The Bowhead Whale, Balaena mysticetus: Its Historic and Current Status

The bowhead whale, Balaena mysticetus, is currently listed as endangered under the Endangered Species Act of 1973 and as depleted under the Marine Mammal Protection Act of 1972. Literature on the species is updated since 1984, and elements are reviewed that may contribute to the evaluation of the status of bowhead whale stocks

Spotted Seals, Phoca largha, in Alaska

The worldwide literature on management of spotted seals, Phoca largha, was reviewed and updated, and aerial surveys weref lown in 1992 and 1993 to determine the species' distribution and abundance in U.S. waters. In April, spotted seals were found only in the Bering Sea ice front. In June, they were seen along deteriorating ice floes and fast ice in Norton Sound. Surveys along most of Alaska's western coast in August and September found over 2,500 spotted seals in Kuskokwim Bay and concentrations of 100-400 seals around Nunivak Island, Scammon Bay, Golovnin Bay/Norton Sound, Cape Espenberg/Kotzebue Sound, and Kasegaluk Lagoon. All of these sites have been used by spotted seals in the past. The sum of the highest counts, irrespective of year, was 3,570 seals (CV =0.06). This is not an abundance estimate for all spotted seals in the Bering Sea, because it does not account for animals in the water, and we did not survey the Asian coast and some islands. Also, spotted seals and harbor seals, Phoca vitulina, are too similar in appearance to be identified accurately from the air, so our results probably include a mix of these species where their ranges overlap

In situ transmission electron microscopy studies of shear bands in a bulk metallic glass based composite

In situ straining transmission electron microscopy (TEM) experiments were performed to study the propagation of the shear bands in the Zr56.3Ti13.8Cu6.9Ni5.6Nb5.0Be12.5 bulk metallic glass based composite. Contrast in TEM images produced by shear bands in metallic glass and quantitative parameters of the shear bands were analyzed. It was determined that, at a large amount of shear in the glass, the localization of deformation occurs in the crystalline phase, where formation of dislocations within the narrow bands are observed

Assessment of potential exposure to friable insulation materials containing asbestos

Asbestos and the procedures for assessing potential exposure hazards are discussed. Assessment includes testing a bulk sample of the suspected material for the presence of asbestos, and monitoring the air, if necessary. Based on field inspections and laboratory analyses, the health hazard is evaluated, and abatement measures are taken if a potential hazard exists. Throughout the assessment and abatement program, all applicable regulations are administered as specified by the Environmental Protection Agency and the Occupational Safety and Health Administration

Modeling of the Earth's gravity field using the New Global Earth Model (NEWGEM)

Traditionally, the global gravity field was described by representations based on the spherical harmonics (SH) expansion of the geopotential. The SH expansion coefficients were determined by fitting the Earth's gravity data as measured by many different methods including the use of artificial satellites. As gravity data have accumulated with increasingly better accuracies, more of the higher order SH expansion coefficients were determined. The SH representation is useful for describing the gravity field exterior to the Earth but is theoretically invalid on the Earth's surface and in the Earth's interior. A new global Earth model (NEWGEM) (KIM, 1987 and 1988a) was recently proposed to provide a unified description of the Earth's gravity field inside, on, and outside the Earth's surface using the Earth's mass density profile as deduced from seismic studies, elevation and bathymetric information, and local and global gravity data. Using NEWGEM, it is possible to determine the constraints on the mass distribution of the Earth imposed by gravity, topography, and seismic data. NEWGEM is useful in investigating a variety of geophysical phenomena. It is currently being utilized to develop a geophysical interpretation of Kaula's rule. The zeroth order NEWGEM is being used to numerically integrate spherical harmonic expansion coefficients and simultaneously determine the contribution of each layer in the model to a given coefficient. The numerically determined SH expansion coefficients are also being used to test the validity of SH expansions at the surface of the Earth by comparing the resulting SH expansion gravity model with exact calculations of the gravity at the Earth's surface

Neutron and muon-induced background studies for the AMoRE double-beta decay experiment

