7,781 research outputs found

    Mars 2000

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    Twenty years after the Viking Mission, Mars is again being scrutinized in the light of a flood of information from spacecraft missions to Mars, the Hubble Space Telescope, and the SNC meteorites. This review provides an overview of the current understanding of Mars, especially in light of the data being returned from the Mars Global Surveyor Mission. Mars does not now have a global magnetic field, but the presence of crustal anomalies indicates that a global field existed early in Martian history. The topography, geodetic figure, and gravitational field are known to high precision. The northern hemisphere is lower and has a thinner and stronger crust than the southern hemisphere. The global weather and the thermal structure of the atmosphere have been monitored for more than a year. Surface-atmosphere interaction has been investigated by observations of surface features, polar caps, atmospheric dust, and condensate clouds. The surface has been imaged at very high resolution and spectral measures have been obtained to quantify surface characteristics and geologic processes. Many questions remain unanswered, especially about the earliest period of Mars' history

    Wild Emptiness: A Zen Approach to Environmental Ethics

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    When Buddhism took root in China and integrated with the nation’s Taoist intellectual climate, the tradition retained the orthodox central objective of overcoming suffering. While conserving this principal aspiration, the rise of Zen is associated with deviation from the orthodox practice of monasticism and toward the practical embodiment of emptiness while integrated in society, which can be likened to the practice of unwavering compassion. This piece offers a Zen approach to environmental ethics such that it is an attempt to explicate how and why an individual practicing Zen should compassionately engage with the earth. With respect to the Buddhist employment of skillful means, different approaches are offered as tailored ethical frameworks to appeal to individuals at different stages in their path to awakening. Furthermore, the environmental ethic appealed to by the awakened individual is explicated as spontaneous harmonization with the flow of emptiness, that which the Buddhists regard to be the driving force of the phenomenal realm. The awakened individual is considered to non-deliberately take on a lifestyle that provides perpetual intimacy with the rhythms of wild emptines

    Mantle dynamics and geodesy

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    Both completed work and work that is still in progress are presented. The completed work presented includes: (1) core-mantle boundary topography; (2) absolute value for mantle viscosity; (3) code development; (4) lateral heterogeneity of subduction zone rheology; and (5) planning for the Coolfront meeting. The work presented that is still in progress includes: (1) geoid anomalies for a chemically stratified mantle; and (2) geoid anomalies with lateral variations in viscosity

    Intraplate deformation, stress in the lithosphere and the driving mechanism for plate motions

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    The initial research proposed was to use the predictions of geodynamical models of mantle flow, combined with geodetic observations of intraplate strain and stress, to better constrain mantle convection and the driving mechanism for plate motions and deformation. It is only now that geodetic observations of intraplate strain are becoming sufficiently well resolved to make them useful for substantial geodynamical inference to be made. A model of flow in the mantle that explains almost 90 percent of the variance in the observed longwavelength nonhydrostatic geoid was developed

    The Mars Observer database

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    Mars Observer will study the surface, atmosphere, and climate of Mars in a systematic way over an entire Martian year. The observations of the surface will provide a database that will be invaluable to the planning of a future Mars sample return mission. Mars Observer is planned for a September 1992 launch from the Space Shuttle, using an upper-stage. After the one year transit the spacecraft is injected into orbit about Mars and the orbit adjusted to a near-circular, sun-synchronous low-altitude, polar orbit. During the Martian year in this mapping orbit the instruments gather both geoscience data and climatological data by repetitive global mapping. The scientific objectives of the mission are to: (1) determine the global elemental and mineralogical character of the surface material; (2) define globally the topography and gravitational field; (3) establish the nature of the magnetic field; (4) determine the time and space distribution, abundance, sources, and sinks of volatile material and dust over a seasonal cycle; and (5) explore the structure and aspects of the circulation of the atmosphere. The science investigations and instruments for Mars Observer have been chosen with these objectives in mind. These instruments, the principal investigator or team leader and the objectives are discussed

    Educating the leaders of tomorrow : the library without walls

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    A description of library services offered to students in distance programs within Canada and Ecuador

    How useful are the stages of change for targeting interventions? randomized test of a brief intervention to reduce smoking

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    Objectives. To see whether the stages of change are useful for targeting a brief intervention to reduce smoking based on implementation intentions. A second objective was to rule out demand characteristics as an alternative explanation for the findings of intervention studies based on the transtheoretical model and implementation intentions. Design. Participants (N = 350) were randomized to a passive control condition (questionnaire only), active control condition (questionnaire-plus-instruction to plan to quit) or experimental condition (questionnaire, plan to quit, form an implementation intention). Their behavior and psychosocial orientation to quit were measured at baseline and 2-month follow-up. Main Outcome Measures. Theory of planned behavior variables, nicotine dependence and quitting. Results. Significantly more people quit smoking in the experimental condition than in the control conditions, and the planning instructions changed intention to quit and perceived control over quitting, but not behavior. Stage of change moderated these effects such that implementation intentions worked best for individuals who were in the preparation stage at baseline. Conclusion. Harnessing both motivational and volitional processes seems to enhance the effectiveness of smoking cessation programs, although further work is required to clarify inconsistencies in the literature using the stages of change.</p

    COMPARING PRODUCTION OPTIMIZATION STRATEGIES FOR TEXAS PANHANDLE PRODUCERS IN RESPONSE TO DECLINING WATER AVAILABILITY DUE TO DECLINE IN THE OGALLALA AQUIFER

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    In response to the declining availability of irrigation water from the Ogallala aquifer, irrigation at the level where MVP=MFC increases net returns over either irrigating to maximize production or meet 100% of the evapotranspiration (PET) requirements. This prolongs the economic life of the aquifer and increases the efficiency of irrigation.Resource /Energy Economics and Policy,
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