Electrocatalysis of fuel cell reactions: Investigation of alternate electrolytes

Oxygen reduction and transport properties of the electrolyte in the phosphoric acid fuel cell are studied. The areas covered were: (1) development of a theoretical expression for the rotating ring disk electrode technique; (2) determination of the intermediate reaction rate constants for oxygen reduction on platinum in phosphoric acid electrolyte; (3) determination of oxygen reduction mechanism in trifluoreomethanesulfonic acid (TFMSA) which was considered as an alternate electrolyte for the acid fuel cells; and (4) the measurement of transport properties of the phosphoric acid electrolyte at high concentrations and temperatures

Electrocatalysis of fuel cell reactions: Investigation of alternate electrolytes

Oxygen reduction and transport properties of the electrolyte in the phosphoric acid fuel cell are studied. A theoretical expression for the rotating ring-disk electrode technique; the intermediate reaction rate constants for oxygen reduction on platinum in phosphoric acid electrolyte; oxygen reduction mechanism in trifluoromethanesulfonic acid (TFMSA), considered as an alternate electrolyte for the acid fuel cells; and transport properties of the phosphoric acid electrolyte at high concentrations and temperatures are covered

A study of the effects of environmental and ablator performance uncertainties on heat shielding requirements for hyperbolic entry vehicles. Volume 2 - Summary of calculations

Calculated ablative quantities for nylon phenolic heat shielding materials of hyperbolic reentry vehicle

Partial Glycerides Synthesis by Lipase of Aspergillus niger

The lipase of Aspergillus niger was examined for partial glycerides synthesis. A significant degree of synthesis (more than 50%) was achieved using lamate as one of the substrates. This can be further improved by optimizing the reaction conditions. A synthesis degree of almost 80% was obtained in the presence of 3.0 g of molecular sieve pellets for water absorption in the reaction system

Multimedia object placement for hybrid transparent data replication

In this paper, we address present an optimal solution for the problem of multimedia object placement for hybrid transparent data replication. The performance objective is to minimize the total access cost by considering both transmission cost and transcoding cost. The performance of the proposed solution is evaluated with a set of carefully designed simulation experiments for various performance metrics over a wide range of system parameters. The simulation results show that our solution consistently and significantly outperforms comparison solutions in terms of all the performance metrics considered. © 2005 IEEE.published_or_final_versio

Multimedia object placement for hybrid transparent data replication

© 2005 IEEEIn this paper, we address present an optimal solution for the problem of multimedia object placement for hybrid transparent data replication. The performance objective is to minimize the total access cost by considering both transmission cost and transcoding cost. The performance of the proposed solution is evaluated with a set of carefully designed simulation experiments for various performance metrics over a wide range of system parameters. The simulation results show that our solution consistently and significantly outperforms comparison solutions in terms of all the performance metrics considered

Analytical and experimental study of stratification and liquid-ullage coupling, 1 June 1964 - 31 May 1965

Closed-form solution for stratification of subcooled fluids in containers subjected to heating, and for liquid-ullage vapor couplin

Memory usage verification using Hip/Sleek.

Embedded systems often come with constrained memory footprints. It is therefore essential to ensure that software running on such platforms fulfils memory usage specifications at compile-time, to prevent memory-related software failure after deployment. Previous proposals on memory usage verification are not satisfactory as they usually can only handle restricted subsets of programs, especially when shared mutable data structures are involved. In this paper, we propose a simple but novel solution. We instrument programs with explicit memory operations so that memory usage verification can be done along with the verification of other properties, using an automated verification system Hip/Sleek developed recently by Chin et al.[10,19]. The instrumentation can be done automatically and is proven sound with respect to an underlying semantics. One immediate benefit is that we do not need to develop from scratch a specific system for memory usage verification. Another benefit is that we can verify more programs, especially those involving shared mutable data structures, which previous systems failed to handle, as evidenced by our experimental results

Cryopreservation of Coffea liberica Seeds and Embryos following desiccation and freezing treatments

Desiccation of Coffea liberica seeds for 6 days in an air-conditioned room reduced seed and attached emltryo moisture from 52.58% and 47.49% to 14.58% and 12.56% respectively. Seed germination and viability of the attached emltryo were maintained at moderate levels of 66% and 38% respectively. However, none of the desiccated seeds or embryos survived freezing in liquid nitrogen. Excised emltryos desiccated in the lamina flow cabinet lost their moisture very rapidly from 36.8% to 9.27% within 1.5 hours. More than 70% of these emltryos survived the desiccation. Moreover, partially desiccated emltryos at 17.17% moisture or less survived subfreezing temperatures. Between 35% to 50% survived slow freezing to -3ffC, but this was reduced to approximately 30% when they were subsequently plunged into liquid nitrogen. Fast freezing by direct plunge into liquid nitrogen also resulted in 10% to 35% survival. Desiccation ofexcised coffee embryos for 0.5h to 17.17% moisture was optimal for eryopreservation, irrespective of the speed offreezing. Differential thermal analyses of seed tissues suggest that the absence of freezable water is an important factor for successful eryopreservation of excised coffee emltryos. However, the importance of initial vigour, moisture variation and recovery media is also discussed