196,129 research outputs found

    High-Throughput Quantification of Trace Haloanisole and Halophenol Off-Flavor Compounds in Cork Wine Stoppers

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    A high-throughput, nondestructive quantification solution for the trace analysis of haloanisole and halophenol off-flavor compounds in cork wine stoppers based on chemical ionization time-of-flight mass spectrometry is presented. Using a fully automated workflow, individual cork stoppers can be measured continuously with a sample-to-sample time of less than 3 s, with limits of quantification in the range of 0.1 ng/L for all target compounds. This approach allows comprehensive, quality control of cork stopper production while at the same time opening new possibilities for research on the origin of off-flavors in natural matrices

    Dr. Duane M. Jackson, Morehouse College, July 2011

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    This video is a conversation with Dr. Duane M. Jackson. Dr. Jackson talks about his paper, "Recall and the Serial Position Effect: The Role of Primacy and Recency on Accounting Students' Performance." Jackie Daniel, AUC Woodruff Library, is the interviewer

    "Reflections on the subject of Emigration from Europe with a view to Settlement in the United States" By M. Carey.

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    "Reflections on the subject of Emigration from Europe with a view to Settlement in the United States: containing bried sketches of the moral and political character of those states. By M. Carey, member of the American philosophical, and of the American Antiquarian Society, and author of The Olive Branch, Cindiciae Hibernicae, essays on banking, on political economy, and on internal improvement. To which are now added the English editor's comments on the subject; together with Important Advice to Emigrants, and Cautions Against Impositions Practiced in the Outports

    Dispelling the Myths Behind First-author Citation Counts

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    We conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more sophisticated methods

    Thermal Desorption-Vocus Enables Online Nondestructive Quantification of 2,4,6-Trichloroanisole in Cork Stoppers below the Perception Threshold

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    2,4,6-Trichloroanisole (TCA) contamination of wine determines huge economic losses for the wine industry estimated to amount to several billion dollars yearly. Over 50 years of studies have determined that this problem is often caused by TCA contamination of the cork stopper, which releases TCA into the wine. The human threshold for TCA is extremely low. A wine contaminated by 1-2 ng/L TCA can be perceived as tainted. Contaminations with <0.5 ng/L TCA are commonly considered negligible and are not perceivable. The possibility of prescreening cork stoppers for TCA contamination would be an enormous advantage. Therefore, the demand for a fast, nondestructive method capable of quantifying the TCA contamination in cork stoppers is impelling. Vastly used analytical methods have so far struggled to provide a fast and reliable solution, whereas sensory analysis by trained panelists is expensive and time-consuming. Here we propose a novel approach based on chemical ionization-time-of-flight (CI-TOF) mass spectrometry employing the "Vocus"ion source and ion-molecule reactor. The technique proved capable of nondestructively quantifying TCA contamination in a single cork stopper in 3 s, with a limit of quantification below the perception threshold. A real test on the industrial scale, quantifying TCA contamination in more than 10000 cork stoppers in a few hours is presented, representing the largest data set of TCA analysis on cork stoppers within the literature and proving the possibility to apply the technique in an industrial environment. The correlation with standard methods for releasable TCA quantification is also discussed

    Dr. Glendon Swarthout

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    Hosted by Roger M. Busfield, MSU Assistant Professor of Speech and Theater, Meet the Author is designed to introduce a general audience to a contemporary author and their work through in-depth interviews. This episode features a conversation between Dr. Glendon Swarthout, prolific author and English professor at MSU, and assistant professors Sam S. Baskett and Theodore B. Strandness

    Detection of Volatile Organic Compounds with Secondary Electrospray Ionization and Proton Transfer Reaction High-Resolution Mass Spectrometry: A Feature Comparison

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    The analysis of volatiles is of high relevance for a wide range of applications from environmental air sampling and security screening to potential medical applications. High-resolution mass spectrometry methods offer a particularly wide compound coverage, sensitivity, and selectivity. Online approaches allow direct analysis in real time without the need for sample preparation. For the first time, we systematically compared the analysis of volatile organic compounds with secondary electrospray ionization (SESI) and proton transfer reaction (PTR) high-resolution mass spectrometry. The selected instruments had comparable mass resolving powers with m/Delta m >= 15000, which is particularly suitable for nontargeted analysis, for example, of exhaled breath. Exhalations from 14 healthy adults were analyzed simultaneously on both instruments. In addition, 97 reference standards from nine chemical classes were analyzed with a liquid evaporation system. Surprisingly, in breath, we found more complementary than overlapping features. A clear mass dependence was observed for each method with the highest number of detected m/z features for SESI in the high mass region (m/z = 150-250) and for PTR in the low mass region (m/z = 50-150). SESI yielded a significantly higher numbers of peaks (828) compared to PTR (491) among a total of 1304 unique breath m/z features. The number of signals observed by both methods was lower than expected (133 features) with 797 unique SESI features and 374 unique PTR features. Hypotheses to explain the observed mass-dependent differences are proposed

