1,291 research outputs found

    Solid state switch provides high input-to-output isolation

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    Switch uses a combination of N-channel and P-channel Metal Oxide Semiconductor Field Effect Transistors /MOSFET/ to obtain a normally open switch with no power applied. Series-shunt-series MOSFET switching achieves high input-output isolation

    Shellfish Tissue Monitoring in Piscataqua Region Estuaries 2013

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    Originally conducted by the Gulf of Maine Council on the Marine Environment from 1993 to 2011, the Gulfwatch Program examined trends in the water quality of the Gulf of Maine by monitoring toxic contaminant concentrations in the tissues of shellfish. Starting in 2012 the Piscataqua Region Estuaries Partnership (PREP) continued this program in the Piscataqua Region. Each year, PREP collects blue mussels at three sites: Dover Point, NH (NHDP), Clark Cove on Seavey Island, ME (MECC), and Hampton-Seabrook Harbor (NHHS). The mussel tissue is analyzed to determine the concentrations of toxic contaminantss including heavy metals, chlorinated pesticides, polychlorinated biphenyls (PCBs), and polycyclic aromatic hydrocarbons (PAHs)

    Shellfish Tissue Monitoring in Piscataqua Region Estuaries 2010: Final Report

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    Gulfwatch examines the effects of decades of development and industrialization on the water quality of the Gulf as it relates to human health primarily through assessing contaminant exposure of marine organisms. Gulfwatch scientists collect blue mussels at over 60 US and Canadian sites Gulfwide, and analyze the organisms’ tissue for potentially harmful levels and concentrations of toxins including heavy metals, chlorinated pesticides, polychlorinated biphenyls (PCBs), and polycyclic aromatic hydrocarbons (PAHs). New Hampshire increased the number of Gulfwatch sampling locations from two sites per year in 1997 to an average of five sites per year from 1998-2010. The increased spatial coverage provides comprehensive information for contaminant concentrations throughout the New Hampshire estuarine waters. All samples collected for the Gulfwatch monitoring program, from the Canadian provinces as well as the New England states involved, have been sent to the same laboratories for analysis. All of the samples have been analyzed at the same time in the same laboratories in an effort to reduce error and variability. This practice has ensured the consistency that was necessary to allow a region-wide assessment of the health of the Gulf. During the 2010 sampling season, mussels were collected at six sampling locations in New Hampshire and Maine (MECC, NHHS, NHDP, NHRH, NHPI and NHLH). Project Goals and Objectives The goal of this project was to provide data for two PREP indicators of estuarine condition: TOX1 and TOX3. These two indicators report on “Shellfish tissue concentrations relative to FDA standards” and “Trends in shellfish tissue contaminant concentrations”, respectively. Both of these indicators depend on data from the Gulfwatch Program. In particular, TOX3 requires annual data at benchmark sites to assess trends. In 2010, PREP supported the collection and analysis of tissue samples from benchmark mussel sites in Hampton-Seabrook Harbor and Dover Point

    Shellfish Tissue Monitoring in Piscataqua Region Estuaries 2010 and 2011

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    Conducted by a committee of Canadian and US government and university scientists, Gulfwatch examines the effects of decades of development and industrialization on the water quality of the Gulf as it relates to human health primarily through assessing contaminant exposure of marine organisms. Gulfwatch scientists collect blue mussels at over 60 US and Canadian sites Gulfwide, and analyze the organisms’ tissue for potentially harmful levels and concentrations of toxins including heavy metals, chlorinated pesticides, polychlorinated biphenyls (PCBs), and polycyclic aromatic hydrocarbons (PAHs)

    Shellfish Tissue Monitoring in Piscataqua Region Estuaries 2012

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    Originally conducted by a committee of Canadian and US governments and university scientists, Gulfwatch examined the effects of decades of development and industrialization on the water quality of the Gulf of Maine as it relates to human health primarily through assessing contaminant exposure of marine organisms from 1993 to 2010. The NH Gulfwatch Program continues these efforts by collecting blue mussels at two sites in the Great Bay Estuary and one in the Hampron-Seabrook Estuary, and analyzes the organisms’ tissue for potentially harmful levels and concentrations of toxins including heavy metals, chlorinated pesticides, polychlorinated biphenyls (PCBs), and polycyclic aromatic hydrocarbons (PAHs). During the 2012 sampling season, mussels were collected at three sampling locations in New Hampshire and Maine (MECC, NHHS and NHDP)

    Ultra-low-noise microwave amplifiers

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    The highlights of 20 years of maser use and development are presented. Masers discussed include cavity, traveling wave, K band, and S band. Noise temperatures measured since 1960 are summarized. Use of masers in the Deep Space Network is presented. Costs associated with the construction of masers systems are given

    An 8.4-GHz dual-maser front-end system for Parkes reimplementation

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    An 8.4-GHz front-end system consisting of a feedhorn, a waveguide feed assembly, dual masers, and downconverters was reimplemented at Parkes as part of the Parkes Canberra Telemetry Array for the Voyager Neptune encounter. The front-end system was originally assembled by the European Space Agency and installed on the Parkes antenna for the Giotto project. It was also used on a time-sharing basis by the Deep Space Network as part of the Parkes Canberra Telemetry Array to enhance the data return from the Voyager Uranus encounter. At the conclusion of these projects in 1986, part of the system was then shipped to JPL on loan for reimplementation at Parkes for the Voyager Neptune encounter. New design and implementation required to make the system operable at Parkes included new microwave front-end control cabinets, closed-cycle refrigeration monitor system, noise-adding radiometer system, front-end controller assembly, X81 local oscillator multiplier, and refurbishment of the original dual 8.4-GHz traveling-wave masers and waveguide feed system. The front-end system met all requirements during the encounter and was disassembled in October 1989 and returned to JPL

    Shellfish Tissue Monitoring in Piscataqua Region Estuaries 2010 and 2011

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    The goal of this project was to provide data for two PREP indicators of estuarine condition: TOX1 and TOX3. These two indicators report on “Shellfish tissue concentrations relative to FDA standards” and “Trends in shellfish tissue contaminant concentrations”, respectively. Both of these indicators depend on data from the Gulfwatch Program. In particular, TOX3 requires annual data at benchmark sites to assess trends. In 2010 and 2011, PREP supported the collection and analysis of tissue samples from benchmark mussel sites in Hampton-Seabrook Harbor and Dover Point
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