Spherically Symmetric, Self-Similar Spacetimes

Self-similar spacetimes are of importance to cosmology and to gravitational collapse problems. We show that self-similarity or the existence of a homothetic Killing vector field for spherically symmetric spacetimes implies the separability of the spacetime metric in terms of the co-moving coordinates and that the metric is, uniquely, the one recently reported in [cqg1]. The spacetime, in general, has non-vanishing energy-flux and shear. The spacetime admits matter with any equation of state.Comment: Submitted to Physical Review Letter

Buying Practices and Prevalence of Adulteration in Selected Food items in a Rural Area of Wardha District: A Cross - Sectional Study

Introduction: Food adulteration in India includes both willful adulteration and substandard food which do not confirm to prescribe food standard. There is striking paucity of reliable data with regard to extent of adulteration and documentation of food borne illnesses reflecting lack of attention and focus on this problem. Objectives: To find the prevalence of food adulteration, buying practices of selected food items and their awareness towards food adulteration act. Also assess relationship between per-capita incomes, education of respondents, and food borne illnesses with magnitude of adulteration in each house-hold. Methods: With the best estimate of 50%, sample size comes to 89. By stratifying the village according to social strata and randomly selecting the households with PPS. Questionnaire was administered to fulfill our objectives and food items were tested. Data analyzed by numeral with percentage, Pearson moment correlation, F test and chi square test. Results: In 68.5% Households, wife (home-maker) buys the grocery. Majority of them never read the food labels. All the selected food items were adulterated ranging from 76 % to 11%. Mean percentage of purity was highest in literates (47.5 ± 22.48) than illiterates and just literates. Food borne illness was prevalent in households with low purity of food. Association was found between per capita income and percentage of purity (0.765)

Charged particles in a rotating magnetic field

We study the valence electron of an alkaline atom or a general charged particle with arbitrary spin and with magnetic moment moving in a rotating magnetic field. By using a time-dependent unitary transformation, the Schr\"odinger equation with the time-dependent Hamiltonian can be reduced to a Schr\"odinger-like equation with a time-independent effective Hamiltonian. Eigenstates of the effective Hamiltonian correspond to cyclic solutions of the original Schr\"odinger equation. The nonadiabatic geometric phase of a cyclic solution can be expressed in terms of the expectation value of the component of the total angular momentum along the rotating axis, regardless of whether the solution is explicitly available. For the alkaline atomic electron and a strong magnetic field, the eigenvalue problem of the effective Hamiltonian is completely solved, and the geometric phase turns out to be a linear combination of two solid angles. For a weak magnetic field, the same problem is solved partly. For a general charged particle, the problem is solved approximately in a slowly rotating magnetic field, and the geometric phases are also calculated.Comment: REVTeX, 13 pages, no figure. There are two minor errors in the published version due to incorrect editing by the publisher. The "spin-1" in Sec. I and the "spin 1" in Sec. II below Eq. (2c) should both be changed to "spin" or "spin angular momentum". The preferred E-mail for correspondence is [email protected] or [email protected]

Measuring Pancharatnam's relative phase for SO(3) evolutions using spin polarimetry

In polarimetry, a superposition of internal quantal states is exposed to a single Hamiltonian and information about the evolution of the quantal states is inferred from projection measurements on the final superposition. In this framework, we here extend the polarimetric test of Pancharatnam's relative phase for spin$-{1/2}$ proposed by Wagh and Rakhecha [Phys. Lett. A {\bf 197}, 112 (1995)] to spin $j\geq 1$ undergoing noncyclic SO(3) evolution. We demonstrate that the output intensity for higher spin values is a polynomial function of the corresponding spin$-{1/2}$ intensity. We further propose a general method to extract the noncyclic SO(3) phase and visibility by rigid translation of two $\pi /2$ spin flippers. Polarimetry on higher spin states may in practice be done with spin polarized atomic beams.Comment: New title, minor corrections, journal reference adde

Performance Analysis of MUSIC and Smooth MUSIC Algorithm for DOA Estimation

Smart Antenna Systems is one amongst speedily developing areas of wireless communication. With effective direction of arrival (DOA) and Beam forming techniques Smart Antenna Systems persuade is most effective in terms of quality of signals in wireless communication. This paper analyzed and compares the performance of MUSIC and Smooth MUSIC DOA estimation algorithm on the uniform linear array (ULA) which are used in design of smart antenna system. MUSC algorithm is high resolution subspace based method which is used for DOA estimation of uncorrelated signals while smoothing of MUSIC is introduced for DOA estimation of completely correlated signal. The angular resolution of DOA estimation techniques improves as number of elements in array, snapshots and values of SNR increases. DOI: 10.17762/ijritcc2321-8169.15071

Gravitational Collapse of Null Radiation and a String fluid

We consider the end state of collapsing null radiation with a string fluid. It is shown that, if diffusive transport is assumed for the string, that a naked singularity can form (at least locally). The model has the advantage of not being asymptotically flat. We also analyse the case of a radiation-string two-fluid and show that a locally naked singularity can result in the collapse of such matter. We contrast this model with that of strange quark matter.Comment: RevTeX 4.0 (8 pages - no figures). submitted to Phys Rev D. Some changes to abstract, introduction and conclusion - references update

Final Report of the Commission to Address the Unfunded Liability of the MSRS and the Equity of Retirement Benefits for State Employees and Teachers

The possibility of cryopreservingBalanus amphitrite(Cirripedia; thoracica) nauplii is explored. The effects on the postthaw survival of a range of cryobiological variables are reported; three different cryoprotectants (ethylene glycol, EG; dimethyl sulfoxide, Me<SUB>2</SUB>SO; and glycerol, GL), the influence of the final temperature (−20, −30, −40, and −50°C), and the effect of transferring to liquid nitrogen (−196°C) were studied. The larvae showed increasing susceptibility to cryoprotectant concentration. Equilibration of larvae for 15 min at 5°C with each of the cryoprotectants revealed that GL was the least toxic. EG at 3 to 4Mdid not cause marked damage as the equilibration period was extended up to 2 h. This was not true with Me<SUB>2</SUB>SO and GL. The postthaw survival rate decreased as the final temperature was reduced, and none of the larvae revived after thawing from −50°C. The postthaw survival with 2 mol/liter EG as the cryoprotectant ranged from 86% after cooling to −20°C to 56% after cooling to −40°C. The larvae that were transferred to liquid nitrogen from different temperatures revealed that the greatest survival (36%) was achieved when the larvae were transferred from −40 to −196°C. When the larvae were reared after cooling to −40°C and then transferring to liquid nitrogen, the rate of subsequent metamorphosis was 30% in the case of EG at 3M. Me<SUB>2</SUB>SO and GL gave results that were inferior in comparison to those obtained with EG

Observation of off-diagonal geometric phase in polarized neutron interferometer experiments

Off-diagonal geometric phases acquired in the evolution of a spin-1/2 system have been investigated by means of a polarized neutron interferometer. Final counts with and without polarization analysis enable us to observe simultaneously the off-diagonal and diagonal geometric phases in two detectors. We have quantitatively measured the off-diagonal geometric phase for noncyclic evolutions, confirming the theoretical predictions. We discuss the significance of our experiment in terms of geometric phases (both diagonal and off-diagonal) and in terms of the quantum erasing phenomenon.Comment: pdf, 22 pages + 8 figures (included in the pdf). In print on Phys. Rev.