A report on the occurrence of Bangana dero (Hamilton, 1822) from Deepor beel (Ramsar site no. 1207), Brahmaputra valley, Assam

Deepor beel (Latitude: 26°05?26??N to 26°09?26?? N; Longitude: 90°36' E to 90°41?25?? E) located in Kamrup district, Assam is a large (water spread area of 589 ha) natural wetland and a Ramsar site of international importance (Site number 1207 declared in 2002) having enormous biological and environmental importance. The wetland receives water from surface run-off as well as from two hill streams (Basistha and Kalamoni) and drains into River Brahmaputra, through a small rivulet (Khanajan). The beel supports a number of endemic endangered and threatened animals and plants that are included under IUCN red-list. Past studies indicated the occurrence of 67 fin-fish species in the beel. In a recent survey conducted by us, the beel Bangana dero (Synonyms: Cyprinus dero/ Labeo dero), a cyprinid fish, was collected for the first time from the beel. We collected as many as 28 specimens of B. dero from the beel during October 2016. The total length of the reported specimens ranged from 8.77 - 10.14 cm and weight ranged from 6.74 - 10.61 g. The length-weight relationship of the species was worked out as W = 0.074*L2.103. B. dero reportedly inhabits upland rivers, torrential hill-streams; adults migrate to warm downstream regions during the winter season (December-February). Thus, the occurrence of this species in Deepor beel indicates its possible downstream migration from one or both the feeder rivers (Basistha and Kalamoni) or migration from Brahmaputra River through its connecting channel.&nbsp

Photon sensitivity of superheated drop at room temperature

It has been reported so far that superheated drop detector made of R-12 at room temperature are sensitive to neutrons yet insensitive to photons. This property makes its use as one of the most useful neutron dosimeter. The photon sensitivity of R12 at room temperature when exposed to 59.54kev photons obtained from radioactive Am has been noted for the first time in our laboratory. This discovery is important nt only from the point of view of basic science but more important to the users of R12 in neutron dosimetry to take note of this in assessing the neutron dose correctly.Comment: 3pages, 1 fig. Nuclear Instruments and Method A, 2000, (accepted

INSDOC’S contribution to bibliometrics

Traces the history of bibliometric research, training and activities in INSDOC. Describes briefly the objectives, facilities, services, research activities, and publications of National Centre on Bibliometrics

Standardization of setting temperature and time for fish meat

Meat to water ratio used for washing was 1:3 for oil sardine and mackerel; but for pink perch and croaker, it was 1:2. Again the washing process was repeated three times for oil sardine and mackerel; but two times for pink perch and croaker. The washed meat was mixed with 2.5% NaC1 and set at +5°C and +40°C for 1, 2 and 3hrs. The gel strength and expressible water content was measured. Basing on this study, setting temperature at +40°C was selected and with respect to time 1hr for sardine and mackerel and 3hrs for pink perch and croaker was selected

Superheated drop as a neutron spectrometer

Superheated drops are known to vaporise when exposed to energetic nuclear radiation since the discovery of bubble chamber. As the degree of superheat increases in a given liquid, less and less energetic neutrons are required to cause nucleation. This property of superheated liquids are being utilised to develope the neutron spectromer. A new principle of neutron spectrometry using Superheated liquid are developed and the developed principle has been tested by Am-Be neutron source.Comment: 9 pages, 8 figures. accepted in Nucl.Instru.MethA,200

Model of multifragmentation, Equation of State and phase transition

We consider a soluble model of multifragmentation which is similar in spirit to many models which have been used to fit intermediate energy heavy ion collision data. We draw a p-V diagram for the model and compare with a p-V diagram obtained from a mean-field theory. We investigate the question of chemical instability in the multifragmentation model. Phase transitions in the model are discussed.Comment: Revtex, 9 pages including 6 figures: some change in the text and Fig.

Auger decay of degenerate and Bose-condensed excitons in Cu2_2O

We study the non-radiative Auger decay of excitons in Cu$_2$O, in which two excitons scatter to an excited electron and hole. The exciton decay rate for the direct and the phonon-assisted processes is calculated from first principles; incorporating the band structure of the material leads to a relatively shorter lifetime of the triplet state ortho excitons. We compare our results with the Auger decay rate extracted from data on highly degenerate triplet excitons and Bose-condensed singlet excitons in Cu$_2$O.Comment: 15 pages, revtex, figures available from G. Kavoulaki

Quantum saturation and condensation of excitons in Cu2_2O: a theoretical study

Recent experiments on high density excitons in Cu$_2$O provide evidence for degenerate quantum statistics and Bose-Einstein condensation of this nearly ideal gas. We model the time dependence of this bosonic system including exciton decay mechanisms, energy exchange with phonons, and interconversion between ortho (triplet-state) and para (singlet-state) excitons, using parameters for the excitonic decay, the coupling to acoustic and low-lying optical phonons, Auger recombination, and ortho-para interconversion derived from experiment. The single adjustable parameter in our model is the optical-phonon cooling rate for Auger and laser-produced hot excitons. We show that the orthoexcitons move along the phase boundary without crossing it (i.e., exhibit a ``quantum saturation''), as a consequence of the balance of entropy changes due to cooling of excitons by phonons and heating by the non-radiative Auger two-exciton recombination process. The Auger annihilation rate for para-para collisions is much smaller than that for ortho-para and ortho-ortho collisions, explaining why, under the given experimental conditions, the paraexcitons condense while the orthoexcitons fail to do so.Comment: Revised to improve clarity and physical content 18 pages, revtex, figures available from G. Kavoulakis, Physics Department, University of Illinois, Urban

Processing of aluminum-graphite particulate metal matrix composites by advanced shear technology

Copyright @ 2009 ASM International. This paper was published in Journal of Materials Engineering and Performance 18(9) and is made available as an electronic reprint with the permission of ASM International. One print or electronic copy may be made for personal use only. Systematic or multiple reproduction, distribution to multiple locations via electronic or other means, duplications of any material in this paper for a fee or for commercial purposes, or modification of the content of this paper are prohibited.To extend the possibilities of using aluminum/graphite composites as structural materials, a novel process is developed. The conventional methods often produce agglomerated structures exhibiting lower strength and ductility. To overcome the cohesive force of the agglomerates, a melt conditioned high-pressure die casting (MC-HPDC) process innovatively adapts the well-established, high-shear dispersive mixing action of a twin screw mechanism. The distribution of particles and properties of composites are quantitatively evaluated. The adopted rheo process significantly improved the distribution of the reinforcement in the matrix with a strong interfacial bond between the two. A good combination of improved ultimate tensile strength (UTS) and tensile elongation (e) is obtained compared with composites produced by conventional processes.EPSR