747 research outputs found
Analytic models of ducted turbomachinery tone noise sources. Volume 2: Subprogram documentation
Analytical models were developed for computing the periodic sound pressures of subsonic fans in an infinite hardwall annular duct with uniform flow. The computer programs are described which are used for numerical computations of sound pressure mode amplitudes. The data are applied to the acoustic properties of turbomachinery
Analytic models of ducted turbomachinery tone noise sources. Volume 1: Analysis
The analytic models developed for computing the periodic sound pressure of subsonic fans and compressors in an infinite, hardwall annular duct with uniform flow are described. The basic sound-generating mechanism is the scattering into sound waves of velocity disturbances appearing to the rotor or stator blades as a series of harmonic gusts. The models include component interactions and rotor alone
Analytic models of ducted turbomachinery tone noise sources. Volume 3: Program test case results
Computer programs for analyzing the acoustic properties of turbomachinery with ducted flow were developed. The models include component interactions and rotor alone. Test case results determined from the computer programs are presented
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STONE 6: Artificial Sedimentary Meteorites in Space
The STONE 6 experiment demonstrated the survivability of carbonaceous and microfossiliferous martian analogue sediments during atmospheric re-entry. Doped endoliths died but their carbonised cells remained
Psychometric and biomedical outcomes of glycated haemoglobin target-setting in adults with type 1 and type 2 diabetes:Protocol for a mixed-methods parallel-group randomised feasibility study
BACKGROUND: The disease burden of diabetes can have wide-ranging implications on patients’ psychological well-being and health-related quality of life. Glycated haemoglobin targets are commonly used to guide patient management in diabetes to reduce the future risk of developing diabetes complications, but little is known of the psychological impact of glycated haemoglobin target-setting. This protocol describes a study to determine the feasibility of evaluating psychological outcomes when setting explicit glycated haemoglobin targets in people with diabetes. METHODS: This single-centre randomised feasibility study will follow a mixed-methods approach across four sub-studies. In sub-study A, eligible adults (aged 18 and over) with type 1 or type 2 diabetes will complete baseline validated psychometric questionnaires evaluating health-related quality of life (EuroQoL-5D-5L), diabetes-related distress (Problem Areas In Diabetes), self-care (Summary of Diabetes Self-Care Activities), well-being (Well-Being Quetionnaire-12) and diabetes-related psychosocial self-efficacy (Diabetes Empowerment Scale-Long Form). Participants will be randomised to receive explicit glycated haemoglobin intervention targets 5mmol/mol above or below current glycated haemoglobin readings. Rates of eligibility, recruitment, retention and questionnaire response rate will be measured. Psychometric outcomes will be re-evaluated 3-months post-intervention. Sub-studies B and C will use qualitative semi-structured interviews to evaluate experiences, views and opinions of diabetes patients and healthcare professionals in relation to the acceptability of study processes, the use of glycated haemoglobin targets, the impact of diabetes on psychological well-being and, in sub-study D, barriers to participation in diabetes research. DISCUSSION: This mixed-methods study aims to provide a novel insight into the psychological implications of glycated haemoglobin target-setting for people with diabetes in secondary care, alongside testing the feasibility of undertaking a larger project of this nature. TRIAL REGISTRATION: The study is registered with the ISRCTN (registration number: 12461724; date registered: 11(th) June 2021). Protocol version: 2.0.5, 26(th) February 2021
The European Space Analogue Rock Collection (ESAR) at the OSUC-Orleans for in situ planetary missions
International audienceThe ESAR is a collection of well-characterised planetary analogue rocks and minerals that can be used for testing in situ instrumentation for planetary exploration. An online database of all relevant structural, compositional and geotechnics information is also available to the instrument teams and to aid data interpretation during missions
On biosignatures for Mars
In this work, we address the difficulty of reliably identifying traces of life on Mars. Several independent lines of evidence are required to build a compelling body of proof. In particular, we underline the importance of correctly interpreting the geological and mineralogical context of the sites to be explored for the presence of biosignatures. We use as examples to illustrate this, ALH84001 (where knowledge of the geological context was very limited) and other terrestrial deposits, for which this could be properly established. We also discuss promising locations and formations to be explored by ongoing and future rover missions, including Oxia Planum, which, dated at 4.0 Ga, is the most ancient Mars location targeted for investigation yet
Microbial Contamination of Allende and Murchison Carbonaceous Chondrites; Developing a Protocol for Life Detection in Extraterrestrial Materials Using Biotechnology
The arguments used to refute the McKay et al., (1996) hypothesis of possible Martian life in ALH84001 failed to use contamination of the meteorite as a source. This has worrying implications for our ability to detect terrestrial microbiota in meteorites and therefore any potential extraterrestrial biosignatures in both meteorites and possible returned samples. We report on imaging and microbial culturing of both Allende and Murchison carbonaceous chondrites and on the use of molecular biology techniques on a sample of Allende. Contaminating fungi and bacteria were observed (in the case of Murchison) and cultured from both meteorites. DNA was successfully extracted and subsequent PCR showed the presence of both bacterial and fungal DNA although no Archaea were detected. These results show that it is possible to use molecular biological techniques on very small quantities (300 mg) of extraterrestrial material
Habitability on Early Mars and the Search for Biosignatures with the ExoMars Rover
The second ExoMars mission will be launched in 2020 to target an ancient location interpreted to have strong
potential for past habitability and for preserving physical and chemical biosignatures (as well as abiotic/prebiotic
organics). The mission will deliver a lander with instruments for atmospheric and geophysical investigations and a
rover tasked with searching for signs of extinct life. The ExoMars rover will be equipped with a drill to collect
material from outcrops and at depth down to 2 m. This subsurface sampling capability will provide the best chance
yet to gain access to chemical biosignatures. Using the powerful Pasteur payload instruments, the ExoMars
science team will conduct a holistic search for traces of life and seek corroborating geological context information.
Key Words: Biosignatures—ExoMars—Landing sites—Mars rover—Search for life. Astrobiology 17, 471–510
Rodenticide Exposure Among Endangered Kit Foxes Relative to Habitat Use in an Urban Landscape
Endangered San Joaquin kit foxes (Vulpes macrotis mutica) inhabiting Bakersfield, California exhibit a high incidence of exposure to anticoagulant rodenticides (ARs). We examined kit fox habitat use in an effort to determine potential sources of AR exposure. Kit fox capture, den, night, and mortality locations were assigned to one of 10 habitat categories. Using all available locations, foxes that tested positive for second generation anticoagulant rodenticides (SGARs) were located more frequently on golf courses while those testing negative were located more frequently in commercial areas. Foxes that tested positive for first generation anticoagulant rodenticides (FGARs) were located more frequently in industrial areas while those testing negative were located more frequently on golf courses. Based on night locations (when foxes are foraging), foxes that tested positive for SGARs were found more frequently in undeveloped and golf course habitats. Foxes that tested positive for FGARs were found more frequently in undeveloped, campus, and industrial habitats. Although available data were not sufficient to identify specific point-sources of AR exposure for foxes, golf courses appeared to be used more frequently by foxes exposed to SGARs. However, sources of exposure likely are abundant and widespread in the urban environment. Based on the results of this study, we recommend (1) investigating patterns of AR use in Bakersfield, (2) conducting an outreach program to emphasize the risk from ARs to kit foxes and other wildlife, and (3) continuing to monitor the incidence and patterns of AR exposure among kit foxes in Bakersfield
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