Sample records for wet mars plentiful

  1. WET MARS: Plentiful, Readily-Available Martian Water and its Implications

    Energy Technology Data Exchange (ETDEWEB)

    Hyde, R.; Ishikawa, M.; Nuckolls, J.; Whitehead, J.; Wood, L.


    /oxygen/fuel plant exploiting Martian atmospheric water. All of the oxygen, water and propellants necessary for life-support, extensive exploration and Earth-return can be provided readily by the host planet. Crewed exploration of Mars launched from LEO with on1.V 2 Shuttle-loads of equipment and consumables--a commercial total cost-equivalent of {approx}$650 M--thereby becomes feasible. The most challenging current problem with respect to human expeditions to Mars is escape from Earth's deep, 11.2 km/s gravity well, and is largely an economic issue. Living on Mars, exploring it extensively and returning to Earth, each hitherto major technical issues, are actually much less difficult, thanks in no small part to the effective ''wetness'' of Mars. Similar considerations apply to other water-rich locations in the Solar system, e.g. Europa.

  2. The Geologic Evidence for a Warm and Wet Early Mars (United States)

    Craddock, R. A.; Irwin, R. P.; Howard, A. D.; Morgan, A. M.


    The geologic evidence supporting a warm and wet climate on early Mars is presented. The case against an "icy highlands" scenario is also made. Climate models are converging to a solution, but any theoretical data must explain the empirical data.

  3. Sequence stratigraphy on an early wet Mars (United States)

    Barker, Donald C.; Bhattacharya, Janok P.


    The evolution of Mars as a water-bearing body is of considerable interest for the understanding of its early history and evolution. The principles of terrestrial sequence stratigraphy provide a useful conceptual framework to hypothesize about the stratigraphic history of the planets northern plains. We present a model based on the hypothesized presence of an early ocean and the accumulation of lowland sediments eroded from highland terrain during the time of the valley networks and later outflow channels. Ancient, global environmental changes, induced by a progressively cooling climate would have led to a protracted loss of surface and near surface water from low-latitudes and eventual cold-trapping at higher latitudes - resulting in a unique and prolonged, perpetual forced regression within basins and lowland depositional environments. The Messinian Salinity Crisis (MSC) serves as a potential terrestrial analogue of the depositional and environmental consequences relating to the progressive removal of large standing bodies of water. We suggest that the evolution of similar conditions on Mars would have led to the emplacement of diagnostic sequences of deposits and regional scale unconformities, consistent with intermittent resurfacing of the northern plains and the progressive loss of an early ocean by the end of the Hesperian era.

  4. Early Mars: A Warm Wet Niche for Life (United States)

    Gibson, Everett K.; McKay, David S.; Thomas-Keprta, Kathie L.; Clemett, Simon J.


    Exploration of Mars has begun to unveil the history of the planet. Combinations of remote sensing, in situ compositional measurements and photographic observations have shown Mars had a dynamic and active geologic evolution. Mars geologic evolution had conditions that were suitable for supporting life. A habitable planet must have water, carbon and energy sources along with a dynamic geologic past. Mars meets all of these requirements. The first 600 Ma of Martian history were ripe for life to develop because of the abundance of: (i) Water-as shown by carved canyons and oceans or lakes with the early presence of near surface water shown by precipitated carbonates in ALH84001, well-dated at approx.3.9 Ga, (ii) Energy from the original accretional processes, a molten core which generated a strong magnetic field leaving a permanent record in the early crust, active volcanism continuing throughout Martian history, and continuing impact processes, (iii) Carbon, water and a likely thicker atmosphere from extensive volcanic outgassing (i.e. H2O, CO2, CH4, CO, O2, N2, H2S, SO2, etc.) and (iv) crustal tectonics as revealed by faulting and possible plate movement reflected by the magnetic patterns in the crust [1]. The question arises: "Why would life not develop from these favorable conditions on Mars in its first 600 Ma?" During this period, environmental near-surface conditions on Mars were more favorable to life than at any later time. Standing bodies of water, precipitation and flowing surface water, and possibly abundant hydrothermal energy would favor the formation of early life. (Even if life developed elsewhere on Earth, Venus, or on other bodies-it was transported to Mars where surface conditions were suitable for life to evolve)

  5. Detection of Organics at Mars: How Wet Chemistry Onboard SAM Helps (United States)

    Buch, A.; Freissinet, Caroline; Szopa, C.; Glavin, D.; Coll, P.; Cabane, M.; Eigenbrode, J.; Navarro-Gonzalez, R.; Coscia, D.; Teinturier, S.; hide


    For the first time in the history of space exploration, a mission of interest to astrobiology could be able to analyze refractory organic compounds in the soil of Mars. Wet chemistry experiment allow organic components to be altered in such a way that improves there detection either by releasing the compounds from sample matricies or by changing the chemical structure to be amenable to analytical conditions. The latter is particular important when polar compounds are present. Sample Analysis at Mars (SAM), on the Curiosity rover of the Mars Science Laboratory mission, has onboard two wet chemistry experiments: derivatization and thermochemolysis. Here we report on the nature of the MTBSTFA derivatization experiment on SAM, the detection of MTBSTFA in initial SAM results, and the implications of this detection.

  6. Four Types of Deposits From Wet Conditions on Early Mars (United States)


    Each of these four panels shows a close-up view of a different type of geological deposit formed with the involvement of water, based on observations by NASA's Mars Reconnaissance Orbiter. All four date from the earliest period of Martian history, called the Noachian Period. The upper-left panel shows carbonates overlying clays in the Nili Fossae region of Mars. The view combines color-coded information from infrared spectral observations by the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) with an underlying black-and-white image from the High Resolution Imaging Science Experiment (HiRISE) camera. Beneath a rough-textured capping rock unit (purple) lie banded olivine-bearing layers (yellow), which in some places have been partially or wholly altered to carbonate (green). The upper-right panel shows phyllosilicates and chlorides in the Terra Sirenum region, observed by CRISM and HiRISE. Medium-toned, finely fractured rocks containing chloride salts either underlie higher-standing, light-toned phyllosilicates or fill in low spots between them. Both sit on dark, eroded volcanic material. The lower-left panel shows the upper portion of canyon wall in Coprates Chasma, observed by HiRISE and CRISM. The chasm rim cuts across the middle of the image. The wall slopes down to the top of the image and continues outside the region shown, exposing multiple phyllosilicate-bearing layers in a section of rock 7 kilometers (4 miles) thick. Two of the layers shown here are finely fractured aluminum clays that dominate the lower half of the image, underlain by thin beds of iron-magnesium clays at the top of the image. The dark material is a remnant of an overlying layer of basaltic sand that has been partly eroded away by the wind. The lower-right panel shows phyllosilicates with vertically layered compositions in Mawrth Vallis, observed by HiRISE (presented in enhanced color) and CRISM. The brown-colored knob in the middle of the scene is a remnant of cap rock that

  7. The Effects of Punctuated Warm and Wet Environments on Phyllosilicate Formation - or How Long was Early Mars Wet? (United States)

    Bishop, J. L.; Baker, L.; Rampe, E. B.; Velbel, M. A.


    Abundant phyllosilicates and aqueous minerals are observed nearly everywhere we can see the ancient rocks on Mars [1,2]. Most bountiful among these is Fe/Mg-smectite. So, what can these smectite clays tell us about the early Martian environment? Studies of smectite formation [3,4] indicate that they form faster at elevated (>100 °C) temperatures. There is a trade-off between temperature and time such that lower temperatures require more time for smectite formation. We postulate that short-term warm and wet environments could have enabled formation of the observed smectite occurrences on Mars without requiring long-term bodies of water on the planet. Smectites form in weathering environments by transformation from primary silicates or by neoformation from allophane and related amorphous materials [3,5]. The highest smectite abundances are observed in low rainfall climates (Allophane and imogolite form in near neutral waters in well-drained environments as Al and Si are leached from volcanic ash and tephra [6]. In dry environments allophane and related nanophase materials can persist long-term. Allophane and imogolite have been identified in Martian surface material from orbit [7,8] and amorphous components have been found at Gale crater [9]. Because amorphous phases such as opal, ferrihydrite, allophane and imogolite are highly reactive and mobile in aqueous environments, finding these on the surface of Mars and in martian meteorites [10] suggests that the planet has been dry since their formation. In fact, Bishop & Rampe [7] suggest that the transition from smectite to allophane on Mars marks a change in climate. References: [1] Carter J. et al. (2015) Icarus, 248, 373. [2] Murchie S.L. et al. (2009) JGR, 114. [3] Eberl D.D. et al. (1984) PTRS London A, 311, 241. [4] Kloprogge J.T. et al. (1999) CCM, 47, 529. [5] Velbel M.A. & W.W. Barker (2008) CCM, 56, 111. [6] Parfitt R. L. (2009) ClayMiner. 44, 135. [7] Bishop J.L. & E.B. Rampe (2016) EPSL, 448, 42. [8] Rampe

  8. Sulfate-rich eolian and wet interdune deposits, erebus crater, meridiani Planum, Mars (United States)

    Metz, J.M.; Grotzinger, J.P.; Rubin, D.M.; Lewis, K.W.; Squyres, S. W.; Bell, J.F.


    This study investigates three bedrock exposures at Erebus crater, an ?? 300 m diameter crater approximately 4 km south of Endurance crater on Mars. These outcrops, called Olympia, Payson, and Yavapai, provide additional evidence in support of the dune-interdune model proposed for the formation of the deposits at the Opportunity landing site in Meridiani Planum. There is evidence for greater involvement of liquid water in the Olympia outcrop exposures than was observed in Eagle or Endurance craters. The Olympia outcrop likely formed in a wet interdune and sand sheet environment. The facies observed within the Payson outcrop, which is likely stratigraphically above the Olympia outcrop, indicate that it was deposited in a damp-wet interdune, sand sheet, and eolian dune environment. The Yavapai outcrop, which likely stratigraphically overlies the Payson outcrop, indicates that it was deposited in primarily a sand sheet environment and also potentially in an eolian dune environment. These three outcrop exposures may indicate an overall drying-upward trend spanning the stratigraphic section from its base at the Olympia outcrop to its top at the Yavapai outcrop. This contrasts with the wetting-upward trend seen in Endurance and Eagle craters. Thus, the series of outcrops seen at Meridiani by Opportunity may constitute a full climatic cycle, evolving from dry to wet to dry conditions. ?? 2009, SEPM (Society for Sedimentary Geology).

  9. Evidences of Wet Climate on Early Mars from Analysis of HRSC Observations (United States)

    Jaumann, Ralf; Tirschj, Daniela; Adeli, Solmaz


    Both Geomorphological and mineralogical evidence point to the episodic availability of liquid water on the surface of early Mars. However, the distribution of water was not uniform over space and time. Considerable environmental and climate variations due to latitudinal or elevation effects combined with a diverse surface geology caused distinctively different of local conditions that influenced the planet`s water content. The history of water on Mars has been constantly revised and refined during the past years. Landforms such as widespread valley networks, fluvial deposits and associated assemblages of hydrated clay minerals support the hypothesis that the Martian climate was to some extend warm and wet during the early history of Mars [e.g.,1,2]. At the boundary between the Late Noachian and the Early Hesperian, environmental and climate conditions changed significantly and resulted in a transition towards a colder and dryer climate. The intensity of aqueous activity decreased throughout the Hesperian, including a transition from long-term and repeated precipitation-induced fluvial activity towards reduced, short-term, spatially isolated and groundwater-dominated fluvial erosion [e.g.,3,4,5,6]. At the end of the Hesperian, fluvial erosion has mostly ceased and volcanic, aeolian and glacial processes are interpreted to be dominant on Mars. The Early Amazonian was characterized most likely by a cold and dry climate that was similar to the conditions on recent Mars. However, Mars' climate and aqueous history, in particular the timing of the termination of fluvial activity and the transition from precipitation-induced toward groundwater-dominated erosion as well as the temperature with time, is still subject to debate. Modeling of flow transport processes revealed that the formation of deltas on Mars geologically requires only brief timespans [7] and, based on discharge estimates, the formation of erosional valleys also needs less than a few million years and seems

  10. Ancient wet aeolian environments on Earth: Clues to presence of fossil/live microorganisms on Mars (United States)

    Mahaney, W.C.; Milner, M.W.; Netoff, D.I.; Malloch, D.; Dohm, J.M.; Baker, V.R.; Miyamoto, H.; Hare, T.M.; Komatsu, G.


    Ancient wet aeolian (wet-sabkha) environments on Earth, represented in the Entrada and Navajo sandstones of Utah, contain pipe structures considered to be the product of gas/water release under pressure. The sediments originally had considerable porosity allowing the ingress of living plant structures, microorganisms, clay minerals, and fine-grained primary minerals of silt and sand size from the surface downward in the sedimentary column. Host rock material is of a similar size and porosity and presumably the downward migration of fine-grained material would have been possible prior to lithogenesis and final cementation. Recent field emission scanning electron microscopy (FESEM) and EDS (energy-dispersive spectrometry) examination of sands from fluidized pipes in the Early Jurassic Navajo Sandstone reveal the presence of fossil forms resembling fungal filaments, some bearing hyphopodium-like structures similar to those produced by modern tropical leaf parasites. The tropical origin of the fungi is consistent with the paleogeography of the sandstone, which was deposited in a tropical arid environment. These fossil fungi are silicized, with minor amounts of CaCO3 and Fe, and in some cases a Si/Al ratio similar to smectite. They exist as pseudomorphs, totally depleted in nitrogen, adhering to the surfaces of fine-grained sands, principally quartz and orthoclase. Similar wet aeolian paleoenvironments are suspected for Mars, especially following catastrophic sediment-charged floods of enormous magnitudes that are believed to have contributed to rapid formation of large water bodies in the northern plains, ranging from lakes to oceans. These events are suspected to have contributed to a high frequency of constructional landforms (also known as pseudocraters) related to trapped volatiles and water-enriched sediment underneath a thick blanket of materials that were subsequently released to the martian surface, forming piping structures at the near surface and

  11. Ancient wet aeolian environments on Earth: clues to presence of fossil/live microorganisms on Mars (United States)

    Mahaney, William C.; Milner, Michael W.; Netoff, D. I.; Malloch, David; Dohm, James M.; Baker, Victor R.; Miyamoto, Hideaki; Hare, Trent M.; Komatsu, Goro


    Ancient wet aeolian (wet-sabkha) environments on Earth, represented in the Entrada and Navajo sandstones of Utah, contain pipe structures considered to be the product of gas/water release under pressure. The sediments originally had considerable porosity allowing the ingress of living plant structures, microorganisms, clay minerals, and fine-grained primary minerals of silt and sand size from the surface downward in the sedimentary column. Host rock material is of a similar size and porosity and presumably the downward migration of fine-grained material would have been possible prior to lithogenesis and final cementation. Recent field emission scanning electron microscopy (FESEM) and EDS (energy-dispersive spectrometry) examination of sands from fluidized pipes in the Early Jurassic Navajo Sandstone reveal the presence of fossil forms resembling fungal filaments, some bearing hyphopodium-like structures similar to those produced by modern tropical leaf parasites. The tropical origin of the fungi is consistent with the paleogeography of the sandstone, which was deposited in a tropical arid environment. These fossil fungi are silicized, with minor amounts of CaCO 3 and Fe, and in some cases a Si/Al ratio similar to smectite. They exist as pseudomorphs, totally depleted in nitrogen, adhering to the surfaces of fine-grained sands, principally quartz and orthoclase. Similar wet aeolian paleoenvironments are suspected for Mars, especially following catastrophic sediment-charged floods of enormous magnitudes that are believed to have contributed to rapid formation of large water bodies in the northern plains, ranging from lakes to oceans. These events are suspected to have contributed to a high frequency of constructional landforms (also known as pseudocraters) related to trapped volatiles and water-enriched sediment underneath a thick blanket of materials that were subsequently released to the martian surface, forming piping structures at the near surface and

  12. Chemical Weathering on a Cold and Wet Ancient Mars: New Insights from a Glacial Mars Analog Site (United States)

    Scudder, N.; Horgan, B. H. N.; Rutledge, A. M.; Rampe, E. B.


    If cold climates prevailed on ancient Mars, we should expect to see corroborating mineralogical evidence preserved in the geologic record. However, the extent to which the diverse alteration mineralogy observed on Mars can be explained by cold climate weathering is currently unknown, as the alteration phases that result from weathering by snow and ice are poorly understood. If cold climate weathering produces distinct alteration signatures, they may be a useful climate indicator on Mars. On Earth, poorly crystalline or short order silicates, such as allophane, tend to dominate in alpine and arctic soils where weathering mainly occurs through rapid seasonal melting of ice and snow. This mineralogy is distinct from the crystalline phyllosilicates that are common in more temperate climates. Thus, we hypothesize that high abundances of poorly crystalline material could indicate cold climate weathering. Here we report new results from a field campaign at the mafic and glaciated Three Sisters volcanic complex in Oregon, USA, to determine the mineralogy and chemistry of cold climate weathering in a Mars analog environment. We find that high abundances of poorly crystalline phases are generated in this environment and that these phases may be detectable using orbital spectroscopy. Ongoing chemical and mineralogical analyses of glacial till and sediments from glacier-fed lakes and streams will allow us to determine the specific distribution and composition of mineral phases in Mars-relevant glacial environments. Poorly crystalline phases have been detected on Mars: modeling of TES data suggests a regionally distributed allophane component, while MER and MSL results indicate up to 40-50% amorphous components in rocks and sediments at Gusev and Gale Craters. We hypothesize that these could be the result of weathering by ice and snow. However, it is not clear that more crystalline alteration phases observed elsewhere on Mars could be formed under a globally cold climate.

  13. Mars Surveyor Program '01 Mars Environmental Compatibility Assessment wet chemistry lab: a sensor array for chemical analysis of the Martian soil (United States)

    Kounaves, Samuel P.; Lukow, Stefan R.; Comeau, Brian P.; Hecht, Michael H.; Grannan-Feldman, Sabrina M.; Manatt, Ken; West, Steven J.; Wen, Xiaowen; Frant, Martin; Gillette, Tim


    The Mars Environmental Compatibility Assessment (MECA) instrument was designed, built, and flight qualified for the now canceled MSP (Mars Surveyor Program) '01 Lander. The MECA package consisted of a microscope, electrometer, material patch plates, and a wet chemistry laboratory (WCL). The primary goal of MECA was to analyze the Martian soil (regolith) for possible hazards to future astronauts and to provide a better understanding of Martian regolith geochemistry. The purpose of the WCL was to analyze for a range of soluble ionic chemical species and electrochemical parameters. The heart of the WCL was a sensor array of electrochemically based ion-selective electrodes (ISE). After 20 months storage at -23 degrees C and subsequent extended freeze/thawing cycles, WCL sensors were evaluated to determine both their physical durability and analytical responses. A fractional factorial calibration of the sensors was used to obtain slope, intercept, and all necessary selectivity coefficients simultaneously for selected ISEs. This calibration was used to model five cation and three anion sensors. These data were subsequently used to determine concentrations of several ions in two soil leachate simulants (based on terrestrial seawater and hypothesized Mars brine) and four actual soil samples. The WCL results were compared to simulant and soil samples using ion chromatography and inductively coupled plasma optical emission spectroscopy. The results showed that flight qualification and prolonged low-temperature storage conditions had minimal effects on the sensors. In addition, the analytical optimization method provided quantitative and qualitative data that could be used to accurately identify the chemical composition of the simulants and soils. The WCL has the ability to provide data that can be used to "read" the chemical, geological, and climatic history of Mars, as well as the potential habitability of its regolith.

  14. Mars Surveyor Program '01 Mars Environmental Compatibility Assessment wet chemistry lab: a sensor array for chemical analysis of the Martian soil. (United States)

    Kounaves, Samuel P; Lukow, Stefan R; Comeau, Brian P; Hecht, Michael H; Grannan-Feldman, Sabrina M; Manatt, Ken; West, Steven J; Wen, Xiaowen; Frant, Martin; Gillette, Tim


    The Mars Environmental Compatibility Assessment (MECA) instrument was designed, built, and flight qualified for the now canceled MSP (Mars Surveyor Program) '01 Lander. The MECA package consisted of a microscope, electrometer, material patch plates, and a wet chemistry laboratory (WCL). The primary goal of MECA was to analyze the Martian soil (regolith) for possible hazards to future astronauts and to provide a better understanding of Martian regolith geochemistry. The purpose of the WCL was to analyze for a range of soluble ionic chemical species and electrochemical parameters. The heart of the WCL was a sensor array of electrochemically based ion-selective electrodes (ISE). After 20 months storage at -23 degrees C and subsequent extended freeze/thawing cycles, WCL sensors were evaluated to determine both their physical durability and analytical responses. A fractional factorial calibration of the sensors was used to obtain slope, intercept, and all necessary selectivity coefficients simultaneously for selected ISEs. This calibration was used to model five cation and three anion sensors. These data were subsequently used to determine concentrations of several ions in two soil leachate simulants (based on terrestrial seawater and hypothesized Mars brine) and four actual soil samples. The WCL results were compared to simulant and soil samples using ion chromatography and inductively coupled plasma optical emission spectroscopy. The results showed that flight qualification and prolonged low-temperature storage conditions had minimal effects on the sensors. In addition, the analytical optimization method provided quantitative and qualitative data that could be used to accurately identify the chemical composition of the simulants and soils. The WCL has the ability to provide data that can be used to "read" the chemical, geological, and climatic history of Mars, as well as the potential habitability of its regolith.

  15. There's Plenty of Room at the Bottom

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 16; Issue 9. There's Plenty of Room at the Bottom. Richard P Feynman. Classics Volume 16 Issue 9 September 2011 pp 890-905. Fulltext. Click here to view fulltext PDF. Permanent link: ...

  16. Ice-Covered Lakes in Gale Crater Mars: The Cold and Wet Hypothesis (United States)

    Kling, A. M.; Haberle, R. M.; Mckay, C. P.; Bristow, T. F.


    Recent geological discoveries from the Mars Science Laboratory provide evidence that Gale crater may have intermittently hosted a fluvio-lacustine environment during the Hesperian, with individual lakes lasting for a period of tens to hundreds of thousands of years. (Grotzinger et al., Science, 350 (6257), 2015). Estimates of the CO2 content of the atmosphere at the time the Gale sediments formed are far less than needed by any climate model to warm early Mars (Bristow et al., Geology, submitted), given the low solar energy input available at Mars 3.5 Gya. We have therefore explored the possibility that the lakes in Gale during the Hesperian were perennially covered with ice using the Antarctic Lakes as an analog. Using our best estimate for the annual mean surface temperature at Gale at this time (approx. 230K) we computed the thickness of an ice-covered lake. These thickness range from 10-30 meters depending on the ablation rate and ice transparency and would likely inhibit sediments from entering the lake. Thus, a first conclusion is that the ice must not be too cold. Raising the mean temperature to 245K is challenging, but not quite as hard as reaching 273K. We found that a mean annual temperature of 245K ice thicknesses range from 3-10 meters. These values are comparable to the range of those for the Antarctic lakes (3-6 m), and are not implausible. And they are not so thick that sediments cannot penetrate the ice. For the ice-covered lake hypothesis to work, however, a melt water source is needed. This could come from subaqueous melting of a glacial dam in contact with the lakes (as is the case for Lake Untersee) or from seasonal melt water from nearby glaciers (as is the case for the Dry Valley lakes). More work is needed to better assess these possibilities. However, the main advantage of the ice-covered lake model (and the main reason we pursued it) is that it relaxes the requirement for a long-lived active hydrological cycle involving rainfall and runoff

  17. A wet-geology and cold-climate Mars model: Punctuation of a slow dynamic approach to equilibrium (United States)

    Kargel, J. S.


    It was suggested that Mars may have possessed a relatively warm humid climate and a vigorous hydrological cycle involving meteoric precipitation, oceans, and continental ice sheets. Baker hypothesized that these geologically active conditions may have been repeated several times; each of these dynamic epochs was followed by a collapse of the climate and hydrologic cycle of Mars into essentially current conditions, completing what is termed a 'Baker cycle'. The purpose is to present an endmember possibility that Martian glacial landscapes, including some that were previously considered to have formed under warm climatic conditions, might be explained by processes compatible with an extremely cold surface. Two aspects of hypothesized Martian glacial terrains were cited as favoring a warm climate during Baker cycles: (1) the formation of some landscapes, including possible eskers, tunnel channels, drumlins, and outwash plains, appears to have required liquid water, and (2) a liquid-surfaced ocean was probably necessary to feed the glaciers. The requirement for liquid water, if these features were correctly interpreted, is difficult to avoid; it is entirely possible that a comparatively warm climate was involved, but it is not clear that formation of landforms by wet-based glaciers actually requires a warm climate. Even less certain is the supposed requirement for liquid oceans. Formation of glaciers only requires a source of water or ice to supply an amount of precipitation that exceeds losses due to melting and sublimation. At Martian temperatures precipitation is very low, but so are melting and sublimation, so a large body of ice that is unstable with respect to sublimation may take the role of Earth's oceans in feeding the glaciers. Recent models suggest that even current Martian polar caps, long thought to be static bodies of ice and dust, might actually be slow-moving, cryogenic continental glaciers. Is it possible that subglacial processes beneath cryogenic

  18. Mars

    CERN Document Server

    Day, Trevor


    Discusses the fundamental facts concerning this mysterious planet, including its mass, size, and atmosphere, as well as the various missions that helped planetary scientists document the geological history of Mars. This volume also describes Mars'' seasons with their surface effects on the planet and how they have changed over time.

  19. Mars

    CERN Document Server

    Payment, Simone


    This curriculum-based, fun, and approachable book offers everything young readers need to know to begin their study of the Red Planet. They will learn about the fundamental aspects of the Mars, including its size, mass, surface features, interior, orbit, and spin. Further, they will learn about the history of the missions to Mars, including the Viking spacecraft and the Curiosity and MAVEN rovers. Finally, readers will learn about why scientists think there's a chance that Mars is or was suitable for life. With stunning imagery from NASA itself, readers will have a front seat-view of the missi

  20. CLASSICS There's Plenty of Room at the Bottom

    Indian Academy of Sciences (India)

    copy of every book in our library by striking off a copy from the master plate in a few hours and mailing it in an envelope no bigger or heavier than any other ordinary air mail letter. Now, the name of this talk is “There is Plenty of Room at the Bottom” – not just “There is Room at the Bottom.” What I have demonstrated is that ...

  1. Mixtures of Silica and Disulfide Rocks Can Explain the Coeval Formation of Mineral Sequences on a Cold and Wet Early Mars (United States)

    Fairén, A. G.; Mateo, E.; Gago-Duport, L.; Losa-Adams, E.; Chevrier, V.; Gil-Lozano, C.


    The presence of Mg-Fe-phyllosilicate, carbonate and sulfate bearing rocks on Mars is consistent with a wide variety of aqueous environments ―from alkaline-neutral to acidic waters― existing in the past, which are usually explained assuming the existence of subsurface hydrothermal environments and a drastic climate change early on Mars' history. Here we present aqueous alteration experiments on different olivine and pyrite powdered mixtures, prepared by weight to analyze their weathering products under early Mars surface conditions: a CO2 atmosphere (PCO2 = 0.5 bar), low temperature (i.e., not hydrothermal conditions, <20º C), low fluid-to-rock ratio ( 10), and UV irradiation, recreating the geological setting of surface ponded water, to discuss the effect that the host-rock composition could have on the resulting mineral assemblage. We used mechanically active pyrite as the source of sulfur because it's ability to produce both acidic and oxidizing conditions through aqueous alteration without the addition of an external oxidizing agent. Consequently, pyrite is able to promoting the formation of iron hydroxides and sulfates even in oxygen limited conditions. In addition, we analyze the stability of the surface products after UV irradiation inside a simulation Planetary Atmosphere and Surface Chamber (PASC) at CAB. Preliminary results (time of aqueous reaction: 42 days, plus 5 days until total water evaporation) show appreciable differences in the altered samples, mostly related to sulfate and carbonate compounds. As the pyrite content increased, the most acidic and oxidizing conditions of the leaching solution caused the increase of the rate of olivine dissolution, modifying the formation pathways of secondary products. These results suggest that some of the alteration products identified on Mars could have formed on the surface coevally, without the necessity to invoke subsurface hydrothermalism, abrupt atmospheric changes or long periods of warming on early

  2. EnviroAtlas - Clean and Plentiful Water Metrics for the Conterminous United States (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas web service supports research and online mapping activities related to EnviroAtlas ( The Clean and Plentiful Water...

  3. Groundwater influence on the aeolian sequence stratigraphy of the Mechertate-Chrita-Sidi El Hani system, Tunisian Sahel: Analogies to the wet-dry aeolian sequence stratigraphy at Meridiani Planum, Terby crater, and Gale crater, Mars (United States)

    Essefi, Elhoucine; Komatsu, Goro; Fairén, Alberto G.; Chan, Marjorie A.; Yaich, Chokri


    watershed. Then, due to the rise of the water table, wet sediments of a sabkha rest atop the dry aeolian cycle to comprise a retrogradational sequence. At Terby and Gale craters, an opposite stratigraphic sequence starts with the wet deposition of the sabkha fill. Then, due to the fall of the water table, the dry aeolian sedimentation progrades atop to the sabkha fill to comprise a progradational sequence. We conclude that the various stratigraphic sequences at the MCSH system, described here, represent different possible analog scenarios for diverse depositional sequences on Mars, in all cases involving groundwater activity.

  4. There's Plenty of Boole at the Bottom: A Reversible CA Against Information Entropy

    NARCIS (Netherlands)

    Berto, F.; Tagliabue, J.; Rossi, G.


    “There’s Plenty of Room at the Bottom”, said the title of Richard Feynman’s 1959 seminal conference at the California Institute of Technology. Fifty years on, nanotechnologies have led computer scientists to pay close attention to the links between physical reality and information processing. Not

  5. Vaginitis test - wet mount (United States)

    Wet prep - vaginitis; Vaginosis - wet mount; Trichomoniasis - wet mount; Vaginal candida - wet mount ... a rash, painful intercourse, or odor after intercourse. Trichomoniasis , a sexually transmitted disease. Vaginal yeast infection .

  6. Mars Micromissions


    Matousek, Steve; Leschly, Kim; Gershman, Bob; Reimer, John


    A Mars micromission launches as an Ariane 5 secondary as early as November I, 2002. One possible mission is a Comm/nav micromission .orbiter. The other possible mission is a Mars airplane. Both missions are enabled by a lowcost, common micromisson bus design. The future of Mars micromissions has at least two micromissions per Mars Opportunity In cooperation with CNES. Other destinations besides Mars are possible by small changes and technology Infusion in the micromission system design detail...

  7. Modeled Wet Nitrate Deposition (United States)

    U.S. Environmental Protection Agency — Modeled data on nitrate wet deposition was obtained from Dr. Jeff Grimm at Penn State Univ. Nitrate wet depostion causes acidification and eutrophication of surface...

  8. When Plentiful Platforms Pay Off: Assessment Orientation Moderates the Effect of Assortment Size on Choice Engagement and Product Valuation


    Mathmann, F.; Chylinski, M.; DE RUYTER, K; Higgins, T


    Popular digital platforms, such as Netflix and GrubHub, purposefully aggregate offerings, according to the premise that customers value products chosen from plentiful assortments. Yet academic literature provides little clarity about when, for whom, or how larger online retail assortments affect the value of the products. To provide new insights, the current article aims to address ambiguous extant findings about the effects of larger product assortments. Specifically, this research tests whe...

  9. Mars bevares

    DEFF Research Database (Denmark)

    Hendricks, Vincent Fella; Hendricks, Elbert


    2009 er femåret for Mission Mars. I den anledning opridser de to kronikører, far og søn, hvorfor man bør lade planer om en bemandet tur til Mars forblive i skrivebordsskuffen......2009 er femåret for Mission Mars. I den anledning opridser de to kronikører, far og søn, hvorfor man bør lade planer om en bemandet tur til Mars forblive i skrivebordsskuffen...

  10. The Small Mars System (United States)

    Fantino, E.; Grassi, M.; Pasolini, P.; Causa, F.; Molfese, C.; Aurigemma, R.; Cimminiello, N.; de la Torre, D.; Dell'Aversana, P.; Esposito, F.; Gramiccia, L.; Paudice, F.; Punzo, F.; Roma, I.; Savino, R.; Zuppardi, G.


    The Small Mars System is a proposed mission to Mars. Funded by the European Space Agency, the project has successfully completed Phase 0. The contractor is ALI S.c.a.r.l., and the study team includes the University of Naples ;Federico II;, the Astronomical Observatory of Capodimonte and the Space Studies Institute of Catalonia. The objectives of the mission are both technological and scientific, and will be achieved by delivering a small Mars lander carrying a dust particle analyser and an aerial drone. The former shall perform in situ measurements of the size distribution and abundance of dust particles suspended in the Martian atmosphere, whereas the latter shall demonstrate low-altitude flight in the rarefied planetary environment. The mission-enabling technology is an innovative umbrella-like heat shield, known as IRENE, developed and patented by ALI. The mission is also a technological demonstration of the shield in the upper atmosphere of Mars. The core characteristics of SMS are the low cost (120 M€) and the small size (320 kg of wet mass at launch, 110 kg at landing), features which stand out with respect to previous Mars landers. To comply with them is extremely challenging at all levels, and sets strict requirements on the choice of the materials, the sizing of payloads and subsystems, their arrangement inside the spacecraft and the launcher's selection. In this contribution, the mission and system concept and design are illustrated and discussed. Special emphasis is given to the innovative features and to the challenges faced in the development of the work.

  11. Europe goes to Mars - preparations are well under way (United States)


    carefully selected site on Isidis Planitia, a plain just north of the equator near where the ancient, cratered southern highlands meet the younger, smooth northern lowlands. Beagle 2 will complete its mission in about six months. The Mars Express orbiter instruments will: * Image the entire surface at high resolution (10m/pixel) and selected areas at super resolution (2m/pixel) (HRSC instrument) * Produce a map of the mineral composition of the surface at 100m resolution (OMEGA instrument) * Map the composition of the atmosphere and determine its global circulation (PFS instrument) * Determine the structure of the sub-surface to a depth of a few kilometres (MARSIS instrument) * Determine the water vapour and ozone in the atmosphere (SPICAM instrument) * Determine the interaction of the atmosphere with the solar wind (ASPERA instrument and MaRS experiment) (see below for list of full instrument names, acronyms and Principal Investigators) The Beagle 2 lander will: * Determine the geology and the mineral and chemical composition of the landing site * Search for life signatures (exobiology) * Study the weather and climate Mars Express will provide unique investigations that will contribute to an understanding of many of the unknowns about Mars. Here are a few: * If Mars really was warm and wet during its early history, where did the water go? Some may have been lost to space and some may be buried underground. ASPERA will measure water loss to space and MARSIS is the only instrument planned for any mission with the capability of looking for water or ice down to a depth of a few kilometres. The presence of underground water would have a considerable impact on the prospects for future manned missions to the planet. * If there was water could there have been, or still be, life? Beagle 2 will scoop up soil and rock samples and analyse them there and then for some of the key chemical signatures of life. The results will be far more telling than anything yet found in Martian

  12. Wetting, Prewetting and Superfluidity


    Taborek, P.


    Experiments on adsorption and wetting of quantum fluids (4He and 3He) on weakly binding alkali metal substrates are reviewed. Helium on weak substrates can undergo a variety of phase transitions including wetting, prewetting, layering, and liquid-vapor transitions. Another characteristic feature of weak substrates is the absence of an immobile quasi solid layer which is present on all conventional strong substrates. Both the absence of the immobile layer and the interaction with surface phase...

  13. Wet gas sampling

    Energy Technology Data Exchange (ETDEWEB)

    Welker, T.F.


    The quality of gas has changed drastically in the past few years. Most gas is wet with hydrocarbons, water, and heavier contaminants that tend to condense if not handled properly. If a gas stream is contaminated with condensables, the sampling of that stream must be done in a manner that will ensure all of the components in the stream are introduced into the sample container as the composite. The sampling and handling of wet gas is extremely difficult under ideal conditions. There are no ideal conditions in the real world. The problems related to offshore operations and other wet gas systems, as well as the transportation of the sample, are additional problems that must be overcome if the analysis is to mean anything to the producer and gatherer. The sampling of wet gas systems is decidedly more difficult than sampling conventional dry gas systems. Wet gas systems were generally going to result in the measurement of one heating value at the inlet of the pipe and a drastic reduction in the heating value of the gas at the outlet end of the system. This is caused by the fallout or accumulation of the heavier products that, at the inlet, may be in the vapor state in the pipeline; hence, the high gravity and high BTU. But, in fact, because of pressure and temperature variances, these liquids condense and form a liquid that is actually running down the pipe as a stream or is accumulated in drips to be blown from the system. (author)

  14. Wet oxidation of quinoline

    DEFF Research Database (Denmark)

    Thomsen, A.B.; Kilen, H.H.


    The influence of oxygen pressure (0.4 and 2 MPa). reaction time (30 and 60 min) and temperature (260 and 280 degrees C) on the wet oxidation of quinoline has been studied. The dominant parameters for the decomposition of quinoline were oxygen pressure and reaction temperature. whereas the reaction...... if low oxygen pressure or long reaction times were used. The reaction products derived from the experiment in which quinoline was mostly decomposed were studied with respect to biological degradation. The results showed that these products were highly digestible under activated sludge treatment....... The combined wet oxidation and biological treatment of reaction products resulted in 91% oxidation of the parent compound to CO2 and water. Following combined wet oxidation and biological treatment the sample showed low toxicity towards Nitrosomonas and no toxicity towards Nitrobacter. (C) 1998 Elsevier...

  15. Wetting of Water on Graphene


    Bera, Bijoyendra; Shahidzadeh, Noushine; Mishra, Himanshu; Bonn, Daniel


    The wetting properties of graphene have proven controversial and difficult to assess. The presence of a graphene layer on top of a substrate does not significantly change the wetting properties of the solid substrate, suggesting that a single graphene layer does not affect the adhesion between the wetting phase and the substrate. However, wetting experiments of water on graphene show contact angles that imply a large amount of adhesion. Here, we investigate the wetting of graphene by measurin...

  16. Wetting of real surfaces

    CERN Document Server

    Bormashenko, Edward Yu


    The problem of wetting and drop dynamics on various surfaces is very interesting from both the scientificas well as thepractical viewpoint, and subject of intense research.The results are scattered across papers in journals, sothis workwill meet the need for a unifying, comprehensive work.


    Energy Technology Data Exchange (ETDEWEB)

    Hugo S. Caram; Natalie Foster


    The elastic modulus E of wet granular material was found to be of the order of 0.25 MPa, this value does not compare well with the value predicted for a cubic array of spheres under Hertzian contact were the predicted values were in the order of 250 MPa . The strain-stress behavior of a wet granular media was measured using a split Parfitt tensile tester. In all cases the stress increases linearly with distance until the maximum uniaxial tensile stress is reached. The stress then decreases exponentially with distance after this maximum is reached. The linear region indicates that wet solids behave elastically for stresses below the tensile stresses and can store significant elastic energy. The elastic deformation cannot be explained by analyzing the behavior of individual capillary bridges and requires accounting for the deformation of the solids particles. The elastic modulus of the wet granular material remains unexplained. New information was found to support the experimental finding and a first theory to explain the very small elastic modulus is presented. A new model based on the used of the finite element method is being developed.

  18. The Wet Chaparral


    Hope, Audrey Marie


    The Wet Chaparral: Poetry at Home (Out There) is an MFA thesis exhibition of new sculptures by Audrey Hope. The thesis paper describes the exhibition, discusses the artist’s personal and artistic motivations, and analyzes writings relevant to the work.

  19. Deep-water carbonate ion shifts during the last glacial termination in the Bay of Plenty, New Zealand (United States)

    Allen, K. A.; Sikes, E. L.; Elmore, A.; Hoenisch, B.; Guilderson, T. P.; Cook, M. S.; Rosenthal, Y.


    It has been suggested that a greater amount of CO2 was stored in the deep sea during glacial periods via changes in biologic pump efficiency and increased uptake by a more alkaline ocean, characterized by carbonate ion concentrations higher than today. Reconstructing past ocean carbonate ion will enable better quantification of the relative roles of different CO2 storage mechanisms. Here, we present records of deep water carbonate chemistry since the Last Glacial Maximum derived from sediment cores located in New Zealand's Bay of Plenty. Today, Bay of Plenty mid- to deep waters consist of a relatively fresh Antarctic Intermediate Water overlying southern-sourced Circumpolar Deep Water, which in turn is underlain by CO2-enriched deep water, partially derived from the North Pacific. We reconstruct past changes in bottom water carbonate chemistry from the trace element and stable isotopic composition recorded in shells of the epibenthic foraminifer Cibicidoides wuellerstorfi. The boron to calcium ratio (B/Ca) in these shells indicates that during the last glacial maximum (LGM), deep water ΔCO32- was slightly less than the modern value of ~ 20 µmol/kg. When combined with shifts in carbon isotopes, these results imply changes in respired CO2 storage, with low-ΔCO32-, low-δ13C waters dominating during the LGM and higher-ΔCO32-, higher-δ13C waters prevailing in the Holocene. During the transition between LGM and Holocene, ΔCO32- shifts rapidly in the mid-depth record (~1,600 m), rising from ~5 µmol/kg at about 18 ka to a peak of 30 µmol/kg at 16 ka. To determine whether these sharp changes are due to vertical shifts in water mass boundaries or rapid changes in source water formation regions, shallower and deeper cores (~1,200 m and ~3,000 m) from the same region are also being evaluated.

  20. Dry Mars: Parched Rocks and Fallen Dust (United States)

    Treiman, Allan H.


    While "following the water" to find life on Mars, it is easy to overlook evidence that Mars is harshly dry, and to neglect ideas that do not invoke water. Direct evidence for a dry Mars comes from the ALH 84001 meteorite, which has seen little or no liquid water during its last 3.9 billion years on Mars. Its aridity is difficult to reconcile with a Mars of abundant near-surface surface water or with episodes of warm wet climate. Alternative scenarios are also possible, even likely, for the martian gullies and debris flows that have been cited as evidence of liquid water. It is reasonable that the gullies flows are the remnants of massive dust avalanches, comparable to large climax snow avalanches seen on Earth. Mars' surface is now desiccated, and at least part of it has been equally desiccated for the past 3.9 billion years. With this background, and the wealth of atmospheric, imaging, and chemical data available from Mars, one must be very cautious in evaluating claims for liquid water recently at or near Mars' surface. Additional information is contained in the original extended abstract.

  1. Mar Capeans

    CERN Multimedia


    Mar Capeans, CERN researcher, answers the question to "What can we do in the world of sciences and innovation to make visible the invisible?". This piece belongs to a series of videos made by the Spanish Aquae Foundation, a supporter of the CERN & Society Foundation.


    Energy Technology Data Exchange (ETDEWEB)



    The yield locus, tensile strength and fracture mechanisms of wet granular materials were studied. The yield locus of a wet material was shifted to the left of that of the dry specimen by a constant value equal to the compressive isostatic stress due to pendular bridges. for materials with straight yield loci, the shift was computed from the uniaxial tensile strength, either measured in a tensile strength tester or calculated from the correlation, and the angle of internal friction of the material. The predicted shift in the yield loci due to different moisture contents compare well with the measured shift in the yield loci of glass beads, crushed limestone, super D catalyst and Leslie coal. Measurement of the void fraction during the shear testing was critical to obtain the correct tensile strength theoretically or experimentally.

  3. Wetting in Color


    Burgess, Ian Bruce


    Colorimetric litmus tests such as pH paper have enjoyed wide commercial success due to their inexpensive production and exceptional ease of use. However, expansion of colorimetry to new sensing paradigms is challenging because macroscopic color changes are seldom coupled to arbitrary differences in the physical/chemical properties of a system. In this thesis I present in detail the development of Wetting in Color Technology, focusing primarily on its application as an inexpensive and highly...

  4. Workshop on Water on Mars (United States)

    Clifford, S. (Editor)


    The opening session of the Workshop focused on one of the most debated areas of Mars volatiles research-the size of the planet's past and present bulk water content. Current estimates of the inventory of H2O on Mars range from an equivalent layer of liquid 10-1000 meters deep averaged over the planet's surface. The most recent of these estimates, presented at the Workshop, is based on the now popular belief that the SNC class of meteorites represent actual samples of the Martian crust. From a model of planetary accretion and degassing founded on this assumption, it was determined that the present inventory of H2O on Mars is equivalent to a global layer no more than 50 meters deep. During the discussion generated by this estimate, several investigators expressed reservations about an H2O inventory as small as a few tens of meters, for it appears to directly contradict the seemingly abundant morphologic evidence that Mars is (or has been) water rich. Others, however, argued that the interpretation of much of this morphologic evidence is at best equivocal and that the case for a wet Mars is far from established. Atmospheric water vapor measurements, compiled by Earth based telescopes and the Viking Orbiter Mars Atmospheric Water Detectors (MAWD), now span a period of over six Martian years. Analysis of this data suggests that the seasonal cycle is governed by both the sublimation and condensation of H2O at the poles and by its adsorption/desorption within the regolith. So far, efforts to simulate the seasonal vapor cycle have failed to reproduce the observed behavior.

  5. Wetting in Color (United States)

    Burgess, Ian Bruce

    Colorimetric litmus tests such as pH paper have enjoyed wide commercial success due to their inexpensive production and exceptional ease of use. However, expansion of colorimetry to new sensing paradigms is challenging because macroscopic color changes are seldom coupled to arbitrary differences in the physical/chemical properties of a system. In this thesis I present in detail the development of Wetting in Color Technology, focusing primarily on its application as an inexpensive and highly selective colorimetric indicator for organic liquids. The technology exploits chemically-encoded inverse-opal photonic crystals to control the infiltration of fluids to liquid-specific spatial patterns, projecting minute differences in liquids' wettability to macroscopically distinct, easy-to-visualize structural color patterns. It is shown experimentally and corroborated with theoretical modeling using percolation theory that the high selectivity of wetting, upon-which the sensitivity of the indicator relies, is caused by the highly symmetric structure of our large-area, defect-free SiO2 inverse-opals. The regular structure also produces a bright iridescent color, which disappears when infiltrated with liquid - naturally coupling the optical and fluidic responses. Surface modification protocols are developed, requiring only silanization and selective oxidation, to facilitate the deterministic design of an indicator that differentiates a broad range of liquids. The resulting tunable, built-in horizontal and vertical chemistry gradients allow the wettability threshold to be tailored to specific liquids across a continuous range, and make the readout rely only on countable color differences. As wetting is a generic fluidic phenomenon, Wetting in Color technology could be suitable for applications in authentication or identification of unknown liquids across a broad range of industries. However, the generic nature of the response also ensures chemical non-specificity. It is shown

  6. Thermonuclear land of plenty (United States)

    Gasior, P.


    Since the process of energy production in the stars has been identified as the thermonuclear fusion, this mechanism has been proclaimed as a future, extremely modern, reliable and safe for sustaining energetic needs of the humankind. However, the idea itself was rather straightforward and the first attempts to harness thermonuclear reactions have been taken yet in 40s of the twentieth century, it quickly appeared that physical and technical problems of domesticating exotic high temperature medium known as plasma are far from being trivial. Though technical developments as lasers, superconductors or advanced semiconductor electronics and computers gave significant contribution for the development of the thermonuclear fusion reactors, for a very long time their efficient performance was out of reach of technology. Years of the scientific progress brought the conclusions that for the development of the thermonuclear power plants an enormous interdisciplinary effort is needed in many fields of science covering not only plasma physics but also material research, superconductors, lasers, advanced diagnostic systems (e.g. spectroscopy, interferometry, scattering techniques, etc.) with huge amounts of data to be processed, cryogenics, measurement-control systems, automatics, robotics, nanotechnology, etc. Due to the sophistication of the problems with plasma control and plasma material interactions only such a combination of the research effort can give a positive output which can assure the energy needs of our civilization. In this paper the problems of thermonuclear technology are briefly outlined and it is shown why this domain can be a broad field for the experts dealing with electronics, optoelectronics, programming and numerical simulations, who at first glance can have nothing common with the plasma or nuclear physics.

  7. Land of Plenty? (United States)

    Passerini, Ed


    Possible future scenarios for the United States are described. As resources become scarce, the exploding U.S. population will inevitably lead to rapid inflation, greater unemployment, greater likelihood of war, and the virtual impossibility of maintaining social services such as education and old-age security programs at current levels. (RM)

  8. Plentiful forest, happy people?

    DEFF Research Database (Denmark)

    Buhmann, Karin; Nathan, Iben


    address social sustainability as well as the environment but do not (yet) deliver legality verification required by the EU Timber Regulation from March 2013. We also discuss possible contributions that could follow from adding a Corporate Social Responsibility (CSR) perspective to the FLEGT approach...

  9. PREFACE: Wetting: introductory note (United States)

    Herminghaus, S.


    The discovery of wetting as a topic of physical science dates back two hundred years, to one of the many achievements of the eminent British scholar Thomas Young. He suggested a simple equation relating the contact angle between a liquid surface and a solid substrate to the interfacial tensions involved [1], γlg cos θ = γsg - γsl (1) In modern terms, γ denotes the excess free energy per unit area of the interface indicated by its indices, with l, g and s corresponding to the liquid, gas and solid, respectively [2]. After that, wetting seems to have been largely ignored by physicists for a long time. The discovery by Gabriel Lippmann that θ may be tuned over a wide range by electrochemical means [3], and some important papers about modifications of equation~(1) due to substrate inhomogeneities [4,5] are among the rare exceptions. This changed completely during the seventies, when condensed matter physics had become enthusiastic about critical phenomena, and was vividly inspired by the development of the renormalization group by Kenneth Wilson [6]. This had solved the long standing problem of how to treat fluctuations, and to understand the universal values of bulk critical exponents. By inspection of the critical exponents of the quantities involved in equation~(1), John W Cahn discovered what he called critical point wetting: for any liquid, there should be a well-defined transition to complete wetting (i.e., θ = 0) as the critical point of the liquid is approached along the coexistence curve [7]. His paper inspired an enormous amount of further work, and may be legitimately viewed as the entrance of wetting into the realm of modern physics. Most of the publications directly following Cahn's work were theoretical papers which elaborated on wetting in relation to critical phenomena. A vast amount of interesting, and in part quite unexpected, ramifications were discovered, such as the breakdown of universality in thin film systems [8]. Simultaneously, a number

  10. Wet steam wetness measurement in a 10 MW steam turbine

    Directory of Open Access Journals (Sweden)

    Kolovratník Michal


    Full Text Available The aim of this paper is to introduce a new design of the extinction probes developed for wet steam wetness measurement in steam turbines. This new generation of small sized extinction probes was developed at CTU in Prague. A data processing technique is presented together with yielded examples of the wetness distribution along the last blade of a 10MW steam turbine. The experimental measurement was done in cooperation with Doosan Škoda Power s.r.o.

  11. The Mojave vadose zone: a subsurface biosphere analogue for Mars. (United States)

    Abbey, William; Salas, Everett; Bhartia, Rohit; Beegle, Luther W


    If life ever evolved on the surface of Mars, it is unlikely that it would still survive there today, but as Mars evolved from a wet planet to an arid one, the subsurface environment may have presented a refuge from increasingly hostile surface conditions. Since the last glacial maximum, the Mojave Desert has experienced a similar shift from a wet to a dry environment, giving us the opportunity to study here on Earth how subsurface ecosystems in an arid environment adapt to increasingly barren surface conditions. In this paper, we advocate studying the vadose zone ecosystem of the Mojave Desert as an analogue for possible subsurface biospheres on Mars. We also describe several examples of Mars-like terrain found in the Mojave region and discuss ecological insights that might be gained by a thorough examination of the vadose zone in these specific terrains. Examples described include distributary fans (deltas, alluvial fans, etc.), paleosols overlain by basaltic lava flows, and evaporite deposits.

  12. Mars Public Engagement Overview (United States)

    Johnson, Christine


    This viewgraph presentation reviews the Mars public engagement goal to understand and protect our home planet, explore the Universe and search for life, and to inspire the next generation of explorers. Teacher workshops, robotics education, Mars student imaging and analysis programs, MARS Student Imaging Project (MSIP), Russian student participation, MARS museum visualization alliance, and commercialization concepts are all addressed in this project.

  13. Oxychlorine Species on Mars: Implications from Gale Crater Samples (United States)

    Archer, P. Douglas, Jr.; Ming, Douglas W.; Sutter, Brad; Morris, Richard V.; Clark, B. C.; Mahaffy, P. H.; Wray, J. J.; Fairen, A. G.; Gellert, Ralf; Yen, Albert; hide


    Evidence of oxychlorine species such as perchlorates or chlorates have been detected in nearly every acquired sample analyzed on the surface of Mars. Perchlorates were first discovered by the Wet Chemistry Laboratory (WCL) instrument on the Phoenix lander in 2008. The Sample Analysis at Mars (SAM) instrument on the Mars Science Laboratory (MSL) has analyzed twelve samples from Gale Crater (as of July 2016), nine drilled samples and three scooped samples. After delivery to SAM, samples are heated to approximately 850 C and evolved gases are measured by a quadrupole mass spectrometer.

  14. Forced wetting and hydrodynamic assist (United States)

    Blake, Terence D.; Fernandez-Toledano, Juan-Carlos; Doyen, Guillaume; De Coninck, Joël


    Wetting is a prerequisite for coating a uniform layer of liquid onto a solid. Wetting failure and air entrainment set the ultimate limit to coating speed. It is well known in the coating art that this limit can be postponed by manipulating the coating flow to generate what has been termed "hydrodynamic assist," but the underlying mechanism is unclear. Experiments have shown that the conditions that postpone air entrainment also reduce the apparent dynamic contact angle, suggesting a direct link, but how the flow might affect the contact angle remains to be established. Here, we use molecular dynamics to compare the outcome of steady forced wetting with previous results for the spontaneous spreading of liquid drops and apply the molecular-kinetic theory of dynamic wetting to rationalize our findings and place them on a quantitative footing. The forced wetting simulations reveal significant slip at the solid-liquid interface and details of the flow immediately adjacent to the moving contact line. Our results confirm that the local, microscopic contact angle is dependent not simply only on the velocity of wetting but also on the nature of the flow that drives it. In particular, they support an earlier suggestion that during forced wetting, an intense shear stress in the vicinity of the contact line can assist surface tension forces in promoting dynamic wetting, thus reducing the velocity-dependence of the contact angle. Hydrodynamic assist then appears as a natural consequence of wetting that emerges when the contact line is driven by a strong and highly confined flow. Our theoretical approach also provides a self-consistent model of molecular slip at the solid-liquid interface that enables its magnitude to be estimated from dynamic contact angle measurements. In addition, the model predicts how hydrodynamic assist and slip may be influenced by liquid viscosity and solid-liquid interactions.

  15. Mars One - Bemanede missioner til Mars


    Jørgensen, Joan; Kryger, Benjamin; Bundgaard, Silke Sophie; Albarazi, Lujain


    The Mars One Project has been widely reported in the media recently. However many people are skeptical about the project and do not believe it is realistic at all. In this project we explore the Mars One Project as we look into the psychological and physiological elements that can influence the mission. We look into personal interaction, group dynamics and zoom in on isolation and the consequences of isolation on people. We compare the situation on Mars with similar theories. We include da...

  16. Beyond water on Mars


    Grotzinger, John


    Mars exploration has been guided by the search for water. The more complex quest by Mars Science Laboratory for habitable environments should illuminate the Martian environmental history, and possibly deliver insights into extraterrestrial life.

  17. Mars - Water Ice Clouds (United States)


    The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO.

  18. Mars Gashopper Airplane Project (United States)

    National Aeronautics and Space Administration — The Mars Gas Hopper Airplane, or "gashopper" is a novel concept for propulsion of a robust Mars flight and surface exploration vehicle that utilizes indigenous CO2...

  19. Saltation transport on Mars


    Parteli, Eric J. R.; Herrmann, Hans J.


    We present the first calculation of saltation transport and dune formation on Mars and compare it to real dunes. We find that the rate at which grains are entrained into saltation on Mars is one order of magnitude higher than on Earth. With this fundamental novel ingredient, we reproduce the size and different shapes of Mars dunes, and give an estimate for the wind velocity on Mars.

  20. Mars: The Viking Discoveries. (United States)

    French, Bevan M.

    This booklet describes the results of NASA's Viking spacecraft on Mars. It is intended to be useful for the teacher of basic courses in earth science, space science, astronomy, physics, or geology, but is also of interest to the well-informed layman. Topics include why we should study Mars, how the Viking spacecraft works, the winds of Mars, the…

  1. From Independence Day to Land of Plenty: Screening American Patriotism from German Émigré Perspectives before and after 9/11

    Directory of Open Access Journals (Sweden)

    Frank Mehring


    Full Text Available Independence Day and Land of Plenty are two tropes referring to the basis of American national identity: the Declaration of Independence with its guarantee of equal and inalienable rights and the promise of an inexhaustible abundance of resources. Independence Day and Land of Plenty are also two American feature films directed by German émigrés, the first being a science fiction blockbuster from 1996 by Roland Emmerich, the second an independent road movie from 2003 by Wim Wenders. Both films confront the issue of American patriotism albeit from different angles and at different times. Independence Day wholeheartedly embraces the American founding myths and translates them into a science fiction scenario. Wenders manoeuvres into an artistic space producing what I call patriotism of dissent. The films engage in a kind of dialectic dialogue on American patriotism. This article takes a close look at émigré perspectives on American patriotism before and after 9/11. By turning to the four patterns which political theorist Samuel P. Huntington identified as possible responses to the discrepancy between principles and practices of American democracy, I will analyse Independence Day as a filmic strategy to deny democratic gaps and Land of Plenty as a representative example of a moralistic reaction to democratic gaps. In the discourse of screening American patriotism from German émigré perspectives before and after 9/11, the work of Emmerich and Wenders exemplifies the spectrum of approaches to negotiate the fantasy of, desire for, and experience of American culture in the medium of film.

