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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.
1

Herausforderung Eurasien / Challenge Eurasia

January 2011 (has links)
Im Osten was Neues: Seit zehn Jahren gibt es die Shanghai-Gruppe. Für die Geschichtsschreibung ein kleiner, ein winziger Zeitraum. Welchen Platz die Organisation einst in Geschichtsbüchern einnehmen wird, ist ungewiss. Die strategische Bedeutung, die Entscheidungsprozesse sowie die Ziele der Shanghai-Gruppe sind bislang nicht konturscharf einzuschätzen gewesen. Im Thema untersuchen Kenner der Gruppe die Interessen der Akteure, vor allem jene Chinas und Russlands. Sie werfen einen Blick auf die geostrategische Relevanz Zentralasiens und machen auf das kritische Verhältnis zwischen der Allianz und den USA aufmerksam.
2

Micro and nanoactuators based on bistable molecular materials / Micro et nano-actionneurs à base de matériaux moléculaires bistables

Manrique Juarez, Maria Dolores 28 November 2017 (has links)
Les systèmes microélectromécaniques (MEMS) sont des dispositifs de taille micrométrique capables de transformer un signal mécanique en un signal électrique et vice-versa. Ils sont aujourd'hui largement répandus dans notre vie quotidienne pour la détection, la transformation de l'énergie et l'actionnement de dispositifs grâce à leur faible dissipation énergétique, leur réponse ultra-rapide et leur grande sensibilité. Même si depuis plusieurs décennies, les progrès technologiques ont entraîné la miniaturisation des ces dispositifs, il reste nombreux challenges à surmonter dont l'un des plus importantes est l'intégration à l'échelle nanométrique d'actionneurs à base des matériaux dit " intelligents " (à ces dimensions, les matériaux habituellement utilisés perdent leurs propriétés d'actionnement). Dans ce contexte, ce travail de thèse avait pour objectif d'explorer l'utilisation des matériaux moléculaires à transition de spin pour le développement d'actionneurs électromécaniques. Dans ce but, nous avons conçu des microleviers en silicium que nous avons recouvert par différentes molécules à transition de spin soit par sublimation, soit par " spray-coating ". Les MEMS ont été caractérisés à température et pression variables en modes dynamique et statique à l'aide d'un unique dispositif expérimental. Les résultats obtenus démontrent que les molécules à transition de spin peuvent être intégrées, à l'aide de différents procédés de fabrication, dans des dispositifs MEMS et qu'il est possible de réaliser l'actionnement à l'aide d'une source d'énergie thermique (chauffage et refroidissement) et/ou lumineuse. Simultanément, cette étude a également permis d'évaluer les propriétés mécaniques des matériaux à transition de spin (module de Young, coefficient de Poisson) qui restent mal connues. / Microelectromechanical systems (MEMS) are micrometric devices able to transform a mechanical signal into an electrical one and vice-versa. In the past years they have been successfully employed in different fields of our everyday life for sensing, transducing different forms of energy and for actuating purposes thanks to their low energy dissipation, fast response and high sensibility. Even if recent technological progress has allowed a considerable miniaturization of these devices, several challenges remain. In particular the integration of smart actuating materials at the nanometric scale remains arduous because in most cases they lose their actuating properties at reduced sizes. In this context, this thesis work aimed for exploring the possibility of using molecular spin crossover materials for the development of electromechanical actuators. To this aim we have conceived silicon microcantilevers, which have been coated by various spin crossover molecules using either thermal evaporation or spray-coating methods. The MEMS have been characterized at variable temperature and pressure both in dynamical and static modes using a single experimental setup. The results prove that spin crossover molecules can be successfully integrated into silicon MEMS devices using different fabrication processes and their actuation can be achieved using either a thermal energy source or light irradiation. In parallel, this work has allowed us to extract relevant mechanical properties of spin crossover materials (Young's modulus, Poisson's ratio), which have been largely unknown previously.
3

