Chiral phase transition of (2+1)-flavor QCD

We present here results on the determination of the critical temperature in the chiral limit for (2+1)-flavor QCD. We propose two novel estimators of the chiral critical temperature where quark mass dependence is strongly suppressed compared to the conventional estimator using pseudo-critical temperatures. We have used the HISQ/tree action for the numerical simulation with lattices with three different temporal extent $N_{\tau}=$6, 8, 12 and varied the aspect ratio over the range $4 \leq N_{\sigma}/N_{\tau} \leq 8$. To approach the chiral limit, the light quark mass has been decreased keeping the strange quark mass fixed at its physical value. Our simulations correspond to the range of pion masses, 55 MeV $\leq m_{\pi} \leq$ 160 MeV.Comment: Prepared for the proceedings of Quark Matter 201

Toward a unified theory of sparse dimensionality reduction in Euclidean space

Let $\Phi\in\mathbb{R}^{m\times n}$ be a sparse Johnson-Lindenstrauss transform [KN14] with $s$ non-zeroes per column. For a subset $T$ of the unit sphere, $\varepsilon\in(0,1/2)$ given, we study settings for $m,s$ required to ensure $$\mathop{\mathbb{E}}_\Phi \sup_{x\in T} \left|\|\Phi x\|_2^2 - 1 \right| < \varepsilon ,$$ i.e. so that $\Phi$ preserves the norm of every $x\in T$ simultaneously and multiplicatively up to $1+\varepsilon$. We introduce a new complexity parameter, which depends on the geometry of $T$, and show that it suffices to choose $s$ and $m$ such that this parameter is small. Our result is a sparse analog of Gordon's theorem, which was concerned with a dense $\Phi$ having i.i.d. Gaussian entries. We qualitatively unify several results related to the Johnson-Lindenstrauss lemma, subspace embeddings, and Fourier-based restricted isometries. Our work also implies new results in using the sparse Johnson-Lindenstrauss transform in numerical linear algebra, classical and model-based compressed sensing, manifold learning, and constrained least squares problems such as the Lasso

Night sky at the Indian Astronomical Observatory during 2000-2008

We present an analysis of the optical night sky brightness and extinction coefficient measurements in UBVRI at the Indian Astronomical Observatory (IAO), Hanle, during the period 2003-2008. They are obtained from an analysis of CCD images acquired at the 2 m Himalayan Chandra Telescope at IAO. Night sky brightness was estimated using 210 HFOSC images obtained on 47 nights and covering the declining phase of solar activity cycle-23. The zenith corrected values of the moonless night sky brightness in mag/square arcsecs are 22.14(U), 22.42(B), 21.28(V), 20.54(R) and 18.86(I) band. This shows that IAO is a dark site for optical observations. No clear dependency of sky brightness with solar activity is found. Extinction values at IAO are derived from an analysis of 1325 images over 58 nights. They are found to be 0.36 in U-band, 0.21 in B-band, 0.12 in V-band, 0.09 in R-band and 0.05 in I-band. On average, extinction during the summer months is slightly larger than that during the winter months. No clear evidence for a correlation between extinction in all bands and the average night time wind speed is found. Also presented here is the low resolution moonless optical night sky spectrum for IAO covering the wavelength range 3000-9300 \AA. Hanle region thus has the required characteristics of a good astronomical site in terms of night sky brightness and extinction, and could be a natural candidate site for any future large aperture Indian optical-infrared telescope(s).Comment: 18 pages, 7 figures, uses basi.cls, accepted for publication in Bulletin of the Astronomical Society of Indi

Propagation of Small Disturbance Waves in a Fluid Flow across the Junctions between Rigid and Compliant Panels

The problem of wave propagation in a fluid flow across the junction between the rigid and the compliantpanelsin a channelhas beenstudied.In vorticalTollmien-Schlichting-type waves, thejump conditions are obtainedby the half-Fouriertransforms definedon both the sides of thejunction along withthe adjointmethod. The methoddevelopedis fairlygenericand is applicableto similarproblems. A comparison of the results obtained in the present study with those obtained from direct numerical simulations' shows good agreement

A wave driver theory for vortical waves propagating across junctions with application to those between rigid and compliant walls

A theory is described for propagation of vortical waves across alternate rigid and compliant panels. The structure in the fluid side at the junction of panels is a highly vortical narrow viscous structure which is idealized as a wave driver. The wave driver is modelled as a ‘half source cum half sink’. The incoming wave terminates into this structure and the outgoing wave emanates from it. The model is described by half Fourier–Laplace transforms respectively for the upstream and downstream sides of the junction. The cases below cutoff and above cutoff frequencies are studied. The theory completely reproduces the direct numerical simulation results of Davies & Carpenter (J. Fluid Mech., vol. 335, 1997, p. 361). Particularly, the jumps across the junction in the kinetic energy integral, the vorticity integral and other related quantities as obtained in the work of Davies & Carpenter are completely reproduced. Also, some important new concepts emerge, notable amongst which is the concept of the pseudo group velocity

Free convective combustion on vertical surfaces-variable property analysis and experiments

This paper treats the problem of free convective combustion of near vertical fuel surfaces in quiescent oxidant atmosphere, both theoretically and experimentally. The theory improves on existing theories in terms of taking into account variable thermodynamic and transport properties. The locally similar solutions obtained numerically are compared with earlier predictions as well as experiments on mass burn rate, flame stand off and other features. While comparison in the case of some fuels seems bettered by the use of variable properties, the not-too good a comparision in other cases is traced to experimental inaccuracies more particularly related to the non-achievement of steady combustion. To remedy this, an experimental apparatus was carefully designed and the results of these experiments show good comparison with theoretical predictions in all cases considered

Comparative Studies on Antimicrobial and Antifungal Efficacy from Bixa Orellana L., Lantana Camara L., Stachytarpheta Jamaicensis (l.)vahl., Hyptis Suaveolens (l.) Poit.with Triclosan

The aim of the present study was to assess the Antimicrobial and Antifungal activities of the Phenolic leaf extracts of Bixa orellana L., Lantana camara L and Stachytarpheta jamaicensis (L.) Vahl. Hyptis suaveolens (L.) Piot. and the Triclosan, a chlorinated aromatic compound with antibacterial and antifungal properties used in common house hold and personal care products and to compare household and personal care products and to compare their effectiveness against 4 bacterial strains - 2 Gram Positive strains – Staphylococcus aurens and Bacillus substitis and 2 Gram negative strains – Escherischia coli and Pseudomonas fluorescens and 3 Fungi- Aspergillus niger, Aspergillus flavus and Mucor Sp., by Agar well diffusion Assay. The phenolic extracts of all the 4 plants showed Maximum (80-100%), Relative inhibition against Pseudomonas fluorescence, Moderate inhibition (30-70%) against Staphylococcus aurens and Bacillus substilis and least inhibition (30-47%) against Escherischia coli, while, the Antifungal efficacy of all the 4 Phenolic plant extracts were observed to be effective at the concentration ranging from 70-300 µg. The plant phenolic extracts for Antimicrobial and Antifungal properties were compared with Standard Triclosan, a chlorinated compound. Our studies showed that the phenolic components of plant origin for antibacterial activity were equivalent to Triclosan with the same concentration, while for antifungal activity slightly higher concentrations could be a better alternative and hence there could be a substitution for Triclosan by Plant Phenolic Extracts used in house hold and personal care products, in future days to come