Dissertations / Theses: 'Phage safety'

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Pereira, Carla Sofia Gomes. "Phage therapy: a new technology for depuration of bivalves." Doctoral thesis, Universidade de Aveiro, 2016. http://hdl.handle.net/10773/18602.

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Doutoramento em Biologia
De forma a reduzir a transmissão de agentes patogénicos através do consumo de bivalves, devem ser desenvolvidas novas tecnologias a associar à depuração, tal como a terapia fágica. A eficácia da utilização de fagos para controlar infeções bacterianas tem sido relatada em diversos estudos. No entanto, relativamente à utilização da terapia fágica para inativar bactérias patogénicas durante a depuração de bivalves, existe apenas um estudo preliminar, feito sem circulação de água (contrariamente ao que acontece na depuração industrial). O sucesso da combinação destas duas tecnologias depende da compreensão detalhada da dinâmica sazonal e espacial da comunidade bacteriana total, incluindo bactérias associadas a doenças devido ao consumo de bivalves e indicadores de qualidade microbiológica da água, nas zonas de produção de bivalves. Durante o Verão, a comunidade bacteriana total apresentou uma maior complexidade e aumento da abundância dos principais grupos de bactérias patogénicas, indicando que deste pode ser um período crítico onde a terapia fágica deve ser aplicada. No entanto, devido ao impacto das fontes de poluição antropogénicas e outras fontes de contaminação, a terapia fágica poderá ter que ser aplicada também durante a estação fria. Cinco novos fagos foram isolados e caracterizados para controlar Salmonella Typhimurium (phSE-1, phSE-2 e phSE-5) e Escherichia coli (phT4A e EC2A), a fim de avaliar a sua potencial aplicação durante a depuração de bivalves. Os ensaios in vitro demonstraram que o uso de fagos individuais (phT4A e EC2A), pode ser uma alternativa eficaz para o controlo de E. coli, em particular, quando combinados em cocktail. A depuração num sistema estático com MOI 1 usando os fagos phT4A e EC2A, foi a condição em que se obteve melhores resultados (diminuição ~2.0 log CFU/g) em berbigões artificialmente contaminados. Quando berbigões naturalmente contaminados foram tratados em sistema estático com as suspensões de fagos individuais e cocktails de fagos, foram obtidas reduções semelhantes na concentração de E. coli (diminuição ~0.7 log UFC/g). Quando os berbigões naturalmente contaminados foram depurados com o fago phT4A com circulação de água, a concentração de bactéria foi reduzida mais rapidamente que na ausência de fagos. Os resultados dos ensaios in vitro mostraram igualmente que o controlo de S. Typhimurium com fagos phSE-5 e phSE-2 e o cocktail destes dois fagos foi eficiente. A aplicação do fago phSE-5 e cocktail (phSE-2/phSE-5) inativou eficazmente S. Typhimurium em berbigões contaminados artificialmente (redução de 1.7 UFC/g com o fago phSE-5 e 0.7 log UFC/g com o cocktail phSE-2/phSE-5) e em berbigões naturalmente contaminados (redução de 0.9 log UFC/g para ambos para a suspensão simples e para o cocktail) durante a depuração em sistema estático, especialmente quando são usadas suspensões do fago phSE-5 a uma MOI baixa. Os berbigões artificialmente contaminados também foram mais eficazmente descontaminados durante a depuração com circulação de água na presença do fago phSE-5 que quando foi usada apenas depuração sem adição de fagos (i.e. o processo convencional de depuração). Este é o primeiro trabalho em que foi testado o uso de fagos durante a depuração de berbigões naturalmente contaminados e contaminados artificialmente em sistemas com circulação de água, tal como acontece na depuração industrial de bivalves, provando assim que esta tecnologia poderá ser transposta para a indústria. Os resultados obtidos usando fagos de E. coli e de S. Typhimurium mostraram que a combinação da terapia fágica e depuração melhora a segurança microbiana dos bivalves para consumo humano, melhorando a eficiência de descontaminação. Além disso, esta abordagem também permite reduzir o tempo necessário para a depuração e consequentemente, os custos a ela associados. No entanto, a seleção e caracterização dos fagos e determinação da MOI mais adequado para ser utilizado durante a terapia fágica, é essencial para o sucesso da terapia fágica no controlo de bactérias patogénicas.
In order to reduce the infections by microbial pathogens through the consumption of bivalves, it is essential to develop alternative approaches to the conventional depuration practices. One new promising approaches is to combine the depuration of bivalves with phage therapy. The use of phages to control bacterial infections has been reported across numerous fields by many researchers. However, relatively the combination of depuration and phage therapy to eliminate pathogenic bacteria in bivalves there is only one study, and this study did not replicate industrial depuration procedures. The successful combination of those two technologies depends on a detailed understanding of the seasonal and spatial dynamics of the overall bacterial communities, including the bacteria implicated in bivalves-related illness and the indicators of microbiological water quality, in the harvesting areas. During the summer, the total bacterial community presented high complexity and an increase of abundance of the main pathogenic bacteria, indicating that this season is the critical time frame when phage therapy should be applied. However, due to the impact anthropogenic and other sources of contamination, phage therapy could be necessary also during the cold season. Five new phages were isolated and characterized to control Escherichia coli (phT4A and ECA2) and Salmonella Typhimurium (phSE-1, phSE-2 and phSE- 5) in order to evaluate their potential application during depuration. The in vitro assays indicated that the use of phages individually (phT4A and EC2A) or combined in cocktails (phT4A/EC2A), can be an effective alternative to control of E. coli, particularly if combined in a phage cocktail. Depuration in static seawater at MOI 1 with phage phT4A and ECA2 revealed to be the best condition (decreased of the 2.0 log CFU/g) in artificially contaminated cockles. When naturally contaminated cockles were treated in static seawater with single phage suspensions and the phage cocktail, similar decreases in the concentration of E. coli (decreased of the 0.7 log CFU/g) were achieved. When naturally contaminated cockles were depurated using conventional practices with phage phT4A, bacterial concentration was reduced sooner. The assays in vitro, demonstrated that the control S. Typhimurium with phages phSE-5 and phSE-2 and with these two phages combined in a cocktail was efficient, paving way for the in vivo studies. The efficiency of bacterial inactivation with single phage suspensions of phSE-5 and phSE-2 leaded to further in vivo studies to control of Salmonella in bivalves. The application of phage phSE-5 and phage cocktail phSE-2/phSE-5 can be successfully employed to inactivate S. Typhimurium (reduction of 1.7 log CFU/g for phSE-5 and 0.7 log CFU/g for phSE-2/phSE-5 in artificially contaminated cockles and reduction of 0.9 log CFU/g for both in naturally contaminated cockles) during depuration in static system, especially if phSE-5 phage is used individually and if a low MOI is employed. Using conventional depuration practices in the presence of phage phSE-5, bacterial concentration is more quickly and efficiently reduced in artificially contaminated cockles. To our knowledge, this is the first report of a depuration trial using phages in the artificially and naturally contaminated cockles using industrial depuration procedures, proving that this technology can be ported into the bivalves industry. The obtained results using phages of E. coli and S. Typhimurium indicated that combining phage therapy with depuration procedures enhance bivalve microbial safety for human consumption by improving decontamination efficiency. Moreover, this approach also displays the advantage of reducing the time required for depuration and consequently its associated costs. However, the selection and characterization of appropriate phages and the most adequate multiplicity of infection to be used in phage therapy is a critical stage to achieve a successful phage-mediated control of pathogenic bacteria.

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Rodrigues, Fernando Vieira. "Seleção de peptídeos ligantes a Staphylococcus aureus: obtenção de novas ferramentas diagnósticas de contaminações alimentares." Universidade Federal de Uberlândia, 2013. https://repositorio.ufu.br/handle/123456789/12389.

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Fundação de Amparo a Pesquisa do Estado de Minas Gerais
Consumption of food contaminated with strains of Staphylococcus aureus can cause diseases, whose signs and symptoms include gastroenteritis, nausea, vomiting, diarrhea, abdominal pain within one to six hours post-consumption of contaminated food. In this way, rapid methods of detection and identification of S. aureus are essential for food quality control and food safety. At this study, objectived to select peptide that binds to S.aureus, through the technique of Phage Display (PD), for development of fast diagnostic tools, of easy handling and low cost. At this study was used bioppaning for selection of peptides that express on the surface filamentous phage peptides that binds to S. aureus. The phage DNA selected was sequenced and subjected to in silico analysis (BioEdit v7.0.9). The sequences obtained were aligned and clones underwent pre-screening (ELISA) for the evaluation of binding specificity to S. aureus. The titles of input and output in biopanning were constant. Nine valid sequences were obtained after sequencing 40 clones selected after 3 rounds of biopanning. The analysis demonstrated that four clones presented reactivity in bacteria, although tests have demonstrated that the peptides exhibited no specific binding capacity in Staphylococcus aureus. Nevertheless, the peptide H06 showed binding specificity in gram-positive bacteria used in the test of reactivity. Furthermore, the in silico analysis showed that the recombinant peptides share chemical characteristics essential the proteins of the bacterial cells. Although the S. aureus specificity had not been observed, the peptide can be used as a method of detecting contamination of food in gram-positive bacteria. In food contamination, fast screening and identification of bacterial groups, allows establish decisions about the marketing and distribution of foods and may prevent outbreaks of food intoxication and ensure food security.
O consumo de alimentos contaminados com cepas de Staphylococcus aureus pode causar doenças, cujos sinais incluem gastroenterites, náuseas, vômitos, diarreia, dor abdominal intensa dentro de uma a seis horas após o consumo do alimento contaminado. Por esta razão, métodos rápidos de detecção de S.aureus são essenciais para o controle da qualidade e da garantia da segurança alimentar. Assim, o presente estudo teve por objetivo selecionar peptídeos ligantes à S.aureus, por meio da técnica de Phage Display (PD), para desenvolvimento de ferramentas diagnósticas rápidas, de fácil manipulação e baixo custo. Neste estudo, foi realizado bioppaning para seleção de peptídeos expressos na superfície de fagos filamentosos que apresentassem peptídeos ligantes a S.aureus. O DNA dos fagos selecionados foi sequenciado e submetido a analise in silico(BioEdit v7.0.9). As sequências obtidas foram alinhadas e os clones foram submetidos à pre-screening (ELISA) para avaliação de especificidade de ligação à S. aureus. Os títulos de entrada e saída obtidos no biopanning foram constantes. Nove sequências válidas foram obtidas após o sequenciamento dos 40 clones selecionados após 3 ciclos de biopanning. A análise de reatividade demonstrou que quatro clones apresentaram reatividade à bactéria, embora os testes de especificidade demonstraram que os peptídeos não exibiram capacidade de ligação específica a S. aureus. Apesar disto, o peptídeo E06 mostrou especificidade de ligação a bactérias do gênero Staphylococcus usadas no teste de reatividade. Além disso, as análises in sílico revelaram que os peptídeos recombinantes compartilham características químicas essenciais a proteínas das bactérias. Embora a especificidade a S.aureus não tenha sido observada, neste estudo o peptídeo pode ser utilizado como um método de detecção a contaminação de alimentos por estafilococos. Nas contaminações de alimentos, a triagem rápida e métodos de identificação de grupos bacterianos permitem estabelecer decisões sobre a comercialização e distribuição e podem prevenir um surto de intoxicação, garantindo a segurança alimentar.
Mestre em Biologia Celular e Estrutural Aplicadas

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Skarpheđinsson, Hjalmar. "Novel oxidatively activated safety catch linkers." Thesis, University of Oxford, 2005. http://ora.ox.ac.uk/objects/uuid:68179292-c0b4-438c-9c25-d60bfcce907f.

