A multifaceted approach to hydrogen storage

The widespread adoption of hydrogen as an energy carrier could bring significant benefits, but only if a number of currently intractable problems can be overcome. Not the least of these is the problem of storage, particularly when aimed at use onboard light-vehicles. The aim of this overview is to look in depth at a number of areas linked by the recently concluded HYDROGEN research network, representing an intentionally multi-faceted selection with the goal of advancing the field on a number of fronts simultaneously. For the general reader we provide a concise outline of the main approaches to storing hydrogen before moving on to detailed reviews of recent research in the solid chemical storage of hydrogen, and so provide an entry point for the interested reader on these diverse topics. The subjects covered include: the mechanisms of Ti catalysis in alanates; the kinetics of the borohydrides and the resulting limitations; novel transition metal catalysts for use with complex hydrides; less common borohydrides; protic-hydridic stores; metal ammines and novel approaches to nano-confined metal hydrides.     

Development of an LC–DAD Method for Analysis of Dexketoprofen, Tramadol, and Haloperidol. Study of the Stability of Mixtures Used for Patient-Controlled Analgesia

A novel LC method was applied to enhance the peak resolution of two ecdysteroids: 20-hydroxyecdysone and its 3-epimer. An isocratic solvent system of methanol–water (6:4, v/v) was used on a C18 column, and 100 μL of water was injected during the development in such a manner that the eluted solvent peak appeared exactly between the two overlapping peaks. This resulted in the increased retardation of the later-eluted peak, and in a good separation of the two compounds within 4.5 min.     

Structure,chemistry and stereochemistry of rastevione,a sequiterpenoid from the genus stevia

The structure and relative stereochemistry of rastevione (1a), the main constituent of the roots of S. serrata and S. rhombifolia, were deduced from chemical transformations combined with spectral data and by a single crystal X-ray diffraction study of rastevione acetate (1b). Chemical correlation of a rastevione derivative with a molecule thought to have structure IVb, suggests the structures of several previously described longipinene and longipinane derivatives, should be revised. The behaviour of longipinane-7α,8β,9β-triol-l-one in the presence of periodic acid was studied, and the structure of the reaction product established from deuterium labeling experiments showed the 7α,8β diol split.     

Interactive method for computation of viscous flow with recirculation

An interactive method is proposed for the solution of two-dimensional, laminar flow fields with identifiable regions of recirculation, such as the shear layer driven cavity flow. The method treats the flow field as composed of two regions, with an appropriate mathematical model adopted for each region. The shear layer is computed by the compressible boundary layer equations, and the slowly recirculating flow by the incompressible Navier-Stokes equations. The flow field is solved iteratively by matching the local solutions in the two regions. For this purpose a new matching method utilizing an overlap between the two computational regions is developed, and shown to be most satisfactory. Matching of u, v, as well as u/y is amply accomplished using the present approach, and the stagnation points corresponding to separation and reattachment of the dividing streamline are computed as part of the interactive solution. The interactive method is applied to the test problem of shear layer driven cavity. The computational results are used to show the validity and applicability of the present approach.     

Methodology to determine stresses due to own weight by using residual stresses techniques

Experimental Techniques -     

Vibrational spectroscopy of indium-doped Pb0.9Mn0.1Te alloy

Raman scattering and far-infrared reflection spectra of 0.5 at.% In doped Pb_0.9Mn_0.1Te single crystal at temperatures between 10 and 300K are presented. The infrared spectra have been fitted using a modified plasmon-phonon interaction model with an additional oscillator (at about 122 cm^?1) representing a local In-impurity mode. Phonons in this mixed crystal exhibit intermediate mode behavior. The plasma frequency decreases on cooling from 300 to 25K and increases sharply between 20 and 10 K. The results of galvanomagnetic measurements are also presented.     

New Product Evaluation Using a Bayesian Dynamic Program

A method of scheduling new product evaluation steps is proposed. The method presented offers promise in reducing the costs of this evaluation. The value of each evaluation is based on Bayesian methods.     

Compositional and structural medium energy ion scattering study of the temperature mediated diffusion determination at the Co/V interface in Co/V/MgO(100)

The impact of annealing at 300 °C on the elemental composition and the atomic structure of the Co/V interface in the 2.5 Å Co/70 Å V/MgO (100) system has been investigated by medium energy ion scattering (MEIS) using 100 keV He⁺ ions. By combining the experimental MEIS results with simulations we show that, while the Co/V interface is abrupt for the system kept at room temperature, annealing at 300 °C induces a strong interdiffusion leading to a Co_0.5V_0.5 surface bcc alloy with a high degree of disorder. Additionally, the MEIS data suggest that the surface of the annealed system is slightly rumpled by ~ 0.2 Å.