Segui questo link per vedere altri tipi di pubblicazioni sul tema: Htr fuel.
Tesi sul tema "Htr fuel"
Cita una fonte nei formati APA, MLA, Chicago, Harvard e in molti altri stili
Vedi i top-37 saggi (tesi di laurea o di dottorato) per l'attività di ricerca sul tema "Htr fuel".
Accanto a ogni fonte nell'elenco di riferimenti c'è un pulsante "Aggiungi alla bibliografia". Premilo e genereremo automaticamente la citazione bibliografica dell'opera scelta nello stile citazionale di cui hai bisogno: APA, MLA, Harvard, Chicago, Vancouver ecc.
Puoi anche scaricare il testo completo della pubblicazione scientifica nel formato .pdf e leggere online l'abstract (il sommario) dell'opera se è presente nei metadati.
Vedi le tesi di molte aree scientifiche e compila una bibliografia corretta.
1
Van, der Merwe Jacobus Johannes. "Modelling silver transport in spherical HTR fuel". Thesis, Pretoria : [s. n.], 2009. http://upetd.up.ac.za/thesis/available/etd-10172009-102536/.
Testo completo
2
Murovhi, Phathutshedzo. "Low temperature thermal properties of HTR nuclear fuel composite graphite". Diss., University of Pretoria, 2013. http://hdl.handle.net/2263/33156.
Testo completoAbstract (sommario):
Graphite and graphite composite materials are of great importance in various applications; however, they have been widely used in nuclear applications. Primarily in nuclear applications such, as a moderator where its primary aim is to stop the fast neutrons to thermal neutron.
The composite graphite (HTR-10) has potential applications as a moderator and other applications including in aerospace field. Structurally the composite shows stable hexagonal form of graphite and no traces of the unstable Rhombohedral patterns. Thermal conductivity indicates the same trends observed and known for nuclear graded graphite.
The composite was made as a mixture of 64 wt% of natural graphite, 16 wt% of synthetic graphite binded together by 20 wt% of phenolic resin. The resinated graphite powder was uni-axially pressed by 19.5 MPa to form a disc shaped specimen. The disc was then cut and annealed to 1800 °C. The composite was further cut into two directions (parallel and perpendicular) to the pressing direction. For characterization the samples were cut into 2.5 x 2.5 x 10 mm3. There were exposed to proton irradiation for 3 and 4.5 hrs respectively and characterized both structurally and thermally.
Through the study what we have observed was that as the composite is exposed to proton irradiation there is an improvement structurally. Thus, the D peak in the Raman spectroscopy has decreased substantially with the irradiated samples. XRD has indicated that there is no un-stable Rhombohedral phase pattern in both the pristine and the irradiated samples.
However this was further confirmed with that thermal conductivity is also increasing with irradiation exposure. This is anomalous to irradiated graphite in which defects are supposedly induced. Looking into the electrical resistivity we have noted that pristine samples have higher resistivity as compared to the irradiated samples. Seebeck coefficient indicates that there is some form of structural perfection and the samples have a phonon drag dip at the known graphite temperature of 35 K. This has shown us there are no impurities induced by irradiation of the samples.Dissertation (MSc)--University of Pretoria, 2013.
gm2014
Physics
Unrestricted
3
Rohbeck, Nadia. "The high temperature mechanical properties of silicon carbide in TRISO particle fuel". Thesis, University of Manchester, 2014. https://www.research.manchester.ac.uk/portal/en/theses/the-high-temperature-mechanical-properties-of-silicon-carbide-in-triso-particle-fuel(275b2e07-8a5e-4b22-b575-3ded9c6b9008).html.
Testo completoAbstract (sommario):
The high temperature reactor (HTR) requires a completely new fuel design as it operates at around 1000°C in normal conditions and can reach up to 1600°C in case of an accident. The fuel and its cladding consist fully of ceramic materials, which precludes the possibility of a core meltdown and thus ensures inherent safety. The integral part of all HTR core designs is the tristructural-isotropic (TRISO) particle, which encapsulates the fissionable materials in succeeding coatings of pyrolytic carbon and silicon carbide (SiC). An exceptional mechanical integrity of the silicon carbide layer in all conditions is required to ensure full fission product retention. Within this work simulated TRISO fuel has been fabricated by fluidized bed chemical vapour deposition and was annealed in protective atmosphere up to 2200°C for short durations. Subsequent mechanical tests showed only minor reductions in the fracture strength of the SiC up to 2000°C. Substantial weight loss and crystal growth were observed after annealing at 2100°C and above. Raman spectroscopy identified the formation of a multi-layered graphene film covering the SiC grains after annealing and scanning electron microscopy revealed significant porosity formation within the coating from 1800°C onwards. These observations were attributed towards an evaporation-precipitation mechanism of SiC at very elevated temperatures that only slightly diminishes the hardness, elastic modulus or fracture strength, but might still be problematic in respect to fission product retention of the SiC layer. The new technique of high temperature nanoindentation was applied to measure the elastic modulus and hardness of SiC in-situ up to 500°C in argon atmosphere. The elastic modulus was found to be only slightly reduced over the measurement range, while the hardness showed a significant drop. Investigations of the deformation zone beneath the indenter tip executed by transmission electron microscopy showed slip and deformation twinning. On specimens that had been subject to neutron irradiation an irradiation hardening effect was noted. The elastic modulus showed only a minor increase compared with the non-irradiated samples. Oxidation experiments were carried out in air up to 1500°C. Analysis of the oxidation layer showed the formation of amorphous silica and cristobalite for the highest temperatures.
4
Zhang, Zhan. "Neutron energy spectrum reconstruction method based for htr reactor calculations". Thesis, Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/41195.
Testo completoAbstract (sommario):
In the deep burn research of Very High Temperature Reactor (VHTR), it is desired to make an accurate estimation of absorption cross sections and absorption rates in burnable poison (BP) pins. However, in traditional methods, multi-group cross sections are generated from single bundle calculations with specular reflection boundary condition, in which the energy spectral effect in the core environment is not taken into account. This approximation introduces errors to the absorption cross sections especially for BPs neighboring reflectors and control rods.
In order to correct the BP absorption cross sections in whole core diffusion calculations, energy spectrum reconstruction (ESR) methods have been developed to reconstruct the fine group spectrum (and in-core continuous energy spectrum). Then, using the reconstructed spectrum as boundary condition, a BP pin cell local transport calculation serves an imbedded module within the whole core diffusion code to iteratively correct the BP absorption cross sections for improved results.
The ESR methods were tested in a 2D prismatic High Temperature Reactor (HTR) problem. The reconstructed fine-group spectra have shown good agreement with the reference spectra. Comparing with the cross sections calculated by single block calculation with specular reflection boundary conditions, the BP absorption cross sections are effectively improved by ESR methods. A preliminary study was also performed to extend the ESR methods to a 2D Pebble Bed Reactor (PBR) problem. The results demonstrate that the ESR can reproduce the energy spectra on the fuel-outer reflector interface accurately.
5
Chiuta, Steven. "The potential utilization of nuclear hydrogen for synthetic fuels production at a coal–to–liquid facility / Steven Chiuta". Thesis, North-West University, 2010. http://hdl.handle.net/10394/4840.
Testo completoAbstract (sommario):
The production of synthetic fuels (synfuels) in coal–to–liquids (CTL) facilities has contributed
to global warming due to the huge CO2 emissions of the process. This corresponds to
inefficient carbon conversion, a problem growing in importance particularly given the limited
lifespan of coal reserves. These simultaneous challenges of environmental sustainability and
energy security associated with CTL facilities have been defined in earlier studies. To reduce
the environmental impact and improve the carbon conversion of existing CTL facilities, this
paper proposes the concept of a nuclear–assisted CTL plant where a hybrid sulphur (HyS)
plant powered by 10 modules of the high temperature nuclear reactor (HTR) splits water to
produce hydrogen (nuclear hydrogen) and oxygen, which are in turn utilised in the CTL
plant. A synthesis gas (syngas) plant mass–analysis model described in this paper
demonstrates that the water–gas shift (WGS) and combustion reactions occurring in
hypothetical gasifiers contribute 67% and 33% to the CO2 emissions, respectively. The
nuclear–assisted CTL plant concept that we have developed is entirely based on the
elimination of the WGS reaction, and the consequent benefits are investigated. In this kind of
plant, the nuclear hydrogen is mixed with the outlet stream of the Rectisol unit and the
oxygen forms part of the feed to the gasifier. The significant potential benefits include a 75%
reduction in CO2 emissions, a 40% reduction in the coal requirement for the gasification
plant and a 50% reduction in installed syngas plant costs, all to achieve the same syngas
output. In addition, we have developed a financial model for use as a strategic decision
analysis (SDA) tool that compares the relative syngas manufacturing costs for conventional
and nuclear–assisted syngas plants. Our model predicts that syngas manufactured in the
nuclear–assisted CTL plant would cost 21% more than that produced in the conventional
CTL plant when the average cost of producing nuclear hydrogen is US$3/kg H2. The model
also evaluates the cost of CO2 avoided as $58/t CO2. Sensitivity analyses performed on the
costing model reveal, however, that the cost of CO2 avoided is zero at a hydrogen
production cost of US$2/kg H2 or at a delivered coal cost of US$128/t coal. The economic
advantages of the nuclear–assisted plant are lost above the threshold cost of $100/t CO2.
