• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 12
  • 3
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 18
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 2
  • 2
  • 2
  • 2
  • 2
  • 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

LAUE MONOCHROMATOR PERFORMANCE CALCULATIONS FOR A FUTURE CANADIAN LIGHT SOURCE DIFFRACTION BEAMLINE

Dina, Gabriel 31 October 2011 (has links)
The computational investigation of perfect and bent crystals both cylindrically and sagittaly, have led to the development of sets of optimized parameters to be used for the high energy wiggler beamline monochromator being built at the CLS. Using both Si and Ge in Bragg and Laue geometries, the developed algorithms examine parameter space for most photon flux at the crystal. Using programs in XOP, the calculation analysis for a single incident beam revealed that for symmetric flat crystals the reflection (1,1,1) in the Bragg geometry is most preferable for producing the most throughput at energies below 24keV. For cylindrically bent crystals at energies higher than 24keV, a Laue geometry is more preferred as a result of an increase in the rocking curve width and throughput. Development of a program that calculates the diffracted intensity and energy resolution of a saddle bent crystal with varying asymmetry angles are presented here.
2

Design of a low power analog to digital converter in a 130nmCMOS technology

Radhakrishnan, Venkataraman January 2011 (has links)
Communication technology has become indispensable in a modernsociety. Its importance is growing day by day. One of the main reasonsbehind this growth is the advancement in the analog and mixed signalcircuit design.Analog to digital converter (ADC) is an essential part in a modernreceiver system. Its development is driven by the progress of CMOStechnologies with an aim to reduce area and power consumption. In thearea of RF integrated circuits for wireless application low operationalvoltage, and less current consumption are the central aspects of thedesign. The aim of this master thesis is the development and design ofa low-power analog to digital converter for RF applications.The basic specifications are:· High Speed, Low Current (1.5 V supply voltage)· Maximum input frequency 3.5 MHz· 8-bit resolution· Sampling rate < 100 MHzThus, this work comprises a theoretical concept phase in whichdifferent ADC topologies will be investigated. Based on which anappropriate ADC architecture will be fixed. Later, the chosen design willbe implemented in an industrial 130 nm CMOS process.
3

Study of Transport Properties and Microstructure of Materials for Polymer Electrolyte Fuel Cells

Sun, Che-Nan 15 March 2011 (has links)
No description available.
4

Design of a high performance soft x-ray emission spectrometer for the REIXS beamline at the Canadian Light Source

Muir, David Ian 28 November 2006
The optical design of a soft X-ray (90-1100~eV) emission spectrometer for the Resonant Elastic and Inelastic X-ray Scattering (REIXS) beamline to be implemented at the CLS is presented. An overview of soft X-ray optical theory as it relates to diffraction gratings is given. The initial constraints and the process that led to this design are outlined. Techniques and software tools that were developed, using ray-tracing and diffraction grating efficiency calculations, are discussed. The analysis completed with these tools to compare existing soft X-ray emission spectrometer designs is presented. Based on this analysis, a new design with superior performance for this application is proposed and reviewed. This design employs Rowland circle geometry to achieve a resolving power in excess of 2,500 in the range of interest. In addition, a novel design is proposed for a larger extremely high resolution spectrometer which will provide resolving powers exceeding 10,000 throughout the higher end of this range. A review is given of research into the components, manufacturing techniques and tolerances that will be required to produce this spectrometer.
5

Design of a high performance soft x-ray emission spectrometer for the REIXS beamline at the Canadian Light Source

Muir, David Ian 28 November 2006 (has links)
The optical design of a soft X-ray (90-1100~eV) emission spectrometer for the Resonant Elastic and Inelastic X-ray Scattering (REIXS) beamline to be implemented at the CLS is presented. An overview of soft X-ray optical theory as it relates to diffraction gratings is given. The initial constraints and the process that led to this design are outlined. Techniques and software tools that were developed, using ray-tracing and diffraction grating efficiency calculations, are discussed. The analysis completed with these tools to compare existing soft X-ray emission spectrometer designs is presented. Based on this analysis, a new design with superior performance for this application is proposed and reviewed. This design employs Rowland circle geometry to achieve a resolving power in excess of 2,500 in the range of interest. In addition, a novel design is proposed for a larger extremely high resolution spectrometer which will provide resolving powers exceeding 10,000 throughout the higher end of this range. A review is given of research into the components, manufacturing techniques and tolerances that will be required to produce this spectrometer.
6

