A scaling theory of quantum breakdown in solids

We propose a new scaling theory for general quantum breakdown phenomena. We show, taking Landau-Zener type breakdown as a particular example, that the breakdown phenomena can be viewed as a quantum phase transition for which the scaling theory is developed. The application of this new scaling theory to Zener type breakdown in Anderson insulators, and quantum quenching has been discussed.Comment: 3 page

DABCO- and DBU-promoted one-pot reaction of N-sulfonyl ketimines with Morita–Baylis–Hillman carbonates: a sequential approach to (2-hydroxyaryl)nicotinate derivatives

An intriguing DABCO-catalyzed and DBU-promoted one-pot synthesis of an important class of (2-hydroxyaryl)pyridine derivatives bearing a carboxylate or a nitrile group suitably placed at C3 position of the aza-ring has been achieved in acceptable chemical yields with a broad functional group tolerance. This sequential C–C/C–N bond making process proceeds through a regioselective allylic alkylation/aza-Michael reaction between MBH carbonates derived from an acrylate/acrylonitrile and N-sulfonyl ketimines as C,N-binucleophiles catalyzed by DABCO, followed by elimination of SO2 under the influence of base and subsequent aromatization in an open atmosphere

Semisolid Processing of A380 Al Alloy Using Cooling Slope

This study is aimed toward obtaining near spherical microstructural features of Rheocast A380 aluminum alloy. Cooling slope (CS) technique has been used to generate semisolid slurry from the superheated alloy melt. Spherodization of primary grains is the heart of semisolid processing which improves mechanical properties significantly in the parts cast from semisolid state compared to the conventional casting processes. Keeping in view of the desired microstructural morphology, i.e., rosette or spherical shape of primary a-Al phase, successive slurry samples have been collected during melt flow and oil quenched to investigate the microstructure evolution mechanism. Conventionally cast A380 Al alloy sample shows dendritic grains surrounded by large eutectic phase whereas finer, near spherical grains have been observed within the cooling slope processed slurry and also in the solidified castings which confirms the effectiveness of semisolid processing of the alloy following cooling slope technique. Grain refiner addition into the alloy melt is found to have favorable effect which leads to the generation of finer primary grains within the slurry with higher degree of sphericity

Asymptomatic papules over central and pericentral areas of the face

We report the case of a 24-year-old college girl, presenting with numerous acneiform papular eruptions over the central part of the face

Fractal models of earthquake dynamics

Our understanding of earthquakes is based on the theory of plate tectonics. Earthquake dynamics is the study of the interactions of plates (solid disjoint parts of the lithosphere) which produce seismic activity. Over the last about fifty years many models have come up which try to simulate seismic activity by mimicking plate plate interactions. The validity of a given model is subject to the compliance of the synthetic seismic activity it produces to the well known empirical laws which describe the statistical features of observed seismic activity. Here we present a review of two such models of earthquake dynamics with main focus on a relatively new model namely The Two Fractal Overlap Model

Metal- and Solvent-Free Approach to Diversely Substituted Picolinates via Domino Reaction of Cyclic Sulfamidate Imines with β,γ-Unsaturated α‑Ketocarbonyls

An efficient, solvent-free, and eco-friendly domino reaction of 5/6-membered cyclic sulfamidate imines with a variety of β,γ-unsaturated α-ketocarbonyls in neat conditions under MW irradiation promoted by DABCO as a solid organobase has been developed for the rapid construction of a novel class of densely functionalized picolinates. This interesting metal–solvent-free tactic allows a wide range of useful functionalities on the aryl rings and delivers good to excellent yields of the aforesaid aza-heterocycles within short time spans (20–40 min). A biologically promising imidazo­[1,2-<i>a</i>]­pyridine was successfully synthesized through our unique procedure