On the Class of Exact Solutions of an Incompressible Second-order Fluid Flow by Creating Sinusoidal Disturbances

Exact solution of an incompressible fluid of second-order by causing disturbances in theliquid, which is initially at rest due to bottom oscillating sinusoidally, has been obtained in thisstudy. The results presented are in terms of nondimensional elasticoviscosity parameter ( )which depends on the non-Newtonian coefficient and the frequency of excitation of the externaldisturbance while considering the porosity (K) of the medium. The flow parameters are foundto be identical with that of Newtonian case as0 and K

Exact Solutions of an Incompressible Fluid Flow of Second Order byForced Oscillations on the Porous Boundary

Exact solution of an incompressible fluid of second-order type  by causing forced oscillationsin the liquid of finite depth bounded by a porous bottom has been obtained.  The results presentedare in terms of nondimensional elastico-viscosity parameter () which depends on the non-Newtonian coefficient and the frequency of excitation () of the external disturbance whileconsidering the porosity (K) of the medium. The flow parameters are found to be identical withthat of  Newtonian case as  and K.  It is seen that the effect of  and the porosityof the bounding surface has significant effect on the velocity parameter.  Further, the nature ofthe paths of the fluid particles have also been studied with reference to  and the porosity ofthe bounding surface

Flow of an Elastico-viscous Fluid Past an Infinite Platewith Variable Suction

Unsteady state flow of an incompressible elastico-viscous fluid of second-order type pastan infinite vertical porous flat plate by considering uniform and variable suction normal to theplate has been studied  and an exact solution is obtained for the velocity field. In the presentsituation, only two prescribed boundary conditions are available while the governing equationof motion is of third-order due to the presence of elastico-viscosity parameter.  The conceptfollowing Walters has been used for a much more meaningful solution.  The results for thevelocity distribution and skin friction have been analysed and discussed for different values ofthe parameters encountered in the governing equation of motion and skin friction on the plate.It is found that the effect of elastico-viscosity  and suction has significant contribution on thebackflow at the wal

X-Y converter family: A new breed of buck boost converter for high step-up renewable energy applications

A new breed of a buck boost converter, named as the XY converter family is proposed in this article. In the XY family, 16 topologies are presented which are highly suitable for renewable energy applications which require a high ratio of DC-DC converter; such as a photovoltaic multilevel inverter system, high voltage automotive applications and industrial drives. Compared to the traditional boost converter and existing recent converters, the proposed XY converter family has the ability to provide a higher output voltage by using less number of power devices and reactive components. Other distinct features of the XY converter family are i) Single control switch ii) Provide negative output voltage iii) Non-isolated topologies iv) High conversion ratio without making the use of high duty cycle and v) modular structure. XY family is compared with the recent high step-up converters and the detailed description of XY converter family and its topologies are presented. The simulation results are provided and it confirms the feasibility, functionality and validity of the concepts of the proposed XY converter family

Using Wireless Sensor Network Human Face Action Recognition System

In this project victimisation the Wireless device Network we have a tendency to implement the Human Face Action Recognition System by police investigation movements of human is one of the key applications of life science. Here we have a tendency to implementing face action recognition system by victimisation image process and algorithms with devices nodes for higher potency Existing techniques area unit police investigation movements of a target victimisation face following in wireless device network work with efficiency however victimisation sensor node we have a tendency to will collect the data, knowledge concerning human facial expressions and movements of human body and examination recent knowledge captured by sensors to the new capturing knowledge, if knowledge is matching then we have a tendency to find that person. Its authenticating the person by capturing, succeed following ability with high accuracy victimisation Wireless device Networks for that we have a tendency to area unit making new framework. we have a tendency to use the Haar Removing rule, LBP rule, optimum choice rule, Image process Technique, Face Action Recognition, huge knowledge analysis. Victimisation java, tools like web bins and varied sensors

PTF11iqb: cool supergiant mass-loss that bridges the gap between Type IIn and normal supernovae

The supernova (SN) PTF11iqb was initially classified as a Type IIn event caught very early after explosion. It showed narrow Wolf–Rayet (WR) spectral features on day 2 (as in SN 1998S and SN 2013cu), but the narrow emission weakened quickly and the spectrum morphed to resemble Types II-L and II-P. At late times, H? exhibited a complex, multipeaked profile reminiscent of SN 1998S. In terms of spectroscopic evolution, we find that PTF11iqb was a near twin of SN 1998S, although with somewhat weaker interaction with circumstellar material (CSM) at early times, and stronger interaction at late times. We interpret the spectral changes as caused by early interaction with asymmetric CSM that is quickly (by day 20) enveloped by the expanding SN ejecta photosphere, but then revealed again after the end of the plateau when the photosphere recedes. The light curve can be matched with a simple model for CSM interaction (with a mass-loss rate of roughly 10?4 M? yr?1) added to the light curve of a normal SN II-P. The underlying plateau requires a progenitor with an extended hydrogen envelope like a red supergiant at the moment of explosion, consistent with the slow wind speed (<80?km?s?1) inferred from narrow H? emission. The cool supergiant progenitor is significant because PTF11iqb showed WR features in its early spectrum – meaning that the presence of such WR features does not necessarily indicate a WR-like progenitor. Overall, PTF11iqb bridges SNe IIn with weaker pre-SN mass-loss seen in SNe II-L and II-P, implying a continuum between these types