However, the cost of CO2 avoided in our model works out to below this threshold for the
range of critical assumptions considered in the sensitivity analyses. Consequently, this paper
demonstrates the practicality, feasibility and economic attractiveness of the nuclear–assisted
CTL plant.Thesis (M.Ing. (Nuclear Engineering))--North-West University, Potchefstroom Campus, 2011.
6
Izenson, Michael G. (Michael Gary). "Effects of fuel particle and reactor core design on modular HTGR source terms". Thesis, Massachusetts Institute of Technology, 1986. http://hdl.handle.net/1721.1/14787.
Testo completoAbstract (sommario):
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Nuclear Engineering, 1987.MICROFICHE COPY AVAILABLE IN ARCHIVES AND SCIENCE.
Bibliography: v.3, leaves 516-522.
by Michael G. Izenson.
Ph.D.
7
Gopalan, Babu. "INVESTIGATION OF HYDROGEN STORAGE IN IDEAL HPR INNER MATRIX MICROSTRUCTURE USING FINITE ELEMENT ANALYSIS". Ohio University / OhioLINK, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1159476259.
Testo completo
8
Tshamala, Mubenga Carl. "Simulation and control implications of a high-temperature modular reactor (HTMR) cogeneration plant". Thesis, Stellenbosch : Stellenbosch University, 2014. http://hdl.handle.net/10019.1/86264.
Testo completoAbstract (sommario):
Thesis (MScEng)--Stellenbosch University, 2014.ENGLISH ABSTRACT: Traditionally nuclear reactor power plants have been optimised for electrical power generation only. In the light of the ever-rising cost of dwindling fossil fuel resources as well the global polluting effects and consequences of their usage, the use of nuclear energy for process heating is becoming increasingly attractive. In this study the use of a so-called cogeneration plant in which a nuclear reactor energy source is optimised for the simultaneous production of superheated steam for electrical power generation and process heat is considered and analysed. The process heat superheated steam is generated in a once-through steam generator of heat pipe heat exchanger with intermediate fluid while steam for power generation is generated separately in a once-through helical coil steam generator. A 750 °C, 7 MPa helium cooled HTMR has been conceptually designed to simultaneously provide steam at 540 °C, 13.5 MPa for the power unit and steam at 430 °C, 4 MPa for a coal-to-liquid fuel process. The simulation and dynamic control of such a typical cogeneration plant is considered. In particular, a theoretical model of a typical plant will be simulated with the aim of predicting the transient and dynamic behaviour of the HTMR in order to provide guideline for the control of the plant under various operating conditions. It was found that the simulation model captured the behaviour of the plant reasonably well and it is recommended that it could be used in the detailed design of plant control strategies. It was also found that using a 1500 MW-thermal HTMR the South African contribution to global pollution can be reduced by 1.58%.
AFRIKAANSE OPSOMMING: Tradisioneel is kernkragaanlegte vir slegs elektriese kragopwekking geoptimeer. In die lig van die immer stygende koste van uitputbare fossielbrandstohulpbronne asook die besoedelingsimpak daarvan wêreldwyd, word die gebruik van kernkrag vir prosesverhitting al hoe meer aanlokliker. In hierdie studie word die gebruik van ‘n sogenaamde mede-opwekkingsaanleg waarin ‘n kernkragreaktor-energiebron vir die gelyktydige produksie van oorverhitte stoom vir elektriese kragopwekking en proseshitte oorweeg ontleed word. Die oorvehitte stoom word in ‘n enkeldeurvloei-stoomopwekking van die hittepyp-hitteruiler met tussenvloeistof opgewek en stoom vir kragopwekking word apart in ‘n enkeldeurvloei-spiraalspoel-stoomopwekker opgewek. ‘n 750 °C, 7 MPa heliumverkoelde HTMR is konseptueel ontwerp vir die gelytydige veskaffing van stoom by 540 °C, 13.5 MPa, vir die kragopwekkings eenheid, en stoom by 430 °C, 4 MPa, vir ‘n steenkool-tot-vloeibare (CTL) brandstoff proses. Die simulasie en dinamiese beheer van ‘n tipiese HTMR mede-opwekkingsaanleg word beskou. ‘n die besonder word ‘n teoretiese model van die transiënte en dinamiese gedrag van die aanleg gesimuleer om sodoene riglyne te identifiseer vir die ontwikkeling van dinamiese beheer strategië vir verskillende werkstoestande van die aanleg. Daar was ook gevind dat die simulasie model van die aanleg se gedrag goed nageboots word en dat dit dus gebruik kan word vir beheer strategie doeleindes. Indien so ‘n 1500 MW-termies HTMR gebruik word sal dit die Suid Afrikaanse besoedling met 1.58% sal kan verminder.
9
Magnusson, Ann-Sofie. "Sveriges universitets- och högskoleförbunds-modellen : Har införandet av SUHF-modellen ökat förtroendet för lärosätenas redovisning av indirekta kostnader hos forskningsfinansiärerna?" Thesis, Högskolan i Gävle, Avdelningen för ekonomi, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-14899.
Testo completoAbstract (sommario):
Abstrakt Titel: SUHF-modellen Nivå: C-uppsats i ämnet företagsekonomi Författare: Ann-Sofie Magnusson Handledare: Jan Svanberg Datum: 2013 – juni Syfte: Syftet med studien är att utforska hur SUHF-modellen är uppbyggd och om övergången till SUHF-modellen har lett till att forskningsfinansiärernas förtroende för lärosätenas redovisning av indirekta kostnader har förbättrats. Metod: I studien har en hermeneutisk kvalitativ metod med förstående epistemologi använts. Metoden innehöll en induktiv empirisk prövning av problemformuleringen. Den induktiva empiriska undersökningen bestod av semi-strukturerade intervjuer med fyra lärosäten och fyra forskningsfinansiärer. Resultat och slutsats: Studien visar att SUHF-modellen inte är tillräckligt tydlig när det gäller gränsdragningen mellan vilka kostnader som är direkta respektive indirekta. Kommunikationen och samarbetet mellan parterna har ökat. Lärosätena upplever att förtroendet har ökat hos finansiärerna samtidigt som forskningsfinansiärernas upplevelse är olika, allt från minskat förtroende till ökat förtroende. Förslag till fortsatt forskning: Undersöka ytterligare forskningsfinansiärer och lärosäten för att kunna säkerställa att resultaten från denna studie är korrekta samt undersöka orsaken till varför förtroendet är oförändrat och dessutom har minskat hos forskningsfinansiärer efter införandet av SUHF-modellen. Nyckelord: SUHF-modell, full kostnadstäckning, indirekta kostnader, förtroende, engagemang, kommunikation, samarbeteAbstract Title: SUHF model Level: Final assignment for Bachelor Degree in Business Administration Author: Ann-Sofie Magnusson Supervisor: Jan Svanberg Date: 2013 - June Aim: The purpose of this study is to explore how the SUHF model is built and if the transition to the SUHF model has led to improvement of research funder’s confidence in the institutions´ accounting of indirect costs. Method: The study has been carried out with a qualitative hermeneutic approach with understanding epistemology. The method included an inductive empirical test of the problem formulation. The inductive empirical study consisted of semi-structured interviews with four universities and four research funders. Result and Conclusions: The study shows that the SUHF model is not sufficiently clear about the distinction between the costs that are direct and indirect. Communication and cooperation between the parties has increased. The universities feel that their confidence has improved among financiers while the research funders' experience is different, ranging from loss of confidence to increased confidence. Suggestions for future research: Investigate additional research funders and universities in order to ensure that the results from this study are reliable and investigate the reasons why the confidence is unchanged and also has reduced with research funders after the introduction of the SUHF model. Key words: SUHF model, full costs recovery, indirect costs, trust, commitment, communication, cooperation
10
Tiwari, Housila. "INVESTIGATION OF THE FEASIBILTY OF METALS, POLYMERIC FOAMS, AND COMPOSITE FOAM FOR ON-BOARD VEHICULAR HYDROGEN STORAGE VIA HYDROSTATIC PRESSURE RETAINMENT (HPR) USING IDEAL BCC MICROSTRUCTURE". Ohio University / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1186967436.
Testo completo
11
Caruso, Naomi. "Chava Shapiro : a woman before her time". Thesis, McGill University, 1991. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=60615.
