260 research outputs found

    Explosive-actuated valve design concept that eliminates blow-by

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    A method of evaluating the normally open normally closed, explosive actuated valves that were selected for use in the trajectory correction propulsion subsystem of the Thermoelectric Outer Planet Spacecraft (TOPS) program is presented. The design philosophy which determined the requirements for highly reliable valves that could provide the performance capability during long duration (10 year) missions to the outer planets is discussed. The techniques that were used to fabricate the valves and manifold ten valves into an assembly with the capability of five propellant-flow initiation/isolation sequences are described. The test program, which was conducted to verify valve design requirements, is outlined and the more significant results are shown

    Combined effects of hydrazine exposure and endurance testing on solenoid-actuated valve performance

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    Results are presented from a test program which was conducted to assess the capability of various solenoid-actuated valve design concepts to provide performance characteristics commensurate with long-duration (ten-year) missions to explore the outer planets. The valves were installed in a hydrazine flow test setup and periodically cycled during a nine-month test period under test conditions comparable to anticipated mission operating conditions. In situ valve performance was periodically determined, and leakage was continuously monitored

    Full-flow fluid filter

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    Etched-disk filter was developed with fluid passageways in configuration which allows relatively unrestricted flow of fluid and has stagnation areas for collection of impurities. In addition, filter housing without center post was developed to improve flow characteristics

    Stacked-disc structure for fluid filter or valve silencer

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    A stacked-disc structure is comprised of a stack of annular discs (13) scalloped along the outer edge to provide lobes (13a) and etched on one side to provide lands (13a). A web (13d) is retained in the lobes to strengthen the discs so that they will not collapse due to high fluid pressure. The stack of discs is retained by a housing (10) having a fluted interior wall to retain the ends of the lobes. End plates (11 and 12) secure the stack of discs with a spacer (14) at one end having lands (14a) on lobes which match the lobes of the stacked discs to allow fluid to flow into, or out of, the spaces between the lobes of the stacked discs. The spaces between the lands on the etched discs provide passages for fluid flow into or out of the hollow core of the stack. The height of the lands (i.e., depth of the etch) determines the size of the smallest particle that will be permitted to flow through. The stacked-disc structure may be connected to the inlet of a valve, or be incorporated into the valve housing on the inlet side of the valve seat to assure substantially constant fluid velocity, and thereby reduce valve noise when the valve is operated

    Detection of plant stress through multispectral photography

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    There are no author-identified significant results in this report

    A Method for Distinctly Marking Honey Bees, Apis mellifera, Originating from Multiple Apiary Locations

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    Inexpensive and non-intrusive marking methods are essential to track natural behavior of insects for biological experiments. An inexpensive, easy to construct, and easy to install bee marking device is described in this paper. The device is mounted at the entrance of a standard honey bee Apis mellifera L. (Hymenoptera: Apidae) hive and is fitted with a removable tube that dispenses a powdered marker. Marking devices were installed on 80 honey bee colonies distributed in nine separate apiaries. Each device held a tube containing one of five colored fluorescent powders, or a combination of a fluorescent powder (either green or magenta) plus one of two protein powders, resulting in nine unique marks. The powdered protein markers included egg albumin from dry chicken egg whites and casein from dry powdered milk. The efficacy of the marking procedure for each of the unique markers was assessed on honey bees exiting each apiary. Each bee was examined, first by visual inspection for the presence of colored fluorescent powder and then by egg albumin and milk casein specific enzyme-linked immunosorbent assays (ELISA). Data indicated that all five of the colored fluorescent powders and both of the protein powders were effective honey bee markers. However, the fluorescent powders consistently yielded more reliable marks than the protein powders. In general, there was less than a 1% chance of obtaining a false positive colored or protein-marked bee, but the chance of obtaining a false negative marked bee was higher for “protein-marked” bees

    Point-light biological motion perception activates human premotor cortex

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    Motion cues can be surprisingly powerful in defining objects and events. Specifically, a handful of point-lights attached to the joints of a human actor will evoke a vivid percept of action when the body is in motion. The perception of point-light biological motion activates posterior cortical areas of the brain. On the other hand, observation of others' actions is known to also evoke activity in motor and premotor areas in frontal cortex. In the present study, we investigated whether point-light biological motion animations would lead to activity in frontal cortex as well. We performed a human functional magnetic resonance imaging study on a high-field-strength magnet and used a number of methods to increase signal, as well as cortical surface-based analysis methods. Areas that responded selectively to point-light biological motion were found in lateral and inferior temporal cortex and in inferior frontal cortex. The robust responses we observed in frontal areas indicate that these stimuli can also recruit action observation networks, although they are very simplified and characterize actions by motion cues alone. The finding that even point-light animations evoke activity in frontal regions suggests that the motor system of the observer may be recruited to "fill in" these simplified displays

    A Success Story? An Exploration of the Consolidation Efforts in the University System of Georgia

