Sample records for sublime martian scene

  1. Effects of varying obliquity on Martian sublimation thermokarst landforms (United States)

    Dundas, Colin M.


    Scalloped depressions in the Martian mid-latitudes are likely formed by sublimation of ice-rich ground. The stability of subsurface ice changes with the planetary obliquity, generally becoming less stable at lower axial tilt. As a result, the relative rates of sublimation and creep change over time. A landscape evolution model shows that these variations produce internal structure in scalloped depressions, commonly in the form of arcuate ridges, which emerge as depressions resume growth after pausing or slowing. In other scenarios, the formation of internal structure is minimal. Significant uncertainties in past climate and model parameters permit a range of scenarios. Ridges observed in some Martian scalloped depressions could date from obliquity lows or periods of low ice stability occurring <5 Ma, suggesting that the pits are young features and may be actively evolving.

  2. Simulating hyperspectral images for Martian 3D scenes. (United States)

    Douté, S.


    We present a tool for simulating hyperspectral images for 3D Martian scenes. Several lines of development are considered for achieving a high degree of realism : high resolution digital elevation models, description of material distribution with fractal characteristics, bidirectional reflectance measured in the laboratory as a function of geometry and wavelength for a series analogue materials, mixing of spectral signatures at different scales, 3D radiative transfer between atmosphere and surface. The simulator addresses two main needs (i) developing and testing methods for the correction of atmospheric and photometric effects images taken by orbiter around Mars (ii) developing and testing methods for the linear and nonlinear spectral unmixing applied to hyperspectral images.

  3. Periodic bedforms generated by sublimation on terrestrial and martian ice sheets under the influence of the turbulent atmospheric boundary layer (United States)

    Bordiec, Maï; Carpy, Sabrina; Perret, Laurent; Bourgeois, Olivier; Massé, Marion


    growth rate, migration direction and velocity of the ripples. The present approach has been first used to model the atmospheric flow developing over wavy terrestrial ice bedforms in the Blue Ice Areas of Antarctica. Both the predicted preferential wavelength and propagation direction of the ice ripple have been found to be in agreement with the observations. The present model has subsequently been applied to the same flow configuration but on Mars. Ice ripples are indeed likely to exist there, given that temperature and pressure conditions in the martian atmosphere favors sublimation/condensation as the dominant mass-transport process. The model has proved able to predict not only the development of ice-ripple on Mars (i.e it showed that some most amplified wavelength also exist under Martian atmospheric conditions) but also both their wavelength and propagation direction. The preferential wavelength of ices-ripples on the Martian polar caps appears to be much larger than on the Earth. Finally, a good match between the most likely ice-ripple wavelength predicted by the model and those deduced from recent available observations of the surface of Martian polar caps is shown.

  4. The Sublime and Education (United States)

    Carson, Jamin


    The sublime is a theory of aesthetics that reached its highest popularity in British literature during the Romantic period (c. 1785-1832). This article (1) explicates philosophers' different meanings of the sublime; (2) show how the sublime is relevant to education; and (3) show how the sublime "works" in literature by analyzing William Blake's…

  5. Instant Sublime Text starter

    CERN Document Server

    Haughee, Eric


    A starter which teaches the basic tasks to be performed with Sublime Text with the necessary practical examples and screenshots. This book requires only basic knowledge of the Internet and basic familiarity with any one of the three major operating systems, Windows, Linux, or Mac OS X. However, as Sublime Text 2 is primarily a text editor for writing software, many of the topics discussed will be specifically relevant to software development. That being said, the Sublime Text 2 Starter is also suitable for someone without a programming background who may be looking to learn one of the tools of

  6. Martian 'Kitchen Sponge' (United States)


    This picture is illuminated by sunlight from the upper left. It shows a tiny 1 kilometer by 1 kilometer (0.62 x 0.62 mile) area of the martian north polar residual ice cap as it appears in summertime.The surface looks somewhat like that of a kitchen sponge--it is flat on top and has many closely-spaced pits of no more than 2 meters (5.5 ft) depth. The upper, flat surface in this image has a medium-gray tone, while the pit interiors are darker gray. Each pit is generally 10 to 20 meters (33-66 feet) across. The pits probably form as water ice sublimes--going directly from solid to vapor--during the martian northern summer seasons. The pits probably develop over thousands of years. This texture is very different from what is seen in the south polar cap, where considerably larger and more circular depressions are found to resemble slices of swiss cheese rather than a kitchen sponge.This picture was taken by the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) during northern summer on March 8, 1999. It was one of the very last 'calibration' images taken before the start of the Mapping Phase of the MGS mission, and its goal was to determine whether the MOC was properly focused. The crisp appearance of the edges of the pits confirmed that the instrument was focused and ready for its 1-Mars Year mapping mission. The scene is located near 86.9oN, 207.5oW, and has a resolution of about 1.4 meters (4 ft, 7 in) per pixel.Malin Space Science Systems and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. 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.

  7. Sublimation, culture, and creativity. (United States)

    Kim, Emily; Zeppenfeld, Veronika; Cohen, Dov


    Combining insights from Freud and Weber, this article explores whether Protestants (vs. Catholics and Jews) are more likely to sublimate their taboo feelings and desires toward productive ends. In the Terman sample (Study 1), Protestant men and women who had sexual problems related to anxieties about taboos and depravity had greater creative accomplishments, as compared to those with sexual problems unrelated to such concerns and to those reporting no sexual problems. Two laboratory experiments (Studies 2 and 3) found that Protestants produced more creative artwork (sculptures, poems, collages, cartoon captions) when they were (a) primed with damnation-related words, (b) induced to feel unacceptable sexual desires, or (c) forced to suppress their anger. Activating anger or sexual attraction was not enough; it was the forbidden or suppressed nature of the emotion that gave the emotion its creative power. The studies provide possibly the first experimental evidence for sublimation and suggest a cultural psychological approach to defense mechanisms.

  8. A sublimation heat engine. (United States)

    Wells, Gary G; Ledesma-Aguilar, Rodrigo; McHale, Glen; Sefiane, Khellil


    Heat engines are based on the physical realization of a thermodynamic cycle, most famously the liquid-vapour Rankine cycle used for steam engines. Here we present a sublimation heat engine, which can convert temperature differences into mechanical work via the Leidenfrost effect. Through controlled experiments, quantified by a hydrodynamic model, we show that levitating dry-ice blocks rotate on hot turbine-like surfaces at a rate controlled by the turbine geometry, temperature difference and solid material properties. The rotational motion of the dry-ice loads is converted into electric power by coupling to a magnetic coil system. We extend our concept to liquid loads, generalizing the realization of the new engine to both sublimation and the instantaneous vapourization of liquids. Our results support the feasibility of low-friction in situ energy harvesting from both liquids and ices. Our concept is potentially relevant in challenging situations such as deep drilling, outer space exploration or micro-mechanical manipulation.


    Directory of Open Access Journals (Sweden)

    Martha de Almeida


    Full Text Available A obra Uma investigação filosófica sobre a origem de nossas idéias do sublime e dobelo, do sensualista inglês Edmund Burke (1757, data as origens do sublime na Modernidade. Nosublime ocorre é um prazer ligado à dor, um "horror delicioso" que sentimos quando acreditamosque estamos em perigo sem que isso esteja ocorrendo realmente. Em O mundo como Vontade erepresentação Schopenhauer assume as influências que sofreu de Kant no que diz respeito à suainterpretação sobre o belo e o sublime, porém difere dele quanto à natureza dessa impressão. ParaSchopenhauer a experiência estética pressupõe a dissolução da subjetividade num movimento decontemplação das idéias livre do querer imposto pela vontade individual. As idéias deSchopenhauer influenciaram a estética do Nietzsche de O nascimento da tragédia.

  10. Modelling Sublimation of Carbon Dioxide (United States)

    Winkel, Brian


    In this article, the author reports results in their efforts to model sublimation of carbon dioxide and the associated kinetics order and parameter estimation issues in their model. They have offered the reader two sets of data and several approaches to determine the rate of sublimation of a piece of solid dry ice. They presented several models…

  11. Los cuerpos sublimes

    Directory of Open Access Journals (Sweden)

    Juan Pablo Zangara


    Full Text Available La narración de crímenes en la prensa de masas y las pantallas parece constituir una versión contemporánea del magnetismo según Edgar Allan Poe. La estetización mediática (ya no la información de una serie reciente de feminicidios permite reconocer una cierta lógica de lo sublime como clave de la producción de noticias-mercancías. En su variante clásica, la ficción policial funciona como una matriz ideológica decisiva de la enunciación periodística.

  12. Sublime Views and Beautiful Explanations

    DEFF Research Database (Denmark)

    Barry, Daved; Meisiek, Stefan; Hatch, Mary Jo

    To create a generative theory that provides beautiful explanations and sublime views requires both a crafts and an art approach to scientific theorizing. The search for generativity leads scholars to perform various theorizing moves between the confines of simple, yet eloquent beauty, and the ran......To create a generative theory that provides beautiful explanations and sublime views requires both a crafts and an art approach to scientific theorizing. The search for generativity leads scholars to perform various theorizing moves between the confines of simple, yet eloquent beauty...

  13. Eisenhower and the American Sublime (United States)

    O'Gorman, Ned


    This essay presents Dwight D. Eisenhower's presidential rhetoric as an iteration of an American synecdochal sublime. Eisenhower's rhetoric sought to re-aim civic sight beyond corporeal objects to the nation's transcendental essence. This rhetoric is intimately connected to prevailing political anxieties and exigencies, especially the problem of…

  14. Finite agents, sublime feelings: response to Hanauer


    Deligiorgi, Katerina


    Tom Hanauer's thoughtful discussion of my article “The Pleasures of Contra-purposiveness: Kant, the Sublime, and Being Human” (2014) puts pressure on two important issues concerning the affective phenomenology of the sublime. My aim in that article was to present an analysis of the sublime that does not suffer from the problems identified by Jane Forsey in “Is a Theory of the Sublime Possible?” (2007). I argued that Kant's notion of reflective judgment can help with this task, because it allo...

  15. Enthalpies of sublimation of fullerenes by thermogravimetry

    Energy Technology Data Exchange (ETDEWEB)

    Martínez-Herrera, Melchor; Campos, Myriam; Torres, Luis Alfonso; Rojas, Aarón, E-mail:


    Graphical abstract: - Highlights: • Enthalpies of sublimation of fullerenes were measured by thermogravimetry. • Results of enthalpies of sublimation are comparable with data reported in literature. • Not previously reported enthalpy of sublimation of C{sub 78} is supplied in this work. • Enthalpies of sublimation show a strong dependence with the number of carbon atoms in the cluster. • Enthalpies of sublimation are congruent with dispersion forces ruling cohesion of solid fullerene. - Abstract: The enthalpies of sublimation of fullerenes, as measured in the interval of 810–1170 K by thermogravimetry and applying the Langmuir equation, are reported. The detailed experimental procedure and its application to fullerenes C{sub 60}, C{sub 70}, C{sub 76}, C{sub 78} and C{sub 84} are supplied. The accuracy and uncertainty associated with the experimental results of the enthalpy of sublimation of these fullerenes show that the reliability of the measurements is comparable to that of other indirect high-temperature methods. The results also indicate that the enthalpy of sublimation increases proportionally to the number of carbon atoms in the cluster but there is also a strong correlation between the enthalpy of sublimation and the polarizability of each fullerene.

  16. Schopenhauer, Nietzsche, and the Aesthetically Sublime (United States)

    Vandenabeele, Bart


    Much has been written on the relationship between Arthur Schopenhauer and Friedrich Nietzsche. Much remains to be said, however, concerning their respective theories of the sublime. In this article, the author first argues against the traditional, dialectical view of Schopenhauer's theory of the sublime that stresses the crucial role the sublime…

  17. Sacred Space and Sublime Sacramental Piety

    DEFF Research Database (Denmark)

    Petersen, Nils Holger


    Analyses and Discussions of Mozart's Sacramental Litanies K. 125 and K. 243 in relation to the notions of the Sacred and the Sublime.......Analyses and Discussions of Mozart's Sacramental Litanies K. 125 and K. 243 in relation to the notions of the Sacred and the Sublime....

  18. Martian Fingerprints (United States)


    9 April 2005 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows patterned ground on the martian northern plains. The circular features are buried meteor impact craters; the small dark dots associated with them are boulders. The dark feature at left center is a wind streak. Location near: 75.1oN, 303.0oW Image width: 3 km (1.9 mi) Illumination from: lower left Season: Northern Summer

  19. Martian Graffiti (United States)


    9 March 2006 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a variety of textures observed on a south middle-latitude plain east-southeast of Hellas Planitia. Dark streaks left by passing dust devils are practically ubiquitous across the scene, including the transition from the texturally-smooth area (the majority of the image) onto the circular, rough feature near the right (east) edge of the image. The circular feature might once have been the site of an impact crater; perhaps this is the remains of its floor, and the rest of the crater and the rock in which it formed was removed by erosion. Location near: 60.4oS, 242.5oW Image width: 3 km (1.9 mi) Illumination from: upper left Season: Southern Summer

  20. Formation of martian araneiforms by gas-driven erosion of granular material

    DEFF Research Database (Denmark)

    de Villiers, S.; Nermoen, A.; Jamtveit, B.


    Sublimation at the lower surface of a seasonal sheet of translucent CO2 ice at high southern latitudes during the Martian spring, and rapid outflow of the CO2 gas generated in this manner through holes in the ice, has been proposed as the origin of dendritic 100 m–1 km scale branched channels kno...

  1. Schopenhauer e os paradoxos do sublime

    Directory of Open Access Journals (Sweden)

    François Arnaud


    Full Text Available principal distinção entre a concepção schopenhaueriana e kantiana do sublime reside, segundo este artigo, no fato que o observador, no último caso, deve ser submetido a um perigo apenas possível, enquanto no primeiro caso ele deve ser realmente amedrontado. O principal impulso do sentimento do sublime é de fato, em Schopenhauer, a intervenção da vontade, que deve ser portanto realmente ameaçada. Daí resultam alguns paradoxos e originalidades da teoria do sublime de Schopenhauer, principalmente de um ponto de vista ético, cujos vestígios eu tento seguir.

  2. System and method for suppressing sublimation using opacified aerogel (United States)

    Sakamoto, Jeff S. (Inventor); Snyder, G. Jeffrey (Inventor); Calliat, Thierry (Inventor); Fleurial, Jean-Pierre (Inventor); Jones, Steven M. (Inventor); Palk, Jong-Ah (Inventor)


    The present invention relates to a castable, aerogel-based, ultra-low thermal conductivity opacified insulation to suppress sublimation. More specifically, the present invention relates to an aerogel opacified with various opacifying or reflecting constituents to suppress sublimation and provide thermal insulation in thermoelectric modules. The opacifying constituent can be graded within the aerogel for increased sublimation suppression, and the density of the aerogel can similarly be graded to achieve optimal thermal insulation and sublimation suppression.

  3. Alan Paton's Sublime: Race, Landscape and the Transcendence of ...

    African Journals Online (AJOL)

    This article develops a postcolonial reading of the sublime by suggesting that aesthetic theories of the sublime were, in their classical philosophical formulations by Edmund Burke and Immanuel Kant, founded on problematic assumptions of racial difference. In the colonial sphere, it is argued, the sublime could discursively ...

  4. Art, Terrorism and the Negative Sublime

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    Arnold Berleant


    Full Text Available The range of the aesthetic has expanded to cover not only a wider range of objects and situations of daily life but also to encompass the negative. This includes terrorism, whose aesthetic impact is central to its use as a political tactic. The complex of positive and negative aesthetic values in terrorism are explored, introducing the concept of the sublime as a negative category to illuminate the analysis and the distinctive aesthetic of terrorism.

  5. Liquid Water in the Extremely Shallow Martian Subsurface (United States)

    Pavlov, A.; Shivak, J. N.


    Availability of liquid water is one of the major constraints for the potential Martian biosphere. Although liquid water is unstable on the surface of Mars due to low atmospheric pressures, it has been suggested that liquid films of water could be present in the Martian soil. Here we explored a possibility of the liquid water formation in the extremely shallow (1-3 cm) subsurface layer under low atmospheric pressures (0.1-10 mbar) and low ("Martian") surface temperatures (approx.-50 C-0 C). We used a new Goddard Martian simulation chamber to demonstrate that even in the clean frozen soil with temperatures as low as -25C the amount of mobile water can reach several percents. We also showed that during brief periods of simulated daylight warming the shallow subsurface ice sublimates, the water vapor diffuses through porous surface layer of soil temporarily producing supersaturated conditions in the soil, which leads to the formation of additional liquid water. Our results suggest that despite cold temperatures and low atmospheric pressures, Martian soil just several cm below the surface can be habitable.

  6. Martian north polar cap summer water cycle (United States)

    Brown, Adrian J.; Calvin, Wendy M.; Becerra, Patricio; Byrne, Shane


    A key outstanding question in Martian science is "are the polar caps gaining or losing mass and what are the implications for past, current and future climate?" To address this question, we use observations from the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) of the north polar cap during late summer for multiple Martian years, to monitor the summertime water cycle in order to place quantitative limits on the amount of water ice deposited and sublimed in late summer. We establish here for the first time the summer cycle of water ice absorption band signatures on the north polar cap. We show that in a key region in the interior of the north polar cap, the absorption band depths grow until Ls = 120, when they begin to shrink, until they are obscured at the end of summer by the north polar hood. This behavior is transferable over the entire north polar cap, where in late summer regions 'flip' from being net sublimating into net condensation mode. This transition or 'mode flip' happens earlier for regions closer to the pole, and later for regions close to the periphery of the cap. The observations and calculations presented herein estimate that on average a water ice layer ∼70 microns thick is deposited during the Ls = 135-164 period. This is far larger than the results of deposition on the south pole during summer, where an average layer 0.6-6 microns deep has been estimated by Brown et al. (2014) Earth Planet. Sci. Lett., 406, 102-109.

  7. Practical bomb scene investigation

    National Research Council Canada - National Science Library

    Thurman, James T


    .... The book also uses examples of chain of custody and scene administration forms, diagrams and tables, methods of equipment decontamination, explosives residue collection procedures and spread sheets...

  8. Sublime dinâmico e pintura: Turner e Pollock

    Directory of Open Access Journals (Sweden)

    Jair Barboza


    Full Text Available texto tem por objetivo mostrar como a concepção filosófica do sublime em Kant e Schopenhauer pode nos ajudar a ver algumas obras pictóricas de Turner e Pollock. Nesse sentido temos um sublime figurativo (Turner e um sublime não figurativo (Pollock na pintura.

  9. Possible Habilability of Martian Regolity and Research of Ancient Life "Biomarkers" (United States)

    Pavlov, A. K.


    We consider environments of modern subsurface martian regolith layer as possible habitats of the terrestrial like microorganisms. Recent experimental studies demonstrate that low atmospheric pressure, low temperature and high level of cosmic rays ionizing radiation are not able to sterilize the subsurface layer of Mars. Even nonextremofile microorganisms can reproduce in martian regolith using films of liquid water which are produced by absorption of water vapor of subsurface ice sublimation. Areas of possible seasonal subsurface water flow (recurring slope lineae, dark dune spots) and methane emission regions are discussed as perspective sites for discovering of modern life on Mars. Degradation of "biomarkers" (complex organic molecules and isotopic ratio 13C/12C) in martian soil under high level of cosmic rays radiation is analyzed. We show the ancient biomarkers are effectively destroyed within period 108 -109 years. As result, probability of its discovering in shallow subsurface martian layer is low.

  10. Science Sublime: The Philosophy of the Sublime, Dewey's Aesthetics, and Science Education (United States)

    Cavanaugh, Shane


    Feelings of awe, wonder, and appreciation have been largely ignored in the working lives of scientists and, in turn, science education has not accurately portrayed science to students. In an effort to bring the affective qualities of science into the classroom, this work draws on the writings of the sublime by Burke, Kant, Emerson, and Wordsworth…

  11. Exposed subsurface ice sheets in the Martian mid-latitudes. (United States)

    Dundas, Colin M; Bramson, Ali M; Ojha, Lujendra; Wray, James J; Mellon, Michael T; Byrne, Shane; McEwen, Alfred S; Putzig, Nathaniel E; Viola, Donna; Sutton, Sarah; Clark, Erin; Holt, John W


    Thick deposits cover broad regions of the Martian mid-latitudes with a smooth mantle; erosion in these regions creates scarps that expose the internal structure of the mantle. We investigated eight of these locations and found that they expose deposits of water ice that can be >100 meters thick, extending downward from depths as shallow as 1 to 2 meters below the surface. The scarps are actively retreating because of sublimation of the exposed water ice. The ice deposits likely originated as snowfall during Mars' high-obliquity periods and have now compacted into massive, fractured, and layered ice. We expect the vertical structure of Martian ice-rich deposits to preserve a record of ice deposition and past climate. Copyright © 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

  12. Por uma metafísica do sublime

    Directory of Open Access Journals (Sweden)

    Martha de Almeida


    Full Text Available The sublime has been analyzed since ancient times with a striking compared with tragedy, whether as a literary genre, whether through Poetics, Aristotle's catharsis we translate the feeling the sublime. In modernity, new names were coming to work with this theory: Hume himself, in his essay The Tragedy, was impressed by the ability of this art form has to produce such strong effects on the viewer. But who else has strengthened analysis of the sublime in modernity, providing the basis for their own Kant was Edmund Burke, with his piece A philosophical investigation on the ideas of the sublime and the beautiful. The third criticism of Kant devoted a special moment to the analysis of the sublime, which had served as basis also for Schopenhauer, however, from her built his own aesthetic that would be of paramount importance Nieztsche for the young, mainly due to the consideration of music as sublime art. Nietzsche, then built his tragic wisdom, with based on the experience of the sublime tragedy.The question this paper wants to treat it exactly: It is possible think of a metaphysics of the sublime, based on Nietzsche?

  13. The Religious-Sublime in Music, Literature and Architecture

    DEFF Research Database (Denmark)

    Cifuentes-Aldunate, Claudio


    their mechanisms with other modalities of sublimeness. The sublime will be regarded as the representation (in the sens of staging) of a perception. I will demonstrate how this subjective perception - in this case 'of the divinity' - is (re)constructed by the subject in a piece of Spanish Gothic literature...

  14. Conditions for Sublimating Water Ice to Supply Ceres' Exosphere (United States)

    Landis, M. E.; Byrne, S.; Schörghofer, N.; Schmidt, B. E.; Hayne, P. O.; Castillo-Rogez, J.; Sykes, M. V.; Combe, J.-P.; Ermakov, A. I.; Prettyman, T.; Raymond, C. A.; Russell, C. T.


    We explore the conditions for sublimating water ice on Ceres to explain the observed water vapor output from telescopic observations. We find that while a buried ice table cannot produce enough vapor via sublimation to explain the exosphere, exposed surface ice (given it is exposed at the right time during the Ceres day and year, and at the right location) can.

  15. Reassessing Aesthetic Appreciation of Nature in the Kantian Sublime (United States)

    Brady, Emily


    The sublime has been a relatively neglected topic in recent work in philosophical aesthetics, with existing discussions confined mainly to problems in Kant's theory. Given the revival of interest in his aesthetic theory and the influence of the Kantian sublime compared to other eighteenth-century accounts, this focus is not surprising. Kant's…

  16. Sublime science: Teaching for scientific sublime experiences in middle school classrooms (United States)

    Cavanaugh, Shane

    Due to a historical separation of cognition and emotion, the affective aspects of learning are often seen as trivial in comparison to the more 'essential' cognitive qualities - particularly in the domain of science. As a result of this disconnect, feelings of awe, wonder, and astonishment as well as appreciation have been largely ignored in the working lives of scientists. In turn, I believe that science education has not accurately portrayed the world of science to our students. In an effort to bring the affective qualities of science into the science classroom, I have drawn on past research in the field of aesthetic science teaching and learning as well as works by, Burke, Kant, and Dewey to explore a new construct I have called the "scientific sublime". Scientific sublime experiences represent a sophisticated treatment of the cognitive as well as affective qualities of science learning. The scientific sublime represents feelings of awe, wonder, and appreciation that come from a deep understanding. It is only through this understanding of a phenomenon that we can appreciate its true complexity and intricacies, and these understandings when mixed with the emotions of awe and reverence, are sublime. Scientific sublime experiences are an attempt at the re-integration of cognition and feeling. The goal of this research was twofold: to create and teach a curriculum that fosters scientific sublime experiences in middle school science classes, and to better understand how these experiences are manifested in students. In order to create an approach to teaching for scientific sublime experiences, it was first necessary for me to identify key characteristics of such an experience and a then to create a pedagogical approach, both of which are described in detail in the dissertation. This research was conducted as two studies in two different middle schools. My pedagogical approach was used to create and teach two five-week 7 th grade science units---one on weather

  17. Hydrogen in Martian Meteorites (United States)

    Peslier, A. H.; Hervig, R.; Irving, T.


    Most volatile studies of Mars have targeted its surface via spacecraft and rover data, and have evidenced surficial water in polar caps and the atmosphere, in the presence of river channels, and in the detection of water bearing minerals. The other focus of Martian volatile studies has been on Martian meteorites which are all from its crust. Most of these studies are on hydrous phases like apatite, a late-stage phase, i.e. crystallizing near the end of the differentiation sequence of Martian basalts and cumulates. Moreover, calculating the water content of the magma a phosphate crystallized from is not always possible, and yet is an essential step to estimate how much water was present in a parent magma and its source. Water, however, is primarily dissolved in the interiors of differentiated planets as hydrogen in lattice defects of nominally anhydrous minerals (olivine, pyroxene, feldspar) of the crust and mantle. This hydrogen has tremendous influence, even in trace quantities, on a planet's formation, geodynamics, cooling history and the origin of its volcanism and atmosphere as well as its potential for life. Studies of hydrogen in nominally anhydrous phases of Martian meteorites are rare. Measuring water contents and hydrogen isotopes in well-characterized nominally anhydrous minerals of Martian meteorites is the goal of our study. Our work aims at deciphering what influences the distribution and origin of hydrogen in Martian minerals, such as source, differentiation, degassing and shock.

  18. Sublimation of antimycotic agents as proved by various analytical methods. (United States)

    Jäckel, A; Schmelzer, C E H; Wartewig, S; Neubert, R H H


    Qualitative and quantitative results demonstrate that the pure substances amorolfine base, amorolfine hydrochloride, two selected morpholine derivatives and terbinafine hydrochloride are clearly able to sublimate. As amorolfine hydrochloride is also capable to sublimate from galencial forms laquer and cream in this experimental setup, a clinical relevance of sublimation phenomenon at least for topical treatment of onychomycosis has to be considered. This phenomenon could be one reason for advantageous clinical and mycological cure rates of amorolfine nail laquer to comparable topical products reported in the literature.

  19. A Martian Air Battery Project (United States)

    National Aeronautics and Space Administration — This project will investigate an entirely new battery chemistry by developing A Martian Air Battery. Specifically the project will explore the concept of a Martian...

  20. Carbon-Sublimation Production of Fullerenes. (United States)

    Tinker, Frank Albert


    Carbon-sublimation production of fullerenes enjoys wide use in both experimental and industrial application worldwide. Although it has been nearly five years since the inception of the technique, little is known about the roles various parameters play in the production process. This work attempts to shed light, both experimentally and theoretically, on the basic processes at work in this type of fullerene production. Experimental results herein show that a functional relationship exists among the C_{60 }, C_{70}, C_{76}, C_ {78}, and C_{84} fullerenes produced in carbon arcs. This result is interpreted to mean that an equilibrium description of the production process may be valid. Theoretical calculations are then offered in support of such a view. The theory goes on to show details of an equilibrium description that reproduce essential features of fullerene mass-spectra. It is shown that equilibrium abundances of n-atom -sized clusters are highly dependent on the stoichiometric equation chosen to describe the system. However, common traits of the investigated equilibrium descriptions lead to useful conclusions.

  1. Sublimation in bright spots on (1) Ceres (United States)

    Nathues, A.; Hoffmann, M.; Schaefer, M.; Le Corre, L.; Reddy, V.; Platz, T.; Cloutis, E. A.; Christensen, U.; Kneissl, T.; Li, J.-Y.; Mengel, K.; Schmedemann, N.; Schaefer, T.; Russell, C. T.; Applin, D. M.; Buczkowski, D. L.; Izawa, M. R. M.; Keller, H. U.; O'Brien, D. P.; Pieters, C. M.; Raymond, C. A.; Ripken, J.; Schenk, P. M.; Schmidt, B. E.; Sierks, H.; Sykes, M. V.; Thangjam, G. S.; Vincent, J.-B.


    The dwarf planet (1) Ceres, the largest object in the main asteroid belt with a mean diameter of about 950 kilometres, is located at a mean distance from the Sun of about 2.8 astronomical units (one astronomical unit is the Earth-Sun distance). Thermal evolution models suggest that it is a differentiated body with potential geological activity. Unlike on the icy satellites of Jupiter and Saturn, where tidal forces are responsible for spewing briny water into space, no tidal forces are acting on Ceres. In the absence of such forces, most objects in the main asteroid belt are expected to be geologically inert. The recent discovery of water vapour absorption near Ceres and previous detection of bound water and OH near and on Ceres (refs 5, 6, 7) have raised interest in the possible presence of surface ice. Here we report the presence of localized bright areas on Ceres from an orbiting imager. These unusual areas are consistent with hydrated magnesium sulfates mixed with dark background material, although other compositions are possible. Of particular interest is a bright pit on the floor of crater Occator that exhibits probable sublimation of water ice, producing haze clouds inside the crater that appear and disappear with a diurnal rhythm. Slow-moving condensed-ice or dust particles may explain this haze. We conclude that Ceres must have accreted material from beyond the ‘snow line’, which is the distance from the Sun at which water molecules condense.

  2. Martian Environment Electrostatic Precipitator (United States)

    McDougall, Michael Owen


    As part of the planned manned mission to Mars, NASA has noticed that shipping oxygen as a part of life support to keep the astronauts alive continuously is overly expensive, and impractical. As such, noting that the Martian atmosphere is 95.37% CO2, NASA chemists noted that one could obtain oxygen from the Martian atmosphere. The plan, as part of a larger ISRU (in-situ resource utilization) initiative, would extract water from the regolith, or the Martian soil which can be electrolyzed by solar panel produced voltage into hydrogen and oxygen. The hydrogen can then be used in the Sabatier reaction with carbon dioxide to produce methane and water producing a net reaction that does not lose water and outputs methane and oxygen for use as rocket fuel and breathing.

  3. Sublimity and beauty: A view from nursing aesthetics. (United States)

    Siles-González, José; Solano-Ruiz, Carmen


    Several authors have focused on the aesthetics of nursing care from diverse perspectives; however, there are few studies about the sublime and the beautiful in nursing. To identify beautiful and sublime moments in the context of the aesthetics of nursing care. A theoretical reflection has been contemplated about sublime and beautiful values in the context of the aesthetics of nursing care from the cultural history perspective. For that purpose, a revision of this issue has been completed. The terms 'beautiful' and 'sublime' have been analysed to identify the characteristics of both in the context of nursing care. We have followed all ethical requirements regarding the sources, conducting research and authorship. There is no conflict of interest in this paper. With aesthetic knowledge, the nurse expresses the artistic nature of nursing care by appreciating the act of caring for individuals. The sublime is a complex phenomenon, since apparently contrary feelings are interwoven. Nursing care is an art with an anthropological object-subject on which the 'artist' applies their prior knowledge and skills. Feelings and emotions that develop during the clinical nursing practice - especially at times sublime and beautiful, aesthetic - constitute experiences which are professionally significant. © The Author(s) 2015.

  4. O Sublime explicado às crianças

    Directory of Open Access Journals (Sweden)

    Virginia Figueiredo


    Full Text Available Como o próprio título indica, este ensaio pretende dialogar com a recepção do sublime kantiano pela filosofia francesa contemporânea, sobretudo com Jean-François Lyotard. Dessa forma, ao invés de ressaltar as consequências inevitável ou sistematicamente morais do sublime kantiano, como fez, de um modo geral, o comentário mais tradicional da filosofia crítica de Kant, este ensaio tenta interpretar o sublime como sendo essencialmente uma experiência da arte, seguindo assim de perto aquela tradição francesa. Mas, ao mesmo tempo, tomando alguma distância, este texto quer fazer uma objeção ao fundamento exclusivamente burkiano da concepção de sublime de Lyotard. Em suma, quero defender que é possível privilegiar o tempo (aspecto central do sublime de Edmund Burke, segundo Lyotard também na experiência do sublime kantiano.

  5. O paradoxo sublime ou a alforria da arte

    Directory of Open Access Journals (Sweden)

    Virgínia Figueiredo


    Full Text Available Neste texto, pretendo analisar a tese principal do ensaio “A verdade sublime” de Philippe Lacoue-Labarthe, a qual poderia ser formulada do seguinte modo: a verdade sublime é o Ereignis, esse é o fundamento a partir do qual se desenvolveu uma dificílima operação que consistiu em modificar a tradição do sublime sempre apresentado negativamente naquilo que Lacoue-Labarthe chamou de "compreensão afirmativa do sublime ou da grande arte". O autor estabelece uma astuciosa aliança entre o que há de mais radical no pensamento de Heidegger e o sublime, tratado de maneira bastante polêmica, como a principal teoria da arte de Kant. Dessa articulação fundamental, pode-se concluir que ele não está apenas à procura de uma “Estética” (sequer de uma “Teoria da Arte” sublime, mas, em busca de algo que é muito mais ambicioso, a saber: de um pensamento do sublime. Portanto, na minha opinião, o ensaio lacouelabarthiano constitui, por um lado, uma referência indispensável não só a quem quer que pretenda estudar a tradição do sublime, mas, por outro, compreender o pensamento heideggeriano sobre a arte e sua tentativa de encontrar uma determinação mais essencial e, sobretudo, ousaria dizer, mais política da arte.

  6. Demonstrating Martian Gravity

    CERN Document Server

    Pirkola, Patrik


    The surface gravity on Mars is smaller than the surface gravity on Earth, resulting in longer falling times. This effect can be simulated on Earth by taking advantage of air resistance and buoyancy, which cause low density objects to fall slowly enough to approximate objects falling on the surface of Mars. We describe a computer simulation based on an experiment that approximates Martian gravity, and verify our numerical results by performing the experiment.

  7. The Martian magnetic field (United States)

    Russell, C. T.


    The paper presents an overview of the Martian magnetic field measurements and the criticisms made of them. The measurements of the Mars 2, 3, and 5 spacecraft were interpreted by Dolginov et al. (1976, 1978) to be consistent with an intrinsic planetary magnetic moment of 2.5 times 10 to the 22nd power gauss cu cm, basing this result on the apparent size of the obstacle responsible for deflecting the solar wind and an apparent encounter of the spacecraft with the planetary field. It is shown that if the dependence of the Martian magnetic moment on the rotation rate was linear, the estimate of the moment would be far larger than reported by Dolginov et al. An upper limit of 250 km is calculated for the dynamo radius using the similarity law, compared with 500 km obtained by Dolginov et al. It is concluded that the possible strength of a Martian dynamo is below expectations, and it is likely that the Mars dynamo is not presently operative.

  8. Por uma metafí­sica do sublime


    Almeida, Martha de


     O sublime vem sendo analisado desde a antiguidade com uma marcante relaçáo com a tragédia, seja como gênero literário, seja por meio da Poética, de Aristóteles que nos traduz pela catarse o sentimento do sublime. Na modernidade, novos nomes foram chegando para colaborar com esta teoria: o próprio Hume, em seu ensaio Da tragédia, mostrou-se impressionado com a capacidade que esta forma de arte tem de produzir efeitos táo intensos no espectador. Porém, quem mais fortaleceu a análise do sublime...

  9. Sublimation rates of explosive materials : method development and initial results.

    Energy Technology Data Exchange (ETDEWEB)

    Phelan, James M.; Patton, Robert Thomas


    Vapor detection of explosives continues to be a technological basis for security applications. This study began experimental work to measure the chemical emanation rates of pure explosive materials as a basis for determining emanation rates of security threats containing explosives. Sublimation rates for TNT were determined with thermo gravimetric analysis using two different techniques. Data were compared with other literature values to provide sublimation rates from 25 to 70 C. The enthalpy of sublimation for the combined data was found to be 115 kJ/mol, which corresponds well with previously reported data from vapor pressure determinations. A simple Gaussian atmospheric dispersion model was used to estimate downrange concentrations based on continuous, steady-state conditions at 20, 45 and 62 C for a nominal exposed block of TNT under low wind conditions. Recommendations are made for extension of the experimental vapor emanation rate determinations and development of turbulent flow computational fluid dynamics based atmospheric dispersion estimates of standoff vapor concentrations.

  10. Micro-computed tomography observation of sublimation interface and image analysis on sublimation process during freeze-drying. (United States)

    Xiao, Xin; Tao, Le-Ren; Hua, Tse-Chao


    The freeze-drying process is complicated with complex heat and mass transfer during sublimation. The sublimation interface of freeze-drying has become more attractive and meaningful recently. In this study, apple slices undergoing sublimation were scanned by a Micro-CT scanner. The cross-sectional images were reconstructed with those scanning images respectively. The technique of grey value analysis was used to recognize the procedure. The results showed that, from direct scanning images and 2-D reconstructed images, a 3-D moving mode of sublimation interface which contracted to the centre of the sample could be seen, sublimation process proceeded from edge to center gradually. The grey value of ice crystals was determined to be 154 through gauss calculation. By comparing frozen sample with freeze-dried one, the ice crystals regions in the beginning became the porous regions after drying, grey values increased correspondingly. Samples shrunk slightly after drying for 3 to 7 hours, which could be distinguished by the change in grey values.

  11. Chlorine Abundances in Martian Meteorites (United States)

    Bogard, D.D.; Garrison, D.H.; Park, J.


    Chlorine measurements made in martian surface rocks by robotic spacecraft typically give Chlorine (Cl) abundances of approximately 0.1-0.8%. In contrast, Cl abundances in martian meteorites appear lower, although data is limited, and martian nakhlites were also subjected to Cl contamination by Mars surface brines. Chlorine abundances reported by one lab for whole rock (WR) samples of Shergotty, ALH77005, and EET79001 range 108-14 ppm, whereas Cl in nakhlites range 73-1900 ppm. Measurements of Cl in various martian weathering phases of nakhlites varied 0.04-4.7% and reveal significant concentration of Cl by martian brines Martian meteorites contain much lower Chlorine than those measured in martian surface rocks and give further confirmation that Cl in these surface rocks was introduced by brines and weathering. It has been argued that Cl is twice as effective as water in lowering the melting point and promoting melting at shallower martian depths, and that significant Cl in the shergottite source region would negate any need for significant water. However, this conclusion was based on experiments that utilized Cl concentrations more analogous to martian surface rocks than to shergottite meteorites, and may not be applicable to shergottites.

  12. The experimental investigations of peculiarities of metalorganic compounds sublimation

    Directory of Open Access Journals (Sweden)

    Bochkareva Elena


    Full Text Available The paper presents the results of experimental investigations of convective heat and mass transfer by sublimation of a single particle of metallorganic compounds mixture in an argon flow. The gas temperature is 180-290 ºС, the flow velocity is up to 2 m/s. The influence of the Zr(dpm4 and Y(dpm3 proportions on the characteristics of the transport processes was considered. An increase in the fraction of the more fusible component reduces the temperature of the particle during the sublimation process.

  13. Of images and ills. Uses and malaises of sublimation

    Directory of Open Access Journals (Sweden)

    Georges Didi-Huberman


    Full Text Available This text is published as postface to the new edition of Invention de l'hystérie. Charcot et l’iconographie photographique de l’hystérie (Macula, Paris, 2012, pp. 364-405 with the title Des images et des maux. It’s also the full version of the lecture organized by the Association Psychanalytique de France (September 24, 2011, entitled L’Usage de la sublimation. Starting from some considerations on his first book, the Author examines limits and potentials of the notion of sublimation in reference with art and artistic creation, and suggests a different way to approach it.

  14. Feasibility study of CO2 capture by anti-sublimation

    NARCIS (Netherlands)

    Schach, M.O.; Oyarzun, B.A.; Schramm, H.; Schneider, R.; Repke, J.U.


    Processes for carbon capture and storage have the drawback of high energy demand. In this work the application of CO2 capture by anti-sublimation is analyzed. The process was simulated using Aspen Plus. Process description is accomplished by phase equilibria models which are able to reproduce the

  15. Vapor transport and sublimation on Mullins Glacier, Antarctica (United States)

    Lamp, J. L.; Marchant, D. R.


    We utilize an environmental chamber capable of recreating the extreme polar conditions of the McMurdo Dry Valleys (MDV) of Antarctica to investigate the sublimation rate of the Mullins Valley debris-covered glacier (hereafter Mullins Glacier), reportedly one of the oldest debris-covered alpine glaciers in the world. We measure ice loss via sublimation beneath sediment thicknesses ranging from 0 to 69 mm; from this, we determine an effective diffusivity for Fickian vapor transport through Mullins till of (5.2 ± 0.3) ×10-6 m2s-1 at -10 °C. We use this value, coupled with micrometeorological data from Mullins Valley (atmospheric temperature, relative humidity, and soil temperature) to model the sublimation rate of buried glacier ice near the terminus of Mullins Glacier, where the overlying till thickness approaches 70 cm. We find that the ice-lowering rate during the modeled year (2011) was 0.066 mm under 70 cm of till, a value which is in line with previous estimates for exceedingly slow rates of ice sublimation. These results provide further evidence supporting the probable antiquity of Mullins Glacier ice and overall landscape stability in upland regions of the MDV.

  16. Some attributes of snow occurrence and snowmelt/sublimation rates ...

    African Journals Online (AJOL)

    We present attributes of snow occurrence and dissipation rates (melt and sublimation) for the Lesotho Highlands, based on remotely-sensed MODIS images from 2003–2016. Multi-temporal imagery is used, with SNOMAP and NDSI algorithms applied to MODIS Rapid Response images. The spatial extent of snow loss was ...

  17. Sublimation-Induced Shape Evolution of Silver Cubes

    KAUST Repository

    Ding, Yong


    The heat is on: Surface sublimation and shape transformation of silver cubes, enclosed by {100} surfaces and about 100nm in size, are examined by in situ transmission electron microscopy (see picture). High-index surfaces, such as {110}, of face-centered cubic metals are more stable when the temperature is close to the melting point.

  18. Modular Porous Plate Sublimator /MPPS/ requires only water supply for coolant (United States)

    Rathbun, R. J.


    Modular porous plate sublimators, provided for each location where heat must be dissipated, conserve the battery power of a space vehicle by eliminating the coolant pump. The sublimator requires only a water supply for coolant.

  19. Sublimation of amino acids with enantiomeric excess amplification (United States)

    Guillemin, Jean-Claude; Guillemin, Jean-Claude; Bellec, Aurelien

    The notion of chirality was first reported in 1848 by Pasteur, when he mechanically separated the two enantiomers of tartrate salts.[1] Amino acids are considered as the most important building blocks of life with sugars. On the Earth, the living systems are only composed of L- amino acids and D-sugars. Nowadays, the origin of homochirality on Earth is still unknown, and there are many theories trying to explain this phenomenon. Recently Cooks [2] and Feringa [3] reported that the sublimation of small amounts of L and D amino acid mixtures containing an excess of one of them leads to a huge enantiomeric excess (ee) enhancement of the sublimate. We reinvestigated these experiments to determine the rules leading to this enhancement. Starting from mixtures of L- and DL leucine we observed increasing and decreasing of the ee in function of the starting ratios. By the use of 13C derivatives, the origin of the sublimed enantiomers has been precised. Various parameters (L and D, or L and DL mixtures, dissolution in water before sublimation, . . . ) were studied. We also took into consideration the recently proposed hypothesis of the role played by the eutectic ee in the sublimation. [4] The application of these results to find an explanation of the enantiomeric excess in meteorites or in the Primitive Earth scenarios will be discussed. 1 Pasteur, L. Ann. Phys., 1848, 24, 442. 2 R. H. Perry, C. Wu, M. Nefliu, R. G. Cooks, Chem. Commun., 2007, 1071-1073. 3 S. P. Fletcher, R. B. C. Jagt, B. L. Feringa, Chem. Commun., 2007, 2578-2580. 4 D. G. Blackmond, M. Klussmannb Chem. Commun., 2007, 3990-3996.

  20. Hydrological AnthropoScenes (United States)

    Cudennec, Christophe


    The Anthropocene concept encapsulates the planetary-scale changes resulting from accelerating socio-ecological transformations, beyond the stratigraphic definition actually in debate. The emergence of multi-scale and proteiform complexity requires inter-discipline and system approaches. Yet, to reduce the cognitive challenge of tackling this complexity, the global Anthropocene syndrome must now be studied from various topical points of view, and grounded at regional and local levels. A system approach should allow to identify AnthropoScenes, i.e. settings where a socio-ecological transformation subsystem is clearly coherent within boundaries and displays explicit relationships with neighbouring/remote scenes and within a nesting architecture. Hydrology is a key topical point of view to be explored, as it is important in many aspects of the Anthropocene, either with water itself being a resource, hazard or transport force; or through the network, connectivity, interface, teleconnection, emergence and scaling issues it determines. We will schematically exemplify these aspects with three contrasted hydrological AnthropoScenes in Tunisia, France and Iceland; and reframe therein concepts of the hydrological change debate. Bai X., van der Leeuw S., O'Brien K., Berkhout F., Biermann F., Brondizio E., Cudennec C., Dearing J., Duraiappah A., Glaser M., Revkin A., Steffen W., Syvitski J., 2016. Plausible and desirable futures in the Anthropocene: A new research agenda. Global Environmental Change, in press, Brondizio E., O'Brien K., Bai X., Biermann F., Steffen W., Berkhout F., Cudennec C., Lemos M.C., Wolfe A., Palma-Oliveira J., Chen A. C-T. Re-conceptualizing the Anthropocene: A call for collaboration. Global Environmental Change, in review. Montanari A., Young G., Savenije H., Hughes D., Wagener T., Ren L., Koutsoyiannis D., Cudennec C., Grimaldi S., Blöschl G., Sivapalan M., Beven K., Gupta H., Arheimer B., Huang Y

  1. Automatic structural scene digitalization. (United States)

    Tang, Rui; Wang, Yuhan; Cosker, Darren; Li, Wenbin


    In this paper, we present an automatic system for the analysis and labeling of structural scenes, floor plan drawings in Computer-aided Design (CAD) format. The proposed system applies a fusion strategy to detect and recognize various components of CAD floor plans, such as walls, doors, windows and other ambiguous assets. Technically, a general rule-based filter parsing method is fist adopted to extract effective information from the original floor plan. Then, an image-processing based recovery method is employed to correct information extracted in the first step. Our proposed method is fully automatic and real-time. Such analysis system provides high accuracy and is also evaluated on a public website that, on average, archives more than ten thousands effective uses per day and reaches a relatively high satisfaction rate.

  2. Semantic Reasoning for Scene Interpretation

    DEFF Research Database (Denmark)

    Jensen, Lars Baunegaard With; Baseski, Emre; Pugeault, Nicolas


    In this paper, we propose a hierarchical architecture for representing scenes, covering 2D and 3D aspects of visual scenes as well as the semantic relations between the different aspects. We argue that labeled graphs are a suitable representational framework for this representation and demonstrat...

  3. Advanced Techniques for Scene Analysis (United States)


    example, 3D movies . The change of demand results in an attention for smooth visual quality of the reconstructed scene. In this case, visual quality of the...Vergauwen, and L. Van Gool, “Automated reconstruction of 3D scenes from sequences of images,” ISPRS Journal Of Photogrammetry And Remote Sensing, vol. 55

  4. The viability of native microbial communities in martian environment (model) (United States)

    Vorobyova, Elena; Cheptcov, Vladimir; Pavlov, Anatolyi; Vdovina, Mariya; Lomasov, Vladimir

    For today the important direction in astrobiology is the experimental simulation of extraterrestrial habitats with the assessment of survivability of microorganisms in such conditions. A new task is to investigate the resistance of native microbial ecosystems which are well adapted to the environment and develop unique protection mechanisms that enable to ensure biosphere formation. The purpose of this research was to study the viability of microorganisms as well as viability of native microbial communities of arid soils and permafrost under stress conditions simulating space environment and martian regolith environment, estimation of duration of Earth like life in the Martian soil. The experimental data obtained give the proof of the preservation of high population density, biodiversity, and reproduction activity under favorable conditions in the Earth analogues of Martian soil - arid soils (Deserts of Israel and Morocco) and permafrost (East Siberia, Antarctica), after the treatment of samples by ionizing radiation dose up to 100 kGy at the pressure of 1 torr, temperature (- 50oC) and in the presence of perchlorate (5%). It was shown that in simulated conditions close to the parameters of the Martian regolith, the diversity of natural bacterial communities was not decreased, and in some cases the activation of some bacterial populations occurred in situ. Our results allow suggesting that microbial communities like those that inhabit arid and permafrost ecosystems on the Earth, can survive at least 500 thousand years under conditions of near surface layer of the Martian regolith. Extrapolation of the data according to the intensity of ionizing radiation to the open space conditions allows evaluating the potential lifespan of cells inside meteorites as 20-50 thousand years at least. In this work new experimental data have been obtained confirming the occurrence of liquid water and the formation of wet soil layer due to sublimation of ice when the temperature of the

  5. Sublimator Driven Coldplate Engineering Development Unit Test Results (United States)

    Sheth, Rubik B.; Stephan, Ryan A.; Leimkuehler, Thomas O.


    The Sublimator Driven Coldplate (SDC) is a unique piece of thermal control hardware that has several advantages over a traditional thermal control scheme. The principal advantage is the possible elimination of a pumped fluid loop, potentially increasing reliability and reducing complexity while saving both mass and power. Because the SDC requires a consumable feedwater, it can only be used for short mission durations. Additionally, the SDC is ideal for a vehicle with small transport distances and low heat rejection requirements. An SDC Engineering Development Unit was designed and fabricated. Performance tests were performed in a vacuum chamber to quantify and assess the performance of the SDC. The test data was then used to develop correlated thermal math models. Nonetheless, an Integrated Sublimator Driven Coldplate (ISDC) concept is being developed. The ISDC couples a coolant loop with the previously described SDC hardware. This combination allows the SDC to be used as a traditional coldplate during long mission phases and provides for dissimilar system redundancy

  6. Sublimation Kinetic Studies of the Zr(tmhd4 Complex

    Directory of Open Access Journals (Sweden)

    T. S. Arul Jeevan


    Full Text Available The thermal behaviour of tetrakis(2,2,6,6-tetramethyl-3,5-heptanedionatozirconium(IV, [Zr(tmhd4] was investigated by nonisothermal and isothermal thermogravimetric methods in a high pure nitrogen atmosphere. The influence of the heating rate in dynamic measurements (6, 8, 10, and 12°C/min on activation energy was also studied. The nonisothermal sublimation activation energy values determined following the procedures of Arrhenius, Coats and Redfern, Kissinger, and Flynn-Wall yielded 76±5, 92±2, 81±8, and 72±7 kJ/mol, respectively, and the isothermal sublimation activation energy was found to be 87±4 kJ/mol over the temperature range of 411–462 K. Different reaction mechanisms were used to compare with this value. Analysis of the experimental results suggested that the actual reaction mechanism was an Rn deceleration type.

  7. Surface engineering of SiC via sublimation etching

    Energy Technology Data Exchange (ETDEWEB)

    Jokubavicius, Valdas, E-mail: [Department of Physics, Chemistry and Biology, Linköping University, 581 83 Linköping (Sweden); Yazdi, Gholam R.; Ivanov, Ivan G. [Department of Physics, Chemistry and Biology, Linköping University, 581 83 Linköping (Sweden); Niu, Yuran; Zakharov, Alexei [Max Lab, Lund University, S-22100 Lund (Sweden); Iakimov, Tihomir; Syväjärvi, Mikael; Yakimova, Rositsa [Department of Physics, Chemistry and Biology, Linköping University, 581 83 Linköping (Sweden)


    Highlights: • Comparison of 6H-, 4H- and 3C-SiC sublimation etching. • Effects of Si-C and Si-C-Ta chemical systems on etching mechanisms. • Effect of etching ambient on surface reconstruction. • Application of etched 4H-SiC surface for the growth of graphene nanoribbons is illustrated. - Abstract: We present a technique for etching of SiC which is based on sublimation and can be used to modify the morphology and reconstruction of silicon carbide surface for subsequent epitaxial growth of various materials, for example graphene. The sublimation etching of 6H-, 4H- and 3C-SiC was explored in vacuum (10{sup −5} mbar) and Ar (700 mbar) ambient using two different etching arrangements which can be considered as Si-C and Si-C-Ta chemical systems exhibiting different vapor phase stoichiometry at a given temperature. The surfaces of different polytypes etched under similar conditions are compared and the etching mechanism is discussed with an emphasis on the role of tantalum as a carbon getter. To demonstrate applicability of such etching process graphene nanoribbons were grown on a 4H-SiC surface that was pre-patterned using the thermal etching technique presented in this study.

  8. El Silencio de la Sirena: lo Sublime en Alejandra Pizarnik

    Directory of Open Access Journals (Sweden)

    Julieta Lerman


    Full Text Available Algunas poéticas de las décadas del cincuenta y del sesenta parecerían constituirse en torno a un vacío, un silencio que a veces inspira la palabra poética y otras veces la aborta. Esa ambigüedad, característica de la poética de Alejandra Pizarnik, podemos entenderla como una “reedición” de la estética de lo sublime. Lo sublime es un concepto estético-filosófico que plantearon filósofos como Inmanuel Kant y Edmund Burke para pensar el arte romántico y, en el siglo XX, otros autores como Jean-François Lyotard, lo retomaron para analizar el arte de vanguardia. Así, lo sublime nos permite repensar la poética de Pizarnik en sus coincidencias y oposiciones a otras de la tradición moderna (como la de Charles Baudelaire o de las vanguardias latinoamericanas (como Oliverio Girondo y Vicente Huidobro.

  9. El Silencio de la Sirena: lo Sublime en Alejandra Pizarnik

    Directory of Open Access Journals (Sweden)

    Julieta Lerman


    Full Text Available Algunas poéticas de las décadas del cincuenta y del sesenta parecerían constituirse en torno a un vacío, un silencio que a veces inspira la palabra poética y otras veces la aborta. Esa ambigüedad, característica de la poética de Alejandra Pizarnik, podemos entenderla como una “reedición” de la estética de lo sublime. Lo sublime es un concepto estético-filosófico que plantearon filósofos como Inmanuel Kant y Edmund Burke para pensar el arte romántico y, en el siglo XX, otros autores como Jean-François Lyotard, lo retomaron para analizar el arte de vanguardia. Así, lo sublime nos permite repensar la poética de Pizarnik en sus coincidencias y oposiciones a otras de la tradición moderna (como la de Charles Baudelaire o de las vanguardias latinoamericanas (como Oliverio Girondo y Vicente Huidobro.

  10. Sedimentation waves on the Martian North Polar Cap: Analogy with megadunes in Antarctica (United States)

    Herny, C.; Massé, M.; Bourgeois, O.; Carpy, S.; Le Mouélic, S.; Appéré, T.; Smith, I. B.; Spiga, A.; Rodriguez, S.


    Complex interactions between katabatic winds and the cryosphere may lead to the formation of sedimentation waves at the surface of ice sheets. These have been first described and named snow megadunes in Antarctica. Here we use topographic data, optical images, subsurface radar soundings and spectroscopic data acquired by Mars orbiters, to show that the surface of the Martian North Polar Cap displays two superimposed sets of sedimentation waves with differing wavelengths. These sedimentation waves have similarities with Antarctic snow megadunes regarding their surface morphology, texture, grain size asymmetry, and internal stratigraphic architecture. Both sets of Martian sedimentation waves present young ice and occasional sastrugi fields, indicative of net accumulation, on their shallow-dipping upwind sides, their tops and the intervening troughs. Old layers of dusty ice, indicative of net ablation, are exhumed on the steep-dipping downwind sides of the larger waves. Smooth surfaces of coarse-grained ice, indicative of reduced accumulation associated with sublimation metamorphism, cover the steep-dipping downwind sides of the smaller waves. These surface characteristics and the internal stratigraphy revealed by radar soundings are consistent with the interpretation that both sets of Martian sedimentation waves grow and migrate upwind in response to the development of periodic accumulation/ablation patterns controlled by katabatic winds. The recognition of these sedimentation waves provides the basis for the development of a common model of ice/wind interaction at the surface of Martian and terrestrial glaciers. Martian smaller waves, characterized by reduced net accumulation on their downwind sides, are analogous to Antarctic snow megadunes that have been described so far. A terrestrial equivalent remains to be discovered for the larger Martian waves, characterized by net ablation on their downwind sides.

  11. Research in interactive scene analysis (United States)

    Tenenbaum, J. M.; Barrow, H. G.; Weyl, S. A.


    Cooperative (man-machine) scene analysis techniques were developed whereby humans can provide a computer with guidance when completely automated processing is infeasible. An interactive approach promises significant near-term payoffs in analyzing various types of high volume satellite imagery, as well as vehicle-based imagery used in robot planetary exploration. This report summarizes the work accomplished over the duration of the project and describes in detail three major accomplishments: (1) the interactive design of texture classifiers; (2) a new approach for integrating the segmentation and interpretation phases of scene analysis; and (3) the application of interactive scene analysis techniques to cartography.

  12. The significance of vertical moisture diffusion on drifting snow sublimation near snow surface (United States)

    Huang, Ning; Shi, Guanglei


    Sublimation of blowing snow is an important parameter not only for the study of polar ice sheets and glaciers, but also for maintaining the ecology of arid and semi-arid lands. However, sublimation of near-surface blowing snow has often been ignored in previous studies. To study sublimation of near-surface blowing snow, we established a sublimation of blowing snow model containing both a vertical moisture diffusion equation and a heat balance equation. The results showed that although sublimation of near-surface blowing snow was strongly reduced by a negative feedback effect, due to vertical moisture diffusion, the relative humidity near the surface does not reach 100 %. Therefore, the sublimation of near-surface blowing snow does not stop. In addition, the sublimation rate near the surface is 3-4 orders of magnitude higher than that at 10 m above the surface and the mass of snow sublimation near the surface accounts for more than half of the total snow sublimation when the friction wind velocity is less than about 0.55 m s-1. Therefore, the sublimation of near-surface blowing snow should not be neglected.

  13. Forensic 3D Scene Reconstruction

    Energy Technology Data Exchange (ETDEWEB)



    Traditionally law enforcement agencies have relied on basic measurement and imaging tools, such as tape measures and cameras, in recording a crime scene. A disadvantage of these methods is that they are slow and cumbersome. The development of a portable system that can rapidly record a crime scene with current camera imaging, 3D geometric surface maps, and contribute quantitative measurements such as accurate relative positioning of crime scene objects, would be an asset to law enforcement agents in collecting and recording significant forensic data. The purpose of this project is to develop a feasible prototype of a fast, accurate, 3D measurement and imaging system that would support law enforcement agents to quickly document and accurately record a crime scene.

  14. Cultural differences in scene perception


    Alotaibi, Albandari


    Do individuals from different cultures perceive scenes differently? Does culture have an influence on visual attention processes? This thesis investigates not only what these influences are, and how they affect eye movements, but also examines some of the proposed mechanisms that underlie the cultural influence in scene perception. Experiments 1 & 2 showed that Saudi participants directed a higher number of fixations to the background of images, in comparison to the British participants. Brit...

  15. Figure del desiderio: l'amore fra distruzione e sublime

    Directory of Open Access Journals (Sweden)

    Mabel Franzone


    Full Text Available Attraverso due racconti di Cortázar, l'analisi di due figure del desiderio ci permette esplorare due estremi seguendo una verticalità. La distruzione, doppio tenebroso della nostra anima, ci rivela un erotismo legato alla morte e al desiderio morboso di possedere l'Altro; il suo contraltare è un'ascesa vertiginosa accompagnata da un godimento estetico, dall'amore sublime prossimo all'esperienza mistica che si concluderà con una discesa progressiva e nel rispetto di questo Altro. La creazione letteraria si presenta come uno sfogo alle nostre angosce, che sono anche una sorta d'espressione dell'erotismo.

  16. On the importance of sublimation to an alpine snow mass balance in the Canadian Rocky Mountains

    Directory of Open Access Journals (Sweden)

    M. K. MacDonald


    Full Text Available A modelling study was undertaken to evaluate the contribution of sublimation to an alpine snow mass balance in the Canadian Rocky Mountains. Snow redistribution and sublimation by wind, snowpack sublimation and snowmelt were simulated for two winters over an alpine ridge transect located in the Canada Rocky Mountains. The resulting snowcover regimes were compared to those from manual snow surveys. Simulations were performed using physically based blowing snow (PBSM and snowpack ablation (SNOBAL models. A hydrological response unit (HRU-based spatial discretization was used rather than a more computationally expensive fully-distributed one. The HRUs were set up to follow an aerodynamic sequence, whereby eroded snow was transported from windswept, upwind HRUs to drift accumulating, downwind HRUs. That snow redistribution by wind can be adequately simulated in computationally efficient HRUs over this ridge has important implications for representing snow transport in large-scale hydrology models and land surface schemes. Alpine snow sublimation losses, in particular blowing snow sublimation losses, were significant. Snow mass losses to sublimation as a percentage of cumulative snowfall were estimated to be 20–32% with the blowing snow sublimation loss amounting to 17–19% of cumulative snowfall. This estimate is considered to be a conservative estimate of the blowing snow sublimation loss in the Canadian Rocky Mountains because the study transect is located in the low alpine zone where the topography is more moderate than the high alpine zone and windflow separation was not observed. An examination of the suitability of PBSM's sublimation estimates in this environment and of the importance of estimating blowing snow sublimation on the simulated snow accumulation regime was conducted by omitting sublimation calculations. Snow accumulation in HRUs was overestimated by 30% when neglecting blowing snow sublimation calculations.

  17. The pleasures of contra-purposiveness: Kant, the sublime, and being human


    Deligiorgi, Katerina


    When Paul Guyer surveyed the literature on the sublime about twenty years ago, he noted the flourishing of psychoanalytic and deconstructionist interpretations of the sublime by literary theorists and offered his own interpretative essay on Kant’s sublime as a contribution to a sparsely populated field. Today the situation is reversed. In the field of philosophical aesthetics, understood to include analytic aesthetics as well as theoretical approaches to literary and visual culture, serious d...

