Preservation of Bombay duck (Harpodon nehereus) and Rohu (Labeo rohita) by gamma irradiation

The gamma irradiation procedures for preservation of Bombay duck and rohu were studied in collaboration with Bhabha Atomic Research Centre, Bombay. Irradiation at 0.1 M rad extended the storage life of Bombay duck to 20-22 days at 0-2°C due to partial destruction of spoilage organisms as against rapid deterioration of un-irradiated samples within 5-6 days. In the case of the fresh water fish, rohu, the storage life was enhanced by about 7-10 days by the same dose of irradiation over the control under identical storage condition. In all the cases, empirical relations were worked out between organoleptic rating and total volatile nitrogen

On the ice-storage characteristics of Catla catla and Labeo fimbriatus

The ice-storage characteristics of Catla catla and Labeo fimbriatus are reported. Muscle pH, moisture, total volatile nitrogen, alpha amino nitrogen and peroxide value and also the changes in total bacterial count are studied. C. catla and L. fimbriatus both could be stored in ice for 18 days

Integration of biocontrol agents with fungicide, weedicide and plant growth regulator for management of stem and root rot of jute

Combination of chemical fungicides (viz., Carbendazim 50 WP and Tebuconazole 250 EC) and biocontrol agents (viz., Pseudomonas fluorescens Psfl1, P. striata Pst1, Azotobacter chrococcum Azbc3, Bradyrhizobium japonicum Brj4, Trichoderma aureoviridae S12, T. harzianum JTV2, T. virens JPG1, Aspergillus niger AN15 strains respectively either singly or in consortium) were used to counteract Macrophomina phaseolina, the causal organism of stem and root rot of jute. In addition, suitable plant growth regulator viz., Indole-3-acetic acid (100-1.0 µg/ppm) and herbicide Quizalofop ethyl 5 % EC were used to augment the activity of Trichoderma. T. aureoviridae strain S12 was found to be the best among the eight isolates screened for tolerance against the two fungicides and herbicide at a concentration of 10000 - 500 µg respectively as well as against M. phaseolina (Inhibition=72.33 %) in-vitro. This strain showed best compatibility with other strains and highest tolerance to fungicide i.e., Carbendazim 50 % (up to 500 ?g). Highest number (13.7×106) of active spores was recorded at a concentration of 25 ppm of IAA under in-vitro condition. S12 recorded a biocontrol efficiency of 61.8 % against stem rot of jute along with significant plant growth promotion and fibre production. Plant biomass also increased up to 7.5-12.1 % and fibre production 37.0-39.9 % with fungal and bacterial consortium + carbendazim seed dressing and soil drenching. These biocontrol fungi and PGPR consortium with high tolerance to fungicide, weedicide and plant growth regulator up to certain extent may be potentially exploited in IDM which may be a low cost technology in jute and allied fibre crops

Recycled aggregate concrete: a sustainable built Environment

In the present study the influence of recycled coarse aggregate (RCA) obtained from three different sources having different ages of structures are on the properties of recycled aggregate concrete (RAC) are investigated. RAC mixes are prepared with each source of RCA separately. In order to assess the performance of RAC in comparison with normal concrete, two normal concrete mixes prepared with 100% natural coarse aggregate. Locally available natural sand is used in all mixes. The compressive strength and the characteristics of interfacial transition zone (ITZ) viz. porosity and microhardness of RAC are studied. The results reveal that the ITZ of RAC is relatively loose and porous than the ITZ in normal concrete

Development of a steady state creep behavior model of polycrystalline tungsten for bimodal space reactor application

The fuel element for one of the many reactor concepts being currently evaluated for bimodal applications in space consists of spherical fuel particles clad with tungsten or alloys of tungsten. The fuel itself consists of stabilized UO{sub 2}. One of the life limiting phenomena for the fuel element is failure of the cladding because of creep deformation. This report summarizes the information available in literature regarding the creep deformation of tungsten and its alloys and proposes a relation to be used for calculating the creep strains for elevated temperatures in the low stress region ({sigma} {le} 20 MPa). Also, results of the application of this creep relation to one of the reactor design concepts (NEBA-3) are discussed. Based on the traditional definition of creep deformation, the temperatures of 1500 K to 2900 K for tungsten and its alloys are considered to be in the {open_quotes}high{close_quotes} temperature range. In this temperature range, the rate controlling mechanisms for creep deformation are believed to be non-conservative motion of screw dislocations and short circuit diffusional paths. Extensive theoretical work on creep and in particular for creep of tungsten and its alloys have been reported in the literature. These theoretical efforts have produced complex mathematical models that require detailed materials properties. These relations, however, are not presently suitable for the creep analysis because of lack of consistent material properties required for their use. Variations in material chemistry and thermomechanical pre-treatment of tungsten have significant effects on creep and the mechanical properties. Analysis of the theoretical models and limited data indicates that the following empirical relation originally proposed by M. Jacox of INEL and the Air Force Phillips Laboratory, for calculating creep deformation of tungsten cladding, can be used for the downselection of preliminary bimodal reactor design concepts

