9,267 research outputs found

    Mechanism of lubrication by tricresylphosphate (TCP)

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    The coefficient of friction was measured as a function of temperature on a pin-on-disk tribometer. Pins and disks of 440C and 52100 steels were lubricated with tricresylphosphate (TCP), 3.45 percent TCP in squalene, and pure squalene. The M-50 pins and disks were lubricated with 3.45 percent TCP in squalene and pure squalene. Experiments were conducted under limited lubrication conditions in dry ( 100 ppm H2O) air and dry ( pp H2O) nitrogen at 50 rpm (equivalent to a sliding velocity of 13 cm sec) and a constant load of 9.8 N (1 kg). Characteristic temperatures T sub r were identified for TCP on 52100 steel and for squalene on M-50 and 52100 steels, where the friction decreased because of a chemical reaction between the lubricant and the metal surface. The behavior of squalene obscured the influence of 3.45 percent TCP solute on the friction of the system. Wear volume measurements demonstrated that wear was lowest at temperatures just above T sub r. Comparing the behavior of TCP on M-50, 440C, and 52100 steels revealed that the TCP either reacted to give T sub r behavior or produced initial failure in the temperature range 223 + or - 5 C

    Stemming the Global Trade in Falsified and Substandard Medicines

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    Drug safety and quality is an essential assumption of clinical medicine, but there is growing concern that this assumption is not always correct. Poor manufacturing and deliberate fraud occasionally compromises the drug supply in the United States, and the problem is far more common and serious in low- and middle-income countries with weak drug regulatory systems. An Institute of Medicine consensus committee report identified the causes and possible solutions to the problem of falsified and substandard drugs around the world. The vocabulary people use to discuss the problem is itself a concern. The word counterfeit is often used innocuously to describe any drug that is not what it seems, but some NGOs and emerging manufacturing nations object to this term. These groups see hostility to generic pharmaceuticals in a discussion of counterfeit medicines. These groups see hostility to generic pharmaceuticals in a discussion of counterfeit medicines. Precisely speaking, a counterfeit drug infringes on a registered trademark, and trademark infringement in not necessarily a problem of public health consequence. Instead of talking broadly about counterfeit drugs, the WHO and other stakeholders should consider two main categories of drug quality problems. Falsified medicines misrepresent the product’s identity or source or both. Substandard drugs fail to meet the national specifications given in an accepted pharmacopeia or the manufacturer’s dossier. In practice, there is often considerable overlap between categories. There is considerable uncertainty about the size of the falsified and substandard drug market. Improved pharmacovigilance, especially in developing countries, give a better picture of the scope of the problem. In the United States, tighter regulatory controls on the wholesale market and a mandatory drug tracking system would improve drug safety. In developing countries, development finance organizations should invest in small- and medium-sized pharmaceutical manufacturers, and governments should use tools such as franchising, accreditation, low-interest loans, and task shifting to encourage private sector investment in drug retail. Finally, the WHO should work with stakeholders such as the UNODC and the WCO to develop an international code of practice on falsified and substandard drugs

    Effective Faculty Onboarding

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    New Academic Faculty face a deluge of new information when they arrive on campus. This is in addition to the stresses associated with a new campus environment, and for many the first position requiring completely independent planning and organization. Many faculty contribute career success or failure to successful and comprehensive support from colleagues from the very start of new positions. This workshop will require and assist all participants to develop an onboarding framework document that they can employ at their respective academic units/institutions. Topics to be discussed and included in such an onboarding guide include clear articulations of (1) Unit Mission and Goals (2) Structure (3) Guidelines for Research Centers and Clusters (4) Role of Heads/Associate Heads/Program Directors (5) Faculty governance and voting (6) Institute/College and Unit Committees and committee assignments (7) Curriculum Committee, Course Proposals and Development (8) Academic Actions: Probations and Suspensions, policies on incomplete grades and grade disputes, (9) Policies on Academic Integrity and Dishonesty, (10) Faculty Availability/Office Hours, (11) Lab Safety - Training/Disposal Information, (12) External Grant Proposal Process and Development, (13) Academic Advising, (14) Syllabus construction/examination scheduling and re-scheduling, (15) Degree Audits and registration for graduation, (15) Faculty positions, ranks, contracts, workloads, evaluations, mid-tenure review, tenure review, promotion criteria, (16) Institutional (internal) grants, (17) Publication and Page Charge policies, (18) Teaching buyout and overloads, (19) Institutional hiring and employment policies, (20) Space Policies, (21) computer/software and technology support policies, (22) Travel policies, (23) Class size guidelines, and (24) Purchasing policies

