). No. of bitstreams: 1 FELIPE VIEIRA SANTOS - DISSERTAÇÃO PPGEQ 2015..pdf: 2547099 bytes, checksum: 7ba6e13e6f00650d6050d29d5473f708 (MD5) Previous issue date: 2015-03-17 / Durante a produção do cloro diversas impurezas são incorporadas ao produto e sua remoção se dá durante o processamento. A remoção das impurezas é fator fundamental não só para garantir a qualidade do produto final como também do ponto de vista de segurança, pois determinados contaminantes geram riscos de explosão. Nas etapas de processamento a remoção de uma das principais impurezas se dá no pré-resfriador, equipamento que consiste numa torre de pratos que tem função de além de remover os contaminantes pesados também reduz a temperatura do gás para sucção do compressor. O objetivo principal deste trabalho foi desenvolver uma simulação estacionária em simulador comercial que reproduza as condições de operação de um pré-resfriador de cloro tais como perfil de temperatura nas bandejas, perfil de pressão e hidráulica da coluna, tendo como estudo de caso um dos equipamentos de uma das plantas de processamento de cloro da Braskem S.A. Foi realizada uma descrição detalhada da função do equipamento no processo e um breve histórico contemplando as atualizações tecnológicas realizadas desde a primeira identificação da necessidade deste tipo de equipamento no processamento de cloro até o impacto na última década com a assinatura do protocolo de Montreal. Também foi realizada uma discussão sobre os principais parâmetros hidráulicos de colunas de pratos que afetam seu desempenho e estabilidade. É apresentada uma breve discussão sobre eficiência de pratos e os métodos para a estimativa deste parâmetro. No desenvolvimento da simulação foi utilizado o simulador comercial ASPEN Plus V8.4. Foi utilizado bloco RADFRAC para as seções da coluna além de um bloco separado para o refervedor. Foi realizado ajuste dos parâmetros da simulação aos dados de planta e realizada análise de sensibilidade para identificação da resposta dos principais parâmetros às variáveis chave e realização de diagnóstico quanto ao desempenho do equipamento. Foi verificado que a simulação reproduziu satisfatoriamente os dados de planta e que para os parâmetros normais de operação existem limitações hidráulicas que levam a instabilidade do mesmo. Foram realizadas recomendações para ajuste do sistema e estabilização da operação do equipamento. / During the Chlorine production many impurities are incorporated to de product and it´s removed along the chlorine processing. Impurities removal is a key factor to assure not only product quality but also from a safety stand point, due to the fact that many of these impurities represent explosion hazards. On the processing process, the removal of one of the most hazardous impurity takes place at the pre-cooler, a trayed-column that besides removing the heavy impurities chills the chlorine gas prior to compression. The main objective of the present work was to develop a steady-state simulation on a commercial simulation software that represents the operating parameters of a pre-cooler like temperature profile along the trays, pressure profile and column hydraulics using as a case study a piece of equipment installed at one of Braskem S.A. chlorine processing plants. A detailed description of the equipment purpose and a brief description of the main technology updates since the first designed one back to 1930 until the Montreal Protocol signature and it´s impacts on the technology. It is also presented a discussion regarding the main hydraulic parameters and its effects on column performance and stability. A brief discussion regarding plate efficiency and the predictive methods. The simulation was developed under ASPEN Plus V8.4. A RADFRAC block was the choice to model the column sessions and a separated FLASH block to reboiler. Plant data were used to adjust and validate the simulation and a sensitivity analysis took place to verify the response of the process parameter to variation on the key process input variables, a diagnostic of equipment performance was performed as well. It was concluded that the use of the simulation was satisfactory to reproduce plant data and identified that some hydraulic constrains that leads to operational instability are possibly in place. Recommendations are given to stabilize the equipment operation and adjust at the equipment design.

In the first part of my diploma work we are getting to know some important law order information connected with the law and duties of producers and transporters of dangerous substances and safe activities with the dangerous substance. Next my work contains basic legislature connected with integrated rescue systém. The last part is devoted to chemical disaster likvidation in Český Krumlov.

