9 research outputs found
PHYTOCHEMICAL ANALYSIS OF BAS FROM THE ABOVEGROUND PARTS OF SOME SPECIES OF THE GENUS SUAEDA FROM THE CHENOPODIACEAE FAMILY AND THE STUDY OF THEIR ANTIOXIDANT ACTIVITY
This article is dedicated to the search of sources of biologically active substances from plants with antioxidant activity.Among the plants of the genus Suaeda from the Chenopodiaceae family there are many representatives having antioxidant activity. During our research work the qualitative analysis and the bioscreening on the antioxidant activity of the plants Suaeda vera and Suaeda spicata from the Chenopodiaceae family were carried out.For the preliminary components evaluation of two types of aboveground part of plants from the genus Suaeda were obtained 30%, 50%, 70% and 90% aqueous ethanol; 50% aqueous buthanol and ethyl acetate extractions. The BAS evaluation was carried out on the basis of qualitative reactions specific to each group of biologically active substances.Thus, in the aboveground part of the studied plants were identified and found flavonoids, carbohydrates, polysaccharides, coumarins, saponins, alkaloids, tannins, amino acids and other substances.According to test results, Suaeda spicata showed the highest antioxidant activity.This article is dedicated to the search of sources of biologically active substances from plants with antioxidant activity.Among the plants of the genus Suaeda from the Chenopodiaceae family there are many representatives having antioxidant activity. During our research work the qualitative analysis and the bioscreening on the antioxidant activity of the plants Suaeda vera and Suaeda spicata from the Chenopodiaceae family were carried out.For the preliminary components evaluation of two types of aboveground part of plants from the genus Suaeda were obtained 30%, 50%, 70% and 90% aqueous ethanol; 50% aqueous buthanol and ethyl acetate extractions. The BAS evaluation was carried out on the basis of qualitative reactions specific to each group of biologically active substances.Thus, in the aboveground part of the studied plants were identified and found flavonoids, carbohydrates, polysaccharides, coumarins, saponins, alkaloids, tannins, amino acids and other substances.According to test results, Suaeda spicata showed the highest antioxidant activity
Digital demodulator of the quadrature amplitude modulation signals
In this paper, the digital algorithm and the device for the demodulation of the quadrature amplitude modulation signals are considered. The fundamental advantages of our approach are simple hardware implementation, minimal number of arithmetic operations required over the signal period as well as the potential interference immunity in the presence of Gaussian noise. The expressions have been found for the error probability and their inaccuracy has been estimated. By means of the statistical simulation methods, the practical interference immunity of the introduced demodulator, together with the influence of phase locking errors have been tested. The introduced demodulator can be implemented either as a device independent from the programmable logic devices, or as an installation unit of the receiver equipment
Numerical Examination of the Stability of an Exact Two-dimensional Solution for Flux Pile-up Magnetic Reconnection
The Kelvin--Helmholtz (KH) and tearing instabilities are likely to be
important for the process of fast magnetic reconnection that is believed to
explain the observed explosive energy release in solar flares. Theoretical
studies of the instabilities, however, typically invoke simplified initial
magnetic and velocity fields that are not solutions of the governing
magnetohydrodynamic (MHD) equations. In the present study, the stability of a
reconnecting current sheet is examined using a class of exact global MHD
solutions for steady state incompressible magnetic reconnection, discovered by
Craig & Henton. Numerical simulation indicates that the outflow solutions where
the current sheet is formed by strong shearing flows are subject to the KH
instability. The inflow solutions where the current sheet is formed by a fast
and weakly sheared inflow are shown to be tearing unstable. Although the
observed instability of the solutions can be interpreted qualitatively by
applying standard linear results for the KH and tearing instabilities, the
magnetic field and plasma flow, specified by the Craig--Henton solution, lead
to the stabilization of the current sheet in some cases. The sensitivity of the
instability growth rate to the global geometry of magnetic reconnection may
help in solving the trigger problem in solar flare research.Comment: Accepted for publication in ApJ. Associated movie files and a PDF
with high-resolution figures are available at
http://www.pha.jhu.edu/~shirose/Craig
Digital Demodulator of the Quadrature Amplitude Modulation Signals
In this paper, the digital algorithm and the device for the demodulation of the quadrature amplitude modulation signals are considered. The fundamental advantages of our approach are simple hardware implementation, minimal number of arithmetic operations required over the signal period as well as the potential interference immunity in the presence of Gaussian noise. The expressions have been found for the error probability and their inaccuracy has been estimated. By means of the statistical simulation methods, the practical interference immunity of the introduced demodulator, together with the influence of phase locking errors have been tested. The introduced demodulator can be implemented either as a device independent from the programmable logic devices, or as an installation unit of the receiver equipment
Information characteristics of an orbital side-scan synthetic aperture radar
Ratios are given for estimating the amount of information in the channels of sensing and data transmission of the orbital synthetic aperture radars (SAR) based on information-theoretic and statistical methods. They are presented in terms of the indicators characterizing the amount of information received about the state of the object of observation. It is shown that the sensing channel should use significantly redundant information in relation to the final result of radar observation. On the example of the SAR of the “Venera-15” and “Venera-16” spacecrafts, the specific conditions of an orbital radar imaging are illustrated, and its informational characteristics are given for both methods of transmitting observation data. The qualitative consideration carried out in the paper makes it possible to estimate the potentially achievable reduction in the amount of information in the data transmission channel when using on-board SAR signal processing under specific radar imaging conditions
Digital demodulator of the quadrature amplitude modulation signals
In this paper, the digital algorithm and the device for the demodulation of the quadrature amplitude modulation signals are considered. The fundamental advantages of our approach are simple hardware implementation, minimal number of arithmetic operations required over the signal period as well as the potential interference immunity in the presence of Gaussian noise. The expressions have been found for the error probability and their inaccuracy has been estimated. By means of the statistical simulation methods, the practical interference immunity of the introduced demodulator, together with the influence of phase locking errors have been tested. The introduced demodulator can be implemented either as a device independent from the programmable logic devices, or as an installation unit of the receiver equipment
Fast digital algorithms for the noncoherent demodulation of the differential phase-shift keyed binary signals
In this paper, the fast digital algorithms for noncoherent demodulation of the binary and four position differential phase-shift keyed signals providing the minimum number of arithmetic operations over the carrier period have been studied. The properties of the demodulator responses have been considered and the expressions for the incorrect reception probability have been found while the useful signal is distorted by Gaussian white noise. It is shown that the presented algorithms realize the functional frequency selection, they provide a potential interference immunity against Gaussian noises and, as a result, they implement an optimal signal extraction in broad-band noises. Operability and efficiency of the introduced demodulators have been confirmed by experimental data obtained from statistical simulation
Fast digital algorithms for the noncoherent demodulation of the differential phase-shift keyed binary signals
In this paper, the fast digital algorithms for noncoherent demodulation of the binary and four position differential phase-shift keyed signals providing the minimum number of arithmetic operations over the carrier period have been studied. The properties of the demodulator responses have been considered and the expressions for the incorrect reception probability have been found while the useful signal is distorted by Gaussian white noise. It is shown that the presented algorithms realize the functional frequency selection, they provide a potential interference immunity against Gaussian noises and, as a result, they implement an optimal signal extraction in broad-band noises. Operability and efficiency of the introduced demodulators have been confirmed by experimental data obtained from statistical simulation