• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 768
  • 563
  • 153
  • 99
  • 59
  • 59
  • 41
  • 40
  • 40
  • 34
  • 28
  • 22
  • 12
  • 9
  • 8
  • Tagged with
  • 2175
  • 461
  • 263
  • 202
  • 187
  • 164
  • 155
  • 145
  • 144
  • 134
  • 122
  • 111
  • 107
  • 105
  • 103
  • 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.
221

Graph Invariants - A Tool to Analyze Hydrogen Bonding in Ice and Water Clusters

Kuo, Jer-Lai January 2003 (has links)
No description available.
222

Sustainability-Linked Bonds : A study comparing the yields of sustainability-linked bonds and green bonds.

Karlsson, Hannah, De Jounge, Arendt January 2024 (has links)
This paper analyzes the difference in yield to maturity between two types of ESG-fixed income instruments, and aims to answer the research question "Is there a yield difference between sustainable-linked bonds and green bonds issued in Europe?". The sample consists of a total of 1499 bonds, issued between the time period 2019-2023, where the databases Bloomberg and Refinitive Eikon have been used to collect and filter the data. The null hypothesis is that there is no significant difference between the two bond types, the alternative hypothesis states that one of them has a premium towards the other. For the methodology, the sustainability-linked bonds (SLBs) are matched with green bonds, creating pairs based on similar characteristics. This procedure, which corresponds to previous work by Kölbel & Lambillon (2022), alongside an OLS regression, are used to answer the research question. The results show that there is no significant yield difference between the bond types. This conclusion is drawn from using a Wilcoxon test on the paired bond sample. The result from the regression implies that the yield on green bonds is explained by the defined independent variables to a greater extent than the yield on SLBs. There are amble number of prior studies which have found a present premium on the ESG instruments green bonds (Fatica et al., 2019; Baker et al., 2018; MacAskill et al. 2021; Kapraun, 2021; Löffler et al., 2021; and Zerbib, 2018) and SLBs (Kölbel & Lambillon, 2022; Feldhütter et al., 2023). This essay aspires to use previous research findings as reference for comparing bond types against each other rather than their performance against conventional bonds. Additionally, the SLB instrument is still considered relatively novel and hence this essay aims to contribute to existing knowledge with new inputs and findings.
223

Glass Fiber Reinforced Polymer Bars as the Top Mat Reinforcement for Bridge Decks

DeFreese, James Michael 20 December 2001 (has links)
The primary objective of this research was to experimentally investigate material and bond properties of three different types of fiber reinforced polymer (FRP) bars, and determine their effect on the design of a bridge deck using FRP bars as the top mat of reinforcement. The properties evaluated include the tensile strength, modulus of elasticity, bond behavior, and maximum bond stress. The experimental program included 47 tensile tests and 42 beam end bond tests performed with FRP bars. Tensile strength of the bars from the tensile testing ranged from 529 MPa to 859 MPa. The average modulus, taken from all the testing, for each type of bar was found to range from 40 GPa to 43.7 GPa. The maximum bond stress from the beam end bond tests ranged from 9.17 MPa to 25 MPa. From the tests, design values were found in areas where the properties investigated were related. These design values include design tensile strength, design modulus of elasticity, bond coefficient for deflection calculations, bond coefficient for crack width calculations, and development length. The results and conclusions address design concerns of the different types of FRP bars as applied in the top mat of reinforcement of a bridge deck. A secondary objective was to evaluate the disparity in results between direct pullout tests, and beam end bond tests. Results from the experimentally performed beam end bond test were compared to previous literature involving the direct pullout tests. Results from the performed beam end bond tests were higher than all of the literature using direct pullout results. No recommendations were given on the disparity between the two test methods. / Master of Science
224

Obchodování s dluhopisy na kapitálovém trhu v ČR / Bonds Trading on the Capital Market in the Czech Republic

SVOBODOVÁ, Hana January 2008 (has links)
Themes my diploma is ,,Bonds trading on the capital market in the Czech Republic``. In introductory part of my thesis I deal with theoretic summary and functioning of capital market, regulation and supervision of capital market and individual subjects acting in this market. In more detail I deal with describeing the Prague Stock Exchange and company RM-System. I further define conception the bond and I describe long bonds, theirs basic kinds and conceptions used in the bonds. I also allude to series of different kinds of the bonds, that the offer on the international markets. Next part of my thesis is aimed to describe the development of the Czech market of bonds. I analyze the development of bonds trading in the last of several years on the regulated markets and the OTC-markets in the Czech Republic. In the close of my thesis I analyze the development of bonds trading on the Czech market of bonds in comparasion with Slovakian, Polish and Hungarian markets. This analysis was take in on comparision of the Stock Exchange of chosen countries.
225

