The sizes of galaxy halos in galaxy cluster Abell 1689

The multiple images observed in galaxy cluster Abell 1689 provide strong constraints not only on the mass distribution of the cluster but also on the ensemble properties of the cluster galaxies. Using parametric strong lensing models for the cluster, and by assuming well motivated scaling laws between the truncation radius s and the velocity dispersion sigma of a cluster galaxy we are able to derive sizes of the dark matter halos of cluster galaxies. For the scaling law expected for galaxies in the cluster environment (s propto sigma), we obtain s = 64^{+15}_{-14} (sigma / 220 km/s) kpc. For the scaling law used for galaxies in the field with s propto sigma^2 we find s = 66^{+18}_{-16} (sigma / 220 km/s)^2 kpc. Compared to halos of field galaxies, the cluster galaxy halos in Abell 1689 are strongly truncated.Comment: 12 pages, 4 figures. Accepted for publication in the Ap

Constraining the Collisional Nature of the Dark Matter Through Observations of Gravitational Wakes

We propose to use gravitational wakes as a direct observational probe of the collisional nature of the dark matter. We calculate analytically the structure of a wake generated by the motion of a galaxy in the core of an X-ray cluster for dark matter in the highly-collisional and collisionless limits. We show that the difference between these limits can be recovered from detailed X-ray or weak lensing observations. We also discuss the sizes of sub-halos in these limits. Preliminary X-ray data on the motion of NGC 1404 through the Fornax group disfavors fluid-like dark matter but does not exclude scenarios in which the dark matter is weakly collisional.Comment: 29 pages, 3 figures, submitted to Ap

HYALURONAN-A NOVEL POLYMER ISOLATED FROM MUTATED CLINICAL BACTERIAL ISOLATE

Objective: This study was done to optimize the production parameters involved in the isolation of hyaluronan (HA) from UV mutated a clinical strain of Klebsiella pneumonia (M 3020).Methods: Glucose and nitrogen enriched media (D-glucose, L-glutamic acid, and peptone) were utilized to cultivate the clinical isolate K. pneumoniae. The strain was Ultra Violet (UV) radiation mutated (254 nm, 25 min) and HA production was optimized by parameters such as pH and temperature. The isolated HA from the fermented broth was subjected to purification by isopropyl alcohol and silica gel and further dried by lyophilization. Produced HA was confirmed with UV and Fourier Transform Infra-Red (FT-IR) spectroscopy.Results: UV treated strain at 254 nm for 25 min predominantly produce a high quantity of HA (3.5 g/l) in 37 °C, 300 rpm and pH 6.8 at 24 h run. UV and IR spectrum of produced HA showed strong similarity with the standard hyaluronan.Conclusion: To conclude, high quantity and quality of HA can be isolated from mutated clinical strains of K. pneumoniae

Electrochemical aspects of grinding media-mineral interaction on sulphide flotation

Galvanic interaction between electrically conducting minerals may affect the mineral surface and influence their flotabilities. The metallographic examinations as well as hardness measurements have been made with grinding media. Rest potential, combination potential, galvanic current and polarization studies were made to understand the probable electrochemical interaction between grinding media and chalcopyrite. The galvanic contact lowered the flotability of chalcopyrite. AES and ESCA indicated that galvanic coupling of chalcopyrite with grinding media resulted in the formation of oxy-hydroxide species of iron on the chalcopyrite surface. Scanning electron microscopy was used to study the surface morphological changes on the grinding media due to galvanic interaction with chalcopyrite

A new type of charged defect in amorphous chalcogenides

We report on density-functional-based tight-binding (DFTB) simulations of a series of amorphous arsenic sulfide models. In addition to the charged coordination defects previously proposed to exist in chalcogenide glasses, a novel defect pair, [As4]--[S3]+, consisting of a four-fold coordinated arsenic site in a seesaw configuration and a three-fold coordinated sulfur site in a planar trigonal configuration, was found in several models. The valence-alternation pairs S3+-S1- are converted into [As4]--[S3]+ pairs under HOMO-to-LUMO electronic excitation. This structural transformation is accompanied by a decrease in the size of the HOMO-LUMO band gap, which suggests that such transformations could contribute to photo-darkening in these materials.Comment: 5 pages, 2 figure

INFLUENCE OF CADMIUM ON GROWTH AND BIOCHEMICAL CONTENTS OF TOMATO PLANTS

The increasing concentrations (10, 25, 50, 75 and 100 mg /kg) of soil cadmium on growth and biochemical contents in tomato plants were analysed on 30th sampling days. Control plants were maintained separately. Plants were grown in pots containing 3 kg of air dried sandy loam soil and treated with different concentrations (mg/kg) of cadmium (0, 10, 25, 50, 75 and 100 ). Treatments decreased the growth parameters such as root and shoot length  and biochemical constituents such as, protein,(except, proline and  phenol content) contents in tomato plants compared to untreated plants. The shoot length of cadmium treated tomato plants was higher than the root length. proline and phenol content of root of  tomato plants was higher than the shoot

A Dorsal Hand Vein Recognition-based on Local Gabor Phase Quantization with Whitening Transformation

The hand vein pattern is a biometric feature in which the actual pattern is the shape of the vein network and its characteristics are the vein features. This paper investigates a new approach for dorsal hand vein pattern identification from grey level dorsal hand vein information. In this study Gabor filter quadrature pair is employed to compute locally in a window for every pixel position to extract the phase information. The phases of six frequency coefficients are quantized and it is used to form a descriptor code for the local region. These local descriptors are decorrelated using whitening transformation and a histogram is generated for every pixel which describes the local pattern.  Experiments are evaluated on North China University of Technology  dorsal hand vein image dataset with minimum distance classifier and the results are analyzed for recognition rate, run time and equal error rate. The proposed method gives 100 per cent recognition rate and 1 per cent EER for fusion of both left and right hands.Defence Science Journal, 2014, 64(2), pp. 159-167. DOI: http://dx.doi.org/10.14429/dsj.64.465

CHANGES IN BIOCHEMICAL CONSTITUTION OF RADISH (Raphanus sativus L.) UNDER COPPER TOXICITY

The effect of copper stress on the biochemical content of Raphanussativus L.were studied. The plants were grown in pots containing the soil with different concentrations of copper (0, 50, 100, 150,200 and 250 mg kg-1). Five replicates were maintained for each level.  Biochemical contents such as total sugar, starch, amino acid, proline and   protein) contents were analyzed on 45th day. Biochemical contents such as total sugar, starch, amino acid and protein were increased in low level of copper (50 mg kg-1) and decreased in high level of copper in the soil (100-250 mg kg-1).  But the proline content increased in high level of copper in the soil (100-250 mg kg -1) when compared to control and 50 mg kg-1