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

Reentrainment of Submicron Solid Particles

Mortazavi, Ramin 01 January 2005 (has links)
In this work, an experimental method is developed to study the effects of particle size, flow rate, pulsation, particle/substrate material, and temperature on the short-term reentrainment of submicron particles. The particles tested are in the size range of 10-900 nm and are deposited by wetting the inside of capillary tubes with a liquid suspension. The tubes are then dried in a desiccator. The particles are reentrained under turbulent dry air flow conditions and a condensation particle counter is used to measure the number of entrained particles.There has been very limited work done with nanoscale particles in general and no previous experimental work has reported about this particular parameter set. In order to interpret the data, a bimodal lognormal probability density for the ratio of adhesion force to removal forces is suggested. The majority of particles is attached to the surface by strong forces and cannot be entrained. However, a small fraction of particles, called loose particles, is attached to the surface by much smaller forces. Based on experimental data, an analytical equation for the fraction of loose particles in terms of a dimensionless force is developed. This dimensionless force is a function of particle size and gas flow rate. The temporal variations of fraction of deposited particles are calculated by incorporating the fraction of loose particles with the model of Wen and Kasper (1989).The experimental data confirmed the theoretical expectation that entrainment strongly depends on particle size and decreases as the size of the particle decreases. Both higher flow rates and pulsation of the flow increase the entrainment. Pulsation causes the distribution of forces to broaden. It is shown that the effect of particle/substrate material on entrainment can be predicted by the compound Hamaker constant provided that the morphology and the roughness of the system remain the same. Otherwise, the effect of roughness or morphology may override the effect of Hamaker constant.
12

Towards a Hermeneutic of Yoga in Modern Times: A Comparative Study of Practice and Detachment in Hinduism and Christianity

Corigliano, Stephanie Heather January 2015 (has links)
Thesis advisor: Catherine Cornille / This dissertation contributes to a scholarly understanding of Yoga in modern times by considering the dialectical tension between life-affirming goals in Yoga (health, balance, well-being) and the world-renouncing asceticism of the classical text, Patañjali’s Yogasūtras. In particular, I focus on the teaching tradition of the 19th century guru Tirumalai Krishnamacharya and the prominent teachers who learned from him, K. Pattabhi Jois, BKS Iyengar, and TKV Desikachar. Through a study of the classical text, historical commentators, recent scholarship, and modern teachers, I advance an understanding of the structure and general rubric of the Yogasūtras as a text that emphasizes process, the attainment of accomplishment/power, and ultimately the need for detachment from power. I further contend that this rubric may provide an insightful means for interpreting the Yogasūtras as an authoritative and informative text for Yoga in modern times. The teaching tradition of Krishnamacharya is notable for its effort to revive Yoga and the Yogasūtras within India and for an international audience. However, the core concept of detachment, while prominent throughout the Yogasūtras, appears to be at odds with the modern tradition, which emphasizes attachment oriented goals like health and well-being. Thus, I introduce a comparative study of detachment in the work of the 18th century Jesuit, Jean Pierre de Caussade, in order to further consider the dialectic between detachment, action, and love. The practice of Comparative Theology is perhaps most effective at creating a new light with which the individual can freshly examine her own tradition. The comparison between Caussade, Krishnamacharya, and the Yogasūtras highlights the role of devotion in relation to detachment and offers particular challenges and points for further consideration for the on-going tradition of Yoga in modern times. / Thesis (PhD) — Boston College, 2015. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Theology.
13

An investigation of some biochemical and cellular properties of subretnal fluids.

