3,462 research outputs found
Multiple quantum coherences experiment, simulations and applications
No full textMULTIPLE QUANTUM COHERENCES EXPERIMENT, SIMULATIONS AND APPLICATIONS
ARMAN SAINOVITCH KUSSAINOV
Dissertation under the direction of Professor Daniel F. Gochberg
This dissertation discuses the intermolecular Multilpe Quantum Coherence (iMQC) phenomenon in nuclear magnetic resonance (NMR). This effect originates from the coherent long range dipole-dipole interaction between spins. A short introduction to nuclear magnetic resonance and the CRAZED experiment (the primary method to observe and study iMQC) is given. We perform numerical simulations of the CRAZED experiment, including relaxation processes, instantaneous radio frequency pulses and gradients, as well as phase cycling, phantom positioning, and sample rotation. The signal dependence on the sample
orientation, applied gradient strength and direction, and the underlying sample structure length scale has been determined experimentally and by numerical simulations for two biological tissues: rat sciatic nerve and mice fibrotic liver. The results indicate that the CRAZED signal may provide a unique means for elucidating sample structures at the hundreds of micrometers distance scale
Letter from Daniel F. Goggin, May 1, 1948
No full textThis letter confirms that Tsugitada Kanamori worked for Daniel Goggin in an Ordnance Shop as the superintendent at the Yokohama Area Engineer Equipment Pool. Mr. Goggin explains that Kanamori is "invaluable"and he would absolutely recommend Mr. Kanamori for any position.This collection contains one box of documents belonging to Tsugitada Kanamori. Materials in this collection mostly pertain to Kanamori’s efforts regarding canceling his renunciation and reinstating his American citizenship
'Response by the author, Daniel F. Vukovich.'
No full textResponse by the author (Vukovich) to a review of Illiberal China (my 2019 monograph
Phoebolampta excellens F. Walker 1869
No full textPhoebolampta excellens (F. Walker, 1869) [= P. magnifica] Perez-Gelabert, 2001: 68. Distribution. Hispaniola. Notes. This name is included in the catalogs of Bolívar (1888), Gundlach (1891) and Rehn (1909). This last author suggests that this listing likely represents Phoebolampta cubensis.Published as part of Yong, Sheyla & Perez-Gelabert, Daniel E., 2014, Grasshoppers, Crickets and Katydids (Insecta: Orthoptera) of Cuba: an annotated checklist, pp. 401-438 in Zootaxa 3827 (4) on page 433, DOI: 10.11646/zootaxa.3827.4.1, http://zenodo.org/record/22858
Detection of Short CO2 Pulses
No full textTitle: Detection of Short CO2 Pulses, Author: Daniel F. Rollin, Location: ThodeA passively mode-locked multi-atmosphere CO2 laser was used to produce sub-nanosecond pulses. After up-conversion of the 10.6 um radiation in a proustite crystal detction was done with a streak camera-optical multichannel analyser combination. Pulses shorter than 100 psec (FWHM) were recorded.ThesisMaster of Engineering (ME
Dr. Shanesha R.F. Brooks-Tatum, RWWL AUC, July 2011
No full textThis video is a conversation with Dr. Shanesha R.F. Brooks-Tatum. Dr. Brooks-Tatum talks about her book, "The Encyclopedia of Hip Hop Literature." Daniel Le, AUC Woodruff Library, is the interviewer
Multi-exponential T2 Myelin Water Imaging in Ex-Vivo Rodent Brain at 7T and 15.2T
No full textTo apply MWI techniques to excised, fixed rodent brains, multi-exponential T2 (MET2) data were acquired at high (7T) and ultra-high (15.2T) fields with and without tissue doping with Gadolinium to increase SNR efficiency. From relaxivity measurements, optimal scan parameters are found based on the minimal Cramér-Rao lower bounds (CRLB) of variance of myelin water fraction (MWF). Subsequently acquired MET2 data were analyzed to obtain myelin water fraction (MWF) maps with and without contrast agent at each field strength with various techniques, displaying the potential for MWI in rodent brain in the study of myelin content across whole brain
Ethnic identity, political identity and ethnic conflict: simulating the effect of congruence between the two identities on ethnic violence and conflict
No full textThis thesis outlines and presents an alternative hypothetical process to the emergence of ethnic conflict. Ethnic conflicts, rather than being dependent upon pre-existing 'ancient hatreds', are instead the result of a congruence between ethnic and political identity which grants individuals the ability to use ethnicity to identify and eliminate political threats. This hypothesis is formed by the examination of three case studies of ethnic conflict: Lebanon, Northern Ireland and Croatia. This hypothesis is then formalised and tested using an agent based simulation in which agent interactions are dependent upon ethnic and political identity and the congruence between the two. As predicted there was a strong positive correlation between how accurately ethnic identity reflected political identity and the level of ethnically motivated violence in the simulation, although the relationship was not linear. Furthermore the effect of a shift in congruence was found to be roughly comparable to the effect of initialising agents with a moderate level of pre-existing ethnic antagonism
Development and Characterization of NMR and MRI Methods for Assessment of Tumor Oxygen Consumption
No full textA common feature of invasive cancers is that they have an upregulation of glucose metabolism and reduced oxygen utilization. The overall goal of this research was to develop a 17Oxygen MRI method to access this aberrant tumor metabolism using a T1ρ weighted pulse sequence on a Bruker NMR Spectrometer. An assessment of the reliability of this pulse sequence for quantifying the ratio of concentrations of H217O (necessary for measuring the metabolic rate in vivo) water in 4 pairs of phantoms was preformed. Specifically, we varied the pH and concentration of Gadopentetic acid (Gd-DTPA) (which modulated T1 and T2 profiles) in 4 different combinations to mimic conditions in the tumor microeviorment. We then used the signal decay data collected at a low and high spin lock power and inserted this data into an eqaution. This equation was then used to compute the ratio of concentration between an enriched and unenriched phantom in each of the 4 pairs.
The two -frequency method was able to quantify [H217O] successfully in the phantoms without Gd-DTPA using the fitted signal data but failed to yield the correct result for the raw data. Thus, to further evaluate these approaches we need employ studies at clinical field strengths. Nevertheless, our results suggest that the quantification of H217O is insensitive to pH but sensitive to changes in T1 and T2
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