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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.
41

Exploring push and pull factors experienced by South African self-initiated expatriates

Mostert, Elsje January 2013 (has links)
A preliminary literature review indicated that not much research has been done on self-initiated expatriation (SIE), particularly in a South African context. The purpose of this study is twofold: Firstly, by reviewing previous research, this study aims to make a valuable contribution to the literature on SIE, particularly regarding the motivations behind SIE. Secondly, this study aims to explore and develop a deeper understanding of the push and pull factors experienced by South African self-initiated expatriates (SASIEs). An empirical, exploratory qualitative approach, through the utilisation of qualitative field research, was employed as a means of inquiry. Furthermore, interpretivism was used as a research paradigm. Purposive sampling was applied, and the sample used consisted of nine individual South African self-initiated expatriates who had been working in their host countries for a minimum of six months. Data were obtained through in-depth semi-structured interviews. By implication only a few research questions were generated to guide the interview; however, participants were not limited to certain responses. This allowed for rich data to be obtained that were systematically analysed using grounded theory analysis to steer the process in a practical manner through the transcription of data and the rigorous extraction of codes towards the results that could best answer the original set of research questions. Criteria for rigour, authenticity, trustworthiness and credibility were applied and demonstrated throughout. The conceptual framework of the study was kept in mind during the research, the themes that emerged were explored, and the findings that were reached were substantiated through an extensive literature review. The conclusion was reached that South African self-initiated expatriates experienced certain push factors from the home country (South Africa), and that there were equally strong or stronger pull factors to the host country. All these factors contributed to the participants’ decision to expatriate. Interestingly, there seemed to be no real push factors from the host country; these were rather perceived as challenges that had to be endured. Furthermore it seemed that, as far as the sample group in this study were concerned, South Africa did not offer strong pull factors, and that, if the participants were to repatriate to South Africa, it would be for sentimental reasons. This could hold some implications for South African organisations especially in terms of retaining skilled labour or attract the skilled labour who has already expatriated. Recommendations and opportunities regarding future research were also mentioned. / Dissertation (MCom)--University of Pretoria, 2013. / gm2014 / Human Resource Management / unrestricted
42

Physiological Importance of 1,25(OH)<sub>2</sub>D<sub>3</sub> Membrane-Initiated and Nuclear Actions in Chickens as a Function of Growth, and Maturation in Male and Female Chickens

Larsson, Birgitta 01 May 2002 (has links)
It is well established that l,25(OH)2D3 is a major regulator of calcium homeostasis. The steroid exerts its effects on its target organs by two mechanisms, a slow mechanism mediated by nuclear vitamin D receptors (nVDR), and a rapid mechanism mediated by the l,25(OH)2D3 membrane-associated rapid response steroid binding protein (l,25D3-MARRS bp). In this dissertation, the physiological relevance of membrane initiated steroid signaling was investigated by studying the correlation of age in male and female chickens with the magnitude of responses to l,25(OH)2D3 in duodena from 7-, 14-, 28-, and 58-week-old birds. Measurements of l,25(OH)2D3 (130 pM) responsiveness as a function of age showed an age-related decrease in intestinal Ca2+ transport for both male and female birds. Western analyses on isolated basal lateral membranes (BLM) indicated a decreased expression of 1,25D3-MARRS bp with increasing age in male chickens, while its expression increased with age in female birds. Saturation analyses of [3H]l,25(OH)2D3 binding to BLM revealed an allosteric interaction identified as cooperative binding for both male and female birds. The degree of positive cooperativity increased with increasing age. Both genders showed a significant increase in dissociation constant (Kd) with increasing age, indicating decreasing affinity. No age-related changes in the number of binding sites, Bmax, were observed in male chickens, while female birds showed an increase in Bmax with increasing age. Data obtained in parallel binding analyses of [3H]l,25(OH)2D3 to nuclear fraction nVDR in contrast, indicated an absence of cooperative binding and an absence of significant changes in Kd or Bmax with age for both male and female birds. Membrane-initiated signal transduction by l,25(OH)2D3 was assessed by determination of protein kinase C (PKC) and A (PKA) activities. Both male and female birds showed an age-related decrease in stimulation of PKC activity in response to l,25(OH)2D3, while PKA activity increased. In conclusion, this dissertation demonstrates that there is a decrease in l,25(OH)2D3-induced intestinal calcium uptake as a function of age in duodena of both male and female chickens, which can be correlated to a decreased affinity for l,25(OH)2D3, and a decreased PKC activity.
43

