1,320 research outputs found

    Roosevelt Island: Completing an Urban Community

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    The thesis became an architectural exploration of what makes neighborhood and community at two scales: at the scale of the city (macrocosm), represented by the urban plan; and at the scale of the individual (microcosm), represented by the concept of the house and housing. At these two contrasting scales, the main focus of the study was to explore how an urban design can shape community and to explore the role that housing plays in the making of urban fabric/neighborhood. These two main issues of urban planning and housing prototypes, and the set of questions they generated, became the framework for the proposed completion of Roosevelt Island\u27s urban structure and housing types. In the end, Roosevelt Island as a site became a very compelling factor in focusing the direction of the investigation, both at the urban planning level, and at the scale of the housing prototypes. At this point, I would like to outline the history of Roosevelt\u27s Island\u27s development before discussing in detail the thesis\u27s urban design proposal and the housing prototype investigation

    The Role of Fire in Managing Red Fir Forests

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    Fire has long been a major factor in the ecology of forests in North America (Ahlgren and Ahlgren, 1960). Its role in the red fir forest of the Sierra Nevada, however, has received little study. Investigations in mixed conifer forests in Sequoia, Kings Canyon, and Yosemite National Parks by Biswell (1961), Hartesveldt (1964), and Reynolds (1959) lead to the conclusion that fires have been less numerous during the past 50 years than they were in primitive forests. Estimates of frequency in such primitive forests range from a fire every year or two to one every 21 years (1961), with a generally agreed upon average of something like 8 to 10 years between fires for individual trees. A conservative estimate would be that each tree was burned every 10 to 20 years. This is confirmed by the fire scars which some of the trees bear. As such, fires were an integral and important environmental factor in the evolution and maintenance of many plant communities in the Sierra Nevada before effective and widespread fire suppression activities came into being

    Application of Computer Axial Tomography (CAT) to measuring crop canopy geometry

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    The feasibility of using the principles of computer axial topography (CAT) to quantify the structure of crop canopies was investigated because six variables are needed to describe the position-orientation with time of a small piece of canopy foliage. Several cross sections were cut through the foliage of healthy, green corn and soybean canopies in the dent and full pod development stages, respectively. A photograph of each cross section representing the intersection of a plane with the foliage was enlarged and the air-foliage boundaries delineated by the plane were digitized. A computer program was written and used to reconstruct the cross section of the canopy. The approach used in applying optical computer axial tomography to measuring crop canopy geometry shows promise of being able to provide needed geometric information for input data to canopy reflectance models. The difficulty of using the CAT scanner to measure large canopies of crops like corn is discussed and a solution is proposed involving the measurement of plants one at a time

    Microbiological methods for the water recovery systems test, revision 1.1

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    Current microbiological parameters specified to verify microbiological quality of Space Station Freedom water quality include the enumeration of total bacteria, anaerobes, aerobes, yeasts and molds, enteric bacteria, gram positives, gram negatives, and E. coli. In addition, other parameters have been identified as necessary to support the Water Recovery Test activities to be conducted at the NASA/MSFC later this year. These other parameters include aerotolerant eutrophic mesophiles, legionellae, and an additional method for heterotrophic bacteria. If inter-laboratory data are to be compared to evaluate quality, analytical methods must be eliminated as a variable. Therefore, each participating laboratory must utilize the same analytical methods and procedures. Without this standardization, data can be neither compared nor validated between laboratories. Multiple laboratory participation represents a conservative approach to insure quality and completeness of data. Invariably, sample loss will occur in transport and analyses. Natural variance is a reality on any test of this magnitude and is further enhanced because biological entities, capable of growth and death, are specific parameters of interest. The large variation due to the participation of human test subjects has been noted with previous testing. The resultant data might be dismissed as 'out of control' unless intra-laboratory control is included as part of the method or if participating laboratories are not available for verification. The purpose of this document is to provide standardized laboratory procedures for the enumeration of certain microorganisms in water and wastewater specific to the water recovery systems test. The document consists of ten separate cultural methods and one direct count procedure. It is not intended nor is it implied to be a complete microbiological methods manual

    Water quality monitoring in the Yellow River Watershed 2005

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    https://ir.uiowa.edu/igs_tis/1049/thumbnail.jp

    Welding, brazing, and soldering handbook

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    Handbook gives information on the selection and application of welding, brazing, and soldering techniques for joining various metals. Summary descriptions of processes, criteria for process selection, and advantages of different methods are given

    The cryogenic wind tunnel concept for high Reynolds number testing

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    Theoretical considerations indicate that cooling the wind-tunnel test gas to cryogenic temperatures will provide a large increase in Reynolds number with no increase in dynamic pressure while reducing the tunnel drive-power requirements. Studies were made to determine the expected variations of Reynolds number and other parameters over wide ranges of Mach number, pressure, and temperature, with due regard to avoiding liquefaction. Practical operational procedures were developed in a low-speed cryogenic tunnel. Aerodynamic experiments in the facility demonstrated the theoretically predicted variations in Reynolds number and drive power. The continuous-flow-fan-driven tunnel is shown to be particularly well suited to take full advantage of operating at cryogenic temperatures

    Incarcerated Women\u27s Identity Development: Becoming a Self at the Margins

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    This study explores the developmental experience of women at the margins of society. Our findings suggest that the role of connection is problematic for these women and gives rise to a self that has a restricted degree of agency, but one that is paradoxically resilient and sensitive to her social context

    Full-scale aircraft simulation with cryogenic tunnels and status of the National Transonic Facility

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    The effect of thermal and caloric imperfections in cryogenic nitrogen on boundary layers was determined to indicate that in order to simulate nonadiabatic laminar or turbulent boundary layers in a cryogenic nitrogen wind tunnel, the flight enthalpy ratio, rather than the temperature ratio, should be reproduced. The absence of significant real gas effects on both viscous and inviscid flows makes it unlikely that there will be large real gas effects on the cryogenic tunnel simulation of shock boundary layer interactions or other complex flow conditions encountered in flight. Condensation effects were studied to determine the minimum usable temperature and indicated that under most circumstances free stream Mach number rather than maximum local Mach number determines the onset of condensation effects
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