Single crystal of an organic nonlinear optical (NLO) material, Glycine picrate (GP), was grown by slow cooling method. The structural perfection of the grown crystal was analyzed by highresolution X-ray diffraction (rocking curve) measurements. UV-Visible-NIR spectral analysis was used to determine the optical constants and band gap of GP. The nature of variation of dielectric constant with fre...

We present spectral analysis from XMM-Newton observations of the Vela pulsar. We analyzed thermal emission from the pulsar dominating below ∼ 1 keV since extracted spectra are heavily contaminated by nebular emission at higher energy. Featureless high-resolution spectra of the Reflection Grating Spectrometer aboard XMM-Newton suggest the presence of a hydrogen atmosphere, as previously indicate...

Phonon heat transport in mesoscopic systems is investigated using methods analogous to the Landauer description of electrical conductance. A “universal heat conductance” expression that depends on the properties of the conducting pathway only through the mode cutoff frequencies is derived. Corrections due to reflections at the junction between the thermal body and the conducting bridge are foun...

The existing disk instability model for dwarf nova eruptions is reviewed, in the light of recent progress in the understanding of angular momentum transport in accretion disks. It is proposed that the standard lower branch in the “S-curve” in the effective temperature-surface density plane may not exist. Rather, angular momentum transport may be suppressed in quiescence as a result of cooling. ...

We consider a class of fully self-gravitating accretion disks, for which efficient cooling mechanisms are assumed to maintain the disk close to the margin of Jeans instability. For such self-regulated disks the equations become very simple in the outer regions, where the angular momentum convective transport approximately balances the viscous transport. These latter equations are shown to lead ...

Fe-based nanoparticles were prepared by laser-driven pyrolysis. The assynthesised powder consists of α-Fe and Fe3O4/γ-Fe2O3 nanoparticles embedded in a pyrolytic carbon matrix. The crystallite size of 1.8 nm for α-Fe was calculated using the Scherrer formula. The as-synthesised nanopowder was superparamagnetic. The maximum of the zero-field cooling curve was observed at 32 K and the distributio...

The present paper describes the designing of a thermally and economically optimum mechanical draft counter-flow wet cooling tower. The design model allows the use of a variety of packing materials in the cooling tower toward optimizing heat transfer. Once the optimum packing type is chosen, a compact cooling tower with low fan power consumption is modelled within the known design variables....

This paper presents a universal engineering model, which can be used to formulate both counterflow and crossflow cooling towers. By using fundamental laws of mass and energy balance, the effectiveness of heat exchange is approximated by a second order polynomial equation. Gauss-Newton and Levenberg-Marquardt methods are then used to determine the coefficients from manufactures data. Compared wi...

A recent optical monitoring campaign on the prominent quasar 3C 279 revealed at least one period of a remarkably clean exponential decay of monochromatic (BVRI) fluxes with time, with a time constant of τd = 12.8 d, over about 14 days. This is clearly too long to be associated with radiative cooling. Here we propose that this may be the signature of the deceleration of the synchrotron emitting ...

In a polymer membrane fuel cell more than half of the chemical energy of hydrogen is converted to heat during generation of electricity. This causes an increase in the cell temperature. The Cooling field design has a significant role in cell cooling. The cell's performance and stability are reduced due to inappropriate heat dissipation. In this paper, the cooling flow and heat transfer in cooli...