This thesis has detailed the extensive analysis of the XAS and RIXS spectra of LiFePO4 and FePO4, with the primary focus on LiFePO4. One of the primary motivations for this study was to understand the electronic structure of the two compounds and, in particular, shed some light on the nature of electron correlation within the samples. Two classes of band structure calculations have come to light. One solution uses the Hubbard U parameter, and this solution exhibits a band gap of about 4 eV. Other solutions that use standard DFT electron correlation functionals yield band gaps between 0 and 1.0 eV. <p>The RIXS spectra of LiFePO4 and FePO4 were analyzed using Voigt function fitting, an uncommon practice for RIXS spectra. Each of the spectra was fit to a series of Voigt functions in an attempt to localize the peaks within the spectra. These peaks were determined to be RIXS events, and the energetic centers of these peaks were compared to a small band gap band structure calculation. The results of the RIXS analysis strongly indicate that the small gap solution is correct. This was a surprising result, given that LiFePO4 is an ionic, insulating transition metal oxide, showing all of the usual traits of a Mott-type insulator. <p>This contradiction was explained in terms of polaron formation. Polarons can severely distort the lattice, which changes the local charge density. This changes the local DOS such that the DOS probed by XAS or RIXS experiments is not necessarily in the ground state. In particular, polaron formation can reduce the band gap. Thus, the agreement between the small gap solution and experiment is false, in the sense that the physical assumptions that formed the basis of the small gap calculations do not reflect reality. Polaronic distortion was also tentatively put forward as an explanation for the discrepancy between partial fluorescence yield, total fluorescence yield, and total electron yield measurements of the XAS spectra of LiFePO4 and FePO4.

In this paper, I'll introduce the applications of Mathematica 7th and 8th edition in probability and statistics. The major contents are statistical data and charts, basis statistics, probability distributions, hypothesis testing, distribution fitting, regression analysis, cluster analysis and so on. Except introducing variously related commands, this paper will provides corresponding examples, so it can be regarded as a toolbook for people interested in the probabilities and statistical parts of this software.

A total of 10 vertical 226Ra profiles from the North Pacific was published as part of the GEOSECS program. These profiles are located on an east-west section along ~300N. The purpose of this thesis is to use one-dimensional and two-dimensional diffusion-advection models to estimate some important geochemical parameters. There are some discrepancies between the modeling results and the observed tracer distributions due to restrictions on end-members in the models. Fitting the observed data to the model, one obtains values of the Z* between 0.8 and 1.0 km from potential temperature and that of JBa/w between 0.0020 and 0.0064 nM/kg/m from Ba. Where Ba profiles are available, the corresponding 226Ra profiles are similar from the surface to the deep water, showing a linear correlation with a slope at 0.22 dpm/100nM or 4.4¡Ñ10-9 for the Ra/Ba molal ratio. The slope has an intercept of 0.48 nM/kg on the Ba axis. That 226Ra is linearly correlated with Ba from surface water to deep water is probably because algebraic sum of the production term and the radioactive decay is nearly constant. Thus the revised model has a form equivalent to that for Ba. Where Ba profiles are available, one can fit the observed data to the model to obtain the needed parameters with (JRa-£fCRa)/JBa as a constant. The upwelling velocity, w, obtained from model calculations on the Ba profiles is: 3.8 m/yr at 204; 4.8 m/yr at 212; 3.5 m/yr at 226, 1.2 m/yr at 224. These values are consistent with those (1 to 12m/yr) reported for the Pacific deep water based on other methods. Fitting 226Ra profile data to the vertical one-dimensional diffusion-advection model for the in-situ production rate, J, and the associated upwelling velocity, w, one finds that J and w are coupled with a negative correlation. This is consistent with that reported in the literature. Profiles from the northeast Pacific show a deep Ra maximum, with an ¡§excess¡¨ which extends westward while decreasing and finally vanishing in the northwest Pacific near Japan. A horizontal diffusivity of 5 ¡Ñ105 cm2/s was obtained based on this ¡§excess¡¨ 226Ra with a horizontal 1-D model by Chung and Craig (1980). A numerical finite-difference method is applied to the 2-D model fitting on the potential temperature data for the horizontal diffusivity, Kx. A Kx of 4.58 ¡Ñ105 cm2/s is obtained within the depth range of 1000m to 3000m. The value is 4.82 ¡Ñ105 cm2/s for the depth range from 1000m to 4000m. These two approaches yield nearly identical results.

No description available.

The purpose of this study was to compare the use of behind-the-ear and in-the-ear hearing aids with a geriatric population. The aids were compared to see which type of aid the subjects could learn to use most easily and to see which type of aid they preferred to use.Subjects were fitted with acoustically similar in-the-ear and behind-the-ear hearing aids for alternate one week periods. The aids were evaluated in two ways: 1) A rating scale evaluating the subjects’ abilities to use the hearing aid (insert battery, insert aid, remove aid, remove battery, adjust volume) and 2) A questionnaire exploring the subjects’ reaction to care of hearing aid use and general aid preference.With respect to the rating scale, no significant differences were found. Subjects could perform the tasks covered with both types of aids. With respect to the questionnaire, significant differences were found in favor of the in-the-ear hearing aid. In general, the results of this study tend to indicate that geriatric subjects can handle in-the-ear hearing aids and behind-the-ear hearing aids with about equal success but that they have a clear preference for in-the-ear hearing aids.

