skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information
  1. Waveform frequency notching

    The various technologies presented herein relate to incorporating one or more notches into a radar spectrum, whereby the notches relate to one or more frequencies for which no radar transmission is to occur. An instantaneous frequency is monitored and if the frequency is determined to be of a restricted frequency, then a radar signal can be modified. Modification can include replacing the signal with a signal having a different instantaneous amplitude, a different instantaneous phase, etc. The modification can occur in a WFS prior to a DAC, as well as prior to a sin ROM component and/or a cos ROMmore » component. Further, the notch can be dithered to enable formation of a deep notch. The notch can also undergo signal transitioning to enable formation of a deep notch. The restricted frequencies can be stored in a LUT against which an instantaneous frequency can be compared.« less
  2. Frequency-Dependent Blanking with Digital Linear Chirp Waveform Synthesis

    Wideband radar systems, especially those that operate at lower frequencies such as VHF and UHF, are often restricted from transmitting within or across specific frequency bands in order to prevent interference to other spectrum users. Herein we describe techniques for notching the transmitted spectrum of a generated and transmitted radar waveform. The notches are fully programmable as to their location, and techniques are given that control the characteristics of the notches.
  3. Energy and cost analysis of a solar-hydrogen combined heat and power system for remote power supply using a computer simulation

    A simulation program, based on Visual Pascal, for sizing and techno-economic analysis of the performance of solar-hydrogen combined heat and power systems for remote applications is described. The accuracy of the submodels is checked by comparing the real performances of the system's components obtained from experimental measurements with model outputs. The use of the heat generated by the PEM fuel cell, and any unused excess hydrogen, is investigated for hot water production or space heating while the solar-hydrogen system is supplying electricity. A 5 kWh daily demand profile and the solar radiation profile of Melbourne have been used in amore » case study to investigate the typical techno-economic characteristics of the system to supply a remote household. The simulation shows that by harnessing both thermal load and excess hydrogen it is possible to increase the average yearly energy efficiency of the fuel cell in the solar-hydrogen system from just below 40% up to about 80% in both heat and power generation (based on the high heating value of hydrogen). The fuel cell in the system is conventionally sized to meet the peak of the demand profile. However, an economic optimisation analysis illustrates that installing a larger fuel cell could lead to up to a 15% reduction in the unit cost of the electricity to an average of just below 90 c/kWh over the assessment period of 30 years. Further, for an economically optimal size of the fuel cell, nearly a half the yearly energy demand for hot water of the remote household could be supplied by heat recovery from the fuel cell and utilising unused hydrogen in the exit stream. Such a system could then complement a conventional solar water heating system by providing the boosting energy (usually in the order of 40% of the total) normally obtained from gas or electricity. (author)« less
  4. Middle Fork and Upper Salmon River Habitat Improvement Implementation Plan, FY 1988-1992.

    This document presents an implementation plan for completing the phase II portion of the Middle Fork and Upper Salmon River Habitat Improvement Agreement. Underseeding of spawning adult salmon and steelhead, high instream sediment levels, a lack of habitat diversity in the form of overhanging riparian vegetation and edge, and barriers to both adult and juvenile anadromous fish migration were identified as the principal factors limiting anadromous fish production in the project area. Underseeding is being addressed in other projects sponsored and funded by the Bonneville Power Administration while this implementation plan lays out a schedule for resolving the other identifiedmore » limiting factors. The primary goal of this program is to increase the quality and quantity of anadromous fish habitat (spring chinook and summer steelhead) with an emphasis on the survival of the wild stocks. This goal will be achieved by reducing the impact of sediment loading, improving riparian vegetation, eliminating passage barriers, and increasing habitat diversity. Meeting the above goal will provide off-site mitigation under the manadate of the pacific northwest electric power planning and conservation act of 1980. Project implementation will follow measures in the Northwest Power Council's Columbia River Fish and Wildlife Program. 9 refs., 3 figs., 5 tabs.« less
  5. Heat pump impact upon solar collector design and cost

    Required collector area in series solar assisted heat pump systems is determined for three cities as a function of collector performance characteristics and compared with systems in which the solar-derived heat is used directly. Effect on system performance of improvements in heat pump performance is discussed. A cost vs yield analysis of several existing collectors is performed.
  6. Anadronous Fish Habitat Enhancement for the Middle Fork and Upper Salmon River, 1988 Annual Report.

