196,060 research outputs found

    Production, characterization and biotechnological potential of lipopeptide biosurfactants from a novel marine Bacillus stratosphericus strain FLU5

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    This work aimed at studying the potential of a new hydrocarbonoclastic marine bacterium, Bacillus stratosphericus FLU5, to produce an efficient surface-active agent BS-FLU5. Biosurfactant production was examined on different carbon sources; using the surface tension measurement and the oil displacement test. Strain FLU5 showed its capacity to produce biosurfactants from all tested substrates, in particular the residual frying oil, which is a cheap renewable carbon source alternative, thus minimizing the high cost of producing those surfactants. MALDI-TOF MS/MS analysis confirmed the presence of lipopeptides, which are identified as members of surfactin and pumilacidin series. The critical micelle concentration (CMC) of the purified lipopeptides produced by strain FLU5 was 50 mg/l. At this concentration, the surface tension of the water was reduced from 72 to 28 mN/m. Furthermore, the crude lipopeptides showed an interesting stability against a broad range of pH, temperature and salinity. In addition, the application of BS-FLU5 in oil recovery from hydrocarbons-contaminated soil (used motor oil) showed that it was more effective on the hydrocarbon-remobilization than some tested synthetic surfactants. Interestingly, the biosurfactant BS-FLU5 showed a negligible cytotoxic effect against the mammalian cells HEK293. These results highlight the applicability of the lipopeptides BS-FLU5 in different fields, especially in environmental remediation processes

    Biodegradation of hydrocarbons and biosurfactants production by a newly halotolerant Pseudomonas sp. strain isolated from contaminated seawater

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    A strain NAPH6 of Pseudomonas aeruginosa, isolated from contaminated seawater taken from the fishing harbor of Sfax, Tunisia, was able to degrade almost completly the naphthalene (200 mg/l) and the aliphatic hydrocarbons of crude oil (1%, v/v), after 7 and 20 days of culture, respectively, at 30 g/l NaCl. Moreover, the isolated NAPH6 exhibited a notable potentiality to synthesize biological surfactants (BS-NAPH6) on inexpensive carbon sources. The Fourier Transform Infrared (FTIR) analysis suggested that BS-NAPH6 belonged to the glycolipid family. Besides, BS-NAPH6 displayed a high steadiness against a wide spectrum of pHs, temperatures and salinities. The treatment of human HEK293 cells by different concentrations of BS-NAPH6 displayed that this latter exhibited no cytotoxic effect at concentrations below 200 μg/mL. Furthermore, the application of BS-NAPH6 in hydrocarbons removal from polluted soil, demonstrated that it was more efficient than tested chemical surfactants. Interestingly, BS-NAPH6 highlighted a significant healing activity on the wound site in a rat model compared to a commercial cream. Due to their attractive biological properties, strain NAPH6 as well as its biosurfactant BS-NAPH6 are considered as promising candidates for various applications including environmental and biomedical ones

    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

    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

    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

    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

    Transition to turbulence in a qblique shock-wave/boundary-layer interaction at M=15

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    Direct numerical simulations are carried out for different forcing techniques to trigger transition during the interaction between an oblique shock-wave and a laminar boundary-layer at M = 1.5. Three forcing methods are used: a) forcing of oblique unstable modes, whose shape and behaviour are determined by the local linear stability theory, b) broadband free-stream acoustic disturbances, and c) a cold plasma flow control device. While the oblique-mode breakdown is dominant for low-amplitude forcing, long streaky structures drive the transition process in a high-amplitude disturbance environment. LES are also performed on the experimental setup by the Institute of Theoretical and Applied Mechanics (ITAM) from Novosibirsk State University with cold plasma actuation. As well as the disturbance type, the effect of Reynolds number and forcing amplitude will be investigated

    Letter from Cedrick M. Shimo to the Office of Redress Administration, June 4, 1991

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    A letter from Cedrick M. Shimo to the Office of Redress Administration arguing that John Y. Udaka is entitled to a redress payment.These materials are from box 73 and 74 of the Frank Chin Papers. The Frank Chin Papers contain personal and professional correspondence between Frank Chin and Michi Weglyn relating to particular projects on which either author was working as well as files related to the Day of Remembrance Tribute to Michi Weglyn
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