374 research outputs found

    Human Thermal Model Evaluation Using the JSC Human Thermal Database

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    The human thermal database developed at the Johnson Space Center (JSC) is used to evaluate a set of widely used human thermal models. This database will facilitate a more accurate evaluation of human thermoregulatory response using in a variety of situations, including those situations that might otherwise prove too dangerous for actual testing--such as extreme hot or cold splashdown conditions. This set includes the Wissler human thermal model, a model that has been widely used to predict the human thermoregulatory response to a variety of cold and hot environments. These models are statistically compared to the current database, which contains experiments of human subjects primarily in air from a literature survey ranging between 1953 and 2004 and from a suited experiment recently performed by the authors, for a quantitative study of relative strength and predictive quality of the models. Human thermal modeling has considerable long term utility to human space flight. Such models provide a tool to predict crew survivability in support of vehicle design and to evaluate crew response in untested environments. It is to the benefit of any such model not only to collect relevant experimental data to correlate it against, but also to maintain an experimental standard or benchmark for future development in a readily and rapidly searchable and software accessible format. The Human thermal database project is intended to do just so; to collect relevant data from literature and experimentation and to store the data in a database structure for immediate and future use as a benchmark to judge human thermal models against, in identifying model strengths and weakness, to support model development and improve correlation, and to statistically quantify a model s predictive quality

    Oceanographic signals at the Benthic Boundary Layer in the Mediterranean Sea

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    The Benthic Boundary Layer (BBL) is considered a quite homogeneous environment where a wide variety of processes (chemical, physical, geological and biological) occur often producing front structures or inducing turbulence phenomena. The typical stratification of these zones can be interrupted by episodic events which effects can diffuse to the ocean interior exploiting by local current and mixing processes. According to hydrodynamic definition, the BBL thickness may vary from few millimetres up to 100 metres depending on the friction intensity with the sea bed and the stability of water column above it. Generally in deep-sea condition, the BBL thickness is defined by the ratio between the friction velocity and the Coriolis parameter according to the Ekman scale. In the latest years several experiments have been carried out in the deep water of Mediterranean Sea, focusing on the survey and study of benthic processes following a multidisciplinary approach. Benthic observatories, such as SN-1 and GEOSTAR, allow to record long time-series of geochemical, seismological, geomagnetic, geodetic and oceanographic data and allow to understand the dynamics and evolution of the processes though comparison and interpolation of different types of signals. From a oceanographic point of view, the technology of these benthic observatories brings the possibility to observe and measure directly the hydrological properties at the seafloor collecting data for long-time series and with high sampling rate. The observatories deployed in Mediterranean Sea, have provided good information about variations and oscillations of hydrological parameters in deep water where the monitoring is almost lacking. In some cases it has been possible to link these deep-sea datasets with upper data collected by ship-handled system during the same period or during different cruises. This allows to have a more complete idea of the linkage between surface, intermediate and bottom sea. Hence the multidisciplinary approach represents a very important aspect for this kind of study, because it allows not only a cross check of functionality among all the instruments but also an important tool to recognise and better understand possible nonphysical- oceanographic phenomena

    Performance of a Multifunctional Space Evaporator- Absorber-Radiator (SEAR)

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    The Space Evaporator-Absorber-Radiator (SEAR) is a nonventing thermal control subsystem that combines a Space Water Membrane Evaporator (SWME) with a Lithium Chloride Absorber Radiator (LCAR). The LCAR is a heat pump radiator that absorbs water vapor produced in the SWME. Because of the very low water vapor pressure at equilibrium with lithium chloride solution, the LCAR can absorb water vapor at a temperature considerably higher than the SWME, enabling heat rejection by thermal radiation from a relatively small area radiator. Prior SEAR prototypes used a flexible LCAR that was designed to be installed on the outer surface of a portable life support system (PLSS) backpack. This paper describes a SEAR subsystem that incorporates a very compact LCAR. The compact, multifunctional LCAR is built in the form of thin panels that can also serve as the PLSS structural shell. We designed and assembled a 2 sq ft prototype LCAR based on this design and measured its performance in thermal vacuum tests when supplied with water vapor by a SWME. These tests validated our models for SEAR performance and showed that there is enough area available on the PLSS backpack shell to enable heat rejection from the LCAR

    Space Evaporator Absorber Radiator (SEAR) for Thermal Storage on Manned Spacecraft