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Solid phase organic synthesis is a powerful technique to facilitate rapid synthesis and easy purification of organic compounds. The advancement of linkers and cleavage strategies is of paramount importance for the success of this approach. This thesis is concerned with the development of a robust safety catch linker system aimed to allow a broad range of commonly used reagents to be employed in a synthetic sequence carried out on a solid support. Chapter 1 outlines the principles of solid phase organic synthesis, the terminology associated with this approach and the advantages and disadvantages compared to conventional solution phase methods. Common attachment and release strategies for various functional groups are described and the safety catch principle is introduced. Chapter 2 discusses the design features of the linker system. Proof of principle is demonstrated for the attachment and release strategies with a simple solution phase model system. Chapter 3 describes the adaptation of the linker system to the solid phase. Key transformations are modelled with solution phase experiments and subsequently applied to solid phase. The loading determination of the solid phase system is also described. Chapter 4 reports an assessment of the reactivity of the linker system in the coupling transformation of aliphatic alcohols and amines. The chemoselectivity and efficiency of the CAN debenzylation/cyclorelease protocol is also evaluated. Chapter 5 demonstrates the utility of the linker system with the optimisation of a simple synthetic sequence in solution followed by adaptation to the solid phase. The synthesis of a pilot library of aryl alcohols utilizing a Suzuki coupling on solid support is described. The attachment and release of amines is also demonstrated with solid phase examples. Chapter 6 examines the potential of the linker system as an analytical tool to assess the outcome of stereoselective transformations. A chiral auxiliary is attached to the solid phase by aid of the safety catch linker and released into solution. A solution phase model system is developed to aid preliminary investigations in solution prior to adaptation to the solid phase.

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Pettitt, Glenn Nigel. "Characterisation of two phase releases." Thesis, London South Bank University, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.303967.

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Kenyon, Yvonne Michelle. "Two-phase flows accompanying fires in enclosures." Thesis, University of Central Lancashire, 2003. http://clok.uclan.ac.uk/19138/.

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The dispersed phase that accompanies enclosure fires, for example, soot, ash, sprinkler droplets and extinguishing powder, could exert a significant influence on the dynamics of the background fluid. In this thesis, the results of a numerical study into the effects of this dispersed phase on the flow in a fire compartment are presented. A two-dimensional computational fluid dynamics solver, with appropriate approximations for low Mach number flows and mathematical sub-models for twophase flows, has been developed in order to simulate fire induced convective motions in planar compartments. The description of the dispersed particulate is based on a twocontinuum approach, whereby the dispersed phase and the gaseous phase are assumed to be two mutually interacting and penetrating continua. In this thesis, two 'passive' models and an 'active' model of the dispersed phase are considered. In the passive models the particulate acts as a tracer only and has no hydrodynamical influence on the gas phase. The second passive model differs from the first in that the production of gases in the fire compartment, for example arising from combustion or propellant gases due to extinguishment of the fire, is taken into account. This second passive model more accurately predicts the growth of pressure in a sealed fire compartment for weak fires. As the volume fraction of the particulate increases the spatial-temporal hydrodynamic influence exerted on the gaseous flow by the dispersed phase becomes significant and, under certain conditions, a passive representation is insufficient. An active onetemperature and one-velocity model is proposed which is appropriate for the description of a hydrodynamically active particulate with an instantaneous velocity and thermal relaxation time. In this thesis, computational fluid dynamics is used as a tool in order to characterise the applicability of the passive models and the active model. The ability of the passive models to accurately predict the growth of pressure in a compartment for 'surface' fires, for example smouldering combustion and weak fires, is investigated. The active model is used to study the hydrodynamics of powder extinguishing media in a compartment with an open doorway.

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Russell, Helen Elizabeth. "Novel thermally cleavable safety-catch linkers for combinatorial chemistry." Thesis, University of Southampton, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.313129.

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Corneliussen, Kjell. "Well Safety. Risk Control in the Operational Phase of Offshore Wells." Doctoral thesis, Norwegian University of Science and Technology, Norwegian University of Science and Technology, 2006. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-1876.

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The main objective of this thesis has been the development of procedures and methods for risk assessment of oil and gas wells. The work is limited to the well operational phase. The procedures and methods provide status of the well risk level during the life cycle from installation to abandonment of the well. The main focus is on the two main safety functions of the well:

a. To prevent uncontrolled leakage of well fluids from the well to the environment. This function is usually referred to as well integrity and is a continuous safety function that may fail at any instant of time.

b. To shut in the well flow in case of a dangerous incident on the downstream side of the x-mas tree. The shut-in function is an on demand function activated in a random critical situation.

In this context a systematic approach means to describe a procedure for risk assessment, with focus on quantitative/predictive analysis as a means to provide input to the assessment. The risk assessment is based on existing and new methods and knowledge gained during the PhD work.

The following contributions from the thesis are identified:

• A systematic approach for well risk assessment in the operational phase. A set of WRFs are identified that influence the total well risk. The procedure is primarily aimed at risk assessment in the operational phase after a well component failure has occurred.

• A method for constructing barrier diagrams. A barrier diagram is a structured way of describing a well as a barrier system. In the thesis it is shown how to calculate failure probability directly from the barrier diagram. Alternatively, the barrier diagram construction rules allows for converting the barrier diagram to a fault tree.

• A framework for assessing well component failure causes, acceptable deviations in well component performance, and dependent failures.

• A method for calculating the safety unavailability of safety functions, and a method for calculating the safety unavailability for different configurations of surface controlled subsurface safety valves.

Paper II reprinted with kind permission of Elsevier, sciencedirect.com

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Li, Qing. "Interim monitoring efficacy, safety and futility in phase III clinical trials." Thesis, Birmingham, Ala. : University of Alabama at Birmingham, 2008. https://www.mhsl.uab.edu/dt/2008p/li.pdf.

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Mandali, Sridhar. "Site-specific recombination of P2-like phages; possible tools for safe gene therapy : A focus on phage ΦD145." Doctoral thesis, Stockholms universitet, Institutionen för genetik, mikrobiologi och toxikologi, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-45940.

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P2-like bacteriophages integrate their genome into the E. coli host cell by a site-specific recombination event upon lysogenization. The integrative recombination occurs between a specific sequence in the phage genome, attP, and a specific sequence in the host genome, attB, generating the host-phage junctions attL and attR. The integration is mediated by the phage enzyme integrase (Int) and the host factor IHF. The excisive recombination takes place between attL and attR, and is mediated by Int, IHF and phage encoded protein Cox. For safe integration of foreign genes into eukaryotic chromosome a recombinases is necessary which can perform the integration site-specifically. P2-like phage integrases have the potential to become tools for safe gene therapy. Their target is simple but specific, and once integration has occurred it is very stable in the absence of the Cox protein. The site-specific recombination mechanism has to be understood at the molecular level. Therefore, I have initiated the characterization of the site-specific recombination system of the P2-like phage ΦD145. In this work, Int and IHF are shown to bind to the different attachment sites cooperatively. One of two possible inverted repeats in attP is shown to be the Int core recognition site. The attP core of this phage has high identity with a site on human chromosome, denoted as ΨattB. In this study we have shown that in in vivo recombination ΦD145 Int can accept ΨattB in both bacteria and in eukaryotic cells. Also shown that Int consists of an intrinsic nuclear localization signal. A study also reveled that ΦD145 Int activity was affected by the Tyr-phosphorylation. Attempts have been made to change the specificity of the other P2-like phage P2 and WΦ integrases and also structural and functional analysis was done. A study on comparative analysis of Cox proteins and Cox binding sites gave us the basic information about the recombination mechanism.
At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 2: Manuscript. Paper 3: Manuscript.

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Bettis, R. J. "Two phase releases following rapid vessel failure." Thesis, London South Bank University, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.376541.

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McCurdy, Robert J. "The use of vapor phase ultraviolet spectroscopy to characterize flammable liquids recovered from fire debris." Thesis, University of Strathclyde, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.249051.

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Gattoc, Leda, Paula M. Frew, Shontell N. Thomas, Kirk A. Easley, Laura Ward, H.-H. Sherry Chow, Chiemi A. Ura, and Lisa Flowers. "Phase I dose-escalation trial of intravaginal curcumin in women for cervical dysplasia." DOVE MEDICAL PRESS LTD, 2016. http://hdl.handle.net/10150/622729.

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Background: This is a Phase I trial demonstrating safety and tolerability of intravaginal curcumin for future use in women with cervical neoplasia. Objective: The objective of this study was to assess the safety, tolerability, and pharmacokinetics of intravaginal curcumin in healthy women. Study design: We conducted a 3+3 dose-escalation Phase I trial in a group of women aged 18-45 years. Thirteen subjects were given one of four doses of curcumin powder (500 mg, 1,000 mg, 1,500 mg, and 2,000 mg) packed in gelatin capsules, which was administered intra-vaginally daily for 14 days. The primary end point for this study was safety based on severe adverse events regarding laboratory toxicity, clinical findings, and colposcopic abnormalities. We administered an acceptability questionnaire to assess product experience and attributes. Results: No dose-limiting toxicities (0/13) were experienced (95% confidence interval: 0.0%-22.8%) in this study. The pharmacokinetics data demonstrated that curcumin and curcumin conjugates were not measurable in the serum and negligible in the urine of the study participants. Although 23 adverse events occurred during the course of the trial, all events were grade I based on the National Cancer Institute Common Terminology Criteria for Adverse Events Version 4.0 and were resolved by the end of the study in an average of 9 days. Fifty-six percent of the adverse events were related to the study drug, which included genital pruritus (23% of subjects), vaginal discharge (100%), vaginal dryness (15%), abnormal prothrombin (23%), and hypokalemia (8%). Conclusion: Intravaginal curcumin was well tolerated by all subjects and safe. In this Phase I trial, there were no severe adverse events observed at any of the administered dose levels. All adverse events were grade I and did not result in early termination of the study. There was no evidence of systemic absorption or significant local absorption of intravaginally administered curcumin.

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Md-Ulang, Norhidayah. "Communication of construction health and safety information in design." Thesis, Loughborough University, 2012. https://dspace.lboro.ac.uk/2134/9817.

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Occupational health and safety (H&S) is important to the design, construction, maintenance, refurbishment and demolition of buildings and facilities in all branches of industry, business and commerce. H&S issues have been a major consideration in construction. Far too many people get hurt, injured or die even though the situation has improved over recent years. Accident and fatality rates continue to be significantly higher than other industry sectors. Although all parties involved in the construction industry may address their respective responsibilities, the lack of integration between each organization often results in communication problems which jeopardize H&S. Of particular note is the communication during the design phase. All information pertaining to the project must be readily accessible for all parties, to ensure smooth and hitch-free project execution. This research reviews the challenges in the communication of health and safety information in the design phase of construction projects. It characterizes the various aspects of collaborative communications at this stage and highlights the problem area. The research was conducted in the UK based on a combination of qualitative research methods including literature review, interviews and analysis of focus group interviews data. Observations on documentation and interviews are used to investigate the current industry practice. The literature reviews revealed that communication industry is facing challenges with its communication system due to the nature of industry itself. The construction industry is a fragmented and complex industry with too many parties involved in a project. These parties come from various backgrounds and involved in the project in a temporary duration. The parties who become team members must be able to establish a relationship in such a short period of time and create a communication system that enables all of the parties to collaborate and interact with each other.

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Hare, John Andrew. "The venting of a runaway esterification reaction on both the laboratory and pilot scales." Thesis, London South Bank University, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.245039.

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Pinho, Jorge. "Experimental investigation of cavitation in a safety relief valve using water: extension to cryogenic fluids." Doctoral thesis, Universite Libre de Bruxelles, 2015. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/209095.