An Analysis of the Swedish Real  Estate Bond Market:  Characteristics, Opportunities, and  Risks : A combination of a qualitative and quantitative study / Analys om den Svenska fastighetsobligationsmarknaden: Karaktärsdrag, möjligheter och risker : En kombination av en kvalitativ och en kvantitativ studie

Landstedt, Hanna, Kulti, Mikaela January 2023 (has links)
In the aftermath of the 2008 financial crisis, the debt capital market in Sweden experienced rapid growth, resulting in a doubling of its size. In recent years, real estate companies have become increasingly dependent on financing through the capital markets. As a result, the interdependence between the real estate and financial sectors has significantly increased. Today, the real estate market constitutes for around 50 per cent of the Swedish corporate bond market. In 2023, approximately SEK 100 bn worth of bonds are expected to mature, followed by around SEK 150 bn set to mature in 2024, compelling Sweden's property companies to implement significant alterations to their methods of financing operations. This study aims to analyse the current state of the Swedish real estate bond market, as well as an examination of opportunities and risks for investors given the current market situation. The research questions follows: What are the current characteristics of the Swedish real estate bond market? What opportunities and risks are present in the Swedish real estate bond market for investors? The study is limited to the corporate real estate bond market in Sweden, with a particular emphasis on Swedish issuers and financiers. A combination of a qualitative and quantitative method was conducted, and the study adopts an abductive approach. The findings revealed that the Swedish real estate bond market holds a prominent role in the corporate bond market and is characterised as a young market that has undergone significant growth. It presents opportunities for alternative financing, investing in distressed real estate assets, promoting sustainability and better returns from a risk-reward perspective. From a risk perspective there are several risks: the challenge of refinancing, a change in market conditions thus increasing capital costs, the credit risk, the liquidity risk, credit ratings downgrades, risk of valuations, sceptical investors and creative capital structures in the Swedish real estate market and the bond market. / I efterdyningarna av finanskrisen 2008 upplevde den svenska skuldkapitalmarknaden en snabb tillväxt, vilket resulterade i en fördubbling av dess storlek. Fastighetsbolagens ökade beroende av kapitalmarknaderna för upplåning de senaste åren har ökat exponeringen mellan fastighets- och finanssektorn. Idag utgör fastighetssektorn cirka 50 procent av den svenska företagsobligationsmarknaden. År 2023 förväntas cirka 100 miljarder kronor i obligationer förfalla, följt av cirka 150 miljarder kronor år 2024, vilket tvingar Sveriges fastighetsbolag att genomföra betydande förändringar i sina finansieringsstrukturer. Denna studie syftar till att analysera det aktuella läget på den svenska fastighetsobligationsmarknaden, samt dess möjligheter och risker för investerare. Forskningsfrågorna följer: Vilka är de nuvarande karaktärsdragen hos den svenska fastighetsobligationsmarknaden? Vilka möjligheter och risker finns på den svenska fastighetsobligationsmarknaden för investerare? Studien är begränsad till företagsfastighetsobligationsmarknaden i Sverige, med särskild tonvikt på svenska emittenter och finansiärer. En kombination av en kvalitativ och kvantitativ metod genomfördes och studien antar ett abduktivt tillvägagångssätt. Resultatet avslöjade att den svenska fastighetsobligationsmarknaden har en framträdande roll på företagsobligationsmarknaden och karaktäriseras som en ung marknad som har genomgått betydande tillväxt. Det ger möjligheter till alternativ finansiering, investeringar i nödställda fastighetstillgångar, främjar hållbarhet och bättre avkastning ur ett risk-belöningsperspektiv. Ur ett riskperspektiv finns det flera risker: utmaning med refinansiering, förändrade marknadsförhållanden som ökar kapitalkostnaderna, kreditrisk, likviditetsrisk, skeptiska investerare, nedgraderingar av kreditbetyg, risk för värderingar och kreativa kapitalstrukturer på den svenska fastighetsmarknaden och obligationsmarknaden.
226

Achieving High Performance in Local Government: Linking Government Outcomes with Human Resource Management Practices

