Study of QCD generalized ghost dark energy in FRW universe

A phenomenological generalized ghost dark energy model has been studied under the framework of FRW universe. In ghost dark energy model the energy density depends linearly on Hubble parameter (H) but in this dark energy model, the energy density contains a the sub-leading term which is depends on $\mathcal{O} (H^2)$, so the energy density takes the form $\rho_D=\alpha H+ \beta H^2$, where $\alpha$ and $\beta$ are the constants. The solutions of the Friedman equation of our model leads to a stable universe. We have fitted our model with the present observational data including Stern data set. With the help of best fit results we find the adiabatic sound speed remains positive throughout the cosmic evolution, that claims the stability of the model. The flipping of the signature of deceleration parameter at the value of scale factor $a=0.5$ indicates that the universe is at the stage of acceleration i.e. de Sitter phase of the universe at late time. Our model shows that the acceleration of the universe begin at redshift $z_{ace}\approx 0.617$ and the model is also consistent with the current observational data.Comment: 9 pages, 9 figure

Truncated Harmonic Osillator and Parasupersymmetric Quantum Mechanics

We discuss in detail the parasupersymmetric quantum mechanics of arbitrary order where the parasupersymmetry is between the normal bosons and those corresponding to the truncated harmonic oscillator. We show that even though the parasusy algebra is different from that of the usual parasusy quantum mechanics, still the consequences of the two are identical. We further show that the parasupersymmetric quantum mechanics of arbitrary order p can also be rewritten in terms of p supercharges (i.e. all of which obey $Q_i^{2} = 0$). However, the Hamiltonian cannot be expressed in a simple form in terms of the p supercharges except in a special case. A model of conformal parasupersymmetry is also discussed and it is shown that in this case, the p supercharges, the p conformal supercharges along with Hamiltonian H, conformal generator K and dilatation generator D form a closed algebra.Comment: 9 page

Josephson Coupling in the Dissipative State of a Thermally Hysteretic μ\mu-SQUID

Micron-sized superconducting interference devices ($\mu$-SQUIDs) based on constrictions optimized for minimizing thermal runaway are shown to exhibit voltage oscillations with applied magnetic flux despite their hysteretic behavior. We explain this remarkable feature by a significant supercurrent contribution surviving deep into the resistive state, due to efficient heat evacuation. A resistively shunted junction model, complemented by a thermal balance determining the amplitude of the critical current, describes well all experimental observations, including the flux modulation of the (dynamic) retrapping current and voltage by introducing a single dimensionless parameter. Thus hysteretic $\mu$-SQUIDs can be operated in the voltage read-out mode with a faster response. The quantitative modeling of this regime incorporating both heating and phase dynamics paves the way for further optimization of $\mu$-SQUIDs for nano-magnetism.Comment: 10 pages, 11 figures, Revise

Low-energy quenching of positronium by helium

Very low-energy scattering of orthopositronium by helium has been investigated for simultaneous study of elastic cross section and pick-off quenching rate using a model exchange potential. The present calculational scheme, while agrees with the measured cross section of Skalsey et al, reproduces successfully the parameter ^ 1Z_{\makebox{eff}}, the effective number of electrons per atom in a singlet state relative to the positron. Together with the fact that this model potential also leads to an agreement with measured medium energy cross sections of this system, this study seems to resolve the long-standing discrepancy at low energies among different theoretical calculations and experimental measurements.Comment: 4 latex pages, 3 postscript figure

Controlling hysteresis in superconducting constrictions with a resistive shunt

We demonstrate control of the thermal hysteresis in superconducting constrictions by adding a resistive shunt. In order to prevent thermal relaxation oscillations, the shunt resistor is placed in close vicinity of the constriction, making the inductive current-switching time smaller than the thermal equilibration time. We investigate the current-voltage characteristics of the same constriction with and without the shunt-resistor. The widening of the hysteresis-free temperature range is explained on the basis of a simple model.Comment: 6 pages, 7 figures, including Supplementary Informatio

Nonterminal incorporation of guanosine monophosphate from guanosine triphosphate by an enzyme system from spinach chloroplasts