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This thesis addresses the experimental investigation of the cavitation phenomenon and its main consequences on the normal operation of a safety relief valve (SRV). More particularly, limitation of the mass flux discharged and alteration of the hydraulic fluid forces behavior is of main interest for the proper design and sizing of such devices. In nuclear or thermal engineering systems, the use of SRVs is mandatory since it represents the ultimate protection device before an accident occurs, caused by a sudden pressurization of the system. A careful design and sizing of the SRV is therefore essential. The complete understanding of the physics taking place in the flow through the valve is required to guaranty and optimize the security of the protected process.

In order to investigate the above effects of cavitation in a SRV, two different orifice sized valves (API 2J3 type and a transparent model based on an API 1 1/2G3 type) are tested in two different experimental facilities expressly built for this purpose. Instead of using a spring, the design of both valves allows the adjustment of the disc at any desired lift. Hence the static behavior of the valves is investigated. Both facilities, operating at different magnitude scales, allow the study of single phase and cavitating flow conditions required to properly determine the most important hydraulic characteristics, and access on any potential scaling effect between both sized SRVs. Experimental techniques used for the determination of the hydraulic characteristics include temperature, flow rate, fluid forces and pressure measurements both upstream and downstream the test sections.

Results show a similar influence of cavitation on the flow characteristics of both valves, minimizing any potential scaling effect. The liquid pressure recovery factor FL, which is normally used to identify a choked flow condition in a control valve, is experimentally determined for the first time in a SRV. The existence of a local minimum located at small openings of the lift indicates a change on the flow characteristics of both valves, which is related to the location of the minimum cross section of the flow that does not remain constant for every lift position. An extended experimental campaign is performed to analyse the effect of the blowdown ring adjustment located around the nozzle of the API 2J3 valve. Results confirm that the position of the ring has an important contribution for the hydraulic forces acting on the valve disc.

In the second part of the research, precise optical diagnostic techniques are successfully applied in the transparent valve to locally characterize the flow topology in a SRV experiencing cavitation. These results are innovative and enrich the experimental database available in the literature for the characterization and understanding of the flow physics in such devices. In a first configuration, high speed visualization is applied to observe qualitatively the flow pattern and the inception of liquid vaporization. Particle tracking results suggest that vapor bubbles are formed in the core of vortices detached from the shear layers attached to the valve. These rotational structures promote lower pressure regions allowing the liquid to vaporize. In the second configuration, particle image velocimetry is applied to extract the velocity field in both single phase and cavitating flow conditions. Results of PIV confirm the existence of a submerged jet just downstream the minimum section. This jet is characterized by two non-symmetric shear layers at its sides. Under cavitation conditions, PIV results confirm that vapor bubbles are formed preferentially inside the jet shear layers. The phenomenon of mass flux limitation caused by cavitation is reproduced at small openings of the valve and interaction with the flow topology is highlighted. It is observed that limitation of the flow occurs when the vena contracta is shifted towards the minimum geometrical section of the flow. Finally, instabilities of the flow downstream the critical section are investigated in the frequency domain by means of time resolved data. Results suggest that vortex shedding mechanism is dominated by a constant Strouhal number which is slightly affected by the valve opening.

In the last part of the research, the methodology used in water is extended and applied to cryogenic liquids. Two different geometries are investigated experimentally and numerically using water and liquid nitrogen as working fluids. Results suggest that both the flow coefficient (determined at single flow conditions), and the liquid recovery factor (used to identify choked flows), are independent on the fluid properties and therefore, an hydraulic similarity relation can be proposed.

This research project was carried out at the von Karman Institute for Fluid Dynamics (VKI), in Belgium, in close collaboration and with the funding of Centre Technique des Industries Mécaniques (CETIM) in France.
Doctorat en Sciences de l'ingénieur
info:eu-repo/semantics/nonPublished

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Rowland, Rosalind. "Evaluation of the safety and immunogenicity of candidate tuberculosis vaccines through Phase I Clinical Trials." Thesis, University of Southampton, 2014. https://eprints.soton.ac.uk/374738/.

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Vander, Giessen Steven Thomas. "Evaluation of an active wildlife-sensing driver warning system at Trapper's Point, Wyoming phase I /." Laramie, Wyo. : University of Wyoming, 2007. http://proquest.umi.com/pqdweb?did=1402175051&sid=1&Fmt=2&clientId=18949&RQT=309&VName=PQD.

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Zippe, Winfried, Jochen Zschau, Vladimir Valentinovich Kontelev, Vladimir Ivanovitsch Melnikov, Andrej Duncev, Robert Zboray, Leonid Karlovitsch Stoppel, Valery Nikolajevich Chochlov, Horst-Michael Prasser, and Vadim Vladimirovich Ivanov. "Local and integral ultrasonic gauges for two-phase flow instrumentation in nuclear reactor and safety technology." Forschungszentrum Dresden, 2010. http://nbn-resolving.de/urn:nbn:de:bsz:d120-qucosa-29896.

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Das vorliegende Projekt wurde im Rahmen einer Kooperationsvereinbarung zwischen dem Forschungszentrum Rossendorf (FZR) und der wissenschaftlichen Gruppe von Prof. Melnikon von der Technischen Universität Nishny Novgorod (TUNN) der Russischen Föderation durchgeführt. Es ist Teil des Wissenschaftsunterstützungsprogramms / FSU der Bundesregierung im Rahmen der Beratungshilfe für den Aufbau von Demokratie und sozialer Marktwirtschaft (TRANSFORM). Neue Methoden der Instrumentierung für Zweiphasenströmungen wurden entwickelt: Ultraschall-Wellenleitersonden können zur lokalen Gas- bzw. Dampfgehaltsmessung eingesetzt werden. Der neue Ultraschall-Gittersensor erlaubt eine Visualisierung der Zweiphasenströmung mit ca. 250 Bildern/Sekunde. Sowohl die lokalen Sonden als auch der Ultraschall-Gittersensor können erfolgreich unter den Bedingungen von Wasser-Dampf-Gemisch bei hohem Druck und hoher Temperatur, sowie in anderen Fluiden, wie organischen Flüssigkeiten und Kältemitteln, eingesetzt werden. Darüber hinaus wurden berührungslos arbeitende Wellenleitersonden für die Durchschallung von Rohrleitungen und Dichtesensoren, die auf der Messung der Ausbreitungsgeschwindigkeit von Ultraschall in Wellenleitern beruhen, die sich im Messmedium befinden, entwickelt und getestet. Bei dem gegenwärtigen Stand der Entwicklung können die berührungslosen Sensoren lediglich als qualitativer Nachweis von Gas in einer Flüssigkeitsströmung dienen. Die Funktion der Dichtesensoren wurde anhand von Messungen in verschiedenen einphasigen Flüssigkeiten unterschiedlicher Dichte demonstriert. Für einen praktischen Einsatz ist die weitere Verbesserung der elektronischen Signalerfassung erforderlich. Die hauptsächliche Innovation wird durch den Ultraschall-Gittersensor verkörpert, dessen Auflösung mit der von schnellen elektrischen Gittersensoren und ultraschnellen Röntgentomographen vergleichbar ist, während das Gerät selbst sehr robust und preiswert ist.

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Catchpole, Roger. "Establishing cost-effective safety management for major oil and gas exploitation projects in the design phase." Thesis, Open University, 2012. http://oro.open.ac.uk/54513/.

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Disasters such as Deepwater Horizon in the Gulf of Mexico, in April 2010, continue to blight the oil and gas industry despite a significant amount of research effort carried out by academia, regulatory bodies, and oil and gas companies to understand how safety-related incidents, especially disasters, can be prevented. While these have contributed to the discussion around reducing risk, they often lack the systemic influences that determine the value drivers affecting decision-making, and the ability to achieve continuous and sustainable improvements in safety performance. Consequently, this research aims to provide a more holistic approach to understanding the nature of disasters in the oil and gas industry, and identifying how future disasters can be prevented by establishing "more cost-effective strategies. Quantitative research was carried out to determine the type and validity of the data used to construct trends in major accident safety performance, and qualitative research was carried out to assess the key factors that influence safety performance, and whether these are effectively applied. The conclusions of this research are that the industry has not demonstrated effective implementation of an Occupational Health and Safety Management System (OH&S-MS). Historically safety performance shows wide annual variations where trends are difficult to define and extrapolate, making it difficult to provide any significant benefit for major accident prevention. There is no evidence to indicate that moving from a prescriptive, to a goal-setting regime, has improved safety performance, and reduced the prospect of future major accidents. Disaster investigation reports have shown that the role of the regulator has been ineffective. However, the adoption of a more comprehensive, and effective approach to inherently safer designs, and the way projects are managed, have the potential to make safety management more cost-effective and reduce the prospect of future disasters.

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20

Zippe, Winfried, Jochen Zschau, Vladimir Valentinovich Kontelev, Vladimir Ivanovitsch Melnikov, Andrej Duncev, Robert Zboray, Leonid Karlovitsch Stoppel, Valery Nikolajevich Chochlov, Horst-Michael Prasser, and Vadim Vladimirovich Ivanov. "Local and integral ultrasonic gauges for two-phase flow instrumentation in nuclear reactor and safety technology." Forschungszentrum Rossendorf, 2000. https://hzdr.qucosa.de/id/qucosa%3A21816.

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Das vorliegende Projekt wurde im Rahmen einer Kooperationsvereinbarung zwischen dem Forschungszentrum Rossendorf (FZR) und der wissenschaftlichen Gruppe von Prof. Melnikon von der Technischen Universität Nishny Novgorod (TUNN) der Russischen Föderation durchgeführt. Es ist Teil des Wissenschaftsunterstützungsprogramms / FSU der Bundesregierung im Rahmen der Beratungshilfe für den Aufbau von Demokratie und sozialer Marktwirtschaft (TRANSFORM). Neue Methoden der Instrumentierung für Zweiphasenströmungen wurden entwickelt: Ultraschall-Wellenleitersonden können zur lokalen Gas- bzw. Dampfgehaltsmessung eingesetzt werden. Der neue Ultraschall-Gittersensor erlaubt eine Visualisierung der Zweiphasenströmung mit ca. 250 Bildern/Sekunde. Sowohl die lokalen Sonden als auch der Ultraschall-Gittersensor können erfolgreich unter den Bedingungen von Wasser-Dampf-Gemisch bei hohem Druck und hoher Temperatur, sowie in anderen Fluiden, wie organischen Flüssigkeiten und Kältemitteln, eingesetzt werden. Darüber hinaus wurden berührungslos arbeitende Wellenleitersonden für die Durchschallung von Rohrleitungen und Dichtesensoren, die auf der Messung der Ausbreitungsgeschwindigkeit von Ultraschall in Wellenleitern beruhen, die sich im Messmedium befinden, entwickelt und getestet. Bei dem gegenwärtigen Stand der Entwicklung können die berührungslosen Sensoren lediglich als qualitativer Nachweis von Gas in einer Flüssigkeitsströmung dienen. Die Funktion der Dichtesensoren wurde anhand von Messungen in verschiedenen einphasigen Flüssigkeiten unterschiedlicher Dichte demonstriert. Für einen praktischen Einsatz ist die weitere Verbesserung der elektronischen Signalerfassung erforderlich. Die hauptsächliche Innovation wird durch den Ultraschall-Gittersensor verkörpert, dessen Auflösung mit der von schnellen elektrischen Gittersensoren und ultraschnellen Röntgentomographen vergleichbar ist, während das Gerät selbst sehr robust und preiswert ist.

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Bopf, Tara-Louise. "Mathematical modelling of worker interactions and the impact on workplace safety." Thesis, Queensland University of Technology, 2017. https://eprints.qut.edu.au/104384/1/Tara-Louise_Bopf_Thesis.pdf.

