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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Synthesis and Flame Retardant Studies of Bromoester of 2,4-Pentadienoic Acid

Ghane, Hessam 01 January 1978 (has links) (PDF)
The synthesis and fire retardancy of several bromoesters of 2,4-pentadienoic acid were investigated. The synthesis of 2,4-pentadienoic acid was accomplished by liquid phase reaction of acrolein and malonic acid in the presence of pyridine. The conversion of the acid to bromoesters was performed by two different procedures. In the first procedure, the corresponding acid chloride was prepared from the acid via reaction with SOCl2 in the presence of powdered (3A°) molecular sieves. The molecular sieves serve as an internal trap for by-product HC1 and inhibit the competing polymerization reaction of the acid chloride. Reaction of the acid chloride with various alcohols provided the unsaturated esters. The final step in the first procedure is total bromination of the unsaturated esters. The second procedure involved bromination of 2,4-pentadienoic acid and followed by reaction of the bromo acid with SOCl₂ to produce the corresponding bromo acid chloride. Reaction of the brominated acid chloride with alcohol provided the corresponding brominated esters. A simple laboratory test was developed to measure and compare the flame retardancy of the bromoesters.
12

Biodegration of Benzene

Kim, Kimyoung January 1987 (has links)
This study was conducted to estimate the kinetic constants of benzene-acclimated biomass at optimum conditions and investigate the effectiveness of soil inoculation to expedite the biodegradation of benzene. A complete-mix, bench-scale, continuous-flow, activated-sludge reactor was used to develop organisms capable of utilizing benzene as a sole carbon and energy source. Settled pond water was used as seeding inocula and about 2000 mg/I of MLSS was maintained at the steady state with the MCRT of 7 days. The culture was used to inoculate the experimental bottle equipped with a sampling port. A series of different initial concentrations of benzene were established in the bottles for the batch growth tests. Samples were drawn every hour and the optical densities were measured at 540 nm in order to assess the growth rate. A nonlinear least-squares regression technique was employed to estimate the constants of the Haldane equation (an inhibition function). µ<sub>m</sub> was 0.31 hr⁻¹, K₂ was 1.36 mg/I and K<sub>i</sub>, was 1.50x10¹⁵' mg/I in the range of 14 - 491 mg/I of benzene. A small amount of the acclimated bacteria was added to the normal moist subsoil containing 100 mg/I of benzene and enough mineral nutrients. The soils were put in septum-capped glass bottles and incubated in the dark for a month. The benzene concentration in the autoclaved bottles did not decrease during the incubation period while that in the inoculated bottles was reduced to zero within 4 days and that in the uninoculated bottles was reduced to zero within 13 days. / M.S.
13

Fire safety and interior textiles

Perez, Virginia 17 March 2010 (has links)
The role of the interior designer in providing for fire safe interiors is an important one. The textile end-products they specify play an important part in the start and/or spread of interior fires. Furthermore, the rate of developments in textile testing and products makes it difficult for designers to keep abreast of the latest information. This thesis provides a program for updating interior designers on fire safe interior textiles. A one hour update program was developed as part of the thesis and delivered to members of the Southwest Regional Chapter of ASID in Roanoke, Virginia. An analysis of data from a survey showed that participants believe there is a need for an educational program such as this course and that they would attend a five hour CEU course developed on this subject. Responses to questions on textile fibers, standard tests, and new products on the market supported the perceived need for continuing education on the subject of fire safe textiles. The course evaluation in turn, determined that some areas of the program needed to be revised. This thesis provides a packaged program which can be easily updated. Furthermore, anyone with a textile background can use this program in preparing and delivering a CEU course on fire safety and interior textiles. / Master of Science
14

