37 research outputs found

    Instrumentation for measuring the dynamic pressure on rotating compressor blades

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    To establish the capability for measurement of oscillatory pressure on rotating blades, miniature fast response semiconductor strain gage pressure transducers (2mm x 0.33mm) were mounted in several configurations on thin titanium and steel compressor blades and subjected to pressure cycles from 1 to 310 kPa during static tests and spin tests. Static test conditions included 20 C to 150 C, 0 to 3000 tensile microstrain, -1000 to +1000 bending microstrain and + or - 650G vibration. The spin test conditions included 20 C to 82 C at 0 to 90,000G. Durability was excellent. Pressure transducer sensitivity changed by only a few percent over this range of environmental conditions. Noise signal due to oscillatory acceleration normal to the diaphragm was acceptable (0.33Pa/G). Noise signal due to oscillatory strain was acceptable (0.5 Pa/microstrain) when the transducer was mounted on a 0.05mm rubber pad, with a total buildup of 0.38mm on the measure surface. Back mounting or partial recessing to eliminate buildup, increased the strain effect to 1.2 Pa/microstrain. Flush mounting within the blade to eliminate buildup reduced the strain effect, but required development of a special transducer shape. This transducer was not available in time for spin tests. Unpredictable zero drift + or - 14 kPa ruled out the use of these mounting arrangements for accurate steady-state (D.C.) measurements on rotating blades. The two best configurations fully developed and spin tested were then successfully applied in the NAS3-20606 rotating fan flutter program for quantitative measurement of oscillatory pressure amplitudes

    Measuring unsteady pressure on rotating compressor blades

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    Miniature semiconductor strain gage pressure transducers mounted in several arrangements were studied. Both surface mountings and recessed flush mountings were tested. Test parameters included mounting arrangement, blade material, temperature, local strain in the acceleration normal to the transducer diaphragm, centripetal acceleration, and pressure. Test results show no failures of transducers or mountings and indicate an uncertainty of unsteady pressure measurement of approximately + or - 6 percent + 0.1 kPa for a typical application. Two configurations were used on a rotating fan flutter program. Examples of transducer data and correction factors are presented

    Management at the service of research: ReOmicS, a quality management system for omics sciences

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    Management and research represent a binomial almost unknown, whose potentialities and requirements have not yet been fully exploited even if, recently, the scientific and social communities have felt the burden of producing results and data requiring at the same time reproducibility, reliability, safety and efficacy of the discoveries, as well as a profitable use of resources. A Quality Management System (QMS) could represent a valid tool for these purposes, improving the quality of the research. The research community could ask whether and how it is possible to apply this approach in a research laboratory without hindering their creativity, and what the possible benefits might be. On the other hand, an international standard for a quality management system appropriate for a research laboratory is yet to come. The choice, the design and the application of a QMS, inspired by the Good Laboratory Practices, in a research laboratory specialized on “omics” sciences, is fully described in this paper. Its application has already shown good outcomes as testified by specific metric of efficiency and effectiveness. The approach is innovative as there is no obvious requirement for research laboratories to develop and define quality objectives. The paper highlights how the QMS approach enhances the relationship with public and private sectors by increasing customer confidence and loyalty, as well as improving the overall performance of the laboratory in terms of throughput and value of research. These results encourage proposing it as a QMS model providing a new and scalable operational strategy to be applied in a research environment with the same target and even in a generic research laboratory