SAD Phasing of Proteins Using Xenon Gas

2015 April 1900 (has links)
Structural biology is a branch of science related to biochemistry, biophysics, and molecular biology that deals with the molecular structures of biological macromolecules, in particular nucleic acids and proteins. Structure-guided drug design uses three-dimensional knowledge of protein structures to design small molecules which block the action of specific proteins. When crystals of theses macromolecules and their complexes can be obtained, their crystal structures can be determined by using isomorphous differences between a native structure and a derivative structure. This allows crystallographers to determine the coordinates of a small number of heavy atoms which provide initial phases for macromolecules. The advent of synchrotron radiation allowed determination of a heavy atom substructure by use of anomalous differences using either multiple wavelengths (MAD) or a single wavelength (SAD); the latter has become the most common phasing method in crystallography and is the method used in this study. The use of SeMet has been by far the most successful method employed in SAD. However, in some cases production of SeMet proteins is not possible thus necessitating additional options, for example, xenon. Noble gases such as xenon may be used in SAD experiments by binding to various, non-specific sites. Advances in noble gas pressurization systems like the Hampton Research Xenon Chamber have greatly eased the production of noble gas derivatives, xenon itself being a prime candidate with a very strong anomalous signal when compared to lighter noble gases like krypton and argon. Investigation of the phasing properties of xenon was carried out on test proteins hen egg white lysozyme (HEWL), thermolysin, glucose isomerase, and thaumatin II. Phases were successfully determined for all four proteins including thaumatin II which did not bind xenon but was successful due to the anomalous signal from 17 native sulfurs. The three remaining proteins showed varying occupancies and numbers of sites including xenon sites in thermolysin and glucose isomerase which have not been observed previously. This document will serve as a guide for the preparation of xenon derivative crystals and provides a strategy for the collection and processing of data from xenon derivatives.
7

Verksamhetsanpassning av IT-baserat finanssystem / Business Configuration of IT-based Treasury System

Fors, Lisa January 2012 (has links)
If P&C Insurance Company faces a challenge when their treasury system needs a new interface to a software as a service application. They need a suggestion for configuration for how the system and the application can work together. The work presented in this report is a suggestion for how you can make business configuration of an IT-based Treasury System in general. The exact configuration for the case received from If is presented as a separate report, found in Appendix A and is called the If-report. The If-report presents the suggested technical set-up of the configuration. It is not company specific but system and application specific. The work made in that report will be a standard in future version of the treasury system. The work made in this report is presented to the Royal Institute of Technology and can work as an example of how to approach a business configuration that needs to be done in an IT-based Treasury System.
8

XPS Study of Calcium Lanthanum Sulfide Ceramics

Butkus, Brian E 01 January 2023 (has links) (PDF)
Long wave infrared (LWIR) optics that transmit in the 8 to 14 m wavelength range and, additionally, can withstand severe physical and thermal stresses are needed for advanced remote sensing, guidance and communication-based applications. However, most non-oxide transparent LWIR optics do not have the wider transmission range, nor the hardness and resistance to thermal shock needed for extreme environments. Because of these limitations, research is circling back to a promising material, calcium lanthanum sulfide (CLS), that could meet LWIR needs for extreme environments. In this thesis, we will demonstrate the abilities of x-ray photoelectron spectroscopy (XPS) as a technique for characterizing CLS powders and ceramics for elemental analysis, valence state and stoichiometry evaluation. Three preliminary studies were conducted - a binary metal sulfide evaluation of lanthanum sulfide (La2S3) and calcium sulfide (CaS), and a calibration curve of mixtures of the two binary metal sulfide powders from a known concentration matrix. Based on these results, a methodology was developed to evaluate CLS powder and ceramics via XPS. We showcase the power of XPS to reliably determine CLS stoichiometry, identify impurities and defects as related to the presence of carbon and oxygen during processing, and predict the bonding environment of sulfur which can lead to better quality CLS ceramics. This thesis demonstrates the use of XPS as a potential characterization tool in CLS to identify contaminants, determine if stoichiometry is met, and identify the bonding environments to assist in processing improvements for producing higher-quality ceramics.
9