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This research involves applying mathematical modelling techniques coupled with data on work and safety practices to investigate workplace safety programs and improvement strategies. The thesis investigated the potential impact of different safety intervention programs prior to their implementation within the workplace. As there was a lack of mathematical modelling of the interactions between workers and workplace safety intervention programs and how these interactions and programs impacted the safety of the worker while at work, this research presents mathematical models that may be used as a basis for further investigation regarding Occupational Health and Safety.

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Lucas, D., and F. P. Weiß. "TOPFLOW-Experimente, Modellentwicklung und Validierung von CFD-Codes für Wasser-Dampf-Strömungen mit Phasenübergang." Helmholtz-Zentrum Dresden-Rossendorf, 2012. http://nbn-resolving.de/urn:nbn:de:bsz:d120-qucosa-85355.

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Das Ziel des Vorhabens bestand in der Ertüchtigung von CFD-Codes für Wasser-Dampf-Strömungen mit Phasenübergang. Während CFD-Verfahren für einphasige Strömungen bereits breite Anwendung in der Industrie finden, steht ein entsprechender Einsatz für Zweiphasenströmungen auf Grund der komplexen Phasengrenzfläche und den davon beeinflussten Wechselwirkungen erst am Anfang. Für die Weiterentwicklung und Validierung geeigneter Schließungsmodelle werden experimentelle Daten mit hoher Orts- und Zeitauflösung benötigt. Solche Daten wurden an der TOPFLOW-Versuchsanlage des HZDR durch Kombination von Experimenten bei praxisnahen Parametern für die Reaktorsicherheit (große Skalen, hohe Drücke und Temperaturen) und innovativer Messtechnik gewonnen. Die Gittersensortechnik, mit der detaillierte Informationen über die Phasengrenzfläche gewonnen werden können, wurde in adiabaten Wasser-Luft-Experimenten sowie Kondensations- und Druckentlastungsexperimenten in einem großen DN200-Rohr eingesetzt. Umfangreiche Datenbasen mit hoher Qualität stehen im Ergebnis des Vorhabens zur Verfügung. Die Technologie für die schnelle Röntgentomographie, die Messungen ohne Strömungsbeeinflussung ermöglicht, wurde weiter entwickelt und in einer ersten Messserie erfolgreich eingesetzt. Hochaufgelöste Daten wurden auch in Experimenten zu verschiedenen Strömungssituationen (z.B. Gegenstrombegrenzung) in einem Modell des heißen Strangs eines Druckwasserreaktors gewonnen. Für die Wasser-Dampf-Experimente bei Drücken von bis zu 5 MPa wurde dabei erstmals die neu entwickelte innovative Drucktanktechnologie eingesetzt. Zur Ertüchtigung von CFD-Codes für Zweiphasenströmungen wurde das Inhomogene MUSIG-Modell für Phasenübergänge in Kooperation mit ANSYS erweitert und anhand der o.g. TOPFLOW-Experimente validiert. Außerdem erfolgten Verbesserungen u.a. für die Turbulenzmodellierung in Blasenströmungen sowie Simulationen zur Validierung der Modelle für Blasenkräfte und Blasenkoaleszenz und -zerfall. Ein wesentlicher Fortschritt wurde bei der Modellierung freier Oberflächen durch die Verallgemeinerung des AIAD-Modells erreicht. Die am Heißstrangmodell ermittelten Flut¬kurven können unter Nutzung dieses Modells in guter Übereinstimmung berechnet werden.

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23

Kourakos, Vasilios. "Experimental study and modeling of single- and two-phase flow in singular geometries and safety relief valves." Doctoral thesis, Universite Libre de Bruxelles, 2011. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/209827.

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This research project was carried out at the von Karman Institute for Fluid Dynamics (VKI), in Belgium, in collaboration and with the funding of Centre Technique des Industries Mécaniques (CETIM) in France.

The flow of a mixture of two fluids in pipes can be frequently encountered in nuclear, chemical or mechanical engineering, where gas-liquid eactors, boilers, condensers, evaporators and combustion systems can be used. The presence of section changes or more generally geometrical singularities in pipes may affect significantly the behavior of twophase flow and subsequently the resulting pressure drop and mass flow rate. Therefore, it is an important subject of investigation in particular when the application concerns industrial safety valves.

This thesis is intended to provide a thorough research on two-phase (air-water) flow phenomena under various circumstances. The project is split in the following steps. At first, experiments are carried out in simple geometries such as smooth and sudden divergence and convergence singularities. Two experimental facilities are built; one in smaller scale in von Karman Institute and one in larger scale in CETIM. During the first part of the study, relatively simple geometrical discontinuities are investigated. The characterization and modeling of contraction and expansion nozzles (sudden and smooth change of section) is carried out. The pressure evolution is measured and pressure drop correlations are deduced. Flow visualization is also performed with a high-speed camera; the different flow patterns are identified and flow regime maps are established for a specific configuration.

A dual optical probe is used to determine the void fraction, bubble size and velocity upstream and downstream the singularities.

In the second part of the project, a more complex device, i.e. a Safety Relief Valve (SRV), mainly used in nuclear and chemistry industry, is thoroughly studied. A transparent model of a specific type of safety valve (1 1/2" G 3") is built and investigated in terms of pressure evolution. Additionally, flow rate measurements for several volumetric qualities and valve openings are carried out for air, water and two-phase mixtures. Full optical access allowed identification of the structure of the flow. The results are compared with measurements performed at the original industrial valve. Flowforce analysis is performed revealing that compressible and incompressible flowforces in SRV are inversed above a certain value of valve lift. This value varies with critical pressure ratio, therefore is directly linked to the position at which chocked flow occurs during air valve operation. In two-phase flow, for volumetric quality of air=20%, pure compressible flow behavior, in terms of flowforce, is remarked at full lift. Numerical simulations with commercial CFD code are carried out for air and water in axisymmetric 2D model of the valve in order to verify experimental findings.

The subject of modeling the discharge through a throttling device in two-phase flow is an important industrial problem. The proper design and sizing of this apparatus is a crucial issue which would prevent its wrong function or accidental operation failure that could cause a hazardous situation. So far reliability of existing models predicting the pressure drop and flow discharge in two-phase flow through the valve for various flow conditions is questionable. Nowadays, a common practice is widely adopted (standard ISO 4126-10 (2010), API RP 520 (2000)); the Homogeneous Equilibrium Method with the so-called !-method, although it still needs further validation. Additionally, based on !-methodology, Homogeneous Non-Equilibrium model has been proposed by Diener and Schmidt (2004) (HNE-DS), introducing a boiling delay coefficient. The accuracy of the aforementioned models is checked against experimental data both for transparent model and industrial SRV. The HNE-DS methodology is proved to be the most precise among the others. Finally, after application of HNE-DS method for air-water flow with cavitation, it is concluded that the behavior of flashing liquid is simulated in such case. Hence, for the specific tested conditions, this type of flow can be modeled with modified method of Diener and Schmidt (CF-HNE-DS) although further validation of this observation is required.
Doctorat en Sciences de l'ingénieur
info:eu-repo/semantics/nonPublished

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Wittmann, Johannes Clinical School South Western Sydney Faculty of Medicine UNSW. "Phase I animal safety study of new second generation porphyrin based photosensitizers in the Syrian Golden hamster." Awarded by:University of New South Wales, 2007. http://handle.unsw.edu.au/1959.4/39833.

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Pancreatic cancer kills over 1700 people each year in Australia. In 2000, there were 1908 new cases diagnosed and it remains one of the least treatable malignancies. In the USA, it was the fourth leading cause of cancer death in 2004, with 31,860 new cases and 31,270 recorded deaths. Photodynamic therapy (PDT) is a novel, potentially useful treatment for locally advanced pancreatic cancer with only limited research and clinical work addressing this until now. PDT induces non-thermal, cytotoxic and ischaemic injury to a targeted volume of tissue. During PDT, a photosensitizer is activated by non-thermal light in the presence of oxygen, generating cytotoxic oxygen species and inducing cellular injury and microvascular occlusion. The aim of this thesis was to conduct an animal safety study using two second generation photosensitizers, talaporfin sodium and verteporfin, to assess the risks of pancreatic PDT by looking at injury to organs adjacent to the pancreas and assessing recovery from PDT treatment of the pancreas. The Syrian Golden hamster animal model was used to compare the results of this research to previous work by other authors. The study design incorporated a number of additional experiments, including quantitative tissue fluorescence techniques, plasma level analysis and histopathology techniques. The methods for the animal safety study were similar to the approach used in the clinical setting and provided vital data on the likely risks and side effects of phototherapy in humans. The first study, looking at talaporfin sodium, found likely risks of duodenal injury, gastric injury and death with a limited effect on normal pancreas at photosensitizer doses likely to be employed for pancreatic cancer PDT. The second study, using verteporfin, found similar results with a more potent effect on the normal pancreas at studied drug doses. Both agents had short drug-light intervals, ranging from 15 minutes to 2 hours, reducing the need for pre-treatment hospitalization and short photosensitivity periods of about one to two weeks. Some animals suffered minor cutaneous photosensitivity injuries. A human pancreatic cancer PDT pilot study is feasible and the risks and complications should be acceptable.

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Berst, Frédéric. "The development of a solid-phase route to cyclic tetrapeptoids using a new 'latent' safety-catch linker." Thesis, University of Cambridge, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.620287.

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Maringa, Joshua, and Thorbjørn Sæther. "Specification of Requirements for Safety in the Early Development Phases - Misuse Case and HAZOP in the Concept Phase." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for datateknikk og informasjonsvitenskap, 2011. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-13999.

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In the course TDT4520 - Specialization Project, the preparatory course to this thesis, we looked at several safety analysis methods and how they could be exploited to identify software hazards in the early stages of development. After our evaluation, and with the results from a survey conducted on experts in the field, we proposed a procedure to improve software hazard identification in the concept phase of projects. The procedure consisted of a Misuse Case analysis with a sub-sequential HAZOP analysis. Our case study showed that this procedure will indeed aid in the identification process. However, testing the procedure on others is needed to see if this is correct. That is the main theme for this thesis. We performed an experiment with undergraduate students and an interview with an expert in the field. We use the results from the experiment to validate our assumptions and identify modifications that might be needed. The experiment gave us a good illustration of how the procedure would work in a real hazard analysis project, and the data collected showed us the differences between it and the more commonly used Preliminary Hazard Analysis. Our hypothesis was that the Misuse Case and HAZOP approach would improve the hazard identification with focus on software. The experiment resulted in no clear difference in non-software parts of the system, but a clear improvement on the software parts. Afterwards we conducted an interview with an expert in the field, in which we clarified many of our questions and assumptions, and aided us in modifying the procedure to the better.Although the procedure still needs to be tested thoroughly with real projects in the industry to make a final decision on whether it has merit or not, our conclusion is that the procedure deserves further attention. Software hazard identification in the concept phase is difficult but based on our findings, the Misuse Case and HAZOP combination can improve this problem.

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27

Moncalvo, Davide [Verfasser]. "The influence of fluid properties on single and two-phase two-component flows in safety valves / Davide Moncalvo." Aachen : Shaker, 2010. http://d-nb.info/109804035X/34.

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Mehlitz, Philipp-Mathias [Verfasser]. "Safety profile of CAP7.1 obtained during Phase I Trial in adult patients with refractory malignancies / Philipp-Mathias Mehlitz." Berlin : Medizinische Fakultät Charité - Universitätsmedizin Berlin, 2016. http://d-nb.info/1121007368/34.