Testo completoAbstract (sommario):
This is a study of Chava Shapiro, a woman writer, born in 1876 in the Ukraine, who died in 1943 in Nazi Czechoslovakia. It describes her conventional Hasidic upbringing, her successful rebellion against it and her subsequent studies in Switzerland which led to a career in Hebrew journalism. It follows her return to Russia in 1914, her escape to Czechoslovakia after the pogroms of 1919 and 24 years later her tragic end in Terezin.Dominating the study is the well-known Hebrew writer, Reuven Brainin, 1862-1939, with whom Chava Shapiro fell in love and who exerted an extraordinary influence on her life.
Using original, never before published materials from the Jewish Public Library Archives in Montreal, the study seeks to define the woman as a feminist and a Hebrew writer.
12
Schachter, Tammy. "As her world turns : women and soap opera". Thesis, McGill University, 1998. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=21264.
Testo completoAbstract (sommario):
Mass produced narratives that have been designed and targeted for predominantly female audiences have been marginalized by dominant culture. Throughout the history of art and English literature, women have been both objectified and misrepresented. All that has been deemed domestic, emotional and of the personal sphere has been declared valueless by patriarchy. The soap opera genre reverses this negative valorization. It is one that perpetuates the feminine tradition of creating communities through words---talk, gossip, testimony. In this work, the American soap opera is discussed as a venue for the exploration of issues that concern women's lives, as a site for the generation of female pleasure, and as the mother of subcultural networks that inform a female community. While the narratives address women's concerns, the soap opera fan magazines and fan clubs celebrate a form that highlights orality, emotion and empathy in a culture that often depreciates them.
13
Wright, Michele E. "Power suits her : an arts-based portrayal of women and power". Thesis, McGill University, 2002. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=79813.
Testo completoAbstract (sommario):
This arts-based study examines how three women, who hold senior positions in development organizations, perceive of power. Emphasis is placed not only on how the participants describe their power identities, but also on how those identities can be portrayed. Based on data collected in interviews and drawing on the metaphors of portraiture, the power suit and the feminist conception of "voice", the women's power identities are represented in three ways: textually (in the form of "power identity profiles"), visually (in the form of "power suit" costume designs) and aurally (in the form of dramatic monologues). Through notes, descriptions, outlines and explanations the entire process of this aesthetic/interpretive inquiry is documented.While not being offered as a generalizable or even representative sample, the three women in this study illustrate the importance of diverse, individualized inquiry approaches in order to appreciate and represent the nuance and contradiction inherent to women's thoughts and feelings about power.
14
Slowe, Martha. "In defense of her sex : women apologists in early Stuart letters". Thesis, McGill University, 1992. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=39756.
Testo completoAbstract (sommario):
This study explores the problem of female defense in relation to the constitution of women as disempowered speaking subjects within the dominant rhetorical structures of early Stuart literature. The discourse of male rhetoricians defines a subordinate place for women in the order of language. The English formal controversy arguments over the nature of women in the sixteenth and early seventeenth centuries similarly deploy tropes of male precedence and female subordination to restrain women in the symbolic order and to inhibit any form of female discourse. In order to construct an effective defense a female apologist must reconstitute herself by working within and subverting these constraints. Early Stuart drama provides numerous instances in which women confront and contest the pre-established limits for female speech in their efforts to defend themselves and/or their sex. However, in the dramas selected for this scrutiny, despite the forceful defense strategies that female characters use in their attempts to negotiate their negative positions in language, they are ultimately marginalized. My final chapter therefore examines the rhetorical strategies whereby in her life and writing one woman author, Elizabeth Cary, successfully appropriated and transformed the gendered tropes into compelling female defenses.
15
Li, Xiaorong 1969. "Woman writing about women : Li Shuyi (1817-?) and her gendered project". Thesis, McGill University, 2000. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=33300.
Testo completoAbstract (sommario):
This thesis examines the life and poetry collection of the woman poet Li Shuyi (1817--?) within the context of women's literary culture in late imperial China. In particular, the textuality of Li Shuyi's poetry collection Shuyinglou mingshu baiyong (One Hundred Poems from Shuying Tower on Famous Women) forms the centre of critical analysis, which aims to articulate her gendered intervention into representations of women's image in poetry. The thesis is organized into three interconnected sections: the reconstruction of Li Shuyi's life in order to provide a context to articulate her relationship to writing, a reading of Li Shuyi's self-preface to discuss her motivation to write, and critical analysis of poems according to the three thematic categories of "beauty, talent, and qing ." The thesis demonstrates how a woman author's self-perception leads to her becoming a conscious writing subject, and how this self-realization then motivates her to produce a gendered writing project.
16
Aldelaijan, Saad. "Reference dosimetry of HDR Ir-192 brachytherapy source using radiochromic film". Thesis, McGill University, 2010. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=95205.
Testo completoAbstract (sommario):
A protocol of establishing radiochromic film based reference dosimetry for high dose rate Ir-192 brachytherapy source was assessed and described. A comparison between calibration curves created in water and Solid Water are provided. Solid Water was shown to be a viable alternative to water in establishing calibration curve for Ir-192 radiation beam. A Monte Carlo correction factor was calculated to convert the dose to water into dose to Solid Water and the experimental methods that we performed agreed with the Monte Carlo results where the ratio (DSW/DW)Ir-192 was found to be 0.9808 ± 0.14% (1σ). EBT-2 GAFCHROMIC film model was also investigated for absorption properties and found to be a less sensitive than its predecessor (EBT-1) in terms of net change of absorbance, but that did not affect the dosimetric value that this film possesses. A dose error assessment method has been described for EBT-2 film model (and is applicable to other types as well) that can establish the time error constraints on the post-irradiation scanning time that will still provide an acceptable dose error for clinical applications if the protocol employing the shorter post-irradiation scanning time is implemented in the clinic. We show that for two post-irradiation scanning times of 30 minutes and 24 hours the 1% dose error can be granted if the scanning time window is less than ± 5 minutes and ± 2 hours, respectively. Performance of EBT-2 model was also evaluated in water and it was concluded that a suggested correction protocol is necessary for immersion times that exceed 2 hours. This correction was tested with the calibration curve created from water setup and found to be effective when compared to the dose-corrected calibration curve in Solid Water.Un protocole d'établir film radiochromique dosimétrie de référence en fonction de débit de dose élevé source Ir-192 curiethérapie été évalués et décrits. Une comparaison entre les courbes d'étalonnage créé dans l'eau et Solid WaterTM sont fournis. Solid WaterTM s'est révélée être une alternative viable à l'eau dans l'établissement de la courbe d'étalonnage pour les Ir-192 faisceau de rayonnement. Un facteur de correction de Monte Carlo a été calculé pour convertir la dose à l'eau en dose à Solid WaterTM et les méthodes expérimentales que nous avons réalisé d'accord avec les résultats de Monte Carlo où le ratio (DSW/DW)Ir-192 a été trouvé à 0.9808 ± 0.14% (1σ). EBT-2 modèle GAFCHROMICTM film a également été étudiée pour les propriétés d'absorption et jugé être un moins sensible que son prédécesseur (EBT-1) en termes de variation nette de l'absorbance, mais cela n'a pas d'incidence sur la valeur dosimétrique que ce film possède. Une méthode d'évaluation des doses d'erreur a été décrit pour le modèle EBT-2 film (et est applicable à d'autres types ainsi) qui permet d'établir les contraintes de temps d'erreur sur le post-irradiation temps de balayage, qui va encore donner une erreur de dose acceptable pour des applications cliniques, si le protocole emploie le plus court post-irradiation de numérisation temps est mis en uvre dans la clinique. Nous montrons que pour deux post-irradiation de numérisation fois de 30 minutes et 24 heures, la dose d'erreur de 1% peut être accordée si la fenêtre de temps de balayage est inférieure à ± 5 minutes et de ± 2 heures, respectivement. Performance de la EBT-2 modèle a également été évaluée dans l'eau et il a été conclu un protocole de correction proposé est nécessaire pour que les temps d'immersion supérieure à 2 heures. Cette correction a été testé avec la courbe de calibration créée à partir d'installation de l'eau et ont été jugés effic
17
Gemmill, Kathleen. "Jane Austen as critic: a study of her novelistic theory and practice". Thesis, McGill University, 2009. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=66822.
