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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

Investigation on the properties of nanowire structures and hillocks of Group-III nitride materials

Bao, An January 2018 (has links)
Group-III nitride materials are increasingly important, because of their semiconducting properties and bandgaps tuneable across a wide range from the infrared to ultraviolet. They are of particular interest for optoelectronic and power electronic applications. The studies on nitride materials are comprehensive, and one way to categorise them is based on the scale of the material, namely: (a) 3D bulk materials, for example the development of 3D bulk nitride substrate; (b) epitaxial layers, for example GaN/InGaN 2D quantum well based light emitting diodes (LEDs); (c) 1D nitride nanowires and (d) 0D quantum dots, for example InGaN quantum dot based single photon sources. This thesis uses a multimicroscopy concept to investigate various group-III nitride nanowires and hillocks. Multiple different microscopy techniques were applied to the same specific nanostructure or defect. This allows the properties of the materials of interest to be linked directly to the nanostructures or defects, providing a more complete picture of the samples that have been studied. The multiple microscopy techniques used to conduct the work in this thesis include (scanning) transmission electron microscopy ((S)TEM), cathodoluminescence (CL), focused ion beam (FIB) and atomic force microscopy (AFM). Specifically, AFM was used to characterise the morphology of the sample on a sub-nanometer scale. The crystalline structures were characterised using (S)TEM, and the in-situ energy dispersive X-ray spectroscopy (EDS) was used to conduct compositional analysis of the selected sites. CL was used to reveal the optoelectronic properties by analysing the emission wavelengths of the materials, excited by the electron beam. FIB was the technique used to prepare site-specific samples to be measured in (S)TEM. A detailed explanation of these characterisation techniques was also included. In the context of the studies on nitride materials, nitride nanowires and their heterostructures are a particular research focus. They combine the unique properties of III-nitride materials together with the advantages induced by the nanowire geometry. This thesis explores three different nanowire systems: a GaN nanowire structure incorporating a GaN/Sc$_x$Ga$_{1-x}$N axial heterostructure grown by molecular beam epitaxy (MBE); GaN/InGaN core-shell nanowires fabricated by a hybrid approach combining metalorganic vapour phase epitaxy (MOVPE) and dry etching techniques; and AlGaN nanowires on free standing AlGaN substrates fabricated by MBE and inductively coupled plasma (ICP) etching. The optoelectronic properties, compositions and structures of these nanowires were studied in detail. Moreover, a comprehensive review on the properties, growth methods and applications of group-III nitride nanowires is also included in this thesis. Apart from nanowires, a lot of effort has been focusing on the improvement of the quality of epitaxial layers of GaN and its alloys, and they currently have an even wider perspective than nitride nanowires. The understanding of defects within the epitaxial layers is crucial in order to mitigate the their adverse effects, leading to the increased emphasis on defect analysis. Hillocks are a type of defects found on GaN epilayers, which are less well studied than other defects such as dislocations and stacking faults. As a consequence, the formation mechanisms of hillocks remain controversial. In this context, after a review on the past studies on GaN hillocks, this thesis also investigates two types of hillocks, i.e. hillocks on GaN p-i-n diodes and hillocks on GaN grown on patterned sapphire substrates (PSS). Their nanoscale structures, properties and formation mechanisms are studied.
12

The impact and challenges of Basel III implementation in Saudi Arabia

Almuqati, Mohammed Marzouq January 2018 (has links)
This thesis is devoted to examining the legal framework for, and efficacy of, the implementation of the Basel III framework that governs capital, liquidity and market disclosure standards. It is set against the backdrop of the 2007 to 2008 financial crisis and attempts to unpack the myriad challenges associated with current efforts to harmonise international risk regulation standards in the context of legal diversity. These challenges are sharply illustrated in the context of Saudi Arabia's Islamic legal system and its uneasy relationship with the government's ongoing attempts to subject Saudi banks to the Basel III authored market and risk regulation disciplines. Paralleling the growth of Islamic (equity driven) finance markets worldwide, Islamic banks in Saudi Arabia now compete in the global market for conventional (debt centred) banking products. The growth of, and demand for, conventional financial services in Saudi Arabia highlights the duality of the Saudi legal system and its banking sector, despite apparent divergences between conventional and Islamic finance models, legally and normatively. These divergences manifest themselves, both in the differential treatment of Islamic and conventional banking customs and norms in the context of the overall Saudi legal system, and in respect of the general suitability of the conventional basis of the Basel regulatory model as applied to Islamic finance contexts and instruments. The thesis will challenge the convention that Islamic financial practices are self-evidently less risk averse, or more ethical, than their conventional alternatives. In a second step, this thesis will consider whether the national implementation of Basel III standards provides Saudi banks with sufficient protection against future threats to the stability of the country's Saudi market-economy in periods of economic volatility. These aims will be synthesised to provide an overarching analysis of the 'gaps' in Saudi banking institutions and applicable law. Comparing the Saudi banking regime with the dual banking sector in Malaysia, this thesis will conclude with a defence of strengthened corporate governance regulation, transparency and 'rule of law' reforms in Saudi Arabia's legal system. These recommendations should be further accompanied by concrete efforts to formulate, and, more effectively, reconcile, local and Islamic disclosure and accountability related standards with Basel III-approved technical measures on risk-mitigation and measurement.
13

