461 research outputs found

    A Transcript Analysis of the Graduates of Two Postsecondary Institutions in North Dakota: A General Education Profile

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    This study examined general education at a university and a community college in North Dakota in regard to purpose, structure, content, core, breadth, and coherence. The purpose of the study was to determine actual general education course-taking patterns by all graduates of the institutions and by differentiated majors. The research methodology was a case study and a profile of actual course-taking patterns as recorded on the transcripts of the 1990 baccalaureate degree graduates of the university and the 1989 and 1990 associate degree graduates at the community college. The profiles of general education coursework at the two institutions were similar. The stated purposes of general education were not directly linked to the general education structure or approved courses. Assessment was not defined. The structure of general education at the two institutions was distributional and spread among four disciplinary fields with some parameters in terms of departments and course selections. The content of the general education coursework completed was largely introductory. Although 50 percent of the total general education enrollments occurred in twenty-seven courses at the university and fourteen courses at the community college, there was an extremely limited pattern of common experiences for all graduates, particularly at the university. Fifty percent of the graduates completed only three courses in common at the university and seven courses in common at the community college. The core of common coursework was greater when differentiated by major; however, the common courses were closely related to the major and not balanced by discipline. Breadth of general education occurred to some degree in social sciences, humanities, and mathematics, but was limited in all other areas. Coursework coherence, measured by sequencing courses according to grade level, demonstrated 50 percent coherence at the community college for freshmen and sophomores but for only seniors at the university.Recommendations from this study included the need to conduct a general education case study at all institutions in the state higher education system, include general education transfer coursework in such a study, review institutional general education policies and practices considering the reported data, and develop general education assessment procedures

    Catalytic Combustion of Gasified Coal for Low-Emissions Gas Turbines

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    In response to the Department of Energy’s (DOE) goals of developing low emission, coal-based power systems, Precision Combustion, Inc. is developing a low, single digit ppm NOx emissions system for high firing temperature IGCC systems. The present paper presents emissions data for syngas and alternate fuels tested successfully. Subscale testing results at 10 atmospheres include NOx emissions meeting DOE\u27s target of 0.01 lbs/MMBtu (3 ppm at 15% O2) and were below this value under some operating conditions during parametric testing

    Measurement Of The Complex Nonlinear Refractive-Index Of Single-Crystal P-Toluene Sulfonate At 1064-Nm

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    Z-scan at 1064 nm was used with single, 35 ps pulses to measure the nonlinear refraction and absorption in single crystal PTS (p-toluene sulfonate). Detailed analysis of the Z-scan data based on DELTAn = n2I + n3I2 and DELTAalpha = alpha2I + alpha3I2 yielded n2 = 5(+/-1) X 10(-12) cm2/W, alpha2 = 100(+/-20) cm/GW, n3 = 5(+/-1)X 10(-21) cm4/W2 and alpha3 = - 5 (+/- 1) cm3/GW.2 The resulting two photon figure of merit T for PTS is marginal for high throughput, all-optical waveguide switching at 1064 nm

    Auto-labelling of Markers in Optical Motion Capture by Permutation Learning

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    Optical marker-based motion capture is a vital tool in applications such as motion and behavioural analysis, animation, and biomechanics. Labelling, that is, assigning optical markers to the pre-defined positions on the body is a time consuming and labour intensive postprocessing part of current motion capture pipelines. The problem can be considered as a ranking process in which markers shuffled by an unknown permutation matrix are sorted to recover the correct order. In this paper, we present a framework for automatic marker labelling which first estimates a permutation matrix for each individual frame using a differentiable permutation learning model and then utilizes temporal consistency to identify and correct remaining labelling errors. Experiments conducted on the test data show the effectiveness of our framework

    Intensity correlations in electronic wave propagation in a disordered medium: the influence of spin-orbit scattering

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    We obtain explicit expressions for the correlation functions of transmission and reflection coefficients of coherent electronic waves propagating through a disordered quasi-one-dimensional medium with purely elastic diffusive scattering in the presence of spin-orbit interactions. We find in the metallic regime both large local intensity fluctuations and long-range correlations which ultimately lead to universal conductance fluctuations. We show that the main effect of spin-orbit scattering is to suppress both local and long-range intensity fluctuations by a universal symmetry factor 4. We use a scattering approach based on random transfer matrices.Comment: 15 pages, written in plain TeX, Preprint OUTP-93-42S (University of Oxford), to appear in Phys. Rev.