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    Future manned exploration spacecraft will need to operate in challenging thermal environments. State-of the- art technology for active thermal control relies on sublimating water ice and venting the vapor overboard in very hot environments. This approach can lead to large loss of water and a significant mass penalty for the spacecraft. This paper describes an innovative thermal control system that uses a Space Evaporator Absorber Radiator (SEAR) to control spacecraft temperatures in highly variable environments without venting water. SEAR uses heat pumping and energy storage by LiCl/water absorption to enable effective cooling during hot periods and regeneration during cool periods. The LiCl absorber technology has the potential to absorb over 800 kJ per kg of system mass, compared to phase change heat sink systems that typically achieve approx. 50 kJ/kg. The optimal system is based on a trade-off between the mass of water saved and extra power needed to regenerate the LiCl absorber. This paper describes analysis models and the predicted performance and optimize the size of the SEAR system, estimated size and mass of key components, and power requirements for regeneration. We also present a concept design for an ISS test package to demonstrate operation of a subscale system in zero gravity

    Persistent and context-dependent effects of the larval feeding environment on post-metamorphic performance through the adult stage

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    One of the central issues in ecology is the identification of processes affecting the population structure and dynamics of species with complex life cycles. In such species, variation in both the number of larvae that enter a population and their phenotype are important drivers of survival and growth after metamorphosis. Larval experience can have strong effects on key post-metamorphic traits, but the temporal scale of such ‘trait-mediated effects’ may be short, and their magnitude may depend on the environment experienced after metamorphosis. We used an intertidal barnacle to study the long-term consequences of trait-mediated effects under different post-metamorphic conditions by manipulating larval food concentration and monitoring patterns of survival and growth in juveniles at 2 intertidal levels over a 5 mo period. In 2 replicated experiments, higher food levels resulted in increased body size, mass and reserves (measured from elemental composition) in the settling larval stage and increased body size of newly metamorphosed juveniles. In Expt 1, high food concentration reduced juvenile mortality at low intertidal levels, while on the upper intertidal, mortality was high for all larval food concentrations. By contrast, in Expt 2, low larval food concentration decreased juvenile survival at both shore levels. When present, effects were established early (Weeks 1 or 2) and persisted for over 10 wk in Expt 1 and 22 wk in Expt 2. Interactive effects of the larval and juvenile environments can have important implications for population size: trait-mediated effects may persist for long periods, helping to explain patterns of adult abundance

    Performance of a Multifunctional Space Evaporator-Absorber-Radiator (SEAR)

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    The Space Evaporator-Absorber-Radiator (SEAR) is a nonventing thermal control subsystem that combines a Space Water Membrane Evaporator (SWME) with a Lithium Chloride Absorber Radiator (LCAR). The LCAR is a heat pump radiator that absorbs water vapor produced in the SWME. Because of the very low water vapor pressure at equilibrium with lithium chloride solution, the LCAR can absorb water vapor at a temperature considerably higher than the SWME, enabling heat rejection sufficient for most EVA activities by thermal radiation from a relatively small area radiator. Prior SEAR prototypes used a flexible LCAR that was designed to be installed on the outer surface of a portable life support system (PLSS) backpack. This paper describes a SEAR subsystem that incorporates a very compact LCAR. The compact, multifunctional LCAR is built in the form of thin panels that can also serve as the PLSS structural shell. We designed and assembled a 2 ft prototype LCAR based on this design and measured its performance in thermal vacuum tests when supplied with water vapor by a SWME. These tests validated our models for SEAR performance and showed that there is enough area available on the PLSS backpack shell to enable rejection of metabolic heat from the LCAR. We used results of these tests to assess future performance potential and suggest approaches for integrating the SEAR system with future space suits

    High-Capacity Spacesuit Evaporator Absorber Radiator (SEAR)

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    Future human space exploration missions will require advanced life support technology that can operate across a wide range of applications and environments. Thermal control systems for space suits and spacecraft will need to meet critical requirements for water conservation and multifunctional operation. This paper describes a Space Evaporator Absorber Radiator (SEAR) that has been designed to meet performance requirements for future life support systems. A SEAR system comprises a lithium chloride absorber radiator (LCAR) for heat rejection coupled with a space water membrane evaporator (SWME) for heat acquisition. SEAR systems provide heat pumping to minimize radiator size, thermal storage to accommodate variable environmental conditions, and water absorption to minimize use of expendables. We have built and tested a flight-like, high-capacity LCAR, demonstrated its performance in thermal vacuum tests, and explored the feasibility of an ISS demonstration test of a SEAR system. The new LCAR design provides the same cooling capability as prior LCAR prototypes while enabling over 30% more heat absorbing capacity. Studies show that it should be feasible to demonstrate SEAR operation in flight by coupling with an existing EMU on the space station