This thesis explores the feasibility of the application of statistical regression theory to the curve fitting of mortality data. Equations derived from Makeham's first law were used. These include:1x = ksxgcXlog lx=a+hx+bcx color pX = A + BcxThe 1941 CSO and 1958 CSO mortality tables were used for initial study.Extending this work, pure raw mortality data in conjunction with a modified version of the last equation above was employed. Results were quite interesting.

Thesis (M.S.)--Rochester Institute of Technology, 1989. / Includes bibliographical references (leaves 72-73).

abstract: Many species e.g. sea urchin form amorphous calcium carbonate (ACC) precursor phases that subsequently transform into crystalline CaCO3. It is certainly possible that the biogenic ACC might have more than 10 wt% Mg and &sim; 3 wt% of water. The structure of ACC and the mechanisms by which it transforms to crystalline phase are still poorly understood. In this dissertation our goal is to determine an atomic structure model that is consistent with diffraction and IR measurements of ACC. For this purpose a calcite supercell with 24 formula units, containing 120 atoms, was constructed. Various configurations with substitution of Ca by 6 Mg ions (6 wt.%) and insertion of 3-5 H2O molecules (2.25-3.75 wt.%) in the interstitial positions of the supercell, were relaxed using a robust density function code VASP. The most noticeable effects were the tilts of CO3 groups and the distortion of Ca sub-lattice, especially in the hydrated case. The distributions of Ca-Ca nearest neighbor distance and CO3 tilts were extracted from various configurations. The same methods were also applied to aragonite. Sampling from the calculated distortion distributions, we built models for amorphous calcite/aragonite of size &sim; 1700 nm3 based on a multi-scale modeling scheme. We used these models to generate diffraction patterns and profiles with our diffraction code. We found that the induced distortions were not enough to generate a diffraction profile typical of an amorphous material. We then studied the diffraction profiles from several nano-crystallites as recent studies suggest that ACC might be a random array of nanocryatallites. It was found that the generated diffraction profile from a nano-crystallite of size &sim; 2 nm3 is similar to that from the ACC. / Dissertation/Thesis / Ph.D. Physics 2012

Dissertação (mestrado)—Universidade de Brasília, Instituto de Ciências Exatas, Departamento de Matemática, 2017. / Submitted by Albânia Cézar de Melo (albania@bce.unb.br) on 2017-04-04T14:51:32Z No. of bitstreams: 1 2017_SaraRaissaSilvaRodrigues.pdf: 2150217 bytes, checksum: 58576539eefd04b409a3bbf9c7cff7e9 (MD5) / Approved for entry into archive by Raquel Viana(raquelviana@bce.unb.br) on 2017-04-25T21:09:40Z (GMT) No. of bitstreams: 1 2017_SaraRaissaSilvaRodrigues.pdf: 2150217 bytes, checksum: 58576539eefd04b409a3bbf9c7cff7e9 (MD5) / Made available in DSpace on 2017-04-25T21:09:40Z (GMT). No. of bitstreams: 1 2017_SaraRaissaSilvaRodrigues.pdf: 2150217 bytes, checksum: 58576539eefd04b409a3bbf9c7cff7e9 (MD5) / Um grupo G é chamado um grupo Engel se para todos x e g em G a identidade [x, g, . . . , g] = 1 vale em G, onde g é repetido no comutador um número suficiente de vezes que depende de x e g. É bem conhecido que qualquer grupo localmente nilpotente é um grupo Engel. Mas, a recíproca não vale em geral. No entanto, em [26] J. S. Wilson e E. I. Zelmanov provaram que todo grupo profinito Engel ´e localmente nilpotente.Dados um elemento g em G e um inteiro positivo n, seja En(g) o subgrupo gerado por todos os comutadores [x, g, . . . , g] onde, x varia em G e g é repetido n vezes. Esta dissertação está baseada no artigo Almost Engel finite and profinite groups [13] de E. I. Khukhro e P. Shumyatsky. Mostramos que se G é um grupo profinito tal que, para todo g em G existe um inteiro positivo n = n(g) com a propriedade que En(g) é finito, então G possui um subgrupo normal finito N tal que G/N ´e localmente nilpotente. Um resultado da mesma natureza e de tipo quantitativo ´e provado para um grupo finito G, deduzindo informações sobre a ordem do subgrupo residual nilpotente γ(G) de G. / A group G is called an Engel group if for every x and g in G the equation [x, g, . . . , g] = 1 holds in G, where g is repeated in the commutator sufficiently many times depending on x and g. It is well known that any locally nilpotent group is an Engel group, but the converse does not hold in general. However, in [26] J. S. Wilson and E. I. Zelmanov proved that any Engel profinite group is locally nilpotent. Given an element g in G and a positive integer n, let En(g) be the subgroup generated by all commutators [x, g, . . . , g] over x in G, where g is repeated n times. This master’s dissertation is based on the article Almost Engel finite and profinite groups [13] of E. I. Khukhro e P. Shumyatsky. It is shown that if G is a profinite group such that, for every g in G there is a positive integer n = n(g) such that En(g) is finite, then G has a finite normal subgroup N such that G/N is locally nilpotent. A similar result of quantitative nature holds for a finite group G, and it gives information about the order of the nilpotent residual subgroup ɣ(G) of G.

Uncomfortable listening level (UCL) is a behavioral measure which is currently used to set the maximum outputs of hearing aids. This study explored the feasibility of prescribing the maximum outputs of hearing aids by using results obtained from auditory brainstern response (ABR) testing. More specifically, this study compared ABR wave latencies with behaviorally-measured UCLs for a single cycle 3 kHz stimulus in normal-hearing adults.