Limiting fragmentation in high-energy heavy-ion reactions and preequilibrium

The space-time evolution towards equilibrium of heavy-ion fragments in high-energy reactions investigated. An initial excitation which is generated during the collision process in a small region on the surface of the fragment leads to a characteristic angular and energy spectrum of light emitted particles which is characterized by an “up-down” asymmetry.     

Can cosmic strangelets reach the earth?

The mechanism for the propagation of strangelets with low baryon number through the atmosphere of the Earth has been explored. It has been shown that, under suitable initial conditions, such strangelets may indeed reach depths near mountain altitudes with mass numbers and charges close to the observed values in cosmic ray experiments.     

Two-stage network DEA: when intermediate measures can be treated as outputs from the second stage

This paper investigates efficiency measurement in a two-stage data envelopment analysis (DEA) setting. Since 1978, DEA literature has witnessed the expansion of the original concept to encompass a wide range of theoretical and applied research areas. One such area is network DEA, and in particular two-stage DEA. In the conventional closed serial system, the only role played by the outputs from Stage 1 is to behave as inputs to Stage 2. The current paper examines a variation of that system. In particular, we consider settings where the set of final outputs comprises not only those that result from Stage 2, but can include, in addition, certain outputs from the previous (first) stage. The difficulty that this situation creates is that such outputs are attempting to play both an input and output role in the same stage. We develop a DEA-based methodology that is designed to handle what we term ‘time-staged outputs’. We then examine an application of this concept where the DMUs are schools of business.     

Making and Breaking of C−N Bonds: Applications in the Synthesis of Unsymmetric Tertiary Amines and α-Amino Carbonyl Derivatives

An operationally simple process has been developed for the synthesis of unsymmetrical amines and α-amino carbonyl derivatives in the absence of a catalyst, ligand, oxidant, or any additives. Contrary to known reductive amination methods, this protocol is amenable to substrates containing other reducible groups. This process effectively results in consecutive cleavage and formation of C−N bonds. DFT studies and Hammett analysis provide useful insight into the mechanism. The role of noncovalent interactions as a stabilizing factor have been examined in the protocol. A wide range of alkyl-bromides have been coupled efficiently with a variety of dimethyl anilines to get unsymmetric tertiary amines with yields up to 90%. This methodology was further extended to the synthesis of α-amino carbonyl derivatives with yields up to 93%.