Facility Siting and Layout Optimization Based on Process Safety

Jung, Seungho 2010 December 1900 (has links)
In this work, a new approach to optimize facility layout for toxic release, fire and explosion scenarios is presented. By integrating a risk analysis in the optimization formulation, safer assignments for facility layout and siting have been obtained. Accompanying with the economical concepts used in a plant layout, the new model considers the cost of willing to avoid a fatality, i.e. the potential injury cost due to accidents associated with toxic release near residential areas. For fire and explosion scenarios, the building or equipment damage cost replaces the potential injury cost. Two different approaches have been proposed to optimize the total cost related with layout. In the first phase using continuous-plane approach, the overall problem was initially modeled as a disjunctive program where the coordinates of each facility and cost-related variables are the main unknowns. Then, the convex hull approach was used to reformulate the problem as a Mixed Integer Non-Linear Program (MINLP) that identifies potential layouts by minimizing overall costs. This approach gives the coordinates of each facility in a continuous plane, and estimates for the total length of pipes, the land area, and the selection of safety devices. Finally, the 3D-computational fluid dynamics (CFD) was used to compare the difference between the initial layout and the final layout in order to see how obstacles and separation distances affect the dispersion or overpressures of affected facilities. One of the CFD programs, ANSYS CFX was employed for the dispersion study and Flame Acceleration Simulator (FLACS) for the fires and explosions. In the second phase for fire and explosion scenarios, the study is focused on finding an optimal placement for hazardous facilities and other process plant buildings using the optimization theory and mapping risks on the given land in order to calculate risk in financial terms. The given land is divided in a square grid of which the sides have a certain size and in which each square acquires a risk-score. These risk-scores such as the probability of structural damage are to be multiplied by prices of potential facilities which would be built on the grid. Finally this will give us the financial risk. Accompanying the suggested safety concepts, the new model takes into account construction and operational costs. The overall cost of locations is a function of piping cost, management cost, protection device cost, and financial risk. This approach gives the coordinates of the best location of each facility in a 2-D plane, and estimates the total piping length. Once the final layout is obtained, the CFD code, FLACS is used to simulate and consider obstacle effects in 3-D space. The outcome of this study will be useful in assisting the selection of location for process plant buildings and risk management.
15

Shielding effect to the flammable fibres offered by inherently flame retardant fibres

Khan, Jasra January 2019 (has links)
Flame retardant chemicals were used to make flammable fibres or fabrics flame retardant. Flame retardants protect the flammable material from fire by delaying or preventing the ignition process. The problem with flame retardants is unreliable durability when applied physically or bonded chemically on the surface of the fibre or fabric. This thesis project investigated the implementation of inherently flame retardant fibres as a shield form flame for flammable fibres. The most widely used flammable textiles fibres (cotton and polyester) were mixed with inherently flame retardant fibres (modacrylic and Lenzing FR) pairwise at fibre level for non-woven fabric and both fibre &amp; yarn level for knitted fabric. The vertical flame test, where the fabric hung vertically and burned from the bottom, was used to characterise their burning behaviour. With the vertical flame test, it was found that flame shielding ability of inherently flame retardant fibres towards flammable fibres improves with an increasing proportion of inherently flame retardant fibres in the fabric. Also, fabric structure influences the shielding properties of the flame retardant fibres. A comparison between fibre and yarn level mixing for knitted fabric yarn level mixing was found to have better flame shielding properties. Thesis work points out the issue with flame retardant chemical and presents an alternative approach for conventional flame retardant.
16

Vliv změny požárně technických charakteristik na požárně bezpečnostní řešení stavby penzionu / Effect of changes of fire technical characteristics of fire safety solution of building for the accomodation

Mžik, Libor January 2013 (has links)
The content of this thesis is to find out how the changes of fire technical characteristics could affect the fire safety solution of building for the accommodation. The method to work out fire safety solution is used on the stated object. This method is described in the beginning of the text. There are designed the further objects, based on the basic object, on which they are made to fire technical changes that lead to different results. For the type of change is primarily considered to substitute non-flammable structural system for flammable structural system and one floor extension. These changes are the result of increases levels of fire safety and extension of the fire danger zone. The conclusion of this work is a preview of the differences in fire safety solution of the building for accommodation and the office building.
17

Determinação da extensão de áreas classificadas para liberações bifásicas.