  2. Wetting of Water on Graphene

    KAUST Repository

    Bera, Bijoyendra


    The wetting properties of graphene have proven controversial and difficult to assess. The presence of a graphene layer on top of a substrate does not significantly change the wetting properties of the solid substrate, suggesting that a single graphene layer does not affect the adhesion between the wetting phase and the substrate. However, wetting experiments of water on graphene show contact angles that imply a large amount of adhesion. Here, we investigate the wetting of graphene by measuring the mass of water vapor adsorbing to graphene flakes of different thickness at different relative humidities. Our experiments unambiguously show that the thinnest of graphene flakes do not adsorb water, from which it follows that the contact angle of water on these flakes is ~180o. Thicker flakes of graphene nanopowder, on the other hand, do adsorb water. A calculation of the van der Waals (vdW) interactions that dominate the adsorption in this system confirms that the adhesive interactions between a single atomic layer of graphene and water are so weak that graphene is superhydrophobic. The observations are confirmed in an independent experiment on graphene-coated water droplets that shows that it is impossible to make liquid \\'marbles\\' with molecularly thin graphene.

  3. Surface structure determines dynamic wetting (United States)

    Shiomi, Junichiro; Wang, Jiayu; Do-Quang, Minh; Cannon, James; Yue, Feng; Suzuki, Yuji; Amberg, Gustav


    Dynamic wetting, the spontaneous spreading process after droplet contacts a solid surface, is important in various engineering processes, such as in printing, coating, and lubrication. In the recent years, experiments and numerical simulations have greatly progressed the understanding in the dynamic wetting particularly on ``flat'' substrates. To gain further insight into the governing physics of the dynamic wetting, we perform droplet-wetting experiments on microstructured surfaces, just a few micrometers in size, with complementary numerical simulations, and investigate the dependence of the spreading rate on the microstructure geometries and fluid properties. We reveal that the influence of microstructures can be quantified in terms of a line friction coefficient for the energy dissipation rate at the contact line, and that this can be described in a simple formula in terms of the geometrical parameters of the roughness and the line-friction coefficient of the planar surface. The systematic study is also of practical importance since structures and roughness are omnipresent and their influence on spreading rate would give us additional degrees of freedom to control the dynamic wetting. This work was financially supported in part by, the Japan Society for the Promotion of Science (J.W., J.C., and J.S) and Swedish Governmental Agency for Innovation Systems (M.D.-Q. and G.A.).

  4. Plague cycles in two rodent species from China: Dry years might provide context for epizootics in wet years (United States)

    Eads, David A.; Biggins, Dean E.; Xu, Lei; Liu, Qiyong


    Plague, a rodent-associated, flea-borne zoonosis, is one of the most notorious diseases in history. Rates of plague transmission can increase when fleas are abundant. Fleas commonly desiccate and die when reared under dry conditions in laboratories, suggesting fleas will be suppressed during droughts in the wild, thus reducing the rate at which plague spreads among hosts. In contrast, fleas might increase in abundance when precipitation is plentiful, producing epizootic outbreaks during wet years. We tested these hypotheses using a 27-yr data set from two rodents in Inner Mongolia, China: Mongolian gerbils (Meriones unguiculatus) and Daurian ground squirrels (Spermophilus dauricus). For both species of rodents, fleas were most abundant during years preceded by dry growing seasons. For gerbils, the prevalence of plague increased during wet years preceded by dry growing seasons. If precipitation is scarce during the primary growing season, succulent plants decline in abundance and, consequently, herbivorous rodents can suffer declines in body condition. Fleas produce more offspring and better survive when parasitizing food-limited hosts, because starving animals tend to exhibit inefficient behavioral and immunological defenses against fleas. Further, rodent burrows might buffer fleas from xeric conditions aboveground during dry years. After a dry year, fleas might be abundant due to the preceding drought, and if precipitation and succulent plants become more plentiful, rodents could increase in density, thereby creating connectivity that facilitates the spread of plague. Moreover, in wet years, mild temperatures might increase the efficiency at which fleas transmit the plague bacterium, while also helping fleas to survive as they quest among hosts. In this way, dry years could provide context for epizootics of plague in wet years.

  5. Solar Power on Mars (United States)


    This chart illustrates the variation in available solar power for each of NASA's twin Mars Exploration Rovers over the course of approximately two Mars years. Two factors affect the amount of available power: the tilt of Mars' axis and the eccentricity of the Mars' orbit about the sun. The horizontal scale is the number of Martian days (sols) after the Jan. 4, 2004, (Universal Time) landing of Spirit at Mars' Gusev Crater. The vertical scale on the right indicates the amount of available solar power as a ratio of the amount available at the equator when Mars is closest to the sun (perihelion). The red line indicates power availability at Spirit's landing site (Gusev). The blue line indicates power availability at Opportunity's landing site (Meridiani). The vertical scale on the right applies to the dotted line, indicating the latitude north or south of Mars' equator where the noon sun is overhead at different times of the Martian year.

  6. Mars Solar Power (United States)

    Landis, Geoffrey A.; Kerslake, Thomas W.; Jenkins, Phillip P.; Scheiman, David A.


    NASA missions to Mars, both robotic and human, rely on solar arrays for the primary power system. Mars presents a number of challenges for solar power system operation, including a dusty atmosphere which modifies the spectrum and intensity of the incident solar illumination as a function of time of day, degradation of the array performance by dust deposition, and low temperature operation. The environmental challenges to Mars solar array operation will be discussed and test results of solar cell technology operating under Mars conditions will be presented, along with modeling of solar cell performance under Mars conditions. The design implications for advanced solar arrays for future Mars missions is discussed, and an example case, a Martian polar rover, are analyzed.

  7. Atmospheric Loss and Warming Of The Early Mars (United States)

    Airapetian, V.; Gronoff, G.; Grocer, A.; Khazanov, G. V.; Hébrard, E.


    Today Mars represents an inhospitable world with a thin 6-mbar atmosphere that cannot support surface water. Current evidence suggests that the early Mars was a wet and at least somewhat warmer world that could support life. How hospitable Mars was for life? The atmospheric evolution of Mars over the last 4 billion years was affected by the rate of atmospheric loss and the chemical changes induced by space weather events from the evolving Sun and the planet's early outgassing history. We apply our atmospheric model enhanced with chemistry that describes photo-collisional dissociation and ionization of molecular nitrogen and carbon dioxide rich atmosphere of the early Mars due to XUV emission and penetration of energetic protons accelerated in extended shock waves driven by super Carrington events from the young Sun. We calculate the rate of atmospheric loss of oxygen ions from the atmosphere of early Mars to be 200 kg/s. This suggests that the early Martian atmosphere was subject to significant erosion, which implies the large rate of outgassing due to tectonic and volcanic activity. We also show that energetic protons produce multiple generations of secondary electrons that contribute to the destruction of N2 into reactive nitrogen, and the subsequent destruction of CO2 and CH4 efficiently producing N2O, a powerful greenhouse gas. The efficient production of nitrous oxide in the Martian troposphere can explain the longstanding problem of the Faint Young Sun paradox for Mars.

  8. Liturgical calendar for Mars

    Directory of Open Access Journals (Sweden)

    Piotr Karocki


    Full Text Available This article presents problems related to creating liturgical calendar for Mars colonists, assumed to land on Mars (accordingly to Mars One Project in year 2024. It consist of five parts: why to colonize space; brief history of Earth calendar; deep correlation of liturgical calendar (e.g. fests with astronomical events; last two parts present idea of civil Martian calendar and list difficulties related to extraterrestrial liturgical calendar.

  9. Liturgical calendar for Mars


    Piotr Karocki


    This article presents problems related to creating liturgical calendar for Mars colonists, assumed to land on Mars (accordingly to Mars One Project) in year 2024. It consist of five parts: why to colonize space; brief history of Earth calendar; deep correlation of liturgical calendar (e.g. fests) with astronomical events; last two parts present idea of civil Martian calendar and list difficulties related to extraterrestrial liturgical calendar.

  10. Mars at Opposition (United States)

    Riddle, Bob


    On January 29, Mars will reach opposition, a point along its orbit around the Sun where Mars will be directly opposite from the Sun in a two-planet and Sun line-up with the Earth in between. At this opposition, the Earth and Mars will be separated by nearly 100 million km. An opposition is similar to a full Moon in that the planet at opposition…

  11. Digital cartography of Mars (United States)

    Batson, R. M.


    A medium-resolution Digital Image Model (DIM) of Mars is being compiled. A DIM is a mosaic of radiometrically corrected, photometrically modelled spacecraft images displaying accurate reflectance properties at uniform resolution, and geometrically tied to the best available control. The Mars medium-resolution DIM contains approximately 4700 Viking Orbiter image frames that were used to compile the recently completed 1:2,000,000-scale controlled photomosaic series of Mars. This DIM provides a planimetric control base to which all other Mars maps will be registered. A similar control base of topographic elevations (Digital Terrain Model, or DTM) is also being compiled. These products are scheduled for completion in 1989.

  12. Mars Stratigraphy Mission (United States)

    Budney, C. J.; Miller, S. L.; Cutts, J. A.


    The Mars Stratigraphy Mission lands a rover on the surface of Mars which descends down a cliff in Valles Marineris to study the stratigraphy. The rover carries a unique complement of instruments to analyze and age-date materials encountered during descent past 2 km of strata. The science objective for the Mars Stratigraphy Mission is to identify the geologic history of the layered deposits in the Valles Marineris region of Mars. This includes constraining the time interval for formation of these deposits by measuring the ages of various layers and determining the origin of the deposits (volcanic or sedimentary) by measuring their composition and imaging their morphology.

  13. Wet water glass production plant

    Directory of Open Access Journals (Sweden)

    Stanković Mirjana S.


    Full Text Available The IGPC Engineering Department designed basic projects for a wet hydrate dissolution plant, using technology developed in the IGPC laboratories. Several projects were completed: technological, machine, electrical, automation. On the basis of these projects, a production plant of a capacity of 75,000 t/y was manufactured, at "Zeolite Mira", Mira (VE, Italy, in 1997. and 1998, increasing detergent zeolite production, from 50,000 to 100,000 t/y. Several goals were realized by designing a wet hydrate dissolution plant. The main goal was increasing the detergent zeolite production. The technological cycle of NaOH was closed, and no effluents emitted, and there is no pollution (except for the filter cake. The wet water glass production process is fully automatized, and the product has uniform quality. The production process can be controlled manually, which is necessary during start - up, and repairs. By installing additional process equipment (centrifugal pumps and heat exchangers technological bottlenecks were overcome, and by adjusting the operation of autoclaves, and water glass filters and also by optimizing the capacities of process equipment.

  14. Different regimes of dynamic wetting (United States)

    Gustav, Amberg; Wang, Jiayu; Do-Quang, Minh; Shiomi, Junichiro; Physiochemical fluid mechanics Team; Maruyama-Chiashi Laboratory Team


    Dynamic wetting, as observed when a droplet contacts a dry solid surface, is important in various engineering processes, such as printing, coating, and lubrication. Our overall aim is to investigate if and how the detailed properties of the solid surface influence the dynamics of wetting. Here we discuss how surface roughness influences the initial dynamic spreading of a partially wetting droplet by studying the spreading on a solid substrate patterned with microstructures just a few micrometers in size. This is complemented by matching numerical simulations. We present a parameter map, based on the properties of the liquid and the solid surface, which identifies qualitatively different spreading regimes, where the spreading speed is limited by either the liquid viscosity, the surface properties, or the liquid inertia. The peculiarities of the different spreading regimes are studied by detailed numerical simulations, in conjuction with experiments. This work was financially supported in part by, the Japan Society for the Promotion of Science (J.W. and J.S) and Swedish Governmental Agency for Innovation Systems (M.D.-Q. and G.A).

  15. Measurements of Oxychlorine species on Mars (United States)

    Sutter, B.; Quinn, R. C.; Archer, P. D.; Glavin, D. P.; Glotch, T. D.; Kounaves, S. P.; Osterloo, M. M.; Rampe, E. B.; Ming, D. W.


    Mars landed and orbiter missions have instrumentation capable of detecting oxychlorine phases (e.g. perchlorate, chlorate) on the surface. Perchlorate (~0.6 wt%) was first detected by the Wet Chemistry Laboratory in the surface material at the Phoenix Mars Landing site. Subsequent analyses by the Thermal Evolved Gas Analyser aboard the same lander detected an oxygen release (~465°C) consistent with the thermal decomposition of perchlorate. Recent thermal analysis by the Mars Science Laboratory's Sample Analysis at Mars instrument has also indicated the presence of oxychlorine phases (up to 1.2 wt%) in Gale Crater materials. Despite being at detectable concentrations, the Chemistry and Mineralogy (CheMin) X-ray diffractometer has not detected oxychlorine phases. This suggests that Gale Crater oxychlorine may exist as poorly crystalline phases or that perchlorate/chlorate mixtures exist, so that individual oxychlorine concentrations are below CheMin detection limits (~1 wt%). Although not initially designed to detect oxychlorine phases, reinterpretation of Viking Gas Chromatography/Mass Spectrometer data also suggest that oxychlorine phases are present in the Viking surface materials. Remote near-infrared spectral analyses by the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) instrument indicate that at least some martian recurring slope lineae (RSL) have spectral signatures consistent with the presence of hydrated perchlorates or chlorates during the seasons when RSL are most extensive. Despite the thermal emission spectrometer, Thermal Emission Imaging System, Observatoire pour la Minéralogie, l'Eau, les Glaces et l'Activité and CRISM detection of hundreds of anhydrous chloride (~10-25 vol%) deposits, expected associated oxychlorine phases (>5-10 vol%) have not been detected. Total Cl and oxychlorine data sets from the Phoenix Lander and the Mars Science Laboratory missions could be used to develop oxychlorine versus total Cl correlations, which

  16. Deciphering the Noachian Geological and Climate History of Mars: A Stratigraphic, Geologic Process and Mineralogical Perspective — Part 1: Current Knowns and Unknowns (United States)

    Head, J. W.; Wordsworth, R.; Forget, F.; Turbet, M.


    The Late Noachian climate, be it warm and wet or cold and icy, is inherited from events that occurred earlier in Mars history. We outline what is known and what remains unexplained about Noachian/Hesperian history and events.

  17. European wet deposition maps based on measurements

    NARCIS (Netherlands)

    Leeuwen EP van; Erisman JW; Draaijers GPJ; Potma CJM; Pul WAJ van; LLO


    To date, wet deposition maps on a European scale have been based on long-range transport model results. For most components wet deposition maps based on measurements are only available on national scales. Wet deposition maps of acidifying components and base cations based on measurements are needed

  18. Microscope on Mars (United States)


    This image taken at Meridiani Planum, Mars by the panoramic camera on the Mars Exploration Rover Opportunity shows the rover's microscopic imager (circular device in center), located on its instrument deployment device, or 'arm.' The image was acquired on the ninth martian day or sol of the rover's mission.

  19. Rat on Mars (United States)


    This image taken on Mars by the panoramic camera on the Mars Exploration Rover Opportunity shows the rover's rock abrasion tool, also known as 'rat' (circular device in center), located on its instrument deployment device, or 'arm.' The image was acquired on the ninth martian day or sol of the rover's mission.

  20. Mold management of wetted carpet. (United States)

    Ong, Kee-Hean; Dixit, Anupma; Lewis, Roger D; MacDonald Perkins, Maureen; Backer, Denis; Condoor, Sridhar; Emo, Brett; Yang, Mingan


    This study evaluated the growth and removal of fungi on wetted carpet using newly designed technologies that rely on physical principles of steam, heat, and fluid flow. Sixty samples of carpet were embedded with heat-treated house dust, followed by embedding, wearing with a hexapod, and wetting. Samples were inoculated using a liquid suspension of Cladosporium sphaerospermum prior to placement over a water-saturated foam pad. Incubation times were 24 hr, 7 days, and 30 days. Cleaning was performed using three methods; high-flow hot water extraction, hot water and detergent, and steam. Fungal loading increased from approximately 1500 colony forming units per area (CFU/cm(2)) in 24 hr to a maximum of approximately 10,200 CFU/cm(2) after 7 days with a slight decline to 9700 CFU/cm(2) after 30 days incubation. Statistically significant differences were found among all three methods for removal of fungi for all three time periods (p mold spore decline from wetted carpet after 24 hr and 30 days, and over 92% efficiency after 7 days. The alternative methods exhibited lower efficiencies with a decline over time, from a maximum of 82% and 81% at 24 hr down to 60% and 43% at 30 days for detergent-hot water and high-flow, hot water extraction, respectively. The net effect of the mold management study demonstrates that while steam has a consistent fungal removal rate, the detergent and high-flow, hot water methods decline in efficiency with increasing incubation time.

  1. Coal combustion by wet oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Bettinger, J.A.; Lamparter, R.A.; McDowell, D.C.


    The combustion of coal by wet oxidation was studied by the Center for Waste Management Programs, of Michigan Technological University. In wet oxidation a combustible material, such as coal, is reacted with oxygen in the presence of liquid water. The reaction is typically carried out in the range of 204/sup 0/C (400/sup 0/F) to 353/sup 0/C (650/sup 0/F) with sufficient pressure to maintain the water present in the liquid state, and provide the partial pressure of oxygen in the gas phase necessary to carry out the reaction. Experimental studies to explore the key reaction parameters of temperature, time, oxidant, catalyst, coal type, and mesh size were conducted by running batch tests in a one-gallon stirred autoclave. The factors exhibiting the greatest effect on the extent of reaction were temperature and residence time. The effect of temperature was studied from 204/sup 0/C (400/sup 0/F) to 260/sup 0/C (500/sup 0/F) with a residence time from 600 to 3600 seconds. From this data, the reaction activation energy of 2.7 x 10/sup 4/ calories per mole was determined for a high-volatile-A-Bituminous type coal. The reaction rate constant may be determined at any temperature from the activation energy using the Arrhenius equation. Additional data were generated on the effect of mesh size and different coal types. A sample of peat was also tested. Two catalysts were evaluated, and their effects on reaction rate presented in the report. In addition to the high temperature combustion, low temperature desulfurization is discussed. Desulfurization can improve low grade coal to be used in conventional combustion methods. It was found that 90% of the sulfur can be removed from the coal by wet oxidation with the carbon untouched. Further desulfurization studies are indicated.

  2. Wet/Dry Vacuum Cleaner (United States)

    Reimers, Harold; Andampour, Jay; Kunitser, Craig; Thomas, Ike


    Vacuum cleaner collects and retains dust, wet debris, and liquids. Designed for housekeeping on Space Station Freedom, it functions equally well in normal Earth Gravity or in microgravity. Generates acoustic noise at comfortably low levels and includes circuitry that reduces electromagnetic interference to other electronic equipment. Draws materials into bag made of hydrophobic sheet with layers of hydrophilic super-absorbing pads at downstream end material. Hydrophilic material can gel many times its own weight of liquid. Blower also provides secondary airflow to cool its electronic components.

  3. Probing Mars’ atmosphere with ExoMars Mars Climate Sounder


    Irwin, Patrick G. J.; Calcutt, S. B.; Read, P. L.; Bowles, N. E.; Lewis, S.


    The 2016 Mars Trace Gas Mission will carry with it the ExoMars Mars Climate Sounder instrument, a development of the very successful Mars Climate Sounder instrument already in orbit about Mars on NASA's Mars Reconnaissance Orbiter spacecraft. EMCS will continue the monitoring of Mars global temperature/pressure/aerosol field, and will also be able to measure the vertical profile of water vapour across the planet from 0 – 50 km. Key components of EMCS will be provided by Oxford, Reading and Ca...

  4. Mineralogical Results from the Mars Science Laboratory Rover Curiosity (United States)

    Blake, David Frederick.


    NASA's CheMin instrument, the first X-ray Diffractometer flown in space, has been operating on Mars for nearly five years. CheMin was first to establish the quantitative mineralogy of the Mars global soil (1). The instrument was next used to determine the mineralogy of a 3.7 billion year old lacustrine mudstone, a result that, together with findings from other instruments on the MSL Curiosity rover, documented the first habitable environment found on another planet (2). The mineralogy of this mudstone from an ancient playa lake was also used to derive the maximum concentration of CO2 in the early Mars atmosphere, a surprisingly low value that calls into question the current theory that CO2 greenhouse warming was responsible for the warm and wet environment of early Mars. CheMin later identified the mineral tridymite, indicative of silica-rich volcanism, in mudstones of the Murray formation on Mt. Sharp. This discovery challenges the paradigm of Mars as a basaltic planet and ushers in a new chapter of comparative terrestrial planetology (3). CheMin is now being used to systematically sample the sedimentary layers that comprise the lower strata of Mt. Sharp, a 5,000 meter sequence of sedimentary rock laid down in what was once a crater lake, characterizing isochemical sediments that through their changing mineralogy, document the oxidation and drying out of the Mars in early Hesperian time.

  5. Elucidating the mysteries of wetting.

    Energy Technology Data Exchange (ETDEWEB)

    Webb, Edmund Blackburn, III (,; ); Bourdon, Christopher Jay; Grillet, Anne Mary; Sackinger, Philip A.; Grest, Gary Stephen; Emerson, John Allen; Ash, Benjamin Jesse; Heine, David R.; Brooks, Carlton, F.; Gorby, Allen D.


    Nearly every manufacturing and many technologies central to Sandia's business involve physical processes controlled by interfacial wetting. Interfacial forces, e.g. conjoining/disjoining pressure, electrostatics, and capillary condensation, are ubiquitous and can surpass and even dominate bulk inertial or viscous effects on a continuum level. Moreover, the statics and dynamics of three-phase contact lines exhibit a wide range of complex behavior, such as contact angle hysteresis due to surface roughness, surface reaction, or compositional heterogeneities. These thermodynamically and kinetically driven interactions are essential to the development of new materials and processes. A detailed understanding was developed for the factors controlling wettability in multicomponent systems from computational modeling tools, and experimental diagnostics for systems, and processes dominated by interfacial effects. Wettability probed by dynamic advancing and receding contact angle measurements, ellipsometry, and direct determination of the capillary and disjoining forces. Molecular scale experiments determined the relationships between the fundamental interactions between molecular species and with the substrate. Atomistic simulations studied the equilibrium concentration profiles near the solid and vapor interfaces and tested the basic assumptions used in the continuum approaches. These simulations provide guidance in developing constitutive equations, which more accurately take into account the effects of surface induced phase separation and concentration gradients near the three-phase contact line. The development of these accurate models for dynamic multicomponent wetting allows improvement in science based engineering of manufacturing processes previously developed through costly trial and error by varying material formulation and geometry modification.

  6. Mars Equipment Transport System (United States)

    Sorrells, Cindy; Geiger, Michelle; Ohanlon, Sean; Pieloch, Stuart; Brogan, Nick


    Mechanical Engineering Senior Design Project 1 (ME4182) is a part of the NASA/University Advanced Design Program. Under this program, NASA allocates money and resources to students to be used in design work for a specified topic. The current topic is the exploration and colonization of Mars. The specific area in which we are to work is the transportation of the modules in which astronauts will live while on Mars. NASA is concerned about the weight of the module transferring system, as the shipping cost to Mars is quite expensive. NASA has specified that the weight of the system is to be minimized in order to reduce the shipping costs.

  7. Airbag Tracks on Mars (United States)


    The circular shapes seen on the martian surface in these images are 'footprints' left by the Mars Exploration Rover Opportunity's airbags during landing as the spacecraft gently rolled to a stop. Opportunity landed at approximately 9:05 p.m. PST on Saturday, Jan. 24, 2004, Earth-received time. The circular region of the flower-like feature on the right is about the size of a basketball. Scientists are studying the prints for more clues about the makeup of martian soil. The images were taken at Meridiani Planum, Mars, by the panoramic camera on the Mars Exploration Rover Opportunity.

  8. Mars Technology Project (United States)

    National Aeronautics and Space Administration — NASA’s Mars Exploration Program (MEP) calls for a series of highly ambitious missions over the next decade and beyond. The overall goals of the MEP must be...

  9. Mars Rover Photos API (United States)

    National Aeronautics and Space Administration — This API is designed to collect image data gathered by NASA's Curiosity, Opportunity, and Spirit rovers on Mars and make it more easily available to other...

  10. Mars Meteor Survey (United States)

    McGown, R. D.; Walden, B. E.; Billings, T. L.; York, C. L.; Taylor, A. G.; Frederick, R. D.


    We propose instruments be included on one or more Mars landers to identify and characterize the meteoroid flux at Mars. Mars orbiting spacecraft and ground operations, both manned and unmanned, are vulnerable to meteoroids. There is pure scientific interest in knowing the frequency, intensity, and radiants of martian meteor showers. Being in a different orbit than Earth and closer to the asteroid belt, Mars has unknown cycles and intensities of meteoroid hazards. Knowledge of these hazards can help us manage risk in future missions, particularly extended and crewed missions. To be most effective the detectors should be continuously active, day and night, for as long a period as possible. Detectors that rely on energy intensive transmitters, such as lasers, radio bounce or radar, are therefore less desirable. A staring instrument is preferable to one which must rapidly skew to track a meteor (requiring extra mechanical parts and susceptible to failure), and should be able to detect multiple meteors simultaneously.


    National Aeronautics and Space Administration — The Mars Pathfinder (MPF) Radio Science (RS) data archive contains both raw radio tracking data collected during the surface lifetime of the MPF Lander and results...

  12. Airbag Deflates on Mars (United States)


    This image, taken by the navigation camera onboard the Mars Exploration Rover Spirit, shows the airbags used to protect the rover during landing. One bright, dust-covered bag is slightly puffed up against the lander.

  13. Status of MARS Code

    Energy Technology Data Exchange (ETDEWEB)

    N.V. Mokhov


    Status and recent developments of the MARS 14 Monte Carlo code system for simulation of hadronic and electromagnetic cascades in shielding, accelerator and detector components in the energy range from a fraction of an electronvolt up to 100 TeV are described. these include physics models both in strong and electromagnetic interaction sectors, variance reduction techniques, residual dose, geometry, tracking, histograming. MAD-MARS Beam Line Build and Graphical-User Interface.

  14. The way to Mars (United States)

    Glushko, V.; Gorshkov, L.; Semenov, Y.


    An article from the Soviet newspaper, Pravda, is presented, which discusses issues related to missions to Mars. The type of vehicle needed for a Martian mission is examined, including the propulsion system, construction of the vehicle in earth orbit, living quarters, safety considerations, and the landing vehicle. Options for the mission route and ways of returning to earth are considered. Also, a proposal for a three phase program leading up to a manned mission to Mars is outlined.

  15. Modern myths of Mars (United States)

    Levin, Gilbert V.


    July 30, 2006 was the 30 th anniversary of the Viking Mission's first Labeled Release (LR) life detection experiment on Mars. The strong response, together with supporting results from eight additional LR tests of Martian soil, established the presence of an active agent that was inhibited by heating. The data satisfied the pre-mission criteria for the detection of living microorganisms. However, the scientific community reacted cautiously, generally concluding that the activity in the soil was caused by chemistry or physics. Over the last three decades, investigation of Mars has greatly increased. Soil, rock and atmospheric analyses have been made. Multi-spectral observations have been made from Mars and Earth orbits and from Earth-based telescopes. Knowledge of extreme habitats and bizarre life forms that populate them on Earth has increased dramatically. However, this vast amount of new astrobiological information has yet to be integrated into an objective scientific evaluation of the LR results and the possibilities for life on Mars. Indeed, in part upon misinterpretations of the new findings, myths have been embedded into the scientific literature of Mars. Based on these myths as key ingredients, a false "standard model" of Martian life potential has been developed. It has been accepted by much of the astrobiological community, and, through its endorsement, the world at large. This paper attempts to bring the supportable facts together in calling for a revision of the current consensus regarding life on Mars. It recommends actions to facilitate the paradigm change.

  16. Life on Mars (United States)

    McKay, Christopher P.; Cuzzi, Jeffrey (Technical Monitor)


    Although the Viking results may indicate that Mars has no life today, the possibility exists that Mars may hold the best record of the events that led to the origin of life. There is direct geomorphological evidence that in the past Mars had large amounts of liquid water on its surface. Atmospheric models would suggest that this early period of hydrological activity was due to the presence of a thick atmosphere and the resulting warmer temperatures. From a biological perspective the existence of liquid water, by itself motivates the question of the origin of life on Mars. From studies of the Earth's earliest biosphere we know that by 3.5 Gyr. ago, life had originated on Earth and reached a fair degree of biological sophistication. Surface activity and erosion on Earth make it difficult to trace the history of life before the 3.5 Gyr timeframe. If Mars did maintain a clement environment for longer than it took for life to originate on Earth, then the question of the origin of life on Mars follows naturally.

  17. POVERTY IN PLENTY, THE MATRIX. (United States)



  18. The MARS2013 Mars analog mission. (United States)

    Groemer, Gernot; Soucek, Alexander; Frischauf, Norbert; Stumptner, Willibald; Ragonig, Christoph; Sams, Sebastian; Bartenstein, Thomas; Häuplik-Meusburger, Sandra; Petrova, Polina; Evetts, Simon; Sivenesan, Chan; Bothe, Claudia; Boyd, Andrea; Dinkelaker, Aline; Dissertori, Markus; Fasching, David; Fischer, Monika; Föger, Daniel; Foresta, Luca; Fritsch, Lukas; Fuchs, Harald; Gautsch, Christoph; Gerard, Stephan; Goetzloff, Linda; Gołebiowska, Izabella; Gorur, Paavan; Groemer, Gerhard; Groll, Petra; Haider, Christian; Haider, Olivia; Hauth, Eva; Hauth, Stefan; Hettrich, Sebastian; Jais, Wolfgang; Jones, Natalie; Taj-Eddine, Kamal; Karl, Alexander; Kauerhoff, Tilo; Khan, Muhammad Shadab; Kjeldsen, Andreas; Klauck, Jan; Losiak, Anna; Luger, Markus; Luger, Thomas; Luger, Ulrich; McArthur, Jane; Moser, Linda; Neuner, Julia; Orgel, Csilla; Ori, Gian Gabriele; Paternesi, Roberta; Peschier, Jarno; Pfeil, Isabella; Prock, Silvia; Radinger, Josef; Ramirez, Barbara; Ramo, Wissam; Rampey, Mike; Sams, Arnold; Sams, Elisabeth; Sandu, Oana; Sans, Alejandra; Sansone, Petra; Scheer, Daniela; Schildhammer, Daniel; Scornet, Quentin; Sejkora, Nina; Stadler, Andrea; Stummer, Florian; Taraba, Michael; Tlustos, Reinhard; Toferer, Ernst; Turetschek, Thomas; Winter, Egon; Zanella-Kux, Katja


    We report on the MARS2013 mission, a 4-week Mars analog field test in the northern Sahara. Nineteen experiments were conducted by a field crew in Morocco under simulated martian surface exploration conditions, supervised by a Mission Support Center in Innsbruck, Austria. A Remote Science Support team analyzed field data in near real time, providing planning input for the management of a complex system of field assets; two advanced space suit simulators, four robotic vehicles, an emergency shelter, and a stationary sensor platform in a realistic work flow were coordinated by a Flight Control Team. A dedicated flight planning group, external control centers for rover tele-operations, and a biomedical monitoring team supported the field operations. A 10 min satellite communication delay and other limitations pertinent to human planetary surface activities were introduced. The fields of research for the experiments were geology, human factors, astrobiology, robotics, tele-science, exploration, and operations research. This paper provides an overview of the geological context and environmental conditions of the test site and the mission architecture, in particular the communication infrastructure emulating the signal travel time between Earth and Mars. We report on the operational work flows and the experiments conducted, including a deployable shelter prototype for multiple-day extravehicular activities and contingency situations.

  19. Differential wetting characterization of hair fibers. (United States)

    Vaynberg, Abe; Stuart, Mark; Wu, Xiang-Fa


    Surface wetting is one of the key properties of human hair used to indicate the extent of chemical/mechanical damage and the outcome of conditioning treatment. Characterization of hair wetting property is a challenging task due to the non-homogeneous nature of hair fibers and the requirement for sensitive equipment. Motivated by these considerations, we developed a new methodology, termed a differential wetting characterization (DWC), which would allow rapid and reliable characterization of the wetting property of hair fibers. This method is based on observation of a number of droplets suspended on a pair of parallel fibers stretched in a horizontal plane. The wetting behavior of the fibers can be deduced from the shape assumed by the droplets. When the wetting properties of the two hair fibers are identical, the droplets suspended between the fibers assume a symmetric configuration. In contrast, on the fibers with dissimilar wetting characteristics, the droplets will assume a skewed configuration towards a more hydrophilic fiber. This makes it possible to differentiate the hydrophobicities of the tested fibers. In this paper it is demonstrated that the proposed DWC method is capable of differentiating the changes in wetting property of hair surfaces in response to either chemical or physical treatment. Results of the paper indicate that the DWC method is applicable for broad wetting differentiation of various fibers.

  20. Carbon nanotube fiber spun from wetted ribbon

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Yuntian T; Arendt, Paul; Zhang, Xiefei; Li, Qingwen; Fu, Lei; Zheng, Lianxi


    A fiber of carbon nanotubes was prepared by a wet-spinning method involving drawing carbon nanotubes away from a substantially aligned, supported array of carbon nanotubes to form a ribbon, wetting the ribbon with a liquid, and spinning a fiber from the wetted ribbon. The liquid can be a polymer solution and after forming the fiber, the polymer can be cured. The resulting fiber has a higher tensile strength and higher conductivity compared to dry-spun fibers and to wet-spun fibers prepared by other methods.

  1. The Mars Environmental Compatibility Assessment (MECA) (United States)

    Meloy, Thomas P.; Marshall, John; Hecht, Michael


    The Mars Environmental Compatibility Assessment (MECA) will evaluate the Martian environment for soil and dust-related hazards to human exploration as part of the Mars Surveyor Program 2001 Lander. Sponsored by the Human Exploration and Development of Space (HEDS) enterprise, MECA's goal is to evaluate potential geochemical and environmental hazards that may confront future martian explorers, and to guide HEDS scientists in the development of high fidelity Mars soil simulants. In addition to objectives related to human exploration, the MECA data set will be rich in information relevant to basic geology, paleoclimate, and exobiology issues. The integrated MECA payload contains a wet-chemistry laboratory, a microscopy station, an electrometer to characterize the electrostatics of the soil and its environment, and arrays of material patches to study the abrasive and adhesive properties of soil grains. MECA is allocated a mass of 10 kg and a peak power usage of 15 W within an enclosure of 35 x 25 x 15 cm (figures I and 2). The Wet Chemistry Laboratory (WCL) consists of four identical cells that will accept samples from surface and subsurface regions accessible to the Lander's robotic arm, mix them with water, and perform extensive analysis of the solution. Using an array of ion-specific electrodes (ISEs), cyclic voltammetry, and electrochemical techniques, the chemistry cells will wet soil samples for measurement of basic soil properties of pH, redox potential, and conductivity. Total dissolved material, as well as targeted ions will be detected to the ppm level, including important exobiological ions such as Na, K+, Ca++, Mg++, NH4+, Cl, S04-, HC03, as well as more toxic ions such as Cu++, Pb++, Cd++, Hg++, and C104-. MECA's microscopy station combines optical and atomic-force microscopy (AFM) to image dust and soil particles from millimeters to nanometers in size. Illumination by red, green, and blue LEDs is augmented by an ultraviolet LED intended to excite

  2. Guidelines for 2008 MARS exercise

    CERN Multimedia

    HR Department


    Full details of the Merit Appraisal and Recognition Scheme (MARS) are available via the HR Department’s homepage or directly on the Department’s MARS web page: You will find on these pages: MARS procedures including the MARS timetable for proposals and decisions; Regulations with links to the scheme’s statutory basis; Frequently Asked Questions; Useful documents with links to relevant documentation; e.g. mandate of the Senior Staff Advisory Committee (SSAC); Related links and contacts. HR Department Tel. 73566

  3. Defined wetting properties of optical surfaces (United States)

    Felde, Nadja; Coriand, Luisa; Schröder, Sven; Duparré, Angela; Tünnermann, Andreas


    Optical surfaces equipped with specific functional properties have attracted increasing importance over the last decades. In the light of cost reduction, hydrophobic self-cleaning behavior is aspired. On the other side, hydrophilic properties are interesting due to their anti-fog effect. It has become well known that such wetting states are significantly affected by the surface morphology. For optical surfaces, however, this fact poses a problem, as surface roughness can induce light scattering. The generation of optical surfaces with specific wetting properties, hence, requires a profound understanding of the relation between the wetting and the structural surface properties. Thus, our work concentrates on a reliable acquisition of roughness data over a wide spatial frequency range as well as on the comprehensive description of the wetting states, which is needed for the establishment of such correlations. We will present our advanced wetting analysis for nanorough optical surfaces, extended by a vibration-based procedure, which is mainly for understanding and tailoring the wetting behavior of various solid-liquid systems in research and industry. Utilizing the relationships between surface roughness and wetting, it will be demonstrated how different wetting states for hydrophobicity and hydrophilicity can be realized on optical surfaces with minimized scatter losses.

  4. 7 CFR 29.1083 - Wet (W). (United States)


    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Wet (W). 29.1083 Section 29.1083 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... Type 92) § 29.1083 Wet (W). Any sound tobacco containing excessive moisture to the extent that it is in...

  5. 7 CFR 29.2570 - Wet (W). (United States)


    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Wet (W). 29.2570 Section 29.2570 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing...-Cured Tobacco (u.s. Types 22, 23, and Foreign Type 96) § 29.2570 Wet (W). Any sound tobacco containing...

  6. 7 CFR 29.3077 - Wet (W). (United States)


    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Wet (W). 29.3077 Section 29.3077 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... Wet (W). Any sound tobacco containing excessive moisture to the extent that it is in an unsafe or...

  7. 7 CFR 29.2316 - Wet (W). (United States)


    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Wet (W). 29.2316 Section 29.2316 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... INSPECTION Standards Official Standard Grades for Virginia Fire-Cured Tobacco (u.s. Type 21) § 29.2316 Wet (W...

  8. 7 CFR 29.3567 - Wet (W). (United States)


    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Wet (W). 29.3567 Section 29.3567 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... Type 95) § 29.3567 Wet (W). Any sound tobacco containing excessive moisture to the extent that it is in...

  9. Characteristics of wet work in nurses

    NARCIS (Netherlands)

    Jungbauer, FHW; Steenstra, FB; Groothoff, JW; Coenraads, PJ

    Background objectives: Nursing is known for its high prevalence of hand dermatitis, mainly caused by the intense exposure to wet work in nursing activities. We aimed to study the characteristics of wet work exposure in nursing. Method: Trained observers monitored the duration and frequency of

  10. SAR-sensing of vegetation wetness

    NARCIS (Netherlands)

    de Jong, JJM; Klaassen, W


    The goal of this study is to measure rain induced forest canopy wetness. The approach used is ERS tandem mission C-band SAR backscatter change detection between successive dry and rainy days. The observed backscatter change is positively related with modelled canopy wetness change. It is therefore

  11. Wet work in relation to occupational dermatitis

    NARCIS (Netherlands)

    Jungbauer, Franciscus Henricus Wilhelmus


    This thesis describes the nature and the quantity of work-related skin exposure in occupations where ‘wet work’ is performed. Activities that cause one or both hands to become wet, in contact with detergents or other skin irritating substances or activities that need to be done with occlusive gloves

  12. The Mars Plasma Environment

    CERN Document Server

    Russell, C. T


    Mars sits very exposed to the solar wind and, because it is a small planet, has but a weak hold on its atmosphere. The solar wind therefore plays an important role in the evolution of the martian atmosphere. Over the last four decades a series of European missions, first from the Soviet Union and more recently from the European Space Agency, together with a single investigation from the U.S., the Mars Global Surveyor spacecraft, have added immeasurably to our understanding of the interplay between the solar wind and Mars atmosphere. Most recently the measurements of the plasma and fast neutral populations, conducted on the Mars Express spacecraft by the ASPERA-3 instrument have been acquired and analyzed. Their presentation to the public, most notably at the workshop "The Solar Wind Interaction and Atmosphere Evolution of Mars" held in Kiruna in early 2006, was the inspiration for this series of articles. However participation in the Kiruna conference was not a selection criterion for this volume. The papers ...

  13. Simulating "Mars on Earth" (United States)

    Clancey, William J.; Clancy, Daniel (Technical Monitor)


    By now, everyone who's heard of the Haughton-Mars Project knows that we travel to Devon Island to learn how people will live and work on Mars. But how do we learn about Mars operations from what happens in the Arctic? We must document our experience--traverses, life in the hab, instrument deployment, communications, and so on. Then we must analyze and formally model what happens. In short, while most scientists are studying the crater, other scientists must be studying the expedition itself. That's what I have done in the past four field seasons. I study field science, both as it naturally occurs at Haughton (unconstrained by a "Mars Sam") and as a constrained experiment using the Flashline Mars Arctic Research Station. During the second week of July 2001, I lived and worked in the hab as part of the Phase 2 crew of six. Besides participating in all activities, I took many photographs and time lapse video. The result of my work will be a computer simulation of how we lived and worked in the hab. It won't be a model of particular people or even my own phase per se, but a pastiche that demonstrates (a proof of concept) that we have appropriate tools for simulating the layout of the hab and daily routines followed by the group and individual scientists. Activities-how people spend their time-are the focus of my observations for building such a simulation model.

  14. Dynamic wetting at the nanoscale (United States)

    Amberg, Gustav; Nakamura, Yoshinori; Carlson, Andreas; Shiomi, Junichiro


    Although the capillary spreading of a drop on a dry substrate is well studied, the physical mechanisms that govern the dynamics remain challenging. Here we study the dynamics of spreading of partially wetting nano-droplets, by combining molecular dynamics and continuum simulations. The latter accounts for all the relevant hydrodynamics, i.e. capillarity, inertia and viscous stresses. By coordinated continuum and molecular dynamics simulations, the macroscopic model parameters are extracted. For a Lennard-Jones fluid spreading on a planar surface, the liquid slip on the substrate is found to be crucial for the motion of the contact line. Evaluation of the different contributions to the energy transfer shows that the liquid slip generates dissipation of the same order as the bulk viscous dissipation or the energy transfer to kinetic energy. We also study the dynamics of spreading on a substrate with a periodic nanostructure. Here it is found that a nanostructure with a length scale commensurate with molecular size completely inhibits the liquid slip. This reduces the spreading speed by about 30%. This work is partially supported by the Japan Science and Technology Agency, CREST, the Swedish Research Council, the Japan Society for the Promotion of Science, and the Sasakawa foundation.

  15. Origin of the Mars Trojans (United States)

    Jacobson, Seth A.; Polishook, David; Morbidelli, Alessandro; Ahronson, Oded


    The Mars Trojan Eureka and associated fragments possess a rare olivine-rich minerology spectrally identified as A-type. High olivine content rocks are typically associated with the interiors of differentiated bodies like Mars. Here, we show that impact ejecta from Mars is likely to have been captured as Mars Trojans in the final stages of terrestrial planet formation.We simulated the ejection of thousands of asteroids from Mars and modeled with the Symba N-body code how their orbits evolved with time due to perturbations from Mars and the other 7 planets. Scholl et al. identified a stable region in eccentricity (e < 0.2) and inclination (10° + 20° (e / 0.25) < i < 30) for Mars Trojans, so we measured what fraction of ejecta obtained these eccentricities and inclinations as a function of semi-major axis away from Mars.During the end stages of planet formation, the semi-major axis of Mars changed significantly for the final time. This last jump is responsible for capturing the Mars Trojans. Using simulations of terrestrial planet formation, we assessed the size and timing of this last jump relative to planetesimals accretion on Mars. By combining this analsysis with the orbital evolution of impact ejecta, we obtained Mars Trojan production rates of order 1 per 105. The production rate of Mars Trojans as a function of time between the impact which created the impact debris on Mars and the final semi-major axis jumpt of Mars. The production rate is per 105 ejecta, since it is expected that a Borealis Basin sized impact on Mars would create approximately that much debris with a diameter of 2 km or greater. Clearly, obtaining the Eureka progenitor from Mars ejecta is likely.

  16. Sediment distribution and dynamics inferred by integrated electromagnetic, optical and acoustic benthic profiling in the western Bay of Plenty (New Zealand) (United States)

    Kulgemeyer, T.; von Dobeneck, T. F.; Müller, H.; Bryan, K. R.; de Lange, W. P.; Battershill, C.


    In October 2011, New Zealand experienced a marine pollution disaster after the MV RENA ran aground in the western Bay of Plenty. To estimate the transport and burial potential of contaminants, local sediment distribution and dynamics had to be assessed quickly. Our study made use of the benthic profiler NERIDIS III of the University of Bremen. 33 cross-shore profiles, each ca. 8 km long, have been surveyed. The main instrument is a controlled-source electromagnetic (CSEM) sensor, which is measuring the electric conductivity and magnetic susceptibility of the seafloor. High-resolution, overlapping seafloor photos have been taken by a bow-mounted digital camera. An on-board CTD with turbidity sensor complete the sensor arrangement. From the EM data, porosity and magnetite concentrations have been calculated and interpolated. The resulting maps show specific zones of magnetite enrichment, higher concentrations are correlated to low porosity. Photos have been used along with acoustic backscatter measured by a sidescan sonar to sketch out a preliminary map of sediment facies. Based on this, sides for grab sampling were selected. By taking grain size and mineralogy into account, a detailed map of the regional lithofacies could be created. Local sediment dynamics have been inferred by the observation of bedforms, the turbidity of bottom water and lithofacies. The results show two anti-parallel longshore transport paths dependent on differing weather conditions and water depths. The longshore magnetite distribution indicates that the heavy mineral fraction is mainly affected by storm-induced sediment transport. Our study demonstrates how integrated benthic profiling adds to the interpretability of data obtained by established methods. By bridging the gap between area-covering, but indirect data from hydroacoustics and precise, but punctual data from samples, benthic profiling enables fast and detailed assessment of sediment distribution and dynamics on a large scale.

  17. Telecommunications systems evolution for Mars Exploration (United States)

    Noreen, Gary; De Paula, Ramon P.; Edwards, Charles D. Jr; Komarek, Thomas; Edwards, Bernard L.; Edwards, Bernard L.; Kerridge, Stuart J.; Diehl, Roger; Franklin, Stephen F.


    This paper describes the evolution of telecommunication systems at Mars. It reviews the telecommunications capabilities, technology and limiting factors of current and planned Mars orbiters from Mars Global Surveyor to the planned Mars Telecommunications Orbiter (MTO).

  18. Mars Radiation Surface Model (United States)

    Alzate, N.; Grande, M.; Matthiae, D.


    Planetary Space Weather Services (PSWS) within the Europlanet H2020 Research Infrastructure have been developed following protocols and standards available in Astrophysical, Solar Physics and Planetary Science Virtual Observatories. Several VO-compliant functionalities have been implemented in various tools. The PSWS extends the concepts of space weather and space situational awareness to other planets in our Solar System and in particular to spacecraft that voyage through it. One of the five toolkits developed as part of these services is a model dedicated to the Mars environment. This model has been developed at Aberystwyth University and the Institut fur Luft- und Raumfahrtmedizin (DLR Cologne) using modeled average conditions available from Planetocosmics. It is available for tracing propagation of solar events through the Solar System and modeling the response of the Mars environment. The results have been synthesized into look-up tables parameterized to variable solar wind conditions at Mars.

  19. Magnetic storms on Mars

    DEFF Research Database (Denmark)

    Vennerstrøm, Susanne


    Based on data from the Mars Global Surveyor magnetometer we examine periods of significantly enhanced magnetic disturbances in the martian space environment. Using almost seven years of observations during the maximum and early declining phase of the previous solar cycle the occurrence pattern...... and typical time profile of such periods is investigated and compared to solar wind measurements at Earth. Typical durations of the events are 20–40h, and there is a tendency for large events to last longer, but a large spread in duration and intensity are found. The large and medium intensity events at Mars...... field disturbance at Mars is solar wind dynamic pressure variations associated with the eccentricity of the martian orbit around the Sun....

  20. Remanent magnetism at Mars (United States)

    Curtis, S. A.; Ness, N. F.


    It is shown that a strong case can be made for an intrinsic magnetic field of dynamo origin for Mars earlier in its history. The typical equatorial magnetic field intensity would have been equal to about 0.01-0.1 gauss. The earlier dynamo activity is no longer extant, but a significant remanent magnetic field may exist. A highly non-dipole magnetic field could result from the remanent magnetization of the surface. Remanent magnetization may thus play an important role in the Mars solar wind interactions, in contrast to Venus with its surface temperatures above the Curie point. The anomalous characteristics of Mars'solar wind interaction compared to that of Venus may be explicable on this basis.

  1. Aqueous alteration detection in Tikhonravov crater, Mars (United States)

    Mancarella, F.; Fonti, S.; Alemanno, G.; Orofino, V.; Blanco, A.


    The existence of a wet period lasting long enough to allow the development of elementary forms of life on Mars has always been a very interesting issue. Given this perspective, the research for geological markers of such occurrences has been continually pursued. Once a favorable site is detected, effort should be spent to get as much information as possible aimed at a precise assessment of the genesis and evolution of the areas showing the selected markers. In this work, we discuss the recent finding of possible deposits pointing to the past existence of liquid water in Tikhonravov crater located in Arabia Terra. Comparison of CRISM spectra and those of laboratory minerals formed by aqueous alteration has led us to the conclusion that the studied areas within the impact crater host phyllosilicates deposits. In addition, analysis of the CRISM spectra has resulted in the tentative identification of carbonates mixed with phyllosilicates.

  2. Meteorites on Mars (United States)

    Flynn, G. J.; Mckay, D. S.


    Four types of meteoritic material should be found on Mars: (1) micrometeorites, many of which will survive atmospheric entry unmelted, which should fall relatively uniformly over the planet's surface, (2) ablation products from larger meteorites which ablate, break up and burn up in the Mars atmosphere, (3) debris from large, crater forming objects, which, by analogy to terrestrial and lunar impact events, will be concentrated in the crater ejecta blankets (except for rare, large events, such as the proposed C-T event on earth, which can distribute debris on a planetary scale), and (4) debris from the early, intense bombardment, which, in many areas of the planet, may now be incorporated into rocks by geologic processes subsequent to the intense bombardment era. To estimate the extent of meteoritic addition to indigenous Martian material, the meteoritic flux on Mars must be known. It is estimated that the overall flux is twice that for the Moon and 1.33 that for Earth. For small particles, whose orbital evolution is dominated by Poynting Robertson drag, the flux at Mars can be estimated from the Earth flux. The smaller Martian gravitational enhancement as well as the decrease in the spatial density of interplanetary dust with increasing heliocentric distance should reduce the flux of small particles at Mars to about 0.33 times the flux at Earth. Because of the smaller planetary cross-section the total infalling mass at Mars is then estimated to be 0.09 time the infalling mass in the micrometeorite size range at Earth.

  3. Mars Aqueous Processing System Project (United States)

    National Aeronautics and Space Administration — The Mars Aqueous Processing System (MAPS) is a novel technology for recovering oxygen, iron, and other constituents from lunar and Mars soils. The closed-loop...

  4. The geology of Mars (United States)

    Mutch, T. A.; Arvidson, R. E.; Head, J. W., III; Jones, K. L.; Saunders, R. S.


    The book constitutes a topographic/geologic atlas of Mars compiled on the basis of data from the various Mariner missions. A large number of maps has been included which systematically describe the character and distribution of the principal landforms: craters, channels, volcanoes, and faults; also related properties such as albedo, elevation, and wind streaks. Pictures of all the important topographic features have been included. The discussion of the material is carried out with a minimum of technical detail, and Mars is examined within a context of interplanetary comparisons.

  5. Lakes on Mars

    CERN Document Server

    Cabrol, Nathalie A


    On Earth, lakes provide favorable environments for the development of life and its preservation as fossils. They are extremely sensitive to climate fluctuations and to conditions within their watersheds. As such, lakes are unique markers of the impact of environmental changes. Past and current missions have now demonstrated that water once flowed at the surface of Mars early in its history. Evidence of ancient ponding has been uncovered at scales ranging from a few kilometers to possibly that of the Arctic ocean. Whether life existed on Mars is still unknown; upcoming missions may find critic

  6. Hematite on Mars! (United States)


    This spectrum captured by the Mars Exploration Rover Opportunity's mini-thermal emission spectrometer shows the presence of grey hematite in the martian soil at Meridiani Planum, Mars. On Earth, hematite forms in the presence of water, at the bottom of lakes, springs and other bodies of standing water. But it can also arise without water in volcanic regions. Scientists hope to discover the origins of martian hematite with the help of Opportunity's robotic set of geological tools. The yellow line represents the spectrum, or light signature, of the martian soil, while the red line shows the spectrum of pure hematite.

  7. Mars Observer Camera


    Malin, M. C.; Danielson, G. E.; Ingersoll, A. P.; Masursky, H.; J. Veverka(Massachusetts Institute of Technology, Cambridge, U.S.A.); Ravine, M. A.; Soulanille, T.A.


    The Mars Observer camera (MOC) is a three-component system (one narrow-angle and two wide-angle cameras) designed to take high spatial resolution pictures of the surface of Mars and to obtain lower spatial resolution, synoptic coverage of the planet's surface and atmosphere. The cameras are based on the “push broom” technique; that is, they do not take “frames” but rather build pictures, one line at a time, as the spacecraft moves around the planet in its orbit. MOC is primarily a telescope f...

  8. EquiMar

    DEFF Research Database (Denmark)

    Johnstone, C. M.; McCombes, T.; Bahaj, A. S.


    / financiers etc when attempting to quantify the performance of a device since it makes it very difficult to reference and benchmark the performance of a marine energy converter. The EC Framework Programme VII EquiMar project has set out to develop a suite of Best Practices to be adopted when undertaking...... the performance evaluation of such systems in order to address this deficiency. This paper reports the development of a set of ‘Best Practices’ within the ECFPVII EquiMar project to be adopted for the performance quantification of wave and tidal energy converters as they evolve from an engineering concept...

  9. Mars Obliquity Cycle Illustration (United States)


    The tilt of Mars' spin axis (obliquity) varies cyclically over hundreds of thousands of years, and affects the sunlight falling on the poles. Because the landing site of NASA's Phoenix Mars Lander is so near the north pole, higher sun and warmer temperatures during high obliquity lead to warmer, more humid surface environments, and perhaps thicker, more liquid-like films of water in soil. The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  10. Technical Efficiency of Wet Season Melon Farming

    Directory of Open Access Journals (Sweden)

    Ananti Yekti


    Full Text Available Melon is one of high-value horticulture commodity which is cultivated widely in Kulon Progo regency. The nature of agricultural products is heavily dependent on the season, so it causes the prices of agricultural products always fluctuated every time. In wet season the price of agricultural products tends to be more expensive. Melon cultivation in wet season provide an opportunity to earn higher profits than in the dry season. The price of agricultural products tends to be more expensive in wet season, thus melon cultivation in wet season prospectively generate high profits. In order to achieve high profitability, melon farming has to be done efficiently. Objective of this study was to 1 determined the factors that influence melon production in wet season 2 measured technical efficiency of melon farming and 3 identified the factors that influanced technical efficiency. Data collected during April – June 2014. Location determined by multistage cluster sampling. 45 samples of farmers who cultivated melon during wet season obtained based on quota sampling technique. Technical efficiency was measured using Cobb-Douglas Stochastic Frontier. The result reveals that 1 land use, quantity of seed, K fertilizer contributed significantly increasing melon production, while N fertilizer decreased melon production significantly 2 technical efficiency indeces ranged from 0.40 to 0.99, with a mean of  0.77; 3 farmer’s experience gave significant influence to technical efficiency of melon farming in wet season.

  11. Vulkanisme en water op Mars?

    NARCIS (Netherlands)

    Van Loef, J.; Schmets, A.J.M.


    In januari 2004 werd Mars bezocht door de tweeling robotverkenners Spirit en Opportunity. Zij werden erop uitgestuurd om eindelijk het definitieve antwoord te geven op de vraag of er leven op Mars is geweest. Alles wijst er inmiddels op dat er op Mars ooit vloeibaar water stroomde. Of daarmee een

  12. Mars exploration: follow the water (United States)

    Park, Young Ho


    Over the centuries, the red planet Mars has been a subject of imagination as well as intense scientific interest. As the overwhelming success of two Mars Exploration Rovers unfolds before us, this article provides an overview of and rationale for NASA's Mars exploration program.

