2,134 research outputs found
Studies of Neotropical caddisflies, XII: Rhyacophilidae, Glossosomatidae, Philopotamidae, and Psychomyiidae from the Amazon Basin (Trichoptera)
Based primarily on colleçtions of FITTKAU and MARLIER, adults of the Amazonian species in four families of Trichoptera are described and figured. Keys are provided to the Latin American families (except those exclusively Chilean), potentially Amazonian genera, and described species. Fifty-five species (of which 52 are described as new) are placed in the genera: Atopsyche (1 species), Antoptila (1 species), Protoptila (10 species), Wormaldia (1 species), Dolophilodes (1 species), Chimarra (8 species), Polyplectropus (4 species), Nyctiophylar (1 species), Cyrnellus (7 species), and Cernotína (21 species)
Documentation and Control of Flow Separation on a Low Pressure Turbine Linear Cascade of Pak-B Blades Using Plasma Actuators
This work involved the documentation and control of flow separation that occurs over low pressure turbine (LPT) blades at low Reynolds numbers. A specially constructed linear cascade was utilized to study the flow field over a generic LPT cascade consisting of Pratt & Whitney "Pak-B" shaped blades. Flow visualization, surface pressure measurements, LDV measurements, and hot-wire anemometry were conducted to examine the flow fields with and without separation control. Experimental conditions were chosen to give a range of chord Reynolds numbers (based on axial chord and inlet velocity) from 10,000 to 100,000, and a range of freestream turbulence intensities from u'/U(infinity) = 0.08 to 2.85 percent. The blade pressure distributions were measured and used to identify the region of separation that depends on Reynolds number and the turbulence intensity. Separation control was performed using dielectric barrier discharge (DBD) plasma actuators. Both steady and unsteady actuation were implemented and found to work well. The comparison between the steady and unsteady actuators showed that the unsteady actuators worked better than the steady ones. For the steady actuators, it was found that the separated region is significantly reduced. For the unsteady actuators, where the signal was pulsed, the separation was eliminated. The total pressure losses (a low Reynolds number) was reduced by approximately a factor of two. It was also found that lowest plasma duty cycle (10 percent in this work) was as effective as the highest plasma duty cycle (50 percent in this work). The mechanisms of the steady and unsteady plasma actuators were studied. It was suggested by the experimental results that the mechanism for the steady actuators is turbulence tripping, while the mechanism for the unsteady actuators is to generate a train of spanwise structures that promote mixing
Шляхи підвищення ефективності фінансово-господарської діяльності підприємства
Мета даної статті полягає в необхідності виробити заходи з підвищення ефективності фінансово-господарської діяльності підприємства (на прикладі Кримського республіканського підприємства «Виробниче підприємство водопровідно-каналізаційної галузі» м. Сімферополя)
Use of Plasma Actuators as a Moving-Wake Generator
The work documented in this report tests the concept of using plasma actuators as a simple and easy way to generate a simulated moving-wake and the disturbances associated with it in turbines. This wake is caused by the blades of the upstream stages of the turbine. Two types of devices, one constructed of arrays of NACA 0018 airfoils, and the one constructed of flat plates were studied. The airfoils or plates were equipped with surface mounted dielectric barrier discharge (DBD) plasma actuators, which were used to generate flow disturbances resembling moving-wakes. CTA hot-wire anemometry and flow visualization using a smoke-wire were used to investigate the wake independence at various spacings and downstream locations. The flat plates were found to produce better results than the airfoils in creating large velocity fluctuations in the free-stream flow. Different dielectric materials, plasma actuator locations, leading edge contours, angles of attack and plate spacings were investigated, some with positive results. The magnitudes of the velocity fluctuations were found to be comparable to existing mechanical moving-wake generators, thus proving the feasibility of using plasma actuators as a moving-wake generator
Polysaccharide utilization loci and nutritional specialization in a dominant group of butyrate-producing human colonic Firmicutes
Acknowledgements The Rowett Institute of Nutrition and Health (University of Aberdeen) receives financial support from the Scottish Government Rural and Environmental Sciences and Analytical Services (RESAS). POS is a PhD student supported by the Scottish Government (RESAS) and the Science Foundation Ireland, through a centre award to the APC Microbiome Institute, Cork, Ireland. Data Summary The high-quality draft genomes generated in this work were deposited at the European Nucleotide Archive under the following accession numbers: 1. Eubacterium rectale T1-815; CVRQ01000001–CVRQ0100 0090: http://www.ebi.ac.uk/ena/data/view/PRJEB9320 2. Roseburia faecis M72/1; CVRR01000001–CVRR010001 01: http://www.ebi.ac.uk/ena/data/view/PRJEB9321 3. Roseburia inulinivorans L1-83; CVRS01000001–CVRS0 100 0151: http://www.ebi.ac.uk/ena/data/view/PRJEB9322Peer reviewedPublisher PD
Unique Organization of Extracellular Amylases into Amylosomes in the Resistant Starch-Utilizing Human Colonic Firmicutes Bacterium Ruminococcus bromii
ACKNOWLEDGMENTS We acknowledge support from BBSRC grant no. BB/L009951/1, from the Scottish government Food, Land and People program, and from the Society for Applied Microbiology. E.A.B. is supported by a grant (no. 1349/13) from the Israel Science Foundation (ISF), Jerusalem, Israel, and by a grant from the United States-Israel Binational Science Foundation (BSF). E.A.B. is the incumbent of the Maynard I. and Elaine Wishner Chair of Bio-organic Chemistry. Thanks are due to Fergus Nicol for proteomic analysis and to Auriane Bernard for enzyme assays on stationary-phase cultures. We also thank Julian Parkhill and Keith Turner (Wellcome Trust Sanger Institute, Cambridge, United Kingdom) for making the R. bromii L2-63 genome sequence available for analysis.Peer reviewedPublisher PD
High Temperature Laser Sintering: An investigation into mechanical properties and shrinkage characteristics of Poly (Ether Ketone) structures
Copyright © 2014 Elsevier. NOTICE: this is the author’s version of a work that was accepted for publication in Materials and Design. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Materials and Design, Vol. 61 (2014). DOI: 10.1016/j.matdes.2014.04.035This paper presents an investigation into the properties of Poly Ether Ketone (PEK) components using the commercial high temperature laser sintering system, EOSINT P800. The shrinkage and the mechanical performance of components across the entire build chamber have been tested and a non-linear shrinkage profile has been obtained. The middle of the build chamber recorded the highest degree of shrinkage and the shrinkage in Z direction had the largest variation. The laser sintered components built in X and Y directions recorded a 10% lower tensile strength than the injection moulded samples of the same material where those built in the Z direction showed an approximately 50% decrease in strength in comparison with the injection moulded test specimens. The crystallinity between the skin and the core of the sintered samples was different; varied with the position within the build chamber and coincided with noticeable sample colour changes
Muon Simulations for Super-Kamiokande, KamLAND and CHOOZ
Muon backgrounds at Super-Kamiokande, KamLAND and CHOOZ are calculated using
MUSIC. A modified version of the Gaisser sea level muon distribution and a
well-tested Monte Carlo integration method are introduced. Average muon energy,
flux and rate are tabulated. Plots of average energy and angular distributions
are given. Implications on muon tracker design for future experiments are
discussed.Comment: Revtex4 33 pages, 16 figures and 4 table
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