6,929 research outputs found

    Cavitation Inception in Spool Valves

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    Cavitation has been investigated in directional control valves in order to identify damage mechanisms characteristic of components of aircraft hydraulic systems. Tests have been conducted in a representative metal spool valve and in a model three times larger. Data taken under noncavitating conditions with both valves showed that the position of the high-velocity annular jet shifts orientation, depending upon valve opening and Reynolds number. By means of high-frequency response pressure transducers strategically placed in the valve chamber cavitation could be sensed by the correlation of noise with a cavitation index. The onset of cavitation can be detected by comparing energy spectra for a fixed valve opening and a constant discharge. Another sensitive indicator of cavitation inception is the ratio of cavitating to noncavitating spectral densities. The incipient cavitation number as defined in this investigation is correlated with the Reynolds number for both valves

    NFAT5 genes are part of the osmotic regulatory system in Atlantic salmon (Salmo salar)

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    Acknowledgements This study was supported by a grant from the Biotechnology and Biological Sciences Research Council (BBSRC, BB/H008063/1), UK to DGH and SAM. Funding also came from Research Council Norway for project number 241016 for DGH and EJ. This work was carried out as part of a PhD thesis funded by the Marine Alliance of Science and Technology Scotland (MASTS).Peer reviewedPublisher PD

    A Comparison of the Merger and Acquisition Provisions of Present Law with the Provisions in the Senate Finance Committee\u27s Draft Bill

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    Mr. Thompson presents a detailed comparison of the corporate merger and acquisition provisions of present law with the changes proposed by the Senate Finance Committee Staff Report and the Draft Bill, prepared by the Senate Finance Committee staff. Professor Ginsburg attempts to illustrate how the changes proposed by the SFC Report do not resolve many of the more sophisticated problems generated by use of multiple corporations and selective acquisitions of some of the target\u27s assets or stocks. Professor Ginsburg argues that the rules work well in the unreal world of one corporation operating one business, but not in the real world of multiple commonly controlled entities. He provides several examples of corporations that operate through affiliates that may end up with results not necessarily by the proposed changes

    Immune responses to prebiotics in farmed salmonid fish : How transcriptomic approaches help interpret responses

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    Funding This work was supported by the University of Aberdeen and Skretting Ltd. Open access via Elsevier agreementPeer reviewedPublisher PD

    Bridging the social and the biomedical: engaging the social and political sciences in HIV research

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    This supplement to the Journal of the International AIDS Society focuses on the engagement of the social and political sciences within HIV research and, in particular, maintaining a productive relationship between social and biomedical perspectives on HIV. It responds to a number of concerns raised primarily by social scientists, but also recognized as important by biomedical and public health researchers. These concerns include how best to understand the impact of medical technologies (such as HIV treatments, HIV testing, viral load testing, male circumcision, microbicides, and pre-and post-exposure prophylaxis) on sexual cultures, drug practices, relationships and social networks in different cultural, economic and political contexts. The supplement is also concerned with how we might examine the relationship between HIV prevention and treatment, understand the social and political mobilization required to tackle HIV, and sustain the range of disciplinary approaches needed to inform and guide responses to the global pandemic. The six articles included in the supplement demonstrate the value of fostering high quality social and political research to inform, guide and challenge our collaborative responses to HIV/AIDS

    Season of the year influences infection rates following total hip arthroplasty

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    To research the influence of season of the year on periprosthetic joint infections. METHODS We conducted a retrospective review of the entire Medicare files from 2005 to 2014. Seasons were classified as spring, summer, fall or winter. Regional variations were accounted for by dividing patients into four geographic regions as per the United States Census Bureau (Northeast, Midwest, West and South). Acute postoperative infection and deep periprosthetic infections within 90 d after surgery were tracked. RESULTS In all regions, winter had the highest incidence of periprosthetic infections (mean 0.98%, SD 0.1%) and was significantly higher than other seasons in the Midwest, South and West (P \u3c 0.05 for all) but not the Northeast (P = 0.358). Acute postoperative infection rates were more frequent in the summer and were significantly affected by season of the year in the West. CONCLUSION Season of the year is a risk factor for periprosthetic joint infection following total hip arthroplasty (THA). Understanding the influence of season on outcomes following THA is essential when risk-stratifying patients to optimize outcomes and reduce episode of care costs. Š The Author(s) 2017

    Amplitude- and phase-resolved nano-spectral imaging of phonon polaritons in hexagonal boron nitride