Testo completoAbstract (sommario):
This MA Thesis is a study of the relationship between Jane Austen's critical views on the novel and her own creative practice as a novelist. The first chapter delineates Austen's novelistic theory using the five letters on fiction that Austen wrote to Anna Lefroy. The second chapter focuses on "Opinions of Mansfield Park" and "Opinions of Emma," examining how Austen's editorial ventriloquism of the opinions reflects her own critical voice. The third chapter shows how Austen modified her reviewers' hints from "Plan of a Novel" to fit within her own novelistic standards in Persuasion. The fourth chapter comprises a comparative reading of the cancelled and published versions of the final chapters of Persuasion, observing the effects of Austen's literary standards on her writing practice. Collectively, these chapters explore the degree to which Austen's theoretical literary standards, and her reflections on the criticisms that her readership made of her own works, inflect her own novelistic technique.La présente thèse de maîtrise étudie le rapport entre les idées théoriques de Jane Austen sur le genre du roman, et sa propre pratique créative comme romancière. Le premier chapitre extrait sa théorie du roman des cinq lettres qu'elle a écrites à propos du roman de sa nièce, Anna Lefroy. Le deuxième chapitre porte sur les « Opinions of Mansfield Park » et « Opinions of Emma » rassemblées par Austen. Ce chapitre examine la manière dont sa ventriloquie et sa mise au point des opinions reflètent sa voix de critique. Le troisième chapitre montre comment Austen a modifié les suggestions des critiques dans « Plan of a Novel » pour les rendre compatibles avec ses principes littéraires dans Persuasion. Le quatrième chapitre compare les deux versions, publiée et non publiée, des derniers chapitres de Persuasion. Ce chapitre examine les effets des normes littéraires d'Austen sur sa pratique comme ro mancière. Collectivement, ces chapitres évaluent dans quelle mesure ses principes littéraires, et ses réflexions sur les critiques que ses lecteurs ont faites de ses œuvres, guident sa propre technique comme romancière.
18
Kachroo, Meera. "The goddess and her powers : the Tantric identities of the Saundarya laharï". Thesis, McGill University, 2005. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=83185.
Testo completoAbstract (sommario):
This thesis is a study of the Saundarya Lahari, a Sanskrit poem associated with the Srividya Sakta Tantric tradition. It traces the movement of meaning between textual, ritual, and cultural spaces in order to understand the performed possibilities of the text. The Goddess as Sakti (power) both grants enjoyment and is the principle of that enjoyment: beauty, love, and worldly powers. These powers follow the movements of the text: its scanning of the Goddess from shining head to toe; the twinned movements of publicity (exoterism) and secrecy (esoterism); and the gestures and utterances of ritual performance. First the text is located among classical Sanskrit aesthetics, then as a devotional song (stotra), and finally as a manual for occult practice (prayoga). Situated in these contexts, the multivalence of the text comes to the foreground; mapping the tensions between these meanings is the starting point for the development of a Tantric hermeneutic.
19
Huang, Qiaole 1976. "Writing from within a women's community : Gu Taiqing (1799-1877) and her poetry". Thesis, McGill University, 2004. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=81496.
Testo completoAbstract (sommario):
This thesis examines the life and poetry of the woman poet Gu Taiqing (1799-1877) within the context of a community of gentry women in mid-nineteenth century Beijing. This group of women was a "community" in the sense that their contact, sociability, friendship and poetry writing were meaningfully intertwined in their lives. The thesis is divided into three interconnected chapters. Two separate biographical accounts of Gu Taiqing's life---one centered around the relationship with her husband, and the second around her relationship with her female friends---are reconstructed in the first chapter. This biographical chapter underlines the importance of situating Gu in the women's community to understand her life and poetry. The second is comprised of a reconstruction of this women's community, delineating its members and distinctive features. In the third chapter, a close-reading of Gu's poems in relation to the women's community focuses on the themes of xian (leisure), parting, and friendship. This chapter shows how each of these themes are represented by Gu and how her representations are closely related to the experiences of this women's group.
20
Boyd, Shelley Elizabeth. "How does her garden grow? : the garden topos and trope in Canadian women's writing". Thesis, McGill University, 2006. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=102791.
Testo completoAbstract (sommario):
This study offers additional nuance to the garden topos and trope within nineteenth- and twentieth-century Canadian women's writing and extends the critical discussion of landscape and the garden as archetype in Canadian literature. This dissertation cross-fertilizes literary analysis with garden theory, using the work of such garden historians as John Dixon Hunt, Mark Francis, and Randolph Hester. The argument emphasizes that gardens in literature, like their actual counterparts, are an art of milieu, reflective of their socio-physical contexts. Both real and textual gardens are rhetorical: their content and formal features invite interpretation. A textual garden performs similarly to an actual garden by providing a spatial frame; a means of naturalization; a vivid exemplar of growth, fertility and beauty; a mediation of the artificial and the natural; a space of paradox; and a site of social performance.The specific focus of this study is "domestic gardens": gardens that are intimate, immediate to the home, and part of daily life. Chapter one separates the garden from archetypal models by studying the garden as an actual place (specifically, the backwoods kitchen garden) described in the works of Susanna Moodie and Catharine Parr Traill. Chapter two examines how the garden influences Moodie's and Traill's writing of the "transplanted" female emigrant. Chapter three presents the bower as an important precursor to the domestic garden through Gabrielle Roy's Enchantment and Sorrow (1984) and "Garden in the Wind" (1975). Through the bower, Roy mediates the female artist's ambivalence toward home in her pursuit of independence. Chapter four explores Carol Shields' sanctification of the domestic in her fiction through the concept of paradise as both an ideal setting and a mode of being. Chapter five provides a "garden tour" of the poetry of Lorna Crozier, culminating in the garden as a model for the text itself and for the genre of palimpsest. For these writers, literal and figurative gardens are ways of "planting" their characters and personae, "plotting" their narratives, mediating social conventions, and providing an interpretative lens through which readers may perceive the texts as a whole.
21
Park, Chulhoon. "Parallel implementation of hierarchical tetrahedral - octahedral (HTO) subdivision for 3-D finite element mesh refinement". Thesis, McGill University, 2006. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=99529.
Testo completoAbstract (sommario):
Parallel computing is being used more and more frequently in 3-D finite element (FE) mesh generation in electromagnetics, due to its improvements in efficiency. When applying parallel computing, the computational problem usually needs to be broken into discrete pieces, so that it can be solved simultaneously with multiple compute resources. Less time is then required than with a single compute resource. In this thesis, an algorithm for hierarchical tetrahedral---octahedral (HTO) subdivision was studied and implemented with a parallel message passing interface (MPI). The data structure was designed in such a way as to store the geometric data during the mesh computation. Also, broadcasting and data gathering was used to build up the final geometric file. The experimental results and the enhancement of system performance are presented, comparing sequential computing with parallel computing. The program was implemented in C language/MPI, and the results obtained have made use of the CLUMEQ1 supercomputer Centre facilities at McGill University.1CLUMEQ stands for Consortium Laval UQAM McGill and Eastern Quebec for high performance computing.
22
Larson, Erik. "Serotonin modulates electrosensory processing via 5-HT2 receptors in the weakly electric fish «Apteronotus leptorhynchus»". Thesis, McGill University, 2014. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=123302.
Testo completoAbstract (sommario):
Accurate sensory processing of the environment is a critical function for any organism to survive. In order to accomplish this function neurons must be specifically tuned to respond optimally to relevant stimuli in their environment. One effective way of efficiently encoding information is for neurons to adapt their responses to stimuli arising from different behavioral contexts. Neuromodulators such as serotonin (5-HT) are thought to help mediate such adaptations. The 5-HT system has been well conserved through evolution across vertebrates, suggesting that its function also been conserved. In the weakly electric fish Apteronotus leptorhynchus, 5-HT has been previously shown to increase sensory pyramidal neurons responses located within the electrosensory lateral line lobe (ELL) to stimuli caused by same-sex conspecifics by making them more excitable in vivo. Remarkably, application of 5-HT in vitro has been shown to also render these neurons more excitable through downregulation of both small-conductance calcium-activated (SK) and M-type potassium channels. However, the nature of the 5-HT receptors present in pyramidal neurons is unknown. By using occlusion experiments while recording from pyramidal neurons in vitro, we show that the selective 5-HT2 antagonist, ketanserin, was able to occlude the effects of 5-HT on pyramidal cells as quantified by changes in firing rate, burst fraction, afterhyperpolarization, and mutual information. Our results show that downregulation of both M and SK currents is most likely achieved through the same receptor family and pave the way for future molecular studies performing in situ hybridization or immunohistochemistry to confirm that 5-HT2 receptors are indeed present in the ELL and solely mediate the effects of 5-HT observed both in vitro and in vivo.Traitement sensoriel précis de l'environnement est une fonction essentielle pour tout organisme de survivre. Afin d'accomplir ces neurones doivent être spécialement réglés pour répondre au mieux aux stimuli pertinents dans leur environnement. Un moyen efficace de coder efficacement l'information est pour les neurones à adapter leurs réponses à des stimuli provenant de différents contextes de comportement. Neuromodulateurs comme la sérotonine (5-HT) sont pensés pour aider à la médiation de ces adaptations. Le système 5 -HT a été bien conservé à travers l'évolution des vertébrés, ce qui suggère que sa fonction a également été conservée. En Apteronotus leptorhynchus, un des poissons électriques du genre gymnotiformes, 5-HT a déjà été démontré pour augmenter sensorielles pyramidales neurones réponses situées dans le lobe de la ligne-latérale électrosensoriel (LLE) aux stimuli provoqués par des congénères de même sexe en les rendant plus excitable in vivo. Remarquablement, l'application de la 5-HT in vitro a été démontré également de rendre ces neurones plus excitables à travers à la fois la régulation négative de courants potassiques sensibles au calcium (SK) et les courants potassique de type M. Cependant, la nature des récepteurs 5-HT présents dans les neurones pyramidaux est inconnue. En utilisant les expérimentés d'occlusion lors de l'enregistrement de neurones pyramidaux in vitro, nous montrons que l'antagoniste sélectif 5-HT2, ketanserin, a peut bloquer les effets de la 5-HT sur les cellules pyramidales quantifiées par des changements dans le taux de le potentiel d'action, fraction de le potentiel d'action dans une «bouffée», après-hyperpolarisation, et l'information mutuelle. Nos résultats montrent que la régulation négative des courants à la fois M et SK est probablement atteint par la même famille récepteur et ouvrir la voie à des études moléculaires futures comme l'hybridisation in situ ou l'immunohistochimie pour confirmer que les récepteurs 5-HT2 sont bien présents dans le LLE et permettent les effets de la 5-HT a observé à la fois in vitro et in vivo.