Coexistence Mechanisms for Bluetooth SCO Link and IEEE 802.11 WLAN

Chiang, Shao-Hsien 17 January 2007 (has links)
Wireless network systems, such as IEEE 802.11 wireless local area networks (WLANs) and Bluetooth, are increasingly constructed in our surrounding environment. Although devices running these two wireless systems operate with different technologies, they both work in the 2.4 GHz ISM (Industrial, Scientific, and Medical) band, and therefore lead to interference. The problem of Bluetooth interfering with a WLAN is particularly serious with a Bluetooth device located in an area with more than one overlapping WLAN. Interference is not a significant problem if it only degrades data throughput. However, it is unacceptable if it causes disconnection of the Bluetooth SCO link (i.e., voice connection). This study presents mechanisms to sustain the quality of Bluetooth SCO link, under the interference, with only at a minor cost of WLAN¡¦s data throughput.
4

The Influence of Copper Binding on the Stability of the SCO Protein from Bacillus subtilis

Davidson, David Eduards 25 September 2007 (has links)
Every aerobic organism expresses cytochrome c oxidase to catalyze reduction of molecular oxygen to water, and takes advantage of this energy releasing reaction to produce an electrochemical gradient used in cellular energy production. The protein SCO (Synthesis of cytochrome c oxidase) is a required assembly factor for the oxidase, conserved across many species. SCO is implicated in the assembly of one of two copper centres (ie., CuA) of cytochrome oxidase. The exact mechanism of SCO’s participation in CuA assembly is not known. SCO has been proposed to bind and deliver copper, or alternatively to act in reductive preparation of the CuA site within the oxidase. In this body of work, the strength and stability of Cu(II) binding to Bacillus subtilis SCO is explored via electronic absorption and fluorescence spectroscopies and by calorimetric methods. An equilibrium dissociation constant (Kd) of 3.5x10-12 M was determined as an upper limit for the BsSCO-Cu(II) interaction, via differential scanning calorimetry. In the first reported case for a SCO homolog, dissociation kinetics of Cu(II) from BsSCO were characterized, and found to be dependent on both ionic strength and the presence of free Cu(II) in solution. Further differential scanning calorimetry experiments performed at high ionic strength support a two-step model of BsSCO and Cu(II) binding. The implications of this model for the BsSCO-Cu(II) interaction are presented in relation to the mechanism of interaction between SCO and the CuA site of cytochrome c oxidase. / Thesis (Master, Biochemistry) -- Queen's University, 2007-09-21 16:00:23.621
5

Researching on Shanghai Cooperation Organization from Neorealism

Hsu, Shu-li 04 September 2008 (has links)
The collapse of the USSR has caused the vacuum of power and ideology in the Middle Asian region; therefore, such situation has resulted in the coveat from the world power and terrorism.The discovery of natural resource (petroleum in particular) assures the strategic value of this region, which is a crucial factor of causing pivotal change if this region.The region of sovereignty is always interrelated to the geological location.In other words, the shift of sovereignty also restructures the relationship between the power and geological location.The establishment of Shanghai Cooperation Organization (SCO) was jointly organized by China and Russia on the basis of such political and geological background.However, after the tragedy of 911, globalwide anti-terrorism has reached to its peak, which provides an opportunity to the US taking a position in this region. Due to this dramatic change, Middle Asian area has become a region of competition for the USA, Russia and China. This paper starts with the discussion of the development of Realism, followed by the comparison of Realism and the correction of Neo-Realism. The basis of analysis on the historical background of Shanghai Cooperation Organization(SCO)is from the Neo-Realism perspective.SCO is not a military alliance but an organization to maintain regional safety and economic development, which also exclude the possibility of sole power in one region and result to certain type of power balance in one region.Since its establishment, SCO has played an influential role; however, China and Russia are the two leading countries that may change the current balanced situation. Many countries in Middle Asian area would like to use SCO as a diplomatic leverage and both Russia and China also try to make SCO as a tool to expand its power, which change the features of international order in 21th century. This kind of change is vital to Taiwan. If the relationship among China and Russia or other countries in this area is stable, China will not have to worry about the threats from the north and be able to concentrate on the problems in Taiwan Strait and South Sea.For this reason,it is worthy for us to pay close attention to this issue.
6

