337 research outputs found
The Breakdown Mechanism of Hollow Cathode Discharge
In a low pressure discharge, if the cathode incorporates a cylindrical or slit shaped hole, the discharge current can be several orders of magnitude higher than in one with plane parallel electrodes under the same pressure and voltage conditions. In this work hollow cathode discharges in Helium under the influence of variable parameters such as gas pressure, applied voltage, electrode gap spacing, external magnetic field, etc., are investigated by means of electrical and optical diagnostic techniques.
The results indicate that a hollow cathode discharge develops in two stages. The initial breakdown occurs along the longest straight path of the system, i.e., from the anode to the bottom of the cathode hole. This predischarge is confined to a narrow filament along the axis and carries a current up to l00\u27s of mA. The resulting distortion of the electric field in the cathode hole is assumed to cause a subsequent radial breakdown from the filamentary plasma on the axis to the edge of the cathode hole. After this second breakdown an increase in current by more than three orders of magnitude is observed. Experimental results with axial magnetic fields support the two-stage model
An investigation into conspicuous consumption in a transitional economy: A study of emerging urban Vietnamese consumers
Ph.DDOCTOR OF PHILOSOPH
Engineering protein biosynthesis apparatus, advanced design and screening strategies for small and fluorinated substrates in orthogonal translation
Protein engineering is a comprehensive toolbox for the chemical modification of enzymes in particular, and for the expansion of molecular functional diversity in general. In recent decades, two different categories have become established for the engineering of proteins. These include the approach of directed evolution approaches on the one hand and the strategies of rational protein design on the other hand. In particular, the use of noncanonical amino acids to introduce new functionalities has gained importance in the engineers’ toolbox. These include isostructural analogues of canonical amino acids as well as molecules with reactivities that can provide sites for further protein modifications.
In this study, we have presented a strategy for manipulating the protein biosynthesis machinery towards the incorporation of noncognate fluorinated substrates. In general, fluorinated amino acids are not genetically encoded. These mainly synthetic building block are valuable for the design of particularly stable protein folds and for targeting highly specific protein-protein interactions. Fluorine is small and has a very low polarizability and the strongest inductive effect among the chemical elements found on earth. Due to these unique stereoelectronic properties, fluorine substitution is advantageously used in protein and peptide design. In this context, the strategy of directed evolution was applied to construct isoleucyl-transfer ribonucleic acid synthetase libraries for the isoleucine AUA rare codon reassignment with small aliphatic fluorinated amino acids, such as L-trifluoroethylglycine, by random mutagenesis. A suitable screening plasmid containing a mutant of superfolder green fluorescent protein (sfGFP) as reporter protein and a modified isoleucine transfer ribonucleic acid (tRNA_UAU) from Escherichia coli was produced to create an enhanced molecular adaptor level for gene expression. However, the required selection strain could not be constructed by genome editing due to the complexity of essential gene modification.
In the second part of the study, different reporter proteins were used in advanced design with noncanonical amino acids for improvement of their biophysical, chemical, and biological properties. A robust alkene-tagged sfGFP variant was obtained, which is a valuable target in medicinal chemistry. In addition, the residue-specific incorporation of proline analogues into green fluorescent protein (GFP) derivates ─ enhanced green fluorescent protein (EGFP), NowGFP, and KillerOrange ─ enables the study of the role of prolines in the typical β-barrel structure organization
Rational Multi-Curve Models with Counterparty-Risk Valuation Adjustments
We develop a multi-curve term structure setup in which the modelling
ingredients are expressed by rational functionals of Markov processes. We
calibrate to LIBOR swaptions data and show that a rational two-factor lognormal
multi-curve model is sufficient to match market data with accuracy. We
elucidate the relationship between the models developed and calibrated under a
risk-neutral measure Q and their consistent equivalence class under the
real-world probability measure P. The consistent P-pricing models are applied
to compute the risk exposures which may be required to comply with regulatory
obligations. In order to compute counterparty-risk valuation adjustments, such
as CVA, we show how positive default intensity processes with rational form can
be derived. We flesh out our study by applying the results to a basis swap
contract.Comment: 34 pages, 9 figure
La Voix Enfantine De L\u27apres-60: Refus Du Double Normatif, Recherche Du Double Marginal
Notre these vise a examiner les romans de l\u27enfance de l\u27apres-60, de France et du Quebec, qui representent la dialectique enfant/adulte, et parallelement celle qui oppose le personnel et le social, le marginal et l\u27ideologie dominante. Les ouvrages qui font plus precisement l\u27objet de cette etude sont ceux ou le conflit vecu par un narrateur enfant est inscrit dans la trame thematique et structurelle du texte, qui sont tout entiers paradigmes d\u27une impossibilite relationnelle. Ils mettent en scene un affrontement entre le regard despotique de l\u27autre et les tentatives de recuperation de soi, entre les paroles mensongeres de l\u27adulte et celles rebelles de l\u27enfant.;Dans le cadre de cet affrontement, le protagoniste enfant va jusqu\u27a demonter les rouages de l\u27enonciation classique et les rapports de force qu\u27elle implique pour reduire la position mai tresse du narrateur adulte, pour abattre avec elle les figures stereotypees et s\u27instaurer des lors en point de vue