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    Phonon polaritons are quasiparticles resulting from strong coupling of photons with optical phonons. Excitation and control of these quasiparticles in 2D materials offer the opportunity to confine and transport light at the nanoscale. Here, we image the phonon polariton (PhP) spectral response in thin hexagonal boron nitride (hBN) crystals as a representative 2D material using amplitude- and phase-resolved near-field interferometry with broadband mid-IR synchrotron radiation. The large spectral bandwidth enables the simultaneous measurement of both out-of-plane (780 cm-1) and in-plane (1370 cm-1) hBN phonon modes. In contrast to the strong and dispersive in-plane mode, the out-of-plane mode PhP response is weak. Measurements of the PhP wavelength reveal a proportional dependence on sample thickness for thin hBN flakes, which can be understood by a general model describing two-dimensional polariton excitation in ultrathin materials

    The Ursinus Weekly, March 8, 1965

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    Freshmen women receive UC colors, learn meaning in 35th annual observance • William James scholar to speak in faculty Forum • Faculty agrees to publish next Weekly issue • Carousel features queen and court, Cub and Key seven: Fine decorations, Al Raymond band add to evening • Psych Club hears Phila. social worker • Two seniors win electrochemical scholarships • Students produce House hearing on Watkins case • 33 men join fraternities: Five frats bid • Applications urged for political internship plan • Track notice • Editorial: Fraternity rushing • Red China today: Still growing • Letters to the editor • Book review: Good grief, it\u27s Candy • Snellbelles smash East Stroudsburg 63-48, return match no match: Regester, Kohn lead offense with 38; Day, Smiley control defensive boards • Wrestlers end, tie last match • Fircroft takes the field; Spring finds us ready • UC grad presents flag flown over South Pole • UC student lectures to DAR • Advice column • Dean\u27s listhttps://digitalcommons.ursinus.edu/weekly/1242/thumbnail.jp

    Studies of a Lacustrine-Volcanic Mars Analog Field Site with Mars-2020-like Instruments

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    On the upcoming Mars‐2020 rover two remote sensing instruments, Mastcam‐Z and SuperCam, and two microscopic proximity science instruments, SHERLOC and PIXL, will collect compositional (mineralogy, chemistry, and organics) data essential for paleoenvironmental reconstruction. The synergies between and limitations of these instruments were evaluated via study of a Mars analog field site in the Mojave Desert, using instruments approximating the data that will be returned by Mars‐2020. A ground truth dataset was generated for comparison to validate the results. The site consists of a succession of clay‐rich mudstones of lacustrine origin, interbedded tuffs, a carbonate‐silica travertine deposit, and gypsiferous mudstone strata. The major geological units were mapped successfully using simulated Mars‐2020 data. Simulated Mastcam‐Z data identified unit boundaries and Fe‐bearing weathering products. Simulated SuperCam passive shortwave infrared and green Raman data were essential in identifying major mineralogical composition and changes in lacustrine facies at distance; this was possible even with spectrally downsampled passive IR data. LIBS and simulated PIXL data discriminated and mapped major element chemistry. Simulated PIXL revealed mm‐scale zones enriched in zirconium, of interest for age dating. SHERLOC‐like data mapped sulfate and carbonate at sub‐mm scale; silicates were identified with increased laser pulses/spot or by averaging of hundreds of spectra. Fluorescence scans detected and mapped varied classes of organics in all samples, characterized further with follow‐on spatially targeted deep‐UV Raman spectra. Development of dedicated organics spectral libraries is needed to aid interpretation. Given these observations, the important units in the outcrop would be sampled and cached for sample return

    Composition of uroliths in a tertiary hospital in South East Nigeria

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    Background: Urolithiasis affects primarily the urinary tract and complications as debilitating as renal failure may develop. Determining the chemical composition of uroliths can aid management and prevention of recurrence in patients.Objective: To determine the chemical composition and anatomical distribution of uroliths in Nigeria.Methods: This descriptive cross-sectional study was conducted between March 2014 and February 2016, in a tertiary hospital in Nigeria. We reviewed the outcomes of uroliths of adult patients sent to our laboratory for chemical analyses. Samples were analyzed using simple qualitative tests.Results: 52 adult patients were included with a mean age (SD) of 46.6 (12.6) years. Males (76.9%) were more affected than females (23.1%). For both sexes, highest occurrence of stones was in bladder (85.7%). Calcium-containing stones had the highest occurrence (85.2%) and predominated in the renal, ureter and urethra, followed by struvite stones (59.5%). In the bladder, struvite stones were predominant (85.8%), with calcium-containing stones accounting for 71.4%.Conclusion: This study showed that struvite and calcium phosphate-containing stones constitute majority of uroliths in our setting with low occurrence of calcium oxalate stones. This indicates that urinary tract infection most likely plays a substantial role in the formation of uroliths in Nigerians. Modern methods of stone analysis is advocated to further define management options.Keywords: Uroliths, calcium oxalate, chemical composition, struvite, stone, calculi
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