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29

Vo, Do. "Automation, Annunciation, and Emergency Safety Shutdown of a Laboratory Microgrid Using a Real-Time Automation Controller (RTAC)." DigitalCommons@CalPoly, 2021. https://digitalcommons.calpoly.edu/theses/2292.

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Over the last decade, microgrid deployments throughout the world have increased. In 2019, a record number of 546 microgrids were installed in the United States [1]. This trend continues upward to combat extreme weather conditions and power shortages throughout the country. To better equip students with the necessary skillsets and knowledge to advance in the microgrid field, Cal Poly San Luis Obispo's Electrical Engineering Department and the Power Energy Institute have invested resources to develop a laboratory microgrid. This thesis sets to improve the laboratory microgrid's existing automation using the Schweitzer Engineering Laboratory SEL-3530 Real-time Automation Controller (RTAC). The improved automation features a new load-shedding scheme, LCD annunciator and meter panel, and emergency safety shutdown system. The load shedding scheme aims to enhance the grid's frequency stability when the inverter-based power output declines. The LCD annunciator and meter panels provide real-time oversight of the microgrid operating conditions via the RTAC Human Machine Interface (HMI). The emergency safety shutdown enables prompt de-energization and complete isolation of the laboratory microgrid in hazardous conditions such as earthquake, fire, arcing, and equipment malfunction and activates an audible siren to alert help. This safety system provides safety and peace of mind for students and faculties who operate the Microgrid. Lastly, this thesis provides an operating procedure for ease of operation and experiment.

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Fouchier, Charline. "Investigation of the Pollutant Dispersion Driven by a Condensed-Phase Explosion in an Urban Environment." Doctoral thesis, Universite Libre de Bruxelles, 2020. https://dipot.ulb.ac.be/dspace/bitstream/2013/312560/3/PhD.pdf.

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Understanding and predicting the consequences of dangerous phenomena linked to the industrial activity is critical to ensure the highest safety level possible. Explosions represent a high risk of fatalities and economic loss and even though the phenomenon is studied in the literature, accidents still occur.The explosion in air of a heterogeneous charge (i.e. an explosive charge surrounded or mixed with a gaseous, solid, or liquid pollutant) has various consequences. While the presence of buildings around the explosion will reduce considerably the impact of most of them, it will affect in more complex ways the propagation of the pressure released, also called bast wave, and the pollutant dispersion. Simplified models to characterize the blast propagation and the dispersion following an explosion are necessary tools for industries to access a first estimation of the risks related to their activities. However, the existing models do not take into account the effect of the urban environment.The global objective of the project is to improve the understanding of the blast propagation and the dispersion inside an urban environment by generating a quantitative database. In parallel to the project, simplified models are being developed by the Commissariat à l’Energie Atomique et aux Energies Alternatives (CEA) Gramat (center from the Direction des Applications Militaires (DAM)) and will be validated by the generated experimental database. To achieve this goal, experimental techniques are developed and applied to a controlled reduced-scale urban environment, and a CFD approach is used to facilitate the understanding of the blast experimental results. The challenges associated with the creation of a new experimental system led to innovative solutions in response to technical issues. The main originality of the project is the investigation of explosively driven dispersion under a controlled atmospheric boundary layer, which represents a novelty in the area from the author's knowledge. Existing experimental techniques have been extended and validated for the large dynamic ranges involved in the explosive dispersion. The research is separated into two parts: the investigation of the blast, and the investigation of the dispersion driven by an explosion, both inside an urban environment in a 1:200 reduced scale.In the first part, the blast propagation has been first investigated in free field to characterize the energy, the geometry, and the repeatability of each studied explosives. Then the blast has been studied inside four selected typical urban configurations. To help the understanding of the blast path, a numerical model has been developed in OpenFoam to simulate the propagation and a good overlap between the experimental and numerical results has been observed. The second part of the research focuses on the investigation of the explosively driven dispersion. Micro-sized talc particles have been added around the explosives to simulate the pollutant dispersion. Large-Scale Particle Image Velocimetry (LS-PIV) and Mie-Scattering techniques have been first investigated and validated on a supersonic jet. They have been thereafter applied to the explosively driven dispersion. Three atmospheric conditions, two masses of talc, and two diameters of powder have been investigated, both in free field and inside a T-junction.The experimental techniques used to characterize the explosion of a heterogeneous charge show promising results. They are powerful tools to investigate complex large-scale and large dynamic range flows.
Doctorat en Sciences de l'ingénieur et technologie
info:eu-repo/semantics/nonPublished

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Owens, Brandon D. (Brandon Dewain). "Using phase space attractors to evaluate system safety constraint enforcement : case study in space shuttle mission control procedure rework." Thesis, Massachusetts Institute of Technology, 2009. http://hdl.handle.net/1721.1/53216.

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Thesis (Ph. D.)--Massachusetts Institute of Technology, Engineering Systems Division, 2009.
Vita. Cataloged from PDF version of thesis.
Includes bibliographical references (p. 390-409).
As the complexity and influence of engineering systems in modern society increases, so too does their potential to create counterintuitive and catastrophic accidents. Increasingly, the accidents encountered in these systems are defying the linearized notions of accident causality that-though developed for the simpler engineered systems of the past-are prevalently used for accident prevention today. In this dissertation, an alternative approach to accident prevention based on systems theory-the Systems-Theoretic Accident Model and Processes (STAMP) and STAMP-based hazard analysis (STPA)-is augmented with the notion of using phase space attractors to evaluate how well STAMP safety control structures enforce system safety constraints. Phase space attractors are mathematical results that emerge from the behavior of systems with dynamic structures that draw or constrain these systems to specific regions of their phase space in spite of a range of conditions. Accordingly, the goal in using this notion for the evaluation of safety constraint enforcement is to identify and analyze the attractors produced by a safety control structure to determine if it will adequately "attract" the system to safe states in spite of a range of unforeseeable conditions. Support for this approach to evaluating STAMP safety control structures is provided through the study of a safety control structure in an existing complex, socio-technical system. This case study is focused on a safety control process-referred to as Procedure Rework-used in Space Shuttle Mission Control to update procedures during in-flight operations as they are invalidated by changes in the state of the Space Shuttle and its environment.
(cont.) Simulation models of procedure rework are developed through physical and human factors principles and calibrated with data from five Space Shuttle missions; producing simulation results with deviations from the historical data that are-as characterized by Theil Inequality Statistics-small and primarily due to cycles and noise that are not relevant to the models' purpose. The models are used to analyze the attractor produced by the Procedure Rework Process across varied conditions, including a notional crewed spacecraft mission to a distant celestial body. A detrimental effect in the process is identified-and shown to be potentially far more severe than light delay on a mission to a distant celestial body-and approaches to mitigating the effect are explored. Finally, the analysis conducted is described as a generalizeable process for using phase space attractors to evaluate system safety constraint enforcement in engineering systems.
by Brandon D. Owens.
Ph.D.

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Kotikalapudi, Siddhartha. "Characteristics and contributory causes related to large truck crashes (phase-II) - all crashes." Thesis, Kansas State University, 2012. http://hdl.handle.net/2097/14027.

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Master of Science
Department of Civil Engineering
Sunanda Dissanayake
In order to improve safety of the overall surface transportation system, each of the critical areas needs to be addressed separately with more focused attention. Statistics clearly show that large-truck crashes contribute significantly to an increased percentage of high-severity crashes. It is therefore important for the highway safety community to identify characteristics and contributory causes related to large-truck crashes. During the first phase of this study, fatal crash data from the Fatality Analysis Reporting System (FARS) database were studied to achieve that objective. In this second phase, truck-crashes of all severity levels were analyzed with the intention of understanding characteristics and contributory causes, and identifying factors contributing to increased severity of truck-crashes, which could not be achieved by analyzing fatal crashes alone. Various statistical methodologies such as cross-classification analysis and severity models were developed using Kansas crash data. Various driver-, road-, environment- and vehicle- related characteristics were identified and contributory causes were analyzed. From the cross-classification analysis, severity of truck-crashes was found to be related with variables such as road surface (type, character and condition), accident class, collision type, driver- and environment-related contributory causes, traffic-control type, truck-maneuver, crash location, speed limit, light and weather conditions, time of day, functional class, lane class, and Average Annual Daily Traffic (AADT). Other variables such as age of truck driver, day of the week, gender of truck-driver, pedestrian- and truck-related contributory causes were found to have no relationship with crash severity of large trucks. Furthermore, driver-related contributory causes were found to be more common than any other type of contributory cause for the occurrence of truck-crashes. Failing to give time and attention, being too fast for existing conditions, and failing to yield right of way were the most dominant truck-driver-related contributory causes, among many others. Through the severity modeling, factors such as truck-driver-related contributory cause, accident class, manner of collision, truck-driver under the influence of alcohol, truck maneuver, traffic control device, surface condition, truck-driver being too fast for existing conditions, truck-driver being trapped, damage to the truck, light conditions, etc. were found to be significantly related with increased severity of truck-crashes. Truck-driver being trapped had the highest odds of contributing to a more severe crash with a value of 82.81 followed by the collision resulting in damage to the truck, which had 3.05 times higher odds of increasing the severity of truck-crashes. Truck-driver under the influence of alcohol had 2.66 times higher odds of contributing to a more severe crash. Besides traditional practices like providing adequate traffic signs, ensuring proper lane markings, provision of rumble strips and elevated medians, use of technology to develop and implement intelligent countermeasures were recommended. These include Automated Truck Rollover Warning System to mitigate truck-crashes involving rollovers, Lane Drift Warning Systems (LDWS) to prevent run-off-road collisions, Speed Limiters (SLs) to control the speed of the truck, connecting vehicle technologies like Vehicle-to-Vehicle (V2V) integration system to prevent head-on collisions etc., among many others. Proper development and implementation of these countermeasures in a cost effective manner will help mitigate the number and severity of truck-crashes, thereby improving the overall safety of the transportation system.

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Radosevic, Aleksandar 1974. "Clinical efficacy and safety of a new hybrid radiofrequency electrode for treatment of liver malignancies : Phase I and phase II randomized clinical trial using radiofrequency versus microwave ablation." Doctoral thesis, TDX (Tesis Doctorals en Xarxa), 2021. http://hdl.handle.net/10803/671844.

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La ablación con radiofrecuencia y microondas son opciones terapéuticas útiles para el tratamiento de tumores malignos hepáticos en pacientes seleccionados. Aunque comparables, sus resultados son todavía inferiores a los obtenidos con cirugía. Se han intentado crear dispositivos capaces de producir ablaciones mayores y con geometrías más favorables. Uno de estos dispositivos es Gnomon, el electrodo híbrido experimental desarrollado por nuestro equipo cuya validación clínica en las fases I y II del ensayo clínico constituye el objeto de esta tesis. Inicialmente confirmamos que este electrodo es seguro para el uso clínico y posteriormente, a través de un estudio randomizado, hemos comparado este electrodo con el sistema de microondas de última generación. Aunque no hemos encontrado mejoría en cuanto a geometría de la zona de ablación, los resultados técnicos y clínicos parecen que están en a la altura de los resultados obtenidos con uno de los sistemas de microondas de última generación.
Radiofrequency ablation and MWA have each been reported as offering a useful therapeutic option for the treatment of liver malignancy in selected patients. Although comparable, their results are still inferior to results obtained through surgical resection. Efforts have been made to develop devices that are able to produce larger ablation zones with a more favorable geometry. One of these devices is Gnomon, an experimental hybrid electrode developed by our team whose clinical testing through Phase I and Phase II trials is the object of this thesis. We have initially confirmed that this electrode is safe for clinical use and posteriorly, through a randomized clinical trial, we compared this electrode with the latest generation microwave system. Although we did not confirm improvement of the ablation zone geometry, the technical and clinical outcomes seem to be in the range of those obtained with one of the latest generation of microwave systems.

