13,538 research outputs found
The PDF method for turbulent combustion
Probability Density Function (PDF) methods provide a means of calculating the properties of turbulent reacting flows. They have been successfully applied to many turbulent flames, including some with finite rate kinetic effects. Here the methods are reviewed with an emphasis on computational issues and their application to turbulent combustion
Braneworld localisation in hyperbolic spacetime
We present a construction employing a type IIA supergravity and 3-form flux
background together with an NS5-brane that localises massless gravity near the
5-brane worldvolume. The nonsingular underlying type IIA solution is a lift to
10D of the vacuum solution of the 6D Salam-Sezgin model and has a hyperbolic
structure in the lifting dimensions. A fully
back-reacted solution including the NS5-brane is constructed by recognising the
10D Salam-Sezgin vacuum solution as a "brane resolved through transgression."
The background hyperbolic structure plays a key r\^ole in generating a mass gap
in the spectrum of the transverse-space wave operator, which gives rise to the
localisation of gravity on the 6D NS5-brane worldvolume, or, equally, in a
further compactification to 4D. Also key to the successful localisation of
gravity is the specific form of the corresponding transverse wavefunction
Schr\"odinger problem, which asymptotically involves a
potential, where is the transverse-space radius, and for which the
NS5-brane source gives rise to a specific choice of self-adjoint extension for
the transverse wave operator. The corresponding boundary condition as
ensures the masslessness of gravity in the effective braneworld
theory. Above the mass gap, there is a continuum of massive states which give
rise to small corrections to Newton's law.Comment: 32 pages, 2 figures; misprints corrected & some clarification adde
Miniature ingestible telemeter devices to measure deep-body temperature
A telemetry device comprised of a pill-size ingestible transmitter developed to obtain deep body temperature measurements of a human is described. The device has particular utility in the medical field where deep body temperatures provide an indication of general health
Effect of Soil Buffer Capacity on Soil Reaction (pH) Modification and Subsequent Effects on Growth and Nutrient Uptake of Plantanus occidentalis L. Seedlings
The buffer capacity of a soil is a significant factor in determining the longevity of soil reaction (pH) adjustments by aluminum sulfate, Al2(SO4)3, or calcium carbonate, CaCO₂. After 12 weeks the modified pH values of the highly buffered Emory silt loam had changed substantially toward the original pH value of 7.6. Modified pH values for the Groseclose silt loam soil remained essentially unchanged under the same conditions. These differences in soil response to modified soil pH are related to the differences in the percentage of vermiculite chlorite and chlorite in the clay fractions of the two soils. The longevity of soil pH modification is related to total sycamore seedling dry weight and nutrient uptake. Though these components were significantly affected for plants grown in a Groseclose soil, the lack of significant response differences, except at the extremely low pH adjustment (5.21), in the Emory soil suggests a rapid change in modified soil pH toward the original soil pH value. The condition of the seedlings coupled with total dry weight accumulation and foliar nutrient content elimiates acid toxicity as a factor affecting growth and nutrient uptake. Plants grown in the Groseclose soil at pH 4.31 could be the exception
Effect of Soil Buffer Capacity on Soil Reaction (pH) Modification and Subsequent Effects on Growth and Nutrient Uptake of Plantanus occidentalis L. Seedlings
The buffer capacity of a soil is a significant factor in determining the longevity of soil reaction (pH) adjustments by aluminum sulfate, Al2(SO4)3, or calcium carbonate, CaCO₂. After 12 weeks the modified pH values of the highly buffered Emory silt loam had changed substantially toward the original pH value of 7.6. Modified pH values for the Groseclose silt loam soil remained essentially unchanged under the same conditions. These differences in soil response to modified soil pH are related to the differences in the percentage of vermiculite chlorite and chlorite in the clay fractions of the two soils. The longevity of soil pH modification is related to total sycamore seedling dry weight and nutrient uptake. Though these components were significantly affected for plants grown in a Groseclose soil, the lack of significant response differences, except at the extremely low pH adjustment (5.21), in the Emory soil suggests a rapid change in modified soil pH toward the original soil pH value. The condition of the seedlings coupled with total dry weight accumulation and foliar nutrient content elimiates acid toxicity as a factor affecting growth and nutrient uptake. Plants grown in the Groseclose soil at pH 4.31 could be the exception
An ingestible temperature-transmitter
Pill-sized transmitter measures deep body temperature in studies of circadian rhythm and indicates general health. Ingestible device is a compromise between accuracy, circuit complexity, size and transmission range
A Modified Hypersensitization Procedure for Eastman Kodak I-Z Spectroscopic Plates
Modified hypersensitization procedure for Eastman Kodak I-Z spectroscopic plate
Mass of Rotating Black Holes in Gauged Supergravities
The masses of several recently-constructed rotating black holes in gauged
supergravities, including the general such solution in minimal gauged
supergravity in five dimensions, have until now been calculated only by
integrating the first law of thermodynamics. In some respects it is more
satisfactory to have a calculation of the mass that is based directly upon the
integration of a conserved quantity derived from a symmetry principal. In this
paper, we evaluate the masses for the newly-discovered rotating black holes
using the conformal definition of Ashtekar, Magnon and Das (AMD), and show that
the results agree with the earlier thermodynamic calculations. We also consider
the Abbott-Deser (AD) approach, and show that this yields an identical answer
for the mass of the general rotating black hole in five-dimensional minimal
gauged supergravity. In other cases we encounter discrepancies when applying
the AD procedure. We attribute these to ambiguities or pathologies of the
chosen decomposition into background AdS metric plus deviations when scalar
fields are present. The AMD approach, involving no decomposition into
background plus deviation, is not subject to such complications. Finally, we
also calculate the Euclidean action for the five-dimensional solution in
minimal gauged supergravity, showing that it is consistent with the quantum
statistical relation.Comment: Typos corrected and references update
- …