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

Structural relaxation in a system of dumbbell molecules

The interaction-site-density-fluctuation correlators, the dipole-relaxation functions, and the mean-squared displacements of a system of symmetric dumbbells of fused hard spheres are calculated for two representative elongations of the molecules within the mode-coupling theory for the evolution of glassy dynamics. For large elongations, universal relaxation laws for states near the glass transition are valid for parameters and time intervals similar to the ones found for the hard-sphere system. Rotation-translation coupling leads to an enlarged crossover interval for the mean-squared displacement of the constituent atoms between the end of the von Schweidler regime and the beginning of the diffusion process. For small elongations, the superposition principle for the reorientational $\alpha$-process is violated for parameters and time intervals of interest for data analysis, and there is a strong breaking of the coupling of the $\alpha$-relaxation scale for the diffusion process with that for representative density fluctuations and for dipole reorientations.Comment: 15 pages, 14 figures, Phys. Rev. E in pres

State-driven Corporate Social Responsibility (CSR)?: mediating offshore outsourcing and CSR in Malaysia

Offshore outsourcing of business activities from the Global North to the Global South does not only relocate investments and jobs, but has also brought about new business demands on suppliers activities and their social and environmental impact. The article explores whether, how and why offshore outsourcing transactions between foreign firms and Malaysian firms affect the upgrading of the CSR activities of Malaysia incorporated firms, taking the particular institutional context of Malaysia into consideration. The focus is on recipient country vendors, contract manufacturers or subcontractors and their reception of and strategising about corporate social responsibility. The findings of the study indicate, firstly, that the amount of foreign (sub)contracting influences the CSR strategising of domestic firms while the global value chain position is only conditioning the offshore outsourcing portfolio. Secondly, both the corporate governance of Malaysian affiliate and the Malaysian government play an important role shaping the perception, rhetoric and organisation of CSR activities by firms in Malaysia with a domestic value chain position. Hence, firms in Malaysia are squeezed by international business linkages and the local institutional context

Next-to-leading order QCD predictions for A0γA^{0}\gamma associated production at the CERN Large Hadron Collider

We calculate the complete next-to-leading-order (NLO) QCD corrections (including SUSY QCD corrections) to the inclusive total cross sections of the associated production processes $pp\rightarrow A^{0}\gamma+X$ in the minimal supersymmetric standard model (MSSM) at the CERN Large Hadron Collider (LHC). Our results show that the enhancement of the total cross sections from the NLO QCD corrections can reach $15$ for 200 GeV$<m_{A}<500$ GeV and $\tan\beta=50$. The scale dependence of the total cross section is improved by the NLO corrections, which is less than 5%. We also show the Monte Carlo simulation results for the $\tau^{+}\tau^{-}+\gamma$ signature including the complete NLO QCD effects, and find an observable signature above the standard model (SM) background for a normal luminosity of 100 fb$^{-1}$ at the LHC.Comment: Published version in Phys.Rev.

Operational approach to the Uhlmann holonomy

We suggest a physical interpretation of the Uhlmann amplitude of a density operator. Given this interpretation we propose an operational approach to obtain the Uhlmann condition for parallelity. This allows us to realize parallel transport along a sequence of density operators by an iterative preparation procedure. At the final step the resulting Uhlmann holonomy can be determined via interferometric measurements.Comment: Added material, references, and journal reference

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

Aeroacoustic and flow assessments of the poro-serrated trailing edges

This paper reports an aeroacoustic study of a NACA0012 aerofoil with a nonflat plate type serrated trailing edge, and a number of Poro-Serrated trailing edge devices that contain porous materials of various air flow resistances at the gaps between adjacent members of the serrated sawtooth. Free field noise measurements were performed inside an aeroacoustic wind tunnel facility, where the range of jet speeds was between 20 ms-1 and 60 ms-1. Flow measurements were also conducted in the same facility for the very near wake. The main objective of this work is to determine whether multiple-mechanisms on the broadband noise reduction can co-exist on a poro-serrated trailing edge. The results demonstrate that having low flow resistivity at the sawtooth gaps could not completely suppress the vortex shedding tone at low frequency, but it can achieve reasonably well broadband noise reduction at high frequency. With high flow resistivity at the sawtooth gaps, the denser porous material almost renders the poro-serrated trailing edge to becoming a straight trailing edge again, thus undermining the serration effect and causing a drop in the noise performance. The optimal range of flow resistivity for the poro-serrated trailing edge is found to be around 10 kN.s.m-4, where it can even perform slightly better than the conventional serrated trailing edge in terms of the turbulent broadband noise reduction while still completely suppresses the vortex shedding noise. From the analysis of the wake data, the overall drag force will not increase when a poro-serrated trailing edge is used.The EPSRC Impact Acceleration Account – Readiness in the United Kingdom

Composting paper and grass clippings with anaerobically treated palm oil mill effluent

Purpose The purpose of this study is to investigate the composting performance of anaerobically treated palm oil mill effluent (AnPOME) mixed with paper and grass clippings. Methods Composting was conducted using a laboratory scale system for 40 days. Several parameters were determined: temperature, mass reduction, pH, electrical conductivity, colour, zeta potential, phytotoxicity and final compost nutrients. Results The moisture content and compost mass were reduced by 24 and 18 %, respectively. Both final compost pH value and electrical conductivity were found to increase in value. Colour (measured as PtCo) was not suitable as a maturity indicator. The negative zeta potential values decreased from −12.25 to −21.80 mV. The phytotoxicity of the compost mixture was found to decrease in value during the process and the final nutrient value of the compost indicates its suitability as a soil conditioner. Conclusions From this study, we conclude that the addition of paper and grass clippings can be a potential substrate to be composted with anaerobically treated palm oil mill effluent (AnPOME). The final compost produced is suitable for soil conditioner

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