Life Support Filtration System Trade Study for Deep Space Missions

The National Aeronautics and Space Administrations (NASA) technical developments for highly reliable life support systems aim to maximize the viability of long duration deep space missions. Among the life support system functions, airborne particulate matter filtration is a significant driver of launch mass because of the large geometry required to provide adequate filtration performance and because of the number of replacement filters needed to a sustain a mission. A trade analysis incorporating various launch, operational and maintenance parameters was conducted to investigate the trade-offs between the various particulate matter filtration configurations. In addition to typical launch parameters such as mass, volume and power, the amount of crew time dedicated to system maintenance becomes an increasingly crucial factor for long duration missions. The trade analysis evaluated these parameters for conventional particulate matter filtration technologies and a new multi-stage particulate matter filtration system under development by NASAs Glenn Research Center. The multi-stage filtration system features modular components that allow for physical configuration flexibility. Specifically, the filtration system components can be configured in distributed, centralized, and hybrid physical layouts that can result in considerable mass savings compared to conventional particulate matter filtration technologies. The trade analysis results are presented and implications for future transit and surface missions are discussed

Preparing for Planetary Surface Exploration by Measuring Habitat Dust Intrusion with Filter Tests During an Analogue Mars Mission

As humans venture deeper into space more issues related to operations will become apparent. While the perils ofdust particles may not be widely recognized, it is one of the major issues astronauts will face on the surface of theMoon and Mars. Dust particles present a problem for both astronaut health and equipment as revealed during theApollo era lunar surface missions. Dust particles cling to spacesuits and field gear, which upon ingress would begincirculating throughout the spacecraft or habitat. An astronaut's health is compromised by the dust particle's potentialto embed in the lungs and cause respiratory illnesses. The extreme abrasiveness and granularity of the particles makeit near impossible to completely shield a spacecraft or habitat from dust related damage. NASA's Glenn ResearchCenter collaborated with Crew 188 at the Mars Desert Research Station (MDRS) in Utah to measure how much dustentered the habitat during a series of extravehicular activities (EVAs), or surface excursions. A NASA GRCdeveloped multistage filter system, coined the Scroll Filter System, was tested, for its effectiveness in removing dustthat entered the airlock and habitat after the EVAs. An optical particle counter measured the ambient airlockparticulates five times including: before the start of operations; after the crew left for EVA; in the middle of the EVAwith the settled air; before the crew entered the airlock after EVA; and finally, after the crew simulated repressurizationand suit brushing off in the airlock. Data was also collected in several of the working environmentlocations around MDRS and outside the habitat in the wind. Data collected from this research will help establishfilter equipment for life support systems and prescribed operations for astronaut transition from a planetary surfaceinto a desired clean habitat. Measurements may aid in updating a baseline expected dust load for a surface habitatand further facilitate the mitigation of astronaut's exposure to dust particles on the surface of celestial bodies

Exploration Mission Particulate Matter Filtration Technology Performance Testing in a Simulated Spacecraft Cabin Ventilation System

Human deep space exploration missions will require advances in long-life, low maintenance airborne particulate matter filtration technology. As one of the National Aeronautics and Space Administrations (NASA) developments in this area, a prototype of a new regenerable, multi-stage particulate matter filtration technology was tested in an International Space Station (ISS) module simulation facility. As previously reported, the key features of the filter system include inertial and media filtration with regeneration and in-place media replacement techniques. The testing facility can simulate aspects of the cabin environment aboard the ISS and contains flight-like cabin ventilation system components. The filtration technology test article was installed at the inlet of the central ventilation system duct and instrumented to provide performance data under nominal flow conditions. In-place regeneration operations were also evaluated. The real-time data included pressure drop across the filter stages, process air flow rate, ambient pressure, humidity and temperature. In addition, two video cameras positioned at the filtration technology test articles inlet and outlet were used to capture the mechanical performance of the filter media indexing operation under varying air flow rates. Recent test results are presented and future design recommendations are discussed

Filter Efficiency and Pressure Testing of Returned ISS Bacterial Filter Elements (BFEs)