  18. Preparation of 2:1 urea-succinic acid cocrystals by sublimation (United States)

    Zhang, Tian; Yu, Qiushuo; Li, Xiaorui; Ma, Xiaoxun


    The aim of this study is to introduce a sublimation method for preparing cocrystals. The 2:1 urea-succinic acid cocrystals were generated by a simple sublimation apparatus, analyzed by Powder X-ray Diffraction (PXRD), Transmission Fourier Transform Infrared (FTIR) and Differential Scanning Calorimetry (DCS). The role of supersaturations in vapor crystallization was also discussed in detail. This work showed sublimation was a promising method for cocrystallization.

  19. Magnesium Based Rockets for Martian Exploration Project (United States)

    National Aeronautics and Space Administration — We propose to develop Mg rockets for Martian ascent vehicle applications. The propellant can be acquired in-situ from MgO in the Martian regolith (5.1% Mg by mass)...

  20. Fluvial valleys and Martian palaeoclimates (United States)

    Gulick, Virginia C.; Baker, Victor R.


    Theoretical models of early Martian atmospheric evolution describe the maintenance of a dense CO2 atmosphere and a warm, wet climate until the end of the heavy-bombardment phase of impacting. However, the presence of very young, earthlike fluvial valleys on the northern flank of Alba Patera conflicts with this scenario. Whereas the widespread ancient Martian valleys generally have morphologies indicative of sapping erosion by the slow outflow of subsurface water, the local Alba valleys were probably formed by surface-runoff processes. Because subsurface water flow might be maintained by hydrothermal energy inputs and because surface-runoff valleys developed late in Martian history, it is not necessary to invoke drastically different planet-wide climatic conditions to explain valley development on Mars. The Alba fluvial valleys can be explained by hydrothermal activity or outflow-channel discharges that locally modified the atmosphere, including precipitation and local overland flow on low-permeability volcanic ash.

  1. D/H fractionation during the sublimation of water ice (United States)

    Lécuyer, Christophe; Royer, Aurélien; Fourel, François; Seris, Magali; Simon, Laurent; Robert, François


    Experiments of sublimation of pure water ice have been performed in the temperature range -105 °C to -30 °C and atmospheric partial pressures ranging from 10-6 to 10-1 mb. Sampling of both vapour and residual ice fractions has been performed with the use of a vacuum line designed for the extraction and purification of gases before the measurement of their D/H ratios. Sublimation was responsible for sizable isotopic fractionation factors in the range 0.969-1.123 for temperatures lying between -105 °C and -30 °C. The fractionation factor exhibits a cross-over at temperatures around -50 °C with the water vapour fraction being D-depleted relative to the residual ice fraction at T deuterium enrichment or depletion between ice and water vapour cannot explain the differences in the D/H ratios amongst Jupiter comets and long-period comets families nor those that have been documented between Earth's and cometary water.

  2. Conditions for Sublimating Water Ice to Supply Ceres' Exosphere (United States)

    Landis, M. E.; Byrne, S.; Schörghofer, N.; Schmidt, B. E.; Hayne, P. O.; Castillo-Rogez, J.; Sykes, M. V.; Combe, J.-P.; Ermakov, A. I.; Prettyman, T. H.; Raymond, C. A.; Russell, C. T.


    Observations of a water vapor exosphere around Ceres suggest that the dwarf planet may be episodically outgassing at a rate of 6 kg s-1 from unknown sources. With data from the Dawn mission as constraints, we use a coupled thermal and vapor diffusion model to explore three different configurations of water ice (global buried pore-filling ice, global buried excess ice, and local exposed surface ice) that could be present on Ceres. We conclude that a buried ice table cannot alone explain the vapor production rates previously measured, but newly exposed surface ice, given the right conditions, can exceed that vapor production rate. Sublimation lag deposits form that bury and darken this surface ice over a large range of timescales (from <1 year to approximately hundreds of kyr) that depend on latitude and ice regolith content. Sublimating water vapor can loft regolith particles from the surface of exposed ice, possibly prolonging the visible lifespan of those areas. We find that this process is only effective for regolith grains smaller than approximately ones of microns.

  3. Nonlinear Spectral Mixture Modeling to Estimate Water-Ice Abundance of Martian Regolith (United States)

    Gyalay, Szilard; Chu, Kathryn; Zeev Noe Dobrea, Eldar


    We present a novel technique to estimate the abundance of water-ice in the Martian permafrost using Phoenix Surface Stereo Imager multispectral data. In previous work, Cull et al. (2010) estimated the abundance of water-ice in trenches dug by the Mars Phoenix lander by modeling the spectra of the icy regolith using the radiative transfer methods described in Hapke (2008) with optical constants for Mauna Kea palagonite (Clancy et al., 1995) as a substitute for unknown Martian regolith optical constants. Our technique, which uses the radiative transfer methods described in Shkuratov et al. (1999), seeks to eliminate the uncertainty that stems from not knowing the composition of the Martian regolith by using observations of the Martian soil before and after the water-ice has sublimated away. We use observations of the desiccated regolith sample to estimate its complex index of refraction from its spectrum. This removes any a priori assumptions of Martian regolith composition, limiting our free parameters to the estimated real index of refraction of the dry regolith at one specific wavelength, ice grain size, and regolith porosity. We can then model mixtures of regolith and water-ice, fitting to the original icy spectrum to estimate the ice abundance. To constrain the uncertainties in this technique, we performed laboratory measurements of the spectra of known mixtures of water-ice and dry soils as well as those of soils after desiccation with controlled viewing geometries. Finally, we applied the technique to Phoenix Surface Stereo Imager observations and estimated water-ice abundances consistent with pore-fill in the near-surface ice. This abundance is consistent with atmospheric diffusion, which has implications to our understanding of the history of water-ice on Mars and the role of the regolith at high latitudes as a reservoir of atmospheric H2O.

  4. Crime Scenes as Augmented Reality

    DEFF Research Database (Denmark)

    Sandvik, Kjetil


    , physical damage: they are all readable and interpretable signs. As augmented reality the crime scene carries a narrative which at first is hidden and must be revealed. Due to the process of investigation and the detective's ability to reason and deduce, the crime scene as place is reconstructed as virtual......Using the concept of augmented reality, this article will investigate how places in various ways have become augmented by means of different mediatization strategies. Augmentation of reality implies an enhancement of the places' emotional character: a certain mood, atmosphere or narrative surplus...... of meaning has been implemented. This may take place at different levels, which will be presented and investigated in this article and exemplified by some cases from the fields of tourism and computer games.                       The article suggests that we may use the forensic term crime scene in order...

  5. Categorization of natural dynamic audiovisual scenes.

    Directory of Open Access Journals (Sweden)

    Olli Rummukainen

    Full Text Available This work analyzed the perceptual attributes of natural dynamic audiovisual scenes. We presented thirty participants with 19 natural scenes in a similarity categorization task, followed by a semi-structured interview. The scenes were reproduced with an immersive audiovisual display. Natural scene perception has been studied mainly with unimodal settings, which have identified motion as one of the most salient attributes related to visual scenes, and sound intensity along with pitch trajectories related to auditory scenes. However, controlled laboratory experiments with natural multimodal stimuli are still scarce. Our results show that humans pay attention to similar perceptual attributes in natural scenes, and a two-dimensional perceptual map of the stimulus scenes and perceptual attributes was obtained in this work. The exploratory results show the amount of movement, perceived noisiness, and eventfulness of the scene to be the most important perceptual attributes in naturalistically reproduced real-world urban environments. We found the scene gist properties openness and expansion to remain as important factors in scenes with no salient auditory or visual events. We propose that the study of scene perception should move forward to understand better the processes behind multimodal scene processing in real-world environments. We publish our stimulus scenes as spherical video recordings and sound field recordings in a publicly available database.

  6. Multiagent architecture for scene interpretation (United States)

    Ealet, Fabienne; Collin, Bertrand; Sella, G.; Garbay, Catherine


    Scene interpretation is a crucial problem for navigation and guidance systems. The necessary integration of a large variety of heterogeneous knowledge leads us to design an architecture that distributes knowledge and that performs parallel and concurrent processing. We choose a multi- agent approach which specialized agents implementation is based on incrementality, distribution, cooperation, attention mechanism and adaptability.

  7. The anatomy of the crime scene

    DEFF Research Database (Denmark)

    Sandvik, Kjetil


    Crime scenes are constituted by a combination of a plot and a place. The crime scene is a place which has been in a certain state of transformation at a certain moment in time, the moment at which the place constituted the scene for some kind of criminal activity. As such the place has been encod...

  8. Multiwavelength Scophony Infrared Scene Projector (United States)

    Killius, Jim; Elder, Brent; Siegel, Larry; Allweiss, Michael B.


    A Scophony Infrared Scene Projector (IRSP) is being developed for use in evaluating thermal-imaging guidance systems. The Scophony IRSP is configured to be a very high frame rate laser-scanned projection system incorporating Scophony modulation. Scophony modulation offers distinct advantages over conventional flying-spot scanning, for example, longer pixel dwell times and multiple pixel projection. The Scophony IRSP serves as the image projection system in a 'hardware in the loop' therminal-phase guidance simulation. It is capable of projecting multiband, target engagement scenarios with high fidelity using Aura's proprietary software/electronic control system. The Scophony IRSP utilizes acoustooptical (AO) devices to produce the required imagery at four separate wavelengths simultaneously. The four separate scenes are then combined and projected into the imaging guidance system.

  9. Laser scophony infrared scene project (United States)

    Kircher, James R.; Marlow, Steven A.; Bastow, Michael


    A scophony infrared scene projector (IRSP) was developed by AURA Systems Inc. for use in evaluating thermal imaging guidance systems. The IRSP is a laser-scanned projector system incorporating scophony modulation with acousto-optical devices to produce multiband 96 X 96 image frames. A description of the system and preliminary test results with the Seeker Endo/Exo Demonstration Development breadboard interceptor are addressed.

  10. On the use of semiempirical models of (solid + supercritical fluid) systems to determine solid sublimation properties

    Energy Technology Data Exchange (ETDEWEB)

    Tabernero, Antonio; Martin del Valle, Eva M., E-mail:; Galan, Miguel A.


    Research highlights: We propose a method to determine sublimation properties of solids. Low deviations were produced calculating sublimation enthalpies and pressures. It is a required step to determine the vaporization enthalpy of the solid. It is possible to determine solid properties using semiempirical models solid-SCF. - Abstract: Experimental solubility data of solid-supercritical fluids have significantly increased in the last few years, and semiempirical models are emerging as one of the best choices to fit this type of data. This work establishes a methodology to calculate sublimation pressures using this type of equations. It requires the use of Bartle's equation to model equilibria data solid-supercritical fluids with the aim of determining the vaporization enthalpy of the compound. Using this method, low deviations were obtained by calculating sublimation pressures and sublimation enthalpies. The values of the sublimation pressures were subsequently used to successfully model different multiphasic equilibria, as solid-supercritical fluids and solid-solvent-supercritical fluids with the Peng-Robinson equation of state (without considering the sublimation pressure as an adjustable parameter). On the other hand, the sublimation pressures were also used to calculate solid sublimation properties and acetaminophen solvation properties in some solvents. Also, solubility data solid-supercritical fluids from 62 pharmaceuticals were fitted with different semiempirical equations (Chrastil, Kumar-Johnston and Bartle models) in order to present the values of solvation enthalpies in sc-CO{sub 2} and vaporization enthalpies for these compounds. All of these results highlight that semiempirical models can be used for any other purpose as well as modeling (solid + supercritical fluids) equilibria.

  11. Debate on sublime in the end of 18th century: Burke, Kant, Schiller

    Directory of Open Access Journals (Sweden)

    Jeremić-Molnar Dragana


    Full Text Available In the article the authors are examining three positions within the 18th Century aesthetic discussion on the sublime - Edmund Burke's, Immanuel Kant's and Friedrich Schiller's. They are also trying to reconstruct the political backgrounds of each of this theoretical positions: old regime conservatism (Burke, republican liberalism (Schiller and romantic longing for the 'third way' (Kant. The most sophisticated and mature theory of sublime is found in Schiller's aesthetic works, especially in those following his disappointment in French Revolution, in which the relationship between sublime and paradoxes of historical violence is most thoroughly reflected.

  12. A steamy proposal for Martian clays (United States)

    Schaefer, Laura


    Martian clays present a conundrum: the models proposed to explain their formation require conditions that are not predicted by computational climate simulations. Experiments now suggest an alternative scenario.

  13. Classification of Martian Volcanoes on Basis of Volcano Ground Ice Interaction (United States)

    Helgason, J.


    Most Martian volcanoes have common morphological features indicating mass wasting and erosion compatible with large scale break down of ground ice. While some features suggest the ground ice melted rapidly resulting in catastrophic erosive events, other features indicate a slow melting process (e.g sublimation) resulting in collapse structures. To determine relative volcano age and activity on Mars it is suggested that volcano interactions with an overlying ice sheet may be helpful. Examples of the various morphological features indicating volcano-ice interaction are drawn from the literature: (1) valley formation that probably formed in response to joekulhlaups and subglacial volcanism, (2) isolated thermocarst depressions probably formed by geothermal melting of ground ice, (3) large scale sublimation of distal strata, (4) small fluvial valleys, (5) large scale failure of volcano flanks through aureole development, (6) rimless craters without ash collars, (7) rampart craters on volcanoes, (8) channels, (9) mud flows or lahars. A Viking Orbiter image showing possible thermocarst landscape on the flank of the volcano Hadriaca Patera (Dao Vallis). Although various other explanations can account for some of these features they are all compatible with a ground ice-volcano interaction. These features suggests that to an extent most Martian volcanoes are covered with sheet of ground ice of variable thickness. Over a vast time interval this ground ice layer (or ice sheet) has been failing to a variable extent and in a number of ways depending on different volcano characteristics. As a result it is suggested that Martian volcanoes can be classified or assigned an evolutionary status depending on how widespread their interaction is with the ground ice layer. Thus, for example, within the Tharsis region the volcanoes Olympus Mons and Arsia Mons can be regarded as two evolutionary end points. Volcanism in the former has completely built up through and destroyed the ice sheet

  14. Strong Water Isotopic Anomalies in the Martian Atmosphere: Probing Current and Ancient Reservoirs (United States)

    Villanueva, G. L.; Mumma, M. J.; Novak, R. E.; Käufl, H. U.; Hartogh, P.; Encrenaz, T.; Tokunaga, A.; Khayat, A.; Smith, M. D.


    We measured maps of atmospheric water (H2O) and its deuterated form (HDO) across the martian globe, showing strong isotopic anomalies and a significant high deuterium/hydrogen (D/H) enrichment indicative of great water loss. The maps sample the evolution of sublimation from the north polar cap, revealing that the released water has a representative D/H value enriched by a factor of about 7 relative to Earth's ocean [Vienna standard mean ocean water (VSMOW)]. Certain basins and orographic depressions show even higher enrichment, whereas high-altitude regions show much lower values (1 to 3 VSMOW). Our atmospheric maps indicate that water ice in the polar reservoirs is enriched in deuterium to at least 8 VSMOW, which would mean that early Mars (4.5 billion years ago) had a global equivalent water layer at least 137 meters deep.

  15. Mimeses do sublime: a recepção de Kant pelo Romantismo e pelo Expressionismo Mimesis of sublime: the Romantism and Expressionism reception of Kant

    Directory of Open Access Journals (Sweden)

    Priscila Rossinetti Rufinoni


    Full Text Available Partindo das analises do criticismo kantiano, este texto investiga as concepções romântica e moderna de sublime e de imaginação. Se, por um lado, a concepção romântica inaugura o mundo moderno, por outro, a expressionista mostra os limites dessa mesma modernidade. Para ambas, entretanto, a Crítica do Juízo de Kant é o âmbito privilegiado no qual podemos precisar as distinções.Starting from the analysis of the Kantian criticism, this text investigates the romantic and the modern conceptions of sublime and imagination. On the one hand, the romantic conceptions of sublime inaugurate the modern world. On the other hand, the expressionist conceptions show the confines of this world. The Critique of Judgment is the very locus where such distinctions can be drawn with precision.

  16. Rousseau's Ethics of Truth: a sublime science of simple souls

    Directory of Open Access Journals (Sweden)

    Jason Neildleman


    Full Text Available ROUSSEAU’S ETHICS OF TRUTH - A SUBLIME SCIENCE OF SIMPLE SOULS Resumo: este artigo é um resumo do livro com o mesmo título, publicado pelas edições da Routledge, nos Estados Unidos. Tanto no livro quanto neste artigo, o autor pretende discutir a coerência dos textos de Rousseau, na qual é possível prospectar uma "ética da verdade" cujo objetivo seja alcançar um vínculo de comunhão com as pessoas e com as coisas. O autor tenta ainda discutir as implicações da ética da verdade de Rousseau sobre o nosso sentido de si mesmo e o sentido de existência no mundo. Palavras-chave: Rousseau. Ética. Verdade. Filosofia. Abstract: This paper is a summary of the book published by Routledge in the United States. The author aims to discuss the coherence of Rousseau’s texts thought which it is possible to prospect an “ethics of truth”, so to achieve a communion bond with people and things. The author tries also to discuss the implications of Rousseau’s ethics of truth on our sense of self and the implications in the real existence in the world. Keywords: Rousseau. Ethics. Truth. Philosophy.


    Directory of Open Access Journals (Sweden)

    J. Campbell


    Full Text Available Polycyclic aromatic hydrocarbons (PAHs are considered to be important in theories of abiogenesis (Allamandola, 2011 . There is evidence that PAHs have been detected on two icy Saturnian satellites using the Visual and Infrared Mapping Spectrometer (VIMS on the Cassini spacecraft (Cruikshank et al., 2007. The hypothesised presence of PAHs in Mars south polar cap has not been systematically examined even though the Mars south polar cap may allow the preservation of organic molecules that are typically destroyed at the Martian surface by UV radiation (Dartnell et al. 2012. This hypothesis is supported by recent analyses of South Polar Residual Cap (SPRC structural evolution (Thomas et al., 2009 that suggest the possibility that seasonal and long term sublimation may excavate dust particles from within the polar ice. Periodic sublimation is believed to be responsible for the formation of so-called “Swiss Cheese Terrain”, a unique surface feature found only in the Martian south polar residual cap consisting of flat floored, circular depressions (Byrne, 2009. We show the first examples of work towards the detection of PAHs in Swiss Cheese Terrain, using data from the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM, on board NASA’s Mars Reconnaissance Orbiter (MRO. CRISM is designed to search for mineralogical indications of past and present water, thus providing extensive coverage of the south polar cap. In this work, we discuss whether CRISM infrared spectra can be used to detect PAHs in Swiss Cheese Terrain and demonstrate a number of maps showing shifts in spectral profiles over the SPRC.

  18. Integrated Sublimator Driven Coldplate for use in Active Thermal Control System Project (United States)

    National Aeronautics and Space Administration — The original Sublimator Driven Coldplate (SDC) design sought to provide significant mass savings over a traditional pumped fluid loop by combining the functions of a...

  19. Investigation of the extruded products based on lupins, lentils and sublimated meat hydrophilic properties

    Directory of Open Access Journals (Sweden)

    A. N. Ostrikov


    Full Text Available Using the calorimetric method have been studied the swelling kinetics of developed vegetable-meat mixture on the basis of lentils, lupine and sublimated meat to create extruded functionality products.

  20. In situ transmission electron microscopy observations of sublimation in silver nanoparticles. (United States)

    Asoro, Michael A; Kovar, Desiderio; Ferreira, Paulo J


    In situ heating experiments were performed in a transmission electron microscope (TEM) to monitor the thermal stability of silver nanoparticles. The sublimation kinetics from isothermal experiments on individual nanoparticles was used to assess the actual temperatures of the nanoparticles by considering the localized heating from the electron beam. For isolated nanoparticles, beam heating under normal TEM operating conditions was found to increase the temperature by tens of degrees. For nominally isothermal experiments, the observed sublimation temperatures generally decreased with decreasing particle size, in agreement with the predictions from the Kelvin equation. However, sublimation of smaller nanoparticles was often observed to occur in discrete steps, which led to faceting of the nanoparticles. This discrete behavior differs from that predicted by conventional theory as well as from experimental observations in larger nanoparticles where sublimation was continuous. A hypothesis that explains the mechanism for this size-dependent behavior is proposed.

  1. Imaging spectroscopy for scene analysis

    CERN Document Server

    Robles-Kelly, Antonio


    This book presents a detailed analysis of spectral imaging, describing how it can be used for the purposes of material identification, object recognition and scene understanding. The opportunities and challenges of combining spatial and spectral information are explored in depth, as are a wide range of applications. Features: discusses spectral image acquisition by hyperspectral cameras, and the process of spectral image formation; examines models of surface reflectance, the recovery of photometric invariants, and the estimation of the illuminant power spectrum from spectral imagery; describes

  2. Finding edges in noisy scenes (United States)

    Machuca, R.; Gilbert, A. L.


    Edge detection in the presence of noise is a well-known problem. This paper examines an applications-motivated approach for solving the problem using novel techniques and presents a method developed by the authors that performs well on a large class of targets. ROC curves are used to compare this method with other well-known edge detection operators, with favorable results. A theoretical argument is presented that favors LMMSE filtering over median filtering in extremely noisy scenes. Simulated results of the research are presented.

  3. Boron enrichment in martian clay.

    Directory of Open Access Journals (Sweden)

    James D Stephenson

    Full Text Available We have detected a concentration of boron in martian clay far in excess of that in any previously reported extra-terrestrial object. This enrichment indicates that the chemistry necessary for the formation of ribose, a key component of RNA, could have existed on Mars since the formation of early clay deposits, contemporary to the emergence of life on Earth. Given the greater similarity of Earth and Mars early in their geological history, and the extensive disruption of Earth's earliest mineralogy by plate tectonics, we suggest that the conditions for prebiotic ribose synthesis may be better understood by further Mars exploration.

  4. Boron Enrichment in Martian Clay (United States)

    Nagashima, Kazuhide; Freeland, Stephen J.


    We have detected a concentration of boron in martian clay far in excess of that in any previously reported extra-terrestrial object. This enrichment indicates that the chemistry necessary for the formation of ribose, a key component of RNA, could have existed on Mars since the formation of early clay deposits, contemporary to the emergence of life on Earth. Given the greater similarity of Earth and Mars early in their geological history, and the extensive disruption of Earth's earliest mineralogy by plate tectonics, we suggest that the conditions for prebiotic ribose synthesis may be better understood by further Mars exploration. PMID:23762242

  5. Blowing snow sublimation and transport over Antarctica from 11 years of CALIPSO observations (United States)

    Palm, Stephen P.; Kayetha, Vinay; Yang, Yuekui; Pauly, Rebecca


    Blowing snow processes commonly occur over the earth's ice sheets when the 10 m wind speed exceeds a threshold value. These processes play a key role in the sublimation and redistribution of snow thereby influencing the surface mass balance. Prior field studies and modeling results have shown the importance of blowing snow sublimation and transport on the surface mass budget and hydrological cycle of high-latitude regions. For the first time, we present continent-wide estimates of blowing snow sublimation and transport over Antarctica for the period 2006-2016 based on direct observation of blowing snow events. We use an improved version of the blowing snow detection algorithm developed for previous work that uses atmospheric backscatter measurements obtained from the CALIOP (Cloud-Aerosol Lidar with Orthogonal Polarization) lidar aboard the CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation) satellite. The blowing snow events identified by CALIPSO and meteorological fields from MERRA-2 are used to compute the blowing snow sublimation and transport rates. Our results show that maximum sublimation occurs along and slightly inland of the coastline. This is contrary to the observed maximum blowing snow frequency which occurs over the interior. The associated temperature and moisture reanalysis fields likely contribute to the spatial distribution of the maximum sublimation values. However, the spatial pattern of the sublimation rate over Antarctica is consistent with modeling studies and precipitation estimates. Overall, our results show that the 2006-2016 Antarctica average integrated blowing snow sublimation is about 393 ± 196 Gt yr-1, which is considerably larger than previous model-derived estimates. We find maximum blowing snow transport amount of 5 Mt km-1 yr-1 over parts of East Antarctica and estimate that the average snow transport from continent to ocean is about 3.7 Gt yr-1. These continent-wide estimates are the first of their kind

  6. Noncondensables As Predictors of Martian Climate and Chemistry (United States)

    England, C.; Delitsky, M. L.


    The substantial seasonal changes in atmospheric pressure on Mars result from massive sublimation of carbon dioxide at the Poles. When CO2 is condensing, the mixing ratios of the low-boiling components (O2, CO, Ne, N2, Ar, Kr, and O3) in the atmosphere can increase locally up to 20-fold [1]. These non-condensing gases will disperse from the Pole prior to reintroduction of the CO2 into the atmosphere in the warmer seasons. As a result, there will exist a ``wave" of changing composition for minor components in the atmosphere that precedes the seasonal global pressure wave. The compositional wave can be a predictor of changes in martian climate, which is caused by the gross seasonal variation in atmospheric mass. The greatest seasonal change is attributable to sublimation at the South Pole, which, in the fall and winter, removes up to 30% of the atmosphere. Selective condensation of CO2 may result locally in an atmosphere with up to 2.8% oxygen and over 50% nitrogen [1]. The average global mixing ratios of the non-condensables will change measurably. Increasing mixing ratios will anticipate the coming global rise in pressure and atmospheric mass. Because the compositional wave will not be uniform over the planet's surface, the changes in mixing ratio throughout the year can be indicators of the detailed movement of the atmosphere as it oscillates between poles. Inert gases such as neon and krypton act as invariant tracers for atmospheric transport, while oxygen, carbon monoxide and ozone are subject to transport and chemistry. Of particular theoretical interest is the apparent deficit of carbon monoxide, produced from CO2 in amounts twice that of oxygen, but is present at only half the latter's concentration. Continuous and quantitative measurement of trace components over the full year may provide the key information for understanding the atmosphere, how it is affected by seasonal effects, and how it interacts with the regolith. Engineering methods to utilize the

  7. JMSS-1: a new Martian soil simulant (United States)

    Zeng, Xiaojia; Li, Xiongyao; Wang, Shijie; Li, Shijie; Spring, Nicole; Tang, Hong; Li, Yang; Feng, Junming


    It is important to develop Martian soil simulants that can be used in Mars exploration programs and Mars research. A new Martian soil simulant, called Jining Martian Soil Simulant (JMSS-1), was developed at the Lunar and Planetary Science Research Center at the Institute of Geochemistry, Chinese Academy of Sciences. The raw materials of JMSS-1 are Jining basalt and Fe oxides (magnetite and hematite). JMSS-1 was produced by mechanically crushing Jining basalt with the addition of small amounts of magnetite and hematite. The properties of this simulant, including chemical composition, mineralogy, particle size, mechanical properties, reflectance spectra, dielectric properties, volatile content, and hygroscopicity, have been analyzed. On the basis of these test results, it was demonstrated that JMSS-1 is an ideal Martian soil simulant in terms of chemical composition, mineralogy, and physical properties. JMSS-1 would be an appropriate choice as a Martian soil simulant in scientific and engineering experiments in China's Mars exploration in the future.

  8. Oxidation and sublimation of porous graphite during fiber laser irradiation (United States)

    Phillips, Grady T.; Bauer, William A.; Gonzales, Ashley E.; Herr, Nicholas C.; Perram, Glen P.


    Porous graphite plates, cylinders and cones with densities of 1.55-1.82 g/cm3 were irradiated by a 10 kW fiber laser at 0.075 -3.525 kW/cm2 for 120 s to study mass removal and crater formation. Surface temperatures reached steady state values as high as 3767 K. The total decrease in sample mass ranged from 0.06 to 6.29 g, with crater volumes of 0.52 - 838 mm3, and penetration times for 12.7 mm thick plates as short as 38 s. Minor contaminants in the graphite samples produced calcium and iron oxide to be re-deposited on the graphite surface. Significantly increased porosity of the sample is observed even outside of the laser-irradiated region. Total mass removed increases with deposited laser energy at a rate of 4.83 g/MJ for medium extruded graphite with an apparent threshold of 0.15 MJ. Visible emission spectroscopy reveals C2 Swan and CN red, CN violet bands and Li, Na, and K 2P3/2,1/2 - 2S1/2 doublets. The reacting boundary layer is observed using a mid-wave imaging Fourier transform spectrometer (IFTS) at 2 cm-1 spectral resolution, 0.5 mm/pixel spatial resolution, and 0.75 Hz data cube rate. A two-layer radiative transfer model was used to determine plume temperature, CO, and CO2 concentrations from spectral signatures. The new understanding of graphite combustion and sublimation during laser irradiation is vital to the more complex behavior of carbon composites.


    Directory of Open Access Journals (Sweden)

    R. A. Barykin


    Full Text Available Summary. The main directions of use of freeze-dryed products and ingredients are revealed. The analysis of sales markets of freeze-dryed products is provided. It is shown that introduction of innovative production technologies will allow to develop dynamically not only to the large companies, but also small firms that will create prerequisites for growth of the Russian market of freeze-dryed products. Tendencies of development of the freeze-drying equipment are analysed. Relevance of development of energy saving freeze-dryers is proved The integrated approach to creation of competitive domestic technologies and the equipment for sublimation dehydration of thermolabile products consists in use of the effective combined remedies of a power supply, a process intensification, reduction of specific energy consumption and, as a result, decrease in product cost at achievement of high quality indicators. Advantages of thermoelectric modules as alternative direction to existing vapor-compression and absorbing refrigerating appliances are given. Researches of process of freeze-drying dehydration with use of thermoelectric modules are conducted. It is scientifically confirmed, that the thermoelectric module working at Peltier effect, promotes increase in refrigerating capacity due to use of the principle of the thermal pump. Options of use of thermoelectric modules in designs of dryers are offered. Optimum operating modes and number of modules in section are defined. Ways of increase of power efficiency of freeze-dryers with use of thermoelectric modules are specified. The received results will allow to make engineering calculations and design of progressive freeze-drying installations with various ways of a power supply.

  10. Scene and object vision in rats. (United States)

    Simpson, E L; Gaffan, E A


    Dark Agouti rats learned to discriminate large visual displays ("scenes") in a computer-controlled Y-maze. Each scene comprised several shapes ("objects") against a contrasting background. The constant-negative paradigm was used; in each problem, one constant scene was presented on every trial together with a trial-unique variable scene, and rats were rewarded for approaching the variable scene. By varying the manner in which variables differed from the constant, we investigated what aspects of scenes and the objects comprising them were salient. In Experiment 1, rats discriminated constant scenes more easily if they contained four objects rather than six, and they showed a slight attentional bias towards the lower halves of the screens. That bias disappeared in Experiment 2. Experiments 3 and 4 showed that rats could discriminate scenes even if the objects that comprised them were closely matched in position, luminance, and area. Therefore, they encoded the form of individual objects. Rats perceived shapes of the same class (e.g. two ellipses) as more similar than shapes from different classes (e.g. ellipse and polygon) regardless of whether they also differed in area. This paradigm is suitable for studying the neuropsychology of perceiving spatial relationships in multi-object scenes and of identifying visual objects.

  11. Audiovisual integration facilitates unconscious visual scene processing. (United States)

    Tan, Jye-Sheng; Yeh, Su-Ling


    Meanings of masked complex scenes can be extracted without awareness; however, it remains unknown whether audiovisual integration occurs with an invisible complex visual scene. The authors examine whether a scenery soundtrack can facilitate unconscious processing of a subliminal visual scene. The continuous flash suppression paradigm was used to render a complex scene picture invisible, and the picture was paired with a semantically congruent or incongruent scenery soundtrack. Participants were asked to respond as quickly as possible if they detected any part of the scene. Release-from-suppression time was used as an index of unconscious processing of the complex scene, which was shorter in the audiovisual congruent condition than in the incongruent condition (Experiment 1). The possibility that participants adopted different detection criteria for the 2 conditions was excluded (Experiment 2). The audiovisual congruency effect did not occur for objects-only (Experiment 3) and background-only (Experiment 4) pictures, and it did not result from consciously mediated conceptual priming (Experiment 5). The congruency effect was replicated when catch trials without scene pictures were added to exclude participants with high false-alarm rates (Experiment 6). This is the first study demonstrating unconscious audiovisual integration with subliminal scene pictures, and it suggests expansions of scene-perception theories to include unconscious audiovisual integration. (c) 2015 APA, all rights reserved).

  12. Measured and modelled sublimation on the tropical Glaciar Artesonraju, Perú

    Directory of Open Access Journals (Sweden)

    M. Winkler


    Full Text Available Sublimation plays a decisive role in the surface energy and mass balance of tropical glaciers. During the dry season (May–September low specific humidity and high surface roughness favour the direct transition from ice to vapour and drastically reduce the energy available for melting. However, field measurements are scarce and little is known about the performance of sublimation parameterisations in glacier mass balance and runoff models.

    During 15 days in August 2005 sublimation was measured on the tongue of Glaciar Artesonraju (8°58' S, 77°38' W in the Cordillera Blanca, Perú, using simple lysimeters. Indicating a strong dependence on surface roughness, daily totals of sublimation range from 1–3 kg m−2 for smooth to 2–5 kg m−2 for rough conditions. (The 15-day means at that time of wind speed and specific humidity were 4.3 m s−1 and 3.8 g kg−1, respectively.

    Measured sublimation was related to characteristic surface roughness lengths for momentum (zm and for the scalar quantities of temperature and water vapour (zs, using a process-based mass balance model. Input data were provided by automatic weather stations, situated on the glacier tongue at 4750 m a.s.l. and 4810 m a.s.l., respectively. Under smooth conditions the combination zm=2.0 mm and zs=1.0 mm appeared to be most appropriate, for rough conditions zm=20.0 mm and zs=10.0 mm fitted best.

    Extending the sublimation record from April 2004 to December 2005 with the process-based model confirms, that sublimation shows a clear seasonality. 60–90% of the energy available for ablation is consumed by sublimation in the dry season, but only 10–15% in the wet season (October–April. The findings are finally used to evaluate the parameterisation of sublimation in the lower-complexity mass

  13. Can perchlorates be transformed to hydrogen peroxide (H2O2) products by cosmic rays on the Martian surface? (United States)

    Crandall, Parker B.; Góbi, Sándor; Gillis-Davis, Jeffrey; Kaiser, Ralf I.


    Due to their oxidizing properties, perchlorates (ClO4-) are suggested by the planetary science community to play a vital role in the scarcity of organics on the Martian surface. However, alternative oxidation agents such as hydrogen peroxide (H2O2) have received surprisingly little attention. In this study, samples of magnesium perchlorate hexahydrate (Mg(ClO4)2 · 6H2O) were exposed to monoenergetic electrons and D2+ ions separately, sequentially, and simultaneously to probe the effects of galactic cosmic ray exposure of perchlorates and the potential incorporation of hydrogen (deuterium) into these minerals. The experiments were carried out under ultrahigh-vacuum conditions at 50 K, after which the samples were slowly heated to 300 K while the subliming products were monitored by a quadrupole mass spectrometer. In all cases, molecular oxygen (O2) was detected upon the onset of irradiation and also during the warmup phase. In case of a simultaneous D2+-electron exposure, deuterated water (D2O) and deuterium peroxide (D2O2) were also detected in the warmup phase, whereas only small amounts of D2O2 were found after an exclusive D2+ irradiation. These experiments yield the first data identifying hydrogen peroxide as a potential product in the interaction of cosmic rays with perchlorates in the Martian regolith revealing that perchlorates are capable of producing multiple oxidizing agents (O2 and D2O2) that may account for the destruction of organics on the Martian surface.

  14. Eye Movement Control during Scene Viewing: Immediate Effects of Scene Luminance on Fixation Durations (United States)

    Henderson, John M.; Nuthmann, Antje; Luke, Steven G.


    Recent research on eye movements during scene viewing has primarily focused on where the eyes fixate. But eye fixations also differ in their durations. Here we investigated whether fixation durations in scene viewing are under the direct and immediate control of the current visual input. Subjects freely viewed photographs of scenes in preparation…

  15. A model of Martian surface chemistry (United States)

    Oyama, V. I.; Berdahl, B. J.


    Alkaline earth and alkali metal superoxides and peroxides, gamma-Fe2O3 and carbon suboxide polymer, are proposed to be constituents of the Martian surface material. These reactive substances explain the water modified reactions and thermal behaviors of the Martian samples demonstrated by all of the Viking Biology Experiments. It is also proposed that the syntheses of these substances result mainly from electrical discharges between wind-mobilized particles at Martian pressures; plasmas are initiated and maintained by these discharges. Active species in the plasma either combine to form or react with inorganic surfaces to create the reactive constituents.

  16. Effects of insolation on habitability and the isotopic history of Martian water (United States)

    Moores, John

    Three aspects of the Habitability of the Northern Plains of Mars to organics and terrestrial-like microbial life were assessed. (1) Protection offered by small surface features and; (2) the breakdown of rocks to form soils were examined using a radiative transfer computer model. Two separate sublimation experiments provided a basis to improve; (3) estimates of the amount of available water today and in the past by determining the fractionation of HDO between present-day reservoirs. (1) UV radiation sterilizes the hardiest of terrestrial organisms within minutes on the Martian surface. Small surface features including pits, trenches, flat faces and overhangs may create "safe havens" for organisms by blocking much of the UV flux. In the most favorable cases, this flux is sufficiently reduced such that organic in-fall could accumulate beneath overhanging surfaces and in pits and cracks while terrestrial microorganisms could persist for several tens of martian years. (2) The production of soils on the surface is considered by analogy with the arid US Southwest. Here differential insolation of incipient cracks of random orientations predicts crack orientation distributions consistent with field observations by assuming that only crack orientations which shield their interiors, minimizing their water loss, can grow, eventually disrupting the clast. (3) Disaggregated water ice to simulate the polar caps was produced by flash freezing in liquid nitrogen and crushing. When dust was added to the mixtures, the D/H ratio of the sublimate gas was seen to decrease with time from the bulk ratio. The more dust was added to the mixture, the more pronounced was this effect. The largest fractionation factor observed during these experiments was 2.5. Clean ice was also prepared and overlain by dust to simulate ground ice. Here, the movement of water vapor was modeled using an effective diffusivity that incorporated both adsorption on grains and diffusion. For low temperatures (<-55

  17. History Scene Investigations: From Clues to Conclusions (United States)

    McIntyre, Beverly


    In this article, the author introduces a social studies lesson that allows students to learn history and practice reading skills, critical thinking, and writing. The activity is called History Scene Investigation or HSI, which derives its name from the popular television series based on crime scene investigations (CSI). HSI uses discovery learning…

  18. The visual light field in real scenes

    NARCIS (Netherlands)

    Xia, L.; Pont, S.C.; Heynderickx, I.E.J.R.


    Human observers’ ability to infer the light field in empty space is known as the “visual light field.” While most relevant studies were performed using images on computer screens, we investigate the visual light field in a real scene by using a novel experimental setup. A “probe” and a scene were

  19. Isothermal and non-isothermal sublimation kinetics of zirconium tetrachloride (ZrCl{sub 4}) for producing nuclear grade Zr

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Jae Hong [Department of Materials Engineering, Hanyang University, Ansan 426-791 (Korea, Republic of); Choi, Mi Sun [Research Institute of Industrial Science and Technology (RIST), Pohang 790-330 (Korea, Republic of); Min, Dong Joon [Department of Materials Science and Engineering, Yonsei University, Seoul 120-749 (Korea, Republic of); Park, Joo Hyun, E-mail: [Department of Materials Engineering, Hanyang University, Ansan 426-791 (Korea, Republic of)


    Sublimation of ZrCl{sub 4} is important for the production of nuclear grade metallic Zr in Kroll's process. The sublimation kinetics of ZrCl{sub 4} was investigated by thermogravimetric analysis under both isothermal and non-isothermal conditions. The sublimation rate of ZrCl{sub 4} increased with increasing temperature under isothermal conditions. ZrCl{sub 4} sublimation was confirmed to be a zero-order process under isothermal conditions, whereas it was first-order kinetics under non-isothermal conditions. The activation energy of ZrCl{sub 4} sublimation under isothermal conditions was 21.7 kJ mol{sup −1}. The activation energy for non-isothermal sublimation was 101.4 kJ mol{sup −1} and 108.1 kJ mol{sup −1} with the Kissinger method and Flynn–Wall–Ozawa method, respectively. These non-isothermal activation energies were very close to the heat of sublimation (103.3 kJ mol{sup −1}). Sublimation occurs by two elementary steps: surface reaction and desorption. Therefore, the overall activation energy of ZrCl{sub 4} sublimation is 104.8 (±3.4) kJ mol{sup −1}. The activation energy of the surface reaction and desorption steps are proposed to be 83.1 kJ mol{sup −1} and 21.7 kJ mol{sup −1}, respectively. - Highlights: • Sublimation kinetics of ZrCl{sub 4} was quantitatively analyzed using TGA method. • Isothermal and non-isothermal sublimation kinetics were quantitatively evaluated. • Activation energies of isothermal and non-isothermal kinetics were obtained. • Sublimation mechanism was proposed from kinetic analyses and SEM observations. • This kinetic information will be very useful in production of nuclear grade Zr.

  20. Mechanism and kinetics for ammonium dinitramide (ADN) sublimation: a first-principles study. (United States)

    Zhu, R S; Chen, Hui-Lung; Lin, M C


    The mechanism for sublimation of NH(4)N(NO(2))(2) (ADN) has been investigated quantum-mechanically with generalized gradient approximation plane-wave density functional theory calculations; the solid surface is represented by a slab model and the periodic boundary conditions are applied. The calculated lattice constants for the bulk ADN, which were found to consist of NH(4)(+)[ON(O)NNO(2)](-) units, instead of NH(4)(+)[N(NO(2))(2)](-), agree quite well with experimental values. Results show that three steps are involved in the sublimation/decomposition of ADN. The first step is the relaxation of the surface layer with 1.6 kcal/mol energy per NH(4)ON(O)NNO(2) unit; the second step is the sublimation of the surface layer to form a molecular [NH(3)]-[HON(O)NNO(2)] complex with a 29.4 kcal/mol sublimation energy, consistent with the experimental observation of Korobeinichev et al. (10) The last step is the dissociation of the [H(3)N]-[HON(O)NNO(2)] complex to give NH(3) and HON(O)NNO(2) with the dissociation energy of 13.9 kcal/mol. Direct formation of NO(2) (g) from solid ADN costs a much higher energy, 58.3 kcal/mol. Our calculated total sublimation enthalpy for ADN(s) → NH(3)(g) + HON(O)NNO(2)) (g), 44.9 kcal/mol via three steps, is in good agreement with the value, 42.1 kcal/mol predicted for the one-step sublimation process in this work and the value 44.0 kcal/mol computed by Politzer et al. (11) using experimental thermochemical data. The sublimation rate constant for the rate-controlling step 2 can be represented as k(sub) = 2.18 × 10(12) exp (-30.5 kcal/mol/RT) s(-1), which agrees well with available experimental data within the temperature range studied. The high pressure limit decomposition rate constant for the molecular complex H(3)N···HON(O)NNO(2) can be expressed by k(dec) = 3.18 × 10(13) exp (-15.09 kcal/mol/RT) s(-1). In addition, water molecules were found to increase the sublimation enthalpy of ADN, contrary to that found in the ammonium

  1. Regional variations in the observed morphology and activity of martian linear gullies (United States)

    Morales, Kimberly Marie; Diniega, Serina; Austria, Mia; Ochoa, Vincent; HiRISE Science and Instrument Team


    The formation mechanism for martian linear gullies has been much debated, because they have been suggested as possible evidence of liquid water on Mars. This class of dune gullies is defined by long (up to 2 km), narrow channels that are relatively uniform in width, and range in sinuosity index. Unlike other gullies on Earth and Mars that end in depositional aprons, linear gullies end in circular depressions referred to as terminal pits. This particular morphological difference, along with the difficulty of identifying a source of water to form these features, has led to several ‘dry’ hypotheses. Recent observations on the morphology, distribution, and present-day activity of linear gullies suggests that they could be formed by subliming blocks of seasonal CO2 ice (“dry ice”) sliding downslope on dune faces. In our study, we aimed to further constrain the possible mechanism(s) responsible for the formation of linear gullies by using HiRISE images to collect morphological data and track seasonal activity within three regions in the southern hemisphere-Hellespontus (~45°S, 40°E), Aonia Terra (~50°S, 290°E), and Jeans (~70°S, 155°E) over the last four Mars years. General similarities in these observations were reflective of the proposed formation process (sliding CO2 blocks) while differences were correlated with regional environmental conditions related to the latitude or general geologic setting. This presentation describes the observed regional differences in linear gully morphology and activity, and investigates how environmental factors such as surface properties and local levels of frost may explain these variations while still supporting the proposed model. Determining the formation mechanism that forms these martian features can improve our understanding of both the climatic and geological processes that shape the Martian surface.

  2. Distributed modelling of climate change impacts on snow sublimation in Northern Mongolia

    Directory of Open Access Journals (Sweden)

    L. Menzel


    Full Text Available Sublimation of snow is an important factor of the hydrological cycle in Mongolia and is likely to increase according to future climate projections. In this study the hydrological model TRAIN was used to assess spatially distributed current and future sublimation rates based on interpolated daily data of precipitation, air temperature, air humidity, wind speed and solar radiation. An automated procedure for the interpolation of the input data is provided. Depending on the meteorological parameter and the data availability for the individual days, the most appropriate interpolation method is chosen automatically from inverse distance weighting, Ordinary Least Squares interpolation, Ordinary or Universal Kriging. Depending on elevation simulated annual sublimation in the period 1986–2006 was 23 to 35 mm, i.e. approximately 80% of total snowfall. Moreover, future climate projections for 2071–2100 of ECHAM5 and HadCM3, based on the A1B emission scenario of the Intergovernmental Panel on Climate Change, were analysed with TRAIN. In the case of ECHAM5 simulated sublimation increases by up to 17% (26...41 mm while it remains at the same level for HadCM3 (24...34 mm. The differences are mainly due to a distinct increase in winter precipitation for ECHAM5. Simulated changes of the all-season hydrological conditions, e.g. the sublimation-to-precipitation ratio, were ambiguous due to diverse precipitation patterns derived by the global circulation models.

  3. Experimental Study of influence on The Moving of Sublimation Interface by Precooling Rate and Drying Temperature During Freeze-drying (United States)

    Xiao, Xin; Tao, Le-Ren


    For complex heat and mass transfer during freeze-drying, the shape and the moving rate of sublimation interface have not been clearly recognized yet. In this paper, Micro-CT scanner was used to follow the moving interface during sublimation. Apple slices cut into 16mm in diameter and 8mm in thickness were used as experimental samples, they were scanned every two hours during sublimation. The scanning images were analyzed and measured, then variation curves of grey value and curves of sublimation rate in two directions were obtained. The moving rates of sublimation interface under various precooling rates and primary drying temperatures were compared. The results show that, heat and mass transfer happens both at the upper and the under surface of the sample. Also it happens at the side surface to some extent. The interface shows as a three-dimensional moving mode, contracts to the geometric centre of the sample and presents an approximately spheral shape. Apple samples frozen at low rate sublimated more quickly than those by high rate. While drying temperature was higher, the sublimation interface moved more quickly. Under slow precooling condition, the sublimation rate rose quickly near the end of sublimation not only in vertical direction, but in horizontal direction.

  4. The role of sublimation and condensation in the formation of ice sheet surface at Mizuho Station, Antarctica (United States)

    Fujii, Yoshiyuki; Kusunoki, Kou


    Three methods were used to determine the sublimation and condensation at Mizuho Station in 1977-1978, that is, direct observations with an evaporimeter filled with ice and repeated measurements of offset stakes and indirect estimation using an empirical formula derived from meteorological parameters. A comparison of three methods shows satisfactory agreement, especially in the weekly average of sublimation in the 1977-1978 summer, while condensation is insignificantly small. Condensation prevailed from the middle of April to the middle of September and sublimation in the remainder of 1977. The annual amounts of condensation and sublimation in 1977 are estimated to be 0.6 g cm-2 and 5.4 g cm-2, respectively. The daily amount of sublimation showed its maximum of 92 mg cm-2 on December 22, 1977, at the summer solstice. The annual amount of sublimation much affected the annual net accumulation of 5.8 g. The sublimation and condensation contributed in the formation of glazed surface consisting of multilayered ice crusts. This glazed surface is representative in the katabatic wind region in Mizuho Plateau, and the structure of the ice crust reflects the mass balance due to sublimation and condensation on both sides of the crust. Sublimation rate varies with the direction of the sloping faces of sastrugi, being the maximum on the north-facing slope, which receives the maximum solar radiation.

  5. Real-time scene generator (United States)

    Lord, Eric; Shand, David J.; Cantle, Allan J.


    This paper describes the techniques which have been developed for an infra-red (IR) target, countermeasure and background image generation system working in real time for HWIL and Trial Proving applications. Operation is in the 3 to 5 and 8 to 14 micron bands. The system may be used to drive a scene projector (otherwise known as a thermal picture synthesizer) or for direct injection into equipment under test. The provision of realistic IR target and countermeasure trajectories and signatures, within representative backgrounds, enables the full performance envelope of a missile system to be evaluated. It also enables an operational weapon system to be proven in a trials environment without compromising safety. The most significant technique developed has been that of line by line synthesis. This minimizes the processing delays to the equivalent of 1.5 frames from input of target and sightline positions to the completion of an output image scan. Using this technique a scene generator has been produced for full closed loop HWIL performance analysis for the development of an air to air missile system. Performance of the synthesis system is as follows: 256 * 256 pixels per frame; 350 target polygons per frame; 100 Hz frame rate; and Gouraud shading, simple reflections, variable geometry targets and atmospheric scaling. A system using a similar technique has also bee used for direct insertion into the video path of a ground to air weapon system in live firing trials. This has provided realistic targets without degrading the closed loop performance. Delay of the modified video signal has been kept to less than 5 lines. The technique has been developed using a combination of 4 high speed Intel i860 RISC processors in parallel with the 4000 series XILINX field programmable gate arrays (FPGA). Start and end conditions for each line of target pixels are prepared and ordered in the I860. The merging with background pixels and output shading and scaling is then carried out in

  6. Martian Length of Day Measurements from Rovers (United States)

    Eubanks, T. M.; Bills, B.


    Changes in the Martian Length of Day (LOD) can be determined at a scientifically use level by a combination of regular (but not necessarily frequent) range and Doppler measurements from Earth and dead reckoning in a Kalman filter.

  7. Magnesium Based Rockets for Martian Exploration Project (United States)

    National Aeronautics and Space Administration — In the proposed Phase II program, we will continue the development of Mg bipropellant rockets for Martian PAV applications. In Phase I, we proved the feasibility of...

  8. The Effect of CO2 Ice Cap Sublimation on Mars Atmosphere (United States)

    Batterson, Courtney


    Sublimation of the polar CO2 ice caps on Mars is an ongoing phenomenon that may be contributing to secular climate change on Mars. The transfer of CO2 between the surface and atmosphere via sublimation and deposition may alter atmospheric mass such that net atmospheric mass is increasing despite seasonal variations in CO2 transfer. My study builds on previous studies by Kahre and Haberle that analyze and compare data from the Phoenix and Viking Landers 1 and 2 to determine whether secular climate change is happening on Mars. In this project, I use two years worth of temperature, pressure, and elevation data from the MSL Curiosity rover to create a program that allows for successful comparison of Curiosity pressure data to Viking Lander pressure data so a conclusion can be drawn regarding whether CO2 ice cap sublimation is causing a net increase in atmospheric mass and is thus contributing to secular climate change on Mars.

  9. The sublime in the anthropic landscape by means of modern photography

    Directory of Open Access Journals (Sweden)

    María Antonia Blanco Arroyo


    Full Text Available This article expounds on a conceptual analysis of the sublime, employing the anthropic landscape as the field of study, and registering both projections within the discipline of photography. Therefore, a narrative is formulated with the photographic production from the last few decades, in order to address both sublime nature and the current day industrial sublime. The conceptual constants from several artistic discourses define the line of argument running through this article to establish a theoretical framework for human existence in today’s post-industrial landscape. The artists selected provide a crucial unifying thread permitting the evolution and transformation of universal concepts of landscape to be examined; providing us with an updated conceptualization of the relationship between humans and their altered environment.

  10. Numerical modeling and analytical modeling of cryogenic carbon capture in a de-sublimating heat exchanger (United States)

    Yu, Zhitao; Miller, Franklin; Pfotenhauer, John M.


    Both a numerical and analytical model of the heat and mass transfer processes in a CO2, N2 mixture gas de-sublimating cross-flow finned duct heat exchanger system is developed to predict the heat transferred from a mixture gas to liquid nitrogen and the de-sublimating rate of CO2 in the mixture gas. The mixture gas outlet temperature, liquid nitrogen outlet temperature, CO2 mole fraction, temperature distribution and de-sublimating rate of CO2 through the whole heat exchanger was computed using both the numerical and analytic model. The numerical model is built using EES [1] (engineering equation solver). According to the simulation, a cross-flow finned duct heat exchanger can be designed and fabricated to validate the models. The performance of the heat exchanger is evaluated as functions of dimensionless variables, such as the ratio of the mass flow rate of liquid nitrogen to the mass flow rate of inlet flue gas.

  11. Traumatic Sublime: Genealogy of the Term and Relation to Contemporary Art and Media

    Directory of Open Access Journals (Sweden)

    Sonja Jankov


    Full Text Available Prolonging the concept in art theory related to Andy Warhol’s art, whose (photographic series are characterized by “traumatic”, id est repetitive, operation of technique, Hal Foster introduces the term traumatic sublime to describe Bill Viola’s video works. The term relates not only to themes presented in the videos, but also to the media presenting them. Through his HD installation Ocean Without Shore at the 52nd Venice Biennale, Viola emphasised how important technical specifications of media are for his work, defining the colour saturation on the video with water curtains. This paper gives an overview of the technical evolution of Bill Viola’s works and of the term sublime, from Longinus, over Immanuel Kant, to Hal Foster and Jean-François Lyotard. It concludes that traumatic sublime can be related to several forms of new media art, not exclusively to Bill Viola’s work.

  12. Scenes of the self, and trance

    Directory of Open Access Journals (Sweden)

    Jan M. Broekman


    Full Text Available Trance shows the Self as a process involved in all sorts and forms of life. A Western perspective on a self and its reifying tendencies is only one (or one series of those variations. The process character of the self does not allow any coherent theory but shows, in particular when confronted with trance, its variability in all regards. What is more: the Self is always first on the scene of itself―a situation in which it becomes a sign for itself. That particular semiotic feature is again not a unified one but leads, as the Self in view of itself does, to series of scenes with changing colors, circumstances and environments. Our first scene “Beyond Monotheism” shows semiotic importance in that a self as determining component of a trance-phenomenon must abolish its own referent and seems not able to answer the question, what makes trance a trance. The Pizzica is an example here. Other social features of trance appear in the second scene, US post traumatic psychological treatments included. Our third scene underlines structures of an unfolding self: beginning with ‘split-ego’ conclusions, a self’s engenderment appears dependent on linguistic events and on spoken words in the first place. A fourth scene explores that theme and explains modern forms of an ego ―in particular those inherent to ‘citizenship’ or a ‘corporation’. The legal consequences are concentrated in the fifth scene, which considers a legal subject by revealing its ‘standing’. Our sixth and final scene pertains to the relation between trance and commerce. All scenes tie together and show parallels between Pizzica, rights-based behavior, RAVE music versus disco, commerce and trance; they demonstrate the meaning of trance as a multifaceted social phenomenon.

  13. Trans-modern AesthesiS In The Eurasian Borderlands And The Decolonial Anti-sublime


    Madina Tlostanova


    El artículo estudia la aesthesis transmoderna en relación con la agenda de liberar la esfera estética de los mitos de la modernidad occidental. La autora ofrece un resumen crítico de las principales corrientes estéticas occidentales frente al anti-sublime decolonial como modelo alternativo analizado en el artículo. Se presta especial atención al mecanismo de este sublime, fundado en una hermenéutica pluritópica y una “comunidad de sentido” decolonial que une a quienes fueron marcados por la “...

  14. How the sublime became "now": time, modernity and aesthetics in Lyotard's rewriting of Kant


    Cunningham, D.I.


    Writing in the late 1980s, Nancy gives as examples of the "recent fashion for the sublime" not only the theoreticians of Paris, but the artists of Los Angeles, Berlin, Rome, and Tokyo. At the beginning of the twenty-first century, the sublime may of course no longer seem quite so "now" as it did back then, whether in North America, Europe, or Japan. Simon Critchley, for one, has suggested that, at least as regards the issue of its conceptual coupling to "postmodernism," the "debate" concernin...

  15. Scene analysis in the natural environment

    DEFF Research Database (Denmark)

    Lewicki, Michael S; Olshausen, Bruno A; Surlykke, Annemarie


    that hinder further progress. Here we take the view that scene analysis is a universal problem solved by all animals, and that we can gain new insight by studying the problems that animals face in complex natural environments. In particular, the jumping spider, songbird, echolocating bat, and electric fish......, all exhibit behaviors that require robust solutions to scene analysis problems encountered in the natural environment. By examining the behaviors of these seemingly disparate animals, we emerge with a framework for studying scene analysis comprising four essential properties: (1) the ability to solve...

  16. Scene Integration for Online VR Advertising Clouds

    Directory of Open Access Journals (Sweden)

    Michael Kalochristianakis


    Full Text Available This paper presents a scene composition approach that allows the combinational use of standard three dimensional objects, called models, in order to create X3D scenes. The module is an integral part of a broader design aiming to construct large scale online advertising infrastructures that rely on virtual reality technologies. The architecture addresses a number of problems regarding remote rendering for low end devices and last but not least, the provision of scene composition and integration. Since viewers do not keep information regarding individual input models or scenes, composition requires the consideration of mechanisms that add state to viewing technologies. In terms of this work we extended a well-known, open source X3D authoring tool.

  17. Three interactive scenes of The Crystal Cabinet


    Unander-Scharin, Åsa


    The interactive scenes of The Crystal Cabinet (2008) constitute the first part in my choreographic research project exploring volatile bodies and multistable corporealities. This performance took the form of a dream play opera in twelve scenes including texts and images from William Blake’s (1757-1827) illuminated books. To create his books Blake invented a printing-machine with which he could print his handwritten poems and images. We transformed this idea into an interactive stage area wher...

  18. Unsupervised Moving Target Detection in Dynamic Scenes (United States)


    training the algorithm to learn the background parameters. The need to train such algorithms for each scene separately limits their ability to be...deployed for automatic surveillance tasks, where manual re- training of the module to operate in each new scene is not feasible. A further shortcoming in...and (b). The camera panning is such that the objects of interest, viz. the two cyclists , undergo very small motion in the image coordinates. Figure 1

  19. Scene content is predominantly conveyed by high spatial frequencies in scene-selective visual cortex. (United States)

    Berman, Daniel; Golomb, Julie D; Walther, Dirk B


    In complex real-world scenes, image content is conveyed by a large collection of intertwined visual features. The visual system disentangles these features in order to extract information about image content. Here, we investigate the role of one integral component: the content of spatial frequencies in an image. Specifically, we measure the amount of image content carried by low versus high spatial frequencies for the representation of real-world scenes in scene-selective regions of human visual cortex. To this end, we attempted to decode scene categories from the brain activity patterns of participants viewing scene images that contained the full spatial frequency spectrum, only low spatial frequencies, or only high spatial frequencies, all carefully controlled for contrast and luminance. Contrary to the findings from numerous behavioral studies and computational models that have highlighted how low spatial frequencies preferentially encode image content, decoding of scene categories from the scene-selective brain regions, including the parahippocampal place area (PPA), was significantly more accurate for high than low spatial frequency images. In fact, decoding accuracy was just as high for high spatial frequency images as for images containing the full spatial frequency spectrum in scene-selective areas PPA, RSC, OPA and object selective area LOC. We also found an interesting dissociation between the posterior and anterior subdivisions of PPA: categories were decodable from both high and low spatial frequency scenes in posterior PPA but only from high spatial frequency scenes in anterior PPA; and spatial frequency was explicitly decodable from posterior but not anterior PPA. Our results are consistent with recent findings that line drawings, which consist almost entirely of high spatial frequencies, elicit a neural representation of scene categories that is equivalent to that of full-spectrum color photographs. Collectively, these findings demonstrate the

  20. Scene content is predominantly conveyed by high spatial frequencies in scene-selective visual cortex.

    Directory of Open Access Journals (Sweden)

    Daniel Berman

    Full Text Available In complex real-world scenes, image content is conveyed by a large collection of intertwined visual features. The visual system disentangles these features in order to extract information about image content. Here, we investigate the role of one integral component: the content of spatial frequencies in an image. Specifically, we measure the amount of image content carried by low versus high spatial frequencies for the representation of real-world scenes in scene-selective regions of human visual cortex. To this end, we attempted to decode scene categories from the brain activity patterns of participants viewing scene images that contained the full spatial frequency spectrum, only low spatial frequencies, or only high spatial frequencies, all carefully controlled for contrast and luminance. Contrary to the findings from numerous behavioral studies and computational models that have highlighted how low spatial frequencies preferentially encode image content, decoding of scene categories from the scene-selective brain regions, including the parahippocampal place area (PPA, was significantly more accurate for high than low spatial frequency images. In fact, decoding accuracy was just as high for high spatial frequency images as for images containing the full spatial frequency spectrum in scene-selective areas PPA, RSC, OPA and object selective area LOC. We also found an interesting dissociation between the posterior and anterior subdivisions of PPA: categories were decodable from both high and low spatial frequency scenes in posterior PPA but only from high spatial frequency scenes in anterior PPA; and spatial frequency was explicitly decodable from posterior but not anterior PPA. Our results are consistent with recent findings that line drawings, which consist almost entirely of high spatial frequencies, elicit a neural representation of scene categories that is equivalent to that of full-spectrum color photographs. Collectively, these findings

  1. Scene change detection based on multimodal integration (United States)

    Zhu, Yingying; Zhou, Dongru


    Scene change detection is an essential step to automatic and content-based video indexing, retrieval and browsing. In this paper, a robust scene change detection and classification approach is presented, which analyzes audio, visual and textual sources and accounts for their inter-relations and coincidence to semantically identify and classify video scenes. Audio analysis focuses on the segmentation of audio stream into four types of semantic data such as silence, speech, music and environmental sound. Further processing on speech segments aims at locating speaker changes. Video analysis partitions visual stream into shots. Text analysis can provide a supplemental source of clues for scene classification and indexing information. We integrate the video and audio analysis results to identify video scenes and use the text information detected by the video OCR technology or derived from transcripts available to refine scene classification. Results from single source segmentation are in some cases suboptimal. By combining visual, aural features adn the accessorial text information, the scence extraction accuracy is enhanced, and more semantic segmentations are developed. Experimental results are proven to rather promising.

