1,146 research outputs found

    Natural and Induced Environment around the International Space Station (ISS) as Observed during On-Orbit Operations of the Robotic External Leak Locator (RELL)

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    Final Document is attached. The Robotic External Leak Locator (RELL) was deployed to the International Space Station (ISS) with the goal of detecting and locating on-orbit leaks around the ISS. Three activities to investigate and corroborate the background natural and induced environment of ISS were performed with RELL as part of the on-orbit validation and demonstration conducted in November December 2016. The first demonstration activity pointed RELL directly in the ram and wake directions for one orbit each. The ram facing measurements showed high partial pressure for mass-to-charge ratio 16, corresponding to atomic oxygen (AO), as well as the presence of mass-to-charge ratio 17. RELLs view in the wake-facing direction included more ISS structure and several Environmental Control and Life Support System (ECLSS) on-orbit vents were detected, including the Carbon Dioxide Removal Assembly (CDRA), Russian segment ECLSS, and Sabatier vents. The second demonstration activity pointed RELL at three faces of the P1 Truss segment. Effluents from ECLSS and European Space Agency (ESA) Columbus module on-orbit vents were detected by RELL. The partial pressures of mass-to-charge ratios 17 and 18 remained consistent with the first on-orbit activity of characterizing the natural environment. The third demonstration activity involved RELL scanning an Active Thermal Control System (ATCS) radiator. Three locations along the radiator were scanned and the angular position of RELL with respect to the radiator was varied. Mass-to-charge ratios 16 and 17 both had upward shifts in partial pressure when pointing toward the Radiator Beam Valve Modules (RBVMs), likely corresponding to a known, small ammonia leak

    International Space Station (ISS) Environmental Control and Life Support System (ECLSS) Vent Flow Reflection and Detection by Robotic External Leak Locator (RELL)

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    On-orbit Robotic External Leak Locator (RELL) (i.e., mass spectrometer and ion gauge) measurements on the International Space Station (ISS) are presented to show the detection of recurring Environmental Control and Life Support System (ECLSS) vents at multiple ISS locations and RELL pointing directions. The path of ECLSS effluents to the RELL detectors is not entirely obvious at some locations, but the data indicates that diffuse gas-surface reflection or scattering resulting from plume interaction with vehicle surfaces is responsible. RELL was also able to confirm the ISS ECLSS constituents and distinguish them from the ammonia leak based on the ion mass spectra and known venting times during its operation to locate a leak in the ISS port-side External Active Thermal Control System (EATCS) coolant loop

    Natural and Induced Environment Around the International Space Station (ISS) as Observed During On-Orbit Operations of the Robotic External Leak Locator (RELL)

    Get PDF
    The Robotic External Leak Locator (RELL) was deployed to the International Space Station (ISS) with the goal of detecting and locating on-orbit leaks around the ISS. Three activities to characterize the background natural and induced environment of ISS were performed with RELL as part of the on-orbit validation and demonstration conducted in November and December 2016. The first demonstration activity pointed RELL directly in the ram (+X) and wake (-X) directions for one orbit each. The ram facing measurements showed high partial pressure for mass-to-charge ratio 16, corresponding to atomic oxygen (AO), as well as the presence of mass-to-charge ratio 17. RELL's view in the wake-facing direction included more ISS structure and several Environmental Control and Life Support System (ECLSS) on-orbit vents were detected, including the Carbon Dioxide Removal Assembly (CDRA), Russian segment ECLSS, and Sabatier vents. The second demonstration activity pointed RELL at three faces of the P1 Truss segment. Effluents from ECLSS and European Space Agency (ESA) Columbus module on-orbit vents were detected by RELL. The partial pressures of mass-to-charge ratios 17 and 18 remained consistent with the first on-orbit activity of characterizing the natural environment. The third demonstration activity involved RELL scanning an Active Thermal Control System (ATCS) radiator. Three locations along the radiator were scanned and the angular position of RELL with respect to the radiator was varied. Mass-to-charge ratios 16 and 17 both had upward shifts in partial pressure when pointing toward the Radiator Beam Valve Modules (RBVMs), likely corresponding to a known, small ammonia leak

    Impact of malaria during pregnancy on pregnancy outcomes in a Ugandan prospective cohort with intensive malaria screening and prompt treatment

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    Malaria in pregnancy (MiP) is a major public health problem in endemic areas of sub-Saharan Africa and has important consequences on birth outcome. Because MiP is a complex phenomenon and malaria epidemiology is rapidly changing, additional evidence is still required to understand how best to control malaria. This study followed a prospective cohort of pregnant women who had access to intensive malaria screening and prompt treatment to identify factors associated with increased risk of MiP and to analyse how various characteristics of MiP affect delivery outcomes

    Risk factors for mortality among children under 5 years of age with severe diarrhea in low- and middle-income countries: Findings from the WHO-coordinated Global Rotavirus and Pediatric Diarrhea Surveillance Networks.

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    BACKGROUND: Diarrhea is the second leading cause of death in children under five years of age globally. The burden of diarrheal mortality is concentrated in low-resource settings. Little is known about the risk factors for childhood death from diarrheal disease in low and middle-income countries. METHODS: Data from the WHO-coordinated Global Rotavirus and Pediatric Diarrhea Surveillance Networks, which are composed of active, sentinel, hospital-based surveillance sites, were analyzed to assess mortality in children less than five years of age who were hospitalized with diarrhea between 2008-2018. Case fatality risks were calculated, and multivariable logistic regression was performed to identify risk factors for mortality. RESULTS: This analysis is comprised of 234,781 cases, including 1,219 deaths, across 57 countries. The overall case fatality risk was found to be 0.5%. Risk factors for death in the multivariable analysis included younger age (for <6 months compared with older ages, OR = 3.54; 95% CI = 2.81-4.50), female sex (OR = 1.18; 95% CI= 1.06-1.81), presenting with persistent diarrhea (OR = 1.91; 95% CI= 1.01-3.25), no vomiting (OR = 1.13, 95% CI= 0.98-1.30), severe dehydration (OR = 3.79; 95% CI = 3.01-4.83), and being negative for rotavirus on an ELISA test (OR = 2.29; 95% CI= 1.92-2.74). Cases from the African Region had the highest odds of death compared with other WHO Regions (OR = 130.62 comparing the African Region to the European region; 95% CI= 55.72-422.73), while cases from the European region had the lowest odds of death. CONCLUSIONS: Our findings support known risk factors for childhood diarrheal mortality and highlight the need for interventions to address dehydration and rotavirus-negative diarrheal infections

    Moving beyond Marcuse: gentrification, displacement and the violence of un-homing

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    Displacement has become one of the most prominent themes in contemporary geographical debates, used to describe processes of dispossession and forced eviction at a diverse range of scales. Given its frequent deployment in studies describing the consequences of gentrification, this paper seeks to better define and conceptualise displacement as a process of un-homing, noting that while gentrification can prompt processes of eviction, expulsion and exclusion operating at different scales and speeds, it always ruptures the connection between people and place. On this basis – and recognising displacement as a form of violence – this paper concludes that the diverse scales and temporalities of displacement need to be better elucidated so that their negative emotional, psychosocial and material impacts can be more fully documented, and resisted
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