  13. Authentic Mars Research in the High School (United States)

    Kortekaas, Katie; Leach, Dani


    As a 11th and 12th grade Astrobiology class we were charged with developing a scientific research question about the potential for life on Mars. We narrowed our big picture question to, 'Where should the next Mars rover land in order to study the volcanic and water features to find evidence of past or present extremophiles on Mars?'After a lot of searching through images on JMARS (although not extensive due to high school time constraints) we narrowed our interest to three areas of Mars we thought could be good candidates to land a rover there to do further research. We know from extremophiles on Earth that microscopic life need water and energy. It seems reasonable that Mars would be no different. We developed a research question, 'Does Kasei Valles, Dzigai Vallis and Hecate Tholus have volcanic features (lava flow, fractures, volcanoes, cryovolcanoes) and water features (layers of ice, hematite, carbonate, chaos)?'This question is important and interesting because by having a deeper understanding of whether these places have evidence of volcanic and water features, we will be able to decide where the best place to land a future rover would be. Evidence of volcanic and water features are important to help determine where to land our rover because in those areas, temperatures could have been warm and the land could be wet. In these conditions, the probability of life is higher.We individually did research through JMARS (CTX, THEMIS) in order to establish if those three areas could contain certain land features (volcanic and water features) that could possibly lead to the discovery of extremophiles. We evaluated the images to determine if the three areas have evidence of those volcanic and water features.Although we are not experts at identifying features we believe we have evidence to say that all three areas are interesting, astrobiologically, but Dzigai Vallis shows the most number of types of volcanic and water features. More importantly, through this process we

  14. Mission from Mars

    DEFF Research Database (Denmark)

    Dindler, Christian; Eriksson, Eva; Iversen, Ole Sejer


    In this paper a particular design method is propagated as a supplement to existing descriptive approaches to current practice studies especially suitable for gathering requirements for the design of children's technology. The Mission from Mars method was applied during the design of an electronic...

  15. Ancient aliens on mars

    CERN Document Server

    Bara, Mike


    Best-selling author and Secret Space Program researcher Bara brings us this lavishly illustrated volume on alien structures on Mars. Was there once a vast, technologically advanced civilization on Mars, and did it leave evidence of its existence behind for humans to find eons later? Did these advanced extraterrestrial visitors vanish in a solar system wide cataclysm of their own making, only to make their way to Earth and start anew? Was Mars once as lush and green as the Earth, and teeming with life? Did Mars once orbit a missing member of the solar system, a "Super Earth” that vanished in a disaster that devastated life on Earth and Venus and left us only the asteroid belt as evidence of its once grand existence? Did the survivors of this catastrophe leave monuments and temples behind, arranged in a mathematical precision designed to teach us the Secret of a new physics that could lift us back to the stars? Does the planet have an automated defense shield that swallows up robotic probes if they wander int...

  16. Watersporen op Mars

    NARCIS (Netherlands)

    Seijmonsbergen, A.C.; Cammeraat, L.H.; Jansen, B.


    SAMENVATTING De discussie over het voorkomen van water op Mars, in vaste of vloeibare vorm, nu en in het verleden, is nog steeds in volle gang. Dat geldt ook voor het effect van mogelijk aanwezig water op de landschapsontwikkeling van de Rode Planeet. Met het vrijkomen van steeds meer nieuwe

  17. Mars Observer Orbit Insertion Briefing (United States)


    Steve Wall is the host of this video entitled, "Return to the Red Planet". Live animation of the Mars Observer orbiting Mars is presented. Steve Wall explains the spacecraft insertion maneuver and also explains the purpose for the Mars Observer launch. Live coverage of the Cape Canaveral launch of the Mars Observer is also presented. Suzanne Dodd, Chief of the Mission Planning team describes the burn start and how the spacecraft will be captured by Mars' gravity. Glenn Cunningham, Mars Observer Project Manager, gives background information on the Mars Observer and describes the organizations behind the Mars Observer Spacecraft, such as the Deep Space Network, the Mission Operation Support Office, Science Investigators, the Flight Engineering Office, Operations Office, and the Ground Data System Office. Dr. William Piotrowski, Acting Director, Solar System Exploration Division, NASA, talks about the purpose of the Mars Pathfinder which is to develop the technology and systems for landing small science packages on Mars. Mr. Roger Gibbs, Former Mars Observer Spacecraft Systems Engineer, tells us how the Mars Observer was built and describes the structural elements on the Mars Observer. The 11-month cruise period for the spacecraft is given by Joseph Beerer, Manager of the Engineering office. The thrust for the Mars Orbit Insertion is described by Ronald Klemetson, Technical Manager, Propulsion Subsystem Jet Propulsion Laboratory (JPL). George Chen, Lead Engineer Attitude and Articulation Subsystem Spacecraft Team, explains the importance of the attitude control engines on the Spacecraft. Marvin Traxler, Manager of Tracking and Data Acquisition, describes how searching for a signal from the Mars Observer works. See NONP-NASA-VT-2000081555 for a continuation of this discussion with Marvin Traxler.

  18. Mars Surface Environmental Issues (United States)

    Charles, John


    Planetary exploration by astronauts will require extended periods of habitation on a planet's surface, under the influence of environmental factors that are different from those of Earth and the spacecraft that delivered the crew to the planet. Human exploration of Mars, a possible near-term planetary objective, can be considered a challenging scenario. Mission scenarios currently under consideration call for surface habitation periods of from 1 to 18 months on even the earliest expeditions. Methods: Environmental issues associated with Mars exploration have been investigated by NASA and the National Space Biomedical Research Institute (NSBRI) as part of the Bioastronautics Critical Path Roadmap Project (see http :// Results: Arrival on Mars will immediately expose the crew to gravity only 38% of that at Earth's surface in possibly the first prolonged exposure to gravity other than the 1G of Earth's surface and the zero G of weightless space flight, with yet unknown effects on crew physiology. The radiation at Mars' surface is not well documented, although the planet's bulk and even its thin atmosphere may moderate the influx of galactic cosmic radiation and energetic protons from solar flares. Secondary radiation from activated components of the soil must also be considered. Ultrafine and larger respirable and nonrespirable particles in Martian dust introduced into the habitat after surface excursions may induce pulmonary inflammation exacerbated by the additive reactive and oxidizing nature of the dust. Stringent decontamination cannot eliminate mechanical and corrosive effects of the dust on pressure suits and exposed machinery. The biohazard potential of putative indigenous Martian microorganisms may be assessed by comparison with analog environments on Earth. Even in their absence, human microorganisms, if not properly controlled, can be a threat to the crew's health. Conclusions: Mars' surface offers a substantial challenge to the

  19. Tafoni - A Llink Between Mars and Earth (United States)

    Iacob, R. H.; Iacob, C. E.


    Remarkable rock erosion structures on the planetary surface, tafoni represent an important instrument for investigating the specific environmental conditions causing such rock formations. From simple cavities to refined honeycomb or other intricate patterns, tafoni are a reflection of the complex interaction between the rock structure and the environmental factors. On the genesis of tafoni, there is no unique breakdown mechanism at work, but a multitude of physical and chemical processes developing over time. However, some of these formation mechanisms are typically predominant. Tafoni can be found on a variety of rock substrates, from sandstone and vesicular lava rocks to granite and basalt, and in a variety of environments, from wet coastal areas to the extreme dry zones of hot deserts, high plateaus or frozen lands of Antarctica. During various NASA missions, tafoni were also identified on rock formations on Mars. Comparative study of the environmental conditions leading to the formation of tafoni on Earth and Mars can help explain past and present surface erosion mechanisms on the Red Planet. The mechanisms responsible for tafoni formation on Earth include wind erosion, exfoliation, frost shattering, and, in the majority of cases, salt weathering. Microclimate variations of temperature, evaporation of salt water, disaggregation of mineral grains, as well as sandblasting, are among most common contributors that initiate the pitting of the rock surface, giving way to further development of tafoni alveoli, cavities and other erosion patterns. Dissolution of calcium carbonates and siliceous cements, or hydration of feldspars, are representative examples of tafoni erosion involving rain water, sea water or air moisture. Live organisms and biochemical processes are significant contributors to the formation and evolution of tafoni, especially in humid or water reach environments. In many instances, tafoni reflect erosion mechanism specific to environmental conditions

  20. Wet granular matter a truly complex fluid

    CERN Document Server

    Herminghaus, Stephan


    This is a monograph written for the young and advanced researcher who is entering the field of wet granular matter and keen to understand the basic physical principles governing this state of soft matter. It treats wet granulates as an instance of a ternary system, consisting of the grains, a primary, and a secondary fluid. After addressing wetting phenomena in general and outlining the basic facts on dry granular systems, a chapter on basic mechanisms and their effects is dedicated to every region of the ternary phase diagram. Effects of grain shape and roughness are considered as well. Rather than addressing engineering aspects such as existing books on this topic do, the book aims to provide a generalized framework suitable for those who want to understand these systems on a more fundamental basis. Readership: For the young and advanced researcher entering the field of wet granular matter.

  1. ROE Wet Nitrate Deposition 2011-2013 (United States)

    U.S. Environmental Protection Agency — The raster data represent the amount of wet nitrate deposition in kilograms per hectare from 2011 to 2013. Summary data in this indicator were provided by EPA’s...

  2. ROE Wet Nitrate Deposition 1989-1991 (United States)

    U.S. Environmental Protection Agency — The raster data represent the amount of wet nitrate deposition in kilograms per hectare from 1989 to 1991. Summary data in this indicator were provided by EPA’s...

  3. ROE Wet Sulfate Deposition 2009-2011 (United States)

    U.S. Environmental Protection Agency — The raster data represent the amount of wet sulfate deposition in kilograms per hectare from 2009 to 2011. Summary data in this indicator were provided by EPA’s...

  4. Biodegradation of wet-white leather


    Ollé Otero, Lluís; Jorba Rafart, Montse; Font Vallès, Joaquim; Shendrik, Alexander; Bacardit Dalmases, Anna


    This paper deals with the study of the physical, chemical and biological processes associated with the deterioration of wet-white leather. The samples of leather were exposed for eight months to outdoor weathering and then their properties were subsequently evaluated. The results indicate that resistance and dimensional stability of wet-white (THPS-syntan) leather is higher than that of chrometanned leather. The comparative work with chrome leather was described earlier.

  5. Thermal neutron diffusion cooling in wet quartz

    Energy Technology Data Exchange (ETDEWEB)

    Drozdowicz, K. [Henryk Niewodniczanski Institute of Nuclear Physics, Polish Academy of Sciences, ul. Radzikowskiego 152, PL-31-342 Cracow (Poland)]. E-mail:; Krynicka, E. [Henryk Niewodniczanski Institute of Nuclear Physics, Polish Academy of Sciences, ul. Radzikowskiego 152, PL-31-342 Crakcw (Poland); Dabrowska, J. [Henryk Niewodniczanski Institute of Nuclear Physics, Polish Academy of Sciences, ul. Radzikowskiego 152, PL-31-342 Cracow (Poland)


    The thermal neutron diffusion parameters of a rock material depend on the rock matrix itself and on the water content. The effect has been studied in quartz by Monte Carlo (MC) simulations of the variable buckling experiment for nine series of samples. A hyperbolic dependence of the density-removed diffusion cooling coefficient on the water content shows a variability of this parameter by two orders of magnitude. The function obtained for wet quartz is compared with the analogous dependence for wet dolomite.

  6. 2005 Earth-Mars Round Trip (United States)


    This paper presents, in viewgraph form, the 2005 Earth-Mars Round Trip. The contents include: 1) Lander; 2) Mars Sample Return Project; 3) Rover; 4) Rover Size Comparison; 5) Mars Ascent Vehicle; 6) Return Orbiter; 7) A New Mars Surveyor Program Architecture; 8) Definition Study Summary Result; 9) Mars Surveyor Proposed Architecture 2003, 2005 Opportunities; 10) Mars Micromissions Using Ariane 5; 11) Potential International Partnerships; 12) Proposed Integrated Architecture; and 13) Mars Exploration Program Report of the Architecture Team.

  7. Happy Mars Solstice! (United States)


    This image was acquired by NASA's Phoenix Mars Lander's Surface Stereo Imager (SSI) in the late afternoon of the 30th Martian day of the mission, or Sol 30 (June 25, 2008). This is hours after the beginning of Martian northern summer. SSI used its natural-color filters, therefore the color is the color you would see on Mars. The image shows shadows from the SSI (left) and from the meteorological station mast (right) stretching toward the east as the sun dropped low in the west. The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is led by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver

  8. Seismology on Mars (United States)

    Anderson, D. L.; Miller, W. F.; Latham, G. V.; Nakamura, Y.; Toksoz, M. N.; Dainty, A. M.; Duennebier, F. K.; Lazarewicz, A. R.; Kovach, R. L.; Knight, T. C. D.


    High-quality data (uncontaminated by lander or wind noise) obtained with a three-axis short-period seismometer operating on Mars in the Utopia Planitia region are analyzed. No large events have been detected during the first five months of operation covered in the present paper. This indicates that Mars is less seismically active than the earth. Winds, and therefore a seismic background, began to intrude into the nighttime hours, starting with sol 119 (sol is a Martian day). The seismic background correlates well with wind velocity, and is proportional to the square of the wind velocity, as is appropriate for turbulent flow. A local seismic event of a magnitude of 3 and a distance of 110 km was detected on sol 80. It is interpreted as a natural seismic event.

  9. The politics of Mars (United States)

    Schmitt, Harrison H.


    A discussion is presented comparing past and present major accomplishments of the U.S. and the Soviet Union in space. It concludes that the Soviets are presently well ahead of the U.S. in several specific aspects of space accomplishment and speculates that the Soviet strategy is directed towards sending a man to the vicinity of Mars by the end of this century. A major successful multinational space endeavor, INTELSAT, is reviewed and it is suggested that the manned exploration of Mars offers a unique opportunity for another such major international cooperative effort. The current attitude of U.S. leadership and the general public is assessed as uniformed or ambivalent about the perceived threat of Soviet dominance in space.

  10. Polygonal terrains on Mars

    Directory of Open Access Journals (Sweden)

    Pedro Pina


    Full Text Available The presence of water ice on Mars is well established. Some featureson the planet point to the occurrence of processes similar to those that take place in periglacial areas of Earth. One of the clues for this is the existence of small-scale polygonal terrains. In this paper, we present a methodology that aims at the automated identification of polygonal patterns on high-spatial resolution images of the surface of Mars. In the context of the research project TERPOLI, this step will be complemented with a full characterization, in both geometric and topological terms, of thenetworks detected. In this manner, we hope to collect data that will lead to a better understanding of the conditions of formation of the polygons, and of their temporal evolution; namely, we intend to identify different groups of polygons and to compare them with terrestrial examples.

  11. Fossil life on Mars (United States)

    Walter, M. R.


    Three major problems beset paleontologists searching for morphological evidence of life on early Earth: selecting a prospective site; finding biogenic structures; and distinguishing biogenic from abiogenic structures. The same problems arise on Mars. Terrestrial experience suggests that, with the techniques that can be employed remotely, ancient springs, including hot springs, are more prospective than lake deposits. If, on the other hand, the search is for chemical evidence, the strategy can be very different, and lake deposits are attractive targets. Lakes and springs frequenly occur in close proximity, and therefore a strategy that combines the two would seem to maximize the chance of success. The strategy for a search for stromatolite on Mars is discussed.

  12. Chemical composition of Mars (United States)

    Morgan, J. W.; Anders, E.


    The chemical composition of Mars is estimated from the cosmochemical model of Ganapathy and Anders (1974) with additional petrological and geophysical constraints. The model assumes that planets and chondrites underwent the same fractionation processes in the solar nebula, and constraints are imposed by the abundance of the heat-producing elements, U, Th and K, the volatile-rich component and the high density of the mantle. Global abundances of 83 elements are presented, and it is noted that the mantle is an iron-rich garnet wehrlite, nearly identical to the bulk moon composition of Morgan at al. (1978) and that the core is sulfur poor (3.5% S). The comparison of model compositions for the earth, Venus, Mars, the moon and a eucrite parent body suggests that volatile depletion correlates mainly with size rather than with radial distance from the sun.

  13. Removal of atmospheric ethanol by wet deposition (United States)

    Felix, J. David; Willey, Joan D.; Thomas, Rachel K.; Mullaugh, Katherine M.; Avery, G. Brooks; Kieber, Robert J.; Mead, Ralph N.; Helms, John; Giubbina, Fernanda F.; Campos, M. Lucia A. M.; Cala, John


    The global wet deposition flux of ethanol is estimated to be 2.4 ± 1.6 Tg/yr with a conservative range of 0.2-4.6 Tg/yr based upon analyses of 219 wet deposition samples collected at 12 locations globally. This estimate calculated by using observed wet deposition ethanol concentrations is in agreement with previous models (1.4-5 Tg/yr) predicting the wet deposition sink using Henry's law coefficients and atmospheric ethanol concentrations. Wet deposition is estimated to remove between 6 and 17% of the total ethanol emitted to the atmosphere on an annual basis. The concentration of ethanol in marine rain (25 ± 6 nM) is an order of magnitude less than in the majority of terrestrial rains (345 ± 280 nM). Terrestrial rain samples collected in locations impacted by high local sources of biofuel usage and locations downwind from ethanol distilleries were an order of magnitude higher in ethanol concentration (3090 ± 448 nM) compared to rain collected in terrestrial locations not impacted by these sources. These results indicate that wet deposition of ethanol is heavily influenced by local sources. Results of this study are important because they suggest that as biofuel production and usage increase, the concentration of ethanol in the atmosphere will increase as well the wet deposition flux. Additional research constraining the sources, sinks, and atmospheric impacts of ethanol is necessary to better assist in the debate as whether or not to increase consumption of the alcohol as a biofuel.

  14. Mars Aqueous Processing System (United States)

    Berggren, Mark; Wilson, Cherie; Carrera, Stacy; Rose, Heather; Muscatello, Anthony; Kilgore, James; Zubrin, Robert


    The goal of the Mars Aqueous Processing System (MAPS) is to establish a flexible process that generates multiple products that are useful for human habitation. Selectively extracting useful components into an aqueous solution, and then sequentially recovering individual constituents, can obtain a suite of refined or semi-refined products. Similarities in the bulk composition (although not necessarily of the mineralogy) of Martian and Lunar soils potentially make MAPS widely applicable. Similar process steps can be conducted on both Mars and Lunar soils while tailoring the reaction extents and recoveries to the specifics of each location. The MAPS closed-loop process selectively extracts, and then recovers, constituents from soils using acids and bases. The emphasis on Mars involves the production of useful materials such as iron, silica, alumina, magnesia, and concrete with recovery of oxygen as a byproduct. On the Moon, similar chemistry is applied with emphasis on oxygen production. This innovation has been demonstrated to produce high-grade materials, such as metallic iron, aluminum oxide, magnesium oxide, and calcium oxide, from lunar and Martian soil simulants. Most of the target products exhibited purities of 80 to 90 percent or more, allowing direct use for many potential applications. Up to one-fourth of the feed soil mass was converted to metal, metal oxide, and oxygen products. The soil residue contained elevated silica content, allowing for potential additional refining and extraction for recovery of materials needed for photovoltaic, semiconductor, and glass applications. A high-grade iron oxide concentrate derived from lunar soil simulant was used to produce a metallic iron component using a novel, combined hydrogen reduction/metal sintering technique. The part was subsequently machined and found to be structurally sound. The behavior of the lunar-simulant-derived iron product was very similar to that produced using the same methods on a Michigan iron

  15. Guidelines for 2007 MARS exercise

    CERN Multimedia

    HR Department


    Following the introduction of the new Merit Appraisal and Recognition Scheme (MARS), full details of the scheme are now available via the HR Department's homepage or directly on the Department's MARS web page: in English: or French: You will find on this page: 'Introduction to MARS' with detailed information presented in Frequently Asked Questions; these include the MARS timetable for proposals and decisions; 'Regulations' with links to the scheme's statutory documents; 'Procedures and Forms' and 'Useful Information' with links to all the relevant documentation; these include the mandates of the Senior Staff Advisory Committee (SSAC) and the Technical Engineers and Administrative Careers Committee (TEACC). HR Department Tel. 73566

  16. Wetting and adsorption modification in the system

    Directory of Open Access Journals (Sweden)

    Yuliya Bogdanova


    Full Text Available Regularities of wetting and adsorption modification of surfaces of continual membranes made from highly permeable glassy polymers poly[1-(trimethylsilyl-1-propyne] (PTMSP and poly(4-methyl-2-pentyn (PMP with aqueous ethanol solutions and alcohol solutions containing organic dyes (Solvent Blue 35 and Remazol Brilliant Blue were investigated. Isotherms of stress wetting of polymer membrane surface by etanol solutions were found out to have maximums in the range of concentrations corresponding to the beginning of liquid sorption into the membrane and polymer swelling. Thus, the principal possibility of optimization of nanofiltration experiments by liquid wetting angle measurements on continuous polymer membrane surfaces was shown. The presence of the dye was shown not to affect PMP wetting. But in the case of PTMSP, it leads to shear of the maximum of stress wetting isotherms to the range of higher concentrations. It was found out the effectiveness of the adsorption surface modification of continuous polymer membrane surfaces by ethanol solutions containing dyes does not dependent on chemical nature of the dye. At the same time, there are different trends in the energy characteristics of the membrane surface.

  17. Membrane-based wet electrostatic precipitation. (United States)

    Bayless, David J; Shi, Liming; Kremer, Gregory; Stuart, Ben J; Reynolds, James; Caine, John


    Emissions of fine particulate matter, PM2.5, in both primary and secondary form, are difficult to capture in typical dry electrostatic precipitators (ESPs). Wet (or water-based) ESPs are well suited for collection of acid aerosols and fine particulates because of greater corona power and virtually no re-entrainment. However, field disruptions because of spraying (misting) of water, formation of dry spots (channeling), and collector surface corrosion limit the applicability of current wet ESPs in the control of secondary PM2.5. Researchers at Ohio University have patented novel membrane collection surfaces to address these problems. Water-based cleaning in membrane collectors made of corrosion-resistant fibers is facilitated by capillary action between the fibers, maintaining an even distribution of water. This paper presents collection efficiency results of lab-scale and pilot-scale testing at FirstEnergy's Bruce Mansfield Plant for the membrane-based wet ESP. The data indicate that a membrane wet ESP was more effective at collecting fine particulates, acid aerosols, and oxidized mercury than the metal-plate wet ESP, even with approximately 15% less collecting area.

  18. Dynamic wetting on anisotropic patterned surfaces (United States)

    Do-Quang, Minh; Wang, Jiayu; Nita, Satoshi; Shiomi, Junichiro; Amberg, Gustav; Physiochemical fluid mechanics Team; Maruyama-Chiashi Laboratory Team


    Dynamic wetting, as occurs when a droplet of a wetting liquid is brought in contact with a dry solid, is important in various engineering processes, such as printing, coating, and lubrication. Our overall aim is to investigate if and how the detailed properties of the solid surface influence the dynamics of wetting. We have recently quantified the hindering effect of fairly isotropic micron-sized patterns on the substrate. Here we will study highly anisotropic surfaces, such as parallel grooves, either perpendicular or parallel to an advancing contact line. This is done by detailed phase field simulations and experiments on structured silicon surfaces. The dynamic wetting behavior of drops on the grooved surfaces is governed by the combined interplay of the wetting line friction and the internal viscous dissipation. Influence of roughness is quantified in terms of the energy dissipation rate at the contact line using the experiment-simulation combined analysis. The energy dissipation of the contact line at the different part of the groove will be discussed. The performance of the model is assessed by comparing its predictions with the experimental data. This work was financially supported in part by, the Japan Society for the Promotion of Science (J.W., S.N., and J.S) and Swedish Governmental Agency for Innovation Systems (M.D.-Q. and G.A).

  19. Energy and heat balance in wet DCT

    Energy Technology Data Exchange (ETDEWEB)

    Saxena, Viren; Moser, Alexander; Schaefer, Michael; Ritschel, Michael [BorgWarner Drivetrain Engineering GmbH, Ketsch (Germany)


    Wet clutch systems are well known for their thermal robustness and versatility in a wide range of automotive applications. Conventional automatics have used them for a long time as torque converter lock-up clutches, shift elements and launch clutches. With the development of DCTs, wet clutch technology has evolved in terms of launch and shift performance, controllability, robustness and efficiency. This paper discusses improvements in the wet clutch and their impact on today's vehicle applications in terms of heat and energy management. Thermal robustness is a crucial aspect for an automatic transmission. In addition to the clutch thermal performance, the influence of transmission oil cooler and oil sump warm-up behavior are discussed. Based on our latest development activities, test results and simulations, we shall discuss the latest friction material enhancement and its impact on DCTs in terms of efficiency and performance. Drag loss is a much-discussed topic during the development of wet clutch systems. This paper discusses in detail the cause and break-up of various energy losses in a wet DCT. Efficient energy management strategies for actuation systems, cooling, and lubrication, clutch apply, and pre-selection in modern power trains with engine start / stop are evaluated based on the latest test and simulation results. Finally, the paper summarizes the performance and efficiency optimized moist clutch system. (orig.)

  20. Advanced methods for the treatment of organic aqueous wastes: wet air oxidation and wet peroxide oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Debellefontaine, Hubert; Chakchouk, Mehrez; Foussard, Jean Noel [Institut National des Sciences Appliquees (INSA), 31 - Toulouse (France). Dept. de Genie des Procedes Industriels; Tissot, Daniel; Striolo, Phillipe [IDE Environnement S.A., Toulouse (France)


    There is a growing concern about the problems of wastes elimination. Various oxidation techniques are suited for elimination of organic aqueous wastes, however, because of the environmental drawbacks of incineration, liquid phase oxidation should be preferred. `Wet Air Oxidation` and `Wet Peroxide Oxidation`are alternative processes which are discussed in this paper. 17 refs., 13 figs., 4 tabs.

  1. Evaporation from rain-wetted forest in relation to canopy wetness, canopy cover, and net radiation

    NARCIS (Netherlands)

    Klaassen, W.


    Evaporation from wet canopies is commonly calculated using E-PM, the Penman-Monteith equation with zero surface resistance. However, several observations show a lower evaporation from rain-wetted forest. Possible causes for the difference between E-PM and experiments are evaluated to provide rules

  2. Methane Propulsion Elements for Mars (United States)

    Percy, Tom; Polsgrove, Tara; Thomas, Dan


    Human exploration beyond LEO relies on a suite of propulsive elements to: (1) Launch elements into space, (2) Transport crew and cargo to and from various destinations, (3) Provide access to the surface of Mars, (4) Launch crew from the surface of Mars. Oxygen/Methane propulsion systems meet the unique requirements of Mars surface access. A common Oxygen/Methane propulsion system is being considered to reduce development costs and support a wide range of primary & alternative applications.

  3. Understanding Hydrological and Climate Conditions on Early Mars Through Sulfate Cycling and Microbial Activity in Terrestrial Volcanic Systems (United States)

    Szynkiewicz, A.; Mikucki, J.; Vaniman, D.


    Our study is a type of Earth-based investigation in a Mars-analog environment that allows for determination of how changing wet and dry conditions in active volcanic/hydrothermal system affect sulfate fluxes into surface water and groundwater.

  4. Winter Storm Zones on Mars (United States)

    Hollingsworth, J. L.; Haberle, R. M.; Barnes, J. R.; Bridger, A. F. C.; Cuzzi, Jeffrey N. (Technical Monitor)


    Preferred regions of weather activity in Mars' winter middle latitudes-so called 'storm zones' are found in a general circulation model of Mars' atmospheric circulation. During northern winter, these storm zones occur in middle latitudes in the major planitia (low-relief regions) of the western and eastern hemisphere. In contrast, the highlands of the eastern hemisphere are mostly quiescent. Compared to Earth's storm zones where diabatic heating associated with land-sea thermal contrasts is crucial, orography on Mars is fundamental to the regionalization of weather activity. Future spacecraft missions aimed at assessing Mars' climate and its variability need to include such regions in observation strategies.

  5. Wet powder seal for gas containment (United States)

    Stang, Louis G.


    A gas seal is formed by a compact layer of an insoluble powder and liquid filling the fine interstices of that layer. The smaller the particle size of the selected powder, such as sand or talc, the finer will be the interstices or capillary spaces in the layer and the greater will be the resulting sealing capacity, i.e., the gas pressure differential which the wet powder layer can withstand. Such wet powder seal is useful in constructing underground gas reservoirs or storage cavities for nuclear wastes as well as stopping leaks in gas mains buried under ground or situated under water. The sealing capacity of the wet powder seal can be augmented by the hydrostatic head of a liquid body established over the seal.

  6. Novel design for Konin wet FGD

    Energy Technology Data Exchange (ETDEWEB)

    Zawacki, T.; Bengtsson, S. [ZEPAK, Konin (Poland)


    The Konin Power Station, Poland, with a total production capacity of 538 MW{sub e} and 462 MW{sub th} and belonging to the ZEPAK group, is extensively rebuilding units Nos 7 and 8 and retrofitting with wet flue gas desulphurisation. ZEPAK evaluated wet FGD technologies in 1992 and 1993 and decided for a novel concrete absorber-in-stack concept for a limestone forced oxidation system, that will produce commercial grade gypsum. The FGD plant is now under construction and commissioning is scheduled to commence in first quarter of 1997. The paper will provide the background for the choice of wet FGD and present details on both execution and technology for this novel absorber-in-stack concept for power plant FGD.

  7. Sphere impact and penetration into wet sand

    KAUST Repository

    Marston, J. O.


    We present experimental results for the penetration of a solid sphere when released onto wet sand. We show, by measuring the final penetration depth, that the cohesion induced by the water can result in either a deeper or shallower penetration for a given release height compared to dry granular material. Thus the presence of water can either lubricate or stiffen the granular material. By assuming the shear rate is proportional to the impact velocity and using the depth-averaged stopping force in calculating the shear stress, we derive effective viscosities for the wet granular materials.

  8. Mars aqueous chemistry experiment (United States)

    Clark, Benton C.; Mason, Larry W.


    The Mars Aqueous Chemistry Experiment (MACE) is designed to conduct a variety of measurements on regolith samples, encompassing mineral phase analyses, chemical interactions with H2O, and physical properties determinations. From these data, much can be learned or inferred regarding the past weathering environment, the contemporaneous soil micro-environments, and the general chemical and physical state of the Martian regolith. By analyzing both soil and duricrust samples, the nature of the latter may become more apparent. Sites may be characterized for comparative purposes and criteria could be set for selection of high priority materials on future sample return missions. Progress for the first year MACE PIDDP is reported in two major areas of effort: (1) fluids handling concepts, definition, and breadboard fabrication and (2) aqueous chemistry ion sensing technology and test facility integration. A fluids handling breadboard was designed, fabricated, and tested at Mars ambient pressure. The breadboard allows fluid manipulation scenarios to be tested under the reduced pressure conditions expected in the Martian atmosphere in order to validate valve operations, orchestrate analysis sequences, investigate sealing integrity, and to demonstrate efficacy of the fluid handling concept. Additional fluid manipulation concepts have also been developed based on updated MESUR spacecraft definition. The Mars Aqueous Chemistry Experiment Ion Selective Electrode (ISE) facility was designed as a test bed to develop a multifunction interface for measurements of chemical ion concentrations in aqueous solution. The interface allows acquisition of real time data concerning the kinetics and heats of salt dissolution, and transient response to calibration and solubility events. An array of ion selective electrodes has been interfaced and preliminary calibration studies performed.

  9. Do Martian Blueberries Have Pits? -- Artifacts of an Early Wet Mars (United States)

    Lerman, L.


    Early Martian weather cycles would have supported organic chemical self-organization, the assumed predecessor to an independent "origin" of Martian life. Artifacts of these processes are discussed, including the possibility that Martian blueberries nucleated around organic cores.

  10. Mars At Opposition (United States)


    These NASA Hubble Space Telescope views provide the most detailed complete global coverage of the red planet Mars ever seen from Earth. The pictures were taken on February 25, 1995, when Mars was at a distance of 65 million miles (103 million km).To the surprise of researchers, Mars is cloudier than seen in previous years. This means the planet is cooler and drier, because water vapor in the atmosphere freezes out to form ice-crystal clouds. Hubble resolves Martian surface features with a level of detail only exceeded by planetary probes, such as impact craters and other features as small as 30 miles (50 kilometers) across.[Tharsis region] - A crescent-shaped cloud just right of center identifies the immense shield volcano Olympus Mons, which is 340 miles (550 km) across at its base. Warm afternoon air pushed up over the summit forms ice-crystal clouds downwind from the volcano. Farther to the east (right) a line of clouds forms over a row of three extinct volcanoes which are from north to south: Ascraeus Mons, Pavonis Mons, Arsia Mons. It's part of an unusual, recurring 'W'-shaped cloud formation that once mystified earlier ground-based observers.[Valles Marineris region] - The 16 mile-high volcano Ascraeus Mons pokes through the cloud deck along the western (left) limb of the planet. Other interesting geologic features include (lower left) Valles Marineris, an immense rift valley the length of the continental United States. Near the image center lies the Chryse basin made up of cratered and chaotic terrain. The oval-looking Argyre impact basin (bottom) appears white due to clouds or frost.[Syrtis Major region] - The dark 'shark fin' feature left of center is Syrtis Major. Below it the giant impact basin Hellas. Clouds cover several great volcanos in the Elysium region near the eastern (right) limb. As clearly seen in the Hubble images, past dust storms in Mars' southern hemisphere have scoured the plains of fine light dust and transported the dust northward. This

  11. Astrolabe observations of Mars (United States)

    Standish, E. M.; Debarbat, S.; Sanchez, M.


    A previously reported bias in the right ascension residuals of astrolabe observations of Mars is removed by correcting for equinox motion and relating the observations to the Jet Propulsion Laboratory's planetary ephemeris, DE111. The remaining residuals show a 'phase effect', the magnitude of which is solved for and compared with that previously found for meridian transit observations. The final residuals reveal no significant offset in either right ascension or declination. In modifying the residuals, use is also made of Fricke's (1980) correction for the motion of the FK 4 equinox.

  12. Mars Observer spacecraft (United States)

    Potts, Dennis L.


    The technical aspects of the spacecraft for the Mars Observer mission are discussed. The spacecraft development focuses on using existing flight subsystem designs and production techniques to offer a low-cost, reliable, production-type spacecraft. The scientific objectives of the mission and the scientific payloads of the spacecraft are considered. The spacecraft system and its performance are discussed. The subsystems are described in detail, including attitude and articulation control, electrical power supply, propulsion, structure, thermal control, command and data handling, telecommunications, mechanics, and flight software.

  13. Wetting properties and performance test of modified rigid collector in wet electrostatic precipitators. (United States)

    Xu, Chunyan; Chang, Jingcai; Meng, Zhen; Wang, Xiang; Zhang, Jing; Cui, Lin; Ma, Chunyuan


    The fine particles are considered a significant pollution problem. The wet electrostatic precipitators (ESPs) have advantages of efficient collection of the fine particles with lower pressure drop and eliminating reentrainment. The wetting properties of the collector surfaces have significantly important effect on wet ESPs' stable and secure operation. The modified rigid collector (MRC) was modified by coating specific vinyl ester resin composites and loose glass fiber cloth over the conventional carbon steel in a certain way. The rigid collector surfaces before and after modification had been characterized by scanning electron microscopy (SEM) and interface tensiometer. The effect of operating temperatures on the wetting properties of the rigid collector surfaces before and after modification was investigated. The temperature range was 40~90 °C, and the wetting properties contained liquid holdup, surface flow rate, film rate, average film thickness, and critical saturation time. The modified rigid collector surface exhibited excellent wetting properties at the operating temperatures. The fine particles collection performance compared among the MRC, the conventional rigid collector (CRC), and the flexible collector (FC) in the wet ESPs was investigated. The effects of the applied voltage, the water film, corona power, and the specific collecting area on the fine particles collection were evaluated. The modified rigid collector provided high fine particles collection effect with lower energy and water consumption. To improve the submicron particles collection efficiency and decrease energy and water consumption, the formation of uniform water film over the collector surfaces has been widely studied. The modified rigid collector was modified by coating specific vinyl ester resin composites and loose glass fiber cloth (ERGF) over the conventional carbon steel (CCS) in a certain way. The modified rigid collector surface exhibited excellent wetting properties. The wet

  14. Water and Life on Mars (United States)

    McKay, Christopher P.; DeVincenzi, Donald (Technical Monitor)


    Mars appears to be cold dry and dead world. However there is good evidence that early in its history it had liquid water, more active volcanism, and a thicker atmosphere. Mars had this earth-like environment over three and a half billion years ago, during the same time that life appeared on Earth. The main question in the exploration of Mars then is the search for a independent origin of life on that planet. Ecosystems in cold, dry locations on Earth - such as the Antarctic - provide examples of how life on Mars might have survived and where to look for fossils. Although the Viking results may indicate that Mars has no life today, there is direct geomorphological evidence that, in the past, Mars had large amounts of liquid water on its surface - possibly due to a thicker atmosphere. From a biological perspective the existence of liquid water, by itself motivates the question of the origin of life on Mars. One of the martian meteorites dates back to this early period and may contain evidence consistent with life. From studies of the Earth's earliest biosphere we know that by 3.5 Gyr. ago, life had originated on Earth and reached a fair degree of biological sophistication. Surface activity and erosion on Earth make it difficult to trace the history of life before the 3.5 Gyr timeframe. Ecosystems in cold, dry locations on Earth - such as the Antarctic - provide examples of how life on Mars might have survived and where to look for fossils.

  15. 'Endurance' Courtesy of Mars Express (United States)


    NASA's Mars Exploration Rover Opportunity used its panoramic camera to capture this false-color image of the interior of 'Endurance Crater' on the rover's 188th martian day (Aug. 4, 2004). The image data were relayed to Earth by the European Space Agency's Mars Express orbiter. The image was generated from separate frames using the cameras 750-, 530- and 480-nanometer filters.

  16. Catalytic gasification of dry and wet biomass

    NARCIS (Netherlands)

    van Rossum, G.; Potic, B.; Kersten, Sascha R.A.; van Swaaij, Willibrordus Petrus Maria


    Catalytic gasification of dry biomass and of wet biomass streams in hot compressed water are reviewed and discussed as potential technologies for the production of synthesis gas, hydrogen- and methane-rich gas. Next to literature data also new experimental results from our laboratory on catalytic

  17. Wet oxidation of salicylic acid solutions. (United States)

    Collado, Sergio; Garrido, Laura; Laca, Adriana; Diaz, Mario


    Salicylic acid is a frequent pollutant in several industrial wastewaters. Uncatalyzed wet air oxidation, which is a promising technique for the treatment of phenolic effluents, has not been analyzed yet for the removal of salicylic acid. The effect of different conditions of pH (1.3-12.3), pressure (1.0-4.1 MPa), temperature (413-443 K), and initial concentrations (1.45-14.50 mM) on the wet oxidation of salicylate/salicylic acid solutions have here been investigated. The pH value of the reaction media was found to be a key parameter for the rate of the oxidation process with an optimum at pH 3.1, when the concentrations of salicylic acid and salicylate were similar. The oxidation reaction followed pseudofirst-order kinetics with respect to salicylic acid and 0.82 order with respect to dissolved oxygen. Additionally, the evolution of the color during the wet oxidation was analyzed and discussed in relation with the formation of intermediate compounds. Then, a reaction pathway for the noncatalytic wet oxidation of the salicylic acid was proposed.

  18. Curvature controlled wetting in two dimensions

    DEFF Research Database (Denmark)

    Gil, Tamir; Mikheev, Lev V.


    layer lW, leading to a power law lW∝r01/3. At a critical wetting transition of a planar substrate, curvature adds a relevant field; the corresponding multiscaling forms are readily available. The method allows for the systematic evaluation of corrections to the leading behavior; the next to the leading...

  19. Theory of the forced wetting transition

    NARCIS (Netherlands)

    Chan, Tak Shing; Snoeijer, Jacobus Hendrikus; Eggers, J.


    We consider a solid plate being withdrawn from a bath of liquid which it does not wet. At low speeds, the meniscus rises below a moving contact line, leaving the rest of the plate dry. At a critical speed of withdrawal, this solution bifurcates into another branch via a saddle-node bifurcation: two

  20. Directional wetting on chemically patterned substrates

    NARCIS (Netherlands)

    Kooij, Ernst S.; Jansen, H.P.; Bliznyuk, O.; Poelsema, Bene; Zandvliet, Henricus J.W.


    The directional wetting behavior of chemically defined stripe-patterned anisotropic surfaces is presented. The equilibrium shapes of asymmetric droplets, arising from patterns of alternating hydrophilic and hydrophobic stripes with dimensions in the low-micrometer range, are investigated in relation

  1. Accretion Dynamics on Wet Granular Materials (United States)

    Saingier, Guillaume; Sauret, Alban; Jop, Pierre


    Wet granular aggregates are common precursors of construction materials, food, and health care products. The physical mechanisms involved in the mixing of dry grains with a wet substrate are not well understood and difficult to control. Here, we study experimentally the accretion of dry grains on a wet granular substrate by measuring the growth dynamics of the wet aggregate. We show that this aggregate is fully saturated and its cohesion is ensured by the capillary depression at the air-liquid interface. The growth dynamics is controlled by the liquid fraction at the surface of the aggregate and exhibits two regimes. In the viscous regime, the growth dynamics is limited by the capillary-driven flow of liquid through the granular packing to the surface of the aggregate. In the capture regime, the capture probability depends on the availability of the liquid at the saturated interface, which is controlled by the hydrostatic depression in the material. We propose a model that rationalizes our observations and captures both dynamics based on the evolution of the capture probability with the hydrostatic depression.

  2. Cohesion and agglomeration of wet powders (United States)

    Raux, Pascal S.; Biance, Anne-Laure


    Wet high-shear granulation consists in vigorously mixing grains and a liquid binder to create agglomerates of various sizes. The process results from a balance between cohesion of the wet granular agglomerates and fragmentation due to the high mixing. By performing a simple test with glass beads and various liquids, we first focus on the static cohesion of wet granular media. Contrary to previous works, we extend the study to larger values of the liquid fraction w . After the well-documented plateau, the cohesive strength increases again with w , a behavior we capture by a simple model. We then focus on the dynamical cohesion of the media and we design an agglomeration process that consists in vibrating a bead/liquid mixture at a large amplitude. The vibrations induce not only the fluidization of the wet granular material but also the formation of aggregates. As expected, their size is affected by the liquid content, the frequency, and the amplitude of the vibrations, similarly to high-shear granulation data. However, the number of beads in an agglomerate does not depend on the bead size, showing a self-similar mechanism of agglomeration. The role of the static cohesion strength in this dynamical process remains therefore ambiguous.

  3. Microwave moisture sensing of wet bales (United States)

    Sensing of moisture in very wet lint bales is unique due to the fact that moisture distribution is typically non-uniform and can in some instances be highly localized. This issue is even further complicated by the use of a sensor that reads only a portion of the bale and/or with a sensor that provid...

  4. Ovine wet carcass syndrome of unknown aetiology

    African Journals Online (AJOL)

    plicating cachexia, inflammatory processes, lymphoedema, cardiac failure, glycogen storage or myxoedema in the pathogenesis of the syndrome. In conclusion, despite intensive investigation the aeti- ology of the wet carcase syndrome remains unknown. At present the possibility of a histamine reaction due to insect bites is ...

  5. Mars Exploration Rover mission (United States)

    Crisp, Joy A.; Adler, Mark; Matijevic, Jacob R.; Squyres, Steven W.; Arvidson, Raymond E.; Kass, David M.


    In January 2004 the Mars Exploration Rover mission will land two rovers at two different landing sites that show possible evidence for past liquid-water activity. The spacecraft design is based on the Mars Pathfinder configuration for cruise and entry, descent, and landing. Each of the identical rovers is equipped with a science payload of two remote-sensing instruments that will view the surrounding terrain from the top of a mast, a robotic arm that can place three instruments and a rock abrasion tool on selected rock and soil samples, and several onboard magnets and calibration targets. Engineering sensors and components useful for science investigations include stereo navigation cameras, stereo hazard cameras in front and rear, wheel motors, wheel motor current and voltage, the wheels themselves for digging, gyros, accelerometers, and reference solar cell readings. Mission operations will allow commanding of the rover each Martian day, or sol, on the basis of the previous sol's data. Over a 90-sol mission lifetime, the rovers are expected to drive hundreds of meters while carrying out field geology investigations, exploration, and atmospheric characterization. The data products will be delivered to the Planetary Data System as integrated batch archives.

  6. From Mars with love. (United States)

    Young, R S; Devincenzi, D L


    1) Sample return missions from Mars are feasible in the 1980's. 2) The least expensive missions (direct sample return without sterilization) may be criticizable because of the possibility of back-contamination, although upgrading the handling and containment facilities could make unsterile return acceptable. 3) Sample sterilization decreases the total scientific value appreciably, depending on the measurements to be made. Geology is least affected and biology and organic chemistry are most affected. 4) Quarantine in earth orbit, in the same sense as for the lunar samples, would not be feasible without very large increases in cost. Orbital quarantine facilities, either automated or manned, would be very expensive, risky, and of limited use because of size limitations. 5) Orbital quarantine may be feasible if the sample is split, part of it sterilized and returned to the earth for study, and the remainder studied for pathogenicity in the automated mode as best we can in the limited space available in orbit. Ground studies of sterilized material plus "live" studies in orbit may convince us of the safety of returning the remaining sample to the earth under carefully prescribed conditions. 6) Additional unmanned, Vikingtype missions to Mars can add considerably to our knowledge about a martian biota, or its absence, and thus increase the likelihood of being able to return an unaltered sample safely to the earth.

  7. Water on early Mars (United States)

    Carr, M.H.


    Large flood channels, valley networks and a variety of features attributed to the action of ground ice indicate that Mars emerged from heavy bombardment 3.8 Ga ago, with an inventory of water at the surface equivalent to at least a few hundred metres spread over the whole planet, as compared with 3 km for the Earth. The mantle of Mars is much drier than that of the Earth, possibly as a result of global melting at the end of accretion and the lack of plate tectonics to subsequently reintroduce water into the interior. The surface water resided primarily in a porous, kilometres-thick megaregolith created by the high impact rates. Under today's climatic conditions groundwater is trapped below a thick permafrost zone. At the end of heavy bombardment any permafrost zone would have been much thinner because of the high heat flows, but climatic conditions may have been very different then, as suggested by erosion rates 1000 times higher than subsequent rates. Water trapped below the permafrost periodically erupted onto the surface to form large flood channels and lakes. Given abundant water at the surface and sustained volcanism, hydrothermal activity must have frequently occurred but we have yet to make the appropriate observations to detect the results of such activity.

  8. Safety during MARS exercise

    CERN Multimedia


    It is MARS(1) time again! All employed members of the CERN personnel are currently undergoing the annual MARS evaluations.   This is also a good occasion for supervisors and their supervisees to fill in or update the OHS-0-0-3 form(2) “Identification of occupational hazards”. Filling in the OHS-0-0-3 form is an opportunity to assess any safety issues related to the supervisee's activities.  Each of us should, together with our supervisor, regularly identify and assess the hazards we may be exposed to in the course of our professional activities and reflect on how to control and mitigate them. When filling in the OHS form for the first time, it is important to determine any potential hazards as well as the corresponding preventive measures, in particular training and protective equipment. When updating the form, please review the available information to ensure that it still corresponds to the current activities. The form should be updated w...

  9. Surface clay formation during short-term warmer and wetter conditions on a largely cold ancient Mars (United States)

    Bishop, Janice L.; Fairén, Alberto G.; Michalski, Joseph R.; Gago-Duport, Luis; Baker, Leslie L.; Velbel, Michael A.; Gross, Christoph; Rampe, Elizabeth B.


    The ancient rock record for Mars has long been at odds with climate modelling. The presence of valley networks, dendritic channels and deltas on ancient terrains points towards running water and fluvial erosion on early Mars1, but climate modelling indicates that long-term warm conditions were not sustainable2. Widespread phyllosilicates and other aqueous minerals on the Martian surface3-6 provide additional evidence that an early wet Martian climate resulted in surface weathering. Some of these phyllosilicates formed in subsurface crustal environments5, with no association with the Martian climate, while other phyllosilicate-rich outcrops exhibit layered morphologies and broad stratigraphies7 consistent with surface formation. Here, we develop a new geochemical model for early Mars to explain the formation of these clay-bearing rocks in warm and wet surface locations. We propose that sporadic, short-term warm and wet environments during a generally cold early Mars enabled phyllosilicate formation without requiring long-term warm and wet conditions. We conclude that Mg-rich clay-bearing rocks with lateral variations in mixed Fe/Mg smectite, chlorite, talc, serpentine and zeolite occurrences formed in subsurface hydrothermal environments, whereas dioctahedral (Al/Fe3+-rich) smectite and widespread vertical horizonation of Fe/Mg smectites, clay assemblages and sulphates formed in variable aqueous environments on the surface of Mars. Our model for aluminosilicate formation on Mars is consistent with the observed geological features, diversity of aqueous mineralogies in ancient surface rocks and state-of-the-art palaeoclimate scenarios.

  10. Austere Human Missions to Mars (United States)

    Price, Hoppy; Hawkins, Alisa M.; Tadcliffe, Torrey O.


    The Design Reference Architecture 5 (DRA 5) is the most recent concept developed by NASA to send humans to Mars in the 2030 time frame using Constellation Program elements. DRA 5 is optimized to meet a specific set of requirements that would provide for a robust exploration program to deliver a new six-person crew at each biennial Mars opportunity and provide for power and infrastructure to maintain a highly capable continuing human presence on Mars. This paper examines an alternate architecture that is scaled back from DRA 5 and might offer lower development cost, lower flight cost, and lower development risk. It is recognized that a mission set using this approach would not meet all the current Constellation Mars mission requirements; however, this 'austere' architecture may represent a minimum mission set that would be acceptable from a science and exploration standpoint. The austere approach is driven by a philosophy of minimizing high risk or high cost technology development and maximizing development and production commonality in order to achieve a program that could be sustained in a flat-funded budget environment. Key features that would enable a lower technology implementation are as follows: using a blunt-body entry vehicle having no deployable decelerators, utilizing aerobraking rather than aerocapture for placing the crewed element into low Mars orbit, avoiding the use of liquid hydrogen with its low temperature and large volume issues, using standard bipropellant propulsion for the landers and ascent vehicle, and using radioisotope surface power systems rather than a nuclear reactor or large area deployable solar arrays. Flat funding within the expected NASA budget for a sustained program could be facilitated by alternating cargo and crew launches for the biennial Mars opportunities. This would result in two assembled vehicles leaving Earth orbit for Mars per Mars opportunity. The first opportunity would send two cargo landers to the Mars surface to

  11. Wet adhesion and adhesive locomotion of snails on anti-adhesive non-wetting surfaces.

    Directory of Open Access Journals (Sweden)

    Neil J Shirtcliffe

    Full Text Available Creating surfaces capable of resisting liquid-mediated adhesion is extremely difficult due to the strong capillary forces that exist between surfaces. Land snails use this to adhere to and traverse across almost any type of solid surface of any orientation (horizontal, vertical or inverted, texture (smooth, rough or granular or wetting property (hydrophilic or hydrophobic via a layer of mucus. However, the wetting properties that enable snails to generate strong temporary attachment and the effectiveness of this adhesive locomotion on modern super-slippy superhydrophobic surfaces are unclear. Here we report that snail adhesion overcomes a wide range of these microscale and nanoscale topographically structured non-stick surfaces. For the one surface which we found to be snail resistant, we show that the effect is correlated with the wetting response of the surface to a weak surfactant. Our results elucidate some critical wetting factors for the design of anti-adhesive and bio-adhesion resistant surfaces.

  12. Wet adhesion and adhesive locomotion of snails on anti-adhesive non-wetting surfaces. (United States)

    Shirtcliffe, Neil J; McHale, Glen; Newton, Michael I


    Creating surfaces capable of resisting liquid-mediated adhesion is extremely difficult due to the strong capillary forces that exist between surfaces. Land snails use this to adhere to and traverse across almost any type of solid surface of any orientation (horizontal, vertical or inverted), texture (smooth, rough or granular) or wetting property (hydrophilic or hydrophobic) via a layer of mucus. However, the wetting properties that enable snails to generate strong temporary attachment and the effectiveness of this adhesive locomotion on modern super-slippy superhydrophobic surfaces are unclear. Here we report that snail adhesion overcomes a wide range of these microscale and nanoscale topographically structured non-stick surfaces. For the one surface which we found to be snail resistant, we show that the effect is correlated with the wetting response of the surface to a weak surfactant. Our results elucidate some critical wetting factors for the design of anti-adhesive and bio-adhesion resistant surfaces.

  13. Geologic map of Mars (United States)

    Tanaka, Kenneth L.; Skinner, James A.; Dohm, James M.; Irwin, Rossman P.; Kolb, Eric J.; Fortezzo, Corey M.; Platz, Thomas; Michael, Gregory G.; Hare, Trent M.


    This global geologic map of Mars, which records the distribution of geologic units and landforms on the planet's surface through time, is based on unprecedented variety, quality, and quantity of remotely sensed data acquired since the Viking Orbiters. These data have provided morphologic, topographic, spectral, thermophysical, radar sounding, and other observations for integration, analysis, and interpretation in support of geologic mapping. In particular, the precise topographic mapping now available has enabled consistent morphologic portrayal of the surface for global mapping (whereas previously used visual-range image bases were less effective, because they combined morphologic and albedo information and, locally, atmospheric haze). Also, thermal infrared image bases used for this map tended to be less affected by atmospheric haze and thus are reliable for analysis of surface morphology and texture at even higher resolution than the topographic products.

  14. Mars Under the Microscope (United States)


    This magnified look at the martian soil near the Mars Exploration Rover Opportunity's landing site, Meridiani Planum, shows coarse grains sprinkled over a fine layer of sand. The image was captured by the rover's microscopic imager on the 10th day, or sol, of its mission. Scientists are intrigued by the spherical rocks, which can be formed by a variety of geologic processes, including cooling of molten lava droplets and accretion of concentric layers of material around a particle or 'seed.'The examined patch of soil is 3 centimeters (1.2 inches) across. The circular grain in the lower left corner is approximately 3 millimeters (.12 inches) across, or about the size of a sunflower seed.

  15. Polygon on Mars (United States)


    This image shows a small-scale polygonal pattern in the ground near NASA's Phoenix Mars Lander. This pattern is similar in appearance to polygonal structures in icy ground in the arctic regions of Earth. Phoenix touched down on the Red Planet at 4:53 p.m. Pacific Time (7:53 p.m. Eastern Time), May 25, 2008, in an arctic region called Vastitas Borealis, at 68 degrees north latitude, 234 degrees east longitude. This image was acquired by the Surface Stereo Imager shortly after landing. On the Phoenix mission calendar, landing day is known as Sol 0, the first Martian day of the mission. The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  16. Pedogenetic processes on Mars (United States)

    Chiara Tangari, Anna; Marinangeli, Lucia; Piluso, Eugenio; Pompilio, Loredana; Scarciglia, Fabio


    Clay minerals, such as Fe/Mg smectite and Al-rich phyllosilicates (i.e., montmorillonite and kaolinite) were detected in the last years on Mars by numerous missions[1,2]. These minerals can be formed by fluid/rock interaction. Therefore, their study may provide important information on the climatic conditions and consequent habitability of the Martian surface. In this work we compare the mineralogy observed with CRISM data in the eastern part of Valles Marineris (Coprates-Ganges-Capri-Eos Chasmata), Margaritifer Terra and Margaritifer Chaos regions, with soils sampled on the Etna volcano (Sicily) and Cerviero Mount (Calabria, Southern Italy). We use an integrated approach of remote sensing coupled with pedological, petrographical and mineralogical investigations. Our purpose, here, is to find possible analogies between some Andosols developed on the basaltic substrates of Etna and Cerviero Mount, and the Martian soils, based on their spectral response and formation processes. CRISM data show poor abundance of clay minerals, such as illite, smectite and montmorillonite, in the eastern part of Valles Marineris. On the contrary, these phases are widely exposed in the Margaritifer Terra and Margaritifer Chaos, where we detected allophone (poorly crystalline clay), vermiculite, chlorite and other phyllosilicates belonging to the smectite group, such as saponite and nontronite. The surrounding area shows dominant signatures of basaltic composition.Our preliminary analysis on terrestrial soil profiles, using X-ray diffraction analysis, shows similar characteristics to Mars in terms of bedrock composition and clay mineralogy. Etnean soils, formed from lavas and pyroclastics of various ages (from 12 ka to 122 BC) [3] show the presence of clay minerals, such as kaolinite and small amounts of illite. The Cerviero Mount soils, developed on pillow basalts of Maastrichtian-Paleocene ages [4] are composed of vermiculite, illite, chlorite and interstratified clays such as

  17. The Mars water cycle (United States)

    Davies, D. W.