The energy scale of the 3-flavour Lambda parameter

Bruno, Mattia 27 April 2016 (has links)
Alle dimensionsbehafteten Gitter-QCD-Observablen muessen in Einheiten einer Referenzskala ausgedrueckt werden und die Bestimmung dieser ist haeufig der erste Schritt in der Berechnung anderer Observablen. In dieser Arbeit beschreiben wir eine scale setting-Strategie fuer eine neue Satz an Ensembles mit großem Volumen, die von CLS generiert worden sind. Die Simulationen enthalten up, down und strange O(a)-verbesserte Wilson-Fermionenfelder. Die Eichfeld-dynamik ist mit Luescher-Weisz-Wirkung implementiert. Um das freezing der Topologie bei kleinen Gitterabstaenden zu ueberwinden, wurden offene Randbedingungen in Zeitrichtung verwendet. Außerdem wurde twisted mass reweighting eingesetzt, eine Technik, um die Fermionbeitraege in der Infrarotregion zu stabilisieren und zu regularisieren. In dieser Arbeit diskutieren wir deren Auswirkungen auf mesonische Spektralgroeßen. Wir berechnen die Gitterabstaende fuer unsere vier β Werte unter Verwendung der pseudoskalaren Zerfallskonstanten, die wir aus den Simulationen mit offenen Randbedingungen extrahieren. Außerdem bestimmen wir die Observable t0 und extrapolieren sie zum Kontinuum. / In lattice computations all dimensionful observables have to be expressed in units of a reference scale and its determination is often the first step before proceeding to other quantities. In this thesis we describe the scale setting strategy for a new set of large-volume ensembles generated within the CLS effort. The simulations have been carried out including up, down and strange quark fields, discretized a là Wilson and following the O(a)-improvement program. The gauge field dynamics is implemented with the improved Luescher-Weisz action. To overcome the freezing of topology in simulations at small lattice spacings, open boundary conditions in the time direction have been adopted, together with twisted-mass reweighting, a technique to regularize and stabilize the fermionic contributions in the infrared region. In this thesis we discuss their implications on mesonic spectral quantities. We compute the lattice spacings, for our four values of β, using the pseudo-scalar decay constants, extracted in the presence of open boundary conditions. In addition to that, we determine the observable t0 and extrapolate it to the continuum.
10

A Soft X-Ray Emission Endstation for the Canadian Light Source

2013 October 1900 (has links)
Based on a previously completed design for a soft X-ray (50-1100 eV) emission spectrometer, an endstation was constructed for the Resonant Elastic and Inelastic X-ray Scattering (REIXS) beamline at the CLS. The optical design employed techniques and software tools developed in-house using ray-tracing and diffraction grating efficiency calculations to analyze and compare existing designs and to propose a new design with superior performance. This design employs Rowland circle geometry to achieve a theoretical resolving power in excess of 2,500 in our range of interest. In addition, a novel optical design for a larger extremely high resolution spectrometer has been completed to provide theoretical resolving powers exceeding 10,000 throughout the higher end of the spectrum. To accommodate this optical design a completely new mechanical design was required, involving significant mechanical, electrical, vacuum and software engineering. Countless custom fabricated parts were required along with numerous o -the-shelf secondary instruments and systems. All told, this entirely student-managed project has cost over $1.5M and taken over 5 years. Construction is finally complete and the endstation is currently being commissioned. Necessary design changes made during the mechanical design process resulting in the selection of a more suitable, but lower resolution, detector. This reduced the theoretical maximum resolving power to 1,800 for the first order gratings and roughly 5,000 for the third order gratings. Commissioning is still underway, but first order resolutions in the range of 1,000 - 2,000 have been recorded as have third order resolutions exceeding 4,000. Publication quality data has been collecting by members of this research group and invited external users have successfully grown and measured samples here. Two of the optical elements required rework and upon their delivery the system commissioning will be completed and peer-reviewed access will begin.

Page generated in 0.0334 seconds