  2. Surface energy balance, melt and sublimation at Neumayer Station, East Antarctica

    NARCIS (Netherlands)

    van den Broeke, M.R.; König-Langlo, G.; Picard, G.; Kuipers Munneke, P.; Lenaerts, J.T.M.


    A surface energy balance model is forced by 13 years of high-quality hourly observations from the Antarctic coastal station Neumayer. The model accurately reproduces observed surface temperatures. Surface sublimation is significant in summer, when absorbed solar radiation heats the surface.

  3. How to Kill a Journalism School: The Digital Sublime in the Discourse of Discontinuance (United States)

    McDevitt, Michael; Sindorf, Shannon


    The authors argue that journalism's uncertain identity in academia has made it vulnerable to unreflective instrumentalism in the digital era. They show how instrumentalism intertwined with the digital sublime constitutes a rhetorically resonate rationale for closing a journalism school. Evidence comes from documents and testimony associated with…

  4. Undergraduate Laboratory Experiment Facilitating Active Learning of Concepts in Transport Phenomena: Experiment with a Subliming Solid (United States)

    Utgikar, Vivek P.


    An experiment based on the sublimation of a solid was introduced in the undergraduate Transport Phenomena course. The experiment required the students to devise their own apparatus and measurement techniques. The theoretical basis, assignment of the experiment, experimental results, and student/instructor observations are described in this paper.…

  5. Estimation of Continental-Basin-Scale Sublimation in the Lena River Basin, Siberia

    Directory of Open Access Journals (Sweden)

    Kazuyoshi Suzuki


    Full Text Available The Lena River basin in Siberia produces one of the largest river inflows into the Arctic Ocean. One of the most important sources of runoff to the river is spring snowmelt and therefore snow ablation processes have great importance for this basin. In this study, we simulated these processes with fine resolution at basin scale using MicroMet/SnowModel and SnowAssim. To assimilate snow water equivalent (SWE data in SnowAssim, we used routine daily snow depth data and Sturm’s method. Following the verification of this method for SWE estimation in the basin, we evaluated the impact of snow data assimilation on basin-scale snow ablation. Through validation against MODIS snow coverage data and in situ snow survey observations, we found that SnowAssim could not improve on the original simulation by MicroMet/SnowModel because of estimation errors within the SWE data. Vegetation and accumulated snowfall control the spatial distribution of sublimation and we established that sublimation has an important effect on snow ablation. We found that the ratio of sublimation to snowfall in forests was around 26% and that interannual variation of sublimation modulated spring river runoff.

  6. Sublimation of natural amino acids and induction of asymmetry by meteoritic amino acids (United States)

    Tarasevych, Arkadii V.; Guillemin, Jean-Claude

    It is believed that the homochirality of building blocks of life like amino acids (AAs) and sugars is a prerequisite requirement for the origin and evolution of life. Among different mechanisms that might have triggered the initial disparity in the enantiomeric ratio on the primitive Earth, the key roles were assigned to: (i) local chiral symmetry breaking and (ii) the inflow of extraterrestrial matter (eg the carbonaceous meteorites containing non-racemic AAs). Recently it has been revealed that sublimation, a subject almost completely neglected for a long time, gives a pathway to enantioenrichment of natural AAs (1,2 and references herein). Sublimation is however one of the key physical processes that occur on comets. Starting from a mixture with a low content of an enantiopure AA, a partial sublimation gives an important enrichment of the sublimate (1,2). The resulted disparity in the ratio between enantiomers of a partial sublimate is determined by the crystalline nature of the starting mixture: we observed a drastic difference in the behavior of (i) mixtures based on true racemic compounds and (ii) mechanical mixtures of two enantiopure solid phases. On the other hand, combination of crystallization and sublimation can lead to segregation of enantioenriched fractions starting from racemic composition of sublimable aliphatic AAs (Ala, Leu, Pro, Val) in mixtures with non-volatile enantiopure ones (Asn, Asp, Glu, Ser, Thr) (3). The resulted sense of chirality correlates with the handedness of the non-volatile AAs: the observed changes in enantiomeric ratios clearly demonstrate the preferential homochiral interactions and a tendency of natural amino acids to homochiral self-organization. It is noteworthy that just these 5 (Asn, Asp, Glu, Ser, Thr) out of 22 proteinogenic amino acids are able to local symmetry breaking. On the other hand, recent data on the enantiomeric composition of the Tagish Lake, a C2-type carbonaceous meteorite, revealed a large L

  7. Subsurface volatile content of martian double-layer ejecta (DLE) craters (United States)

    Viola, Donna; McEwen, Alfred S.; Dundas, Colin M.; Byrne, Shane


    Excess ice is widespread throughout the martian mid-latitudes, particularly in Arcadia Planitia, where double-layer ejecta (DLE) craters also tend to be abundant. In this region, we observe the presence of thermokarstically-expanded secondary craters that likely form from impacts that destabilize a subsurface layer of excess ice, which subsequently sublimates. The presence of these expanded craters shows that excess ice is still preserved within the adjacent terrain. Here, we focus on a 15-km DLE crater that contains abundant superposed expanded craters in order to study the distribution of subsurface volatiles both at the time when the secondary craters formed and, by extension, remaining today. To do this, we measure the size distribution of the superposed expanded craters and use topographic data to calculate crater volumes as a proxy for the volumes of ice lost to sublimation during the expansion process. The inner ejecta layer contains craters that appear to have undergone more expansion, suggesting that excess ice was most abundant in that region. However, both of the ejecta layers had more expanded craters than the surrounding terrain. We extrapolate that the total volume of ice remaining within the entire ejecta deposit is as much as 74 km3 or more. The variation in ice content between the ejecta layers could be the result of (1) volatile preservation from the formation of the DLE crater, (2) post-impact deposition in the form of ice lenses; or (3) preferential accumulation or preservation of subsequent snowfall. We have ruled out (2) as the primary mode for ice deposition in this location based on inconsistencies with our observations, though it may operate in concert with other processes. Although none of the existing DLE formation hypotheses are completely consistent with our observations, which may merit a new or modified mechanism, we can conclude that DLE craters contain a significant quantity of excess ice today.

  8. Glacier mass balance reconstruction by sublimation induced enrichment of chemical species on Cerro Tapado (Chilean Andes

    Directory of Open Access Journals (Sweden)

    P. Ginot


    Full Text Available A 36 m long ice core down to bedrock from the Cerro Tapado glacier (5536 m a.s.l, 30°08' S, 69°55' W was analyzed to reconstruct past climatic conditions for Northern Chile. Because of the marked seasonality in the precipitation (short wet winter and extended dry summer periods in this region, major snow ablation and related post-depositional processes occur on the glacier surface during summer periods. They include predominantly sublimation and dry deposition. Assuming that, like measured during the field campaign, the enrichment of chloride was always related to sublimation, the chemical record along the ice core may be applied to reconstruct the history of such secondary processes linked to the past climatic conditions over northern Chile. For the time period 1962–1999, a mean annual net accumulation of 316 mm water equivalent (weq and 327 mm weq loss by sublimation was deduced by this method. This corresponds to an initial total annual accumulation of 539 mm weq. The annual variability of the accumulation and sublimation is related with the Southern Oscillation Index (SOI: higher net-accumulation during El-Niño years and more sublimation during La Niña years. The deepest part of the ice record shows a time discontinuity; with an ice body deposited under different climatic conditions: 290 mm higher precipitation but with reduced seasonal distribution (+470 mm in winter and –180 mm in summer and –3°C lower mean annual temperature. Unfortunately, its age is unknown. The comparison with regional proxy data however let us conclude that the glacier buildup did most likely occur after the dry mid-Holocene.

  9. Life on Mars: Evidence from Martian Meteorites (United States)

    McKay, David S.; Thomas-Keptra, Katie L.; Clemett, Simon J.; Gibson, Everett K., Jr.; Spencer, Lauren; Wentworth, Susan J.


    New data on martian meteorite 84001 as well as new experimental studies show that thermal or shock decomposition of carbonate, the leading alternative non-biologic explanation for the unusual nanophase magnetite found in this meteorite, cannot explain the chemistry of the actual martian magnetites. This leaves the biogenic explanation as the only remaining viable hypothesis for the origin of these unique magnetites. Additional data from two other martian meteorites show a suite of biomorphs which are nearly identical between meteorites recovered from two widely different terrestrial environments (Egyptian Nile bottomlands and Antarctic ice sheets). This similarity argues against terrestrial processes as the cause of these biomorphs and supports an origin on Mars for these features.

  10. Young drug addicts and the drug scene. (United States)

    Lucchini, R


    The drug scene generally comprises the following four distinct categories of young people: neophytes, addicts who enjoy a high status vis-à-vis other addicts, multiple drug addicts, and non-addicted drug dealers. It has its own evolution, hierarchy, structure and criteria of success and failure. The members are required to conform to the established criteria. The integration of the young addict into the drug scene is not voluntary in the real sense of the word, for he is caught between the culture that he rejects and the pseudo-culture of the drug scene. To be accepted into the drug scene, the neophyte must furnish proof of his reliability, which often includes certain forms of criminal activities. The addict who has achieved a position of importance in the drug world serves as a role model for behaviour to the neophyte. In a more advanced phase of addiction, the personality of the addict and the social functions of the drug scene are overwhelmed by the psychoactive effects of the drug, and this process results in the social withdrawal of the addict. The life-style of addicts and the subculture they develop are largely influenced by the type of drug consumed. For example, it is possible to speak of a heroin subculture and a cocaine subculture. In time, every drug scene deteriorates so that it becomes fragmented into small groups, which is often caused by legal interventions or a massive influx of new addicts. The fragmentation of the drug scene is followed by an increase in multiple drug abuse, which often aggravates the medical and social problems of drug addicts.

  11. A search for nitrates in Martian meteorites (United States)

    Grady, Monica M.; Wright, I. P.; Pillinger, C. T.


    Martian atmospheric nitrogen is highly enriched in N-15; nitrates formed by interaction of the atmosphere with the Martian regolith should therefore also be characterized by an elevated delta N-15 value. A search has been made for nitrates in two Martian meteorites, in order to determine the extent of possible regolith-atmosphere interaction. Shock-produced glass from the Elephant Moraine (EET) A79001 shergottite (E1,149) and a water-soluble extract from Nakhla were analyzed by Fourier transform infrared (FTIR) spectroscopy and stepped combustion-stable isotope mass spectrometry. FTIR of both meteorites had features at 1375/cm and 1630/cm, consistent with nitrates. On account of their low thermal stability, nitrates break down at temperatures below 600 C; in this temperature range, E1,149 yeilded approximately 1250 ppb nitrogen with delta N-15 -8 +/- 5%. If this nitrogen is from a nitrate, then it cannot be distinquished from terrestial salts by its isotopic composition. The water-soluble extract from Nakhla also released nitrogen at low temperatures, approximately 17 ppb with delta N-15 approximately -11 +/- 4%. Since Nakhla is an observed 'fall', this is unlikely to be a terrestial weathering product. Nitrates apparently occur in E1,149 and Nakhla, but in very low abundance, and their origin is unclear. The isotopic composition of the salts, which is within the range of that proposed for Martian magmatic volatiles, is far removed from that of nitrogen in the present-day Martian atmosphere. If the nitrates are Martian in origin, they did not form in recent times from reactions involving atmospheric gases. Rather, the nitrates could be the result of an earlier episode of atmospheric interaction with the regolith, or with implantation of magmatic volatiles introduced during degassing.

  12. Martian Soil Inside Phoenix's Robotic Arm Scoop (United States)


    This image from NASA's Phoenix Mars Lander's Robotic Arm Camera (RAC) shows material from the Martian surface captured by the Robotic Arm (RA) scoop during its first test dig and dump on the seventh Martian day of the mission, or Sol 7 (June 1, 2008). The test sample shown was taken from the digging area informally known as 'Knave of Hearts.' 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.

  13. Geopolymers from lunar and Martian soil simulants (United States)

    Alexiadis, Alessio; Alberini, Federico; Meyer, Marit E.


    This work discusses the geopolymerization of lunar dust simulant JSC LUNAR-1A and Martian dust simulant JSC MARS-1A. The geopolymerization of JSC LUNAR-1A occurs easily and produces a hard, rock-like, material. The geopolymerization of JSC MARS-1A requires milling to reduce the particle size. Tests were carried out to measure, for both JSC LUNAR-1A and JSC MARS-1A geopolymers, the maximum compressive and flexural strengths. In the case of the lunar simulant, these are higher than those of conventional cements. In the case of the Martian simulant, they are close to those of common building bricks.

  14. A Hypothesis for the Abiotic and Non-Martian Origins of Putative Signs of Ancient Martian Life in ALH84001 (United States)

    Treiman, Allan H.


    Putative evidence of martian life in ALH84001 can be explained by abiotic and non-martian processes consistent with the meteorite's geological history. Additional information is contained in the original extended abstract.

  15. Experimental Investigation of CO_2 Solubility in Primitive Martian Basalts Similar to Yamato 980459 and Implications for Martian Atmospheric Evolution (United States)

    Schaub, D. R.; Stanley, B. D.; Hirschmann, M. M.


    Experimental studies on a synthetic material similar to martian meteorite Yamato 980459 showed lower than expected CO_2 solubility, implying that models of an early martian greenhouse that are dependent on CO_2 may need reexamination.

  16. Correlated Topic Vector for Scene Classification. (United States)

    Wei, Pengxu; Qin, Fei; Wan, Fang; Zhu, Yi; Jiao, Jianbin; Ye, Qixiang


    Scene images usually involve semantic correlations, particularly when considering large-scale image data sets. This paper proposes a novel generative image representation, correlated topic vector, to model such semantic correlations. Oriented from the correlated topic model, correlated topic vector intends to naturally utilize the correlations among topics, which are seldom considered in the conventional feature encoding, e.g., Fisher vector, but do exist in scene images. It is expected that the involvement of correlations can increase the discriminative capability of the learned generative model and consequently improve the recognition accuracy. Incorporated with the Fisher kernel method, correlated topic vector inherits the advantages of Fisher vector. The contributions to the topics of visual words have been further employed by incorporating the Fisher kernel framework to indicate the differences among scenes. Combined with the deep convolutional neural network (CNN) features and Gibbs sampling solution, correlated topic vector shows great potential when processing large-scale and complex scene image data sets. Experiments on two scene image data sets demonstrate that correlated topic vector improves significantly the deep CNN features, and outperforms existing Fisher kernel-based features.

  17. Maxwellian Eye Fixation during Natural Scene Perception

    Directory of Open Access Journals (Sweden)

    Jean Duchesne


    Full Text Available When we explore a visual scene, our eyes make saccades to jump rapidly from one area to another and fixate regions of interest to extract useful information. While the role of fixation eye movements in vision has been widely studied, their random nature has been a hitherto neglected issue. Here we conducted two experiments to examine the Maxwellian nature of eye movements during fixation. In Experiment 1, eight participants were asked to perform free viewing of natural scenes displayed on a computer screen while their eye movements were recorded. For each participant, the probability density function (PDF of eye movement amplitude during fixation obeyed the law established by Maxwell for describing molecule velocity in gas. Only the mean amplitude of eye movements varied with expertise, which was lower in experts than novice participants. In Experiment 2, two participants underwent fixed time, free viewing of natural scenes and of their scrambled version while their eye movements were recorded. Again, the PDF of eye movement amplitude during fixation obeyed Maxwell’s law for each participant and for each scene condition (normal or scrambled. The results suggest that eye fixation during natural scene perception describes a random motion regardless of top-down or of bottom-up processes.

  18. Moving through a multiplex holographic scene (United States)

    Mrongovius, Martina


    This paper explores how movement can be used as a compositional element in installations of multiplex holograms. My holographic images are created from montages of hand-held video and photo-sequences. These spatially dynamic compositions are visually complex but anchored to landmarks and hints of the capturing process - such as the appearance of the photographer's shadow - to establish a sense of connection to the holographic scene. Moving around in front of the hologram, the viewer animates the holographic scene. A perception of motion then results from the viewer's bodily awareness of physical motion and the visual reading of dynamics within the scene or movement of perspective through a virtual suggestion of space. By linking and transforming the physical motion of the viewer with the visual animation, the viewer's bodily awareness - including proprioception, balance and orientation - play into the holographic composition. How multiplex holography can be a tool for exploring coupled, cross-referenced and transformed perceptions of movement is demonstrated with a number of holographic image installations. Through this process I expanded my creative composition practice to consider how dynamic and spatial scenes can be conveyed through the fragmented view of a multiplex hologram. This body of work was developed through an installation art practice and was the basis of my recently completed doctoral thesis: 'The Emergent Holographic Scene — compositions of movement and affect using multiplex holographic images'.

  19. Scene analysis in the natural environment

    Directory of Open Access Journals (Sweden)

    Michael S Lewicki


    Full Text Available The problem of scene analysis has been studied in a number of different fields over the past decades. These studies have led to a number of important insights into problems of scene analysis, but not all of these insights are widely appreciated. Despite this progress, there are also critical shortcomings in current approaches that hinder further progress. Here we take the view that scene analysis is a universal problem solved by all animals, and that we can gain new insight by studying the problems that animals face in complex natural environments. In particular, the jumping spider, songbird, echolocating bat, and electric fish, all exhibit behaviors that require robust solutions to scene analysis problems encountered in the natural environment. By examining the behaviors of these seemingly disparate animals, we emerge with a framework for studying analysis comprising four essential properties: 1 the ability to solve ill-posed problems, 2 the ability to integrate and store information across time and modality, 3 efficient recovery and representation of 3D scene structure, and 4 the use of optimal motor actions for acquiring information to progress towards behavioral goals.

  20. Reading the climate record of the martian polar layered deposits (United States)

    Hvidberg, C. S.; Fishbaugh, K. E.; Winstrup, M.; Svensson, A.; Byrne, S.; Herkenhoff, K. E.


    The martian polar regions have layered deposits of ice and dust. The stratigraphy of these deposits is exposed within scarps and trough walls and is thought to have formed due to climate variations in the past. Insolation has varied significantly over time and caused dramatic changes in climate, but it has remained unclear whether insolation variations could be linked to the stratigraphic record. We present a model of layer formation based on physical processes that expresses polar deposition rates of ice and dust in terms of insolation. In this model, layer formation is controlled by the insolation record, and dust-rich layers form by two mechanisms: (1) increased summer sublimation during high obliquity, and (2) variations in the polar deposition of dust modulated by obliquity variations. The model is simple, yet physically plausible, and allows for investigations of the climate control of the polar layered deposits (PLD). We compare the model to a stratigraphic column obtained from the north polar layered deposits (NPLD) (Fishbaugh, K.E., Hvidberg, C.S., Byrne, S., Russel, P.S., Herkenhoff, K.E., Winstrup, M., Kirk, R. [2010a]. Geophys. Res. Lett., 37, L07201) and show that the model can be tuned to reproduce complex layer sequences. The comparison with observations cannot uniquely constrain the PLD chronology, and it is limited by our interpretation of the observed stratigraphic column as a proxy for NPLD composition. We identified, however, a set of parameters that provides a chronology of the NPLD tied to the insolation record and consistently explains layer formation in accordance with observations of NPLD stratigraphy. This model dates the top 500 m of the NPLD back to ∼1 million years with an average net deposition rate of ice and dust of 0.55 mm a-1. The model stratigraphy contains a quasi-periodic ∼30 m cycle, similar to a previously suggested cycle in brightness profiles from the NPLD (Laskar, J., Levrard, B., Mustard, F. [2002]. Nature, 419, 375

  1. La libertad entre lo visible y lo invisible: límites y alcances de lo sublime katiano.

    Directory of Open Access Journals (Sweden)

    Ana María Amaya Villarreal .


    Full Text Available The following essay is a view of the Kantian refection on the sublime in light of an interpretation that understands the Critique of Judgement as a project that is born from a concern for the relationship that appears within the sensible and suprasensible dimension of the human being. Influenced by the view presented by Lyotard in Lessons on the analytics of the sublime, I explore some of the consequences brought on for the comprehension of Kantian morality and freedom by its contact with the category of the sublime.

  2. "Back-fire to lust": G. Stanley Hall, sex-segregated schooling, and the engine of sublimation. (United States)

    Graebner, William


    G. Stanley Hall was an advocate of sex-segregated schooling long after most Americans had accepted coeducation. His position was based in part on personal experience: observations of his father and mother, a repressed and guilt-ridden boyhood sexuality, and his conviction that his own career success was a product of sublimated sexual desire, of erotic energy converted into mental energy. Hall theorized that coeducation put sublimation at risk, and that sex-segregated schools, by contributing to proper gendered development and by prolonging and sublimating the sexual tensions of adolescence, would produce social progress.

  3. Martian Electron Foreshock: New Results from MAVEN (United States)

    Mazelle, C. X.; Meziane, K.; Mitchell, D. L.; Romanelli, N. J.; McFadden, J. P.; Espley, J. R.; Connerney, J. E. P.; Halekas, J. S.; Jakosky, B. M.; Hamza, A. M.


    Observations upstream from the Martian bow shock obtained by the MAVEN Solar Wind Electron Analyzer (SWEA) experiment are presented. Significant flux enhancements associated with electrons in the energies 50-400 eV range are always observed when MAVEN spacecraft is magnetically connected to the shock. The electron flux reaches a maximum near the shock surface. In addition, electron spikes with energies up to 1.5 keV are also observed near the Martian foreshock boundary. A detailed examination of the pitch angle distribution shows that the enhanced fluxes correspond to electrons moving sunward away from Mars. Also, the full 3-D angular distributions show that the phase space density values are peaked at a non-zero pitch angle and that the electrons appear in a ring centered along the IMF direction. The gyrotropic feature is observed over a large range of the shock geometry from quasi-parallel to quasi-perpendicular. These signatures in the electron distribution function strongly suggest that the reflection off the shock is the main mechanism for the production of Martian foreshock electrons. Although striking differences exist between the Earth and Mars shock structures, these observations show strong similarities in both the Terrestrial and Martian electronic foreshocks.

  4. Gravitomagnetic Separation of Bipolar Charged Martian Dust (United States)

    Arias, FJ


    In this work it is shown that magnetic anomalies on Mars can actually boost gravitational spatial separation of bipolar charged Martian dust. If so, these places are prone for high electrical activity and then formation of chemical process requiring electrical sparks.

  5. Water retention of selected microorganisms and Martian soil simulants under close to Martian environmental conditions (United States)

    Jänchen, J.; Bauermeister, A.; Feyh, N.; de Vera, J.-P.; Rettberg, P.; Flemming, H.-C.; Szewzyk, U.


    Based on the latest knowledge about microorganisms resistant towards extreme conditions on Earth and results of new complex models on the development of the Martian atmosphere we quantitatively examined the water-bearing properties of selected extremophiles and simulated Martian regolith components and their interaction with water vapor under close to Martian environmental conditions. Three different species of microorganisms have been chosen and prepared for our study: Deinococcus geothermalis, Leptothrix sp. OT_B_406, and Xanthoria elegans. Further, two mineral mixtures representing the early and the late Martian surface as well as montmorillonite as a single component of phyllosilicatic minerals, typical for the Noachian period on Mars, were selected. The thermal mass loss of the minerals and bacteria-samples was measured by thermoanalysis. The hydration and dehydration properties were determined under close to Martian environmental conditions by sorption isotherm measurements using a McBain-Bakr quartz spring balance. It was possible to determine the total water content of the materials as well as the reversibly bound water fraction as function of the atmospheres humidity by means of these methods. Our results are important for the evaluation of future space mission outcomes including astrobiological aspects and can support the modeling of the atmosphere/surface interaction by showing the influence on the water inventory of the upper most layer of the Martian surface.

  6. Preliminary design of a universal Martian lander (United States)

    Norman, Timothy L.; Gaskin, David E.; Adkins, Sean; Gunawan, Mary; Johnson, Raquel; Macdonnell, David; Parlock, Andrew; Sarick, John; Bodwell, Charles; Hashimoto, Kouichi


    In the next 25 years, mankind will be undertaking yet another giant leap forward in the exploration of the solar system: a manned mission to Mars. This journey will provide important information on the composition and history of both Mars and the Solar System. A manned mission will also provide the opportunity to study how humans can adapt to long term space flight conditions and the Martian environment. As part of the NASA/USRA program, nineteen West Virginia University students conducted a preliminary design of a manned Universal Martian Lander (UML). The UML's design will provide a 'universal' platform, consisting of four modules for living and laboratory experiments and a liquid-fuel propelled Manned Ascent Return Vehicle (MARV). The distinguishing feature of the UML is the 'universal' design of the modules which can be connected to form a network of laboratories and living quarters for future missions thereby reducing development and production costs. The WVU design considers descent to Mars from polar orbit, a six month surface stay, and ascent for rendezvous. The design begins with an unmanned UML landing at Elysium Mons followed by the manned UML landing nearby. During the six month surface stay, the eight modules will be assembled to form a Martian base where scientific experiments will be performed. The mission will also incorporate hydroponic plant growth into a Controlled Ecological Life Support System (CELSS) for water recycling, food production, and to counteract psychological effects of living on Mars. In situ fuel production for the MARV will be produced from gases in the Martian atmosphere. Following surface operations, the eight member crew will use the MARV to return to the Martian Transfer Vehicle (MTV) for the journey home to Earth.

  7. Preliminary design of a universal Martian lander (United States)

    Norman, Timothy L.; Gaskin, David E.; Adkins, Sean; Gunawan, Mary; Johnson, Raquel; Macdonnell, David; Parlock, Andrew; Sarick, John; Bodwell, Charles; Hashimoto, Kouichi

    In the next 25 years, mankind will be undertaking yet another giant leap forward in the exploration of the solar system: a manned mission to Mars. This journey will provide important information on the composition and history of both Mars and the Solar System. A manned mission will also provide the opportunity to study how humans can adapt to long term space flight conditions and the Martian environment. As part of the NASA/USRA program, nineteen West Virginia University students conducted a preliminary design of a manned Universal Martian Lander (UML). The UML's design will provide a 'universal' platform, consisting of four modules for living and laboratory experiments and a liquid-fuel propelled Manned Ascent Return Vehicle (MARV). The distinguishing feature of the UML is the 'universal' design of the modules which can be connected to form a network of laboratories and living quarters for future missions thereby reducing development and production costs. The WVU design considers descent to Mars from polar orbit, a six month surface stay, and ascent for rendezvous. The design begins with an unmanned UML landing at Elysium Mons followed by the manned UML landing nearby. During the six month surface stay, the eight modules will be assembled to form a Martian base where scientific experiments will be performed. The mission will also incorporate hydroponic plant growth into a Controlled Ecological Life Support System (CELSS) for water recycling, food production, and to counteract psychological effects of living on Mars. In situ fuel production for the MARV will be produced from gases in the Martian atmosphere. Following surface operations, the eight member crew will use the MARV to return to the Martian Transfer Vehicle (MTV) for the journey home to Earth.

  8. Nature of Reduced Carbon in Martian Meteorites (United States)

    Gibson, Everett K., Jr.; McKay, D. S.; Thomas-Keprta, K. L.; Clemett, S. J.; White, L. M.


    Martian meteorites provide important information on the nature of reduced carbon components present on Mars throughout its history. The first in situ analyses for carbon on the surface of Mars by the Viking landers yielded disappointing results. With the recognition of Martian meteorites on Earth, investigations have shown carbon-bearing phases exist on Mars. Studies have yielded presence of reduced carbon, carbonates and inferred graphitic carbon phases. Samples ranging in age from the first approximately 4 Ga of Mars history [e.g. ALH84001] to nakhlites with a crystallization age of 1.3 Ga [e.g. Nakhla] with aqueous alteration processes occurring 0.5-0.7 Ga after crystallizaton. Shergottites demonstrate formation ages around 165-500 Ma with younger aqueous alterations events. Only a limited number of the Martian meteorites do not show evidence of significance terrestrial alterations. Selected areas within ALH84001, Nakhla, Yamato 000593 and possibly Tissint are suitable for study of their indigenous reduced carbon bearing phases. Nakhla possesses discrete, well-defined carbonaceous phases present within iddingsite alteration zones. Based upon both isotopic measurements and analysis of Nakhla's organic phases the presence of pre-terrestrial organics is now recognized. The reduced carbon-bearing phases appear to have been deposited during preterrestrial aqueous alteration events that produced clays. In addition, the microcrystalline layers of Nakhla's iddingsite have discrete units of salt crystals suggestive of evaporation processes. While we can only speculate on the origin of these unique carbonaceous structures, we note that the significance of such observations is that it may allow us to understand the role of Martian carbon as seen in the Martian meteorites with obvious implications for astrobiology and the pre-biotic evolution of Mars. In any case, our observations strongly suggest that reduced organic carbon exists as micrometer- size, discrete structures

  9. Initiation and growth of martian ice lenses (United States)

    Sizemore, Hanna G.; Zent, Aaron P.; Rempel, Alan W.


    Water ice in the upper meters of the martian regolith is a major volatile reservoir. Although the geographic extent, burial depth, and thermal stability of this shallow ice are well understood, its origin, history, and stratigraphy are not. Over the past decade, a growing body of observational evidence has indicated that shallow ground ice exceeds the pore volume of its host soil over large regions of both martian hemispheres. This is confounding, given that (1) the physical theory that accurately predicts the location of ground ice also assumes that ice should be pore-filling in the upper meter of regolith, and (2) the Phoenix spacecraft uncovered far more pore-filling ice than excess ice at its landing site in the northern hemisphere. The development of ice lenses by low-temperature in situ segregation - analogous to the processes that generate frost heave on Earth - has been hypothesized to explain shallow excess ice on Mars. We have developed a numerical model of ice lens initiation and growth in the martian environment, and used it to test this hypothesis for the first time. We carried out a large suite of numerical simulations in order to place quantitative constraints on the timing and location of ice lens initiation, and on the magnitude of ice lens growth in a variety of host soils. We find that ice lens initiation is a ubiquitous process in the martian high latitudes, but the ultimate magnitude of lens growth, or frost heave, is sensitive to the properties of the host soil. Depending on the specific properties of martian soils, in situ segregation may be a very slow process sufficient to explain the excess ice observed in the Dodo-Goldilocks trench at the Phoenix landing site, but without regionally significant effects. Alternatively, if clay-sized particles or perchlorate salts are present, in situ segregation may be a vigorous process that has significantly affected the stratigraphy of ground ice in the upper meter of regolith throughout the high

  10. Fast crystalline ice formation at extremely low temperature through water/neon matrix sublimation. (United States)

    Hama, Tetsuya; Ishizuka, Shinnosuke; Yamazaki, Tomoya; Kimura, Yuki; Kouchi, Akira; Watanabe, Naoki; Sugimoto, Toshiki; Pirronello, Valerio


    Crystalline ice formation requires water molecules to be sufficiently mobile to find and settle on the thermodynamically most stable site. Upon cooling, however, diffusion and rearrangement become increasingly kinetically difficult. Water ice grown by the condensation of water vapor in laboratory is thus generally assumed to be in a metastable amorphous form below 100 K. Here, we demonstrate the possibility of crystalline ice formation at extremely low temperature using a water/neon matrix (1/1000, 30 000 monolayers) prepared at 6 K, which is subsequently warmed to 11-12 K. In situ infrared spectroscopy revealed the assembly of the dispersed water molecules, forming crystalline ice I during the sublimation of the neon matrix for 40-250 seconds. This finding indicates that the high mobility of the water molecules during matrix sublimation can overcome the kinetic barrier to form crystals even at extremely low temperature.

  11. Isothermal close space sublimation for II-VI semiconductor filling of porous matrices (United States)


    Isothermal close space sublimation, a simple and low-cost physical vapour transport technique, was used to infiltrate ZnTe and CdSe semiconductors in porous silicon. The structure of the embedded materials was determined by X-ray diffraction analysis while Rutherford backscattering spectra allowed determining the composition profiles of the samples. In both cases, a constant composition of the II-VI semiconductors throughout the porous layer down to the substrate was found. Resonance Raman scattering of the ZnTe samples indicates that this semiconductor grows in nanostructured form inside the pores. Results presented in this paper suggest that isothermal close space sublimation is a promising technique for the conformal growth of II-VI semiconductors in porous silicon. PMID:22823959

  12. Water Drops Dancing on Ice: How Sublimation Leads to Drop Rebound (United States)

    Antonini, C.; Bernagozzi, I.; Jung, S.; Poulikakos, D.; Marengo, M.


    Drop rebound is a spectacular event that appears after impact on hydrophobic or superhydrophobic surfaces but can also be induced through the so-called Leidenfrost effect. Here we demonstrate that drop rebound can also originate from another physical phenomenon, the solid substrate sublimation. Through drop impact experiments on a superhydrophobic surfaces, a hot plate, and solid carbon dioxide (commonly known as dry ice), we compare drop rebound based on three different physical mechanisms, which apparently share nothing in common (superhydrophobicity, evaporation, and sublimation), but lead to the same rebound phenomenon in an extremely wide temperature range, from 300°C down to even below -79°C. The formation and unprecedented visualization of an air vortex ring around an impacting drop are also reported.

  13. Darwin's sublime: the contest between reason and imagination in On the Origin of Species. (United States)

    Bradley, Benjamin Sylvester


    Recent Darwin scholarship has provided grounds for recognising the Origin as a literary as well as a scientific achievement. While Darwin was an acute observer, a gifted experimentalist and indefatigable theorist, this essay argues that it was also crucial to his impact that the Origin transcended the putative divide between the scientific and the literary. Analysis of Darwin's development as a writer between his journal-keeping on HMS Beagle and his construction of the Origin argues the latter draws on the pattern of the Romantic or Kantian sublime. The Origin repeatedly uses strategies which challenge the natural-theological appeal to the imagination in conceiving nature. Darwin's sublime coaches the Origin's readers into a position from which to envision nature that reduces and contains its otherwise overwhelming complexity. As such, it was Darwin's literary achievement that enabled him to fashion a new 'habit of looking at things in a given way' that is the centrepiece of the scientific revolution bearing his name.

  14. Spectroscopy of lithium atoms sublimated from isolation matrix of solid Ne. (United States)

    Sacramento, R L; Scudeller, L A; Lambo, R; Crivelli, P; Cesar, C L


    We have studied, via laser absorption spectroscopy, the velocity distribution of (7)Li atoms released from a solid neon matrix at cryogenic temperatures. The Li atoms are implanted into the Ne matrix by laser ablation of a solid Li precursor. A heat pulse is then applied to the sapphire substrate sublimating the matrix together with the isolated atoms at around 12 K. We find interesting differences in the velocity distribution of the released Li atoms from the model developed for our previous experiment with Cr [R. Lambo, C. C. Rodegheri, D. M. Silveira, and C. L. Cesar, Phys. Rev. A 76, 061401(R) (2007)]. This may be due to the sublimation regime, which is at much lower flux for the Li experiment than for the Cr experiment, as well as to the different collisional cross sections between those species to the Ne gas. We find a drift velocity compatible with Li being thermally sublimated at 11-13 K, while the velocity dispersion around this drift velocity is low, around 5-7 K. With a slow sublimation of the matrix we can determine the penetration depth of the laser ablated Li atoms into the Ne matrix, an important information that is not usually available in most matrix isolation spectroscopy setups. The present results with Li, together with the previous results with Cr suggest this to be a general technique for obtaining cryogenic atoms, for spectroscopic studies, as well as for trap loading. The release of the isolated atoms is also a useful tool to study and confirm details of the matrix isolated atoms which are masked or poorly understood in the solid. © 2011 American Institute of Physics


    Directory of Open Access Journals (Sweden)

    Elena Morgunova


    Full Text Available El artículo se centra en la argumentación de la estructura de la metáfora humorística del humor sublime garciamarqueño. Se abordan los mecanismos de la generación de la connotación axiológica a la luz de la indagación en el resquebrajamiento de las fronteras entre los distintos valores estéticos.

  16. Vapor pressures and sublimation enthalpies of seven heteroatomic aromatic hydrocarbons measured using the Knudsen effusion technique

    Energy Technology Data Exchange (ETDEWEB)

    Goldfarb, Jillian L., E-mail: [Division of Engineering, Brown University, Providence, RI 02912 (United States); Suuberg, Eric M., E-mail: Eric_Suuberg@brown.ed [Division of Engineering, Brown University, Providence, RI 02912 (United States)


    The vapor pressures of seven heteroatom-containing cyclic aromatic hydrocarbons, ranging in molecular weight from (168.19 to 208.21) g . mol{sup -1} were measured over the temperature range of (301 to 486) K using the isothermal Knudsen effusion technique. The compounds measured include: anthraquinone, 9-fluorenone, 9-fluorenone oxime, phenoxazine, phenoxathiin, and 9H-pyrido[3,4-b]indole. These solid-state sublimation measurements provided values that are compared to vapor pressures of parent aromatic compounds (anthracene and fluorene) and to others with substituent groups in order to examine the effects of alcohol, ketone, pyridine, and pyrrole functionality on this property. The enthalpies and entropies of sublimation for each compound were determined from the Clausius-Clapeyron equation. Though there is no consistent trend in terms of the effects of substitutions on changes in the enthalpy or entropy of sublimation, we note that the prevalence of enthalpic or entropic driving forces on vapor pressure depend on molecule-specific factors and not merely molecular weight of the substituents.

  17. Characterization of Sulfur and Nanostructured Sulfur Battery Cathodes in Electron Microscopy Without Sublimation Artifacts

    Energy Technology Data Exchange (ETDEWEB)

    Levin, Barnaby D. A.; Zachman, Michael J.; Werner, Jörg G.; Sahore, Ritu; Nguyen, Kayla X.; Han, Yimo; Xie, Baoquan; Ma, Lin; Archer, Lynden A.; Giannelis, Emmanuel P.; Wiesner, Ulrich; Kourkoutis, Lena F.; Muller, David A.



    Lithium sulfur (Li–S) batteries have the potential to provide higher energy storage density at lower cost than conventional lithium ion batteries. A key challenge for Li–S batteries is the loss of sulfur to the electrolyte during cycling. This loss can be mitigated by sequestering the sulfur in nanostructured carbon–sulfur composites. The nanoscale characterization of the sulfur distribution within these complex nanostructured electrodes is normally performed by electron microscopy, but sulfur sublimates and redistributes in the high-vacuum conditions of conventional electron microscopes. The resulting sublimation artifacts render characterization of sulfur in conventional electron microscopes problematic and unreliable. Here, we demonstrate two techniques, cryogenic transmission electron microscopy (cryo-TEM) and scanning electron microscopy in air (airSEM), that enable the reliable characterization of sulfur across multiple length scales by suppressing sulfur sublimation. We use cryo-TEM and airSEM to examine carbon–sulfur composites synthesized for use as Li–S battery cathodes, noting several cases where the commonly employed sulfur melt infusion method is highly inefficient at infiltrating sulfur into porous carbon hosts.

  18. Matrix sublimation/recrystallization for imaging proteins by mass spectrometry at high spatial resolution. (United States)

    Yang, Junhai; Caprioli, Richard M


    We have employed matrix deposition by sublimation for protein image analysis on tissue sections using a hydration/recrystallization process that produces high-quality MALDI mass spectra and high-spatial-resolution ion images. We systematically investigated different washing protocols, the effect of tissue section thickness, the amount of sublimated matrix per unit area, and different recrystallization conditions. The results show that an organic solvent rinse followed by ethanol/water rinses substantially increased sensitivity for the detection of proteins. Both the thickness of the tissue section and the amount of sinapinic acid sublimated per unit area have optimal ranges for maximal protein signal intensity. Ion images of mouse and rat brain sections at 50, 20, and 10 μm spatial resolution are presented and are correlated with hematoxylin and eosin (H&E)-stained optical images. For targeted analysis, histology-directed imaging can be performed using this protocol where MS analysis and H&E staining are performed on the same section.

  19. Characterization of Sulfur and Nanostructured Sulfur Battery Cathodes in Electron Microscopy Without Sublimation Artifacts. (United States)

    Levin, Barnaby D A; Zachman, Michael J; Werner, Jörg G; Sahore, Ritu; Nguyen, Kayla X; Han, Yimo; Xie, Baoquan; Ma, Lin; Archer, Lynden A; Giannelis, Emmanuel P; Wiesner, Ulrich; Kourkoutis, Lena F; Muller, David A


    Lithium sulfur (Li-S) batteries have the potential to provide higher energy storage density at lower cost than conventional lithium ion batteries. A key challenge for Li-S batteries is the loss of sulfur to the electrolyte during cycling. This loss can be mitigated by sequestering the sulfur in nanostructured carbon-sulfur composites. The nanoscale characterization of the sulfur distribution within these complex nanostructured electrodes is normally performed by electron microscopy, but sulfur sublimates and redistributes in the high-vacuum conditions of conventional electron microscopes. The resulting sublimation artifacts render characterization of sulfur in conventional electron microscopes problematic and unreliable. Here, we demonstrate two techniques, cryogenic transmission electron microscopy (cryo-TEM) and scanning electron microscopy in air (airSEM), that enable the reliable characterization of sulfur across multiple length scales by suppressing sulfur sublimation. We use cryo-TEM and airSEM to examine carbon-sulfur composites synthesized for use as Li-S battery cathodes, noting several cases where the commonly employed sulfur melt infusion method is highly inefficient at infiltrating sulfur into porous carbon hosts.

  20. MTF characteristics of a Scophony scene projector (United States)

    Schildwachter, Eric F.; Boreman, Glenn D.


    The Scophony scene projector has been examined in detail. Modulation transfer function was measured and found to be significantly lower than expected. The discrepancy is shown to be due to variation in the Bragg angle with input frequency. Experimental data is compared with calculated performance.

  1. 3-D Scene Reconstruction from Aerial Imagery (United States)


    navigate along interstate routes at speeds in excess of 110 mph, and the inclusion of the first down line in televised football games [28]. These...roughly 2000 feet above the target based on the Sadr City scene dimensions and scaling fac - tors. Images were rendered at a resolution of 1000×1000 as

  2. Vocational Guidance Requests within the International Scene (United States)

    Goodman, Jane; Gillis, Sarah


    This article summarizes the work of a diverse group of researchers and practitioners from 5 continents on "Vocational Guidance Requests Within the International Scene" presented in the discussion group at a symposium of the International Association for Educational and Vocational Guidance, the Society for Vocational Psychology, and the…

  3. Behind the scenes at the LHC inauguration

    CERN Multimedia


    On 21 October the LHC inauguration ceremony will take place and people from all over CERN have been busy preparing. With delegations from 38 countries attending, including ministers and heads of state, the Bulletin has gone behind the scenes to see what it takes to put together an event of this scale.

  4. Parafoveal Semantic Processing of Emotional Visual Scenes (United States)

    Calvo, Manuel G.; Lang, Peter J.


    The authors investigated whether emotional pictorial stimuli are especially likely to be processed in parafoveal vision. Pairs of emotional and neutral visual scenes were presented parafoveally (2.1[degrees] or 2.5[degrees] of visual angle from a central fixation point) for 150-3,000 ms, followed by an immediate recognition test (500-ms delay).…

  5. Perceived glossiness in high dynamic range scenes. (United States)

    Doerschner, Katja; Maloney, Laurence T; Boyaci, Huseyin


    We investigated how spatial pattern, background, and dynamic range affect perceived gloss in brightly lit real scenes. Observers viewed spherical objects against uniform backgrounds. There were three possible objects. Two were black matte spheres with circular matte white dots painted on them (matte-dot spheres). The third sphere was painted glossy black (glossy black sphere). Backgrounds were either black or white matte, and observers saw each of the objects in turn on each background. Scenes were illuminated by an intense collimated source. On each trial, observers matched the apparent albedo of the sphere to an albedo reference scale and its apparent gloss to a gloss reference scale. We found that matte-dot spheres and the black glossy sphere were perceived as glossy on both backgrounds. All spheres were judged to be significantly glossier when in front of the black background. In contrast with previous research using conventional computer displays, we find that background markedly affects perceived gloss. This finding is surprising because darker surfaces are normally perceived as glossier (F. Pellacini, J. A. Ferwerda, & D. P. Greenberg, 2000). We conjecture that there are cues to surface material signaling glossiness present in high dynamic range scenes that are absent or weak in scenes presented using conventional computer displays.

  6. OpenSceneGraph 3 Cookbook

    CERN Document Server

    Wang, Rui


    This is a cookbook full of recipes with practical examples enriched with code and the required screenshots for easy and quick comprehension. You should be familiar with the basic concepts of the OpenSceneGraph API and should be able to write simple programs. Some OpenGL and math knowledge will help a lot, too.

  7. Thermal Stability and Anisotropic Sublimation of Two-Dimensional Colloidal Bi2Te3 and Bi2Se3 Nanocrystals

    CERN Document Server

    Buha, Joka; Castillo, Antonio Esau Del Rio; Bonaccorso, Francesco; Manna, Liberato


    The structural and compositional stabilities of two dimensional 2D Bi2Te3 and Bi2Se3 nanocrystals, produced by both colloidal synthesis and by liquid phase exfoliation, were studied by in situ transmission electron microscopy TEM during annealing at temperatures between 350 and 500 C. The sublimation process induced by annealing is structurally and chemically anisotropic and takes place through the preferential dismantling of the prismatic 011-0 type planes, and through the preferential sublimation of Te or Se.

  8. A graph theoretic approach to scene matching (United States)

    Ranganath, Heggere S.; Chipman, Laure J.


    The ability to match two scenes is a fundamental requirement in a variety of computer vision tasks. A graph theoretic approach to inexact scene matching is presented which is useful in dealing with problems due to imperfect image segmentation. A scene is described by a set of graphs, with nodes representing objects and arcs representing relationships between objects. Each node has a set of values representing the relations between pairs of objects, such as angle, adjacency, or distance. With this method of scene representation, the task in scene matching is to match two sets of graphs. Because of segmentation errors, variations in camera angle, illumination, and other conditions, an exact match between the sets of observed and stored graphs is usually not possible. In the developed approach, the problem is represented as an association graph, in which each node represents a possible mapping of an observed region to a stored object, and each arc represents the compatibility of two mappings. Nodes and arcs have weights indicating the merit or a region-object mapping and the degree of compatibility between two mappings. A match between the two graphs corresponds to a clique, or fully connected subgraph, in the association graph. The task is to find the clique that represents the best match. Fuzzy relaxation is used to update the node weights using the contextual information contained in the arcs and neighboring nodes. This simplifies the evaluation of cliques. A method of handling oversegmentation and undersegmentation problems is also presented. The approach is tested with a set of realistic images which exhibit many types of sementation errors.

  9. Martian Liquid CO2 and Metabolic Heat Regenerated Temperature Swing Adsorption for Portable Life Support Systems (United States)

    Iacomini, Christine; MacCallum, Taber; Morin, Tom; Straub-Lopez, Kathrine; Paul, Heather


    Two of the fundamental problems facing the development of a Portable Life Support System (PLSS) for use on Mars, are (i) heat rejection (because traditional technologies use sublimation of water, which wastes a scarce resource and contaminates the premises), and (ii) rejection of CO2 in an environment with a ppCO2 of 0.4-0.9 kPa. This paper presents a conceptual system for CO2 collection, compression, and cooling to produce sub-critical (liquid) CO2. A first order estimate of the system mass and energy to condense and store liquid CO2 outside at Mars ambient temperature at 600 kPa is discussed. No serious technical hurdles were identified and it is likely that better overall performance would be achieved if the system were part of an integrated ISRU strategy rather than a standalone system. Patent-pending Metabolic heat regenerated Temperature Swing Adsorption (MTSA) technology for CO2 removal from a PLSS vent loop, where the Martian liquid CO2 is used as the heat sink is developed to utilize the readily available liquid CO2. This paper will describe the technology and present data in support of its design.

  10. Hyperspectral characterisation of the Martian south polar residual cap using CRISM (United States)

    Campbell, J. D.; Sidiropoulos, P.; Muller, J.-P.


    We present our research on hyperspectral characterization of the Martian South Polar Residual Cap (SPRC), with a focus on the detection of organic signatures within the dust content of the ice. The SPRC exhibits unique CO2 ice sublimation features known colloquially as 'Swiss Cheese Terrain' (SCT). These flat floored, circular depressions are highly dynamic, and may expose dust particles previously trapped within the ice in the depression walls and partially on the floors. Here we identify suitable regions for potential dust exposure on the SPRC, and utilise data from the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) on board NASA's Mars Reconnaissance Orbiter (MRO) satellite to examine infrared spectra of dark regions to establish their mineral composition, to eliminate the effects of ices on sub-pixel dusty features, and to assess whether ther might be signatures indicative of Polycyclic Aromatic Hydrocarbons (PAHs). Spectral mapping has identified compositional differences between depression rims and the majority of the SPRC and CRISM spectra have been corrected to minimise the influence of CO2 and H2O ice. Whilst no conclusive evidence for PAHs has been found, depression rims are shown to have higher water content than regions of featureless ice, and there are indications of magnesium carbonate within the dark, dusty regions.

  11. Acetamidobenzoic acid isomers: Studying sublimation and fusion processes and their relation with crystal structures

    Energy Technology Data Exchange (ETDEWEB)

    Manin, Alex N.; Voronin, Alexander P.; Perlovich, German L., E-mail:


    Graphical abstract: - Highlights: • Thermodynamic characteristics of sublimation process were investigated for 2-, 3- and 4-acetamidobenzoic acids. • Thermophysic parameters of melting processes were determined and enthalpies of vaporization were calculated for the isomers. • Sublimation thermodynamic parameters were compared with crystal structures of the isomers. - Abstract: Temperature dependencies of saturated vapor pressure for i-acetamidobenzoic acids (i = 2, 3 and 4) were obtained by flow inert gas-carrier transfer method. Thermodynamic parameters of sublimation were calculated for 2-acetamidobenzoic acid (2-AcAm-BA), 3-acetamidobenzoic acid (3-AcAm-BA) and 4-acetamidobenzoic acid (4-AcAm-BA) (2-AcAm-BA: ΔG{sub sub}{sup 298}=54.4 kJ mol{sup −1}; ΔH{sub sub}{sup 298}=116±1 kJ mol{sup −1}; ΔS{sub sub}{sup 298}=205±4 J K{sup −1} mol{sup −1}; 3-AcAm-BA: ΔG{sub sub}{sup 298}=73.2 kJ mol{sup −1}; ΔH{sub sub}{sup 298}=137±1 kJ mol{sup −1}; ΔS{sub sub}{sup 298}=215±4 J K{sup −1} mol{sup −1}; 4-AcAm-BA: ΔG{sub sub}{sup 298}=72.3 kJ mol{sup −1}; ΔH{sub sub}{sup 298}=138±1 kJ mol{sup −1}; ΔS{sub sub}{sup 298}=221±8 J K{sup −1} mol{sup −1}). Thermochemical parameters of fusion process for investigated substances were obtained, and vaporization enthalpies were estimated from fusion and sublimation enthalpies. The thermal data obtained in all experiments were used to find relationships between the thermal properties of these compounds and other benzoic acid derivatives and their structural properties. A correlation between enthalpy of sublimation and melting point was obtained. The influence of size and position of substituents on crystal lattice energy was discussed.

  12. Spatial, temporal, and inter-annual variability of the Martian northern seasonal polar cap (United States)

    Mount, Christopher P.

    Earth and Mars have nearly the same axial tilt, so seasons on these two bodies progress in a similar manner. During fall and winter on Mars, the primarily CO2 atmosphere (~95% by volume) condenses out onto the poles as ice. Approximately 25% of the entire Martian atmosphere condenses, and then sublimes in the spring, making this cycle a dominant driver in the global climate. Because the water and dust cycles are coupled to this CO2 cycle, we must examine seasonal CO2 processes to understand the global (seasonal) distribution of H2O on Mars. The density of the ice may indicate whether it condensed in the atmosphere and precipitated as "snow" or condensed directly onto the surface as "slab". Variations in density may be controlled by geographic location and surface morphology. The distribution and variations in densities of seasonal deposits on the Martian poles gives us insight to the planet's volatile inventories. Here we analyze density variations over time on Mars' Northern Polar Seasonal Cap (NPSC) using observational data and energy balance techniques. We calculate the bulk density of surface CO2 ice by dividing the column mass abundance (the mass of CO2 per unit area) by the depth of the ice cap at a given location. We use seasonal rock shadow measurements from High Resolution Imaging Science Experiment (HiRISE) images to estimate ice depth. The length of a rock's shadow is related to its height through the solar incidence angle and the slope of the ground. From differences in the height of a rock measured in icy vs. ice-free images, we estimate the depth of surface ice at the time of the icy observation. Averaging over many rocks in a region yields the ice depth for that region. This technique yields minimums for ice depth and therefore maximums for density. Thermal properties of rocks may play an important role in observed ice depths. Crowns of ice may form on the tops of rocks with insufficient heat capacity to inhibit ice condensation, and may cause an

  13. Emotional and neutral scenes in competition: orienting, efficiency, and identification. (United States)

    Calvo, Manuel G; Nummenmaa, Lauri; Hyönä, Jukka


    To investigate preferential processing of emotional scenes competing for limited attentional resources with neutral scenes, prime pictures were presented briefly (450 ms), peripherally (5.2 degrees away from fixation), and simultaneously (one emotional and one neutral scene) versus singly. Primes were followed by a mask and a probe for recognition. Hit rate was higher for emotional than for neutral scenes in the dual- but not in the single-prime condition, and A' sensitivity decreased for neutral but not for emotional scenes in the dual-prime condition. This preferential processing involved both selective orienting and efficient encoding, as revealed, respectively, by a higher probability of first fixation on--and shorter saccade latencies to--emotional scenes and by shorter fixation time needed to accurately identify emotional scenes, in comparison with neutral scenes.

  14. Computational Auditory Scene Analysis Based Perceptual and Neural Principles

    National Research Council Canada - National Science Library

    Wang, DeLiang


    .... This fundamental process of auditory perception is called auditory scene analysis. of particular importance in auditory scene analysis is the separation of speech from interfering sounds, or speech segregation...

  15. On to Mars! chronicles of Martian simulations

    CERN Document Server

    PLETSER, Vladimir


    This book introduces the Martian simulations, one installed on Devon Island, an uninhabited island in the Canadian Arctic, well within the polar circle, and two in the desert of Utah, several hundreds of kilometers South of Salt Lake City. The book is based on the diaries during the simulations, held by Vladimir Pletser, a physicist-engineer, who was selected to attend these simulations. It relates the details of everyday life in these Martian habitats and of the scientific and exploratory work conducted in these extreme environments in preparation for future manned missions to Mars. Through the real experiences described in the book, readers will find space explorations and living on Mars more tangible. .

  16. Iron snow in the Martian core? (United States)

    Davies, Christopher J.; Pommier, Anne


    The decline of Mars' global magnetic field some 3.8-4.1 billion years ago is thought to reflect the demise of the dynamo that operated in its liquid core. The dynamo was probably powered by planetary cooling and so its termination is intimately tied to the thermochemical evolution and present-day physical state of the Martian core. Bottom-up growth of a solid inner core, the crystallization regime for Earth's core, has been found to produce a long-lived dynamo leading to the suggestion that the Martian core remains entirely liquid to this day. Motivated by the experimentally-determined increase in the Fe-S liquidus temperature with decreasing pressure at Martian core conditions, we investigate whether Mars' core could crystallize from the top down. We focus on the "iron snow" regime, where newly-formed solid consists of pure Fe and is therefore heavier than the liquid. We derive global energy and entropy equations that describe the long-timescale thermal and magnetic history of the core from a general theory for two-phase, two-component liquid mixtures, assuming that the snow zone is in phase equilibrium and that all solid falls out of the layer and remelts at each timestep. Formation of snow zones occurs for a wide range of interior and thermal properties and depends critically on the initial sulfur concentration, ξ0. Release of gravitational energy and latent heat during growth of the snow zone do not generate sufficient entropy to restart the dynamo unless the snow zone occupies at least 400 km of the core. Snow zones can be 1.5-2 Gyrs old, though thermal stratification of the uppermost core, not included in our model, likely delays onset. Models that match the available magnetic and geodetic constraints have ξ0 ≈ 10% and snow zones that occupy approximately the top 100 km of the present-day Martian core.

  17. Relaxation with Immersive Natural Scenes Presented Using Virtual Reality. (United States)

    Anderson, Allison P; Mayer, Michael D; Fellows, Abigail M; Cowan, Devin R; Hegel, Mark T; Buckey, Jay C


    Virtual reality (VR) can provide exposure to nature for those living in isolated confined environments. We evaluated VR-presented natural settings for reducing stress and improving mood. There were 18 participants (9 men, 9 women), ages 32 ± 12 yr, who viewed three 15-min 360° scenes (an indoor control, rural Ireland, and remote beaches). Subjects were mentally stressed with arithmetic before scenes. Electrodermal activity (EDA) and heart rate variability measured psycho-physiological arousal. The Positive and Negative Affect Schedule and the 15-question Modified Reality Judgment and Presence Questionnaire (MRJPQ) measured mood and scene quality. Reductions in EDA from baseline were greater at the end of the natural scenes compared to the control scene (-0.59, -0.52, and 0.32 μS, respectively). The natural scenes reduced negative affect from baseline ( 1.2 and 1.1 points), but the control scene did not ( 0.4 points). MRJPQ scores for the control scene were lower than both natural scenes (4.9, 6.7, and 6.5 points, respectively). Within the two natural scenes, the preferred scene reduced negative affect ( 2.4 points) more than the second choice scene ( 1.8 points) and scored higher on the MRJPQ (6.8 vs. 6.4 points). Natural scene VR provided relaxation both objectively and subjectively, and scene preference had a significant effect on mood and perception of scene quality. VR may enable relaxation for people living in isolated confined environments, particularly when matched to personal preferences.Anderson AP, Mayer MD, Fellows AM, Cowan DR, Hegel MT, Buckey JC. Relaxation with immersive natural scenes presented using virtual reality. Aerosp Med Hum Perform. 2017; 88(6):520526.

  18. Iron Redox Systematics of Martian Magmas (United States)

    Righter, K.; Danielson, L.; Martin, A.; Pando, K.; Sutton, S.; Newville, M.


    Martian magmas are known to be FeO-rich and the dominant FeO-bearing mineral at many sites visited by the Mars Exploration rovers (MER) is magnetite [1]. Morris et al. [1] propose that the magnetite appears to be igneous in origin, rather than of secondary origin. However, magnetite is not typically found in experimental studies of martian magmatic rocks [2,3]. Magnetite stability in terrestrial magmas is well understood, as are the stability of FeO and Fe2O3 in terrestrial magmas [4,5]. In order to better understand the variation of FeO and Fe2O3, and the stability of magnetite (and other FeO-bearing phases) in martian magmas we have undertaken an experimental study with two emphases. First we document the stability of magnetite with temperature and fO2 in a shergottite bulk composition. Second, we determine the FeO and Fe2O3 contents of the same shergottite bulk composition at 1 bar and variable fO2 at 1250 C, and at variable pressure. These two goals will help define not only magnetite stability, but pyroxene-melt equilibria that are also dependent upon fO2.

  19. Martian Atmospheric Pressure Static Charge Elimination Tool (United States)

    Johansen, Michael R.


    A Martian pressure static charge elimination tool is currently in development in the Electrostatics and Surface Physics Laboratory (ESPL) at NASA's Kennedy Space Center. In standard Earth atmosphere conditions, static charge can be neutralized from an insulating surface using air ionizers. These air ionizers generate ions through corona breakdown. The Martian atmosphere is 7 Torr of mostly carbon dioxide, which makes it inherently difficult to use similar methods as those used for standard atmosphere static elimination tools. An initial prototype has been developed to show feasibility of static charge elimination at low pressure, using corona discharge. A needle point and thin wire loop are used as the corona generating electrodes. A photo of the test apparatus is shown below. Positive and negative high voltage pulses are sent to the needle point. This creates positive and negative ions that can be used for static charge neutralization. In a preliminary test, a floating metal plate was charged to approximately 600 volts under Martian atmospheric conditions. The static elimination tool was enabled and the voltage on the metal plate dropped rapidly to -100 volts. This test data is displayed below. Optimization is necessary to improve the electrostatic balance of the static elimination tool.

  20. Electrical Activity in Martian Dust Storms (United States)

    Majid, W.; Arabshahi, S.; Kocz, J.


    Dust storms on Mars are predicted to be capable of producing electrostatic fields and discharges, even larger than those in dust storms on Earth. Such electrical activity poses serious risks to any Human exploration of the planet and the lack of sufficient data to characterize any such activity has been identified by NASA's MEPAG as a key human safety knowledge gap. There are three key elements in the characterization of Martian electrostatic discharges: dependence on Martian environmental conditions, frequency of occurrence, and the strength of the generated electric fields. We will describe a recently deployed detection engine using NASA's Deep Space Network (DSN) to carry out a long term monitoring campaign to search for and characterize the entire Mars hemisphere for powerful discharges during routine tracking of spacecraft at Mars on an entirely non-interfering basis. The resulting knowledge of Mars electrical activity would allow NASA to plan risk mitigation measures to ensure human safety during Mars exploration. In addition, these measurements will also allow us to place limits on presence of oxidants such as H2O2 that may be produced by such discharges, providing another measurement point for models describing Martian atmospheric chemistry and habitability. Because of the continuous Mars telecommunication needs of NASA's Mars-based assets, the DSN is the only instrument in the world that combines long term, high cadence, observing opportunities with large sensitive telescopes, making it a unique asset worldwide in searching for and characterizing electrostatic activity at Mars from the ground.

  1. Opportunity's Second Martian Birthday at Cape Verde (United States)


    A promontory nicknamed 'Cape Verde' can be seen jutting out from the walls of Victoria Crater in this approximate true-color picture taken by the panoramic camera on NASA's Mars Exploration Rover Opportunity. The rover took this picture on martian day, or sol, 1329 (Oct. 20, 2007), more than a month after it began descending down the crater walls -- and just 9 sols shy of its second Martian birthday on sol 1338 (Oct. 29, 2007). Opportunity landed on the Red Planet on Jan. 25, 2004. That's nearly four years ago on Earth, but only two on Mars because Mars takes longer to travel around the sun than Earth. One Martian year equals 687 Earth days. The overall soft quality of the image, and the 'haze' seen in the lower right portion, are the result of scattered light from dust on the front sapphire window of the rover's camera. This view was taken using three panoramic-camera filters, admitting light with wavelengths centered at 750 nanometers (near infrared), 530 nanometers (green) and 430 nanometers (violet).