PTF11iqb: cool supergiant mass-loss that bridges the gap between Type IIn and normal supernovae

The supernova (SN) PTF11iqb was initially classified as a Type IIn event caught very early after explosion. It showed narrow Wolf–Rayet (WR) spectral features on day 2 (as in SN 1998S and SN 2013cu), but the narrow emission weakened quickly and the spectrum morphed to resemble Types II-L and II-P. At late times, H? exhibited a complex, multipeaked profile reminiscent of SN 1998S. In terms of spectroscopic evolution, we find that PTF11iqb was a near twin of SN 1998S, although with somewhat weaker interaction with circumstellar material (CSM) at early times, and stronger interaction at late times. We interpret the spectral changes as caused by early interaction with asymmetric CSM that is quickly (by day 20) enveloped by the expanding SN ejecta photosphere, but then revealed again after the end of the plateau when the photosphere recedes. The light curve can be matched with a simple model for CSM interaction (with a mass-loss rate of roughly 10?4 M? yr?1) added to the light curve of a normal SN II-P. The underlying plateau requires a progenitor with an extended hydrogen envelope like a red supergiant at the moment of explosion, consistent with the slow wind speed (<80?km?s?1) inferred from narrow H? emission. The cool supergiant progenitor is significant because PTF11iqb showed WR features in its early spectrum – meaning that the presence of such WR features does not necessarily indicate a WR-like progenitor. Overall, PTF11iqb bridges SNe IIn with weaker pre-SN mass-loss seen in SNe II-L and II-P, implying a continuum between these types

Gravitational collapse of a Hagedorn fluid in Vaidya geometry

The gravitational collapse of a high-density null charged matter fluid, satisfying the Hagedorn equation of state, is considered in the framework of the Vaidya geometry. The general solution of the gravitational field equations can be obtained in an exact parametric form. The conditions for the formation of a naked singularity, as a result of the collapse of the compact object, are also investigated. For an appropriate choice of the arbitrary integration functions the null radial outgoing geodesic, originating from the shell focussing central singularity, admits one or more positive roots. Hence a collapsing Hagedorn fluid could end either as a black hole, or as a naked singularity. A possible astrophysical application of the model, to describe the energy source of gamma-ray bursts, is also considered.Comment: 14 pages, 2 figures, to appear in Phys. Rev.

From core collapse to superluminous: The rates of massive stellar explosions from the Palomar Transient Factory

We present measurements of the local core-collapse supernova (CCSN) rate using SN discoveries from the Palomar Transient Factory (PTF). We use a Monte Carlo simulation of hundreds of millions of SN light-curve realizations coupled with the detailed PTF survey detection efficiencies to forward model the SN rates in PTF. Using a sample of 86 CCSNe, including 26 stripped-envelope SNe (SESNe), we show that the overall CCSN volumetric rate is CCv=9.10-1.27+1.56× 10-5SNe yr-1Mpc-3, h703 at za = 0.028, and the SESN volumetric rate is SEv=2.41-0.64+0.81× 10-5SNe yr-1Mpc-3, h703. We further measure a volumetric rate for hydrogen-free superluminous SNe (SLSNe-I) using eight events at z ≤ 0.2 of SLSN-Iv=35-13+25 SNe yr-1Gpc-3, h703, which represents the most precise SLSN-I rate measurement to date. Using a simple cosmic star formation history to adjust these volumetric rate measurements to the same redshift, we measure a local ratio of SLSN-I to SESN of ∼1/810+1500-94, and of SLSN-I to all CCSN types of ∼1/3500+2800-720. However, using host galaxy stellar mass as a proxy for metallicity, we also show that this ratio is strongly metallicity dependent: in low-mass (logM∗ < 9.5 M·) galaxies, which are the only environments that host SLSN-I in our sample, we measure an SLSN-I to SESN fraction of 1/300+380-170 and 1/1700+1800-720 for all CCSN. We further investigate the SN rates a function of host galaxy stellar mass, and show that the specific rates of all CCSNe decrease with increasing stellar mass