    Kartlegging av dagens rutiner for informasjonsutveksling ved utskrivning av pasienter som trenger kommunale helse- og omsorgstjenester

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    Masteroppgave i helse- og sosialinformatikk HSI500 2012 – Universitetet i Agder, GrimstadMasterprosjektet er gjennomført i samarbeid med Sørlandet sykehus HF. Prosjektet omfatter en kartlegging av dagens rutiner for informasjonsutveksling ved utskrivning av pasienter som trenger kommunale helse- og omsorgstjenester. I dag preges samarbeidet mellom sykehuset og den kommunale helse- og omsorgtjenesten av samhandlingsreformen. Intensjonen med samhandlingsreformen er at den skal føre til kortere liggetid for pasienter i sykehus, samt at kommunen skal overta pasientene tidligere i behandlingsforløpet. Dette medfører en enorm omstilling for begge parter som vil kreve bedre samhandling, økt kompetanse, klare retningslinjer og endringer i organisasjonene. Prosjektet bygger på intervjuer hvor informantene er relevante mennesker i helsetjenesten. Det er utført 11 kvalitative intervju av sykepleiere ansatt ved Sørlandet sykehus HF. Informantene har ulik alder og bakgrunn som sykepleiere. Målet med undersøkelsen er å kartlegge dagens utskrivningsrutiner samt å finne kritiske suksessfaktorer som kan være avgjørende ved implementeringen av et IS- system. I denne sammenhengen er IS- systemet som skal innføres elektroniske pleie- og omsorgsmeldinger. Datasamlingen foregikk over to uker, deretter ble det gjennomført transkribering og analyse av funn. I tilegg er det lest litteratur, faglige artikler og rapporter på det aktuelle tema. Gjennom intervjuene kom det frem beskrivelser av hvordan utskrivningen av pasienter fra SSHF til den kommunale helse- og omsorgstjenesten foregår. Det kom også frem utfordringer, og positive og negative erfaringer som er knyttet til utskrivning av disse pasientene. Funnene viser at rutiner i forhold til utskrivning varierer fra avdeling til avdeling, og at retningslinjene sykehuset har for utskrivning av pasienter som trenger kommunale pleie- omsorgs- og rehabiliteringstjenester ikke blir fulgt. Mange av sykepleierne kjenner heller ikke til retningslinjene som gjelder på deres arbeidsplass. Det er også, ved hjelp av litteraturen, identifisert flere suksessfaktorer som bør vektlegges ved implementering av elektroniske PLO-meldinger

    Monitoring of a methane-seeping pockmark by cabled benthic observatory (Patras Gulf, Greece)

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    A new seafloor observatory, the gas monitoring module (GMM), has been developed for continuous and long-term measurements of methane and hydrogen sulphide concentrations in seawater, integrated with temperature (T), pressure (P) and conductivity data at the seafloor. GMM was deployed in April 2004 within an active gas-bearing pockmark in the Gulf of Patras (Greece), at a water depth of 42 m. Through a submarine cable linked to an onshore station, it was possible to remotely check, via direct phone connection, GMM functioning and to receive data in nearreal time. Recordings were carried out in two consecutive campaigns over the periods April–July 2004, and September 2004–January 2005, amounting to a combined dataset of ca. 6.5 months. This represents the first long-term monitoring ever done on gas leakage from pockmarks by means of CH4+H2S+T+P sensors. The results show frequent T and P drops associated with gas peaks, more than 60 events in 6.5 months, likely due to intermittent, pulsation-like seepage. Decreases in temperature in the order of 0.1–1°C (up to 1.7°C) below an ambient T of ca. 17°C (annual average) were associated with short-lived pulses (10–60 min) of increased CH4+H2S concentrations. This seepage “pulsation” can either be an active process driven by pressure build-up in the pockmark sediments, or a passive fluid release due to hydrostatic pressure drops induced by bottom currents cascading into the pockmark depression. Redundancy and comparison of data from different sensors were fundamental to interpret subtle proxy signals of temperature and pressure which would not be understood using only one sensor.Published297-302JCR Journalreserve
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