• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 84
  • 51
  • 19
  • 15
  • 2
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 184
  • 90
  • 40
  • 34
  • 30
  • 28
  • 22
  • 20
  • 18
  • 17
  • 17
  • 17
  • 16
  • 16
  • 12
  • 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.
151

Modulation der Hypoxie-Empfindlichkeit medullärer Netzwerke in einem Maus-Modell des Rett-Syndroms / Modulation of hypoxia-susceptibility of medullary networks in a mouse-modell of Rett-syndrome

Zimmermann, Jasper Lukas 14 February 2012 (has links)
No description available.
152

Variations in magma composition in time and space along the Central Andes (13°S-28°S) / Variations in magma composition in time and space along the Central Andes (13°S-28°S) / Variationen der Magmenzusammensetzung entlang der Zentralen Anden (13°S- 28°S) in Raum und Zeit / Variaciones en la composición del magma en tiempo y espacio a lo largo de los Andes Centrales (13°S-28°S)

Mamani-Huisa, Mirian-Irene 24 October 2006 (has links)
No description available.
153

Visualization of the Ca2+-dependent regulation of voltage-gated Ether-à-go-go channels by FRET microscopy /

Goncalves, Jose Tiago 03 July 2006 (has links)
No description available.
154

Essays on indexability of stochastic sheduling and dynamic allocation problems

Ruíz Hernández, Diego 13 April 2007 (has links)
In this Thesis, we first deploy Gittins index theory to establish the indexability of inter-alia general families of restless bandits that arise in problems of stochastic scheduling with switching penalties and machine maintenance. We also give formulae for the resulting indices. Numerical investigations testify the strong performance of the index heuristics.The second class of problems concerns two families of Markov decision problems. The spinning plates problem concerns the optimal management of a portfolio of assets whose yields grow with investment but otherwise decline. In the model of asset exploitation called the squad system, the yield from an asset declines when it is utilised but will recover when the asset is at rest. Simply stated conditions are given which guarantee general indexability of the problem together with necessary and sufficient conditions for strict indexability. The index heuristics, which emerge from the analysis, are assessed numerically and found to perform strongly.
155

Determinants of Citizens’ 311 Use Behaviors: 311 Citizen-initiated Contact, Contact Channel Choice, and Frequent Use

Wu, Wei-Ning 05 1900 (has links)
Facing increasingly complex policy issues and diminishing citizen satisfaction with government and service performance, managing the quality of citizen relationship management has become a main challenge for public managers. Solutions to complex policy problems of service performance and low level of citizen participation often must be developed by encouraging citizens to make their voices heard through the various participation mechanisms. Reflecting on this need, the municipal governments in the U.S. have developed centralized customer systems for citizen relationship management. 311 centralized customer system (named 311 in this study) has the functions of citizen-initiated contact, service-coproduction, and transaction, and many local governments launch 311 to maintain or enhance their relationship with the public. Using 311 is an easy and free technically for citizens, but ensuring some degree of citizen engagement and citizens’ 311 use has been challenging for local public managers of municipalities. Despite calls for the importance of 311 in the service and information delivery process, fair treatment and access to use of governmental information, citizen participation, government responsiveness, and citizen satisfaction, to the best of our understanding, no empirical studies explore citizens’ 311 behaviors in the micro and individual level in the field of public administration. This dissertation provides a comprehensive understanding of the 311 centralized customer system, helps local public managers know citizens’ perceived perspectives toward the operation of 311, and assists these managers to develop an effective 311 system in municipalities. The dissertation’s main purpose is to clarify the importance of 311 to citizen relationship management and provide insights into citizens’ 311 use behaviors. More specifically, this dissertation tries to answers the following questions: a. Why do citizens use 311? Do the various groups of the population access and use 311 in San Francisco equally? If not, what factors influence the citizens’ 311 citizen-initiated contact behaviors? b. Why do citizens choose the 311 digital channel to contact with local governments? c. Why do citizens use 311 frequently? This dissertation will address these questions and draws on data from the 2011 citizen survey of City of San Francisco to explore citizens’ 311 use behaviors by examining them from citizens’ perspectives. The main arguments of each question listed above are: 1. 311 citizen-initiated contact is different from traditional citizen-initiated contact, and exposure to governmental-ICT environment, gender, income, and race are the factors influencing 311 citizen-initiated contact. 2. The digital divide, including the social side of the digital divide and access-side of the digital divide, influences citizens’ 311 channel choice. 3. Citizens’ technology acceptance, citizen satisfaction, and frequent use of public services influence the frequency of citizens’ 311 use.
156