January 1994 (has links)
by Xu Xun. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1994. / Includes bibliographical references (leaves 78-87). / Chapter CHAPTER 1 --- INTRODUCTION --- p.1 / Chapter CHAPTER 2 --- LITERATURE REVIEW --- p.6 / Chapter 2.1 --- Anatomy of retina and vitreous --- p.6 / Chapter 2.2 --- Rhegmatogenous retinal detachment --- p.8 / Chapter 2.2.1 --- Retinal breaks --- p.8 / Chapter 2.2.2 --- Retinal detachment and subretinal fluid --- p.8 / Chapter 2.3 --- Proliferative vitreoretinopathy --- p.9 / Chapter 2.4 --- Total protein in subretinal fluid --- p.11 / Chapter 2.5 --- Fibroblast growth factor --- p.12 / Chapter 2.5.1 --- Structure of b and a FGF and their gene --- p.13 / Chapter 2.5.2 --- Expression of bFGF and aFGF in neuroretinal and pigment epithelial cells --- p.14 / Chapter 2.5.3 --- The FGF receptors --- p.15 / Chapter 2.5.4 --- In vitro biological effect of FGF --- p.15 / Chapter 2.5.5 --- FGF in retinal diseases --- p.16 / Chapter 2.6 --- Cellular study of proliferative vitreoretinopathy --- p.18 / Chapter 2.6.1 --- Experimental study --- p.18 / Chapter 2.6.2 --- Pathogenesis of intravitreal proliferation --- p.20 / Chapter 2.6.3 --- Cellular components of proliferative tissue --- p.20 / Chapter 2.6.4 --- Cellular components of subretinal fluid --- p.22 / Chapter CHAPTER 3 --- MATERIALS AND METHODS --- p.24 / Chapter 3.1 --- Specimens --- p.24 / Chapter 3.2 --- Determination of total protein --- p.24 / Chapter 3.2.1 --- Study population --- p.24 / Chapter 3.2.2 --- Quantitation of total protein --- p.25 / Chapter 3.3 --- Determination of bFGF --- p.27 / Chapter 3.3.1 --- Study population --- p.27 / Chapter 3.3.2 --- Quantitation of bFGF --- p.28 / Chapter 3.4 --- Celular study --- p.30 / Chapter 3.4.1 --- Study population --- p.30 / Chapter 3.4.2 --- Fixation of samples --- p.30 / Chapter 3.4.3 --- Immunocytology --- p.32 / Chapter 3.4.4 --- Examination of autofluorescence --- p.35 / Chapter 3.4.5 --- Hematoxylin and eosin staining --- p.36 / Chapter CHAPTER 4 --- RESULTS --- p.37 / Chapter 4.1 --- Total protein --- p.37 / Chapter 4.1.2 --- Total protein in subretinal fluids --- p.38 / Chapter 4.1.3 --- Total protein in normal vitreous of autopsy and sera of patients --- p.40 / Chapter 4.1.4 --- Relationship of protein level and size of retinal break --- p.40 / Chapter 4.1.5 --- Relationship of protein level and duration of retinal detachment --- p.43 / Chapter 4.1.6 --- Relationship of protein level and degree of PVR --- p.45 / Chapter 4.2 --- Basic FGF in subretinal fluids --- p.47 / Chapter 4.2.1 --- Standard curve for determination of bFGF in SRF --- p.47 / Chapter 4.2.2 --- The levels of bFGF in both SRF and controls --- p.48 / Chapter 4.2.3 --- Levels of bFGF in different degrees of PVR --- p.50 / Chapter 4.2.4 --- Levels of bFGF in SRF of RD with and without previous cryotherapy --- p.54 / Chapter 4.2.5 --- The relationship of level of protein and bFGF --- p.55 / Chapter 4.3 --- Results of cytological examination --- p.57 / Chapter 4.3.1 --- Pigment examingnation by autofluorescence --- p.57 / Chapter 4.3.2 --- Cellular study of subretinal fluids --- p.59 / Chapter 4.3.3 --- Cellular study of subretinal fluid in eyes with prior cryotherapy --- p.62 / Chapter CHAPTER 5 --- DISCUSSION --- p.68 / Chapter 5.1 --- Evaluaton of method for obtaining specimens --- p.68 / Chapter 5.2 --- Total protein of SRF in retinal detachment --- p.69 / Chapter 5.3 --- Basic FGF in subretinal fluids --- p.71 / Chapter 5.4 --- Elevated level of bFGF in eye after cryotherapy --- p.74 / Chapter 5.5 --- Cell components in SRF of PVR --- p.75 / REFERENCES --- p.78
14

How commitment and detachment influence members' discourse about the National Education Association

Sanford, Amy Aldridge 01 January 2006 (has links)
The National Education Association (NEA) has experienced negative publicity and discontent amongst its membership in recent years, thus causing some members to completely withdraw from the organization and still others to become detached. Yet some members remain completely committed. It is through examining the members' talk about identification, involvement, and loyalty that his/her level of commitment or detachment is explored. In-depth interviews were conducted with 15 NEA members at two different local affiliates in the southern region of the United States. The conversations were transcribed and served as the text for content analysis. The major identification barrier for the informants was the NEA's liberal policies, specifically when it came to homosexuality. One local was more organized and committed to the national association, thus allowing their members to be more involved at the local, state, and national levels. The major barriers to involvement were overwork and life cycle issues (i.e., spouses, children, church, social obligations). There were four major themes surrounding loyalty to the NEA: recruitment, incentives for staying, future plans, and reasons for quitting. Most of the members were recruited as student teachers because they felt they needed the liability insurance. Most of them stay for the insurance. Committed members discuss their futures in the organization; detached members do not. The predominant reason members withdraw is because they disapprove of how the NEA handled a local grievance. NEA members are most likely to converse about the organization with their family members and this is usually in defense of the organization. The committed members reported avoiding conservatives when discussing the union. Topics of conversation include goals of the NEA, complaints about the organization, and the nonunion alternative. Prior to this research, identification was often the only variable considered when studying commitment of organizational research. Involvement and loyalty were virtually ignored. This research highlights that identification and loyalty are best understood by listening to the members' talk. Involvement can be easily measured with a survey. Additionally, both the local affiliate and the members' commitment need to be considered when pondering commitment or detachment of a member.
15