    A model has been developed to test the hypothesis that the observed seasonal and latitudinal distribution of water on Mars is controlled by the sublimation and condensation of surface ice deposits in the Arctic and Antarctic, and the meridional transport of water vapor. Besides reproducing the observed water vapor distribution, the model correctly reproduces the presence of a large permanent ice cap in the Arctic and not in the Antarctic. No permanent ice reservoirs are predicted in the temperate or equatorial zones. Wintertime ice deposits in the Arctic are shown to be the source of the large water vapor abundances observed in the Arctic summertime, and the moderate water vapor abundances in the northern temperate region. Model calculations suggest that a year without dust storms results in very little change in the water vapor distribution. The current water distribution appears to be the equilibrium distribution for present atmospheric conditions.

  18. Belly Dancing on Mars (United States)


    This image shows a screenshot from the software used by engineers to drive the Mars Exploration Rover Spirit. The software simulates the rover's movements across the martian terrain, helping to plot a safe course for the rover. The virtual 3-D world around the rover is built from images taken by Spirit's stereo navigation cameras. Regions for which the rover has not yet acquired 3-D data are represented in beige. The red dart to the left shows a target destination for the rover. Red lines indicate the path the rover's wheels will follow to reach the target, and the blue line denotes the path of the rover's 'belly button,' as engineers like to call it.

  19. Mars: a small terrestrial planet (United States)

    Mangold, N.; Baratoux, D.; Witasse, O.; Encrenaz, T.; Sotin, C.


    Mars is characterized by geological landforms familiar to terrestrial geologists. It has a tenuous atmosphere that evolved differently from that of Earth and Venus and a differentiated inner structure. Our knowledge of the structure and evolution of Mars has strongly improved thanks to a huge amount of data of various types (visible and infrared imagery, altimetry, radar, chemistry, etc) acquired by a dozen of missions over the last two decades. In situ data have provided ground truth for remote-sensing data and have opened a new era in the study of Mars geology. While large sections of Mars science have made progress and new topics have emerged, a major question in Mars exploration—the possibility of past or present life—is still unsolved. Without entering into the debate around the presence of life traces, our review develops various topics of Mars science to help the search of life on Mars, building on the most recent discoveries, going from the exosphere to the interior structure, from the magmatic evolution to the currently active processes, including the fate of volatiles and especially liquid water.

  20. NASA Mars Science Laboratory Rover (United States)

    Olson, Tim


    Since August 2012, the NASA Mars Science Laboratory (MSL) rover Curiosity has been operating on the Martian surface. The primary goal of the MSL mission is to assess whether Mars ever had an environment suitable for life. MSL Science Team member Dr. Tim Olson will provide an overview of the rover's capabilities and the major findings from the mission so far. He will also share some of his experiences of what it is like to operate Curiosity's science cameras and explore Mars as part of a large team of scientists and engineers.

  1. Approach to Mars Field Geology (United States)

    Muehlberger, William; Rice, James W.; Parker, Timothy; Lipps, Jere H.; Hoffman, Paul; Burchfiel, Clark; Brasier, Martin


    The goals of field study on Mars are nothing less than to understand the processes and history of the planet at whatever level of detail is necessary. A manned mission gives us an unprecedented opportunity to use the immense power of the human mind to comprehend Mars in extraordinary detail. To take advantage of this opportunity, it is important to examine how we should approach the field study of Mars. In this effort, we are guided by over 200 years of field exploration experience on Earth as well as six manned missions exploring the Moon.

  2. Ten Blue Links on Mars


    Clarke, Charles L. A.; Cormack, Gordon V.; Lin, Jimmy; Roegiest, Adam


    This paper explores a simple question: How would we provide a high-quality search experience on Mars, where the fundamental physical limit is speed-of-light propagation delays on the order of tens of minutes? On Earth, users are accustomed to nearly instantaneous response times from search engines. Is it possible to overcome orders-of-magnitude longer latency to provide a tolerable user experience on Mars? In this paper, we formulate the searching from Mars problem as a tradeoff between "effo...

  3. Mars Express wins unanimous support (United States)


    "The green light for Mars Express shows that Europe is perfectly capable of seizing special chances in exploring space," said Roger Bonnet, ESA's director of science. "At a cost to ESA of 150 million ECU, Mars Express is the cheapest Mars mission ever, yet its importance and originality are far greater than the price tag suggests." Bonnet continued: "Mars Express has been advertised by the Science Programme Committee as a test case for new approaches in procuring and managing future science projects, with a view to achieving major savings. In the international arena, Mars Express will confirm Europe's interest in a major target for space research in the new century, when we make our forceful debut at the Red Planet. In fact, Mars Express is designed to be a pivotal element of an international multi-mission, global effort for the exploration of Mars." Development of the spacecraft will now proceed swiftly, to meet the deadline of an exceptionally favourable launch window early in June 2003. Mars Express will go into orbit around Mars at Christmas 2003. Seven scientific instruments on board will include a high-resolution camera, a range of spectrometers, and a radar to penetrate below the surface. For the first time in the history of the exploration of the Red Planet, scientists can hope to detect sub-surface water, whether it exists in the form of undergound rivers, pools, glaciers or permafrost. Signs of life on Mars, whether extinct or continuing today, may reveal themselves to a lander carried by Mars Express. This is Beagle 2, a project led by the Open University in the United Kingdom, with contributions from many other European countries. The lander also promises invaluable information about the chemistry of the Martian surface and atmosphere. Beagle 2 is to be independently funded. Some of the necessary funds have already been raised and ESA has agreed with the principal investigator to keep a place for Beagle 2 aboard Mars Express. The financial situation

  4. Illustration of Launching Samples Home from Mars (United States)


    One crucial step in a Mars sample return mission would be to launch the collected sample away from the surface of Mars. This artist's concept depicts a Mars ascent vehicle for starting a sample of Mars rocks on their trip to Earth.

  5. Critical Casimir forces and anomalous wetting

    Indian Academy of Sciences (India)

    Laboratoire de Physique Statistique de l´Ecole Normale Supérieure, associé au CNRS et aux Universités Paris 6 et 7, 24 rue Lhomond, 75231 Paris Cedex 05, France. E-mail: Abstract. We present a review of critical Casimir forces in connection with successive experiments on wetting near the critical ...

  6. Making Activated Carbon by Wet Pressurized Pyrolysis (United States)

    Fisher, John W.; Pisharody, Suresh; Wignarajah, K.; Moran, Mark


    A wet pressurized pyrolysis (wet carbonization) process has been invented as a means of producing activated carbon from a wide variety of inedible biomass consisting principally of plant wastes. The principal intended use of this activated carbon is room-temperature adsorption of pollutant gases from cooled incinerator exhaust streams. Activated carbon is highly porous and has a large surface area. The surface area depends strongly on the raw material and the production process. Coconut shells and bituminous coal are the primary raw materials that, until now, were converted into activated carbon of commercially acceptable quality by use of traditional production processes that involve activation by use of steam or carbon dioxide. In the wet pressurized pyrolysis process, the plant material is subjected to high pressure and temperature in an aqueous medium in the absence of oxygen for a specified amount of time to break carbon-oxygen bonds in the organic material and modify the structure of the material to obtain large surface area. Plant materials that have been used in demonstrations of the process include inedible parts of wheat, rice, potato, soybean, and tomato plants. The raw plant material is ground and mixed with a specified proportion of water. The mixture is placed in a stirred autoclave, wherein it is pyrolized at a temperature between 450 and 590 F (approximately between 230 and 310 C) and a pressure between 1 and 1.4 kpsi (approximately between 7 and 10 MPa) for a time between 5 minutes and 1 hour. The solid fraction remaining after wet carbonization is dried, then activated at a temperature of 500 F (260 C) in nitrogen gas. The activated carbon thus produced is comparable to commercial activated carbon. It can be used to adsorb oxides of sulfur, oxides of nitrogen, and trace amounts of hydrocarbons, any or all of which can be present in flue gas. Alternatively, the dried solid fraction can be used, even without the activation treatment, to absorb

  7. Wetting and phase separation at surfaces

    Indian Academy of Sciences (India)

    comparable to the RHS of figure 1. The averaging yields ψav(z, t) ≃ ψ0 = 0 in the bulk, where the phase-separation profiles are randomly oriented. However, a systematic behavior is seen at the surface. The wetting profiles are characterized by the zero-crossings of ψav(z, t) − ψ0. We denote the first and second zeros as.

  8. Wet flue gas desulphurization and new fuels

    Energy Technology Data Exchange (ETDEWEB)

    Kiil, S.; Dam-Johansen, K.; Michelsen, M.L.


    This thesis describes experimental and theoretical investigations of wet flue gas desulphurization (FGD). A review of the current knowledge of the various rate determining steps in wet FDG plants is presented. The mechanism underlying the rate of dissolution of finely grained limestone particles was examined in a laboratory batch apparatus using acid titration. Three Danish limestones of different origin were tested. A transient, mass transport controlled, mathematical model was developed to describe the dissolution process. Model predictions were found to be qualitatively in good agreement with experimental data. Empirical correlations for the dimensionless mass transfer coefficients in a pilot plant (falling-film column) were determined. The presence of inert particles in the liquid phase was found to decrease the rate of gas phase mass transport with up to 15%, though the effect could not be correlated. A detailed model for a wet FGD pilot plant, based on the falling film principle, was developed. All important rate determining steps, absorption of SO{sub 2}, oxidation of HSO{sub 3}{sup -}, dissolution of limestone, and crystallisation of gypsum were included. Model predictions were compared to experimental data such as gas phase concentration profiles of SO{sub 2}, slurry pH-profiles, solids contents of slurry, liquid phase concentrations, and residual limestone in the gypsum. The possibility of co-firing straw and coal was investigated in a full-scale power plant. No effects on the overall performance of the wet FGD plant were observed, though laboratory experiments with fine dust and fly ash from the full-scale experiments showed a decrease in limestone reactivity. (EG) EFP-95. 45 refs.; Also ph.d. thesis of Soeren Kiil

  9. Boots on Mars: Earth Independent Human Exploration of Mars (United States)

    Burnett, Josephine; Gill, Tracy R.; Ellis, Kim Gina


    This package is for the conduct of a workshop during the International Space University Space Studies Program in the summer of 2017 being held in Cork, Ireland. It gives publicly available information on NASA and international plans to move beyond low Earth orbit to Mars and discusses challenges and capabilities. This information will provide the participants a basic level of insight to develop a response on their perceived obstacles to a future vision of humans on Mars.

  10. Magnetic activity at Mars - Mars Surface Magnetic Observatory

    DEFF Research Database (Denmark)

    Vennerstrøm, Susanne; Menvielle, M.; Merayo, José M.G.


    We use the extensive database of magnetic observations from the Mars Global Surveyor to investigate magnetic disturbances in the Martian space environment statistically, both close to and far from crustal anomalies. We discuss the results in terms of possible ionospheric and magnetospheric currents...... a magnetic experiment at the martian surface, the Mars Surface Magnetic Observatory (MSMO) including the science objectives, science experiment requirements, instrument and basic operations. We find the experiment to be feasible within the constraints of proposed stationary landing platforms....

  11. On the Current Thermal State of Mars. (United States)

    Grott, M.; Breuer, D.


    similar to that of [3]. We ignore crustal production and assume that the bulk of the crust is primordial. Starting from given initial conditions the thermal evolution of Mars is calculated and the current elastic thickness and mantle temperatures are evaluated. Elastic thicknesses are calculated using the strength envelope formalism for given crustal and mantle rheologies [3] and the potential for partial mantle melting is parameterized using the minimum temperature difference between the mantle temperature and the solidus of peridotite which is given by [6]. Partial melting will occur if temperatures locally exceeds the solidus of peridotite Tsol. As lateral inhomogeneities due to thickness variations of the insulating crust can locally increase temperatures by up to 100 K [7] and plumes rising from the coremantle boundary may further increase temperatures by up to 50 K, we will assume that partial mantle melting is feasible if temperatures are lower than Tsol by at most 150 K. Parameters: The current thermal state of Mars is most sensitive to the amount and distribution of radioactive ele- ments and the efficiency of mantle energy transport, which is a strong function of mantle viscosity. We vary the fraction of radiogenic elements in the crust ? between 20 and 80 % and the fraction of radiogenic elements with respect to the reference compositional model ? [4] between 30 and 100 %. The reference mantle viscosity at 1600 K was varied between ?0 = 1019 and 1021 Pa s, corresponding to wet and dry olivine rheologies. Other parameters were kept constant and we use an initial upper mantle temperature of 1800 K, an initial core temperature of 2100 K, a crustal thermal conductivity of 3 W m-1 K-1, a mantle thermal conductivity of 4 W m-1 K-1 and a crustal thickness of 50 km. Fig. 1 shows the temperature structure of one model having 50 % of the radioactive elements in the crust (? = 0.5) and the fraction of radiogenic elements with respect to the reference model is 70 % ? = 0

  12. Study of polycaprolactone wet electrospinning process

    Directory of Open Access Journals (Sweden)

    E. Kostakova


    Full Text Available Wet electrospinning is a useful method for 3-dimensional structure control of nanofibrous materials. This innovative technology uses a liquid collector instead of the metal one commonly used for standard electrospinning. The article compares the internal structural features of polycaprolactone (PCL nanofibrous materials prepared by both technologies. We analyze the influence of different water/ethanol compositions used as a liquid collector on the morphology of the resultant polycaprolactone nanofibrous materials. Scanning electron micro-photographs have revealed a bimodal structure in the wet electrospun materials composed of micro and nanofibers uniformly distributed across the sample bulk. We have shown that the full-faced, twofold fiber distribution is due to the solvent composition and is induced and enhanced by increasing the ethanol weight ratio. Moreover, the comparison of fibrous layers morphology obtained by wet and dry spinning have revealed that beads that frequently appeared in dry spun materials are created by Plateau-Rayleigh instability of the fraction of thicker fibers. Theoretical conditions for spontaneous and complete immersion of cylindrical fibers into a liquid collector are also derived here.

  13. Bioinspired Dynamic Wetting on Multiple Fibers. (United States)

    Wang, Pengwei; Bian, Ruixin; Meng, Qing'an; Liu, Huan; Jiang, Lei


    Natural fibers have versatile strategies for interacting with water media and better adapting to the local environment, and these strategies offer inspiration for the development of artificial functional fibers with diverse applications. Wetting on fibers is a dynamic liquid-moving process on/in fibrous systems with various patterns, and the process is normally driven by the structural gradient, chemical gradient, elasticity of a single fiber, or the synergistic effect of these factors in multiple fibers in an integrated system in which the spatial geometry of the fibers is involved. Compared with the directional liquid movement on a single fiber, wetting on multiple fibers in both the micro- and macroscales is particularly fascinating, with various performances, including directional liquid transport, controllable liquid transfer, efficient liquid encapsulation, and capillary-induced fibrous coalescence. Based on these properties, fibrous materials offer an alternative open system for liquid manipulation that is applicable to various functional liquid materials. Here, recent achievements in bioinspired dynamic wetting on multiple fibers are highlighted, and perspectives on future directions are presented. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Cost estimation for advanced wet MOX plant

    Energy Technology Data Exchange (ETDEWEB)

    Kamiya, Masahito; Kojima, Hisao [Power Reactor and Nuclear Fuel Development Corp., Tokai, Ibaraki (Japan). Tokai Works


    PNC proposes a design concept of an advanced wet MOX plant based on low-level decontamination reprocessing plant and a simple fuel fabrication method. It significantly changes the boundary condition for design of reprocessing, fuel fabrication and reactor to alter the wet MOX cycle into a convenient form as simple as that of metal fuel cycle. According to the concept, the reprocessing process is substantially simplified by holding the decontamination level low, so that both reprocessing and fabrication processes can be installed in a single facility utilizing common utilities including a liquid waste processing facility. This report summarizes the results of the conceptual design of the plant and cost evaluation. Construction costs were estimated for the current plant constructed by means of the current technology, for the standard plant based on the improved technology of high-level decontamination cycle, and for the advanced plant based on the wet MOX cycle concept. It was concluded then that the construction costs in unit of the cost of the current plant were evaluated to be 0.60 for the standard plant (handling capacity 50 t/y) and 0.66 or 0.50 for the advanced plant (handling capacity 100 t/y or 50 t/y). (H. Baba)

  15. Florida's wet weather demonstration project : final report, January 2009. (United States)


    The Florida Department of Transportation (FDOT) established a wet-weather pavement marking demonstration project with goals to gather performance data, evaluate various wet-weather marking systems, and develop a measurement protocol for measuring ret...

  16. Interplay of wetting and phase separation at surfaces (United States)

    Puri, Sanjay


    We review our understanding of surface-directed spinodal decomposition (SDSD), i.e., the interplay of wetting and phase separation in an unstable AB mixture placed in contact with a wetting surface. In this context, we present results for two problems, viz., SDSD in a semi-infinite geometry with a completely wet surface; and SDSD in a thin-film geometry with partially wet surfaces.

  17. Control Systems for the Mars Pathfinder Mission


    Liu, Dankai; Franklin, Steve


    The Mars Pathfinder Project began in October 1993, along with the Near Earth Asteroid Rendezvous Program, as one of the first Discovery Program missions funded by NASA. The Mars Pathfinder Project is planned, designed, launched and operated by JPL Mars Pathfinder Project Team under the management of JPL Mars Exploration Project Office. The project is intended to be JPL's most visible demonstration of a successful better, faster, cheaper mission in accordance with NASA's new direction. Mars...

  18. Characterization of MarR Superrepressor Mutants


    Alekshun, Michael N.; Levy, Stuart B.


    MarR negatively regulates expression of the multiple antibiotic resistance (mar) locus in Escherichia coli. Superrepressor mutants, generated in order to study regions of MarR required for function, exhibited altered inducer recognition properties in whole cells and increased DNA binding to marO in vitro. Mutations occurred in three areas of the relatively small MarR protein (144 amino acids). It is surmised that superrepression results from increased DNA binding activities of these mutant pr...

  19. MARVY: Mars Velocity Sensor Project (United States)

    National Aeronautics and Space Administration — The successful landing of the large Mars rover Curiosity on August 5, 2012 outlined the increasing complexity of safely landing large rovers on the planet. A precise...

  20. Properties of cryobrines on Mars

    DEFF Research Database (Denmark)

    Möhlmann, D.; Thomsen, Kaj


    Brines, i.e. aqueous salty solutions, increasingly play a role in a better understanding of physics and chemistry (and eventually also putative biology) of the upper surface of Mars. Results of physico-chemical modeling and experimentally determined data to characterize properties of cryobrines...... of potential interest with respect to Mars are described. Eutectic diagrams, the related numerical eutectic values of composition and temperature, the water activity of Mars-relevant brines of sulfates, chlorides, perchlorides and carbonates, including related deliquescence relative humidity, are parameters...... and properties, which are described here in some detail. The results characterize conditions for liquid low-temperature brines ("cryobrines") to evolve and to exist, at least temporarily, on present Mars. (C) 2010 Elsevier Inc. All rights reserved....

  1. Mars Aqueous Processing System Project (United States)

    National Aeronautics and Space Administration — Mars Aqueous Processing System (MAPS) is an innovative method to produce useful building materials from Martian regolith. Acids and bases produced from the regolith...

  2. Mars Solar Balloon Lander Project (United States)

    National Aeronautics and Space Administration — The Mars Solar Balloon Lander (MSBL) is a novel concept which utilizes the capability of solar-heated hot air balloons to perform soft landings of scientific...

  3. Is There Life on Mars? (United States)

    Allen, Bruce C.; Herreid, Clyde Freeman


    Presents a conflict scenario for a case study on whether there is evidence of past life on Mars. Includes details about the use of this case study in developing an interdisciplinary approach to scientific ethics. (DDR)

  4. Mars Regolith Water Extractor Project (United States)

    National Aeronautics and Space Administration — The Mars Regolith Water Extractor (MRWE) is a system for acquiring water from the Martian soil. In the MRWE, a stream of CO2 is heated by solar energy or waste heat...

  5. A new remote optical wetness sensor and its applications

    NARCIS (Netherlands)

    Heusinkveld, B.G.; Berkowicz, S.M.; Jacobs, A.F.G.; Hillen, W.C.A.M.; Holtslag, A.A.M.


    An optical wetness sensor (OWS) was developed for continuous surface wetness measurements. The sensor is an all-weather instrument that does not interfere with the surface wetting and drying process and is unaffected by solar radiation. It is equipped with its own light source with which it can scan

  6. Characteristics of wet work in the cleaning industry

    NARCIS (Netherlands)

    Jungbauer, F H W; Van Der Harst, J J; Schuttelaar, M L; Groothoff, J W; Coenraads, P J

    Wet work is the main cause of occupational contact dermatitis in the cleaning industry. Dermatologists and occupational physicians need to base their primary and secondary prevention for workers in the cleaning industry on the characteristics of wet work exposures. We quantified the burden of wet

  7. Aeroshell for Mars Science Laboratory (United States)


    This image from July 2008 shows the aeroshell for NASA's Mars Science Laboratory while it was being worked on by spacecraft technicians at Lockheed Martin Space Systems Company near Denver. This hardware was delivered in early fall of 2008 to NASA's Jet Propulsion Laboratory, Pasadena, Calif., where the Mars Science Laboratory spacecraft is being assembled and tested. The aeroshell encapsulates the mission's rover and descent stage during the journey from Earth to Mars and shields them from the intense heat of friction with that upper atmosphere during the initial portion of descent. The aeroshell has two main parts: the backshell, which is on top in this image and during the descent, and the heat shield, on the bottom. The heat shield in this image is an engineering unit for testing. The heat shield to be used in flight will be substituted later. The heat shield has a diameter of about 15 feet. For comparison, the heat shields for NASA's Mars Exploraton Rovers Spirit and Opportunity were 8.5 feet and the heat shields for the Apollo capsules that protected astronauts returning to Earth from the moon were just under 13 feet. In addition to protecting the Mars Science Laboratory rover, the backshell provides structural support for the descent stage's parachute and sky crane, a system that will lower the rover to a soft landing on the surface of Mars. The backshell for the Mars Science Laboratory is made of an aluminum honeycomb structure sandwiched between graphite-epoxy face sheets. It is covered with a thermal protection system composed of a cork/silicone super light ablator material that originated with the Viking landers of the 1970s. This ablator material has been used on the heat shields of all NASA Mars landers in the past, but this mission is the first Mars mission using it on the backshell. The heat shield for Mars Science Laboratory's flight will use tiles made of phenolic impregnated carbon ablator. The engineering unit in this image does not have the

  8. Mars Exploration Using Biomorphic Flyers (United States)

    Thakoor, S.; Chahl, J.; Srinivasan, M.; Cabrol, N.; Young, L.; Hine, B.; Zornetzer, S.

    Mars imagery obtained by the Mariner, Viking, Pathfinder, Mars Global Surveyor and Mars Odyssey Missions suggests the previous existence of abundant liquid water (considered essential for life as we know it). It is not clear what transpired on the Martian climate to have turned the planet in to the desert that it is today. Developing a comprehensive understanding of the past and present climatic events for our sister planet Mars may provide important information relevant to the future health and well being of our own planet. Following and exploring water flow features is a valuable strategy in the search for extant or extinct life, it satisfies our fundamental scientific curiosity, and could provide answers to the fundamental questions surrounding the question of the origins of life in our solar system. Low altitude air-borne exploration of Mars offers a means for covering large areas, perhaps up to several hundred kilometers, quickly and efficiently. Aerial exploration should provide a close-up birds eye view of the planetary terrain. Exploration that can only be imagined today could become a reality if we develop methods to fly on Mars and navigate through its difficult terrain to image/study sites of interest. Mars offers a substantial challenge to conventional flight due to its thin atmosphere (about a hundredth that on Earth); lack of magnetic compassing for navigation, and the limited telecommunications or navigational infrastructure. To meet and overcome these challenges, we are adapting for Mars exploration principles proven successful in nature to achieve stable flight control and navigation. By incorporating engineering solutions modeled on successful biological solutions we will provide novel and highly effective micro flyer capabilities suitable for aerial surveillance of Mars. We will describe a few example sites on Mars whose exploration absolutely requires the ability to cover several hundred kilometers. We will illustrate how autonomous biomorphic

  9. Key science questions from the second conference on early Mars: geologic, hydrologic, and climatic evolution and the implications for life. (United States)

    Beaty, David W; Clifford, Stephen M; Borg, Lars E; Catling, David C; Craddock, Robert A; Des Marais, David J; Farmer, Jack D; Frey, Herbert V; Haberle, Robert M; McKay, Christopher P; Newsom, Horton E; Parker, Timothy J; Segura, Teresa; Tanaka, Kenneth L


    In October 2004, more than 130 terrestrial and planetary scientists met in Jackson Hole, WY, to discuss early Mars. The first billion years of martian geologic history is of particular interest because it is a period during which the planet was most active, after which a less dynamic period ensued that extends to the present day. The early activity left a fascinating geological record, which we are only beginning to unravel through direct observation and modeling. In considering this time period, questions outnumber answers, and one of the purposes of the meeting was to gather some of the best experts in the field to consider the current state of knowledge, ascertain which questions remain to be addressed, and identify the most promising approaches to addressing those questions. The purpose of this report is to document that discussion. Throughout the planet's first billion years, planetary-scale processes-including differentiation, hydrodynamic escape, volcanism, large impacts, erosion, and sedimentation-rapidly modified the atmosphere and crust. How did these processes operate, and what were their rates and interdependencies? The early environment was also characterized by both abundant liquid water and plentiful sources of energy, two of the most important conditions considered necessary for the origin of life. Where and when did the most habitable environments occur? Did life actually occupy them, and if so, has life persisted on Mars to the present? Our understanding of early Mars is critical to understanding how the planet we see today came to be.

  10. Mars : a small terrestrial planet


    Mangold, N.; Baratoux, David; Witasse, O.; Encrenaz, T.; Sotin, C.


    Mars is characterized by geological landforms familiar to terrestrial geologists. It has a tenuous atmosphere that evolved differently from that of Earth and Venus and a differentiated inner structure. Our knowledge of the structure and evolution of Mars has strongly improved thanks to a huge amount of data of various types (visible and infrared imagery, altimetry, radar, chemistry, etc) acquired by a dozen of missions over the last two decades. In situ data have provided ground truth for rem...

  11. Survival of Trichomonas vaginalis in wet preparation and on wet mount. (United States)

    Stoner, Kevin A; Rabe, Lorna K; Meyn, Leslie A; Hillier, Sharon L


    Microscopy is an insensitive method for detection of Trichomonas vaginalis, but is widely used because it is both rapid and inexpensive. Diagnosis of trichomoniasis by microscopy requires that motile forms be identified in vaginal fluid samples. However, microscopy cannot always be performed immediately after sample collection. The objective of this study was to assess the impact of sample storage at room temperature on trichomonad motility. Vaginal swab samples from 77 women positive for T vaginalis infection were collected to determine the impact of storage on wet preparations (swabs in plastic tubes with saline) and wet mounts (samples placed onto a glass slide with a coverslip). Samples were read at 400× every 30 min for the first hour and then once per hour thereafter until there were no motile trichomonads observed. For wet preparations, motility was 100% at 30 min, 99% at 60 min and decreased by 3%-15% each subsequent hour, with samples having a lower density of trichomonads losing motility more quickly. Trichomonad motility diminished more rapidly in wet mounts compared with wet preparations, with a 20% decrement in motility in 60 min. These data suggest that vaginal fluid samples for diagnosis of trichomoniasis should be stored in saline rather than on microscope slides until they are examined under the microscope and samples should be evaluated by microscopy within an hour of collection. These findings also suggest that clinical sites which cannot perform microscopy within 1 h of sample collection should consider the use of other diagnostic tests.

  12. A carbonate-silicate aqueous geochemical cycle model for Mars (United States)

    Schaefer, M. W.; Leidecker, H.


    A model for the carbonate-silicate geochemical cycle of an early, wet Mars is under development. The results of this study will be used to constrain models of the geochemical history of Mars and the likely mineralogy of its present surface. Although Mars today is a cold, dry planet, it may once have been much warmer and wetter. Values of total outgassed CO2 from several to about 10 bars are consistent with present knowledge (Pollack et al. 1987), and this amount of CO2 implies an amount of water outgassed at least equal to an equivalent depth of 500-1000 meters (Carr 1986). Pollack et al. (1987), in addition, estimate that a thick CO2 atmosphere may have existed for an extended period of time, perhaps as long as a billion years. The greenhouse effect of such an atmosphere would permit the presence of liquid water on the surface, most likely in the form of a shallow sea in the lowest regions of the planet, such as the northern plains (Schaefer 1990). The treatment of geochemical cycles as complex kinetic chemical reactions has been undertaken for terrestrial systems in recent years with much success (Lasaga 1980, 1981; Berner et al. 1983; Lasaga et al. 1985). Although the Martian system is vastly less well understood, and hence less well-constrained, it is also a much simpler system, due to the lack of biogenic reactions that make the terrestrial system so complex. It should be possible, therefore, to use the same techniques to model the Martian system as have been used for terrestrial systems, and to produce useful results. A diagram of the carbonate-silicate cycle for Mars (simplified from the terrestrial system) is given.

  13. Earth and Mars: Water inventories as clues to accretional histories (United States)

    Carr, M.H.; Wanke, H.


    The Earth has 2.7 km of water on its surface. Its mantle contains at least 150 ppm water, and probably significantly more depending on the amount of undepleted mantle and subducted crustal water that is present. Geologic evidence suggests that a few hundred meters of water are close to the Martian surface, but evidence from SNC meteorites indicates that the Martian mantle is very dry, containing no more than about 35 ppm water. Part of the difference in water content of the mantles of the two planets is attributed to plate tectonics. However, the Earth's mantle appears to contain at least several times the water content of the Martian mantle, even accounting for plate tectonics. We attribute the difference to two possible causes. The first possibility is that melting of the Earth's surface during accretion, as a result of the development of a steam atmosphere, allowed impact-devolatized water at the surface to dissolve into the Earth's interior. In contrast, because of Mars' smaller size and greater distance from the Sun, the Martian surface may not have melted, so that the devolatilized water could not dissolve into the surface. A second and preferred possibility is that Mars, like the Earth, acquired a late volatile rich veneer, but it did not get folded into the interior as with the Earth, but instead remained as a water-rich veneer. The perception of Mars as having a wet surface, but a dry interior, is consistent with what we know of the geologic history of Mars, which can be viewed as the progressive intrusion and overplating of a water-rich crust by dry, mantle-derived volcanic rocks. ?? 1992.

  14. Mars manned fusion spaceship (United States)

    Hedrick, James; Buchholtz, Brent; Ward, Paul; Freuh, Jim; Jensen, Eric


    Fusion Propulsion has an enormous potential for space exploration in the near future. In the twenty-first century, a usable and efficient fusion rocket will be developed and in use. Because of the great distance between other planets and Earth, efficient use of time, fuel, and payload is essential. A nuclear spaceship would provide greater fuel efficiency, less travel time, and a larger payload. Extended missions would give more time for research, experiments, and data acquisition. With the extended mission time, a need for an artificial environment exists. The topics of magnetic fusion propulsion, living modules, artificial gravity, mass distribution, space connection, and orbital transfer to Mars are discussed. The propulsion system is a magnetic fusion reactor based on a tandem mirror design. This allows a faster, shorter trip time and a large thrust to weight ratio. The fuel proposed is a mixture of deuterium and helium-3. Helium-3 can be obtained from lunar mining. There will be minimal external radiation from the reactor resulting in a safe, efficient propulsion system.

  15. Modeling Mars' Hydrogen Exosphere (United States)

    Holmstrom, M.


    Traditionally, exospheric densities and velocity distributions are modelled by spherical symmetric analytical Chamberlain functions, assuming gravity is the only force acting on the neutrals. Planetary exospheres are however not spherical symmetric to any good approximation, as evident from observations, due to non- uniformexobase conditions and effects such as photoionization, radiation pressure, charge exchange, recombination and planetary rotation. To account for these effects numerical simulations are needed. Using Monte Carlo test particle simulations it is possible to account for the above effects (if ion distributions are assumed). Even though neutrals in the exospheres by definition do not collide often, collisions occur. Especially near the exobase the transition is gradual from collision dominated regions at lower heights (with Maxwellian velocity distributions) to essentially collisionless regions at greater heights. We present exospheric simulations that include collisions self consistently using the direct simulation Monte Carlo (DSMC) approach. The code is three dimensional, parallel and uses an adaptive grid, allowing many particles to be included in the simulations, leading to accurate results. In particular, we here study Mars' hydrogen exosphere and the effects of the above processes, including thermal escape rates.

  16. Mars aqueous chemistry experiment (United States)

    Clark, Benton C.; Mason, Larry W.


    Mars Aqueous Chemistry Experiment (MACE) is designed to conduct a variety of measurements on regolith samples, encompassing mineral phase analyses, chemical interactions with H2O, and physical properties determinations. From these data, much can be learned or inferred regarding the past weathering environment, the contemporaneous soil micro-environments, and the general chemical and physical state of the Martian regolith. By analyzing both soil and duricrust samples, the nature of the latter may become more apparent. Sites may be characterized for comparative purposes and criteria could be set for selection of high priority materials on future sample return missions. The second year of the MACE project has shown significant progress in two major areas. MACE Instrument concept definition is a baseline design that has been generated for the complete MACE instrument, including definition of analysis modes, mass estimates and thermal model. The design includes multiple reagent reservoirs, 10 discrete analysis cells, sample manipulation capability, and thermal control. The MACE Measurement subsystems development progress is reported regarding measurement capabilities for aqueous ion sensing, evolved gas sensing, solution conductivity measurement, reagent addition (titration) capabilities, and optical sensing of suspended particles.

  17. [Dentists on Mars (United States)

    Duke, P. J.


    The oral health of astronauts, last studied in the mid- 1970s on Skylab, has not been a priority area of study for NASA due to the short length of shuttle stays. But with longer stays on the International Space Station, and planning for a trip to Mars, investigations into how spaceflight affects oral health are needed. The objective of this symposium is to introduce the dental research community to changes occurring in humans who go into space, and how these changes might impact oral health. Dr. Millie Hughes-Fulford, an astronaut-scientist, will review what happens to humans who go into space, and the difficulties of living, and carrying out experiments in space. She will then discuss her research on cell cultures of osteoblasts in space, and in hypergravity Dr. Gerald Sonnenfeld will review immunological changes that occur in spaceflight, and relate the observed decreases in various types of immunological responses to possible effects on oral immunological factors. Dr. Marian Lewis will discuss the effects of spaceflight on gene expression using results from her spaceflight experiments on various cell types. Dr. Jack van Loon, fiom the Dutch Experiment Support Center, will review what is known about bone loss in humans and rats and metatarsal cultures which go into space, and review ground based models (head down bedrest, and tail suspension) that simulate the unloading of spaceflight. Attendees will gain a knowledge of spaceflight research, and information on getting their own experiments in space. The symposium is supported by the NASA Office of Bioastronautics

  18. We can all go to Mars-The Mars outpost proposal

    National Research Council Canada - National Science Library

    Louis D Friedman; Bruce C Murray


      Friedman and Murray of the Planetary Society propose Mars Outposts, which would consist of specially designated research sites on Mars, equipped with permanent communications, navigational systems...

  19. Wet oxidation processes for water pollution remediation


    García Molina, Verónica


    The main objective of this work was to test the efficiency of wet oxidation processes when treating several types of aqueous wastes. On one side its performance for the abatement of chloro-organic aromatic toxic pollutants, such as 4-chlorophenol and 2,4-dichlorophenol has been studied. On the other hand, wastewater from pulp and paper mills, which has been reported to be an indirect source of entry of chlorophenols in the aquatic environment, has been investigated. More in detail, it has bee...

  20. Collapse of granular media subjected to wetting

    Directory of Open Access Journals (Sweden)

    El Korchi Fatima Zahra


    Full Text Available This paper focuses on the collapse of granular materials subjected to wetting action. For soils, the collapse potential depends on several parameters such as liquid limit, matric suction, compactness, initial water content and the amount of fine particles. The effect of grain size, which plays a key role in the rearrangement of grains, remains little studied and poorly understood. To investigate the capillary origin of the collapse phenomenon, we present an experimental study on macroscopic and local scales. Our results show the effect of grain size and water content on collapse.

  1. Mars Science Laboratory Drill (United States)

    Okon, Avi B.; Brown, Kyle M.; McGrath, Paul L.; Klein, Kerry J.; Cady, Ian W.; Lin, Justin Y.; Ramirez, Frank E.; Haberland, Matt


    This drill (see Figure 1) is the primary sample acquisition element of the Mars Science Laboratory (MSL) that collects powdered samples from various types of rock (from clays to massive basalts) at depths up to 50 mm below the surface. A rotary-percussive sample acquisition device was developed with an emphasis on toughness and robustness to handle the harsh environment on Mars. It is the first rover-based sample acquisition device to be flight-qualified (see Figure 2). This drill features an autonomous tool change-out on a mobile robot, and novel voice-coil-based percussion. The drill comprises seven subelements. Starting at the end of the drill, there is a bit assembly that cuts the rock and collects the sample. Supporting the bit is a subassembly comprising a chuck mechanism to engage and release the new and worn bits, respectively, and a spindle mechanism to rotate the bit. Just aft of that is a percussion mechanism, which generates hammer blows to break the rock and create the dynamic environment used to flow the powdered sample. These components are mounted to a translation mechanism, which provides linear motion and senses weight-on-bit with a force sensor. There is a passive-contact sensor/stabilizer mechanism that secures the drill fs position on the rock surface, and flex harness management hardware to provide the power and signals to the translating components. The drill housing serves as the primary structure of the turret, to which the additional tools and instruments are attached. The drill bit assembly (DBA) is a passive device that is rotated and hammered in order to cut rock (i.e. science targets) and collect the cuttings (powder) in a sample chamber until ready for transfer to the CHIMRA (Collection and Handling for Interior Martian Rock Analysis). The DBA consists of a 5/8-in. (.1.6- cm) commercial hammer drill bit whose shank has been turned down and machined with deep flutes designed for aggressive cutting removal. Surrounding the shank of the

  2. Mars Analytical Microimager (United States)

    Batory, Krzysztof J.; Govindjee; Andersen, Dale; Presley, John; Lucas, John M.; Sears, S. Kelly; Vali, Hojatollah

    Unambiguous detection of extraterrestrial nitrogenous hydrocarbon microbiology requires an instrument both to recognize potential biogenic specimens and to successfully discriminate them from geochemical settings. Such detection should ideally be in-situ and not jeopardize other experiments by altering samples. Taken individually most biomarkers are inconclusive. For example, since amino acids can be synthesized abiotically they are not always considered reliable biomarkers. An enantiomeric imbalance, which is characteristic of all terrestrial life, may be questioned because chirality can also be altered abiotically. However, current scientific understanding holds that aggregates of identical proteins or proteinaceous complexes, with their well-defined amino acid residue sequences, are indisputable biomarkers. Our paper describes the Mars Analytical Microimager, an instrument for the simultaneous imaging of generic autofluorescent biomarkers and overall morphology. Autofluorescence from ultraviolet to near-infrared is emitted by all known terrestrial biology, and often as consistent complex bands uncharacteristic of abiotic mineral luminescence. The MAM acquires morphology, and even sub-micron morphogenesis, at a 3-centimeter working distance with resolution approaching a laser scanning microscope. Luminescence is simultaneously collected via a 2.5-micron aperture, thereby permitting accurate correlation of multi-dimensional optical behavior with specimen morphology. A variable wavelength excitation source and photospectrometer serve to obtain steady-state and excitation spectra of biotic and luminescent abiotic sources. We believe this is the first time instrumentation for detecting hydrated or desiccated microbiology non-destructively in-situ has been demonstrated. We have obtained excellent preliminary detection of biota and inorganic matrix discrimination from terrestrial polar analogues, and perimetric morphology of individual magnetotactic bacteria. Proposed

  3. Nitrogen on Mars: Insights from Curiosity (United States)

    Stern, J. C.; Sutter, B.; Jackson, W. A.; Navarro-Gonzalez, Rafael; McKay, Chrisopher P.; Ming, W.; Archer, P. Douglas; Glavin, D. P.; Fairen, A. G.; Mahaffy, Paul R.


    Recent detection of nitrate on Mars indicates that nitrogen fixation processes occurred in early martian history. Data collected by the Sample Analysis at Mars (SAM) instrument on the Curiosity Rover can be integrated with Mars analog work in order to better understand the fixation and mobility of nitrogen on Mars, and thus its availability to putative biology. In particular, the relationship between nitrate and other soluble salts may help reveal the timing of nitrogen fixation and post-depositional behavior of nitrate on Mars. In addition, in situ measurements of nitrogen abundance and isotopic composition may be used to model atmospheric conditions on early Mars.

  4. Communication strategies for colonization mission to Mars


    Machuca Varela, Pablo Antonio


    Earth-Mars cycler trajectories could be used as a periodic and cost-efficient human transportation system from Earth to Mars in a future mission to colonize Mars. Continuous and reliable communication between Mars and the Earth will be required in such a mission. In a circular-coplanar model, the existance of a particularly interesting cycler trajectory (ballistic outbound Earth-Mars S1L1 cycler trajectory) is proven, which has relatively short Earth-Mars transfer times, low relative velociti...

  5. Guidelines for the 2011 MARS exercise

    CERN Document Server

    HR Department


    Full details of the Merit Appraisal and Recognition Scheme (MARS) are available via the HR Department’s homepage or directly on the Department’s MARS web page: You will find on these pages: MARS procedures, including the MARS timetable for proposals and decisions; regulations with links to the scheme’s statutory basis; a list of frequently asked questions; useful documents with links to relevant documentation, e.g. mandate of the Senior Staff Advisory Committee (SSAC); and related links and contacts. Tel. 70674 / 72728  

  6. Europe is going to Mars (United States)


    The Agency's Science Programme Committee (SPC) approved Mars Express after ESA's Council, meeting at ministerial level in Brussels on 11 and 12 May, had agreed the level of the science budget for the next 4 years, just enough to make the mission affordable. "Mars Express is a mission of opportunity and we felt we just had to jump in and do it. We are convinced it will produce first-rate science", says Hans Balsiger, SPC chairman. As well as being a first for Europe in Mars exploration, Mars Express will pioneer new, cheaper ways of doing space science missions. "With a total cost of just 150 million euros, Mars Express will be the cheapest Mars mission ever undertaken", says Roger Bonnet, ESA's Director of Science. Mars Express will be launched in June 2003. When it arrives at the red planet six months later, it will begin to search for water and life. Seven instruments, provided by space research institutes throughout Europe, will make observations from the main spacecraft as it orbits the planet. Just before the spacecraft arrives, it will release a small lander, provided by research institutes in the UK, that will journey on to the surface to look for signs of life. The lander is called Beagle 2 after the ship in which Charles Darwin sailed round the world in search of evidence supporting his theory of evolution. But just as Darwin had to raise the money for his trip, so the search is on for public and private finance for Beagle 2. "Beagle 2 is an extremely important element of the mission", says Bonnet. Europe's space scientists have envisaged a mission to Mars for over fifteen years. But limited funding has prevented previous proposals from going ahead. The positioning of the planets in 2003, however, offers a particularly favourable passage to the red planet - an opportunity not to be missed. Mars Express will be joined by an international flotilla of spacecraft that will also be using this opportunity to work together on scientific questions and pave the way

  7. A wetting and drying scheme for ROMS (United States)

    Warner, John C.; Defne, Zafer; Haas, Kevin; Arango, Hernan G.


    The processes of wetting and drying have many important physical and biological impacts on shallow water systems. Inundation and dewatering effects on coastal mud flats and beaches occur on various time scales ranging from storm surge, periodic rise and fall of the tide, to infragravity wave motions. To correctly simulate these physical processes with a numerical model requires the capability of the computational cells to become inundated and dewatered. In this paper, we describe a method for wetting and drying based on an approach consistent with a cell-face blocking algorithm. The method allows water to always flow into any cell, but prevents outflow from a cell when the total depth in that cell is less than a user defined critical value. We describe the method, the implementation into the three-dimensional Regional Oceanographic Modeling System (ROMS), and exhibit the new capability under three scenarios: an analytical expression for shallow water flows, a dam break test case, and a realistic application to part of a wetland area along the Georgia Coast, USA.

  8. Wet paper codes with improved embedding efficiency (United States)

    Fridrich, Jessica; Goljan, Miroslav; Soukal, David


    Construction of steganographic schemes in which the sender and the receiver do not share the knowledge about the location of embedding changes requires wet paper codes. Steganography with non-shared selection channels empowers the sender as now he is able to embed secret data by utilizing arbitrary side information, including a high-resolution version of the cover object (perturbed quantization steganography), local properties of the cover (adaptive steganography), and even pure randomness, e.g., coin flipping, for public key steganography. In this paper, we propose a new approach to wet paper codes using random linear codes of small codimension that at the same time improves the embedding efficiency-the number of message bits embedded per embedding change. We describe a practical algorithm, test its performance experimentally, and compare the results to theoretically achievable bounds. We point out an interesting ripple phenomenon that should be taken into account by practitioners. The proposed coding method can be modularly combined with most steganographic schemes to allow them to use non-shared selection channels and, at the same time, improve their security by decreasing the number of embedding changes.

  9. Further progress in watermark evaluation testbed (WET) (United States)

    Kim, Hyung C.; Lin, Eugene T.; Guitart, Oriol; Delp, Edward J., III


    While Digital Watermarking has received much attention in recent years, it is still a relatively young technology. There are few accepted tools/metrics that can be used to evaluate the suitability of a watermarking technique for a specific application. This lack of a universally adopted set of metrics/methods has motivated us to develop a web-based digital watermark evaluation system called the Watermark Evaluation Testbed or WET. There have been more improvements over the first version of WET. We implemented batch mode with a queue that allows for user submitted jobs. In addition to StirMark 3.1 as an attack module, we added attack modules based on StirMark 4.0. For a new image fidelity measure, we evaluate conditional entropy as an image fidelity measure for different watermarking algorithms and different attacks. Also, we show the results of curve fitting the Receiver Operating Characteristic (ROC) analysis data using the Parzen window density estimation. The curve fits the data closely while having only two parameters to estimate.

  10. Space radiation protection: Destination Mars (United States)

    Durante, Marco


    National space agencies are planning a human mission to Mars in the XXI century. Space radiation is generally acknowledged as a potential showstopper for this mission for two reasons: a) high uncertainty on the risk of radiation-induced morbidity, and b) lack of simple countermeasures to reduce the exposure. The need for radiation exposure mitigation tools in a mission to Mars is supported by the recent measurements of the radiation field on the Mars Science Laboratory. Shielding is the simplest physical countermeasure, but the current materials provide poor reduction of the dose deposited by high-energy cosmic rays. Accelerator-based tests of new materials can be used to assess additional protection in the spacecraft. Active shielding is very promising, but as yet not applicable in practical cases. Several studies are developing technologies based on superconducting magnetic fields in space. Reducing the transit time to Mars is arguably the best solution but novel nuclear thermal-electric propulsion systems also seem to be far from practical realization. It is likely that the first mission to Mars will employ a combination of these options to reduce radiation exposure.

  11. WetLab-2: Wet Lab RNA SmartCycler Providing PCR Capability on ISS (United States)

    Parra, Macarena; Schonfeld, Julie


    The WetLab-2 system will provide sample preparation and qRT-PCR analysis on-board the ISS, a capability to enable using the ISS as a real laboratory. The system will be validated on SpX-7, and is planned for its first PI use on SpX-9.

  12. Doubly Reentrant Cavities Prevent Catastrophic Wetting Transitions on Intrinsically Wetting Surfaces

    KAUST Repository

    Domingues, Eddy


    Omniphobic surfaces, i.e. which repel all known liquids, have proven of value in applications ranging from membrane distillation to underwater drag reduction. A limitation of currently employed omniphobic surfaces is that they rely on perfluorinated coatings, increasing cost and environmental impact, and preventing applications in harsh environments. There is, thus, a keen interest in rendering conventional materials, such as plastics, omniphobic by micro/nano-texturing rather than via chemical make-up, with notable success having been achieved for silica surfaces with doubly reentrant micropillars. However, we found a critical limitation of microtextures comprising of pillars that they undergo catastrophic wetting transitions (apparent contact angles, θr → 0° from θr > 90°) in the presence of localized physical damages/defects or on immersion in wetting liquids. In response, a doubly reentrant cavity microtexture is introduced, which can prevent catastrophic wetting transitions in the presence of localized structural damage/defects or on immersion in wetting liquids. Remarkably, our silica surfaces with doubly reentrant cavities could exhibited apparent contact angles, θr ≈ 135° for mineral oil, where the intrinsic contact angle, θo ≈ 20°. Further, when immersed in mineral oil or water, doubly reentrant microtextures in silica (θo ≈ 40° for water) were not penetrated even after several days of investigation. Thus, microtextures comprising of doubly reentrant cavities might enable applications of conventional materials without chemical modifications, especially in scenarios that are prone to localized damages or immersion in wetting liquids, e.g. hydrodynamic drag reduction and membrane distillation.

  13. Network science landers for Mars

    DEFF Research Database (Denmark)

    Harri, A.M.; Marsal, O.; Lognonne, P.


    The NetLander Mission will deploy four landers to the Martian surface. Each lander includes a network science payload with instrumentation for studying the interior of Mars, the atmosphere and the subsurface, as well as the ionospheric structure and geodesy. The NetLander Mission is the first...... FMI (the Finnish Meteorological Institute), DLR (the German Space Agency), and other research institutes. According to current plans, the NetLander Mission will be launched in 2005 by means of an Ariane V launch, together with the Mars Sample Return mission. The landers will be separated from...... the spacecraft and targeted to their locations on the Martian surface several days prior to the spacecraft's arrival at Mars. The landing system employs parachutes and airbags. During the baseline mission of one Martian year, the network payloads will conduct simultaneous seismological, atmospheric, magnetic...

  14. The Athena Mars Rover Investigation (United States)

    Squyres, S. W.; Arvidson, R. E.; Bell, J. F., III; Carr, M.; Christensen, P.; DesMarais, D.; Economou, T.; Gorevan, S.; Haskin, L.; Herkenhoff, K.


    The Mars Surveyor program requires tools for martian surface exploration, including remote sensing, in-situ sensing, and sample collection. The Athena Mars rover payload is a suite of scientific instruments and sample collection tools designed to: (1) Provide color stereo imaging of martian surface environments, and remotely-sensed point discrimination of mineralogical composition; (2) Determine the elemental and mineralogical composition of martian surface materials; (3) Determine the fine-scale textural properties of these materials; and (4) Collect and store samples. The Athena payload is designed to be implemented on a long-range rover such as the one now under consideration for the 2003 Mars opportunity. The payload is at a high state of maturity, and most of the instruments have now been built for flight.

  15. 2001 Mars Odyssey Project Report (United States)

    Spencer, David A.; Gibbs, Roger G.; Mase, Robert A.


    The Mars Odyssey Project is the latest in an ongoing series of robotic missions to Mars within NASA's Mars Exploration Program. The Program goals include the global observation of Mars, to enable understanding of the Mars climatic and geologic history, including the search for liquid water and the evidence of prior or extant life. The Odyssey orbiter carries scientific payloads that will determine surface elemental composition, mineralogy and morphology, and measure the Mars radiation environment from orbit. In addition, the orbiter will serve as a data relay for future landers. Odyssey was designed and developed through a partnership between the Jet Propulsion Laboratory in Pasadena, California, and Lockheed Martin Astronautics in Denver, Colorado. Odyssey was launched atop a Boeing 7925 launch vehicle on April 7, 2001, from Kennedy Space Center. The 200-day journey to Mars was marked by four trajectory correction maneuvers, and numerous spacecraft and payload calibration activities. The final maneuver was performed 12 days prior to encounter, and successfully targeted the spacecraft to the desired arrival conditions 300 km above the North Pole of Mars. The 20-minute orbit insertion burn was the only use of the bipropellant propulsion system on the spacecraft. The burn executed as planned on October 24, 2001, capturing the spacecraft into an 18.6-hour orbit around Mars. The subsequent aerobraking phase was designed to gradually reduce the orbit period by flying through the upper atmosphere of Mars on each orbit, allowing atmospheric drag to remove energy from the orbit. Aerobraking was the most demanding operational phase of the mission, requiring continuous monitoring and control of the spacecraft to ensure health and safety. The aerobraking phase was successfully completed on January 11, 2002 after 76 days and 332 drag passes through the Martian atmosphere. Following completion of the aerobraking phase, a series of five propulsive maneuvers were performed to

  16. Cultivando el mar

    Directory of Open Access Journals (Sweden)

    Ricardo Radulovich


    Full Text Available Las conocidas y crecientes limitaciones a la agricultura, pesca y disponibilidad de agua para riego tienen pocas soluciones viables y muy probablemente se acrecentarán con el cambio climático. Para contrarrestar estos y otros problemas, estamos desarrollando con y para pobladores costeros empobrecidos, unos sistemas productivos flotantes altamente innovativos, a mar abierto, en aguas protegidas de alto oleaje -comenzando en el Golfo de Nicoya, Costa Rica, que es un sitio representativo que cubre miles de km2-. Estos sistemas de propósito múltiple, y de multi-estratos, que hemos probado por 3 años y que describimos aquí, consisten de: hortalizas orgánicas u otros cultivos de alto valor, en macetas sobre isletas o jardineras flotantes, construidas con botellas plásticas recicladas y otros materiales de bajo costo; maricultura de poco insumo bajo el agua (peces, crustáceos, otros con cultivo de algas flotando en la superficie; producción de agua dulce para riego y otros usos por destilación solar pasiva y cosecha de agua de lluvia; pesca desde las estructuras flotantes; facilidades para recreación; y, todavía por explorar, producción alternativa de energía. Se considera aquí también una variedad de aspectos relacionados con el ambiente y la biodiversidad. Estos sistemas compuestos, únicos en el mundo a la fecha, tienen una productividad general alta al sumar la productividad de todo el año de cada uno de varios componentes eco-amigables y de bajo insumo, lo cual permite optimizar la rentabilidad en función ambiental. Esperamos que, una vez que estén validados, la implementación equitativa a escala de estos nuevos sistemas proveerá a los pobladores costeros, alrededor del mundo tropical y subtropical, oportunidades para derivar su ingreso a partir de esta generación de nueva riqueza, incrementándose así y ganando en seguridad la capacidad mundial de producción de alimentos y agua, practicándose a la vez un uso de los

  17. Physisorbed Water on Silica at Mars Temperatures (United States)

    Sutter, B.; Sriwatanapongse, W.; Quinn, R.; Klug, C.; Zent, A.


    The usefulness of nuclear magnetic resonance spectroscopy in probing water interactions on silica at Mars temperatures is discussed. Results indicate that two types of water occur with silica at Mars temperatures. Additional information is contained in the original extended abstract.

  18. Mars Integrated Propellant Production System Project (United States)

    National Aeronautics and Space Administration — The Integrated Mars In-Situ Propellant Production System (IMISPPS) is an end-to-end system that will produce rocket propellant on Mars from CO2 in the Martian...

  19. Warming Ancient Mars with Water Clouds (United States)

    Hartwick, V. L.; Toon, O. B.


    High altitude clouds in the present day Mars atmosphere may form on interplanetary dust particles (IDPs). Paleo fluences of IDPs were likely higher, and similar clouds are expected to influence the Mars paleo-climate.

  20. The Soil of Mars - Planetary Geology (United States)

    Bullock, Mark A.


    What would it be like to walk on Mars, to let martian dirt run through your fingers? Planetary geologists, aided by amateur astronomers, are slowly figuring out what Mars is like. With a sidebar by Jack D. Farmer.

  1. The Detection of Evolved Oxygen from the Rocknest Eolian Bedform Material by the Sample Analysis at Mars(SAM) instrument at the Mars Curiosity Landing Site (United States)

    Sutter, B.; Archer, D.; Ming, D.; Eigenbrode, J. L.; Franz, H.; Glavin, D. P.; McAdam, A.; Mahaffy, P.; Stern, J.; Navarro-Gonzalex, R.; hide


    The Sample Analysis at Mars (SAM) instrument onboard the Curiosity rover detected an O2 gas release from the Rocknest eolain bedform (Fig. 1). The detection of perchlorate (ClO4-) by the Mars Phoenix Lander s Wet Chemistry Laboratory (WCL) [1] suggests that perchlorate is a possible candidate for evolved O2 release detected by SAM. The perchlorate would also serve as a source of chlorine in the chlorinated hydrocarbons detected by the SAM quadrupole mass spectrometer (QMS) and gas chromatography/mass spectrometer (GCMS) [2,3]. Chlorates (ClO3-) [4,5] and/or superoxides [6] may also be sources of evolved O2 from the Rocknest materials. The work objectives are to 1) evaluate the O2 release temperatures from Rocknest materials, 2) compare these O2 release temperatures with a series of perchlorates and chlorates, and 3) evaluate superoxide O2- sources and possible perchlorate interactions with other Rocknest phases during QMS analysis.

  2. Mars Sample Quarantine Protocol Workshop (United States)

    DeVincenzi, Donald L. (Editor); Bagby, John (Editor); Race, Margaret (Editor); Rummel, John (Editor)


    The Mars Sample Quarantine Protocol (QP) Workshop was convened to deal with three specific aspects of the initial handling of a returned Mars sample: 1) biocontainment, to prevent uncontrolled release of sample material into the terrestrial environment; 2) life detection, to examine the sample for evidence of live organisms; and 3) biohazard testing, to determine if the sample poses any threat to terrestrial life forms and the Earth's biosphere. During the first part of the Workshop, several tutorials were presented on topics related to the workshop in order to give all participants a common basis in the technical areas necessary to achieve the objectives of the Workshop.

