Superconductivity and Magnetism in REFeAsO1-xFx (RE=Rare Earth Elements)

Fluoride-doped iron-based oxypnictides containing rare-earth gadolinium (GdFeAsO0.8F0.2) and co-doping with yttrium (Gd0.8Y0.2FeAsO0.8F0.2) have been prepared via conventional solid state reaction at ambient pressure. The non-yttrium substituted oxypnictide show superconducting transition as high as 43.9 K from temperature dependent resistance measurements with the Meissner effect observed at a lower temperature of 40.8 K from temperature dependent magnetization measurements. By replacing a small amount of gadolinium with yttrium Tc was observed to be lowered by 10 K which might be caused by a change in the electronic or magnetic structures since the crystal structure was not altered.Comment: 4 pages, 4 figures, Journal of Physics: Conference Series (Proceedings in the LT25 Low Temperature Physics Conference) Submitte

Parallel computations and control of adaptive structures

The equations of motion for structures with adaptive elements for vibration control are presented for parallel computations to be used as a software package for real-time control of flexible space structures. A brief introduction of the state-of-the-art parallel computational capability is also presented. Time marching strategies are developed for an effective use of massive parallel mapping, partitioning, and the necessary arithmetic operations. An example is offered for the simulation of control-structure interaction on a parallel computer and the impact of the approach presented for applications in other disciplines than aerospace industry is assessed

Effects of multi-stage dehumidified-air drying on the polyphenol content of Hydrocotyle bonariensis

Traditional drying methods involve high temperatures that degrade heat-sensitive compounds. Dehumidified-air drying, an alternative to traditional drying methods, is suitable for heat-sensitive compounds; however, it consumes a large amount of energy and is comparatively expensive. In this study, a multi-chamber dehumidified-air dryer was designed to dry Hydrocotyle bonariensis, and the retention of the polyphenol content of Hydrocotyle bonariensis under various drying conditions was examined. Multi-chamber dehumidified-air drying involves two chambers; each chamber was operated at temperatures of 30, 40, and 50°C with air volumetric flow rates of 30 and 50 L/min. The results indicated that the highest retention of total phenolic content and total flavonoid content, 24.67 mg of GAE/g dry weight (DW) and 2.204 mg of catechin/g DW, respectively, was obtained at 50°C with a 50 L/min air flow rate in the first drying chamber. Multi-stage dehumidified-air dryers have the potential to dry heat-sensitive products with reduced energy consumption

Improving the economic value of photographic screening for optical coherence tomography-detectable macular oedema : a prospective, multicentre, UK study

Peer reviewedPublisher PD

Matrix models on the fuzzy sphere

Field theory on a fuzzy noncommutative sphere can be considered as a particular matrix approximation of field theory on the standard commutative sphere. We investigate from this point of view the scalar $\phi^4$ theory. We demonstrate that the UV/IR mixing problems of this theory are localized to the tadpole diagrams and can be removed by an appropiate (fuzzy) normal ordering of the $\phi^4$ vertex. The perturbative expansion of this theory reduces in the commutative limit to that on the commutative sphere.Comment: 6 pages, LaTeX2e, Talk given at the NATO Advanced Research Workshop on Confiment, Topology, and other Non-Perturbative Aspects of QCD, Stara Lesna, Slovakia, Jan. 21-27, 200

A mode-coupling theory for the glassy dynamics of a diatomic probe molecule immersed in a simple liquid

Generalizing the mode-coupling theory for ideal liquid-glass transitions, equations of motion are derived for the correlation functions describing the glassy dynamics of a diatomic probe molecule immersed in a simple glass-forming system. The molecule is described in the interaction-site representation and the equations are solved for a dumbbell molecule consisting of two fused hard spheres in a hard-sphere system. The results for the molecule's arrested position in the glass state and the reorientational correlators for angular-momentum index $\ell = 1$ and $\ell = 2$ near the glass transition are compared with those obtained previously within a theory based on a tensor-density description of the molecule in order to demonstrate that the two approaches yield equivalent results. For strongly hindered reorientational motion, the dipole-relaxation spectra for the $\alpha$-process can be mapped on the dielectric-loss spectra of glycerol if a rescaling is performed according to a suggestion by Dixon et al. [Phys. Rev. Lett. {\bf 65}, 1108 (1990)]. It is demonstrated that the glassy dynamics is independent of the molecule's inertia parameters.Comment: 19 pages, 10 figures, Phys. Rev. E, in prin

Alternative new notation for quantum information theory

A new notation has been introduced for the quantum information theory. By this notation,some calculations became simple in quantum information theory such as quantum swapping, quantum teleportation.Comment: submitte

Impacts of hydrophilic nanofillers on separation performance of thin film nanocomposite reverse osmosis membrane

The membrane technology is still considered a costly method to produce potable water. In view of this, RO membrane with enhanced water permeability without trade-off in salt rejection is desirable as it could further reduce the cost for water desalination. In this study, thin film nanocomposite (TFN) membranes containing 0.05 or 0.10 w/v% hydrophilic nanofillers in polyamide layer were synthesized via interfacial polymerization of piperazine and trimesoyl chloride monomers. The resultant TFN membranes were characterized and compared with a control thin film composite (TFC) membrane. Results from the filtration experiments showed that TFN membranes exhibited higher water permeability, salt rejection and fouling resistance compared to that of the TFC membrane. Excessive amount of nanofillers incorporated in the membrane PA layer however negatively affected the cross-linking in the polymer matrix, thus deteriorating the membrane salt rejection. TFN membrane containing 0.05 w/v% of nanofillers showed better performances than the TFC membrane, recording a pure water flux of 11.2 L/m2∙he membsalt rejection of 95.4%, 97.3% and 97.5% against NaCl, Na2SO4 and MgSO4, respectively

Oil film interferometry in high Reynolds number turbulent boundary layers

There is continuing debate regarding the validity of skin friction measurements that are dependent on the functional form of the mean velocity profile, for example, the Clauser chart method. This has brought about the need for independent and direct measures of wall shear stress, tw. Of the independent methods to measure tw, oil film interferometry is the most promising, and it has been extensively used recently at low and moderately high Reynolds number. The technique uses interferometry to measure the thinning rate of an oil film, which is linearly related to the level of shear stress acting on the oil film. In this paper we report on the use of this technique in a high Reynolds number boundary layer up to Rq = 50,000. Being an independent measure of tw, the oil film measurement can be used as a means to validate more conventional techniques, such as the Preston tube and Clauser chart at these high Reynolds numbers. The oil-film measurement is validated by making comparative measurements of tw in a large-scale fully-developed channel flow facility where the skin friction is known from the pressure gradient along the channe