23
Marentette, Paula F. (Paula Frances). "It's in her hands : a case study of the emergence of phonology in American Sign Language". Thesis, McGill University, 1995. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=40189.
Testo completoAbstract (sommario):
A case study of American Sign Language (ASL) acquisition revealed an emerging phonological system influenced by biological, cognitive, and linguistic factors. A hearing child (SJ), acquiring ASL from her Deaf parents, was videotaped over seven sessions between the ages of 1:0 and 2:1. Of the 1,699 manual behaviors observed, 804 were lexical items, or signs. All signs were phonetically coded. Detailed analyses were undertaken to discover acquisition patterns for the three major parameters of ASL signs (handshape, hand location and movement).Overall, SJ's signs were well-formed and adhered to ASL phonological constraints. Location primes were produced accurately, due to SJ's knowledge of the structure of her body. Errors occurred with body parts that were not perceptually salient. Movement parameters were not mastered by SJ during the period of study; no systematic set of substitutions was observed. Handshapes were produced with low accuracy. SJ relied on a small set of maximally contrastive handshapes (i.e., (5,1,A)). These handshapes represent the convergence of ease of production, distribution in the target language phonology, and perceptual salience. SJ used three processes to fit target handshapes to her emerging phonological system: spreading of selected fingers, changing of selected fingers from a marked to an unmarked set, and changing to an open position. These processes reflect anatomical and perceptual preferences as well as linguistic influences.
SJ's sign production showed a small improvement in accuracy and a marked reduction in variability between the ages of 1:0 AND 2:1. Visual feedback did not affect the sign accuracy. A passive hand was more likely to be added to one-handed signs produced outside the visual field, possibly increasing tactile feedback. Path movement and horizontal-place primes were more accurate when tactile feedback was present. There was no evidence that SJ used lexical selection or imitation as strategies for phonological acquisition.
Finally, many of the same factors that influence phonological acquisition in speech guided SJ's acquisition of handshape primes. Her acquisition of location primes, by contrast, did not resemble processes observed in phonological acquisition in speech.
24
Rissel, Jacob, e Felicia Jarméus. "Motivation och ledningsarbete i samband med en omställning : En kvalitativ fallstudie om hur motivation och ledarskapet har förändrats i samband med en omställning inom ett svenskägt försäkringsaktiebolag". Thesis, Linköpings universitet, Företagsekonomi, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-178164.
Testo completoAbstract (sommario):
Bakgrund: I samband med Covid-19 drastiska ökning under våren 2020 tvingades samhället genomgå stora förändringar för att minimera smittspridningen av den rådande pandemin. Försäkringsbranschen är en av de branscher som tvingats genomgå en omställning på arbetsplatsen. Omställningen på det svenskägda försäkringsaktiebolaget har lett till att majoriteten av de anställda tvingats arbeta hemifrån. Då försäkringsbranschen måste fungera väl oavsett samhällssituation är det av extra vikt att bolagets anställda känner sig motiverade till att prestera på arbetet. Eftersom motivation är ett styrmedel som stödjer prestation finner vi det intressant att studera hur ledningen aktivt arbetar med motivationsfrågor samt hur väl det fungerar hos anställda med olika anställningsform. Syfte: Syftet med studien är att studera hur cheferna upprätthåller motivationen på en avdelning inom ett svenskägt försäkringsaktiebolag i samband med en omställning till distansarbete som följd av pandemin. Metod: Studien präglas av en kvalitativ fallstudie där kvalitativa intervjuer har genomförts som metod för att bygga studiens empiriska material. Slutsats: De anställda känner sig mindre motiverade till arbetet i samband med omställningen. Vidare föreligger det skillnader mellan heltid- och deltidsanställda gällande motivation till arbetet, där deltidsanställda är mer motiverade till arbetet än heltidsanställda. Slutligen tillämpar cheferna digitala verktyg för att främja heltidsanställdas motivation. Arbetet med att främja deltidsanställdas motivation har således uteblivit. Cheferna medger att de hade kunnat arbeta mer med att främja motivationen hos heltid- och deltidsanställda.Background: In connection to the drastic increase in Covid-19 during the spring of 2020, society was forced to undergo major changes to minimize the spread of the current pandemic. The insurance industry is one of the industries that has been forced to undergo a change in the workplace due to the current pandemic. Due to the adaption, the swedish insurance company forced the majority of employees to work from home. It's important that employees feel motivated to perform at work as the insurance industry must function well regardless of the societal situation. Due to the fact that motivation is a tool that supports performance, we find it interesting to study howmanagement actively works with motivation issues and how well it works with employees with different forms of employment. Purpose: The purpose of the study is to analyze how managers maintain motivation of a department within a Swedish-owned insurance company, in connection with a transition to telework as a result of the pandemic. Completion: The study is characterized by a qualitative case study where qualitative interviews have been conducted as a method for building the study's empirical material. Conclusions: The employees feel less motivated to work in connection with the work change. Furthermore, there are differences between full-time and part-time employees regarding motivation for work, where part-time employees are more motivated to work than full-time employees. Finally, the management applies digital tools to promote the motivation of full-time employees. The work of promoting the motivation of part-time employees has thus failed. The management admits that they could have worked more to promote the motivation of the employees.
25
Verney, Allison. "Is a Peruvian mother's new pregnancy associated with changes in the dietary intakes of her breastfeeding child?" Thesis, McGill University, 2011. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=104873.
Testo completoAbstract (sommario):
Childhood malnutrition is attributed partly to inadequate feeding practices. This study examined the association of a pregnancy-breastfeeding overlap on dietary intakes of 89 children (10-36 mo) living in Lima, Peru. Their mothers were either not pregnant (NP; n=27), in early, 1st or 2nd trimester, pregnancy (EP; n=27), or in late, 3rd trimester, pregnancy (LP; n=35). Six-hour breast milk and complementary food intakes were measured between 9 AM- 3 PM and anthropometry, socioeconomic, and demographic data were collected. An overlap was associated with decreased breast milk intake in both the EP and LP groups compared to the NP group, however, there were no group differences in 6-hr total energy intake per kilogram of body weight after controlling for confounders. Complementary foods provide the vast majority of the diet and therefore, assuring their quality is key for child nutrition education.Dans les bas quartiers de Lima, au Pérou, la malnutrition chez les enfants est en partie attribuée à des pratiques alimentaires inadéquates. L'objectif de cette étude était de déterminer l'association entre le chevauchement grossesse-allaitement chez les femmes péruviennes et les apports alimentaires de leurs enfants. Au total, 54 dyades mères-bébés ont été recrutées. Certaines mères n'étaient pas enceintes (n=27) tandis que le reste se trouvait dans le premier ou deuxième trimestre de grossesse (n=27). Les apports alimentaires des enfants ont été observés pendant une période de 6 heures, de 9h à 15h. Le lait maternel et les aliments de complément ont été pesés grâce à des tests standard. Les données anthropométriques, socioéconomiques et démographiques ont également été collectées. Le chevauchement de l'allaitement et d'une nouvelle grossesse a été associé à une diminution de l'apport en lait maternel mais à une augmentation de l'apport énergétique total, après avoir pris en compte les variables confondantes. Sans égard à la décision de la mère de continuer à allaiter pendant sa grossesse, ces résultats démontrent que les aliments de complément sont majoritaires dans la diète. Ainsi, il est essentiel d'inclure des notions de qualité de ces aliments dans l'éducation nutritionnelle visant les enfants de cet âge.
