10,760 research outputs found

    Studies in the Cinnoline Series

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    Recent work by Castle and Kruse (16) has partially elucidated the range of reactivity of the chlorine atom in the compounds 4-chlorocinnoline and 4-chloro-6,7-dimethoxycinnoline. Condensations between the chlorinated cinnolines and certain phenylacetonitriles were found to proceed readily; however, condensations with compounds of the malonic ester type were unsuccessful. It was found that hydrolysis of the condensation product obtained from 4-chlorocinnoline and phenylacetontrile by hot 60% sulfuric acid caused decarboxylation of the intermediate acid, the final product being 4-benzylcinnoline. This compound has a formal resemblance to the basic ring structure of papaverine

    Archaeological Investigation of the San Juan Dam, 41BX266, Bexar County, Texas

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    On April 18, 1988, an archaeological crew from the Center for Archaeological Research at The University of Texas at San Antonio conducted a testing program at the historic dam for Mission San Juan Capistrano, San Antonio, Texas. The results of the excavations and the corresponding archival research are reported. Conclusions are drawn as to the dam\u27s location, formation, and function

    The Design of a Dual Method Metal-Organic Chemical Vapor Deposition System

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    For the fabrication of semiconductor devices, solar cells, and infrared detectors, thin film deposition methods are required. Of the deposition methods currently available including MBE, LPE, and MOCVD; MOCVD is preferred due to its relatively low cost per wafer, versatility, and high wafer throughput. Requirements which must be considered in the design of a deposition system are discussed. An MOCVD system is designed such that MOCVD can be carried out by plasma enhanced deposition (PED) or low pressure metal-organic chemical vapor deposition (LPMOCVD). As a result of the inherent characteristics of the two methods, a wide range of operational temperatures and pressures are possible. Software is developed for system control including a graphical display of the process schematic. The deposition of GaAS on Si is given as one possible application for this type system

    Requested, Recommended and Allowed Returns to Equity: Serendipity or Substance

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    R. Charles Moyer is Professor of Finance and Chairman of the Area of Finance in the College of Business Administration. Texas Tech University. Raymond E. Spudeck is an Assistant Professor in the Department of Finance, College of Commerce and lndlustry at the University of Wyoming. David B. Cox is an Instructor in the Area of Finance in the College of Business Administration at Texas Tech University

    Tracking Cyber Adversaries with Adaptive Indicators of Compromise

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    A forensics investigation after a breach often uncovers network and host indicators of compromise (IOCs) that can be deployed to sensors to allow early detection of the adversary in the future. Over time, the adversary will change tactics, techniques, and procedures (TTPs), which will also change the data generated. If the IOCs are not kept up-to-date with the adversary's new TTPs, the adversary will no longer be detected once all of the IOCs become invalid. Tracking the Known (TTK) is the problem of keeping IOCs, in this case regular expressions (regexes), up-to-date with a dynamic adversary. Our framework solves the TTK problem in an automated, cyclic fashion to bracket a previously discovered adversary. This tracking is accomplished through a data-driven approach of self-adapting a given model based on its own detection capabilities. In our initial experiments, we found that the true positive rate (TPR) of the adaptive solution degrades much less significantly over time than the naive solution, suggesting that self-updating the model allows the continued detection of positives (i.e., adversaries). The cost for this performance is in the false positive rate (FPR), which increases over time for the adaptive solution, but remains constant for the naive solution. However, the difference in overall detection performance, as measured by the area under the curve (AUC), between the two methods is negligible. This result suggests that self-updating the model over time should be done in practice to continue to detect known, evolving adversaries.Comment: This was presented at the 4th Annual Conf. on Computational Science & Computational Intelligence (CSCI'17) held Dec 14-16, 2017 in Las Vegas, Nevada, US

    Development of a Low-Cost Sub-Scale Aircraft for Flight Research: The FASER Project

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    An inexpensive unmanned sub-scale aircraft was developed to conduct frequent flight test experiments for research and demonstration of advanced dynamic modeling and control design concepts. This paper describes the aircraft, flight systems, flight operations, and data compatibility including details of some practical problems encountered and the solutions found. The aircraft, named Free-flying Aircraft for Sub-scale Experimental Research, or FASER, was outfitted with high-quality instrumentation to measure aircraft inputs and states, as well as vehicle health parameters. Flight data are stored onboard, but can also be telemetered to a ground station in real time for analysis. Commercial-off-the-shelf hardware and software were used as often as possible. The flight computer is based on the PC104 platform, and runs xPC-Target software. Extensive wind tunnel testing was conducted with the same aircraft used for flight testing, and a six degree-of-freedom simulation with nonlinear aerodynamics was developed to support flight tests. Flight tests to date have been conducted to mature the flight operations, validate the instrumentation, and check the flight data for kinematic consistency. Data compatibility analysis showed that the flight data are accurate and consistent after corrections are made for estimated systematic instrumentation errors

    Introductory Diversity Audits

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    Results from some initial diversity audits at the Egan Library, following a professional development course on the topic. Suggestions for developing and conducting your own diversity audit, which is an activity which can be entirely done from home!Ye

    The Development of a Grazing Rating Index to Identify the Biomass Removed and the Plant Species and Parts Eaten by Grazing Sheep

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    Determining the diet selection of grazing animals is inherently difficult and a trade-off exists between obtaining accurate information and interfering with the normal grazing behaviour of an animal. The botanical composition of a grazing animal’s diet may be estimated using one or a number of techniques in combination. A six-point grazing rating index was developed to identify the plant species consumed by sheep grazing within a heterogeneous native grassland and the extent to which each species within a quadrat was grazed. The method was developed to remove error from visual estimates that prevents detection of significant reductions in biomass for minor species from grazing between two samplings and to determine animal preference
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