ANJOS, Deborah Almeida dos. 18 October 2018 (has links)
Submitted by Maria Medeiros (maria.dilva1@ufcg.edu.br) on 2018-10-18T11:49:34Z No. of bitstreams: 1 DEBORAH ALMEIDA DOS ANJOS - DISSERTAÇÃO (PPGEQ) 2017.pdf: 3469250 bytes, checksum: 3edf8a20f21e939dbbc3493542611649 (MD5) / Made available in DSpace on 2018-10-18T11:49:34Z (GMT). No. of bitstreams: 1 DEBORAH ALMEIDA DOS ANJOS - DISSERTAÇÃO (PPGEQ) 2017.pdf: 3469250 bytes, checksum: 3edf8a20f21e939dbbc3493542611649 (MD5) Previous issue date: 2017-03-24 / Muitos acidentes envolvem lançamentos bifásicos de produtos químicos perigosos para a atmosfera, sendo eles muitas vezes armazenados e transportados na forma de gases liquefeitos sob a sua pressão saturada. Nestes casos, ao entrar em contato com o ambiente, o produto liberado irá se dispersar como um jato de vapor com pequenas gotículas, as quais evaporam provocando alterações na temperatura e composição do gás circundante. As gotículas maiores podem cair sobre o solo (rainout) formando uma poça que irá espalhar-se e evaporar. Gotas menores que um tamanho crítico permanecerão no jato e serão evaporadas devido ao ar arrastado. Nesse sentido, tendo em vista que a estimativa do comportamento do material liberado é necessária para a avaliação do perigo, este trabalho tem como objetivo determinar a extensão da área classificada para liberações bifásicas, utilizando como estudo de caso situações de vazamento com gás liquefeito de butano, em seu estado saturado à temperatura ambiente, e propano armazenado à 321 K e 20,64 bar. Utilizou-se o modelo proposto por Long para jato turbulento subsônico e o modelo para jato bifásico apresentado em Kukkonen para prever esta extensão. A partir da análise dos resultados observou-se para o propano como componente da liberação, um resultado satisfatório quando comparado ao obtido em CFD, apresentando ambos aproximadamente 1,3 m de extensão. A extensão para a situação de vazamento do butano apresentou um valor conservativo (86 m), tendo em vista que o orifício de vazamento possui um diâmetro considerável. Estes resultados são importantes uma vez que podem auxiliar em situações semelhantes na classificação de áreas. Tendo em vista que não há na literatura dados de extensão, este trabalho possui uma inovação prática podendo servir como base para normatização do cálculo de extensão de áreas classificadas para liberações bifásicas. / Many accidents involve biphasic release of hazardous chemicals into the atmosphere; they are often stored and transported in the form of liquefied gas under its saturated pressure. In these cases, in the contact with the environment, the released product will disperse as a steam jet with small droplets, which evaporate causing changes in temperature and composition of the surrounding gas. The larger droplets may fall on the ground (rainout) forming a pool that will spread and evaporate. Droplets smaller than a critical size will remain on the jet and will be evaporated due to entrained air. In this case, in view of estimate of the behavior of the released material is useful for a hazard assessment, this work aims to determine the extent of the classified area for biphasic releases, using as case studies liquefied gas leakage of butane, in its Saturated state at ambient temperature, and propane at 321 K and 20,64 bar. Used the model proposed by Long for turbulent subsonic jet and model for two-phase jet in Kukkonen to predict this extension. From the analysis of the results it was observed for propane as a release component, a satisfactory result when compared to the one obtained in CFD, presenting approximately 1.3 m extension. The extent to the leakage situation of the butane presented a conservative value (86 m), considering that the pouring hole has a considerable diameter. These results are important since they may help in similar situations in the classification of areas. In view of the lack of extension data available in the literature, this work has a practical innovation and can serve as a basis for standardization of the calculation of extension of classified areas for biphasic releases.
18

Experimental Investigation into Combustion Torch Jet Ignition of Methane-Air, Ethylene-Air, and Propane-Air Mixtures