  3. Global color views of Mars (United States)

    McEwen, A. S.; Soderblom, L. A.; Becker, T. L.; Lee, E. M.; Batson, R. M.

    About 1000 Viking Orbiter red and violet filter images have been processed to provide global color coverage of Mars at a scale of 1 km/pixel. Individual image frames acquired during a single spacecraft revolution ('rev') were first processed through radiometric calibration, cosmetic cleanup, geometric control, reprojection, and mosaicking. A total of 57 'single-rev' mosaics have been produced. Phase angles range from 13 to 85 degrees. All the mosaics are geometrically tied to the Mars digital image mosaic (MDIM), a black-and-white base map with a scale of 231 m/pixel.

  4. Mars Exploration Rover's image analysis: Evidence of Microbialites on Mars. (United States)

    Bianciardi, Giorgio; Rizzo, Vincenzo; Cantasano, Nicola


    The Mars Exploration Rovers, Opportunity and Spirit, investigated Martian plains, where sedimentary rocks are present. The Mars Exploration Rover's Athena morphological investigation showed microstructures organized in intertwined filaments of microspherules: a texture we have also found on samples of terrestrial (biogenic) stromatolites and other microbialites. We performed a quantitative image analysis to compare images of microbialites with the images photographed by the Rovers (corresponding, approximately, to 25,000/25,000 microstructures, Earth/Mars). Contours were extracted and morphometric indexes were obtained: geometric and algorithmic complexities, entropy, tortuosity, minimum and maximum diameters. Terrestrial and Martian textures present a multifractal aspect. Mean values and confidence intervals from the Martian images overlapped perfectly with those from the terrestrial samples. The probability of this occurring by chance is 1/2^8, less than pstromatolite images or Martian images with a less ordered texture (p<0.001). Our work shows the presumptive evidence of microbialites in the Martian outcroppings: the presence of unicellular life widespread on the ancient Mars.

  5. Soil wetting processes at high temporal resolution in a semiarid mediterranean watershed with scattered tree cover (United States)

    Lozano-Parra, Javier; van Schaik, Loes; Schnabel, Susanne; Gómez-Gutiérrez, Álvaro


    Soil wetting processes play a key role for the distribution of water and solutes and thereby for the water availability for plants. However, characterization of such processes (from slower to faster flows), frequency of occurrence, and factors that cause them, are still poorly known. This characterization is important in hydrological studies because enables a better understanding of spatio-temporal variability of water resources and allows improving the design of models. Using a method based on the maximal soil water increase registered by a sensor over a minimum given time interval during a rainfall event, types of soil wetting processes were classified and quantified. For this, capacitance sensors which registered the volumetric water content at high temporal resolution (30-min) along of more than two hydrological years (mainly for 2010-2011 and 2011-2012), were installed in soil profiles at 5, 15 cm, and 5 cm above the bedrock and depending on soil depth. This distribution along the soil profile is justified because soils are generally very shallow and most of the roots are concentrated in the upper layer. The sensors were gathered in 9 soil moisture stations characterized by lithology, topographic position, as well as by different vegetation covers: under tree canopy, under shrub, and in open spaces or grasslands. Besides, the data mining technique Multivariate Adaptive Regression Spline (MARS) was used to identify and rank the factors influencing flow types as well as modelling their occurrence. The work was carried out in an experimental catchment of the Spanish region of Extremadura. Results indicated that there is a general behavior or pattern of soil moisture dynamics in the catchment with a dominant occurrence of slower soil wetting processes (>50%), which may be considered as matrix flows, and a low occurrence of those faster processes (process, so that the ecological role of both flow types becomes prominent in water-limited environments. Statistical

  6. Proteomic effects of wet cupping (Al-hijamah). (United States)

    Almaiman, Amer A


    Wet cupping (Al-hijamah) is a therapeutic technique practiced worldwide as a part of the Unani system of medicine. It involves bloodletting from acupoints on a patient's skin to produce a therapeutic outcome. A thorough review of research articles on wet cupping with relevance to proteomics field that are indexed by Google Scholar, PubMed, and/or Science Direct databases was performed. Eight original research articles were summarized in this paper. Overall, wet cupping did not have a significant effect on C-reactive protein, Hsp-27, sister chromatid exchanges, and cell replication index. In contrast, wet cupping was found to produce higher oxygen saturation, eliminate lactate from subcutaneous tissues, remove blood containing higher levels of malondialdehyde and nitric oxide, and produce higher activity of myeloperoxidase. The proteomic effects of wet cupping therapy have not been adequately investigated. Thus, future studies on wet cupping that use systemic and sound protocols to avoid bias should be conducted.

  7. Wet-cupping removes oxidants and decreases oxidative stress. (United States)

    Tagil, Suleyman Murat; Celik, Huseyin Tugrul; Ciftci, Sefa; Kazanci, Fatmanur Hacievliyagil; Arslan, Muzeyyen; Erdamar, Nazan; Kesik, Yunus; Erdamar, Husamettin; Dane, Senol


    Wet-cupping therapy is one of the oldest known medical techniques. Although it is widely used in various conditions such as acute\\chronic inflammation, infectious diseases, and immune system disorders, its mechanism of action is not fully known. In this study, we investigated the oxidative status as the first step to elucidate possible mechanisms of action of wet cupping. Wet cupping therapy is implemented to 31 healthy volunteers. Venous blood samples and Wet cupping blood samples were taken concurrently. Serum nitricoxide, malondialdehyde levels and activity of superoxide dismutase and myeloperoxidase were measured spectrophotometrically. Wet cupping blood had higher activity of myeloperoxidase, lower activity of superoxide dismutase, higher levels of malondialdehyde and nitricoxide compared to the venous blood. Wet cupping removes oxidants and decreases oxidative stress. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. Tympanoplasty: does dry or wet temporalis fascia graft matter? (United States)

    Singh, G B; Kumar, D; Aggarwal, K; Garg, S; Arora, R; Kumar, S


    To evaluate the success rate of dry and wet temporalis fascia grafts in type I underlay tympanoplasty. A prospective, randomised study was conducted. One hundred adult patients (males and females) with chronic suppurative otitis media (mucosal type) were divided into 2 groups of 50 each: one group underwent dry graft tympanoplasty and the other underwent wet graft tympanoplasty. Fibroblast count was calculated in dry and wet grafts. The dry graft and wet graft groups had overall surgical success rates of 82 and 90 per cent, respectively; this finding was not statistically significant. A statistically significant high fibroblast count was observed in wet grafts, but it did not correlate with surgical success. A dry or wet temporalis fascia graft does not influence the outcome of tympanoplasty type I.

  9. Wick wetting for water condensation systems (United States)

    Hering, Susanne Vera; Spielman, Steven Russel; Lewis, Gregory Stephen; Kreisberg, Nathan Michael


    A system and method for particle enlargement with continuously wetted wicks includes a container into which a flow of particle-laden air is introduced in a laminar manner through an inlet and to an outlet. The container has a first section, a second section and a third section though which the particle-laden air flows between the inlet and the outlet. The temperature of the second section is warmer than that of the first section at the inlet and the third section at the outlet. In one embodiment, a continuous wick spanning an interior wall of the first second, second section and third section, said wick being capable of internally transporting liquid water along its length is provided.


    Directory of Open Access Journals (Sweden)

    Tamara STANCIU


    Full Text Available The heat losses of human body are greater in underwater environment than in dry, normal atmosphere, due to the great heat capacity of water. Body temperature of divers in immersion was studied taking into account the pressure the divers are subjected to. The theoretic equation that describes the total heat transfer- at both levels: skin and respiratory system- was established, considering conduction, convection and respiratory gas heating and humidification. The body temperature of the divers was measured in a series of dives at different depths of immersion, conducted in the wet simulator of the Diving Center, in Constanta. The experimental results were in good accordance with the temperature predicted by the mathematical model.


    Energy Technology Data Exchange (ETDEWEB)

    Youmans-Mcdonald, L.


    Analysis for beryllium by fluorescence is now an established method which is used in many government-run laboratories and commercial facilities. This study investigates the use of this technique using commercially available wet wipes. The fluorescence method is widely documented and has been approved as a standard test method by ASTM International and the National Institute for Occupational Safety and Health (NIOSH). The procedure involves dissolution of samples in aqueous ammonium bifluoride solution and then adding a small aliquot to a basic hydroxybenzoquinoline sulfonate fluorescent dye (Berylliant{trademark} Inc. Detection Solution Part No. CH-2) , and measuring the fluorescence. This method is specific to beryllium. This work explores the use of three different commercial wipes spiked with beryllium, as beryllium acetate or as beryllium oxide and subsequent analysis by optical fluorescence. The effect of possible interfering metals such as Fe, Ti and Pu in the wipe medium is also examined.

  12. Improved bitumen extraction using wet combustion

    Energy Technology Data Exchange (ETDEWEB)

    Wylie, I.; Hagen, D.; McGuire, A. [VAST Power Systems Inc., Elkhart, IN (United States)


    This presentation outlined the main concerns regarding the current combustion paradigm for steam assisted gravity drainage (SAGD) bitumen extraction and provided a solution that is more energy efficient with less environmental impact. SAGD operations currently use dry steam injection to deliver heat and reduce the viscosity bitumen, but this results in heat loss, restricted fuel choices, high water use and high emissions. Vast Power Systems Inc. has developed a wet flue gas known as VASTgas{sup TM} for efficient extraction. The downhole fluid has a much higher heat output and much lower emissions of nitrogen oxides, carbon monoxide and carbon dioxide. Other key advantages include net clean water from combustion and electricity as a by-product. This presentation also described the advantages of the VASThermogenerator{sup TM} for SAGD which solves some of the concerns regarding the combustion paradigm of mined bitumen and tailings pond purification. figs.

  13. Wet-Bulb-Globe Temperature Data Report (United States)


    ARL‐SR‐0317 ● MAR 2015          US Army Research Laboratory      Wet‐ Bulb –Globe Temperature Data Report    by David P Sauter...originator.         ARL‐SR‐0317 ● MAR 2015      US Army Research Laboratory      Wet‐ Bulb –Globe Temperature Data Report    by David P Sauter...March 2015 2. REPORT TYPE  Special Report 3. DATES COVERED (From ‐ To)  11 Aug 2014–23 Aug 2014 4. TITLE AND SUBTITLE  Wet- Bulb –Globe Temperature

  14. Modeling the early stages of reactive wetting. (United States)

    Wheeler, Daniel; Warren, James A; Boettinger, William J


    Recent experimental studies of molten metal droplets wetting high-temperature reactive substrates have established that the majority of triple-line motion occurs when inertial effects are dominant. In light of these studies, this paper investigates wetting and spreading on reactive substrates when inertial effects are dominant using a thermodynamically derived diffuse interface model of a binary three-phase material. The liquid-vapor transition is modeled using a van der Waals diffuse interface approach, while the solid-fluid transition is modeled using a phase field approach. The results from the simulations demonstrate an O(t(-1/2)) spreading rate during the inertial regime and oscillations in the triple-line position when the metal droplet transitions from inertial to diffusive spreading. It is found that the spreading extent is reduced by enhancing dissolution by manipulating the initial liquid composition. The results from the model exhibit good qualitative and quantitative agreement with a number of recent experimental studies of high-temperature droplet spreading, particularly experiments of copper droplets spreading on silicon substrates. Analysis of the numerical data from the model suggests that the extent and rate of spreading are regulated by the spreading coefficient calculated from a force balance based on a plausible definition of the instantaneous interface energies. A number of contemporary publications have discussed the likely dissipation mechanism in spreading droplets. Thus, we examine the dissipation mechanism using the entropy-production field and determine that dissipation primarily occurs in the locality of the triple-line region during the inertial stage but extends along the solid-liquid interface region during the diffusive stage.

  15. Bed wetting in school children of Karachi. (United States)

    Mithani, Shoaib; Zaidi, Zafar


    To estimate the frequency of primary nocturnal enuresis (PNE) in Pakistani children and to examine the factors associated with it. A randomly selected cross-sectional study was conducted in five elementary schools, one in each of five districts of Karachi. The parents of 5000 children age between 3-13 years were asked to complete a questionnaire which included items about the frequency of daytime wetting and nocturnal enuresis, family history, urinary tract infection, parents and child's own concern about this problem and acquisition of treatments. Over all corrected response rate to the questionnaire was 69% (3395). Enuresis was present in 9.1% (308). There were 166 (53.9%) boys and 142 (46%) girls with a median age of 7 years. Only 54% (166) children sought help for their problem of which 26% consulted doctors, 16% visited homeopaths while 11% used hakeems and home remedies. Of the bed wetters, 30% were wet every night, 30% for more than three nights a week and 40% for less than three nights every week. Parents of 68.5% (211) children reported concern for the problem while 69.8% (215) children were also anxious about their enuresis. Among the concerned children group, 22% parents were not concerned about their child's problem. Family history of enuresis was present in 25.6% (79) children. The frequency of enuresis among the school going children in Karachi is 9.1% and is similar to that reported in European countries and other Asian countries including Korea and Taiwan. Enuresis causes concern to both parents and children, but only a small percentage of parents seek medical help for this problem.

  16. Etude des transferts d'eau et de nitrate dans les sols ferrallitiques de Maré (Nouvelle-Calédonie) : risques de pollution des lentilles d'eau douce


    Duwig, Céline


    The purpose of tbis study was to determine the risk of groundwater pollution from intensified agricultural practices on Maré, in the Loyalty Islands of New Caledonia. To achieve this goal, the water and nitrogen balances were established during three quite different wet seasons, and under different agricultural treatments and soil-cover conditions. Maré is an uplifted coral atoll which is build upon an underlying volcanic structure. Underneath, fresh water lenses are located inside the coral ...

  17. The Investigation of Perchlorate/Iron Phase Mixtures as A Possible Source of Oxygen Detected by the Sample Analysis at Mars (SAM) Instrument in Gale Crater, Mars (United States)

    Sutter, B.; Heil, E.; Morris, R. V.; Archer, P. D.; Ming, D. W.; Niles, P. B.; Eigenbrode, J. L.; Franz, H.; Freissinet C.; Glavin, D. P.; hide


    The Sample Analysis at Mars (SAM) instrument onboard the Curiosity rover detected O2 and HCl gas releases from the Rocknest (RN) eolian bedform and the John Klein (JK) and Cumberland (CB) drill hole materials in Gale Crater. Chlorinated hydrocarbons have also been detected by the SAM quadrupole mass spectrometer (QMS) and gas chromatography/mass spectrometer (GCMS). These detections along with the detection of perchlorate (ClO4-) by the Mars Phoenix Lander's Wet Chemistry Laboratory (WCL) suggesting perchlorate is a possible candidate for evolved O2 and chlorine species. Laboratory thermal analysis of individual per-chlorates has yet to provide an unequivocal temperature match to the SAM O2 and HCl release data. These detections along with the detection of perchlorate (ClO4-) by the Mars Phoenix Lander's Wet Chemistry Laboratory suggested perchlorate is a possible candidate for evolved O2 and chlorine species. Laboratory thermal analysis of pure perchlorates has yet to provide an unequivocal temperature match to the SAM O2 and HCl release data. Analog laboratory analysis of iron mineralogy detected in Gale materials that was physically mixed with Ca- and Mg-perchlorate has been shown to catalyze lower O2 release temperatures and approach some SAM O2 release data. Instead of physical mixtures used in previous work, the work presented here utilized perchlorate solutions added to Fe phases. This technique allowed for perchlorate to come in closer contact with the Fe-phase and may more closely mimic Mars conditions where humidity can increase enough to cause deliquescence of the highly hygroscopic perchlorate phases. The objective of this work is to: 1) Utilize a laboratory SAM analog instrument to evaluate the O2 release temperatures from Mg- and Ca-perchlorates solutions applied to Fephases detetected in Gale Crate; and 2) Determine if perchlorate solutions can provide improved matches with the SAM O2 temperature release profiles.

  18. Pavement Marking Visibility Requirements During Wet Night Conditions


    Gibbons, Ronald B. (Ronald Bruce)


    This study investigated the performance of pavement markings in wet night conditions. Typically, performance will decrease in wet conditions. The degradation is a result of flooding of the marking optics and a change in the optical media, thereby reducing retroreflectivity and the visibility distance. Several technologies are available to improve the visibility of markings under wet conditions. This study used four technologies and evaluated them in a dynamic situation. In the experiment, veh...

  19. Advanced Stellar Compass - Alenia Mars Express

    DEFF Research Database (Denmark)

    Kilsgaard, Søren; Betto, Maurizio; Jørgensen, John Leif


    This document, submitted in reply to an Alenia R.f.P., is a proposal to implement the Advanced Stellar Compass (ASC) in the Mars Express mission.The Mars Express is an ESA dedicated mission to Mars scientific investigation.The ASC is a very advanced instrument designed by the Space Instrumentation...

  20. Midlatitude Ice-Rich Ground on Mars: An Important Target for Science and In Situ Resource Utilization on Human Missions (United States)

    Stoker, Carol; Heldmann, Jennifer


    The region of ROI is characterized by proven presence of near surface ground ice and numerous periglacial features. Midlatitude ground ice on Mars is of significant scientific interest for understanding the history and evolution of ice stability on Mars, the impact that changes in insolation produced by variations in Mars’ orbital parameters has on the regions climate, and could provide human exploration with a reliable and plentiful in situ resource. For both science and exploration, assessing the astrobiological potential of the ice is important in terms of (1) understanding the potential for life on Mars and (2) evaluating the presence of possible biohazards in advance of human exploration. Heldmann et al. (2014) studied locations on Mars in the Amazonis Planitia region where near surface ground ice was exposed by new impact craters (Byrne et al. 2009). The study examined whether sites in this region were suitable for human exploration including reviewing the evidence for midlatitude ground ice, discussing the possible explanations for its occurrence, assessing its potential habitability for modern life, and evaluating the resource potential. They systematically analyzed remote-sensing data sets to identify a viable landing site. Five sites where ground ice was exposed were examined with HiRise imaging and were classified according to (1) presence of polygons as a proxy for subsurface ice, (2) presence and abundance of rough topographic obstacles (e.g., large cracks, cliffs, uneven topography), (3) rock density, (4) presence and abundance of large boulders, and (5) presence of craters. A suitable landing site was found having ground ice at only 0.15m depth, and no landing site hazards within a 25 km landing ellipse. This paper presents results of that study and examines the relevance of this ROI to the workshop goals.

  1. Were lakes on early Mars perennially were ice-covered? (United States)

    Sumner, D. Y.; Rivera-Hernandez, F.; Mackey, T. J.


    Paleo-lake deposits indicate that Mars once sustained liquid water, supporting the idea of an early "wet and warm" Mars. However, liquid water can be sustained under ice in cold conditions as demonstrated by perennially ice-covered lakes (PICLs) in Antarctica. If martian lakes were ice-covered, the global climate on early Mars could have been much colder and dryer than if the atmosphere was in equilibrium with long-lived open water lakes. Modern PICLs on Earth have diagnostic sedimentary features. Unlike open water lakes that are dominated by mud, and drop stones or tills if icebergs are present, previous studies determined that deposits in PICLs can include coarser grains that are transported onto the ice cover, where they absorb solar radiation, melt through the ice and are deposited with lacustrine muds. In Lake Hoare, Antarctica, these coarse grains form conical sand mounds and ridges. Our observations of ice-covered lakes Joyce, Fryxell, Vanda and Hoare, Antarctica suggest that the distributions of grains depend significantly on ice characteristics. Deposits in these lakes contain moderately well to moderately sorted medium to very coarse sand grains, which preferentially melt through the ice whereas granules and larger grains remain on the ice surface. Similarly, high albedo grains are concentrated on the ice surface, whereas low albedo grains melt deeper into the ice, demonstrating a segregation of grains due to ice-sediment interactions. In addition, ice cover thickness may determine the spatial distribution of sand deposited in PICLs. Localized sand mounds and ridges composed of moderately sorted sand are common in PICLs with rough ice covers greater than 3 m thick. In contrast, lakes with smooth and thinner ice have disseminated sand grains and laterally extensive sand layers but may not have sand mounds. At Gale Crater, Mars, the Murray formation consists of sandy lacustrine mudstones, but the depositional process for the sand is unknown. The presence of

  2. Wet-Peeling Technique of Deep Anterior Lamellar Keratoplasty With Hypotonic Water and Blunt Dissection for Healed Hydrops. (United States)

    Zhao, Zelin; Li, Jinyang; Zheng, Qinxiang; Lin, Wei; Jhanji, Vishal; Chen, Wei


    To describe the surgical technique and outcomes of "wet-peeling" deep anterior lamellar keratoplasty (DALK) using sterile water and blunt dissection in cases with corneal scarring after healed corneal hydrops. Manual DALK using a "wet-peeling" technique was performed in 20 eyes of 20 consecutive patients with healed corneal hydrops between June 2011 and October 2013. Intraoperative microperforations were encountered in 2 (10%) cases. None of the cases required conversion to penetrating keratoplasty. There was significant improvement in mean best-corrected visual acuity at the end of 24 months postoperatively (0.99 ± 0.30 logMAR vs. 0.20 ± 0.11 logMAR; P < 0.001). The postoperative mean residual stromal bed thickness was 48.9 ± 5.9 μm, and mean central corneal thickness was 557.2 ± 50.3 μm. The mean endothelial density was 2021 ± 236 cells/mm at the final follow-up. Manual DALK using sterile water can be successfully performed in corneas with healed hydrops. Favorable visual outcomes may be attributed to thin residual bed thickness postoperatively.

  3. Habitability: Where to look for life? Halophilic habitats: Earth analogs to study Mars habitability (United States)

    Gómez, F.; Rodríguez-Manfredi, J. A.; Rodríguez, N.; Fernández-Sampedro, M.; Caballero-Castrejón, F. J.; Amils, R.


    Oxidative stress, high radiation doses, low temperature and pressure are parameters which made Mars's surface adverse for life. Those conditions found on Mars surface are harsh conditions for life to deal with. Life, as we know it on Earth, needs several requirements for its establishment but, the only "sine qua nom" element is water. Extremophilic microorganisms widened the window of possibilities for life to develop in the universe, and as a consequence on Mars. Recently reported results in extreme environments indicate the possibility of presence of "oasys" for life in microniches due to water deliquescence in salts deposits. The compilation of data produced by the ongoing missions (Mars Global Surveyor, Mars Odyssey, Mars Express and Mars Exploration Rover Opportunity) offers a completely different view from that reported by Viking missions: signs of an early wet Mars and rather recent volcanic activity. The discovery of important accumulations of sulfates, and the existence of iron minerals like jarosite, goethite and hematite in rocks of sedimentary origin has allowed specific terrestrial models related with this type of mineralogy to come into focus. Río Tinto (Southwestern Spain, Iberian Pyritic Belt) is an extreme acidic environment, product of the chemolithotrophic activity of microorganisms that thrive in the massive pyrite-rich deposits of the Iberian Pyritic Belt. The high concentration of ferric iron and sulfates, products of the metabolism of pyrite, generate a collection of minerals, mainly gypsum, jarosite, goethite and hematites, all of which have been detected in different regions of Mars. Some particular protective environments or elements could house organic molecules or the first bacterial life forms on Mars surface. Terrestrial analogs could help us to afford its comprehension. We are reporting here some preliminary studies about endolithic niches inside salt deposits used by phototrophs for taking advantage of sheltering particular light

  4. Mars Science Laboratory Engineering Cameras (United States)

    Maki, Justin N.; Thiessen, David L.; Pourangi, Ali M.; Kobzeff, Peter A.; Lee, Steven W.; Dingizian, Arsham; Schwochert, Mark A.


    NASA's Mars Science Laboratory (MSL) Rover, which launched to Mars in 2011, is equipped with a set of 12 engineering cameras. These cameras are build-to-print copies of the Mars Exploration Rover (MER) cameras, which were sent to Mars in 2003. The engineering cameras weigh less than 300 grams each and use less than 3 W of power. Images returned from the engineering cameras are used to navigate the rover on the Martian surface, deploy the rover robotic arm, and ingest samples into the rover sample processing system. The navigation cameras (Navcams) are mounted to a pan/tilt mast and have a 45-degree square field of view (FOV) with a pixel scale of 0.82 mrad/pixel. The hazard avoidance cameras (Haz - cams) are body-mounted to the rover chassis in the front and rear of the vehicle and have a 124-degree square FOV with a pixel scale of 2.1 mrad/pixel. All of the cameras utilize a frame-transfer CCD (charge-coupled device) with a 1024x1024 imaging region and red/near IR bandpass filters centered at 650 nm. The MSL engineering cameras are grouped into two sets of six: one set of cameras is connected to rover computer A and the other set is connected to rover computer B. The MSL rover carries 8 Hazcams and 4 Navcams.

  5. NASA Facts, Mars and Earth. (United States)

    National Aeronautics and Space Administration, Washington, DC. Educational Programs Div.

    Presented is one of a series of National Aeronautics and Space Administration (NASA) facts about the exploration of Mars. In this publication, emphasis is placed on the sun's planetary system with note made that there is no one theory for the origin and subsequent evolution of the Solar System that is generally accepted. Ideas from many scientists…

  6. Earth Based Views of Solute Profiles on Mars (Invited) (United States)

    Amundson, R.


    'Historical accounts of planetary evolution are mostly written in stone' (1), but the last chapter of that history is embedded in its soil. Soil properties reflect the effects of prevailing environmental boundary conditions. Solute profiles are powerful indicators of the direction and magnitude of water flow. I briefly review the chemistry of salt profiles from deserts formed by upward vs. downward migrating water, use this as a basis for interpreting aspects of Mars hydrological history. The Noachian-aged Meridiani Planum land surface is exposed in the Endurance and Victoria Craters. These craters have been estimated to be ~ physical alteration, suggest modest pedogenic alteration of the landsurface sometime prior to impact. The sequence of the SO3 and Cl is consistent only with downward aqueous transport, as clearly illustrated by comparison to Earth soils that form by groundwater evaporation vs. downward moving meteoric water. While the total water required to create the profiles is not easy to constrain, the meter scale depth of the alteration requires precipitation events well beyond mere surficial wetting. (1) Grotzinger et al. (2005). Earth and Planetary Science Letters 240:11-72. (2) Golombek, M.P. (2012) Timescale of small crater modification on Meridiani Planum, Mars. 43rd Lunar and Planetary Science Conference. (3) Arvidson et al. (2011). J. of Geophysical Research 116, E00F15, doi:10.1029/2010JE003746, 2011 (4) Amundson et al. (2008) Geochim. Cosmochim. Acta 72:3845-3864.

  7. Letting Wet Spots be Wet: Restoring Natural Bioreactors in the Dissected Glacial Landscape (United States)

    Schilling, Keith E.; McLellan, Eileen; Bettis, E. Arthur


    In this paper, we argue that there is tremendous potential for nitrate-N reductions to occur throughout the Corn Belt region of the USA if we simply let naturally occurring wet spots on the landscape be wet. Geologic and hydrologic data gathered in the Walnut Creek watershed located in south-central Iowa provides compelling evidence that substantial nutrient-processing capacity exists in this dissected glacial landscape. Self-similarity of stratigraphy, sedimentology and hydrology observed at all spatial scales in the watershed suggests that Holocene alluvial fill deposits provide a natural bioreactor for denitrification of upland groundwater nitrate-N; the occurrence of such deposits can be mapped to identify potential nitrogen sinks across the landscape. This approach to identifying potential nitrogen sinks is geology focused and extends potential locations for nutrient processing upstream into the headwater catchments of individual fields.

  8. Human Mars Landing Site and Impacts on Mars Surface Operations (United States)

    Hoffman, Stephen J.; Bussey, Ben


    This paper describes NASA's initial steps for identifying and evaluating candidate Exploration Zones (EZs) and Regions of Interests (ROIs) for the first human crews that will explore the surface of Mars. NASA's current effort to define the exploration of this planet by human crews, known as the Evolvable Mars Campaign (EMC), provides the context in which these EZs and ROIs are being considered. The EMC spans all aspects of a human Mars mission including launch from Earth, transit to and from Mars, and operations on the surface of Mars. An EZ is a collection of ROIs located within approximately 100 kilometers of a centralized landing site. ROIs are areas relevant for scientific investigation and/or development/maturation of capabilities and resources necessary for a sustainable human presence. The EZ also contains one or more landing sites and a habitation site that will be used by multiple human crews during missions to explore and utilize the ROIs within the EZ. With the EMC as a conceptual basis, the EZ model has been refined to a point where specific site selection criteria for scientific exploration and in situ resource utilization can be defined. In 2015 these criteria were distributed to the planetary sciences community and the in situ resource utilization and civil engineering communities as part of a call for EZ proposals. The resulting "First Landing Site/Exploration Zone Workshop for Human Missions to the Surface of Mars" was held in October 2015 during which 47 proposals for EZs and ROIs were presented and discussed. Proposed locations spanned all longitudes and all allowable latitudes (+/- 50 degrees). Proposed justification for selecting one of these EZs also spanned a significant portion of the scientific and resource criteria provided to the community. Several important findings resulted from this Workshop including: (a) a strong consensus that, at a scale of 100 km (radius), multiple places on Mars exist that have both sufficient scientific interest

  9. Preparing for Mars: The Evolvable Mars Campaign 'Proving Ground' Approach (United States)

    Bobskill, Marianne R.; Lupisella, Mark L.; Mueller, Rob P.; Sibille, Laurent; Vangen, Scott; Williams-Byrd, Julie


    As the National Aeronautics and Space Administration (NASA) prepares to extend human presence beyond Low Earth Orbit, we are in the early stages of planning missions within the framework of an Evolvable Mars Campaign. Initial missions would be conducted in near-Earth cis-lunar space and would eventually culminate in extended duration crewed missions on the surface of Mars. To enable such exploration missions, critical technologies and capabilities must be identified, developed, and tested. NASA has followed a principled approach to identify critical capabilities and a "Proving Ground" approach is emerging to address testing needs. The Proving Ground is a period subsequent to current International Space Station activities wherein exploration-enabling capabilities and technologies are developed and the foundation is laid for sustained human presence in space. The Proving Ground domain essentially includes missions beyond Low Earth Orbit that will provide increasing mission capability while reducing technical risks. Proving Ground missions also provide valuable experience with deep space operations and support the transition from "Earth-dependence" to "Earth-independence" required for sustainable space exploration. A Technology Development Assessment Team identified a suite of critical technologies needed to support the cadence of exploration missions. Discussions among mission planners, vehicle developers, subject-matter-experts, and technologists were used to identify a minimum but sufficient set of required technologies and capabilities. Within System Maturation Teams, known challenges were identified and expressed as specific performance gaps in critical capabilities, which were then refined and activities required to close these critical gaps were identified. Analysis was performed to identify test and demonstration opportunities for critical technical capabilities across the Proving Ground spectrum of missions. This suite of critical capabilities is expected to

  10. Modeling Shoreline Evolution on Mars (United States)

    Kraal, E. R.; Ashpaug, E. I.; Lorenz, R. D.


    Geomorphic evidence of surface water on Mars has important implications for planetary surface evolution, as well as for the continuing exploration of the planet as future landing sites are selected. Here we present the initial results from forward models of crater lake basin evolution motivated by the identification of intracrater landforms on Mars which exhibit possible evidence for a history of surface water. Proposed lacustrine Martian landforms include shorelines, terraces, and wave cut benches - features that have received considerable attention in terrestrial lacustrine geomorphology but which have never been quantitatively addressed with sufficient rigor on Mars. In particular, the existing body of terrestrial research has yet to be applied adequately to planets of different gravity, temperature (or working fluid) and atmospheric pressure, such as Mars and Titan. The 2-D model includes wave generation, shore erosion, and other factors. Wave generation depends primarily on wind speed and basin size. The erosive power of the generated waves along the shoreline depends on wave size and period, initial topography, rock hardness, and the effects of crater impact formation on the bedrock. Other factors include water loss to evaporation and infiltration, sediment transport within the basin, wind transported sediment, and ice cover. Waves are generated using terrestrial empirical equations that have been modified for the lower gravity on Mars. Erosion is based on equations for terrestrial rocky coastline evolution models that have been modified for Martian conditions. Results presented here will focus on the first two aspects, wave generation and shoreline erosion. Additional research will include exploring the effect of different air pressures on the system as well as modifying the model for application to possible crater lakes of liquid hydrocarbons on Titan.

  11. Biodiesel production from wet microalgae feedstock using sequential wet extraction/transesterification and direct transesterification processes. (United States)

    Chen, Ching-Lung; Huang, Chien-Chang; Ho, Kao-Chia; Hsiao, Ping-Xuan; Wu, Meng-Shan; Chang, Jo-Shu


    Although producing biodiesel from microalgae seems promising, there is still a lack of technology for the quick and cost-effective conversion of biodiesel from wet microalgae. This study was aimed to develop a novel microalgal biodiesel producing method, consisting of an open system of microwave disruption, partial dewatering (via combination of methanol treatment and low-speed centrifugation), oil extraction, and transesterification without the pre-removal of the co-solvent, using Chlamydomonas sp. JSC4 with 68.7 wt% water content as the feedstock. Direct transesterification with the disrupted wet microalgae was also conducted. The biomass content of the wet microalgae increased to 56.6 and 60.5 wt%, respectively, after microwave disruption and partial dewatering. About 96.2% oil recovery was achieved under the conditions of: extraction temperature, 45°C; hexane/methanol ratio, 3:1; extraction time, 80 min. Transesterification of the extracted oil reached 97.2% conversion within 15 min at 45°C and 6:1 solvent/methanol ratio with simultaneous Chlorophyll removal during the process. Nearly 100% biodiesel conversion was also obtained while conducting direct transesterification of the disrupted oil-bearing microalgal biomass. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. The Icebreaker Mission to Search for Life on Mars (United States)

    Stoker, C.; Mckay, C.; Brinckerhoff, W.; Davila, A.; Parro, V.; Quinn, R.


    The search for evidence of life on Mars is the ultimate motivation for its scientific exploration. The results from the Phoenix mission indicate that the high N. latitude ice-rich regolith at low elevations is likely to be a recently habitable place on Mars [Stoker et al., 2010]. The near-surface ice likely provided adequate water activity during periods of high obliquity, 3 to 10 Myr ago. Carbon dioxide and nitrogen are present in the atmosphere, and nitrates may be present in the soil. Together with iron in basaltic rocks and perchlorate in the soil they provide carbon and energy sources, and oxidative power to drive metabolism. Furthermore, the presence of organics is possible, as thermally reactive perchlorate would have prevented their detection by Viking and Phoenix. The Mars Icebreaker Life mission [McKay et al., 2013] focuses on the following science goals: (1) Search for biomolecular evidence of life; (2) Search for organic matter from either exogeneous or endogeneous sources using methods that are not effected by the presence of perchlorate; (3) Characterize oxidative species that produced reactivity of soils seen by Viking; and 4) Assess the habitability of the ice bearing soils. The Icebreaker Life payload (Figure 1) includes a 1-m rotary percussive drill that brings cuttings samples to the surface where they are delivered to three instruments (Fig. 1), the Signs of Life Detector (SOLID) [Parro et al., 2011] for biomolecular analysis, Laser Desorption Mass Spectrometer (LDMS) [??? 2015]) for broad spectrum organic analysis, and Wet Chemistry Laboratory (WCL) [Hecht et al., 2009] for detecting soluble species of nutrients and reactive oxidants. The Icebreaker payload fits on the Phoenix spacecraft and can land at the well-characterized Phoe-nix landing site in 2020 in a Discovery-class mission.

  13. Elemental mercury removal using a wet scrubber.

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, E.; Livengood, C. D.; Martin, K.; Mendelsohn, M. H.; Zhou, C. Q.


    Mercury (Hg) is a toxic metal that is emitted into the environment by both natural and human activities. Acute and chronic exposure to mercury and methyl mercury in humans results in central nervous system damage, kidney damage, and even death. Although some Hg emission sources have been regulated, coal-fired utilities have not been. In anticipation of federal regulations on mercury emissions from coal-fired power plants, Argonne National Laboratory (ANL) has designed a flue gas simulation system to study the removal of elemental mercury. The simulated flue gas enters the system and combines with the inlet mercury vapor (from a calibrated permeation tube), carried by nitrogen gas. This combined gas continues past the flow meter and the pressure gage to the reactor inlet. Inside the reactor chamber, the flue gas is sprayed with NOXSORB{reg_sign}, a chloric acid solution, which reacts with elemental mercury. The amount of reaction (oxidation) of elemental mercury is important since mercury in an oxidized form is highly soluble, In this form, the Hg can be picked up downstream by a wet scrubber from fossil-fuel burning utilities. Experiments on mercury removal from flue gases have been conducted at ANL, with the participation of a senior design team from Purdue University Calumet. Temperature variations ranging from room temperature to 350 F have been studied. Other parameters, such as the concentration of NOXSORB{reg_sign}, were also tested. Furthermore, pump speed and sprayer droplet sizes of the NOXSORB{reg_sign} solution were studied. A literature survey on the current and proposed mercury control legislation, along with the existing control technologies, has been performed as part of the senior design project. With guidance from ANL, an understanding of the simulation system has been developed. This information has been used to determine the mass transfer. Another literature survey was performed on the reaction kinetics of mercury. The information obtained was

  14. Bifid Mandibular Condyle: A rare in plenty

    Directory of Open Access Journals (Sweden)

    V G Mahima


    Full Text Available The bifid mandibular condyle has also been termed as Double Headed Condyle or Condylar Duplication. Bifid condyle was first reported by Hrdlicka in 1941. Since then, to the best of our knowledge, about 49 cases of bifid condyle have been reported in medical literature. We present here six cases of bifid mandibular condyle that we encountered during the span of one year. These were incidental findings on panoramic radiographs and were later confirmed with coronal computed tomographs. This article also reviews the relevant literature.

  15. Home offices: Plenty of untapped potential


    Brenke, Karl


    As far as the share of individuals with a home office is concerned, Germany is below the EU average and lags considerably behind other countries such as France, the UK, or the Scandinavian countries. Only 12 percent of all employees in Germany work primarily or occasionally from home, although this would theoretically be possible in 40 percent of jobs. In most cases, an employee's desire to work from home is not recognized by employers. If these employers were to reconsider their position, ho...

  16. PLA 2010 Conference: Plenty for the Price (United States)

    Miller, Rebecca


    This article outlines Public Library Association (PLA) 2010 annual conference to be held in Oregon Convention Center, Portland on March 23-27. The days quickly fill up with the picks of over 100 programs as well as valuable "talk tables" and special events. The well-organized schedule, divided into eight broad tracks (e.g., technology,…

  17. Spatial and temporal variations in the occurrences of wet periods ...

    Indian Academy of Sciences (India)

    This study highlights the hydro-climatic features of the five wet periods contributing in different percentages to the annual rainfall total over major river basins in India. Spatial and temporal variations in the parameters such as starting date, duration and rainfall intensity of these wet periods throughout India have been ...

  18. Method for wetting a boron alloy to graphite (United States)

    Storms, E.K.


    A method is provided for wetting a graphite substrate and spreading a a boron alloy over the substrate. The wetted substrate may be in the form of a needle for an effective ion emission source. The method may also be used to wet a graphite substrate for subsequent joining with another graphite substrate or other metal, or to form a protective coating over a graphite substrate. A noneutectic alloy of boron is formed with a metal selected from the group consisting of nickel (Ni), palladium (Pd), and platinum (Pt) with excess boron, i.e., and atomic percentage of boron effective to precipitate boron at a wetting temperature of less than the liquid-phase boundary temperature of the alloy. The alloy is applied to the substrate and the graphite substrate is then heated to the wetting temperature and maintained at the wetting temperature for a time effective for the alloy to wet and spread over the substrate. The excess boron is evenly dispersed in the alloy and is readily available to promote the wetting and spreading action of the alloy. 1 fig.

  19. Spatial and temporal variations in the occurrences of wet periods ...

    Indian Academy of Sciences (India)

    This study highlights the hydro-climatic features of the five wet periods contributing in different percentages to the annual rainfall total over major river basins in India.Spatial and temporal variations in the parameters such as starting date,duration and rainfall intensity of these wet periods throughout India have been ...

  20. Electrophoretic deposition of titania nanoparticles: Wet density of ...

    Indian Academy of Sciences (India)


    Abstract. Electrophoretic deposition (EPD) of titania nanoparticles was performed at different voltages and times. The wet density of deposits was calculated according to the Archimedes' principle. The wet density as well as the electric field over the deposits increased with time and attained the plateau at longer times. The.

  1. Hydrodynamics of a Multistage Wet Scrubber Incineration Conditions (United States)

    Said, M. M.; Manyele, S. V.; Raphael, M. L.


    The objective of the study was to determine the hydrodynamics of the two stage counter-current cascade wet scrubbers used during incineration of medical waste. The dependence of the hydrodynamics on two main variables was studied: Inlet air flow rate and inlet liquid flow rate. This study introduces a new wet scrubber operating features, which are…

  2. The Influence of Wetting Rate and Electrolyte Concentration on the ...

    African Journals Online (AJOL)

    Substantial macroscopic swelling of rapidly wetted soil was attributed to air compressed into the largest available voids. Consequent soil matrix failure resulted in macroscopic swelling and increased sorption of water. Hydraulic conductivity appeared to be a non-linear function of wetting rate over the range w = 0-30 mm ...

  3. Phase change materials and the perception of wetness

    NARCIS (Netherlands)

    Bergmann Tiest, W.M.; Kosters, N.D.; Kappers, A.M.L.; Daanen, H.A.M.


    Phase change materials (PCMs) are increasingly incorporated in textiles in order to serve as a thermal buffer when humans change from a hot to a cold environment and the reverse. Due to the absence of wetness sensors in the skin, cooling of the skin may be perceived as a sensation of wetness instead

  4. Phase Change Materials and the perception of wetness.

    NARCIS (Netherlands)

    Bergmann Tiest, W.M.; Kappers, A.M.L.; Daanen, H.A.M.


    Phase change materials (PCMs) are increasingly incorporated in textiles in order to serve as a thermal buffer when humans change from a hot to a cold environment and the reverse. Due to the absence of wetness sensors in the skin, cooling of the skin may be perceived as a sensation of wetness instead

  5. Evaluation of wetting ability of five new saliva substitutes on ...

    African Journals Online (AJOL)

    Introduction: The aim of this study was to evaluate & compare the wetting ability of five saliva substitutes & distilled water on heat-polymerized acrylic resin. Contact angle of the saliva substitute on denture base can be taken as an indicator of wettability. Good wetting of heat-polymerized acrylic resin is critical for optimum ...

  6. Comparative Batch and Column Evaluation of Thermal and Wet ...

    African Journals Online (AJOL)

    ABSTRACT: The efficiency of regenerated spent commercial activated carbon for synthetic dye removal was studied using thermal and wet ... Keywords: Activated Carbon, Methyl Red, Chromatography Capacity, Wet and Thermal Regeneration. INTRODUCTION ... processes in wastewater treatment. A number of techniques ...

  7. Southern African Regional Science Initiative (SAFARI 2000): wet season campaigns

    CSIR Research Space (South Africa)

    Otter, LB


    Full Text Available The Southern African Regional Science Initiative (SAFARI 2000) involved two wet season and one dry season field campaigns. This paper reports on the wet season campaigns. The first was conducted at five sites along the Kalahari Transect in Zambia...

  8. Effect of Hydrochloric Acid, Mechanical Scarification, Wet Heat ...

    African Journals Online (AJOL)

    Michael Horsfall

    HCL), Wet heat. ABSTRACT; The effect of different ... treatments observed showed 100% for wet heat, 90% for scarification (sand paper) and 70% for HCL of 50% ... the principle constant being a dry season of 5-7 month/year. It may grow in ...

  9. Fluorinated Silsesquioxanes: Structure, Solubility, and Wetting (Briefing charts) (United States)


    Charts 3. DATES COVERED (From - To) July 2015-July 2015 4. TITLE AND SUBTITLE FLUORINATED SILSESQUIOXANES: STRUCTURE, SOLUBILITY , AND WETTING...FLUORINATED SILSESQUIOXANES: STRUCTURE, SOLUBILITY , AND WETTING Joseph Mabry, Andrew Guenthner, Scott Iacono, Raymond Campos, Sean Ramirez, Brian Moore...Crystalline solids • Soluble in fluorinated solvents 5DISTRIBUTION A. Approved for public release; distribution unlimited. • Spin-cast surface of FD

  10. Electrophoretic deposition of titania nanoparticles: Wet density of ...

    Indian Academy of Sciences (India)

    Electrophoretic deposition (EPD) of titania nanoparticles was performed at different voltages and times. The wet density of deposits was calculated according to the Archimedes' principle. The wet density as well as the electric field over the deposits increased with time and attained the plateau at longer times. The velocity at ...

  11. Moon-Mars Analogue Mission (EuroMoonMars 1 at the Mars Desert Research Station) (United States)

    Lia Schlacht, Irene; Voute, Sara; Irwin, Stacy; Foing, Bernard H.; Stoker, Carol R.; Westenberg, Artemis

    The Mars Desert Research Station (MDRS) is situated in an analogue habitat-based Martian environment, designed for missions to determine the knowledge and equipment necessary for successful future planetary exploration. For this purpose, a crew of six people worked and lived together in a closed-system environment. They performed habitability experiments within the dwelling and conducted Extra-Vehicular Activities (EVAs) for two weeks (20 Feb to 6 Mar 2010) and were guided externally by mission support, called "Earth" within the simulation. Crew 91, an international, mixed-gender, and multidisciplinary group, has completed several studies during the first mission of the EuroMoonMars campaign. The crew is composed of an Italian designer and human factors specialist, a Dutch geologist, an American physicist, and three French aerospace engineering students from Ecole de l'Air, all with ages between 21 and 31. Each crewmember worked on personal research and fulfilled a unique role within the group: commander, executive officer, engineer, health and safety officer, scientist, and journalist. The expedition focused on human factors, performance, communication, health and safety pro-tocols, and EVA procedures. The engineers' projects aimed to improve rover manoeuvrability, far-field communication, and data exchanges between the base and the rover or astronaut. The crew physicist evaluated dust control methods inside and outside the habitat. The geologist tested planetary geological sampling procedures. The crew designer investigated performance and overall habitability in the context of the Mars Habitability Experiment from the Extreme-Design group. During the mission the crew also participated in the Food Study and in the Ethospace study, managed by external groups. The poster will present crew dynamics, scientific results and daily schedule from a Human Factors perspective. Main co-sponsors and collaborators: ILEWG, ESA ESTEC, NASA Ames, Ecole de l'Air, SKOR, Extreme

  12. Tactile cues significantly modulate the perception of sweat-induced skin wetness independently of the level of physical skin wetness. (United States)

    Filingeri, Davide; Fournet, Damien; Hodder, Simon; Havenith, George


    Humans sense the wetness of a wet surface through the somatosensory integration of thermal and tactile inputs generated by the interaction between skin and moisture. However, little is known on how wetness is sensed when moisture is produced via sweating. We tested the hypothesis that, in the absence of skin cooling, intermittent tactile cues, as coded by low-threshold skin mechanoreceptors, modulate the perception of sweat-induced skin wetness, independently of the level of physical wetness. Ten males (22 yr old) performed an incremental exercise protocol during two trials designed to induce the same physical skin wetness but to induce lower (TIGHT-FIT) and higher (LOOSE-FIT) wetness perception. In the TIGHT-FIT, a tight-fitting clothing ensemble limited intermittent skin-sweat-clothing tactile interactions. In the LOOSE-FIT, a loose-fitting ensemble allowed free skin-sweat-clothing interactions. Heart rate, core and skin temperature, galvanic skin conductance (GSC), and physical (w(body)) and perceived skin wetness were recorded. Exercise-induced sweat production and physical wetness increased significantly [GSC: 3.1 μS, SD 0.3 to 18.8 μS, SD 1.3, P FIT and LOOSE-FIT (P > 0.05). However, the limited intermittent tactile inputs generated by the TIGHT-FIT ensemble reduced significantly whole-body and regional wetness perception (P < 0.01). This reduction was more pronounced when between 40 and 80% of the body was covered in sweat. We conclude that the central integration of intermittent mechanical interactions between skin, sweat, and clothing, as coded by low-threshold skin mechanoreceptors, significantly contributes to the ability to sense sweat-induced skin wetness. Copyright © 2015 the American Physiological Society.

  13. Reversible wetting of titanium dioxide films (United States)

    Toh, A. G. G.; Nolan, M. G.; Cai, R.; Butler, D. L.


    Titanium dioxide (TiO II) films were rendered hydrophilic through ultraviolet (UV) light irradiation (254nm) and returned to their previous hydrophobic condition when exposed to a sealed pressurized nitrogen atmosphere. UV light irradiation on TiO II films resulted in super-hydrophilic surfaces with water contact angles of 40°. The switching of TiO II surface wettability could be repeated on the same surface with little hysteresis in water contact angle values. The mechanism behind the hydrophilic and hydrophobic reversal in TiO II surfaces is proposed to be due to UV light mediated photocatalysis and physio- adsorption of N II molecules respectively. The non-intrusive control of TiO II surface wettability could be an attractive alternative to other wettability-based microfluidic valving strategies like electrowetting and photochromic wetting variation. The above results are discussed in terms of the potential use of the films in wettability based valving and repeated wettability patterning of TiO II surfaces for open and sealed microfluidic systems.

  14. Wet process technology in the semiconductor manufacturing process. 1. Physics and chemistry of wet cleaning process; Handotai process ni okeru wet process. Wet senjo no butsuri kagaku

    Energy Technology Data Exchange (ETDEWEB)

    Ryuta, J. [Mitsubishi Materials Corp., Tokyo (Japan)


    The wet cleaning consists of a cleaning process in chemicals and a rinse process using ultra-pure water. Among a series of cleaning process, this paper focuses on the SC1 (standard cleaning 1) process using NH4OH, H2O2, and H2O. During the SC1 process, two reactions progress simultaneously, i.e., natural oxidation and etching reactions on the wafer surface. As a consequence of measurement of the oxide film thickness, it was found that the reaction rate during the initial oxidation is extremely high. As a result of measurement of the etching rate, it was also found that the etching reaction is affected by the oxidation reaction. It is illustrated that pits, which are caused by defects in the crystal, are formed during the repeated SC1 process. It is also illustrated that the adsorption and desorption of Fe occur simultaneously on the wafer surface during the SC1 process. It was found that a clean wafer surface can be obtained by removing the particles and metal impurities in the cleaning liquid. 10 refs., 12 figs., 1 tab.

  15. Photochemical organonitrate formation in wet aerosols

    Directory of Open Access Journals (Sweden)

    Y. B. Lim


    Full Text Available Water is the most abundant component of atmospheric fine aerosol. However, despite rapid progress, multiphase chemistry involving wet aerosols is still poorly understood. In this work, we report results from smog chamber photooxidation of glyoxal- and OH-containing ammonium sulfate or sulfuric acid particles in the presence of NOx and O3 at high and low relative humidity. Particles were analyzed using ultra-performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS. During the 3 h irradiation, OH oxidation products of glyoxal that are also produced in dilute aqueous solutions (e.g., oxalic acids and tartaric acids were formed in both ammonium sulfate (AS aerosols and sulfuric acid (SA aerosols. However, the major products were organonitrogens (CHNO, organosulfates (CHOS, and organonitrogen sulfates (CHNOS. These were also the dominant products formed in the dark chamber, indicating non-radical formation. In the humid chamber (> 70 % relative humidity, RH, two main products for both AS and SA aerosols were organonitrates, which appeared at m ∕ z− 147 and 226. They were formed in the aqueous phase via non-radical reactions of glyoxal and nitric acid, and their formation was enhanced by photochemistry because of the photochemical formation of nitric acid via reactions of peroxy radicals, NOx and OH during the irradiation.

  16. Cardiovascular magnetic resonance in wet beriberi

    Directory of Open Access Journals (Sweden)

    Giri Shivraman


    Full Text Available Abstract The clinical presentation of beriberi can be quite varied. In the extreme form, profound cardiovascular involvement leads to circulatory collapse and death. This case report is of a 72 year-old male who was admitted to the Neurology inpatient ward with progressive bilateral lower extremity weakness and parasthesia. He subsequently developed pulmonary edema and high output cardiac failure requiring intubation and blood pressure support. With the constellation of peripheral neuropathy, encephalopathy, ophthalmoplegia, unexplained heart failure, and lactic acidosis, thiamine deficiency was suspected. He was empirically initiated on thiamine replacement therapy and his thiamine level pre-therapy was found to be 23 nmol/L (Normal: 80-150 nmol/L, consistent with the diagnosis of beriberi. Cardiovascular magnetic resonance (CMR showed severe left ventricular systolic dysfunction, markedly increased myocardial T2, and minimal late gadolinium enhancement (LGE. After 5 days of daily 100 mg IV thiamine and supportive care, the hypotension resolved and the patient was extubated and was released from the hospital 3 weeks later. Our case shows via CMR profound myocardial edema associated with wet beriberi.

  17. Metal--nanotube interactions -- wetting properties (United States)

    Zhu, Ruzeng; Cui, Shuwen


    The wetting properties of metal nanoparticles in large-diameter single Carbon nanotubes (LDSWNT) is studied by considering the size effect on surface tension of the metal cluster. For the case of macro-nonwetting, we get finite critical atom number N such that the metal cluster with any atom number smaller than it has contact angle π , and so it shrinks into a ball. For an experiential formula of the surface tension of cluster expressed by the number of atoms, we determine the parameters in it for Pd and Pt respectively by density functional theory (DFT). Taking a graphene sheet as a representative of LDSWNT and using the known data of the surface tensions of solid and liquid, we obtain solid-liquid interface tension through Berthelot rule. Based on these results, we obtain N=5 for Pd and N=6 for Pt. For cluster containing 13 Pd atoms and that containing 13 Pt atoms, we use the above mentioned experiential formula to obtain their contact angles in LDSWNT consistent with those shown by the pictures given by DFT (A Maiti and A Ricca, Chem Phys Letters 395 (2004) 7--11), and thus the validity of our method is proved. Project supported by the National Natural Science Foundation of China (Grant No.11072242).

  18. Curation of Samples from Mars (United States)

    Lindstrom, D.; Allen, C.

    One of the strong scientific reasons for returning samples from Mars is to search for evidence of current or past life in the samples. Because of the remote possibility that the samples may contain life forms that are hazardous to the terrestrial biosphere, the National Research Council has recommended that all samples returned from Mars be kept under strict biological containment until tests show that they can safely be released to other laboratories. It is possible that Mars samples may contain only scarce or subtle traces of life or prebiotic chemistry that could readily be overwhelmed by terrestrial contamination. Thus, the facilities used to contain, process, and analyze samples from Mars must have a combination of high-level biocontainment and organic / inorganic chemical cleanliness that is unprecedented. We have been conducting feasibility studies and developing designs for a facility that would be at least as capable as current maximum containment BSL-4 (BioSafety Level 4) laboratories, while simultaneously maintaining cleanliness levels exceeding those of the cleanest electronics manufacturing labs. Unique requirements for the processing of Mars samples have inspired a program to develop handling techniques that are much more precise and reliable than the approach (currently used for lunar samples) of employing gloved human hands in nitrogen-filled gloveboxes. Individual samples from Mars are expected to be much smaller than lunar samples, the total mass of samples returned by each mission being 0.5- 1 kg, compared with many tens of kg of lunar samples returned by each of the six Apollo missions. Smaller samp les require much more of the processing to be done under microscopic observation. In addition, the requirements for cleanliness and high-level containment would be difficult to satisfy while using traditional gloveboxes. JSC has constructed a laboratory to test concepts and technologies important to future sample curation. The Advanced Curation

  19. Emirates Mars Mission (EMM) Overview (United States)

    Sharaf, Omran; Amiri, Sarah; AlMheiri, Suhail; Alrais, Adnan; Wali, Mohammad; AlShamsi, Zakareyya; AlQasim, Ibrahim; AlHarmoodi, Khuloud; AlTeneiji, Nour; Almatroushi, Hessa; AlShamsi, Maryam; AlAwadhi, Mohsen; McGrath, Michael; Withnell, Pete; Ferrington, Nicolas; Reed, Heather; Landin, Brett; Ryan, Sean; Pramann, Brian


    United Arab Emirates (UAE) has entered the space exploration race with the announcement of Emirates Mars Mission (EMM), the first Arab Islamic mission to another planet, in 2014. Through this mission, UAE is to send an unmanned probe, called Hope probe, to be launched in summer 2020 and reach Mars by 2021 to coincide with UAE's 50th anniversary. Through a sequence of subsequent maneuvers, the spacecraft will enter a large science orbit that has a periapsis altitude of 20,000 km, an apoapsis altitude of 43,000 km, and an inclination of 25 degrees. The mission is designed to (1) characterize the state of the Martian lower atmosphere on global scales and its geographic, diurnal and seasonal variability, (2) correlate rates of thermal and photochemical atmospheric escape with conditions in the collisional Martian atmosphere, and (3) characterize the spatial structure and variability of key constituents in the Martian exosphere. These objectives will be met by four investigations with diurnal variability on sub-seasonal timescales which are (1) determining the three-dimensional thermal state of the lower atmosphere, (2) determining the geographic and diurnal distribution of key constituents in the lower atmosphere, (3) determining the abundance and spatial variability of key neutral species in the thermosphere, and (4) determining the three-dimensional structure and variability of key species in the exosphere. EMM will collect these information about the Mars atmospheric circulation and connections through a combination of three distinct instruments that image Mars in the visible, thermal infrared and ultraviolet wavelengths and they are the Emirates eXploration Imager (EXI), the Emirates Mars InfraRed Spectrometer (EMIRS), and the EMM Mars Ultraviolet Spectrometer (EMUS). EMM has passed its Mission Concept Review (MCR), System Requirements Review (SRR), System Design Review (SDR), and Preliminary Design Review (PDR) phases. The mission is led by Emiratis from Mohammed

  20. A Little Vacation on Mars: Mars Simulation Microbial Challenge Experiments (United States)

    Boston, P.; Todd, P.; Van De Camp, J.; Northup, D.; Spilde, M.