Tryptophan Oxidative Metabolism Catalyzed by Geobacillus Stearothermophilus: A Thermophile Isolated from Kuwait Soil Contaminated with Petroleum Hydrocarbons

Tryptophan metabolism has been extensively studied in humans as well as in soil. Its metabolism takes place mainly through kynurenine pathway yielding hydroxylated, deaminated and many other products of physiological significance. However, tryptophan metabolism has not been studied in an isolated thermophilic bacterium. Geobacillus stearothermophilus is a local thermophile isolated from Kuwait desert soil contaminated with petroleum hydrocarbons. The bacterium grows well at 65 °C in 0.05 M phosphate buffer (pH 7), when supplied with organic compounds as a carbon source and has a good potential for transformation of steroids and related molecules. In the present study, we used tryptophan ethyl ester as a carbon source for the bacterium to study the catabolism of the amino acid at pH 5 and pH 7. In this endeavor, we have resolved twenty one transformation products of tryptophan by GC/LC and have identified them through their mass spectral fragmentation

Dynamical properties of the unitary Fermi gas: collective modes and shock waves

We discuss the unitary Fermi gas made of dilute and ultracold atoms with an infinite s-wave inter-atomic scattering length. First we introduce an efficient Thomas-Fermi-von Weizsacker density functional which describes accurately various static properties of the unitary Fermi gas trapped by an external potential. Then, the sound velocity and the collective frequencies of oscillations in a harmonic trap are derived from extended superfluid hydrodynamic equations which are the Euler-Lagrange equations of a Thomas-Fermi-von Weizsacker action functional. Finally, we show that this amazing Fermi gas supports supersonic and subsonic shock waves.Comment: 9 pages, 3 figures, invited talk at the International Workshop "Critical Stability 2011" (Erice, October 2011), to be published in the journal Few Body System

Development of a fast fiber based UV-Vis multiwavelength detector for an ultracentrifuge

The advantages of simultaneously detecting multiple wavelengths in ultracentrifugation experiments are obvious, especially for interacting systems. In addition, the detection of the wavelength dependence of turbidity opens up the possibility to obtain independent information on the particle size in addition to the usual sedimentation coefficient distribution for colloidal systems. We therefore made an effort to develop a fast UV/Vis detector, which is able to simultaneously detect the range from 200-800 nm. This is possible by the use of a modern CCD chip based generation of UV-Vis spectrometers, which translates the dispersed white light onto a CCD chip, where each pixel corresponds to a particular wavelength. In addition to the simultaneous detection of a large number of wavelengths in the range 200-800 nm, also with non integer values, these spectrometers are very fast. Current typical spectrum scan times with the necessary scan quality in the ultracentrifuge are in the range of 100 ms but this time can be significantly shortened down to 3 ms for higher light intensities and even down to 10 μs for a new generation of CCD chip based spectrometers. The introduction of a fiber based UV-Vis optics into a preparative XL-80K ultracentrifuge with the associated hardware developments will be described as a first generation prototype. In this study, we use a wavelength dependent optical lens system instead of the necessary but more complex wavelength independent mirror optical system for a first check on possibilities and limitations of the optical system. First examples for biopolymers and latexes will be presented and compared to those obtained in the commercial XL-A ultracentrifuge. Already the fast detection enables completely new possibilities like the determination of a particle size distribution in a few minutes. Multiwavelength detection at constant position in dependence of time will be demonstrated, which is an important mode for the use of speed profiles for very polydisperse samples. Also, the use of radial multiwavelength scans will be demonstrated producing a three dimensional data space for monitoring the sedimentation via radial scans with multiwavelength detection. However, despite the advantages, the current problems with the detector will also be discussed including the main problem that much intensity is lost in the important UV range as a result of fiber coupling and bending. © Springer-Verlag Berlin Heidelberg 2006