59 research outputs found

    FlĂŒssiges unterkĂŒhltes GrenzflĂ€chenwasser in der MarsoberflĂ€che

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    Diese Arbeit befasst sich mit den noch ungeklĂ€rten aber zentralen Fragen der Marsforschung, wie viel flĂŒssiges GrenzflĂ€chenwasser sich in den oberen Schichten mittlerer und niederer Breiten befinden kann und wie viel davon bei Temperaturen unter 0 °C in flĂŒssiger Form vorliegt. Die Erfassung des Wassergehaltes und des Aggregatzustandes in Böden erfolgte ĂŒber die Messung der DielektrizitĂ€tskonstante der Böden im Temperaturbereich 25 °C bis -70 °C. Zwei dielektrische Messsysteme wurden zur Bestimmung des Wassergehaltes entwickelt: Ein Plattenkondensator mit einem Messfrequenzbereich 10 Hz bis 1,1 MHz und ein Time Domain Reflectometry (TDR)-System mit einer Messfrequenz von 600 MHz. Die damit durchgefĂŒhrten Messungen erfolgten an zwei marsrelevanten Böden: Bentonit (stark montmorillonithaltiger Ton) und JSC Mars 1 (vulkanisches Material). Anhand der Birchak-Mischungsregel, die sich als geeignetes Instrument zur Beschreibung der einzelnen DielektrizitĂ€tskonstanten der Bodenbestandteile erwies, wurde eine erfolgreiche experimentelle Methode zur Bestimmung des FlĂŒssigwasseranteils und Eisanteils in Böden geschaffen. Die Auswertung ergab einen FlĂŒssigwassergehalt der untersuchten Böden von ca. 2 Monolagen bei -70 °C. Die Ergebnisse wurden mit einem erst kĂŒrzlich entwickelten Schichten-Modell fĂŒr GrenzflĂ€chenwasser verglichen, das auf der Hamaker-Theorie zur Beschreibung der van der Waals-KrĂ€fte basiert. Hier zeigte sich eine sehr gute Übereinstimmung beim FlĂŒssigwasseranteil unter 0 °C. Weiter wurden mit dem Schichten-Modell die Hamaker-Konstanten von Bentonit und JSC Mars 1 bestimmt sowie das Sorptionsverhalten der Böden untersucht. Experimentell konnte gezeigt werden, dass ca. 1 Monolage Wasser in JSC Mars 1 auch bei einer relativen Feuchte kleiner 0,05 %r.F., die wĂ€hrend der Mittagszeit in mittleren und niederen Breiten am Mars erreicht wird, zu erwarten ist. Mit der entwickelten Experiment- und Messtechnik und der zugehörigen Auswertungsmethode sind erste Voraussetzungen geschaffen worden, um aus den zu erwartenden in-situ Feuchtemessungen von MiniHUM (ExoMars) auf den FlĂŒssigwassergehalt der oberen Schichten des Marsbodens schließen zu können

    Protein patterns of black fungi under simulated Mars-like conditions

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    Two species of microcolonial fungi – Cryomyces antarcticus and Knufia perforans - and a species of black yeasts–Exophiala jeanselmei - were exposed to thermo-physical Mars-like conditions in the simulation chamber of the German Aerospace Center. In this study the alterations at the protein expression level from various fungi species under Mars-like conditions were analyzed for the first time using 2D gel electrophoresis. Despite of the expectations, the fungi did not express any additional proteins under Mars simulation that could be interpreted as stress induced HSPs. However, up-regulation of some proteins and significant decreasing of protein number were detected within the first 24 hours of the treatment. After 4 and 7 days of the experiment protein spot number was increased again and the protein patterns resemble the protein patterns of biomass from normal conditions. It indicates the recovery of the metabolic activity under Martian environmental conditions after one week of exposure

    Shoulder Dislocation Incidence and Risk Factors-Rural vs. Urban Populations of Poland.