26
Clout, Karen. "Mi suete leuedi, her mi béne : the power and patronage of the heroine in Middle English romance". Thesis, McGill University, 1998. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=21202.
Testo completoAbstract (sommario):
This thesis examines the heroines in Middle English romances and argues that, like the noblewomen who lived in England during the Plantagenet period, they are not helpless princesses simply waiting to be rescued by the brave, strong hero. In fact, these heroines show an enormous amount of intelligence, ingenuity, perseverance, and strength of character. Many play a pivotal role in the hero's success in his quest by giving him a token, providing knowledge, or teaching him a lesson. Also, it is the heroines who provide the heroes with rewards after the quests are completed. The present thesis offers a contribution to the study of Medieval English Romances in providing a revision of standard feminist analyses. In many of these studies there seems to be a lack of appreciation for the role of female characters and their relation to the outcome of the hero's quest. Even studies written from a feminist perspective tend to overlook the strength of the heroine's character, the attainment of her goals, and the fact that she is often a powerful figure who is of much higher status than her suitor. In these romances the female characters wield a substantial amount of both private and public power, an aspect of the genre which has often been ignored.
27
Hohenthal, Johanna, e Edvard Setterberg. "CEPs effekt på FP i fossila bränsleintensiva företag: Påverkas relationen om företaget har en CSR-kommitté? : En kvantitativ studie av 827 publika globala bolag". Thesis, Högskolan i Gävle, Avdelningen för ekonomi, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-29201.
Testo completoAbstract (sommario):
Syfte: Företagens miljömässiga ansvar har blivit en allt mer central fråga för företagets intressenter. Tidigare studier som har behandlat relationen mellan Corporate Environmental Performance CEP och Financial Performance FP har resulterat i varierande utfall. Två faktorer som anses påverka denna relation är olikheter mellan branscher och brister i det interna organisationsarbetet. För att få en tydligare bild av relationen mellan CEP och FP behöver forskningen utvecklas för företag som agerar i en ur miljösynpunkt tung bransch. Syftet med studien är att förklara om det finns ett samband mellan CEP och FP i fossila bränsleintensiva företag och se om sambandet är starkare eller svagare om företaget använder en CSR-kommitté. Metod: Studien utgår från en positivistisk forskningsfilosofi med en deduktiv ansats. Studien har en kvantitativ strategi och har formats av en longitudinell design, där sekundärdata har inhämtats för åren 2014-2017 från databasen Thomson Reuters Datastream. Detta har genererat ett urval bestående av 827 publika bolag från hela världen vars data har analyserats i statistikprogrammet SPSS och presenteras i tabeller. Resultat & slutsats: Studiens resultat visar att det finns ett positivt samband mellan miljödimensionen CEP och den finansiella prestationen mätt utifrån både redovisningsmåttet ROE och marknadsmåttet Tobins Q för fossila bränsleintensiva företag. För de fossila bränsleintensiva företagen med en CSR-kommitté visade även resultatet ett starkare samband mellan CEP och FP än för företag utan CSR-kommitté. En jämförelse mellan olika sektorer visade en tydlig variation mellan resultaten, där vissa sektorer hade ett negativt samband mellan CEP och FP. Examensarbetets bidrag: Studien bidrar till den empiriska forskningen och utökar förståelsen för relationen mellan CEP och FP genom att studera fossila bränsleintensiva företag, som är en miljömässigt tung bransch. Studien bidrar även med teoretisk information om huruvida kontinuerligt arbete via CSR-kommittéer påverkar denna relation. Vidare ger studien ett praktiskt bidrag genom att uppmuntra företag att engagera sig i CEP-aktiviteter, istället för uppkomsten av tvingande miljöregleringar, för att nå lönsamhet. Förslag till fortsatt forskning: Ett förslag till fortsatt forskning är att gå djupare ner bland fler sektorer för att kunna se skillnader mellan branscher och göra djupare analyser mellan dessa för att få en större förståelse om relationen mellan CEP och FP. Det kan också finnas skillnader mellan företag av olika storlek, därför är ett andra förslag att dela upp och jämföra resultaten mellan stora och små företag.Aim: The company's environmental responsibility has become an increasingly central issue for the company's stakeholders. Earlier studies that have addressed the relationship between Corporate Environmental Performance CEP and Financial Performance FP have resulted in varying outcomes. Two factors that are considered to affect this relationship are differences between industries and shortcomings in internal organization work. In order to get a clearer picture of the relationship between CEP and FP, research needs to be developed for companies acting in an environmentally heavy industry. The purpose of the study is to explain if there is a connection between CEP and FP in fossil fuel firms and see if the association is stronger or weaker if the company uses a CSR committée. Method: This study is based on a positivistic research philosophy with a deductive approach. The study has a quantitative strategy and has been formed of a longitudinal design, where secondary data has been collected for the years 2014-2017 from the Thomson Reuters Datastream database. This has generated a sample of 827 public companies worldwide whose data has been analyzed in the SPSS statistics program and presented in tables. Result & Conclusions: The result of the study shows that there is a positive correlation between the environmental dimension CEP and the financial performance, measured based on both the accounting measure ROE and the market measure Tobins Q for fossil fuel firms. For the fossil fuel firms with a CSR committée, the result also showed a stronger relationship between CEP and FP than for companies without a CSR committée. A comparison between sectors showed a clear variation between the results, where some sectors had a negative link between CEP and FP. Contribution of the thesis: The study contributes to empirical research and understanding of the relationship between CEP and FP by studying fossil fuel firms, which is an environmentally heavy industry. The study also contributes with theoretical information about whether continuous work through CSR committees affects this relationship. The study also provides a practical contribution by encouraging companies to engage in CEP activities, instead of the emergence of compelling environmental regulations, to achieve profitability. Suggestions for future research: A proposal for further research is to go deeper into more sectors to see differences between industries and to make deeper analyzes between them to gain a better understanding of the relationship between CEP and FP. There may also be differences between companies of different sizes, so a second proposal is to divide and compare the results between large and small companies.
28
Laplante, Patricia. "The functional role of 5-HT7 receptors in rat hippocampal neurons : glucocorticoid receptor regulation and therapeutic action of amitriptyline". Thesis, McGill University, 1998. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=21583.
Testo completoAbstract (sommario):
Handling for the first week of life has been observed to increase glucocorticoid receptor (GR) levels selectively in the hippocampus and frontal cortex. The handling effect is specific to GR, mineralocorticoid receptor (MR) levels are not altered. Handling results in a high turnover of serotonin. In vitro, serotonin (5-hydroxytryptamine, 5-HT) treatment markedly increases cAMP formation and GR expression in hippocampal neurons. We wanted to explore the cellular mechanism involved in GR regulation. Primary hippocampal cell cultures treated with 5-carboxamidotryptamine (5-CT) or 5-HT for five days resulted in an increase in GR levels as measured by receptor binding and Western blotting. This effect was abolished by methiothepin and H8, a protein kinase A inhibitor, but not by pindolol. Cyclic AMP formation was enhanced with 5-CT treatment and was blocked by methiothepin and ritanserin, but not by pindolol. These results led us to examine the possibility of a 5-HT7 receptor mediating the effect of 5-HT on GR expression.We also investigated the therapeutic action of amitriptyline on GR expression. (Abstract shortened by UMI.)
29
Richer, Maxime. "Characterization of the serotonergic and noradrenergic systems in mice lacking the 5-HTA receptor and its relevance to the mechanism of action of antidepressant drugs". Thesis, McGill University, 2001. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=33831.
Testo completoAbstract (sommario):
The implication of central noradrenergic and serotonergic systems in the control of mood has been known for forty years. Indeed, the different classes of molecules prescribed in the treatment of major depression directly interfere with the transmission mediated by these amines, either at the level of the synthesis, the release, the stimulation of receptors, the reuptake or the degradation. According to the leading theory in the field, the increase in serotonergic transmission is the final convergence point of currently prescribed antidepressant drugs.Pharmacological and electrophysiological studies have shown the essential role of the somatodendritic 5-HT1A autoreceptor in the control of dorsal raphe 5-HT neuronal firing frequency and release; these characteristics make this receptor an extremely interesting target for adjuvant drugs that potentiate or even accelerate the effect of actual antidepressants molecules. In fact, augmentation of synaptic levels of 5-HT, thought to be necessary for the beneficial action of antidepressants in mood, does not immediately occur subsequent to acute administration of those molecules but depends on the desensitization of 5-HT1A somatodendritic autoreceptors located in the dorsal raphe, a phenomenom temporally correlated with the onset of action of all antidepressant classes.
30
Bartku, Elaine Cleare. "In-Situ Recycling: Applications, Guidelines, and Case Study for Local Governments". Thesis, Virginia Tech, 2014. http://hdl.handle.net/10919/49669.