axial ou en mai tre du recit. C\u27est par consequent sur le mode de la negation que s\u27inscrit la voix enfantine: il s\u27agit d\u27aneantir l\u27autre despotique, de parodier ou de mutiler son discours et son histoire, afin d\u27exposer la faille du systeme et le gouffre de l\u27insignifiance sociale. Dans cet elan d\u27emancipation par rapport aux voix et aux structures institutionalisees, le narrateur enfant finit par s\u27identifier a l\u27adulte marginal pour celebrer avec lui le triomphe d\u27un monde desarticule.;Dans le cadre de cette these, nous partons par consequent d\u27un survol historique du sentiment litteraire et social de l\u27enfance pour mettre en evidence l\u27emergence et l\u27impact grandissant de cette voix enfantine rebelle. Nous nous penchons ensuite sur certains ouvrages afin d\u27offrir une etude thematique et une analyse de quelques procedes narratifs employes dans les romans de l\u27enfance de l\u27apres-60 que nous avons definis
Antecedents and Consequences of Status Consumption Among Urban Vietnamese Consumers
This study examines the antecedents and consequences of status consumption in the transitional economy of Vietnam. Both qualitative (focus groups and in-depth interviews) and quantitative methods (survey) were employed in this investigation. To test the proposed model and hypotheses, a large consumer survey was conducted in the two biggest cities in Vietnam. The results of Structural Equation Modeling provided empirical evidence for the significant impact of most of the proposed antecedents of status consumption. Specifically, modern status orientation, the ‘success’ component of materialism, and both the individualistic self and collectivistic self were found to have a positive impact on status consumption. Traditional status orientation and consumer ethnocentrism were found to be negatively related to status consumption. The findings also suggested the positive consequences of status consumption on satisfaction with status consumption and satisfaction with life in general. Discussion of the research findings and managerial implications are also provided
A Quest for a New Model of Public University Governance That Promotes Incentives for Academic Excellence for Modern Vietnam: Lessons from Multi-site Comparative Case studies in East Asia
This study aims to develop a new model of governance that will promote incentives for academic excellence in Vietnamese public universities. To achieve this aim, this study empirically investigated four models of public university governance in four East Asian contexts. Guided by the two mutually reinforcing theoretical lenses of neo-institutional and resource dependency theory, four comparative case studies of models of public university governance were conducted in four flagship public universities, one in Vietnam, and three others in Thailand, Hong Kong, and China, each with an international reputation for academic excellence and good practices of public university governance. Using a mix of research instruments, including formal documents (sourced from respective governments and universities); semi-structured interviews (with university executives); and surveys (among department leaders), each case study examined (1) the context of each model; (2) the degree of structural clarity; (3) the degree of resource dependence; (4) internal leadership responses; and (5) the impacts of structural clarity and resource dependence on internal leadership responses. Using multi-level thematic frameworks, each case study provided insights into its model of public university governance in context. The cross-case comparisons revealed that though models outside Vietnam, shaped by their distinctive contexts, have their particularities, they share some common features in model design and implementation. The major findings suggest that while additional resources are necessary, Vietnam s current model of external control needs to be reoriented toward a proposed model of dual external supervision and support with central features of a higher degree of structural clarity and a lower degree of a university s dependence on Government resources, which can significantly contribute to higher internal leadership responses, thus promoting incentives for academic excellence. This study is significant as it remediates the problem of minimal Vietnamese-led research, joining model design and implementation perspectives in providing sound guidance for Vietnamese policy makers and university leaders. Being positioned in the Vietnamese context, supported by rigorous theories, empirical data evidence, and the large body of literature on university governance, this proposed model, its associated lessons and recommendations have applicability both to Vietnam, and to similar countries
Chăn-hênh: Sustainable Animal Productivity for Livelihoods, Nutrition and Gender inclusion in the Northwest Highlands of Vietnam, Work package 2: Livestock-derived foods as part of diverse diets
Towards local government strategic planning in Vietnam: systemic governance interventions for sustainability
Canad
Antecedents of the Intention and Behavior Toward Purchase of Counterfeit Luxury Goods in an Emerging Economy: a Study of Young Vietnamese Consumers
This study examines some antecedents of the intention and behavior toward buying counterfeit luxury goods among young consumers in Vietnam, an Asian emerging economy. The data was obtained from university undergraduate students in Hanoi, the capital of Vietnam. The results of structural equation modeling show support for most of our hypotheses. The findings indicate that materialism (the centrality component) has positive impact on attitude toward purchase of counterfeit luxury goods. Attitude and subjective norm toward counterfeit luxury goods are found to be positively related to purchase intention, while perceived behavioral control is not found to have a direct impact on purchase intention. In addition, perceived behavioral control and purchase intention are found to be significant predictors of purchase behavior. The research findings are discussed and implications for managers and policy makers are provided.
 
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