    Estimation of Weapon Yield from Inversion of Dose Rate Contours

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    This research studies the uncertainty in yield estimation from inversion of dose rate contours. The Hazard Prediction and Assessment Capability (HPAC) and a simple FORTRAN95 based Fallout Deposition Code (FDC) are used to recreate dose rate contours from historic nuclear tests. Fallout footprints from six atomic tests are recreated using balloon wind soundings and high resolution mesoscale weather reanalysis data. Dose rate contour plots are created for different yields for a single set of weather conditions. Dose rate contours are compared to determine uncertainty in yield estimation from inversion of dose rate contour plots. Results of these dose rate recreations are compared to historical patterns found in the Defense Nuclear Agency\u27s (DNA) DNA 1251-1-EX Compilation of Local Fallout Data From Test Detonations 1945-1962 Extracted from DASA 1251. Recreated dose rate contours are compared against historic patterns using a Figure of Merit (FOM) developed from the Measure of Effectiveness (MOE) and the Normalized Absolute Difference (NAD) techniques. This research provides a method to estimate the minimum yield required to create a dose rate contour to within a factor of two. This research determined that use of ground zero balloon soundings and reanalysis winds thereafter allowed the most accurate recreation of historic dose rate contours

    On the spin modulated circular polarization from the intermediate polars NY Lup and IGRJ1509-6649

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    We report on high time resolution, high signal/noise, photo-polarimetry of the intermediate polars NY Lup and IGRJ1509-6649. Our observations confirm the detection and colour dependence of circular polarization from NY Lup and additionally show a clear white dwarf, spin modulated signal. From our new high signal/noise photometry we have unambiguously detected wavelength dependent spin and beat periods and harmonics thereof. IGRJ1509-6649 is discovered to also have a particularly strong spin modulated circularly polarized signal. It appears double peaked through the I filter and single peaked through the B filter, consistent with cyclotron emission from a white dwarf with a relatively strong magnetic field. We discuss the implied accretion geometries in these two systems and any bearing this may have on the possible relationship with the connection between polars and soft X-ray-emitting IPs. The relatively strong magnetic fields is also suggestive of them being polar progenitors.Comment: 8 pages, 6 figures and 1 table. Accepted for publication in MNRA

    Particle methods for a virtual patient

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    The particle systems approach is a well known technique in computer graphics for modelling fuzzy objects such as fire and clouds. The algorithm has also been applied to different biomedical applications and this paper presents two such methods: a charged particle method for soft tissue deformation with integrated haptics; and a blood flow visualization technique based on boids. The goal is real time performance with high fidelity results

    The Irish grey partridge conservation strategy: an update 1995-1998.