In vitro and in vivo studies of biocompatibility of intraocular tamponade agents /

Lui, Wing-chi. January 2009 (has links)
Thesis (M. Phil.)--University of Hong Kong, 2010. / Includes bibliographical references (leaves 116-130). Also available online.
16

In vitro and in vivo studies of biocompatibility of intraocular tamponade agents

Lui, Wing-chi. January 2009 (has links)
Thesis (M. Phil.)--University of Hong Kong, 2010. / Includes bibliographical references (leaves 116-130). Also available in print.
17

IMPACT OF ACTIVE LAYER DETACHMENTS ON SEASONAL DYNAMICS OF NITROGEN EXPORT IN HIGH ARCTIC WATERSHEDS

Louiseize, NICOLE 29 May 2014 (has links)
This study examined the impact of active layer detachments (ALDs) on seasonal dissolved nitrogen (N) export from continuous permafrost headwater catchments at the Cape Bounty Arctic Watershed Observatory (CBAWO), Melville Island, Nunavut. Runoff samples collected throughout the summer of 2012 from an undisturbed catchment (Goose; GS) and from one that was disturbed by ALDs (Ptarmigan; PT) were analyzed for dissolved inorganic ions and species of total dissolved N (TDN), including dissolved organic N (DON) and dissolved inorganic N (DIN; ammonium (NH4+), nitrite (NO2-), and nitrate (NO3-)). Rainfall samples were also collected for dissolved ions analyses. Select runoff and rainfall samples were analyzed for stable isotopes of nitrogen and oxygen in NO3- (δ15N-NO3- and δ18O-NO3-, respectively) to determine its origin streamwater. Data from 2012 were compared to predisturbance data to assess the long-term effects of ALDs on N export. ALDs increased the proportion of DIN/TDN in PT from 4% (predisturbance) to 37% in 2012. The increase in DIN/TDN in PT largely resulted from significantly higher NO3- in runoff. Values of δ18O and δ15N-NO3- as well as correlations between NO3- and major ions indicated that the higher NO3- in PT was due to the exposure of mineral soils in ALDs, which likely reduced NO3- sinks (e.g. plant uptake) and increased inputs of nitrified-NO3-. Values of δ18O-NO3- during initial runoff showed that NO3- supplied from the snowpack overwhelmed NO3- sinks in PT, leading to a twelve-fold higher peak NO3- concentration relative to GS. Low δ18O-NO3- values in runoff during stormflow indicated that inputs of DIN from rainfall (1545 ± 148 and 1838 ± 174 g N-DIN to GS and PT, respectively) supplied less than 30% of the NO3- in both streams, and that exceptionally high NO3- concentrations in PT resulted from flushing of mineralized-NO3- from the mineral soils. Seasonal DIN flux was 95% higher in PT relative to GS, because NO3- export from PT was 27 times that of GS. This is the first study to show that ALDs can have persistent impacts on DIN export from High Arctic watersheds, and that this results from enhanced export of mineralized-NO3-. / Thesis (Master, Geography) -- Queen's University, 2014-05-27 10:30:38.874
18

Examining the Relationship Between Callings and Employee Well-being

Lukjan, Kristyn 05 1900 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Although the occupational callings literature has largely focused on positive outcomes of living a calling, there are some emerging findings that suggest that callings may have a “negative” side as well. Drawing upon past studies within the callings literature, as well as upon theoretical perspectives such as self-regulation theory, identity theory, and the Effort-Recovery model, I tested a theoretical model to examine psychological detachment as a mechanism that accounts for the relationship between living a calling (also referred to as one’s calling intensity) and two well-being outcomes: sleep quality and burnout. Further, I built on previous work in the callings literature by examining the moderating impact of two individual differences (trait mindfulness, perfectionism) on the relationship between calling intensity and psychological detachment. Study hypotheses were tested using a two-wave study design with 358 emergency medical professionals. Results revealed that for called emergency medical professionals, trait mindfulness strengthened the negative relationship between calling intensity and psychological detachment, which had downstream negative effects on sleep quality. In addition, one facet of perfectionism, namely perfectionistic strivings, exacerbated the negative indirect effect of calling intensity on sleep quality via psychological detachment. Ultimately, this study contributed to the occupational callings literature by examining the impact of differential levels of trait mindfulness and perfectionism on employee well-being. Implications for enhancing employee well-being are discussed.
19

