1,088 research outputs found

    Mars aqueous chemistry experiment

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

    Brake lock mechanism for the two axis pointing system

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    Six months prior to shipment of the Broadband X-ray Telescope to the Kennedy Space Center for flight aboard the Space Shuttle Columbia, a major system failure occurred. During modal survey testing of the telescope's gimbal pointing system, the roll axis brake unexpectedly released. Low level vibration and static preloads present during the modal survey were within the expected flight environment. Brake release during shuttle liftoff or ascent was an unacceptable risk to mission success; thus, a Brake Lock Mechanism (BLM) was developed

    REVIEW OF BIRD REPELLENTS

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    Despite a general perception that there is an abundance of nonlethal control technologies, the fact remains that there are fewer registered products and active ingredients for repellents in the U.S. than there were 10 and 20 years ago. This review discusses the technical issues relating to the discovery, formulation, and delivery of chemical repellents, and suggests future avenues of research that would improve our ability to develop effective chemical repellents

    Master of Social Work

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    thesisThe purpose of this study was to provide some initial research in four general areas of concern related to the mentally retarded in utah. The first and chief area of consideration was guardianship. The purpose here was to determine whether the parents of mentally retarded children, who were either residents or who had pre-admission status at the Utah State Training School, were interested in guardianship provisions for their children. A second area was sterilization. The purpose related to this subject was to elicit and analyze attitudes and opinions on the subject by the same above identified parents. The other two areas which were considered in the study were marriage of the mentally retarded, and the quality of care provided by the Utah State Training School for the mentally retarded. The purpose for these two was also to obtain opinions and attitudes from the parents

    Near optimal sequencing :N jobs and M machines; all jobs to be processed through the same order of machines

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    There is a need, in industry, for an efficient method of determining an optimal sequence for processing a number of jobs through two or more machines. A method which requires a minimum amount of time would be most beneficial. The purpose of this study has been to define such a method. Tests on the method described indicate that although an optimal solution is not always obtained, the solutions obtained are quite good and due to the time factor the method would be beneficial to industry --Abstract, page ii

    Integrated Solar Concentrator and Shielded Radiator

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    A shielded radiator is integrated within a solar concentrator for applications that require protection from high ambient temperatures with little convective heat transfer. This innovation uses a reflective surface to deflect ambient thermal radiation, shielding the radiator. The interior of the shield is also reflective to provide a view factor to deep space. A key feature of the shield is the parabolic shape that focuses incoming solar radiation to a line above the radiator along the length of the trough. This keeps the solar energy from adding to the radiator load. By placing solar cells along this focal line, the concentration of solar energy reduces the number and mass of required cells. By shielding the radiator, the effective reject temperature is much lower, allowing lower radiator temperatures. This is particularly important for lower-temperature processes, like habitat heat rejection and fuel cell operations where a high radiator temperature is not feasible. Adding the solar cells in the focal line uses the concentrating effect of the shield to advantage to accomplish two processes with a single device. This shield can be a deployable, lightweight Mylar structure for compact transport

    Brown Tree Snakes Methods and Approaches for Control

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    This chapter summarizes the existing and emerging tools and strategies for the control of the invasive brown tree snake (Boiga irregularis, or BTS) on Guam and the prevention of its accidental transport to, and subsequent establishment on, other snake-free Pacific islands. The brown tree snake has long served as an example of the ecological and economic damages that can be wrought by a single generalist vertebrate predator upon introduction to ecosystems that evolved in isolation and without native predators (Fritts and Rodda 1998; Wiles et al. 2003; Rodda and Savidge 2007). Our attempt to summarize the state of the art for control technology development and use is not intended to be an exhaustive survey of all the brown tree snake literature. Rather, it is intended to introduce the reader to the main concepts, methods, and strategic management uses of the tools in an effort to control brown tree snakes on the island landscape and interdict their passage at ports. Significant practical advances for brown tree snake control have been made since the first comprehensive summaries were published by Rodda et al. (1999e), and there is great promise for future refinements and broader implementation for control efforts on an islandwide scale

    Carrion Seeking in Brown Tree Snakes: Importance of Olfactory and Visual Cues

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    We performed field experiments to examine brown tree snake (Boiga irregularis) attraction to carrion. These snakes were attracted to carrion and entered traps baited with dead mice as readily as traps baited with live mice. Using the cues arising from both live and dead prey, we examined the relative importance of visual and chemical cues to brown tree snakes. With carrion lures, chemical cues alone were sufficient for attracting and capturing snakes, but with live prey lures visual cues were required to attract and capture brown tree snakes. Our study presents the first experimental field evidence showing carrion to be attractive to an ophidian predator and suggests that the relative importance of chemical and visual sensory stimuli to brown tree snakes is context-specific

    Madaba Plains Project -- Tall Al-\u27Umayri, 2008

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