Influences of alkaline earth metal substitution on the crystal structure and physical properties of magnetic RuSr1.9A0.1GdCu2O8 (A = Ca, Sr, and Ba) superconductors

We have investigated the effect of alkaline earth metal substitution on the crystal structure and physical properties of magnetic superconductors RuSr(1.9)A(0.1)GdCu(2)O(8) (A = Ca, Sr, and Ba) in order to probe an interaction between the magnetic coupling of the RuO(2) layer and the superconductivity of the CuO(2) layer. X-ray diffraction and X-ray absorption spectroscopic analyses demonstrate that the isovalent substitution of Sr ions with Ca or Ba ions makes it possible to tune the interlayer distance between the CuO(2) and the RuO(2) layers. From the measurements of electrical resistance and magnetic susceptibility, it was found that, in contrast to negligible change of magnetization, both of the alkaline earth metal substitutions lead to a notable depression of zero-resistance temperature T(c) (DeltaT(c) approximately 17-19 K). On the basis of the absence of a systematic correlation between the T(c) and the interlayer distance/magnetization, we have concluded that the internal magnetic field of the RuO(2) layer has insignificant influence on the superconducting property of the CuO(2) layer in the ruthenocuprate.     

Solvent and pH effects on fast and ultrasensitive 1,1'-oxalyldi(4-methyl)imidazole chemiluminescence

Solvent and pH effects on fast and ultrasensitive 1,1'-oxalyldi(4-methyl)imidazole chemiluminescence (OD4MI-CL) were studied. The influences of these two factors on the complex OD4MI-CL reaction are discussed within a conceptual prototype for developing aqueous and non-aqueous capillary electrophoresis (ACE and NACE) devices with OD4MI-CL detection. The reaction channel length and OD4MI yield from the reaction between bis(2,4,6-trichlorophenyl) oxalate (TCPO) and 4-methylimidazole in the channel will be influenced by pH, water volume fraction, and cosolvent properties of the solution. Optimum OD4MI-CL efficiency is observed at pH 6.5 when 1-propanol, which has a low dielectric constant (epsilon = 20.8), is used as the NACE solvent in the separation channel. Water (epsilon = 80.1), the solvent in the ACE separation channel, acts similarly to a high dielectric constant organic solvent in NACE because the disadvantages normally associated with TCPO-CL reactions in water disappear due to the faster OD4MI-CL reaction versus OD4MI decomposition in aqueous solution. Therefore, it is expected that the OD4MI-CL detection system can be used in both NACE and ACE devices without requiring detector modifications. We also conclude that OD4MI-CL detection in NACE and ACE devices will be much more sensitive than the TCPO-CL detection used in current NACE devices.     

Développement par déplacement sur échangeurs d'Ions séparation de plus de deux ions

In the separation of several substances by displacement development, the minimum distance is calculated that the band must travel to obtain a separation of the solutes into zones.The method has been applied to the separation of lithium, sodium, ammonium and potassium ions on Dowex-50 resin, using calcium ions as the developer.     

Label-free cell separation and sorting in microfluidic systems

Cell separation and sorting are essential steps in cell biology research and in many diagnostic and therapeutic methods. Recently, there has been interest in methods which avoid the use of biochemical labels; numerous intrinsic biomarkers have been explored to identify cells including size, electrical polarizability, and hydrodynamic properties. This review highlights microfluidic techniques used for label-free discrimination and fractionation of cell populations. Microfluidic systems have been adopted to precisely handle single cells and interface with other tools for biochemical analysis. We analyzed many of these techniques, detailing their mode of separation, while concentrating on recent developments and evaluating their prospects for application. Furthermore, this was done from a perspective where inertial effects are considered important and general performance metrics were proposed which would ease comparison of reported technologies. Lastly, we assess the current state of these technologies and suggest directions which may make them more accessible.     

Low-Pressure Plasma Reactor with a Cylindrical Electrode for Eco-friendly Processing in the Semiconductor Industry

Thin film deposition processes emit large amounts of NF₃ and by-product particles, which are of great concerns in the semiconductor industry, from the environmental and economic points of view. With an objective to overcome these concerns, plasmas are generated from a cylindrical reactor placed before a vacuum pump. The discharge stability is evaluated by monitoring the changes in the plasma images with the pressure. By using a particle sampler and a particle trap, the size and quantity of the by-product particles are compared during plasma-on and plasma-off. The effects of adding O₂ and H₂O to the by-products of the NF₃ abatement process are investigated by analyzing the spectra obtained with a Fourier transform infrared spectroscopy. Further, the H₂O flow rate is optimized for the highest destruction and removal efficiency of NF₃. Finally, the applicability of our device to the after-treatment equipment is discussed.     

On symplectic quotients of K3 surfaces

In this note, we construct generalized Shioda-Inose structures on K3 surfaces using cyclic covers and almost functoriality of Shioda-Inose structures with respect to normal subgroups of a given group of symplectic automorphisms.