The air quality control equipment aboard the International Space Station (ISS) and future deep space exploration vehicles provide the vital function of maintaining a clean cabin environment for the crew and the hardware. This becomes a serious challenge in pressurized space compartments since no outside air ventilation is possible, and a larger particulate load is imposed on the filtration system due to lack of sedimentation. The ISS Environmental Control and Life Support (ECLS) system architecture in the U.S. Segment uses a distributed particulate filtration approach consisting of traditional High-Efficiency Particulate Air (HEPA) filters deployed at multiple locations in each U.S. Seg-ment module; these filters are referred to as Bacterial Filter Elements, or BFEs. In our previous work, we presented results of efficiency and pressure drop measurements for a sample set of two returned BFEs with a service life of 2.5 years. In this follow-on work, we present similar efficiency, pressure drop, and leak tests results for a larger sample set of six returned BFEs. The results of this work can aid the ISS Program in managing BFE logistics inventory through the stations planned lifetime as well as provide insight for managing filter element logistics for future exploration missions. These results also can provide meaningful guidance for particulate filter designs under consideration for future deep space exploration missions

Cultura organizacional y bienestar laboral de los trabajadores de la Red de Salud Huamalíes

Objective. To determine the relationship between the organizational culture and the labor welfare of the workers of the Red de Salud Huamalíes, 2019. Methods. This was a quantitative, relational, prospective and observational research. The population consisted of 80 workers, 60 of whom were selected by non-probabilistic sampling, for the convenience. The technique used was the interview, whose instruments were general characteristics, a questionnaire for measuring organizational culture and a questionnaire on labor welfare, which were previously validated and validated. A descriptive analysis of the variables was performed and the chi-square statistic was used for p ≤ 0.05 to test the hypotheses. The ethical considerations for the research were applied. Results. The 81.7 % (49) of the workers perceived a strong level of organizational culture and 18.3 % (11) were at a moderate level; the level of labor welfare reached a high level in 70 % (42) and an intermediate level in 30 % (18). A significant relationship (p ≤ 0.05) was observed between strong organizational culture and high labor welfare in the dimensions: development at work, interrelationship with the boss, opportunities and incentives and work environment. Conclusions. The organizational culture is significantly related to the development of labor welfare perceived by the workers of the Red de Salud Huamalíes, 2019.Objetivo. Determinar la relación entre la cultura organizacional y el bienestar laboral de los trabajadores de la Red de Salud Huamalíes, 2019. Métodos. Fue una investigación de enfoque cuantitativo, de nivel relacional, prospectiva y observacional. La población estuvo conformada por 80 trabajadores de los que fueron seleccionados 60 por muestreo no probabilístico, por conveniencia. La técnica utilizada fue la entrevista, cuyos instrumentos fueron la cultura organizacional y el de bienestar laboral, los cuales fueron previamente validados y fiabilizados. Se realizó el análisis descriptivo de las variables y en la comprobación de las hipótesis se empleó el estadístico chi cuadrado para p ≤ 0,05. Se aplicaron las consideraciones éticas para la investigación. Resultados. El 81,7 % (49) de los trabajadores percibieron un nivel fuerte de la cultura organizacional y el 18,3 % (11) se ubicó en el nivel moderado; el nivel de bienestar laboral alcanzó en el 70 % (42) un nivel alto y en el 30 % (18) un nivel intermedio. Se observó relación significativa (p ≤ 0,05) entre la cultura organizacional fuerte y el bienestar laboral alto en las dimensiones: desarrollo en el trabajo, interrelación con el jefe, oportunidades e incentivos y ambiente de trabajo. Conclusiones. La cultura organizacional se relaciona de forma significativa con el desarrollo del bienestar laboral percibido por los trabajadores de la Red de Salud Huamalíes, 2019

International Space Station (ISS) Bacterial Filter Elements (BFEs): Filter Efficiency and Pressure Drop Testing of Returned Units

The air quality control equipment aboard the International Space Station (ISS) and future deep space exploration vehicles provide the vital function of maintaining a clean cabin environment for the crew and the hardware. This becomes a serious challenge in pressurized space compartments since no outside air ventilation is possible, and a larger particulate load is imposed on the filtration system due to lack of sedimentation. The ISS Environmental Control and Life Support (ECLS) system architecture in the U.S. Segment uses a distributed particulate filtration approach consisting of traditional High-Efficiency Particulate Air (HEPA) filters deployed at multiple locations in each U.S. Seg-ment module; these filters are referred to as Bacterial Filter Elements, or BFEs. In our previous work, we presented results of efficiency and pressure drop measurements for a sample set of two returned BFEs with a service life of 2.5 years. In this follow-on work, we present similar efficiency, pressure drop, and leak tests results for a larger sample set of six returned BFEs. The results of this work can aid the ISS Program in managing BFE logistics inventory through the stations planned lifetime as well as provide insight for managing filter element logistics for future exploration missions. These results also can provide meaningful guidance for particulate filter designs under consideration for future deep space exploration missions

