5,293 research outputs found

    A normative price for energy from an electricity generation system: An Owner-dependent Methodology for Energy Generation (system) Assessment (OMEGA). Volume 1: Summary

    Get PDF
    The utility owned solar electric system methodology is generalized and updated. The net present value of the system is determined by consideration of all financial benefits and costs (including a specified return on investment). Life cycle costs, life cycle revenues, and residual system values are obtained. Break even values of system parameters are estimated by setting the net present value to zero. While the model was designed for photovoltaic generators with a possible thermal energy byproduct, it applicability is not limited to such systems. The resulting owner-dependent methodology for energy generation system assessment consists of a few equations that can be evaluated without the aid of a high-speed computer

    A normative price for energy from an electricity generation system: An Owner-dependent Methodology for Energy Generation (system) Assessment (OMEGA). Volume 2: Derivation of system energy price equations

    Get PDF
    The methodology presented is a derivation of the utility owned solar electric systems model. The net present value of the system is determined by consideration of all financial benefits and costs including a specified return on investment. Life cycle costs, life cycle revenues, and residual system values are obtained. Break-even values of system parameters are estimated by setting the net present value to zero

    Meteoroid detector

    Get PDF
    A meteoroid detector is described which uses, a cold cathode discharge tube with a gas-pressurized cell in space for recording a meteoroid puncture of the cell and for determining the size of the puncture

    SAM 2 data user's guide

    Get PDF
    This document is intended to serve as a guide to the use of the data products from the Stratospheric Aerosol Measurement (SAM) 2 experiment for scientific investigations of polar stratospheric aerosols. Included is a detailed description of the Beta and Aerosol Number Density Archive Tape (BANAT), which is the SAM 2 data product containing the aerosol extinction data available for these investigations. Also included are brief descriptions of the instrument operation, data collection, processing and validation, and some of the scientific analyses conducted to date

    SAGE 3: A visible wavelength limb sounder

    Get PDF
    A brief description is presented for the SAGE 3 (Stratospheric Aerosol and Gas Experiment 3) instrument that has been selected to fly onboard the National Polar Platform 1 (NPOP 1) for the Earth Observational System (Eos) in 1996. The SAGE 3 instrument will perform earth limb sounding with the solar occultation technique measuring the ultraviolet (UV), the visible, and the near infrared (IR) wavelength solar radiation. The instrument will produce atmospheric data for the vertical distribution of aerosol, ozone, nitrogen dioxide, water vapor, and oxygen. The details of the instrument design, data flow, and processing requirements are discussed

    Observations of atmospheric water vapor with the SAGE 2 instrument

    Get PDF
    The Stratospheric Aerosol and Gas Experiment 2 (SAGE 2) is discussed. The SAGE 2 instrument was a multichannel spectrometer that inferred the vertical distribution of water vapor, aerosols, nitrogen dioxide, and ozone by measuring the extinction of solar radiation at spacecraft sunrise/sunset. At altitudes above 20 km, the SAGE 2 and LIMS (Limb Infrared Monitor of the Stratosphere) data are in close agreement. The discrepancies below this altitude may be attributed to differences in the instruments' field of view and time of data acquisition

    A methodology for design of lightweight robotic arm links in harsh environments

    Get PDF
    A methodology for the creation of functionally graded material (FGM) parts in harsh environments has been developed. It uses a two-stage optimisation approach that focusses first on the task-dependent material choice and then on the topological optimisation (TO) of the part. Constraints are in place to ensure the part can be manufactured, including the extent/smoothness of material blending and the minimum feature size and layer thickness. Thought is also put into space-specific concerns, such as radiation and cyclic thermal heating. The methodology assumes an initial design solution has already been generated, and covers from the beginning of the CAD phase to the end of the computational testing phase. Design constraints are created with additive manufacture (AM) in mind, and suggestions are made for material mixing processes for FGM, material layout strategies and manufacturability, including scanning strategies and surface finish

    The design of a robotic arm link using functionally graded materials : a case study

    Get PDF
    The development and design of a functionally-graded material (FGM) robotic arm for supporting and manipulating a vision system is discussed in this paper. The aim is to understand if using FGMs effectively reduce mass compared to single material parts. The evolution of ideas using topological optimisation (TO) and FGMs towards the design are shown and reviewed. The final design uses TO, and as such needs to be manufactured using additive manufacture (AM). Constraints have been put in place to ensure physical manufacturability is possible. The final design reduces the mass compared to the original arm by 61.4%

    Left ventricular dysfunction after acute myocardial infarction: Results of a prospective multicenter study

    Get PDF
    In a multicenter prospective study of 866 patients who survived the coronary care unit phase of an acute myocardial infarction, variables reflecting left ventricular function were examined to assess their impact on 2 year survival. Single variables that reflected left ventricular dysfunction before infarction and in the acute and recovery phases were, respectively, history of prior myocardial infarction, rales in the coronary care unit dichotomized at greater than bibasilar and predischarge radionuclide ejection fraction dichotomized at less than 0.40. When combined in a stepwise fashion, patients lacking these three risk characteristics had a 2 year 4.2% mortality rate, whereas patients possessing all three characteristics had a 45% mortality rate.Rales in the coronary care unit and predischarge ejection fraction act independently, and each contributes to mortality. Fifty-two patients with advanced rales but an ejection fraction of 0.40 or greater had a 21 % mortality rate. Similarly, 208 patients with few rales but an ejection fraction of less than 0.40 had a 15% mortality rate. These data suggest that the mortality risk imposed by those factors that assess permanent left ventricular damage is independent of and additive to the mortality risk contributed by dynamic, acute phase dysfunction. These data fit the hypothesis that acute phase dysfunction is, in part, due to transient ischemia that, on reversal, can restore function toward normal.The results suggest 1) that assessment of left ventricular function during the acute and recovery phases of myocardial infarction is necessary to define prognostic characteristics of an individual patient, and 2) that of particular importance is the identification of patients whose postinfarction course is consistent with reversible ischemia
    corecore