This article does not have an abstract

Role of B-ring of colchicine in its binding to tubulin

The chemical specificity of the colchicine-binding site of tubulin is less stringent for the presence of the B-ring than the A- and C-rings of colchicine, Colchicine analogues with modifications in the B-ring bind to tubulin at the same site as colchicine. Analogues with smaller or no substituents in the B-ring bind tubulin remarkably faster than colchicine. Thus, a compound without the B-ring [2-methoxy-5-(2',3',4'-trimethoxyphenyl)tropone] binds tubulin even at 4 °C and the binding is almost instantaneous at 37 °C. Colcemid and 2-methoxy-5-(2',3',4'-trimethoxyphenyl)tropone bind reversibly to tubulin, whereas colchicine and desacetamidocolchicine bind almost irreversibly, suggesting that the size of the B-ring moiety of colchicine is not related to the reversibility of binding. We conclude that although the presence of the B-ring of colchicine does not appear to be an essential prerequisite for the drug-tubulin interaction, the B-ring substituents play an important role in determining the binding properties of colchicine to tubulin

Isospin mode splitting and mixing in asymmetric nuclear matter

We estimate exclusive density and asymmetry parameter dependent dispersion relations of various charged states of pions in asymmetric nuclear matter. The possibility of matter induced mixing of $\pi^0$ with $\eta$ is clearly exposed with the further mass modification of $\pi^0$ meson due to mixing. Asymmetry driven mass splitting and mixing amplitude are of the same order as the corresponding values in vacuum. Closed form analytic results for the mass shifts and dispersion relations with and without mixing are presented. Furthermore, we discuss the sensitivity of our results on the scalar mean field within the framework of Quantum Hadrodynamics.Comment: 8 pages, 4 Figure

Effect of farm yard manure, phosphorus and sulphur on yield parameters, yield, nodulation, nutrient uptake and quality of chickpea (Cicer arietinum L.)

Field experiments were conducted for three years at Pulses and Oilseeds Research Station, Berhampore, Murshidabad, West Bengal, India during rabi 2010-11, 2011-12 and 2012-13 to study the effects of farm yard manure (FYM), phosphorus and sulphur on yield parameters, yield, nodulation, nutrient uptake and quality of chickpea. The experiment was laid out in a factorial randomized block design with three replications having twelve treatment combinations viz. two levels of FYM (F0-0 t ha-1, F1 -5 t ha-1) as factor A , three levels of phosphorus (P0 -0 kg ha-1, P30 -30 kg ha-1, P60 -60 kg ha-1) as factor B and two levels of sulphur (S0 -0 kg ha-1, S20 -20 kg ha-1) as factor C. Experimental results revealed that yield attributing characters, yield and protein content of chickpea were significantly influenced by FYM, phosphorus, sulphur and interaction effects of these three factors. Significantly higher seed yield (2458.03 kg ha-1) was obtained with the application of FYM 5 t ha-1 over it’s non application. Application of 60 kg ha-1 phosphorus recorded significantly higher seed yield (2735.50 kg ha-1) of chickpea cultivar Anuradha. Application of 20 kg ha-1 sulphur recorded significantly higher seed yield (2532.32 kg ha-1) over it’s non application in a sulphur deficient soil. Among the interaction effects application of 60 kg ha-1 phosphorus and 20 kgha-1 sulphur in Farm yard manure(5 t ha-1 ) treated plot recorded highest seed yield (2979.3 kg ha-1) . Application of sulphur 20 kg ha-1 increased the nodule no. by 14.4 %. Application of 60 kg ha-1 phosphorus and 20 kg ha-1 sulphur in Farm yard manure treated plot (5 t ha-1) increased the nodule no. by 62.3%. Varying levels of phosphorus along with sulphur and FYM significantly improved the nutrient uptake by chickpea in a sulphur deficient soil. Application of 60 kg ha-1 phosphorus and 20 kg ha-1 sulphur in Farm yard manure treated plot (5 t ha-1) along with recommended dose of nitrogen and potassium proved to be the best treatment combination for increasing the productivity of chickpea and thereby increasing the pulse production of the country