  2. Unusual Iron Redox Systematics of Martian Magmas (United States)

    Danielson, L.; Righter, K.; Pando, K.; Morris, R. V.; Graff, T.; Agresti, D.; Martin, A.; Sutton, S.; Newville, M.; Lanzirotti, A.


    Martian magmas are known to be FeO-rich and the dominant FeO-bearing mineral at many sites visited by the Mars Exploration rovers (MER) is magnetite. Morris et al. proposed that the magnetite appears to be igneous in origin, rather than of secondary origin. However, magnetite is not typically found in experimental studies of martian magmatic rocks. Magnetite stability in terrestrial magmas is well understood, as are the stabilities of FeO and Fe2O3 in terrestrial magmas. In order to better understand the variation of FeO and Fe2O3, and the stability of magnetite (and other FeO-bearing phases) in martian magmas, we have undertaken an experimental study with two emphases. First, we determine the FeO and Fe2O3 contents of super- and sub-liquidus glasses from a shergottite bulk composition at 1 bar to 4 GPa, and variable fO2. Second, we document the stability of magnetite with temperature and fO2 in a shergottite bulk composition.

  3. Memory, scene construction, and the human hippocampus. (United States)

    Kim, Soyun; Dede, Adam J O; Hopkins, Ramona O; Squire, Larry R


    We evaluated two different perspectives about the function of the human hippocampus--one that emphasizes the importance of memory and another that emphasizes the importance of spatial processing and scene construction. We gave tests of boundary extension, scene construction, and memory to patients with lesions limited to the hippocampus or large lesions of the medial temporal lobe. The patients were intact on all of the spatial tasks and impaired on all of the memory tasks. We discuss earlier studies that associated performance on these spatial tasks to hippocampal function. Our results demonstrate the importance of medial temporal lobe structures for memory and raise doubts about the idea that these structures have a prominent role in spatial cognition.

  4. Additional Crime Scenes for Projectile Motion Unit (United States)

    Fullerton, Dan; Bonner, David


    Building students' ability to transfer physics fundamentals to real-world applications establishes a deeper understanding of underlying concepts while enhancing student interest. Forensic science offers a great opportunity for students to apply physics to highly engaging, real-world contexts. Integrating these opportunities into inquiry-based problem solving in a team environment provides a terrific backdrop for fostering communication, analysis, and critical thinking skills. One such activity, inspired jointly by the museum exhibit "CSI: The Experience"2 and David Bonner's TPT article "Increasing Student Engagement and Enthusiasm: A Projectile Motion Crime Scene,"3 provides students with three different crime scenes, each requiring an analysis of projectile motion. In this lesson students socially engage in higher-order analysis of two-dimensional projectile motion problems by collecting information from 3-D scale models and collaborating with one another on its interpretation, in addition to diagramming and mathematical analysis typical to problem solving in physics.

  5. The scene and the unseen: Manipulating photographs for experiments on change blindness and scene memory: Image manipulation for change blindness

    National Research Council Canada - National Science Library

    Ball, Felix; Elzemann, Anne; Busch, Niko A


    The change blindness paradigm, in which participants often fail to notice substantial changes in a scene, is a popular tool for studying scene perception, visual memory, and the link between awareness and attention...

  6. Martian meteorites and Martian magnetic anomalies: a new perspective from NWA 7034 (Invited) (United States)

    Gattacceca, J.; Rochette, P.; Scozelli, R. B.; Munayco, P.; Agee, C. B.; Quesnel, Y.; Cournede, C.; Geissman, J. W.


    The magnetic anomalies observed above the Martian Noachian crust [1] require strong crustal remanent magnetization in the 15-60 A/m range over a thickness of 20-50 km [2,3]. The Martian rocks available for study in the form of meteorites do contain magnetic minerals (magnetite and/or pyrrhotite) but in too small amount to account for such strong remanent magnetizations [4]. Even though this contradiction was easily explained by the fact that Martian meteorites (mostly nakhlites and shergottites) are not representative of the Noachian Martian crust, we were left with no satisfactory candidate lithology to account for the Martian magnetic anomalies. The discovery in the Sahara of a new type of Martian meteorite (NWA 7034 [5] and subsequent paired stones which are hydrothermalized volcanic breccia) shed a new light on this question as it contains a much larger amount of ferromagnetic minerals than any other Martian meteorite. We present here a study of the magnetic properties of NWA 7034, together with a review of the magnetic properties of thirty other Martian meteorites. Magnetic measurements (including high and low temperature behavior and Mössbauer spectroscopy) show that NWA 7034 contains about 15 wt.% of magnetite with various degrees of substitution and maghemitization up to pure maghemite, in the pseudo-single domain size range. Pyrrhotite, a common mineral in other Martian meteorites is not detected. Although it is superparamagnetic and cannot carry remanent magnetization, nanophase goethite is present in significant amounts confirming that NWA 7034 is the most oxidized Martian meteorite studied so far, as already indicated by the presence of maghemite (this study) and pyrite [5]. These magnetic properties show that a kilometric layer of a lithology similar to NWA 7034 magnetized in a dynamo field would be enough to account for the strongest Martian magnetic anomalies. Although the petrogenesis of NWA 7034 is still debated, as the brecciation could be either

  7. Static Scene Statistical Non-Uniformity Correction (United States)


    Error NUC Non-Uniformity Correction RMSE Root Mean Squared Error RSD Relative Standard Deviation S3NUC Static Scene Statistical Non-Uniformity...Deviation ( RSD ) which normalizes the standard deviation, σ, to the mean estimated value, µ using the equation RS D = σ µ × 100. The RSD plot of the gain...estimates is shown in Figure 4.1(b). The RSD plot shows that after a sample size of approximately 10, the different photocount values and the inclusion

  8. Using Ignorance in 3D Scene Understanding


    Bogdan Harasymowicz-Boggio; Barbara Siemiątkowska


    Awareness of its own limitations is a fundamental feature of the human sight, which has been almost completely omitted in computer vision systems. In this paper we present a method of explicitly using information about perceptual limitations of a 3D vision system, such as occluded areas, limited field of view, loss of precision along with distance increase, and imperfect segmentation for a better understanding of the observed scene. The proposed mechanism integrates metric and semantic infere...

  9. Lunar and Planetary Science XXXV: Martian Meteorites: Chemical Weathering (United States)


    The session "Martian Meteorites: Chemical Weathering" included the following reports:Chemical Weathering Records of Martian Soils Preserved in the Martian Meteorite EET79001; Synchrotron X-Ray Diffraction Analysis of Meteorites in Thin Section: Preliminary Results; A Survey of Olivine Alteration Products Using Raman Spectroscopy; and Rb-Sr and Sm-Nd Isotope Systematics of Shergottite NWA 856: Crystallization Age and Implications for Alteration of Hot Desert SNC Meteorites.

  10. Magnesium isotope systematics in Martian meteorites (United States)

    Magna, Tomáš; Hu, Yan; Teng, Fang-Zhen; Mezger, Klaus


    Magnesium isotope compositions are reported for a suite of Martian meteorites that span the range of petrological and geochemical types recognized to date for Mars, including crustal breccia Northwest Africa (NWA) 7034. The δ26Mg values (per mil units relative to DSM-3 reference material) range from -0.32 to -0.11‰; basaltic shergottites and nakhlites lie to the heavier end of the Mg isotope range whereas olivine-phyric, olivine-orthopyroxene-phyric and lherzolitic shergottites, and chassignites have slightly lighter Mg isotope compositions, attesting to modest correlation of Mg isotopes and petrology of the samples. Slightly heavier Mg isotope compositions found for surface-related materials (NWA 7034, black glass fraction of the Tissint shergottite fall; δ26Mg > -0.17‰) indicate measurable Mg isotope difference between the Martian mantle and crust but the true extent of Mg isotope fractionation for Martian surface materials remains unconstrained. The range of δ26Mg values from -0.19 to -0.11‰ in nakhlites is most likely due to accumulation of clinopyroxene during petrogenesis rather than garnet fractionation in the source or assimilation of surface material modified at low temperatures. The rather restricted range in Mg isotope compositions between spatially and temporally distinct mantle-derived samples supports the idea of inefficient/absent major tectonic cycles on Mars, which would include plate tectonics and large-scale recycling of isotopically fractionated surface materials back into the Martian mantle. The cumulative δ26Mg value of Martian samples, which are not influenced by late-stage alteration processes and/or crust-mantle interactions, is - 0.271 ± 0.040 ‰ (2SD) and is considered to reflect δ26Mg value of the Bulk Silicate Mars. This value is robust taking into account the range of lithologies involved in this estimate. It also attests to the lack of the Mg isotope variability reported for the inner Solar System bodies at current

  11. Functional imaging of auditory scene analysis. (United States)

    Gutschalk, Alexander; Dykstra, Andrew R


    Our auditory system is constantly faced with the task of decomposing the complex mixture of sound arriving at the ears into perceptually independent streams constituting accurate representations of individual sound sources. This decomposition, termed auditory scene analysis, is critical for both survival and communication, and is thought to underlie both speech and music perception. The neural underpinnings of auditory scene analysis have been studied utilizing invasive experiments with animal models as well as non-invasive (MEG, EEG, and fMRI) and invasive (intracranial EEG) studies conducted with human listeners. The present article reviews human neurophysiological research investigating the neural basis of auditory scene analysis, with emphasis on two classical paradigms termed streaming and informational masking. Other paradigms - such as the continuity illusion, mistuned harmonics, and multi-speaker environments - are briefly addressed thereafter. We conclude by discussing the emerging evidence for the role of auditory cortex in remapping incoming acoustic signals into a perceptual representation of auditory streams, which are then available for selective attention and further conscious processing. This article is part of a Special Issue entitled Human Auditory Neuroimaging. Copyright © 2013 Elsevier B.V. All rights reserved.

  12. Ultraviolet Radiation-induced Alteration of Martian Surface Materials (United States)

    Yen, A. S.


    The nature and origin of martian surface materials cannot be fully characterized without addressing the unusual reactivity of the soil and the effects of exposure to the unique martian environment. Our laboratory experiments show that ultraviolet radiation at the martian surface can result in the oxidation of metal atoms and the creation of reactive oxygen species on grain surfaces. This process is important in understanding the nature and evolution of martian soils. It can explain the reactivity discovered by the Viking Landers and possibly the origin of the ferric component of the soil.

  13. An Electrostatic Precipitator System for the Martian Environment (United States)

    Calle, C. I.; Mackey, P. J.; Hogue, M. D.; Johansen, M. R.; Phillips, J. R., III; Clements, J. S.


    Human exploration missions to Mars will require the development of technologies for the utilization of the planet's own resources for the production of commodities. However, the Martian atmosphere contains large amounts of dust. The extraction of commodities from this atmosphere requires prior removal of this dust. We report on our development of an electrostatic precipitator able to collect Martian simulated dust particles in atmospheric conditions approaching those of Mars. Extensive experiments with an initial prototype in a simulated Martian atmosphere showed efficiencies of 99%. The design of a second prototype with aerosolized Martian simulated dust in a flow-through is described. Keywords: Space applications, electrostatic precipitator, particle control, particle charging

  14. 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.

  15. Measuring Enthalpy of Sublimation of Volatiles by Means of Piezoelectric Crystal Microbalances (United States)

    Dirri, Fabrizio; Palomba, Ernesto; Longobardo, Andrea; Zampetti, Emiliano


    Piezoelectric Crystal Microbalances (PCM's) are widely used to study the chemical processes involving volatile compounds in any environment, such as condensation process. Since PCM's are miniaturized sensor, they are very suitable for planetary in situ missions, where can be used to detect and to measure the mass amount of astrobiologically significant compounds, such as water and organics. This work focuses on the realization and testing of a new experimental setup, able to characterize volatiles which can be found in a planetary environment. In particular the enthalpy of sublimation of some dicarboxylic acids has been measured. The importance of dicarboxylic acids in planetology and astrobiology is due to the fact that they have been detected in carbonaceous chondritic material (e.g. Murchinson), among the most pristine material present in our Solar System. In this work, a sample of acid was heated in an effusion cell up to its sublimation. For a set of temperatures (from 30 °C to 75 °C), the deposition rate on the PCM surface has been measured. From these measurements, it has been possible to infer the enthalpy of sublimation of Adipic acid, i.e. ΔH = 141.6 ± 0.8 kJ/mol and Succinic acid, i.e. ΔH = 113.3 ± 1.3 kJ/mol. This technique has so demonstrated to be a good choice to recognise a single compound or a mixture (with an analysis upstream) even if some improvements concerning the thermal stabilization of the system will be implemented in order to enhance the results' accuracy. The experiment has been performed in support of the VISTA (Volatile In Situ Thermogravimetry Analyzer) project, which is included in the scientific payload of the ESA MarcoPolo-R mission study.

  16. Wasting the Future: The Technological Sublime, Communications Technologies, and E-waste

    Directory of Open Access Journals (Sweden)

    Sebine Label


    Full Text Available Literally speaking, e-waste is the future of communications. E-waste is the fastest growing waste stream in the world, much of it communications technologies from cell phones to laptops, televisions to peripherals. As a result of policies of planned obsolescence working computers, cell phones, and tablets are routinely trashed. One of the most powerful and enduring discourses associated with emerging technologies is the technological sublime, in which technology is seen as intellectually, emotionally, or spiritually transcendent. It comprises a contradictory impulse that elevates technology with an almost religious fervor, while simultaneously overlooking some of the consequences of industrialism, as well as ignoring the necessity of social, economic, and governmental infrastructures necessary to the implementation and development of new technologies. The idea that a new technology will not pollute or harm the environment is a persistent, though often quickly passed over, theme in the technological sublime, echoed in discourses about emerging technologies such as the silicon chip, the internet, and other ICTs. In this paper, I make connections between the discourse of newness, the practice of planned obsolescence, and the mountains of trashed components and devices globally. Considering the global context demonstrates the realities of the penetration of ICTs and their enduring pollution and negative implications for the health of humans and nonhumans, including plants, animals, waterways, soil, air and so on. I use the discourse of the technological sublime to open up and consider the future of communications, to argue that this discourse not only stays with us but also contains within it two important and related components, the promise of ecological harmony and a future orientation. I argue that these lingering elements keep us from considering the real future of communications – e-waste – and that, as communications scholars, we must also

  17. Origin and effective reduction of inversion domains in aluminum nitride grown by a sublimation method (United States)

    Shigetoh, Keisuke; Horibuchi, Kayo; Nakamura, Daisuke


    Owing to the large differences in the chemical properties between Al and N polarities in aluminum nitride (AlN), the choice of the polar direction for crystal growth strongly affects not only the quality but also the shape (facet formation) of the grown crystal. In particular, N-polar (0 0 0 -1) has been considered to be a more preferable direction than Al-polar (0 0 0 1) for sublimation growth because compared to Al-polar (0 0 0 1), N-polar (0 0 0 -1) exhibits better stability at high growth rate (high supersaturation) conditions and enables easier lateral enlargement of the crystal. However, some critical growth conditions induce polarity inversion and hinder stable N-polar growth. Furthermore, the origin of the polarity inversion in AlN growth by the sublimation method is still unclear. To ensure stable N-polar growth without polarity inversion, the formation mechanism of the inversion domain during AlN sublimation growth must be elucidated. Therefore, herein, we demonstrate homoepitaxial growth on an N-polar seed and carefully investigate the obtained crystal that shows polarity inversion. Annular bright-field scanning transmission electron microscopy reveals that polarity is completely converted to the Al polarity via the formation of a 30 nm thick mixed polar layer (MPL) just above the seed. Moreover, three-dimensional atom probe tomography shows the segregation of the oxygen impurities in the MPL with a high concentration of about 3 atom%. Finally, by avoiding the incorporation of oxygen impurity into the crystal at the initial stage of the growth, we demonstrate an effective reduction (seven orders of magnitude) of the inversion domain boundary formation.

  18. Influence of a psychological perspective on scene viewing and memory for scenes. (United States)

    Kaakinen, Johanna K; Hyönä, Jukka; Viljanen, Minna


    In the study, 33 participants viewed photographs from either a potential homebuyer's or a burglar's perspective, or in preparation for a memory test, while their eye movements were recorded. A free recall and a picture recognition task were performed after viewing. The results showed that perspective had rapid effects, in that the second fixation after the scene onset was more likely to land on perspective-relevant than on perspective-irrelevant areas within the scene. Perspective-relevant areas also attracted longer total fixation time, more visits, and longer first-pass dwell times than did perspective-irrelevant areas. As for the effects of visual saliency, the first fixation was more likely to land on a salient than on a nonsalient area; salient areas also attracted more visits and longer total fixation time than did nonsalient areas. Recall and recognition performance reflected the eye fixation results: Both were overall higher for perspective-relevant than for perspective-irrelevant scene objects. The relatively low error rates in the recognition task suggest that participants had gained an accurate memory for scene objects. The findings suggest that the role of bottom-up versus top-down factors varies as a function of viewing task and the time-course of scene processing. © 2011 The Experimental Psychology Society

  19. Det sublime og det skjønne som estetisk kvalitet i nyere norsk bildebokkritikk

    Directory of Open Access Journals (Sweden)

    Goga, Nina


    Full Text Available This article analyses a specific number of picture book reviews on prize-winning Norwegian picture books from 1998-2008. The subject for the analysis is to examine what kind of aesthetic thinking that is expressed in the reviewer’s judgement of the book. I found that it was possible to relate the reviews to two well established concepts in classic aesthetic theory, namely the concept of the beauty and the sublime. To illustrate this I have studied more exhaustive a smaller number of reviews on two different books

  20. Symptôme, sublimation, sexuation: les prolongements du symptôme

    Directory of Open Access Journals (Sweden)

    Geneviève More


    Full Text Available à partir du commentaire de Lacan sur Joyce, j'ai développé une thèse lacanienne fondamentale pour penser la transmission entre les générations avec un autre concept que celui de l'identification : le prolongement du symptôme. De plus, l'accent mis sur le sinthome par Lacan, n'empêche pas de situer la sublimation comme l'un des autres prolongements possibles du symptôme initial de Joyce.

  1. “Quedarán siempre las afueras”: hacia un nuevo sublime periférico

    Directory of Open Access Journals (Sweden)

    Cristina Gutiérrez Valencia


    Full Text Available Dentro de la variedad de poéticas en el actual panorama español hay un grupo de autores (Alberto Santamaría, García Casado, Mercedes Díaz Villarías y Fernández Mallo que, aunque diferentes, tienen en común un nuevo romanticismo de ascendencia americana caracterizado por la búsqueda de un nuevo sublime basado en lo periférico de su escenario y su nueva mirada sobre la realidad.

  2. A Bayesian Analysis Shows That a Spruce Beetle Outbreak Reduces Snow Interception and Sublimation in a Subalpine Spruce-Fir Forest (United States)

    Frank, J. M.; Massman, W. J.; Ewers, B. E.; Williams, D. G.


    Sublimation is a key component in the water cycle of cold, snow dominated ecosystems. In many high elevation spruce-fir forests of western North America, recent spruce beetle outbreaks have caused widespread tree mortality, opened the canopy, and potentially altered the processes that control sublimation. This study evaluates three hypotheses: in these ecosystems the dominant source for sublimation originates from canopy intercepted snow, the loss of canopy following a beetle disturbance leads to significantly less sublimation, and major sublimation events are driven by the flow of sensible heat into the canopy. Bayesian analysis is used to evaluate a two source energy and canopy mass model that explains seventeen years (2000-2016) of winter eddy-covariance flux data at the GLEES AmeriFlux sites where a spruce beetle outbreak caused 75-85% basal area mortality. The model estimated that the resistance to snow sublimation from the canopy was an order of magnitude less than from the snowpack and that the maximum snow loading in the canopy was reduced to 25-56% of its pre-outbreak capacity. Comparing model results obtained using the observed decrease in leaf area index versus a "no beetle" condition, there has been a significant decrease in ecosystem sublimation since 2011. In the past few years, a 5-11% increase in snowpack sublimation has been offset by 28-32% less sublimation from canopy intercepted snow, with the net being 17-25% less total sublimation. This is equivalent to 3-6% of the total precipitation. Informing the model with information other than the above-canopy fluxes indicates that a near snowpack eddy covariance system decreases the canopy contribution to sublimation, including observed sensible heat fluxes requires a correction to resolve the surface energy imbalance, and stable isotopes of water vapor extend sublimation events. Because tree growth and ecological succession are slow in spruce-fir forests, these results could persist for decades.

  3. Applying artificial vision models to human scene understanding. (United States)

    Aminoff, Elissa M; Toneva, Mariya; Shrivastava, Abhinav; Chen, Xinlei; Misra, Ishan; Gupta, Abhinav; Tarr, Michael J


    How do we understand the complex patterns of neural responses that underlie scene understanding? Studies of the network of brain regions held to be scene-selective-the parahippocampal/lingual region (PPA), the retrosplenial complex (RSC), and the occipital place area (TOS)-have typically focused on single visual dimensions (e.g., size), rather than the high-dimensional feature space in which scenes are likely to be neurally represented. Here we leverage well-specified artificial vision systems to explicate a more complex understanding of how scenes are encoded in this functional network. We correlated similarity matrices within three different scene-spaces arising from: (1) BOLD activity in scene-selective brain regions; (2) behavioral measured judgments of visually-perceived scene similarity; and (3) several different computer vision models. These correlations revealed: (1) models that relied on mid- and high-level scene attributes showed the highest correlations with the patterns of neural activity within the scene-selective network; (2) NEIL and SUN-the models that best accounted for the patterns obtained from PPA and TOS-were different from the GIST model that best accounted for the pattern obtained from RSC; (3) The best performing models outperformed behaviorally-measured judgments of scene similarity in accounting for neural data. One computer vision method-NEIL ("Never-Ending-Image-Learner"), which incorporates visual features learned as statistical regularities across web-scale numbers of scenes-showed significant correlations with neural activity in all three scene-selective regions and was one of the two models best able to account for variance in the PPA and TOS. We suggest that these results are a promising first step in explicating more fine-grained models of neural scene understanding, including developing a clearer picture of the division of labor among the components of the functional scene-selective brain network.

  4. Applying artificial vision models to human scene understanding

    Directory of Open Access Journals (Sweden)

    Elissa Michele Aminoff


    Full Text Available How do we understand the complex patterns of neural responses that underlie scene understanding? Studies of the network of brain regions held to be scene-selective – the parahippocampal/lingual region (PPA, the retrosplenial complex (RSC, and the occipital place area (TOS – have typically focused on single visual dimensions (e.g., size, rather than the high-dimensional feature space in which scenes are likely to be neurally represented. Here we leverage well-specified artificial vision systems to explicate a more complex understanding of how scenes are encoded in this functional network. We correlated similarity matrices within three different scene-spaces arising from: 1 BOLD activity in scene-selective brain regions; 2 behavioral measured judgments of visually-perceived scene similarity; and 3 several different computer vision models. These correlations revealed: 1 models that relied on mid- and high-level scene attributes showed the highest correlations with the patterns of neural activity within the scene-selective network; 2 NEIL and SUN – the models that best accounted for the patterns obtained from PPA and TOS – were different from the GIST model that best accounted for the pattern obtained from RSC; 3 The best performing models outperformed behaviorally-measured judgments of scene similarity in accounting for neural data. One computer vision method – NEIL (Never-Ending-Image-Learner, which incorporates visual features learned as statistical regularities across web-scale numbers of scenes – showed significant correlations with neural activity in all three scene-selective regions and was one of the two models best able to account for variance in the PPA and TOS. We suggest that these results are a promising first step in explicating more fine-grained models of neural scene understanding, including developing a clearer picture of the division of labor among the components of the functional scene-selective brain network.

  5. Pedestal Craters in Utopia Planitia and Malea Planum: Evidence for a Past Ice-Rich Substrate from Marginal Sublimation Pits. (United States)

    Kadish, S. J.; Head, J. W.; Barlow, N. G.; Marchant, D. R.


    Introduction: Pedestal craters (Pd) are a subclass of impact craters unique to Mars [1] characterized by a crater perched near the center of a pedestal (mesa or plateau) that is surrounded by a quasi-circular, outward-facing scarp. The marginal scarp is usually several crater diameters from the crater rim (Figs. 2,4,5), and tens to over 100 meters above the surrounding plains (Fig. 2). Pd have been interpreted to form by armoring of the proximal substrate during the impact event. Hypotheses for the armoring mechanism include an ejecta covering [e.g., 3], increased ejecta mobilization caused by volatile substrates [4], distal glassy/melt-rich veneers [5], and/or an atmospheric blast/thermal effect [6]. Subsequently, a marginal scarp forms by preferential erosion of the substrate surrounding the armored region, most commonly thought to involve eolian removal of fine-grained, non-armored material [e.g., 3]. An understanding of the distribution of Pd, which form predominantly poleward of ~40°N and S latitude [7-9] (Fig. 1), and the role of redistribution of ice and dust during periods of climate change [e.g., 10-11], suggests that the substrate might have been volatile-rich [8-9, 12-14]. As such, some researchers [e.g., 8-9] have proposed a model for Pd formation that involves impact during periods of higher obliquity, when mid- to high-latitude substrates were characterized by thick deposits of snow and ice [e.g., 15]. Subsequent sublimation of the volatile units, except below the armored regions, yielded the perched Pd. Thus, this model predicts that thick deposits of snow/ice should underlie Pd. This is in contrast to the eolian model [3], which calls primarily for deflation of sand and dust. Here, we show the results of our study [8,16] that has documented and characterized 2461 Pd on Mars equatorward of ~65° N and S latitude (Fig. 1) in order to test these hypotheses for the origin of pedestal craters. In particular, we report on the detection of 50 Pd in Utopia

  6. Martian meteorite Dhofar 019: A new shergottite (United States)

    Taylor, L. A.; Nazarov, M. A.; Shearer, C. K.; McSween, H. Y., Jr.; Cahill, J.; Neal, C. R.; Ivanova, M. A.; Barsukova, L. D.; Lentz, R. C.; Clayton, R. N.; Mayeda, T. K.


    Dhofar 019 is a new martian meteorite found in the desert of Oman. In texture, mineralogy, and major and trace element chemistry, this meteorite is classified as a basaltic shergottite. Olivine megacrysts are set within a groundmass composed of finer grained olivine, pyroxene (pigeonite and augite), and maskelynite. Minor phases are chromite-ulvöspinel, ilmenite, silica, K-rich feldspar, merrillite, chlorapatite, and pyrrhotite. Secondary phases of terrestrial origin include calcite, gypsum, celestite, Fe hydroxides, and smectite. Dhofar 019 is most similar to the Elephant Moraine (EETA) 79001 lithology A and Dar al Gani (DaG) 476/489 shergottites. The main features that distinguish Dhofar 019 from other shergottites are lack of orthopyroxene; lower Ni contents of olivine; the heaviest oxygen-isotopic bulk composition; and larger compositional ranges for olivine, maskelynite, and spinel, as well as a wide range for pyroxenes. The large compositional ranges of the minerals are indicative of relatively rapid crystallization. Modeling of olivine chemical zonations yield minimum cooling rates of 0.5-0.8 ?C/h. Spinel chemistry suggests that crystallization took place under one of the most reduced conditions for martian meteorites, at an oxygen fugacity of 3 log units below the quartz-fayalite-magnetite (QFM) buffer. The olivine megacrysts are heterogeneously distributed in the rock. Crystal size distribution analysis suggests that they constitute a population formed under steady-state conditions of nucleation and growth, although a few grains may be cumulates. The parent melt is thought to have been derived from partial melting of a light rare earth element- and platinum group element-depleted mantle source. Shergottites, EETA79001 lithology A, DaG 476/489, and Dhofar 019, although of different ages, comprise a particular type of martian rocks. Such rocks could have formed from chemically similar source(s) and parent melt(s), with their bulk compositions affected by

  7. TMS to object cortex affects both object and scene remote networks while TMS to scene cortex only affects scene networks. (United States)

    Rafique, Sara A; Solomon-Harris, Lily M; Steeves, Jennifer K E


    Viewing the world involves many computations across a great number of regions of the brain, all the while appearing seamless and effortless. We sought to determine the connectivity of object and scene processing regions of cortex through the influence of transient focal neural noise in discrete nodes within these networks. We consecutively paired repetitive transcranial magnetic stimulation (rTMS) with functional magnetic resonance-adaptation (fMR-A) to measure the effect of rTMS on functional response properties at the stimulation site and in remote regions. In separate sessions, rTMS was applied to the object preferential lateral occipital region (LO) and scene preferential transverse occipital sulcus (TOS). Pre- and post-stimulation responses were compared using fMR-A. In addition to modulating BOLD signal at the stimulation site, TMS affected remote regions revealing inter and intrahemispheric connections between LO, TOS, and the posterior parahippocampal place area (PPA). Moreover, we show remote effects from object preferential LO to outside the ventral perception network, in parietal and frontal areas, indicating an interaction of dorsal and ventral streams and possibly a shared common framework of perception and action. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Trans-modern AesthesiS In The Eurasian Borderlands And The Decolonial Anti-sublime

    Directory of Open Access Journals (Sweden)

    Madina Tlostanova


    Full Text Available El artículo estudia la aesthesis transmoderna en relación con la agenda de liberar la esfera estética de los mitos de la modernidad occidental. La autora ofrece un resumen crítico de las principales corrientes estéticas occidentales frente al anti-sublime decolonial como modelo alternativo analizado en el artículo. Se presta especial atención al mecanismo de este sublime, fundado en una hermenéutica pluritópica y una “comunidad de sentido” decolonial que une a quienes fueron marcados por la “herida colonial”. El artículo se enfoca en la reformulación decolonial de problemáticas estéticas usuales, como la correlación de belleza y aesthesis, la relación de conocimiento y arte, de la esfera moral y la estética, etc. Finalmente, una larga sección se dedica a la aesthesis decolonial de la zona fronteriza euroasiática, los territorios en el Este (Asia Central y Sur (Cáucaso del continente euroasiático, que antes eran colonias rusas/soviéticas, y producen hoy instancias complejas de arte decolonial en las obras de Saule Suleymenova, Zorito Dorzhiev y otros.

  9. Sublimator Driven Coldplate Engineering Development Unit Test Results and Development of Second Generation SDC (United States)

    Stephan, Ryan A.; Sheth, Rubik B.


    The Sublimator Driven Coldplate (SDC) is a unique piece of thermal control hardware that has several advantages over a traditional thermal control scheme. The principal advantage is the possible elimination of a pumped fluid loop, potentially increasing reliability and reducing complexity while saving both mass and power. Furthermore, the Integrated Sublimator Driven Coldplate (ISDC) concept couples a coolant loop with the previously described SDC hardware. This combination allows the SDC to be used as a traditional coldplate during long mission phases. The previously developed SDC technology cannot be used for long mission phases due to the fact that it requires a consumable feedwater for heat rejection. Adding a coolant loop also provides for dissimilar redundancy on the Altair Lander ascent module thermal control system, which is the target application for this technology. Tests were performed on an Engineering Development Unit at NASA s Johnson Space Center to quantify and assess the performance of the SDC. Correlated thermal math models were developed to help explain the test data. The paper also outlines the preliminary results of an ISDC concept being developed.

  10. Verdad sublime y madre asesina en Christine V., versión de Marguerite Duras

    Directory of Open Access Journals (Sweden)

    Juliana González Holguín


    Full Text Available Todo relato es ficción, versión y, así mismo, verdad, bajo una u otra concepción de la misma, es decir, desde una perspectiva que se enfoca según la intención y la subjetividad de uno o más actores, de uno o más narradores. El texto de Marguerite Duras intitulado Sublime forcément sublime Christine V. involucra, por su contenido y su contexto, varias versiones que contrastan y se interrogan entre sí. La escritora se posiciona de tal manera que, a través de recursos propios del oficio literario, desentraña una verdad que puede no ajustarse a la realidad o al saber, pero que nos enfrenta a los límites de lo pulsional y lo ominoso.

  11. Physical properties of sublimated zinc telluride thin films for solar cell applications

    Energy Technology Data Exchange (ETDEWEB)

    Shah, Nazar Abbas, E-mail:; Mahmood, Waqar


    Zinc telluride (ZnTe) thin films were fabricated by using closed space sublimation (CSS) technique on glass substrate under vacuum. Pre-fabricated ZnTe thin films were doped with silver (Ag) by ion exchange method. X-ray diffraction showed the preferred orientation (111) of ZnTe thin film with polycrystalline behavior. Scanning electron microscope images were taken to estimate the grain boundaries; energy dispersive X-ray results confirmed the Ag composition in doped-ZnTe samples. Electrical measurements were performed to determine the resistivity, mobility and carrier concentrations of un-doped thin films and Ag-doped samples. The electrical resistivity was of the order of 10{sup 6} Ω-cm before doping. Ag-doped ZnTe samples exhibits low resistivity of the order of 10{sup 3} Ω-cm along with a change in the carrier concentrations and mobility as well at room temperature. The angle resolved optical transmission data, taken by spectrophotometer, was used to find the optical properties before and after Ag doping. Energy band gap showed decreasing trend with increasing Ag doping time. - Highlights: • Zinc telluride thin films were grown by closed space sublimation technique. • Ag was doped, by ion exchange process. • Physical properties were investigated before and after doping.

  12. Viscous drops bounce faster: prompt tumbling-rebound from a sublimating slope (United States)

    Antonini, Carlo; Jung, Stefan; Wetzel, Andreas; Heer, Emmanuel; Schoch, Philippe; Mazloomi, M. Ali; Chikatamarla, Shyam S.; Karlin, Ilya; Marengo, Marco; Poulikakos, Dimos


    We discovered a new drop rebound regime, characteristic of highly viscous liquids impacting onto tilted sublimating surfaces. By focusing on non-axisymmetric impact conditions at increasing viscosity, we demonstrate that low viscous drops show a ``slide, spread, recoil and rebound'' behavior, whereas viscous drops exhibit a ``prompt tumbling-rebound'' behavior. As such, viscous glycerol drops surprisingly rebound faster than three orders of magnitude less viscous water drops. This is made possible by a small conversion of translational to rotational kinetic energy, at non-axisymmetric impact conditions, as also confirmed by additional Lattice Boltzmann simulations: a rapid transition of the internal angular velocity prior to rebound to a constant value, as in a tumbling solid body, promotes a rapid rebound of more viscous drops, which are capable to rebound without recoiling. By studying drop impact dynamics, we explore the drop behavior in contactless and frictionless conditions, and identify the Ohnesorge number as the primary parameter to predict the transition between different impact regimes on tilted sublimating slopes, with tumbling observed for Ohnesorge numbers higher than unity.

  13. How drops bounce and dance on ice: the role of sublimating surfaces (United States)

    Antonini, Carlo; Bernagozzi, Ilaria; Jung, Stefan; Poulikakos, Dimos; Marengo, Marco; Laboratory of Thermodynamics in Emerging Technologies Team; Themal Physics Laboratory Team


    Drop rebound is a spectacular event that appears after impact on superhydrophobic surfaces, due to low drop-solid substrate adhesion, and on hot substrates in Leidenfrost conditions, thanks to a vapor layer forming at the liquid-substrate interface, caused by drop evaporation. However, at temperatures below water freezing temperature, i.e. 0C, even superhydrophobicity can get lost. In the present work, we demonstrate that drop rebound can also be originated by another physical phenomenon, i.e. the solid substrate sublimation, at temperatures as low as -79C. To prove this mechanism, drop impact experiments were conducted on solid carbon dioxide, commonly known as dry ice. Drop dynamics and rebound were analyzed, together with the cases of drop impacting on a superhydrophobic surface and on a hot plate, to show how three different physical mechanisms, which apparently share nothing in common, i.e. superhydrophobicity, evaporation and sublimation, can all lead to drop rebound, in an extremely wide temperature range, from 300C down to even below -79C. Additional glycol drop impact tests proved the independence of the observed phenomena from the chosen liquid. Finally, the formation and visualization of an air vortex ring around an impacting drop is also reported. The authors acknowledge funding from Regione Lombardia and European Community (Marie Curie Fellowship).

  14. Formulation and evaluation of fast dissolving tablets of cinnarizine using superdisintegrant blends and subliming material

    Directory of Open Access Journals (Sweden)

    Biswajit Basu


    Full Text Available The aim of this investigation was to develop fast dissolving tablet of cinnarizine. A combination of super disintegrants, i.e., sodium starch glycolate (SSG and crosscarmellose sodium (CCS were used along with camphor as a subliming material. An optimized concentration of camphor was added to aid the porosity of the tablet. A 3 2 full factorial design was applied to investigate the combined effect of two formulation variables: Amount of SSG and CCS. Infrared (IR spectroscopy was performed to identify the physicochemical interaction between drug and polymer. IR spectroscopy showed that there is no interaction of drug with polymer. In the present study, direct compression was used to prepare the tablets. The powder mixtures were compressed into tablet using flat face multi punch tablet machine. Camphor was sublimed from the tablet by exposing the tablet to vacuum drier at 60°C for 12 hours. All the formulations were evaluated for their characteristics such as average weight, hardness, wetting time, friability, content uniformity, dispersion time (DT, and dissolution rate. An optimized tablet formulation (F 9 was found to have good hardness of 3.30 ± 0.10 kg/cm 2 , wetting time of 42.33 ± 4.04 seconds, DT of 34.67 ± 1.53 seconds, and cumulative drug release of not less than 99% in 16 minutes.

  15. Coastal geomorphology of the Martian northern plains (United States)

    Parker, Timothy J.; Gorsline, Donn S.; Saunders, Stephen R.; Pieri, David C.; Schneeberger, Dale M.


    The paper considers the question of the formation of the outflow channels and valley networks discovered on the Martian northern plains during the Mariner 9 mission. Parker and Saunders (1987) and Parker et al. (1987, 1989) data are used to describe key features common both in the lower reaches of the outflow channels and within and along the margins of the entire northern plains. It is suggested, that of the geological processes capable of producing similar morphologies on earth, lacustrine or marine deposition and subsequent periglacial modification offer the simplest and most consistent explanation for the suit of features found on Mars.

  16. Modelling the Martian CO2 Ice Clouds (United States)

    Listowski, Constantino; Määttänen, A.; Montmessin, F.; Lefèvre, F.


    Martian CO2 ice cloud formation represents a rare phenomenon in the Solar System: the condensation of the main component of the atmosphere. Moreover, on Mars, condensation occurs in a rarefied atmosphere (large Knudsen numbers, Kn) that limits the growth efficiency. These clouds form in the polar winter troposphere and in the mesosphere near the equator. CO2 ice cloud modeling has turned out to be challenging: recent efforts (e.g. [1]) fail in explaining typical small sizes (80 nm-130 nm) observed for mesospheric clouds [2]. Supercold pockets (TWood, S. E., (1999), Ph.D. thesis, UCLA [6] Young, J. B., J. Geophys. Res., 36, 294-2956, 1993

  17. The Martian stratigraphy - Short review and perspectives (United States)

    Masson, P. L.


    The main aspects of the Martian stratigraphy have been determined from the detailed study of Mariner 9 and Viking Orbiter images. Three major stratigraphic systems, the Noachian System, the Hesperian System, and the Amazonian System, are inferred from these studies. Stratigraphy reveals that tectonism and volcanism were widespread during two major periods (Noachian and Lower Hesperian) and became more localized during the Upper Hesperian and Amazonian periods. The transition between these two major periods occurred about 2 Gyr ago, and significant geologic activity could still be present.

  18. Pb evolution in the Martian mantle (United States)

    Bellucci, J. J.; Nemchin, A. A.; Whitehouse, M. J.; Snape, J. F.; Bland, P.; Benedix, G. K.; Roszjar, J.


    The initial Pb compositions of one enriched shergottite, one intermediate shergottite, two depleted shergottites, and Nakhla have been measured by Secondary Ion Mass Spectrometry (SIMS). These values, in addition to data from previous studies using an identical analytical method performed on three enriched shergottites, ALH 84001, and Chassigny, are used to construct a unified and internally consistent model for the differentiation history of the Martian mantle and crystallization ages for Martian meteorites. The differentiation history of the shergottites and Nakhla/Chassigny are fundamentally different, which is in agreement with short-lived radiogenic isotope systematics. The initial Pb compositions of Nakhla/Chassigny are best explained by the late addition of a Pb-enriched component with a primitive, non-radiogenic composition. In contrast, the Pb isotopic compositions of the shergottite group indicate a relatively simple evolutionary history of the Martian mantle that can be modeled based on recent results from the Sm-Nd system. The shergottites have been linked to a single mantle differentiation event at 4504 Ma. Thus, the shergottite Pb isotopic model here reflects a two-stage history 1) pre-silicate differentiation (4504 Ma) and 2) post-silicate differentiation to the age of eruption (as determined by concordant radiogenic isochron ages). The μ-values (238U/204Pb) obtained for these two different stages of Pb growth are μ1 of 1.8 and a range of μ2 from 1.4-4.7, respectively. The μ1-value of 1.8 is in broad agreement with enstatite and ordinary chondrites and that proposed for proto Earth, suggesting this is the initial μ-value for inner Solar System bodies. When plotted against other source radiogenic isotopic variables (Sri, γ187Os, ε143Nd, and ε176Hf), the second stage mantle evolution range in observed mantle μ-values display excellent linear correlations (r2 > 0.85) and represent a spectrum of Martian mantle mixing-end members (depleted

  19. Performativity and Genesis of the Scene

    Directory of Open Access Journals (Sweden)

    Sílvia Fernandes


    Full Text Available From the recognition of the tension between reality and fiction in contemporary theatre, generally defined as theatre of the real, we intend to make an intersection of this phenomenon with the theoretical field of performativity, which focuses on the work in process, dynamic transformation and experience. The intention is to associate the theory of performativity to observations about the latest work of Theatre Vertigo, directed by Antonio Araujo, Bom Retiro 958 metros. The use of genetic ways to approach theatre will serve as a motto to interpret some aspects of the creative process and the scene.

  20. Image policy, subjectivation and argument scenes

    Directory of Open Access Journals (Sweden)

    Ângela Cristina Salgueiro Marques


    Full Text Available This paper is aimed at discussing, with focus on Jacques Rancière, how an image policy can be noticed in the creative production of scenes of dissent from which the political agent emerge, appears and constitute himself in a process of subjectivation. The political and critical power of the image is linked to survival acts: operations and attempts that enable to resist to captures, silences and excesses comitted by the media discourses, by the social institutions and by the State.

  1. The gay bashing scene chez Proust. (United States)

    Campbell, T


    This essay presents a contemporary translation of and brief commentary on the gay bashing scene found in Marcel Proust's A la Recherche du Temps perdu: Le Côté de Guermantes, Tome I. The paper notes that Proust argues in this passage for the acceptance of homosexuality for two main reasons: because gay bashing won't eradicate it; and because gayness is the simple, direct movement of a being toward perceived beauty. The paper suggests that Proust reveals his own gayness (and that of his protagonist) by employing the latter argument in defense of homosexuality whereas, throughout the novel, he presents heterosexual attraction as an immensely indirect, artistically manufactured construct.

  2. The trapped heavy noble gases in recently found Martian meteorites


    Busemann, H.; Eugster, O.


    The composition of the trapped Ar, Kr, and Xe in the Martian meteorites Los Angeles, Say Al Uhaymir 005/008, and 094 is discussed and found to be consistent with a mixture of Martian mantle and atmosphere noble gases and terrestrial contamination.

  3. Scene construction in developmental amnesia: An fMRI study☆ (United States)

    Mullally, Sinéad L.; Vargha-Khadem, Faraneh; Maguire, Eleanor A.


    Amnesic patients with bilateral hippocampal damage sustained in adulthood are generally unable to construct scenes in their imagination. By contrast, patients with developmental amnesia (DA), where hippocampal damage was acquired early in life, have preserved performance on this task, although the reason for this sparing is unclear. One possibility is that residual function in remnant hippocampal tissue is sufficient to support basic scene construction in DA. Such a situation was found in the one amnesic patient with adult-acquired hippocampal damage (P01) who could also construct scenes. Alternatively, DA patients’ scene construction might not depend on the hippocampus, perhaps being instead reliant on non-hippocampal regions and mediated by semantic knowledge. To adjudicate between these two possibilities, we examined scene construction during functional MRI (fMRI) in Jon, a well-characterised patient with DA who has previously been shown to have preserved scene construction. We found that when Jon constructed scenes he activated many of the regions known to be associated with imagining scenes in control participants including ventromedial prefrontal cortex, posterior cingulate, retrosplenial and posterior parietal cortices. Critically, however, activity was not increased in Jon's remnant hippocampal tissue. Direct comparisons with a group of control participants and patient P01, confirmed that they activated their right hippocampus more than Jon. Our results show that a type of non-hippocampal dependent scene construction is possible and occurs in DA, perhaps mediated by semantic memory, which does not appear to involve the vivid visualisation of imagined scenes. PMID:24231038

  4. Semantic guidance of eye movements in real-world scenes. (United States)

    Hwang, Alex D; Wang, Hsueh-Cheng; Pomplun, Marc


    The perception of objects in our visual world is influenced by not only their low-level visual features such as shape and color, but also their high-level features such as meaning and semantic relations among them. While it has been shown that low-level features in real-world scenes guide eye movements during scene inspection and search, the influence of semantic similarity among scene objects on eye movements in such situations has not been investigated. Here we study guidance of eye movements by semantic similarity among objects during real-world scene inspection and search. By selecting scenes from the LabelMe object-annotated image database and applying latent semantic analysis (LSA) to the object labels, we generated semantic saliency maps of real-world scenes based on the semantic similarity of scene objects to the currently fixated object or the search target. An ROC analysis of these maps as predictors of subjects' gaze transitions between objects during scene inspection revealed a preference for transitions to objects that were semantically similar to the currently inspected one. Furthermore, during the course of a scene search, subjects' eye movements were progressively guided toward objects that were semantically similar to the search target. These findings demonstrate substantial semantic guidance of eye movements in real-world scenes and show its importance for understanding real-world attentional control. Copyright © 2011 Elsevier Ltd. All rights reserved.

  5. A Thermal Plume Model for the Martian Convective Boundary Layer

    CERN Document Server

    Colaïtis, Arnaud; Hourdin, Frédéric; Rio, Catherine; Forget, François; Millour, Ehouarn


    The Martian Planetary Boundary Layer [PBL] is a crucial component of the Martian climate system. Global Climate Models [GCMs] and Mesoscale Models [MMs] lack the resolution to predict PBL mixing which is therefore parameterized. Here we propose to adapt the "thermal plume" model, recently developed for Earth climate modeling, to Martian GCMs, MMs, and single-column models. The aim of this physically-based parameterization is to represent the effect of organized turbulent structures (updrafts and downdrafts) on the daytime PBL transport, as it is resolved in Large-Eddy Simulations [LESs]. We find that the terrestrial thermal plume model needs to be modified to satisfyingly account for deep turbulent plumes found in the Martian convective PBL. Our Martian thermal plume model qualitatively and quantitatively reproduces the thermal structure of the daytime PBL on Mars: superadiabatic near-surface layer, mixing layer, and overshoot region at PBL top. This model is coupled to surface layer parameterizations taking ...

  6. Integration and segregation in auditory scene analysis (United States)

    Sussman, Elyse S.


    Assessment of the neural correlates of auditory scene analysis, using an index of sound change detection that does not require the listener to attend to the sounds [a component of event-related brain potentials called the mismatch negativity (MMN)], has previously demonstrated that segregation processes can occur without attention focused on the sounds and that within-stream contextual factors influence how sound elements are integrated and represented in auditory memory. The current study investigated the relationship between the segregation and integration processes when they were called upon to function together. The pattern of MMN results showed that the integration of sound elements within a sound stream occurred after the segregation of sounds into independent streams and, further, that the individual streams were subject to contextual effects. These results are consistent with a view of auditory processing that suggests that the auditory scene is rapidly organized into distinct streams and the integration of sequential elements to perceptual units takes place on the already formed streams. This would allow for the flexibility required to identify changing within-stream sound patterns, needed to appreciate music or comprehend speech..

  7. Recognition and Memory for Briefly Presented Scenes (United States)

    Potter, Mary C.


    Three times per second, our eyes make a new fixation that generates a new bottom-up analysis in the visual system. How much is extracted from each glimpse? For how long and in what form is that information remembered? To answer these questions, investigators have mimicked the effect of continual shifts of fixation by using rapid serial visual presentation of sequences of unrelated pictures. Experiments in which viewers detect specified target pictures show that detection on the basis of meaning is possible at presentation durations as brief as 13 ms, suggesting that understanding may be based on feedforward processing, without feedback. In contrast, memory for what was just seen is poor unless the viewer has about 500 ms to think about the scene: the scene does not need to remain in view. Initial memory loss after brief presentations occurs over several seconds, suggesting that at least some of the information from the previous few fixations persists long enough to support a coherent representation of the current environment. In contrast to marked memory loss shortly after brief presentations, memory for pictures viewed for 1 s or more is excellent. Although some specific visual information persists, the form and content of the perceptual and memory representations of pictures over time indicate that conceptual information is extracted early and determines most of what remains in longer-term memory. PMID:22371707

  8. Martian Soil Ready for Robotic Laboratory Analysis (United States)


    NASA's Phoenix Mars Lander scooped up this Martian soil on the mission's 11th Martian day, or sol, after landing (June 5, 2008) as the first soil sample for delivery to the laboratory on the lander deck. The material includes a light-toned clod possibly from crusted surface of the ground, similar in appearance to clods observed near a foot of the lander. This approximately true-color view of the contents of the scoop on the Robotic Arm comes from combining separate images taken by the Robotic Arm Camera on Sol 11, using illumination by red, green and blue light-emitting diodes on the camera. The scoop loaded with this sample was poised over an open sample-delivery door of Thermal and Evolved-Gas Analyzer at the end of Sol 11, ready to be dumped into the instrument on the next sol. 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.

  9. Physicochemical properties of concentrated Martian surface waters (United States)

    Tosca, Nicholas J.; McLennan, Scott M.; Lamb, Michael P.; Grotzinger, John P.


    Understanding the processes controlling chemical sedimentation is an important step in deciphering paleoclimatic conditions from the rock records preserved on both Earth and Mars. Clear evidence for subaqueous sedimentation at Meridiani Planum, widespread saline mineral deposits in the Valles Marineris region, and the possible role of saline waters in forming recent geomorphologic features all underscore the need to understand the physical properties of highly concentrated solutions on Mars in addition to, and as a function of, their distinct chemistry. Using thermodynamic models predicting saline mineral solubility, we generate likely brine compositions ranging from bicarbonate-dominated to sulfate-dominated and predict their saline mineralogy. For each brine composition, we then estimate a number of thermal, transport, and colligative properties using established models that have been developed for highly concentrated multicomponent electrolyte solutions. The available experimental data and theoretical models that allow estimation of these physicochemical properties encompass, for the most part, much of the anticipated variation in chemistry for likely Martian brines. These estimates allow significant progress in building a detailed analysis of physical sedimentation at the ancient Martian surface and allow more accurate predictions of thermal behavior and the diffusive transport of matter through chemically distinct solutions under comparatively nonstandard conditions.

  10. Martian cratering. II - Asteroid impact history. (United States)

    Hartmann, W. K.


    This paper considers the extent to which Martian craters can be explained by considering asteroidal impact. Sections I, II, and III of this paper derive the diameter distribution of hypothetical asteroidal craters on Mars from recent Palomar-Leiden asteroid statistics and show that the observed Martian craters correspond to a bombardment by roughly 100 times the present number of Mars-crossing asteroids. Section IV discusses the early bombardment history of Mars, based on the capture theory of Opik and probable orbital parameters of early planetesimals. These results show that the visible craters and surface of Mars should not be identified with the initial, accreted surface. A backward extrapolation of the impact rates based on surviving Mars-crossing asteroids can account for the majority of Mars craters over an interval of several aeons, indicating that we see back in time no further than part-way into a period of intense bombardment. An early period of erosion and deposition is thus suggested. Section V presents a comparison with results and terminology of other authors.

  11. Electrical Breakdown in a Martian Gas Mixture (United States)

    Buhler, C. R.; Calle, C. I.; Nelson, E.


    The high probability for dust interactions during Martian dust storms and dust devils combined with the cold, dry climate of Mars most likely result in airborne dust that is highly charged. On Earth, potential gradients up to 5 kV/m have been recorded and in some cases resulted in lightning. Although the Martian atmosphere is not conducive to lightning generation, it is widely believed that electrical discharge in the form of a corona occurs. In order to understand the breakdown of gases, Paschen measurements are taken which relate the minimum potential required to spark across a gap between two electrodes. The minimum potential is plotted versus the pressure-distance value for electrodes of a given geometry. For most gases, the potential decreases as the pressure decreases. For CO2, the minimum in the curve happens to be at Mars atmospheric pressures (5-7 mm Hg) for many distances and geometries. However, a very small amount (mixing gases radically changes the curve, as noted by Leach. Here, we present the first experimental results of a Paschen curve for a Mars gas mixture compared with 100% pure CO2.

  12. The scene and the unseen: manipulating photographs for experiments on change blindness and scene memory: image manipulation for change blindness. (United States)

    Ball, Felix; Elzemann, Anne; Busch, Niko A


    The change blindness paradigm, in which participants often fail to notice substantial changes in a scene, is a popular tool for studying scene perception, visual memory, and the link between awareness and attention. Some of the most striking and popular examples of change blindness have been demonstrated with digital photographs of natural scenes; in most studies, however, much simpler displays, such as abstract stimuli or "free-floating" objects, are typically used. Although simple displays have undeniable advantages, natural scenes remain a very useful and attractive stimulus for change blindness research. To assist researchers interested in using natural-scene stimuli in change blindness experiments, we provide here a step-by-step tutorial on how to produce changes in natural-scene images with a freely available image-processing tool (GIMP). We explain how changes in a scene can be made by deleting objects or relocating them within the scene or by changing the color of an object, in just a few simple steps. We also explain how the physical properties of such changes can be analyzed using GIMP and MATLAB (a high-level scientific programming tool). Finally, we present an experiment confirming that scenes manipulated according to our guidelines are effective in inducing change blindness and demonstrating the relationship between change blindness and the physical properties of the change and inter-individual differences in performance measures. We expect that this tutorial will be useful for researchers interested in studying the mechanisms of change blindness, attention, or visual memory using natural scenes.

  13. Places: A 10 million Image Database for Scene Recognition. (United States)

    Zhou, Bolei; Lapedriza, Agata; Khosla, Aditya; Oliva, Aude; Torralba, Antonio


    The rise of multi-million-item dataset initiatives has enabled data-hungry machine learning algorithms to reach near-human semantic classification performance at tasks such as visual object and scene recognition. Here we describe the Places Database, a repository of 10 million scene photographs, labeled with scene semantic categories, comprising a large and diverse list of the types of environments encountered in the world. Using the state-of-the-art Convolutional Neural Networks (CNNs), we provide scene classification CNNs (Places-CNNs) as baselines, that significantly outperform the previous approaches. Visualization of the CNNs trained on Places shows that object detectors emerge as an intermediate representation of scene classification. With its high-coverage and high-diversity of exemplars, the Places Database along with the Places-CNNs offer a novel resource to guide future progress on scene recognition problems.

  14. Global scene layout modulates contextual learning in change detection. (United States)

    Conci, Markus; Müller, Hermann J


    Change in the visual scene often goes unnoticed - a phenomenon referred to as "change blindness." This study examined whether the hierarchical structure, i.e., the global-local layout of a scene can influence performance in a one-shot change detection paradigm. To this end, natural scenes of a laid breakfast table were presented, and observers were asked to locate the onset of a new local object. Importantly, the global structure of the scene was manipulated by varying the relations among objects in the scene layouts. The very same items were either presented as global-congruent (typical) layouts or as global-incongruent (random) arrangements. Change blindness was less severe for congruent than for incongruent displays, and this congruency benefit increased with the duration of the experiment. These findings show that global layouts are learned, supporting detection of local changes with enhanced efficiency. However, performance was not affected by scene congruency in a subsequent control experiment that required observers to localize a static discontinuity (i.e., an object that was missing from the repeated layouts). Our results thus show that learning of the global layout is particularly linked to the local objects. Taken together, our results reveal an effect of "global precedence" in natural scenes. We suggest that relational properties within the hierarchy of a natural scene are governed, in particular, by global image analysis, reducing change blindness for local objects through scene learning.

  15. Global scene layout modulates contextual learning in change detection

    Directory of Open Access Journals (Sweden)

    Markus eConci


    Full Text Available Change in the visual scene often goes unnoticed – a phenomenon referred to as ‘change blindness’. This study examined whether the hierarchical structure, i.e., the global-local layout of a scene can influence performance in a one-shot change detection paradigm. To this end, natural scenes of a laid breakfast table were presented, and observers were asked to locate the onset of a new local object. Importantly, the global structure of the scene was manipulated by varying the relations among objects in the scene layouts. The very same items were either presented as global-congruent (typical layouts or as global-incongruent (random arrangements. Change blindness was less severe for congruent than for incongruent displays, and this congruency benefit increased with the duration of the experiment. These findings show that global layouts are learned, supporting detection of local changes with enhanced efficiency. However, performance was not affected by scene congruency in a subsequent control experiment that required observers to localize a static discontinuity (i.e., an object that was missing from the repeated layouts. Our results thus show that learning of the global layout is particularly linked to the local objects. Taken together, our results reveal an effect of global precedence in natural scenes. We suggest that relational properties within the hierarchy of a natural scene are governed, in particular, by global image analysis, reducing change blindness for local objects through scene learning.

  16. Mapping and analysis of Martian landslides (United States)

    Crosta, Giovanni B.; Frattini, Paolo; Valbuzzi, Elena; Russo, Valeria


    This work is part of a larger effort aimed to a more quantitative description of landslide phenomena on Mars and the understanding of rock mass properties and landslide mobility with respect to their Earth equivalents. Recently, large satellite imagery datasets have become available and they have been mosaicked in different suitable tools making mapping an easier job than before. Furthermore, the availability of other georeferenced database makes possible and easily feasible some spatially distributed analyses. We prepared a new landslide inventory to acquire information about: landslide size distribution and areal density, controls of geometrical condition along Martian slopes, landslide typology and mechanism, relationship with impact craters distribution, runout, volume estimates, characteristic features. We adopted Google Earth, Google, Inc. as a mapping tool using both visible and CTX images. Landslides have been mapped according to standard geomorphological criteria, by two landslide experts delineating both the landslide scar and accumulation limits, associating each scarp to a deposit. Multiple accumulations have been differentiated where possible to obtain a more sound dataset. We prevalently mapped landslides located along the Martian valleys and Chasma flanks with only minor attention to classical block and slump instabilities typical of crater rim failures. This because we were mainly interested in long runout landslides or complex failures which could allow to define some rock mass characteristics along these slopes, and to study landslide mobility with respect to Earth equivalent phenomena. So long runout landslides have been mapped also when recognized within crater rims. Topographic characteristics have been extracted by means of the available MOLA dataset. The inventory presently consists of 1232 landslides covering a total area of about 180,000 km2. Landslide size ranges from 0.15 km2 to a maximum of 12,000 km2. We examined area

  17. Testing and Model Correlation of Sublimator Driven Coldplate Coupons and EDU (United States)

    Leimkuehler, Thomas O.


    The Sublimator Driven Coldplate (SDC) is a unique piece of thermal control hardware that has several advantages over a more traditional thermal control system. The principal advantage is the possible elimination of a pumped fluid loop, potentially saving mass, power, and complexity. Because this concept relies on evaporative heat rejection techniques, it is primarily useful for short mission durations. Additionally, the concept requires a conductive path between the heat-generating component and the heat rejection device. Therefore, it is mostly a relevant solution for a vehicle with a relatively low heat rejection requirement and/or short transport distances. Tests were performed on coupons and an Engineering Development Unit (EDU) at NASA s Johnson Space Center to better understand the basic operational principles and to validate the analytical methods being used for the SDC development. This paper outlines the results of the SDC tests, the subsequent thermal model correlation, and a description of the SDC Engineering Development Unit test results.

  18. Optimized heat exchange in a CO2 de-sublimation process (United States)

    Baxter, Larry; Terrien, Paul; Tessier, Pascal; Hoeger, Christopher


    The present invention is a process for removing carbon dioxide from a compressed gas stream including cooling the compressed gas in a first heat exchanger, introducing the cooled gas into a de-sublimating heat exchanger, thereby producing a first solid carbon dioxide stream and a first carbon dioxide poor gas stream, expanding the carbon dioxide poor gas stream, thereby producing a second solid carbon dioxide stream and a second carbon dioxide poor gas stream, combining the first solid carbon dioxide stream and the second solid carbon dioxide stream, thereby producing a combined solid carbon dioxide stream, and indirectly exchanging heat between the combined solid carbon dioxide stream and the compressed gas in the first heat exchanger.

  19. Main-belt comets: sublimation-driven activity in the asteroid belt (United States)

    Hsieh, Henry H.


    Our knowledge of main-belt comets (MBCs), which exhibit comet-like activity likely due to the sublimation of volatile ices, yet orbit in the main asteroid belt, has increased greatly since the discovery of the first known MBC, 133P/Elst-Pizarro, in 1996, and their recognition as a new class of solar system objects after the discovery of two more MBCs in 2005. I review work that has been done over the last 10 years to improve our understanding of these enigmatic objects, including the development of systematic discovery methods and diagnostics for distinguishing MBCs from disrupted asteroids (which exhibit comet-like activity due to physical disruptions such as impacts or rotational destabilization). I also discuss efforts to understand the dynamical and thermal properties of these objects.

  20. Paths of the Sublime: Alain de Botton’s The Art of Travel

    Directory of Open Access Journals (Sweden)

    M.C.C. Mendes


    Full Text Available Bearing in mind the central place of literary, academic, and religious tourism in Cultural Studies and in Alain de Botton’s The Art of Travel (2002, the paper seeks: 1 to identify some remarkable travels of famous writers – the British Wordsworth; the French Karl-Joris Huysmans, Gustave Flaubert, and Charles Baudelaire; 2 to show that in the analysis of such authors’ itineraries (from Europe to the East, there is a search for cultural roots, a mapping of spaces and people, and a deconstruction of labels often related to the Other; 3 to point out that the tourist is also a storyteller, a protagonist, and a creator of fictional worlds; 4 to bring together literary tourism and artistic tourism, through the identification of allusions to other cultural events (painting, music, and architecture; 5 to characterize tourism as a literary and aesthetic experience of the Sublime.