An Investigation into the Use of Density Functional Theory (DFT) Calculations for Predicting Vibrational Transitions for Perfluroinated Sulfonic Acid (PFSA) Ionomer Membranes

Schultz, Spencer Albert 05 February 2019 (has links)
Perfluorinated sulfonic acid (PFSA) ionomer membranes demonstrate great potential for use in proton exchange membrane fuel cells (PEMFCs) due to their favorable electronic properties and excellent efficiency. However, the assignment of key vibrational transitions such as the symmetric sulfonate and ether stretches is not yet fully understood depriving researchers of a quick and simple technique for analyzing morphological changes. The symmetric sulfonate stretch could be used to track changes in the ionic clusters formed within the membrane while the ether stretch will provide insight into the largely semi-crystalline PTFE phase. Alterations in either regime will affect both ion transport and mechanical properties and produce a major shift in device performance. This study focused on predicting the vibrational transitions for Aquivion, 3M PFSA, and Nafion using density functional theory (DFT) with the bulk being performed using the same functional and basis set combination, B3LPY/6-31+G*. For all three ionomers, the predicted vibrational transitions were affected by changes in both the conformer and solvation method with water being used as the solvent. Despite the noted changes, both vibrational transitions were determined to be within the range of 970-1100 cm-1 with the symmetric sulfonate stretch present at around 970-1010 cm-1 and the ether stretch observed at around 1050-1100 cm-1 with solvation present. While the calculated peak positions mirror those found in the experimental spectra within the literature, the traditional normal mode assignments do not match those predicted by our calculations. However, recent studies have hypothesized that these vibrational transitions are coupled, which could explain why they have been so difficult to assign. / Master of Science / Perfluorinated sulfonic acid (PFSA) ionomer membranes show great promise for use in proton exchange membrane fuel cells (PEMFCs) due to their excellent efficiency. However, the current techniques used to determine changes in structural configurations require sophisticated equipment and trained personnel to operate. Simpler techniques exist wherein the vibrations of certain bonds can be measured upon exposure of the sample to measured amounts of infrared light. The problem with this technique is that researchers currently do not fully understand at what wavelengths certain portions of the polymer known as functional groups will vibrate. These vibrations are also known as vibrational transitions. This study was undertaken to predict through numerical solutions to the Schrödinger equation at what wavelengths two particular vibrational transitions would occur for three common ionomers, Aquivion, 3M PFSA, and Nafion. For all three structures, the positions of these transitions mirrored that observed within the literature although the functional groups assigned to these positions did not match with those identified by our calculations. However, recent studies have indicated that these vibrational transitions occur at the same positions, which could explain why they have been so difficult to assign.
157

A window into selective catalytic reduction : a RAIRS study of NO and NH3 on Cu{311}

Sitathani, Krit January 2017 (has links)
This thesis studies the interaction between the bare Cu{311} surface with NO and NH3,individually and co-adsorbed using reflection-absorption infrared spectroscopy (RAIRS). In addition to the bare Cu{311} surface, the interaction of NO and NH3 with the various oxygen phases of the Cu{311} surface phases was also studied. Several other techniques were used in tandem to support the study, such as low energy electron diffraction (LEED) and temperature programmed desorption (TPD) experiments using mass spectrometry. The study was carried out in pursuit an understanding of the underlying mechanism of the selective catalytic reduction (SCR) of NO using NH3 in current diesel engines. The dosing of NO onto the Cu{311} surface at 100 K leads to the initial adsorption of intact NO. After an exposure threshold is reached, individual NO molecules react with another NO molecule to form (NO)2 dimers. These dimer species subsequently form N2O, leaving O(a) on the surface. Oxygen was found to be an inhibitor for the reaction, either due to the reaction in a self-poisoning process or from oxygen pre-dosing onto the Cu{311} surface. Temperature plays a minor role with regards to NO/Cu{311}, as it only affects the amount of NO on the surface along with adsorbate surface mobility. Similarly, NH3 was found to adsorb intact onto the Cu{311} surface and not to react or dissociate at 100 K. Oxygen acts as a site blocker for the adsorption, but can also stabilise NH3 to remain on the surface at higher temperatures due to electronic effects. At 300 K, it was found that both the bare and oxygen pre-covered Cu{311} surface was able to dissociate NH3 into NH2. The co-adsorption of NO and that of NH3 onto the Cu{311} surface were found to be largely independent of each other and the interaction is dominated by the displacement of NO by NH3. However, as NO adsorption on the Cu{311} surface forms O(a), it indirectly affects the adsorption of NH3 by creating an oxygen covered Cu{311} surface, which changes how NH3 adsorbs onto the surface.
158