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    KAVANAGH, B.P., O\u27GORMAN,C.,AND BUCKLEY, C.: THE IRISH GREY PARTRIDGE (PERDIX PERDIX) CONSERVATION STRATEGY: AN UPDATE 1995-1998.In May 1996 a strategy for the conservation of the last remaining population of the Irish Grey partridge was initiated. The strategy is a multipronged approach based on a) predation reduction, b) habitat improvement and c) monitoring of the birds’ response. A full-time game keeper was employed to reduce red fox (Vulpes vulpes), mink (Mustella vison), stoat (Mustella erminea), rat (Rattus norvegicus), grey crow (Corvus corone cornix)and magpie (Pica pica) numbers in a defined study area of 1,000 hectares of cutaway bog at Boora in County Offaly. The habitatis a mozaic of cutaway bogland, conferous forestry, newly created farmland and wetland. The area contianed 6-8 pairs of breeding grey partridge in spring 1996. Bare peat areas within the study area were selected and a mix of either grasser or grains were planted in 0,2 hectare blocks to provide nesting or chick rearing cover for birds. These plots were neither sprayed or harvested and have been left to develop naturally after planting. Fifteen hectares were planted over two years, 1996-97. In spring 1997 a number of male partridges were trapped and fitted with radio collars. Their home range and habitat preferences were recorded continuously for up to ten months. Radio-tracked birds were recorded leaving the keepered area and moving to winter stubble fields on adjoining farmland. Two successful coveys were produced in 1996 which resulted in a autumn count of 27 partridges in the study area. In spring 1997 the population in the study area was again 6-8 pairs. Two successful coveys were again produced in 1997 giving an autumn population was 23 birds within the study area. Winter survival in 1997/98 was poor. In spring 1998 only 4-6 pairs of partridges were found in the study area. Partridge numbers continue to decline both within and outside the study area. The remaining population is now less than 20 breeding pairs in total

    Transposable elements maintain genome-wide heterozygosity in inbred populations.

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    Elevated levels of inbreeding increase the risk of inbreeding depression and extinction, yet many inbred species are widespread, suggesting that inbreeding has little impact on evolutionary potential. Here, we explore the potential for transposable elements (TEs) to maintain genetic variation in functional genomic regions under extreme inbreeding. Capitalizing on the mixed mating system of Arabidopsis lyrata, we assess genome-wide heterozygosity and signatures of selection at single nucleotide polymorphisms near transposable elements across an inbreeding gradient. Under intense inbreeding, we find systematically elevated heterozygosity downstream of several TE superfamilies, associated with signatures of balancing selection. In addition, we demonstrate increased heterozygosity in stress-responsive genes that consistently occur downstream of TEs. We finally reveal that TE superfamilies are associated with specific signatures of selection that are reproducible across independent evolutionary lineages of A. lyrata. Together, our study provides an important hypothesis for the success of self-fertilizing species

    Computational requirements of the virtual patient

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    Medical visualization in a hospital can be used to aid training, diagnosis, and pre- and intra-operative planning. In such an application, a virtual representation of a patient is needed that is interactive, can be viewed in three dimensions (3D), and simulates physiological processes that change over time. This paper highlights some of the computational challenges of implementing a real time simulation of a virtual patient, when accuracy can be traded-off against speed. Illustrations are provided using projects from our research based on Grid-based visualization, through to use of the Graphics Processing Unit (GPU)

    Validation of an Automated Body Condition Scoring System Using 3D Imaging

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    peer-reviewedBody condition scores (BCS) measure a cow’s fat reserves and is important for management and research. Manual BCS assessment is subjective, time-consuming, and requires trained personnel. The BodyMat F (BMF, Ingenera SA, Cureglia, Switzerland) is an automated body condition scoring system using a 3D sensor to estimate BCS. This study assesses the BMF. One hundred and three Holstein Friesian cows were assessed by the BMF and two assessors throughout a lactation. The BMF output is in the 0–5 scale commonly used in France. We develop and report the first equation to convert these scores to the 1–5 scale used by the assessors in Ireland in this study ((0–5 scale × 0.38) + 1.67 → 1–5 scale). Inter-assessor agreement as measured by Lin’s concordance of correlation was 0.67. BMF agreement with the mean of the two assessors was the same as between assessors (0.67). However, agreement was lower for extreme values, particularly in over-conditioned cows where the BMF underestimated BCS relative to the mean of the two human observers. The BMF outperformed human assessors in terms of reproducibility and thus is likely to be especially useful in research contexts. This is the second independent validation of a commercially marketed body condition scoring system as far as the authors are aware. Comparing the results here with the published evaluation of the other system, we conclude that the BMF performed as well or better
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