Many-particle density of states in a finite-dimensional vector space

We demonstrate that the statistical mechanics methods for obtaining the density of states, when applied to a finite dimensional vector space, leads to a Gaussian distribution in the lowest order. Successive approximations lead naturally to the Gram-Charlier series.     

Two wavelength simultaneous DSPI and DSP for 3D displacement field measurements

A novel optical system is proposed that implements digital speckle pattern interferometry (DSPI) and digital speckle photography (DSP) simultaneously using two wavelength illumination of an object for simultaneous measurement of all three components of the displacement vector field. A collimated red light illuminates both the object and a reference surface in a DSPI configuration which is sensitive to out-of-plane displacement field while a blue light illuminates the object in a DSP configuration which is sensitive to in-plane displacement fields. A color 3-CCD camera records the red and blue lights individually through its red and blue channels, respectively. Two reference images and one image in the deformed state of the object are required for quantitative measurement. Experimental results are presented to validate the system.     

Two-wavelength micro-interferometry for 3-D surface profiling

Three-dimensional non-contact optical techniques for rapid and accurate mapping of micro-machined surfaces are important for the optoelectronic industry. Interferometry is a well-established technique for 3-D surface profiling. The conventional interferometric surface profilers using a single wavelength offer excellent vertical resolution, but a serious limitation to their use is that they can only handle smooth profiles and step heights less than half a wavelength. In this paper we describe a two-wavelength micro-interferometric setup for 3-D surface profile characterization of smooth as well as rough micro-specimens. The method removes ambiguity associated with the single-wavelength data and also extends the phase measurement range compared to the conventional single-wavelength interferometry. Seven-phase step algorithm is used for quantitative fringe analysis. The design of the system along with experimental results on smooth and rough micro-specimens is presented.     

Syntheses of Tri- and Tetrahydroxylated 1-Amino-Heptanes

Syntheses of tri- and tetrahydroxylated 1-amino-heptanes from α-D-glucose are described.     

DESORPTION OF LYSINE MODIFIED AND UNMODIFIED PROTEINS FROM SOLID SURFACES - ELUTION OF β -LACTOGLOBULIN ADSORBED ON ALUMINA AND SILICA

The strength of attachment of adsorbed bovine β-lactoglobulin (βlg) and acetylated β-lactoglobulin (Ac-βlg) has been studied by comparing the elution profiles of the adsorbed proteins. βlg binds very loosely to alumina at pH 4.2 and both βlg and Ac-βlg bind very tightly to alumina at pH 5.1 where the proteins showed highest adsorption at alumina/ water interface [ Bhaduri, A & Das, K. P., J. Disp. Sci. Technol., 15, 165-188 (1994)]. Adsorbed protein can only be eluted out if the pH of the elution buffer is raised to 7.6. βlg elutes as a single peak whereas Ac-βlg as two peaks indicating the later is adsorbed to alumina with different affinities. Elution profile of adsorbed βlg at pH 6.3 shows that adsorbed βlg population consists of partly folded elutable fraction and partly unfolded resistant one. The interaction of first layer of protein with the silica surface at pH 5.1 is primarily hydrophobic for βlg and electrostatic for Ac-βlg.     

Diarylimidoylcyanides,an Attractive Class of Intermediate: Novel Synthesis of α‐Anilino‐β‐Nitroenamines,N, N′‐ Disubstituted Amidines and Substituted Phenyl Glyoxate

The first report of the use of diarylimidoyl cyanides for the synthesis of α‐anilino‐β‐nitrostyrenes, benzamides, and glyoxalic esters is presented, and the advantage of this class of intermediate over diarylimidoyl chlorides is discussed.     

Cinnamoyl shikonin

The title compound, 1-(5,8-di­hydro-1,4-di­hydroxy-5,8-dioxo-2-naphthyl)-4-methyl­pent-3-en-1-yl cinnamate, C₂₅H₂₂O₆, crystallizes in space group P2₁. The phenyl ring of the cinnamate is anti to the carbonyl group of the same moiety [C—C—C—C = −175.6 (2)°] and is nearly parallel to the naphthyl ring system. Two six-membered rings formed by intramolecular hydrogen bonds, with O—H⃛O distances of 2.587 (2) and 2.589 (2) Å, occur on either side of the fused ring system, creating a tetracyclic pyrene-shaped system. The phenyl ring forms an intermolecular stack with the benzo­quinone ring, as a result of aromatic π–π interactions.     

Supersymmetric quantum mechanics for two-dimensional disk

The infinite square well potential in one dimension has a smooth supersymmetric partner potential which is shape invariant. In this paper, we study the generalization of this to two dimensions by constructing the supersymmetric partner of the disk billiard. We find that the property of shape invariance is lost in this case. Nevertheless, the WKB results are significantly improved when SWKB calculations are performed with the square of the superpotential. We also study the effect of inserting a singular flux line through the center of the disk.     

Reduction of nitrite to NO in an organised triphasic medium by platinum carbonyl clusters and redox active dyes as electron carriers

Artificial electron donors such as leuco methylene blue and leuco safranin O reduce nitrite ion to nitric oxide. The reaction is effected in a U-tube where nitrite ion and dye in two aqueous layers are separated by a layer of dichloromethane (a close model for a biological liquid membrane) that contains the platinum carbonyl cluster ([Bu(4)N]2[Pt12(CO)24], Chini cluster). On passing dihydrogen an electron transfer chain involving dihydrogen, the dye, the clusters and the nitrite ion is initiated. The cluster catalytically reduces the dye in the presence of dihydrogen, the reduced dye migrates across the phase boundaries and in turn reduces the nitrite ions. The resultant nitric oxide in the effluent gas has been identified by its reactions with cobalamine and myoglobin. When safranin O is the dye, an adduct is formed between the reduced dye and NO. It has been identified by spectroscopic techniques and its probable structure investigated by DFT calculations.