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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.
201

Examining the electronic structure of metal pnictides via X-ray spectroscopy

Blanchard, Peter Ellis Raymond Unknown Date
No description available.
202

Scanning Imaging With High Energy Photons

Emre, Eylem 01 November 2003 (has links) (PDF)
An inspection system was required in order to eliminate the difficulties which appear during the inspection of the vehicles according to specific criteria at Turkish Custom Border in a short time and effectively. In this thesis, we performed experiments on such a system to obtain the overall performance of its inspection quality. We firstly give with reasons, why the source of beam is selected as X-ray source. The subsystems of the main system are the accelerator subsystem and detector subsystem. Their structures and working principles are studied in detail by comparing them with their alternatives. Series of experiments are carried out to verify the general performance of system in terms of radiation security and quality of images produced by the system. These experiments were classified as general scan experiment, inspection performance experiment, image quality indicator experiment, radiation safety experiment and general performance experiment. The container inspection system studied and experimented in this thesis is now used effectively in Turkish Customs Boarder, Edirne Kapikule and Edirne ipsala.
203

An investigation of the crystal structure of sodium hyponitrite

Hollis, Ralph Leroy January 2011 (has links)
Digitized by Kansas State University Libraries
204

An x-ray study of the changes in the structure of wheat starch in staling breads

Root, Marvin Ray January 2011 (has links)
Digitized by Kansas State University Libraries
205

Design and evaluation of a new x-ray diffraction topograph camera

Dreiling, Mark Jerome. January 1964 (has links)
Call number: LD2668 .T4 1964 D77 / Master of Science
206

X-ray analysis of the cis form of 2.5 dimethylthiacyclopentane

Gallagher, George Ray. January 1955 (has links)
Call number: LD2668 .T4 1955 G35 / Master of Science
207

Design and optimisation of thin foil X-ray telescopes

Jalota, Lalit January 1988 (has links)
In this thesis the use of thin foil conical profile X-ray mirrors for high energy, large aperture, and lightweight telescopes is investigated. The telescope performance is studied using analytical solutions and ray tracing simulations. Expressions for the number of mirrors in a module, the collecting area, the efficiency of aperture utilisation, and the resolution are calculated for on-axis sources. For off-axis sources ray tracing is used and expressions to describe the performance are derived empirically. The sensitivity and effect of singly reflected rays on the image are also investigated, and the comparison is made with Wolter (I) profile optics. A technique for the production of super-smooth surfaces using a layer of acrylic lacquer is described. Several materials have been coated using this method to assess their suitability as potential mirror substrates. To quantitatively assess the quality of both substrate and lacquer finishes a program of X-ray scattering measurements has been carried out. Several different types of surfaces have been examined both before and after lacquer coating. Particular attention has been payed to the ability of the lacquer to remove surface features of different spatial wavelengths. An epoxy replicated test flat is also examined which provides an interesting comparison with the lacquer coating technique for the production of thin X-ray mirrors. As a consequence of the wide range of materials examined it has been possible to compare most of the different techniques for producing thin X-ray mirrors. There is no one solution for all applications and thin foil mirrors are indeed a competitive technology.
208

X-ray observations of the outskirts of galaxy clusters

Walker, Stephen Alexander January 2014 (has links)
No description available.
209

Manganese complexes as catalase and superoxide dismutase mimics : structure and reactivity relationships

Kose, Muhammet January 2012 (has links)
Macrocycle (H2L1) was prepared by a Schiff base condensation reaction of 2,6-diformylpyridine and 1,3-diamino-2-propanol in the presence of Ba(II) as template ion. Seven-coordinate Mn(II) complexes were prepared by transmetallation reactions of the initial [Ba(H2L1)(μ1,2-ClO4)]2(ClO4)2 complex. Two mononuclear, ring-contracted complexes were obtained when methanol or ethanol were used as solvents in transmetallation reactions. For both complexes, X-ray analysis showed that the H2L1 macrocycle undergoes a ring-contraction via addition of methanol or ethanol across one imine bond, followed by a nucleophilic addition of the secondary amine across an adjacent imine bond resulting in a six-membered, hexahydropyrimidine ring sitting in a chair conformation. The ring-contraction process reduces the size of the cavity in the macrocycle to accommodate one Mn(II) ion in the macrocycle. The macrocyclic tetraimine ligand (H2L1) gave access to the polynuclear, ring-expanded assemblies, [Mn4(H2L*)Cl4][MnCl4] and [Mn4(H2L*)(N3)4](ClO4)2, when acetonitrile was used as a solvent. The macrocycle (H2L1) undergoes rearrangement from a 20-membered to a 40-membered tetranuclear Mn(II) complex. Manganese complexes of acyclic ligands, derived from 2,6-diformylpyridine and several aminoalcohols and aminophenols, were prepared and structurally characterised by X-ray crystallography. Most of the complexes are seven-coordinate with approximate pentagonal bipyramidal geometry, however, some five, six and seven-coordinate complexes were identified. Asymmetric and symmetric tripodal Schiff base ligands and their manganese complexes were also prepared and characterised. Additionally, N-alkylated benzimidazole 2,6-bis(1-butyl-1H-benzo[d]imidazol-2-yl)pyridine and its Mn(II) complexes were prepared and characterised. The potential application of the complexes has been tested in two main areas: (a) as new catalase mimics and (b) as new superoxide dismutase (SOD) mimics. The trinuclear, acyclic complex, [Mn3(L9)2(OAc)2(MeOH)2] 2MeOH, derived from 2,6-diformylpyridine and 2-aminophenol, was found to be the most efficient catalase mimic of the tested complexes with approximately 500 molecules of H2O2 broken down per second for each complex during the fastest rate of activity. Catalase testing showed that an increase of the arm size of the tripodal complexes produced an increase in activity overall for the complexes. Most of the complexes tested for catalase activity showed an induction period prior to the activity being observed. This may be due to a rearrangement occurring before catalase activity is observed. The tripodal complex, [Mn(L18)](ClO4)2 is the only complex to show a catalase activity without added base, but with a long induction period. The results that are presented indicate that the axial ligands have an effect on both the rate of catalase activity and the observed induction period. The SOD results indicated that the complex, [Mn(H2L6)Cl(H2O)]Cl H2O, derived from 2,6-diformylpyridine and 1 aminopropan-2-ol, shows the highest SOD activity amongst the complexes prepared, with a rate of 2.05x106 M-1s-1 and the IC50 value of 0.78 μM. Most of the complexes showed SOD activity with a rate around 105-106 M-1s-1. The SOD results showed that the axial ligands have an effect on SOD activity; strongly bound ligands such as thiocyanate and azide generally result in lower SOD activity. Most of the complexes showed both SOD and catalase activity. Ring-contracted complexes, [Mn(H3L2)(NCS)2] and [Mn(H3L3)(NCS)2], show high rates of superoxide dismutase activity but possess limited catalase activity.
210

An x-ray absorption fine structure study of semiconductor nanoclusters

Shorrosh, Raed Saed 12 1900 (has links)
Dissertation made openly available per email from author, 6/8/2016.

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