3,444 research outputs found

    On Certain Divisibility Property of Polynomials

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    We review the definition of D-rings introduced by H. Gunji & D. L. MacQuillan. We provide an alternative characterization for such rings that allows us to give an elementary proof of that a ring of algebraic integers is a D-ring. Moreover, we give a characterization for D-rings that are also unique factorization domains to determine divisibility of polynomials using polynomial evaluations

    Public Middle School English Teachers Using LGBT Discriminatory District Curriculum “Multicultural” Guide

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    This paper is part of a dissertation in progress exploring why despite increased LGBT visibility and the legalization of gay marriage, in many U.S classrooms, LGBT students are not provided the same level of representation in the English language arts curriculum that other oppressed groups enjoy

    A study of volatile organic compounds from transgenic arabidopsis thaliana and solanum lycopersicum plants and analytical characterization of pyrolysis bio-oil

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    A dynamic headspace method was developed for the non-targeted analysis of volatile organic compounds (VOC) in Arabidopsis and Micro-Tom plants. The method allowed to determine differences from wild type (WT) and transformed plants overexpressing the carotene cleavage dioxygenase 1 (CCD1) genes. In the Arabidopsis study it was revealed the presence of unsaturated hydrocarbons, aromatic derivatives, alcohols, and terpenes. Among extracted volatiles, the apocarotenoid compound ÎČ-ionone was also detected, four-fold higher in the transgenic plants than the WT. There were not significant differences in the VOCs between the HS of Micro-Tom tomato plants overexpressing the CCD1 genes and WT. The compounds identified were mainly terpenes, and aromatic derivatives and there was no evidence of the presence of any apocarotenoid compound. A static headspace (SHS) method was developed for the analysis of VOCs in Micro-Tom tomato flowers. It was performed by simultaneously using three solid phase microextraction fibers. The non-targeted analysis revealed the presence of 45 volatiles from CCD1 plants and 35 from WT. Of the total VOCs identified, 30 were common to both types of plants, but 15 were specific to the CCD1 plants and 5 to the WT. In another study, bio-oil from tomato plant was generated by pyrolysis process. Bio-oil was fractionated according to its pesticidal properties. Neophytadiene, phytol and a number of fatty acids were identified in the most active fractions. Bioassays using these compounds showed partial insecticidal activity, suggesting that other unidentified compounds in the bio-oil fractions were also responsible for observed insecticidal activities

    DYNAMAC media distribution system

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    This thesis describes the initial development of a multiplatform client-server based system capable of distributing content derived from a new format over an IP network. The system will also provide digital rights management and secure transmission of video content utilizing the DYNAMAC video compression/decompression algorithm. The work presented here is part of the Digital Media Research Group, which is focused on the use of the DYNAMAC algorithm for digital rights management and distribution of high definition media content in real time, while achieving better efficiency on bandwidth usages. Three components were created with this initial development: a player capable of rendering video content compressed with the DYNAMAC algorithm, a server that distributes the compress video content over an IP network, and a protocol specially design to communicate and transfer the video content from the server to the client. Since the development was based on the Java Media Framework, the client and the server of the distribution system will be able to be installed and run on any computer platform with a Java Runtime Environment. The fact that the system is written in Java also means that any changes can be made to single components without having to change the entire system. In this paper I intent to describe the approach taken to develop the system and the results obtain, were several videos are transmitted demonstrating the functionalities of the DYNAMAC algorithm and the DYNAMAC media distribution system

    Drag force in a string model dual to large-N QCD

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    We compute the drag force exerted on a quark and a di-quark systems in a background dual to large-N QCD at finite temperature. We find that appears a drag force in the former setup with flow of energy proportional to the mass of the quark while in the latter there is no dragging as in other studies. We also review the screening length.Comment: 15 pages, typos removed, error corrected, refs adde

    The intrinsic three-dimensional shape of galactic bars

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    We present the first statistical study on the intrinsic three-dimensional (3D) shape of a sample of 83 galactic bars extracted from the CALIFA survey. We use the galaXYZ code to derive the bar intrinsic shape with a statistical approach. The method uses only the geometric information (ellipticities and position angles) of bars and discs obtained from a multi-component photometric decomposition of the galaxy surface-brightness distributions. We find that bars are predominantly prolate-triaxial ellipsoids (68%), with a small fraction of oblate-triaxial ellipsoids (32%). The typical flattening (intrinsic C/A semiaxis ratio) of the bars in our sample is 0.34, which matches well the typical intrinsic flattening of stellar discs at these galaxy masses. We demonstrate that, for prolate-triaxial bars, the intrinsic shape of bars depends on the galaxy Hubble type and stellar mass (bars in massive S0 galaxies are thicker and more circular than those in less massive spirals). The bar intrinsic shape correlates with bulge, disc, and bar parameters. In particular with the bulge-to-total (B/T) luminosity ratio, disc g-r color, and central surface brightness of the bar, confirming the tight link between bars and their host galaxies. Combining the probability distributions of the intrinsic shape of bulges and bars in our sample we show that 52% (16%) of bulges are thicker (flatter) than the surrounding bar at 1σ\sigma level. We suggest that these percentages might be representative of the fraction of classical and disc-like bulges in our sample, respectively.Comment: 18 pages, 11 figures, accepted for publication in MNRA
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