AMoRE (Advanced Mo-based Rare process Experiment) is an experiment to search a neutrinoless double-beta decay of $^{100}$Mo in molybdate crystals. The neutron and muon-induced backgrounds are crucial to obtain the zero-background level (<$10^{-5}$ counts/(keV$\cdot$kg$\cdot$yr)) for the AMoRE-II experiment, which is the second phase of the AMoRE project, planned to run at YEMI underground laboratory. To evaluate the effects of neutron and muon-induced backgrounds, we performed Geant4 Monte Carlo simulations and studied a shielding strategy for the AMORE-II experiment. Neutron-induced backgrounds were also included in the study. In this paper, we estimated the background level in the presence of possible shielding structures, which meet the background requirement for the AMoRE-II experiment

Solid state image sensor research Final technical report

Fifty-element linear arrays of InAs photodiode

Non-volatile bistability effect based on electrically controlled phase transition in scaled magnetic semiconductor nanostructures

We explore the bistability effect in a dimensionally scaled semiconductor nanostruncture consisting of a diluted magnetic semiconductor quantum dot (QD) and a reservoir of itinerant holes separated by a barrier. The bistability stems from the magnetic phase transition in the QD mediated by the changes in the hole population. Our calculation shows that when properly designed, the thermodynamic equilibrium of the scaled structure can be achieved at two different configurations; i.e., the one with the QD in a ferromagnetic state with a sufficient number of holes and the other with the depopulated QD in a paramagnetic state. Subsequently, the parameter window suitable for this bistability formation is discussed along with the the conditions for the maximum robustness/non-volatility. To examine the issue of scaling, an estimation of the bistabiity lifetime is made by considering the thermal fluctuation in the QD hole population via the spontaneous transitions. A numerical evaluation is carried out for a typical carrier-mediated magnetic semiconductor (e.g., GaMnAs) as well as for a hypothetical case of high Curie temperature for potential room temperature operation.Comment: 9 pages, 7 figure

Generalized BFT Formalism of Electroweak Theory in the Unitary Gauge

We systematically embed the SU(2)$\times$U(1) Higgs model in the unitary gauge into a fully gauge-invariant theory by following the generalized BFT formalism. We also suggest a novel path to get a first-class Lagrangian directly from the original second-class one using the BFT fields.Comment: 14 pages, Latex, no figure

Application of Suction-cup-attached VHF Transmitters to the Study of Beluga, Delphinapterus leucas, Surfacing Behavior in Cook Inlet, Alaska

Suction-cup-attached VHF radio transmittes were deployed on belugas, Delphinapterus leucas, in Cook Inlet, Alaska, in 1994 and 1995 to characterize the whales' surfacing behavior. Data from video recordings were also used to characterize behavior of undisturbed whales and whales actively pursued for tagging. Statistics for dive intervals (time between the midpoints of contiguous surfacings) and surfacing intevals (time at the surface per surfacing) were estimated. Operations took place on the tidal delta of the Susitna and Little Susitna Rivers. During the 2-yr study, eight whales were successfully tagged, five tags remained attached for >60 min, and data from these were used in the analyses. Mean dive interval was 24.1 sec (interwhale SD=6.4 sec, n=5). The mean surfacing interval, as determined from the duration of signals received from the radio transmitters, was 1.8 sec (SD=0.3 sec, n=125) for one of the whales. Videotaped behaviors were categorized as "head-lifts" or "slow-rolls." Belugas were more likely to head-lift than to slow-roll during vessel approaches and tagging attempts when compared to undisturbed whales. In undisturbed groups, surfacing intervals determined from video records were significantly different between head-lifting (average = 1.02 sect, SD=0.38 sed, n=28) and slow-rolling whales (average = 2.45 sec, SD=0.37 sec, n=106). Undisturbed juveniles exhibited shorter slow-roll surfacing intervals (average = 2.25 sec, SD=0.32 sec, n=36) than adults (average = 2.55 sec, SD=0.36 sec, n=70). We did not observe strong reactions by the belugas to the suction-cup tags. This tagging method shows promise for obtaining surfacing data for durations of several days