An account of two species of Zeuxine Lindl. (Orchidaceae) occurring in Tripura is presented in this paper. Zeuxine longilabris (Lindl.) Benth. ex Hook.f. turned out to be a new distributional record ...for the state of Tripura.
We study the quark deconfinement phase transition in hot \(\beta\)-stable hadronic matter. Assuming a first order phase transition, we calculate the enthalpy per baryon of the hadron-quark phase ...transition. We calculate and compare the nucleation rate and the nucleation time due to thermal and quantum nucleation mechanisms. We compute the crossover temperature above which thermal nucleation dominates the finite temperature quantum nucleation mechanism. We next discuss the consequences for the physics of proto-neutron stars. We introduce the concept of limiting conversion temperature and critical mass \(M_{cr}\) for proto-hadronic stars, and we show that proto-hadronic stars with a mass \(M < M_{cr}\) could survive the early stages of their evolution without decaying to a quark star.
The saturation properties of the nuclear matter taking pion correlations into account is studied. We construct a Bogoliubov transformations for the pion pair operators and calculate the energy ...associated with the pion pairs. The pion dispersion relation is investigated. We next study the correlation energy due to one pion exchange in nuclear matter and neutron matter at random phase approximation using the generator coordinate method. The techniques of the charged pion correlations are discussed in the neutron matter calculations. We observe that there is no sign of the pion condensation in this model.
In the present article, we investigate stellar matter obtained within the quark-meson-coupling (QMC) model for fixed temperature and with the entropy of the order of 1 or 2 Boltzmann units per baryon ...for neutrino-free matter and matter with trapped neutrinos. A new prescription for the calculation of the baryon effective masses in terms of the free energy is used. Comparing the results of the present work with those obtained from the nonlinear Walecka model, smaller strangeness and neutrino fractions are predicted within QMC. As a consequence, QMC has a smaller window of metastability for conversion into a low-mass blackhole during cooling.
Quark meson coupling (QMC) models can be successfully applied to the description of compact star properties in nuclear astrophysics as well as to nuclear matter. In the regime of hot hadronic matter ...very few calculations exist using the QMC model, in particular when applied to particle yields in heavy ion collisions. In the present work, we identify the free energy of the bag with the effective mass of the baryons and we calculate the particle production yields on a Au+Au collision at RHIC with the QMC model and compare them with results obtained previously with other relativistic models. A smaller temperature for the fireball, T=132 MeV, is obtained due to the smaller effective baryon masses predicted by QMC. QMC was also applied to the description of particle yields at SPS in Pb+Pb collisions.
ZrO
2
-Al
2
O
3
-SiC
w
composite powder mixtures were prepared by carbothermal reduction of natural silicates (e.g., zircon, sillimanite and kaolin). Activated charcoal was used as the reducing ...agent. The reactions were carried out in a graphite furnace at 1650°C in argon atmosphere at a positive pressure of 0.15 MPa. XRD investigation of the product phases confirms the completion of the reaction and the phases were identified as monoclinic zirconia, tetragonal zirconia, α-alumina and β-silicon carbide. SEM investigation of the powders reveals the whisker morphology of β-silicon carbide. It was observed that a small amount of zirconia was present in tetragonal form in addition to monoclinic form which could be due to fine particle size of the starting powder.
We study the effect of a strong magnetic field on the properties of neutron stars with a quark-hadron phase transition. It is shown that the magnetic field prevents the appearance of a quark phase, ...enhances the leptonic fraction, decreases the baryonic density extension of the mixed phase and stiffens the total equation of state, including both the stellar matter and the magnetic field contributions. Two parametrisations of a density dependent static magnetic field, increasing, respectively, fast and slowly with the density and reaching \(2-4\times 10^{18}\)G in the center of the star, are considered. The compact stars with strong magnetic fields have maximum mass configurations with larger masses and radius and smaller quark fractions. The parametrisation of the magnetic field with density has a strong influence on the star properties.
Unmanned Air Vehicle and Simulation Krishana, P. S.; Panda, P. K.; Jayaraman, J.
Defense science journal,
05/1997, Letnik:
47, Številka:
3
Journal Article
Recenzirano
A general account of unmanned air vehicles (UAVs) is given and their various roles, both lethal and non-lethal ones, are discussed. Elements of an UAV system used for reconnaissance, surveillance and ...target designation have been described to highlight the role of simulation in acquisition, design, development, testing, evaluation, and operation of such a system. Various applications of simulation studies for UAVs are mentioned. An attempt has been made to highlight how simulation helps in identifying design deficiencies and thus improve the design through the following three typical problems encountered during design and development of UAVs at the Aeronautical Development establishment:(i) launch dynamics of Lakshya, (ii) tow system dynamics, Lakshya tow body, and (iii) hardware in-line simulation -way point navigation-Nishant.
Primary Production in River Birupa, India Sukla, Basanti; Patra, A. K.; Panda, R. P.
Proceedings of the National Academy of Sciences, India. Section B: Biological sciences,
12/2013, Letnik:
83, Številka:
4
Journal Article
Seasonal changes of primary production in relation to water temperature, secchi transparency and rainfall were measured from January 2009 to December 2010 by using light-and-dark bottle technique at ...three different sampling sites along the course of river Birupa between 20°36
′
57
″
north latitude and 86°24
′
29
″
east longitude of Odisha, India. The Gross Primary Production (GPP) and Net Primary Production (NPP) were least during monsoon (August) and attained peak during summer (April) at all stations except GPP during March at station 3. Community Respiration (CR) was minimum from February to April and maximum from October to January among the stations. GPP and NPP were significantly correlated,both temporally and spatially,with water temperature, secchi transparency and rainfall. Annual GPP was maximum at station 2 and minimum at station 3. Annual GPP for both the years was found to be 1.364 gC m
−2
day
−1
or 497.86 gC m
−2
year
−1
in river Birupa. This value was compared to some other temperate and tropical rivers.
PDF