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Dorris, Kathleen. "A comparison of safety and efficacy of cytotoxic versus molecularly targeted agents in pediatric phase I solid tumor oncology trials." University of Cincinnati / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1330023465.

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Tormey, Peter J. "The effect of diurnal phase on performance physiology and immune system." Thesis, Edinburgh Napier University, 2017. http://researchrepository.napier.ac.uk/Output/1023141.

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The circadian cycle, although seasonally adjusted, consists of two phases: a nocturnal period of darkness and a diurnal period of light. Many parameters of human physiology display either a nocturnal or diurnal peak as seen in athletic performance, immune, endocrine, physiology and cognitive function, respectively. The studies included in this thesis focused on the diurnal (morning or AM versus evening or PM) effect of high-intensity self-paced exercise on physiological and immunological measures and the influence of individual preference for activity or chronotype on these responses. Self-paced time-trials were completed in an environmental chamber (6°C) in the AM and PM and displayed a similar effect on physiological and biological parameters. Performance times were non-statistically quicker (P > 0.05) at PM. Physiological parameters heart rate, rate of perceived exertion, lung function and self-paced treadmill speed were not found to be statistically different at AM or PM trial (p > 0.05). Core body temperature (CBT), was significantly higher (p0.05). CD8+ T-lymphocyte cell-surface markers for naïve/senescence and differentiation (CD27CD45RA and CD27CD28) reported no diurnal difference between AM and PM exercise in experienced and experienced/recreational distance runners respectively (P > 0.05). However, a higher percentage of highly differentiated phenotypes were found in the recreationally active population. Neutrophils displayed a pronounced elevation in response to PM exercise with the mechanism driving this response unclear at this time. Cortisol concentration displayed less inflammatory responses in the morning compared to the evening with higher values pre, post and one-hour post AM trials. Chronotype showed no effect on physiology or biology at rest or in response to exercise. Chapter 4 presents data from a study that investigated diurnal physiology and immune response to high-intensity exercise in highly-trained men. Recreational and experienced endurance male runners at differing diurnal time-points were investigated in Chapter 5, while individual chronotype differences and circadian phase responses were explored in Chapter 6.In summary, it is concluded from this work that there was a lack of evidence showing a diurnal effect on running performance and subsequent immune response. Elevated circulating immune counts prior to exercise, irrespective of diurnal phase, appear to govern exercise-induced responses. The effect of high intensity exercise is subject to three distinct variables: the fitness status and experience of the individual completing the exercise, the time of day at which the exercise is undertaken, and the phase response of exercise at that point of the circadian cycle. No diurnal phase mediated a divergent effect on variables examined was observed at 09.00hrs and 17.00hrs. These time-points should be considered not sufficiently dissimilar to elucidate diurnal variation in trained and healthy males.

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Bari, Khurram. "Safety and Efficacy of Budesonide as an alternative to Prednisone for Liver Transplant Immune Suppression: Results of a pilot phase 2a trial." University of Cincinnati / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1573575278794713.

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McLaggan, Martyn Scott. "Novel fire testing frameworks for Phase Change Materials and hemp-lime insulation." Thesis, University of Edinburgh, 2016. http://hdl.handle.net/1842/15896.

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Modern buildings increasingly include the usage of innovative materials aimed at improving sustainability and reducing the carbon footprint of the built environment. Phase Change Materials (PCMs) are one such group of novel materials which reduce building energy consumption. These materials are typically flammable and contained within wall linings yet there has been no detailed assessment of their fire performance. Current standard fire test methods provide means to compare similar materials but do not deliver knowledge on how they would behave in the event of a real fire. Thus, the aim of this thesis is to develop a novel testing framework to assess the behaviour of these materials in realistic fire scenarios. For PCMs, a flammability study is conducted in the bench-scale cone calorimeter to evaluate the fire risk associated with these materials. Then, micro-scale Thermogravimetric Analysis (TGA) is used to identify the fundamental chemical reactions to be able to confidently interpret the flammability results. Finally, intermediate-scale standard fire tests are conducted to evaluate the applicability of the bench-scale results to realistic fire scenarios. These take the form of modified Lateral Ignition and Flame spread Test (LIFT) and Single Burning Item (SBI) tests to understand flame spread and compartment fires respectively. Finally, a simplified method to combine this knowledge for use in building design is proposed. This method allows the balancing of potential energy benefits with quantified fire performance to achieve the specified goals of the designer. Hemp-lime insulation is a material which has also becoming increasingly popular in the drive towards sustainability. The porous nature of the material means that smouldering combustions are the dominant reaction mode but there is currently no standardised test method for this type of behaviour. Thus, hemp-lime materials also represent an unquantified risk. The work in this thesis defines a simple, accessible and economically viable bench-scale method for quantifying the fire risk associated with rigid porous materials. This is applicable for both downward opposed flow and upward forward flow smoulder propagation conditions. The behaviour is then interpreted using micro-scale thermogravimetric analysis to understand the underlying pyrolysis and oxidation reactions. Designers can utilise this framework to quantify the smouldering risk associated with hemp-lime materials to enable their usage in the built environment. The holistic fire risk assessment performed in this thesis has quantified the behaviour of PCMs and hemp-lime insulation applicable to realistic fire scenarios. The simplified design method empowers designers to be able to realise innovative buildings through fundamental understanding of the fire behaviour of these materials. The outcomes of this thesis allow designers to mitigate the fire risk associated with these materials and achieve optimised engineering solutions. Furthermore, the novel fire testing frameworks provide the economically viable means to assess the fire performance of future PCMs and hemp-lime products which ensures lasting relevance of this research in the future.

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Qvick, August, and Anton Hansson-Böe. "Fuktsäkerhetsarbete i produktionsskedet : Alsters förskola utformas till ett referensobjekt." Thesis, Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-43642.

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Many buildings in Sweden have some kind of moisture problem and the reason for this can in a lot of cases be attributed to the production phase. A suggested measure by Boverket is to increase feedback to reduce errors in the production phase. This study will therefore contribute to the experience feedback by describing the process of moisture safety during the production phase at Skanska’s construction of Alster’s preschool. The starting point for this study is a moisture survey carried out on Alster’s preschool. The result from the moisture survey suggests that the work with moisture safety has been successful during the construction of Alster’s preschool. The aim of this study is therefore to make Alster’s preschool into an object of reference regarding moisture safety during the production phase. The method involved a theoretical study of building components and materials used in the construction of Alster’s preschool and the moisture aspects that must be taken into account. The method also involved an examination of Skanska’s documents from the construction of Alster’s preschool, supplemented with verbal conversations with Skanska employees. The result describes the process of moisture safety during the production phase at Alster’s preschool. The description includes how the construction was built, material management, examinations that were carried out and the anomalies that occurred. One conclusion that was drawn regarding the applicability of Alster’s preschool as an object of reference is that some similarities should coincide with the new building. Similarities such as supporting structures of wood, meet the passive house standard, one floor construction, and that the building is constructed in a similar climate. Another conclusion that was drawn is that the work with moisture safety in the production phase always should strive to keep building moisture levels below critical numbers. A measure taken in the disposal to make this possible was to achieve a favorable climate regarding moisture in the building. But it is important to consider the required air tightness in the construction before the heating process starts in the building.

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Isambert, N., M. Campone, E. Bourbouloux, M. Drouin, A. Major, W. Yin, Paul M. Loadman, R. Capizzi, C. Grieshaber, and P. Fumoleau. "Evaluation of the safety of C-1311 (SYMADEX) administered in a phase 1 dose escalation trial as a weekly infusion for 3 consecutive weeks in patients with advanced solid tumours." Elsevier, 2010. http://hdl.handle.net/10454/4563.

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PURPOSE: C-1311 is a member of the novel imidazoacridinone family of anticancer agents. This phase 1 trial was designed to investigate the safety, tolerability and preliminary anti-tumour activity of C-1311. PATIENTS AND METHODS: This was a phase 1, inter-subject dose escalating and pharmacokinetic study of intravenous (IV) C-1311, administered weekly during 3consecutive weeks followed by 1week rest (constituting 1 cycle) in subjects with advanced solid tumours. RESULTS: Twenty-two (22) patients were treated with C-1311, the highest dose given was 640mg/m(2). All subjects experienced one or more treatment-related adverse events (AEs). The most frequently observed treatment-related AEs were neutropaenia and nausea (50% each), followed by vomiting (27%), anaemia (23%), asthenia (23%) and diarrhoea (18%). Most treatment-related AEs were of Common Terminology Criteria for Adverse Events (CTCAE) grades 1-2, except for the blood and lymphatic system disorders, which were primarily of grades 3-4. The recommended dose (RD) of C-1311 administered as once weekly IV infusions for 3weeks every 4weeks is 480mg/m(2), with the dose limiting toxicity (DLT) being grade 4 neutropaenia lasting more than 7days. Treatment at this dose offers a predictable safety profile and excellent tolerability. CONCLUSION: The safety profile and preliminary anti-tumour efficacy of C-1311, observed in this broad-phase dose-finding study, warrants further evaluation of the compound.

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Galindo, Amparo. "Prediction of phase equilibria of associating fluids with the SAFT approach." Thesis, University of Sheffield, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.242291.

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Huber, Christian [Verfasser], Andreas [Akademischer Betreuer] [Gutachter] Jossen, and Markus [Gutachter] Lienkamp. "Phase Change Material in Battery Thermal Management Applications : An assessment of efficiency and safety / Christian Huber ; Gutachter: Andreas Jossen, Markus Lienkamp ; Betreuer: Andreas Jossen." München : Universitätsbibliothek der TU München, 2017. http://d-nb.info/1140586580/34.

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Paricaud, Patrice. "Understanding the fluid phase behaviour of polymer systems with the SAFT theory." Thesis, Imperial College London, 2003. http://hdl.handle.net/10044/1/7465.

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Sadeghi, Leyla. "Aide à la décision pour l'intégration de la sécurité au plus tôt en phase de conception : approche innovante de reconception de machines agricoles." Thesis, Cachan, Ecole normale supérieure, 2014. http://www.theses.fr/2014DENS0031/document.

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Les travaux de recherche exposés dans ce mémoire se positionnent dans le domaine de la conception sécuritaire. Cette thèse s’intéresse plus particulièrement à rendre opérationnelle la méthode IRAD (Innovative Risk Assessment Design), qui intègre la sécurité de manière systématique tout au long du processus de conception. Dans cet objectif, nous proposons dans un premier temps de formaliser un type de retour d’expérience (les rapports d’accident) qui détaille les faits liés aux éléments d’une situation de travail et à des événements qui ont mené à un accident. Ensuite, nous proposons deux démarches complémentaires de reconception sécuritaire: une démarche d’ingénierie inverse fonctionnelle pour la sécurité (FRES) et une démarche de réingénierie fonctionnelle pour la sécurité (FR2ES). FRES permet d’extraire les connaissances à la fois sur l’accident et sur la conception du système impliqué dans l’accident. Elle permet ensuite d’évaluer le niveau de sécurité du système par l’estimation d’un indicateur de sécurité dépendant notamment du type de risque identifié. Cet indicateur est utilisé comme paramètre d’aide à la décision lors de la phase de reconception du système. La deuxième démarche, FR2ES, permet de définir les objectifs de sécurité liés à chaque phase de la conception dans le but d’éliminer ou de réduire un risque donné. Les solutions les plus sécuritaires possibles sont ensuite obtenues d’une part en intégrant ces objectifs de sécurité dans le processus de reconception et d’autre part à l’aide de l’indicateur de sécurité appliqué aux solutions proposées. Enfin, l’applicabilité de ces démarches a été démontrée sur deux types de liaisons tracteurs-outils, l’arbre de transmission à cardans et la liaison trois points - systèmes permettant d’atteler les outils aux tracteurs et de les motoriser
The research presented in this thesis is positioned in the field of design for safety. This thesis is particularly interested in operationalizing the IRAD (Innovative Risk Assessment Design) method, which integrates safety systematically throughout the design process. For this purpose, in first step, we propose to formalize a type of experience feedback (accident reports) detailing the facts relating to the elements of a working situation and the events that led to an accident. In the next step, we propose two complementary approaches to redesign for safety: functional reverse engineering for safety (FRES) and functional re-engineering for safety (FR2ES). FRES is used to extract knowledge on both the accident and the design of the system involved in the accident. This approach allows assessing the safety level of the system by estimating a safety indicator depending on the type of identified risk. This indicator is used as a parameter for decision support during the redesign of the system. FR2ES defines the safety objectives related to each phase of the design in order to eliminate or reduce a given risk. The safest solutions are then obtained, on the one hand, by incorporating these safety objectives in the redesign process and, on the other hand, by using the safety indicator applied to the proposed solutions. Finally, the applicability of these approaches is demonstrated on two types of tractor-implement hitches: the power take off shaft and the three point hitch systems

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Maine, Andrew. "Reducing the risk of Type 2 diabetes in people with intellectual disabilities : a three phase study." Thesis, Edinburgh Napier University, 2018. http://researchrepository.napier.ac.uk/Output/1510775.