    X-linked hypophosphatemic rickets: An Italian experts' opinion survey

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    Background: X-linked hypophosphatemic rickets (XLH) is the first cause of inherited hypophosphatemia and is caused by mutation in the PHEX gene, resulting in excessive expression of the phosphaturic factor FGF23. Symptoms are mainly related to rickets in children and osteomalacia in adults and cause several complications that can be highly invalidating. Due to its rarity, XLH is poorly known and diagnosis is frequently delayed. Conventional treatment is based on oral phosphate salts supplementation and activated vitamin D analogs, which however, cannot cure the disease in most cases. Objective: Due to the low prevalence of XLH, an experts' opinion survey was conducted across Italian centers to collect data on XLH and on its management. Methods: A questionnaire was developed by a group of experts to collect data on XLH epidemiology, diagnosis and treatment in Italy. Results: Data from 10 Italian centers (nine of which pediatric) on 175 patients, followed between 1998 and 2017, were included in the survey. Most patients were followed since childhood and 63 children became adults during the investigated period. The diagnosis was made before the age of 1 and between 1 and 5 years in 11 and 50% of cases, respectively. Clinically apparent bone deformities were present in 95% of patients. These were ranked moderate/severe in 75% of subjects and caused growth stunting in 67% of patients. Other frequent complications included bone pain (40%), dental abscesses (33%), and dental malpositions (53%). Treatment protocols varied substantially among centers. Nephrocalcinosis was observed in 34% of patients. Tertiary hyperparathyroidism developed in 6% of patients. Conclusions: XLH remains a severe condition with significant morbidities

    X-linked hypophosphatemic rickets: An Italian experts' opinion survey

    Get PDF
    Background X-linked hypophosphatemic rickets (XLH) is the first cause of inherited hypophosphatemia and is caused by mutation in the PHEX gene, resulting in excessive expression of the phosphaturic factor FGF23. Symptoms are mainly related to rickets in children and osteomalacia in adults and cause several complications that can be highly invalidating. Due to its rarity, XLH is poorly known and diagnosis is frequently delayed. Conventional treatment is based on oral phosphate salts supplementation and activated vitamin D analogs, which however, cannot cure the disease in most cases. Objective Due to the low prevalence of XLH, an experts\u2019 opinion survey was conducted across Italian centers to collect data on XLH and on its management. Methods A questionnaire was developed by a group of experts to collect data on XLH epidemiology, diagnosis and treatment in Italy. Results Data from 10 Italian centers (nine of which pediatric) on 175 patients, followed between 1998 and 2017, were included in the survey. Most patients were followed since childhood and 63 children became adults during the investigated period. The diagnosis was made before the age of 1 and between 1 and 5\u2009years in 11 and 50% of cases, respectively. Clinically apparent bone deformities were present in 95% of patients. These were ranked moderate/severe in 75% of subjects and caused growth stunting in 67% of patients. Other frequent complications included bone pain (40%), dental abscesses (33%), and dental malpositions (53%). Treatment protocols varied substantially among centers. Nephrocalcinosis was observed in 34% of patients. Tertiary hyperparathyroidism developed in 6% of patients. Conclusions XLH remains a severe condition with significant morbidities

    Strong Host-Feeding Preferences of the Vector Triatoma infestans Modified by Vector Density: Implications for the Epidemiology of Chagas Disease

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    Chagas disease is a complex zoonosis with more than 150 mammalian host species, nearly a dozen blood-sucking triatomine species as main vectors, and 9–11 million people infected with Trypanosoma cruzi (its causal agent) in the Americas. Triatoma infestans, a highly domesticated species and one of the main vectors, feeds more often on domestic animals than on humans in northern Argentina. The question of whether there are host-feeding preferences among dogs, cats, and chickens is crucial to estimating transmission risks and predicting the effects of control tactics targeting them. This article reports the first host choice experiments of triatomine bugs conducted in small huts under natural conditions. The results demonstrate that T. infestans consistently preferred dogs to chickens or cats, with host shifts occurring more frequently at higher vector densities. Combined with earlier findings showing that dogs have high infection rates, are highly infectious, and have high contact rates with humans and domestic bugs, our results reinforce the role of dogs as the key reservoirs of T. cruzi. The strong bug preference for dogs can be exploited to target dogs with topical lotions or insecticide-impregnated collars to turn them into baited lethal traps or use them as transmission or infestation sentinels
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