    Communities of microbial organisms isolated from a variety of extreme environments were subjected to 1 to 5 weeks of simulated Martian environmental conditions using the Mars Environment Simulation Chamber at the Techshot, Inc. facility in Greenville, Indiana. The goal of the overall experiment program was to assess survival of test Earth organisms under Mars full spectrum sunlight, low-latitude daily temperature profile and various Mars-atmosphere pressures (~50 mbar to 500 mbar, 100% CO2) and low moisture content. Organisms surviving after 5 weeks at 100 mbar included those from gypsum surface fracture communities in a Permian aged evaporite basin, desert varnish on andesite lavas around a manganese mine, and iron and manganese oxidizing organisms isolated from two caves in Mew Mexico. Phylogenetic DNA analysis revealed strains of cyanobacteria, bacterial genera (present in all surviving communities) Asticacaulis, Achromobacter, Comamonas, Pantoea, Verrucomicrobium, Bacillus, Gemmatimonas, Actinomyces, and others. At least one microcolonial fungal strain from a desert varnish community and at least one strain from Utah survived simulations. Strains related to the unusual cave bacterial group Bacteroidetes are present in survivor communities that resist isolation into pure culture implying that their consortial relationships may be critical to their survival.

  1. Wetting of silicone oil onto a cell-seeded substrate (United States)

    Lu, Yongjie; Chan, Yau Kei; Chao, Youchuang; Shum, Ho Cheung


    Wetting behavior of solid substrates in three-phase systems containing two immiscible liquids are widely studied. There exist many three-phase systems in biological environments, such as droplet-based microfluidics or tamponade of silicone oil for eye surgery. However, few studies focus on wetting behavior of biological surfaces with cells. Here we investigate wetting of silicone oil onto cell-seeded PMMA sheet immersed in water. Using a simple parallel-plate cell, we show the effect of cell density, viscosity of silicone oil, morphology of silicone oil drops and interfacial tension on the wetting phenomenon. The dynamics of wetting is also observed by squeezing silicone oil drop using two parallel plates. Experimental results are explained based on disjoining pressure which is dependent on the interaction of biological surfaces and liquid used. These findings are useful for explaining emulsification of silicone oil in ophthalmological applications.

  2. Using wet microalgae for direct biodiesel production via microwave irradiation. (United States)

    Cheng, Jun; Yu, Tao; Li, Tao; Zhou, Junhu; Cen, Kefa


    To address the large energy consumption of microalgae dewatering and to simplify the conventional two-step method (cellular lipid extraction and lipid transesterification) for biodiesel production, a novel process for the direct conversion of wet microalgae biomass into biodiesel by microwave irradiation is proposed. The influences of conventional thermal heating and microwave irradiation on biodiesel production from wet microalgae biomass were investigated. The effects of using the one-step (simultaneous lipid extraction and transesterification) and two-step methods were also studied. Approximately 77.5% of the wet microalgal cell walls were disrupted under microwave irradiation. The biodiesel production rate and yield from wet microalgae biomass obtained through the one-step process using microwave irradiation were 6-fold and 1.3-fold higher than those from wet microalgae obtained through the two-step process using conventional heating. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. Experimental and Theoretical Investigations of Wet Flue Gas Desulphurisation

    DEFF Research Database (Denmark)

    Kiil, Søren

    This thesis describes experimental and theoretical investigations of wet flue gas desulphurisa-tion (FGD). A review of the current knowledge of the various rate determining steps in wet FGD plants is presented. The experimental work covers laboratory studies as well as pilot- and full-scale...... was found to decrease the rate of gas phase mass transport with up to 15 %, though the effect could not be correlated.A detailed model for a wet FGD pilot plant, based on the falling film principle, was devel-oped. All important rate determining steps, absorption of SO2, oxidation of HSO3-, dissolution...... - 333 K, pertinent for full-scale wet FGD packed towers. The possibility of co-firing straw and coal was investigated in a full-scale power plant. No ef-fects on the overall performance of the wet FGD plant were observed, though laboratory ex-periments with fine dust and fly ash from the full-scale...

  4. Repeated bouncing of drops on wetting and non-wetting surfaces mediated by a persisting thin air film

    NARCIS (Netherlands)

    de Ruiter, J.; Lagraauw, R.; van den Ende, Henricus T.M.; Mugele, Friedrich Gunther


    Abstract Submitted for the DFD14 Meeting of The American Physical Society Repeated bouncing of drops on wetting and non-wetting sur- faces mediated by a persisting thin air lm JOLET DE RUITER, RUDY LAGRAAUW, DIRK VAN DEN ENDE, FRIEDER MUGELE, MESA+ Institute for Nanotechnology, University of Twente

  5. Quantification of wet-work exposure in nurses using a newly developed wet-work exposure monitor

    NARCIS (Netherlands)

    Visser, Maaike J.; Behroozy, Ali; Verberk, Maarten M.; Semple, Sean; Kezic, Sanja


    Occupational contact dermatitis (OCD) is an important work-related disease. A major cause of OCD is 'wet work': frequent contact of the skin with water, soap, detergents, or occlusive gloves. The German guidance TRGS 401 recommends that the duration of wet work (including use of occlusive gloves)

  6. Imaging of oil layers, curvature and contact angle in a mixed‐wet and a water‐wet carbonate rock

    National Research Council Canada - National Science Library

    Singh, Kamaljit; Bijeljic, Branko; Blunt, Martin J


    ...‐wet), whereas the untreated rock (without doped oil) was weakly water‐wet (θ=47 ± 9°). Using X‐ray micro‐tomography, we show that the brine displaces oil in larger pores during brine injection in the mixed...

  7. Radioresistant Bacteria Came From Mars? (United States)

    Pavlov, A.; Kalinin, V.; Konstantinov, A.; Shelegedin, V.

    We propose that the radioresistant bacteria (i.e. Deinococcus radiodurans) has been originated on Mars. This bacteria possesses an ability which should have been ab- solutely "unnecessary" in the Earth environment. It can survive very high doses of the ionizing radiation. Our experiments demonstrate that different kinds of non- radioresistant bacteria are able to develop very high radioresistance ability also. To develop radioresistance we exposed different bacterial cultures to several dozens of cycles of high irradiation. Therefore, radioresistance is not a result of some early spontaneous bacterial mutation but rather a consequence of the very specific plane- tary environment. Polar regions of Mars are the most probable (if not the only) place in the Solar System for such a periodical high-dosage irradiation process. We pro- pose a plausible scenario of where and when such an adaptation process could have taken place and also discuss indirect arguments of the Martian origin of Deinococcus Radiodurans based on their specific genetic structure.

  8. CCD-Based XRD/XRF for Determining Environmental Mineralogy on Mars (United States)

    Vaniman, D. T.; Bish, D. L.; Blake, D. F.; Chipera, S. J.


    Health effects from Martian dusts will be a concern for any manned Mars missions. Nuisance dusts plagued the Apollo astronauts, but dusts of more hazardous mineralogy, in habitats occupied by Mars astronauts weakened by a long-duration mission, may be more than a nuisance. Chemical hazards in Martian regolith attributable to S, Cl, Br, Cd, and Pb are known or strongly suspected to be present, but terrestrial studies of the health effects of dusts indicate that accurate determination of mineralogy is a critical factor in evaluating inhalation hazards. Mineral inhalation hazards such as the Group-I carcinogenic zeolite erionite, which is demonstrated to cause mesothelioma, cannot be identified by chemical analysis alone. Studies of palagonite analogs raise the possibility that erionite may occur on Mars. In addition to health effects concerns, environmental mineralogy has significant importance in resource extraction, groundwater use, and sustained agriculture. The high sulfur and chlorine content of Martian regolith will affect all of these uses, but the nature of mineralogic reservoirs for S and Cl will determine their uptake and concentration in extracted groundwater and in agricultural applications of regolith. Wet chemistry experiments planned for the Mars Environmental Compatibility Assessment (MECA) will define some of the consequences of water/soil interaction, but an understanding of the mineralogic basis for water-rock reactions is needed to understand the mechanisms of reaction and to apply the results of a few experiments to larger scales and different conditions.

  9. Efficacy of the Novel Medical Adhesive, MAR-VIVO-107, in an Acute Porcine Liver Resection Model. (United States)

    Tanaka, Hirokazu; Fukushima, Kenji; Srinivasan, Pramod Kadaba; Pawlowsky, Kerstin; Koegel, Babette; Hata, Koichiro; Ku, Yonson; Uemoto, Shinji; Tolba, René H


    Despite modern surgical techniques, insufficient hemostasis after liver trauma is still a major cause of morbidity and mortality after injury. Therefore, efficient hemostatic agents are indicated. In this study, we evaluated the hemostatic efficacy of a novel synthetic wound adhesive (MAR-VIVO-107) based on polyurethane/polyurea, compared with a widely used fibrin adhesive (Tisseel). Twelve German Landrace pigs were randomly assigned to 2 groups. The animals were operated under sterile conditions. A midline laparotomy was performed and the left liver lobe was isolated and resected, using a surgical scissor, in order to induce hepatic trauma. MAR-VIVO-107 or Tisseel was applied to the resected area. The animals were monitored for 60 minutes; thereafter, they were sacrificed under anesthesia. Blood and tissue samples were collected pre- and postresection for biochemical and hematological analyses. MAR-VIVO-107 versus Tisseel (mean ± SD, P value)-postsurgical survival rate was 100% in both groups. Bleeding time was significantly higher in Tisseel compared with MAR-VIVO-107 (10.3 ± 5.0 vs 3.7 ± 1.5 minutes, P = .0124). In trend, blood loss was less in the MAR-VIVO-107 group (54.3 ± 34.9 vs 105.5 ± 65.8 g, P = .222). Aspartate transaminase levels were significantly lower in the MAR-VIVO-107 group when compared with the Tisseel group (39.0 ± 10.0 vs 72.4 ± 23.4 U/L, P = .0459). The efficacy of MAR-VIVO-107 and comparable performance to the gold standard fibrin have been shown under pre-clinical conditions. MAR-VIVO-107 permits hemorrhage control within seconds, even in wet environment.

  10. The nitrogen cycle on Mars (United States)

    Mancinelli, Rocco L.


    Nirtogen is an essential element for the evolution of life, because it is found in a variety of biologically important molecules. Therefore, N is an important element to study from a exobiological perspective. In particular, fixed nitrogen is the biologically useful form of nitrogen. Fixed nitrogen is generally defines as NH3, NH4(+), NO(x), or N that is chemically bound to either inorganic or organic molecules, and releasable by hydrolysis to NH3 or NH4(+). On Earth, the vast majority of nitrogen exists as N2 in the atmosphere, and not in the fixes form. On early Mars the same situations probably existed. The partial pressure of N2 on early Mars was thought to be 18 mb, significantly less than that of Earth. Dinitrogen can be fixed abiotically by several mechanisms. These mechanisms include thernal shock from meteoritic infall and lightning, as well as the interaction of light and sand containing TiO2 which produces NH3 that would be rapidly destroyed by photolysis and reaction with OH radicals. These mechanisms could have been operative on primitive Mars.The chemical processes effecting these compounds and possible ways of fixing or burying N in the Martian environment are described. Data gathered in this laboratory suggest that the low abundance of nitrogen along (compared to primitive Earth) may not significantly deter the origin and early evolution of a nitrogen utilizing organisms. However, the conditions on current Mars with respect to nitrogen are quite different, and organisms may not be able to utilize all of the available nitrogen.

  11. Pirarucu: The Mars Moon Prospector (United States)


    Since neither Mars nor Phobos have a significant magnetic field, no magnetic torques are considered. Additionally, no atmospheric drag torques are...Phobos. Once the relative orbit around Phobos is acquired the mothership will perform remote observation of Phobos, as well as deploy the six 12U...reflectance factor which simplifies SRP torque calculations; 2) the mothership and CubeSats are at a constant distance from the sun for the duration

  12. Mars Gusts Blow Toward Spirit (United States)


    This movie clip shows several gusts and whirlwinds carrying dust as they move toward NASA's Mars Exploration Rover Spirit. It consists of frames taken by the navigation camera on Spirit during the afternoon of the rover's 501st martian day, or sol (May 31, 2005). The camera was facing into the wind. Contrast has been enhanced for anything in the images that changes from frame to frame, that is, for the dust moved by wind.

  13. Photovoltaic Cell Operation on Mars (United States)

    Landis, Geoffrey A.; Kerslake, Thomas; Jenkins, Phillip P.; Scheiman, David A.


    The Martian surface environment provides peculiar challenges for the operation of solar arrays: low temperature, solar flux with a significant scattered component that varies in intensity and spectrum with the amount of suspended atmospheric dust, and the possibility of performance loss due to dust deposition on the array surface. This paper presents theoretical analyses of solar cell performance on the surface of Mars and measurements of cells under Martian conditions.

  14. Undercooled water in basaltic regoliths and implications for fluidized debris flows on Mars (United States)

    Gooding, James L.


    Pursuant to the past attribution of many geomorphic features on Mars to the movements of water- or ice-lubricated debris, experiments have been conducted for water freezing in wet, sand-like basaltic substrates. It is found that substantial undercooling can be achieved under Martian conditions, independently of freezing-point depressions due to soluble salts. Attention is given to results for a clay-poor soil with negligible salinity from Mauna Kea, Hawaii, which demonstrate that the degree of undercooling is essentially independent of both soil particle size and water/soil mass ratio, albeit with cooling rate variations.

  15. Recent ice ages on Mars. (United States)

    Head, James W; Mustard, John F; Kreslavsky, Mikhail A; Milliken, Ralph E; Marchant, David R


    A key pacemaker of ice ages on the Earth is climatic forcing due to variations in planetary orbital parameters. Recent Mars exploration has revealed dusty, water-ice-rich mantling deposits that are layered, metres thick and latitude dependent, occurring in both hemispheres from mid-latitudes to the poles. Here we show evidence that these deposits formed during a geologically recent ice age that occurred from about 2.1 to 0.4 Myr ago. The deposits were emplaced symmetrically down to latitudes of approximately 30 degrees--equivalent to Saudi Arabia and the southern United States on the Earth--in response to the changing stability of water ice and dust during variations in obliquity (the angle between Mars' pole of rotation and the ecliptic plane) reaching 30-35 degrees. Mars is at present in an 'interglacial' period, and the ice-rich deposits are undergoing reworking, degradation and retreat in response to the current instability of near-surface ice. Unlike the Earth, martian ice ages are characterized by warmer polar climates and enhanced equatorward transport of atmospheric water and dust to produce widespread smooth deposits down to mid-latitudes.

  16. Wet melting along the Tonga Volcanic Arc (United States)

    Cooper, L. B.; Plank, T.; Arculus, R. J.; Hauri, E. H.; Hall, P.


    Melting in the mantle at convergent margins is driven by water from the subducting slab. Previous work has found a strong role for water-fluxed melting from correlations between the concentration of water in the mantle source, (H2O)o, and the extent of melting beneath backarcs, Fba. Here we explore how wet melting beneath the Lau Backarc Basin relates to that beneath the Tonga Arc, Farc, by providing the first systematic study of water contents in Tonga arc magmas. We have measured volatiles and major and trace elements in melt inclusions, glasses, and whole rocks obtained from recently sampled submarine and subaerial Tonga arc volcanoes. The compositions are varied and range mostly between andesite and basalt/boninite, and least-degassed water contents range from 2 to 5 wt%. We estimate (H2O)o and Farc independently by combining pressure (P) and temperature (T) estimates from an olivine-orthopyroxene-melt thermobarometer with a wet melting productivity model. When P, T, and (H2O)o are known, Farc is uniquely constrained. Results for the volcanoes in the Tonga Arc are bimodal with respect to T: volcanoes located near active backarc spreading centers reflect cooler melting (~1275°C) than those located far from active spreading centers (~1365°C). The cooler primary T’s may result from removal of the heat of fusion during prior melting beneath the Lau backarc, Fba. In the northern portion of the arc, the warmest primary T’s may be due to proximity to the Samoan mantle plume. Farc varies non-systematically along-strike, indicating that Fba is the primary driver of along-arc variability in primary melt compositions. Farc can also be used to calculate the TiO2 concentration of the arc mantle source, (TiO2)o (a proxy for source depletion), which varies monotonically along the Tonga Arc. Arc volcanoes adjacent to the Southern Lau Rifts and Valu Fa Ridge melt mantle with a fertile N-MORB TiO2, while those adjacent to the northern extent of the Eastern Lau Spreading

  17. Quantitative Morphometric Analysis of Terrestrial Glacial Valleys and the Application to Mars (United States)

    Allred, Kory

    Although the current climate on Mars is very cold and dry, it is generally accepted that the past environments on the planet were very different. Paleo-environments may have been warm and wet with oceans and rivers. And there is abundant evidence of water ice and glaciers on the surface as well. However, much of that comes from visual interpretation of imagery and other remote sensing data. For example, some of the characteristics that have been utilized to distinguish glacial forms are the presence of landscape features that appear similar to terrestrial glacial landforms, constraining surrounding topography, evidence of flow, orientation, elevation and valley shape. The main purpose of this dissertation is to develop a model that uses quantitative variables extracted from elevation data that can accurately categorize a valley basin as either glacial or non-glacial. The application of this model will limit the inherent subjectivity of image analysis by human interpretation. The model developed uses hypsometric attributes (elevation-area relationship), a newly defined variable similar to the equilibrium line altitude for an alpine glacier, and two neighborhood search functions intended to describe the valley cross-sectional curvature, all based on a digital elevation model (DEM) of a region. The classification model uses data-mining techniques trained on several terrestrial mountain ranges in varied geologic and geographic settings. It was applied to a select set of previously catalogued locations on Mars that resemble terrestrial glaciers. The results suggest that the landforms do have a glacial origin, thus supporting much of the previous research that has identified the glacial landforms. This implies that the paleo-environment of Mars was at least episodically cold and wet, probably during a period of increased planetary obliquity. Furthermore, the results of this research and the implications thereof add to the body of knowledge for the current and past

  18. Recent Basal Melting of a Mid-Latitude Glacier on Mars (United States)

    Butcher, Frances E. G.; Balme, M. R.; Gallagher, C.; Arnold, N. S.; Conway, S. J.; Hagermann, A.; Lewis, S. R.


    Evidence for past basal melting of young (late Amazonian-aged), debris-covered glaciers in Mars' mid-latitudes is extremely rare. Thus, it is widely thought that these viscous flow features (VFFs) have been perennially frozen to their beds. We identify an instance of recent, localized wet-based mid-latitude glaciation, evidenced by a candidate esker emerging from a VFF in a tectonic rift in Tempe Terra. Eskers are sedimentary ridges deposited in ice-walled meltwater conduits and are indicative of glacial melting. We compare the candidate esker to terrestrial analogues, present a geomorphic map of landforms in the rift, and develop a landsystem model to explain their formation. We propose that the candidate esker formed during a transient phase of wet-based glaciation. We then consider the similarity between the geologic setting of the new candidate esker and that of the only other candidate esker to be identified in association with an existing mid-latitude VFF; both are within tectonic graben/rifts proximal to volcanic provinces. Finally, we calculate potential basal temperatures for a range of VFF thicknesses, driving stresses, mean annual surface temperatures, and geothermal heat fluxes, which unlike previous studies, include the possible role of internal strain heating. Strain heating can form an important additional heat source, especially in flow convergence zones, or where ice is warmer due to elevated surface temperatures or geothermal heat flux. Elevated geothermal heat flux within rifts, perhaps combined with locally-elevated strain heating, may have permitted wet-based glaciation during the late Amazonian, when cold climates precluded more extensive wet-based glaciation on Mars.

  19. Concept Study For A Near-term Mars Surface Sample Return Mission (United States)

    Smith, M. F.; Thatcher, J.; Sallaberger, C.; Reedman, T.; Pillinger, C. T.; Sims, M. R.

    The return of samples from the surface of Mars is a challenging problem. Present mission planning is for complex missions to return large, focused samples sometime in the next decade. There is, however, much scientific merit in returning a small sample of Martian regolith before the end of this decade at a fraction of the cost of the more ambitious missions. This paper sets out the key elements of this concept that builds on the work of the Beagle 2 project and space robotics work in Canada. The paper will expand the science case for returning a regolith sample that is only in the range of 50-250g but would nevertheless include plenty of interesting mate- rial as the regolith comprises soil grains from a wide variety of locations i.e. nearby rocks, sedimentary formations and materials moved by fluids, winds and impacts. It is possible that a fine core sample could also be extracted and returned. The mission concept is to send a lander sized at around 130kg on the 2007 or 2009 opportunity, immediately collect the sample from the surface, launch it to Mars orbit, collect it by the lander parent craft and make an immediate Earth return. Return to Earth orbit is envisaged rather than direct Earth re-entry. The lander concept is essen- tially a twice-size Beagle 2 carrying the sample collection and return capsule loading equipment plus the ascent vehicle. The return capsule is envisaged as no more than 1kg. An overall description of the mission along with methods for sample acquisition, or- bital rendezvous and capsule return will be outlined and the overall systems budgets presented. To demonstrate the near term feasibility of the mission, the use of existing Canadian and European technologies will be highlighted.

  20. HEDS-UP Mars Exploration Forum (United States)

    Budden, Nancy Ann (Editor); Duke, Micheal B. (Editor)


    In the early 1990s, Duke and Budden convened a series of workshops addressing mission rationale, exploration objectives, and key constraints and issues facing human crews on Mars. The focal point was "why" the U.S. should fly humans to Mars. In the mid-1990s, strategies for a Mars mission matured and evolved, driven formally by NASA Johnson Space Center's Office of Exploration. In 1997, NASA published a report capturing the current thinking: the NASA Mars Reference Mission. In the 1997-1998 school year, HEDS-UP sponsored six universities to conduct design studies on Mars exploration, using the Reference Mission as a basis for their work. The 1998 Mars Exploration Forum presents the results of these university studies, suggesting "how" we might explore Mars, in terms of specific technical components that would enable human missions to Mars. A primary objective of the HEDS-UP Mars Exploration Forum was to provide a forum for active interaction among NASA, industry, and the university community on the subject of human missions to Mars. NASA scientists and engineers were asked to present the state of exploration for Mars mission options currently under study. This status "snapshot" of current Mars strategies set the stage for the six HEDS-UP universities to present their final design study results. Finally, a panel of industry experts discussed readiness for human missions to Mars as it pertains to the aerospace industries and technologies. A robust poster session provided the backdrop for government-industry-university discussions and allowed for feedback to NASA on the Mars Reference Mission. The common thread woven through the two days was discussion of technologies, proven and emerging, that will be required to launch, land, and sustain human crews on the Red Planet. As this decade (and indeed this millenium) draws to a close, Mars will continue to loom in our sights as the next target for human space exploration. It is our hope that the efforts of the Mars

  1. Flame Stabilization on Microscopic Scale of Wet Biogas with Microflame (United States)

    Ida, Tamio; Fuchihata, Manabu; Mizuno, Satoru

    Harvesting, transportation, energy conversion and the high-efficient utilization, cascade method and market formation besides become with the indispensable element in order to utilize the biomass resource. There are two type biogases; it is gasified gas from dried biomass by partially combustion and wet biogas from wet biomass by methane fermentation, especially from the livestock excrement resources. This paper discusses an experimental study for flame stabilization on microscopic scale with wet biogas (mainly 0.6CH4+0.4CO2). In this study, the microflame with the wet biogas fuels are formed by the diffusion flame on the coppered straight pipes of inner diameter 0.02mm ˜ 1.5mm. This study is obtained stability mapping on microscopic scale of formed microflame by wet biogas fuels. The flame stability limit conditions on microscopic scale of wet biogas is drawn with blow off and extinction flame double limit lines. It is suggested that minimum mixing spatial scale change by the each mixing ratio of the wet biogas.

  2. The Environment of Early Mars (United States)

    Matsubara, Yo


    A hydrologic routing model was applied to the Noachian cratered highlands to establish the climatic conditions required to maintain lakes and valley networks on early Mars. We used the ratio of precipitation and evaporation (the X-ratio) to express climatic conditions. Simulations were conducted using various X-ratios. The results from the lake analysis showed that many of the lakes that were not identified as overflowing probably overflowed as well. Because overflowing lakes can place constrain on possible climatic condition of early Mars, it is essential to identify as many overflowing craters as possible to understand the environment of early Mars. The multiple regression analyses indicate that incision depth is strongly influenced by gradient and weakly related to discharge. The factors determining incision depend partly on the type of channel bed. However, post-flow modification of the valleys precludes direct determination of bed morphology. We found through both lake and incision depth analysis that climatic conditions on early Mars were at least as moist as those that occurred in the Great Basin region during the Pleistocene (X ≤ 4). We also report on two studies motivated by the occurrence of sinuous paleochannels on Mars. Unconfined meanders require cohesive channel banks, which is obtained commonly by a vegetation cover coupled with high suspended sediment load. The Quinn River, Nevada is a sinuous channel that flows through lacustrine sediments resulting in the river having both bed and banks composed of sediment containing at least 40% mud. In addition, ion chromatography data and SEM images indicate the presence of high solute concentrations. In the absence of vegetation, bank cohesion is provided by mud with salts aiding flocculation and possibly providing additional cohesion through cementation. A 1D depth-averaged linearized meander evolution model was calibrated using the field data collected at the Quinn River. Both approaches gave similar

  3. Normal Fault Growth on Mars (United States)

    Morris, A. P.; Wyrick, D. Y.; Ferrill, D. A.


    Displacement versus length relationships of faults on Earth and Mars have been used to describe and interpret the evolution of faults and fault systems, infer differences in the relative strengths of strata, and evaluate variations in fault-system response to differences in gravity from planet to planet. In this presentation, we focus on maximum throw versus trace length (Dmax/L) of continuously mappable faults and Dmax/L of individual fault segments. Fault analyses on Mars have the advantage of a planetary surface devoid of vegetation and largely unaffected by weathering and erosion. Areas on the flanks of Alba Patera, Mars, were chosen because they are well imaged by all generations of data coverage, contain fault systems that have a range of developmental characteristics, and formed in a relatively simple tectonic setting dominated by extension. Footwall and hanging wall cutoff traces of more than 300 faults were interpreted using Viking imagery and ArcGIS software. Throw was obtained by calculating the elevation difference between adjacent footwall and hanging wall points using Mars Orbiter Laser Altimeter data. Throw versus along-strike trace length plots were constructed for each interpreted fault. Single fault segments are defined as having one well-defined displacement maximum bounded by two near-zero displacement minima. Segments within a multi-segment fault were identified by counting displacement maxima along the fault trace. The number of segments incorporated into multi-segment faults is positively correlated with the fault trace length. In a plot of Dmax versus L, whole faults are distributed approximately along a locus of Dmax = K × Ln, where K = 5 × 10-4 to 5 × 10-2 and n = 1. This is in agreement with previous studies of faults on Mars. Single fault segments form a distinct population whose distribution is described approximately by the same equation but where K = 1.7 × 10-3. Dmax/L ratios for multi-segment faults represent an apparently self

  4. Magnetic Storms at Mars and Earth

    DEFF Research Database (Denmark)

    Vennerstrøm, Susanne; Falkenberg, Thea Vilstrup

    In analogy with magnetic storms at the Earth, periods of significantly enhanced global magnetic activity also exist at Mars. The extensive database of magnetic measurements from Mars Global Surveyor (MGS), covering almost an entire solar cycle, is used in combination with geomagnetic activity...... indices at Earth to compare the occurrence of magnetic storms at Mars and Earth. Based on superposed epochs analysis the time-development of typical magnetic storms at Mars and Earth is described. In contradiction to storms at Earth, most magnetic storms at Mars are found to be associated...... with heliospheric current sheet crossings, where the IMF changes polarity. While most storms at the Earth occur due to significant southward excursions of the IMF associated with CMEs, at Mars most storms seem to be associated with the density enhancement of the heliospheric current sheet. Density enhancements...

  5. Human Mars Surface Mission Nuclear Power Considerations (United States)

    Rucker, Michelle A.


    A key decision facing Mars mission designers is how to power a crewed surface field station. Unlike the solar-powered Mars Exploration Rovers (MER) that could retreat to a very low power state during a Martian dust storm, human Mars surface missions are estimated to need at least 15 kilowatts of electrical (kWe) power simply to maintain critical life support and spacecraft functions. 'Hotel' loads alone for a pressurized crew rover approach two kWe; driving requires another five kWe-well beyond what the Curiosity rover’s Radioisotope Power System (RPS) was designed to deliver. Full operation of a four-crew Mars field station is estimated at about 40 kWe. Clearly, a crewed Mars field station will require a substantial and reliable power source, beyond the scale of robotic mission experience. This paper explores the applications for both fission and RPS nuclear options for Mars.

  6. Effects of a CME on Mars

    DEFF Research Database (Denmark)

    Falkenberg, Thea Vilstrup; Vennerstrøm, Susanne; Brain, D.

    We investigate the effects of a Coronal Mass Ejection (CME) on Mars. The magnetic field in the magnetic pileup region on Mars is dominated by the dynamic pressure from the solar as increased dynamic pressure compresses the magnetic pileup region causing a larger magnetic pressure, until...... this balances the solar wind pressure. As the dynamic pressure is severely increased during a CME, so is the magnetic pressure. A CME are also typically connected to a Solar Energetic Particle (SEP) event, causing large amounts of radiation. When the shock front of a CME arrives at Mars strong signals are seen...... in both the magnetic field data and in the radiation data. Based on Mars Global Surveyor (MGS) Magnetometer (MAG) and Electron Reflectometer (ER) data we study the radiation and magnetic field variations on Mars during a CME event. We also compare the effects on Mars to the effects on Earth for the same...

  7. Strategies to Support Exploration of Mars' Surface (United States)

    Kirkland, L.; Sykes, M.; Farr, T.; Adams, J.; Blaney, D.


    Surface Visible infrared spectroscopy has a long history of providing fundamental compositional discoveries in the solar system. However, we are entering a new era of Mars exploration in which missions will take place nearly every 2 years.The visible infrared spectral community thus faces a more rapid influx in data volume and variety than it has previously handled.Visible- infrared instruments are on the 1996 Mars Global Surveyor, 2001 Mars Odyssey 2003 Mars Exploration Rovers, 2003 Mars Express, 2005 Mars Reconnaissance Orbiter; and likely on the 2007 and 2009 missions. Interpretations of those data sets provide a critical foundation for geologic and climatic interpretations as well as an opportunity to select landing sites.

  8. Landscapes of Mars A Visual Tour

    CERN Document Server

    Vogt, Gregory L


    Landscapes of Mars is essentially a picture book that provides a visual tour of Mars. All the major regions and topographical features will be shown and supplemented with chapter introductions and extended captions. In a way, think of it as a visual tourist guide. Other topics covered are Martian uplands on the order of the elevation of Mt. Everest, Giant volcanoes and a rift system, the Grand Canyon of Mars, craters and the absence of craters over large regions (erosion), and wind shadows around craters, sand dunes, and dust devils. The book includes discussions on the search for water (braided channels, seepage, sedimentary layering, etc.) as well as on the Viking mission search for life, Mars meteorite fossil bacteria controversy, and planetary protection in future missions. The book concludes with an exciting gallery of the best 3D images of Mars making the book a perfect tool for understanding Mars and its place in the solar system.

  9. Mars' surface radiation environment measured with the Mars science laboratory's curiosity rover

    National Research Council Canada - National Science Library

    Hassler, D.M; Zeitlin, C; Wimmer-Schweingruber, R.F; Ehresmann, B; Rafkin, S; Eigenbrode, J.L; Brinza, D.E; Weigle, G; Böttcher, S; Böhm, E; Burmeister, S; Guo, J; Köhler, J; Martin, C; Reitz, G; Cucinotta, F.A; Kim, M.-H; Grinspoon, D; Bullock, M.A; Posner, A; Gómez-Elvira, J; Vasavada, A; Grotzinger, J.P; MSL Science Team, the|info:eu-repo/dai/nl/292012217


    The Radiation Assessment Detector (RAD) on the Mars Science Laboratory’s Curiosity rover began making detailed measurements of the cosmic ray and energetic particle radiation environment on the surface of Mars on 7 August 2012...


    National Aeronautics and Space Administration — Mars Pathfinder bounced down and rolled to a stop on the surface of Mars on July 4, 1997. It landed in an ancient floodplain in the Ares Vallis region of Chryse...

  11. Mars Ascent Vehicle Gross Lift-off Mass Sensitivities for Robotic Mars Sample Return (United States)

    Dux, Ian J.; Huwaldt, Joseph A.; McKamey, R. Steve; Dankanich, John W.


    The Mars ascent vehicle is a critical element of the robotic Mars Sample Return (MSR) mission. The Mars ascent vehicle must be developed to survive a variety of conditions including the trans-Mars journey, descent through the Martian atmosphere and the harsh Martian surface environments while maintaining the ability to deliver its payload to a low Mars orbit. The primary technology challenge of developing the Mars ascent vehicle system is designing for all conditions while ensuring the mass limitations of the entry descent and landing system are not exceeded. The NASA In-Space Propulsion technology project has initiated the development of Mars ascent vehicle technologies with propulsion system performance and launch environments yet to be defined. To support the project s evaluation and development of various technology options the sensitivity of the Mars ascent vehicle gross lift-off mass to engine performance, inert mass, target orbits, and launch conditions has been completed with the results presented herein.

  12. Utah Marbles and Mars Blueberries: Comparitive Terrestrial Analogs for Hematite Concretions on Mars (United States)

    Chan, M. A.; Beitler, B.; Parry, W. T.; Ormö, J.; Komatsu, G.


    Compelling comparisons show why Utah iron oxide-cemented "marbles" are a good analog for Mars hematite "blueberries". Terrestrial examples offer valuable models for interpreting the diagenetic history and importance of water on Mars.

  13. High Spatial Resolution Visible Color Units on Mars from the Mars Odyssey THEMIS/VIS Instrument (United States)

    Bell, J. F., III; McConnochie, T.; Savransky, D.; Stiglitz, B.; Wolff, M. J.; Christensen, P. R.; Mehall, G.; James, P. B.; Malin, M.; Caplinger, M.; Ravine, M.; Cherednik, L. L.; Bender, K. C.; Murray, K.; Themis Science Team


    This presentation describes the calibration and new results from the Mars Odyssey THEMIS/VIS instrument, which is obtaining five-color visible wavelength images from Mars orbit at scales of 18 72 m/pixel.

  14. Partial wetting gas-liquid segmented flow microreactor. (United States)

    Kazemi Oskooei, S Ali; Sinton, David


    A microfluidic reactor strategy for reducing plug-to-plug transport in gas-liquid segmented flow microfluidic reactors is presented. The segmented flow is generated in a wetting portion of the chip that transitions downstream to a partially wetting reaction channel that serves to disconnect the liquid plugs. The resulting residence time distributions show little dependence on channel length, and over 60% narrowing in residence time distribution as compared to an otherwise similar reactor. This partial wetting strategy mitigates a central limitation (plug-to-plug dispersion) while preserving the many attractive features of gas-liquid segmented flow reactors.

  15. Wet combing for the eradication of head lice. (United States)


    Manual removal (using conditioner and comb or a wet comb) can be used in the treatment of head lice. Head lice infestation (Pediculosis humanus capitis) is a common problem. It is diagnosed by visualising the lice. As half of people infested with head lice will not scratch, all people in contact with a person affected with head lice should be manually checked for infestations. Wet combing is easily and safely performed at home, but persistence is needed. This article describes the process of head lice removal using a wet comb. It has NHMRC Level 2 evidence of efficacy and no serious adverse effects have been reported.

  16. Modelling of wetting tests for a natural pyroclastic soil

    Directory of Open Access Journals (Sweden)

    Moscariello Mariagiovanna


    Full Text Available The so-called wetting-induced collapse is one of the most common problems associated with unsaturated soils. This paper applies the Modified Pastor-Zienkiewicz model (MPZ to analyse the wetting behaviour of undisturbed specimens of an unsaturated air-fall volcanic (pyroclastic soil originated from the explosive activity of the Somma-Vesuvius volcano (Southern Italy. Both standard oedometric tests, suction-controlled oedometeric tests and suction-controlled isotropic tests are considered. The results of the constitutive modelling show a satisfactory capability of the MPZ to simulate the variations of soil void ratio upon wetting, with negligible differences among the measured and the computed values.

  17. Mars Ascent Vehicle Design for Human Exploration (United States)

    Polsgrove, Tara; Thomas, Dan; Sutherlin, Steven; Stephens, Walter; Rucker, Michelle


    In NASA's evolvable Mars campaign, transportation architectures for human missions to Mars rely on a combination of solar electric propulsion and chemical propulsion systems. Minimizing the Mars ascent vehicle (MAV) mass is critical in reducing the overall lander mass and also eases the requirements placed on the transportation stages. This paper presents the results of a conceptual design study to obtain a minimal MAV configuration, including subsystem designs and mass summaries.

  18. Nuclear technologies for Moon and Mars exploration

    Energy Technology Data Exchange (ETDEWEB)

    Buden, D.


    Nuclear technologies are essential to successful Moon and Mars exploration and settlements. Applications can take the form of nuclear propulsion for transport of crews and cargo to Mars and the Moon; surface power for habitats and base power; power for human spacecraft to Mars; shielding and life science understanding for protection against natural solar and cosmic radiations; radioisotopes for sterilization, medicine, testing, and power; and resources for the benefits of Earth. 5 refs., 9 figs., 3 tabs.

  19. Wet gas compression. Experimental investigation of the aerodynamics within a centrifugal compressor exposed to wet gas

    Energy Technology Data Exchange (ETDEWEB)

    Gruener, Trond Gammelsaeter


    The demand for more efficient oil and gas production requires improved technology to increase production rates and enhance profitable operation. The centrifugal compressor is the key elements in the compression system. Preliminary studies of wet gas compressor concepts have demonstrated the benefits of wet gas boosting. An open-loop test facility was designed for single-stage wet gas compressor testing. Experimental investigators have been performed to reveal the impact of liquid on the aerodynamics of centrifugal compressor. The investigation consisted of two test campaigns with different impeller/diffuser configurations. Atmospheric air and water were used as experimental fluids. The two configurations showed a different pressure ratio characteristics when liquid as present. The results from test campaign A demonstrated a pronounced pressure ratio decrease at high flow and a minor pressure ration increase pressure ratio with reducing gas mass fraction (GMF). The deviation in pressure ratio characteristic for the two test campaigns was attributed to the volute operating characteristic. Both impeller/diffuser configurations demonstrated a reduction in maximum volume flow with decreasing GMF. The impeller pressure ratio was related to the diffuser and/or the volute performance). Air and water are preferable experimental fluids for safety reasons and because a less extensive facility design is required. An evaluation of the air/water tests versus hydrocarbon tests was performed in order to reveal whether the results were representative. Air/water tests at atmospheric conditions reproduced the general performance trend of hydrocarbon wet gas compressor tests with an analogous impeller at high pressures. Aerodynamic instability limits the operating range because of feasible severe damage of the compressor and adverse influence on the performance. It is essential to establish the surge margin at different operating conditions. A delayed instability inception was

  20. Choosing Mars-Time: Analysis of the Mars Exploration Rover Experience (United States)

    Bass, Deborah S.; Wales,Roxana C.; Shalin, Valerie L.


    This paper focuses on the Mars Exploration Rover (MER) mission decision to work on Mars Time and the implications of that decision on the tactical surface operations process as personnel planned activities and created a new command load for work on each Martian sol. The paper also looks at tools that supported the complexities of Mars Time work, and makes some comparisons between Earth and Mars time scheduling.

  1. Human Mars Ascent Configuration and Design Sensitivities (United States)

    Polsgrove, Tara P.; Gernhardt, Mike; Collins, Tim; Martin, John


    Human missions to Mars may utilize several small cabins where crew members could live for days up to a couple of weeks. At the end of a Mars surface mission the Mars Ascent Vehicle (MAV) crew cabin would carry the crew to their destination in orbit in a matter of hours or days. Other small cabins in support of a Mars mission would include pressurized rovers that allow crew members to travel great distances from their primary habitat on Mars while unconstrained by time limits of typical EVAs. An orbital crew taxi could allow for exploration of the moons of Mars with minimum impact to the primary Earth-Mars transportation systems. A common crew cabin design that can perform in each of these applications is desired and could reduce the overall mission cost. However, for the MAV, the crew cabin size and mass can have a large impact on vehicle design and performance. The total ascent vehicle mass drives performance requirements for the Mars descent systems and the Earth to Mars transportation elements. Minimizing MAV mass is a priority and minimizing the crew cabin size and mass is one way to do that. This paper explores the benefits and impacts of using a common crew cabin design for the MAV. Results of a MAV configuration trade study will be presented along with mass and performance estimates for the selected design.

  2. The cool and distant formation of Mars (United States)

    Brasser, R.; Mojzsis, S. J.; Matsumura, S.; Ida, S.


    With approximately one ninth of Earth's mass, Mars is widely considered to be a stranded planetary embryo that never became a fully-grown planet. A currently popular planet formation theory predicts that Mars formed near Earth and Venus and was subsequently scattered outwards to its present location. In such a scenario, the compositions of the three planets are expected to be similar to each other. However, bulk elemental and isotopic data for martian meteorites demonstrate that key aspects of Mars' composition are markedly different from that of Earth. This suggests that Mars formed outside of the terrestrial feeding zone during primary accretion. It is therefore probable that Mars always remained significantly farther from the Sun than Earth; its growth was stunted early and its mass remained relatively low. Here we identify a potential dynamical pathway that forms Mars in the asteroid belt and keeps it outside of Earth's accretion zone while at the same time accounting for strict age and compositional constraints, as well as mass differences. Our uncommon pathway (approximately 2% probability) is based on the Grand Tack scenario of terrestrial planet formation, in which the radial migration by Jupiter gravitationally sculpts the planetesimal disc at Mars' current location. We conclude that Mars' formation requires a specific dynamical pathway, while this is less valid for Earth and Venus. We further predict that Mars' volatile budget is most likely different from Earth's and that Venus formed close enough to our planet that it is expected to have a nearly identical composition from common building blocks.

  3. Optimal parking orbits for manned Mars missions (United States)

    Cupples, Michael L.; Nordwall, Jill A.

    This paper summarizes a Mars parking orbit optimization effort. This parking orbit study includes the selection of optimal elliptic Mars parking orbits that meet mission constraints and that include pertinent apsidal misalignment losses. Mars missions examined are for the opportunity years of 2014, 2016, and 2018. For these mission opportunities, it is shown that the optimal parking orbits depend on the year that the mission occurs and are coupled with the outbound, Mars stay, and return phases of the mission. Constraints included in the parking orbit optimization process are periapsis lighting angle (related to a daylight landing requirement), periapsis latitude (related to a landing latitude range requirement) and the vehicle Trans-Earth-Injection stage mass. Also, effects of mission abort requirements on optimal parking orbits are investigated. Off-periapsis maneuvers for Mars orbit capture were found to be cost effective in reducing the mission delta-V for the 2016 abort from Mars capture scenario. The total capture and departure delta-V was `split' between the capture maneuver and the departure maneuver to reduce the 2016 Mars departure delta-V to below the level of the corresponding stage of the 2014 baseline mission. Landing results are provided that show Mars landing site access from the optimal elliptic parking orbits for Mars excursion vehicles with low (0.2) and high (1.3 and 1.6) lift to drag ratio.

  4. Solvent content and dentin bond strengths using water-wet, ethanol-wet and deproteinization bonding techniques. (United States)

    Faria-e-Silva, André Luis; Araújo, José Everton; Rocha, Gilliane Pereira; de Oliveira, Aline da Silva; de Moraes, Rafael Ratto


    To evaluate the impact of solvent content in two-step, etch-and-rinse adhesives on the dentin bond strengths obtained via water-wet, ethanol-wet or deproteinization techniques. A model photocurable Bis-GMA/HEMA blend was diluted in ethanol (7.5, 15 or 30 mass%) or acetone (15, 30 or 60 mass%) (low, medium or high solvent content, respectively). Viscosity of the solutions was measured with an oscillatory viscometer and data analyzed using ANOVA on Ranks (5%). Dentin bond strengths were evaluated using microshear bond test. After acid-etching and rinsing, the dentin was kept wet (water-wet), treated with ascending ethanol concentrations (ethanol-wet) or with 10% NaOCl solution (deproteinization). Composite cylinders built-up on the surfaces for the microshear test. Data from each bonding technique were submitted to two-way ANOVA and Fisher's LSD method (5%). Failure modes were classified under magnification and data analyzed using chi-square tests (5%). Viscosity of ethanol-based agents was remarkably higher than acetone solutions. For the water-wet technique, lower bond strength was observed for the low compared with medium and high ethanol contents. For the ethanol-wet technique, the bond strength for both solvents types was low dentin bond strengths for the conventional and ethanol bonding techniques.

  5. Ionospheric Electron Densities at Mars: Comparison of Mars Express Ionospheric Sounding and MAVEN Local Measurement

    Czech Academy of Sciences Publication Activity Database

    Němec, F.; Morgan, D. D.; Fowler, C.M.; Kopf, A.J.; Andersson, L.; Gurnett, D. A.; Andrews, D.J.; Truhlík, Vladimír

    in press (2017) E-ISSN 2169-9402 Institutional support: RVO:68378289 Keywords : Mars * ionosphere * MARS IS * Mars Express * MAVEN * radar sounding Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics

  6. The Influence of Mineralogy on Recovering Organic Acids from Mars Analogue Materials Using the One-Pot Derivatization Experiment on the Sample Analysis at Mars(SAM) Instrument Suite (United States)

    Stalport, Fabien; Glavin, Daniel P.; Eigenbrode, J. L.; Bish, D.; Blake, D.; Coll, P.; Szopa, C.; Buch, A.; McAdam, A.; Dworkin, J. P.; hide


    The search for complex organic molecules on Mars, including important biomolecules such as amino acids and carboxylic acids, will require a chemical extraction and a derivatization step to transform these organic compounds into species that are sufficiently volatile to be detected by gas chromatography mass spectrometry (GCMS). We have developed a ''one-pot'' extraction and chemical derivatization protocol using N-methyl-N-(tert-butyldimethylsilyl) trifluoroacetamide (MTBSTFA) and dimethylformamide (DMF) for the Sample Analysis at Mars (SAM) experiment instrument suite on NASA's the Mars Science Laboratory (MSL) mission. The temperature and duration of the derivatization reaction, pre-concentration of chemical derivatives, and gas chromatographic separation parameters have been optimized under SAM instrument design constraints. MTBSTFA/DMF extraction and derivatization at 300 1C for several minutes of a variety of terrestrial Mars analog materials facilitated the detection of amino acids and carboxylic acids in a surface soil sample collected from the Atacama Desert and a carbonate-rich stromatolite sample from Svalbard. However, the rapid reaction of MTBSTFA with water in several analog materials that contained high abundances of hydrated minerals, and the possible deactivation of derivatized compounds by iron oxides, as detected by XRD/XRF using the CheMin field unit Terra, proved to be highly problematic for the direct extraction of organics using MTBSTFA. The combination of pyrolysis and two different wet-chemical derivatization methods employed by SAM should enable a wide range of organic compounds to be detected by GCMS if present on Mars.

  7. The Investigation of Chlorates as a Possible Source of Oxygen and Chlorine Detected by the Sample Analysis at Mars (SAM) Instrument in Gale Crater, Mars (United States)

    Sutter, B.; Archer, D. P.; Ming, D. W.; Niles, P. B.; Eigenbrode, J. L.; Franz, H.; Glavin, D. P.; McAdam, A. C.; Mahaffy, P; Stern, J. C.; hide


    The Sample Analysis at Mars (SAM) instrument onboard the Curiosity rover detect-ed O2 and HCl gas releases from the Rocknest (RN) eolian bedform and the John Klein (JK) and Cumberland (CB) drill hole materials in Gale Crater. Chlorinated hydrocarbons have also been detected by the SAM quadrupole mass spectrometer (QMS) and gas chromatography/mass spectrometer (GCMS). These detections along with the detection of perchlorate (ClO4-) by the Mars Phoenix Lander’s Wet Chemistry Laboratory (WCL) suggesting perchlorate is a possible candidate for evolved O2 and chlorine species. Laboratory thermal analysis of perchlorates has yet to provide an unequivocal temperature match to the SAM O2 and HCl release data. Iron mineralogy found in the Rocknest materials when mixed with Ca-perchlorate does cause O2 release temperatures to be closer match to the SAM O2 release data but more work is required in evaluating the catalytic effects of Fe mineralogy on perchlorate decomposition. Chlorates (ClO3-) are relevant Mars materials and potential O2 and Cl sources. The objective of this work is to evaluate the thermal decomposition of select chlorate (ClO3-) salts as possible sources of the O2 and HCl releases in the Gale Crater materials.

  8. SAFARI 2000 PAR Measurements, Kalahari Transect, Botswana, Wet Season 2000 (United States)

    National Aeronautics and Space Administration — ABSTRACT: Ceptometer data from a Decagon AccuPAR (Model PAR-80) were collected at four sites in Botswana during the SAFARI 2000 Kalahari Transect Wet Season Campaign...

  9. SAFARI 2000 PAR Measurements, Kalahari Transect, Botswana, Wet Season 2000 (United States)

    National Aeronautics and Space Administration — Ceptometer data from a Decagon AccuPAR (Model PAR-80) were collected at four sites in Botswana during the SAFARI 2000 Kalahari Transect Wet Season Campaign (March,...

  10. Advanced Wet Tantalum Capacitors: Design, Specifications and Performance (United States)

    Teverovsky, Alexander


    Insertion of new types of commercial, high volumetric efficiency wet tantalum capacitors in space systems requires reassessment of the existing quality assurance approaches that have been developed for capacitors manufactured to MIL-PRF-39006 requirements. The specifics of wet electrolytic capacitors is that leakage currents flowing through electrolyte can cause gas generation resulting in building up of internal gas pressure and rupture of the case. The risk associated with excessive leakage currents and increased pressure is greater for high value advanced wet tantalum capacitors, but it has not been properly evaluated yet. This presentation gives a review of specifics of the design, performance, and potential reliability risks associated with advanced wet tantalum capacitors. Problems related to setting adequate requirements for DPA, leakage currents, hermeticity, stability at low and high temperatures, ripple currents for parts operating in vacuum, and random vibration testing are discussed. Recommendations for screening and qualification to reduce risks of failures have been suggested.

  11. Bioaccumulation of heavy metals in two wet retention ponds

    DEFF Research Database (Denmark)

    Søberg, Laila C.; Vollertsen, Jes; Blecken, Godecke-Tobias


    Metal accumulation in stormwater ponds may contaminate the inhabiting fauna, thus jeopardizing their ecosystem servicing function. We evaluated bioaccumulation of metals in natural fauna and caged mussel indicator organisms in two wet retention ponds. Mussel cages were distributed throughout...

  12. ROE Wet Sulfate Deposition Raster 1989-1991 (United States)

    U.S. Environmental Protection Agency — The raster data represent the amount of wet sulfate deposition in kilograms per hectare from 1989 to 1991. Summary data in this indicator were provided by EPA’s...

  13. In silico and wet lab approaches to study transcriptional regulation

    NARCIS (Netherlands)

    Hestand, Matthew Scott


    Gene expression is a complicated process with multiple types of regulation, including binding of proteins termed transcription factors. This thesis looks at transcription factors and transcription factor binding site discovery through computational predictions and wet lab work to better elucidate

  14. Wet-aerosol leakage through simulated containment leak paths

    Energy Technology Data Exchange (ETDEWEB)

    Sutradhar, S.C. [Atomic Energy of Canada Limited, Chalk River, Ontario (Canada)


    Some types of postulated accidents in a nuclear reactor can result in the formation of radioactive wet aerosols in containment and their subsequent release into the environment. Wet-aerosol leakage was investigated using simulated leak paths for isolation damper valves and airlock door seals. Leakage was calculated from measured uranine concentrations deposited on high-quality filters positioned downstream of the simulated leak paths. Test results indicated that a small fraction of wet aerosols leaked through the simulated isolation damper valves, whereas a large fraction leaked through the simulated airlock door seals. Data on wet-aerosol leakage through containment leak paths are needed to develop and validate models in safety analysis codes. (author)

  15. Combined wet oxidation and alkaline hydrolysis of polyvinylchloride

    DEFF Research Database (Denmark)

    Sørensen, E.; Bjerre, A.B.


    In view of the widespread aversion to burning polyvinylchloride (PVC) together with municipal waste, we have attempted an alternative approach to its decomposition. This paper describes a combined wet oxidation/alkaline hydrolysis yielding water soluble, biodegradable products. Experiments were...

  16. Simulations of tropical rainforest albedo: is canopy wetness important?

    National Research Council Canada - National Science Library

    Silvia N.M. Yanagi; Marcos H. Costa


    .... Therefore, it was investigated the role of canopy wetness on the simulated albedo of a tropical rainforest by modifying the IBIS canopy radiation transfer code to incorporate the effects of canopy...

  17. The Forensic and Legal Implications of Water, Wet, or Fry

    National Research Council Canada - National Science Library

    Susan M. Chlebowski; Cecilia Leonard


    ...), has several names, such as water, wet, illy, and fry. Individuals who commit crimes under the influence of this substance are often violent and may appear psychotic, with symptoms resembling schizophrenia or delirium...

  18. Characterization of silver nanoparticles prepared by wet chemical ...

    African Journals Online (AJOL)

    Characterization of silver nanoparticles prepared by wet chemical method and their antibacterial and cytotoxicity activities. Manal A Awad, Awatif A Hendi, Khalid MO Ortashi, Reem A Alotaibi, Maha Sh Sharafeldin ...

  19. Regulated wet nursing: managed care or organized crime?

    National Research Council Canada - National Science Library

    Obladen, Michael


    .... When artificial feeding lost its threat thanks to sewage disposal, improved plumbing, the introduction of rubber teats, cooling facilities and commercial formula, wet nursing declined towards the end of the 19th century.

  20. Wet cooling towers: rule-of-thumb design and simulation

    Energy Technology Data Exchange (ETDEWEB)

    Leeper, Stephen A. [EG and G Idaho, Inc., Idaho Falls, ID (United States)


    A survey of wet cooling tower literature was performed to develop a simplified method of cooling tower design and simulation for use in power plant cycle optimization. The theory of heat exchange in wet cooling towers is briefly summarized. The Merkel equation (the fundamental equation of heat transfer in wet cooling towers) is presented and discussed. The cooling tower fill constant (Ka) is defined and values derived. A rule-of-thumb method for the optimized design of cooling towers is presented. The rule-of-thumb design method provides information useful in power plant cycle optimization, including tower dimensions, water consumption rate, exit air temperature, power requirements and construction cost. In addition, a method for simulation of cooling tower performance at various operating conditions is presented. This information is also useful in power plant cycle evaluation. Using the information presented, it will be possible to incorporate wet cooling tower design and simulation into a procedure to evaluate and optimize power plant cycles.

  1. SAFARI 2000 Leaf Spectral Measurements, Kalahari Transect, Wet Season 2000 (United States)

    National Aeronautics and Space Administration — ABSTRACT: The Boston University team collected several data sets along the Kalahari Transect during the SAFARI 2000 wet season field campaign between March 3 and...

  2. SAFARI 2000 Leaf Spectral Measurements, Kalahari Transect, Wet Season 2000 (United States)

    National Aeronautics and Space Administration — The Boston University team collected several data sets along the Kalahari Transect during the SAFARI 2000 wet season field campaign between March 3 and March 18,...