Moskaus nützliches Instrument? : Russland und die Shanghai-Gruppe / Moscows useful tool? : Russia and the SCO

de Haas, Marcel January 2011 (has links)
Russland sieht in der Shanghai-Gruppe ein wichtiges außen- und sicherheitspolitisches Instrument. Damit sollen sowohl das internationale Profil verbessert als auch militärische Interessen (Waffenexporte) umgesetzt werden. Obwohl sich das Verhältnis zu China deutlich verbesserte, ist es russisches Interesse, mittels der SCO Chinas Einfluss in Zentralasien zu begrenzen. Angesichts der strategischen Differenzen zwischen Moskau und Peking stellt sich das Problem des möglichen Bruchs der Shanghai-Gruppe.
7

The Study of Catalytic Oxidation of Ammonia in an Air Stream over Cu/Ce Catalyst

Yang, Sheng-Fu 11 July 2002 (has links)
Abstract Ammonia (NH3) is one of valuable chemicals which is commonly used in manufacturing the fertilizer, synthetic fiber, synthetic plastics, and dynamites, and is used in the factories such as papermaking, textile mill, camera and electrical. NH3 is also a typical pollutant which is found to be emitted from industrial processes, agriculture areas and livestock farm. It causes burn damage due to the corrosion and has a long-term impact on human bronchus. This study was to investigate the performance and kinetics in oxidation of ammonia by using a method of selective catalytic oxidation (denoted by SCO) over a series catalysts of Cu/Ce . The major parameters were performed at the following conditions: initial concentration NH3 of influent in ranging from 500 ppm to 1000 ppm, temperatures ranging from 150¢J to 500¢J, oxygen content in inlet stream in ranging from 4¢Hto 20¢Hand humidity in ranging from 1¢Hto 20¢H(or an absolute humidity of 607 ppm-12136 ppm). In the first stage experiments, the purpose was to select a best catalyst, which had the great activity and highest selectivity on nitrogen. The catalysts used in this work were prepared into three types in the following: Cu/La/Ce (molar ratio: 8/1/1, 7/1/2, 7/2/1, 6/1/3, 6/2/2 and 6/3/1), Cu/La (molar ratio: 6/4, 7/3, 8/2 and 9/1) and Cu/Ce (molar ratio: 6/4, 7/3, 8/2 and 9/1); total numbers of catalysts were 14. Test results showed the molar ratio 6:4 of Cu/Ce catalyst was found to have the best activity and selectivity to convert NH3 in this work. The second stage experiments were carried to investigate the effect of parameters on conversion of NH3 over a Cu/Ce catalyst of molar ratio 6:4. The conversion of NH3 in process of SCO increased with operation conditions such as the going up of temperature, and the increasing both of oxygen content and of residence time. The lower conversion of NH3 was achieved by an increasing on initial concentration of NH3, space velocity and humidity. The third stage experiments were conducted to investigate the effect of operation period on deactivation of NH3 over the above catalyst. At constant initial concentration of NH3, oxygen content and space velocity for 30 hr continuously, we found Cu/Ce catalyst had an excellent stability in conversion of NH3. Further tests by XRD, SEM and EA were determined. The kinetics of SCO over a Cu/Ce catalyst of molar ratio 6:4 in oxidation of NH3, using differential method, was found that a pseudo-first order reaction could be described by Mars-Van Krevelend model. An equation of destruction efficiency in terms of NH3 was obtained, and a good fitting was got between the predicted and the experimental values.
8

Die Rolle der mitochondrialen Sco-Proteine: Molekularbiologische Untersuchungen zur Beteiligung an der oxidativen Stressabwehr