Welfare Impact of Carbon Dioxide Euthanasia on Laboratory Mice and Rats : A Systematic Review

Background: There has been increased concern about the suitability of CO as a method for euthanasia of laboratory mice and rats, including the potential discomfort, pain or distress that animals may experience prior to loss of consciousness; time to loss of consciousness; best methods for use of CO; and the availability of better alternatives. These discussions have been useful in providing new information, but have resulted in significant confusion regarding the acceptability of CO for rodent euthanasia. In some cases, researchers and veterinarians have become uncertain as to which techniques to recommend or use for euthanasia of laboratory mice and rats. Methods: The International Association of Colleges of Laboratory Animal Medicine (IACLAM) convened a taskforce to examine the evidence for adverse welfare indicators in laboratory rats and mice undergoing CO euthanasia using a SYRCLE-registered systematic review protocol. Of 3,772 papers identified through a database search (PubMed, Web of Science, CAB Direct, Agricola, and grey literature) from 1900 to 2017, 37 studies were identified for detailed review (some including more than one species or age group), including 15 in adult mice, 21 in adult rats, and 5 in neonates of both species. Experiments or reports were excluded if they only assessed parameters other than those directly affecting animal welfare during CO induction and/or euthanasia. Results: Study design and outcome measures were highly variable and there was an unclear to high risk of bias in many of the published studies. Changes in the outcome measures evaluated were inconsistent or poorly differentiated. It is likely that repeated exposures to carbon dioxide inhalation are aversive to adult rats and mice, based on avoidance behavior studies; however, this effect is largely indistinguishable from aversion induced by repeated exposures to other inhalant anesthetic gasses. Conclusion: There is insufficient evidence to permit an unbiased assessment of the effect of CO inhalation during euthanasia on welfare indicators in laboratory mice and rats. Additional well-designed, unbiased, and adequately powered studies are needed to accurately assess the welfare of laboratory mice and rats undergoing euthanasia via CO gas

Resonant inelastic soft-x-ray scattering spectra at the N1s and C1s edges of poly(pyridine-2,5-diyl)

Resonant inelastic scattering measurements of poly(pyridine-2,5-diyl) have been performed at the N1s and C1s edges using synchrotron radiation. For comparison, molecular orbital calculations of the spectra have been carried out with the repeat unit as a model molecule of the polymer chain. The resonant emission spectra show depletion of the p electron bands which is consistent with symmetry selection and momentum conservation rules. The depletion is most obvious in the resonant inelastic scattering spectra of carbon while the nitrogen spectra are dominated by lone pair n orbital emission of s symmetry and are less excitation energy dependent. By comparing the measurements to calculations an isomeric dependence of the resonant spectra is found giving preference to two of the four possible isomers in the polymer.Comment: 6 pages, 3 figures, http://www.sciencedirect.com/science/article/pii/S036820489800354

The electronic structure of poly(pyridine-2,5-diyl) investigated by soft x-ray absorption and emission spectroscopies

The electronic structure of the poly-pyridine conjugated polymer has been investigated by resonant and nonresonant inelastic X-ray scattering and X-ray absorption spectroscopies using synchrotron radiation. The measurements were made for both the carbon and nitrogen contents of the polymer. The analysis of the spectra has been carried out in comparison with molecular orbital calculations taking the repeat-unit cell as a model molecule of the polymer chain. The simulations indicate no significant differences in the absorption and in the non-resonant X-ray scattering spectra for the different isomeric geometries, while some isomeric dependence of the resonant spectra is predicted. The resonant emission spectra show depletion of the {\pi} electron bands in line with symmetry selection and momentum conservation rules. The effect is most vizual for the carbon spectra; the nitrogen spectra are dominated by lone pair n orbital emission of {\sigma} symmetry and are less frequency dependent.Comment: 11 pages, 7 figures, 1 table, http://www.sciencedirect.com/science/article/pii/S030101049800262