Minimizing makespan in parallel flowshops

In this study, a new class of proportional parallel flow shop problems with the objective of minimizing the makespan has been addressed. A special case for this problem in which jobs are processed on only one machine as opposed to two or more machines in a flow shop, is the well-known multiple processor problem which is NP-complete. The parallel processor problem is a restricted version of the problems addressed in this paper and hence are NP-complete. We develop and test heuristic and simulation approaches to solve large scale problems, while using exact procedures for smaller problems. The performance of the heuristics relative to the LP lower bound as well as a comparison with the truncated integer programming solution are reported. The performance of the heuristics and the simulation results were encouraging.     

Elastic anomalies in strontium titanate

The anomalies of the second and third-order elastic constants have been considered for the phase transition of strontium titanate within the framework of Landau’s theory. All the anomalies of the second-order elastic constants have been obtained in a single formula using Kronecker delta functions and relations among them have been established. The real parts ofC*₁₁ andC*₄₄ decrease steeply across the transition temperature and thereafter flatly tend to their asymptotic values in the low temperature phase agreeing qualitatively with experimental observations. We have also derived expressions for the third-order elastic anomalies and discussed the temperature variation of the real part ofC*₁₁₁. We have derived expressions for the attenuation of the longitudinal and transverse waves along certain simple symmetry directions and have shown that there is nearly good agreement with experimental observations.     

Spin squeezing and quantum correlations

We discuss the notion of spin squeezing considering two mutually exclusive classes of spin-s states, namely, oriented and non-oriented states. Our analysis shows that the oriented states are not squeezed while non-oriented states exhibit squeezing. We also present a new scheme for construction of spin-s states using 2s spinors oriented along different axes. Taking the case of s=1, we show that the ‘non-oriented’ nature and hence squeezing arise from the intrinsic quantum correlations that exist among the spinors in the coupled state.     

Kinetics and mechanism of the addition of iodine monochloride to some alkenes in nitrobenzene solvent. Effect of polarity of the solvent

The kinetics of the addition of iodine monochloride (ICl) to some vinyl compounds in nitrobenzene solvent was investigated. In all cases the reaction follows second order dependence on ICl and first order on the substrate, making the total order three. Rate constants were measured for each substrate at 20°, 30°, 40° and 50°C.Arrhenius plots were made from which activation energies were evaluated. Other kinetic and thermodynamic parameters are reported. A suitable mechanism is proposed for the reaction and based on this, the various parameters are discussed. Solvent effects are discussed and the data with nitrobenzene and acetic acid solvents are compared.

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Kinetik und Mechanismus der Addition vonICl zu einigen Alkenen in Nitrobenzol als Lösungsmittel. Effekt der Polarität des Lösungsmittels

Zusammenfassung Die Kinetik der Addition von ICl zu einigen Vinylverbindungen in Nitrobenzol als Lösungsmittel wurde untersucht. In allen Fällen ist die Reaktion von zweiter Ordnung hinsichtlich ICl und von erster Ordnung hinsichtlich des Substrats, d. h. mit einer Gesamtordnung von drei. Geschwindigkeitskonstanten wurden für jedes Substrat bei 20°, 30°, 40° und 50°C gemessen. AusArrhenius-Diagrammen wurden Aktivierungsenergien ermittelt und auch andere kinetische und thermodynamische Parameter wurden bestimmt. Ein Mechanismus wird vorgeschlagen, wobei die verschiedenen Parameter diskutiert werden. Lösungsmitteleffekte werden ebenfalls diskutiert und die Daten mit Nitrobenzol und Essigsäure als Lösungsmittel miteinander verglichen.

     

Superconductivity of neutron irradiated Mo3Os

The effect of high energy neutron irradiation (E>1 MeV) on the superconducting transition temperature, T_c, of the A-15 compound Mo₃Os is reported. T_c was found to decrease with increasing neutron dose, but at a rate considerably less than observed in other A-15 compounds composed of non-transition metals. The results lend support to the idea that the effect of ordering on T_c is smaller for A-15 compounds composed only of transition metals than those composed of transition and non-transition metals.     

High performance liquid chromatographic analysis of six conjugated and unconjugated estrogens in serum.

Six estrogens-estrone, equilin, estradiol, sodium estrone sulphate, sodium equilin sulphate and sodium 17-alpha-dihydroequilin sulphate in dog serum were successfully separated and quantified by a high performance liquid chromatographic method developed in our laboratories. The mobile phase was optimized by studying the effects of an organic modifier (acetonitrile) and an ion pairing reagent (tetrabutylammonium hydroxide). The serum sample work-up procedure was designed to recover both conjugated and unconjugated estrogens. The optimum method involved acetonitrile to precipitate serum proteins/peptides and extract estrogens. Residues were reconstituted in 50% acetonitrile in water for injection. The detection limits for these six estrogens via UV detection ranged from 0.5 to 5 ng on-column with a signal-to-noise ratio (S/N) of 10 for a 20 microL injection and via fluorescence 0.1 ng on-column for 17-beta-estradiol. Validation data are included for all six estrogens.     

The 2880-Å emission spectrum of I2: Ion-pair states near 47 000 cm−1

An emission system of I₂ in Ar in the region 2830–2890 Å is examined under high resolution and found to display fine violet-degraded band structure. This system is interpreted as a charge-transfer transition originating from an ion-pair state near 47 000 cm^?1 and terminating on a weakly bound state which dissociates to two ground-state atoms. This interpretation is supported by spectral simulations employing a bound-free model. The transition is tentatively assigned as $\text{0}{}_{\mathrm{<mtext>g</mtext>}}{}^{\mathrm{?}}\text{→ 2431 0}{}_{\mathrm{<mtext>u</mtext>}}{}^{\mathrm{?}}\text{(}{}^3\text{Π}\text{)}$, according to which the excited state becomes the fourth ion-pair state near 47 000 cm^?1 to be experimentally characterized, and the lower state is the last component of the lowest ³Π state to be identified. The vibrational assignments include about 45 bands in ¹²⁷I₂ and ¹²⁹I₂, spanning v′ = 0–4 and v″ = 6–19, but with the numbering of the lower state remaining uncertain by several units. The main spectroscopic constants for the excited state are T_e = 47 070 cm^?1, ?_e = 105.7 cm^?1, ?_ex_e = 0.49 cm^?1. The spectral simulations place the lower state's potential curve 34 650 cm^?1 below the upper state at R = R′_e, with slope ?850 cm^?1/Å. For our “best” numbering of the lower state, ?_e = 20.5 cm^?1, ?_ex_e = 0.29 cm^?1, T_e = 12 190 cm^?1, and D_e = 360 cm^?1.     

Magnetic monopoles in SU(3) and SU(2) gauge theories without Higgs' scalars

We show that certain known singular solutions for pure SU(3) Yang-Mills theory carry magnetic charges with respect to both U(1) subgroups of SU(3). A topological characterisation in terms of monopoles is given to the SU(2) singular solutions of Wu and Yang.