Kost, Luise 14 February 2022 (has links)
Die sowohl in Pro- als auch in Eukaryoten vorkommenden Sco-Proteine übernehmen eine wichtige Funktion bei der Assemblierung der Cytochrom c Oxidase (COX, Komplex IV der Atmungskette). Eine Reihe von Publikationen legen zudem die Vermutung nahe, dass die Sco-Proteine neben der COX-Assemblierung weitere Funktionen ausführen können. Strukturelle Ähnlichkeiten zu antioxidativen Proteinen sowie experimentelle Daten, vor allem aus Prokaryoten, weisen auf eine mögliche Funktion im Zusammenhang mit der Abwehr von oxidativem Stress hin. Die Untersuchung dieser putativen Funktion war Gegenstand der vorliegenden Arbeit. Als Modellorganismus diente die fakultativ anaerobe Hefe Saccharomyces cerevisiae, um eine von der COX-Assemblierung unabhängige Untersuchung zu ermöglichen. Da die potenzielle antioxidative Funktion der Sco-Proteine möglicherweise durch andere antioxidative Enzyme kompensiert und somit maskiert wird, wurden in Vorarbeiten Doppelmutanten generiert, in denen neben einem der SCO-Gene die Superoxid-Dismutase 1 (SOD1) deletiert ist (Δsco1Δsod1 u. Δsco2Δsod1). Diese Doppeldeletionsmutanten zeigten eine hohe Sensitivität gegenüber oxidativem Stress und bildeten den Ausgangspunkt der Experimente. Durch phänotypische Analysen sowie die Quantifizierung der intrazellulären ROS-Level konnte bestätigt werden, dass die Stämme Δsco1Δsod1 und Δsco2Δsod1 erhöhtem oxidativen Stress ausgesetzt sind. Mittels 2D-DIGE-Analyse konnte außerdem gezeigt werden, dass bereits bei Einzeldeletion eines der beiden SCO-Gene die Abundanz mehrerer an der oxidativen Stressabwehr beteiligter Proteine erhöht ist. Letztlich konnte in einem inversen Ansatz aufgezeigt werden, dass die Überexpression von Sco2p in der Doppeldeletionsmutante Δsco2Δsod1 eine erhöhte Toleranz gegenüber PQ und geringere intrazelluläre ROS-Level im Vergleich zum Ausgangsstamm bewirkt. Als zweiter Modellorganismus wurde die Pflanze Arabidopsis thaliana ausgewählt, die ebenfalls zwei Sco-Homologe (HCC1/HCC2) besitzt. Während HCC1 an der COX-Assemblierung beteiligt ist, wurde für HCC2 eine mögliche Rolle bei der Aufrechterhaltung der Redox-Homöostase postuliert. Ein weiterer Schwerpunkt dieser Arbeit lag daher auf der Untersuchung der möglichen Funktion von HCC2. In mehreren Kreuzungsschritten wurden dafür – analog zum Ansatz in S. cerevisiae – Linien mit Knock-out von HCC2 und einem SOD-Gen erzeugt. Nach Identifizierung potenzieller Doppelmutanten und Nachweis der gewünschten Knock-out-Mutationen mittels Expressionsanalyse erfolgten phänotypische Untersuchungen unter verschiedensten Stressbedingungen. Unter dem Einfluss von Salzstress konnte für die Doppelmutanten mit Knock-out von HCC2 und SOD1 eine erhöhte Sensitivität beobachtet werden. Um jedoch eine Aussage über das mögliche Ausmaß von oxidativen Schäden in diesen Linien treffen zu können, sind weitere Untersuchungen notwendig. Während die Ergebnisse aus den Versuchen mit A. thaliana nur vermuten lassen, dass die Sco-Proteine an der Abwehr von oxidativem Stress beteiligt sind, lieferten die Versuche mit S. cerevisiae eindeutige Hinweise, die für eine antioxidative Funktion der Sco-Proteine sprechen. Die möglichen, dieser Funktion zugrunde liegenden Mechanismen werden diskutiert.
9

