Indigenous Development of a Track Etch Detector

Solid state nuclear track detectors (SSNTDs) have been recognised by IAEA as a standard method for estimation of radon, thoron and their daughter products in the environment. The detectors that are commonly used in environmental monitoring are generally made from cellulose nitrate (LR-115) and polycarbonates (CR-39). In view of the non-availability of these detectors in India, need was felt to develop them indigenously. Accordingly, an attempt has been made to develop cellulose nitrate films for their use in SSNTD. Cellulose nitrate with a particular nitrogen content was used for preparing these films by a cast method. This films were annealed, evaluated and then compared with imported films. The background track density and alpha track density after exposure to 150 nCi of /sup 241/Am source at 2.5 cm distance were found to be comparable with those of imported films

Identification of Shocks in the Spectra from Black Holes

We study the spectral properties of a low angular momentum flow as a function of the shock strength, compression ratio, accretion rate and flow geometry. In the absence of a satisfactory description of magnetic fields inside the advective disk, we consider the presence of only stochastic fields and use the ratio of the field energy to the gravitational energy density as a parameter. We not only include `conventional' synchrotron emission and Comptonization by Maxwell-Bolzmann electrons in the gas, but we also compute these effects due to power-law electrons. For strong shocks, a bump is produced due to the post-shock flow. A power-law spectral components due to the thermal and non-thermal electrons appear after this bump.Comment: 8 pages, 5 figures, Astronomy and Space Science (in press), Proceedings of the Hong Kong Conference (2004) Edited by Cheng and Romer

Response of wheat cultivars to foliar potassium fertilization under irrigated saline environment

A field experiment with split-split plot design (SSPD) was conducted to study the response of two winter wheat (Triticumaestivum L.) cultivars (viz. salt tolerant cultivar KRL-1-4 and salt non-tolerant cultivar HD-2894) under saline irrigation regimes with and without foliar potassium fertilization on growth and grain yield of wheat during rabi 2011-12 and 2012-13. Potassium in the ratio of K+: Na+ (1: 10) was applied as foliar application during the heading stage of the crop. Results showed that the grain yield of KRL-1-4 and HD-2894 cultivars with foliar potassium fertilization at the heading stage increased by 6.5 to 22% and 3 to 15% during rabi 2011-2012, respectively under different saline irrigation regimes as compared to the control. Moreover, the results of rabi 2012-13 showed an increase in grain yield ranging from 4.5 to 20% for KRL-1-4 as compared to the control. Statistical analysis of grain yield parameter showed that the foliar potassium application in both varieties resulted in significant yield difference at 0.05 probability level as compared to the non-foliar application. Overall, it was observed that the foliar potassium fertilization increased the grain yield of both wheat cultivars, while the salt tolerant cultivar performed better than the salt non-tolerant cultivar under irrigated saline regimes

Retrieval of Pharyngeal Foreign Body Through Oral Approach in Three Dogs

Three dogs aged between 2 to 4 years old were presented to the Referral Veterinary Polyclinic, Indian Veterinary Research Institute, Izatnagar with clinical signs of anorexia, hypersalivation and repeated attempts at swallowing. Two cases showed shaking of head, pawing at the mouth and rubbing the head against wall, while in one case behavioral signs of depression were observed. Clinical examination and lateral plain radiograph of head and neck revealed radio opaque foreign body in the pharynx of all the animals. The foreign bodies were retrieved through the oral approach under general anaesthesia. This clinical paper reports the successful management of pharyngeal foreign bodies through oral approach using long curved artery forceps without any complication

Synthesis and liquid crystalline behaviour of substituted (E)-phenyl-4-(phenyldiazenyl) benzoate derivatives and their photo switching ability

Azobenzene derivatives containing phenyl/4-halogen-phenyl 4-{(E)-[4-(pent-4-en-1-yloxy)phenyl]diazenyl}benzoate group with different electronegative substituent (H, F, Cl, Br and I) at other end was synthesised. These azo-based benzoate derivatives have been characterised by FTIR, 1H-NMR, 13C-NMR, elemental analyser, POM and UV-Vis spectroscopy. Photosaturation at 358 nm obtained after 82 s of UV irradiation and the longest thermal back relaxation time of 45 h recorded by UV-Vis. The azo derivative could be possible photolock under UV light, as observed by the improved thermal back relaxation time. The resulting photolockable chain of azobenzene might prove valuable in the development of optical device application. These azobenzene moieties also exhibit liquid crystalline behaviour with respect to the halogen substitution as an electron withdrawing group shows that strong structure property relationship exists among them

