1,514 research outputs found
Multiscale self-organized criticality and powerful X-ray flares
A combination of spectral and moments analysis of the continuous X-ray flux
data is used to show consistency of statistical properties of the powerful
solar flares with 2D BTW prototype model of self-organized criticality
Multiscale SOC in turbulent convection
Using data obtained in a laboratory thermal convection experiment at high
Rayleigh numbers, it is shown that the multiscaling properties of the observed
mean wind reversals are quantitatively consistent with analogous multiscaling
properties of the Bak-Tang-Wiesenfeld prototype model of self-organized
criticality in two dimensions
Logarithmically modified scaling of temperature structure functions in thermal convection
Using experimental data on thermal convection, obtained at a Rayleigh number
of 1.5 , it is shown that the temperature structure functions
, where is the absolute value of the temperature
increment over a distance , can be well represented in an intermediate range
of scales by , where the are the scaling
exponents appropriate to the passive scalar problem in hydrodynamic turbulence
and the function . Measurements are made in the
midplane of the apparatus near the sidewall, but outside the boundary layer
Logarithmic scaling in the near-dissipation range of turbulence
A logarithmic scaling for structure functions, in the form , where is the Kolmogorov dissipation scale and
are the scaling exponents, is suggested for the statistical
description of the near-dissipation range for which classical power-law scaling
does not apply. From experimental data at moderate Reynolds numbers, it is
shown that the logarithmic scaling, deduced from general considerations for the
near-dissipation range, covers almost the entire range of scales (about two
decades) of structure functions, for both velocity and passive scalar fields.
This new scaling requires two empirical constants, just as the classical
scaling does, and can be considered the basis for extended self-similarity
Sign-symmetry of temperature structure functions
New scalar structure functions with different sign-symmetry properties are
defined. These structure functions possess different scaling exponents even
when their order is the same. Their scaling properties are investigated for
second and third orders, using data from high-Reynolds-number atmospheric
boundary layer. It is only when structure functions with disparate
sign-symmetry properties are compared can the extended self-similarity detect
two different scaling ranges that may exist, as in the example of convective
turbulence.Comment: 18 pages, 5 figures, accepted for publication in Physical Review
Mussel pollution at Korapuzha estuary (Malabar), with an account of certain coliform types
Oysters, mussels and other shell-fish are highly nutritious foods, which,
apart from their usual proximate principles, contain fairly high amounts
of minerals like iodine, copper, iron, etc., and vitamins. In the shallow rocky
areas of Malabar Coast there are numerous green mussel (Mytilus edulis)
beds from which large quantities of mussels are taken out almost throughout
the year, which form an important item of food for people of low incomes.
As the mussels grow in shallow areas subject to the influence of land drainage,
sewage and river systems, these beds constitute a potential hazard to
public health on account of possible epidemic infections being carried by
the shell-fish
Sulphur and methionine content of some fresh water fishes of Madras
The importance of sulphur amino acids, especially of methionine, in our nutrition is too well known to be emphasized. But adequate data on the sulphur and methionine contents of the cheapest of our animal foods viz., fish, are not available. In this note, the total sulphur and methionine content of 18 common fresh water fishes is presented. Total sulphur was determined by Osborne perioxide method (Winton & Winton, 1945) and methionine by the colorimetric method of Horn. (Horn et al., 1946
Spoilage of mackerels preserved in oil
While studying the preservation of mackerels
in oil, we came across a type of spoilage similar
to "sulfide stinker". Evolution of a stream
of bubbles was noticed in less than 48 hours
and within a week the fish disintegrated into
a pulpy mass
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