1,430 research outputs found

    CARS Temperature Measurements in a Hypersonic Propulsion Test Facility

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    Nonintrusive diagnostic measurements were performed in the supersonic reacting flow of the Hypersonic Propulsion Test Cell 2 at NASA-Langley. A Coherent Anti-stokes Raman Spectroscopy (CARS) system was assembled specifically for the test cell environment. System design considerations were: (1) test cell noise and vibration; (2) contamination from flow field or atmospheric borne dust; (3) unwanted laser or electrically induced combustion (inside or outside the duct); (4) efficient signal collection; (5) signal splitting to span the wide dynamic range present throughout the flow field; (6) movement of the sampling volume in the flow; and (7) modification of the scramjet model duct to permit optical access to the reacting flow with the CARS system. The flow in the duct was a nominal Mach 2 flow with static pressure near one atmosphere. A single perpendicular injector introduced hydrogen into the flow behind a rearward facing step. CARS data was obtained in three planes downstream of the injection region. At least 20 CARS data points were collected at each of the regularly spaced sampling locations in each data plane. Contour plots of scramjet combustor static temperature in a reacting flow region are presented

    Selecting and preparing seed corn.

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    The following circular has been prepared in answer to the many letters which are being received daily asking for information regarding the purchasing and testing of seed corn and its preparation for planting. When we consider that more than nine million acres, considerably over one-fourth of the entire area of the state, will be planted to corn the coming season and that it will require more than 1,300,000 bushels of seed to plant this area; and when we realize that the character of the seed, its vitality, breeding, purity, adaptability to the soil and climate and uniformity in both size and shape of kernels, all exercise a great influence on the future yield, the great importance of paying the closest attention to the testing and the preparation of the seed corn for the planter cannot be over estimated

    Extended Debridement and Skin Graft as Local Treatment of Cobra Snake Bite Injury: A Case Report

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    Snakebite is a serious issue in rural areas of developing countries as Uganda. In children above all snakebite seems to be more common. Availability of anti-venoms is very poor. Local tissue damage caused by snake venom, either cytotoxic or necrotic, can continue even after systemic crisis has expired. We report the case of a 5 years old male child, born in Kitgum district, Northern Uganda, carried in hospital for a Cobra snake bite on the right foot who could not receive anti-venom. Debridement of the bite site, wound lavage, amputation and skin graft were required. Progression of the local infection associated to the reappearance of high fever induced us to bring the debridement up to the leg almost at the level of the knee in order to prevent unset of tibial Osteomyelitis and to be able to perform skin grafting.Keywords: Snakebite, Cobra, surgical treatment, debridement, skin graft, osteomyeliti

    Effectiveness of a workshop-based intervention to reduce bullying and violence at work: A 2-year quasi-experimental intervention study

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    INTRODUCTION: Bullying and violence at work are associated with reduced wellbeing of the victims, but few evidence-based interventions are available to prevent these offensive behaviours. We developed and examined the effectiveness of an intervention aimed at prevention of bullying and violence at work through modifications in psychosocial work environment. METHODS: In accordance with pre-published protocol, employees and supervisors of 12 work units in 3 cities (intervention group A: n = 315; intervention group B: n = 271) received a workshop-based intervention on organizational practices to prevent bullying and violence, including supervisor support, supervisor justice, workplace social capital, and psychological safety and were compared to a reference group (n = 2310) which did not receive the intervention. Latent change score modelling (LCSM) was used to estimate between- and within-individual differences in changes of organizational practices and prevalence of bullying and violence from baseline (2020) to follow-up (2022). RESULTS: No direct or indirect effects of intervention were observed. Of the potential mediator variables, supervisor support (B = 0.04; 95% confidence interval 0.006, 0.07) and supervisor justice (0.04; 0.01, 0.08) improved in the intervention group B between the measurements and compared to control group, but the result was not replicated in intervention group A. No changes were observed between the measurement points in bullying or violence at work. CONCLUSIONS: No intervention effects on bullying and violence at work were observed. It may be worthwhile to develop the intervention further to focus more on supervisor and co-worker relationships and on psychosocial resources of work team

    Challenges and solutions in determining dilution ratios and emission factors from chase measurements of passenger vehicles

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    Vehicle chase measurements used for studying real-world emissions apply various methods for calculating emission factors. Currently available methods are typically based on the dilution of emitted carbon dioxide (CO2) and the assumption that other emitted pollutants dilute similarly. A problem with the current methods arises when the studied vehicle is not producing CO2, e.g. during engine-motoring events, such as on downhill sections. This problem is also encountered when studying non-exhaust particulate emissions, e.g. from electric vehicles. In this study, we compare multiple methods previously applied for determining the dilution ratios. Additionally, we present a method applying multivariate adaptive regression splines and a new method called near-wake dilution. We show that emission factors for particulate emissions calculated with both methods are in line with the current methods for vehicles producing CO2. In downhill sections, the new methods were more robust to low CO2 concentrations than some of the current methods. The methods introduced in this study can hence be applied in chase measurements with changing driving conditions and be possibly extended to estimate non-exhaust emissions in the future.</p

    LaparostomicTreatment of Diffuse Peritonitis in Northern Uganda

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    No Abstract. Keywords: Bacterial infection, Diagnosis; Surgery, laparostomy, laparostomic treatment, peritonitis, uterine perforation, second look

    Genetic Variation Among Populations of River Otters in North America: Considerations For Reintroducing Projects

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    Horizontal starch gel electrophoresis was used to assess variability at 23 presumptive gene loci of 732 river otters obtained from fur-trappers in 18 states and three Canadian provinces. States and provinces providing otters were sorted into eight geographic regions for genetic comparisons. Multilocus heterozygosity and polymorphism ranged from 0.018 to 0.032 and 0.044 to 0.087, respectively. One locus, esterase-2, (EST-2) demonstrated a high level of polymorphism throughout all regions. Malate dehydrogenase-1 (MDH-1) was polymorphic throughout the Mississippi drainage but not elsewhere. Heterozygosity, occurrence of rare alleles, and mean number of alleles per locus were associated positively with estimated population sizes. Average heterozygosity and polymorphism values for otters within regions were lower than overall averages reported for mammals but similar to the range of those observed in other mammalian carnivores. Patterns of gene flow suggested by the distribution of polymorphism at the MDH-1 locus do not concur with the current taxonomic classification of river otters. Levels of genetic variation detected in this investigation present a positive outlook for the maintenance of genetic diversity in river otter populations, if sound management principles are applied for reintroductions

    Measurement of the Resonant dμtd\mu t Molecular Formation Rate in Solid HD

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    Measurements of muon-catalyzed dt fusion (dμt→4He+n+μ−d\mu t \to ^4He+n+\mu^-) in solid HD have been performed. The theory describing the energy dependent resonant molecular formation rate for the reaction μt\mu t + HD →[(dμt)pee]∗\to [(d\mu t)pee]^* is compared to experimental results in a pure solid HD target. Constraints on the rates are inferred through the use of a Monte Carlo model developed specifically for the experiment. From the time-of- flight analysis of fusion events in 16 and 37 μg⋅cm−2\mu g\cdot cm^{-2} targets, an average formation rate consistent with 0.897±\pm(0.046)stat±_{stat}\pm (0.166)syst_{syst} times the theoretical prediction was obtained.Comment: 4 pages, 5 figure
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