The Solution of Travelling Salesman Problems Based on Industrial Data

This paper partially replicates a comparison of travelling salesman heuristics carried out by Golden et al. more than a decade ago. It differs in two important ways, however. (1) We consider two heuristics—k-OPT and the space filling curve technique—which were developed after the original comparison. These new techniques appear to add little to the quality of solutions to the test problems utilized here. (2) Instead of test problems using geographical data, ours are based on programs for parts produced by a numerically controlled machine. Because of the different characteristics of these test problems we reach somewhat different conclusions concerning the efficacy of the different procedures.     

Discussion on a possible neutrino detector located in India

We have identified some important and worthwhile physics opportunities with a possible neutrino detector located in India. Particular emphasis is placed on the geographical advantage with a stress on the complimentary aspects with respect to other neutrino detectors already in operation.     

On Solutions of Quantum Eigenvalue Problems: A Supersymmetric Approach

We study solutions of various quantum mechanical eigenvalue problems using the formalism of one dimensional supersymmetric quantum mechanics. The problems studied includes among other problems the non-polynomial oscillator and the doubly anharmonic oscillator potentials. The solutions obtained here are of two types — exact analytical solutions and approximate solutions. The method of obtaining exact solutions have been shown to be general enough to be applied to a large class of potentials. The method of obtaining approximate solutions have been studied in details and their accuracy have been compared with exact numerical results.     

Thermal characterization of a nanofluid comprising nanocrystalline ZrO2 dispersed in water and ethylene glycol

Nanofluids, comprising Y₂O₃-stabilized (partially; 3?mol%) ZrO₂ nanoparticles (up to 2?vol%) dispersed in water and ethylene glycol, were developed. A suitable surfactant and stirring routine ensured uniformity and stability of dispersion. Thermal conductivity ratio of the nanofluids, measured using an indigenously developed thermal comparator device, showed a significant increase of up to 100% with only 1.5?vol% nanoparticles. Furthermore, it was analytically shown that shape factor and aspect ratio significantly influence the effective thermal conductivity ratio of nanofluids with comparable vol% nanoparticles. The study demonstrated that a nanofluid of nano-ZrO₂ dispersed in water and ethylene glycol could be usefully applied in closed-loop single-phase heat transfer conditions, such as in refrigerators or microchannels.     

Analysis of pair interaction in a bipolar mesogen 4‐(4‐hydroxylbutyloxy)‐4′‐cyano‐biphenyl: A comparative study based on semiempirical and DFT methods

Structure of 4‐(4‐hydroxylbutyloxy)‐4′‐cyano‐biphenyl (H4CBP) molecule has been optimized using density functional B3LYP with 6‐31G (d) basis set taking crystallographic geometry as input. Using the optimized geometry, electronic structure of the H4CBP molecule has been evaluated on the basis of semiempirical methods and DFT calculations. Intermolecular interaction energy between a pair of H4CBP molecules has been evaluated by using Rayleigh–Schrodinger perturbation theory modified with multicentered multipole expansion method for the electrostatic part while dispersion and repulsion terms have been calculated using Kitaigorodskii formula. The results obtained through semiempirical and DFT calculations have been compared for various interacting conditions, viz.: (a) stacking, (b) in‐plane, and (c) terminal interactions. A comparative analysis of the results has been carried out with a view to examine suitability of different methods to study molecular aggregations in moderately large organic systems. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2011     

Exact bound states for the potentialV(r)=r 2+βr −4+λr −6 using partial algebraization technique

For the potential considered new sets of ground state and first few excited states are obtained. Also the defect of the wave function suggested by Kaushal and Parashar [Phys. Lett. A170 (1992) 335] and Gaurdiala and Ros [J. Phys. A25 (1992) 1351] has been shown.     

Fluctuation and fractality study of target residue in S32- AgBr interaction at 200 A GeV

In this paper we analysed scaled factorial moment in different phase-space intervals to study the dynamical fluctuation of target evaporated particles in ³²S-AgBr interactions at 200 A GeV. In order to gather knowledge about the detailed characteristics of intermittency behaviour, the SFMs are calculated upto 6th order. The analysis indicates the occurence of a nonthermal phase transition and different aspects of particle production. The multifractility among target evaporated particles is also indicated by the data when analysed using the new method proposed by Takagi.     

Spectral index of primary cosmic rays. A QCD-admissible derivation

Summary Considering p-p collisions in terms of Drell-Yan and other related processes, where the interaction at the quark level is represented by a dimensionaless interaction potential, we derive an analytical formula for predicting the spectral index of primary cosmic rays. Adjusting a single free parameter of this formula, we find excellent agreement with experimental data over a wide energy range.

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Riassunto Considerando le collisioni p-p in termini del processo di Drell-Yan e di altri processi ad esse collegati, in cui l'interazione al livello dei quark è rappresentata da un potenziale d'interazione senza dimensioni, si deduce una formula analitica per prevedere l'indice spettrale dei raggi cosmici primari. Adattando un parametro libero singolo di questa formula si trova un eccellente accordo con i dati sperimentali su un ampio intervallo d'energia.

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Резюме Рассматривая p-p соударения в терминах процессов Дрелла-Яна и других связанных процессов, где взаимодействие на кварковом уровне представляется с помощью потенциала безразмерного взаимодействия, мы выводим аналитическое выражение для определения спектрального показателя первичных космических лучей. Подгоняя единственный свободный параметр в этой формуле, мы получаем хорошее согласие с экспериментальными данными в широкой области енергий.