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    (1) Background: The aim of this study was to analyze the incidence of shoulder dislocation and to estimate non-modifiable risk factors in rural and urban subgroups in Poland. (2) Methods: The study covered the entire Polish population, divided into urban and rural subgroups and observed between 1 January 2014 and 31 December 2014. The study population consisted of Polish patients with a diagnosis of shoulder dislocation (S43.0) in accordance with the International Statistical Classification of Diseases and Related Health Problems (ICD-10). Records were obtained from the public health care provider National Health Found (Narodowy Fundusz Zdrowia, NFZ). Based on these data, we assessed shoulder dislocation incidence and risk rates, stratifying the study sample by sex, age and place of residence (rural or urban) using the Central Statistical Office (GUS) personal territorial code (TERYT). (3) The incidence was 25.97/100,000 person-years in rural areas and 25.62/100,000 person-years in urban areas. We did not find significant differences in the incidence between the two subgroups. The highest incidence (75.12/100,000 person-years) and the highest risk for shoulder dislocation were found among subjects 80+ years old living in urban areas. Furthermore, men in the third decade of their life living in urban areas showed the highest risk (OR = 7.8, 95% CI; 6.44-9.45, p < 0.001). In both subgroups, the likelihood of shoulder dislocation was significantly lower for the female sex and among children ≀9 years old. However, girls living in rural areas presented with a significantly higher likelihood for dislocation compared with their peers living in urban environments. (4) Conclusions: No significant difference in the incidence rate of shoulder dislocation between Polish residents living in rural and urban areas emerged. The highest incidence was observed among female subjects 80+ years old living in urban environments. The highest risk was found among men in the third decade of their life living in urban areas. In addition, girls in the first decade of their life living in rural areas had more shoulder dislocations than girls living in urban environments. Shoulder dislocation is dominant in female subjects aged 70-79 living in rural areas and in females 80+ years old living in urban areas

    Construction of Gauge Theories on Curved Noncommutative Spacetime

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    We present a method where derivations of star-product algebras are used to build covariant derivatives for noncommutative gauge theory. We write down a noncommutative action by linking these derivations to a frame field induced by a nonconstant metric. An example is given where the action reduces in the classical limit to scalar electrodynamics on a curved background. We further use the Seiberg-Witten map to extend the formalism to arbitrary gauge groups. A proof of the existence of the Seiberg-Witten-map for an abelian gauge potential is given for the formality star-product. We also give explicit formulas for the Weyl ordered star-product and its Seiberg-Witten-maps up to second order.Comment: 35 pages, v2: references added, v3: PACS added, v4: final version, changes in the order of presentatio

    A Concept for a Mars Boundary Layer Sounding Balloon: Science Case, Technical Concept and Deployment Risk Analysis

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    The Mars Exploration Program Analysis Group has identified measurements of the state and the variability of the Martian atmosphere as high priority investigations for the upcoming years. Balloon-borne instruments could bridge the gap in both temporal and spatial resolution in mesoscale distances between local, stationary landers and global orbiter observations. The idea to use a balloon system for such a purpose is not new in essence and has been proposed already in past decades. While those concepts considered an aerial deployment during entry and descent, the concept outlined in this study revisits a launch off the payload deck of a lander from the Martian surface. This deployment option profits today mainly from the technological advance in micro-electronics and sensor miniaturization, which enables the design of a balloon-probe significantly smaller than earlier proposed systems. This paper presents the feasibility assessment for this instrument and gives further details on the scientific and operational concept, a strawman sensor suite, its system components and the associated size and budget estimates. It is complemented by the analysis scheme proposed to assess, manage and mitigate the deployment risk involved in automatically launching such a balloon-system off a planetary surface

