391 |
Studies on N-Heterocyclic CompoundsArmugam, S 03 1900 (has links)
The thesis entitled "Studies on N-Hetero cyclic Compounds: (a) Reaction of 5,6,7,8-Tetrahydroisoquinolines with Vilsmeier Reagent and (b) Amide Induced in situ Alkylation of 5,6-Dihydroisoquinolines" is presented in two parts. Part I involves a study of the Vilsmeier reaction of 4-cyano-1,3-dihydroxy-5,6,7,8 tetrahydroisoquinoline derivatives, while Part II concerns the in situ alkylation of l-alkyl-4-cyano-3-methoxy-5,6- dihydroisoquinolines in presence of KNH2/liq.NH3.
|
392 |
The Swedish Hedge Fund Industry : An Evaluation of Strategies, Risks and ReturnsPersson, Martin, Carlsson, Henrik, Eliasson, Sofie January 2008 (has links)
<p>The purpose of this study is to analyze Swedish hedge funds in terms of pursued investment strategies, risks and returns.</p><p>The study deals with a large number of quantitative data and delimitations were used to obtain a sample that better fulfills the purpose of this paper. The time frame chosen for increas-ing validity and reliability was almost four years. Furthermore, the study uses secondary data due to difficulties and costs as-sociated with obtaining primary data though this is not consi-dered as lowering the quality of the study.</p><p>The theory section starts by presenting the differences between hedge funds and mutual funds and then focusing on different hedge fund strategies, risks associated with hedge funds and fi-nally risk and return measurements. This section provides an overview for the empirical findings and analysis.</p><p>In the empirical findings and analysis, statistical calculations of and Analysis the risk measurements standard deviation, Sharpe ratio, track-ing error and correlation are conducted for the sample. The re-sults are related to the hedge funds strategies. Later on the strategies are weighted against each other. Finally, all strategies are compared to OMXS to find the investors‟ most appropriate investment structure.</p><p>After categorizing the different hedge funds with respect to pursued strategies, the result shows how there are clear dispari-ties in risk and returns for the different strategies. We found indications of a significant relationship between high return and high risk as well as between low return and low risk.</p><p> </p>
|
393 |
Learning gradients and canonical correlation by kernel methods /Cai, Jia. January 2009 (has links) (PDF)
Thesis (Ph.D.)--City University of Hong Kong, 2009. / "Submitted to Department of Mathematics in partial fulfillment of the requirements for the degree of Doctor of Philosophy." Includes bibliographical references (leaves [52]-58)
|
394 |
Relationships between reflectance and soil physical and chemical propertiesAlrajehy, Abdulrahman Mohammed. January 2002 (has links)
Thesis (M.S.)--Mississippi State University. Department of Agricultural and Biological Engineering. / Title from title screen. Includes bibliographical references.
|
395 |
Partial L's a precise gross score solution of partial and multiple correlation /Alluisi, Earl A. January 1950 (has links) (PDF)
Thesis (M.A.)--Ohio State University, 1950. / Advisor: John R. Kinzer. Text made available in compliance with Section 108 of the Copyright Revision Act of 1976. Includes bibliographical references (leaves 73-77). Online version of print reproduction.
|
396 |
Factors governing the supply of savings in Great Britain since the warRadice, Edward Albert January 1938 (has links)
No description available.
|
397 |
An investigation into the failure of aluminum alloysHickey, William Fassett 03 October 2011 (has links)
The rate dependence of several aluminum alloys (6061, 7075, 5083) was examined through the means of quasi-static tension tests, dynamic tension tests, and split pressure Hopkinson bar tests. The macroscopic strains of the quasi-static and dynamic tension tests were measured after failure within the uniform region and the necked region using high-resolution images and edge detection.
