K-theoretic invariants for Floer homology

This paper defines two K-theoretic invariants, Wh ₁ and Wh ₂, for individual and one-parameter families of Floer chain complexes. The chain complexes are generated by intersection points of two Lagrangian submanifolds of a symplectic manifold, and the boundary maps are determined by holomorphic curves connecting pairs of intersection points. The paper proves that Wh ₁ and Wh ₂ do not depend on the choice of almost complex structures and are invariant under Hamiltonian deformations. The proof of this invariance uses properties of holomorphic curves, parametric gluing theorems, and a stabilization process. Submitted: April 2001, Revised: December 2001, Final version: February 2002.     

On the role of scattering by surface roughness in silicon inversion layers

Experimental results are presented, which strongly suggest that scattering of carriers by surface roughness may be important in the silicon inversion layer of metal-oxide-semiconductor structures. Low temperature data for p-type channels on identical orientation at high surface field show that mobility results in this region are dependent only on the mode of sample preparation and are independent of surface charges. The most reasonable explanation for these observations is offered by a scattering mechanism which is closely associated with the surface condition of the SiSiO₂ interface, namely, scattering by surface roughness. This scattering is a direct result of the fluctuating potential caused by the imperfect interface which is only a small distance from the inversion carriers. A calculation of the effect of surface roughness on surface carrier mobility is also given and found to be in satisfactory agreement with the experimental results. The application of the theory to the observed results permits an estimate to be made of the physical dimensions of the surface roughness of the Si-SiO₂ interface.     

Determination of amines, amine metabolites and some amine metabolizing enzymes by high performance liquid chromatography

Some useful high performance liquid chromatographic methods for the determination of amines, amine metabolites and amine metabolizing enzymes are described. These include the separation of tyramine in wines and beers, determination of tryptamine in urine, assay of monoamine oxidase and catechol-O-methyltransferase and analysis of amine-aldehyde condensation products.     

High-contrast, fast-switching liquid-crystal-on-silicon microdisplay with a frame buffer pixel array

A 64 x 32 liquid-crystal-on-silicon (LCOS) microdisplay with a frame buffer pixel architecture is described. The advantage of frame buffer pixel circuits is an increase in brightness and image contrast ratio. The increase in brightness is attributed to maximizing the overall image viewing time, allowing an image to be displayed at full contrast while the next image is loaded onto the pixels. The LCOS microdisplay employs a fast-switching optically compensated birefringence mode that operates at a 720-Hz frame frequency with a potentially high contrast ratio.     

Analysis of hydroxide, inorganic sulphur species and organic anions in kraft pulping liquors by capillary electrophoresis

A new method has been developed for the determination of hydroxide, sulphide, thiosulphate, sulphate, sulphite, chloride, oxalate and formate in kraft green, white and black liquors by capillary electrophoresis. The method provides baseline resolution of all analytes of interest using an electrolyte composed of 10 mM sodium chromate and 2 mM tetradecyltrimethylammonium hydroxide. Separations are conducted under constant current conditions at 25 degrees C and analytes are quantified by indirect UV-detection at 275 nm. A brief, post run wash of the capillary with 0.5 M NaOH and water gave improved inter- and intra-run repeatability of both migration times and peak areas. Sulphide and other oxysulphur species were relatively stable in white and green liquors diluted in helium-sparged water. However, sulphide present in black liquor samples diluted in the same solvent underwent rapid oxidation to form sulphite and thiosulphate. thereby precluding the measurement of all three anions. We discovered that quinone-type compounds present in black liquor catalyze the oxidation of sulphide and that the addition of reduced glutathione at a concentration of I mg/mL during black liquor dilution completely stabilized sulphide, sulphite and thiosulphate for at least one hour, thus allowing for quantitative analysis of the analytes. A mechanism is proposed to explain the action of both quinones and that of glutathione. Results obtained by the new method compared well with those obtained by ion chromatography, titrimetry, and from spike-recovery experiments.     

Experiments on random packings of ellipsoids

Recent simulations indicate that ellipsoids can pack randomly more densely than spheres and, remarkably, for axes ratios near 1.25:1:0.8 can approach the densest crystal packing (fcc) of spheres, with a packing fraction of 74%. We demonstrate that such dense packings are realizable. We introduce a novel way of determining packing density for a finite sample that minimizes surface effects. We have fabricated ellipsoids and show that, in a sphere, the radial packing fraction phi(r) can be obtained from V(h), the volume of added fluid to fill the sphere to height h. We also obtain phi(r) from a magnetic resonance imaging scan. The measurements of the overall density phi(avr), phi(r) and the core density phi(0) = 0.74 +/- 0.005 agree with simulations.     

Low p T phenomena in A+A and p+A collisions at mid-rapidity

CERN experiment NA44 measures pion and kaon distributions at p _T = 0–320 MeV/c at midrapidity in p+A and A+A collisions at 450 and 200A GeV/c, respectively. Pion production from p+Pb and A+A is slightly enhanced at low p _T relative to p+Be, but less than observed at target rapidity. The low p _T behavior can be understood in the context of the RQMD model as arising from baryonic resonance decays.     

5-Formyl salicylaldehyde as a linker for the synthesis of benzofuran containing insulin sensitivity enhancer compounds

5-Formyl salicylaldehyde was prepared by treatment of 4-hydroxybenzaldehyde with HMTA in TFA. Reaction of this dialdehyde with -haloacetyl aryl compounds gave 2,5-disubstituted benzofurans, from which an Insulin Sensitivity Enhancer compound was prepared.     

Laterally deformable nanomechanical zeroth-order gratings: anomalous diffraction studied by rigorous coupled-wave analysis

We describe a novel optomechanical device that produces strong reflectance and polarization modulation of incident light. The structure is based on a suspended nanomechanical grating with lateral deformability, and rigorous coupled-wave analysis has been used to fully model the optical properties of the device. The grating consists of two interdigitated gratings that may be moved with respect to each other with an applied force. The structures proposed here are designed to be readily manufacturable with device processing developed for surface-micromachined microelectromechanical systems and with known microelectromechanical systems materials, such as silicon, silicon nitride, and amorphous diamond. As the spacing of the grating is changed, an anomalous diffraction effect is observed, a Wood's type anomaly in which there exists a resonance in propagating leaky modes within the grating, resulting in a dramatic change in the reflectance characteristics for slight changes in the grating. One of the unique features of this structure is that a reflected optical signal can be used to detect subangstrom in-plane motion of structures greater than 10 nm.