    Humidity calibration of relative humidity devices in Martian conditions

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    Finnish Meteorological Institute (FMI) has developed relative humidity measurement devices for past and future Mars lander missions: REMS-H for Curiosity, MEDA HS for Mars 2020 and METEO-H for ExoMars 2020. The sensors used in these devices are HUMICAPŸ capacitive thin-film polymer sensors by Vaisala Inc. New calibration measurements are performed with ground reference models of these devices in the Mars Simulation Facility (MSF) and Planetary Analog Simulation Laboratory (PASLAB) at the German Aerospace Center (DLR) in spring 2020. The preliminary results will be given at the EGU 2020. Calibration of relative humidity devices requires in minimum two humidity points over the expected operational temperature and pressure range of the device. With two-point calibration the relative humidity devices can be used for scientific measurements with satisfactory quality but the uncertainty is notable. Stable humidity conditions between dry and saturation humidity in Martian conditions can be achieved reliably in very few laboratories in the whole world and humidity measurements in Martian conditions have been previously performed for the same devices in FMI laboratory and in Michigan Mars Environmental Chamber (MMEC) at the University of Michigan. The new measurement campaign will consist of stable humidity point measurements in multiple temperatures between +10°C to -70°C in CO2 gas and Martian pressure of approximately 7 hPa. The measurements are performed simultaneously for multiple devices in a small pressure vessel with continuous humidified carbon dioxide flow. The new measurement campaign will improve the characterization of the existing relative humidity devices in Mars lander missions and define in more detail the measurement uncertainties

    Calibration and first results of relative humidity sensor MEDA HS onboard M2020 rover

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    MEDA HS is the relative humidity sensor on the Mars 2020 Perseverance rover provided by theFinnish Meteorological Institute (FMI). The sensor is a part of Mars Environmental DynamicAnalyzer (MEDA), a suite of environmental sensors provided by Centro de AstrobiologĂ­a in Madrid,Spain. MEDA HS, along with METEO-H in ExoMars 2022 surface platform, is a successor of REMS-Hon board Curiosity.Calibration of relative humidity (RH) instruments for Mars missions is challenging due to the rangeof RH (from 0 to close to 100%) and temperature conditions (from about -90 ÂșC to + 22 ÂșC) thatneed to be simulated in the lab. Thermal gradients in different parts of the system need to be wellknown and controlled to ensure reliable reference RH readings. For MEDA HS the calibration testshave been performed for different models of MEDA HS in three Martian humidity simulatorlaboratories: FMI laboratory, Michigan Mars Environmental Chamber (MMEC) and DLR PASLAB(Planetary Analog Simulation Laboratory). MEDA HS flight model was tested at FMI together with flight spare and ground reference models inlow pressure dry CO2 gas from +22ÂșC to -70ÂșC and in saturation conditions from -40ÂșC down to-70ÂșC. Further, the MEDA HS flight model final calibration is complemented by calibration datatransferred from an identical ground reference model which has gone through rigorous testingalso after the flight model delivery. During the test campaign at DLR PASLAB that started inAutumn 2020, MEDA HS has been calibrated over the full relative humidity scale between -70 to-40ÂșC in CO2 in the pressure ranges from 5.5 to 9.5 hPa, representative of Martian surfaceatmospheric pressure. The results can be extrapolated to higher and lower temperatures.In this presentation the final flight calibration and performance of the MEDA HS will be presentedtogether with first results expected from the surface of Mars by the Perseverance rover

    Understanding engagement and disengagement from pro-environmental behaviour: The role of neutralization and affirmation techniques in maintaining persistence in and desistance from car use

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    Despite mounting evidence that car use is a prime culprit of global warming, our love affair with the car persists. General awareness of the environmental consequences of car usage is high but fails to correspond to moderated car use. This paper contributes to an understanding of how university students’ environmental beliefs affect decisions to engage in continued car use (persistence) and/or to discontinue or reduce car use (desistance). The aim of the research presented here was to explore the range of neutralizations and counterneutralizations (affirmations) employed by students and to examine the ways in which they are used to justify and maintain either persistence or desistance in car use. The research consisted of six focus group sessions with thirty-four UK-based Higher Education students. Analysis of the study’s data highlights the range of neutralizations and counter-neutralizations employed by students in social settings. The article discusses the usefulness of neutralization theory in accounting for actual and/or intended nonenvironmentally friendly behaviour such as car use. In addition, the study’s findings are discussed in relation to prior research and to potential implications for public policy interventions which favour moderating car usage