Huff, Richard F. 01 January 2007 (has links)
Historically public sector personnel policies and practices have been targets of reform. These reforms consisted of transferring private sector techniques to a public sector perceived to be more bureaucratic and less efficient. Private sector research is replete with evidence of a connection between "superior" human resource management (HRM) practices and the performance outcome of profitability. Public sector outcomes are more difficult to connect directly to management practices. As a result, the focus of public sector reform has become one of improving the processes of management rather than improving the outcomes of government. The linkage between reform and outcome is assumed.This study attempts to add to the literature by tying local government HRM practices to the organization level performance outcome of un-enhanced general obligation municipal bond rating. A database was obtained from the International City/County Management Association (ICMA) containing the results of an HRM survey in 2000 of all U.S. municipalities with a population over 10,000. The municipal bond rating was then used as a performance proxy and dependent variable; the greater the number of high performing HRM practices employed by a municipality, the higher the bond rating or the higher the performance. The study sample consisted of 366 municipalities both responding to the survey and with bond ratings meeting the criteria of the study. The results of a binary logistic regression analysis showed intensive recruitment, family oriented work practices, job flexibility and open communication to be strong predictors of high performance. Decentralized HRM decisions, pay for performance programs and incentives for group participation were not associated with high performance. These findings suggest municipalities are likely to improve their performance by implementing the practices found to be predictive of higher bond ratings. However, differences between private and public sectors need to be considered when implementing change and a systems view helps minimize "deadly combinations" and maximize "powerful connections". Also, organization culture and the structure of the HRM system need to be considered. Additional research is recommended to further develop and validate the use of the municipal bond rating as a measure of a government level performance outcome.
227

Transition Metal Catalysis: Construction of C–N and C–C bonds en route to Nitrogen Heterocycles, Chiral Esters and 6-deoxyerythronolide B

Hsieh, Tom Han-Hsiao 09 January 2012 (has links)
The Dong research group is interested in harnessing the power of transition metal catalysis to transform simple molecules and reagents (such as carbon monoxide, hydrogen gas, olefins, and C–H and C–O bonds) into valuable products (such as functionalized heterocycles, chiral carbonyl compounds and natural products). This thesis will describe our continual effort to achieve this goal. Part I describes the Pd-catalyzed functionalization of sp2 and sp3 C–H bonds. Carbon monoxide is used as a stoichiometric reductant in the cyclization of diarylnitroalkenes to afford biologically relevant 3-arylindoles and other N-containing heterocycles with carbon dioxide as the only stoichiometric byproduct. Also, an aryl sulfoxide moiety is shown to direct the arylation of sp3 C–H bonds to afford beta-functionalized amides. Part II describes the Ru-catalyzed sp3 C–O bond activation of alkoxypyridines and related heterocycles. In this transformation, an O- to N-alkyl migratory rearrangement occurs to afford N-alkylated pyridones which are structures found in many natural products and pharmaceutical agents. Part III describes our pursuit of metal-catalyzed asymmetric synthesis. Readily available benzylic bromides are carbonylated with carbon monoxide in alcoholic solvent mixtures. The resulting medicinally relevant 2-arylpropionic esters are obtained with moderate to good enantioselectivities. Preliminary results for the asymmetric hydrogenation of gem-diarylethylenes and novel ligand development are also disclosed. Part IV describes our efforts towards the total synthesis of 6-deoxyerythronolide B. Our retrosynthetic analysis of the macrolide antibiotic involves disconnections at the lactone linkage and between C7 and C8. The two equally complex fragments were prepared via reliable aldol, hydroboration, crotylation and redox chemistry. Rather than the typical macrolactonization method to form the 14-membered ring, we propose an alternative strategy where we plan to cyclize with a metal-catalyzed ring-closing metathesis event. Currently, this step is under investigation by other members in the group.
228

Transition Metal Catalysis: Construction of C–N and C–C bonds en route to Nitrogen Heterocycles, Chiral Esters and 6-deoxyerythronolide B

