4,014 research outputs found

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    Newspaper article explaining R.B. LeCocq, who graduated law school from University of Michigan in 1912, finally received his doctor degree in 1969 due to updated requirements.https://nwcommons.nwciowa.edu/lecocqnewspaper/1007/thumbnail.jp

    Methodology development for evaluation of selective-fidelity rotorcraft simulation

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    This paper addressed the initial step toward the goal of establishing performance and handling qualities acceptance criteria for realtime rotorcraft simulators through a planned research effort to quantify the system capabilities of 'selective fidelity' simulators. Within this framework the simulator is then classified based on the required task. The simulator is evaluated by separating the various subsystems (visual, motion, etc.) and applying corresponding fidelity constants based on the specific task. This methodology not only provides an assessment technique, but also provides a technique to determine the required levels of subsystem fidelity for a specific task

    Role of Temperature, Dissolved Oxygen, and Backwaters in the Winter Survival of Freshwater Drum (\u3ci\u3eAplodinotus grunniens\u3c/i\u3e) in the Mississippi River

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    Annual winter impingement of large numbers of freshwater drum (Aplodinotus grunniens) on screens of a power station intake on the Mississippi River led to an investigation of the cause of impingement. Impingement occurred most abundantly in winter and early spring and primarily involved juvenile fish. Pronounced drift of moribund and dead fish was found in the main channel above and below the power station in late winter. Laboratory studies indicated that juvenile freshwater drum became disoriented, incapacitated, and suffered increased mortality as water temperature dropped to 1 °C and below. In winter and early spring, temperatures were 0 °C in the main and side channels of the river, but pockets of water above 1 °C existed in some backwaters. Dissolved oxygen concentrations declined through the winter, becoming very low in some backwaters. An aggregation of fishes including freshwater drum was observed in the warmer backwaters. Variations in river flow and dissolved oxygen depletion in some backwaters were postulated to cause periodic disruption of the thermal refuges and an associated appearance of incapacitated and dead juvenile freshwater drum in the drift. If man-induced changes to the river eliminate backwater winter refuges, the ichthyofauna of the river could ultimately be altered

    Recommended Values of Meteorological Factors to Be Considered in the Design of Aircraft Ice-Prevention Equipment

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    Meteorological conditions conducive to aircraft icing are arranged in four classifications: three are associated with cloud structure and the fourth with freezing rain. The range of possible meteorological factors for each classification is discussed and specific values recommended for consideration in the design of ice-prevention equipment for aircraft are selected and tabulated. The values selected are based upon a study of the available observational data and theoretical considerations where observations are lacking. Recommendations for future research in the field are presented

    Design for validation: An approach to systems validation

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    Every complex system built is validated in some manner. Computer validation begins with review of the system design. As systems became too complicated for one person to review, validation began to rely on the application of adhoc methods by many individuals. As the cost of the changes mounted and the expense of failure increased, more organized procedures became essential. Attempts at devising and carrying out those procedures showed that validation is indeed a difficult technical problem. The successful transformation of the validation process into a systematic series of formally sound, integrated steps is necessary if the liability inherent in the future digita-system-based avionic and space systems is to be minimized. A suggested framework and timetable for the transformtion are presented. Basic working definitions of two pivotal ideas (validation and system life-cyle) are provided and show how the two concepts interact. Many examples are given of past and present validation activities by NASA and others. A conceptual framework is presented for the validation process. Finally, important areas are listed for ongoing development of the validation process at NASA Langley Research Center

    Nickel(II) metal-organic frameworks with N,N’-di(4-pyridyl)-1,4,5,8-naphthalenetetracarboxydiimide ligands: influence of secondary building unit geometry on dimensionality and framework dimensions

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    When Ni(NO3)2∙6H2O and N,N’-di(4-pyridyl)-1,4,5,8-naphthalenetetracarboxydiimide (DPNDI) are reacted, a one-dimensional coordination polymer (1) is formed. However, reaction with either terephthalic acid (2) or 2,6-naphthalenedicarboxylic acid (3) affords two-dimensional, pillared metal-organic frameworks. 2 and 3 containing rectangular voids of different dimensions which are dictated by the carboxylate ligand and the arrangement of the [M(k2-O2NO)]2(μ2-O2CR)2] secondary building unit (SBU) that forms the nodes of the framework. The role of SBU geometry, intermolecular face-to-face π–π and lone pair–π interactions involving the DPNDI ligands are discussed
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