Perera, Ukwatte Lokuliyanage Indika Upendra 12 1900 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Ignitability and the ignition delay time of a combustible mixture in a long combustion chamber, ignited by a hot combustion torch jet generated in a pre-chamber was investigated experimentally in relation to application as a viable igniter method for wave rotor combustors. Methane-air, ethylene-air, and propane-air in varying equivalence ratios were investigated as the combustible mixture in the combustion chamber. The effects of variation in the torch jet fuel, initial equivalence ratio in the pre-chamber, and nozzle geometry on the ignitability and the ignition delay time of combustible mixtures were observed and analyzed. The single-channel wave-rotor combustion rig at Combustion and Propulsion Research Laboratory at the Purdue School of Engineering and Technology at Indiana University-Purdue University, Indianapolis was used for this study. High-speed video imaging techniques to observe the ignition and flame propagation in the combustion chamber and fast-response pressure transducers to measure the dynamic pressure fluctuations in the combustion chambers were used in the current study. The present work explains how the experimental procedure and preliminary testing was carried out in order to conduct the necessary testing to find the ignitability and ignition delay time of a combustible mixture. Ignitability of methane, ethylene, and propane were much broader in range compared to conventional spark ignitable lean and rich limit equivalence ratios. The methane and propane ignition lean limits were similar to radical activated ignition lean limits found in previous studies of the same fuels. Ethylene exhibited the widest range in equivalence ratios from 0.4 to 2.4, while methane had the narrowest ranging from equivalence ratio 0.4 to 1.4. The ignition delay studies indicated both chemical kinetics and mixing between the combustion torch jet and the combustible mixture were critical. The mixing phenomena dominated chemical kinetics; unlike in ignition delay studies conducted using shock heated ignition techniques. Ethylene-air mixtures had the shortest ignition delay times ~1 ms for lean but near-stoichiometric mixtures. Methane and propane indicated similar ignition delay time characteristics with lean near-stoichiometric mixtures. The fuel-air equivalence ratio which was used to generate the combustion torch jet and the torch jet nozzle geometry had a direct influence over the ignition delay time in the main chamber combustible mixture. The slightly rich fuel-air ratios used to generate the combustion torch jet had the lowest delay times in igniting the main chamber fuel-air mixtures.
19

THE DEVELOPMENT OF CHEMI-SELECTIVE SENSORS TO DETECT VOLATILE ORGANIC COMPOUNDS AND FLAMMABLE REFRIGERANTS

Nikhil Felix Carneiro (12879038) 16 June 2022 (has links)
<p> </p> <p>Gas sensors have many applications. Volatile organic compound (VOC) sensors are used for monitoring air quality in homes and office spaces, as well as monitoring manufacturing environments where a wide variety of VOCs can be produced. These gases can include formaldehyde, which can be toxic to humans at concentrations as low as 1 ppm. Other applications for gas sensors include flammable refrigerant detection. With the move towards developing more environmentally friendly appliances, many companies have started to use refrigerants such as R600a (isobutane) and R32 (difluoromethane), which have a much lower global warming potential (GWP) than their predecessors, such as R134a and R410a. While this move is beneficial for the environment, steps to ensure their safe usage have not been widely implemented to date. Therefore, sensors to detect VOCs at or below exposure limits, as well as flammable refrigerants at or below lower flammability limits (LFL), should be developed to ensure undue hazards are identified and mitigated. </p>
20

Posouzení bezpečnosti čerpací stanice pohonných hmot / Safety Study of Refuelling Station

Šimková, Markéta January 2008 (has links)
Safety study of refuelling station. Diploma thesis, Institute of Metrology and Quality Assurance Testing, Brno University of Technology. This Diploma thesis deal with quantitative risk assessment of exposure. It means for population, animals and environment stocking, transport and manipulation with vairous fuel at refuelling station in particular area and influence of other industrial effects in close area of this refuelling station. There is more specified a Method of Dow´s fire and explosion Index, method of Guidelines for Quantitative Risk Assessment and method FMEA (Failure Mode and Effect Analysis).

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