Hydrogen may be considered a potential fuel for the future since it is carbon-free and oxidized to water as a combustion product. Bioconversion of synthesis gas (syngas) to hydrogen was demonstrated in continuous stirred tank bioreactor (CSTBR) utilizing acetate as a carbon source. An anaerobic photosynthetic bacterium, Rhodospirillum rubrum catalyzed water-gas shift reaction which was applied ...

endonasal endoscopic laser-assisted dacryocystorhinostomy has many advantages over conventional external dacryocystorhinostomy. this technique avoids a cutaneous scar and causes less surgical trauma and bleeding than that seen in conventional lacrimal surgery. a total of 20 endoscopic laser-assisted dacryocystorhinostomy in 16 patients were performed between 1998 and 1999. the procedure was suc...

The aim of the present study was to verify that the patient/ventilator interaction is similar, regardless of the mode of assisted mechanical ventilation (i.e. pressure- or volume-limited) used, if tidal volume (VT) and peak inspiratory flow (PIF) are matched. Therefore, the authors compared the effects of three different modes of assisted ventilation on the work of breathing (WOB) and gas excha...

Kinetic modeling is an important issue, whose objective is the accurate determination of the rates of various reactions taking place in a reacting system. This issue is a pivotal element in the process design and development particularly for novel processes which are based on reactions taking place between various types of species. The Fischer Tropsch (FT) reactions have been used as the ki...

A number of experimental studies have shown recently that ppm-level additions of nitric oxide (NO) enhance the rate of nitrous oxide (N(2)O) decomposition catalyzed by Fe-ZSM-5 at low temperatures. In the present work, the NO-assisted N(2)O decomposition over mononuclear iron sites in Fe-ZSM-5 was studied on a molecular level using density functional theory (DFT) and transition-state theory. A ...

Understanding the dynamics of pore-scale multicomponent gas and oil mass transfer across water "lms during hydrocarbon gas injection in petroleum reservoirs is important in the design of tertiary oil recovery schemes at the "eld scale. The water "lms prevent oil and gas coming into direct contact and, for miscible gas injection, delay the onset of miscibility. We use a pore-scale model to descr...

investigating the role of drought stress conditions on physiological characteristics of plant may provide means to understand basic drought resistance. differences in leaf emergence rate, leaf relative water content (rwc), membrane stability index (msi), leaf mass area (lma), net photosynthesis (anet), stomatal conductance (gs), transpiration rate (e), intercellular co2 concentration (ci), ...

We present novel techniques for knowledge-assisted annotation and computer-assisted interpretation of seismic data for oil and gas exploration. We describe the existing procedure for oil and gas search which consists of manually extracting information from seismic data and then aggregating it into knowledge in a detail-oriented bottom-up approach. We then point out the weaknesses of this approa...