83 research outputs found

    Aerodynamic Stabilization with a Drag-Makeup Propulsion Unit for Very Low Earth Orbit

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    Power constraints, large RF free-space path losses, and system complexity prevent many researchers from fielding novel sensing hardware aboard nanosatellite missions. Access to lower orbits would decrease downlink losses, improve optical sensor performance, and ensure natural de-orbit for inoperable payloads. Conventional propulsion technologies are capable of providing thrust required to maintain a low orbit but increase system complexity and draw power away from sensors. The United States Naval Academy has developed the Water Vapor Independent Satellite Propulsion system (WISP) to maintain orbits as low as 250km. This system utilizes an aqueous methyl alcohol propellant that passively evaporates across a phase separation boundary, requiring no electrical power during steady state operation. Theoretical calculations show that this system of 1U volume (10 x 10 x 10cm) is capable of providing sufficient thrust to maintain 250km orbit for 3U satellite for approximately 30 days

    Courtroom Questioning and Discourse

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    Questioning in common law accusatorial trials is dominated by the advocates’ belief that it is a legitimate opportunity for advocacy rather than just investigation. Examination is a form of story-telling, leading cross-examiners to rely heavily on rhetorical and suggestive questions that advance the preferred narrative. Empirical research suggests that this style of questioning reduces witness accuracy, reduces public confidence in the trial and deters witnesses from coming forward. However, the English courts’ new initiative to change practice by shifting advocates’ beliefs about the aims of cross-examination shows promise.No Full Tex
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