Enantiodifferentiation of solerol isomers in dried figs and dates

Concentrates of dried fig (Ficus carica L.) and dried date (Phoenix dactylifera L.) fruits were obtained by solvent extraction (pentane: dichloromethane, 2∶1 by vol) and subsequently analysed by HRGC-MS. Using multidimensional gas chromatography (DB-Wax/oktakis2, 6-di-O-methyl-3-O-pentyl-γ-cyclodextrin) simultaneous enantiodifferentiation of 4,5-dihydroxyhexanoic acid-γ-lactone isomers (solerol) was carried out. The presence of this constituent is reported for the first time in figs and dates. Enantiomeric excesses of 80% and 90% were determined for the (4R,5R)-isomer in figs and dates, respectively.     

Off-design analysis of SOFC hybrid system

This paper sets out the results of mathematical modeling and numerical simulations of the off-design (part-load) operation of the solid oxide fuel cell hybrid system (SOFC-HS).     

The Lightweight Nickel Fiber Electrode for Nickel-Based Battery Systems

Development of a high specific energy battery is one of the objectives of the lightweight nickel-hydrogen (Ni-H₂) program at the NASA Lewis Research center. The approach has been to improve the nickel electrode by continuing combined in house and contract efforts to develop a more efficient and lighter weight electrode for the nickel-hydrogen cell. Small fiber diameter nickel plaques are used as conductive supports for the nickel hydrogen active material. These plaques have an advantage of increased surface area available for the deposition of active material. Initial tests include activation and capacity measurements at different discharge rates followed by life cycling.     

A block iterative finite element algorithm for numerical solution of the steady–state,compressible Navier–Stokes equations

An iterative method for numerically solving the time independent Navier–Stokes equations for viscous compressible flows is presented. The method is based upon partial application of the Gauss–Seidel principle in block form to the systems of the non-linear algebraic equations which arise in construction of finite element (Galerkin) models approximating solutions of fluid dynamic problems. The C⁰-cubic element on triangles is employed for function approximation. Computational results for a free shear flow at Re = 1000 indicate significant achievement of economy in iterative convergence rate over finite element and finite difference models which employ the customary time dependent equations and symptotic time marching procedure to steady solution. Numerical results are in excellent agreement with those obtained for the same test problem employing time marching finite element and finite difference solution techniques.