Tunable infrared generation in KTA and applications

Noncollinear difference frequency mixing of dye laser and Nd:YAG second harmonic (fundamental) radiation from a commercial laser system is employed for the generation of 2.7–5.3 μm (1.6–1.7 μm) radiations in a flux-grown KTiOAsO₁ crystal. The generated radiation is used to scan the methane absorption in the fundamental (v ₃) and its first overtone (2v ₃) band at pressure 90 torr in a laboratory made single pass gas cell of length 33 cm.     

Microelectronic array devices and techniques for electric field enhanced DNA hybridization in low-conductance buffers

A variety of electronic DNA array devices and techniques have been developed that allow electric field enhanced hybridization to be carried out under special low-conductance conditions. These devices include both planar microelectronic DNA array/chip devices as well as electronic microtiter plate-like devices. Such "active" electronic devices are able to provide controlled electric (electrophoretic) fields that serve as a driving force to move and concentrate nucleic acid molecules (DNA/RNA) to selected microlocation test-sites on the device. In addition to ionic strength, pH, temperature and other agents, the electric field provides another controllable parameter that can affect and enhance DNA hybridization. With regard to the planar microelectronic array devices, special low-conductance buffers were developed in order to maintain rapid transport of DNA molecules and to facilitate hybridization within the constrained low current and voltage ranges for this type of device. With regard to electronic microtiter plate type devices (which do not have the low current/voltage constraints), the use of mixed buffers (low conductance upper chamber/high conductance lower chamber) can be used in a unique fashion to create favorable hybridization conditions in a microzone within the test site location. Both types of devices allow DNA molecules to be rapidly and selectively hybridized at the array test sites under conditions where the DNA in the bulk solution can remain substantially denatured.     

Working group report: Heavy-ion physics and quark-gluon plasma

This is the report of Heavy Ion Physics and Quark-Gluon Plasma at WHEPP-09 which was part of Working Group-4. Discussion and work on some aspects of quark-gluon plasma believed to have created in heavy-ion collisions and in early Universe are reported.     

Vacuum moulding of a superplastic in two dimensions

A mathematical model is proposed for the process of vacuum superplasticforming. The model exploits the fact that in most industrialapplications the sheet aspect ratio (thickness/sheet width)is small. After an initial consideration of some of the moregeneral properties and the literature of superplastic materials,the elastic/plastic deformation of an internally-inflated thin-walledcylinder is examined. Plates of arbitrary geometry are thenconsidered. A quasisteady model in which the sheet moves througha sequence of steady states is developed. Some simplified closed-formsolutions are examined, but for general cases a system of nonlinearpartial differential equations must be solved numerically. Anefficient and accurate semi-explicit numerical scheme is proposedand a simplified stability analysis is presented; the methodis then used to compute properties of superplastic vacuum mouldedsheets in a number of practically motivated cases.     

Modulated optical lattice as an atomic fabry-perot interferometer

We propose to engineer the atomic band structure in optical lattices in order to design a Fabry-Perot interferometer with large mode spacing and strong nonlinear coupling to be employed in atom optics. The use of an optical lattice allows for a significant reduction of the atomic effective mass, while the slow modulation of its parameters spatially confines the matter waves on a length scale of a few dozen optical wavelengths. As a consequence, the mode spacing in such a cavity would be as high as one-tenth of the recoil energy, allowing for a very efficient filter action, while the nonlinear coupling due to interatomic interactions could lead to bistability and limiting effects in the transmission of the atomic beam.