Likviditetskrav : Är det nödvändigt för svenska storbanker?

Sabuni, Muene, Nobelius, David January 2012 (has links)
Finansiella kriser kostar marknaden flera miljarder kronor. 1974 bildades Baselkommittén för att försöka förhindra framtida kriser. Kommittén har kommit fram till flera regelverk som hela tiden förbättras. De svenska bankerna blir tvungna att anpassa sig till regelverken, vilket påverkar flera aktörer. Med denna studie skall vi undersöka vilka konsekvenser Basel III:s nya kapitalkrav och likviditetskrav kan få på de svenska storbankerna och deras privatkunder. Resultat av studien visar att likviditetskrav är nödvändigt för att banker skall ha tillräckligt med likvida medel samt undvika bankkriser under t.ex. en lågkonjunktur. Regel-verkets likviditetskrav kommer inte ha en signifikant påverkan hos de svenska storbankerna. Bankerna har inte problem med att anskaffa mer likviditet. De svenska storbankerna har stora mängder eget kapital, hög lönsamhet och starka statsfinanser. Samtliga storbanker uppfyller redan de föreslagna kapital-täckningskraven. De svenska storbankerna kommer inte påverkas negativt av de nya kapitalkraven. / Financial market crises cost several billion dollars. In 1974 the Basel Committee was founded to  prevent future crises. The Committee has come up with several regulations that are continuously improved. The Swedish banks are forced to adapt to the regulations, which affect several actors. In this study, we examine what consequences the Basel III's new capital and liquidity requirements may have on the major Swedish banks and their retail customers. Results show that liquidity requirements are necessary for banks to have sufficient liquidity and prevent bank crises during a recession. The liquidity requirements will not have a significant impact at the major Swedish banks. The banks have no problems to raise more liquidity.      The major Swedish banks have large amounts of equity, high profitability and strong public finances. All the major banks already meet the proposed capital adequacy requirements. The major Swedish banks will not be adversely affected by the new capital requirements.
14

Simulating the Formation of Primordial Proto-Stars

Yoshida, Naoki 11 March 2008 (has links)
No description available.
15

Syntheses and mechanistic studies of some octahedral ruthenium (III) amine complexes.

Isabirye, David Awubwa. January 1977 (has links)
Thesis--Ph. D., University of Hong Kong.
16

Synthesis of UQ10 Analogs, Measurement of their Midpoint Potentials and their Effects on the Activity of WT and T61V bc1 Complexes from Rhodobacter sphaeroides

Cedeno, Diana January 2010 (has links)
Cytochrome bc1 (Complex III) is an important enzyme that takes part in the respiratory electron transport chain in vertebrates, yeast, and many bacteria. The complex exists as a dimer, in which each monomer contains three catalytic subunits: cytochrome c1, cytochrome b and the Rieske iron-sulfur protein or ISP. Within the inner mitochondrial membranes of eukaryotes, Complex III catalyzes the transfer of two electrons from ubiquinol (UQH2) to cytochrome c, a water-soluble protein, through a process called the modified Q-cycle mechanism. Under very specific conditions, such as mutations within cytochrome b, disruption of the normal mechanism leads to bypass reactions, including the formation of superoxide and reactive oxygen species. We have sought to restore the activity of a mutant of cytochrome b (T61V) by modifying UQH2, the natural substrate for this enzyme. The structure of the oxidized form, UQ consists of a p-quinone head group and a hydrophobic all-trans polyprenyl unit (tail) that can vary in length, depending on the species in which it is found. The present work highlights modifications to the substituent groups attached to the quinone head and to the all-trans polyprenyl tail. Since the midpoint potentials of these molecules are pH dependent, cyclic voltammetry and spectroelectrochemistry studies in buffered aqueous solutions have been carried out on these molecules (analogs of UQ10). Modifications of the substituent groups attached to the quinone head gave the molecules a different ability to either donate or receive electrons, while modifications to the length of the tail either increased or decreased the solubility of these molecules inside the phospholipid membrane. We examined the normal activity and the production of superoxide in wild-type and (T61V) of bacterial Rhodobacter sphaeroides in the presence of these analogs. We confirmed that to prevent damaging side reactions, normal operation of the Q-cycle requires a fairly narrow window of reduction potentials with respect to the ubiquinol substrate.
17

