111 |
Endor of the 55Mn2+ ion in cubic alkaline-earth oxides.Saxena, Govind Prasad. January 1971 (has links)
No description available.
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112 |
Electron nuclear double resonance of Cr3 and Mn2 in a magnesium oxide lattice.Dyer, Glenn Lionel. January 1967 (has links)
No description available.
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113 |
A Study of Sodalite by Paramagnetic ResonanceLang, Robert 04 1900 (has links)
<p> Single crystals of sodalite have been studied by means of
electron paramagnetic resonance (E. P.R.) both at 0.8 cm. and
3 cm. wavelength. The existence of at least four different E. P. R. spectra
was established of which one was attributed to the manganese impurity
and a possible model for two other spectra is proposed. It was
found that two of the observed spectra disappear upon heat treatment
although the bleaching of the characteristic blue colour of sodalite
crystals does not appear to be related to any of the spectra studied. </P> / Thesis / Master of Science (MSc)
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114 |
A Study of The a-β Phase Transformation in A1PO4:Fe^3+ and Quartz by Electron Paramagnetic ResonanceLang, Robert 10 1900 (has links)
<p> The a-β phase transformation was studied in hydrothermally grown crystals of A1PO4 by measuring the spin-Hamiltonian parameters of Fe^3+ as a function of temperature. </p> <p> The theory of the Blume-Orbach mechanism for the zero-field splitting of s-state ions was generalized and used to calculate the D-tensor of the spin-Hamiltonian. The experimentally observed temperature variation of the spin-Hamiltonian was interpreted in terms of a temperature-dependent point-multipole model of the charge distribution in the crystal lattice. </p> <p> A similar study of the a-S phase transformation in quartz was attempted but E.P.R. measurements could only be taken up to 450°C (123°C below the transformation temperature) because of the instability of the Fe^3+ center at higher temperatures. </p> / Thesis / Doctor of Philosophy (PhD)
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115 |
Development of New Paramagnetic Tags for Solid-State NMR Structural Studies of Natively Diamagnetic ProteinsJayasinha Arachchige, Rajith Madushanka 02 June 2014 (has links)
No description available.
|
116 |
Magnetic and crystallographic investigations of selected single crystal systems /Reppart, William J. January 1985 (has links)
No description available.
|
117 |
EPR of rare-earth impurities in single crystals of ZnSe and CdS.Yu, Jiang-Tsu January 1972 (has links)
No description available.
|
118 |
E.P.R. studies of Li-doped N-type Si before and after electron irradiation /Jayapandian, D. Peter January 1975 (has links)
No description available.
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119 |
Low-field electron paramagnetic resonance studies of the lowest triplet states of 1,2-benzanthracene-d₁₂ and chrysene-d₁₂ in p-terphenyl single crystals /Chen, Mon-Chao January 1975 (has links)
No description available.
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120 |
Spin resonance excitation of Gd-based contrast agents for thermal energy depositionDinger, Steven Conrad January 2016 (has links)
A thesis submitted to the Faculty of Engineering and the Built
Environment, University of the Witwatersrand, Johannesburg, in
fulfilment of the requirements for the degree of Doctor of Philosophy.
Johannesburg, 2016 / The theoretical and experimental investigation of electron spin-resonance relaxation to
deposit thermal energy into liquid gadolinium-based contrast agents for cancer hyperthermia
treatment is presented. Previous works suggest that using protons in water are
inadequate, with a thermal deposition rate of approximately 1 ◦C per two years. A novel
component of this research relies on the use of gadolinium-chelated molecules, which are
currently used as contrast agents in clinical MRI scans. The chelating agents, or ligands,
investigated are Gadobenate (MultiHance R
), Gadopentetate (Magnevist R
), Gadoterate
(DotaremR
) and Gadoteridol (ProHance R
). The gadolinium atom has seven unpaired
electrons in its inner f shell orbital and as a result has a 660 times stronger paramagnetic
response when placed in an external magnetic field. The research tests the hypothesis
that by using an appropriate external homogeneous DC magnetic field, together with a radiofrequency
excited resonator, that a measurable amount of thermal energy is deposited
into a liquid gadolinium-based contrast agent. The aim of this research is to ultimately
discover a new cancer hyperthermia treatment. The research theory suggests that a temperature
rate of 13.4 ◦C · s−1 can be achieved using the gadolinium-based contrast agents
under certain experimental conditions, and a maximum of 29.4 ◦C · s−1 under more optimal
conditions. The temperature rates are calculated using parameter values commonly
found in literature and practice. The simulation and design of the DC magnetic field coil
system is discussed, together with the simulation results and design parameters of the radiofrequency
loop-gap resonator. The experimental results and analysis indicate that the
selected contrast agents have varied responses based on their chemical nature and that
only two out of the four contrast agents, Dotarem and ProHance, show a measurable
effect albeit sufficiently small that statistical techniques were necessary to distinguish
the effect from background. A model fit to the data is performed in order to determine
the spin-lattice relaxation time of the contrast agents under the specified experimental
conditions. The model estimate is significantly smaller than the values found in literature
under similar conditions, with a spin-lattice relaxation time τ1e of approximately 0.2 ps
compared to the literature value of 0.1 ns. Although the observed electron spin resonance
heating rate is in the milli-Watt range it is still notably larger (167 000 times) compared
to the heating rate obtained using protons. The low temperature rates suggest that a
more suitable agent or molecule with a larger spin-relaxation time be used, in order to
achieve clinical useful temperature rates in the range of 14 ◦C · s−1. / MT2017
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