Correlations due to localization in quantum eigenfunctions of disordered microwave cavities

Non-universal correlations due to localization are observed in statistical properties of experimental eigenfunctions of quantum chaotic and disordered microwave cavities. Varying energy {E} and mean free path {l} enable us to experimentally tune from localized to delocalized states. Large level-to-level Inverse Participation Ratio (IPR I_{2}) fluctuations are observed for the disordered billiards, whose distribution is strongly asymmetric about . The density auto-correlations of eigenfunctions are shown to decay exponentially and the decay lengths are experimentally determined. All the results are quantitatively consistent with calculations based upon nonlinear sigma-models.Comment: 4 pages, LaTex, 5 .jpg figures. This paper with 5 embedded postscript figures available (PS,PDF) at http://sagar.physics.neu.edu/preprints

Isospectrality in Chaotic Billiards

We consider a modification of isospectral cavities whereby the classical dynamics changes from pseudointegrable to chaotic. We construct an example where we can prove that isospectrality is retained. We then demonstrate this explicitly in microwave resonators.Comment: 5 pages, 7 figure

Probiotic effects of lactic acid bacteria against Vibrio alginolyticus in Penaeus (Fenneropenaeus) indicus (H. Milne Edwards)

Cell free extracts of four strains of Lactic acid bacteria (LAB) viz. Lactobacillus. acidophilus, Streptococcus.cremoris, Lactobacillus bulgaricus –56 and Lactobacillus bulgaricus –57 inhibited growth of Vibrio alginolyticus in nutrient broth. The antagonism of LAB to Vibrio alginolyticus was further confirmed by streak plating wherein suppression of growth of Vibrio was obtained. Juveniles of Penaeus indicus (average weight 0.985 ± 0.1 g) on administering orally a moist feed base containing 5 × 106 cells·g of the four LAB probionts for a period of four weeks showed better survival (56 to 72%) when challenged with V. alginolyticus by intra-muscular injection of 0.1 ml containing 3 × 109 cells·ml. Animals maintained on a diet devoid of bacterial biomass exhibited 80% mortality

From chaos to disorder: Statistics of the eigenfunctions of microwave cavities

We study the statistics of the experimental eigenfunctions of chaotic and disordered microwave billiards in terms of the moments of their spatial distributions, such as the Inverse Participation Ratio (IPR) and density-density auto-correlation. A path from chaos to disorder is described in terms of increasing IPR. In the chaotic, ballistic limit, the data correspond well with universal results from random matrix theory. Deviations from universal distributions are observed due to disorder induced localization, and for the weakly disordered case the data are well-described by including finite conductance and mean free path contributions in the framework of nonlinear sigma models of supersymetry.Comment: 5 pages + 2 JPG figure

Cytomorphometric Analysis of Normal Exfoliative Cells from Buccal Mucosa in Different Age Groups

Oral exfoliative cytology is a simple and relatively pain free procedure which can be carried out repeatedly with minimum discomfort to the patients. Oral exfoliative cytology has sentivity of 89% and specificity of 89.5%, its accuracy could be enhanced by cytomorphometric analysis of the cells. On reviewing the literature we found numerous articles on cytomorphometric analysis of premalignant and malignant lesions and tobacco chewers-related lesions, but the articles available for the analysis of the normal epithelial cells are relatively few in number. The present study was carried out to assess the cytoplasmic diameter and nuclear diameters of normal buccal mucous membrane under various age groups.Materials and methods:The patients were divided into 3 groups, group-I consists of patients less than 25 years of age, Group – II consists of patients of 25 -50 years of age and Group –III of patients more than 50 years of age. Scrapings were made from the buccal mucosa and immediately fixed with 95% ethanol for a minimum of 15 minutes. In all the cases the Nuclear diameter (ND) and the Cell diameter (CD) were measured in both the horizontal and vertical axes in micrometer. The Nuclear Cytoplasmic(NC) Ratio was also calculated for each case.Statistical analysis:For each age group the mean ND, mean CD, and mean NC ratio were determined. One sample‘t’ test was carried out to find the significance of each sample.Results:The cytomorphometric analysis of the exfoliated normal buccal mucosal cells revealed that the ND varied from 7.4μ to 8.4μ, the cytoplasmic diameter from 46.77μ to 49.34μ and the nuclear cytoplasmic ratio from 0.17μ to 0.20μ. The increase in ND and decrease in CD are due to aging process and decreased cell metabolic activity respectively

Comparative Assessment of the Fracture Behaviour of API‐5L X65 and Micro‐alloyed Steels in E80 Simulated Fuel Ethanol Environment

Monotonic J‐integral tests were carried out on API‐5L X65 steel and micro‐alloyed steel (MAS) in E80 simulated fuel grade ethanol (SFGE) environment using three‐point bend specimens. A ramp rate of 10-04 mm/s was used for loading in each sequence so as to enhance stress corrosion cracking (SCC) influence if any. The influence of the SFGE environment on tearing resistance and fracture toughness of the steels was studied. Both steels exhibited decrease in fracture toughness in E80 in relation to air. The decrease in fracture toughness may be due to anodic dissolution at the crack tip. Ductile tearing resistance of the steels increased in E80 due to decline in toughness property. In comparison with X65 steel, MAS showed better fracture properties

Negative Refraction and Left-handed electromagnetism in Microwave Photonic Crystals

We demonstrate negative refraction of microwaves in metallic photonic crystals. The spectral response of the photonic crystal, which manifests both positive and negative refraction, is in complete agreement with band-structure calculations and numerical simulations. The negative refraction observed corresponds to left-handed electromagnetism and arises due to the dispersion characteristics of waves in a periodic medium. This mechanism for negative refraction is different from that in metamaterials.Comment: 13 pages, 4 figure