519 research outputs found
Observations of current rings in the Antarctic Zone at Drake Passage
Time series of current velocity and temperature from several depths at a site near the center of Drake Passage show features that can plausibly be interpreted as current rings. Between June 1975 and January 1976, five cyclonic rings from the Continental Water Boundary and one anticyclonic ring from the Polar Front passed over the site. The diameters of the rings varied from 30 km to 130 km, and all of them extended vertically to a depth of at least 2500 m. The rings exhibited maximum spin velocities of about 20 cm sec−1 at 1000 m depth and 10 cm sec−1 at 2500 m. Their translatory motion, which was toward the north at about 4 cm sec−1, contained a westward component relative to the ambient flow. The magnitude of the westward component suggests that it may have resulted from an interaction between rings and the sea floor, which slopes downward to the northeast at the mooring site. The total available mechanical energy of the rings (kinetic plus potential) varied from 6.2 × 1013 j in the smallest ring to 9.9 × 1014 in the largest. The available heat, relative to the Antarctic Zone, was several orders of magnitude larger: −3.0 × 1017 j for the smallest ring and −3.6 × 1018 j for the largest. The numbers indicate that current rings may play an important role in dissipating the kinetic energy of the circumpolar fronts and that they may be responsible for a significant poleward flux of heat in the Southern Ocean
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A description of hydrography, winds, and currents during the upwelling season near Newport, Oregon
Several series of measurements of the hydrography, currents,
and winds during the past ten years are used as a basis for an overview
of the physical oceanography and meteorology during the
upwelling season near Newport, Oregon. Data are described using
elementary statistics, progressive vector diagrams, coordinate system
independent spectra, and complex demodulation.
The resulting description strengthens and extends the conceptual
model of coastal upwelling. Averages of various series of data are
calculated with the aim of making the collected information more
readily available and giving perspective to specific data.
The time series analysis indicates which bands of frequencies
contain important portions of the coherent energy. Complex demodulation
is used to show how the energy in selected frequency bands is
distributed as a function of time.
It is concluded that the long-term seasonal average of the winds
and the hydrography behaves smoothly, but the short-term fluctuations
around the average are important. The relationships between the
short-term variations in the current and hydrography are as yet
unclear, but directions are indicated for further analysis and experimentation
Effects of cochlear implantation on binaural hearing in adults with unilateral hearing loss
A FDA clinical trial was carried out to evaluate the potential benefit of cochlear implant (CI) use for adults with unilateral moderate-to-profound sensorineural hearing loss. Subjects were 20 adults with moderate-to-profound unilateral sensorineural hearing loss and normal or near-normal hearing on the other side. A MED-EL standard electrode was implanted in the impaired ear. Outcome measures included: (a) sound localization on the horizontal plane (11 positions, −90° to 90°), (b) word recognition in quiet with the CI alone, and (c) masked sentence recognition with the target at 0° and the masker at −90°, 0°, or 90°. This battery was completed preoperatively and at 1, 3, 6, 9, and 12 months after CI activation. Normative data were also collected for 20 age-matched control subjects with normal or near-normal hearing bilaterally. The CI improved localization accuracy and reduced side bias. Word recognition with the CI alone was similar to performance of traditional CI recipients. The CI improved masked sentence recognition when the masker was presented from the front or from the side of normal or near-normal hearing. The binaural benefits observed with the CI increased between the 1- and 3-month intervals but appeared stable thereafter. In contrast to previous reports on localization and speech perception in patients with unilateral sensorineural hearing loss, CI benefits were consistently observed across individual subjects, and performance was at asymptote by the 3-month test interval. Cochlear implant settings, consistent CI use, and short duration of deafness could play a role in this result
Active optical system for spaceborne telescopes Final report
Active optical system for spaceborne, orbiting telescope
Design and Synthesis of a Novel Alpha-Methylene Lactone Chemotherapeutic Agent
Goniothalamin, a natural product isolated from the dried stem bark of Malaysian plants of the genus Goniothalamus, has been shown to induce apoptosis in cancer cells. The bioactivity of this molecule is though to be due to its ability to react with thiols. One mechanism involves its reaction with glutathione, a natural antioxidant found in all cells. Using a four step synthetic sequence, a novel gamma-lactone analogue of goniothalamin has been prepared that replaces the endocylic double bond in goniothalamin\u27s lactone core with an exocyclic double bond. It is anticipated that this alteration will allow the compound to react more rapidly with thiols and therefore increase its cytotoxicity towards cancer cells
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A Compilation of observations from moored current meters. Vol. 15. Currents, temperature, and pressure collected near the Emperor Sea Mounts, June 1982 - November 1983
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A Compilation of observations from moored current meters. Vol. VII. Oregon continental shelf, July-August 1973
Aanderaa recording current meters, moored off the Oregon coast at fixed depths measured water temperature, current speed, current direction and for some meters, conductivity and pressure. In addition to these subÂsurface meters, surface meteorological buoys were installed to measure wind speed, wind direction, air and water temperature. Data from each current meter string are shown by means of pertinent statistics, real time plots of hourly values, progressive vector diagrams, and rotary spectra
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A compilation of observations from moored current meters. Vol. 12. Currents, temperature and pressure in the Drake Passage during FDRAKE 77, 78, January 1977-January 1979
Internally recording instruments were installed in the Drake Passage in January 1977 and recovered in December 1977. Additional instruments were installed at this time and recovered in January 1979. The first array consisted of 21 Aanderaa current meters on five moorings. The second array was one mooring with three current meters. The data were taken at one hour intervals.
In this report the measurements are summarized through pertinent statistics, progressive vector diagrams, real time plots, stick figures, rotary spectra, and conventional power spectra
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A Compilation of observations from moored current meters. Vol. 6. Oregon continental shelf, April-October 1972
Aanderaa recording current meters, moored in CUE-I off the Oregon coast at specific depths along both the Newport hydrographic line and perpendicular to the isobaths off Depoe Bay, were set to measure water temperature, current speed, current direction and, in some cases, pressure. In addition, surface buoy meteorological stations were moored at points along these same lines to measure wind speed, direction and air and water temperature. Data from
each current meter string are shown by means of pertinent statistics, real time plots of hourly values, progressive vector diagrams and rotary spectra. The appendices describe the actual operation of the Aanderaa current meter and the methods used to process the data
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