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    Consolidation has been practiced in governments, school districts, and business for many years and in higher education since the early 1900s with the primary focus on the efficiency and financial savings found in the process. The nine consolidations in the University System of Georgia (USG) were driven by six principles which sought to achieve better processes and efficiency of services to the regional areas in which the institutions were consolidated into a single entity. This study of the nine consolidations in the USG reveals increases in the budgets at the institutions and the cost of attendance (tuition and fees plus room and board) while finding a decrease in the enrollment at the institutions after consolidation on average. The primary area the study found a positive impact from consolidation was in the area of retention which helped to retain more students at the consolidated institutions as compared to prior to consolidation at the same institutions. In addition to the analysis of institutional data pre- and post-consolidations, analysis of committees at the nine institutions was conducted for consolidation committee member composition and a survey was conducted of committee members at three of the consolidated institutions. Responses to the surveys allowed respondents to rate their view of the success of the consolidation, the biggest obstacles encountered by the committee, and the biggest issues faced by the committee. This study of institutional data and survey of consolidation committee members reveals pathways for future consolidations to reduce problems of future consolidations. Keywords: Consolidation, Enrollment, Retention, Higher Education, Budget, Campus ConsolidationChapter I: INTRODUCTION 1 -- Defining Consolidation 6 -- History of Consolidations in Higher Education 9 -- USG Consolidations 13 -- Chapter II: LITERATURE REVIEW 16 -- Flow Model of Consolidation 16 -- Methods of Consolidation 18 -- Governments 19 -- Business (Mergers, Acquisitions, and Consolidations) 24 -- School Districts 26 -- Higher Education 28 -- Chapter III: METHODOLOGY 35 -- Research Hypotheses 35 -- Methodology 36 -- Chapter IV: FINDINGS. 45 -- Stage One: By the Numbers 45 -- Budget 46 -- Enrollment 61 -- Retention 66 -- Cost of Attendance 72 -- Stage Two: Committee Membership and Survey Data 76 -- Committee Membership 76 -- Survey Data 82 -- Chapter V: DISCUSSION 101 -- Budget 102 -- Enrollment 104 -- Retention 105 -- Cost of Attendance 107 -- Consolidation Committees 110 -- UNG, KSU, and GState Outliers 115 -- Additional Research 117 -- Conclusion 123 -- Recommendations for Futures Consolidations 127 -- REFERENCES 129 -- APPENDIX A: IRB APPROVAL 133 -- APPENDIX B: SURVEY QUESTIONS 135LaPlant, James T.Yehl, Robert P.Hull, Karla M.D.P.A.Public Administratio

    Aflatoxins and other mycotoxins

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    The Oklahoma Cooperative Extension Service periodically issues revisions to its publications. The most current edition is made available. For access to an earlier edition, if available for this title, please contact the Oklahoma State University Library Archives by email at [email protected] or by phone at 405-744-6311

    Heterogeneous origins of human sleep spindles in different cortical layers

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    Sleep spindles are a cardinal feature in human NREM sleep and may be important for memory consolidation. We studied the intracortical organization of spindles in men and women by recording spontaneous sleep spindles from different cortical layers using linear microelectrode arrays. Two patterns of spindle generation were identified using visual inspection, and confirmed with factor analysis. Spindles (10-16Hz) were largest and most common in upper and middle channels, with limited involvement of deep channels. Many spindles were observed in only upper or only middle channels, but about half occurred in both. In spindles involving both middle and upper channels, the spindle envelope onset in middle channels led upper by approximately 25-50ms on average. The phase relationship between spindle waves in upper and middle channels varied dynamically within spindle epochs, and across individuals. Current source density analysis demonstrated that upper and middle channel spindles were both generated by an excitatory supragranular current sink while an additional deep source was present for middle channel spindles only. Only middle channel spindles were accompanied by deep low (25-50Hz) and high (70-170Hz) gamma activity. These results suggest that upper channel spindles are generated by supragranular pyramids, and middle channel by infragranular. Possibly, middle channel spindles are generated by core thalamocortical afferents, and upper channel by matrix. The concurrence of these patterns could reflect engagement of cortical circuits in the integration of more focal (core) and distributed (matrix) aspects of memory. These results demonstrate that at least two distinct intracortical systems generate human sleep spindles.SIGNIFICANCE STATEMENTBursts of approximately 14Hz oscillations, lasting about a second, have been recognized for over 80 years as cardinal features of mammalian sleep. Recent findings suggest that they play a key role in organizing cortical activity during memory consolidation. We used linear microelectrode arrays to study their intracortical organization in humans. We found that spindles could be divided into two types. One mainly engages upper layers of the cortex, which are considered to be specialized for associative activity. The other engages both upper and middle layers, including those devoted to sensory input. The interaction of these two spindle types may help organize the interaction of sensory and associative aspects of memory consolidation
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