A Physically Based Model of the Erosion of Cohesive Soils

Hairsine, Peter Brian, n/a January 1988 (has links)
A new model of the erosion by water of cohesive soils is developed using physical principles. The theoretical framework which is developed recognises the changing nature of the eroding surface of a soil. Raindrop impact and overland flow are considered to act upon a soil surface so removing soil from the cohesive original (or parent) soil. Once this soil enters the overland flow, either as aggregates or primary particles, it is considered to return to the soil bed, from which it may be re-removed. The development of a deposited layer makes it necessary to distinguish between processes removing sediment from the original soil and those processes removing the deposited layer. This layer, being formed by the relatively gentle action of deposition during the current erosion event, is presumed cohesionless. The physical properties of the original soil and the deposited layer are considered to be very different. The development of two experimental apparatus, a rainfall/runoff simulator and a settling tube for the measurement of aggregate settling velocities, is first described. Experimental investigations, using these apparatus, and field observations to inform the description of the erosion and deposition processes, are then presented. The processes by which rainfall impact removes sediment from the original soil and the deposited layer are termed rainfall detachment and rainfall re-detachment respectively. Initially, descriptions of these processes in the presence of deposition, are combined in a model describing net rainfall detachment when removal of sediment from the flow bed by overland flow is not occurring. The developriient of the deposited layer is considered both quantitatively and qualitatively. The solution of the equation describing mass conservation is then given for the equilibrium situation when the mass of the deposited layer, and therefore the sediment concentration, is constant with respect to time. The processes by which overland flow removes sediment from the original soil and the deposited layer are termed entrainment and re-entrainment. The work done by the process of entrainment is considered to be done wholly against the cohesive strength of the original soil. In contrast to the process of entrainment, the work done in re-entraining sediment from the deposited layer is considered only to be done against gravity. The resulting description of these processes is then combined with the previous descriptions of rainfall detachment, rainfall re-detachment and deposition and with the equation describing the conservation of mass of sediment within any arbitary number of size (or settling velocity) classes. A plane geometry model Is developed in which the surface water flow is considered to be uniformily distributed across a plane slope on which all processes act. When the mass of the deposited layer is steady, two possible forms of equilibrium are shown to exist. When the coverage of the original soil by deposited layer is partial, the sediment concentration is limited by the removal of the cohesive original soil by entrainment and rainfall detachment, in the presence of deposition. This situation is termed 'source limiting' and is shown to provide a lower limit to sediment concentration. When the coverage of the deposited layer is complete so that entrainment and rainfall detachment of the original soil are considered not to occur, then the ability of the erosive agents to re-entrain and re-detach sediment in the presence of deposition limits sediment concentration. This situation, termed 'transport limiting', is shown to provide a practical upper limit to sediment concentration. This plane geometry flow model is followed by a revised model in which all processes are considered to occur but the flow of water on a plane surface is modified by the formation of rills. In this 'detailed geometry model' the spatial distribution of the erosive agents is shown to have a marked influence on the resulting processes and sediment concentrations. A potential description of the sediment transport across a change in land slope is also developed. Finally, a discussion of this new modelling approach is presented in which the conceptual developments of this thesis are considered and future developments are suggested. This discussion also includes a comparison of the outcomes of this new work with similar erosion models.
20

L'œuvre de Marguerite Duras ou L'expression d'un tragique moderne / The work of Marguerite Duras or The expression of a modern tragic

Drissi, Hamida 09 December 2008 (has links)
Le tragique semble être au coeur de la littérature contemporaine. En effet, la mort de la tragédie classique ne signifie pas la disparition du tragique. Au contraire, celui-ci survit et prend de nouvelles formes. C'est précisément cette "nouvelle forme" que nous analysons dans notre thèse intitulée "L'oeuvre de Marguerite Duras ou l'expression d'un tragique moderne". L'oeuvre durassienne participe de ce que Jean-Marie Domenach nomme "le retour du tragique". Notre étude porte sur la vision tragique de Duras. Elle examine aussi l'évolution du tragique durassien en le comparant souvent au tragique antique. Nous essayons, également, les rapports complexes qui existent, chez Duras, entre le tragique et le comique. Nous tentons, en outre, de voir comment Duras réussit à dépasser ce tragique moderne en développant une esthétique du détachement / The tragic seems to be at the heart of contemporary literature. Indeed, the death of the tragedy does not mean taht the tragic has disappeared. On the contrary, the latter has survived and has taken on new forms. It is pricesely this "new form" that we analyze in our thesis entitled "The work of Marguerite Duras or the expression of a modern tragic". Duras' work is part of what Jean-Marie Domenach names "the return of the tragic". Our thesis studies Duras' vision of the tragic. It also examines the evolution of this tragic as we compare it with the tragic of the Antiquity. We also try to study the complex link between the tragic and the comic in Duras' work. We attempt to inderstand how Duras succeeds in surpassing the modern tragic as she develops an aesthetic of detachment

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