  3. Advance of Wetting Front in Silt Loam Soil

    Directory of Open Access Journals (Sweden)

    Mohamed Mahmood


    Full Text Available Under drip irrigation , the plant's root is concentrated inside the wetted bulb (region. Thus, the development of these roots and the plant production are greatly affected by the wetting pattern. Therefore, the wetting pattern of soil under drip irrigation must be taken into consideration in the design of drip irrigation system for both single dripping source or multi-overlapping wetting patterns of dripping water sources.2The aim of this study is to evaluate the effect of initial water content of the soil and spacing between two adjacent dripping sources with different flow rate on the movement of the wetting front.This study included 16 tests for monitoring the advancement of the wetting front with time during and after the water application phase. The water advance and water distribution measurement are carried out for two cases of the soil profile: for the first case with initial volumetric water content of 4.08% and for the second case with initial volumetric water content of 12.24%. Two spacing between the emitter were tested 25cm and 50 cm using application flow rates of 0.606, 1.212, 1.818, and 2.424 cm3 /min/cm to show the combined effect of spacing and flow rate on the performance of two adjacent emitter.The study proposed a method for determining the spacing between the two emitting sources , the water application rate and watering time. The proposed method depends on a wetted zone whose depth is equal to the root zone depth with a values equals to the maximum vertical advance of the wetting front underneath the drip line at time when this depth is equal to the depth of wetting at mid­point between the drip line. the study revealed that both the vertical water advance in soil underneath the emitter and the horizontal advance of the wetting front is larger than those in the case of single emitter.Furthermore, the vertical water advance increases with the decrease spacing between the two drip lines. Also, the horizontal advance of the

  4. Landfill Mining - Wet mechanical treatment of fine MSW with a wet jigger. (United States)

    Wanka, Sebastian; Münnich, Kai; Fricke, Klaus


    The motives for landfill mining are various. In the last couple of years Enhanced Landfill Mining (ELFM) has become increasingly important in academic discourse and practical implementation. The main goal of ELFM is to recover as much material as possible from deposited municipal solid waste (MSW). In most of the projects carried out so far, the main focus has been set on coarse materials such as plastics, woods, papers and metals. These fractions can be separated easily by sieving in combination with magnetic separation. In these projects most of the fine materials, which might represent as much as 60-70% of the total mass of the landfill body, had to be deposited again. A further treatment aiming at reducing the masses of these fine materials, which are still a conglomerate of soil, calorific fractions, metals, minerals and residues, usually did not take place. One topic in the framework of the landfill mining project TÖNSLM, in addition to the separation of the calorific fraction and metals has been the treatment of fine materials with the goal to re-use these e.g. for construction purposes. This paper shows the results obtained after the wet mechanical treatment of fine MSW 10-60mm with a wet jigger. The physical principle of this process is the separation of the mass flux due to the different densities of the waste constituents. As a result, three main waste fluxes are obtained: Dense inert and dense fine fraction with a high content of minerals and a lightweight fraction with a high calorific value between 16 and 20MJ/kg. An additional positive effect of wet mechanical treatment is the removal of the finest particles from the surface of the waste material, thus increasing the quality of the generated waste fluxes. The mass fluxes of the different fractions and their qualities as well as possible recovery paths are described below. An economical and ecological consideration of the treatment of the fine materials does not take place within the framework of

  5. Detection of cyanobacteria and methanogens embedded in Mars analogue minerals by the use of Raman spectroscopy (United States)

    de Vera, J.-P. P.; Böttger, U.; Fritz, J.; Weber, I.; Malaszkiewicz, J.; Serrano, P.; Meessen, J.; Ott, S.; Wagner, D.; Hübers, H.-W.


    RLS (Raman Laser Spectrometer - one of the Pasteur Payload Instruments onboard ExoMars 2018) will perform Raman measurements on Mars to identify organic compounds and mineral products as an indication of biological activity. The measurements will be performed on crushed powdered samples inside the Rover's ALD (Analytical Laboratory Drawer). Raman analytics with the same specifications as those onboard the future ExoMars mission are conducted to test their potential of identifying biological material on martian analogue material. Appropriate measurement parameters for the detection of biological material as well as for the determination of the mineral composition will be derived. In addition, we report on problems using Raman spectroscopy to discriminate cells of microorganisms from the mineral background. Two organisms are chosen as test candidates for potential life on Mars: cyanobacteria and methane producing archaea. Prokaryotes like archaea and bacteria appeared on early Earth at least 3.8 to 3.5 billion years ago (Gya). At this time on Mars the climate was more temperate and wet compared to the present day as inferred from geological evidence for liquid water on the ancient martian surface. Thus life might have developed under similar conditions as on Earth or might have been transferred from Earth (or vice versa). Methane is known to be present on Mars, although the origin (if geothermal or biological activity) is still unknown. Cyanobacteria and prokaryotes using photosystem I belong to the oldest microbes on Earth. These organisms use pigments such as scytonemin and β-carotene as UV protection. Especially β-carotene emits a strong Raman signal. Raman analytics are used for detection of biofilm forming cyanobacteria Nostoc commune strain on the below described Mars analogue mineral mixtures. N. commune is known to be resistant to desiccation, UV B radiation and low temperatures, and thus suitable as a candidate for a potential life form on Mars

  6. Titan III Mars Observer Press Showing at the PHSF (United States)


    Live footage of the Titan 3 Mars Observer is shown at the Payload Hazardous Servicing Facility (PHSF). The Mars Observer is a NASA mission to study the surface, atmosphere, interior and magnetic field of Mars from Martian orbit.

  7. Breakthrough in Mars balloon technology (United States)

    Kerzhanovich, V. V.; Cutts, J. A.; Cooper, H. W.; Hall, J. L.; McDonald, B. A.; Pauken, M. T.; White, C. V.; Yavrouian, A. H.; Castano, A.; Cathey, H. M.; Fairbrother, D. A.; Smith, I. S.; Shreves, C. M.; Lachenmeier, T.; Rainwater, E.; Smith, M.


    Two prototypes of Mars superpressure balloons were flight tested for aerial deployment and inflation in the Earth's stratosphere in June, 2002. One was an 11.3 m diameter by 6.8 m high pumpkin balloon constructed from polyethylene film and Zylon (PBO) tendons, the second was a 10 m diameter spherical balloon constructed from 12 μm thick Mylar film. Aerial deployment and inflation occurred under parachute descent at 34 km altitude, mimicing the dynamic pressure environment expected during an actual Mars balloon mission. Two on-board video cameras were used on each flight to provide real-time upward and downward views of the flight train. Atmospheric pressure and temperature were also recorded. Both prototypes successfully deployed from their storage container during parachute descent at approximately 40 m/s. The pumpkin balloon also successfully inflated with a 440 g charge of helium gas injected over a 1.5-min period. Since the helium inflation system was deliberately retained after inflation in this test, the pumpkin balloon continued to fall to the ocean where it was recovered for post-flight analysis. The less robust spherical balloon achieved only a partial (~70%) inflation before a structural failure occurred in the balloon film resulting in the loss of the vehicle. This structural failure was diagnosed to result from the vigorous oscillatory motion of the partially inflated balloon, possibly compounded by contact between the balloon film and an instrumentation box above it on the flight train. These two flights together represent significant progress in the development of Mars superpressure balloon technology and pave the way for future flight tests that will include post-deployment flight of the prototype balloons at a stable altitude.

  8. Surface Tension Triggered Wetting and Point of Care Sensor Design. (United States)

    Falde, Eric J; Yohe, Stefan T; Grinstaff, Mark W


    Rapid, simple, and inexpensive point-of-care (POC) medical tests are of significant need around the world. The transition between nonwetting and wetted states is used to create instrument-free surface tension sensors for POC diagnosis, using a layered electrospun mesh with incorporated dye to change color upon wetting. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Evaluation of the effectiveness of coal and mine dust wetting

    Directory of Open Access Journals (Sweden)

    Krzysztof Cybulski


    This paper presents a method to evaluate the effectiveness of coal or mine dust's moistening conducted with the use of water solutions of wetting agents in order to deprive the dust of its volatility, is based on the method of measurement of time of complete moistening of that dust's one-gram samples with the use of “pure” water or water solutions of the particular wetting agent.

  10. Modeling Reactive Wetting when Inertial Effects are Dominant


    Wheeler, Daniel; Warren, James A.; Boettinger, William J.


    Recent experimental studies of molten metal droplets wetting high temperature reactive substrates have established that the majority of triple-line motion occurs when inertial effects are dominant. In light of these studies, this paper investigates wetting and spreading on reactive substrates when inertial effects are dominant using a thermodynamically derived, diffuse interface model of a binary, three-phase material. The liquid-vapor transition is modeled using a van der Waals diffuse inter...

  11. [Hemicorporectomy with double barreled wet colostomy: an extremely rare procedure]. (United States)

    Ricci, Marco Antonio; Duarte, Enio Lucio Coelho; Souza, Renato Costa Amaral; Albuquerque-Peres, Carlos Michel; Guimaraes, Gustavo Cardoso; Lopes, Ademar


    The Hemicorporectomy associated to Double-barreled wet colostomy is a high complex and heroic procedure and is to be used only exceptionally, when it is the last resource for treating locally advanced pelvic diseases in the absence of evidences of distant metastasis. We retrospectively analyzed the surgical technical details and the results from a hemicorporectomy with double-barreled wet colostomy in a single surgical time in a case of epidermoide carcinoma from a coetaneous pressure ulcer.

  12. Wet Deposition Concentrations and Fluxes of Mercury in Taiwan (United States)

    Sheu, G.; Lin, N.


    Taiwan is located downwind to the largest anthropogenic Hg emission source region, the East Asian continent, and thus model simulations often predicted that Taiwan could receive high Hg input via wet deposition. Therefore, a mercury (Hg) wet deposition monitoring network was established in Taiwan to collect rainwater for total Hg analysis since September 2008. The objective of this network is to establish a national database of wet deposition concentrations and fluxes of Hg. This database will later be used to develop information on spatial and temporal trends in Hg wet deposition and to evaluate the contribution of regional/long-range transport. A total of 12 sampling sites, covering urban, rural, mountain, coastal and remote island areas, were set up. Weekly samples were collected using automated wet-only precipitation collection systems. Acid-cleaned glass funnels were used for rainwater collections and samples were collected into acid-cleaned 1L Teflon bottles. Samples were retrieved and sampling trains were changed every Tuesday morning. Total Hg was quantified by dual amalgamation CVAFS after BrCl oxidation, NH2OH●HCl neutralization, and SnCl2 reduction. In 2009, total Hg concentrations of all the rainwater samples ranged from 2.1 to 82.2 ng/L. Volume-weighted mean (VWM) total Hg concentrations of all the sampling sites ranged between 7.6 and 17.2 ng/L. In general, rainwater Hg concentrations were lower in northern Taiwan sites, likely due to the dilution effect caused by higher rainfall amount. Annual wet depositional Hg fluxes ranged between 12.3 and 37.0 μg/m2 in 2009, with higher values usually observed in northern Taiwan sites. The geographical distribution of wet depositional Hg flux mimicked the distribution of accumulative rainfall amount, suggesting precipitation depth is the primary factor in determining the magnitude of wet depositional Hg flux.

  13. Development of Wet Noodles Based on Cassava Flour


    Abidin, Akhmad Z; Devi, Cinantya; Adeline, A


    Cassava is one of Indonesia’s original commodities and contains good nutrition and has high productivity and a relatively low price. Cassava flour has a high potential as a substitute for imported wheat flour that is widely used in noodle production. The main purpose of this research was to develop wet noodles from cassava flour that can compete with wet noodles from wheat flour. The research consisted of experiments with several variations of composition and production method for producing c...

  14. Microbial community composition of transiently wetted Antarctic Dry Valley soils

    Directory of Open Access Journals (Sweden)

    Thomas D. Neiderberger


    Full Text Available During the summer months, wet (hyporheic soils associated with ephemeral streams and lake edges in the Antarctic Dry Valleys (DV become hotspots of biological activity and are hypothesized to be an important source of carbon and nitrogen for arid DV soils. Recent research in the DV has focused on the geochemistry and microbial ecology of lakes and arid soils, with substantially less information being available on hyporheic soils. Here we determined the unique properties of hyporheic microbial communities, resolved their relationship to environmental parameters and to compared them to archetypal arid DV soils. Generally, pH increased and chlorophyll a concentrations decreased along transects from wet to arid soils (9.0 to ~7.0 for pH and ~0.8 to ~ 5 µg/cm3 for chlorophyll a, respectively. Soil water content decreased to below ~3% in the arid soils. Community fingerprinting-based principle component analyses revealed that bacterial communities formed distinct clusters specific to arid and wet soils; however, eukaryotic communities that clustered together did not have similar soil moisture content nor did they group together based on sampling location. Collectively, rRNA pyrosequencing indicated a considerably higher abundance of Cyanobacteria in wet soils and a higher abundance of Acidobacterial, Actinobacterial, Deinococcus/Thermus, Bacteroidetes, Firmicutes, Gemmatimonadetes, Nitrospira and Planctomycetes in arid soils. The two most significant differences at the genus level were Gillisia signatures present in arid soils and chloroplast signatures related to Streptophyta that were common in wet soils. Fungal dominance was observed in arid soils and Viridplantae were more common in wet soils. This research represents an in-depth characterization of microbial communities inhabiting wet DV soils. Results indicate that the repeated wetting of hyporheic zones has a profound impact on the bacterial and eukaryotic communities inhabiting in these areas.

  15. Hijama (Wet Cupping or Dry Cupping) for Diabetes Treatment


    Vakilinia, Seyed Reza; Bayat, Davood; Asghari, Majid


    Background: Diabetes is known as one of the most common diseases in the world and its treatment is one of the most important healthcare issues. Consequently, different treatment methods of complementary medicine and recent medicine have been used by scientific communities to control and predict the disease. This article considered the effects of dry cupping and wet cupping, based on traditional medicine and recent studies. Methods: At first, the benefits of dry cupping and wet cupping were ta...

  16. Human skin wetness perception: psychophysical and neurophysiological bases (United States)

    Filingeri, Davide; Havenith, George


    The ability to perceive thermal changes in the surrounding environment is critical for survival. However, sensing temperature is not the only factor among the cutaneous sensations to contribute to thermoregulatory responses in humans. Sensing skin wetness (i.e. hygrosensation) is also critical both for behavioral and autonomic adaptations. Although much has been done to define the biophysical role of skin wetness in contributing to thermal homeostasis, little is known on the neurophysiological mechanisms underpinning the ability to sense skin wetness. Humans are not provided with skin humidity receptors (i.e., hygroreceptors) and psychophysical studies have identified potential sensory cues (i.e. thermal and mechanosensory) which could contribute to sensing wetness. Recently, a neurophysiological model of human wetness sensitivity has been developed. In helping clarifying the peripheral and central neural mechanisms involved in sensing skin wetness, this model has provided evidence for the existence of a specific human hygrosensation strategy, which is underpinned by perceptual learning via sensory experience. Remarkably, this strategy seems to be shared by other hygroreceptor-lacking animals. However, questions remain on whether these sensory mechanisms are underpinned by specific neuromolecular pathways in humans. Although the first study on human wetness perception dates back to more than 100 years, it is surprising that the neurophysiological bases of such an important sensory feature have only recently started to be unveiled. Hence, to provide an overview of the current knowledge on human hygrosensation, along with potential directions for future research, this review will examine the psychophysical and neurophysiological bases of human skin wetness perception. PMID:27227008

  17. Mars and Venus: unequal planets. (United States)

    Zimmerman, T S; Haddock, S A; McGeorge, C R


    Self-help books, a pervasive and influential aspect of society, can have a beneficial or detrimental effect on the therapeutic process. This article describes a thematic analysis and feminist critique of the best-selling self-help book, Men are from Mars, Women are from Venus. This analysis revealed that the author's materials are inconsistent with significant family therapy research findings and key principles of feminist theories. His descriptions of each gender and his recommendations for improving relationships serve to endorse and encourage power differentials between women and men.

  18. Science Driven Human Exploration of Mars (United States)

    McKay, Christopher P.


    Mars appears to be cold dry and dead world. However there is good evidence that early in its history it had liquid water, more active volcanism, and a thicker atmosphere. Mars had this earth-like environment over three and a half billion years ago, during the same time that life appeared on Earth. The main question in the exploration of Mars then is the search for a independent origin of life on that planet. Ecosystems in cold, dry locations on Earth - such as the Antarctic - provide examples of how life on Mars might have survived and where to look for fossils. Fossils are not enough. We will want to determine if life on Mars was a separate genesis from life on Earth. For this determination we need to access intact martian life; possibly frozen in the deep old permafrost. Human exploration of Mars will probably begin with a small base manned by a temporary crew, a necessary first start. But exploration of the entire planet will require a continued presence on the Martian surface and the development of a self sustaining community in which humans can live and work for very long periods of time. A permanent Mars research base can be compared to the permanent research bases which several nations maintain in Antarctica at the South Pole, the geomagnetic pole, and elsewhere. In the long run, a continued human presence on Mars will be the most economical way to study that planet in detail. It is possible that at some time in the future we might recreate a habitable climate on Mars, returning it to the life-bearing state it may have enjoyed early in its history. Our studies of Mars are still in a preliminary state but everything we have learned suggests that it may be possible to restore Mars to a habitable climate. Additional information is contained in the original extended abstract.

  19. Hijama (Wet Cupping or Dry Cupping) for Diabetes Treatment. (United States)

    Vakilinia, Seyed Reza; Bayat, Davood; Asghari, Majid


    Diabetes is known as one of the most common diseases in the world and its treatment is one of the most important healthcare issues. Consequently, different treatment methods of complementary medicine and recent medicine have been used by scientific communities to control and predict the disease. This article considered the effects of dry cupping and wet cupping, based on traditional medicine and recent studies. At first, the benefits of dry cupping and wet cupping were taken from some original books of Iranian traditional medicine, such as Canon of Medicine, Kholasat-al-hekma, Tib-e-Akbari and Exir-e-Azam. Then, the information about scientific articles was obtained by studying some of the Iranian traditional medicine journals and searching through PubMed, SID and Google Scholar. In traditional medicine, Hijama is divided into two kinds, namely wet cupping (with sharat, with incision, and blood giving) and dry cupping (without sharat, without incision). Dry cupping causes organ blood absorption, organ warming, and loss of organ humidity. The texts of Iranian traditional medicine refer to the Ziabites disease that its symptoms are like diabetes. This disease is divided into two types including warm and cold ziabetes. The treatments that are recommended for both types are dry cupping for cold ziabetes and wet cupping for warm ziabetes. In addition, according to scientific studies, dry cupping and wet cupping have been recommended for diabetes treatment. Dry cupping and wet cupping can be introduced as the complementary treatment methods beside other treatment methods.

  20. Development of Wet Noodles Based on Cassava Flour

    Directory of Open Access Journals (Sweden)

    Akhmad Z. Abidin


    Full Text Available Cassava is one of Indonesia’s original commodities and contains good nutrition and has high productivity and a relatively low price. Cassava flour has a high potential as a substitute for imported wheat flour that is widely used in noodle production. The main purpose of this research was to develop wet noodles from cassava flour that can compete with wet noodles from wheat flour. The research consisted of experiments with several variations of composition and production method for producing cassava flour-based wet noodles. The best result was then examined for its nutritional value, economical value, and market response, and also a comparison was made between the prepared wet noodles and the standard noodles made from wheat flour. The analysis was based on five characteristics: taste, texture, chewiness, aroma, and appearance. Relations between these characteristics with composition, materials used, and methods applied are discussed. The developed cassava flour-based wet noodle meets physical, nutritional, and economical standards. Raw materials of the noodle were cassava flour and a wheat flour composite with a 5:1 ratio, egg, gluten, soda-ash, water, and vegetable oil, while the process was completed in multiple stages. Market response showed that the cassava flour-based wet noodles were 80% similar to wheat-flour noodles.

  1. Evaluation of the Acidic Wet Deposition Predictions of CMAQ (United States)

    Dennis, R. L.


    Acidic deposition is coming back into importance as part of more encompassing multi-pollutant thinking. Acidic and nutrient deposition is an important component of new multi-pollutant legislation being considered by the Administration. The Community Multiscale Air Quality model, CMAQ, was designed to handle multiple pollutants in a one-atmosphere context. Much of the initial evaluation of CMAQ was directed at the criteria pollutants. CMAQ's predictions of acidic deposition also need to be evaluated, not only because of the importance of deposition but also because deposition sets the lifetime of fine particles in the atmosphere. The controlling deposition is wet deposition, hence, we consider it first. We compare wet deposition for selected months throughout 1990, showing that CMAQ captures the main features of seasonality. We note that the previous problem of overprediction of winter wet deposition associated with the RADM cloud parameterization has been addressed through explicit recognition of icy cloud water. We are still plagued by the difficulty of meteorological models to predict precipitation as input to chemical transport models which produces additional scatter. Interestingly, there is a consistent differential between sulfate and nitrate wet deposition, with nitrate wet deposition being slightly lower. We explore several hypotheses for this behavior, including the hypothesis that this is more an issue of mixing than an issue of cloud chemistry. In general, CMAQ appears to be producing reasonable predictions that demonstrate an improvement in our ability to predict wet deposition, although there is room for improvement.

  2. Mars Trek: An Interactive Web Portal for Current and Future Missions to Mars (United States)

    Law, E.; Day, B.


    NASA's Mars Trek ( provides a web-based Portal and a suite of interactive visualization and analysis tools to enable mission planners, lunar scientists, and engineers to access mapped data products from past and current missions to Mars. During the past year, the capabilities and data served by Mars Trek have been significantly expanded beyond its original design as a public outreach tool. At the request of NASA's Science Mission Directorate and Human Exploration Operations Mission Directorate, Mars Trek's technology and capabilities are now being extended to support site selection and analysis activities for the first human missions to Mars.

  3. Mars Trek: An Interactive Web Portal for Current and Future Missions to Mars (United States)

    Law, E.; Day, B.


    NASA's Mars Trek ( provides a web-based Portal and a suite of interactive visualization and analysis tools to enable mission planners, lunar scientists, and engineers to access mapped data products from past and current missions to Mars. During the past year, the capabilities and data served by Mars Trek have been significantly expanded beyond its original design as a public outreach tool. At the request of NASA's Science Mission Directorate and Human Exploration Operations Mission Directorate, Mars Trek's technology and capabilities are now being extended to support site selection and analysis activities for the first human missions to Mars.

  4. MNSM - A Future Mars Network Science Mission (United States)

    Chicarro, A. F.


    Following ESA' s successful Mars Express mission, European efforts in Mars Exploration are now taking place within the joint ESA-NASA Mars Exploration Programme, starting in 2016 with the Trace Gases Orbiter (TGO) focusing on atmospheric trace gases and in particular methane, and with the Entry and Descent Module (EDM). In 2018, a joint NASA-ESA rover will perform sample caching as well as geological, geochemical and exobiological measurements of the surface and the subsurface of Mars. A number of missions for 2020 and beyond are currently under study. Among those, a possible candidate is a Mars Network Science Mission (MNSM) of 3-6 surface stations, to investigate the interior of the planet, its rotational parameters and its atmospheric dynamics. These important science goals have not been fully addressed by Mars exploration so far and can only be achieved with simultaneous measurements from a number of landers located on the surface of the planet such as a Mars Network mission. In addition, the geology, mineralogy and astrobiological significance of each landing site would be addressed, as three new locations on Mars would be reached. Such Mars Network Science Mission has been considered a significant priority by the planetary science community worldwide for the past two decades. In fact, a Mars Network mission concept has a long heritage, as it was studied a number of times by ESA, NASA and CNES (e.g., Marsnet, Intermarsnet, Netlander and MarsNEXT mission studies) since 1990. Study work has been renewed in ESA recently with MNSM Science and Engineering Teams being set up to update the scientific objectives of the mission and to evaluate its technical feasibility, respectively. The current mission baseline includes three ESA-led small landers with a robotic arm to be launched with a Soyuz rocket and direct communications to Earth (no need of a dedicated orbiter). However, a larger network could be put in place through international collaboration, as several

  5. Biomimetic wet-stable fibres via wet spinning and diacid-based crosslinking of collagen triple helices

    CERN Document Server

    Arafat, M Tarik; Yin, Jie; Wood, David J; Russell, Stephen J


    One of the limitations of electrospun collagen as bone-like fibrous structure is the potential collagen triple helix denaturation in the fibre state and the corresponding inadequate wet stability even after crosslinking. Here, we have demonstrated the feasibility of accomplishing wet-stable fibres by wet spinning and diacid-based crosslinking of collagen triple helices, whereby fibre ability to act as bone-mimicking mineralisation system has also been explored. Circular dichroism (CD) demonstrated nearly complete triple helix retention in resulting wet-spun fibres, and the corresponding chemically crosslinked fibres successfully preserved their fibrous morphology following 1-week incubation in phosphate buffer solution (PBS). The presented novel diacid-based crosslinking route imparted superior tensile modulus and strength to the resulting fibres indicating that covalent functionalization of distant collagen molecules is unlikely to be accomplished by current state-of-the-art carbodiimide-based crosslinking. ...

  6. NASA Facts, Mars as a Planet. (United States)

    National Aeronautics and Space Administration, Washington, DC. Educational Programs Div.

    Presented is one of a series of National Aeronautics and Space Administration (NASA) facts about the exploration of Mars. Photographs, showing Mars as seen from Earth through a telescope, show dark markings and polar caps present. Photographs from Mariner 7, Mariner 4, and Mariner 9 are included. Presented is a composite of several Mariner 9…

  7. Mars Telecom Orbiter mission operations concepts (United States)

    Deutsch, Marie-Jose; Komarek, Tom; Lopez, Saturnino; Townes, Steve; Synnott, Steve; Austin, Richard; Guinn, Joe; Varghese, Phil; Edwards, Bernard; Bondurant, Roy; hide


    The Mars Telecom Orbiter (MTO) relay capability enables next decadal missions at Mars, collecting gigabits of data a day to be relayed back at speeds exceeding 4 Mbps and it facilitates small missions whose limited resources do not permit them to have a direct link to Earth.

  8. Past, present, and future life on Mars (United States)

    McKay, C. P.


    Although the Viking results indicated that the surface of Mars is dry and lifeless, there is direct geomorphological evidence that Mars had large amounts of liquid water on its surface in the past. From a biological perspective the existence of liquid water, by itself, motivates the question of the origin of life on Mars. One of the martian meteorites dates back to this early period and may contain evidence consistent with life. The Mars environment 3.5 to 4.0 Gyr ago was comparable to that on the Earth at this time in that both contained liquid water. Life had originated on Earth and reached a fair degree of biological sophistication by 3.5 Gyr ago. To determine if life similarly arose on Mars may require extensive robotic exploration and ultimately human exploration. Intensive exploration of Mars will require a continued presence on the Martian surface and the development of a self sustaining community in which humans can live and work for very long periods of time. A permanent Mars research station can obtain its life support requirements directly from the martian environment enabling a high degree of self-sufficiency. In the longer term, it is possible that in the future we might restore a habitable climate on Mars, returning it to the life-bearing state it may have enjoyed early in its history.

  9. Perfil. María Rodilla


    Rodilla, María


    [ES] Perfil sobre María Rodilla, ilustradora valenciana que centra su trabajo en el feminismo Rodilla, M. (2017). Perfil. María Rodilla. EME Experimental Illustration, Art & Design. (5):52-53. doi:10.4995/eme.2017.7616. 52 53 5

  10. Past, present, and future life on Mars. (United States)

    McKay, C P


    Although the Viking results indicated that the surface of Mars is dry and lifeless, there is direct geomorphological evidence that Mars had large amounts of liquid water on its surface in the past. From a biological perspective the existence of liquid water, by itself, motivates the question of the origin of life on Mars. One of the martian meteorites dates back to this early period and may contain evidence consistent with life. The Mars environment 3.5 to 4.0 Gyr ago was comparable to that on the Earth at this time in that both contained liquid water. Life had originated on Earth and reached a fair degree of biological sophistication by 3.5 Gyr ago. To determine if life similarly arose on Mars may require extensive robotic exploration and ultimately human exploration. Intensive exploration of Mars will require a continued presence on the Martian surface and the development of a self sustaining community in which humans can live and work for very long periods of time. A permanent Mars research station can obtain its life support requirements directly from the martian environment enabling a high degree of self-sufficiency. In the longer term, it is possible that in the future we might restore a habitable climate on Mars, returning it to the life-bearing state it may have enjoyed early in its history.

  11. Did Water Leave Its Mark on Mars? (United States)

    Secosky, James J.


    Discusses the missing water on Mars. Describes five experiments simulating conditions on Mars: (1) behavior of dry ice; (2) low-pressure vacuum; (3) freezing point depression; (4) water in hydrated minerals and clay; and (5) properties of carbon dioxide. (YP)

  12. Planet Mars story of another world

    CERN Document Server

    Forget, François; Lognonné, Philippe


    Give an insight of Mars by adopting an outline based on history rather than on subtopic (atmosphere, surface, interior). This work looks at its evolution, and incorporates the results from the space missions of Mars Express, Spirit and Opportunity. It also examines its formation from the ashes of dead stars, more than 4 5 billion years ago.

  13. A warmer and wetter solution for early Mars and the challenges with transient warming (United States)

    Ramirez, Ramses M.


    The climate of early Mars has been hotly debated for decades. Although most investigators believe that the geology indicates the presence of surface water, disagreement has persisted regarding how warm and wet the surface must have been and how long such conditions may have existed. Although the geologic evidence is most easily explained by a persistently warm climate, the perceived difficulty that climate models have in generating warm surface conditions has seeded various models that assume a cold and glaciated early Mars punctuated by transient warming episodes. However, I use a single-column radiative convective climate model to show that it is relatively more straightforward to satisfy warm and relatively non-glaciated early Mars conditions, requiring only ∼1% H2 and 3 bar CO2 or ∼20% H2 and 0.55 bar CO2. In contrast, the reflectivity of surface ice greatly increases the difficulty to transiently warm an initially frozen surface. Surface pressure thresholds required for warm conditions increase ∼10 - 60% for transient warming models, depending on ice cover fraction. No warm solution is possible for ice cover fractions exceeding 40%, 70%, and 85% for mixed snow/ice and 25%, 35%, and 49% for fresher snow/ice at H2 concentrations of 3%, 10%, and 20%, respectively. If high temperatures (298-323 K) were required to produce the observed surface clay amounts on a transiently warm early Mars (Bishop et al), I show that such temperatures would have required surface pressures that exceed available paleopressure constraints for nearly all H2 concentrations considered (1-20%). I then argue that a warm and semi-arid climate remains the simplest and most logical solution to Mars paleoclimate.

  14. Are you ready for Mars? - Main media events surrounding the arrival of ESA's Mars Express at Mars (United States)


    Launched on 2 June 2003 from Baikonur (Kazakhstan) on board a Russian Soyuz launcher operated by Starsem, the European probe -built for ESA by a European team of industrial companies led by Astrium - carries seven scientific instruments that will perform a series of remote-sensing experiments designed to shed new light on the Martian atmosphere, the planet’s structure and its geology. In particular, the British-made Beagle 2 lander, named after the ship on which Charles Darwin explored uncharted areas of the Earth in 1830, will contribute to the search for traces of life on Mars through exobiology experiments and geochemistry research. On Christmas Eve the Mars Express orbiter will be steered on a course taking it into an elliptical orbit, where it will safely circle the planet for a minimum of almost 2 Earth years. The Beagle 2 lander - which will have been released from the mother craft a few days earlier (on 19 December) - instead will stay on a collision course with the planet. It too should also be safe, being designed for atmospheric entry and geared for a final soft landing due to a sophisticated system of parachutes and airbags. On arrival, the Mars Express mission control team will report on the outcome of the spacecraft's delicate orbital insertion manoeuvre. It will take some time for Mars Express to manouvre into position to pick communications from Beagle 2. Hence, initially, other means will be used to check that Beagle 2 has landed: first signals from the Beagle 2 landing are expected to be available throughout Christmas Day, either through pick-up and relay of Beagle 2 radio signals by NASA’s Mars Odyssey, or by direct pick-up by the Jodrell Bank radio telescope in the UK. Mars Express will then pass over Beagle 2 in early January 2004, relaying data and images back to Earth. The first images from the cameras of Beagle 2 and Mars Express are expected to be available between the end of the year and the beginning of January 2004. The key dates

  15. Mars NanoOrbiter: A CubeSat for Mars System Science (United States)

    Ehlmann, Bethany; Klesh, Andrew; Alsedairy, Talal


    The Mars NanoOrbiter mission consists of two identical 12U spacecraft, launched simultaneously as secondary payloads on a larger planetary mission launch, and deployed to Earth-escape, as early as with Mars 2020. The nominal mission will last for 1 year, during which time the craft will independently navigate to Mars, enter into elliptical orbit, and achieve close flybys of Phobos and Deimos, obtaining unprecedented coverage of each moon. The craft will additionally provide high temporal resolution data of Mars clouds and atmospheric phenomena at multiple times of day. Two spacecraft provide redundancy to reduce the risk in meeting the science objectives at the Mars moons and enhanced coverage of the dynamic Mars atmosphere. This technology is enabled by recent advances in CubeSat propulsion technology, attitude control systems, guidance, navigation and control. NanoOrbiter builds directly on the systems heritage of the MarCO mission, scheduled to launch with the 2018 Discovery mission Insight.

  16. Candidate cave entrances on Mars (United States)

    Cushing, Glen E.


    This paper presents newly discovered candidate cave entrances into Martian near-surface lava tubes, volcano-tectonic fracture systems, and pit craters and describes their characteristics and exploration possibilities. These candidates are all collapse features that occur either intermittently along laterally continuous trench-like depressions or in the floors of sheer-walled atypical pit craters. As viewed from orbit, locations of most candidates are visibly consistent with known terrestrial features such as tube-fed lava flows, volcano-tectonic fractures, and pit craters, each of which forms by mechanisms that can produce caves. Although we cannot determine subsurface extents of the Martian features discussed here, some may continue unimpeded for many kilometers if terrestrial examples are indeed analogous. The features presented here were identified in images acquired by the Mars Odyssey's Thermal Emission Imaging System visible-wavelength camera, and by the Mars Reconnaissance Orbiter's Context Camera. Select candidates have since been targeted by the High-Resolution Imaging Science Experiment. Martian caves are promising potential sites for future human habitation and astrobiology investigations; understanding their characteristics is critical for long-term mission planning and for developing the necessary exploration technologies.

  17. A Mars Exploration Discovery Program (United States)

    Hansen, C. J.; Paige, D. A.


    The Mars Exploration Program should consider following the Discovery Program model. In the Discovery Program a team of scientists led by a PI develop the science goals of their mission, decide what payload achieves the necessary measurements most effectively, and then choose a spacecraft with the capabilities needed to carry the payload to the desired target body. The primary constraints associated with the Discovery missions are time and money. The proposer must convince reviewers that their mission has scientific merit and is feasible. Every Announcement of Opportunity has resulted in a collection of creative ideas that fit within advertised constraints. Following this model, a "Mars Discovery Program" would issue an Announcement of Opportunity for each launch opportunity with schedule constraints dictated by the launch window and fiscal constraints in accord with the program budget. All else would be left to the proposer to choose, based on the science the team wants to accomplish, consistent with the program theme of "Life, Climate and Resources". A proposer could propose a lander, an orbiter, a fleet of SCOUT vehicles or penetrators, an airplane, a balloon mission, a large rover, a small rover, etc. depending on what made the most sense for the science investigation and payload. As in the Discovery program, overall feasibility relative to cost, schedule and technology readiness would be evaluated and be part of the selection process.

  18. Life On Mars: Past, Present and Future (United States)

    McKay, Christopher P.; DeVincenzi, Donald L. (Technical Monitor)


    Mars appears to be cold dry and dead world. However there is good evidence that early in its history it had liquid water, more active volcanism, and a thicker atmosphere. Mars had this earth-like environment over three and a half billion years ago, during the same time that life appeared on Earth. The main question in the exploration of Mars then is the search for a independent origin of life on that planet. Ecosystems in cold, dry locations on Earth - such as the Antarctic - provide examples of how life on Mars might have survived and where to look for fossils. Although the Viking results may indicate that Mars has no life today, there is direct geomorphological evidence that, in the past, Mars had large amounts of liquid water on its surface - possibly due to a thicker atmosphere. From a biological perspective the existence of liquid water, by itself motivates the question of the origin of life on Mars. One of the martian meteorites dates back to this early period and may contain evidence consistent with life. From studies of the Earth's earliest biosphere we know that by 3.5 Cyr. ago, life had originated on Earth and reached a fair degree of biological sophistication. Surface activity and erosion on Earth make it difficult to trace the history of life before the 3.5 Cyr timeframe. Ecosystems in cold, dry locations on Earth - such as the Antarctic - provide examples of how life on Mars might have survived and where to look for fossils. Human exploration of Mars will probably begin with a small base manned by a temporary crew, a necessary first start. But exploration of the entire planet will require a continued presence on the Martian surface and the development of a self sustaining community in which humans can live and work for very long periods of time. A permanent Mars research base can be compared to the permanent research bases which several nations maintain in Antarctica at the South Pole, the geomagnetic pole, and elsewhere. In the long run, a continued

  19. Mars Molniya Orbit Atmospheric Resource Mining (United States)

    Mueller, Robert P.; Braun, Robert D.; Sibille, Laurent; Sforzo, Brandon; Gonyea, Keir; Ali, Hisham


    This NIAC (NASA Advanced Innovative Concepts) work will focus on Mars and will build on previous efforts at analyzing atmospheric mining at Earth and the outer solar system. Spacecraft systems concepts will be evaluated and traded, to assess feasibility. However the study will primarily examine the architecture and associated missions to explore the closure, constraints and critical parameters through sensitivity studies. The Mars atmosphere consists of 95.5 percent CO2 gas which can be converted to methane fuel (CH4) and Oxidizer (O2) for chemical rocket propulsion, if hydrogen is transported from electrolyzed water on the Mars surface or from Earth. By using a highly elliptical Mars Molniya style orbit, the CO2 atmosphere can be scooped, ram-compressed and stored while the spacecraft dips into the Mars atmosphere at periapsis. Successive orbits result in additional scooping of CO2 gas, which also serves to aerobrake the spacecraft, resulting in a decaying Molniya orbit.

  20. Mars Science Laboratory Heatshield Flight Data Analysis (United States)

    Mahzari, Milad; White, Todd


    NASA Mars Science Laboratory (MSL), which landed the Curiosity rover on the surface of Mars on August 5th, 2012, was the largest and heaviest Mars entry vehicle representing a significant advancement in planetary entry, descent and landing capability. Hypersonic flight performance data was collected using MSLs on-board sensors called Mars Entry, Descent and Landing Instrumentation (MEDLI). This talk will give an overview of MSL entry and a description of MEDLI sensors. Observations from flight data will be examined followed by a discussion of analysis efforts to reconstruct surface heating from heatshields in-depth temperature measurements. Finally, a brief overview of MEDLI2 instrumentation, which will fly on NASAs Mars2020 mission, will be presented with a discussion on how lessons learned from MEDLI data affected the design of MEDLI2 instrumentation.

  1. The transformative value of liberating Mars

    CERN Document Server

    Haqq-Misra, Jacob


    Humanity has the knowledge to solve its problems but lacks the moral insight to implement these ideas on a global scale. New moral insight can be obtained through transformative experiences that allow us to examine and refine our underlying preferences, and the eventual landing of humans on Mars will be of tremendous transformative value. Before such an event, I propose that we liberate Mars from any controlling interests of Earth and allow Martian settlements to develop into a second independent instance of human civilization. Such a designation is consistent with the Outer Space Treaty and allows Mars to serve as a test bed and point of comparison by which to learn new information about the phenomenon of civilization. Rather than develop Mars through a series of government and corporate colonies, let us steer the future by liberating Mars and embracing the concept of planetary citizenship.

  2. Visual wetness perception based on image color statistics. (United States)

    Sawayama, Masataka; Adelson, Edward H; Nishida, Shin'ya


    Color vision provides humans and animals with the abilities to discriminate colors based on the wavelength composition of light and to determine the location and identity of objects of interest in cluttered scenes (e.g., ripe fruit among foliage). However, we argue that color vision can inform us about much more than color alone. Since a trichromatic image carries more information about the optical properties of a scene than a monochromatic image does, color can help us recognize complex material qualities. Here we show that human vision uses color statistics of an image for the perception of an ecologically important surface condition (i.e., wetness). Psychophysical experiments showed that overall enhancement of chromatic saturation, combined with a luminance tone change that increases the darkness and glossiness of the image, tended to make dry scenes look wetter. Theoretical analysis along with image analysis of real objects indicated that our image transformation, which we call the wetness enhancing transformation, is consistent with actual optical changes produced by surface wetting. Furthermore, we found that the wetness enhancing transformation operator was more effective for the images with many colors (large hue entropy) than for those with few colors (small hue entropy). The hue entropy may be used to separate surface wetness from other surface states having similar optical properties. While surface wetness and surface color might seem to be independent, there are higher order color statistics that can influence wetness judgments, in accord with the ecological statistics. The present findings indicate that the visual system uses color image statistics in an elegant way to help estimate the complex physical status of a scene.

  3. Identification of Potential Strain Heterogeneities During Wetting-Induced Compaction

    Directory of Open Access Journals (Sweden)

    Mihalache Constance


    Full Text Available Compaction upon wetting has been reported to occur in various types of unsaturated soils with damaging consequences for infrastructure in field applications. This deformation process is often referred to as “wetting-collapse”, implying that it may be unstable in nature. Recent evidences also indicate that compaction localization represents a possible mode of deformation during wetting, even in the presence of oedometric loading paths. Despite this, little work has been done from a mechanistic perspective to assess the susceptibility of these processes to localization instability. Here we assess the potential for strain localization during wetting through controllability analyses defined in light of a second-order work expression for unsaturated soils. A hydro-mechanical constitutive model with suction-dependent hardening is used to simulate classic experimental data, and the controllability criteria are specialized to capture the potential for shear band formation for a range of band inclinations under water content-controlled and suction-controlled wetting paths. The effect of changes in material characteristics was evaluated, showing that the potential for strain localization upon water-injection increases with increasing values of suction-induced hardening, and that non-associativity may have an effect on both the potential for localization under rapid wetting, as well as on the range of band angles over which it may occur. Specifically, it is possible to distinguish two well-defined stress regions, one within which strain localization is first possible with horizontal band inclinations and another in which inclined localization zones tend to be more critical. Such results provide insight on the factors that may contribute to strain localization during wetting and find general applicability in the interpretation of the response of geo-structures subjected to intense hydrologic forcing.

  4. The effect of surface water and wetting on gecko adhesion. (United States)

    Stark, Alyssa Y; Sullivan, Timothy W; Niewiarowski, Peter H


    Despite profound interest in the mechanics and performance of the gecko adhesive system, relatively few studies have focused on performance under conditions that are ecologically relevant to the natural habitats of geckos. Because geckos are likely to encounter surfaces that are wet, we used shear force adhesion measurements to examine the effect of surface water and toe pad wetting on the whole-animal performance of a tropical-dwelling gecko (Gekko gecko). To test the effect of surface wetting, we measured the shear adhesive force of geckos on three substrate conditions: dry glass, glass misted with water droplets and glass fully submerged in water. We also investigated the effect of wetting on the adhesive toe pad by soaking the toe pads prior to testing. Finally, we tested for repeatability of the adhesive system in each wetting condition by measuring shear adhesion after each step a gecko made under treatment conditions. Wetted toe pads had significantly lower shear adhesive force in all treatments (0.86 ± 0.09 N) than the control (17.96 ± 3.42 N), as did full immersion in water (0.44 ± 0.03 N). Treatments with droplets of water distributed across the surface were more variable and did not differ from treatments where the surface was dry (4.72 ± 1.59 N misted glass; 9.76 ± 2.81 N dry glass), except after the gecko took multiple steps. These findings suggest that surface water and the wetting of a gecko's adhesive toe pads may have significant consequences for the ecology and behavior of geckos living in tropical environments.

  5. Mar enterrado, mar compartido, mar separado. Distintas formas de ser marinero en las Baleares

    Directory of Open Access Journals (Sweden)

    Miquel Novajra, Alejandro


    Full Text Available The author approaches from three angles the connections between the culture of the Balearle Islands and the sea as social, economic and identifying space, within the larger socio-economic context of mass tourism on the Islands. First, he analyzes the paradoxically secondary role that maritime cultural elements play in the identity of the Islanders. Then, he discusses the different mechanism by which life at sea is perceived from the standpoint of the earthbound identities prevalent in the archipelago. Finally, he explains the key components of the perceptions, relationships and cultural reproductions of fishermen in each of the spaces considered.Este artículo aborda a tres niveles las relaciones entre las construcciones de las culturas de las Islas Baleares y el mar como espacio social, económico e identificador. El primer nivel analiza el papel secundario que, paradójicamente, desempeñan los elementos culturales marítimos en las identidades isleñas. El segundo aborda los mecanismos diferentes mediante los cuales se conciben los mundos marineros desde las identidades terrestres y mayoritarias de cada una de las islas componentes. Finalmente, explica los componentes fundamentales de las percepciones, relaciones y reproducciones culturales de los pescadores de cada uno de los espacios analizados. Todo ello en el marco de un universo socioeconómico centrado en el turismo de masas.

  6. Plasma boundary variability at Mars as observed by Mars Global Surveyor and Mars Express

    Directory of Open Access Journals (Sweden)

    N. J. T. Edberg


    Full Text Available We have used Mars Express (MEX and Mars Global Surveyor (MGS simultaneous and non-simultaneous measurements to study the Martian plasma environment. In particular, we have derived quantitative expressions for the altitude of the terminator bow shock (BS and magnetic pileup boundary (MPB as functions of solar wind dynamic pressure, crustal magnetic fields and solar EUV flux. We have also studied the influence of the interplanetary magnetic field (IMF direction. Through simultaneous two-spacecraft case studies we have shown that the dynamic pressure has a strong influence on the location and shape of these boundaries, which is also confirmed through a large statistical study. A higher dynamic pressure pushes the boundaries downward. The IMF direction has a weaker but still significant influence on both boundaries and causes them to move outward in the hemisphere of locally upward electric field. However, the MPB in the Southern Hemisphere is found to actually move inward when the electric field is directed locally upward. The crustal magnetic fields in the Southern Hemisphere have a strong influence on the MPB and cause it to move to higher altitudes over strong crustal magnetic fields. The influence of the crustal magnetic fields on the BS is more ambiguous since there are few crossings over the strongest crustal fields, but there appears to be at least a small trend of a higher BS for stronger crustal fields. An increased solar EUV flux has been found to cause the BS to move outward and the MPB to move inward.

  7. Acid Sulfate Alteration on Mars (United States)

    Ming, D. W.; Morris, R. V.


    A variety of mineralogical and geochemical indicators for aqueous alteration on Mars have been identified by a combination of surface and orbital robotic missions, telescopic observations, characterization of Martian meteorites, and laboratory and terrestrial analog studies. Acid sulfate alteration has been identified at all three landing sites visited by NASA rover missions (Spirit, Opportunity, and Curiosity). Spirit landed in Gusev crater in 2004 and discovered Fe-sulfates and materials that have been extensively leached by acid sulfate solutions. Opportunity landing on the plains of Meridiani Planum also in 2004 where the rover encountered large abundances of jarosite and hematite in sedimentary rocks. Curiosity landed in Gale crater in 2012 and has characterized fluvial, deltaic, and lacustrine sediments. Jarosite and hematite were discovered in some of the lacustrine sediments. The high elemental abundance of sulfur in surface materials is obvious evidence that sulfate has played a major role in aqueous processes at all landing sites on Mars. The sulfate-rich outcrop at Meridiani Planum has an SO3 content of up to 25 wt.%. The interiors of rocks and outcrops on the Columbia Hills within Gusev crater have up to 8 wt.% SO3. Soils at both sites generally have between 5 to 14 wt.% SO3, and several soils in Gusev crater contain around 30 wt.% SO3. After normalization of major element compositions to a SO3-free basis, the bulk compositions of these materials are basaltic, with a few exceptions in Gusev crater and in lacustrine mudstones in Gale crater. These observations suggest that materials encountered by the rovers were derived from basaltic precursors by acid sulfate alteration under nearly isochemical conditions (i.e., minimal leaching). There are several cases, however, where acid sulfate alteration minerals (jarosite and hematite) formed in open hydrologic systems, e.g., in Gale crater lacustrine mudstones. Several hypotheses have been suggested for the

  8. Improved hydrogen sorption kinetics in wet ball milled Mg hydrides

    Energy Technology Data Exchange (ETDEWEB)

    Meng, Li


    In this work, wet ball milling method is used in order to improve hydrogen sorption behaviour due to its improved microstructure of solid hydrogen materials. Compared to traditional ball milling method, wet ball milling has benefits on improvement of MgH{sub 2} microstructure and further influences on its hydrogen sorption behavior. With the help of solvent tetrahydrofuran (THF), wet ball milled MgH{sub 2} powder has much smaller particle size and its specific surface area is 7 times as large as that of dry ball milled MgH{sub 2} powder. Although after ball milling the grain size is decreased a lot compared to as-received MgH{sub 2} powder, the grain size of wet ball milled MgH{sub 2} powder is larger than that of dry ball milled MgH{sub 2} powder due to the lubricant effect of solvent THF during wet ball milling. The improved particle size and specific surface area of wet ball milled MgH{sub 2} powder is found to be determining its hydrogen sorption kinetics especially at relatively low temperatures. And it also shows good cycling sorption behavior, which decides on its industrial applicability. With three different catalysts MgH{sub 2} powder shows improved hydrogen sorption behavior as well as the cyclic sorption behavior. Among them, the Nb{sub 2}O{sub 5} catalyst is found to be the most effective one in this work. Compared to the wet ball milled MgH{sub 2} powder, the particle size and specific surface area of the MgH{sub 2} powder with catalysts are similar to the previous ones, while the grain size of the MgH{sub 2} with catalysts is much finer. In this case, two reasons for hydrogen sorption improvement are suggested: one is the reduction of the grain size. The other may be as pointed out in some literatures that formation of new oxidation could enhance the hydrogen sorption kinetics, which is also the reason why its hydrogen capacity is decreased compared to without catalysts. After further ball milling, the specific surface area of wet ball milled Mg

  9. Aroma recovery from roasted coffee by wet grinding. (United States)

    Baggenstoss, J; Thomann, D; Perren, R; Escher, F


    Aroma recovery as determined by solid phase microextraction-gas chromatography-mass spectrometry (SPME-GC-MS) was compared in coffees resulting from conventional grinding processes, and from wet grinding with cold and hot water. Freshly roasted coffee as well as old, completely degassed coffee was ground in order to estimate the relationship of internal carbon dioxide pressure in freshly roasted coffee with the aroma loss during grinding. The release of volatile aroma substances during grinding was found to be related to the internal carbon dioxide pressure, and wet grinding with cold water was shown to minimize losses of aroma compounds by trapping them in water. Due to the high solubility of roasted coffee in water, the use of wet-grinding equipment is limited to processes where grinding is followed by an extraction step. Combining grinding and extraction by the use of hot water for wet grinding resulted in considerable losses of aroma compounds because of the prolonged heat impact. Therefore, a more promising two-step process involving cold wet grinding and subsequent hot extraction in a closed system was introduced. The yield of aroma compounds in the resulting coffee was substantially higher compared to conventionally ground coffee. © 2010 Institute of Food Technologists®

  10. Physicochemical properties and combustion behavior of duckweed during wet torrefaction. (United States)

    Zhang, Shuping; Chen, Tao; Li, Wan; Dong, Qing; Xiong, Yuanquan


    Wet torrefaction of duckweed was carried out in the temperature range of 130-250°C to evaluate the effects on physicochemical properties and combustion behavior. The physicochemical properties of duckweed samples were investigated by ultimate analysis, proximate analysis, FTIR, XRD and SEM techniques. It was found that wet torrefaction improved the fuel characteristics of duckweed samples resulting from the increase in fixed carbon content, HHVs and the decrease in nitrogen and sulfur content and atomic ratios of O/C and H/C. It can be seen from the results of FTIR, XRD and SEM analyses that the dehydration, decarboxylation, solid-solid conversion, and condensation polymerization reactions were underwent during wet torrefaction. In addition, the results of thermogravimetric analysis (TGA) in air indicated that wet torrefaction resulted in significant changes on combustion behavior and combustion kinetics parameters. Duckweed samples after wet torrefaction behaved more char-like and gave better combustion characteristics than raw sample. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Experimental and Theoretical Investigations of Wet Flue Gas Desulphurisation

    DEFF Research Database (Denmark)

    Kiil, Søren

    This thesis describes experimental and theoretical investigations of wet flue gas desulphurisa-tion (FGD). A review of the current knowledge of the various rate determining steps in wet FGD plants is presented. The experimental work covers laboratory studies as well as pilot- and full-scale exper......This thesis describes experimental and theoretical investigations of wet flue gas desulphurisa-tion (FGD). A review of the current knowledge of the various rate determining steps in wet FGD plants is presented. The experimental work covers laboratory studies as well as pilot- and full...... degree of desulphuri-sation and absorber pH profile for the two limestone types using a holding tank pH of 5.5, but the residual limestone in the gypsum was significantly lower for the chalk. Furthermore, simulations showed that between 10 and 30 % of the limestone dissolves in the absorber de......-pending on the process conditions. A typical holding tank pH of 5-5.5 (also used in full-scale wet FGD packed towers) was found to be a reasonable compromise between residual lime-stone in the gypsum and the degree of desulphurisation. Simulations were only slightly sensi-tive to the temperature in the interval 313...

  12. Iterative metal artefact reduction (MAR) in postsurgical chest CT: comparison of three iMAR-algorithms. (United States)

    Aissa, Joel; Boos, Johannes; Sawicki, Lino Morris; Heinzler, Niklas; Krzymyk, Karl; Sedlmair, Martin; Kröpil, Patric; Antoch, Gerald; Thomas, Christoph


    The purpose of this study was to evaluate the impact of three novel iterative metal artefact (iMAR) algorithms on image quality and artefact degree in chest CT of patients with a variety of thoracic metallic implants. 27 postsurgical patients with thoracic implants who underwent clinical chest CT between March and May 2015 in clinical routine were retrospectively included. Images were retrospectively reconstructed with standard weighted filtered back projection (WFBP) and with three iMAR algorithms (iMAR-Algo1 = Cardiac algorithm, iMAR-Algo2 = Pacemaker algorithm and iMAR-Algo3 = ThoracicCoils algorithm). The subjective and objective image quality was assessed. Averaged over all artefacts, artefact degree was significantly lower for the iMAR-Algo1 (58.9 ± 48.5 HU), iMAR-Algo2 (52.7 ± 46.8 HU) and the iMAR-Algo3 (51.9 ± 46.1 HU) compared with WFBP (91.6 ± 81.6 HU, p algorithms, respectively. iMAR-Algo2 and iMAR-Algo3 reconstructions decreased mild and moderate artefacts compared with WFBP and iMAR-Algo1 (p algorithms led to a significant reduction of metal artefacts and increase in overall image quality compared with WFBP in chest CT of patients with metallic implants in subjective and objective analysis. The iMARAlgo2 and iMARAlgo3 were best for mild artefacts. IMARAlgo1 was superior for severe artefacts. Advances in knowledge: Iterative MAR led to significant artefact reduction and increase image-quality compared with WFBP in CT after implementation of thoracic devices. Adjusting iMAR-algorithms to patients' metallic implants can help to improve image quality in CT.

  13. Dust on Mars: An Aeolian Threat to Human Exploration? (United States)

    Marshall, J.


    The NASA HEDS Program is duly concerned for human explorers regarding the potential hazard posed by the ubiquitous dust mantle on Mars. To evaluate properties of dust that could be hazardous to humans, the NMS 2001 Lander payload will include the Mars Environmental Compatibility Assessment (MECA) experiment. This includes optical and atomic-force microscopy to evaluate soil grains for shape and size, wet chemistry to evaluate toxic substances, electrometry to evaluate triboelectric charging, and test-material palets to evaluate electrostatic and magnetic adhesion, and the hardness/abrasiveness of soil grains; these experimental subcomponents are delivered samples by the camera-equipped robotic arm of the lander which will acquire material from depths of 0.5 to 1.0 m in the soil. Data returned by MECA will be of value to both the hEDS and planetary/astrobiology communities. Dust poses a threat to human exploration because the martian system does not hydrologically or chemically remove fine particles that are being continuously generated by thermal, aeolian, and colluvial weathering, and by volcanism and impact over billions of years. The dust is extremely fine-grained, in copious quantities, ubiquitous in distribution, continually mobile, and a source of poorly-grounded static charges -- a suite of characteristics posing a particulate and electrical threat to explorers and their equipment. Dust is mobilized on global and regional scales, but probably also unpredictably and violently at local scales by dust devils. The latter might be expected in great abundance owing to near surface atmospheric instability (dust devils were detected by Pathfinder during its brief lifetime). Preliminary laboratory experiments suggest that space-suit materials subjected to windblown dust may acquire a uniform, highly adhesive dust layer that is also highly cohesive laterally owing to electrostatic forces. This layer will obscure visibility through the helmet visor, penetrate joints

  14. Basalt weathering in an Arctic Mars-analog site (United States)

    Yesavage, Tiffany; Thompson, Aaron; Hausrath, Elisabeth M.; Brantley, Susan L.


