9,606 research outputs found
The Role of Natural Gas and LNG in Supplying Our Energy Needs
The domestic natural gas industry experienced a spectacular growth during the two decades from 1950 to 1970. Demand for gas continues to rise and production has peaked at a time when the price for other energy sources is escalating. A price increase can stimulate production over the short term. Massive LNG imports can help the intermediate term supply. The long term natural gas situation is bleak and substitute natural gas sources must be employed. A conservation program and reordering of priorities for energy sources is essential for the United States as well as most industrial nations
The effects of Chern-Simons gravity on bodies orbiting the Earth
One of the possible low-energy consequences of string theory is the addition
of a Chern-Simons term to the standard Einstein-Hilbert action of general
relativity. It can be argued that the quintessence field should couple to this
Chern-Simons term, and if so, it drives in the linearized theory a
parity-violating interaction between the gravito-electric and gravitomagnetic
fields. In this paper, the linearized spacetime for Chern-Simons gravity around
a massive spinning body is found to include new modifications to the
gravitomagnetic field that have not appeared in previous work. The orbits of
test bodies and the precession of gyroscopes in this spacetime are calculated,
leading to new constraints on the Chern-Simons parameter space due to current
satellite experiments.Comment: 9 pages, 2 figures; minor corrections made; to appear in PR
High resolution, low temperature photoabsorption cross-section of C2H2 with application to Saturn's atmosphere
New laboratory observations of the VUV absorption cross-section of C2H2, obtained under physical conditions approximating stratospheres of the giant planets, were combined with IUE observations of the albedo of Saturn, for which improved data reduction techniques have been used, to produce new models for that atmosphere. When the effects of C2H2 absorption are accounted for, additional absorption by other molecules is required. The best-fitting model also includes absorption by PH3, H2O, C2H6 and CH4. A small residual disagreement near 1600 A suggests that an additional trace species may be required to complete the model
The construction of a social studies vocabulary test for teachers in training.
Thesis (Ed.M.)--Boston Universit
Fluvio-deltaic avulsions during relative sea-level fall.
Understanding river response to changes in relative sea level (RSL) is essential for predicting fluvial stratigraphy and source-to-sink dynamics. Recent theoretical work has suggested that rivers can remain aggradational during RSL fall, but field data are needed to verify this response and investigate sediment deposition processes. We show with field work and modeling that fluvio-deltaic systems can remain aggradational or at grade during RSL fall, leading to superelevation and continuation of delta lobe avulsions. The field site is the Goose River, Newfoundland-Labrador, Canada, which has experienced steady RSL fall of around 3–4 mm yr⁻¹ in the past 5 k.y. from post-glacial isostatic rebound. Elevation analysis and optically stimulated luminescence dating suggest that the Goose River avulsed and deposited three delta lobes during RSL fall. Simulation results from Delft3D software show that if the characteristic fluvial response time is longer than the duration of RSL fall, then fluvial systems remain aggradational or at grade, and continue to avulse during RSL fall due to superelevation. Intriguingly, we find that avulsions become more frequent at faster rates of RSL fall, provided the system response time remains longer than the duration of RSL fall. This work suggests that RSL fall rate may influence the architecture of falling-stage or forced regression deposits by controlling the number of deposited delta lobes
Four cytotoxic N4-substituted thiosemicarbazones derived from 2-hydroxynaphthalene-1-carboxaldehyde
The X-ray crystal structures are reported of four novel and potentially O,N,S-tridentate donor ligands that demonstrate antitumour activity. These ligands are 1-[(4-methylthiosemicarbazono)methyl]-2-naphthol, C13H13N3OS, (III), 1-[(4-ethylthiosemicarbazono)methyl]-2-naphthol, C14H15N3OS, (IV), 1-[(4-phenylthiosemicarbazono)methyl]-2-naphthol, C18H15N3OS, (V), and 1-[(4,4-dimethylthiosemicarbazono)methyl]-2-naphthol dimethyl sulfoxide solvate, C14H15N3OS.C2H6OS, (VI). These chelators are N4-substituted thiosemicarbazones, each based on the same parent aldehyde, namely 2-zhydroxynaphthalene-1-carboxaldehyde isonicotinoylhydrazone. Conformational variations within this series are discussed in relation to the optimum conformation for metal-ion binding
Some model experiments on continental shelf waves
This paper describes some model experiments that verify the theoretical form of continental shelf waves. Both the dispersion relationship and the positions of the orbital gyres are confirmed. The existence of a maximum frequency for each mode, with a corresponding zero group velocity, may be of significance for field observations
Large Extra Dimensions, Sterile neutrinos and Solar Neutrino Data
Solar, atmospheric and LSND neutrino oscillation results require a light
sterile neutrino, , which can exist in the bulk of extra dimensions.
Solar , confined to the brane, can oscillate in the vacuum to the zero
mode of and via successive MSW transitions to Kaluza-Klein states of
. This new way to fit solar data is provided by both low and
intermediate string scale models. From average rates seen in the three types of
solar experiments, the Super-Kamiokande spectrum is predicted with 73%
probability, but dips characteristic of the 0.06 mm extra dimension should be
seen in the SNO spectrum.Comment: 4 pages, 2 figure
Cosmic Shear of the Microwave Background: The Curl Diagnostic
Weak-lensing distortions of the cosmic-microwave-background (CMB) temperature
and polarization patterns can reveal important clues to the intervening
large-scale structure. The effect of lensing is to deflect the primary
temperature and polarization signal to slightly different locations on the sky.
Deflections due to density fluctuations, gradient-type for the gradient of the
projected gravitational potential, give a direct measure of the mass
distribution. Curl-type deflections can be induced by, for example, a
primordial background of gravitational waves from inflation or by second-order
effects related to lensing by density perturbations. Whereas gradient-type
deflections are expected to dominate, we show that curl-type deflections can
provide a useful test of systematics and serve to indicate the presence of
confusing secondary and foreground non-Gaussian signals.Comment: 8 pages, 3 figures; PRD submitte
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