Détermination théorique des paramètres RMN de métabolites et protéines / Theoretical determination of NMR parameters of metabolites and proteins

Harb, Zeinab 17 October 2011 (has links)
Ce travail présente une étude théorique des spectres RMN de molécules biologiques. Dans la première partie, les calculs DFT des paramètres RMN (déplacements chimiques et constantes de couplage spin-spin) pour les protons liés à des atomes de carbone ont été réalisés pour quatre métabolites de la prostate: la putrescine, la spermidine, la spermine, et la sarcosine, et trois métabolites du cerveau: l'acétate, l'alanine et la sérine. Une étude théorique systématique, dans l'approche DFT, des paramètres de RMN des métabolites a montré que la méthode B3LYP/6-311++G** est un bon compromis entre la précision et les coûts. Les contributions du solvant ont été évaluées en utilisant le modèle PCM, les effets des isomères, pondérés dans l’approximation de Boltzmann, ont été pris en compte, et les corrections de vibration de point zéro ont été estimées en utilisant une approche perturbative au second ordre. La comparaison avec l'expérience a démontré que tous ces effets sont nécessaires pour améliorer l'accord entre les données calculées et expérimentales, aboutissant à des résultats de grande précision. Dans la deuxième partie, nous avons développé un nouveau modèle, BioShift, qui permet la prédiction des déplacements chimiques des différents noyaux (H, N, C ...) pour des molécules biologiques (protéines, ADN, ARN, polyamine ...). Il est simple, rapide, et comporte un nombre limité de paramètres. La comparaison avec des modèles sophistiqués conçus spécialement pour la prédiction des déplacements chimiques des protéines a montré que Bioshift est concurrentiel avec de tels modèles. / The present work presents a theoretical study of the NMR spectra of biological molecules. In the first part, DFT calculations of the spin-Hamiltonian NMR parameters (chemical shifts and spin-spin coupling constants) for protons attached to carbon atoms have been performed for four prostate metabolites: putrescine, spermidine, spermine, and sarcosine, and three brain metabolites: acetate, alanine, and serine. A theoretical investigation, within the DFT approach, of the NMR parameters of metabolites has shown that the B3LYP/6-311++G** level of calculation is a good compromise between accuracy and costs. Contributions from solvent were evaluated using the PCM model, Boltzmann weighted isomer effects were calculated, and zero-point vibrational corrections were estimated using a second order perturbation approach. Comparison with experiment has demonstrated that all these effects are necessary to improve the agreement between calculated and experimental data. In the second part, we have presented a new model, BioShift, that allows the prediction of chemical shifts of different nuclei (H, N, C…) for biological molecules (proteins, DNA, RNA, polyamine …). It is simple, fast, and involves a limited number of parameters. Comparison with well-known sophisticated models designed especially for the prediction of chemical shifts of proteins showed that Bioshift is competitive with such models.
159