Fuel Performance Modeling of Reactivity-Initiated Accidents Using the BISON Code

Folsom, Charles Pearson 01 December 2017 (has links)
The Fukushima Daiichi nuclear accidents in 2011 sparked considerable interest in the U.S. to develop new nuclear fuel with enhanced accident tolerance. Throughout the development of these new fuel concepts they will be extensively modeled using specialized computer codes and experimentally tested for a variety of different postulated accident scenarios. One accident scenario of interest, reactivity-initiated accident, is a nuclear reactor event involving a sudden increase in fission rate that causes a rapid increase in reactor power and temperature of the fuel which can lead to the failure of the fuel rods and are lease of radioactive material. The focus of this work will be on the fuel performance modeling of reactivity-initiated accidents using the BISON code being developed at Idaho National Laboratory. The overall goal of this work is to provide the best possible modeling predictions for future experimental tests. Accurate predictive capability modeling using BISON is important for safe operation of these tests and provides a cheaper alternative to the expensive experiments.
44

Post-disaster Housing and Resident-Initiated Modifications -Spontaneous housing modifications in disaster-induced resettlement sites in Cagayan de Oro, Philippines- / 災害後の住宅再建と住民主導の増改築-フィリピン、カガヤンデオロ市における災害後の再定住地区における自発的な増改築

Sandra, Milena Carrasco Mansilla 23 March 2016 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(地球環境学) / 甲第19873号 / 地環博第147号 / 新制||地環||29(附属図書館) / 32909 / 京都大学大学院地球環境学舎環境マネジメント専攻 / (主査)教授 岡﨑 健二, 准教授 小林 広英, 准教授 ジェーン シンガー / 学位規則第4条第1項該当 / Doctor of Global Environmental Studies / Kyoto University / DFAM
45

Protein-Resistant Polyurethane Prepared by Surface-Initiated Atom Transfer Radical Polymerization of Water-Soluble Polymers

Jin, Zhilin 01 1900 (has links)
<p>This work focused on grafting water-soluble polymers with well-controlled properties such as tuneable polymer chain length and high graft density to improve the biocompatibility of polymer surfaces via surface-initiated atom transfer radical polymerization (s-ATRP); and on gaining improved fundamental understanding of the mechanisms and factors (e.g., graft chain length and surface density of monomer units) in protein resistance of the water-soluble grafts.</p><p>Protein-resistant polyurethane (PU) surfaces were prepared by grafting watersoluble polymers including poly(oligo(ethylene glycol) methacrylate) (poly(OEGMA)) and poly(l-methacryloyloxyethyl phosphorylcholine) (poly(MPC)) via s-ATRP. A typical three-step procedure was used in the ATRP grafting. First, the substrate surface was treated in an oxygen plasma and reactive sites (-OH and -OOH) were formed upon exposure to air. Second, the substrate surface was immersed in 2-bromoisobutyryl bromide (BffiB)-toluene solution to form a layer of ATRP initiator. Finally, target polymer was grafted from the initiator-immobilized surface by s-ATRP with Cu(I)Br/2bpy complex as catalyst. The graft chain length was adjusted by varying the molar ratio of monomer to sacrificial initiator in solution. The modified PU surfaces were characterized by water contact angle, X-ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM).</p><p>Protein adsorption experiments were carried out to evaluate the protein resistance of the surfaces. Adsorption from single and binary protein solutions as well as from plasma decreased significantly after poly(OEGMA) grafting, and decreased with increasing poly(OEGMA) main chain length. Fibrinogen (Fg) adsorption on the most resistant surfaces (chain length 200 units) was in the range of 3-33 ng/cm^2, representing a reduction of more than 96% compared to the control surfaces.</p><p>OEGMA monomers with three different molecular weights (MW 300, 475, 1100 g/mol) were used to achieve different side chain lengths of poly(OEGMA). Fibrinogen (Fg) and lysozyme (Lys) were used as model proteins in adsorption experiments. The effects of side chain length as well as main chain length were then investigated. It was found that adsorption to the poly(OEGMA)-grafted PU (PU/PO) surfaces was protein size dependent. Resistance was greater for the larger protein. For grafts of a given side chain length, the adsorption of both proteins decreased with increasing polymer main chain length. For a given main chain length, the adsorption of Fg, the larger protein, was independent of side chain length. Surprisingly, however, Lys (the smaller protein) adsorption increased with increasing side chain length. A reasonable explanation is that graft main chain density decreased as monomer size and footprint on the surface increased. Protein size-based discrimination suggests that the chain density was lower than required to form layers in the "brush" regime in which protein size is expected to have little effect on protein adsorption.</p><p>In order to achieve high surface densities of ethylene oxide (EO) units, we used a sequential double grafting approach whereby the surface was grafted first with poly(2-hydroxyethyl methacrylate) (HEMA) by s-ATRP. OEGMA grafts were then grown from the hydroxyl groups on HEMA chains by a second ATRP. The effect of EO density on protein-resistant properties was then investigated. Protein adsorption on the sequentiallygrafted poly(HEMA)-poly(OEGMA) surfaces (PU/PH/PO) was not only significantly lower than on the unmodified PU as expected, but also much lower than on the PU/PO surfaces with the same poly(OEGMA) chain length. Moreover, protein adsorption decreased with increasing EO density for these grafts. On the PU/PH/PO surface with a poly(OEGMA) chain length of 100, the adsorption of Ls and Fg were reduced by ~98% and >99%, respectively, compared to the unmodified PU. Binary protein adsorption experiments showed that suppression of protein adsorption on the PU/PH/PO surfaces was essentially independent of protein size. The double-grafted OEG layers resisted both proteins equally.</p><p>The general applicability of this approach which combines oxygen plasma treatment and ATRP grafting was also studied. Various kinds of polymers such as PU, silicone hydrogel, and polydimethylsiloxane (PDMS) were chosen as substrates. Poly(MPC) grafts with different chain lengths were achieved by the three-step ATRPgrafting procedure. It was found that protein adsorption levels on the poly(MPC) grafts were significantly lower than on the respective unmodified surfaces. Protein adsorption decreased with increasing poly(MPC) chain length. Among the surfaces investigated, PU/MPC showed the highest protein resistance for a given chain length.</p> / Thesis / Doctor of Philosophy (PhD)
46