Quantitative Structure-Activity Relationship (QSAR) has been applied extensively in predicting toxicity of Disinfection By-Products (DBPs) in drinking water. Among many toxicological properties, acute and chronic toxicities of DBPs have been widely used in health risk assessment of DBPs. These toxicities are correlated with molecular properties, which are usually correlated with molecular descriptors. The primary goals of this thesis are: 1) to investigate the effects of molecular descriptors (e.g., chlorine number) on molecular properties such as energy of the lowest unoccupied molecular orbital (ELUMO) via QSAR modelling and analysis; 2) to validate the models by using internal and external cross-validation techniques; 3) to quantify the model uncertainties through Taylor and Monte Carlo Simulation. One of the very important ways to predict molecular properties such as ELUMO is using QSAR analysis. In this study, number of chlorine (NCl) and number of carbon (NC) as well as energy of the highest occupied molecular orbital (EHOMO) are used as molecular descriptors. There are typically three approaches used in QSAR model development: 1) Linear or Multi-linear Regression (MLR); 2) Partial Least Squares (PLS); and 3) Principle Component Regression (PCR). In QSAR analysis, a very critical step is model validation after QSAR models are established and before applying them to toxicity prediction. The DBPs to be studied include five chemical classes: chlorinated alkanes, alkenes, and aromatics. In addition, validated QSARs are developed to describe the toxicity of selected groups (i.e., chloro-alkane and aromatic compounds with a nitro- or cyano group) of DBP chemicals to three types of organisms (e.g., Fish, T. pyriformis, and P.pyosphoreum) based on experimental toxicity data from the literature. The results show that: 1) QSAR models to predict molecular property built by MLR, PLS or PCR can be used either to select valid data points or to eliminate outliers; 2) The Leave-One-Out Cross-Validation procedure by itself is not enough to give a reliable representation of the predictive ability of the QSAR models, however, Leave-Many-Out/K-fold cross-validation and external validation can be applied together to achieve more reliable results; 3) ELUMO are shown to correlate highly with the NCl for several classes of DBPs; and 4) According to uncertainty analysis using Taylor method, the uncertainty of QSAR models is contributed mostly from NCl for all DBP classes.

Public water supplies contain disease-causing microorganisms in the water or distribution ducts. In order to kill off these pathogens, a disinfectant, such as chlorine, is added to the water. Chlorine is the most widely used disinfectant in all U.S. water treatment facilities. Chlorine is known to be one of the most powerful disinfectants to restrict harmful pathogens from reaching the consumer. In the interest of obtaining a better understanding of what variables affect the levels of chlorine in the water, this thesis will analyze a particular set of water samples randomly collected from locations in Orange County, Florida. Thirty water samples will be collected and have their chlorine level, temperature, and pH recorded. A linear regression analysis will be performed on the data collected with several qualitative and quantitative variables. Water storage time, temperature, time of day, location, pH, and dissolved oxygen level will be the independent variables collected from each water sample. All data collected will be analyzed through various Statistical Analysis System (SAS®) procedures. Partial residual plots will be used to determine possible relationships between the chlorine level and the independent variables and stepwise selection to eliminate possible insignificant predictors. From there, several possible models for the data will be selected. F tests will be conducted to determine which of the models appears to be the most useful. All tests will include hypotheses, test statistics, p values, and conclusions. There will also be an analysis of the residual plot, jackknife residuals, leverage values, Cook’s D, press statistic, and normal probability plot of the residuals. Possible outliers will be investigated and the critical values for flagged observations will be stated along with what problems the flagged values indicate.

The FSMA Produce Safety Rule (PSR) requires citrus packers to more closely assess, manage, and monitor food safety risks. Although there have been no foodborne illness outbreaks and only one recall in fresh citrus, the risk of pathogens coming in on the fruit and cross contamination during washing still exists. Packhouses have dynamic washing systems and in-plant validations may be the only way to demonstrate compliance with the PSR. In-plant validations use surrogates in place of pathogens, and none have been identified or validated for citrus. The aim of this research was to identify a surrogate for use in fresh citrus packhouses. Potential surrogates were screened for free chlorine resistance, survival under commercial storage conditions, and shedding and attachment characteristics during simulated washing. E. faecium NRRL B-2354 and P. pentosaceus NRRL B-14009 were selected for further study. Resistance to chlorine was not significantly different between E. faecium and L. monocytogenes FSL J1-031 when exposed to 3 ppm free chlorine for 30, 60, 90, and 120 s at 20 and 100 ppm TSB (pE. faecium and P. pentosaceus behavior was significantly different than L. monocytogenes (p=0.05), indicating that neither is a suitable surrogate. In shedding and attachment, either the fruit (shedding) or water (attachment) was inoculated, washing was simulated, and organisms were enumerated from the water (shedding) or fruit (attachment). Both potential surrogates were statistically different than L. monocytogenes (pE. faecium can be used for L. monocytogenes shedding estimates and E. faecium and P. pentosaceus can be used for attachment estimates. Overall, this research suggests that E. faecium NRRL B-2354 can be considered as a surrogate for L. monocytogenes in whole, fresh citrus validation studies on chlorinated washes and – with appropriate adjustments – on shedding and attachment characteristics.

No description available.