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Background: People with intellectual disabilities (ID) remain at high risk of developing type 2 diabetes (T2D) due to lifestyle associated risk factors such poor diets and low physical activity levels. Interventions have been adapted which target ongoing T2D self-management. However, there are no adapted programmes which prevent T2D through reducing risk factors. The present research project addresses this gap through a three-phase study on the existing literature, theoretical basis, and process evaluation of a T2D prevention programme. Methods: Phase 1: The literature reviews identified that the support needs of people with ID with T2D are currently not being met. Appropriate training needs to be delivered so that people with ID can self-manage or reduce the risk of T2D effectively. Given the early onset of T2D in people with ID and their often shorter lifespan, there is rationale for a preventative agenda in T2D education. Four potential mainstream intervention programmes were identified, and the self-efficacy model was found to be the most prevalent successfully implemented theoretical model. Phase 2: Nine sub-themes were identified following analysis of the data: 1) "Mastery through knowledge"; 2) "Mastery through tools and strategies"; 3) "Mastery through autonomy"; 4) "Influence of social setting"; 5) "Positive social comparisons"; 6) "Positive and negative self-statements"; 7) "Feedback from Caregivers"; 8) "Adjustment experiences"; 9) "Symptom awareness". These were mapped onto Bandura's (1977) Four Sources of efficacy enhancement model and were consistentwith its proposed mechanisms. The Four Sources model serves as a useful mode of enquiry for exploring people with ID's experiences and perceptions of self-managing diabetes. It also confirms the appropriateness of ssself-efficacy as a potential intervention component for this population. However, additional support may be required for people with ID to reflect meaningfully on their experiences and thus have a sense of self-efficacy. Phase3: 96% of invited students agreed to participate. The Walking Away programme was positively received, and some short-term impact was described, yet there were limitations to accessibility of the program due to the complexity of the language and materials. Suggestions for further adaptations regarding materials and content were provided, and there was perceived scope for a long-term implementation built into college curriculum. Results: Phase One: The literature reviews identified that the support needs of people with ID with T2D are currently not being met. Appropriate training needs to be delivered so that people with ID can self-manage or reduce the risk of T2D effectively. Given the early onset of T2D in people with ID and their often shorter lifespan, there is rationale for a preventative agenda in T2D education. Four potential mainstream intervention programmes were identified, and the self-efficacy model was found to be the most prevalent successfully implemented theoretical model. Phase Two: Nine sub-themes were identified following analysis of the data: 1) "Mastery through knowledge"; 2) "Mastery through tools and strategies"; 3) "Masterythrough autonomy"; 4) "Influence of social setting"; 5) "Positive social comparisons"; 6) "Positive and negative self-statements"; 7) "Feedback from Caregivers"; 8) "Adjustment experiences"; 9) "Symptom awareness". These were mapped onto Bandura's (1977) Four Sources of efficacy enhancement model and were consistent with its proposed mechanisms. The Four Sources model serves as a useful mode of enquiry for exploring people with ID's experiences and perceptions of self-managing diabetes. It also confirms the appropriateness of self-efficacy as a potential intervention component for this population. However, additional support may be required for people with ID to reflect meaningfully on their experiences and thus have a sense of self-efficacy. Phase Three: 96% of invited students agreed to participate. The Walking Away programme was positively received, and some short-term impact was described, yet there were limitations to accessibility of the program due to the complexity of the language and materials. Suggestions for further adaptations regarding materials and content were provided, and there was perceived scope for a long-term implementation built into college curriculum. Phase Three: 96% of invited students agreed to participate. The Walking Away programme was positively received, and some short-term impact was described, yet there were limitations to accessibility of the program due to the complexity of the language and materials. Suggestions for further adaptations regarding materials and content were provided, and there was perceived scope for a long-term implementation built into college curriculum. Conclusions: The findings provide basis for a further trial incorporating the suggested adaptations. A self-efficacy informed prevention programme was highly acceptability to students and teaching staff. Further education colleges provided a supportive setting and yielded a rich sample.

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Clavier, Rémi. "Étude expérimentale et modélisation des pertes de pression lors du renoyage d’un lit de débris." Thesis, Toulouse, INPT, 2015. http://www.theses.fr/2015INPT0124/document.

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Ce travail de thèse porte sur l’étude des pertes de pression pour des écoulements monophasiques et diphasiques inertiels au travers de milieux poreux. Son objectif est d’aider à la compréhension et à la modélisation des transferts de quantité de mouvement à l’intérieur de lits de particules, en lien avec la problématique de la gestion d’un accident grave dans un réacteur nucléaire. En effet, lors d’un tel accident, la dégradation du coeur du réacteur peut amener celui-ci à s’effondrer pour former un lit de débris, que l’on peut assimiler à un milieu poreux à haute température et dégageant de la chaleur. Ce travail de thèse s’inscrit dans un projet de recherche en sûreté nucléaire visant à prédire la refroidissabilité d’un lit de débris par injection d’eau, ou « renoyage ». Une étude expérimentale des pertes de pression pour des écoulements monodimensionnels monophasiques et diphasiques à froid est proposée dans des situations représentatives du cas réacteur, en termes de granulométrie, de formes de particules et de vitesses d’écoulement. Les expériences réalisées apportent un complément important aux données existantes, en permettant notamment d’explorer les domaines d’écoulements diphasiques avec nombres de Reynolds liquides non nuls, tout en mesurant le taux de vide, ce qui est essentiel pour une modélisation. Des modèles prédictifs pour les pertes de pression à l’intérieur d’écoulements monophasiques et diphasiques au travers de lits de particules sont établis à partir des structures d’équations obtenues par une prise de moyenne volumique des équations de conservation locales. L’observation des écoulements monophasiques montrent que des lois de type Darcy-Forchheimer avec une correction quadratique en vitesse de filtration sont à même de prédire les pertes de pression avec une précision supérieure à 10%. Une étude numérique a montré que ce résultat est applicable pour un lit désordonné de particules peu rugueuses. L’étude des écoulements diphasiques montre qu’une structure d’équations de type Darcy-Forchheimer généralisée, incluant des termes supplémentaires pour prendre en compte les effets inertiels et les frottements interfaciaux, permet de reproduire le comportement des pertes de pression dans cette situation. Un nouveau modèle est proposé, et comparé aux données expérimentales et aux modèles utilisés dans les codes de simulation des accidents graves
This work deals with single and two-phase flow pressure losses in porous media. The aim is to improve understanding and modeling of momentum transfer inside particle beds, in relation with nuclear safety issues concerning the reflooding of debris beds during severe nuclear accidents. Indeed, the degradation of the core during such accidents can lead to the collapse of the fuel assemblies, and to the formation of a debris bed, which can be described as a hot porous medium. This thesis is included in a nuclear safety research project on coolability of debris beds during reflooding sequences. An experimental study of single and two-phase cold-flow pressure losses in particle beds is proposed. The geometrical characteristics of the debris and the hydrodynamic conditions are representative of the real case, in terms of granulometry, particle shapes, and flow velocities. The new data constitute an important contribution. In particular, they contain pressure losses and void fraction measurements in two-phase air-water flows with non-zero liquid Reynolds numbers, which did not exist before. Predictive models for pressure losses in single and two-phase flow through particle beds have been established from experimental data. Their structures are based on macroscopic equations obtained from the volume averaging of local conservation equations. Single-phase flow pressure losses can be described by a Darcy-Forchheimer law with a quadratic correction, in terms of filtration velocity, with a better-than-10 % precision. Numerical study of single-phase flows through porous media shows that this correlation is valid for disordered smooth particle beds. Twophase flow pressure losses are described using a generalized Darcy-Forchheimer structure, involving inertial and cross flow terms. A new model is proposed and compared to the experimental data and to the usual models used in severe accident simulation codes

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Bissen, Edouard. "Semi-analytical methodology for stability and bifurcation analysis in a low pressure boiling channel for GEN4 SFR safety R&D on two-phase flow limit cycles." Thesis, Aix-Marseille, 2019. http://www.theses.fr/2019AIXM0417.

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L'objectif de l'étude entreprise dans ce travail vise à mieux comprendre le comportement fortement non-linéaire d'écoulements di-phasiques (liquide-vapeur). L'établissement de diagrammes de bifurcation pour des configurations académiques simples (écoulements dans un tube cylindrique vertical, chauffé à sa paroi) constitue donc une première étape importante pour la mise en oeuvre de notre approche numérique. Pour parvenir à cet objectif, nous avons développé une approche méthodologique, que nous pensons être assez originale dans ce domaine, puisqu'elle s'appuie sur une méthode de résolution semi-analytique des équations simplifiées du problème (modèle de drift mono-dimensionnel). La méthode de continuation implémentée repose sur la méthode asymptotique numérique, qui nous permet de calculer avec une bonne efficacité numérique (bonne précision et faibles temps de calculs) les solutions stationnaires de l'écoulement de base sur toute la plage d'intérêt (mono-phasique liquide, diphasique liquide-vapeur, mono-phasique vapeur). Lorsque la branche de solutions stationnaires est ainsi calculée, nous procédons ensuite à une analyse linéaire de stabilité, seule partie dans laquelle une quelconque étape linéarisation est introduite. Le modèle est ensuite utilisé pour conduire des études paramétriques permettant de mettre en lumière les paramètres les plus influents sur la stabilité des écoulements, facilitant la compréhension physique des mécanismes en jeux
The objective of the study undertaken in this work is to better understand the highly non-linear behaviour of two-phase flows (liquid-vapour). The establishment of bifurcation diagrams for simple academic configurations (flows in a vertical cylindrical tube, heated at its wall) is therefore an important first step in the implementation of our numerical approach. To achieve this objective, we have developed a methodological approach, which we believe is quite original in this field, since it is based on a semi-analytical method of solving the simplified equations of the problem (one-dimensional drift model). The implemented continuation method is based on the numerical asymptotic method, which allows us to calculate with good numerical efficiency (good accuracy and low computation times) the stationary solutions of the base flow over the entire range of interest (liquid single phase, liquid-vapour two phase, steam single phase). When the branch of stationary solutions is calculated in this way, we then carry out a linear stability analysis, the only part in which any linearization step is introduced. The model is then used to conduct parametric studies to highlight the most influential parameters on flow stability, facilitating the physical understanding of the mechanisms at play

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Varaprasad, K. S., and K. S. R. Murthy. "HELICOPTER BORNE TELEMETRY DATA ACQUISITION SYSTEM FOR DOWN RANGE APPLICATIONS." International Foundation for Telemetering, 2005. http://hdl.handle.net/10150/604927.