    The martian surface has undergone chemical and physical weathering in the past, and these processes may continue intermittently today. To explore whether martian rocks are likely to retain features indicative of weathering, we investigated how basaltic material weathers on Earth. Specifically, we investigated weathering of a Quaternary-aged basaltic flow at the Sverrefjell volcano in Svalbard, above the Arctic Circle. This flow weathered since deglaciation under cold, dry (allophane as the predominant secondary phase. Selective chemical extractions targeting SRO phases indicated lower Al/Si ratios than those observed in volcanic soils reported in warmer localities, which we attribute to Si-rich allophane and/or abundant Si-rich rock coatings. The oxic circumneutral-pH colloidal dispersion experiments mobilized Al, Fe and Ti primarily as 260-415 nm particles and Ca, Mg and Na as solutes. Si was lost both in the colloidal and dissolved forms. Dispersed colloids likely contain allophane and ferrihydrite. Under anoxic conditions, dissolution of Fe oxide cements also released fines. The experiments help to explain elemental loss from the clay-sized regolith fraction at Svalbard: observed depletions in Ca, K, Mg and Na were likely due to solute loss, while particle-reactive Al, Fe, Si and Ti were mostly retained. Wetting/drying was observed to be as effective as freeze/thaw in driving material loss. It is thus possible that cyclic adsorption of water onto basaltic rocks in this dry climate may result in high physical spalling rates that in turn promote chemical leaching. Many observations at Sverrefjell are similar to inferences from Mars: the presence of SRO phases, Si-rich coatings, and/or Si-rich allophane, as well as the persistence of olivine. Given these similarities, it is inferred that Sverrefjell volcano is a good analog for martian weathering and that other processes operating at Sverrefjell may also have occurred on Mars, including Na leaching, surface

  15. Mars Environmental Compatibility Assessment (MECA): Identifying the Hazards of the Martian Soil (United States)

    Meloy, T. P.; Hecht, M. H.; Anderson, M. S.; Frant, M. A.; Fuerstenau, S. D.; Keller, H. U.; Markiewicz, W. J.; Marshall, J.; Pike, W. T.; Quate, C. F.


    Sometime in the next decade NASA will decide whether to send a human expedition to explore the planet Mars. The Mars Environmental Compatibility Assessment (MECA) has been selected by NASA to evaluate the Martian environment for soil and dust hazards to human exploration. The integrated MECA payload contains three elements: a wet-chemistry laboratory, a microscopy station, and enhancements to a lander robot-arm system incorporating arrays of material patches and an electrometer to identify triboelectric charging during soil excavation. The wet-chemistry laboratory will evaluate samples of Martian soil in water to determine the total dissolved solids, redox potential, pH, and quantify the concentration of many soluble ions using ion-selective electrodes. These electrodes can detect potentially dangerous heavy-metal ions, emitted pathogenic gases, and the soil's corrosive potential. MECA's microscopy station combines optical and atomic-force microscopy with a robot-arm camera to provide imaging over nine orders of magnitude, from meters to nanometers. Soil particle properties including size, shape, color, hardness, adhesive potential (electrostatic and magnetic), will be determined on the microscope stage using an ar-ray of sample receptacles and collection substrates, and an abrasion tool,. The simple, rugged atomic-force microscope will image in the submicron size range and has the capability of performing a particle-by-particle analysis of the dust and soil. Although selected by NASA's Human Exploration and Development of Space Enterprise, the MECA instrument suite also has the capability to address basic geology, paleoclimate, and exobiology issues. To understand both contemporaneous and ancient processes on Mars, the mineralogical, petrological, and reactivity of Martian surface materials should be constrained: the NMCA experiment will shed light on these quantities through its combination of chemistry and microscopy. On Earth, the earliest forms of life are

  16. Mars Reconnaissance Orbiter Wrapper Script (United States)

    Gladden, Roy; Fisher, Forest; Khanampornpan, Teerapat


    The MRO OLVM wrapper script software allows Mars Reconnaissance Orbiter (MRO) sequence and spacecraft engineers to rapidly simulate a spacecraft command product through a tool that simulates the onboard sequence management software (OLVM). This script parses sequence files to determine the appropriate time boundaries for the sequence, and constructs the script file to be executed by OLVM to span the entirety of the designated sequence. It then constructs script files to be executed by OLVM, constructs the appropriate file directories, populates these directories with needed input files, initiates OLVM to simulate the actual command product that will be sent to the spacecraft, and captures the results of the simulation run to an external file for later review. Additionally, the tool allows a user to manually construct the script, if desired, and then execute the script with a simple command line.

  17. Hydrogeology of Basins on Mars (United States)

    Arvidson, Raymond E.


    This document summarizes the work accomplished under NASA Grant NAG5-3870. Emphasis was put on the development of the FIDO rover, a prototype for the twin-Mers which will be operating on the surface of Mars in 2004, specifically the primary work was the analysis of FIDO field trials. The grantees also analyzed VIKING Lander 1 XRFS and Pathfinder APXS data. Results show that the Viking site chemistry is consistent with an andesite, and the Pathfinder site is consistent with a basaltic andesite. The grantees also worked to demonstrate the capability to simulate annealing methods to apply to the inversion of remote sensing data. They performed an initial analyses of Sojourner engineering telemetry and imaging data. They performed initial analyses of Viking Lander Stereo Images, and of Hematite deposits in Terra Meridiani. They also acquired and analyzed the New Goldstone radar data.

  18. Increased Science Instrumentation Funding Strengthens Mars Program (United States)

    Graham, Lee D.; Graff, T. G.


    As the strategic knowledge gaps mature for the exploration of Mars, Mars sample return (MSR), and Phobos/Deimos missions, one approach that becomes more probable involves smaller science instrumentation and integrated science suites. Recent technological advances provide the foundation for a significant evolution of instrumentation; however, the funding support is currently too small to fully utilize these advances. We propose that an increase in funding for instrumentation development occur in the near-term so that these foundational technologies can be applied. These instruments would directly address the significant knowledge gaps for humans to Mars orbit, humans to the Martian surface, and humans to Phobos/ Deimos. They would also address the topics covered by the Decadal Survey and the Mars scientific goals, objectives, investigations and priorities as stated by the MEPAG. We argue that an increase of science instrumentation funding would be of great benefit to the Mars program as well as the potential for human exploration of the Mars system. If the total non-Earth-related planetary science instrumentation budget were increased 100% it would not add an appreciable amount to the overall NASA budget and would provide the real potential for future breakthroughs. If such an approach were implemented in the near-term, NASA would benefit greatly in terms of science knowledge of the Mars, Phobos/Deimos system, exploration risk mitigation, technology development, and public interest.

  19. The Mars Gravity Simulation Project (United States)

    Korienek, Gene


    Human beings who make abrupt transitions between one gravitational environment and another undergo severe disruptions of their visual perception and visual- motor coordination, frequently accompanied by "space sickness." Clearly, such immediate effects of exposure to a novel gravitational condition have significant implications for human performance. For example, when astronauts first arrive in Earth orbit their attempts to move about in the spacecraft and to perform their duties are uncoordinated, inaccurate, and inefficient. Other inter-gravitational transitions for which these difficulties can be expected include going from the 0 g of the spacecraft to the. 16 g of the Moon, from 0 g to the .38 g of Mars, and from 0 g back to the 1.0 g of Earth. However, after astronauts have actively interacted with their new gravitational environment for several days, these problems tend to disappear, evidence that some sort of adaptive process has taken place. It would be advantageous, therefore, if there were some way to minimize or perhaps even to eliminate this potentially hazardous adaptive transition period by allowing astronauts to adapt to the altered gravitational conditions before actually entering them. Simultaneous adaptations to both the altered and the normal gravitational environment as a result of repeatedly adapting to one and readapting to the other, a phenomenon known as dual adaptation. The objective of the Mars Gravity Simulator (MGS) Project is to construct a simulation of the visual and bodily effects of altered gravity. This perceptual-motor simulation is created through the use of: 1) differential body pressure to produce simulated hypo-gravity and 2) treadmill-controlled virtual reality to create a corresponding visual effect. It is expected that this combination will produce sensory motor perturbations in the subjects. Both the immediate and adaptive behavioral (postural and ambulatory) responses to these sensory perturbations will be assessed.

  20. MEMOS - Mars Environment Monitoring Satellite (United States)

    Ott, T.; Barabash, S.; von Schéele, F.; Clacey, E.; Pokrupa, N.


    The Swedish Institute of Space Physics (IRF) in cooperation with the Swedish Space Corporation (SSC) has conducted first studies on a Mars Environment Monitoring Satellite (MEMOS). The MEMOS microsatellite (mass 2 kbit/s. The transceiver also implements a coherent transponding mode for orbit determination through two-way Doppler ranging between the parent satellite and MEMOS. In addition ELT is compatible with a future Martian communication and navigation network pursued by NASA, which could be taken advantage of in the future for relaying data or performing ranging via other satellites part of the network. A system design driver for inter-satellite communication at Mars is the high demand of power. This leads to a disk-shape and thus easy to accommodate spacecraft configuration of MEMOS comprising a single sun-pointing solar array favourable in terms of power and spin stability. Multi-junction solar cells, which currently have an efficiency of ~29% under laboratory conditions are a key factor to keep MEMOS solar array area of ~1.15 m2 small compared to the worst case system power requirements of ~105 W. During eclipse periods high-efficient Li-ion batteries (6 x 20 Wh) will ensure power supply. The spacecraft and payload design will incorporate new technology developments such as autonomous navigation, MicroElectroMechanical Systems MEMS, Micro- Opto-ElectroMechanical Systems MOEMS and new materials to achieve low mass at high performance. Thereby it will profit from Swedish developments and heritage in small- / microsatellites like Astrid-2, SMART-1 or the upcoming rendezvous and formation flying demonstration mission PRISMA.

  1. Mars Surface Tunnel Element Concept (United States)

    Rucker, Michelle A.


    How crews get into or out of their ascent vehicle has profound implications for Mars surface architecture. Extravehicular Activity (EVA) hatches and Airlocks have the benefit of relatively low mass and high Technology Readiness Level (TRL), but waste consumables with a volume depressurization for every ingress/egress. Perhaps the biggest drawback to EVA hatches or Airlocks is that they make it difficult to keep Martian dust from being tracked back into the ascent vehicle, in violation of planetary protection protocols. Suit ports offer the promise of dust mitigation by keeping dusty suits outside the cabin, but require significant cabin real estate, are relatively high mass, and current operational concepts still require an EVA hatch to get the suits outside for the first EVA, and back inside after the final EVA. This is primarily because current designs don't provide enough structural support to protect the suits from ascent/descent loads or potential thruster plume impingement. For architectures involving more than one surface element-such as an ascent vehicle and a rover or surface habitat-a retractable tunnel is an attractive option. By pushing spacesuit don/doff and EVA operations to an element that remains on the surface, ascended vehicle mass and dust can be minimized. What's more, retractable tunnels provide operational flexibility by allowing surface assets to be re-configured or built up over time. Retractable tunnel functional requirements and design concepts being developed as part of the National Aeronautics and Space Administration's (NASA) Evolvable Mars Campaign (EMC) work will add a new ingress/egress option to the surface architecture trade space.

  2. Can I Stop Myself From Having a Wet Dream? (For Teens) (United States)

    ... Can I Stop Myself From Having a Wet Dream? KidsHealth > For Teens > Can I Stop Myself From Having a Wet Dream? Print A A A Can I stop myself from having a wet dream? – Tom* You really can't stop wet dreams, ...

  3. Formation of a hybrid-type proto-atmosphere on Mars accreting in the solar nebula (United States)

    Saito, Hiroaki; Kuramoto, Kiyoshi


    Recent studies of the chronology of Martian meteorites suggest that the growth of Mars was almost complete within a few Myr after the birth of the Solar system. During such rapid accretion, proto-Mars likely gravitationally maintained both the solar nebula component and the impact degassing component, containing H2O vapour and reduced gas species, as a proto-atmosphere to be called a hybrid-type proto-atmosphere. Here we numerically analyse the mass and composition of the degassed component and the atmospheric thermal structure sustained by accretional heating. Our results predict that a growing Mars possibly acquired a massive and hot hybrid-type proto-atmosphere with surface pressure and temperature greater than several kbar and 2000 K, respectively, which is sufficient to produce a deep magma ocean. In such a high-temperature and high-pressure environment, a significant amount of H2O, CH4, CO, and H2 is expected to be partitioned into the planetary interior, although this would strongly depend on the dynamics of the magma ocean and mantle solidification. The dissolved H2O may explain the wet Martian mantle implied from basaltic Martian meteorites. Along with the remnant reduced atmosphere after the hydrodynamic atmospheric escape, dissolved reduced gas species may have maintained an earliest Martian surface environment that allowed prebiotic chemical evolution and liquid H2O activities.

  4. Paleohydrology on Mars constrained by mass balance and mineralogy of pre-Amazonian sodium chloride lakes (United States)

    Melwani Daswani, M.; Kite, E. S.


    Chloride-bearing deposits on Mars record high-elevation lakes during the waning stages of Mars' wet era (mid-Noachian to late Hesperian). The water source pathways, seasonality, salinity, depth, lifetime, and paleoclimatic drivers of these widespread lakes are all unknown. Here we combine reaction-transport modeling, orbital spectroscopy, and new volume estimates from high-resolution digital terrain models, in order to constrain the hydrologic boundary conditions for forming the chlorides. Considering a T = 0°C system, we find that (1) individual lakes were >100 m deep and lasted decades or longer; (2) if volcanic degassing was the source of chlorine, then the water-to-rock ratio or the total water volume were probably low, consistent with brief excursions above the melting point and/or arid climate; (3) if the chlorine source was igneous chlorapatite, then Cl-leaching events would require a (cumulative) time of >10 years at the melting point; and (4) Cl masses, divided by catchment area, give column densities 0.1-50 kg Cl/m2, and these column densities bracket the expected chlorapatite-Cl content for a seasonally warm active layer. Deep groundwater was not required. Taken together, our results are consistent with Mars having a usually cold, horizontally segregated hydrosphere by the time chlorides formed.

  5. Methane bursts as a trigger for intermittent lake-forming climates on post-Noachian Mars (United States)

    Kite, Edwin S.; Gao, Peter; Goldblatt, Colin; Mischna, Michael A.; Mayer, David P.; Yung, Yuk L.


    Lakes existed on Mars later than 3.6 billion years ago, according to sedimentary evidence for deltaic deposition. The observed fluviolacustrine deposits suggest that individual lake-forming climates persisted for at least several thousand years (assuming dilute flow). But the lake watersheds’ little-weathered soils indicate a largely dry climate history, with intermittent runoff events. Here we show that these observational constraints, although inconsistent with many previously proposed triggers for lake-forming climates, are consistent with a methane burst scenario. In this scenario, chaotic transitions in mean obliquity drive latitudinal shifts in temperature and ice loading that destabilize methane clathrate. Using numerical simulations, we find that outgassed methane can build up to atmospheric levels sufficient for lake-forming climates, if methane clathrate initially occupies more than 4% of the total volume in which it is thermodynamically stable. Such occupancy fractions are consistent with methane production by water-rock reactions due to hydrothermal circulation on early Mars. We further estimate that photochemical destruction of atmospheric methane curtails the duration of individual lake-forming climates to less than a million years, consistent with observations. We conclude that methane bursts represent a potential pathway for intermittent excursions to a warm, wet climate state on early Mars.

  6. Modeling of GPS tropospheric delay wet Neill mapping function (NMF) (United States)

    Sakidin, Hamzah; Ahmad, Asmala; Bugis, Ismadi


    The modeling of the GPS tropospheric delay mapping function should be revised by modifying or simplify its mathematical model. Some current mapping functions models are separated into hydrostatic and the wet part. The current tropospheric delay models use mapping functions in the form of continued fractions. This model is quite complex and need to be simplified. By using regression method, the wet mapping function models has been selected to be simplified. There are eleven operations for wet mapping function component of Neill Mapping Function (NMF), to be carried out before getting the mapping function scale factor. So, there is a need to simplify the mapping function models to allow faster calculation and also better understanding of the models.

  7. Drying and wetting of building materials and components

    CERN Document Server


    This book, Drying and Wetting of Building Materials and Components, provides a collection of recent contributions in the field of drying and wetting in porous building materials. The main benefit of the book is that it discusses some of the most important topics related to the drying and wetting processes, namely, innovations and trends in drying science and technology, drying mechanism and theory, equipment, advanced modelling, complex simulation and experimentation. At the same time, these topics will be going to the encounter of a variety of scientific and engineering disciplines. The book is divided in several chapters that intend to be a resume of the current state of knowledge for benefit of professional colleagues.

  8. Development of the Internet Watershed Educational Tool (InterWET

    Directory of Open Access Journals (Sweden)

    Shane Parson


    Full Text Available Watershed educational and informational efforts have largely neglected to inform one important group of decision-makers: local government officials. The Internet Watershed Educational Tool (InterWET was developed to help inform local officials about water resources, using as a case study the Spring Creek Watershed in central Pennsylvania. Utilizing the "microworlds" concept, InterWET consists of a set of web pages that present water resource issues and components from different perspectives. Specifically, the components of surface runoff, groundwater flow, detached and delivered sediment, in-stream nutrients, and fish populations are presented from the perspectives of a researcher, a conservationist, and a local official. In addition to informing local officials, InterWET can also be used as a stand-alone informational resource or as part of larger watershed educational efforts.

  9. In situ transesterification of highly wet microalgae using hydrochloric acid. (United States)

    Kim, Bora; Im, Hanjin; Lee, Jae W


    This study addresses in situ transesterification of highly wet microalgae with hydrochloric acid (HCl) as a catalyst. In situ transesterification was performed by heating the mixture of wet algal cells, HCl, methanol, and solvent in one pot, resulting in the fatty acid methyl ester (FAME) yield over 90% at 95°C. The effects of reaction variables of temperature, amounts of catalyst, reactant, and solvent, and type of solvents on the yield were investigated. Compared with the catalytic effect of H2SO4, in situ transesterification using HCl has benefits of being less affected by moisture levels that are as high as or above 80%, and requiring less amounts of catalyst and solvent. For an equimolar amount of catalyst, HCl showed 15wt.% higher FAME yield than H2SO4. This in situ transesterification using HCl as a catalyst would help to realize a feasible way to produce biodiesel from wet microalgae. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Wetting and Spreading of Molten Volcanic Ash in Jet Engines. (United States)

    Song, Wenjia; Lavallée, Yan; Wadsworth, Fabian B; Hess, Kai-Uwe; Dingwell, Donald B


    A major hazard to jet engines posed by volcanic ash is linked to the wetting and spreading of molten ash droplets on engine component surfaces. Here, using the sessile drop method, we study the evolution of the wettability and spreading of volcanic ash. We employ rapid temperature changes up to 1040-1450 °C, to replicate the heating conditions experienced by volcanic ash entering an operating jet engine. In this scenario, samples densify as particles coalesce under surface tension until they form a large system-sized droplet (containing remnant gas bubbles and crystals), which subsequently spreads on the surface. The data exhibit a transition from a heterogeneous to a homogeneous wetting regime above 1315 °C as crystals in the drops are dissolved in the melt. We infer that both viscosity and microstructural evolution are key controls on the attainment of equilibrium in the wetting of molten volcanic ash droplets.

  11. Some specificities of wetting by cyanobiphenyl liquid crystals

    Energy Technology Data Exchange (ETDEWEB)

    Delabre, U; Richard, C; Cazabat, A M, E-mail: cazabat@lps.ens.f [Laboratoire de Physique Statistique, Ecole Normale Superieure, Universite Pierre et Marie Curie, CNRS, 24 rue Lhomond, 75231 Paris Cedex 05 (France)


    The present paper provides an up to date restatement of the wetting behaviour of the series of cyanobiphenyl liquid crystals (LCs) on usual substrates, i.e. oxidized silicon wafers, water and glycerol, at both the macroscopic and microscopic scale, in the nematic range of temperature. We show that on water the systems are close to a wetting transition, especially 5CB and 7CB. In that case, the wetting behaviour is controlled by the presence of impurities. On a mesoscopic scale, we observe for all our (thin LC film-substrate) systems an identical, complex, but well defined general scenario, not accounted for by the available models. In the last part, we present a study on line tension which results from the specific organization of LCs at the edge of the nematic film. We report preliminary results on two-dimensional film coalescence where this line tension plays a major role.

  12. Wetting dynamics beneath fluid drops impacting on hot surfaces (United States)

    Harth, Kirsten; van Limbeek, Michiel A. J.; Shirota, Minori; Sun, Chao; Lohse, Detlef

    Fluid droplets encountering a phase transition when they impact a target surface are involved in many applications, e.g., spray cooling or painting / coating, ink-jet and 3D printing, soldering, firefighting using sprinklers. Drop impact on hot plates is an emerging topic, involving a complex interplay of hydrodynamics, heat flux and the occurring phase transition, involving large spatial and temporal gradients. Whether and to what extent droplets touch the surface is of immense importance for the overall heat transfer. High-speed total internal reflection imaging allows us to discriminate wetted and vapor-covered regions of the substrate. We study the transient wetting behaviour of the plate by varying the latent heat of the droplet. The characteristic cooling time of the plate is not solely determined by the plate properties. In addition to current literature, we show that in those cases the wetting pattern is both spatially and temporally inhomogeneous.

  13. Liquid Metal Phagocytosis: Intermetallic Wetting Induced Particle Internalization. (United States)

    Tang, Jianbo; Zhao, Xi; Li, Jing; Zhou, Yuan; Liu, Jing


    A biomimetic cellular-eating phenomenon in gallium-based liquid metal to realize particle internalization in full-pH-range solutions is reported. The effect, which is called liquid metal phagocytosis, represents a wet-processing strategy to prepare various metallic liquid metal-particle mixtures through introducing excitations such as an electrical polarization, a dissolving medium, or a sacrificial metal. A nonwetting-to-wetting transition resulting from surface transition and the reactive nature of the intermetallic wetting between the two metallic phases are found to be primarily responsible for such particle-eating behavior. Theoretical study brings forward a physical picture to the problem, together with a generalized interpretation. The model developed here, which uses the macroscopic contact angle between the two metallic phases as a criterion to predict the particle internalization behavior, shows good consistency with experimental results.

  14. Helminths in rodents from Wet Markets in Thailand

    Directory of Open Access Journals (Sweden)

    Ribas A.


    Full Text Available Only a few surveys have ever been carried out of the helminths of the commensal rodents found in the traditional wet markets that play such an important part of daily life in South-east Asia. The potential of rodents as reservoirs of zoonoses including helminths is of great interest since in these markets humans and rodents come into closer contact than in other environments and food may be indirectly contaminated via rodent faeces. Helminths in a total of 98 rats belonging to two species (Rattus norvegicus and Rattus exulans were surveyed in eight traditional wet markets in Udon Thani, Thailand. Thirteen species of helminths were recovered, seven of which are potentially zoo-notic, with an overall prevalence of 89.8 %. Our results show that rodents in wet markets could pose a threat to human health as potential reservoirs of zoonotic helminthiases.

  15. Tailoring the microstructure of particle-stabilized wet foams. (United States)

    Gonzenbach, Urs T; Studart, André R; Tervoort, Elena; Gauckler, Ludwig J


    Inorganic colloidal particles which are in situ hydrophobized upon adsorption of short-chain amphiphilic molecules can be used as foam stabilizers. In this study, we tailor the microstructure of particle-stabilized wet foams, namely, the foam air content, average bubble size, and bubble size distribution, by changing the composition of the initial colloidal suspension. Wet foams featuring average bubble sizes between 10 and 200 microm and air contents between 45% and 90% were obtained by adjusting the amphiphile and particle concentration, pH, ionic strength, and particle size in the initial suspension. The influence of these parameters on the bubble size was satisfactorily described in terms of a balance between the shear stress applied during mixing and the counteracting Laplace pressure of the air bubbles. This model, originally developed for oil droplets in emulsions, can therefore be used to deliberately tailor the microstructure of particle-stabilized wet foams.

  16. Psychiatric disturbance, urgency, and bacteriuria in children with day and night wetting. (United States)

    Berg, I; Fielding, D; Meadow, R


    Forty children with day and night wetting were compared with 46 with night wetting only to see if day wetting was then associated with particular clinical features. Interviews with mothers, questionnaries completed by teachers, physical investigations, and measurement of functional bladder capacities were used. Day wetting combined with bed wetting occurred equally in boys and girls and was associated with daytime urgency and greater frequency of psychiatric disturbance. In boys, soiling was also associated. In girls, bacteriuria, which appeared to be caused by the day wetting, occurred in about 50%. Neither daytime frequency nor small functional bladder capacity were specifically related to day wetting. PMID:921313

  17. The resources of Mars for human settlement (United States)

    Meyer, Thomas R.; Mckay, Christopher P.


    Spacecraft exploration of Marshas shown that the essential resources necessary for life support are present on the Martian surface. The key life-support compounds O2, N2, and H2O are available on Mars. The soil could be used as radiation shielding and could provide many useful industrial and construction materials. Compounds with high chemical energy, such as rocket fuels, can be manufactured in-situ on Mars. Solar power, and possibly wind power, are available and practical on Mars. Preliminary engineering studies indicate that fairly autonomous processes can be designed to extract and stockpile Martian consumables.

  18. Simulation and Spacecraft Design: Engineering Mars Landings. (United States)

    Conway, Erik M


    A key issue in history of technology that has received little attention is the use of simulation in engineering design. This article explores the use of both mechanical and numerical simulation in the design of the Mars atmospheric entry phases of the Viking and Mars Pathfinder missions to argue that engineers used both kinds of simulation to develop knowledge of their designs' likely behavior in the poorly known environment of Mars. Each kind of simulation could be used as a warrant of the other's fidelity, in an iterative process of knowledge construction.

  19. Mars Science Laboratory Rover Taking Shape (United States)


    This image taken in August 2008 in a clean room at NASA's Jet Propulsion Laboratory, Pasadena, Calif., shows NASA's next Mars rover, the Mars Science Laboratory, in the course of its assembly, before additions of its arm, mast, laboratory instruments and other equipment. The rover is about 9 feet wide and 10 feet long. Viewing progress on the assembly are, from left: NASA Associate Administrator for Science Ed Weiler, California Institute of Technology President Jean-Lou Chameau, JPL Director Charles Elachi, and JPL Associate Director for Flight Projects and Mission Success Tom Gavin. JPL, a division of Caltech, manages the Mars Science Laboratory project for the NASA Science Mission Directorate, Washington.

  20. Phoning Home from Mars in 2025 (United States)

    Adams, J.


    It's spring at Martian Outpost 3, the year 2025. The Universe Cup's on later today, and next week little Suzie celebrates her fourth birthday. Fortunately, this football fan and parent will be able to participate in both of these activities, albeit at a slight time delay, due completely to the sophisticated, high-speed quasi-real-time multimedia/navigation MarsNet surrounding Mars and tying it to Earth. Capable of moving gigabits a second in either direction, the network supports not only the multiple manned and robotic science needs of teams and devices encircling Mars, but also the very real human need for communication.

  1. Astrobiology field research in Moon/Mars Analogue

    NARCIS (Netherlands)

    Foing, B.H.; Stoker, C.; Ehrenfreund, P.


    Extreme environments on Earth often provide similar terrain conditions to landing/operation sites on Moon and Mars. Several field campaigns (EuroGeoMars2009 and DOMMEX/ILEWG EuroMoonMars from November 2009 to March 2010) were conducted at the Mars Desert Research Station (MDRS) in Utah. Some of the

  2. Mission to Mars to Collect a Storehouse of Scientific Data


    Albee, Arden


    Just after Election Day, the Mars Global Surveyor spacecraft (Figure 1) will embark on a journey to Mars to examine the surface and the seasonal variations of the atmosphere over an entire Mars year. Mars is an extremely rich mission target because the scientific questions it poses touch on geology, geophysics, geochemistry, atmospheric physics, climatology, biology, and—most of all—comparative planetology.

  3. Low Cost Mars Sample Return Utilizing Dragon Lander Project (United States)

    Stoker, Carol R.


    We studied a Mars sample return (MSR) mission that lands a SpaceX Dragon Capsule on Mars carrying sample collection hardware (an arm, drill, or small rover) and a spacecraft stack consisting of a Mars Ascent Vehicle (MAV) and Earth Return Vehicle (ERV) that collectively carry the sample container from Mars back to Earth orbit.

  4. Mars and Phobos DTM's for planning new missions (United States)

    Duxbury, T. C.


    The global digital topography and elevation models of Mars produced by the Mars Global Surveyor (MGS) Mars Orbiter Laser Altimeter (MOLA) and of Mars derived from Viking Orbiter stereo imaging have many uses for geodesy, geophysics, morphology and cartography studies of these two planetary bodies.

  5. Wetting behavior on hybrid surfaces with hydrophobic and hydrophilic properties

    Energy Technology Data Exchange (ETDEWEB)

    Yao, Chun-Wei [Dept. of Mechanical Engineering, Texas A and M University, College Station, TX 77843 (United States); Alvarado, Jorge L., E-mail: [Dept. of Engineering Technology and Industrial Distribution, Texas A and M University, College Station, TX 77843 (United States); Marsh, Charles P. [ERDC – Construction Engineering Research Laboratory, 2902 Newmark Dr., Champaign, IL 61826 (United States); Dept. of Nuclear, Plasma, and Radiological Engineering, University of Illinois at Urbana-Champaign, Champaign, IL 61801 (United States); Jones, Barclay G. [Dept. of Nuclear, Plasma, and Radiological Engineering, University of Illinois at Urbana-Champaign, Champaign, IL 61801 (United States); Collins, Michael K. [ERDC – Construction Engineering Research Laboratory, 2902 Newmark Dr., Champaign, IL 61826 (United States); Dept. of Nuclear, Plasma, and Radiological Engineering, University of Illinois at Urbana-Champaign, Champaign, IL 61801 (United States)


    Hybrid surfaces consisting of a micropillar array of hydrophobic and hydrophilic sites were designed and fabricated to understand the effects of their unique surface morphology and chemistry on droplet condensation. Droplet impingement experiments have revealed that hybrid surfaces exhibit high contact angles, which is characteristic of purely hydrophobic surfaces. However, little is known about the wetting behavior of droplets that nucleate and grow on hybrid surfaces during condensation. In fact, condensed droplets display a distinct wetting behavior during the droplet growth phase which cannot be reproduced by simply impinging droplets on hybrid surfaces. In this study, hybrid surfaces with three different spacing ratios were subjected to condensation tests using an environmental scanning electron microscopy (ESEM) and a condensation cell under ambient conditions. For hybrid surfaces with spacing ratio below 2, droplets were observed to form on top and sides of the micropillars, where they grew, coalesced with adjacent droplets, and shed after reaching a given size. After shedding, the top surface remained partially dry, which allowed for immediate droplet growth. For hybrid surfaces with spacing ratio equal to 2, a different wetting behavior was observed, where droplets basically coalesced and formed a thin liquid film which was ultimately driven into the valleys of the microstructure. The liquid shedding process led to the renucleation of droplets primarily on top of the dry hydrophilic sites. To better understand the nature of droplet wetting on hybrid surfaces, a surface energy-based model was developed to predict the transition between the two observed wetting behaviors at different spacing ratios. The experimental and analytical results indicate that micropillar spacing ratio is the key factor for promoting different wetting behavior of condensed droplets on hybrid surfaces.

  6. Search for Chemical Biomarkers on Mars Using the Sample Analysis at Mars Instrument Suite on the Mars Science Laboratory (United States)

    Glavin, D. P.; Conrad, P.; Dworkin, J. P.; Eigenbrode, J.; Mahaffy, P. R.


    One key goal for the future exploration of Mars is the search for chemical biomarkers including complex organic compounds important in life on Earth. The Sample Analysis at Mars (SAM) instrument suite on the Mars Science Laboratory (MSL) will provide the most sensitive measurements of the organic composition of rocks and regolith samples ever carried out in situ on Mars. SAM consists of a gas chromatograph (GC), quadrupole mass spectrometer (QMS), and tunable laser spectrometer to measure volatiles in the atmosphere and released from rock powders heated up to 1000 C. The measurement of organics in solid samples will be accomplished by three experiments: (1) pyrolysis QMS to identify alkane fragments and simple aromatic compounds; pyrolysis GCMS to separate and identify complex mixtures of larger hydrocarbons; and (3) chemical derivatization and GCMS extract less volatile compounds including amino and carboxylic acids that are not detectable by the other two experiments.

  7. Effect of wet grinding on structural properties of ball clay

    Energy Technology Data Exchange (ETDEWEB)

    Purohit, A., E-mail:; Chander, S.; Dhaka, M. S. [Department of Physics, Mohanlal Sukhadia University, Udaipur-313001 (India); Hameed, A.; Singh, P. [Department of Ceramic Engineering, Govt. College of Engineering and Technology, Bikaner-334004 (India); Nehra, S. P. [Centre of Excellence for Energy and Environmental Studies, Deenbandhu Chhotu Ram University of Science and Technology, Murthal, Sonepat-131039 (India)


    In this paper, the effect of wet grinding on structural properties of ball clay is undertaken. The wet grinding treatment was performed employing ball and vibro mills for different time spells of 2, 4, 8 and 16 hours. The structural properties were carried out using X-ray diffraction (XRD). The structure of ground samples is found to be simple cubic. The crystallographic parameters are calculated and slight change in lattice constant, inter planner spacing and particle size is observed with grinding treatment. The results are in agreement with the available literature.

  8. Wet-air oxidation cleans up black wastewater

    Energy Technology Data Exchange (ETDEWEB)


    Sterling Organics produces the analgesic paracetamol (acetaminophen) at its Dudley, England, plant. The wastewater from the batch process contains intermediates such as para-aminophenol (PAP) and byproducts such as thiosulfates, sulfites and sulfides. To stay ahead of increasingly strict environmental legislation, Sterling Organics installed a wet-air oxidation system at the Dudley facility in August 1992. The system is made by Zimpro Environmental Inc. (Rothschild, Wis.). Zimpro's wet-air oxidation system finds a way around the limitations of purely chemical or physical processes. In the process, compressed air at elevated temperature and pressure oxidizes the process intermediates and byproducts and removes the color from the wastewater.

  9. Wetting of doped carbon nanotubes by water droplets

    DEFF Research Database (Denmark)

    Kotsalis, E. M.; Demosthenous, E.; Walther, Jens Honore


    We study the wetting of doped single- and multi-walled carbon nanotubes by water droplets using molecular dynamics simulations. Chemisorbed hydrogen is considered as a model of surface impurities. We study systems with varying densities of surface impurities and we observe increased wetting......, as compared to the pristine nanotube case, attributed to the surface dipole moment that changes the orientation of the interfacial water. We demonstrate that the nature of the impurity is important as here hydrogen induces the formation of an extended hydrogen bond network between the water molecules...

  10. Final Report: Wetted Cathodes for Low-Temperature Aluminum Smelting

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Craig W


    A low-temperature aluminum smelting process being developed differs from the Hall-Heroult process in several significant ways. The low-temperature process employs a more acidic electrolyte than cryolite, an alumina slurry, oxygen-generating metal anodes, and vertically suspended electrodes. Wetted and drained vertical cathodes are crucial to the new process. Such cathodes represent a significant portion of the capital costs projected for the new technology. Although studies exist of wetted cathode technology with Hall-Heoult cells, the differences make such a study desirable with the new process.

  11. Topographical Anisotropy and Wetting of Ground Stainless Steel Surfaces

    Directory of Open Access Journals (Sweden)

    Cornelia Bellmann


    Full Text Available Microscopic and physico-chemical methods were used for a comprehensive surface characterization of different mechanically modified stainless steel surfaces. The surfaces were analyzed using high-resolution confocal microscopy, resulting in detailed information about the topographic properties. In addition, static water contact angle measurements were carried out to characterize the surface heterogeneity of the samples. The effect of morphological anisotropy on water contact angle anisotropy was investigated. The correlation between topography and wetting was studied by means of a model of wetting proposed in the present work, that allows quantifying the air volume of the interface water drop-stainless steel surface.

  12. Evaluation of wet oxidation pretreatment for enzymatic hydrolysis of softwood

    DEFF Research Database (Denmark)

    Palonen, H.; Thomsen, A.B.; Tenkanen, M.


    The wet oxidation pretreatment (water, oxygen, elevated temperature, and pressure) of softwood (Picea abies) was investigated for enhancing enzymatic hydrolysis. The pretreatment was preliminarily optimized. Six different combinations of reaction time, temperature, and pH were applied......, and the compositions of solid and liquid fractions were analyzed. The solid fraction after wet oxidation contained 58-64% cellulose, 2-16% hemicellulose, and 24-30% lignin. The pretreatment series gave information about the roles of lignin and hemicellulose in the enzymatic hydrolysis. The temperature...

  13. Energy and exergy analysis of counter flow wet cooling towers

    Directory of Open Access Journals (Sweden)

    Saravanan Mani


    Full Text Available Cooling tower is an open system direct contact heat exchanger, where it cools water by both convection and evaporation. In this paper, a mathematical model based on heat and mass transfer principle is developed to find the outlet condition of water and air. The model is solved using iterative method. Energy and exergy analysis infers that inlet air wet bulb temperature is found to be the most important parameter than inlet water temperature and also variation in dead state properties does not affect the performance of wet cooling tower. .

  14. Effect of Atmospheric Press on Wet Bulb Depression (United States)

    Wheeler, Raymond M.; Stasiak, Michael A.; Lawson, Jamie; Wehkamp, Cara Ann P.; Dixon, Michael A.


    Our measurements of wet bulb depression at different pressures matched the modeled adiabatic saturation temps reasonably well. At a dry bulb temp of 25 C, the normal wet bulb temp for 30% RH and 100 kPa is approx.15 C, but this dropped to approx.8 C at 10 kPa. The results suggest that psychrometers need direct calibration at the target pressures or that pressure corrected charts are required. For a given vapour pressure deficit, any moist surfaces, including transpiring plant leaves, will be cooler at lower pressures due to the increased evaporation rates.

  15. Experimental and Theoretical Investigations of Wet Flue Gas Desulphurisation

    DEFF Research Database (Denmark)

    Kiil, Søren

    limestones of dif-ferent origin were tested. A transient, mass transport controlled, mathematical model was de-veloped to describe the dissolution process. Model predictions were found to be qualitatively in good agreement with experimental data. Deviations between measurements and simulations were...... - 333 K, pertinent for full-scale wet FGD packed towers. The possibility of co-firing straw and coal was investigated in a full-scale power plant. No ef-fects on the overall performance of the wet FGD plant were observed, though laboratory ex-periments with fine dust and fly ash from the full...

  16. Wetting ability modifications in biocompatible polymers induced by pulsed lasers (United States)

    Scolaro, C.; Torrisi, L.; Cutroneo, M.; Velardi, L.


    Wetting ability was measured in the surface of different biocompatible polymers, such as mylar, polyethylene, poly-methyl-methacrylate and teflon. Nanosecond pulse lasers at intensities of the order of 108 W/cm2 were employed at different doses to irradiate the polymeric surfaces and to induce wetting ability modifications due to the chemical and physical surface changes vs. irradiation time and laser wavelength. In particular, the contact angle as a function of the surface roughness was investigated, as will be presented and discussed.

  17. The formation of peroxonitrites and oxygen on Mars (United States)

    Plumb, Robert C.; Edwards, John O.


    When Martian regolith samples are moistened with water, a strong oxidant and oxygen gas are released. The many possible oxidants which have been suggested as present, including superoxide (O2(-)) hydrogen peroxide (H2O2(-)), and manganese (IV) oxide (MnO2), as well as peroxonitrite (ONOO(-)), can be distinguished by their ability to account for the numerous observations of the Viking Labelled Release (LR) and Gas Exchange (GEX) experiments. The magnitudes, kinetics, and heat labilities of the LR experiments and the magnitudes and heat labilities of the GEX experiments have been quantitatively replicated with peroxonitrites. Further, it is to be expected from information about the photochemistry of nitrogen in the atmosphere, the calculated fluxes of the NO(x) to the surface, the known reactions of NO(x) with carbonates to produce nitrates and photolysis studies of nitrates, that peroxonitrites are present on Mars. However, considerable uncertainty has existed about the form in which oxygen is stored in photolyzed nitrate crystals. Models have ranged from micropores of O2 to chemically bound oxygen as peroxonitrite (O2NOO(-)), as well as peroxonitrite. Studies of the solution chemistry and solid state photochemistry were completed, which show that much of the oxygen evolved on wetting comes from thermal breakdown of peroxonitrite after it is dissolved. A chemical model is developed for the photochemical processes occurring during UV irradiation of solid nitrates which resolves the several contradictory models discussed in the literature in recent years.

  18. Mars Global Reference Atmospheric Model 2010 Version: Users Guide (United States)

    Justh, H. L.


    This Technical Memorandum (TM) presents the Mars Global Reference Atmospheric Model 2010 (Mars-GRAM 2010) and its new features. Mars-GRAM is an engineering-level atmospheric model widely used for diverse mission applications. Applications include systems design, performance analysis, and operations planning for aerobraking, entry, descent and landing, and aerocapture. Additionally, this TM includes instructions on obtaining the Mars-GRAM source code and data files as well as running Mars-GRAM. It also contains sample Mars-GRAM input and output files and an example of how to incorporate Mars-GRAM as an atmospheric subroutine in a trajectory code.

  19. MarsCAT: Mars Array of ionospheric Research Satellites using the CubeSat Ambipolar Thruster (United States)

    Bering, E. A., III; Pinsky, L.; Li, L.; Jackson, D. R.; Chen, J.; Reed, H.; Moldwin, M.; Kasper, J. C.; Sheehan, J. P.; Forbes, J.; Heine, T.; Case, A. W.; Stevens, M. L.; Sibeck, D. G.


    The MarsCAT (Mars Array of ionospheric Research Satellites using the CubeSat Ambipolar Thruster) Mission is a two 6U CubeSat mission to study the ionosphere of Mars proposed for the NASA SIMPLeX opportunity. The mission will investigate the plasma and magnetic structure of the Martian ionosphere, including transient plasma structures, magnetic field structure and dynamics, and energetic particle activity. The transit plan calls for a piggy back ride with Mars 2020 using a CAT burn for MOI, the first demonstration of CubeSat propulsion for interplanetary travel. MarsCAT will make correlated multipoint studies of the ionosphere and magnetic field of Mars. Specifically, the two spacecraft will make in situ observations of the plasma density, temperature, and convection in the ionosphere of Mars. They will also make total electron content measurements along the line of sight between the two spacecraft and simultaneous 3-axis local magnetic field measurements in two locations. Additionally, MarsCAT will demonstrate the performance of new CubeSat telemetry antennas designed at the University of Houston that are designed to be low profile, rugged, and with a higher gain than conventional monopole (whip) antennas. The two MarsCAT CubeSats will have five science instruments: a 3-axis DC magnetometer, adouble-Langmuir probe, a Faraday cup, a solid state energetic particle detector (Science Enhancement Option), and interspacecraft total electron content radio occulation experiment. The MarsCAT spacecraft will be solar powered and equipped with a CAT thruster that can provide up to 4.8 km/s of delta-V, which is sufficient to achieve Mars orbit using the Mars 2020 piggyback. They have an active attitude control system, using a sun sensor and flight-proven star tracker for determination, and momentum wheels for 3-axis attitude control.

  20. Mars for Earthlings: An Analog Approach to Mars in Undergraduate Education


    Chan, Marjorie; Kahmann-Robinson, Julia


    Mars for Earthlings (MFE) is a terrestrial Earth analog pedagogical approach to teaching undergraduate geology, planetary science, and astrobiology. MFE utilizes Earth analogs to teach Mars planetary concepts, with a foundational backbone in Earth science principles. The field of planetary science is rapidly changing with new technologies and higher-resolution data sets. Thus, it is increasingly important to understand geological concepts and processes for interpreting Mars data. MFE curricul...

  1. Mars exploration program analysis group goal one: determine if life ever arose on Mars. (United States)

    Hoehler, Tori M; Westall, Frances


    The Mars Exploration Program Analysis Group (MEPAG) maintains a standing document that articulates scientific community goals, objectives, and priorities for mission-enabled Mars science. Each of the goals articulated within the document is periodically revisited and updated. The astrobiology-related Goal One, "Determine if life ever arose on Mars," has recently undergone such revision. The finalized revision, which appears in the version of the MEPAG Goals Document posted on September 24, 2010, is presented here.



    Öztürk, Yıldız; erbay, elif


    Anahtar kelimeler: Herbst apareyi, Mars apareyi, Class II maloklüzyon, Fonksiyonel ortopedik tedaviMars apareyi, iskeletsel II. sınıf düzensizliklerin tedavisinde başarı ile kullanılan ve hasta işbirliğini gerektirmeyen sabit bir fonksiyonel aygıttır. Bu yazıda Mars apareyinin özelliklerinden söz edilerek, bu aparey ile tedavi edilen bir vakadan elde edilen klinik ve radyolojik bulgular bildirilmektedir.Key Words: Herbst appliance, Mars appliance, Class II malocclusion, Functional orthopedic ...

  3. Seasonal and Static Gravity Field of Mars from MGS, Mars Odyssey and MRO Radio Science (United States)

    Genova, Antonio; Goossens, Sander; Lemoine, Frank G.; Mazarico, Erwan; Neumann, Gregory A.; Smith, David E.; Zuber, Maria T.


    We present a spherical harmonic solution of the static gravity field of Mars to degree and order 120, GMM-3, that has been calculated using the Deep Space Network tracking data of the NASA Mars missions, Mars Global Surveyor (MGS), Mars Odyssey (ODY), and the Mars Reconnaissance Orbiter (MRO). We have also jointly determined spherical harmonic solutions for the static and time-variable gravity field of Mars, and the Mars k 2 Love numbers, exclusive of the gravity contribution of the atmosphere. Consequently, the retrieved time-varying gravity coefficients and the Love number k 2 solely yield seasonal variations in the mass of the polar caps and the solid tides of Mars, respectively. We obtain a Mars Love number k 2 of 0.1697 +/-0.0027 (3- sigma). The inclusion of MRO tracking data results in improved seasonal gravity field coefficients C 30 and, for the first time, C 50 . Refinements of the atmospheric model in our orbit determination program have allowed us to monitor the odd zonal harmonic C 30 for approx.1.5 solar cycles (16 years). This gravity model shows improved correlations with MOLA topography up to 15% larger at higher harmonics ( l = 60–80) than previous solutions.

  4. Measurements of energetic particle radiation in transit to Mars on the Mars Science Laboratory. (United States)

    Zeitlin, C; Hassler, D M; Cucinotta, F A; Ehresmann, B; Wimmer-Schweingruber, R F; Brinza, D E; Kang, S; Weigle, G; Böttcher, S; Böhm, E; Burmeister, S; Guo, J; Köhler, J; Martin, C; Posner, A; Rafkin, S; Reitz, G


    The Mars Science Laboratory spacecraft, containing the Curiosity rover, was launched to Mars on 26 November 2011, and for most of the 253-day, 560-million-kilometer cruise to Mars, the Radiation Assessment Detector made detailed measurements of the energetic particle radiation environment inside the spacecraft. These data provide insights into the radiation hazards that would be associated with a human mission to Mars. We report measurements of the radiation dose, dose equivalent, and linear energy transfer spectra. The dose equivalent for even the shortest round-trip with current propulsion systems and comparable shielding is found to be 0.66 ± 0.12 sievert.

  5. Mars Pathfinder Spacecraft, Lander, and Rover Testing in Simulated Deep Space and Mars Surface Environments (United States)

    Johnson, Kenneth R.


    The Mars Pathfinder (MPF) Spacecraft was built and tested at the Jet Propulsion Laboratory during 1995/96. MPF is scheduled to launch in December 1996 and to land on Mars on July 4, 1997. The testing program for MPF required subjecting the mission hardware to both deep space and Mars surface conditions. A series of tests were devised and conducted from 1/95 to 7/96 to study the thermal response of the MPF spacecraft to the environmental conditions in which it will be exposed during the cruise phase (on the way to Mars) and the lander phase (landed on Mars) of the mission. Also, several tests were conducted to study the thermal characteristics of the Mars rover, Sojourner, under Mars surface environmental conditions. For these tests, several special test fixtures and methods were devised to simulate the required environmental conditions. Creating simulated Mars surface conditions was a challenging undertaking since Mars' surface is subjected to diurnal cycling between -20 C and -85 C, with windspeeds to 20 m/sec, occurring in an 8 torr CO2 atmosphere. This paper describes the MPF test program which was conducted at JPL to verify the MPF thermal design.

  6. Crystal Water on Mars: Insights from the Mars Exploration Rovers (United States)

    Ming, D. W.; Morris, R. V.; Clark, B. C.


    The purpose of this paper is to constrain the total water contents from crystal H2O and OH in several materials analyzed by the Mars Exploration Rovers (MER). Crystal H2O is part of the unit cell and cannot be removed without changing the structure. Minerals that contain only OH in their structures are anhydrous minerals containing hydroxyls, although they are formed as a product of aqueous activity and will decompose with evolution of H2O when heated. The crystal water and OH contents of a bulk material at the MER landing sites can be estimated from mineralogical composition, which is determined by a combination of Fe-mineralogy obtained by the Mossbauer Spectrometer and mineral abundances based upon the chemical composition determined by the Alpha Particle X-ray Spectrometer. Jarosite, along with Ca- and Mg-sulfates, have been suggested as the sulfur-bearing phases in Meridiani Planum outcrop. Models of various hydration states of Fe-, Ca-, and Mg-sulfates and other possible secondary phases suggest that 6 to 22 wt.% of the outcrop may occur as crystal H2O and/or OH (Clark et al., 2005). This estimate of water is consistent with measurements from the Odyssey orbiter, where 7 % H2O-equivalent H was measured down to a depth of approximately 1 m for the region (Feldman et al., 2004).

  7. Viability of encapsulated Lactobacillus sp. Mar 8

    Directory of Open Access Journals (Sweden)



    Full Text Available Lactobacillus sp. Mar 8 had advantages as probiotic digestive system cholesterol lowering Lactobacillus. Applying in industry, particular processing technique is necessary for gaining product that ready for marketing and consuming. Spray drying is common technique using in various food processing. High processing temperature, 100-200oC, for 3-10 second become the barrier because cells were under extreme temperature stress. Therefore, encapsulate was needed to protect the cells from those extreme conditions. Viability and survival rate of encapsulated Lactobacillus sp. Mar 8 have been investigated. The result showed that Lactobacillus sp. Mar 8 that was encapsulated by 10% skim milk has higher viability than those by 5% skim milk, namely 72.37% and 51.69% respectively. Survival rate of encapsulated Lactobacillus cells will come to zero in 41.28 years. Therefore, encapsulated Lactobacillus sp. Mar 8 may use as probiotic agent.

  8. An origin of life on Mars. (United States)

    McKay, Christopher P


    Evidence of past liquid water on the surface of Mars suggests that this world once had habitable conditions and leads to the question of life. If there was life on Mars, it would be interesting to determine if it represented a separate origin from life on Earth. To determine the biochemistry and genetics of life on Mars requires that we have access to an organism or the biological remains of one-possibly preserved in ancient permafrost. A way to determine if organic material found on Mars represents the remains of an alien biological system could be based on the observation that biological systems select certain organic molecules over others that are chemically similar (e.g., chirality in amino acids).

  9. Enabling Tethered Exploration on Mars Project (United States)

    National Aeronautics and Space Administration — Strong science motivations exist for exploring hard to reach terrain on Mars and the leading systems proposed to do so require tethers. While tethers are used...

  10. CO2 Removal from Mars EMU Project (United States)

    National Aeronautics and Space Administration — CO2 control for during ExtraVehicular Activity (EVA) on mars is challenging. Lithium hydroxide (LiOH) canisters have impractical logistics penalties, and regenerable...

  11. Mars One the ultimate reality TV show?

    CERN Document Server

    Seedhouse, Erik


    This book dissects the hype and hubris of the Mars One venture. Every aspect of the mission design is scrutinized, from the haphazard selection process to the unproven mission architecture. A controversial project, many professional astronauts consider Mars One a reckless attempt, yet it gained popular attention. This go-to reference guide provides the reader with insights into the myriad issues arising from the project's loss of funding, loss of sponsorship, loss of TV rights. It explains what contributed to an overly optimistic assessment of Mars One's mission-specific technology, and what captivated the public and the many willing candidates despite these flaws. From the author of Survival and Sacrifice in Mars Exploration (2015) among many more books on spacefaring, this is yet another up-to-the-minute account of an emerging player in the private space market from an expert on the subject.

  12. Earth-Mars transfers with ballistic capture (United States)

    Topputo, F.; Belbruno, E.


    We construct a new type of transfer from the Earth to Mars, which ends in ballistic capture. This results in substantial savings in capture from that of a classical Hohmann transfer under certain assumptions as well as an alternate way for spacecraft to transfer to Mars. This is accomplished by first becoming captured at Mars, very distant from the planet, and then from there, following a ballistic capture transfer to a desired altitude within a ballistic capture set. This is achieved by using stable sets, which are sets of initial conditions whose orbits satisfy a definition of orbital stability. This transfer type may be of interest for Mars missions because of low capture , flexibility of launch period from the Earth, moderate flight time, and the benign nature of the capture process.

  13. Methanogens as Models for Life on Mars (United States)

    Mickol, R. L.; Waddell, W. H.; Kral, T. A.


    Four methanogen species have been subjected to various martian conditions in order to test their suitability as candidates for life on Mars. These conditions include low pressure, low temperature and analog regoliths.

  14. A Possible Sink for Methane on Mars

    NARCIS (Netherlands)

    Nørnberg, P.; Jensen, S. J. K.; Skibsted, J.; Jakobsen, H. J.; ten Kate, I. L.; Gunnlaugsson, H. P.; Merrison, J. P.; Finster, K.; Bak, E.; Iversen, J. J.; Kondrup, J. C.


    Mechanical simulated wind activation of mineral surfaces act as a trap for Methane through formation of covalent Si-C bonds stable up to temperatures above 250 C. This mechanism is proposed as a Methane sink on Mars.

  15. Photocatalytic Conversion of CO2 on Mars (United States)

    Meier, Annie; Hare, Bryan


    Light on Mars shows potential for providing the energy means necessary for enhanced In-Situ Resource Utilization (ISRU). Through photocatalysis, the energy barrier required to convert CO2 is lowered and CH4 production is favorable.

  16. Computer failure caused loss of Mars spacecraft

    National Research Council Canada - National Science Library

    Zielinski, Sarah


    A computer error that occurred 5 months before NASA lost contact with the Mars Global Surveyor on 2 November 2006 led to the spacecraft's eventual battery failure and subsequent loss of orientation...

  17. Pressure and ion composition boundaries at Mars

    National Research Council Canada - National Science Library

    Xu, Shaosui; Liemohn, Michael W; Dong, Chuanfei; Mitchell, David L; Bougher, Stephen W; Ma, Yingjuan


    This study analyzes results from a multifluid MHD simulation to investigate the shape and structure of the pressure and composition boundaries at Mars, which can provide physical insight for the observational analysis...

  18. CO2 Removal from Mars EMU Project (United States)

    National Aeronautics and Space Administration — A practical CO2 control system for ExtraVehicular Activity (EVA) on Mars have not yet been developed. TDA Research, Inc. proposes to develop a durable,...

  19. Feasibility Study on Lunar and Mars Exploration (United States)

    Mori, Hidehiko; Takazawa, Yoshisada; Kaneko, Yutaka; Kawazoe, Takeshi; Takano, Yutaka; Namura, Eijiro


    This technical memorandum summarizes the results of an in-house study on lunar and Mars drone explorations - observation, landing and mobile explorations and sample returns for lunar and Mars respectively. So far, lunar and planet explorations have been primarily performed by the United States and the Soviet Union. ISAS and ESA have also contributed to some extent. The main purpose has been scientific exploration. There are some arguments that lunar and planet explorations should be performed for scientific purposes and the exploitation of them is not necessary. However, most scientific research involve the existence and survival of humankind, so it is not the fact that they cannot be organized from the side of exploitation. Especially, if NASDA makes approaches to lunar and Mars exploration, it should inevitably embrace exploitation plans. In this preface we provide the outline of lunar and Mars exploitation scenarios set up as a premise of the review on lunar and Mars unmanned exploration plans. Various reviews have been performed on whether the Moon or Mars would allow for human activities or survival. Among them, He mill, the solar powered satellite material mill and construction project of relay station to Mars as well as Mars teraforming plan have important issues. These projects have not yet become feasible because their expected investments are too large to make them practical. However, the present time seems the most appropriate to get with lunar and Mars exploitation projects under international cooperation since the realization of a space station is imminent and the international cooperation is being created with the participation of Russia. The international space station project will be continued until the year 2015. The post project has not yet been decided. Therefore, we expect that Japan would propose two successive projects, one is to construct an orbital service station combining manned abilities of the station and orbital service system and the

  20. Design of a Mars Airplane Propulsion System for the Aerial Regional-Scale Environmental Survey (ARES) Mission Concept (United States)

    Kuhl, Christopher A.


    The Aerial Regional-Scale Environmental Survey (ARES) is a Mars exploration mission concept that utilizes a rocket propelled airplane to take scientific measurements of atmospheric, surface, and subsurface phenomena. The liquid rocket propulsion system design has matured through several design cycles and trade studies since the inception of the ARES concept in 2002. This paper describes the process of selecting a bipropellant system over other propulsion system options, and provides details on the rocket system design, thrusters, propellant tank and PMD design, propellant isolation, and flow control hardware. The paper also summarizes computer model results of thruster plume interactions and simulated flight performance. The airplane has a 6.25 m wingspan with a total wet mass of 185 kg and has to ability to fly over 600 km through the atmosphere of Mars with 45 kg of MMH / MON3 propellant.