  1. Effect of Zn doping on the sublimation rate of pentaerythritol tetranitrate using atomic force microscopy. (United States)

    Mridha, Subrata; Weeks, Brandon L


    A series of Zn ion-doped pentaerythritol tetranitrate (PETN) nanoislands in the form of thin films were prepared on Si substrates using spin coating. The effect of Zn concentrations on the sublimation energy was investigated by atomic force microscopy (AFM). The pure and Zn-doped nanoislands are imaged by AFM in contact mode at room temperature after annealing isothermally for a given time. The volume of the islands starts to decrease after annealing at 45 degrees C for pure PETN, whereas Zn-doped nanoislands start to decrease in height and volume after annealing at 55-58 degrees C. The minimum activation energy is found to be 29.7 Kcal/mol for 1,000 ppm Zn concentration. These studies are important for the long-term stabilization of PETN.

  2. Characteristics of Vacuum Freeze Drying with Utilization of Internal Cooling and Condenser Waste Heat for Sublimation

    Directory of Open Access Journals (Sweden)

    Muhammad Alhamid


    Full Text Available Vacuum freeze drying is an excellent drying method, but it is very energy-intensive because a relatively long drying time is required. This research investigates the utilization of condenser waste heat for sublimation as a way of accelerating the drying rate. In addition, it also investigates the effect of internal cooling combined with vacuum cooling in the pressure reduction process. Jelly fish tentacles were used as the specimen, with different configurations for condenser heat waste and internal cooling valve opening. The results show that heating with condenser heat waste can accelerate the drying rate up to 0.0035 kg/m2.s. In addition, pre-freezing by internal cooling prevents evaporation until the mass of the specimen is 0.47 g and promotes transition of the specimen into the solid phase.

  3. Formation of the molecular crystal structure during the vacuum sublimation of paracetamol (United States)

    Belyaev, A. P.; Rubets, V. P.; Antipov, V. V.; Bordei, N. S.


    The results from structural and thermal studies on the formation of molecular crystals during the vacuum sublimation of paracetamol from its vapor phase are given. It is established that the vapor-crystal phase transition proceeds in a complicated way as the superposition of two phase transitions: a first-order phase transition with a change in density, and a second-order phase transition with a change in ordering. It is shown that the latter is a smeared phase transition that proceeds with the formation of a pretransitional phase that is irreversibly dissipated during phase transformation, leading to the formation of crystals of the rhombic syngony. Data from differential scanning calorimetry and X-ray diffraction analysis are presented along with microphotographs.

  4. Review network for scene text recognition (United States)

    Li, Shuohao; Han, Anqi; Chen, Xu; Yin, Xiaoqing; Zhang, Jun


    Recognizing text in images captured in the wild is a fundamental preprocessing task for many computer vision and machine learning applications and has gained significant attention in recent years. This paper proposes an end-to-end trainable deep review neural network for scene text recognition, which is a combination of feature extraction, feature reviewing, feature attention, and sequence recognition. Our model can generate the predicted text without any segmentation or grouping algorithm. Because the attention model in the feature attention stage lacks global modeling ability, a review network is applied to extract the global context of sequence data in the feature reviewing stage. We perform rigorous experiments across a number of standard benchmarks, including IIIT5K, SVT, ICDAR03, and ICDAR13 datasets. Experimental results show that our model is comparable to or outperforms state-of-the-art techniques.

  5. Wall grid structure for interior scene synthesis

    KAUST Repository

    Xu, Wenzhuo


    We present a system for automatically synthesizing a diverse set of semantically valid, and well-arranged 3D interior scenes for a given empty room shape. Unlike existing work on layout synthesis, that typically knows potentially needed 3D models and optimizes their location through cost functions, our technique performs the retrieval and placement of 3D models by discovering the relationships between the room space and the models\\' categories. This is enabled by a new analytical structure, called Wall Grid Structure, which jointly considers the categories and locations of 3D models. Our technique greatly reduces the amount of user intervention and provides users with suggestions and inspirations. We demonstrate the applicability of our approach on three types of scenarios: conference rooms, living rooms and bedrooms.

  6. Using Ignorance in 3D Scene Understanding

    Directory of Open Access Journals (Sweden)

    Bogdan Harasymowicz-Boggio


    Full Text Available Awareness of its own limitations is a fundamental feature of the human sight, which has been almost completely omitted in computer vision systems. In this paper we present a method of explicitly using information about perceptual limitations of a 3D vision system, such as occluded areas, limited field of view, loss of precision along with distance increase, and imperfect segmentation for a better understanding of the observed scene. The proposed mechanism integrates metric and semantic inference using Dempster-Shafer theory, which makes it possible to handle observations that have different degrees and kinds of uncertainty. The system has been implemented and tested in a real indoor environment, showing the benefits of the proposed approach.

  7. Algorithms for Graph Rigidity and Scene Analysis

    DEFF Research Database (Denmark)

    Berg, Alex Rune; Jordán, Tibor


    We investigate algorithmic questions and structural problems concerning graph families defined by `edge-counts'. Motivated by recent developments in the unique realization problem of graphs, we give an efficient algorithm to compute the rigid, redundantly rigid, M-connected, and globally rigid...... components of a graph. Our algorithm is based on (and also extends and simplifies) the idea of Hendrickson and Jacobs, as it uses orientations as the main algorithmic tool. We also consider families of bipartite graphs which occur in parallel drawings and scene analysis. We verify a conjecture of Whiteley...... by showing that 2d-connected bipartite graphs are d-tight. We give a new algorithm for finding a maximal d-sharp subgraph. We also answer a question of Imai and show that finding a maximum size d-sharp subgraph is NP-hard....

  8. [A doctor's action within possible crime scene]. (United States)

    Sowizdraniuk, Joanna


    Every doctor regardless of specialization in his practice may meet the need to provide assistance to victims of crime-related action. In this article there were disscused the issues of informing the investigative authorities about the crime, ensuring the safety of themselves and the environment at the scene. It also shows the specific elements of necessary procedures and practice to deal with the victims designed to securing any evidence present of potential or committed crime in proper manner. Special attention has been given to medical operation and other, necessary in case of certain criminal groups, among the latter we need to underline: actions against sexual freedom and decency, bodily integrity, life and well-being of human, and specially homicide, infanticide and suicide.

  9. The scene is set for ALICE

    CERN Multimedia


    Now that the electromagnetic calorimeter support and the mini space frame have been installed, practically all ALICE’s infrastructure is in place. The calorimeter support, an austenitic stainless steel shell weighing 30 tonnes, was slid gently inside the detector, in between the face of the magnet and the space frame. With the completion of two major installation projects, the scene is finally set for the ALICE experiment…or at least it nearly is, as a few design studies, minor installation jobs and measurements still need to be carried out before the curtain can finally be raised. The experiment’s chief engineer Diego Perini confirms: "All the heavy infrastructure for ALICE has been in place and ready for the grand opening since December 2007." The next step will be the installation of additional modules on the TOF and TRD detectors between January and March 2008, and physicists have already started testing the equipment with co...

  10. Taking a Hike and Hucking the Stout: The Troublesome Legacy of the Sublime in Outdoor Recreation

    Directory of Open Access Journals (Sweden)

    Georg Drennig


    Full Text Available As Henry Thoreau noted in the 1850s, the simple act of walking can be loaded with political and spiritual meaning. Today, taking a hike as an act of engaging in outdoor recreation is equally non-trivial, and therefore subject of the following analysis. As this paper argues, outdoors recreation is still influenced by the legacy of the Sublime and its construction of wilderness. This troublesome legacy means that the cultural self-representation of outdoor sports – and the practice itself – lays claim to the environment in ways that are socially and sometimes even ethni-cally exclusive. This essay uses William Cronon’s critique of the cultural constructedness of wilderness as a point of departure to see how Western notions of sublime nature have an impact on spatial practice. The elevation of specific parts of the environ-ment into the category of wilderness prescribes certain uses and meanings as na-ture is made into an antidote against the ills of industrial civilization, and a place where the alienated individual can return to a more authentic self. This view then has become a troublesome legacy, informing the cultural self-representation of those uses of “wilderness” that are known as outdoor recreation. In its cultural production, outdoors recreation constructs “healthy” and “athlet-ic” bodies exercising in natural settings and finding refuge from the everyday al-ienation of postmodern society. Yet these bodies are conspicuously white, and the obligatory equipment and fashion expensive. Outdoor recreation is a privileged assertion of leisure, often denoting an urban, affluent, and white, background of the practitioner. These practitioners then lay exclusive claim on the landscapes they use. As trivial as taking a hike or any other form of outdoors recreation may thus seem, they put a cultural legacy into practice that is anything but trivial.

  11. Mass spectrometric study of molecular and ionic sublimation of lanthanum triiodide

    Energy Technology Data Exchange (ETDEWEB)

    Dunaev, A.M., E-mail: [Research Institute of Thermodynamics and Kinetics, Ivanovo State University of Chemistry and Technology, Ivanovo 153000 (Russian Federation); Kudin, L.S.; Motalov, V.B.; Ivanov, D.A.; Butman, M.F. [Research Institute of Thermodynamics and Kinetics, Ivanovo State University of Chemistry and Technology, Ivanovo 153000 (Russian Federation); Krämer, K.W. [Department of Chemistry and Biochemistry, University of Bern, CH-3012 Bern (Switzerland)


    Graphical abstract: - Highlights: • Lanthanum triiodide was investigated by the Knudsen effusion mass spectrometry. • (LaI{sub 3}){sub n} molecules (n = 1–3) and [I(LaI{sub 3}){sub n}]{sup −} ions (n = 0–4) were registered in the saturated vapor. • The sublimation enthalpy was found by the second and third law of thermodynamics. • The enthalpies of ion-molecular reactions with cluster ions were calculated. • The electron work function of the crystalline LaI{sub 3} was obtained. - Abstract: The molecular and ionic composition of saturated vapor over lanthanum triiodide was studied by Knudsen effusion mass spectrometry. The (LaI{sub 3}){sub n} molecules (n = 1–3) and the [I(LaI{sub 3}){sub n}]{sup −} ions (n = 0–4) were observed. The partial pressures of the molecules were determined and the enthalpies of sublimation, Δ{sub s}H° (298.15 K) in kJ mol{sup −1}, in the form of monomers (304 ± 7), dimers (428 ± 25), and trimers (455 ± 50) were obtained by the second and third laws of thermodynamics. The enthalpy of formation, Δ{sub f}H° (298.15 K) in kJ mol{sup −1}, of the LaI{sub 3} (−376 ± 10), La{sub 2}I{sub 6} (−932 ± 25), La{sub 3}I{sub 9} (−1585 ± 50) molecules and the LaI{sub 4}{sup −} (−841 ± 24), La{sub 2}I{sub 7}{sup −} (−1486 ± 32) ions were determined. The electron work function, φ{sub e} = 3.5 ± 0.3 eV, for the LaI{sub 3} crystal was calculated from the thermochemical cycle.

  12. Fe embedded in ice: The impacts of sublimation and energetic particle bombardment (United States)

    Frankland, Victoria L.; Plane, John M. C.


    Icy particles containing a variety of Fe compounds are present in the upper atmospheres of planets such as the Earth and Saturn. In order to explore the role of ice sublimation and energetic ion bombardment in releasing Fe species into the gas phase, Fe-dosed ice films were prepared under UHV conditions in the laboratory. Temperature-programmed desorption studies of Fe/H2O films revealed that no Fe atoms or Fe-containing species co-desorbed along with the H2O molecules. This implies that when noctilucent ice cloud particles sublimate in the terrestrial mesosphere, the metallic species embedded in them will coalesce to form residual particles. Sputtering of the Fe-ice films by energetic Ar+ ions was shown to be an efficient mechanism for releasing Fe into the gas phase, with a yield of 0.08 (Ar+ energy=600 eV). Extrapolating with a semi-empirical sputtering model to the conditions of a proton aurora indicates that sputtering by energetic protons (>100 keV) should also be efficient. However, the proton flux in even an intense aurora will be too low for the resulting injection of Fe species into the gas phase to compete with that from meteoric ablation. In contrast, sputtering of the icy particles in the main rings of Saturn by energetic O+ ions may be the source of recently observed Fe+ in the Saturnian magnetosphere. Electron sputtering (9.5 keV) produced no detectable Fe atoms or Fe-containing species. Finally, it was observed that Fe(OH)2 was produced when Fe was dosed onto an ice film at 140 K (but not at 95 K). Electronic structure theory shows that the reaction which forms this hydroxide from adsorbed Fe has a large barrier of about 0.7 eV, from which we conclude that the reaction requires both translationally hot Fe atoms and mobile H2O molecules on the ice surface.

  13. Formulation design and optimization of fast dissolving clonazepam tablets by sublimation method. (United States)

    Shirsand, S B; Suresh, Sarasija; Kusumdevi, V; Swamy, P V


    Fast dissolving tablets of clonazepam were prepared by sublimation method with a view to enhance patient compliance. A 3(2) full factorial design was applied to investigate the combined effect of two formulation variables: amount of croscarmellose sodium and camphor. Croscarmellose sodium (2-8% w/w) was used as superdisintegrant and camphor (20-40% w/w) was used as subliming agent, to increase the porosity of the tablets, since it helps water to penetrate into the tablets, along with directly compressible mannitol to enhance mouth feel. The tablets were evaluated for hardness, friability, thickness, drug content uniformity, in vitro dispersion time, wetting time and water absorption ratio. Based on in vitro dispersion time (approximately 11 s); the formulation containing 5% w/w croscarmellose sodium and 40% w/w camphor was found to be promising and tested for in vitro drug release pattern (in pH 6.8 phosphate buffer). Short-term stability (at 40°/75% relative humidity for 3 mo) and drug-excipient interaction. Surface response plots are presented to graphically represent the effect of independent variables on the in vitro dispersion time. The validity of the generated mathematical model was tested by preparing two extra-design checkpoints. The optimized tablet formulation was compared with conventional commercial tablet formulation for drug release profiles. This formulation showed nearly nine-fold faster drug release (t(50%) 1.8 min) compared to the conventional commercial tablet formulation (t(50%) 16.4 min). Short-term stability studies on the formulation indicated that there are no significant changes in drug content and in vitro dispersion time (P<0.05).

  14. The fate of meteoric metals in ice particles: Effects of sublimation and energetic particle bombardment (United States)

    Mangan, T. P.; Frankland, V. L.; Murray, B. J.; Plane, J. M. C.


    The uptake and potential reactivity of metal atoms on water ice can be an important process in planetary atmospheres and on icy bodies in the interplanetary and interstellar medium. For instance, metal atom uptake affects the gas-phase chemistry of the Earth's mesosphere, and has been proposed to influence the agglomeration of matter into planets in protoplanetary disks. In this study the fate of Mg and K atoms incorporated into water-ice films, prepared under ultra-high vacuum conditions at temperatures of 110-140 K, was investigated. Temperature-programmed desorption experiments reveal that Mg- and K-containing species do not co-desorb when the ice sublimates, demonstrating that uptake on ice particles causes irreversible removal of the metals from the gas phase. This implies that uptake on ice particles in terrestrial polar mesospheric clouds accelerates the formation of large meteoric smoke particles (≥1 nm radius above 80 km) following sublimation of the ice. Energetic sputtering of metal-dosed ice layers by 500 eV Ar+ and Kr+ ions shows that whereas K reacts on (or within) the ice surface to form KOH, adsorbed Mg atoms are chemically inert. These experimental results are consistent with electronic structure calculations of the metals bound to an ice surface, where theoretical adsorption energies on ice are calculated to be -68 kJ mol-1 for K, -91 kJ mol-1 for Mg, and -306 kJ mol-1 for Fe. K can also insert into a surface H2O to produce KOH and a dangling H atom, in a reaction that is slightly exothermic.

  15. The Sublime Corpse in Gertrudis Gomez de Avellaneda's Women's Journal "Album Cubano de lo Bueno y lo Bello" (1860) (United States)

    LaGreca, Nancy


    This article examines Gertrudis Gomez de Avellaneda's choice to include articles depicting the advanced decay of cadavers, which are simultaneously horrible and awesome, in her women's periodical "Album Cubano de lo Bueno y lo Bello". Background on Avellaneda's biography, women's print culture, and theories of the sublime provide a frame for the…

  16. Evidence for a Second Martian Dynamo from Electron Reflection Magnetometry (United States)

    Lillis, R. J.; Manga, M.; Mitchell, D. L.; Lin, R. P.; Acuna, M. H.


    Present-day Mars does not possess an active core dynamo and associated global magnetic field. However, the discovery of intensely magnetized crust in Mars Southern hemisphere implies that a Martian dynamo has existed in the past. Resolving the history of the Martian core dynamo is important for understanding the evolution of the planet's interior. Moreover, because the global magnetic field provided by an active dynamo can shield the atmosphere from erosion by the solar wind, it may have influenced past Martian climate. Additional information is included in the original extended abstract.

  17. The Martian highland paterae: Evidence for explosive volcanism on Mars (United States)

    Crown, David A.; Greeley, Ronald


    The Martian surface exhibits numerous volcanic landforms displaying great diversity in size, age, and morphology. Most research regarding Martian volcanology has centered around effusive basaltic volcanism, including analyses of individual lava flows, extensive lava plains, and large shield volcanoes. These studies were hindered by a lack of definitive morphologic criteria for the remote identification of ash deposits. Knowledge of the abundances, ages, and geologic settings of explosive volcanic deposits on Mars is essential to a comprehensive understanding of the evolution of the Martian surface, with implications for the evolution of the lithosphere and atmosphere as well as the histories of specific volcanic centers and provinces.

  18. Rover's Wheel Churns Up Bright Martian Soil (United States)


    NASA's Mars Exploration Rover Spirit acquired this mosaic on the mission's 1,202nd Martian day, or sol (May 21, 2007), while investigating the area east of the elevated plateau known as 'Home Plate' in the 'Columbia Hills.' The mosaic shows an area of disturbed soil, nicknamed 'Gertrude Weise' by scientists, made by Spirit's stuck right front wheel. The trench exposed a patch of nearly pure silica, with the composition of opal. It could have come from either a hot-spring environment or an environment called a fumarole, in which acidic, volcanic steam rises through cracks. Either way, its formation involved water, and on Earth, both of these types of settings teem with microbial life. Spirit acquired this mosaic with the panoramic camera's 753-nanometer, 535-nanometer, and 432-nanometer filters. The view presented here is an approximately true-color rendering.

  19. Stratigraphy of the Martian northern plains (United States)

    Tanaka, K. L.


    The northern plains of Mars are roughly defined as the large continuous region of lowlands that lies below Martian datum, plus higher areas within the region that were built up by volcanism, sedimentation, tectonism, and impacts. These northern lowlands span about 50 x 10(exp 6) km(sup 2) or 35 percent of the planet's surface. The age and origin of the lowlands continue to be debated by proponents of impact and tectonic explanations. Geologic mapping and topical studies indicate that volcanic, fluvial, and eolian deposition have played major roles in the infilling of this vast depression. Periglacial, glacial, fluvial, eolian, tectonic, and impact processes have locally modified the surface. Because of the northern plains' complex history of sedimentation and modification, much of their stratigraphy was obscured. Thus the stratigraphy developed is necessarily vague and provisional: it is based on various clues from within the lowlands as well as from highland areas within and bordering the plains. The results are summarized.

  20. Degradation of Adenine on the Martian Surface in the Presence of Perchlorates and Ionizing Radiation: A Reflectron Time-of-flight Mass Spectrometric Study

    Energy Technology Data Exchange (ETDEWEB)

    Góbi, Sándor; Bergantini, Alexandre; Kaiser, Ralf I., E-mail: [Department of Chemistry, University of Hawaii at Mānoa, Honolulu, HI 96822 (United States)


    The aim of the present work is to unravel the radiolytic decomposition of adenine (C{sub 5}H{sub 5}N{sub 5}) under conditions relevant to the Martian surface. Being the fundamental building block of (deoxy)ribonucleic acids, the possibility of survival of this biomolecule on the Martian surface is of primary importance to the astrobiology community. Here, neat adenine and adenine–magnesium perchlorate mixtures were prepared and irradiated with energetic electrons that simulate the secondary electrons originating from the interaction of the galactic cosmic rays with the Martian surface. Perchlorates were added to the samples since they are abundant—and therefore relevant oxidizers on the surface of Mars—and they have been previously shown to facilitate the radiolysis of organics such as glycine. The degradation of the samples were monitored in situ via Fourier transformation infrared spectroscopy and the electron ionization quadruple mass spectrometric method; temperature-programmed desorption profiles were then collected by means of the state-of-the-art single photon photoionization reflectron time-of-flight mass spectrometry (PI-ReTOF-MS), allowing for the detection of the species subliming from the sample. The results showed that perchlorates do increase the destruction rate of adenine by opening alternative reaction channels, including the concurrent radiolysis/oxidation of the sample. This new pathway provides a plethora of different radiolysis products that were identified for the first time. These are carbon dioxide (CO{sub 2}), isocyanic acid (HNCO), isocyanate (OCN{sup −}), carbon monoxide (CO), and nitrogen monoxide (NO); an oxidation product containing carbonyl groups (R{sub 1}R{sub 2}–C=O) with a constrained five-membered cyclic structure could also be observed. Cyanamide (H{sub 2}N–C≡N) was detected in both irradiated samples as well.

  1. Informational factors in identifying environmental sounds in natural auditory scenes. (United States)

    Leech, Robert; Gygi, Brian; Aydelott, Jennifer; Dick, Frederic


    In a non-linguistic analog of the "cocktail-party" scenario, informational and contextual factors were found to affect the recognition of everyday environmental sounds embedded in naturalistic auditory scenes. Short environmental sound targets were presented in a dichotic background scene composed of either a single stereo background scene or a composite background scene created by playing different background scenes to the different ears. The side of presentation, time of onset, and number of target sounds were varied across trials to increase the uncertainty for the participant. Half the sounds were contextually congruent with the background sound (i.e., consistent with the meaningful real-world sound environment represented in the auditory scene) and half were incongruent. The presence of a single competing background scene decreased identification accuracy, suggesting an informational masking effect. In tandem, there was a contextual pop-out effect, with contextually incongruent sounds identified more accurately. However, when targets were incongruent with the real-world context of the background scene, informational masking was reduced. Acoustic analyses suggested that this contextual pop-out effect was driven by a mixture of perceptual differences between the target and background, as well as by higher-level cognitive factors. These findings indicate that identification of environmental sounds in naturalistic backgrounds is an active process that requires integrating perceptual, attentional, and cognitive resources.

  2. Developing Scene Understanding Neural Software for Realistic Autonomous Outdoor Missions (United States)


    salient objects and environments providing mutual context (i.e., a primary or key object in an outdoor scene embedded in a realistic environmental ...tracking: a two part vision system for small robot navigation in forested environment . Proc. SPIE 8387, Unmanned Systems Technology XIV Conference; 2012...of realistic autonomous outdoor missions in complex and changing environments . Scene understanding for realistic outdoor missions has been

  3. The Influence of Color on the Perception of Scene Gist (United States)

    Castelhano, Monica S.; Henderson, John M.


    In 3 experiments the authors used a new contextual bias paradigm to explore how quickly information is extracted from a scene to activate gist, whether color contributes to this activation, and how color contributes, if it does. Participants were shown a brief presentation of a scene followed by the name of a target object. The target object could…

  4. Mental Layout Extrapolations Prime Spatial Processing of Scenes (United States)

    Gottesman, Carmela V.


    Four experiments examined whether scene processing is facilitated by layout representation, including layout that was not perceived but could be predicted based on a previous partial view (boundary extension). In a priming paradigm (after Sanocki, 2003), participants judged objects' distances in photographs. In Experiment 1, full scenes (target),…

  5. CRISP: A Computational Model of Fixation Durations in Scene Viewing (United States)

    Nuthmann, Antje; Smith, Tim J.; Engbert, Ralf; Henderson, John M.


    Eye-movement control during scene viewing can be represented as a series of individual decisions about where and when to move the eyes. While substantial behavioral and computational research has been devoted to investigating the placement of fixations in scenes, relatively little is known about the mechanisms that control fixation durations.…

  6. Emotional Scene Content Drives the Saccade Generation System Reflexively (United States)

    Nummenmaa, Lauri; Hyona, Jukka; Calvo, Manuel G.


    The authors assessed whether parafoveal perception of emotional content influences saccade programming. In Experiment 1, paired emotional and neutral scenes were presented to parafoveal vision. Participants performed voluntary saccades toward either of the scenes according to an imperative signal (color cue). Saccadic reaction times were faster…

  7. Toward seamless multiview scene analysis from satellite to street level

    NARCIS (Netherlands)

    Lefevre, Sebastien; Tuia, Devis; Wegner, Jan Dirk; Produit, Timothee; Nassar, Ahmed Samy


    In this paper, we discuss and review how combined multiview imagery from satellite to street level can benefit scene analysis. Numerous works exist that merge information from remote sensing and images acquired from the ground for tasks such as object detection, robots guidance, or scene

  8. Robust Scene Categorization by Learning Image Statistics in Context

    NARCIS (Netherlands)

    van Gemert, J.C.; Geusebroek, J.M.; Veenman, C.J.; Snoek, C.G.M.; Smeulders, A.W.M.


    We present a generic and robust approach for scene categorization. A complex scene is described by proto-concepts like vegetation, water, fire, sky etc. These proto-concepts are represented by low level features, where we use natural images statistics to compactly represent color invariant texture

  9. Representing the sublime in the VIMAP and empirical aesthetics: Reviving Edmund Burke's A Philosophical Enquiry into the Origins of Our Ideas of the Sublime and Beautiful. Comment on "Move me, astonish me... delight my eyes and brain: The Vienna Integrated Model of top-down and bottom-up processes in Art Perception (VIMAP) and corresponding affective, evaluative, and neurophysiological correlates" by Matthew Pelowski et al. (United States)

    Hur, Y.-J.; McManus, I. C.


    This commentary considers the role of the sublime in the Vienna Integrated Model of Art Perception (VIMAP; Pelowski, Markey, Forster, Gerger, & Leder [17]), and suggest that it is not precisely conceptualised in the model. In part that reflects different views and usages of the sublime in the literature, and here it is recommended that Burke's [2] view of the sublime is used as a primary framework for empirical research on the sublime.

  10. Indoor scene classification of robot vision based on cloud computing (United States)

    Hu, Tao; Qi, Yuxiao; Li, Shipeng


    For intelligent service robots, indoor scene classification is an important issue. To overcome the weak real-time performance of conventional algorithms, a new method based on Cloud computing is proposed for global image features in indoor scene classification. With MapReduce method, global PHOG feature of indoor scene image is extracted in parallel. And, feature eigenvector is used to train the decision classifier through SVM concurrently. Then, the indoor scene is validly classified by decision classifier. To verify the algorithm performance, we carried out an experiment with 350 typical indoor scene images from MIT LabelMe image library. Experimental results show that the proposed algorithm can attain better real-time performance. Generally, it is 1.4 2.1 times faster than traditional classification methods which rely on single computation, while keeping stable classification correct rate as 70%.

  11. Improving text recognition by distinguishing scene and overlay text (United States)

    Quehl, Bernhard; Yang, Haojin; Sack, Harald


    Video texts are closely related to the content of a video. They provide a valuable source for indexing and interpretation of video data. Text detection and recognition task in images or videos typically distinguished between overlay and scene text. Overlay text is artificially superimposed on the image at the time of editing and scene text is text captured by the recording system. Typically, OCR systems are specialized on one kind of text type. However, in video images both types of text can be found. In this paper, we propose a method to automatically distinguish between overlay and scene text to dynamically control and optimize post processing steps following text detection. Based on a feature combination a Support Vector Machine (SVM) is trained to classify scene and overlay text. We show how this distinction in overlay and scene text improves the word recognition rate. Accuracy of the proposed methods has been evaluated by using publicly available test data sets.

  12. Dynamic Frames Based Generation of 3D Scenes and Applications

    Directory of Open Access Journals (Sweden)

    Danijel Radošević


    Full Text Available Modern graphic/programming tools like Unity enables the possibility of creating 3D scenes as well as making 3D scene based program applications, including full physical model, motion, sounds, lightning effects etc. This paper deals with the usage of dynamic frames based generator in the automatic generation of 3D scene and related source code. The suggested model enables the possibility to specify features of the 3D scene in a form of textual specification, as well as exporting such features from a 3D tool. This approach enables higher level of code generation flexibility and the reusability of the main code and scene artifacts in a form of textual templates. An example of the generated application is presented and discussed.

  13. [Factors Influencing Post Traumatic Stress Disorder in Crime Scene Investigators]. (United States)

    Nho, Seon Mi; Kim, Eun A


    The purpose of this study was to verify the relationships among social support, resilience and post traumatic stress disorder (PTSD), and especially to identify factors influencing PTSD in police crime scene investigators. A cross-sectional design was used, with a convenience sample of 226 police crime scene investigators from 7 Metropolitan Police Agencies. Data were collected through self-report questionnaires during July and August, 2015. Data were analyzed using t-test, χ²-test, Fisher's exact test, and binary logistic regression analysis with SPSS/WIN 21.0 program. The mean score for PTSD in police crime scene investigators was 13.69. 11 points. Of the crime scene investigators 181 (80.1%) were in the low-risk group and 45 (19.9%) in high-risk group. Social support (t=5.68, pcrime scene investigators, intervention programs including social support and strategies to increase should be established.

  14. System and method for extracting dominant orientations from a scene (United States)

    Straub, Julian; Rosman, Guy; Freifeld, Oren; Leonard, John J.; Fisher, III; , John W.


    In one embodiment, a method of identifying the dominant orientations of a scene comprises representing a scene as a plurality of directional vectors. The scene may comprise a three-dimensional representation of a scene, and the plurality of directional vectors may comprise a plurality of surface normals. The method further comprises determining, based on the plurality of directional vectors, a plurality of orientations describing the scene. The determined plurality of orientations explains the directionality of the plurality of directional vectors. In certain embodiments, the plurality of orientations may have independent axes of rotation. The plurality of orientations may be determined by representing the plurality of directional vectors as lying on a mathematical representation of a sphere, and inferring the parameters of a statistical model to adapt the plurality of orientations to explain the positioning of the plurality of directional vectors lying on the mathematical representation of the sphere.

  15. Hematite Mineralized Bacterial Remnants: Implications for Martian Hematite Deposits (United States)

    Schelble, Rachel T.; Westall, Frances; Allen, Carlton C.; Brearley, Adrian J.


    Hematite mineralized bacterial remnants in the Gunflint Formation [early Proterozoic] can be used as an analog for potential microfossils in martian iron deposits. Additional information is contained in the original extended abstract.

  16. The martian photoelectron boundary as seen by MAVEN (United States)

    Garnier, P.; Steckiewicz, M.; Mazelle, C.; Xu, S.; Mitchell, D.; Holmberg, M. K. G.; Halekas, J. S.; Andersson, L.; Brain, D. A.; Espley, J. R.; Lillis, R. J.; Luhmann, J. G.; Sauvaud, J.-A.; Jakosky, B. M.


    We analyze here in details the location, drivers, properties, and implications for escape of the martian photoelectron boundary based on the Mars Atmosphere and Volatile Evolution (MAVEN) data obtained from September 2014 until May 2016.

  17. Evidence for explosive volcanic density currents on certain Martian volcanoes (United States)

    Reimers, C. E.; Komar, P. D.


    The morphologies of certain of the smaller Martian volcanoes are discussed as possible results of explosive volcanic density currents. An examination of newly-photographed flank and caldera features of the Martian volcanoes Ceraunius Tholus, Uranius Tholus, Uranius Patera and Hecates Tholus, including steep slope angles, Krakatoa-type caldera morphologies, erosional features (radial channels and anastamosing gullies) and constructional features (blanketed flanks and possible lava deltas) reveals their similarity to terrestrial cones and composite volcanoes such as Barcena Volcano. Crater age data from the surface of Martian domes and shields indicates that such explosive activity occurred more frequently early in Martian geologic history, consistent with the view that the volcanic density currents were base surges rather than nuees ardentes, with the melting of permafrost supplying the water required in base surge generation.

  18. Plasma Catalytic Extraction of Oxygen from the Martian Atmosphere Project (United States)

    National Aeronautics and Space Administration — Plasma catalytic techniques are proposed for the extraction of oxygen from the abundant carbon dioxide contained in the Martian atmosphere (95% CO2).. The Phase I...

  19. Plasma Extraction of Oxygen from Martian Atmosphere Project (United States)

    National Aeronautics and Space Administration — Plasma techniques are proposed for the extraction of oxygen from the abundant carbon dioxide contained in the Martian atmosphere (96 % CO2). In this process, CO2 is...

  20. Effects of Rocks on Martian Ground Ice and Neutron Flux (United States)

    Sizemore, H. G.; Mellon, M. T.


    We present numerical simulations of the three-dimensional distribution of ground ice in a heterogeneous martian soil and discuss the implications of our results for the interpretation of Mars Odyssey Gamma Ray Spectrometer data.

  1. VCHP Radiators for Lunar and Martian Environments Project (United States)

    National Aeronautics and Space Administration — Long-term Lunar and Martian systems present challenges to thermal systems, including changes in thermal load, and large changes in the thermal environment between...

  2. VCHP Radiators for Lunar and Martian Environments Project (United States)

    National Aeronautics and Space Administration — Long-term Lunar and Martian systems present challenges to thermal control systems, including changes in thermal load, and large changes in the thermal environment...

  3. Mobility of icy sand packs, with application to Martian permafrost (United States)

    Durham, W.B.; Pathare, A.V.; Stern, L.A.; Lenferink, H.J.


    [1] The physical state of water on Mars has fundamental ramifications for both climatology and astrobiology. The widespread presence of "softened" Martian landforms (such as impact craters) can be attributed to viscous creep of subsurface ground ice. We present laboratory experiments designed to determine the minimum amount of ice necessary to mobilize topography within Martian permafrost. Our results show that the jammed-to-mobile transition of icy sand packs neither occurs at fixed ice content nor is dependent on temperature or stress, but instead correlates strongly with the maximum dry packing density of the sand component. Viscosity also changes rapidly near the mobility transition. The results suggest a potentially lower minimum volatile inventory for the impact-pulverized megaregolith of Mars. Furthermore, the long-term preservation of partially relaxed craters implies that the ice content of Martian permafrost has remained close to that at the mobility transition throughout Martian history. Copyright 2009 by the American Geophysical Union.

  4. Physical Analog Modeling of Martian Dike-Induced Deformation (United States)

    Wyrick, D. Y.; Watson-Morris, M. J.; Morris, A. P.


    Analog models of dike injection were performed to determine style and magnitude of structural deformation associated with the dike. Primary deformation style is contraction rather than extension, indicating that martian dikes may not create grabens.

  5. Fixations on objects in natural scenes: dissociating importance from salience

    Directory of Open Access Journals (Sweden)

    Bernard Marius e’t Hart


    Full Text Available The relation of selective attention to understanding of natural scenes has been subject to intense behavioral research and computational modeling, and gaze is often used as a proxy for such attention. The probability of an image region to be fixated typically correlates with its contrast. However, this relation does not imply a causal role of contrast. Rather, contrast may relate to an object’s importance for a scene, which in turn drives attention. Here we operationalize importance by the probability that an observer names the object as characteristic for a scene. We modify luminance contrast of either a frequently named (common/important or a rarely named (rare/unimportant object, track the observers’ eye movements during scene viewing and ask them to provide keywords describing the scene immediately after.When no object is modified relative to the background, important objects draw more fixations than unimportant ones. Increases of contrast make an object more likely to be fixated, irrespective of whether it was important for the original scene, while decreases in contrast have little effect on fixations. Any contrast modification makes originally unimportant objects more important for the scene. Finally, important objects are fixated more centrally than unimportant objects, irrespective of contrast.Our data suggest a dissociation between object importance (relevance for the scene and salience (relevance for attention. If an object obeys natural scene statistics, important objects are also salient. However, when natural scene statistics are violated, importance and salience are differentially affected. Object salience is modulated by the expectation about object properties (e.g., formed by context or gist, and importance by the violation of such expectations. In addition, the dependence of fixated locations within an object on the object’s importance suggests an analogy to the effects of word frequency on landing positions in reading.

  6. Scene construction in developmental amnesia: an fMRI study. (United States)

    Mullally, Sinéad L; Vargha-Khadem, Faraneh; Maguire, Eleanor A


    Amnesic patients with bilateral hippocampal damage sustained in adulthood are generally unable to construct scenes in their imagination. By contrast, patients with developmental amnesia (DA), where hippocampal damage was acquired early in life, have preserved performance on this task, although the reason for this sparing is unclear. One possibility is that residual function in remnant hippocampal tissue is sufficient to support basic scene construction in DA. Such a situation was found in the one amnesic patient with adult-acquired hippocampal damage (P01) who could also construct scenes. Alternatively, DA patients' scene construction might not depend on the hippocampus, perhaps being instead reliant on non-hippocampal regions and mediated by semantic knowledge. To adjudicate between these two possibilities, we examined scene construction during functional MRI (fMRI) in Jon, a well-characterised patient with DA who has previously been shown to have preserved scene construction. We found that when Jon constructed scenes he activated many of the regions known to be associated with imagining scenes in control participants including ventromedial prefrontal cortex, posterior cingulate, retrosplenial and posterior parietal cortices. Critically, however, activity was not increased in Jon's remnant hippocampal tissue. Direct comparisons with a group of control participants and patient P01, confirmed that they activated their right hippocampus more than Jon. Our results show that a type of non-hippocampal dependent scene construction is possible and occurs in DA, perhaps mediated by semantic memory, which does not appear to involve the vivid visualisation of imagined scenes. © 2013 Published by Elsevier Ltd.

  7. One high performance technology of infrared scene projection (United States)

    Wang, Hong-jie; Qian, Li-xun; Cao, Chun; Li, Zhuo


    Infrared scenes generation technologies are used to simulate the infrared radiation characteristics of target and background in the laboratory. They provide synthetic infrared imagery for thermal imager test and evaluation application in the infrared imaging systems. At present, many Infrared scenes generation technologies have been widely used, and they make a lot of achievements. In this paper, we design and manufacture one high performance IR scene generation technology, and the whole thin film type transducer is the key, which is fabricated based on micro electro mechanical systems (MEMS). The specific MEMS technological process parameters are obtained from a large number of experiments. The properties of infrared scene generation chip are investigated experimentally. It achieves high resolution, high frame, and reliable performance, which can meet the requirements of most simulation system. The radiation coefficient of the thin film transducer is measured to be 0.86. The frame rate is 160 Hz. The emission spectrum is from 2μm to 12μm in infrared band. Illuminated by the visible light with different intensities the equivalent black body temperature of transducer could be varied in the range of 290K to 440K. The spatial resolution is more than 256×256.The geometric distortion and the uniformity of the generated infrared scene is 5 percent. The infrared scene generator based on the infrared scene generation chip include three parts, which are visual image projector, visual to thermal transducer and the infrared scene projector. The experimental results show that this thin film type infrared scene generation chip meets the requirements of most of hardware-in-the-loop scene simulation systems for IR sensors testing.

  8. Alteration of Sedimentary Clasts in Martian Meteorite Northwest Africa 7034 (United States)

    McCubbin, F. M.; Tartese, R.; Santos, A. R.; Domokos, G.; Muttik, N.; Szabo, T.; Vazquez, J.; Boyce, J. W.; Keller, L. P.; Jerolmack, D. J.; hide


    The martian meteorite Northwest Africa (NWA) 7034 and pairings represent the first brecciated hand sample available for study from the martian surface [1]. Detailed investigations of NWA 7034 have revealed substantial lithologic diversity among the clasts [2-3], making NWA 7034 a polymict breccia. NWA 7034 consists of igneous clasts, impact-melt clasts, and "sedimentary" clasts represented by prior generations of brecciated material. In the present study we conduct a detailed textural and geochemical analysis of the sedimentary clasts.

  9. Refining Martian Ages and Understanding Geological Processes From Cratering Statistics (United States)

    Hartmann, William K.


    Senior Scientist William K. Hartman presents his final report on Mars Data Analysis Program grant number NAG5-12217: The third year of the three-year program was recently completed in mid-2005. The program has been extremely productive in research and data analysis regarding Mars, especially using Mars Global Surveyor and Mars Odyssey imagery. In the 2005 alone, three papers have already been published, to which this work contributed.1) Hartmann, W. K. 200.5. Martian cratering 8. Isochron refinement and the history of Martian geologic activity Icarus 174, 294-320. This paper is a summary of my entire program of establishing Martian chronology through counts of Martian impact craters. 2) Arfstrom, John, and W. K. Hartmann 2005. Martian flow features, moraine-like rieges, and gullies: Terrestrial analogs and interrelationships. Icarus 174,32 1-335. This paper makes pioneering connections between Martian glacier-like features and terrestrial glacial features. 3) Hartmann, W.K., D. Winterhalter, and J. Geiss. 2005 Chronology and Physical Evolution of Planet Mars. In The Solar System and Beyond: Ten Years of ISSI (Bern: International Space Science Institute). This is a summary of work conducted at the International Space Science Institute with an international team, emphasizing our publication of a conference volume about Mars, edited by Hartmann and published in 2001.

  10. Relevance of Pitted Material and Impact Melt to Early Martian Hydrothermalism and Habitability; Ries Ejecta Deposits as a Martian Analogue (United States)

    Caudill, C. M.; Greenberger, R. N.; Tornabene, L. L.; Osinski, G. R.; Flemming, R. L.; Ehlmann, B. L.


    Hydrothermal features are investigated at the Ries impact structure as potentially analogous to crater-related pitted material in Martian ancient terrains, which may reveal shallow sub-surface hydrothermal environments and prime exploration targets.

  11. Art Toys in the contemporary art scene

    Directory of Open Access Journals (Sweden)

    Laura Sernissi


    Full Text Available The Art Toys phenomenon, better known as Art Toy Movement, was born in China in the mid-nineties and quickly spread out to the rest of the world. The toys are an artistic production of serial sculpture, made by handcrafts or on an industrial scale. There are several types of toys, such as custom toys and canvas toys, synonyms of designer toys, although they are often defined according to the constituent material, such as vinyl toys (plastic and plush toys (fabric. Art toys are the heirs of an already pop-surrealist and neo-pop circuit, which since the eighties of the twentieth century has pervaded the Japanese-American art scene, winking to the playful spirit of the avant-garde of the early century. Some psychoanalytic, pedagogical and anthropological studies about “play theories”, may also help us to understand and identify these heterogeneous products as real works of art and not simply as collectible toys.

  12. Crime scene investigation (as seen on TV). (United States)

    Durnal, Evan W


    A mysterious green ooze is injected into a brightly illuminated and humming machine; 10s later, a printout containing a complete biography of the substance is at the fingertips of an attractive young investigator who exclaims "we found it!" We have all seen this event occur countless times on any and all of the three CSI dramas, Cold Cases, Crossing Jordans, and many more. With this new style of "infotainment" (Surette, 2007), comes an increasingly blurred line between the hard facts of reality and the soft, quick solutions of entertainment. With these advances in technology, how can crime rates be anything but plummeting as would-be criminals cringe at the idea of leaving the smallest speck of themselves at a crime scene? Surely there are very few serious crimes that go unpunished in today's world of high-tech, fast-paced gadgetry. Science and technology have come a great distance since Sir Arthur Conan Doyle first described the first famous forensic scientist (Sherlock Holmes), but still have light-years to go. (c) 2010. Published by Elsevier Ireland Ltd.

  13. Anomaly detection and localization in crowded scenes. (United States)

    Li, Weixin; Mahadevan, Vijay; Vasconcelos, Nuno


    The detection and localization of anomalous behaviors in crowded scenes is considered, and a joint detector of temporal and spatial anomalies is proposed. The proposed detector is based on a video representation that accounts for both appearance and dynamics, using a set of mixture of dynamic textures models. These models are used to implement 1) a center-surround discriminant saliency detector that produces spatial saliency scores, and 2) a model of normal behavior that is learned from training data and produces temporal saliency scores. Spatial and temporal anomaly maps are then defined at multiple spatial scales, by considering the scores of these operators at progressively larger regions of support. The multiscale scores act as potentials of a conditional random field that guarantees global consistency of the anomaly judgments. A data set of densely crowded pedestrian walkways is introduced and used to evaluate the proposed anomaly detector. Experiments on this and other data sets show that the latter achieves state-of-the-art anomaly detection results.

  14. Geographic Data Bases Supporting Scene Generation (United States)

    Lukes, George E.


    Recent activity in synthetic reference scene generation from geographic data bases has lead to new and expanding production responsibilities for the mapping community. It has also spawned a new and growing population of geographic data base users. Optimum utilization of this data requires an understanding of the natural and cultural patterns represented as well as knowledge of the conventions and specifications which guide data base preparation. Prudence dictates effective mechanisms for data base inspection by the user. Appropriate implementation of data display procedures can provide this capability while also supporting routine analysis of data base content. This paper first illustrates a set of convenient mechanisms for the display of the elevation and planimetric components of geographic data files. Then, a new USAETL program in Computer-Assisted Photo Interpretation Research (CAPIR) is introduced. The CAPIR program will explore issues of direct data entry to create geographic data bases from stereo aerial photography. CAPIR also provides a technique for displaying geographic data base contents in corresponding three-dimensional photo models. This capability, termed superposition, will impact on the critical tasks of data validation, revision and intensification which are essential for effective management of geographic files.

  15. Medical Monitoring During Firefighter Incident Scene Rehabilitation. (United States)

    Barr, David A; Haigh, Craig A; Haller, Jeannie M; Smith, Denise L


    The objective of this study was to retrospectively investigate aspects of medical monitoring, including medical complaints, vital signs at entry, and vital sign recovery, in firefighters during rehabilitation following operational firefighting duties. Incident scene rehabilitation logs obtained over a 5-year span that included 53 incidents, approximately 40 fire departments, and more than 530 firefighters were reviewed. Only 13 of 694 cases involved a firefighter reporting a medical complaint. In most cases, vital signs were similar between firefighters who registered a complaint and those who did not. On average, heart rate was 104 ± 23 beats·min(-1), systolic blood pressure was 132 ± 17 mmHg, diastolic blood pressure was 81 ± 12 mmHg, and respiratory rate was 19 ± 3 breaths·min(-1) upon entry into rehabilitation. At least two measurements of heart rate, systolic blood pressure, diastolic blood pressure, and respiratory rate were obtained for 365, 383, 376, and 160 cases, respectively. Heart rate, systolic and diastolic blood pressures, and respiratory rate decreased significantly (p firefighters recovered from the physiological stress of firefighting without any medical complaint or symptoms. Furthermore, vital signs were within fire service suggested guidelines for release within 10 or 20 minutes of rehabilitation. The data suggested that vital signs of firefighters with medical symptoms were not significantly different from vital signs of firefighters who had an unremarkable recovery.

  16. -The Influence of Scene Context on Parafoveal Processing of Objects. (United States)

    Castelhano, Monica S; Pereira, Effie J


    Many studies in reading have shown the enhancing effect of context on the processing of a word before it is directly fixated (parafoveal processing of words; Balota et al., 1985; Balota & Rayner, 1983; Ehrlich & Rayner, 1981). Here, we examined whether scene context influences the parafoveal processing of objects and enhances the extraction of object information. Using a modified boundary paradigm (Rayner, 1975), the Dot-Boundary paradigm, participants fixated on a suddenly-onsetting cue before the preview object would onset 4° away. The preview object could be identical to the target, visually similar, visually dissimilar, or a control (black rectangle). The preview changed to the target object once a saccade toward the object was made. Critically, the objects were presented on either a consistent or an inconsistent scene background. Results revealed that there was a greater processing benefit for consistent than inconsistent scene backgrounds and that identical and visually similar previews produced greater processing benefits than other previews. In the second experiment, we added an additional context condition in which the target location was inconsistent, but the scene semantics remained consistent. We found that changing the location of the target object disrupted the processing benefit derived from the consistent context. Most importantly, across both experiments, the effect of preview was not enhanced by scene context. Thus, preview information and scene context appear to independently boost the parafoveal processing of objects without any interaction from object-scene congruency.

  17. Three-dimensional measurement system for crime scene documentation (United States)

    Adamczyk, Marcin; Hołowko, Elwira; Lech, Krzysztof; Michoński, Jakub; MÄ czkowski, Grzegorz; Bolewicki, Paweł; Januszkiewicz, Kamil; Sitnik, Robert


    Three dimensional measurements (such as photogrammetry, Time of Flight, Structure from Motion or Structured Light techniques) are becoming a standard in the crime scene documentation process. The usage of 3D measurement techniques provide an opportunity to prepare more insightful investigation and helps to show every trace in the context of the entire crime scene. In this paper we would like to present a hierarchical, three-dimensional measurement system that is designed for crime scenes documentation process. Our system reflects the actual standards in crime scene documentation process - it is designed to perform measurement in two stages. First stage of documentation, the most general, is prepared with a scanner with relatively low spatial resolution but also big measuring volume - it is used for the whole scene documentation. Second stage is much more detailed: high resolution but smaller size of measuring volume for areas that required more detailed approach. The documentation process is supervised by a specialised application CrimeView3D, that is a software platform for measurements management (connecting with scanners and carrying out measurements, automatic or semi-automatic data registration in the real time) and data visualisation (3D visualisation of documented scenes). It also provides a series of useful tools for forensic technicians: virtual measuring tape, searching for sources of blood spatter, virtual walk on the crime scene and many others. In this paper we present our measuring system and the developed software. We also provide an outcome from research on metrological validation of scanners that was performed according to VDI/VDE standard. We present a CrimeView3D - a software-platform that was developed to manage the crime scene documentation process. We also present an outcome from measurement sessions that were conducted on real crime scenes with cooperation with Technicians from Central Forensic Laboratory of Police.

  18. Picture models for 2-scene comics creating system

    Directory of Open Access Journals (Sweden)

    Miki UENO


    Full Text Available Recently, computer understanding pictures and stories becomes one of the most important research topics in computer science. However, there are few researches about human like understanding by computers because pictures have not certain format and contain more lyric aspect than that of natural laguage. For picture understanding, a comic is the suitable target because it is consisted by clear and simple plot of stories and separated scenes.In this paper, we propose 2 different types of picture models for 2-scene comics creating system. We also show the method of the application of 2-scene comics creating system by means of proposed picture model.

  19. Electric Field Generation in Martian Dust Devils (United States)

    Barth, Erika L.; Farrell, William M.; Rafkin, Scot C. R.


    Terrestrial dust devils are known to generate electric fields from the vertical separation of charged dust particles. The particles present within the dust devils on Mars may also be subject to similar charging processes and so likely contribute to electric field generation there as well. However, to date, no Marsin situ instrumentation has been deployed to measure electric field strength. In order to explore the electric environment of dust devils on Mars, the triboelectric dust charging physics from the MacroscopicTriboelectric Simulation (MTS) code has been coupled to the Mars Regional Atmospheric ModelingSystem (MRAMS). Using this model, we examine how macroscopic electric fields are generated within martian dust disturbances and attempt to quantify the time evolution of the electrodynamical system.Electric fields peak for several minutes within the dust devil simulations. The magnitude of the electric field is a strong function of the size of the particles present, the average charge on the particles and the number of particles lifted. Varying these parameters results in peak electric fields between tens of millivolts per meter and tens of kilovolts per meter.

  20. High-Capacity Communications from Martian Distances (United States)

    Williams, W. Dan; Collins, Michael; Hodges, Richard; Orr, Richard S.; Sands, O. Scott; Schuchman, Leonard; Vyas, Hemali


    High capacity communications from Martian distances, required for the envisioned human exploration and desirable for data-intensive science missions, is challenging. NASA s Deep Space Network currently requires large antennas to close RF telemetry links operating at kilobit-per-second data rates. To accommodate higher rate communications, NASA is considering means to achieve greater effective aperture at its ground stations. This report, focusing on the return link from Mars to Earth, demonstrates that without excessive research and development expenditure, operational Mars-to-Earth RF communications systems can achieve data rates up to 1 Gbps by 2020 using technology that today is at technology readiness level (TRL) 4-5. Advanced technology to achieve the needed increase in spacecraft power and transmit aperture is feasible at an only moderate increase in spacecraft mass and technology risk. In addition, both power-efficient, near-capacity coding and modulation and greater aperture from the DSN array will be required. In accord with these results and conclusions, investment in the following technologies is recommended:(1) lightweight (1 kg/sq m density) spacecraft antenna systems; (2) a Ka-band receive ground array consisting of relatively small (10-15 m) antennas; (3) coding and modulation technology that reduces spacecraft power by at least 3 dB; and (4) efficient generation of kilowatt-level spacecraft RF power.

  1. The new Martians a scientific novel

    CERN Document Server

    Kanas, Nick


    The year is 2035, and the crew from the first expedition to Mars is returning to Earth. The crewmembers are anxious to get home, and ennui pervades the ship. The mood is broken by a series of mysterious events that jeopardize their safety. Someone or something is threatening the crew. Is it an alien being? A psychotic crewmember? A malfunctioning computer? The truth raises questions about the crewmembers’ fate and that of the human race. In this novel, the intent is to show real psychological issues that could affect a crew returning from a long-duration mission to Mars. The storyline presents a mystery that keeps the reader guessing, yet the issues at stake are based on the findings from the author’s research and other space-related work over the past 40+ years. The novel touches on actual plans being discussed for such an expedition as well as notions involving the search for Martian life and panspermia. The underlying science, in particular the psychological, psychiatric, and interpersonal elements...

  2. Ion Heating in the Martian Ionosphere (United States)

    Fowler, C. M.; Ergun, R. E.; Andersson, L.; Peterson, W. K.; Hara, T.; Mcfadden, J.; Espley, J.; Halekas, J.; Mitchell, D. L.; Mazelle, C.; Jakosky, B. M.


    Energetic O+ and O2+ ions with energies of up to a few hundred eV are observed in the Martian ionosphere. Corresponding ion velocity distributions show ion conics, suggesting that the observed ion populations have been heated perpendicular to the local magnetic field before experiencing a magnetic mirror force. Magnetic field observations support these interpretations: wave power at the local O+ and O2+ gyrofrequencies in the spacecraft frame is observed coincident with the energetic ions, within an apparent magnetic field bottle-like topology. Analysis of the observed ion conics leads to estimates of ion temperatures of 10-30 eV. We suggest that the ion populations are initially heated perpendicular to the local magnetic field by wave power propagating inward from the Mars-solar wind interaction. The local magnetic field "balloons out" in response to these enhanced ion temperatures and pressures. The resultant magnetic field topology is bottle like; the transversely heated ions would subsequently experience a magnetic mirror force in the converging field regions, agreeing with the reported observations. Such strong heating events that significantly increase the ion temperature and pressure, thereby decreasing the net magnetic field, are rare and seem to occur under specific interplanetary magnetic field orientations. Events were observed to span the upper exobase region and just above, a region characterized by significant ion densities in an increasingly collisionless domain. Ion heating in this region has the potential to drive significant ion outflows, thus contributing to atmospheric loss from the planet.

  3. Growth of ZnSe(1-x)Tex epilayers by isothermal closed space sublimation (United States)

    Larramendi, Erick M.; Gutiérrez Z-B, Karla; Arens, Christof; Woggon, Ulrike; Schikora, Detlef; Lischka, Klaus


    ZnSe(1-x)Tex (x ˜0.06) epilayers were grown on GaAs(001) substrates at 350 °C by isothermal closed space sublimation (ICSS) technique. The epitaxial growth was performed in low-pressure helium atmosphere (˜0.1 mbar) by sequential exposures of the substrate to vapors of a solid solution of selenium-tellurium and elemental zinc. The use of a mixed source is proposed in order to regulate the partial vapor pressure of the constituents by composition. Strain and composition of the ZnSe(1-x)Tex epilayers were extracted from high resolution x-ray reciprocal space mapping. Structural investigations show a reasonably good crystalline quality of the epilayers. Good reproducibility of composition and control of thickness were obtained although atomic layer epitaxy regimen was not achieved. A growth rate of 1.3 monolayers/cycle was ascribed to multilayer adsorption and the existence of an efficient transport of SeTe in graphite under thermodynamic conditions of ICSS. Both Raman and photoluminescence characterizations suggest the existence of random alloy epilayers with larger composition disorder in the mesoscopic scale than those obtained by molecular beam epitaxy.

  4. The impacts of moisture transport on drifting snow sublimation in the saltation layer

    Directory of Open Access Journals (Sweden)

    N. Huang


    Full Text Available Drifting snow sublimation (DSS is an important physical process related to moisture and heat transfer that happens in the atmospheric boundary layer, which is of glaciological and hydrological importance. It is also essential in order to understand the mass balance of the Antarctic ice sheets and the global climate system. Previous studies mainly focused on the DSS of suspended snow and ignored that in the saltation layer. Here, a drifting snow model combined with balance equations for heat and moisture is established to simulate the physical DSS process in the saltation layer. The simulated results show that DSS can strongly increase humidity and cooling effects, which in turn can significantly reduce DSS in the saltation layer. However, effective moisture transport can dramatically weaken the feedback effects. Due to moisture advection, DSS rate in the saltation layer can be several orders of magnitude greater than that of the suspended particles. Thus, DSS in the saltation layer has an important influence on the distribution and mass–energy balance of snow cover.

  5. Laser Desorption Ionization Mass Spectrometry Imaging of Drosophila Brain Using Matrix Sublimation versus Modification with Nanoparticles. (United States)

    Phan, Nhu T N; Mohammadi, Amir Saeid; Dowlatshahi Pour, Masoumeh; Ewing, Andrew G


    Laser desorption ionization mass spectrometry (LDI-MS) is used to image brain lipids in the fruit fly, Drosophila, a common invertebrate model organism in biological and neurological studies. Three different sample preparation methods, including sublimation with two common organic matrixes for matrix-assisted laser desorption ionization (MALDI) and surface-assisted laser desorption ionization (SALDI) using gold nanoparticles, are examined for sample profiling and imaging the fly brain. Recrystallization with trifluoroacetic acid following matrix deposition in MALDI is shown to increase the incorporation of biomolecules with one matrix, resulting in more efficient ionization, but not for the other matrix. The key finding here is that the mass fragments observed for the fly brain slices with different surface modifications are significantly different. Thus, these approaches can be combined to provide complementary analysis of chemical composition, particularly for the small metabolites, diacylglycerides, phosphatidylcholines, and triacylglycerides, in the fly brain. Furthermore, imaging appears to be beneficial using modification with gold nanoparticles in place of matrix in this application showing its potential for cellular and subcellular imaging. The imaging protocol developed here with both MALDI and SALDI provides the best and most diverse lipid chemical images of the fly brain to date with LDI.

  6. Ag doped ZnTe films prepared by closed space sublimation and an ion exchange process

    Energy Technology Data Exchange (ETDEWEB)

    Aqili, Akram K.S., E-mail: [Department of Physics, Hashemite University, Zarqa (Jordan); Saleh, Ahmad J. [Department of Physics, Hashemite University, Zarqa (Jordan); Ali, Zulfiqar [Optics Laboratories, Islamabad (Pakistan); Al-Omari, S. [Department of Physics, Hashemite University, Zarqa (Jordan)


    Highlights: Black-Right-Pointing-Pointer ZnTe thin films are prepared by low-cost simple technique (CSS). Black-Right-Pointing-Pointer Silver doping is achieved by an ion exchange process. Black-Right-Pointing-Pointer Small peaks appear in the XRD diffraction pattern related to Ag{sub 2}Te. Black-Right-Pointing-Pointer Increase of the films refractive index and shift of optical band was observed. - Abstract: ZnTe thin films were deposited by closed space sublimation (CSS) technique on amorphous glass substrate. The deposited films were immersed in AgNO{sub 3} solution for different time periods, then heated in vacuum. The resistivity of the film, immersed for 30 min, was reduced by less than six orders of magnitudes. The films structures were characterized by X-ray diffraction (XRD). Atomic force microscope (AFM) was used to detect the surface morphology of the films. The films thickness, the optical properties, such as refractive index, absorption coefficient and the optical band gap were determined from transmittance spectra in the wavelength range of 400-2500 nm. The dark electrical conductivities of the films were studied as function of temperature to determine the conductivity activation energy.

  7. Modelling of the sublimation of icy grains in the coma of comet 67P/Churyumov-Gerasimenko (United States)

    Gicquel, A.; Vincent, J.-B.; Shi, X.; Sierks, H.; Rose, M.; Güttler, C.; Tubiana, C.


    The ESA (European Space Agency) Rosetta spacecraft was launched on 2 March 2004, to reach comet 67P/Churyumov-Gerasimenko in August 2014. Since March 2014, images of the nucleus and the coma (gas and dust) of the comet have been acquired by the OSIRIS (Optical, Spectroscopic, and Infrared Remote Imaging System) camera system [1] using both, the wide angle camera (WAC) and the narrow angle camera (NAC). The orbiter will be maintained in the vicinity of the comet until perihelion (Rh=1.3 AU) or even until Rh=1.8 AU post-perihelion (December 2015). Nineteen months of uninterrupted, close-up observations of the gas and dust coma will be obtained and will help to characterize the evolution of comet gas and dust activity during its approach to the Sun. Indeed, for the first time, we will follow the development of a comet's coma from a close distance. Also the study of the dust-gas interaction in the coma will highlight the sublimation of icy grains. Even if the sublimation of icy grains is known, it is not yet integrated in a complete dust-gas model. We are using the Direct Simulation Monte Carlo (DSMC) method to study the gas flow close to the nucleus. The code called PI-DSMC (www.pidsmc. com) can simulate millions of molecules for multiple species.When the gas flow is simulated, we inject the dust particle with a zero velocity and we take into account the 3 forces acting on the grains in a cometary environment (drag force, gravity and radiative pressure). We used the DLL (Dynamic Link Library) model to integrate the sublimation of icy grains in the gas flowand allow studying the effect of the additional gas on the dust particle trajectories. For a quantitative analysis of the sublimation of icy, outflowing grains we will consider an ensemble of grains of various radii with different compositions [2] The evolution of the grains, once they are ejected into the coma, depends on their initial size, their composition and the heliocentric distance (because the temperature of

  8. Embryo disposition and the new death scene

    Directory of Open Access Journals (Sweden)

    Ellison, David


    Full Text Available In the IVF clinic - a place designed principally for the production and implantation of embryos - scientists and IVF recipients are faced with decisions regarding the disposition of frozen embryos. At this time there are hundred of thousands of cryopreserved embryos awaiting such determinations. They may be thawed for transfer to the woman herself, they may be donated for research or for use by other infertile couples, they may remain in frozen storage, or they may variously be discarded by being allowed to 'succumb', or 'perish'. Where the choice is discard, some IVF clients have chosen to formalise the process through ceremony. A new language is emerging in response to the desires of the would-be-parents who might wish to characterise the discard experience as a ‘good death’. This article examines the procedure known as ‘compassionate transfer’ where the embryo to be discarded is placed in the woman’s vagina where it is clear that it will not develop further. An alternate method has the embryo transferred in the usual manner but without the benefit of fertility-enhancing hormones at a point in the cycle unreceptive to implantation. The embryo destined for disposal is thus removed from the realm of technological possibility and ‘returned’ to the female body for a homely death. While debates continue about whether or not embryos constitute life, new practices are developing in response to the emotional experience of embryo discard. We argue that compassionate transfer is a death scene taking shape. In this article, we take the measure of this new death scene’s fabrication, and consider the form, significance, and legal complexity of its ceremonies.