Testo completoAbstract (sommario):
This thesis investigates the application of In-Situ Recycling and provides guidelines for localities to aid in the selection of recycling methods, as well as documents a local government's experience with Cold In-Place Recycling. The recycling methods discussed in this study include Cold In-Place Recycling (CIR), Hot In-Place Recycling (HIR), and Full Depth Reclamation (FDR). These methods are performed onsite and in-place in a continuous process of milling, mixing, and placement.
The In-Situ Recycling guidelines include suggestions based on: traffic characteristics, existing road condition, distress types, road access, local climate, road geometry, and other road characteristics. The guidelines are based on information from sources including NCHRP Synthesis 421, American Recycling and Reclamation Association (ARRA), FHWA, and state agencies with recycling experience.
This study also resulted in documenting obstacles that localities may face when in-situ recycling, as well as the impact of limited experience with recycling. The study also evaluated the construction of Cold In-Place Recycled pavement sections in Christiansburg, VA, using Falling Weight Deflectometer (FWD) and Ground Penetrating Radar (GPR). Additionally, using the FWD and GPR data, alternate recycled designs were proposed in addition to a cost comparison to a conventional design.Master of Science
31
Šmihula, Michal. "Kulturně společenské centrum u brněnské přehrady - architektonická studie objektů pro kulturně společenské i sportovní akce". Master's thesis, Vysoké učení technické v Brně. Fakulta architektury, 2010. http://www.nusl.cz/ntk/nusl-215678.
Testo completoAbstract (sommario):
The design of cultural centre is situated in part Kozia Hôrka( well-known city swimming pool), in its advantage takes natural scenery and calm atmosphere of place. Into action of performance brings a message in form of body of reservoir, function of centre is divided into small parts placed in area Kozia Hôrka. Orientation of objects comes mainly from local natural ispirations. Complex is multifunctional in concept, counts with several sorts of culture - sports events. Whereby the main function of swimming pool is preserved and added for higher comfort of inhabitants. Architecture of objects comes from idea of floating leaf on water level and body of reservoir. Objects stylizely illustrate this idea. The design takes the game of solids of organic and strictly ortogonal shapes. Two mutual opposites, in interaction. Objects smoothy and with respect encroach the environment, which is enough marked by human. Simplicity in used materials ( glass, steel, wood ) give transparency and purity to whole solution.
32
Abdalla, Ayman. "Sensitivity analysis of fuel centerline temperatures in SuperCritical water-cooled reactors (SCWRs)". Thesis, 2012. http://hdl.handle.net/10155/292.
Testo completoAbstract (sommario):
SuperCritical Water-cooled Reactors (SCWRs) are one of the six nuclear-reactor concepts currently being developed under the Generation-IV International Forum (GIF). A main advantage of SCW Nuclear Power Plants (NPPs) is that they offer higher thermal efficiencies compared to those of current conventional NPPs. Unlike today’s conventional NPPs, which have thermal efficiencies between 30 ‒ 35%, SCW NPPs will have thermal efficiencies within a range of 45 ‒ 50%, owing to high operating temperatures and pressures (i.e., coolant temperatures as high as 625°C at 25 MPa pressure).
The use of current fuel bundles with UO2 fuel at the high operating parameters of SCWRs may cause high fuel centerline temperatures, which could lead to fuel failure and fission gas release. Studies have shown that when the Variant-20 (43-element) fuel bundle was examined at SCW conditions, the fuel centerline temperature industry limit of 1850°C for UO2 and the sheath temperature design limit of 850°C might be exceeded. Therefore, new fuel-bundle designs, which comply with the design requirements, are required for future use in SCWRs.
The main objective of this study to conduct a sensitivity analysis in order to identify the main factors that leads to fuel centerline temperature reduction. Therefore, a 54-element fuel bundle with smaller diameter of fuel elements compared to that of the 43-element bundle was designed and various nuclear fuels are examined for future use in a generic Pressure Tube (PT) SCWR. The 54-element bundle consists of 53 heated fuel elements with an outer diameter of 9.5 mm and one central unheated element of 20-mm outer diameter which contains burnable poison. The 54-element fuel bundle has an outer diameter of 103.45 mm, which is the same as the outer diameter of the 43-element fuel bundle. After developing the 54-element fuel bundle, one-dimensional heat-transfer analysis was conducted using MATLAB and NIST REFPROP programs. As a
ii
result, the Heat Transfer Coefficient (HTC), bulk-fluid, sheath and fuel centerline temperature profiles were generated along the heated length of 5.772 m for a generic fuel channel. The fuel centerline and sheath temperature profiles have been determined at four Axial Heat Flux Profiles (AHFPs) using an average thermal power per channel of 8.5 MWth. The four examined AHFPs are the uniform, cosine, upstream-skewed and downstream-skewed profiles.
Additionally, this study focuses on investigating a possibility of using low, enhanced and high thermal-conductivity fuels. The low thermal-conductivity fuels, which have been examined in this study, are uranium dioxide (UO2), Mixed Oxide (MOX) and Thoria (ThO2) fuels. The examined enhanced thermal-conductivity fuels are uranium dioxide – silicon carbide (UO2 - SiC) and uranium dioxide - beryllium oxide (UO2 - BeO). Lastly, uranium carbide (UC), uranium dicarbide (UC2) and uranium nitride (UN) are the selected high thermal-conductivity fuels, which have been proposed for use in SCWRs.
A comparison has been made between the low, enhanced and high thermal-conductivity fuels in order to identify the fuel centerline temperature behaviour when different nuclear fuels are used. Also, in the process of conducting the sensitivity analysis, the HTC was calculated using the Mokry et al. correlation, which is the most accurate supercritical water heat-transfer correlation so far. The sheath and the fuel centerline temperature profiles were determined for two cases. In Case 1, the HTC was calculated based on the Mokry et al. correlation, while in Case 2, the HTC values calculated for Case 1 were multiplied by a factor of 2. This factor was used in order to identify the amount of decrease in temperatures if the heat transfer is enhanced with appendages.
Results of this analysis indicate that the use of the newly developed 54-element fuel bundle along with the proposed fuels is promising when compared with the
iii
Variant-20 (43-element) fuel bundle. Overall, the fuel centerline and sheath temperatures were below the industry and design limits when most of the proposed fuels were examined in the 54-element fuel bundle, however, the fuel centerline temperature limit was exceeded while MOX fuel was examined.UOIT
33
Leotlela, Moebetsi J. "Investigation of the release of gaseous fission products from pebble bed molecular reactor's triso coated fuel particle during the HFR-K5 fuel irradiation test". Thesis, 2010. http://hdl.handle.net/10539/8618.
Testo completoAbstract (sommario):
The effectiveness of the Tri-isotropic (TRISO) fuel particle to perform as an effective barrier to fission product migration and retain all fission products within the fuel particle is based primarily on the ability of the silicon carbide (SiC) layer to maintain its integrity in spite of the operating conditions of the Pebble Bed Modular Reactor (PBMR). However, because of the complexity of the fission product migration phenomena, fission products continue to escape through the fuel barriers in spite all efforts having being done to confine them within the fuel kernel. This suggests that there is still a lot of work still to be done to understand fission gas migration phenomena, which is the subject of this Research Report. This Research Report will concentrate on the analysis of the gaseous fission products released during the HFR-K5 fuel test, as part of the validation of the PBMR gaseous fission product release calculation model. Investigations done on similar fuel by other researchers suggests that some of the most important factors that determine the rate of fission product migration are irradiation temperature, neutron fluence, the diffusion mechanism i.e. vacancy as opposed to interstitial mechanism and the duration of irradiations. The variation of fission product release as a function of these variables has been investigated extensively in the present study. In addition to investigating the correlation between release and these factors, radiation effects such as dimensional change has also been analysed as volumetric change of the TRISO coated particle and is an important parameter in reactor design. The design of the defueling chute of the PBMR must take this into consideration as the diameter of the fuel pebble will have swollen as a result of radiation damage. Based on the findings of the present research study the recommendations of how the research findings can be implemented to provide an improved PBMR fuel are made.
34
Ho, ShinCheng, e 何欣城. "Preparation Nafion®/NMe4TP and Nafion®/HTP composite membranes and application to direct methanol fuel cell". Thesis, 2012. http://ndltd.ncl.edu.tw/handle/59911810898757363882.