    Multiple light scattering in anisotropic random media

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    In the last decade Diffusing Wave Spectroscopy (DWS) has emerged as a powerful tool to study turbid media. In this article we develop the formalism to describe light diffusion in general anisotropic turbid media. We give explicit formulas to calculate the diffusion tensor and the dynamic absorption coefficient, measured in DWS experiments. We apply our theory to uniaxial systems, namely nematic liquid crystals, where light is scattered from thermal fluctuations of the local optical axis, called director. We perform a detailed analysis of the two essential diffusion constants, parallel and perpendicular to the director, in terms of Frank elastic constants, dielectric anisotropy, and applied magnetic field. We also point out the relevance of our results to different liquid crystalline systems, such as discotic nematics, smectic-A phases, and polymer liquid crystals. Finally, we show that the dynamic absorption coefficient is the angular average over the inverse viscosity, which governs the dynamics of director fluctuations.Comment: 23 pages, 12 ps figures, to be published in Phys. Rev.

    Analytical solutions to the third-harmonic generation in trans-polyacetylene: Application of dipole-dipole correlation on the single electron models

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    The analytical solutions for the third-harmonic generation (THG) on infinite chains in both Su-Shrieffer-Heeger (SSH) and Takayama-Lin-Liu-Maki (TLM) models of trans-polyacetylene are obtained through the scheme of dipole-dipole (DDDD) correlation. They are not equivalent to the results obtained through static current-current (J0J0J_0J_0) correlation or under polarization operator P^\hat{P}. The van Hove singularity disappears exactly in the analytical forms, showing that the experimentally observed two-photon absorption peak (TPA) in THG may not be directly explained by the single electron models.Comment: 10 pages, 4 figures, submitted to Phys. Rev.

    Susceptibility calculations for alternating antiferromagnetic chains

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    Earlier work of Duffy and Barr consisting of exact calculations on alternating antiferromagnetic Heisenberg spin‐1/2 chains is extended to longer chains of up to 12 spins, and subsequent extrapolations of thermodynamic properties, particularly the susceptibility, are extended to the weak alternation region close to the uniform limit. This is the region of interest in connection with the recent experimental discovery of spin‐Peierls systems. The extrapolated susceptibility curves are compared with corresponding curves calculated from the model of Bulaevskii, which has been used extensively in approximate theoretical treatments of a variety of phenomena. Qualitative agreement is observed in the uniform limit and persists for all degrees of alternation, but quantitative differences of about 10% are present over the whole range, including the isolated dimer limit. Potential application of the new susceptibility calculations to experiment is discussed

    A novel mutation of the calcium sensing receptor gene is associated with chronic pancreatitis in a family with heterozygous SPINK1 mutations

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    BACKGROUND: The role of mutations in the serine protease inhibitor Kazal type 1 (SPINK1) gene in chronic pancreatitis is still a matter of debate. Active SPINK1 is thought to antagonize activated trypsin. Cases of SPINK1 mutations, especially N34S, have been reported in a subset of patients with idiopathic chronic pancreatitis. However, the inheritance pattern is still unknown. Some cases with N34S heterozygosity have been reported with and without evidence for CP indicating neither an autosomal recessive nor dominant trait. Therefore SPINK1 mutations have been postulated to act as a disease modifier requiring additional mutations in a more complex genetic model. Familial hypocalciuric hypercalcemia (FHH) caused by heterozygous inactivating mutations in the calcium sensing receptor (CASR) gene is considered a benign disorder with elevated plasma calcium levels. Although hypercalcemia represents a risk factor for pancreatitis, increased rates of pancreatitis in patients with FHH have not been reported thus far. METHODS: We studied a family with a FHH-related hypercalcemia and chronic pancreatitis. DNA samples were analysed for mutations within the cationic trypsinogen (N29I, R122H) and SPINK1 (N34S) gene using melting curve analysis. Mutations within CASR gene were identified by DNA sequencing. RESULTS: A N34S SPINK1 mutation was found in all screened family members. However, only two family members developed chronic pancreatitis. These patients also had FHH caused by a novel, sporadic mutation in the CASR gene (518T>C) leading to an amino acid exchange (leucine->proline) in the extracellular domain of the CASR protein. CONCLUSION: Mutations in the calcium sensing receptor gene might represent a novel as yet unidentified predisposing factor which may lead to an increased susceptibility for chronic pancreatitis. Moreover, this family analysis supports the hypothesis that SPINK1 mutations act as disease modifier and suggests an even more complex genetic model in SPINK1 related chronic pancreatitis
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