The pure rotational spectrum of the ScO (X2Σ+) radical

Halfen, D.T., Min, J., Ziurys, L.M. 01 1900 (has links)
The rotational spectrum of ScO (X-2 Sigma(+)) has been measured in the gas phase in the frequency range 30-493 GHz using a combination of Fourier transform microwave/millimeter-wave (FTM/mmW) and submillimeter direct absorption methods. This work is the first pure rotational study of this radical. Both the ground vibrational and v=1 states were observed. ScO was created from the reaction of metal vapor, produced either by a laser ablation source or a Broida-type oven, and N2O, in the former case heavily diluted in argon. Extensive hyperfine structure was observed in the FTM/mmW data, although the spin-rotation splitting was found to be small (similar to 3 MHz). In the mm-wave spectra, however, the fine and hyperfine structure was blended together, resulting in broad, single lines for a given transition N + 1 <- N. The data were analyzed in a combined fit using the very accurate hyperfine measurements of Childs and Steimle (1988), employing a Hund's case b Hamiltonian, and an improved set of rotational and centrifugal distortion constants were determined. These measurements improve the accuracy of predicted frequencies for astronomical searches by 14-18 MHz, or 16-20 km/s, in the 1 mm region - a difference of half to a full linewidth for certain interstellar sources. This work also demonstrates the capabilities of the FTM/mmW spectrometer at 61 GHz.
10

L'organisation de coopération de Shanghai : un nouveau mode de coopération ou une nouvelle intégration régionale? / The Shanghai Cooperation Organization : new model of cooperation or new regional integration?

Nicharapova, Jildiz 27 January 2014 (has links)
La question principale de notre travail de recherche est: A quel type d'organisation internationale appartient l'OCS et quels sont ses buts d'existence ? Pourquoi les pays-membres coopèrent-ils au sein de l'Organisation ? Pourquoi coopèrent-ils dans des domaines dont ils ont établi les règles de coopération et sur quelles questions spécifiques ont-ils choisi de répondre ? Quels sont ses règles et les mécanismes de prise de décision, et quels sont sa structure organisationnelle et son mode de fonctionnement ? La deuxième question est : quelles sont ses raisons d'existence, ses buts et ses objectifs? Et la troisième interrogation est quelles sont ses promesses (potentiels) et ses limites ? En se basant sur la « théorie » des organisations internationales, à quel type d'organisation internationale l'OCS peut-elle appartenir ? Une Organisation de coopération ou d'intégration ? On peut se demander quels sont les véritables objectifs d'une telle organisation. Est-ce que l'OCS a pour but de contrebalancer l'Occident ou y a-t-il d'autres raisons à son existence ? Quelles sont ces raisons ? Pour répondre à ces interrogations, deux hypothèses doivent être mises en évidence. Dans la première hypothèse, l'OCS est une organisation de coopération régionale comme beaucoup d'autres organisations régionales déjà existantes (OTAN, OTSC, CEI, etc.) Dans la deuxième hypothèse, l'OCS est une organisation néo-réaliste ou même néo-libérale étant donné que de simple coopération elle se transforme en une organisation d'intégration régionale, qui conduit à l'apparition d'une nouvelle région unique (unifiée) et qui se dirige vers le régionalisme. / The main question of our research is what kind of international organization is the SCO and what are its reasons for existence? In terms of the theory of international organizations to which type of international organization, the SCO can belong? The Organization of cooperation or integration? One wonders what the real objectives of the organization. Is the SCO aims to counteract the West, or there are other reasons for its existence? What are those reasons? Is it destined to exercise a single regional role in the manner of existing organizations such as CSTO, ECO, CIS, etc..., or does it move into the ranks of a world power? Are the objectives of the existence of this structure is to serve the great powers like Russia and China or it is also to serve to the small countries of Central Asia? Do the member countries have common objectives or individual, selfish? Is the SCO is an instrument of countries to achieve their national interests or they have a common desire to unite and grow together, to be a force in an "unfair" world?To answer these questions, two assumptions should be highlighted.For the first case, the SCO is a regional cooperation organization like many other existing regional organizations (NATO, CSTO, CIS, etc.). The SCO is an instrument of foreign policy of member countries to achieve its objectives joint problem solving as: regional security, economic development and cooperation policyIn the latter case, the SCO is transformed from mere cooperation in the organization of regional integration, which leads to the emergence of a new region (unified) - which moves towards regionalism. To these questions our dissertation is dedicated.

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