    BIOLEX – The Biology and Lunar experiment and the LOGOS Cubes

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    BIOLEX is a concept designed for in situ science on the Moon or in its orbit. As heritage of the polar and space experiment BIOMEX (Biology and Mars Experiment) on the ISS it is a more developed concept. Measurement operations on an exposure platform as well as within a micro-greenhouse device are part of this concept. The goal is to investigate the use of lunar resources as well as to analyse the stability of biomolecules as potential biosignatures serving as reference for future space exploration missions to Mars and the icy ocean moons in the outer solar system. Astrobiological exploration of the solar system is a priority research area such as emphasized by the European Astrobiology Roadmap (AstRoMap). It is focusing on several research topics, such as "Habitability" and on "Biomarkers for the detection of life". Therefore, "space platforms and laboratories", such as the EXPOSE setup installed outside the ISS, are essential to gain more knowledge on space- and planetary environments, which might be an essential basis for improvement of the robotic and human interplanetary exploration (Moon, Mars, Encedalus, Titan and Europa). In reference to these exposure platforms a new generation of hardware is needed to be installed in the lunar orbit or directly on the Moon. The BIOLEX is representing by its LOGOS (Lunar Organisms, Geo-microbiology and Organics Space Experiment) cubes such a concept combining the life detection topics with topics relevant to autonomous life supporting systems. A combination of a sample exposure device and a microhabitat for plants and microorganisms could address a tremendous number of questions from astrobiology and life sciences. The main scientific objectives for the use of BIOLEX-LOGOS cubes are: (i) in situ measurements by spectroscopy methods (such as Raman, IR, UV/VISspectroscopy) for analysis of biosignatures and their stability what is relevant for support of future life detection missions on Mars and the icy moons in the outer solar system); (ii) in situ measurements of environmental conditions (radiation, pressure/vacuum, temperature, pH, humidity) in micro-modules or compartments in reference to planned micro-habitat experiments placed on the Moon or incorporated on an exposure facility in orbit; (iii) in situ measurements of microorganisms’ activity in micro-modules / compartments in reference to planned microhabitat experiments placed on the moon or incorporated in the exposure facility in orbit. In reference to these scientific ideas the Moon is an excellent platform to operate different space experiments which will be of relevance for astrobiology, life sciences and human space missions. BIOLEX tries to fulfil a large number of scientific investigations in reference to these disciplines. The lunar environment is much harsher compared to Mars; and tests on biomolecules in this environment could provide information on their stability and therefore on the value to be used as reference for future space missions to Mars or the icy ocean moons in the outer solar system. Resources of the Moon such as the regolith or the freely available radiation on the surface could be tested by using them in a micro-greenhouse. Within this greenhouse different filters could test the optimal spectra range of the radiation

    Multiple Scenario Generation of Subsurface Models:Consistent Integration of Information from Geophysical and Geological Data throuh Combination of Probabilistic Inverse Problem Theory and Geostatistics

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    Neutrinos with energies above 1017 eV are detectable with the Surface Detector Array of the Pierre Auger Observatory. The identification is efficiently performed for neutrinos of all flavors interacting in the atmosphere at large zenith angles, as well as for Earth-skimming \u3c4 neutrinos with nearly tangential trajectories relative to the Earth. No neutrino candidates were found in 3c 14.7 years of data taken up to 31 August 2018. This leads to restrictive upper bounds on their flux. The 90% C.L. single-flavor limit to the diffuse flux of ultra-high-energy neutrinos with an E\u3bd-2 spectrum in the energy range 1.0 7 1017 eV -2.5 7 1019 eV is E2 dN\u3bd/dE\u3bd < 4.4 7 10-9 GeV cm-2 s-1 sr-1, placing strong constraints on several models of neutrino production at EeV energies and on the properties of the sources of ultra-high-energy cosmic rays
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