    The wild and natural salmon and steelhead populations in the Middle Fork and Upper Salmon River are at a critical low. Habitat enhancement through decreasing sediment loads, increasing vegetative cover, removing passage barriers, and providing habitat diversity is imperative to the survival of these specially adapted fish, until passage problems over the Columbia River dams are solved. Personnel from the Boise and Sawtooth National Forests completed all construction work planned for 1988. In Bear Valley, 1573 feet of juniper revetment was constructed at eleven sites, cattle were excluded from 1291 feet of streambanks to prevent bank breakdown, and a smallmore » ephemeral gully was filled with juniper trees. Work in the Upper Salmon Drainage consisted of constructing nine rock sills/weirs, two rock deflectors, placing riprap along forty feet of streambank, construction of 2.1 miles of fence on private lands, and opening up the original Valley Creek channel to provide spring chinook passage to the upper watershed. A detailed stream survey of anadromous fish habitat covering 72.0 miles of streams in the Middle Fork Sub-basin was completed.« less
  7. Hot water tank for use with a combination of solar energy and heat-pump desuperheating

    A water heater or system which includes a hot water tank having disposed therein a movable baffle to function as a barrier between the incoming volume of cold water entering the tank and the volume of heated water entering the tank which is heated by the circulation of the cold water through a solar collector and/or a desuperheater of a heat pump so as to optimize the manner in which heat is imparted to the water in accordance to the demand on the water heater or system. A supplemental heater is also provided and it is connected so as tomore » supplement the heating of the water in the event that the solar collector and/or desuperheater cannot impart all of the desired heat input into the water.« less
  8. Computer simulation of ground coupled storage in a series solar assisted heat pump system

    A quantitative study of the effect of thermal coupling between the ground and the heat storage element of a series solar assisted heat pump system is presented. The transient simulation computer program TRNSYS is used to simulate the solar portion of this system. A program to simulate the thermal interaction of the storage element with the ground is incorporated into TRNSYS as a sub-routine. This program calculates heat flow through the ground in discrete steps over space and time. Boundary conditions are established. The ground coupled storage is driven by thermal inputs from the solar portion of the system andmore » from the changing ambient and ground temperatures.« less
  9. Alturas Lake Creek Flow Augmentation, 1986 Final Report.

    Two alternatives were outlined in the first statement of work as possibilities for flow augmentation in Alturas Lake Creek. The alternatives were to raise the level of Alturas Lake and to acquire necessary water rights in Alturas Lake Creek. The first alternative considered in the study was raising the water level at Alturas Lake with a low head dam. Raising Alturas Lake, appeared feasible in that it provided the necessary fish flows in Alturas Lake Creek. However, raising the level of Alturas Lake has adverse effects to other resources and forced pursuing the second alternative as defined in this report.more » Some of these effects included: flooding Smokey Bear boat ramp, inundation of recreation beaches for extended periods, flooding of the campground and some of the road system, potentially contaminating the quality of lake water from flooded toilet vaults, and destroying the conifer canopy around the lake. Maintenance and operation costs of the dam, along with the need to have a watermaster to distribute flows over the course of the irrigation season, raised additional concerns that detracted from this alternative. The second alternative considered was the acquisition of water rights. This led to an appraisal of the water right values which was completed by BPA with a comparison appraisal done by the Forest Service.« less

Search for:
All Records
Creator / Author
"Andrews, John"

Refine by:
Resource Type
Publication Date
Creator / Author
Research Organization