Optical storage device

A new holographic image storage device which uses four-wave mixing in two photorefractive crystals is described. Photorefractive crystals promise information storage densities on the order of 10(exp 9) to 10(exp 12) bits per cubic centimeter at real-time rates. Several studies in recent years have investigated the use of photorefractive crystals for storing holographic image information. However, all of the previous studies have focused on techniques for storing information in a single crystal. The disadvantage of using a single crystal is that the read process is destructive. Researchers have developed techniques for fixing the information in a crystal so that it may be read many times. However, when fixed, the information cannot be readily erased and overwritten with new information. It two photorefractive crystals are used, holographic image information may be stored dynamically. That is, the stored image information may be read out more than once, and it may be easily erased and overwritten with new image information

GBCW Support for Shellfish Activities 2003

The Great Bay Coast Watch (GBCW) is a volunteer estuarine monitoring program established in 1989 that includes teachers, students, and local citizens with a diversity of backgrounds. Volunteers participate in a variety of training programs that enable them to monitor water quality parameters in Great Bay and coastal areas, sample for marine phytoplankton blooms and conduct shoreline surveys and habitat evaluations. Since 1997 the New Hampshire Estuaries Project (NHEP) has relied on the ability of GBCW to recruit and train volunteers to assist with the implementation of its plan to protect, restore and manage the states estuarine systems. This year GBCW again participated in plan implementation by assisting the NH Department of Environmental Services (NHDES) Shellfish Program. Volunteers completed a variety of work tasks, including mussel collection, sample collection and transport and general field assistance

Real-time dynamic holographic image storage device

A real-time dynamic holographic image storage device uses four-wave mixing in a pair of photorefractive crystals. An oscillation is produced between the crystals which can be maintained indefinitely after the initial object beam is discontinued. The object beam produces an interference pattern in a first crystal to produce phase-conjugated object beam which is directed towards the second crystal. In the second crystal another interference pattern is created which produces a reconstructed object beam. The reconstructed object beam is directed back towards the first crystal. The interference patterns are produced by interaction of the object and phase-conjugated object beam with a read and write beam in each of the crystals. By manipulation of the ratio of the read and write beam intensities in at least one of the crystals, the phase-conjugate or reconstructed object beam output therefrom can be amplified to maintain stable oscillation between the two crystals

2004 Support for Shellfish Program and Estuarine Education, Meeker, S & Reid, A

Working within the University of New Hampshire (UNH) Cooperative Extension/Sea Grant Program, the Great Bay Coast Watch (GBCW) is New Hampshire’s most wide ranging program for direct citizen involvement in monitoring estuarine and coastal systems. GBCW has a fifteen year history of educating citizens about the Great Bay Estuary, New Hampshire Seacoast, and Gulf of Maine watershed through active participation in monitoring and an accompanying education program. Based in Durham, NH, GBCW coordinates over 100 volunteers drawn from 19 New Hampshire and Southern Maine communities. In 1990, volunteers began monitoring eight sites on a monthly basis April through October. Today, this effort has grown to include 21 sites that are sampled monthly for water quality around the Great Bay estuary, and six coastal sites that are monitored weekly for harmful algae blooms. Volunteers include adults, students, and home schooled families

Tools or Toys? The Impact of High Technology on Scholarly Productivity

Toys. The impact of computers on productivity has been examined directly on macro data and indirectly (on wages) using microeconomic data. This study examines the direct impact on the productivity of scholarship by considering how high technology might alter patterns of coauthoring of articles in economics and their influence. Using all coauthored articles in three major economics journals from 1970-79 and 1992-96, we find: 1) Sharp growth in the percentage of distant coauthorships (those between authors who were not in the same metropolitan areas in the four years prior to publication), as the theory predicts. Contrary to the theory: 2) Lower productivity (in terms of subsequent citations) of distant than close-coauthored papers; and 3) No decline in their relative disadvantage between the 1970s and 1990s. These findings are reconciled by the argument that high-technology functions as a consumption rather than an investment good. As such, it can be welfare-increasing without increasing productivity.