Testo completoAbstract (sommario):
碩士明志科技大學
化學工程研究所
100
Commercial proton exchange membrane Nafion® 117 was modified by using two types of layered titanium phosphates NMe4TP and HTP, respectively. Nafion®/NMe4TP membrane was prepared by first submerging Nafion 117 membrane into TiCl4 solution followed by reaction with a mixture of phosphoric acid and tetramethylammonium hydroxide in a hydrothermal condition at 185C for 3 days. While Nafion®/HTP membrane was obtained by undergoing proton ion exchange for Nafion®/NMe4TP. Impedance measurements at same condition showed that the ionic conductivity of Nafion®/NMe4TP and Nafion®/HTP were 2% and 239% that of Nafion 117, respectively. Whereas, the methanol permeability of Nafion®/NMe4TP and Nafion®/HTP were 38% and 122% that of Nafion 117, respectively. Therefore, the selectivity of Nafion®/NMe4TP and Nafion®/HTP were 6% and 196% that of Nafion® 117, respectively. Both sides of these three types of membranes were coated with catalyst and made into membrane electrode assemblies and then assembled into DMFC single cells. Polarization was measured at 40~90C with methanol concentration of 1M, methanol flow rate 1mL/min, oxygen flow rate 20mL/min. Peak powers were 38~117, 8~13 and 30~142 mW/cm2 for unmodified Nafion® 117, Nafion®/NMe4TP and Nafion®/HTP, respectively.
35
(9187205), Jonova Thomas. "MICROSTRUCTURAL CHARACTERIZATION AND MECHANICAL PROPERTY ASSESSMENT OF A NEUTRON IRRADIATED URANIUM-ZIRCONIUM NUCLEAR FUEL AND HT9 CLADDING". Thesis, 2020.
Cerca il testo completoAbstract (sommario):
Metallic uranium-10 weight percent zirconium (U-10wt.%Zr) nuclear fuels are classified as potential fuels for fast breeder reactors as they possess a high fissile density and have increased compatibility with sodium, a frequently used reactor coolant. Despite their advantages when exposed to neutron irradiation in reactors, the fuels are subject to damage cascades and microstructural alterations. Fuel constituent re-distribution, phase transformation, fuel swelling, and fuel cladding chemical interactions (FCCI) are a few of the major interdependent microstructural alterations that occur in these fuels at the onset of neutron irradiation. The primary objective of this research is to understand the above-mentioned microstructural alterations in different regions of a neutron irradiated U-10wt.%Zr fuel and HT9 cladding that has achieved a cross-sectional burnup of 5.7 atomic percent (at%.). Additionally, this study also aims to provide a relationship between the microstructural alterations and local mechanical property changes exhibited at different regions of the HT9 cladding as a consequence of neutron irradiation, FCCI, and fission product migration.
To achieve this goal, a coordinated group of experiments was performed on the neutron irradiated U-10wt.%Zr/HT9 (fuel/cladding) at the nanoscale, microscale, and mesoscale, respectively. The experimental techniques used for microstructural analysis included the following: (1) transmission electron microscopy of focused ion beam (FIB) lamellas for nanoscale assessments, (2) serial sectioning of FIB cuboids for microscale assessments, and (3) synchrotron micro-computed tomography of FIB obelisks for mesoscale assessment. Following the microstructural assessments, nano-indentation experiments were performed on the neutron irradiated HT9 cladding to determine the changes in mechanical properties as a function of distance from cladding edge to FCCI locality, and the changes in mechanical properties as a consequence of several microstructural alterations. Furthermore, the results produced from the various experiments in this study were compared and correlated to existing literature (both in-reactor and out-of-reactor experiments), and new theories to explain the reason for the observed changes were established. This research also revealed several novel observations such as probable radiation induced segregation in fuels, localized fuel swelling and porosity distribution at different regions in the fuel, crystal structure of phases present at different regions in the fuel and their influence on pore morphologies, and nano mechanical properties of a neutron irradiated HT9 cladding.
36
Shiue, Min-Yue, e 薛旻岳. "Preparation and Application of Nafion® /NMe4TP and Nafion® /HTP Composite Membranes for Proton Exchange Membrane Fuel Cells". Thesis, 2014. http://ndltd.ncl.edu.tw/handle/u44khk.
Testo completoAbstract (sommario):
碩士明志科技大學
化學工程系碩士班
102
In this study, a layered titanium phosphate solid acid HTP was employed for modification of the commercially available poly(perfluorosulfonic acid) Nafion® N-117 membrane. Fundamental physical and chemical properties were evaluated and compared among these membranes. Membrane electrode assemblies (MEAs) based on such membranes were prepared and their electrochemical properties were measured by assembling such MEAs into a fuel cell test fixture. Among the four proton exchange membranes of this study, their proton conductivity, from highest to lowest, has the following sequence: Nafion®/HTP composite membrane, Nafion®/HCl treated membrane, Nafion®117 commercial membrane, and Nafion®/NMe4TP composite membrane. However, after being made into MEAs and measured as a single cell, their electrochemical properties exhibit, from high to low, as the following sequence: Nafion®/HCl treated membrane, Nafion®117 commercial membrane, Nafion®/HTP composite membrane, and Nafion®/NMe4TP composite membrane. It is therefore concluded that the performance of a MEA is not only based on proton conductivity of the membrane, but also other factors. Of all these four types of MEAs, their electrochemical performances at dry cathode were lower than those at dry anode.
37
Förster, Tino. "Entwicklung eines technischen Demonstrators eines wasserstoffbetriebenen Bi-Mode-EMU als Nachrüstlösung für Bestandsfahrzeuge". 2021. https://htw-dresden.qucosa.de/id/qucosa%3A74200.
Testo completoAbstract (sommario):
Die Aufgabenstellung der hier vorgestellten Diplomarbeit befasst sich mit der Integration von nichtfossilen Energieträgern im Eisenbahnbereich. Grundsätzlich soll untersucht werden, inwiefern eine technisch umsetzbare Integrationslösung erarbeitet werden kann, die an ein bereits im Betrieb befindliches Schienenfahrzeug zur Personenbeförderung nachgerüstet werden kann. Durch diese Umrüstung soll das Demonstratorfahrzeug dann in der Lage sein, sowohl die elektrische Energie des Fahrdrahtes als auch die mitgeführte Energie zum Betrieb zu nutzen. Im Ergebnis sollen damit Dieselfahrzeuge ersetzt werden, die bisher auf Strecken ohne Oberleitung eingesetzt werden. Im Ausgangszustand wird ein Triebzug betrachtet, der im ursprünglichen Aufbau für den reinen Oberleitungsbetrieb entwickelt wurde. Aus dem Englischen kommend werden solche Verkehrsmittel auch als EMU bezeichnet, was abgekürzt für Electric Multiple Unit steht.
Um solche Fahrzeuge auch ohne Oberleitung mit Energie zu versorgen, bedarf es der Nachrüstung von Energiespeichern am Triebzug. In diesem Fall bildet gasförmiger Wasserstoff den primären Energiespeicher, dessen chemische Energie durch ein Brennstoffzellensystem in elektrische Energie gewandelt werden soll. Außerdem ist aufgrund verschiedener Randbedingungen ein Akkumulatorsystem als sekundärer Energiespeicher notwendig. Grundsätzlich kann das umgerüstete Fahrzeug dann
als Hybridfahrzeug bezeichnet werden, im Projektkontext wird allerdings aufgrund der zweifachen Energiezuführung von einem Bi-Mode-Fahrzeug gesprochen.
Die Einbauuntersuchung behandelt sowohl volumetrische als auch gravimetrische Fragestellungen, die bei der Integration der genannten Systeme zu beachten sind. So wird beispielsweise durch ein Berechnungsmodell untersucht, welche Auswirkungen die Schwerpunktlage des Wagens auf die Radsatzlasten hat.
Im Ergebnis der Untersuchung kann festgehalten werden, dass unter den gegebenen Randbedingungen die Integration der Komponenten eine deutliche Reduzierung der Personenzahlen notwendig wird.The task of the diploma thesis presented here deals with the integration of non-fossil energy sources in the railroad sector. The basic aim is to investigate the extent to which a technically feasible integration solution can be developed that can be retrofitted to a rail vehicle already in operation for passenger transportation. Through this retrofit, the demonstrator vehicle should then be able to use both the electrical energy of the contact wire and the energy carried for operation. As a result, it is intended to replace diesel vehicles that have been used to date on lines without overhead contact lines. In the initial state, a multiple-unit train is considered that was developed in its original design for pure overhead contact line operation. This type of vehicle is also known as an EMU, which stands for Electric Multiple Unit. In order to supply such vehicles with energy even without an overhead line, energy storage systems have to be retrofitted to the multiple unit. In this case, gaseous hydrogen forms the primary energy storage medium, whose chemical energy is to be converted into electrical energy by a fuel cell system. In addition, due to various boundary conditions, an accumulator system is required as secondary energy storage. In principle, the converted vehicle can then be called a However, in the context of the project, it is referred to as a bi-mode vehicle due to the dual energy supply. The installation study addresses both volumetric and gravimetric issues that need to be considered when integrating the aforementioned systems. For example, a calculation model is used to investigate the effects of the vehicle's center of gravity on the wheelset loads. As a result of the investigation, it can be stated that under the given boundary conditions, the integration of the components will necessitate a significant reduction in the number of passengers.