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ITC/USA 2005 Conference Proceedings / The Forty-First Annual International Telemetering Conference and Technical Exhibition / October 24-27, 2005 / Riviera Hotel & Convention Center, Las Vegas, Nevada
The terminal phase telemetry data acquisition has always been a challenging task especially for long and medium range test launches. The task becomes more complicated if the article under test describes a very low altitude cruise terminal phase trajectory. Generally, for long and medium range missions test fired into sea the terminal phase data is acquired by deploying instrumented ships in the vicinity of impact point but beyond the safety corridor. But for long range missions with low altitude cruise terminal phase trajectory and wide safety corridor this conventional approach will not work out because of limitation of LOS from the ship platforms. Hence, for such applications an air borne telemetry receiving system is also to be added to the down range instrumentation network. This paper describes a typical and cost effective air borne system realized utilizing the Commercial Off The Shelf (COTS) products and technology. This paper also addresses as to how the signal scattering problems are tackled in the design implementation.

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Lucas, D., and F. P. Weiß. "TOPFLOW-Experimente, Modellentwicklung und Validierung von CFD-Codes für Wasser-Dampf-Strömungen mit Phasenübergang." Helmholtz-Zentrum Dresden-Rossendorf, 2011. https://hzdr.qucosa.de/id/qucosa%3A22147.

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Das Ziel des Vorhabens bestand in der Ertüchtigung von CFD-Codes für Wasser-Dampf-Strömungen mit Phasenübergang. Während CFD-Verfahren für einphasige Strömungen bereits breite Anwendung in der Industrie finden, steht ein entsprechender Einsatz für Zweiphasenströmungen auf Grund der komplexen Phasengrenzfläche und den davon beeinflussten Wechselwirkungen erst am Anfang. Für die Weiterentwicklung und Validierung geeigneter Schließungsmodelle werden experimentelle Daten mit hoher Orts- und Zeitauflösung benötigt. Solche Daten wurden an der TOPFLOW-Versuchsanlage des HZDR durch Kombination von Experimenten bei praxisnahen Parametern für die Reaktorsicherheit (große Skalen, hohe Drücke und Temperaturen) und innovativer Messtechnik gewonnen. Die Gittersensortechnik, mit der detaillierte Informationen über die Phasengrenzfläche gewonnen werden können, wurde in adiabaten Wasser-Luft-Experimenten sowie Kondensations- und Druckentlastungsexperimenten in einem großen DN200-Rohr eingesetzt. Umfangreiche Datenbasen mit hoher Qualität stehen im Ergebnis des Vorhabens zur Verfügung. Die Technologie für die schnelle Röntgentomographie, die Messungen ohne Strömungsbeeinflussung ermöglicht, wurde weiter entwickelt und in einer ersten Messserie erfolgreich eingesetzt. Hochaufgelöste Daten wurden auch in Experimenten zu verschiedenen Strömungssituationen (z.B. Gegenstrombegrenzung) in einem Modell des heißen Strangs eines Druckwasserreaktors gewonnen. Für die Wasser-Dampf-Experimente bei Drücken von bis zu 5 MPa wurde dabei erstmals die neu entwickelte innovative Drucktanktechnologie eingesetzt. Zur Ertüchtigung von CFD-Codes für Zweiphasenströmungen wurde das Inhomogene MUSIG-Modell für Phasenübergänge in Kooperation mit ANSYS erweitert und anhand der o.g. TOPFLOW-Experimente validiert. Außerdem erfolgten Verbesserungen u.a. für die Turbulenzmodellierung in Blasenströmungen sowie Simulationen zur Validierung der Modelle für Blasenkräfte und Blasenkoaleszenz und -zerfall. Ein wesentlicher Fortschritt wurde bei der Modellierung freier Oberflächen durch die Verallgemeinerung des AIAD-Modells erreicht. Die am Heißstrangmodell ermittelten Flut¬kurven können unter Nutzung dieses Modells in guter Übereinstimmung berechnet werden.

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Kumar, Mithlesh. "Magnetic flux distorsion in two-phase liquid metal flow." Phd thesis, Toulouse, INPT, 2016. http://oatao.univ-toulouse.fr/15854/1/Kumar_1.pdf.

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A Generation IV Sodium cooled Fast Reactor (SFR) is being researched and developed at CEA, Cadarache France under the project named ASTRID. Monitoring gas presence in SFR is important with respect to its safe operation. In accordance with the principles of diversity, techniques based on different measurement principles have been proposed. This thesis concerns the detection and characterization of void using magnetic flux perturbation principle. An Eddy Current Flow Meter (ECFM) device is used for this purpose. From the technological point of view, the objective is to evaluate the feasibility of ECFM as a flow and/or void monitoring/characterizing device; and to determine which parameters are of interest and what are the precision of these measurements; and whether it is possible to measure the flow rate and void fraction simultaneously with the same ECFM device. From the physics point of view, the ECFM system involves the magnetic flux perturbation due to voids in the presence of Faraday induction and Lorentz force effects. Therefore ECFM integrated signal contains informations about the void, Faraday induction and Lorentz force effects based perturbation in magnetic flux and their couplings. Our objective is to understand the nature and extent of these couplings. Specific experiments have been developed to study the effects of flow velocity, void fraction and magnetic flux pulsations on the response of an ECFM. It consists in modeling the two-phase flow by a moving aluminium rod (plug flow) with holes and grooves to simulate voids. Flow velocity range of variation was 0

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50

Swaidan, Ali. "Study of water injection with evaporation in a heterogeneous highly degraded nuclear reactor core." Thesis, Toulouse, INPT, 2018. http://www.theses.fr/2018INPT0002/document.

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Les accidents graves résultant de la fusion d’un coeur de réacteur nucléaire doivent être anticipés pour améliorer l’efficacité de leur mitigation. De tels accidents sont survenus à TMI-2 (1979) et à Fukushima (2011). Suite à un accident de perte de refroidissement, l’échauffement du coeur et l’oxydation de la gaine de combustible suivie d’un renoyage (injection d’eau) peuvent entraîner l’effondrement des barres de combustible et la formation d’un lit de débris dans le coeur. La vapeur produite lors du renoyage peut activer l’oxydation exothermique du Zircaloy, entraînant la fusion partielle des matériaux. Cette évolution engendre des zones à porosité réduite limitant la pénétration de l’eau et/ou des zones imperméables. Dans cette situation, l’efficacité de l’injection d’eau dans le coeur pour arrêter la progression de la dégradation et empêcher la fusion du coeur du réacteur peut être considérablement réduite. Dans ce cadre, l’IRSN a lancé le programme PEARL visant à étudier la thermohydraulique du renoyage des lits de débris chauds entourés d’une zone plus perméable simulant la présence de zones intactes ou moins endommagées dans le coeur. Dans cette thèse, les expériences PEARL ont été modélisées et simulées avec ICARE/CATHARE pour évaluer l’évolution d’un renoyage d’un lit de débris surchauffé entouré d’un bypass de perméabilité plus grande. La thermohydraulique du processus a été analysée et l’effet de différents paramètres (géométrie, conditions aux limites) sur le comportement de renoyage a été évalué. Sous certaines conditions, l’entraînement de l’eau dans le bypass a été identifié et évalué. Un modèle analytique a été mis au point ensuite pour étudier de façon approfondie le renoyage d’un milieu poreux hétérogène surchauffé composé de deux lits de débris de perméabilité et de porosité différentes et pour décrire l’entraînement de l’eau dans le bypass. Ce modèle calcule les principales variables caractérisant le processus de renoyage, telles que la vitesse du front de trempe, le taux de conversion eau-vapeur et le débit d’eau entraîné dans le bypass.Il fournit de bons résultats qualitatifs et quantitatifs concernant la redistribution du débit d’eau par rapport aux résultats expérimentaux. Ce modèle a plusieurs avantages. Il est écrit sous une forme plutôt générale incluant les termes de correction de Forchheimer et les termes croisés non nuls dans l’équation de Darcy-Forchheimer généralisée. Les différentes options des équations de quantité de mouvement proposées, y compris les changements dans les corrélations et les lois de frottement interfacial, peuvent être testées facilement. La comparaison des calculs avec les résultats expérimentaux indique qu’il est nécessaire d’inclure une loi de frottement interfacial pour obtenir de bonnes prédictions. L’extrapolation à l’échelle du réacteur est simple et des calculs ont été effectués pour évaluer l’impact des paramètres géométriques du lit de débris (granulométrie, porosité, dimensions) ainsi que les conditions thermiques et hydrauliques (température, pression, débit d’injection). Ainsi, le modèle est très utile pour estimer le temps de trempe total et latempérature maximale qui pourraient être atteinte dans le lit de débris à grande échelle. Cela permet d’évaluer la probabilité de réussite du renoyage d’un lit de débris chauds formé lors d’un scénario accidentel hypothétique
Severe accidents arising from the fusion of a nuclear reactor core must be anticipated to enhance the efficiency of their mitigation. Such accidents have occurred at TMI-2 (1979) and Fukushima (2011). Following a loss of coolant accident, core heating and oxidation of the fuel cladding followed by reflooding (injection of water) may lead to the collapse of fuel rods and formation of porous debris bed in the core. Steam produced upon reflooding may activate the exothermic oxidation of Zircaloy leading to partial melting of materials. Such evolution generates zones with reduced porosity limiting coolant penetration and/or impermeable blocked zones. In this situation, the efficiency of injecting water into the core to stop the progress of degradation and prevent the reactor core melting may be significantly reduced. In this scope, IRSN launched PEARL program to investigate the thermal hydraulics of reflooding of hot debris beds surrounded by a more permeable zone simulating the presence of intact or less damaged zones in the core. The PEARL experiments were modeled and simulated using ICARE/CATHARE code to assess the evolution of a bottom reflooding of a superheated debris bed surrounded by a bypass of larger permeability. The thermal hydraulics of the quenching process has been analyzed and the effect of each of the initial conditions on the reflooding behavior was assessed. The effect of pressure was investigated and related to the entrainment of injected water at quench front level into the bypass. An analytical model was then developed to investigate thoroughly the reflooding of a superheated heterogeneous porous medium, composed of two layers of contrasting permeability and porosity, and to describe the water entrainment in the bypass. This model computes the main variables characterizing the reflooding process such as quench front velocity, water-to-steam conversion ratio, and the flow rate of water entrained in the bypass. It provides good qualitative and quantitative results for the two-phase flow redistribution as compared to experimental results. This model has several advantages. It is written in a rather general form including the Forchheimer correction terms and non-zero cross-terms in the generalized Darcy-Forchheimer momentum equation. Variations of proposed momentum equations including changes in correlations andinterfacial friction laws can be tested easily and efficiently. Comparison of the calculations against experimental results indicated that it is necessary to include an interfacial friction law to obtain good predictions. This model allows performing fast evaluations of the efficiency of cooling bycomputing the fraction of the injected flow rate that participates in cooling. Upscaling to the reactor scale is straightforward and calculations were performed to assess the impact of geometric parameters of the debris bed (particle size, porosity, dimensions) as well as thermal hydraulic conditions (temperature, pressure, injection flow rate) on the reflooding process. Thus the model is very useful to estimate the total quenching time and the maximum temperature that could be reached by the hot debris bed at large scales. This allows assessing the probability of a successful quenching of a hot debris bed formed during a hypothetical accidental scenario

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