Nonequilibrium Phase Transition in a Model of Diffusion, Aggregation and Fragmentation

We study the nonequilibrium phase transition in a model of aggregation of masses allowing for diffusion, aggregation on contact and fragmentation. The model undergoes a dynamical phase transition in all dimensions. The steady state mass distribution decays exponentially for large mass in one phase. On the contrary, in the other phase it has a power law tail and in addition an infinite aggregate. The model is solved exactly within a mean field approximation which keeps track of the distribution of masses. In one dimension, by mapping to an equivalent lattice gas model, exact steady states are obtained in two extreme limits of the parameter space. Critical exponents and the phase diagram are obtained numerically in one dimension. We also study the time dependent fluctuations in an equivalent interface model in (1+1) dimension and compute the roughness exponent $\chi$ and the dynamical exponent z analytically in some limits and numerically otherwise. Two new fixed points of interface fluctuations in (1+1) dimension are identified. We also generalize our model to include arbitrary fragmentation kernels and solve the steady states exactly for some special choices of these kernels via mappings to other solvable models of statistical mechanics.Comment: revtex file with 7 figure

Synthesis of ruthenium(II) carbonyl complexes with 2-monosubstituted and 1,2-disubstituted benzimidazoles

The reaction of the polymeric carbonyl complex RuCl 2(CO) 2 x with 2-monosubstituted and 1,2-disubstituted benzimidazoles and 1,4-bis(benzimi-dazol-2-yl)benzene (L 9) in 2-methoxyethanol produces various coloured complexes of the formulae Ru(CO) 2Cl 2(L) 2·xH 2O (L = 1-(o-hydroxybenzyl)-2- -(o-hydroxyphenyl)benzimidazole (L 1), 1-(o-hydroxyphenyl)benzimidazole (L 4), 1-(p-hydroxyphenyl)benzimidazole (L 5), 1-(p-chlorobenzyl)-2-p-chloro-phenyl)benzimidazole (L 7), 1-1-(dimethylamino)benzyl-2-1-(dimethyl- amino)phenylbenzimidazole (L 10), x = 0; L = 2-benzylbenzimidazole (L 8), 1,4-bis(benzimidazol-2-yl)benzene (L 9), x = 2; L = 1-(o-chlorobenzyl)-1-(o- -chlorophenyl)benzimidazole (L 6); x = 3), Ru(CO) 2Cl(L 2) 3Cl·3H 2O and Ru(CO) 2(L 3) 4Cl 2·3H 2O (L 2 = 1-(m-hydroxybenzyl)-2-(m-hydroxyphenyl)- benzimidazole; L 3 = 1-(p-hydroxybenzyl)-2-(p-hydroxyphenyl)benzimidazole). The complexes were characterized by elemental analysis, conductivity measurements, as well as infrared, electronic, 1H- and 13C-NMR spectral studies. © 2009 Copyright (CC) SCS

A critical study on Urdhwashakhagata Vaikalyakara Marma

Marma is considered as the vital point present in the human body which has life in it and the injury to these spots leads to death or death like miseries. In our classics, 107 Marmas are explained. They are grouped separately on the basis of structural classification, based on injury consequences, based on the Pramana, & based on the location in the body. Total 44 Vaikalyakara Marmas are present in our body among which 6 are present in each Urdhwashakha namely Kakshadhara, Lohitaksha, Urvi, Aani, Koorpara and Kurcha. The location, anatomical structures in specific region and effect on injury to each Marma differs from one another

Dynamics and transport properties of Kondo insulators

A many-body theory of paramagnetic Kondo insulators is described, focusing specifically on single-particle dynamics, scattering rates, d.c. transport and optical conductivities. This is achieved by development of a non-perturbative local moment approach to the symmetric periodic Anderson model within the framework of dynamical mean-field theory. Our natural focus is the strong coupling, Kondo lattice regime; in particular the resultant `universal' scaling behaviour in terms of the single, exponentially small low-energy scale characteristic of the problem. Dynamics/transport on all relevant ($\omega, T$) scales are considered, from the gapped/activated behaviour characteristic of the low-temperature insulator through to explicit connection to single-impurity physics at high $\omega$ and/or $T$; and for optical conductivities emphasis is given to the nature of the optical gap, the temperature scale responsible for its destruction, and the consequent clear distinction between indirect and direct gap scales. Using scaling, explicit comparison is also made to experimental results for d.c. transport and optical conductivites of Ce_3Bi_4Pt_3, SmB_6 and YbB_{12}. Good agreement is found, even quantitatively; and a mutually consistent picture of transport and optics results.Comment: 49 pages, 23 figure

Large nonlinear absorption and refraction coefficients of carbon nanotubes estimated from femtosecond Z-scan measurements

Nonlinear transmission of 80 and 140 femtosecond pulsed light with $0.79 \mu m$ wavelength through single walled carbon nanotubes suspended in water containing sodium dodecyl sulphate is studied. Pulse-width independent saturation absorption and negative cubic nonlinearity are observed, respectively, in open and closed aperture Z-scan experiments. The theoretical expressions derived to analyze the z-dependent transmission in the saturable limit require two photon absorption coefficient $\beta_0\sim$ $1.4 cm/MW$ and a nonlinear index $\gamma \sim -5.5 \times10^{-11} cm^2/W$ to fit the data.Comment: 10 pages, 2 figures. Accepted and to appear in Applied Physics Letter

Analysis of structural changes observed in the region of Kukundara Marma in patients suffering from Low back ache

Kukundara Marma is a Prushtagata Sandhi Marma. Injury to it leads to sensory and motor deficit in the lower limb. It is located in Jaghanabahirbhaga on both sides of Prashtavamsha indicates the low lumbar region. Joints in between the lower lumbar vertebras and lumbosacral joint are the structures present in the Kukundara Marma region. Lumbosacral trunk is related in this area which gives contribution to sacral plexus. Back pain is symptom where there will be involvement of muscle, ligaments, bones, joints, and nerves. The most common causes include Mechanical, Destructive, Inflammatory, other causes. With the help of Xray and MRI it was noted that out of 100 patients suffering from low back ache and sensory and motor deficit of lower limb 32 patients had Lumbar canal stenosis and 19 patients had Disc herniation

Correlation between Local Structure Distortions and Martensitic Transformation in Ni-Mn-In alloys

The local structural distortions arising as a consequence of increasing Mn content in Ni_2Mn_1+xIn_1-x (x=0, 0.3, 0.4, 0.5 and 0.6) and its effect on martensitic transformation have been studied using Extended X-ray Absorption Fine Structure (EXAFS) spectroscopy. Using the room temperature EXAFS at the Ni and Mn K-edges in the above compositions, the changes associated with respect to the local structure of these absorbing atoms are compared. It is seen that in the alloys exhibiting martensitic transformation ($x \ge 0.4$) there is a significant difference between the Ni-In and Ni-Mn bond lengths even in the austenitic phase indicating atomic volume to be the main factor in inducing martensitic transformation in Ni-Mn-In Heusler alloys.Comment: 8 pages, 2 figure

ISRO Polyol - The Versatile Binder for Composite Solid Propellants for Launch Vehicles and Missiles

A family of propellants based on a low cost hydroxy terminated binder has been developed and proved in large size motors. It can meet the requirements of Apogee motors as well as large boosters. The system offers advantages comparable with HTPB propellants in terms of high ballistic performance, stringent mechanical properties, ease and reliability of cure even at ambient conditions and high storage stability. The near-Newtonian flow behaviour, simplicity and processing characteristics of this saturated binder propellant are particularly note-worthy