Social Behavior and Emotions at Work: Regulation, Assessment and Feedback

Sipahi Dantas, Alaíde 25 January 2016 (has links)
En una societat basada en els serveis, la qualitat de les relacions entre els col·legues, el proveïdor del servei al client, els directius i els membres dels seus equips determinen una sèrie de resultats, com ara les intencions de facturació, la fidelitat del client o la retenció del talent. En efecte, la qualitat de la relació entre un client i un proveïdor de serveis pot determinar la satisfacció del client, com també la seva predisposició a oblidar els errors (p. ex., Verghese, 2003; Roter, 2006). Això explica per què les organitzacions cada vegada es gasten més diners en formació corporativa en gestió, en general, i en lideratge, en particular. El desenvolupament del lideratge i la gestió encapçalen la llista de les primeres àrees d’inversió. L’any 2013, després de dos anys d’increment de la despesa, la inversió nord-americana en formació corporativa va créixer encara un 15 % -més de 70.000 milions de dòlars als Estats Units i 130.000 milions de dòlars arreu del món (Deloitte Corporate Learning Factbook, 2014). Aquesta tesi doctoral s’inspira en el rol fonamental de les interaccions socials a la feina per tal d‘obtenir una sèrie de resultats empresarials, com la satisfacció al lloc de treball, la satisfacció del client, la retenció del talent i l‘acompliment individual i de l’organització. Cercant de contribuir a l’estudi i a la pràctica del desenvolupament del comportament social a la feina, la motivació principal dels estudis que s’inclouen en aquesta tesi és respondre a la pregunta global: Com poden ser més efectius el comportament social i les emocions de les persones a la feina? Aquesta pregunta global s’ha abordat amb tres estudis, un de teòric, un de metodològic i un d’empíric. La finalitat del primer estudi és descriure els tipus generals del comportament social que una persona pot exhibir en funció de les múltiples vies d’interacció cognitiva-emocional i utilitzar-los com a base per proposar un model de regulació emocional que afavoreixi l’exhibició d’un comportament social més efectiu a la feina. El segon estudi pretén afavorir el desenvolupament d’un comportament social a la feina a través del primer pas fonamental que cal fer, que és avaluar-lo. Amb aquesta finalitat, el segon estudi presenta el desenvolupament i el test de validesa del constructe d’un instrument espanyol per avaluar el comportament personal i social a la feina. El tercer estudi tracta dels intents dels directius per desenvolupar el comportament social dels seus treballadors a través d’un feedback de seguiment de 360º. Investiga les paradoxes que afronta un directiu durant un feedback de seguiment de 360º, com es tradueixen en comportaments de lideratge i incideixen en les reacciones emocionals dels receptors del feedback. / En una sociedad basada en los servicios, la calidad de las relaciones entre los colegas, el proveedor del servicio al cliente, los directivos y los miembros de sus equipos determinan una serie de resultados, como las intenciones de facturación, la fidelidad del cliente o la retención del talento. En efecto, la calidad de la relación entre un cliente y un proveedor de servicios puede determinar la satisfacción del cliente, así como su predisposición a olvidar errores (p. ej., Verghese, 2003; Roter, 2006). Ello explica por qué las organizaciones siguen incrementando sus gastos en formación corporativa en management, en general, y en liderazgo, en particular. El desarrollo del liderazgo y el management encabezan la lista como las primeras áreas de inversión. En 2013, después de dos años de incremento del gasto, la inversión estadounidense en formación corporativa creció un 15% -más de 70.000 millones de dólares en los Estados Unidos y 130.000 millones de dólares en todo el mundo (Deloitte Corporate Learning Factbook, 2014). Esta tesis doctoral se inspira en el rol fundamental de las interacciones sociales en el trabajo para obtener una serie de resultados empresariales, como la satisfacción en el puesto de trabajo, la satisfacción del cliente, la retención del talento y el desempeño individual y de la organización. Buscando contribuir al estudio y a la práctica del desarrollo del comportamiento social en el trabajo, la principal motivación de los estudios que se incluyen en esta tesis es responder a la pregunta global: ¿De qué modo pueden ser más efectivos el comportamiento social y las emociones de las personas en el trabajo? Esta pregunta global ha sido abordada a través de tres estudios, uno teórico, uno metodológico y uno empírico. La finalidad del primer estudio es describir los tipos generales de comportamiento social que una persona puede exhibir en función de las múltiples vías de interacción cognitiva-emocional y utilizarlos como base para proponer un modelo de regulación emocional que favorezca la exhibición de un comportamiento social más efectivo en el trabajo. El segundo estudio pretende respaldar el desarrollo de un comportamiento social en el trabajo a través del primer paso fundamental que se necesita, que es su evaluación. Para ello, el segundo estudio presenta el desarrollo y el test de validez del constructo de un instrumento español para evaluar el comportamiento personal y social en el trabajo. El tercer estudio trata de los intentos de los directivos para desarrollar el comportamiento social de sus trabajadores a través de un feedback de seguimiento de 360º. Investiga las paradojas que afronta un directivo durante un feedback de seguimiento de 360º, cómo se traducen en comportamientos de liderazgo e inciden en las reacciones emocionales de los receptores del feedback. / In a service-based society the quality of the relationships among colleagues, client-service provider, managers and their team members, determine a range of outcomes such as turnover intentions, client loyalty, talent retention. Indeed, the quality of the relationship between a client and a service provider may determine client satisfaction as well as willingness to forgive mistakes (e.g. Verghese, 2003; Roter, 2006). This explains why organizations keep increasing its spending in corporate training in management in general and leadership in particular. Leadership and management development are at the top of the list as the number 1 areas of investment. In 2013, following two years of already increasing spending, the US investment in corporate training grew by 15% - over $70 Billion in the US and $130 Billion worldwide (Deloitte Corporate Learning Factbook, 2014). This doctoral thesis is inspired by the key role of social interactions at work for a series of business outcomes such as job satisfaction, client satisfaction, talent relation, individual and organizational performance. In a quest to contribute to the research and practice of social behavioral development at work the main motivation underlying the studies that encompass this dissertation is to answer the overarching question: How can people`s social behavior and emotions be more effective at work? This overarching question was addressed through three studies, one theoretical, one methodological and one empirical. The aim of the first study is to explore the literature review of neuroscience, psychology and management and, through its integration, provide the mapping of the general types of social behavior a person can display depending on the multiple cognitive-emotion interaction pathways. This review was then used as a basis to propose an emotional regulation model that is expected to facilitate the display of more effective social behavior at work. The second study aims to support the development of social behavior at work through the first fundamental step necessary to it, which is its assessment. To do so the second study presents the development and the construct validity test of a Spanish instrument to assess personal and social behavior at work. The third study managers’ attempts in developing the social behavior of its workers through 360º follow-up feedback. It investigates the paradoxes faced by a manager during a 360º follow-up feedback, how they translate into leadership behaviors and impact the emotional reactions of feedback receivers.
160