  9. Synthesis of Monolithic Fe2O3-Al2O3 Composite Aerogels via Organic Solvent Sublimation Drying

    Directory of Open Access Journals (Sweden)

    Lili Ren


    Full Text Available Monolithic Fe2O3-Al2O3 composite aerogels have been prepared successfully via organic solvent sublimation drying method. The results show that a new phase forms when the right amount of ferric oxide is added to the alumina aerogel. From the TEM pictures we can see a shuttle-type structure with the length of about 15 nm forms, which leads to the high surface areas of composited aerogel.

  10. Hybrid infrared scene projector (HIRSP): a high dynamic range infrared scene projector, part II (United States)

    Cantey, Thomas M.; Bowden, Mark; Cosby, David; Ballard, Gary


    This paper is a continuation of the merging of two dynamic infrared scene projector technologies to provide a unique and innovative solution for the simulation of high dynamic temperature ranges for testing infrared imaging sensors. This paper will present some of the challenges and performance issues encountered in implementing this unique projector system into a Hardware-in-the-Loop (HWIL) simulation facility. The projection system combines the technologies of a Honeywell BRITE II extended voltage range emissive resistor array device and an optically scanned laser diode array projector (LDAP). The high apparent temperature simulations are produced from the luminescent infrared radiation emitted by the high power laser diodes. The hybrid infrared projector system is being integrated into an existing HWIL simulation facility and is used to provide real-world high radiance imagery to an imaging infrared unit under test. The performance and operation of the projector is presented demonstrating the merit and success of the hybrid approach. The high dynamic range capability simulates a 250 Kelvin apparent background temperature to 850 Kelvin maximum apparent temperature signatures. This is a large increase in radiance projection over current infrared scene projection capabilities.

  11. Modified sublimation to isolate phenanthrene-degrading bacteria of the genera Sphingomonas and Burkholderia from Xiamen oil port. (United States)

    Huang, X; Tian, Y; Luo, Y R; Liu, H J; Zheng, Wei; Zheng, T L


    Sublimation was developed by Alley and Brown (2000) in order to isolate bacterial strains that were capable of degrading water insoluble compounds. In this study, sublimation was modified by the use of nutritional agar plates, instead of mineral salt agar, to isolate phenanthrene-degrading bacteria from a mixed culture that had been enriched under the selective pressure of high phenanthrene content. Five strains were obtained with different morphology and degradation ability. Based on the 16S rDNA sequence, two of them were classified as species of the genus Sphingomonas; the others as species of the genus Burkholderia. Denaturing gradient gel electrophoresis (DGGE) was introduced to detect dynamic changes in the bacterial community during enrichment batch culture, and to determine any correlation between the five isolates and the phenanthrene-degrading consortium. The DGGE profile indicated that these five isolates corresponded to four dominant bands of the consortium. Compared to traditional means of isolation, we concluded that modified sublimation is effective and more convenient.


    Directory of Open Access Journals (Sweden)

    Topan Setiawan


    Full Text Available This study aimed to feel the subtle vibrations of a “project” of the ASEAN Economic Community (AEC, the human dimension and its culture. However AEC becomes part of the life history of the nations of Southeast Asia, particularly in the visible measures, such as economic growth, the economic stability of the region or the increasing of intra-regional trade volume. It means, that we feel it in the materialist dimension, or “vibrations” a “rough”. Besides, this study attempted to feel the euphoria of the other aspects. This paper will track a bit more deeply about Indonesian and its culture. Also there will be an effort to seek traces (perhaps disguised in regional sublimation materialism “project” by AEC. Strive to be this insight led to the discovery that regional sublimation Reviews their materialism, for the next attempt to pave the way consciousness. Also, how sublimation material, it is not exactly cornered people and cultures. Another invention is the reification of culture, which it is the manifestation, in the form of Materialization on social relations, by considering it as a thing freely. Similarly, it is forgetting the historical trail of goods/services. Search back on local wisdom, seems to be one way that can be taken.

  13. Earth Virtual-Environment Immersive Scene Display System Project (United States)

    National Aeronautics and Space Administration — In response to the NASA need for a free-standing immersive virtual scene display system interfaced with an exercise treadmill to mimic terrestrial exercise...

  14. The influence of color on emotional perception of natural scenes. (United States)

    Codispoti, Maurizio; De Cesarei, Andrea; Ferrari, Vera


    Is color a critical factor when processing the emotional content of natural scenes? Under challenging perceptual conditions, such as when pictures are briefly presented, color might facilitate scene segmentation and/or function as a semantic cue via association with scene-relevant concepts (e.g., red and blood/injury). To clarify the influence of color on affective picture perception, we compared the late positive potentials (LPP) to color versus grayscale pictures, presented for very brief (24 ms) and longer (6 s) exposure durations. Results indicated that removing color information had no effect on the affective modulation of the LPP, regardless of exposure duration. These findings imply that the recognition of the emotional content of scenes, even when presented very briefly, does not critically rely on color information. Copyright © 2011 Society for Psychophysiological Research.

  15. Big visual data analysis scene classification and geometric labeling

    CERN Document Server

    Chen, Chen; Kuo, C -C Jay


    This book offers an overview of traditional big visual data analysis approaches and provides state-of-the-art solutions for several scene comprehension problems, indoor/outdoor classification, outdoor scene classification, and outdoor scene layout estimation. It is illustrated with numerous natural and synthetic color images, and extensive statistical analysis is provided to help readers visualize big visual data distribution and the associated problems. Although there has been some research on big visual data analysis, little work has been published on big image data distribution analysis using the modern statistical approach described in this book. By presenting a complete methodology on big visual data analysis with three illustrative scene comprehension problems, it provides a generic framework that can be applied to other big visual data analysis tasks.

  16. Synchronous contextual irregularities affect early scene processing: replication and extension. (United States)

    Mudrik, Liad; Shalgi, Shani; Lamy, Dominique; Deouell, Leon Y


    Whether contextual regularities facilitate perceptual stages of scene processing is widely debated, and empirical evidence is still inconclusive. Specifically, it was recently suggested that contextual violations affect early processing of a scene only when the incongruent object and the scene are presented a-synchronously, creating expectations. We compared event-related potentials (ERPs) evoked by scenes that depicted a person performing an action using either a congruent or an incongruent object (e.g., a man shaving with a razor or with a fork) when scene and object were presented simultaneously. We also explored the role of attention in contextual processing by using a pre-cue to direct subjects׳ attention towards or away from the congruent/incongruent object. Subjects׳ task was to determine how many hands the person in the picture used in order to perform the action. We replicated our previous findings of frontocentral negativity for incongruent scenes that started ~ 210 ms post stimulus presentation, even earlier than previously found. Surprisingly, this incongruency ERP effect was negatively correlated with the reaction times cost on incongruent scenes. The results did not allow us to draw conclusions about the role of attention in detecting the regularity, due to a weak attention manipulation. By replicating the 200-300 ms incongruity effect with a new group of subjects at even earlier latencies than previously reported, the results strengthen the evidence for contextual processing during this time window even when simultaneous presentation of the scene and object prevent the formation of prior expectations. We discuss possible methodological limitations that may account for previous failures to find this an effect, and conclude that contextual information affects object model selection processes prior to full object identification, with semantic knowledge activation stages unfolding only later on. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Scene construction in developmental amnesia: An fMRI study


    Mullally, Sinéad L.; Vargha-Khadem, Faraneh; Maguire, Eleanor A.


    Amnesic patients with bilateral hippocampal damage sustained in adulthood are generally unable to construct scenes in their imagination. By contrast, patients with developmental amnesia (DA), where hippocampal damage was acquired early in life, have preserved performance on this task, although the reason for this sparing is unclear. One possibility is that residual function in remnant hippocampal tissue is sufficient to support basic scene construction in DA. Such a situation was found in the...

  18. Experiencing simultanagnosia through windowed viewing of complex social scenes. (United States)

    Dalrymple, Kirsten A; Birmingham, Elina; Bischof, Walter F; Barton, Jason J S; Kingstone, Alan


    Simultanagnosia is a disorder of visual attention, defined as an inability to see more than one object at once. It has been conceived as being due to a constriction of the visual "window" of attention, a metaphor that we examine in the present article. A simultanagnosic patient (SL) and two non-simultanagnosic control patients (KC and ES) described social scenes while their eye movements were monitored. These data were compared to a group of healthy subjects who described the same scenes under the same conditions as the patients, or through an aperture that restricted their vision to a small portion of the scene. Experiment 1 demonstrated that SL showed unusually low proportions of fixations to the eyes in social scenes, which contrasted with all other participants who demonstrated the standard preferential bias toward eyes. Experiments 2 and 3 revealed that when healthy participants viewed scenes through a window that was contingent on where they looked (Experiment 2) or where they moved a computer mouse (Experiment 3), their behavior closely mirrored that of patient SL. These findings suggest that a constricted window of visual processing has important consequences for how simultanagnosic patients explore their world. Our paradigm's capacity to mimic simultanagnosic behaviors while viewing complex scenes implies that it may be a valid way of modeling simultanagnosia in healthy individuals, providing a useful tool for future research. More broadly, our results support the thesis that people fixate the eyes in social scenes because they are informative to the meaning of the scene. Copyright © 2010 Elsevier B.V. All rights reserved.

  19. Martian mud volcanism: Terrestrial analogs and implications for formational scenarios (United States)

    Skinner, J.A.; Mazzini, A.


    The geology of Mars and the stratigraphic characteristics of its uppermost crust (mega-regolith) suggest that some of the pervasively-occurring pitted cones, mounds, and flows may have formed through processes akin to terrestrial mud volcanism. A comparison of terrestrial mud volcanism suggests that equivalent Martian processes likely required discrete sedimentary depocenters, volatile-enriched strata, buried rheological instabilities, and a mechanism of destabilization to initiate subsurface flow. We outline five formational scenarios whereby Martian mud volcanism might have occurred: (A) rapid deposition of sediments, (B) volcano-induced destabilization, (C) tectonic shortening, (D) long-term, load-induced subsidence, and (E) seismic shaking. We describe locations within and around the Martian northern plains that broadly fit the geological context of these scenarios and which contain mud volcano-like landforms. We compare terrestrial and Martian satellite images and examine the geological settings of mud volcano provinces on Earth in order to describe potential target areas for piercement structures on Mars. Our comparisons help to evaluate not only the role of water as a functional component of geological processes on Mars but also how Martian mud volcanoes could provide samples of otherwise inaccessible strata, some of which could contain astrobiological evidence.

  20. Water in Pyroxene and Olivine from Martian Meteorites (United States)

    Peslier, A. H.


    Water in the interior of terrestrial planets can be dissolved in fluids or melts and hydrous phases, but can also be locked as protons attached to structural oxygen in lattice defects in nominally anhydrous minerals (NAM) like olivine, pyroxene, or feldspar [1-3]. Although these minerals contain only tens to hundreds of ppm H2O, this water can amount to at least one ocean in mass when added at planetary scales because of the modal dominance of NAM in the mantle and crust [4]. Moreover these trace amounts of water can have drastic effects on melting temperature, rheology, electrical and heat conductivity, and seismic wave attenuation [5]. There is presently a debate on how much water is present in the martian mantle. Secondary ionization mass spectrometry (SIMS) studies of NAM [6], amphiboles and glass in melt inclusions [7-10], and apatites [11, 12] from Martian meteorites report finding as much water as in the same phases from Earth's igneous rocks. Most martian hydrous minerals, however, generally have the relevant sites filled with Cl and F instead of H [13, 14], and experiments using Cl [15] in parent melts can reproduce Martian basalt compositions as well as those with water [16]. We are in the process of analyzing Martian meteorite minerals by Fourier transform infrared spectrometry (FTIR) in order to constrain the role of water in this planet s formation and magmatic evolution

  1. LU-HF Age of Martian Meteorite Larkman Nunatek 06319 (United States)

    Shafer, J. T.; Brandon, A. D.; Lapen, T. J.; Righter, M.; Beard, B.; Peslier, A. H.


    Lu-Hf isotopic data were collected on mineral separates and bulk rock powders of LAR 06319, yielding an age of 197+/- 29 Ma. Sm-Nd isotopic data and in-situ LA-ICP-MS data from a thin section of LAR 06319 are currently being collected and will be presented at the 2009 LPSC. These new data for LAR 06319 extend the existing data set for the enriched shergottite group. Martian meteorites represent the only opportunity for ground truth investigation of the geochemistry of Mars [1]. At present, approximately 80 meteorites have been classified as Martian based on young ages and distinctive isotopic signatures [2]. LAR 06319 is a newly discovered (as part of the 2006 ANSMET field season) martian meteorite that represents an important opportunity to further our understanding of the geochemical and petrological constraints on the origin of Martian magmas. Martian meteorites are traditionally categorized into the shergottite, nakhlite, and chassignite groups. The shergottites are further classified into three distinct isotopic groups designated depleted, intermediate, and enriched [3,4] based on the isotope systematics and compositions of their source(s).

  2. Crime Scene Reconstruction Using a Fully Geomatic Approach

    Directory of Open Access Journals (Sweden)

    Andrea Lingua


    Full Text Available This paper is focused on two main topics: crime scene reconstruction, based on a geomatic approach, and crime scene analysis, through GIS based procedures. According to the experience of the authors in performing forensic analysis for real cases, the aforesaid topics will be examined with the specific goal of verifying the relationship of human walk paths at a crime scene with blood patterns on the floor. In order to perform such analyses, the availability of pictures taken by first aiders is mandatory, since they provide information about the crime scene before items are moved or interfered with. Generally, those pictures are affected by large geometric distortions, thus - after a brief description of the geomatic techniques suitable for the acquisition of reference data (total station surveying, photogrammetry and laser scanning - it will be shown the developed methodology, based on photogrammetric algorithms, aimed at calibrating, georeferencing and mosaicking the available images acquired on the scene. The crime scene analysis is based on a collection of GIS functionalities for simulating human walk movements and creating a statistically significant sample. The developed GIS software component will be described in detail, showing how the analysis of this statistical sample of simulated human walks allows to rigorously define the probability of performing a certain walk path without touching the bloodstains on the floor.

  3. EigenScape: A Database of Spatial Acoustic Scene Recordings

    Directory of Open Access Journals (Sweden)

    Marc Ciufo Green


    Full Text Available The classification of acoustic scenes and events is an emerging area of research in the field of machine listening. Most of the research conducted so far uses spectral features extracted from monaural or stereophonic audio rather than spatial features extracted from multichannel recordings. This is partly due to the lack thus far of a substantial body of spatial recordings of acoustic scenes. This paper formally introduces EigenScape, a new database of fourth-order Ambisonic recordings of eight different acoustic scene classes. The potential applications of a spatial machine listening system are discussed before detailed information on the recording process and dataset are provided. A baseline spatial classification system using directional audio coding (DirAC techniques is detailed and results from this classifier are presented. The classifier is shown to give good overall scene classification accuracy across the dataset, with 7 of 8 scenes being classified with an accuracy of greater than 60% with an 11% improvement in overall accuracy compared to use of Mel-frequency cepstral coefficient (MFCC features. Further analysis of the results shows potential improvements to the classifier. It is concluded that the results validate the new database and show that spatial features can characterise acoustic scenes and as such are worthy of further investigation.

  4. Separating reflective and fluorescent components for dynamic scenes (United States)

    Ji, Xiangyang; Miao, Changlong; Zhang, Yongbing; Lin, Xing; Dai, Qionghai


    Separating reflective and fluorescent components by hyperspectral (HS) imaging is significant in many applications. This paper designs an imaging system, where both HS reflective images and HS fluorescent images could be obtained from the same scene, even scenes within moving objects. The system consists of a high-frequency-spectra light source and a spatially-spectrally encoded camera. During the capture phase, the light source illuminates the scene with two high-frequency lighting patterns complemented in the spectral domain by turns, then encoded camera captures a image pair accordingly. During the reconstruction phase, sparsity of the natural reflective and fluorescent HS images is utilized to recover reflective and fluorescent spectra from encoded image pair. Benefited from double-shot imaging system, dynamic scene could also be handled. The method is tested in various datasets(including synthetic and real data), and the results demonstrate that the system could achieve high-resolution hyperspectral reflectance and fluorescence recovery with high-accuracy for dynamic scenes, which can be applied for spectral relighting of real scenes.

  5. Noachian Martian Volcanics a Water Source (United States)

    Zent, A. P.; Glaze, L. S.; Baloga, S. M.; Fonda, Mark (Technical Monitor)


    H2O was supplied to the Noachian atmosphere by eruptions, or in association with large impacts. Most water outgassed into an extremely cold atmosphere, and condensate deposits were inevitable. High heat flow could lead to subglacial melting only if ice thicknesses were greater than 500-1000m, which is extremely unlikely. Subareal melting and flow is contingent upon temperatures periodically exceeding 273 K, and retarding evaporative loss of the flow. In still air, evaporation into a dry atmosphere is in the free convection regime, and a stream with 2 cu m/s discharge, flowing 1 m/s could persist for hundreds of days and cover distances greater than any valley reach. The zero-wind-shear condition is considered implausible however. We investigate the possibility that evaporation rates were suppressed because the atmosphere was regionally charged with H2O as it moved over snow/ice fields. Our initial concern is precipitation from volcanic plumes. A Kilauea-style eruption on the martian surface would cover a 10km circular deposit with 10cm of H2O, if all H2O could be precipitated near the vent. The characteristics of the eruption at the vent, (vent size, temperature, H2O content, etc.) are independent of the environmental conditions. The subsequent behavior of the plume, including precipitation of ash and H2O condensate depends strongly on the environment. Hence, the proximal fate of volcanic H2O is amenable to treatment in a model. A simple bulk thermodynamic model of the rise of an H2O plume through a stably stratified CO2 atmosphere, with only adiabatic cooling, produces runaway plume rise. A more complex treatment includes the effects of latent heat release, wind shear along the plume, divergence of ash and H2O, and will yield more realistic estimates of H2O transport in eruptive plumes. Results of these simulations will be presented.

  6. Structural Origins of Martian Pit Chains (United States)

    Wyrick, D.; Ferrill, D. A.; Morris, A. P.; Colton, S. L.; Sims, D. W.


    Pit craters are circular to elliptical depressions found in alignments (chains), which in many cases coalesce into linear troughs, and are common on the surface of Mars. Pit craters lack an elevated rim, ejecta deposits, or lava flows that are associated with impact craters or calderas. It is generally agreed that these features are formed by collapse into a subsurface cavity. Hypotheses regarding the formation of pit crater chains require development of a substantial subsurface void to accommodate collapse of the overlying sediments. Suggested mechanisms of formation include: collapsed lava tubes, dike swarms, collapsed magma chamber, karst dissolution, fissuring beneath loose material, and dilational faulting. The research described here is intended to constrain current interpretations of pit crater chain formation by analyzing their distribution and morphology. The western hemisphere of Mars was systematically mapped using Mars Orbiter Camera (MOC) images to generate ArcView Geographic Information System (GIS) coverages. All visible pit crater chains were mapped, including their orientations and associations with other structures. We found that pit chains commonly occur in areas that show regional extension or local fissuring. There is a strong correlation between pit chains and fault-bounded grabens. Frequently, there are transitions along strike from (i) visible faulting to (ii) faults and pits to (iii) pits alone. We performed a detailed quantitative analysis of pit crater morphology using MOC narrow angle images, Thermal Emission Imaging System (THEMIS) visual images and Mars Orbiter Laser Altimeter (MOLA) data. This allowed us to interpret a pattern of pit chain evolution and calculate pit depth, slope, and volume. The information collected in the study was then compared with non-Martian examples of pit chains and physical analog models. We evaluated the various mechanisms for pit chain development based on the data collected and conclude that dilational

  7. Meteorological conditions associated to high sublimation amounts in semiarid high-elevation Andes decrease the performance of empirical melt models (United States)

    Ayala, Alvaro; Pellicciotti, Francesca; MacDonell, Shelley; McPhee, James; Burlando, Paolo


    Empirical melt (EM) models are often preferred to surface energy balance (SEB) models to calculate melt amounts of snow and ice in hydrological modelling of high-elevation catchments. The most common reasons to support this decision are that, in comparison to SEB models, EM models require lower levels of meteorological data, complexity and computational costs. However, EM models assume that melt can be characterized by means of a few index variables only, and their results strongly depend on the transferability in space and time of the calibrated empirical parameters. In addition, they are intrinsically limited in accounting for specific process components, the complexity of which cannot be easily reconciled with the empirical nature of the model. As an example of an EM model, in this study we use the Enhanced Temperature Index (ETI) model, which calculates melt amounts using air temperature and the shortwave radiation balance as index variables. We evaluate the performance of the ETI model on dry high-elevation sites where sublimation amounts - that are not explicitly accounted for the EM model - represent a relevant percentage of total ablation (1.1 to 8.7%). We analyse a data set of four Automatic Weather Stations (AWS), which were collected during the ablation season 2013-14, at elevations between 3466 and 4775 m asl, on the glaciers El Tapado, San Francisco, Bello and El Yeso, which are located in the semiarid Andes of central Chile. We complement our analysis using data from past studies in Juncal Norte Glacier (Chile) and Haut Glacier d'Arolla (Switzerland), during the ablation seasons 2008-09 and 2006, respectively. We use the results of a SEB model, applied to each study site, along the entire season, to calibrate the ETI model. The ETI model was not designed to calculate sublimation amounts, however, results show that their ability is low also to simulate melt amounts at sites where sublimation represents larger percentages of total ablation. In fact, we

  8. The Northwest Africa 8159 martian meteorite: Expanding the martian sample suite to the early Amazonian (United States)

    Herd, Christopher D. K.; Walton, Erin L.; Agee, Carl B.; Muttik, Nele; Ziegler, Karen; Shearer, Charles K.; Bell, Aaron S.; Santos, Alison R.; Burger, Paul V.; Simon, Justin I.; Tappa, Michael J.; McCubbin, Francis M.; Gattacceca, Jérôme; Lagroix, France; Sanborn, Matthew E.; Yin, Qing-Zhu; Cassata, William S.; Borg, Lars E.; Lindvall, Rachel E.; Kruijer, Thomas S.; Brennecka, Gregory A.; Kleine, Thorsten; Nishiizumi, Kunihiko; Caffee, Marc W.


    Northwest Africa (NWA) 8159 is an augite-rich shergottite, with a mineralogy dominated by Ca-, Fe-rich pyroxene, plagioclase, olivine, and magnetite. NWA 8159 crystallized from an evolved melt of basaltic composition under relatively rapid conditions of cooling, likely in a surface lava flow or shallow sill. Redox conditions experienced by the melt shifted from relatively oxidizing (with respect to known Martian lithologies, ∼QFM) on the liquidus to higher oxygen fugacity (∼QFM + 2) during crystallization of the groundmass, and under subsolidus conditions. This shift resulted in the production of orthopyroxene and magnetite replacing olivine phenocryst rims. NWA 8159 contains both crystalline and shock-amorphized plagioclase (An50-62), often observed within a single grain; based on known calibrations we bracket the peak shock pressure experienced by NWA 8159 to between 15 and 23 GPa. The bulk composition of NWA 8159 is depleted in LREE, as observed for Tissint and other depleted shergottites; however, NWA 8159 is distinct from all other martian lithologies in its bulk composition and oxygen fugacity. We obtain a Sm-Nd formation age of 2.37 ± 0.25 Ga for NWA 8159, which represents an interval in Mars geologic time which, until recently, was not represented in the other martian meteorite types. The bulk rock 147Sm/144Nd value of 0.37 ± 0.02 is consistent with it being derived directly from its source and the high initial ε143Nd value indicates this source was geochemically highly depleted. Cr, Nd, and W isotopic compositions further support a unique mantle source. While the rock shares similarities with the 2.4-Ga NWA 7635 meteorite, there are notable distinctions between the two meteorites that suggest differences in mantle source compositions and conditions of crystallization. Nevertheless, the two samples may be launch-paired. NWA 8159 expands the known basalt types, ages and mantle sources within the Mars sample suite to include a second igneous unit from

  9. Raise two effects with one scene: scene contexts have two separate effects in visual working memory of target faces


    Tanabe-Ishibashi, Azumi; Ikeda, Takashi; Osaka, Naoyuki


    Many people have experienced the inability to recognize a familiar face in a changed context, a phenomenon known as the “butcher-on-the-bus” effect. Whether this context effect is a facilitation of memory by old contexts or a disturbance of memory by novel contexts is of great debate. Here, we investigated how two types of contextual information associated with target faces influence the recognition performance of the faces using meaningful (scene) or meaningless (scrambled scene) backgrounds...

  10. Raise two effects with one scene: Scene contexts have two separate effects in visual working memory of target faces.


    Azumi eTanabe-Ishibashi; Takashi eIkeda; Naoyuki eOsaka


    Many people have experienced the inability to recognize a familiar face in a changed context, a phenomenon known as the butcher-on-the-bus effect. Whether this context effect is a facilitation of memory by old contexts or a disturbance of memory by novel contexts is of great debate. Here, we investigated how two types of contextual information associated with target faces influence the recognition performance of the faces using meaningful (scene) or meaningless (scrambled scene) backgrounds. ...

  11. Metabolic Heat Regenerated Temperature Swing Adsorption for CO2 and Heat Removal/Rejection in a Martian PLSS (United States)

    Iacomini, Christine; Powers, Aaron; Bower, Chad; Straub-Lopez, Kathrine; Anderson, Grant; MacCallum, Taber; Paul, Heather L.


    Two of the fundamental problems facing the development of a Portable Life Support System (PLSS) for use on Mars, are (i) heat rejection (because traditional technologies use sublimation of water, which wastes a scarce resource and contaminates the premises), and (ii) rejection of carbon dioxide (CO2) in an environment with a CO2 partial pressure (ppCO2) of 0.4-0.9 kPa. Patent-pending Metabolic heat regenerated Temperature Swing Adsorption (MTSA) technology is being developed to address both these challenges. The technology utilizes an adsorbent that when cooled with liquid CO2 to near sublimation temperatures (195K) removes metabolically-produced CO2 in the ventilation loop. Once fully loaded, the adsorbent is then warmed externally by the ventilation loop (300K), rejecting the captured CO2 to Mars ambient. Two beds are used to provide a continuous cycle of CO2 removal/rejection as well as facilitate heat exchange out of the ventilation loop. Any cryogenic fluid can be used in the application; however, since CO2 is readily available on Mars and can be easily produced and stored on the Martian surface, the solution is rather elegant and less complicated when employing liquid CO2. As some metabolic heat will need to be rejected anyway, finding a practical use for metabolic heat is also an overall benefit to the PLSS. To investigate the feasibility of the technology, a series of experiments were conducted which lead to the selection and partial characterization of an appropriate adsorbent. The Molsiv Adsorbents 13X 8x12 (also known as NaX zeolite) successfully removed CO2 from a simulated ventilation loop at the prescribed temperature swing anticipated during PLSS operating conditions on Mars using a cryogenic fluid. Thermal conductivity of the adsorbent was also measured to eventually aid in a demonstrator design of the technology. These results provide no show stoppers to the development of MTSA technology and allow its development to focus on other design

  12. Next Steps Forward in Understanding Martian Surface and Subsurface Chemistry (United States)

    Carrier, Brandi L.


    The presence of oxidants such as hydrogen peroxide (H2O2) and perchlorate (ClO4-), which have been detected on Mars, has significant implications for chemistry and astrobiology. These oxidants can increase the reactivity of the Martian soil, accelerate the decomposition of organic molecules, and depress the freezing point of water. The study by Crandall et al. "Can Perchlorates be Transformed to Hydrogen Peroxide Products by Cosmic Rays on the Martian Surface" reveals a new formation mechanism by which hydrogen peroxide and other potential oxidants can be generated via irradiation of perchlorate by cosmic rays. This study represents an important next step in developing a full understanding of Martian surface and subsurface chemistry, particularly with respect to degradation of organic molecules and potential biosignatures.

  13. Iron Redox Systematics of Shergottites and Martian Magmas (United States)

    Righter, Kevin; Danielson, L. R.; Martin, A. M.; Newville, M.; Choi, Y.


    Martian meteorites record a range of oxygen fugacities from near the IW buffer to above FMQ buffer [1]. In terrestrial magmas, Fe(3+)/ SigmaFe for this fO2 range are between 0 and 0.25 [2]. Such variation will affect the stability of oxides, pyroxenes, and how the melt equilibrates with volatile species. An understanding of the variation of Fe(3+)/SigmaFe for martian magmas is lacking, and previous work has been on FeO-poor and Al2O3-rich terrestrial basalts. We have initiated a study of the iron redox systematics of martian magmas to better understand FeO and Fe2O3 stability, the stability of magnetite, and the low Ca/high Ca pyroxene [3] ratios observed at the surface.

  14. AdS/QCD, Light-Front Holography, and Sublimated Gluons

    Energy Technology Data Exchange (ETDEWEB)

    Brodsky, Stanley J.; /SLAC; de Teramond, Guy F.; /Costa Rica U.


    The gauge/gravity duality leads to a simple analytical and phenomenologically compelling nonperturbative approximation to the full light-front QCD Hamiltonian - 'Light-Front Holography', which provides a Lorentz-invariant first-approximation to QCD, and successfully describes the spectroscopy of light-quark meson and baryons, their elastic and transition form factors, and other hadronic properties. The bound-state Schroedinger and Dirac equations of the soft-wall AdS/QCD model predict linear Regge trajectories which have the same slope in orbital angular momentum L and radial quantum number n for both mesons and baryons. Light-front holography connects the fifth-dimensional coordinate of AdS space z to an invariant impact separation variable {zeta} in 3+1 space at fixed light-front time. A key feature is the determination of the frame-independent light-front wavefunctions of hadrons - the relativistic analogs of the Schroedinger wavefunctions of atomic physics which allow one to compute form factors, transversity distributions, spin properties of the valence quarks, jet hadronization, and other hadronic observables. One thus obtains a one-parameter color-confining model for hadron physics at the amplitude level. AdS/QCD also predicts the form of the non-perturbative effective coupling {alpha}{sub s}{sup AdS} (Q) and its {beta}-function with an infrared fixed point which agrees with the effective coupling a{sub g1} (Q{sup 2}) extracted from measurements of the Bjorken sum rule below Q{sup 2} < 1 GeV{sup 2}. This is consistent with a flux-tube interpretation of QCD where soft gluons with virtualities Q{sup 2} < 1 GeV{sup 2} are sublimated into a color-confining potential for quarks. We discuss a number of phenomenological hadronic properties which support this picture.


    Energy Technology Data Exchange (ETDEWEB)

    Hsieh, Henry H. [Institute of Astronomy and Astrophysics, Academia Sinica, P.O. Box 23-141, Taipei 10617, Taiwan (China); Hainaut, Olivier [European Southern Observatory, Karl-Schwarzschild-Straße 2, D-85748 Garching bei München (Germany); Novaković, Bojan [Department of Astronomy, Faculty of Mathematics, University of Belgrade, Studentski trg 16, 11000 Belgrade (Serbia); Bolin, Bryce [Observatoire de la Côte d’Azur, Boulevard de l’Observatoire, B.P. 4229, F-06304 Nice Cedex 4 (France); Denneau, Larry; Haghighipour, Nader; Kleyna, Jan; Meech, Karen J.; Schunova, Eva; Wainscoat, Richard J. [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States); Fitzsimmons, Alan [Astrophysics Research Centre, Queens University Belfast, Belfast BT7 1NN (United Kingdom); Kokotanekova, Rosita; Snodgrass, Colin [Planetary and Space Sciences, Department of Physical Sciences, The Open University, Milton Keynes MK7 6AA (United Kingdom); Lacerda, Pedro [Max Planck Institute for Solar System Research, Justus-von-Liebig-Weg 3, D-37077 Göttingen (Germany); Micheli, Marco [ESA SSA NEO Coordination Centre, Frascati, RM (Italy); Moskovitz, Nick; Wasserman, Lawrence [Lowell Observatory, 1400 W. Mars Hill Road, Flagstaff, AZ 86001 (United States); Waszczak, Adam, E-mail: [Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125 (United States)


    We present an observational and dynamical study of newly discovered main-belt comet 313P/Gibbs. We find that the object is clearly active both in observations obtained in 2014 and in precovery observations obtained in 2003 by the Sloan Digital Sky Survey, strongly suggesting that its activity is sublimation-driven. This conclusion is supported by a photometric analysis showing an increase in the total brightness of the comet over the 2014 observing period, and dust modeling results showing that the dust emission persists over at least three months during both active periods, where we find start dates for emission no later than 2003 July 24 ± 10 for the 2003 active period and 2014 July 28 ± 10 for the 2014 active period. From serendipitous observations by the Subaru Telescope in 2004 when the object was apparently inactive, we estimate that the nucleus has an absolute R-band magnitude of H{sub R} = 17.1 ± 0.3, corresponding to an effective nucleus radius of r{sub e} ∼ 1.00 ± 0.15 km. The object’s faintness at that time means we cannot rule out the presence of activity, and so this computed radius should be considered an upper limit. We find that 313P’s orbit is intrinsically chaotic, having a Lyapunov time of T{sub l} = 12,000 yr and being located near two three-body mean-motion resonances with Jupiter and Saturn, 11J-1S-5A and 10J+12S-7A, yet appears stable over >50 Myr in an apparent example of stable chaos. We furthermore find that 313P is the second main-belt comet, after P/2012 T1 (PANSTARRS), to belong to the ∼155 Myr old Lixiaohua asteroid family.

  16. Mass removal by oxidation and sublimation of porous graphite during fiber laser irradiation (United States)

    Phillips, Grady T.; Bauer, William A.; Fox, Charles D.; Gonzales, Ashley E.; Herr, Nicholas C.; Gosse, Ryan C.; Perram, Glen P.


    The various effects of laser heating of carbon materials are key to assessing laser weapon effectiveness. Porous graphite plates, cylinders, and cones with densities of 1.55 to 1.82 g/cm3 were irradiated by a 10-kW fiber laser at 0.075 to 3.525 kW/cm2 for 120 s to study mass removal and crater formation. Surface temperatures reached steady state values as high as 3767 K. The total decrease in sample mass ranged from 0.06 to 6.29 g, with crater volumes of 0.52 to 838 mm3, and penetration times for 12.7-mm-thick plates as short as 38 s. Minor contaminants in the graphite samples produced calcium and iron oxide to be redeposited on the graphite surface. Dramatic graphite crystalline structures are also produced at higher laser irradiances. Significantly increased porosity of the sample is observed even outside the laser-irradiated region. Total mass removed increases with deposited laser energy at a rate of 4.83 g/MJ for medium extruded graphite with an apparent threshold of 0.15 MJ. At ˜3.5 kW/cm2, the fractions of the mass removed from the cylindrical samples in the crater, surrounding trench, and outer region of decreased porosity are 38%, 47%, and 15%, respectively. Graphite is particularly resistant to damage by high power lasers. The new understanding of graphite combustion and sublimation during laser irradiation is vital to the more complex behavior of carbon composites.

  17. Propafenone HCl fast dissolving tablets containing subliming agent prepared by direct compression method. (United States)

    Abd El Rasoul, Saleh; Shazly, Gamal A


    Propafenone HCl (PPH), an antiarrhythmic drug, has a bitter taste, short half-life, delayed drug dissolution and side effects. Thus, the purpose of this work is to develop orally fast dissolving tablets (OFDTs) containing PPH to provide a rapid drug dissolution and subsequently give rapid onset of action of PPH as an antiarrhythmic drug. Moreover, OFDTs of PPH reduce its side effects and improve its bioavailability. Propafenone HCl (PPH), an antiarrhythmic drug, has a bitter taste, short half-life, delayed drug dissolution and side effects. Direct compression method was used for the preparation of 15 formulations OFDTs containing PPH using directly compressible excipients, subliming agent and superdisintegrants. The prepared tablets were undergone physical characterization, in vitro dissolution and stability studies. All pre- and post-compression tests met the pharmacopoeia specifications. In vitro dissolution of the prepared PPH OFDTs exhibited high dissolution rate than compared to the marketed tablets. It was found that the tablets prepared by using the higher concentration of crospovidone were found to dissolute the drug at a faster rate when compared to other concentrations. A formula containing croscarmellose sodium showed the higher present of PPH dissolved as compared to the other formulations. It was concluded that PPH OFDTs were formulated successfully with acceptable physical and chemical properties with rapid disintegration in the oral cavity, rapid onset of action, and enhanced patient compliance. It was found that F10 showed good stability upon storage at 25 and 40 °C for 3 months. Formulation of PPH OFDTs can result in a significant improvement in the PPH bioavailability since the first pass metabolism will be avoided.

  18. Propafenone HCl fast dissolving tablets containing subliming agent prepared by direct compression method

    Directory of Open Access Journals (Sweden)

    Saleh Abd El Rasoul


    Full Text Available Propafenone HCl (PPH, an antiarrhythmic drug, has a bitter taste, short half-life, delayed drug dissolution and side effects. Thus, the purpose of this work is to develop orally fast dissolving tablets (OFDTs containing PPH to provide a rapid drug dissolution and subsequently give rapid onset of action of PPH as an antiarrhythmic drug. Moreover, OFDTs of PPH reduce its side effects and improve its bioavailability. Propafenone HCl (PPH, an antiarrhythmic drug, has a bitter taste, short half-life, delayed drug dissolution and side effects. Direct compression method was used for the preparation of 15 formulations OFDTs containing PPH using directly compressible excipients, subliming agent and superdisintegrants. The prepared tablets were undergone physical characterization, in vitro dissolution and stability studies. All pre- and post-compression tests met the pharmacopoeia specifications. In vitro dissolution of the prepared PPH OFDTs exhibited high dissolution rate than compared to the marketed tablets. It was found that the tablets prepared by using the higher concentration of crospovidone were found to dissolute the drug at a faster rate when compared to other concentrations. A formula containing croscarmellose sodium showed the higher present of PPH dissolved as compared to the other formulations. It was concluded that PPH OFDTs were formulated successfully with acceptable physical and chemical properties with rapid disintegration in the oral cavity, rapid onset of action, and enhanced patient compliance. It was found that F10 showed good stability upon storage at 25 and 40 °C for 3 months. Formulation of PPH OFDTs can result in a significant improvement in the PPH bioavailability since the first pass metabolism will be avoided.

  19. Digital forensics: an analytical crime scene procedure model (ACSPM). (United States)

    Bulbul, Halil Ibrahim; Yavuzcan, H Guclu; Ozel, Mesut


    In order to ensure that digital evidence is collected, preserved, examined, or transferred in a manner safeguarding the accuracy and reliability of the evidence, law enforcement and digital forensic units must establish and maintain an effective quality assurance system. The very first part of this system is standard operating procedures (SOP's) and/or models, conforming chain of custody requirements, those rely on digital forensics "process-phase-procedure-task-subtask" sequence. An acceptable and thorough Digital Forensics (DF) process depends on the sequential DF phases, and each phase depends on sequential DF procedures, respectively each procedure depends on tasks and subtasks. There are numerous amounts of DF Process Models that define DF phases in the literature, but no DF model that defines the phase-based sequential procedures for crime scene identified. An analytical crime scene procedure model (ACSPM) that we suggest in this paper is supposed to fill in this gap. The proposed analytical procedure model for digital investigations at a crime scene is developed and defined for crime scene practitioners; with main focus on crime scene digital forensic procedures, other than that of whole digital investigation process and phases that ends up in a court. When reviewing the relevant literature and interrogating with the law enforcement agencies, only device based charts specific to a particular device and/or more general perspective approaches to digital evidence management models from crime scene to courts are found. After analyzing the needs of law enforcement organizations and realizing the absence of crime scene digital investigation procedure model for crime scene activities we decided to inspect the relevant literature in an analytical way. The outcome of this inspection is our suggested model explained here, which is supposed to provide guidance for thorough and secure implementation of digital forensic procedures at a crime scene. In digital forensic

  20. Raise two effects with one scene: scene contexts have two separate effects in visual working memory of target faces. (United States)

    Tanabe-Ishibashi, Azumi; Ikeda, Takashi; Osaka, Naoyuki


    Many people have experienced the inability to recognize a familiar face in a changed context, a phenomenon known as the "butcher-on-the-bus" effect. Whether this context effect is a facilitation of memory by old contexts or a disturbance of memory by novel contexts is of great debate. Here, we investigated how two types of contextual information associated with target faces influence the recognition performance of the faces using meaningful (scene) or meaningless (scrambled scene) backgrounds. The results showed two different effects of contexts: (1) disturbance on face recognition by changes of scene backgrounds and (2) weak facilitation of face recognition by the re-presentation of the same backgrounds, be it scene or scrambled. The results indicate that the facilitation and disturbance of context effects are actually caused by two different subcomponents of the background information: semantic information available from scene backgrounds and visual array information commonly included in a scene and its scrambled picture. This view suggests visual working memory system can control such context information, so that it switches the way to deal with the contexts information; inhibiting it as a distracter or activating it as a cue for recognizing the current target.

  1. Raise two effects with one scene: Scene contexts have two separate effects in visual working memory of target faces.

    Directory of Open Access Journals (Sweden)

    Azumi eTanabe-Ishibashi


    Full Text Available Many people have experienced the inability to recognize a familiar face in a changed context, a phenomenon known as the butcher-on-the-bus effect. Whether this context effect is a facilitation of memory by old contexts or a disturbance of memory by novel contexts is of great debate. Here, we investigated how two types of contextual information associated with target faces influence the recognition performance of the faces using meaningful (scene or meaningless (scrambled scene backgrounds. The results showed two different effects of contexts: (1 disturbance on face recognition by changes of scene backgrounds and (2 weak facilitation of face recognition by the re-presentation of the same backgrounds, be it scene or scrambled. The results indicate that the facilitation and disturbance of context effects are actually caused by different two subcomponents of the background information: semantic information available from scene backgrounds and visual-array information commonly included in a scene and its scrambled picture. This view suggests visual working memory system can control such context information, so that it switches the way to deal with the contexts information; inhibiting it as a distracter or activating it as a cue for recognizing the current target.

  2. Mars-relevant phosphate minerals and implications for Martian habitability (United States)

    Adcock, Christopher T.

    This dissertation is comprised of three studies focused on martian phosphate availability, with an introductory chapter introducing and linking the three studies. Chapter two is on the subject of merrillite synthesis. Merrillite is an extraterrestrial Ca-phosphate mineral similar to the mineral whitlockite and is found as a dominant primary phosphate mineral in martian meteorites. The chapter includes methods of whitlockite and merrillite synthesis as well as a detailed characterization of the produced minerals and a mechanism by which charge balance can be maintained when merrillite is synthesized through dehydrogenation of whitlockite. Chapter three presents the results of kinetic and thermodynamic studies on the Mars-relevant minerals chlorapatite and merrillite, as well as the more terrestrially-relevant minerals whitlockite and fluorapatite. The results of these studies indicate that the dominant primary Ca-phosphate minerals on Mars possess higher solubilities that could lead to more than twice the phosphate concentration in solution. Dissolution rates for the Mars-relevant minerals derived in the study, when combined with the higher martian phosphorus abundance, could result in phosphate release rates of up to 45x faster for a given set of aqueous conditions on Mars when compared to Earth. The implications of the results for past or present martian habitability are discussed. In Chapter four, reactive transport modeling was applied to investigate the transport and mobility of phosphate under martian conditions. The kinetic and thermodynamic data derived in Chapter three were combined with Mars mission data, results from an investigation of Mars analog basalts at Craters of the Moon National Monument in Idaho, and previously published data to inform a reactive transport code and model dissolution profiles measured by Mars Exploration Rover (MER) Spirit in Wishstone class rocks. The modeling results suggest phosphate release into near-neutral waters occurred

  3. Earth – Mars Similarity Criteria for Martian Vehicles

    Directory of Open Access Journals (Sweden)

    Octavian TRIFU


    Full Text Available In order to select the most efficient kind of a martian exploring vehicle, the similarity criteria are deduced from the equilibrium movement in the terrestrial and martian conditions. Different invariants have been obtained for the existing (entry capsules, parachutes and rovers and potential martian exploring vehicles (lighter-than-air vehicle, airplane, helicopter and Mars Jumper. These similarity criteria, as non dimensional numbers, allow to quickly compare if such a kind of vehicles can operate in the martian environment, the movement performances, the necessary geometrical dimensions and the power consumption. Following this way of study it was concluded what vehicle is most suitable for the near soil Mars exploration. “Mars Rover” has less power consumption on Mars, but due to the rugged terrain the performances are weak. A vacuumed rigid airship is possible to fly with high performances and endurance on Mars, versus the impossibility of such a machine on the Earth. Due to very low density and the low Reynolds numbers in the Mars atmosphere, the power consumption for the martian airplane or helicopter, is substantial higher. The most efficient vehicle for the Mars exploration it seems to be a machine using the in-situ non-chemical propellants: the 95% CO2 atmosphere and the weak solar radiation. A small compressor, electrically driven by photovoltaics, compresses the gas in a storage tank, in time. If the gas is expanded through a nozzle, sufficient lift and control forces are obtained for a VTOL flight of kilometers over the martian soil, in comparison with tens of meters of the actual Mars rovers.

  4. Petrogenesis of the NWA 7320 enriched martian gabbroic shergottite: Insight into the martian crust (United States)

    Udry, Arya; Howarth, Geoffrey H.; Lapen, Thomas J.; Righter, Minako


    Northwest Africa (NWA) 7320 is classified as a gabbroic shergottite, the second to be recognized in the martian meteorite record. This interpretation is based on: (1) the calculated bulk-rock rare earth element (REE) concentrations, which show the highest Eu positive anomaly (Eu/Eu∗ = 2.2) of all the shergottites, reflecting accumulation of plagioclase; and (2) the highest modal abundance of maskelynitized plagioclase (50 mod.%) compared to the other shergottites. The three-phase symplectite (fayalite + hedenbergite + silica) is present in NWA 7320 and formed as a result of the breakdown of metastable pyroxene/pyroxenoid margins on coarse-grained pyroxenes. The latter is indicative of metastable overgrowths on pyroxene cores during the final stages of crystallization, followed by relatively slow cooling at subsolidus conditions. The NWA 7320 parental melt originated from an incompatible trace element enriched and oxidized (∼FMQ) source as indicated by Sm-Nd, Lu-Hf isotope systematics, ilmenite-titanomagnetite pairs, the partition coefficient of Cr in pyroxene, and merrillite REE compositions. The Ti/Al ratio of pyroxene in NWA 7320 indicates an initial crystallization depth of 30-70 km (P = 4-9 kbar). However, the largest impact craters on Mars are <8 km in depth, indicating that NWA 7320 could not have been ejected from this depth and must have had a polybaric formation history. We suggest that the pyroxene phenocrysts began to crystallize at depth, but were entrained as antecrysts in a basaltic magma ascending to shallower levels in the martian crust. In addition, plagioclase likely crystallized during magma ascent, followed by subsequent accumulation in a shallow magma intrusion or sill, resulting in the gabbroic texture. Furthermore, the similarity in the radiogenic isotope composition of NWA 7320 to that of Los Angeles and NWA 856 suggest that these meteorites were linked to common volcanic system on Mars.

  5. Martian weathering processes: Terrestrial analog and theoretical modeling studies (United States)

    McAdam, Amy Catherine


    Understanding the role of water in the Martian near-surface, and its implications for possible habitable environments, is among the highest priorities of NASA's Mars Exploration Program. Characterization of alteration signatures in surface materials provides the best opportunity to assess the role of water on Mars. This dissertation investigates Martian alteration processes through analyses of Antarctic analogs and numerical modeling of mineral-fluid interactions. Analog work involved studying an Antarctic diabase, and associated soils, as Mars analogs to understand weathering processes in cold, dry environments. The soils are dominated by primary basaltic minerals, but also contain phyllosilicates, salts, iron oxides/oxyhydroxides, and zeolites. Soil clay minerals and zeolites, formed primarily during deuteric or hydrothermal alteration of the parent rock, were subsequently transferred to the soil by physical rock weathering. Authigenic soil iron oxides/oxyhydroxides and small amounts of poorly-ordered secondary silicates indicate some contributions from low-temperature aqueous weathering. Soil sulfates, which exhibit a sulfate- aerosol-derived mass-independent oxygen isotope signature, suggest contributions from acid aerosol-rock interactions. The complex alteration history of the Antarctic materials resulted in several similarities to Martian materials. The processes that affected the analogs, including deuteric/ hydrothermal clay formation, may be important in producing Martian surface materials. Theoretical modeling focused on investigating the alteration of Martian rocks under acidic conditions and using modeling results to interpret Martian observations. Kinetic modeling of the dissolution of plagioclase-pyroxene mineral mixtures under acidic conditions suggested that surfaces with high plagioclase/pyroxene, such as several northern regions, could have experienced some preferential dissolution of pyroxenes at a pH less than approximately 3-4. Modeling of the


    Directory of Open Access Journals (Sweden)

    S. Nowak


    Full Text Available In order to explore planet Mars in detail and search for extra-terrestrial life the observation from orbit is not sufficient. To realize complex exploration tasks the use of automatic operating robots with a robust fault-tolerant method of navigation, independent of any infrastructure is a possibility. This work includes a concept of rotary-wing Unmanned Aerial Vehicles (UAVs and Unmanned Ground Vehicles (UGVs for Martian exploration in a swarm. Besides the scenario of Martian surrounding, with a small number of distinctive landmarks, the challenge consists of a Simultaneous Localization and Mapping (SLAM concept using laser data of all swarm members.

  7. Desert spring mounds: a potential analogue to Martian arid environments? (United States)

    Franchi, F.; Frisia, S.


    Spring carbonates have been often considered as putative analogues of Martian arid environments. On Earth these are believed to form by the interaction of highly saline water and microbial communities, which favor the formation of authigenic micrite. Here we present new data from spring mounds in the western Makgadikgadi Pan (Botswana) and the Great Artesian Basin (South Australia). In both areas, upwelling of ground water give rise to mounds and layered deposits which are close morphological analogues of landforms documented on Mars. The authigenic carbonates and evaporites associated with the spring mounds retain evidence of microbial microfabric founded elsewhere, pointing to the potential existence of similar microbial in the extreme Martian conditions.

  8. Tracer transport in the Martian atmosphere (United States)

    Lian, Y.; Richardson, M. I.; Newman, C. E.; Lee, C.; Toigo, A. D.; Campin, J.


    Transport is crucial to understanding and reproducing the Martian dust and water cycles, and to interpreting putative methane and other trace gas (e.g. Argon) observations. However, as quantified by comparing model predictions with Argon measurements made by the Gamma Ray Spectrometer [e.g. Sprague et al., 2004, 2007], current Mars general circulation models (GCM's) appear to do a poor job at tracer transport [e.g. Nelli et al., 2007]. This invalidates a core assumption of GCM modeling in the last decade - that transport is sufficiently well treated in models that we need focus only on improving physical parameterizations, and that differences between results from different GCM's stem purely from their treatment of physical processes. If instead it is the simulated dynamical processes that need better treatment we need to move towards higher-quality numerics, e.g. based on the finite volume formulation, and introduce a more sophisticated approach to advection following work done for terrestrial chemical transport modeling. Here we present the results of non-condensable tracer transport simulations using our newly developed Mars MITgcm, which has both of the aforementioned desirable attributes: a finite volume core and access to a range of sophisticated advection schemes. Our results are encouraging in that we are able to reproduce the observed peak polar Argon enhancement factor of six (about double that attainable with most other Mars GCMs). Our diagnostics show that the time-averaged zonal-mean advection produces net increases of Argon at the winter poles, while stationary and transient eddies transport Argon away from the poles. Using less diffusive nonlinear advection schemes with flux limiters tends to produce more advective fluxes of tracers into the southern winter pole than the more diffusive linear advection schemes, resulting in a greater net increase of polar Argon abundance. We further utilize a more realistic k-distribution radiative transfer model, an

  9. What Lies Below a Martian Ice Cap (United States)


    [figure removed for brevity, see original site] Click on image for larger annotated version This image (top) taken by the Shallow Radar instrument on NASA's Mars Reconnaissance Orbiter reveals the layers of ice, sand and dust that make up the north polar ice cap on Mars. It is the most detailed look to date at the insides of this ice cap. The colored map below the radar picture shows the topography of the corresponding Martian terrain (red and white represent higher ground, and green and yellow lower). The radar image reveals four never-before-seen thick layers of ice and dust separated by layers of nearly pure ice. According to scientists, these thick ice-free layers represent approximately one-million-year-long cycles of climate change on Mars caused by variations in the planet's tilted axis and its eccentric orbit around the sun. Adding up the entire stack of ice gives an estimated age for the north polar ice cap of about 4 million years a finding that agrees with previous theoretical estimates. The ice cap is about 2 kilometers (1.2 miles) thick. The radar picture also shows that the boundary between the ice layers and the surface of Mars underneath is relatively flat (bottom white line on the right). This implies that the surface of Mars is not sagging, or bending, under the weight of the ice cap and this, in turn, suggests that the planet's lithosphere, a combination of the crust and the strong parts of the upper mantle, is thicker than previously thought. A thicker lithosphere on Mars means that temperatures increase more gradually with depth toward the interior. Temperatures warm enough for water to be liquid are therefore deeper than previously thought. Likewise, if liquid water does exist in aquifers below the surface of Mars, and if there are any organisms living in that water, they would have to be located deeper in the planet. The topography data are from Mars Orbiter Laser Altimeter, which was flown on NASA's Mars Global Surveyor mission. NPLD stands

  10. Video Pedestrian Detection Based on Orthogonal Scene Motion Pattern

    Directory of Open Access Journals (Sweden)

    Jianming Qu


    Full Text Available In fixed video scenes, scene motion patterns can be a very useful prior knowledge for pedestrian detection which is still a challenge at present. A new approach of cascade pedestrian detection using an orthogonal scene motion pattern model in a general density video is developed in this paper. To statistically model the pedestrian motion pattern, a probability grid overlaying the whole scene is set up to partition the scene into paths and holding areas. Features extracted from different pattern areas are classified by a group of specific strategies. Instead of using a unitary classifier, the employed classifier is composed of two directional subclassifiers trained, respectively, with different samples which are selected by two orthogonal directions. Considering that the negative images from the detection window scanning are much more than the positive ones, the cascade AdaBoost technique is adopted by the subclassifiers to reduce the negative image computations. The proposed approach is proved effectively by static classification experiments and surveillance video experiments.

  11. Radio Wave Propagation Scene Partitioning for High-Speed Rails

    Directory of Open Access Journals (Sweden)

    Bo Ai


    Full Text Available Radio wave propagation scene partitioning is necessary for wireless channel modeling. As far as we know, there are no standards of scene partitioning for high-speed rail (HSR scenarios, and therefore we propose the radio wave propagation scene partitioning scheme for HSR scenarios in this paper. Based on our measurements along the Wuhan-Guangzhou HSR, Zhengzhou-Xian passenger-dedicated line, Shijiazhuang-Taiyuan passenger-dedicated line, and Beijing-Tianjin intercity line in China, whose operation speeds are above 300 km/h, and based on the investigations on Beijing South Railway Station, Zhengzhou Railway Station, Wuhan Railway Station, Changsha Railway Station, Xian North Railway Station, Shijiazhuang North Railway Station, Taiyuan Railway Station, and Tianjin Railway Station, we obtain an overview of HSR propagation channels and record many valuable measurement data for HSR scenarios. On the basis of these measurements and investigations, we partitioned the HSR scene into twelve scenarios. Further work on theoretical analysis based on radio wave propagation mechanisms, such as reflection and diffraction, may lead us to develop the standard of radio wave propagation scene partitioning for HSR. Our work can also be used as a basis for the wireless channel modeling and the selection of some key techniques for HSR systems.

  12. Research on hyperspectral dynamic scene and image sequence simulation (United States)

    Sun, Dandan; Gao, Jiaobo; Sun, Kefeng; Hu, Yu; Li, Yu; Xie, Junhu; Zhang, Lei


    This paper presents a simulation method of hyper-spectral dynamic scene and image sequence for hyper-spectral equipment evaluation and target detection algorithm. Because of high spectral resolution, strong band continuity, anti-interference and other advantages, in recent years, hyper-spectral imaging technology has been rapidly developed and is widely used in many areas such as optoelectronic target detection, military defense and remote sensing systems. Digital imaging simulation, as a crucial part of hardware in loop simulation, can be applied to testing and evaluation hyper-spectral imaging equipment with lower development cost and shorter development period. Meanwhile, visual simulation can produce a lot of original image data under various conditions for hyper-spectral image feature extraction and classification algorithm. Based on radiation physic model and material characteristic parameters this paper proposes a generation method of digital scene. By building multiple sensor models under different bands and different bandwidths, hyper-spectral scenes in visible, MWIR, LWIR band, with spectral resolution 0.01μm, 0.05μm and 0.1μm have been simulated in this paper. The final dynamic scenes have high real-time and realistic, with frequency up to 100 HZ. By means of saving all the scene gray data in the same viewpoint image sequence is obtained. The analysis results show whether in the infrared band or the visible band, the grayscale variations of simulated hyper-spectral images are consistent with the theoretical analysis results.

  13. The effect of oxalic acid applied by sublimation on honey bee colony fitness: a comparison with amitraz

    Directory of Open Access Journals (Sweden)

    Ivana Papežíková


    Full Text Available Oxalic acid is one of the organic acids used for controlling Varroa destructor, a mite parasitizing the honey bee (Apis mellifera. The aim of this work was to examine the effect of oxalic acid applied by sublimation on honey bee colony fitness, and to compare it with the effect of amitraz, a routinely used synthetic acaricide. Bee colonies of equal strength were randomly divided into two groups. In December 2014, one group was treated with amitraz in the form of aerosol, and the second group was treated with oxalic acid applied by sublimation. The colonies were monitored over winter. Dead bees found at the bottom of the hive were counted regularly and examined microscopically for infection with Nosema sp. (Microsporidia. At the end of March 2015, living foragers from each hive were sampled and individually examined for Nosema sp. infection. Colony strength was evaluated at the beginning of April. No adverse effect of oxalic acid on colony strength was observed despite the fact that the total number of dead bees was non-significantly higher in the oxalic acid-treated group. Examination of dead bees for Nosema infection did not reveal significant differences in spore numbers between the experimental groups. There was a substantial difference in living individuals, however, with a significantly higher amount of spores per bee found in the amitraz-treated colonies compared to the oxalic acid-treated colonies. Compared to amitraz, oxalic acid applied by sublimation showed no adverse effects on bee colony fitness or on successful overwintering.

  14. Age and stability of sublimation till over buried glacier ice, inferred from 21Ne measurements, Ong Valley, Antarctica (United States)

    Bibby, T.; Putkonen, J.; Morgan, D. J.; Balco, G.


    Ong Valley, in the Central Transantarctic Mountains, contains three distinct glacial drifts deposited by past advances of the Argosy glacier into the valley. Massive ice occurs below two of the till deposits. Potentially, such buried ice under shallow regolith cover could provide access to past climate and biological records more easily than deep ice coring. We measured cosmic-ray produced 21Ne in these tills as a means of constraining the age and stability of the three drifts, as well as the ice below them. We collected samples in vertical profiles from two hand-dug sections through each drift. The pits from two drifts overlying buried ice extended to the buried ice surface. The hypothesis that these are sublimation tills implies that 21Ne concentrations are a function of i) any inheritance from prior exposure; ii) the age since emplacement of the ice and till; iii) the sublimation rate of the ice; and iv) the surface erosion rate of the till. 21Ne concentrations in the youngest drift are ca. 10 M atoms/g and invariant with depth, indicating that they are predominantly due to inheritance, and provide only a weak maximum age constraint of ca. 0.1 Mya. The two older drifts have surface 21Ne concentrations of 200-250 M atoms/ g and depth concentration profiles consistent with a sublimation till origin. Given that 21Ne concentrations in the deepest samples in each of the two older drifts provide an upper limit on the inherited 21Ne concentration, these imply minimum ages of 1 Mya for the middle drift and 1.6 Mya for the oldest. This implies a 1 Mya minimum age for the ice underlying the middle drift.

  15. Martian sub-surface ionising radiation: biosignatures and geology

    Directory of Open Access Journals (Sweden)

    J. M. Ward


    Full Text Available The surface of Mars, unshielded by thick atmosphere or global magnetic field, is exposed to high levels of cosmic radiation. This ionising radiation field is deleterious to the survival of dormant cells or spores and the persistence of molecular biomarkers in the subsurface, and so its characterisation is of prime astrobiological interest. Here, we present modelling results of the absorbed radiation dose as a function of depth through the Martian subsurface, suitable for calculation of biomarker persistence. A second major implementation of this dose accumulation rate data is in application of the optically stimulated luminescence technique for dating Martian sediments.

    We present calculations of the dose-depth profile in the Martian subsurface for various scenarios: variations of surface composition (dry regolith, ice, layered permafrost, solar minimum and maximum conditions, locations of different elevation (Olympus Mons, Hellas basin, datum altitude, and increasing atmospheric thickness over geological history. We also model the changing composition of the subsurface radiation field with depth compared between Martian locations with different shielding material, determine the relative dose contributions from primaries of different energies, and discuss particle deflection by the crustal magnetic fields.

  16. The impact of meteoritic impacts on the early Martian environment (United States)

    Turbet, M.; Forget, F.; Svetsov, V.; Tran, H.; Karatekin, O.; Popova, O.; Gillmann, C.


