1,755 research outputs found
Balance of protein supplements according to the criterion of convertible protein
The main sources of vegetable protein are seeds of legumes and oilseeds, which differ as by total content as by the quality. One of the least expensive and most rapid method of assessing the quality of protein is a chemical method, based on a comparative analysis of its amino acid composition, in particular, essential amino acids (EAA), and "ideal" protein. A widespread indicator of the proximity of the protein to the ideal is the minimum period, which shows how much of it can be used by the body for plastic needs (the main exchange and ensuring of body weight gain). Obviously, the more of this (convertible) protein in the product, the better (but not more than the daily value). One of the methods of obtaining a grain product with an increased convertible protein is blending, i.e. mixing in a certain proportion of different types of protein raw materials. In this case, the content of the converted mixture may be greater than in the components, and the excess less. The article presents a methodology for calculating the proportion of convertible protein in the product, as well as a new approach to the formation of effective mixtures. On the basis of this method, the results of the calculation of such mixtures on the example of a grain product with the use of collapsed white lupine, linseed cake and ginger seeds as components are shown. In all cases, there are rational proportions of the mixture, in which its convertible protein exceeds this figure in the component. The accuracy of the calculations largely depends on the accuracy of the total protein content and EAA.The main sources of vegetable protein are seeds of legumes and oilseeds, which differ as by total content as by the quality. One of the least expensive and most rapid method of assessing the quality of protein is a chemical method, based on a comparative analysis of its amino acid composition, in particular, essential amino acids (EAA), and "ideal" protein. A widespread indicator of the proximity of the protein to the ideal is the minimum period, which shows how much of it can be used by the body for plastic needs (the main exchange and ensuring of body weight gain). Obviously, the more of this (convertible) protein in the product, the better (but not more than the daily value). One of the methods of obtaining a grain product with an increased convertible protein is blending, i.e. mixing in a certain proportion of different types of protein raw materials. In this case, the content of the converted mixture may be greater than in the components, and the excess less. The article presents a methodology for calculating the proportion of convertible protein in the product, as well as a new approach to the formation of effective mixtures. On the basis of this method, the results of the calculation of such mixtures on the example of a grain product with the use of collapsed white lupine, linseed cake and ginger seeds as components are shown. In all cases, there are rational proportions of the mixture, in which its convertible protein exceeds this figure in the component. The accuracy of the calculations largely depends on the accuracy of the total protein content and EAA
Spin degrees of freedom and flattening of the spectra of single-particle excitations in strongly correlated Fermi systems
The impact of long-range spin-spin correlations on the structure of a flat
portion in single-particle spectra , which emerges beyond the point,
where the Landau state loses its stability, is studied. We supplement the
well-known Nozieres model of a Fermi system with limited scalar long-range
forces by a similar long-range spin-dependent term and calculate the spectra
versus its strength . It is found that Nozieres results hold as long as
. However, with changing its sign, the spontaneous magnetization is
shown to arise at any nonzero . The increase of the strength is
demonstrated to result in shrinkage of the domain in momentum space, occupied
by the flat portion of , and, eventually, in its vanishing.Comment: 7 pages, 15 figure
Mathematical model on surface reaction diffusion in the presence of front chemical reaction
The article discusses a mathematical model of solid-phase diffusion over substance surface accompanied a frontal chemical reaction. The purpose of our article is to describe the concentration distribution and surface reacted layer growth. The model is a system parabolic equations, complicated with the presence of mobile front. It takes account of diffusive fluxes redistribution, sublimation from the surface, chemical reaction reversibility. The asymptotic approximation of the obtained nonlinear problem is constructed. Numerical solution was also carried out. Both numerical and analytical solutions conform to each other in a wide range of parameter changes, whereas observed differences are explained. It was obtained that the reaction front at the substrate surface grows as the fourth root of time in the assumed absence of evaporation and reaction reversibility. In the presence of evaporation the logarithmic distribution law ln(t) is obtained. The theoretical possibility of sharp deceleration and stop of reaction product layer growth is obtained. © 2012 Elsevier Ltd. All rights reserved
Spatial correlation properties of the anomalous density matrix in a slab of nuclear matter with realistic NN-forces
Spatial correlation characteristics of the anomalous density matrix
in a slab of nuclear matter with the Paris and Argonne v18 forces are
calculated. A detailed comparison with predictions of the effective Gogny force
is made. It is found that the two realistic forces lead to very close results
which are qualitatively similar to those for the Gogny force. At the same time,
the magnitude of for realistic forces is essentially smaller than the
one for the Gogny force. The correlation characteristics are practically
independent of the magnitude of and turn out to be quite close for the
three kinds of the force. In particular, all of them predict a small value of
the local correlation length at the surface of the slab and a big one, inside.
These results are in agreement with those obtained recently by Pillet at al.
for finite nuclei with the Gogny force.Comment: 19 pages, 13 figure
Theoretical Aspects of Science with Radioactive Nuclear Beams
Physics of radioactive nuclear beams is one of the main frontiers of nuclear
science today. Experimentally, thanks to technological developments, we are on
the verge of invading the territory of extreme N/Z ratios in an unprecedented
way. Theoretically, nuclear exotica represent a formidable challenge for the
nuclear many-body theories and their power to predict nuclear properties in
nuclear terra incognita. It is important to remember that the lesson learned by
going to the limits of the nuclear binding is also important for normal nuclei
from the neighborhood of the beta stability valley. And, of course, radioactive
nuclei are crucial astrophysically; they pave the highway along which the
nuclear material is transported up in the proton and neutron numbers during the
complicated synthesis process in stars.Comment: 26 ReVTeX pages, 11 Postscript figures, uses epsf.sty, to be
published in: Theme Issue on Science with Beams of Radioactive Nuclei,
Philosophical Transactions, ed. by W. Gelletl
Damping effects and the metal-insulator transition in the two-dimensional electron gas
The damping of single-particle degrees of freedom in strongly correlated
two-dimensional Fermi systems is analyzed. Suppression of the scattering
amplitude due to the damping effects is shown to play a key role in preserving
the validity of the Landau-Migdal quasiparticle picture in a region of a phase
transition, associated with the divergence of the quasiparticle effective mass.
The results of the analysis are applied to elucidate the behavior of the
conductivity of the two-dimensional dilute electron gas in the
density region where it undergoes a metal-insulator transition.Comment: 7 pages, 6 figures. Improved and slightly extended version: new
paragraph about Hall effect + new Fig.
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