    Simulation of thermal plant optimization and hydraulic aspects of thermal distribution loops for large campuses

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    Following an introduction, the author describes Texas A&M University and its utilities system. After that, the author presents how to construct simulation models for chilled water and heating hot water distribution systems. The simulation model was used in a $2.3 million Ross Street chilled water pipe replacement project at Texas A&M University. A second project conducted at the University of Texas at San Antonio was used as an example to demonstrate how to identify and design an optimal distribution system by using a simulation model. The author found that the minor losses of these closed loop thermal distribution systems are significantly higher than potable water distribution systems. In the second part of the report, the author presents the latest development of software called the Plant Optimization Program, which can simulate cogeneration plant operation, estimate its operation cost and provide optimized operation suggestions. The author also developed detailed simulation models for a gas turbine and heat recovery steam generator and identified significant potential savings. Finally, the author also used a steam turbine as an example to present a multi-regression method on constructing simulation models by using basic statistics and optimization algorithms. This report presents a survey of the author??s working experience at the Energy Systems Laboratory (ESL) at Texas A&M University during the period of January 2002 through March 2004. The purpose of the above work was to allow the author to become familiar with the practice of engineering. The result is that the author knows how to complete a project from start to finish and understands how both technical and nontechnical aspects of a project need to be considered in order to ensure a quality deliverable and bring a project to successful completion. This report concludes that the objectives of the internship were successfully accomplished and that the requirements for the degree of Degree of Engineering have been satisfied

    Ammonium and non-sea salt sulfate in the EPICA ice cores as indicator of biological activity in the Southern Ocean

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    Sulfate (SO42-) and ammonium (NH4+) flux records over the last 150,000 years from both Antarctic EPICA ice cores (European Project for Ice Coring in Antarctica) are presented. The ice core record from Dome C is influenced by the Indian sector of the Southern Ocean (SO), whereas Dronning Maud Land is facing the Atlantic sector. Generally, they reflect the past atmospheric aerosol load and, thus, potentially reveal the fingerprint of marine biogenic sources from the SO. The most important feature of both, the nssSO42- as well as NH4+ flux records, is the absence of any significant glacial cycles, in contrary to the distinct transitions for mineral dust and sea salt aerosol over the last 150,000 years. This finding challenges the iron fertilization hypothesis on long time scales, as the significant changes in dust, e.g. from the last glacial maximum toward the Holocene have neither an impact on nssSO42- nor on NH4+ fluxes found in interior Antarctica. The inter-site correlation of both species is weak, r2 = 0.42 for the nssSO42- flux and r2 = 0.12 for the NH4+ flux respectively, emphasizing the local source characteristics of biogenic aerosol from the SO. Millennial variability in NH4+ and nssSO42- is within the uncertainty of our flux estimates. Correlation with mineral dust and sea ice derived sodium shows only a very weak influence of dust deposition on those insignificant changes in nssSO42- flux for the Atlantic sector of the Southern Ocean, but also small transport changes or terrigeneous sulfate contributions may contribute to those variations at EDML. © 2009 Elsevier Ltd. All rights reserved

    Intern experience at CH���M Hill, Inc.: an internship report

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    Includes author's vita"Submitted to the College of Engineering of Texas A&M University in partial fulfillment of the requirement for the degree of Doctor of Engineering."Includes bibliographical referencesA review of the author's internship experience with CH���M HILL, Inc. during the period September 1975 through May 1976 is presented. During this nine month internship the author worked as an Engineer II in the Industrial Processes discipline of this large consulting engineering firm... The author's prime responsibility was as one of three lead design engineers on the design of a large wastewater treatment facility for a pulp mill in Hoquiam, Washington owned by ITT Rayonier Inc. The work generally consisted of the design of individual treatment units and associated piping and pumping. The purpose of the project was to provide wastewater treatment capabilities that would satisfy the effluent limitations (standards) imposed upon the mill by the State of Washington Department of Ecology and the U.S. Environmental Protection Agency. The author's assignment also entailed necessary interaction with the project manager and other CH���M HILL design engineers and support staff members, the client's representatives, and representatives of two other consulting engineering firms working on the project. Thus, the internship position at CH���M HILL provided considerable experience coordinating the author's work with the work of other engineers, guiding the design and administrative efforts of a support staff, and interacting regularly with the client and other consulting firms. This broad exposure to a variety of engineering and organizational problems provided a valuable educational experience
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