187 research outputs found
Random Matrix Model for Nakagami-Hoyt Fading
Random matrix model for the Nakagami-q (Hoyt) fading in multiple-input
multiple-output (MIMO) communication channels with arbitrary number of
transmitting and receiving antennas is considered. The joint probability
density for the eigenvalues of H{\dag}H (or HH{\dag}), where H is the channel
matrix, is shown to correspond to the Laguerre crossover ensemble of random
matrices and is given in terms of a Pfaffian. Exact expression for the marginal
density of eigenvalues is obtained as a series consisting of associated
Laguerre polynomials. This is used to study the effect of fading on the Shannon
channel capacity. Exact expressions for higher order density correlation
functions are also given which can be used to study the distribution of channel
capacity.Comment: 11 pages, 4 figure
Structure and the location of the morphotropic phase boundary region in (1-x)[Pb(Mg<SUB>1/3</SUB>Nb<SUB>2/3</SUB>)O<SUB>3</SUB>]-xPbTiO<SUB>3</SUB>
The structure of (1-x)-xPbTiO3 is tetragonal and rhombohedral for x ≥ 0.35 and x ≤ 0.30, respectively. The intrinsic width of the morphotropic phase boundary region (0.30 < x < 0.35) is an order of magnitude smaller than hitherto believed. The structure of the morphotropic phase for x = 0.34 is shown to be monoclinic with space group Pm and not a mixture of rhombohedral and tetragonal phases
Synthesis and Structural Characterization of Highly Tetragonal (1-x)Bi(Zn1/2Ti1/2)O3-xPbTiO3 Piezoceramics
We present here the comprehensive X-ray diffraction (XRD) and dielectric
measurement of (1-x)Bi(Zn1/2Ti1/2)O3-xPbTiO3 (BZT-xPT) piezoceramics with
x=0.65, 0.70, 0.75 and 0.80. Powder X-ray diffraction data reveals the
tetragonal structure (space group P4mm) of BZT-xPT ceramics for all the
compositions.Comment: 2 Pages, 4 Figure
Qualitative and Quantitative Analysis of Aflatoxins in Dry Fruits and Nuts from Central India
In central part of India, dry fruits and nuts are mostly sold in loose conditions and hence may get fungal infections, and may have aflatoxins to the levels beyond the safe limits. The present study is an attempt to showcase the present scenario of aflatoxins in dry fruits and nuts from Central India, both qualitatively and quantatively. Out of 84 samples, 15 were found to have the presence of at least one aflatoxin. HPLC detection showed that AFB1 is the major aflatoxin. The total aflatoxins were found in the range of 25.4 - 393.51 μg kg-1, which is beyond the safe limit set by regulatory authorities. Further, dry figs were the most contaminated among tested dry fruits, and 5 out 12 samples (41.6%) were contaminated, followed by cashew nuts (33.3%). Samples sold in loose packing were found more contaminated with aflatoxins. The study advocates that selling of such dry fruits in loose form should be banned by the regulatory authorities
- …