A new phase-conjugate one-way scheme for phase-distortion correction

In this paper we describe a phase-conjugate scheme in which the pump waves are derived from a distorted optical beam by a spatial filtering technique. Experimental demonstration of this scheme is given for phase-distortion correction. To avoid the problem of back reflection a quasi-real-time reconstruction scheme is adopted. The read out is done with a direct beam from the laser.     

Birkhoff theorem in self-creation cosmology

An analogue of Birkhoff's theorem of general relativity holds for electromagnetic fields in the self-creation cosmology proposed by Barber when the scalar field is independent of time.     

Elastic behaviour of lead fluoride under pressure

The variation of the second-order elastic constants (SOECs) and the longitudinal and shear modulii with hydrostatic pressure for the lead fluoride (PbF₂) has been investigated for the first time by means of a three-body force potential (TBP) model. The significance of three-body interactions (TBI) has been clearly demonstrated in reproducing the elastic constant variations and the pressure derivatives of SOECs of PbF₂. The equation of state for this crystal has also been reported.     

Resonant structures in24Mg+28Si elastic and inelastic scattering

The data on the excitation functions of²⁴Mg+²⁸Si elastic and inelastic (2⁺ ?0⁺, 2⁺ ?2⁺, 4⁺ ?0⁺ and 4⁺ ?2⁺) scattering fromE _c.m.=48.97 to 57.21 MeV have been subjected to a statistical analysis consisting of the calculations of deviation function, cross-correlation function, summed excitation function, cross-channel correlation coefficients, coherence widths, and the distribution of cross sections. Based on the outcome of the analysis resonant structures atE _c.m.=49.23, 50.02, 50.51, 52.10, 52.53, 53.27 and 54.14 MeV have been confirmed and three new structures of the same nature have been identified atE _c.m.=51.42, 54.88 and 55.60 MeV.     

Perturbation expansions for quantum many-body systems

A systematic method for developing high-order, zero-temperature perturbation expansions for quantum many-body systems is presented. The models discussed explicitly are spin models with a variety of interactions, in one and two dimensions. The wide applicability of the method is illustrated by expansions around Hamiltonians with ordered and disordered ground states, namely Ising and dimerized models. Computer implementation of this method is discussed in great detail. Some previously unpublished series are tabulated.     

Zinc silicate-bonded diethyldithiocarbamate — a selective adsorbent for separating transition metal ions and preconcentration of palladium(II)

Summary A new chelating adsorbent, zinc silicate-bonded diethyldithiocarbamate (DTC) has been prepared for the separation and preconcentration of some transition metal ions. The distribution coefficients (Kd values) of 15 metal ions have been estimated in solution at various pH's and some quantitative separations have been achieved. The high selectivity for Pd(II) has been utilized for its preconcentration from dilute aqueous solutions; quantitative elution is effected with acidic 4% thiourea solution.     

A New PVC-Membrane Electrode Based on a Macrocyclic Ionophore for Selective Determination of Ni (II) Ions

A poly(vinyl chloride)-based membrane of 3,4:12,13-dibenzo-1,6,10,15-tetraazacyclooctadecane with sodium tetraphenyl borate (NaTPB) as an anion excluder and dibutylphthalate (DBP), dibutylbutylphosphonate (DBBP), tris(2-ethylhexyl) phosphate (TEHP) and tributyl phosphate (TBP) as plasticizing solvent mediator was prepared and investigated as a Ni(II)-selective electrode. The best performance was observed with the membrane having the ligand-PVC-TEHP-NaTPB composition 1:4:1:1, which worked well over a wide concentration range (2.82 ×10⁻⁶−1.00 × 10⁻¹ M) with a Nernstian slope of 30.5 mV per decade of activity between pH 2.5–7.5. This electrode showed a fast response time of 18 s and was used over a period of 4 months with good reproducibility (S=0.4 mV). The selectivity coefficient over mono-, di- and trivalent cations indicate excellent selectivity for Ni (II) ions over a large number of cations. Anions such as Cl⁻ and NO₃⁻ do not interfere and the electrode also works satisfactorily in a partially non-aqueous medium. It has been used successfully for determination of Ni (II) in real samples.     

NUMERICAL STUDY OF THE TWO-DIMENSIONAL SPRUCE BUDWORM REACTION-DIFFUSION EQUATION WITH DENSITY DEPENDENT DIFFUSION

The spruce budworm model is one of the interesting single species reaction-diffusion problems describing insect dispersal behavior. In this paper, we investigate a two-dimensional model with linear diffusion dependence and a convective wind. This system has been successfully solved using an operator splitting method for various domains and initial conditions. The numerical results show that populations can grow and diffuse in such a way as to produce steady state outbreak populations or steady state inhomogeneous spatial patterns in which they aggregate with low population densities.     

Synthesis of 7-hydroxythioridazine and 7-hydroxysulforidazine

The thioridazine metabolites 7-hydroxythioridazine (2a) and 7-hydroxysulforidazine (2b) were synthesized. Commercial 4-chloro-3-nitrophenylmethylsulfone was converted to the corresponding 4-thiol through an intermediate xanthate ester. Subsequent zinc metal reduction provided the 3-amino thiolate. This salt was condensed with chloroquinone to yield 7-hydroxy-2-methylsulfonylphenothiazine which was then protected as the isopropyl ether. N-Alkylation with 2-(2-chloroethyl)-1-methylpiperidine using sodium hydroxide, then ether cleavage, afforded 2b . The N-alkylation followed by reduction with diisobutylaluminum hydride and deblocking yielded 2a . These reference standards will assist in an exploration of the potential role of meta-bolically formed 2a and 2b in the neuroleptic response to thioridazine.