Hsieh, Tom Han-Hsiao 09 January 2012 (has links)
The Dong research group is interested in harnessing the power of transition metal catalysis to transform simple molecules and reagents (such as carbon monoxide, hydrogen gas, olefins, and C–H and C–O bonds) into valuable products (such as functionalized heterocycles, chiral carbonyl compounds and natural products). This thesis will describe our continual effort to achieve this goal. Part I describes the Pd-catalyzed functionalization of sp2 and sp3 C–H bonds. Carbon monoxide is used as a stoichiometric reductant in the cyclization of diarylnitroalkenes to afford biologically relevant 3-arylindoles and other N-containing heterocycles with carbon dioxide as the only stoichiometric byproduct. Also, an aryl sulfoxide moiety is shown to direct the arylation of sp3 C–H bonds to afford beta-functionalized amides. Part II describes the Ru-catalyzed sp3 C–O bond activation of alkoxypyridines and related heterocycles. In this transformation, an O- to N-alkyl migratory rearrangement occurs to afford N-alkylated pyridones which are structures found in many natural products and pharmaceutical agents. Part III describes our pursuit of metal-catalyzed asymmetric synthesis. Readily available benzylic bromides are carbonylated with carbon monoxide in alcoholic solvent mixtures. The resulting medicinally relevant 2-arylpropionic esters are obtained with moderate to good enantioselectivities. Preliminary results for the asymmetric hydrogenation of gem-diarylethylenes and novel ligand development are also disclosed. Part IV describes our efforts towards the total synthesis of 6-deoxyerythronolide B. Our retrosynthetic analysis of the macrolide antibiotic involves disconnections at the lactone linkage and between C7 and C8. The two equally complex fragments were prepared via reliable aldol, hydroboration, crotylation and redox chemistry. Rather than the typical macrolactonization method to form the 14-membered ring, we propose an alternative strategy where we plan to cyclize with a metal-catalyzed ring-closing metathesis event. Currently, this step is under investigation by other members in the group.
229

C-2 And C-4 Branched Carbohydrates : (i) Synthesis And Studies Of Oligosacchardes With Expanded Glycosidic Linkage At C-4; (ii) Synthesis Of 2-Deoxy-2-C-Alkyl Glycopyranosides

Daskhan, Gour Chand 08 1900 (has links) (PDF)
No description available.
230

Prise en compte de la liaison acier béton dans le comportement d’éléments de structure en béton armé / Development of steel-concrete interface model for structural elements

Turgut, Can 14 December 2018 (has links)
Le comportement de l’interface acier-béton a une grande importance lorsque la fissuration des structures en béton armé est étudiée. Une approche par éléments finis a été proposée par (Torre-Casanova, 2013) et (Mang, 2016) pour représenter l'interface acier-béton dans les simulations de structures à grandes dimensions Le modèle proposé permet de calculer le glissement tangentiel entre l'acier et le béton. L’objectif de cette étude est d’améliorer ce modèle initial pour le rendre plus efficace et plus représentatif. Le document est découpé en trois parties : 1) Le modèle initial de liaison est évalué. Puis amélioré tant en chargement monotone qu’alterné. Le nouveau modèle est validé par plusieurs applications numériques. 2) L'effet de confinement est implémenté dans le modèle de liaison acier-béton. L'effet sur le comportement structural du confinement actif est étudié en utilisant le nouveau modèle. A partir des simulations proposées, il est montré, par l’utilisation du nouveau modèle, que l’effet de confinement actif peut jouer un rôle sur les comportements monotone que cyclique. 3) L'effet goujon est étudié avec le nouveau modèle liaison acier-béton. Deux campagnes expérimentales différentes sont simulées avec différents modelés de renforts (1D barre et poutre) et d’interface (liaison acier-béton et liaison parfaite). Les résultats montrent que le nouveau modèle de liaison acier-béton permet de mieux reproduire les résultats expérimentaux par rapport au modèle de liaison parfaite aux échelles globale et locale. / In numerical applications of reinforced concrete structures, the steel-concrete interface behavior has a vital importance when the cracking properties are investigated. A finite element approach for the steel-concrete interface to be used in large-scale simulations was proposed by (Torre-Casanova, 2013) and (Mang, 2016). It enables to calculate the slip between the steel and concrete in the tangential direction of the interface element representation. The aim is here to improve the initial bond-slip model to be more efficient and more representative. The document is divided into three parts: 1) The existing bond-slip model is evaluated. The bond-slip model is then improved by considering transversal and irreversible bond behaviors under alternative loads. The new bond-slip model is validated with several numerical applications. 2) Confinement effect is implemented in the bond-slip model to capture the effect of external lateral pressure. According to the performed numerical applications, it is demonstrated how the active confinement can play a role, through the steel-concrete bond, during monotonic and cyclic loading cases. 3) Dowel action is finally investigated with the new bond-slip model. Two different experimental campaigns (Push-off tests and four-point bending tests) are reproduced with different reinforcement (1D truss and beam) and interface (new bonds-slip and perfect bond) models. The results show that the proposed simulation strategy including the bond slip model enables to reproduce experimental results by predicting global (force-displacement relation) and local behaviors (crack properties) of the reinforced concrete structures under shear loading better than the perfect bond assumption which is commonly used in the industrial applications.

Page generated in 0.0354 seconds