    We model the environmental effect of meteoritic impacts on Early Mars ( 3.8Gy ago) by combining an hydrocode with a Global Climate Model. We explore if these impact events could trigger the warm & wet conditions, and the precipitation rates required to explain the formation of the Martian valley networks.

  17. Local Dynamics of Baroclinic Waves in the Martian Atmosphere

    KAUST Repository

    Kavulich, Michael J.


    The paper investigates the processes that drive the spatiotemporal evolution of baroclinic transient waves in the Martian atmosphere by a simulation experiment with the Geophysical Fluid Dynamics Laboratory (GFDL) Mars general circulation model (GCM). The main diagnostic tool of the study is the (local) eddy kinetic energy equation. Results are shown for a prewinter season of the Northern Hemisphere, in which a deep baroclinic wave of zonal wavenumber 2 circles the planet at an eastward phase speed of about 70° Sol-1 (Sol is a Martian day). The regular structure of the wave gives the impression that the classical models of baroclinic instability, which describe the underlying process by a temporally unstable global wave (e.g., Eady model and Charney model), may have a direct relevance for the description of the Martian baroclinic waves. The results of the diagnostic calculations show, however, that while the Martian waves remain zonally global features at all times, there are large spatiotemporal changes in their amplitude. The most intense episodes of baroclinic energy conversion, which take place in the two great plain regions (Acidalia Planitia and Utopia Planitia), are strongly localized in both space and time. In addition, similar to the situation for terrestrial baroclinic waves, geopotential flux convergence plays an important role in the dynamics of the downstream-propagating unstable waves. © 2013 American Meteorological Society.

  18. A new tracking mode for improved Martian gravity field measurement (United States)

    Yan, Jianguo; Yang, Xuan; Hao, Weifeng; Ye, Mao; Li, Fei; Qu, Chunkai; Deng, Qingyun; Jin, Weitong; Barriot, Jean-Pierre


    The Martian gravity field has been improved significantly in terms of resolution, with the spatial resolution rising to 100 km and accuracy increasing up to the 110 degree and order, assisted by data collected in Mars exploration missions like MGS, MRO, and Odyssey. However, as the tracking data used for the Martian gravity field solution are from polar orbit at a low height (˜400 km), improvements in the low degree coefficients are possible with high orbiters and various inclinations. In our research, we simulate a future Chinese Mars mission, making use of its orbit, to investigate potential contributions to the Martian gravity field solution. As the Chinese Mars mission will include a lander, we investigate the same beam interferometry tracking mode for a more precise and accurate Martian gravity field solution. Our results show that this tracking mode will substantially improve the gravity field model accuracy in comparison with those models using only polar orbit data. Model accuracy is assessed by power spectrum analysis and precise orbit determination. All the simulation work are accomplished with our independent developed software. Our research will be a reference for the first Chinese Mars exploration mission.

  19. Mapping the Iron Oxidation State in Martian Meteorites (United States)

    Martin, A. M.; Treimann, A. H.; Righter, K.


    Several types of Martian igneous meteorites have been identified: clinopyroxenites (nakhlites), basaltic shergottites, peridotitic shergottites, dunites (chassignites) and orthopyroxenites [1,2]. In order to constrain the heterogeneity of the Martian mantle and crust, and their evolution through time, numerous studies have been performed on the iron oxidation state of these meteorites [3,4,5,6,7,8,9]. The calculated fO2 values all lie within the FMQ-5 to FMQ+0.5 range (FMQ representing the Fayalite = Magnetite + Quartz buffer); however, discrepancies appear between the various studies, which are either attributed to the choice of the minerals/melts used, or to the precision of the analytical/calculation method. The redox record in volcanic samples is primarily related to the oxidation state in the mantle source(s). However, it is also influenced by several deep processes: melting, crystallization, magma mixing [10], assimilation and degassing [11]. In addition, the oxidation state in Martian meteorites is potentially affected by several surface processes: assimilation of sediment/ crust during lava flowing at Mars' surface, low temperature micro-crystallization [10], weathering at the surface of Mars and low temperature reequilibration, impact processes (i.e. high pressure phase transitions, mechanical mixing, shock degassing and melting), space weathering, and weathering on Earth (at atmospheric conditions different from Mars). Decoding the redox record of Martian meteorites, therefore, requires large-scale quantitative analysis methods, as well as a perfect understanding of oxidation processes.

  20. Surface color perception in three-dimensional scenes. (United States)

    Boyaci, Huseyin; Doerschner, Katja; Snyder, Jacqueline L; Maloney, Laurence T


    Researchers studying surface color perception have typically used stimuli that consist of a small number of matte patches (real or simulated) embedded in a plane perpendicular to the line of sight (a "Mondrian," Land & McCann, 1971). Reliable estimation of the color of a matte surface is a difficult if not impossible computational problem in such limited scenes (Maloney, 1999). In more realistic, three-dimensional scenes the difficulty of the problem increases, in part, because the effective illumination incident on the surface (the light field) now depends on surface orientation and location. We review recent work in multiple laboratories that examines (1) the degree to which the human visual system discounts the light field in judging matte surface lightness and color and (2) what illuminant cues the visual system uses in estimating the flow of light in a scene.

  1. Adaptively Combining Local with Global Information for Natural Scenes Categorization (United States)

    Liu, Shuoyan; Xu, De; Yang, Xu

    This paper proposes the Extended Bag-of-Visterms (EBOV) to represent semantic scenes. In previous methods, most representations are bag-of-visterms (BOV), where visterms referred to the quantized local texture information. Our new representation is built by introducing global texture information to extend standard bag-of-visterms. In particular we apply the adaptive weight to fuse the local and global information together in order to provide a better visterm representation. Given these representations, scene classification can be performed by pLSA (probabilistic Latent Semantic Analysis) model. The experiment results show that the appropriate use of global information improves the performance of scene classification, as compared with BOV representation that only takes the local information into account.

  2. A Grouped Threshold Approach for Scene Identification in AVHRR Imagery (United States)

    Baum, Bryan A.; Trepte, Qing


    The authors propose a grouped threshold method for scene identification in Advanced Very High Resolution Radiometer imagery that may contain clouds, fire, smoke, or snow. The philosophy of the approach is to build modules that contain groups of spectral threshold tests that are applied concurrently, not sequentially, to each pixel in an image. The purpose of each group of tests is to identify uniquely a specific class in the image, such as smoke. A strength of this approach is that insight into the limits used in the threshold tests may be gained through the use of radiative transfer theory. Methodology and examples are provided for two different scenes, one containing clouds, forest fires, and smoke; and the other containing clouds over snow in the central United States. For both scenes, a limited amount of supporting information is provided by surface observers.

  3. SAR Raw Data Generation for Complex Airport Scenes

    Directory of Open Access Journals (Sweden)

    Jia Li


    Full Text Available The method of generating the SAR raw data of complex airport scenes is studied in this paper. A formulation of the SAR raw signal model of airport scenes is given. Via generating the echoes from the background, aircrafts and buildings, respectively, the SAR raw data of the unified SAR imaging geometry is obtained from their vector additions. The multipath scattering and the shadowing between the background and different ground covers of standing airplanes and buildings are analyzed. Based on the scattering characteristics, coupling scattering models and SAR raw data models of different targets are given, respectively. A procedure is given to generate the SAR raw data of airport scenes. The SAR images from the simulated raw data demonstrate the validity of the proposed method.

  4. Samples from Martian craters: Origin of the Martian soil by hydrothermal alteration of impact melt deposits and atmospheric interactions with ejecta during crater formation (United States)

    Newsom, Horton E.


    The origin of the Martian soil is an important question for understanding weathering processes on the Martian surface, and also for understanding the global geochemistry of Mars. Chemical analyses of the soil will provide an opportunity to examine what may be a crustal average, as studies of loess on the Earth have demonstrated. In this regard the origin of the Martian soil is also important for understanding the chemical fractionations that have affected the composition of the soil. Several processes that are likely to contribute to the Martian soil are examined.

  5. Color appearance and color rendering of HDR scenes: an experiment (United States)

    Parraman, Carinna; Rizzi, Alessandro; McCann, John J.


    In order to gain a deeper understanding of the appearance of coloured objects in a three-dimensional scene, the research introduces a multidisciplinary experimental approach. The experiment employed two identical 3-D Mondrians, which were viewed and compared side by side. Each scene was subjected to different lighting conditions. First, we used an illumination cube to diffuse the light and illuminate all the objects from each direction. This produced a low-dynamicrange (LDR) image of the 3-D Mondrian scene. Second, in order to make a high-dynamic range (HDR) image of the same objects, we used a directional 150W spotlight and an array of WLEDs assembled in a flashlight. The scenes were significant as each contained exactly the same three-dimensional painted colour blocks that were arranged in the same position in the still life. The blocks comprised 6 hue colours and 5 tones from white to black. Participants from the CREATE project were asked to consider the change in the appearance of a selection of colours according to lightness, hue, and chroma, and to rate how the change in illumination affected appearance. We measured the light coming to the eye from still-life surfaces with a colorimeter (Yxy). We captured the scene radiance using multiple exposures with a number of different cameras. We have begun a programme of digital image processing of these scene capture methods. This multi-disciplinary programme continues until 2010, so this paper is an interim report on the initial phases and a description of the ongoing project.

  6. Durham, North Carolina, Students Study Martian Volcanism (United States)


    This image of the wall of a graben a depressed block of land between two parellel faults in Tyrrhena Terra, in Mars' ancient southern highlands, was taken by the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) at 0914 UTC (4:14 a.m. EST) on February 6, 2008, near 17.3 degrees south latitude, 95.5 degrees east longitude. CRISM's image was taken in 544 colors covering 0.36-3.92 micrometers, and shows features as small as 35 meters (115 feet) across. The region covered is just over 10 kilometers (6.2 miles) wide at its narrowest point. This image was part of an investigation planned by students in four high schools in Durham, North Carolina. The students are working with the CRISM science team in a project called the Mars Exploration Student Data Teams (MESDT), which is part of NASA's Mars Public Engagement Program and Arizona State University's Mars Education Program. Starting with a medium-resolution map of the area, taken as part of CRISM's 'multispectral survey' campaign to map Mars in 72 colors at 200 meters (660 feet) per pixel, the students identified a key rock outcrop to test their hypothesis that the irregular depression was formed by Martian volcanism. They provided the coordinates of the target to CRISM's operations team, who took a high-resolution image of the site. The Context Imager (CTX) accompanied CRISM with a 6 meter (20 feet) per pixel, high-resolution image to sharpen the relationship of spectral variations to the underlying surface structures. The Durham students worked with a mentor on the CRISM team to analyze the data, and presented their results at the 39th Lunar and Planetary Science Conference, held in League City, Texas, on March 10-14, 2008. The upper panel of the image shows the location of the CRISM data and the surrounding, larger CTX image, overlain on an image mosaic taken by the Thermal Emission Imaging System (THEMIS) on Mars Odyssey. The mosaic has been color-coded for elevation using data from the Mars Orbiter Laser

  7. Design of the multiwavelength Scophony infrared scene projector (United States)

    Thompson, Kevin P.; Kircher, James R.; Marlow, Steven A.; Korniski, Ronald J.; Richwine, Robert A.


    An all acousto-optic infrared scene projector (IRSP) has been developed for use in evaluating thermal-imaging guidance systems at the Kinetic Kill Vehicle Hardware-in-the-Loop Simulator (KHILS) facility located at Elgin AFB, Florida. The IRSP is a laser source based projector incorporating Scophony illumination and scanning methods to produce 96 X 96 pixel multi-wavelength images at very high frame rates (400 Hz). The IRSP is composed of five functionally similar optical trains, four of which are fed with a different `color' infrared laser. The separate scenes from each optical train are then combined and projected simultaneously into the imaging guidance system.

  8. Improved content aware scene retargeting for retinitis pigmentosa patients

    Directory of Open Access Journals (Sweden)

    Al-Atabany Walid I


    Full Text Available Abstract Background In this paper we present a novel scene retargeting technique to reduce the visual scene while maintaining the size of the key features. The algorithm is scalable to implementation onto portable devices, and thus, has potential for augmented reality systems to provide visual support for those with tunnel vision. We therefore test the efficacy of our algorithm on shrinking the visual scene into the remaining field of view for those patients. Methods Simple spatial compression of visual scenes makes objects appear further away. We have therefore developed an algorithm which removes low importance information, maintaining the size of the significant features. Previous approaches in this field have included seam carving, which removes low importance seams from the scene, and shrinkability which dynamically shrinks the scene according to a generated importance map. The former method causes significant artifacts and the latter is inefficient. In this work we have developed a new algorithm, combining the best aspects of both these two previous methods. In particular, our approach is to generate a shrinkability importance map using as seam based approach. We then use it to dynamically shrink the scene in similar fashion to the shrinkability method. Importantly, we have implemented it so that it can be used in real time without prior knowledge of future frames. Results We have evaluated and compared our algorithm to the seam carving and image shrinkability approaches from a content preservation perspective and a compression quality perspective. Also our technique has been evaluated and tested on a trial included 20 participants with simulated tunnel vision. Results show the robustness of our method at reducing scenes up to 50% with minimal distortion. We also demonstrate efficacy in its use for those with simulated tunnel vision of 22 degrees of field of view or less. Conclusions Our approach allows us to perform content aware video

  9. Recognizing the Stranger: Recognition Scenes in the Gospel of John

    DEFF Research Database (Denmark)

    Larsen, Kasper Bro

    Recognizing the Stranger is the first monographic study of recognition scenes and motifs in the Gospel of John. The recognition type-scene (anagnōrisis) was a common feature in ancient drama and narrative, highly valued by Aristotle as a touching moment of truth, e.g., in Oedipus’ tragic self......-discovery and Odysseus’ happy homecoming. The book offers a reconstruction of the conventions of the genre and argues that it is one of the most recurrent and significant literary forms in the Gospel. When portraying Jesus as the divine stranger from heaven, the Gospel employs and transforms the formal and ideological...

  10. Randomized Probabilistic Latent Semantic Analysis for Scene Recognition (United States)

    Rodner, Erik; Denzler, Joachim

    The concept of probabilistic Latent Semantic Analysis (pLSA) has gained much interest as a tool for feature transformation in image categorization and scene recognition scenarios. However, a major issue of this technique is overfitting. Therefore, we propose to use an ensemble of pLSA models which are trained using random fractions of the training data. We analyze empirically the influence of the degree of randomization and the size of the ensemble on the overall classification performance of a scene recognition task. A thoughtful evaluation shows the benefits of this approach compared to a single pLSA model.

  11. Cortical Representations of Speech in a Multitalker Auditory Scene. (United States)

    Puvvada, Krishna C; Simon, Jonathan Z


    The ability to parse a complex auditory scene into perceptual objects is facilitated by a hierarchical auditory system. Successive stages in the hierarchy transform an auditory scene of multiple overlapping sources, from peripheral tonotopically based representations in the auditory nerve, into perceptually distinct auditory-object-based representations in the auditory cortex. Here, using magnetoencephalography recordings from men and women, we investigate how a complex acoustic scene consisting of multiple speech sources is represented in distinct hierarchical stages of the auditory cortex. Using systems-theoretic methods of stimulus reconstruction, we show that the primary-like areas in the auditory cortex contain dominantly spectrotemporal-based representations of the entire auditory scene. Here, both attended and ignored speech streams are represented with almost equal fidelity, and a global representation of the full auditory scene with all its streams is a better candidate neural representation than that of individual streams being represented separately. We also show that higher-order auditory cortical areas, by contrast, represent the attended stream separately and with significantly higher fidelity than unattended streams. Furthermore, the unattended background streams are more faithfully represented as a single unsegregated background object rather than as separated objects. Together, these findings demonstrate the progression of the representations and processing of a complex acoustic scene up through the hierarchy of the human auditory cortex.SIGNIFICANCE STATEMENT Using magnetoencephalography recordings from human listeners in a simulated cocktail party environment, we investigate how a complex acoustic scene consisting of multiple speech sources is represented in separate hierarchical stages of the auditory cortex. We show that the primary-like areas in the auditory cortex use a dominantly spectrotemporal-based representation of the entire auditory

  12. Insights into the Martian Regolith from Martian Meteorite Northwest Africa 7034 (United States)

    McCubbin, Francis M.; Boyce, Jeremy W.; Szabo, Timea; Santos, Alison R.; Domokos, Gabor; Vazquez, Jorge; Moser, Desmond E.; Jerolmack, Douglas J.; Keller, Lindsay P.; Tartese, Romain


    Everything we know about sedimentary processes on Mars is gleaned from remote sensing observations. Here we report insights from meteorite Northwest Africa (NWA) 7034, which is a water-rich martian regolith breccia that hosts both igneous and sedimentary clasts. The sedimentary clasts in NWA 7034 are poorly-sorted clastic siltstones that we refer to as protobreccia clasts. These protobreccia clasts record aqueous alteration process that occurred prior to breccia formation. The aqueous alteration appears to have occurred at relatively low Eh, high pH conditions based on the co-precipitation of pyrite and magnetite, and the concomitant loss of SiO2 from the system. To determine the origin of the NWA 7034 breccia, we examined the textures and grain-shape characteristics of NWA 7034 clasts. The shapes of the clasts are consistent with rock fragmentation in the absence of transport. Coupled with the clast size distribution, we interpret the protolith of NWA 7034 to have been deposited by atmospheric rainout resulting from pyroclastic eruptions and/or asteroid impacts. Cross-cutting and inclusion relationships and U-Pb data from zircon, baddelleyite, and apatite indicate NWA 7034 lithification occurred at 1.4-1.5 Ga, during a short-lived hydrothermal event at 600-700 C that was texturally imprinted upon the submicron groundmass. The hydrothermal event caused Pb-loss from apatite and U-rich metamict zircons, and it caused partial transformation of pyrite to submicron mixtures of magnetite and maghemite, indicating the fluid had higher Eh than the fluid that caused pyrite-magnetite precipitation in the protobreccia clasts. NWA 7034 also hosts ancient 4.4 Ga crustal materials in the form of baddelleyites and zircons, providing up to a 2.9 Ga record of martian geologic history. This work demonstrates the incredible value of sedimentary basins as scientific targets for Mars sample return missions, but it also highlights the importance of targeting samples that have not been

  13. Exposed subsurface ice sheets in the Martian mid-latitudes (United States)

    Dundas, Colin M.; Bramson, Ali M.; Ojha, Lujendra; Wray, James J.; Mellon, Michael T.; Byrne, Shane; McEwen, Alfred S.; Putzig, Nathaniel E.; Viola, Donna; Sutton, Sarah; Clark, Erin; Holt, John W.


    Some locations on Mars are known to have water ice just below the surface, but how much has remained unclear. Dundas et al. used data from two orbiting spacecraft to examine eight locations where erosion has occurred. This revealed cliffs composed mostly of water ice, which is slowly sublimating as it is exposed to the atmosphere. The ice sheets extend from just below the surface to a depth of 100 meters or more and appear to contain distinct layers, which could preserve a record of Mars' past climate. They might even be a useful source of water for future human exploration of the red planet.

  14. Terrestrial microbes in martian and chondritic meteorites (United States)

    Airieau, S.; Picenco, Y.; Andersen, G.


    Introduction: The best extraterrestrial analogs for microbiology are meteorites. The chemistry and mineralogy of Asteroid Belt and martian (SNC) meteorites are used as tracers of processes that took place in the early solar system. Meteoritic falls, in particular those of carbonaceous chondrites, are regarded as pristine samples of planetesimal evolution as these rocks are primitive and mostly unprocessed since the formation of the solar system 4.56 billion years ago. Yet, questions about terrestrial contamination and its effects on the meteoritic isotopic, chemical and mineral characteristics often arise. Meteorites are hosts to biological activity as soon as they are in contact with the terrestrial biosphere, like all rocks. A wide biodiversity was found in 21 chondrites and 8 martian stones, and was investigated with cell culture, microscopy techniques, PCR, and LAL photoluminetry. Some preliminary results are presented here. The sample suite included carbonaceous chondrites of types CR, CV, CK, CO, CI, and CM, from ANSMET and Falls. Past studies documented the alteration of meteorites by weathering and biological activity [1]-[4]. Unpublished observations during aqueous extraction for oxygen isotopic analysis [5], noted the formation of biofilms in water in a matter of days. In order to address the potential modification of meteoritic isotopic and chemical signatures, the culture of microbial contaminating species was initiated in 2005, and after a prolonged incubation, some of the species obtained from cell culture were analyzed in 2006. The results are preliminary, and a systematic catalog of microbial contaminants is developing very slowly due to lack of funding. Methods: The primary method was cell culture and PCR. Chondrites. Chondritic meteorite fragments were obtained by breaking stones of approximately one gram in sterile mortars. The core of the rocks, presumably less contaminated than the surface, was used for the present microbial study, and the

  15. Evolution of the martian mantle as recorded by igneous rocks (United States)

    Balta, J. B.; McSween, H. Y.


    Martian igneous rocks provide our best window into the current state of the martian mantle and its evolution after accretion and differentiation. Currently, those rocks have been examined in situ by rovers, characterized in general from orbiting spacecraft, and analyzed in terrestrial laboratories when found as meteorites. However, these data have the potential to bias our understanding of martian magmatism, as most of the available meteorites and rover-analyzed rocks come from the Amazonian (3.8 Ga) have only been examined by orbiters and as the unique meteorite ALH 84001. After initial differentiation, the main planetary-scale changes in the structure of Mars which impact igneous compositions are cooling of the planet and thickening of the crust with time. As the shergottite meteorites give ages Ma1, they might be expected to represent thick-crust, recent volcanism. Using spacecraft measurements of volcanic compositions and whole rock compositions of meteorites, we demonstrate that the shergottite meteorites do not match the composition of the igneous rocks composing the young volcanoes on Mars, particularly in their silica content, and no crystallization or crustal contamination trend reproduces the volcanoes from a shergottite-like parent magma. However, we show that the shergottite magmas do resemble older martian rocks in composition and mineralogy. The Noachian-aged meteorite ALH 84001 has similar radiogenic-element signatures to the shergottites and may derive from a similar mantle source despite the age difference2. Thus, shergottite-like magmas may represent melting of mantle sources that were much more abundant early in martian history. We propose that the shergottites represent the melting products of an originally-hydrous martian mantle, containing at least several hundred ppm H2O. Dissolved water can increase the silica content of magmas and thus plausibly explains the high silica content of the shergottites. A dehydrating martian mantle with time can

  16. A centre-triggered magnesium fuelled cathodic arc thruster uses sublimation to deliver a record high specific impulse (United States)

    Neumann, Patrick R. C.; Bilek, Marcela; McKenzie, David R.


    The cathodic arc is a high current, low voltage discharge that operates in vacuum and provides a stream of highly ionised plasma from a solid conducting cathode. The high ion velocities, together with the high ionisation fraction and the quasineutrality of the exhaust stream, make the cathodic arc an attractive plasma source for spacecraft propulsion applications. The specific impulse of the cathodic arc thruster is substantially increased when the emission of neutral species is reduced. Here, we demonstrate a reduction of neutral emission by exploiting sublimation in cathode spots and enhanced ionisation of the plasma in short, high-current pulses. This, combined with the enhanced directionality due to the efficient erosion profiles created by centre-triggering, substantially increases the specific impulse. We present experimentally measured specific impulses and jet power efficiencies for titanium and magnesium fuels. Our Mg fuelled source provides the highest reported specific impulse for a gridless ion thruster and is competitive with all flight rated ion thrusters. We present a model based on cathode sublimation and melting at the cathodic arc spot explaining the outstanding performance of the Mg fuelled source. A further significant advantage of an Mg-fuelled thruster is the abundance of Mg in asteroidal material and in space junk, providing an opportunity for utilising these resources in space.

  17. La sublimación artística y su objeto // Artistic sublimation and its object

    Directory of Open Access Journals (Sweden)

    David González


    Full Text Available El presente artículo versa sobre la conceptualización de la sublimación artística en la obra freudiana y la enseñanza lacaniana, para dilucidar semejanzas y diferencias, re-actualizando el concepto en el plano de la discusión teórica. De esta manera se realiza un recorrido exploratorio del concepto en ambos autores. Desde una perspectiva psicoanalítica se redefinen los conceptos de objeto y la Cosa contenidos en la definición lacaniana de la sublimación. // This article deals with the conceptualization of artistic sublimation in Freud's work and Lacan's teaching in order to elucidate similarities and differences, and so it updates the concept in terms of the theoretical discussion. In that way, an exploratory route of the concept is carried out in both authors. From a psychoanalytic perspective, the concepts of object and Thing -contained in the Lacanian definition of sublimation- are redefined

  18. Ontology of a scene based on Java 3D architecture.

    Directory of Open Access Journals (Sweden)

    Rubén González Crespo


    Full Text Available The present article seeks to make an approach to the class hierarchy of a scene built with the architecture Java 3D, to develop an ontology of a scene as from the semantic essential components for the semantic structuring of the Web3D. Java was selected because the language recommended by the W3C Consortium for the Development of the Web3D oriented applications as from X3D standard is Xj3D which compositionof their Schemas is based the architecture of Java3D In first instance identifies the domain and scope of the ontology, defining classes and subclasses that comprise from Java3D architecture and the essential elements of a scene, as its point of origin, the field of rotation, translation The limitation of the scene and the definition of shaders, then define the slots that are declared in RDF as a framework for describing the properties of the classes established from identifying thedomain and range of each class, then develops composition of the OWL ontology on SWOOP Finally, be perform instantiations of the ontology building for a Iconosphere object as from class expressions defined.

  19. Understanding road scenes using visual cues and GPS information

    NARCIS (Netherlands)

    Alvarez, J.M.; Lumbreras, F.; Lopez, A.M.; Gevers, T.


    Understanding road scenes is important in computer vision with different applications to improve road safety (e.g., advanced driver assistance systems) and to develop autonomous driving systems (e.g., Google driver-less vehicle). Current vision-based approaches rely on the robust combination of


    Directory of Open Access Journals (Sweden)

    G. Sohn


    Full Text Available This study aims to introduce new methods for classifying key features (power lines, pylons, and buildings comprising utility corridor scene using airborne LiDAR data and modelling power lines in 3D object space. The proposed approach starts from PL scene segmentation using Markov Random Field (MRF, which emphasizes on the roles of spatial context of linear and planar features as in a graphical model. The MRF classifier identifies power line features from linear features extracted from given corridor scenes. The non-power line objects are then investigated in a planar space to sub-classify them into building and non-building class. Based on the classification results, precise localization of individual pylons is conducted through investigating a prior knowledge of contextual relations between power line and pylon. Once the pylon localization is accomplished, a power line span is identified, within which power lines are modelled with catenary curve models in 3D. Once a local catenary curve model is established, this initial model progressively extends to capture entire power line points by adopting model hypothesis and verification. The model parameters are adjusted using a stochastic non-linear square method for producing 3D power line models. An evaluation of the proposed approach is performed over an urban PL corridor area that includes a complex PL scene.

  1. Words Matter: Scene Text for Image Classification and Retrieval

    NARCIS (Netherlands)

    Karaoglu, S.; Tao, R.; Gevers, T.; Smeulders, A.W.M.

    Text in natural images typically adds meaning to an object or scene. In particular, text specifies which business places serve drinks (e.g., cafe, teahouse) or food (e.g., restaurant, pizzeria), and what kind of service is provided (e.g., massage, repair). The mere presence of text, its words, and

  2. Toward Holistic Scene Understanding: Feedback Enabled Cascaded Classification Models. (United States)

    Li, Congcong; Kowdle, Adarsh; Saxena, Ashutosh; Chen, Tsuhan


    Scene understanding includes many related subtasks, such as scene categorization, depth estimation, object detection, etc. Each of these subtasks is often notoriously hard, and state-of-the-art classifiers already exist for many of them. These classifiers operate on the same raw image and provide correlated outputs. It is desirable to have an algorithm that can capture such correlation without requiring any changes to the inner workings of any classifier. We propose Feedback Enabled Cascaded Classification Models (FE-CCM), that jointly optimizes all the subtasks while requiring only a "black box" interface to the original classifier for each subtask. We use a two-layer cascade of classifiers, which are repeated instantiations of the original ones, with the output of the first layer fed into the second layer as input. Our training method involves a feedback step that allows later classifiers to provide earlier classifiers information about which error modes to focus on. We show that our method significantly improves performance in all the subtasks in the domain of scene understanding, where we consider depth estimation, scene categorization, event categorization, object detection, geometric labeling, and saliency detection. Our method also improves performance in two robotic applications: an object-grasping robot and an object-finding robot.

  3. The value of DNA material recovered from crime scenes. (United States)

    Bond, John W; Hammond, Christine


    DNA material is now collected routinely from crime scenes for a wide range of offenses and its timely processing is acknowledged as a key element to its success in solving crime. An analysis of the processing of approximately 1500 samples of DNA material recovered from the property crime offenses of residential burglary, commercial burglary, and theft of motor vehicle in Northamptonshire, U.K. during 2006 identified saliva and cigarette ends as the main sources of DNA recovered (approximately 63% of samples) with blood, cellular DNA, and chewing gum accounting for the remainder. The conversion of these DNA samples into DNA profiles and then into matches with offender profiles held on the U.K. National DNA database is considered in terms of the ease with which Crime Scene Examiners can recover DNA rich samples of different sources, the location of the DNA at the crime scene, and its mobility. A logistical regression of the DNA material recovered has revealed a number of predictors, other than timeliness, that greatly influence its conversion into a DNA profile. The most significant predictor was found to be Crime Scene Examiner accreditation with offense type and DNA sample condition also being relevant. A similar logistical regression of DNA samples profiled that produced a match with an offender on the U.K. National DNA database showed no significance with any of the predictors considered.

  4. Dynamic scene stitching driven by visual cognition model. (United States)

    Zou, Li-hui; Zhang, Dezheng; Wulamu, Aziguli


    Dynamic scene stitching still has a great challenge in maintaining the global key information without missing or deforming if multiple motion interferences exist in the image acquisition system. Object clips, motion blurs, or other synthetic defects easily occur in the final stitching image. In our research work, we proceed from human visual cognitive mechanism and construct a hybrid-saliency-based cognitive model to automatically guide the video volume stitching. The model consists of three elements of different visual stimuli, that is, intensity, edge contour, and scene depth saliencies. Combined with the manifold-based mosaicing framework, dynamic scene stitching is formulated as a cut path optimization problem in a constructed space-time graph. The cutting energy function for column width selections is defined according to the proposed visual cognition model. The optimum cut path can minimize the cognitive saliency difference throughout the whole video volume. The experimental results show that it can effectively avoid synthetic defects caused by different motion interferences and summarize the key contents of the scene without loss. The proposed method gives full play to the role of human visual cognitive mechanism for the stitching. It is of high practical value to environmental surveillance and other applications.

  5. Dynamic Scene Stitching Driven by Visual Cognition Model

    Directory of Open Access Journals (Sweden)

    Li-hui Zou


    Full Text Available Dynamic scene stitching still has a great challenge in maintaining the global key information without missing or deforming if multiple motion interferences exist in the image acquisition system. Object clips, motion blurs, or other synthetic defects easily occur in the final stitching image. In our research work, we proceed from human visual cognitive mechanism and construct a hybrid-saliency-based cognitive model to automatically guide the video volume stitching. The model consists of three elements of different visual stimuli, that is, intensity, edge contour, and scene depth saliencies. Combined with the manifold-based mosaicing framework, dynamic scene stitching is formulated as a cut path optimization problem in a constructed space-time graph. The cutting energy function for column width selections is defined according to the proposed visual cognition model. The optimum cut path can minimize the cognitive saliency difference throughout the whole video volume. The experimental results show that it can effectively avoid synthetic defects caused by different motion interferences and summarize the key contents of the scene without loss. The proposed method gives full play to the role of human visual cognitive mechanism for the stitching. It is of high practical value to environmental surveillance and other applications.

  6. Fuzzy Emotional Semantic Analysis and Automated Annotation of Scene Images

    Directory of Open Access Journals (Sweden)

    Jianfang Cao


    Full Text Available With the advances in electronic and imaging techniques, the production of digital images has rapidly increased, and the extraction and automated annotation of emotional semantics implied by images have become issues that must be urgently addressed. To better simulate human subjectivity and ambiguity for understanding scene images, the current study proposes an emotional semantic annotation method for scene images based on fuzzy set theory. A fuzzy membership degree was calculated to describe the emotional degree of a scene image and was implemented using the Adaboost algorithm and a back-propagation (BP neural network. The automated annotation method was trained and tested using scene images from the SUN Database. The annotation results were then compared with those based on artificial annotation. Our method showed an annotation accuracy rate of 91.2% for basic emotional values and 82.4% after extended emotional values were added, which correspond to increases of 5.5% and 8.9%, respectively, compared with the results from using a single BP neural network algorithm. Furthermore, the retrieval accuracy rate based on our method reached approximately 89%. This study attempts to lay a solid foundation for the automated emotional semantic annotation of more types of images and therefore is of practical significance.

  7. Cultural heritage and history in the European metal scene

    NARCIS (Netherlands)

    Klepper, de S.; Molpheta, S.; Pille, S.; Saouma, R.; During, R.; Muilwijk, M.


    This paper represents an inquiry on the use of history and cultural heritage in the metal scene. It is an attempt to show how history and cultural heritage can possibly be spread among people using an unconventional way. The followed research method was built on an explorative study that included an

  8. Semantic control of feature extraction from natural scenes. (United States)

    Neri, Peter


    In the early stages of image analysis, visual cortex represents scenes as spatially organized maps of locally defined features (e.g., edge orientation). As image reconstruction unfolds and features are assembled into larger constructs, cortex attempts to recover semantic content for object recognition. It is conceivable that higher level representations may feed back onto early processes and retune their properties to align with the semantic structure projected by the scene; however, there is no clear evidence to either support or discard the applicability of this notion to the human visual system. Obtaining such evidence is challenging because low and higher level processes must be probed simultaneously within the same experimental paradigm. We developed a methodology that targets both levels of analysis by embedding low-level probes within natural scenes. Human observers were required to discriminate probe orientation while semantic interpretation of the scene was selectively disrupted via stimulus inversion or reversed playback. We characterized the orientation tuning properties of the perceptual process supporting probe discrimination; tuning was substantially reshaped by semantic manipulation, demonstrating that low-level feature detectors operate under partial control from higher level modules. The manner in which such control was exerted may be interpreted as a top-down predictive strategy whereby global semantic content guides and refines local image reconstruction. We exploit the novel information gained from data to develop mechanistic accounts of unexplained phenomena such as the classic face inversion effect.

  9. Towards Unsupervised Familiar Scene Recognition in Egocentric Videos

    NARCIS (Netherlands)

    Talavera Martínez, Estefanía


    Nowadays, there is an upsurge of interest in using lifelogging devices. Such devices generate huge amounts of image data; consequently, the need for automatic methods for analyzing and summarizing these data is drastically increasing. We present a new method for familiar scene recognition in

  10. The role of memory for visual search in scenes (United States)

    Võ, Melissa Le-Hoa; Wolfe, Jeremy M.


    Many daily activities involve looking for something. The ease with which these searches are performed often allows one to forget that searching represents complex interactions between visual attention and memory. While a clear understanding exists of how search efficiency will be influenced by visual features of targets and their surrounding distractors or by the number of items in the display, the role of memory in search is less well understood. Contextual cueing studies have shown that implicit memory for repeated item configurations can facilitate search in artificial displays. When searching more naturalistic environments, other forms of memory come into play. For instance, semantic memory provides useful information about which objects are typically found where within a scene, and episodic scene memory provides information about where a particular object was seen the last time a particular scene was viewed. In this paper, we will review work on these topics, with special emphasis on the role of memory in guiding search in organized, real-world scenes. PMID:25684693

  11. The role of memory for visual search in scenes. (United States)

    Le-Hoa Võ, Melissa; Wolfe, Jeremy M


    Many daily activities involve looking for something. The ease with which these searches are performed often allows one to forget that searching represents complex interactions between visual attention and memory. Although a clear understanding exists of how search efficiency will be influenced by visual features of targets and their surrounding distractors or by the number of items in the display, the role of memory in search is less well understood. Contextual cueing studies have shown that implicit memory for repeated item configurations can facilitate search in artificial displays. When searching more naturalistic environments, other forms of memory come into play. For instance, semantic memory provides useful information about which objects are typically found where within a scene, and episodic scene memory provides information about where a particular object was seen the last time a particular scene was viewed. In this paper, we will review work on these topics, with special emphasis on the role of memory in guiding search in organized, real-world scenes. © 2015 New York Academy of Sciences.

  12. Semi-Supervised Multitask Learning for Scene Recognition. (United States)

    Lu, Xiaoqiang; Li, Xuelong; Mou, Lichao


    Scene recognition has been widely studied to understand visual information from the level of objects and their relationships. Toward scene recognition, many methods have been proposed. They, however, encounter difficulty to improve the accuracy, mainly due to two limitations: 1) lack of analysis of intrinsic relationships across different scales, say, the initial input and its down-sampled versions and 2) existence of redundant features. This paper develops a semi-supervised learning mechanism to reduce the above two limitations. To address the first limitation, we propose a multitask model to integrate scene images of different resolutions. For the second limitation, we build a model of sparse feature selection-based manifold regularization (SFSMR) to select the optimal information and preserve the underlying manifold structure of data. SFSMR coordinates the advantages of sparse feature selection and manifold regulation. Finally, we link the multitask model and SFSMR, and propose the semi-supervised learning method to reduce the two limitations. Experimental results report the improvements of the accuracy in scene recognition.

  13. Fuzzy emotional semantic analysis and automated annotation of scene images. (United States)

    Cao, Jianfang; Chen, Lichao


    With the advances in electronic and imaging techniques, the production of digital images has rapidly increased, and the extraction and automated annotation of emotional semantics implied by images have become issues that must be urgently addressed. To better simulate human subjectivity and ambiguity for understanding scene images, the current study proposes an emotional semantic annotation method for scene images based on fuzzy set theory. A fuzzy membership degree was calculated to describe the emotional degree of a scene image and was implemented using the Adaboost algorithm and a back-propagation (BP) neural network. The automated annotation method was trained and tested using scene images from the SUN Database. The annotation results were then compared with those based on artificial annotation. Our method showed an annotation accuracy rate of 91.2% for basic emotional values and 82.4% after extended emotional values were added, which correspond to increases of 5.5% and 8.9%, respectively, compared with the results from using a single BP neural network algorithm. Furthermore, the retrieval accuracy rate based on our method reached approximately 89%. This study attempts to lay a solid foundation for the automated emotional semantic annotation of more types of images and therefore is of practical significance.

  14. Modelling Technology for Building Fire Scene with Virtual Geographic Environment (United States)

    Song, Y.; Zhao, L.; Wei, M.; Zhang, H.; Liu, W.


    Building fire is a risky activity that can lead to disaster and massive destruction. The management and disposal of building fire has always attracted much interest from researchers. Integrated Virtual Geographic Environment (VGE) is a good choice for building fire safety management and emergency decisions, in which a more real and rich fire process can be computed and obtained dynamically, and the results of fire simulations and analyses can be much more accurate as well. To modelling building fire scene with VGE, the application requirements and modelling objective of building fire scene were analysed in this paper. Then, the four core elements of modelling building fire scene (the building space environment, the fire event, the indoor Fire Extinguishing System (FES) and the indoor crowd) were implemented, and the relationship between the elements was discussed also. Finally, with the theory and framework of VGE, the technology of building fire scene system with VGE was designed within the data environment, the model environment, the expression environment, and the collaborative environment as well. The functions and key techniques in each environment are also analysed, which may provide a reference for further development and other research on VGE.

  15. Logical unit and scene detection: a comparative survey (United States)

    Petersohn, Christian


    Logical units are semantic video segments above the shot level. Depending on the common semantics within the unit and data domain, different types of logical unit extraction algorithms have been presented in literature. Topic units are typically extracted for documentaries or news broadcasts while scenes are extracted for narrative-driven video such as feature films, sitcoms, or cartoons. Other types of logical units are extracted from home video and sports. Different algorithms in literature used for the extraction of logical units are reviewed in this paper based on the categories unit type, data domain, features used, segmentation method, and thresholds applied. A detailed comparative study is presented for the case of extracting scenes from narrative-driven video. While earlier comparative studies focused on scene segmentation methods only or on complete news-story segmentation algorithms, in this paper various visual features and segmentation methods with their thresholding mechanisms and their combination into complete scene detection algorithms are investigated. The performance of the resulting large set of algorithms is then evaluated on a set of video files including feature films, sitcoms, children's shows, a detective story, and cartoons.

  16. Audio scene segmentation for video with generic content (United States)

    Niu, Feng; Goela, Naveen; Divakaran, Ajay; Abdel-Mottaleb, Mohamed


    In this paper, we present a content-adaptive audio texture based method to segment video into audio scenes. The audio scene is modeled as a semantically consistent chunk of audio data. Our algorithm is based on "semantic audio texture analysis." At first, we train GMM models for basic audio classes such as speech, music, etc. Then we define the semantic audio texture based on those classes. We study and present two types of scene changes, those corresponding to an overall audio texture change and those corresponding to a special "transition marker" used by the content creator, such as a short stretch of music in a sitcom or silence in dramatic content. Unlike prior work using genre specific heuristics, such as some methods presented for detecting commercials, we adaptively find out if such special transition markers are being used and if so, which of the base classes are being used as markers without any prior knowledge about the content. Our experimental results show that our proposed audio scene segmentation works well across a wide variety of broadcast content genres.

  17. Coping with Perceived Ethnic Prejudice on the Gay Scene (United States)

    Jaspal, Rusi


    There has been only cursory research into the sociological and psychological aspects of ethnic/racial discrimination among ethnic minority gay and bisexual men, and none that focuses specifically upon British ethnic minority gay men. This article focuses on perceptions of intergroup relations on the gay scene among young British South Asian gay…

  18. Automatic video surveillance of outdoor scenes using track before detect

    DEFF Research Database (Denmark)

    Hansen, Morten; Sørensen, Helge Bjarup Dissing; Birkemark, Christian M.


    This paper concerns automatic video surveillance of outdoor scenes using a single camera. The first step in automatic interpretation of the video stream is activity detection based on background subtraction. Usually, this process will generate a large number of false alarms in outdoor scenes due ...... if a detected object shows a pattern of movement consistent with predefined rules. The method is tested on a number of video sequences and a substantial reduction in the number of false alarms is demonstrated.......This paper concerns automatic video surveillance of outdoor scenes using a single camera. The first step in automatic interpretation of the video stream is activity detection based on background subtraction. Usually, this process will generate a large number of false alarms in outdoor scenes due...... to e.g. movement of thicket and changes in illumination. To reduce the number of false alarms a Track Before Detect (TBD) approach is suggested. In this TBD implementation all objects detected in the background subtraction process are followed over a number of frames. An alarm is given only...

  19. The Rescue Mission: Assigning Guilt to a Chaotic Scene. (United States)

    Procter, David E.


    Seeks to identify rhetorical distinctiveness of the rescue mission as a form of belligerency--examining presidential discourse justifying the 1985 Lebanon intervention, the 1965 Dominican intervention, and the 1983 Grenada intervention. Argues that the distinction is in guilt narrowly assigned to a chaotic scene and the concomitant call for…

  20. Range and intensity vision for rock-scene segmentation

    CSIR Research Space (South Africa)

    Mkwelo, SG


    Full Text Available This paper presents another approach to segmenting a scene of rocks on a conveyor belt for the purposes of measuring rock size. Rock size estimation instruments are used to monitor, optimize and control milling and crushing in the mining industry...

  1. 3-D Scene Generation On A Shared Memory Parallel Processor (United States)

    Kelly, R. F.


    Realistic 3-D scene generation is now a possibility for many applications. One barrier to increased use of this technique is the large amount of computer processing time needed to render a scene. With the advent of parallel processors that barrier may be overcome if efficient parallel scene generation algorithms can be developed. In general, this has not been true because of restrictions imposed by non-shared memory and limited processor interconnect architectures. In addition, vector processors do not efficiently support the adaptive nature of many of the algorithms. A new parallel computer, the NYU Ultracomputer, has been developed which features a shared memory with a combining network. The com-bining network permits simultaneous reads and writes to the same memory location using a new instruction the Fetch and_Op. These memory references are resolved in the memory access network and result in particularly efficient shared data structures. Basic elements of this architecture are also being used in the design of the gigaflop range RP3 at IBM. Some algorithms typical of image synthesis are explored in the paper and a class of equivalent queue based algorithms are developed. These algorithms are particularly well suited to the Ultra-computer class processor and hold the promise for many new applications of realistic scene generation.

  2. Scene Context Dependency of Pattern Constancy of Time Series Imagery (United States)

    Woodell, Glenn A.; Jobson, Daniel J.; Rahman, Zia-ur


    A fundamental element of future generic pattern recognition technology is the ability to extract similar patterns for the same scene despite wide ranging extraneous variables, including lighting, turbidity, sensor exposure variations, and signal noise. In the process of demonstrating pattern constancy of this kind for retinex/visual servo (RVS) image enhancement processing, we found that the pattern constancy performance depended somewhat on scene content. Most notably, the scene topography and, in particular, the scale and extent of the topography in an image, affects the pattern constancy the most. This paper will explore these effects in more depth and present experimental data from several time series tests. These results further quantify the impact of topography on pattern constancy. Despite this residual inconstancy, the results of overall pattern constancy testing support the idea that RVS image processing can be a universal front-end for generic visual pattern recognition. While the effects on pattern constancy were significant, the RVS processing still does achieve a high degree of pattern constancy over a wide spectrum of scene content diversity, and wide ranging extraneousness variations in lighting, turbidity, and sensor exposure.

  3. Scanning proximal microscopy study of the thin layers of silicon carbide-aluminum nitride solid solution manufactured by fast sublimation epitaxy

    Directory of Open Access Journals (Sweden)

    Tománek P.


    Full Text Available The objective of the study is a growth of SiC/(SiC1−x(AlNx structures by fast sublimation epitaxy of the polycrystalline source of (SiC1−x(AlNx and their characterisation by proximal scanning electron microscopy and atomic force microscopy. For that purpose optimal conditions of sublimation process have been defined. Manufactured structures could be used as substrates for wide-band-gap semiconductor devices on the basis of nitrides, including gallium nitride, aluminum nitride and their alloys, as well as for the production of transistors with high mobility of electrons and also for creation of blue and ultraviolet light emitters (light-emitted diodes and laser diodes. The result of analysis shows that increasing of the growth temperature up to 2300 K allows carry out sublimation epitaxy of thin layers of aluminum nitride and its solid solution.

  4. In Situ Atmospheric Pressure Measurements in the Martian Southern Polar Region: Mars Volatiles and Climate Surveyor Meteorology Package on the Mars Polar Lander (United States)

    Harri, A.-M.; Polkko, J.; Siili, T.; Crisp, D.


    Pressure observations are crucial for the success of the Mars Volatiles and Climate Surveyor (MVACS) Meteorology (MET) package onboard the Mars Polar Lander (MPL), due for launch early next year. The spacecraft is expected to land in December 1999 (L(sub s) = 256 degrees) at a high southern latitude (74 degrees - 78 degrees S). The nominal period of operation is 90 sols but may last up to 210 sols. The MVACS/MET experiment will provide the first in situ observations of atmospheric pressure, temperature, wind, and humidity in the southern hemisphere of Mars and in the polar regions. The martian atmosphere goes through a large-scale atmospheric pressure cycle due to the annual condensation/sublimation of the atmospheric CO2. Pressure also exhibits short period variations associated with dust storms, tides, and other atmospheric events. A series of pressure measurements can hence provide us with information on the large-scale state and dynamics of the atmosphere, including the CO2 and dust cycles as well as local weather phenomena. The measurements can also shed light on the shorter time scale phenomena (e.g., passage of dust devils) and hence be important in contributing to our understanding of mixing and transport of heat, dust, and water vapor.

  5. Formation and evolution of Martian gullies: a terrestrial perspective (United States)

    Haas, T. D.


    Martian Gullies (alcove-fan systems) are among the youngest landforms that may have formed by liquid water on Mars, and therefore of critical importance in resolving the planet's most recent climatic history. Water-free sediment flows, often associated to CO2 ice, debris flows and fluvial flows have all been identified in gullies. These processes require different amounts of liquid water, and therefore their contribution to gully-formation is of key importance for climatic inferences. In contrast to CO2-aided flows, there are terrestrial analogues for debris flows and fluvial flows. Here I compare the morphology, morphometry and sedimentology of the surface and subsurface deposits of Martian gullies as seen on HiRISE imagery to terrestrial analogues in order to determine their formative processes and the climate in which Martian gullies formed. Terrestrial analogues from the hyperarid Atacama Desert (Chile) and Death Valley (USA), the arctic region of Svalbard and a small-scale experimental setup are visited to do so. Secondly, a sediment budget analysis is performed on geophysical-flow deposits in Martian gullies, to infer their return period as well as the amounts of water needed for their formation. Finally, the effect of time on Martian gully evolution is evaluated by comparing the size and morphology of gullies and associated landforms with their host crater age (and thus their time of potential activity). In short, the sedimentology in vertical exposures in Martian gullies is consistent with a formation by debris flows, while surficial debris-flow signatures have often been removed by erosion. Boulder mobility calculations imply that significant gully formation by fluvial sheetfloods is unlikely. Sediment budget analyses of debris-flow deposits in Istok crater imply that debris flows occurred at Earth-like frequencies during high-obliquity periods in the last million years on Mars and that melting must have yielded centimeters of liquid water in the gully

  6. The influence of scene context on object recognition is independent of attentional focus

    Directory of Open Access Journals (Sweden)

    Jaap eMunneke


    Full Text Available Humans can quickly and accurately recognize objects within briefly presented natural scenes. Previous work has provided evidence that scene context contributes to this process, demonstrating improved naming of objects that were presented in semantically consistent scenes (e.g., a sandcastle on a beach relative to semantically inconsistent scenes (e.g., a sandcastle on a football field. The current study was aimed at investigating which processes underlie the scene consistency effect. Specifically, we tested: 1 whether the effect is due to increased visual feature and/or shape overlap for consistent relative to inconsistent scene-object pairs; and 2 whether the effect is mediated by attention to the background scene. Experiment 1 replicated the scene consistency effect of a previous report (Davenport & Potter, 2004. Using a new, carefully controlled stimulus set, Experiment 2 showed that the scene consistency effect could not be explained by low-level feature or shape overlap between scenes and target objects. Experiments 3a and 3b investigated whether focused attention modulates the scene consistency effect. By using a location cueing manipulation, participants were correctly informed about the location of the target object on a proportion of trials, allowing focused attention to be deployed towards the target object. Importantly, the effect of scene consistency on target object recognition was independent of spatial attention, and was observed both when attention was focused on the target object and when attention was focused on the background scene. These results indicate that a semantically consistent scene context benefits object recognition independently of the focus of attention. We suggest that the scene consistency effect is primarily driven by global scene properties, or scene gist, that can be processed with minimal attentional resources.

  7. Martian Methane From a Cometary Source: A Hypothesis (United States)

    Fries, M.; Christou, A.; Archer, D.; Conrad, P.; Cooke, W.; Eigenbrode, J.; ten Kate, I. L.; Matney, M.; Niles, P.; Sykes, M.; hide


    In recent years, methane in the martian atmosphere has been detected by Earth-based spectroscopy, the Planetary Fourier Spectrometer on the ESA Mars Express mission, and the NASA Mars Science Laboratory. The methane's origin remains a mystery, with proposed sources including volcanism, exogenous sources like impacts and interplanetary dust, aqueous alteration of olivine in the presence of carbonaceous material, release from ancient deposits of methane clathrates, and/or biological activity. An additional potential source exists: meteor showers from the emission of large comet dust particles could generate martian methane via UV pyrolysis of carbon-rich infall material. We find a correlation between the dates of Mars/cometary orbit encounters and detections of methane on Mars. We hypothesize that cometary debris falls onto Mars during these interactions, generating methane via UV photolysis.

  8. S.A.M., the Italian Martian Simulation Chamber (United States)

    Galletta, G.; Ferri, F.; Fanti, G.; D'Alessandro, M.; Bertoloni, G.; Pavarin, D.; Bettanini, C.; Cozza, P.; Pretto, P.; Bianchini, G.; Debei, S.


    The Martian Environment Simulator (SAM “Simulatore di Ambiente Marziano”) is a interdisciplinary project of Astrobiology done at University of Padua. The research is aimed to the study of the survival of the microorganisms exposed to the “extreme” planetary environment. The facility has been designed in order to simulate Mars’ environmental conditions in terms of atmospheric pressure, temperature cycles and UV radiation dose. The bacterial cells, contained into dedicated capsules, will be exposed to thermal cycles simulating diurnal and seasonal Martian cycles. The metabolism of the different biological samples will be analysed at different phases of the experiment, to study their survival and eventual activity of protein synthesis (mortality, mutations and capability of DNA reparing). We describe the experimental facility and provide the perspectives of the biological experiments we will perform in order to provide hints on the possibility of life on Mars either autochthonous or imported from Earth.

  9. Filter Media Tests Under Simulated Martian Atmospheric Conditions (United States)

    Agui, Juan H.


    Human exploration of Mars will require the optimal utilization of planetary resources. One of its abundant resources is the Martian atmosphere that can be harvested through filtration and chemical processes that purify and separate it into its gaseous and elemental constituents. Effective filtration needs to be part of the suite of resource utilization technologies. A unique testing platform is being used which provides the relevant operational and instrumental capabilities to test articles under the proper simulated Martian conditions. A series of tests were conducted to assess the performance of filter media. Light sheet imaging of the particle flow provided a means of detecting and quantifying particle concentrations to determine capturing efficiencies. The media's efficiency was also evaluated by gravimetric means through a by-layer filter media configuration. These tests will help to establish techniques and methods for measuring capturing efficiency and arrestance of conventional fibrous filter media. This paper will describe initial test results on different filter media.

  10. Mineral Biomarkers in Martian Meteorite Allan Hills 84001? (United States)

    Thomas-Keprta, K. L.; Bazylinski, D. A.; Wentworth, S. J.; McKay, D. S.; Golden, D. C.; Gibson, E. K., Jr.; Romanek, C. S.


    The occurrence of fine-grained magnetite in the Fe-rich rims surrounding carbonate globules in the martian meteorite ALH84001, originally described in , have been proposed as fossil remains of primitive martian organisms. Here we report observations on size and shape distributions of magnetites from ALH84001 and compare them to biogenic and inorganic magnetite crystals of terrestrial origin. While some magnetite morphology is not unequivocally diagnostic for its biogenicity, such as cubodial forms of magnetite, which are common in inorganically formed magnetites, other morphologies of magnetite (parallel-epiped or elongated prismatic and arrowhead forms) are more likely signatures of biogenic activity. Some ALH 84001 magnetite particles described below have unique morphology and length-to-width ratios that are indistinguishable from a variety of terrestrial biogenic magnetite and distinct from all known inorganic forms of magnetite.

  11. Martian geomorphology and its relation to subsurface volatiles (United States)

    Clifford, Stephen M. (Editor); Rossbacher, Lisa A. (Editor); Zimbelman, James R. (Editor)


    Martian volatile inventory, planetary climatic and atmospheric evolution, and the interpretation of various remote sensing data were discussed. A number of morphologies that were cited as potential indicators of subsurface volatiles were reviewed. Rampart craters and terrain softening were the focus of more in-depth discussion because of the popular attention they have received and the fact that their areal distributions are by far the most extensive of all the proposed indicators.

  12. Pressure effects on martian crustal magnetization near large impact basins

    Czech Academy of Sciences Publication Activity Database

    Kletetschka, Günther; Connerly, J. E. P.; Ness, N. F.; Acuna, M. H.


    Roč. 39, č. 11 (2004), s. 1839-1848 ISSN 1086-9379 R&D Projects: GA AV ČR(CZ) IAA3013406 Keywords : martian magnetism * shock pressure * impact Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.673, year: 2004 http:// eso ads. eso .org//full/2004M%26PS...39.1839K/0001839.000.html

  13. Adolescent Characters and Alcohol Use Scenes in Brazilian Movies, 2000-2008. (United States)

    Castaldelli-Maia, João Mauricio; de Andrade, Arthur Guerra; Lotufo-Neto, Francisco; Bhugra, Dinesh


    Quantitative structured assessment of 193 scenes depicting substance use from a convenience sample of 50 Brazilian movies was performed. Logistic regression and analysis of variance or multivariate analysis of variance models were employed to test for two different types of outcome regarding alcohol appearance: The mean length of alcohol scenes in seconds and the prevalence of alcohol use scenes. The presence of adolescent characters was associated with a higher prevalence of alcohol use scenes compared to nonalcohol use scenes. The presence of adolescents was also associated with a higher than average length of alcohol use scenes compared to the nonalcohol use scenes. Alcohol use was negatively associated with cannabis, cocaine, and other drugs use. However, when the use of cannabis, cocaine, or other drugs was present in the alcohol use scenes, a higher average length was found. This may mean that most vulnerable group may see drinking as a more attractive option leading to higher alcohol use. © The Author(s) 2016.

  14. Using GIS to reconcile crime scenes with those indicated by serial criminals

    CSIR Research Space (South Africa)

    Cooper, Antony K


    Full Text Available includes revisiting the scenes with a GPS receiver to record their coordinates. This quality assurance highlights discrepancies between the crime scenes described in case dockets and those the suspect pointed out, allowing the investigators to link...

  15. Contextual effects of scene on the visual perception of object orientation in depth.

    Directory of Open Access Journals (Sweden)

    Ryosuke Niimi

    Full Text Available We investigated the effect of background scene on the human visual perception of depth orientation (i.e., azimuth angle of three-dimensional common objects. Participants evaluated the depth orientation of objects. The objects were surrounded by scenes with an apparent axis of the global reference frame, such as a sidewalk scene. When a scene axis was slightly misaligned with the gaze line, object orientation perception was biased, as if the gaze line had been assimilated into the scene axis (Experiment 1. When the scene axis was slightly misaligned with the object, evaluated object orientation was biased, as if it had been assimilated into the scene axis (Experiment 2. This assimilation may be due to confusion between the orientation of the scene and object axes (Experiment 3. Thus, the global reference frame may influence object orientation perception when its orientation is similar to that of the gaze-line or object.

  16. A Martian origin for the Mars Trojan asteroids (United States)

    Polishook, D.; Jacobson, S. A.; Morbidelli, A.; Aharonson, O.


    Seven of the nine known Mars Trojan asteroids belong to an orbital cluster1,2 named after its largest member, (5261) Eureka. Eureka is probably the progenitor of the whole cluster, which formed at least 1 Gyr ago3. It has been suggested3 that the thermal YORP (Yarkovsky-O'Keefe-Radzievskii-Paddack) effect spun up Eureka, resulting in fragments being ejected by the rotational-fission mechanism. Eureka's spectrum exhibits a broad and deep absorption band around 1 μm, indicating an olivine-rich composition4. Here we show evidence that the Trojan Eureka cluster progenitor could have originated as impact debris excavated from the Martian mantle. We present new near-infrared observations of two Trojans ((311999) 2007 NS2 and (385250) 2001 DH47) and find that both exhibit an olivine-rich reflectance spectrum similar to Eureka's. These measurements confirm that the progenitor of the cluster has an achondritic composition4. Olivine-rich reflectance spectra are rare amongst asteroids5 but are seen around the largest basins on Mars6. They are also consistent with some Martian meteorites (for example, Chassigny7) and with the material comprising much of the Martian mantle8,9. Using numerical simulations, we show that the Mars Trojans are more likely to be impact ejecta from Mars than captured olivine-rich asteroids transported from the main belt. This result directly links specific asteroids to debris from the forming planets.

  17. Advanced concept for a crewed mission to the martian moons (United States)

    Conte, Davide; Di Carlo, Marilena; Budzyń, Dorota; Burgoyne, Hayden; Fries, Dan; Grulich, Maria; Heizmann, Sören; Jethani, Henna; Lapôtre, Mathieu; Roos, Tobias; Castillo, Encarnación Serrano; Schermann, Marcel; Vieceli, Rhiannon; Wilson, Lee; Wynard, Christopher


    This paper presents the conceptual design of the IMaGInE (Innovative Mars Global International Exploration) Mission. The mission's objectives are to deliver a crew of four astronauts to the surface of Deimos and perform a robotic exploration mission to Phobos. Over the course of the 343 day mission during the years 2031 and 2032, the crew will perform surface excursions, technology demonstrations, In Situ Resource Utilization (ISRU) of the Martian moons, as well as site reconnaissance for future human exploration of Mars. This mission design makes use of an innovative hybrid propulsion concept (chemical and electric) to deliver a relatively low-mass reusable crewed spacecraft (approximately 100 mt) to cis-martian space. The crew makes use of torpor which minimizes launch payload mass. Green technologies are proposed as a stepping stone towards minimum environmental impact space access. The usage of beamed energy to power a grid of decentralized science stations is introduced, allowing for large scale characterization of the Martian environment. The low-thrust outbound and inbound trajectories are computed through the use of a direct method and a multiple shooting algorithm that considers various thrust and coast sequences to arrive at the final body with zero relative velocity. It is shown that the entire mission is rooted within the current NASA technology roadmap, ongoing scientific investments and feasible with an extrapolated NASA Budget. The presented mission won the 2016 Revolutionary Aerospace Systems Concepts - Academic Linkage (RASC-AL) competition.

  18. Potential Antifreeze Compounds in Present-Day Martian Seepage Groundwater

    Directory of Open Access Journals (Sweden)

    Jiin-Shuh Jean


    Full Text Available Is the recently found seepage groundwater on Mars pure H2O, or mixed with salts and other antifreeze compounds? Given the surface conditions of Mars, it is unlikely that pure water could either exist in its liquid state or have shaped Mars¡¦ fluid erosional landforms (gullies, channels, and valley networks. More likely is that Mars¡¦ seepage groundwater contains antifreeze and salt compounds that resist freezing and suppress evaporation. This model better accounts for Mars¡¦ enigmatic surface erosion. This paper suggests 17 antifreeze compounds potentially present in Martian seepage groundwater. Given their liquid state and physical properties, triethylene glycol, diethylene glycol, ethylene glycol, and 1,3-propylene glycol are advanced as the most likely candidate compounds. This paper also explores how a mixing of glycol or glycerol with salts in the Martian seepage groundwater may have lowered water¡¦s freezing point and raised its boiling point, with consequences that created fluid gully and channel erosion. Ethylene glycol and related hydrocarbon compounds have been identified in Martian and other interstellar meteorites. We suggest that these compounds and their proportions to water be included for detection in future explorations.