The study continued with an exploration into the plane-stress ductile fracture of Al 6061 in the T6 and O condition. Digital image correlation (DIC) was used to find the displacement and strain fields, and a numerical method for calculating the stress fields for a power law hardening material was developed. The J-integral was then calculated locally. The effect of strain hardening on the type of fracture (slant or flat) was also investigated. Macroscopic and microscopic observations of the fracture were made with DIC and by dissecting, polishing and/or etching the broken fracture specimens. Local failure strain measurements were made on the grain level and compared with those found through traditional failure strain measurements. / text
|
398 |
Some results on the statistical analysis of directional data黎文傑, Lai, Man-kit. January 1994 (has links)
published_or_final_version / Statistics / Master / Master of Philosophy
|
399 |
MEASUREMENT OF HEAT TRANSFER ENHANCEMENT AND PRESSURE DROP FOR TURBULENCE ENHANCING INSERTS IN LIQUID-TO-AIR MEMBRANE ENERGY EXCHANGERS (LAMEEs)2014 April 1900 (has links)
The fluid flow channels of modern heat exchangers are often equipped with different flow disturbance elements which enhance the convective heat transfer coefficient in each channel. These structural or surface roughness elements induce enhanced flow mixing and convective heat transfer at low Reynolds numbers (500 < Re < 2200) by fluid mixing near the channel walls and increasing the surface area. These elements, however, are accompanied by higher pressure drops in comparison to hollow smooth channels (without inserts).
The Run-Around Membrane Energy Exchanger (RAMEE) system is an air-to-air energy recovery system comprised of two remote liquid-to-air membrane energy exchangers (LAMEEs) coupled by a pumped liquid desiccant loop. LAMEEs use semi-permeable membranes that are permeable to water vapor, but impermeable to liquid water. The membranes separate the liquid desiccant from the air flow channels, while still allowing both heat and water vapor transfer. The air channels are equipped with turbulence enhancing inserts which serve dual purposes: (a) to support the adjacent flexible membranes, and (b) to enhance the convective heat and mass transfer.
This research experimentally investigates the increase in the air pressure drop and average convective heat transfer coefficient after an air-side insert is installed in a Small-scale wind tunnel for exchanger insert testing (WEIT) facility that is designed to simulate the air channels of a LAMEE and to measure all the properties required to determine the flow friction factor and Nusselt number. Experiments are conducted in the test section under steady state conditions at Reynolds numbers between 900 and 2200 for a channel with and without inserts. The 500-mm-long test section has a rectangular cross section (5 mm wide and 152.4 mm high) and is designed to maintain a specified constant heat flux on each side wall. The flow is laminar and hydrodynamically fully developed at the entrance of the test section and, within the test section, thermal development occurs.
Nine different insert panels are tested. Each insert is comprised of several plastic rib spacers, each aligned parallel to the stream-wise direction, and several cross-bars aligned normal to the flow direction. The plastic rib spacers are placed either 30 mm, 20 mm or 10 mm apart, and the distance between the cylindrical bars is either 30 mm, 45 mm, 60 mm or 90 mm. The measured convective heat transfer coefficient and the friction factor have uncertainties that are less than ±7% and ±11%, respectively.
It is found that the Nusselt number and friction factor are dependent on the insert geometry and the Reynolds number. An empirical correlation is developed for the inserts to predict Nusselt number and friction factor within an air channel of a LAMEE. The correlations are able to determine the Nusselt number and the friction factor within ±9% and ±20% of the experimental data. Results show the flow insert bar spacing is the most important factor in determining the convective heat transfer improvement.
As an application of the experimental data in this thesis, the experimental and the numerical results from a LAMEE which has an insert in each airflow channel are presented. The results show that the insert within the air channel of the LAMEE is able to improve the total effectiveness of the LAMEE by 4% to 15% depending on the insert geometry and air flow Reynolds number and operating inlet conditions for the exchanger.
|
400 |
QCD Correlation Functions of Light Quarkonium and Strangeonium Hybrids2014 May 1900 (has links)
The correlation function is the critical ingredient for Quantum Chromodynamics (QCD) sum-rule methods that are used to predict hadronic properties. Thus, in order to perform a sum-rule analysis of hybrids, we need to compute a correlation function involving an operator that probes hybrid states composed to quark-antiquark pair with a gluonic excitation. Using particular combinations of quark and gluon fields and Dirac matrices, we construct currents that probe hybrid states with various J^{PC} quantum numbers. We compute the correlation function to order g_s^3 in QCD, obtaining both perturbative and condensate contributions.
The focus here is on light quarkonium and strangeonium hybrids, which involve quark masses small compared to the external momentum scale (m_q^2 << Q^2). While for light quarkonium the calculations are performed in the massless limit, for strangeonium we include a strange quark mass correction to the perturbative result. While the details of the calculations outlined throughout this thesis are outlined for J^{PC} = 0^{+-} and 1^{--} due to interest in the exotic quantum numbers 0^{+-}, ultimately the correlation function is computed for all J^{PC} values with J=0,1. Comparison with existing results for a subset of these J^{PC} quantum numbers provides a validation of our calculations.
|
Page generated in 0.087 seconds