3,351 research outputs found
Species Profiles: Life Histories and Environmental Requirements of Coastal Fishes and Invertebrates (Mid-Atlantic): Alewife/Blueback Herring
This profile covers life history
and environmental requirements of
both alewife (Alosa pseudoharengus)
and blueback herring (Alosa aestivalis),
since their distribution is
overlapping and their morphology,
ecological role, and environmental
requirements are similar.
The alewife is
an anadromous species found in
riverine, estuarine, and Atlantic
coastal habitats, depending on
life cycle stage, from Newfoundland
(Winters et al. 1973) to
Soutn Carolina (Berry 1964).
Landlocked populations are i n the
Great Lakes, Finger Lakes, and
many other freshwater lakes
(Bigelow and Sch roeder 1953;
Scott and Crossman 1973). The
blueback herring is an anadromous
species found in riverine,
estuarine, and Atlantic coastal
habitats, depending on life stage
cycle, from Nova Scotia to the
St. Johns River, Florida (Hildebrand
1963
Supercritical Conversion Of The 3rd Blue Phase To The Isotropic-Phase In A Highly Chiral Liquid-Crystal
The results of two independent experiments in the vicinity of the “transition” from the third blue phase ( BPIII) to isotropic phase ( I) are reported for a highly chiral liquid crystal. Heat capacity measurements using a high-resolution calorimeter and dynamic light-scattering measurements using circularly polarized light have been performed. The data show a continuous evolution of BPIII into I with no critical fluctuations. This is strong evidence that the BPIII-I transition in this compound is supercritical, indicating that the BPIII and I phases possess the same macroscopic symmetry
Indium oxide diffusion barriers for Al/Si metallizations
Indium oxide (In2O3) films were prepared by reactive rf sputtering of an In target in O2/Ar plasma. We have investigated the application of these films as diffusion barriers in Si/In2O3/Al and Si/TiSi2.3/In2O3/Al metallizations. Scanning transmission electron microscopy together with energy dispersive analysis of x ray of cross-sectional Si/In2O3/Al specimens, and electrical measurements on shallow n + -p junction diodes were used to evaluate the diffusion barrier capability of In2O3 films. We find that 100-nm-thick In2O3 layers prevent the intermixing between Al and Si in Si/In2O3/Al contacts up to 650°C for 30 min, which makes this material one of the best thin-film diffusion barriers on record between Al and Si. (The Si-Al eutectic temperature is 577°C, Al melts at 660°C.) When a contacting layer of titanium silicide is incorporated to form a Si/TiSi2.3/In2O3/Al metallization structure, the thermal stability of the contact drops to 600°C for 30 min heat treatment
Optical nonlinearity enhancement of graded metallic films
The effective linear and third-order nonlinear susceptibility of graded
metallic films with weak nonlinearity have been investigated. Due to the simple
geometry, we were able to derive exactly the local field inside the graded
structures having a Drude dielectric gradation profile. We calculated the
effective linear dielectric constant and third-order nonlinear susceptibility.
We investigated the surface plasmon resonant effect on the optical absorption,
optical nonlinearity enhancement, and figure of merit of graded metallic films.
It is found that the presence of gradation in metallic films yields a broad
resonant plasmon band in the optical region, resulting in a large enhancement
of the optical nonlinearity and hence a large figure of merit. We suggest
experiments be done to check our theoretical predictions, because graded
metallic films can be fabricated more easily than graded particles.Comment: 11 pages, 2 eps figures, submitted to Applied Physics Letter
Response of a WB-47E Airplane to Runway Roughness at Eielson AFB, Alaska, September 1964
An investigation has been conducted to measure the response of a WB-47E airplane to the roughness of the runway at Eielson AFB, Alaska. The acceleration level in the pilot's compartment and the pitching oscillation of the airplane were found to be sufficiently high to possibly cause pilot discomfort and have an adverse effect on the precision of take-off
- …