  19. Meteorite constraints on Martian atmospheric loss and paleoclimate (United States)

    Cassata, William S.


    The evolution of Mars' atmosphere to its currently thin state incapable of supporting liquid water remains poorly understood and has important implications for Martian climate history. Martian meteorites contain trapped atmospheric gases that can be used to constrain both the timing and effectiveness of atmospheric escape processes. In this paper, measurements of xenon isotopes in two ancient Martian meteorites, ALH 84001 and NWA 7034, are reported. The data indicate an early episode of atmospheric escape that mass fractionated xenon isotopes culminated within a few hundred million years of planetary formation, and little change to the atmospheric xenon isotopic composition has occurred since this time. In contrast, on Earth atmospheric xenon fractionation continued for at least two billion years (Pujol et al., 2011). Such differences in atmospheric Xe fractionation between the two planets suggest that climate conditions on Mars may have differed significantly from those on Archean Earth. For example, the hydrogen escape flux may not have exceeded the threshold required for xenon escape on Mars after 4.2-4.3 Ga, which indicates that Mars may have been significantly drier than Earth after this time.

  20. Geochemistry of Martian Meteorites and the Petrologic Evolution of Mars (United States)

    Mittlefehldt, D. W.


    Mafic igneous rocks serve as probes of the interiors of their parent bodies - the compositions of the magmas contain an imprint of the source region composition and mineralogy, the melting and crystallization processes, and mixing and assimilation. Although complicated by their multifarious history, it is possible to constrain the petrologic evolution of an igneous province through compositional study of the rocks. Incompatible trace elements provide one means of doing this. I will use incompatible element ratios of martian meteorites to constrain the early petrologic evolution of Mars. Incompatible elements are strongly partitioned into the melt phase during igneous processes. The degree of incompatibility will differ depending on the mineral phases in equilibrium with the melt. Most martian meteorites contain some cumulus grains, but nevertheless, incompatible element ratios of bulk meteorites will be close to those of their parent magmas. ALH 84001 is an exception, and it will not be discussed. The martian meteorites will be considered in two groups; a 1.3 Ga group composed of the clinopyroxenites and dunite, and a younger group composed of all others.

  1. Infiltration of Martian outflow channel floodwaters into lowland cavernous systems (United States)

    Rodriguez, J. Alexis P.; Bourke, Mary; Tanaka, Kenneth L.; Miyamoto, Hideaki; Kargel, Jeffrey; Baker, Victor; Fairén, Alberto G.; Davies, Richard J.; Bridget, Lynne; Santiago, Rogelio Linares; Hernández, Mario Zarroca; Berman, Daniel C.


    The hydrosphere of Mars has remained mostly concealed within the subsurface for the past ∼3.5 Gyr. Localized rupturing of the permafrost-capped crust led to voluminous groundwater discharges that carved some of the largest known channels in the solar system. However, our knowledge of the nature of the flows and their ultimate fate remains incomplete, partly because diagnostic landforms at outflow channel termini have been largely destroyed or buried. The Hebrus Valles outflow channels were excavated by fluid discharges that emanated from two point sources, and they mostly terminate in systems of fractures and depressions within the northern plains. Our investigation indicates that outflow channel floodwaters were captured and reabsorbed into the subsurface in zones where caverns developed within the northern plains. These findings imply that the study region comprises the only known location in the Martian northern lowlands where the fate of outflow channel discharges can be assessed with confidence. We propose that evacuation of subsurface materials via mud volcanism was an important process in cavern formation. Our conceptual model provides a hypothesis to account for the fate of sediments and fluids from some of the Martian outflow channels. It also reveals a mechanism for lowland cavern formation and upper crustal volatile enrichment after the development of the Martian global cryosphere.

  2. Changes in the Martian atmosphere induced by auroral electron precipitation (United States)

    Shematovich, V. I.; Bisikalo, D. V.; Gérard, J.-C.; Hubert, B.


    Typical auroral events in the Martian atmosphere, such as discrete and diffuse auroral emissions detected by UV spectrometers onboard ESA Mars Express and NASA MAVEN, are investigated. Auroral electron kinetic energy distribution functions and energy spectra of the upward and downward electron fluxes are obtained by electron transport calculations using the kinetic Monte Carlo model. These characteristics of auroral electron fluxes make it possible to calculate both the precipitation-induced changes in the atmosphere and the observed manifestations of auroral events on Mars. In particular, intensities of discrete and diffuse auroral emissions in the UV and visible wavelength ranges (Soret et al., 2016; Bisikalo et al., 2017; Gérard et al., 2017). For these conditions of auroral events, the analysis is carried out, and the contribution of the fluxes of precipitating electrons to the heating and ionization of the Martian atmosphere is estimated. Numerical calculations show that in the case of discrete auroral events the effect of the residual crustal magnetic field leads to a significant increase in the upward fluxes of electrons, which causes a decrease in the rates of heating and ionization of the atmospheric gas in comparison with the calculations without taking into account the residual magnetic field. It is shown that all the above-mentioned impact factors of auroral electron precipitation processes should be taken into account both in the photochemical models of the Martian atmosphere and in the interpretation of observations of the chemical composition and its variations using the ACS instrument onboard ExoMars.

  3. Martian Radiative Transfer Modeling Using the Optimal Spectral Sampling Method (United States)

    Eluszkiewicz, J.; Cady-Pereira, K.; Uymin, G.; Moncet, J.-L.


    The large volume of existing and planned infrared observations of Mars have prompted the development of a new martian radiative transfer model that could be used in the retrievals of atmospheric and surface properties. The model is based on the Optimal Spectral Sampling (OSS) method [1]. The method is a fast and accurate monochromatic technique applicable to a wide range of remote sensing platforms (from microwave to UV) and was originally developed for the real-time processing of infrared and microwave data acquired by instruments aboard the satellites forming part of the next-generation global weather satellite system NPOESS (National Polarorbiting Operational Satellite System) [2]. As part of our on-going research related to the radiative properties of the martian polar caps, we have begun the development of a martian OSS model with the goal of using it to perform self-consistent atmospheric corrections necessary to retrieve caps emissivity from the Thermal Emission Spectrometer (TES) spectra. While the caps will provide the initial focus area for applying the new model, it is hoped that the model will be of interest to the wider Mars remote sensing community.

  4. Thermal and hydraulic considerations regarding the fate of water discharged by the outflow channels to the Martian northern plains (United States)

    Clifford, S. M.


    The identification of possible shorelines in the Martian northern plains suggests that the water discharged by the circum-Chryse outflow channels may have led to the formation of transient seas, or possibly even an ocean, covering as much as one-third of the planet. Speculations regarding the possible fate of this water have included local ponding and reinfiltration into the crust; freezing, sublimation, and eventual cold-trapping at higher latitudes; or the in situ survival of this now frozen water to the present day -- perhaps aided by burial beneath a protective cover of eolian sediment or lavas. Although neither cold-trapping at higher latitudes nor the subsequent freezing and burial of flood waters can be ruled out, thermal and hydraulic considerations effectively eliminate the possibility that any significant reassimilation of this water by local infiltration has occurred given climatic conditions resembling those of today. The arguments against the local infiltration of flood water into the northern plains are two-fold. First, given the climatic and geothermal conditions that are thought to have prevailed on Mars during the Late Hesperian (the period of peak outflow channel activity in the northern plains), the thickness of the cryosphere in Chryse Planitia is likely to have exceeded 1 km. A necessary precondition for the widespread occurrence of groundwater is that the thermodynamic sink represented by the cryosphere must already be saturated with ice. For this reason, the ice-saturated cryosphere acts as an impermeable barrier that effectively precludes the local resupply of subpermafrost groundwater by the infiltration of water discharged to the surface by catastraphic floods. Note that the problem of local infiltration is not significantly improved even if the cryosphere were initially dry, for as water attempts to infiltrate the cold, dry crust, it will quickly freeze, creating a seal that prevents any further infiltration from the ponded water above

  5. A Continuous Flow Diffusion Chamber Study of Sea Salt Particles Acting as Cloud Seeds: Deliquescence, Ice Nucleation and Sublimation (United States)

    Kong, X.; Wolf, M. J.; Garimella, S.; Roesch, M.; Cziczo, D. J.


    Sea Salt Aerosols (SSA) are abundant in the atmosphere, and important to the Earth's chemistry and energy budget. However, the roles of sea salts in the context of cloud formation are still poorly understood, which is partially due to the complexity of the water-salt phase diagram. At ambient temperatures, even well below 0°C, SSA deliquesces at sub-water saturated conditions. Since the ratio of the partial pressure over ice versus super-cooled water continuously declines with decreasing temperatures, it is interesting to consider if SSA continues to deliquesce under a super-saturated condition of ice, or if particles act as depositional ice nuclei when a critical supersaturation is reached. Some recent studies suggest hydrated NaCl and simulated sea salt might deliquesce between -35°C to -44°C, and below that deposition freezing becomes possible. Deliquesced droplets can subsequently freeze via the immersion or homogenous freezing mode, depending on if the deliquescence processes is complete. After the droplets or ice particles are formed, it is also interesting to consider how the different processes influence physical properties after evaporation or sublimation. This data is important for climate modeling that includes bromine burst observed in Antarctica, which is hypothesized to be relevant to the sublimation of blowing snow particles. In this study we use a SPectrometer for Ice Nuclei (SPIN; DMT, Inc., Boulder, CO) to perform experiments over a wide range of temperature and RH conditions to quantify deliquescence, droplet formation and ice nucleation. The formation of droplets and ice particles is detected by an advanced Optical Particle Counter (OPC) and the liquid/solid phases are distinguished by a machine learning method based on laser scattering and polarization data. Using an atomizer, four different sea salt samples are generated: pure NaCl and MgCl2 solutions, synthetic seawater, and natural seawater. Downstream of the SPIN chamber, a Pumped

  6. Sputnik Planitia, Pluto Convection Cell Surface Velocities of ~10 Centimeters per Year Based on Sublimation Pit Distribution (United States)

    Buhler, Peter Benjamin; Ingersoll, Andrew P.


    Sputnik Planitia, Pluto contains cellular landforms with areas on the order of a few 102-103 km2 that are likely the surface manifestation of convective overturn in a vast basin of nitrogen ice. The cells have sublimation pits on them, with smaller pits near their centers and larger pits near their edges. We map over 12,000 pits on seven cells and find that the pit radii increase by between 2.1 ± 0.4 and 5.9 ± 0.8 × 10-3 m per meter away from the cell center, depending on the cell. Due to finite data resolution, this is a lower bound on the size increase. Conservatively accounting for resolution effects yields upper bounds on the size vs. distance distribution of 4.2 ± 0.2 to 23.4 ± 1.5 × 10-3 m m-1. In order to convert the pit size vs. distance distribution into a pit age vs. distance distribution, we use an analytic model to calculate that pit radii grow via sublimation at a rate of 3.6 [+2.1,-0.6] × 10-4 m yr-1. Combined with the mapped distribution of pit radii, this yields surface velocities between 1.5 [+1.0,-0.2] and 6.2 [+3.4,-1.4] cm yr-1 for the slowest cell and surface velocities between 8.1 [+5.5,-1.0] and 17.9 [+8.9,-5.1] cm yr-1 for the fastest cell; the lower bound estimate for each cell accounts for resolution effects, while the upper bound estimate does not. These convection rates imply that the surface ages at the edge of cells reach approximately 4.2 to 8.9 × 105 yr, depending on the cell. The rates we find are comparable to rates of ~6 cm yr-1 that were previously obtained from modeling of the convective overturn in Sputnik Planitia [McKinnon, W.B. et al., 2016, Nature, 534(7605), 82-85]. Finally, we find that the minimum viscosity at the surface of the convection cells is of order 1016 to 1017 Pa s; we find that pits would relax away before sublimating to their observed radii of several hundred meters if the viscosity were lower than this value.

  7. Scene-selectivity and retinotopy in medial parietal cortex

    Directory of Open Access Journals (Sweden)

    Edward Harry Silson


    Full Text Available Functional imaging studies in human reliably identify a trio of scene-selective regions, one on each of the lateral (occipital place area, OPA, ventral (parahippocampal place area, PPA, and medial (retrosplenial complex, RSC cortical surfaces. Recently, we demonstrated differential retinotopic biases for the contralateral lower and upper visual fields within OPA and PPA, respectively. Here, using fMRI, we combine detailed mapping of both population receptive fields (pRF and category-selectivity, with independently acquired resting-state functional connectivity analyses, to examine scene and retinotopic processing within medial parietal cortex. We identified a medial scene-selective region, which was contained largely within the posterior and ventral bank of the parieto-occipital sulcus (POS. While this region is typically referred to as RSC, the spatial extent of our scene-selective region typically did not extend into retrosplenial cortex, and thus we adopt the term medial place area (MPA to refer to this visually defined scene-selective region. Intriguingly MPA co-localized with a region identified solely on the basis of retinotopic sensitivity using pRF analyses. We found that MPA demonstrates a significant contralateral visual field bias, coupled with large pRF sizes. Unlike OPA and PPA, MPA did not show a consistent bias to a single visual quadrant. MPA also co-localized with a region identified by strong differential functional connectivity with PPA and FFA, commensurate with its functional selectivity. Functional connectivity with OPA was much weaker than with PPA, and similar to that with face-selective OFA, suggesting a closer link with ventral then lateral cortex. Consistent with prior research, we also observed differential functional connectivity in medial parietal cortex for anterior over posterior PPA, as well as a region on the lateral surface, the caudal inferior parietal lobule (cIPL. However, the differential connectivity in

  8. What do We Learn by Semantic Scene Understanding for Remote Sensing imagery in CNN framework?


    Li, Haifeng; Peng, Jian; Tao, Chao; Chen, Jie; Deng, Min


    Recently, deep convolutional neural network (DCNN) achieved increasingly remarkable success and rapidly developed in the field of natural image recognition. Compared with the natural image, the scale of remote sensing image is larger and the scene and the object it represents are more macroscopic. This study inquires whether remote sensing scene and natural scene recognitions differ and raises the following questions: What are the key factors in remote sensing scene recognition? Is the DCNN r...

  9. Scene reassembly after multimodal digitization and pipeline evaluation using photorealistic rendering

    DEFF Research Database (Denmark)

    Stets, Jonathan Dyssel; Dal Corso, Alessandro; Nielsen, Jannik Boll


    Transparent objects require acquisition modalities that are very different from the ones used for objects with more diffuse reflectance properties. Digitizing a scene where objects must be acquired with different modalities requires scene reassembly after reconstruction of the object surfaces....... This reassembly of a scene that was picked apart for scanning seems unexplored. We contribute with a multimodal digitization pipeline for scenes that require this step of reassembly. Our pipeline includes measurement of bidirectional reflectance distribution functions and high dynamic range imaging...

  10. Ritual Scenes in the Iliad: Rote, Hallowed, or Encrypted as Ancient Art?

    Directory of Open Access Journals (Sweden)

    Margo Kitts


    Full Text Available Based in oral poetic and ritual theory, this article proposes that ritual scenes in Homer’s Iliad reflect unique compositional constraints beyond those found in other kinds of typical scenes. The focus is on oath-sacrifices and commensal sacrifices. Both ritual scene types exhibit strong identifying features, although they differ in their formal particulars and cultural implications. It is argued that both sorts of sacrificial scenes preserve especially ancient ritual patterns that may have parallels in Anatolian texts.

  11. Biohazard potential of putative Martian organisms during missions to Mars. (United States)

    Warmflash, David; Larios-Sanz, Maia; Jones, Jeffrey; Fox, George E; McKay, David S


    Exploration Class missions to Mars will require precautions against potential contamination by any native microorganisms that may be incidentally pathogenic to humans. While the results of NASA's Viking biology experiments of the 1970s have been generally interpreted as inconclusive for surface organisms, and attributed to active but nonbiological chemistries, the possibility of native surface life has never been ruled out completely. It is possible that, prior to the first human landing on Mars, robotic craft and sample return missions will provide enough data to know with certainty whether future human landing sites harbor extant life forms. If native life were found to exist, it would be problematic to determine whether any of its species might present a medical danger to astronauts. Therefore, it will become necessary to assess empirically the risk that the planet contains pathogens based on terrestrial examples of pathogenicity and to take a reasonably cautious approach to biohazard protection. A survey of terrestrial pathogens was conducted with special emphasis on those whose evolution has not depended on the presence of animal hosts. The history of the development and implementation of Apollo anti-contamination protocol and recommendations of the National Research Council's Space Studies Board regarding Mars were reviewed. Organisms can emerge in Nature in the absence of indigenous animal hosts and both infectious and non-infectious human pathogens are therefore theoretically possible on Mars. Although remote, the prospect of Martian surface life, together with the existence of a diversity of routes by which pathogenicity has emerged on Earth, suggests that the probability of human pathogens on Mars, while low, is not zero. Still, since the discovery and study of Martian life can have long-term benefits for humanity, the risk that Martian life might include pathogens should not be an obstacle to human exploration. As a precaution, it is recommended that EVA

  12. Modelling a crime scene in 3D and adding thermal information

    NARCIS (Netherlands)

    Iersel, M. van; Veerman, H.E.T.; Mark, W. van der


    Once a crime has been perpetrated, forensic traces will only be persevered in the crime scene for a limited time frame. It is therefore necessary to record a crime scene meticulously. Usually, photographs and/or videos are taken at the scene to document it, so that later on one will know the exact

  13. Separate and simultaneous adjustment of light qualities in a real scene

    NARCIS (Netherlands)

    Xia, L.; Pont, S.C.; Heynderickx, I.E.J.R.


    Humans are able to estimate light field properties in a scene in that they have expectations of the objects' appearance inside it. Previously, we probed such expectations in a real scene by asking whether a "probe object" fitted a real scene with regard to its lighting. But how well are observers

  14. Visual search of traffic scenes : on the effect of location expectations.

    NARCIS (Netherlands)

    Theeuwes, J. & Hagenzieker, M.P.


    The present study investigates top-down governed visual selection in natural traffic scenes. The subjects had to search for a target object (for example, a traffic sign, or other road users) which was embedded in a natural traffic scene. Given a particular prototypical scene, the target was located

  15. Scene complexity: influence on perception, memory, and development in the medial temporal lobe

    Directory of Open Access Journals (Sweden)

    Xiaoqian J Chai


    Full Text Available Regions in the medial temporal lobe (MTL and prefrontal cortex (PFC are involved in memory formation for scenes in both children and adults. The development in children and adolescents of successful memory encoding for scenes has been associated with increased activation in PFC, but not MTL, regions. However, evidence suggests that a functional subregion of the MTL that supports scene perception, located in the parahippocampal gyrus (PHG, goes through a prolonged maturation process. Here we tested the hypothesis that maturation of scene perception supports the development of memory for complex scenes. Scenes were characterized by their levels of complexity defined by the number of unique object categories depicted in the scene. Recognition memory improved with age, in participants ages 8-24, for high, but not low, complexity scenes. High-complexity compared to low-complexity scenes activated a network of regions including the posterior PHG. The difference in activations for high- versus low- complexity scenes increased with age in the right posterior PHG. Finally, activations in right posterior PHG were associated with age-related increases in successful memory formation for high-, but not low-, complexity scenes. These results suggest that functional maturation of the right posterior PHG plays a critical role in the development of enduring long-term recollection for high-complexity scenes.

  16. Mirth and Murder: Crime Scene Investigation as a Work Context for Examining Humor Applications (United States)

    Roth, Gene L.; Vivona, Brian


    Within work settings, humor is used by workers for a wide variety of purposes. This study examines humor applications of a specific type of worker in a unique work context: crime scene investigation. Crime scene investigators examine death and its details. Members of crime scene units observe death much more frequently than other police officers…

  17. The role of oxygen in CdS/CdTe solar cells deposited by close-spaced sublimation

    Energy Technology Data Exchange (ETDEWEB)

    Rose, D.H.; Levi, D.H.; Matson, R.J. [National Renewable Energy Lab., Golden, CO (United States)] [and others


    The presence of oxygen during close-spaced sublimation (CSS) of CdTe has been previously reported to be essential for high-efficiency CdS/CdTe solar cells because it increases the acceptor density in the absorber. The authors find that the presence of oxygen during CSS increases the nucleation site density of CdTe, thus decreasing pinhole density and grain size. Photoluminescence showed that oxygen decreases material quality in the bulk of the CdTe film, but positively impacts the critical CdS/CdTe interface. Through device characterization the authors were unable to verify an increase in acceptor density with increased oxygen. These results, along with the achievement of high-efficiency cells (13% AM1.5) without the use of oxygen, led the authors to conclude that the use of oxygen during CSS deposition of CdTe can be useful but is not essential.

  18. La estética de lo sublime en la sección El Jorullo de la Rusticatio Mexicana

    Directory of Open Access Journals (Sweden)

    Dorde Cuvardic García


    Full Text Available El ensayo presenta un análisis de la II sección de la obra Rusticatio Mexicana (1782, del escritor guatemalteco Rafael Landívar (1731-1793, desde la estética de la sublimidad. La narración que hace el autor de la erupción del volcán El jorullo sigue los procedimientos típicos del clasicismo, pero a la vez contribuye con la representación de la singularidad de América, desde la filosofía sensista, y según categorizaciones susceptibles de ser analizadas mediante las teorías estéticas de la sublimidad (Addison, Burke, Kant, que destacan la experiencia humana de lo sublime, que se observa en la naturaleza espectacular, en contraste con la experiencia de la belleza, apreciable en la obra de arte.

  19. Volatilization, transport and sublimation of metallic and non-metallic elements in high temperature gases at Merapi Volcano, Indonesia (United States)

    Symonds, R.B.; Rose, William I.; Reed, M.H.; Lichte, F.E.; Finnegan, David L.


    Condensates, silica tube sublimates and incrustations were sampled from 500-800??C fumaroles and lava samples were collected at Merapi Volcano, Indonesia in Jan.-Feb., 1984. With respect to the magma, Merapi gases are enriched by factors greater than 105 in Se, Re, Bi and Cd; 104-105 in Au, Br, In, Pb and W; 103-104 in Mo, Cl, Cs, S, Sn and Ag; 102-103 in As, Zn, F and Rb; and 1-102 in Cu, K, Na, Sb, Ni, Ga, V, Fe, Mn and Li. The fumaroles are transporting more than 106 grams/day ( g d) of S, Cl and F; 104-106 g/d of Al, Br, Zn, Fe, K and Mg; 103-104 g d of Pb, As, Mo, Mn, V, W and Sr; and less than 103 g d of Ni, Cu, Cr, Ga, Sb, Bi, Cd, Li, Co and U. With decreasing temperature (800-500??C) there were five sublimate zones found in silica tubes: 1) cristobalite and magnetite (first deposition of Si, Fe and Al); 2) K-Ca sulfate, acmite, halite, sylvite and pyrite (maximum deposition of Cl, Na, K, Si, S, Fe, Mo, Br, Al, Rb, Cs, Mn, W, P, Ca, Re, Ag, Au and Co); 3) aphthitalite (K-Na sulfate), sphalerite, galena and Cs-K. sulfate (maximum deposition of Zn, Bi, Cd, Se and In; higher deposition of Pb and Sn); 4) Pb-K chloride and Na-K-Fe sulfate (maximum deposition of Pb, Sn and Cu); and 5) Zn, Cu and K-Pb sulfates (maximum deposition of Pb, Sn, Ti, As and Sb). The incrustations surrounding the fumaroles are also chemically zoned. Bi, Cd, Pb, W, Mo, Zn, Cu, K, Na, V, Fe and Mn are concentrated most in or very close to the vent as expected with cooling, atmospheric contamination and dispersion. The highly volatile elements Br, Cl, As and Sb are transported primarily away from high temperature vents. Ba, Si, P, Al, Ca and Cr are derived from wall rock reactions. Incomplete degassing of shallow magma at 915??C is the origin of most of the elements in the Merapi volcanic gas, although it is partly contaminated by particles or wall rock reactions. The metals are transported predominantly as chloride species. As the gas cools in the fumarolic environment, it becomes saturated

  20. Optically stimulated luminescence dating properties of Martian sediment analogue materials exposed to a simulated Martian solar spectral environment

    Energy Technology Data Exchange (ETDEWEB)

    Detschel, M.J. [Department of Physics, North Dakota State University, 218 South Engineering, Fargo, ND 58102 (United States); Department of Geosciences, North Dakota State University, 218 Stevens Hall, Fargo, ND 58102 (United States)], E-mail:; Lepper, K. [Department of Geosciences, North Dakota State University, 218 Stevens Hall, Fargo, ND 58102 (United States)], E-mail:


    Deciphering the geomorphic, climatic, and hydrologic history of Mars will require an extensive geochronology on numerous time scales from both returned samples and in-situ measurements. Optically stimulated luminescence dating (OSL), or optical dating, is an established terrestrial geochronological method that is being developed as a member of a suite of dating tools for Mars. As part of this development process, we have built an optical system simulating the calculated Martian solar spectral irradiance taking into account seasonal variations due to attenuation of dust and the planet's orbital position and used it to catalogue the UV dosimetric response and optical dating behavior of a group of sediment analogues exposed to a simulated Martian spectral environment (SMSE) for the surface of the planet. Our results suggest that optical dating should not be compromised by the interaction of the enhanced UV radiation in the Martian spectrum with K-feldspar, Ca-feldspar, anhydrite, or hydrous Ca and Mg sulfates on Mars. However, Na-feldspar appears to be capable of acquiring and retaining an OSL signal under SMSE conditions, which could present a challenge for optical dating on Mars in sedimentary deposits containing more than a trace quantity of sodic feldspars.

  1. Atlante del bianco: new dancers on the contemporary scenes

    Directory of Open Access Journals (Sweden)

    Gaia Germanà


    Full Text Available The essay deals with the experience of the newborn Italian dance company Damasco Corner, a group of visually impaired professional dancers working with the choreographer Virgilio Sieni in Firenze, at CANGO_Cantieri Goldonetta. The text looks at the performance process they went through (workshops, training and rehearsals preparing the first official piece of the company: Atlante del bianco. The access of these new dancers to the field of professional artistic education implies different changing, in the studio as well as on the scene. Inclusive approaches are applied, teaching dance techniques, improvisation and creating choreographies. The audience needs to embrace different perspectives to feel and understand the dance that is lived and presented on the scene

  2. A corticothalamic circuit model for sound identification in complex scenes.

    Directory of Open Access Journals (Sweden)

    Gonzalo H Otazu

    Full Text Available The identification of the sound sources present in the environment is essential for the survival of many animals. However, these sounds are not presented in isolation, as natural scenes consist of a superposition of sounds originating from multiple sources. The identification of a source under these circumstances is a complex computational problem that is readily solved by most animals. We present a model of the thalamocortical circuit that performs level-invariant recognition of auditory objects in complex auditory scenes. The circuit identifies the objects present from a large dictionary of possible elements and operates reliably for real sound signals with multiple concurrently active sources. The key model assumption is that the activities of some cortical neurons encode the difference between the observed signal and an internal estimate. Reanalysis of awake auditory cortex recordings revealed neurons with patterns of activity corresponding to such an error signal.

  3. Multimodal computational attention for scene understanding and robotics

    CERN Document Server

    Schauerte, Boris


    This book presents state-of-the-art computational attention models that have been successfully tested in diverse application areas and can build the foundation for artificial systems to efficiently explore, analyze, and understand natural scenes. It gives a comprehensive overview of the most recent computational attention models for processing visual and acoustic input. It covers the biological background of visual and auditory attention, as well as bottom-up and top-down attentional mechanisms and discusses various applications. In the first part new approaches for bottom-up visual and acoustic saliency models are presented and applied to the task of audio-visual scene exploration of a robot. In the second part the influence of top-down cues for attention modeling is investigated. .

  4. Scene From The Birth Of Venus: Kajian Karya Fotografi

    Directory of Open Access Journals (Sweden)

    Agra Locita


    Full Text Available Scene From The Birth Of Venus is a photographic artwork that created in 1949. The artwork was the result of collaboration between Salvador Dali and two photographers, Baron George Hoyningen-Huene and George Platt Lynes. They created Birth of Venus differently with first painting whom created by Bottocelli Sandro. He depicted the goddess Venus graceful and shy, but it recreated by Salvador Dali in an imaginative photographic artwork. In Scene From The Birth Of Venus, the goddess Venus depicted as half human and fish. Two creations in different way but still in the birth of the goddess Venus theme.  Key words: photography, painting, imaginative

  5. A combined feature latent semantic model for scene classification (United States)

    Jiang, Yue; Wang, Runsheng


    Due to vast growth of image databases, scene image classification methods have become increasingly important in computer vision areas. We propose a new scene image classification framework based on combined feature and a latent semantic model which is based on the Latent Dirichlet Allocation (LDA) in the statistical text literature. Here the model is applied to visual words representation for images. We use Gibbs sampling for parameter estimation and use several different numbers of topics at the same time to obtain the latent topic representation of images. We densely extract multi-scale patches from images and get the combined feature on these patches. Our method is unsupervised. It can also well represent semantic characteristic of images. We demonstrate the effectiveness of our approach by comparing it to those used in previous work in this area. Experiments were conducted on three often used image databases, and our method got better results than the others.

  6. Carbon and Oxygen Stable Isotope Measurements of Martian Atmospheric CO2 by the Phoenix Lander (United States)

    Niles, Paul B.; Boynton, W. V.; Hoffman, J. H.; Ming, D. W.; Hamara, D.


    Precise stable isotope measurements of the CO2 in the martian atmosphere have the potential to provide important constraints for our understanding of the history of volatiles, the carbon cycle, current atmospheric processes, and the degree of water/rock interaction on Mars [1]. The isotopic composition of the martian atmosphere has been measured using a number of different methods (Table 1), however a precise value (<1%) has yet to be achieved. Given the elevated Delta(sup 13)C values measured in carbonates in martian meteorites [2-4] it has been proposed that the martian atmosphere was enriched in 13C [8]. This was supported by measurements of trapped CO2 gas in EETA 79001[2] which showed elevated Delta(sup 13)C values (Table 1). More recently, Earth-based spectroscopic measurements of the martian atmosphere have measured the martian CO2 to be depleted in C-13 relative to CO2 in the terrestrial atmosphere[ 7, 9-11]. The Thermal and Evolved Gas Analyzer (TEGA) instrument on the Mars Phoenix Lander [12] included a magnetic-sector mass spectrometer (EGA) [13] which had the goal of measuring the isotopic composition of martian atmospheric CO2 to within 0.5%. The mass spectrometer is a miniature instrument intended to measure both the martian atmosphere as well as gases evolved from heating martian soils.

  7. SpaceTime Environmental Image Information for Scene Understanding (United States)


    Analysis and Machine Intel. 2011;33(12):2341–2353. 31. Song Y, Luo H, Hui B, Chang Z. An improved image dehazing and enhancing method using the end user (Soldier) develop improved course of action strategies based on scene understanding ( algorithms and analysis) incorporating...environmental image information in the data measurement process will lead to 1) improved autonomous intelligent systems supporting Army missions in complex


    Directory of Open Access Journals (Sweden)

    Daniel Santos Costa


    Full Text Available This text presents weavings of a way to make the arts scene using the autobiographical support the creative process. Thus, we elucidate some of these weavings process while legitimizing the production of knowledge through artistic praxis, of sensitive experience. Introducing the concept of autobiography in analogy to the artistic and sequentially present the possibility of a laboratory setting amalgamated into reality/fiction. Keywords: creative process; autobiography; body.

  9. Acoustic simulation in realistic 3D virtual scenes (United States)

    Gozard, Patrick; Le Goff, Alain; Naz, Pierre; Cathala, Thierry; Latger, Jean


    The simulation workshop CHORALE developed in collaboration with OKTAL SE company for the French MoD is used by government services and industrial companies for weapon system validation and qualification trials in the infrared domain. The main operational reference for CHORALE is the assessment of the infrared guidance system of the Storm Shadow missile French version, called Scalp. The use of CHORALE workshop is now extended to the acoustic domain. The main objective is the simulation of the detection of moving vehicles in realistic 3D virtual scenes. This article briefly describes the acoustic model in CHORALE. The 3D scene is described by a set of polygons. Each polygon is characterized by its acoustic resistivity or its complex impedance. Sound sources are associated with moving vehicles and are characterized by their spectra and directivities. A microphone sensor is defined by its position, its frequency band and its sensitivity. The purpose of the acoustic simulation is to calculate the incoming acoustic pressure on microphone sensors. CHORALE is based on a generic ray tracing kernel. This kernel possesses original capabilities: computation time is nearly independent on the scene complexity, especially the number of polygons, databases are enhanced with precise physical data, special mechanisms of antialiasing have been developed that enable to manage very accurate details. The ray tracer takes into account the wave geometrical divergence and the atmospheric transmission. The sound wave refraction is simulated and rays cast in the 3D scene are curved according to air temperature gradient. Finally, sound diffraction by edges (hill, wall,...) is also taken into account.

  10. Optical character recognition in images of natural scenes


    Petek, Rok; Jurc, Maja; Kalan, Janko; Batič, Franc


    This masters thesis presents and describes modern methods of optical character recognition in natural scenes. Methods with high classification results and are robust to illumination and geometric transformations were selected for the thesis. Our work is based on the implementation of three different methods for obtaining features. The basic HOG method, which also underlies the other two methods is one of the most popular feature extraction methods in object detection and character recognition...

  11. Modular and Scalable Firmware for Infrared LED Scene Projectors (United States)


    Department of Electrical and Computer Engineering University of Delaware Newark, DE USA 19716 Abstract: Infrared scene projectors (IRSPs) are a...Program Executive Office for Simulation, Training and Instrumentation (PEO STRI ) under Contract No. W91ZLK-06-C- 0006." (b) "Any opinions, findings...Training and Instrumentation (PEO STRI ).” References 1. R. McGee, K. Nabha, J. Marks, J. Benedict, G. Ejzak, J. Dickason, N. Waite, M. Hernandez

  12. A Scene Text-Based Image Retrieval System (United States)


    images. The majority of OCR engines is designed for scanned text and so depends on segmentation which correctly separates text from background...size is 8×8, cell size is 2×2 and 9 bins for histogram. For each candidate word, HOG feature is extracted and used by the SVM classifier to verify...images. One approach is to extract text appearing in images which often gives an indication of a scene’s semantic content. However, it can be


    Directory of Open Access Journals (Sweden)

    A. A. Shevtsov


    Full Text Available The technics and a technique of experiment on studying kinetic laws of periodic process vacuum and freeze-drying of a fermental preparation inulinase is stated and the algorithm of a choice of optimum loading sublimator on the minimum size of specific power inputs is offered.

  14. Fractionated Noble Gases in Martian Meteorite ALH 84001 — An Indicator for Water-Rock Interaction, or a Sample of Ancient Atmosphere? (United States)

    Schwenzer, S. P.; Bart, G.; Bridges, J. C.; Crowther, S. A.; Filiberto, J.; Gilmour, J. D.; Herrmann, S.; Hicks, L. J.; Kelley, S. P.; Miller, M. A.; Ott, U.; Steer, E. D.; Swindle, T. D.; Treiman, A. H.


    Noble gases in the nakhlite and ALH84001 Martian meteorites are still a mystery, but could tell us about either the history of the Martian atmosphere, Martian water rock interaction or - likely - both!

  15. Describing visual scenes: towards a neurolinguistics based on construction grammar. (United States)

    Arbib, Michael A; Lee, Jinyong


    The present paper is part of a larger effort to locate the production and perception of language within the broader context of brain mechanisms for action and perception more generally. Here we model function in terms of the competition and cooperation of schemas. We use the task of describing visual scenes to explore the suitability of Construction Grammar as an appropriate framework for a schema-based linguistics. We recall the early VISIONS model of schema-based computer analysis of static visual scenes and then introduce SemRep as a graphical representation of dynamic visual scenes designed to support the generation of varied descriptions of episodes. We report preliminary results on implementing the production of sentences using Template Construction Grammar (TCG), a new form of construction grammar distinguished by its use of SemRep to express semantics. We summarize data on neural correlates relevant to future work on TCG within the context of neurolinguistics, and show how the relation between SemRep and TCG can serve as the basis for modeling language comprehension.

  16. Scene articulation: dependence of illuminant estimates on number of surfaces. (United States)

    Linnell, Karina J; Foster, David H


    The ability of observers to detect changes in illuminant over two scenes containing different random samples of reflecting surfaces was determined in an experiment with Mondrian-like patterns containing different numbers of coloured patches. Performance was found to improve as the number of patches increased from 9 to 49. In principle, observers could have used space-average scene colour as the cue ('grey-world' hypothesis) or the colour of the brightest surface in the scene ('bright-is-white' hypothesis), as the two cues generally covary. In a second experiment, observers matched illuminants across different patterns in which the space-average cue and the brightest-patch cue were independently manipulated. The articulation of the patterns was varied: the number of patches increased from 49 (patch width 1 deg visual angle) to over 50000 (patch width 0.03 deg), while the gamut of colours was held constant. Space-average colour was found to be the dominant cue with all patterns except for those with the largest patches.

  17. Higher-order scene statistics of breast images (United States)

    Abbey, Craig K.; Sohl-Dickstein, Jascha N.; Olshausen, Bruno A.; Eckstein, Miguel P.; Boone, John M.


    Researchers studying human and computer vision have found description and construction of these systems greatly aided by analysis of the statistical properties of naturally occurring scenes. More specifically, it has been found that receptive fields with directional selectivity and bandwidth properties similar to mammalian visual systems are more closely matched to the statistics of natural scenes. It is argued that this allows for sparse representation of the independent components of natural images [Olshausen and Field, Nature, 1996]. These theories have important implications for medical image perception. For example, will a system that is designed to represent the independent components of natural scenes, where objects occlude one another and illumination is typically reflected, be appropriate for X-ray imaging, where features superimpose on one another and illumination is transmissive? In this research we begin to examine these issues by evaluating higher-order statistical properties of breast images from X-ray projection mammography (PM) and dedicated breast computed tomography (bCT). We evaluate kurtosis in responses of octave bandwidth Gabor filters applied to PM and to coronal slices of bCT scans. We find that kurtosis in PM rises and quickly saturates for filter center frequencies with an average value above 0.95. By contrast, kurtosis in bCT peaks near 0.20 cyc/mm with kurtosis of approximately 2. Our findings suggest that the human visual system may be tuned to represent breast tissue more effectively in bCT over a specific range of spatial frequencies.

  18. Rapid discrimination of visual scene content in the human brain. (United States)

    Anokhin, Andrey P; Golosheykin, Simon; Sirevaag, Erik; Kristjansson, Sean; Rohrbaugh, John W; Heath, Andrew C


    The rapid evaluation of complex visual environments is critical for an organism's adaptation and survival. Previous studies have shown that emotionally significant visual scenes, both pleasant and unpleasant, elicit a larger late positive wave in the event-related brain potential (ERP) than emotionally neutral pictures. The purpose of the present study was to examine whether neuroelectric responses elicited by complex pictures discriminate between specific, biologically relevant contents of the visual scene and to determine how early in the picture processing this discrimination occurs. Subjects (n = 264) viewed 55 color slides differing in both scene content and emotional significance. No categorical judgments or responses were required. Consistent with previous studies, we found that emotionally arousing pictures, regardless of their content, produce a larger late positive wave than neutral pictures. However, when pictures were further categorized by content, anterior ERP components in a time window between 200 and 600 ms following stimulus onset showed a high selectivity for pictures with erotic content compared to other pictures regardless of their emotional valence (pleasant, neutral, and unpleasant) or emotional arousal. The divergence of ERPs elicited by erotic and non-erotic contents started at 185 ms post-stimulus in the fronto-central midline region, with a later onset in parietal regions. This rapid, selective, and content-specific processing of erotic materials and its dissociation from other pictures (including emotionally positive pictures) suggests the existence of a specialized neural network for prioritized processing of a distinct category of biologically relevant stimuli with high adaptive and evolutionary significance.

  19. The Hip-Hop club scene: Gender, grinding and sex. (United States)

    Muñoz-Laboy, Miguel; Weinstein, Hannah; Parker, Richard


    Hip-Hop culture is a key social medium through which many young men and women from communities of colour in the USA construct their gender. In this study, we focused on the Hip-Hop club scene in New York City with the intention of unpacking narratives of gender dynamics from the perspective of young men and women, and how these relate to their sexual experiences. We conducted a three-year ethnographic study that included ethnographic observations of Hip-Hop clubs and their social scene, and in-depth interviews with young men and young women aged 15-21. This paper describes how young people negotiate gender relations on the dance floor of Hip-Hop clubs. The Hip-Hop club scene represents a context or setting where young men's masculinities are contested by the social environment, where women challenge hypermasculine privilege and where young people can set the stage for what happens next in their sexual and emotional interactions. Hip-Hop culture therefore provides a window into the gender and sexual scripts of many urban minority youth. A fuller understanding of these patterns can offer key insights into the social construction of sexual risk, as well as the possibilities for sexual health promotion, among young people in urban minority populations.

  20. Live User-Guided Intrinsic Video for Static Scenes. (United States)

    Meka, Abhimitra; Fox, Gereon; Zollhofer, Michael; Richardt, Christian; Theobalt, Christian


    We present a novel real-time approach for user-guided intrinsic decomposition of static scenes captured by an RGB-D sensor. In the first step, we acquire a three-dimensional representation of the scene using a dense volumetric reconstruction framework. The obtained reconstruction serves as a proxy to densely fuse reflectance estimates and to store user-provided constraints in three-dimensional space. User constraints, in the form of constant shading and reflectance strokes, can be placed directly on the real-world geometry using an intuitive touch-based interaction metaphor, or using interactive mouse strokes. Fusing the decomposition results and constraints in three-dimensional space allows for robust propagation of this information to novel views by re-projection. We leverage this information to improve on the decomposition quality of existing intrinsic video decomposition techniques by further constraining the ill-posed decomposition problem. In addition to improved decomposition quality, we show a variety of live augmented reality applications such as recoloring of objects, relighting of scenes and editing of material appearance.

  1. Recovery of fingerprints from fire scenes and associated evidence. (United States)

    Deans, J


    A lack of information concerning the potential recovery of fingerprints from fire scenes and related evidence prompted several research projects. Latent prints from good secretors and visible prints (in blood) were placed on a variety of different surfaces and subsequently subjected to "real life" fires in fully furnished compartments used for fire investigation training purposes. The items were placed in various locations and at different heights within the compartments. After some initial success, further tests were undertaken using both latent and dirt/grease marks on different objects within the same types of fire compartments. Subsequent sets of tests involved the recovery of latent and visual fingerprints (in blood, dirt and grease) from different types of weapons, lighters, plastic bags, match boxes, tapers, plastic bottles and petrol bombs that had been subjected to the same fire conditions as previously. Throughout the entire series of projects one of the prime considerations was how the resultant findings could be put into practice by fire scene examiners in an attempt to assist the police in their investigations. This research demonstrates that almost one in five items recovered from fire scenes yielded fingerprint ridge detail following normal development treatments.

  2. Imagery rescripting: Is incorporation of the most aversive scenes necessary? (United States)

    Dibbets, Pauline; Arntz, Arnoud


    During imagery rescripting (ImRs) an aversive memory is relived and transformed to have a more positive outcome. ImRs is frequently applied in psychological treatment and is known to reduce intrusions and distress of the memory. However, little is known about the necessity to incorporate the central aversive parts of the memory in ImRs. To examine this necessity one hundred participants watched an aversive film and were subsequently randomly assigned to one of four experimental conditions: ImRs including the aversive scenes (Late ImRs), ImRs without the aversive scenes (Early ImRs), imaginal exposure (IE) or a control condition (Cont). Participants in the IE intervention reported the highest distress levels during the intervention; Cont resulted in the lowest levels of self-reported distress. For the intrusion frequency, only the late ImRs resulted in fewer intrusions compared to the Cont condition; Early ImRs produced significantly more intrusions than the Late ImRs or IE condition. Finally, the intrusions of the Late ImRs condition were reported as less vivid compared to the other conditions. To conclude, it seems beneficial including aversive scenes in ImRs after an analogue trauma induction.

  3. Object-based attention in real-world scenes. (United States)

    Malcolm, George L; Shomstein, Sarah


    We are continually confronted with more visual information than we can process in a given moment. In order to interact effectively with our environment, attentional mechanisms are used to select subsets of environmental properties for enhanced processing. Previous research demonstrated that spatial regions can be selected based on either their low-level feature or high-level semantic properties. However, the efficiency with which we interact with the world suggests that there must be an additional, midlevel, factor constraining effective attentional space. The present study investigates whether object-based attentional selection is one such midlevel factor that constrains visual attention in complex, real-world scenes. Participants viewed scene images while their eye movements were recorded. During viewing, a cue appeared on an object which participants were instructed to fixate. A target then appeared either on the same object as the cue, on a different object, or floating. Participants initiated saccades faster and had shorter response times to targets presented on the same object as the fixated cue. The results strongly suggest that when attending to a location on an object, the entire object benefits perceptually. This object-based effect on the distribution of spatial attention forms a critical link between low- and high-level factors that direct attention efficiently in complex real-world scenes. (c) 2015 APA, all rights reserved).

  4. Scene classification of infrared images based on texture feature (United States)

    Zhang, Xiao; Bai, Tingzhu; Shang, Fei


    Scene Classification refers to as assigning a physical scene into one of a set of predefined categories. Utilizing the method texture feature is good for providing the approach to classify scenes. Texture can be considered to be repeating patterns of local variation of pixel intensities. And texture analysis is important in many applications of computer image analysis for classification or segmentation of images based on local spatial variations of intensity. Texture describes the structural information of images, so it provides another data to classify comparing to the spectrum. Now, infrared thermal imagers are used in different kinds of fields. Since infrared images of the objects reflect their own thermal radiation, there are some shortcomings of infrared images: the poor contrast between the objectives and background, the effects of blurs edges, much noise and so on. Because of these shortcomings, it is difficult to extract to the texture feature of infrared images. In this paper we have developed an infrared image texture feature-based algorithm to classify scenes of infrared images. This paper researches texture extraction using Gabor wavelet transform. The transformation of Gabor has excellent capability in analysis the frequency and direction of the partial district. Gabor wavelets is chosen for its biological relevance and technical properties In the first place, after introducing the Gabor wavelet transform and the texture analysis methods, the infrared images are extracted texture feature by Gabor wavelet transform. It is utilized the multi-scale property of Gabor filter. In the second place, we take multi-dimensional means and standard deviation with different scales and directions as texture parameters. The last stage is classification of scene texture parameters with least squares support vector machine (LS-SVM) algorithm. SVM is based on the principle of structural risk minimization (SRM). Compared with SVM, LS-SVM has overcome the shortcoming of

  5. The Role of Semantic Interference in Limiting Memory for the Details of Visual Scenes


    Melcher, David; Murphy, Brian


    Many studies suggest a large capacity memory for briefly presented pictures of whole scenes. At the same time, visual working memory (WM) of scene elements is limited to only a few items. We examined the role of retroactive interference in limiting memory for visual details. Participants viewed a scene for 5 s and then, after a short delay containing either a blank screen or 10 distracter scenes, answered questions about the location, color, and identity of objects in the scene. We found that...

  6. Very Nice Indeed: Cyprian Latewood's Masochistic Sublime, and the Religious Pluralism of Against the Day

    Directory of Open Access Journals (Sweden)

    Michael Jarvis


    Full Text Available My paper deals with mythological/religious imagery and syncretic soteriologies in Thomas Pynchon’s 2006 novel 'Against the Day', focusing in particular on the character of Cyprian Latewood, bisexual spy, Orpheus stand-in, and masochist par excellence. Cyprian’s path throughout the novel is specifically an Orphic descent/return myth, but it also deals with issues of mystical transcendence, metempsychosis, Dionysian 'ekstasis', and Buddhist 'nirvana'. These are represented at the macro level in themes such as retreat from the world, neo-monasticism, anarchic activism, or hope for transcendent knowledge, and also within specific images and scenes, such as those involving flight, self-negation, disembodied voices, and the final voyage of the Chums of Chance, a Manichaean allegory of escape. Cyprian’s final home at a Bogomil-Orphic monastery near Thrace serves to tie together disparate religio-political strands within the novel, including a syncretic teleology (Gnostic/Buddhist/Manichaean and countercultural activism. It is simultaneously a retreat from the world – a political move with relevance to the history of the Bogomils as both persecuted sect and social agitators – and also a move towards transcendence through gnostic ritual. There are a few important results of this reading, touching on religious, mythological, and Pynchon studies, and sexual and political discourse. Firstly, it challenges the ease with which Western, and specifically Christian, ideologies appropriate counter-discourses in acts of cultural hegemony, exemplified in one instance by Kathryn Hume’s early reading of the novel’s ethos as explicitly Roman Catholic, even in the face of overwhelming evidence to the contrary (“The Religious and Political Vision of 'Against the Day'”, 2007. Secondly, though other critics have gestured at the presence of Orphism and Buddhism in 'Against the Day', they have failed to convincingly tie these concerns to a larger

  7. Recognition of a Virtual Scene via Simulated Prosthetic Vision

    Directory of Open Access Journals (Sweden)

    Ying Zhao


    Full Text Available In order to effectively aid the blind with optimal low-resolution vision and visual recovery training, pathfinding and recognition tests were performed using a simulated visual prosthetic scene. Simple and complex virtual scenes were built using 3DMAX and Unity, and pixelated to three different resolutions (32 × 32, 64 × 64, and 128 × 128 for real-time pixel processing. Twenty subjects were recruited to complete the pathfinding and object recognition tasks within the scene. The recognition accuracy and time required were recorded and analyzed after the trials. In the simple simulated prosthetic vision (SPV scene, when the resolution was increased from 32 × 32 to 48 × 48, the object recognition time decreased from 92.19 ± 6.97 to 43.05 ± 6.08 s, and the recognition accuracy increased from 51.22 ± 8.53 to 85.52 ± 4.93%. Furthermore, the number of collisions decreased from 10.00 ± 2.31 to 3.00 ± 0.68. When the resolution was increased from 48 × 48 to 64 × 64, the object recognition time further decreased from 43.05 ± 6.08 to 19.46 ± 3.71 s, the recognition accuracy increased from 85.52 ± 4.93 to 96.89 ± 2.06%, and the number of collisions decreased from 3.00 ± 0.68 to 1.00 ± 0.29. In complex scenes, the time required to recognize the room type decreased from 115.00 ± 23.02 to 68.25 ± 17.23 s, and object recognition accuracy increased from 65.69 ± 9.61 to 80.42 ± 7.70% when the resolution increased from 48 × 48 to 64 × 64. When the resolution increased from 64 × 64 to 128 × 128, the time required to recognize the room type decreased from 68.25 ± 17.23 to 44.88 ± 9.94 s, and object recognition accuracy increased from 80.42 ± 7.71 to 85.69 ± 7.39%. Therefore, one can conclude that there are correlations between pathfinding and recognition. When the resolution increased, the time required for

  8. N400 brain responses to spoken phrases paired with photographs of scenes: implications for visual scene displays in AAC systems. (United States)

    Wilkinson, Krista M; Stutzman, Allyson; Seisler, Andrea


    Augmentative and alternative communication (AAC) systems are often implemented for individuals whose speech cannot meet their full communication needs. One type of aided display is called a Visual Scene Display (VSD). VSDs consist of integrated scenes (such as photographs) in which language concepts are embedded. Often, the representations of concepts on VSDs are perceptually similar to their referents. Given this physical resemblance, one may ask how well VSDs support development of symbolic functioning. We used brain imaging techniques to examine whether matches and mismatches between the content of spoken messages and photographic images of scenes evoke neural activity similar to activity that occurs to spoken or written words. Electroencephalography (EEG) was recorded from 15 college students who were shown photographs paired with spoken phrases that were either matched or mismatched to the concepts embedded within each photograph. Of interest was the N400 component, a negative deflecting wave 400 ms post-stimulus that is considered to be an index of semantic functioning. An N400 response in the mismatched condition (but not the matched) would replicate brain responses to traditional linguistic symbols. An N400 was found, exclusively in the mismatched condition, suggesting that mismatches between spoken messages and VSD-type representations set the stage for the N400 in ways similar to traditional linguistic symbols.

  9. Effects of scene content and layout on the perceived light direction in 3D spaces. (United States)

    Xia, Ling; Pont, Sylvia C; Heynderickx, Ingrid


    The lighting and furnishing of an interior space (i.e., the reflectance of its materials, the geometries of the furnishings, and their arrangement) determine the appearance of this space. Conversely, human observers infer lighting properties from the space's appearance. We conducted two psychophysical experiments to investigate how the perception of the light direction is influenced by a scene's objects and their layout using real scenes. In the first experiment, we confirmed that the shape of the objects in the scene and the scene layout influence the perceived light direction. In the second experiment, we systematically investigated how specific shape properties influenced the estimation of the light direction. The results showed that increasing the number of visible faces of an object, ultimately using globally spherical shapes in the scene, supported the veridicality of the estimated light direction. Furthermore, symmetric arrangements in the scene improved the estimation of the tilt direction. Thus, human perception of light should integrally consider materials, scene content, and layout.

  10. REMS Ultraviolet Sensor: First UV measurements from the Martian surface. (United States)

    Zorzano, María-Paz; Martín-Torres, Francisco Javier; Navarro-Gonzalez, Rafael; Martín-Soler, Javier; Javier Gómez-Elvira, REMS Team; the MSL Science Team


    From its arrival to the Martian surface on August 2012, the REMS-UVS (Ultra Violet Sensor) has monitored, daily, the down-welling UV irradiance. These are the first UV irradiance measurements ever acquired from the surface of another planet. The UVS consists of one SiC photodiode dedicated to the full UV spectrum 200-400 nm together with 5 filtered photodiodes for narrower band channels. It has a physical aperture of 30° pointing to the sky. When the solar zenith angle of the Sun is beyond this angle, the sensor monitors only the diffuse irradiance of the sky. Furthermore during the daily usual rover operation it can also be protected from the direct irradiance by shadows casted by the rover mast or arm, allowing for a continuous independent monitoring of the direct and diffuse components of the global UV surface irradiance. The measurements delivered from Gale crater, the landing site of the Mars Science Laboratory (MSL) Rover Curiosity, right after the beginning of operations provide an upper limit to the incident UV irradiance because: i) Gale is almost in the Equator; ii) the Sun-Mars distance was minimal; and (ii) the sky was clear of dust aerosols. These measurements are critical values for the estimates of UV doses on the Martian surface with relevant implications for habitability, and atmospheric and surface photo-chemistry modelling. With the onset of the dust season, and as the total column of dust above Gale increases, the UVS measurements shows an expected depletion on the irradiance reaching the surface as the UV radiation is significantly blocked. The REMS-UVS will deliver all through its operational life daily, hourly, values of these quantities providing an unique dataset that will allow to study the interaction of the solar irradiance with the Martian atmosphere and surface and to monitor the dust cycle.

  11. Rocket dust storms and detached layers in the Martian atmosphere (United States)

    Spiga, A.; Faure, J.; Madeleine, J.; Maattanen, A. E.; Forget, F.


    Airborne dust is the main climatic agent in the Martian environment. Local dust storms play a key role in the dust cycle; yet their life cycle is poorly known. Here we use mesoscale modeling with radiatively-active transported dust to predict the evolution of a local dust storm monitored by OMEGA onboard Mars Express. We show that the evolution of this dust storm is governed by deep convective motions. The supply of convective energy is provided by the absorption of incoming sunlight by dust particles, in lieu of latent heating in moist convection on Earth. We propose to use the terminology "rocket dust storm", or conio-cumulonimbus, to describe those storms in which rapid and efficient vertical transport takes place, injecting dust particles at high altitudes in the Martian troposphere (30 to 50 km). Combined to horizontal transport by large-scale winds, rocket dust storms form detached layers of dust reminiscent of those observed with instruments onboard Mars Global Surveyor and Mars Reconnaissance Orbiter. Detached layers are stable over several days owing to nighttime sedimentation being unable to counteract daytime convective transport, and to the resupply of convective energy at sunrise. The peak activity of rocket dust storms is expected in low-latitude regions at clear season, which accounts for the high-altitude tropical dust maximum unveiled by Mars Climate Sounder. Our findings on dust-driven deep convection have strong implications for the Martian dust cycle, thermal structure, atmospheric dynamics, cloud microphysics, chemistry, and robotic and human exploration.ensity-scaled dust optical depth at local times 1400 1600 and 1800 (lat 2.5°S, Ls 135°) hortwave heating rate at local time 1500 and latitude 2.5°S.

  12. "Martian Boneyards": Sustained Scientific Inquiry in a Social Digital Game (United States)

    Asbell-Clarke, Jordis

    Social digital gaming is an explosive phenomenon where youth and adults are engaged in inquiry for the sake of fun. The complexity of learning evidenced in social digital games is attracting the attention of educators. Martian Boneyards is a proof-of-concept game designed to study how a community of voluntary gamers can be enticed to engage in sustained, high-quality scientific inquiry. Science educators and game designers worked together to create an educational game with the polish and intrigue of a professional-level game, striving to attract a new audience to scientific inquiry. Martian Boneyards took place in the high-definition, massively multiplayer online environment, Blue Mars, where players spent an average of 30 hours in the game over the 4-month implementation period, with some exceeding 200 hours. Most of the players' time was spent in scientific inquiry activities and about 30% of the players' in-game interactions were in the analysis and theory-building phases of inquiry. Female players conducted most of the inquiry, in particular analysis and theory building. The quality of scientific inquiry processes, which included extensive information gathering by players, and the resulting content were judged to be very good by a team of independent scientists. This research suggests that a compelling storyline, a highly aesthetic environment, and the emergent social bonds among players and between players and the characters played by designers were all responsible for sustaining high quality inquiry among gamers in this free-choice experience. The gaming environment developed for Martian Boneyards is seen as an evolving ecosystem with interactions among design, players' activity, and players' progress.

  13. Martian climate - An empirical test of possible gross variations (United States)

    Owen, T.


    There appears to be evidence for a cyclic behavior of the Martian climate in which the surface pressure periodically reaches values compatible with the flow of water in equatorial regions on the planet. A relatively simple test of such hypotheses is pointed out. The premise on which cyclic models are based is that a substantial reservoir of volatils exist in frozen form at one or both poles. The proposed test involves a determination of the relative abundances of neon and argon isotopes. The required measurements may be made after the soft landing next February of Soviet spacecraft presently en route to the planet.

  14. Martian cave air-movement via Helmholtz resonance

    Directory of Open Access Journals (Sweden)

    Kaj E. Williams


    Full Text Available Infrasonic resonance has previously been measured in terrestrial caves by other researchers, where Helmholtz resonance has been suggested as the plausible mechanism resulting in periodic wind reversals within cave entrances. We extend this reasoning to possible Martian caves, where we examine the characteristics of four atypical pit craters (APCs on Tharsis, suggested as candidate cave entrance locations. The results show that, for several possible cave air movement periods, we are able to infer the approximate cave volumes. The utility of inferring cave volumes for planetary cave exploration is discussed.

  15. TDEM for Martian in situ resource prospecting missions

    Directory of Open Access Journals (Sweden)

    G. Tacconi


    Full Text Available This paper presents a TDEM (Time Domain Electromagnetic Methods application, addressed to the search for water on Mars. In this context, the opportunities for a TDEM system as payload in a future mission are investigated for different in situ exploration scenarios. The TDEM sounding capability is evaluated with respect to the expected Martian environment, and some considerations are made about the many unknown variables (above all the background EM noise and the subsoil composition altogether with the limited resources availability (mission constraints in mass, time and power and the way they could represent an obstacle for operations and measurements.

  16. An astrobiological study of high latitude martian analogue environments


    Cousins, C.R.


    The search for life on Mars is in part reliant on the understanding of Martian environments, both past and present, in terms of what life may inhabit these environments, how this life may be preserved in the rock record, and how this rock record may be detected during future missions to Mars. In particular, the upcoming European Space Agency mission ‘ExoMars’ has the primary aim to identify evidence of past or present life on Mars, and the work presented here is carried out within this ...

  17. Photo-induced free radicals on a simulated Martian surface (United States)

    Tseng, S.-S.; Chang, S.


    Results of an electron spin resonance study of free radicals in the ultraviolet irradiation of a simulated Martian surface suggest that the ultraviolet photolysis of CO or CO2, or a mixture of both, adsorbed on silica gel at minus 170 C involves the formation of OH radicals and possibly of H atoms as the primary process, followed by the formation of CO2H radicals. It is concluded that the photochemical synthesis of organic compounds could occur on Mars if the siliceous surface dust contains enough silanol groups and/or adsorbed H2O in the form of bound water.

  18. Martian cave air-movement via Helmholtz resonance (United States)

    Williams, Kaj; Titus, Timothy N.; Okubo, Chris; Cushing, Glen


    Infrasonic resonance has previously been measured in terrestrial caves by other researchers, where Helmholtz resonance has been suggested as the plausible mechanism resulting in periodic wind reversals within cave entrances. We extend this reasoning to possible Martian caves, where we examine the characteristics of four atypical pit craters (APCs) on Tharsis, suggested as candidate cave entrance locations. The results show that, for several possible cave air movement periods, we are able to infer the approximate cave volumes. The utility of inferring cave volumes for planetary cave exploration is discussed.

  19. Gaussian-based filters for detecting Martian dust devils (United States)

    Yang, F.; Mlsna, P.A.; Geissler, P.


    The ability to automatically detect dust devils in the Martian atmosphere from orbital imagery is becoming important both for scientific studies of the planet and for the planning of future robotic and manned missions. This paper describes our approach for the unsupervised detection of dust devils and the preliminary results achieved to date. The algorithm centers upon the use of a filter constructed from Gaussian profiles to match dust devil characteristics over a range of scale and orientation. The classification step is designed to reduce false positive errors caused by static surface features such as craters. A brief discussion of planned future work is included. ?? 2006 IEEE.

  20. Martian water: are there extant halobacteria on Mars? (United States)

    Landis, G. A.


    On Earth, life exists in all niches where water exists in liquid form for at least a portion of the year. On Mars, any liquid water would have to be a highly concentrated brine solution. It is likely, therefore, that any present-day Martian microorganisms would be similar to terrestrial halophiles. Even if present-day life does not exist on Mars, it is an interesting speculation that ancient bacteria preserved in salt deposits could be retrieved from an era when the climate of Mars was more conducive to life.