The In-between: Armature for Inhabitation

Rahman, Afrida Afroz 11 July 2023 (has links)
Flyovers, or grade separated bridges or roads, are a type of urban infrastructure that has been used to facilitate high-speed vehicular movement. This once-popular strategy of the west, despite being considered as a failure for sustainable urban growth, has been adopted in Bangladesh to combat traffic congestion in Dhaka that has a crippling effect on daily life of the citizens. As was anticipated by many urban planners and architects, these expensive structures did little to reduce traffic congestion, but created additional problems of noise and air pollution as well as reduced pedestrian mobility. More importantly, these flyovers created wasted void spaces underneath that are uncomfortable, devoid of human scale and act as physical and visual barriers that cause tears on the urban fabric. The objective of this thesis is to explore how architecture can unlock the potential of the unused spaces under the flyovers in Dhaka, by turning these linear leftover spaces into dignified public places that improves the daily lived experiences of the urban dwellers, by minimizing the disruptions caused by the flyover and by realizing the potential inherent in the robust structure of the flyover. This thesis examines a democratized way of building, where the role of architecture is to facilitate organic and heterogeneous growth, addition and modification to the flyover in order to bring the human scale back to the massive flyover structure through a reconciliation of top-down and bottom-up approaches. The architectural interventions respond to the site conditions, potentials and demands. The architectural outcome is based on the concepts of creating a threshold, architecture as armature and parasitic structures. / Master of Architecture / Flyovers, or grade separated bridges or roads, are a type of urban infrastructure that has been used to facilitate high-speed vehicular movement. This once-popular strategy of the west, despite being considered as a failure for sustainable urban growth, has been adopted in Bangladesh to combat traffic congestion in Dhaka that has a crippling effect on daily life of the citizens. As was anticipated by many urban planners and architects, these expensive structures did little to reduce traffic congestion, but created additional problems of noise and air pollution as well as reduced pedestrian mobility. More importantly, these flyovers created wasted empty spaces underneath that are uncomfortable and act as physical and visual barriers that cause tears on the urban fabric. The objective of this thesis is to explore how architecture can unlock the potential of the unused spaces under the flyovers in Dhaka, by turning these linear leftover spaces into dignified public places that improves the daily lived experiences of the urban dwellers, by minimizing the disruptions caused by the flyover and by realizing the potential inherent in the robust structure of the flyover. This thesis examines a democratized way of building, where the role of architecture is to facilitate organic and de-centralized growth, addition and modification to the flyover in order to bring the human scale back to the massive flyover structure through a reconciliation of top-down and bottom-up approaches. The architectural interventions respond to the site conditions, potentials and demands. The architectural outcome is based on the concepts of creating a threshold, architecture as armature and parasitic structures.
47