日本能源治理之研究: 比較311東日本震災前後之能源政策 / A study on Japan's energy governance: a comparison of Japan's energy policies before and after the March 11 east Japan earthquake

胡佳宜, Hu, Jia Yi Unknown Date (has links)
全球能源消費大國之中,日本的低能源蘊藏量以及高能源利用率常引起多方研究。本文從蒐集並整理日本戰後至2011年間的能源政策、比較311前後兩個執政黨(民主黨、自民黨)的能源政策立場,到探究日本於311後能源政策轉折的方向及原因、並且進一步推敲出日本的能源治理模式。因此發現,日本在二戰之後就開始運用一系列的政策手段與能源市場干預途徑,突破低能源蘊藏量之先天不利條件,達到高能源利用率之後天技術優勢所創造的經濟成長。而當日本經歷2011年3月11日東日本大震災後,政府更強烈介入能源市場,希望進行能源結構的轉型,使得日本得以維持能源高自主率與溫室氣體低排放率的目標。本文因此結論,日本雖然身為能源匱乏國,但是它的能源政策充分體現出了國家介入能源市場由上而下治理模式的特性,使得日本得以突破能源約束,在諸多能源不利之條件下開創了近半世紀的經濟高度發展期。此外,本文亦結論日本於全球能源治理的角色可以歸納為三:(1)全球溫室氣體減量暨全球能源安全提升的追隨者;(2)區域性能源合作的示範者;(3)全球核能安全建立的示範者等三種角色。 / Japan is noted for its low energy endowment but high energy efficiency among the global top energy consuming nations. In this study, collection of the past Japanese energy policies from 1945 to 2011, comparison of the political stances on the energy strategies between the two Japanese ruling parties, Liberal Democratic Party and The Democratic Party, and investigation on factors causing a change of Japan’s energy policy post Fukushima contributed to outlining the pattern of Japan’s energy governance. This study found that Japan’s intervening in its the post-war domestic energy market by means of a string of policy instruments has successfully made Japan overcome the predicament of high energy demands out of low energy reserves, further achieve the edge of high energy efficiency, and therefore create its outstanding economic growth. Nevertheless, after experiencing another energy predicament post Fukushima, Japan made more effort on the intervention into its energy market to transform its domestic energy consumption structure with a view to maintaining high energy self-sufficient rates and low GHGs emissions. To conclude, although Japan is a nation of insufficient energy resources, its energy policies reveal the trait that the state intervenes in the energy market by the top-down governance approach to make its way to break through the energy constraints, creating a nearly half-century’s economic prosperity. Besides, we also conclude that Japan plays three major roles in the domain of global energy governance: 1. a follower of global GHGs emission abatement and global energy security enhancement, 2. a demonstrator on regional energy cooperation and, 3. a model of building global nuclear power safety.

Page generated in 0.0267 seconds