Research studies on polymeric effect of indomethacine transdermal films

The objective of this study was to design and evaluate transdermal patches of Indomethacine using HPMC, EC and Eudragit RLPO using solvent casting technique. The in vitro drug release studies were performed by using the USP (paddle type) dissolution list apparatus in 1000 ml of 0.1N HCl (Medium Employed) at 37o C room temperature for an rpm maintained at 100 within a stipulated time interval of 15 minutes. The withdrawn Samples were analyzed by using UV visible  spectrophotometer at 268 mm using regent blank. The prepared  transdermal patches had undergone physic chemical evaluator parameters such as PMA, PML, swelling index, water vapour transmission rate, film thickness, weight cheek, and folding Endurance and drug content clearance. In vitro dissolution study of drug along with different  combination of polymers; i.e. HPMC, EC and Eudragit has been  performed; out of which batch B6 shows the best moisture of films and the graph representing the best controlled drug release. As the percentage of ethyl cellulose was reduced the rate of the release of the drug was increased. [Batch B6 > HPMC: EC: Eudragit RLPO - 2:1:2]. Films with batch  code B6 shows better stability and suitability. Higuchi’s plot revealed that the predominant Mechanism of drug release was diffusio

Fragmentation cross sections of Fe^{26+}, Si^{14+} and C^{6+} ions of 0.3-10 A GeV on CR39, polyethylene and aluminum targets

New measurements of the total and partial fragmentation cross sections in the energy range 0.3-10 A GeV of Fe^{26+}, Si^{14+} and C^{6+} beams on polyethylene, CR39 and aluminum targets are presented. The exposures were made at Brookhaven National Laboratory (BNL), USA, and Heavy Ion Medical Accelerator in Chiba (HIMAC), Japan. The CR39 nuclear track detectors were used to identify the incident and survived beams and their fragments. The total fragmentation cross sections for all targets are almost energy independent while they depend on the target mass. The measured partial fragmentation cross sections are also discussed.Comment: 4 pages, 5 eps figures. Talk given at the 24th International Conference on Nuclear Tracks in Solids, Bologna, Italy, 1-5 September 200

Effect of Lanthanum Substitution on the Structural, dielectric, Ferroelectric and Piezoelectric Properties of Mechanically Activated PZt Electroceramics

Different compositions of (Pb1-xLax) (Zr0.60Ti0.40)O3 (abbreviated as PLZT x/60/40; x=0, 0.07, 0.08 and 0.10) ceramics were prepared by a combinatorial approach by high energy mechano-chemical ball milling and cold isostatic pressing (CIP). X-ray diffraction patterns and transmission as well as scanning electron microscope were used for the micro-structural and morphological studies. The average particle size of PLZT milled powders was measured from the TEM images and was found to be in the nm range.XRD patterns of the sintered PLZT x/60/40 ceramics confirm the perovskite phase formation after heat treatment. SEM of sintered PLZT x/60/40 ceramics show a close packed dense structure. PLZT 8/60/40 ceramics show the fine grains (~1.3 µm) with density ~97 per cent. Dielectric constant and loss were measured as a function of temperature. PLZT 8/60/40 ceramics shows the highest value of room temperature dielectric constant ~2480 at 1 kHz. Ferroelectric studies were done with the help of polarisation (P-E) and strain (S-E) vs. electric field measurements. PLZT 8/60/40 ceramics shows the maximum value of remnant polarisation (~36 µC/cm2) and strain (~0.27 per cent), respectively. PLZT x/60/40 ceramic samples were poled at optimized poling conditions. The measured values of piezoelectric charge coefficient (d33) and electromechanical coupling factor (kp) of PLZT 8/60/40 ceramics were found to be, ~690 pC/N and ~71 per cent, respectively