Developing a Surface-initiated Polymerization System from a Redox-switchable Catalyst for Polyamide Synthesis:

Xiao, Kexing January 2022 (has links)
Thesis advisor: Jeffery A. Byers / Thesis advisor: Petter Zhang / This thesis discusses the development of a surface-initiated N-carboxyanhydride (NCA) polymerization system from a redox-switchable catalyst for polyamide synthesis and further efforts towards the synthesis of polypeptide-based materials through the integration of NCA synthesis and its polymerization. In Chapter one, the most used methods to obtain polypeptide-based materials as well as their significant limitations are introduced. A new strategy is presented to access the polypeptide-based materials based on the integrated catalysis under spatial and temporal control. In Chapter two, a strategy to allow the attachment of a redox-switchable NCA polymerization catalyst on surface of titania for the synthesis of polyamide brushes will be demonstrated. Investigations about the kinetics of this surface-initiated ring-opening polymerization will be presented by carrying out the reaction in batch and under flow. Chapter three will discuss efforts towards achieving the integration of NCA synthesis and NCA polymerization, which includes an additional anchoring method to support polymerization catalyst and compatibility tests between the two separate reactions. / Thesis (MS) — Boston College, 2022. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Chemistry.
48

FLASH LAG EFFECT MODEL DISCRIMINATION

Gabbard, Stephen R. 23 August 2013 (has links)
No description available.
49

Global Professionals in the Turbulent World : A multi-case study on self-initiated expatriates in the interconnected external environment

Aho, Anna-Maria, Lehtinen, Sanni January 2024 (has links)
Background: Europe has gained an extra amount of volatility, uncertainty, complexity, and ambiguity (VUCA) during recent years, blurring the current and future state of global mobility. The scarce literature regarding the influence of the turbulent and interconnected external environment in the field of global mobility, particularly in the Western world, highlights the importance of examining the current environment and how it influences the perceptions of global professionals carrying vital implications for organizations and their global strategies. Purpose: The purpose of this research is to contribute to the field of global mobility by creating a holistic view of the current and future state of international assignments. We aim to unveil the implications the interconnected external environment, utilizing the VUCA framework, has on global mobility through the perspective of self-initiated expatriates (SIEs). Method: We conducted an inductive qualitative multi-case study rooted in social constructionism and relativistic perspective to ensure catching the subjective experiences and viewpoints of SIEs. We conducted 17 semi-structured interviews with SIEs who were currently on an international assignment in Germany and who, through purposive sampling, fulfilled strict boundary conditions. We analyzed the data using a thematic analysis approach to derive deeper meaning and construct rich empirical findings. Conclusion: The findings indicate that the interconnectedness of SIEs’ strong intrinsic motivation together with personal factors, international assignment environment, and available support mechanisms influence their perceptions of international assignments in the surrounding VUCA environment. Perceived stress caused by the VUCA environment as well as the decision-making regarding international assignments are additionally interdependent with the above factors. Accordingly, this enabled us to derive the current and future status of international assignments in the turbulent VUCA world.
50

A missiological study of the Kimbanguist Church in Katanga Province, Democratic Republic of Congo

Jesse, Fungwa Kipimo 11 1900 (has links)
This is a systematic and critical study of the mission of the Kimbanguist Church in the city of Lubumbashi in the Democratic Republic of the Congo. The research question was: “How do the Kimbanguist members interpret and express the Christian message in and for the context of Katanga province through their communal life, worship and mission?” A historical chapter traces the origins and growth of the church, followed by four chapters that analyze the mission of the church by means of a ‘praxis cycle.’ The chapters look at mission strategies (leadership, church departments, mission methods), followed by mission agents (spiritual head, clergy, chaplains, women, youth), the theological sources of mission (the Bible, the life of Simon Kimbangu, and a code of conduct) and spirituality (liturgy, sacraments, pilgrimages and festivals). In a concluding chapter several critical issues were identified for critical dialogue between the Kimbanguist church and other African churches. / Christian Spirituality, Church History & Missiology / M. Th. (Missiology)

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