WAIS-III psichometrinės charakteristikos / WAIS-III: psychometric characteristics

Geleževičiūtė, Kristina 20 June 2014 (has links)
Santrauka Šio tyrimo tikslas – įvertinti WAIS-III psichometrines charakteristikas. Tyrime iš viso dalyvavo 75 tiriamieji, kuriems kvalifikuoti tyrėjai pateikė WAIS-III užduotis. Atrenkant tyrimo dalyvius, buvo vykdoma tikslinė atranka, remiantis šiais kriterijais: amžiumi, gyvenamąja vieta ir išsilavinimu. Šiame tyrime dalyvavo 36 vyrai ir 39 moterys. Tiriamųjų amžius nuo 16 iki 79 metų. Vertinant WAIS-III psichometrines charakteristikas, buvo įvertintas atskirų subtestų užduočių tinkamumas, naujų užduočių tinkamumas, verbalinių ir neverbalinių subtestų patikimumas dalijimo pusiau metodu ir testo konstrukto validumas. Buvo vertintas verbalinių ir neverbalinių subtestų užduočių tinkamumas, remiantis užduoties sunkumo bei diferencinės galios indeksais, koreguotos koreliacijos koeficientu. Labiausiai pakito Žodyno subtestas, kuriame buvo paliktas 21 originalios versijos žodis ir pridėta 12 naujų žodžių. Panašumų subteste buvo palikta 19 originalios versijos užduočių ir pridėtos 3 naujos. Informacijos subteste buvo palikti 24 originalios versijos klausimai ir pridėta 4 nauji. Supratingumo subteste buvo palikta 18 originalios versijos užduočių ir pridėtos 2 naujos. Visų verbalinių subtestų užduotys buvo išdėliotos nauja tvarka, išskyrus Skaičių eilė ir Raidžių – skaičių eilės. Paveikslėlių užbaigimo, Kubelių kompozicijos, Matricų ir Paveikslėlių užbaigimo užduotys buvo išdėliotos nauja tvarka. Objektų surinkimo subtestas buvo paliktas toks, koks pateikiamas originalioje versijoje... [toliau žr. visą tekstą] / Summary The purpose of this research is to evaluate WAIS-III psychometric characteristics. In total 75 subjects participated in the research; they were provided with WAIS-III tasks by the qualified researchers. When selecting the participants for the research, a target selection was carried out based on the following criteria: age, place of residence and education. 36 men and 39 women participated in this research. The age of the participants was from 16 to 79 years. While evaluating WAIS-III psychometric characteristics suitability of separate tasks of the subtests was estimated, as well as availability of new tasks, reliability of verbal and non-verbal subtests by the odd/even method and also the validity of the construct of the test. Suitability of the tasks of the verbal and non-verbal subtests was evaluated based on the indexes of the complexity of the task and the differential power, coefficient of the adjusted correlation. The Vocabulary subtest was transformed the most, in it 21 words from the original version were maintained and 12 new words added. In the Similarities subtest 19 tasks from the original version were maintained and 3 new tasks added. In the Information subtest 24 questions from the original version were maintained and 4 new questions added. In the Comprehension subtests 18 tasks were maintained from the original version and 2 new tasks were added. All the tasks of verbal subtests were set out in a new order, except for the Digit Span and Letter –... [to full text]
18

Förändring i bankers utlåning till småföretag

Alarik, Martin, Holmér, Douglas January 2014 (has links)
Uppsatsen behandlar bankers kreditbedömning av småföretag, vilka faktorer som spelar in mest vid en kreditbedömning. Vidare undersöker uppsatsen de eventuella förändringar som har skett i och med införandet av Basel III regelverket.
19

Royal finances in the period of baronial reform and rebellion, 1255-1270

Collingwood, James Alexander January 1996 (has links)
No description available.
20

PPAR-alpha-Aktivierung hemmt die Expression von Tissue Factor in humanen Monozyten, Makrophagen und THP-1 Zellen

Incekara, Nurcan, January 2007 (has links)
Ulm, Univ., Diss., 2007.

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