A hydrogen safety sensor is presented which provides high sensitivity and fast response time when operated in air. The target application for the sensor is external deployment near systems using or producing high concentrations of hydrogen. The sensor is composed of a catalytically active metal-oxide sensing electrode and a noble metal reference electrode attached to an yttria-stabilized zirconia (YSZ) electrolyte. The sensing approach is based on the difference in oxidation rate of hydrogen on the different electrode materials. Results will be presented for a sensor using a sensing electrode of tin-doped indium oxide (ITO). Response to H{sub 2}, and cross-sensitivity to hydrocarbon and H{sub 2}O are discussed.

Motivation. The power of multi-sequence comparison forbiological discovery is well established and sequence data from a growinglist of organisms is becoming available. Thus, a need exists forcomputational strategies to visually compare multiple aligned sequencesto support conservation analysis across various species. To be efficientthese visualization algorithms require the ability to universally handlea wide range of evolutionary distances while taking into accountphylogeny Results. We have developed Phylo-VISTA, an interactive tool foranalyzing multiple alignments by visualizing the similarity of DNAsequences among multiple species while considering their phylogenicrelationships. Features include a broad spectrum of resolution parametersfor examining the alignment and the ability to easily compare any subtreeof sequences within a complete alignment dataset. Phylo-VISTA uses VISTAconcepts that have been successfully applied previously to a wide rangeof comparative genomics data analysis problems. Availability Phylo-VISTAis an interactive java applet available for downloading athttp://graphics.cs.ucdavis.edu/~;nyshah/Phylo-VISTA. It is also availableon-line at http://www-gsd.lbl.gov/phylovista and is integrated with theglobal alignment program LAGAN athttp://lagan.stanford.edu.Contactphylovista@lbl.gov

This paper presents a study of non-Darcy fluid flow through porous and fractured rock, which may occur near wells during high-flux injection of waste fluids into underground formations. Both numerical and analytical models are used in this study. General non-Darcy flow is described using the Forchheimer equation, implemented in a three-dimensional, multiphase flow reservoir simulator. The non-Darcy flow through a fractured reservoir is handled using a general dual continuum approach, covering commonly used conceptual models, such as double porosity, dual permeability, explicit fracture, etc. Under single-phase flow conditions, an approximate analytical solution, as an extension of the Warren-Root solution, is discussed. The objectives of this study are (1) to obtain insights into the effect of non-Darcy flow on transient pressure behavior through porous and fractured reservoirs and (2) to provide type curves for well test analyses of non-Darcy flow wells. The type curves generated include various types of drawdown, injection, and buildup tests with non-Darcy flow occurring in porous and fractured reservoirs. In addition, non-Darcy flow into partially penetrating wells is also considered. The transient-pressure type curves for flow in fractured reservoirs are based on the double-porosity model. Type curves provided in this work for non-Darcy flow in porous and …

Inertia welding is widely used to join cylindrically shaped objects such as disks and shafts in turbine engines, turbochargers, etc. Flash control in many of these applications is not critical because the excess material is on external surfaces and can readily be removed by machining. Internal flash on hollow vessels, however, may be difficult or impossible to remove and may be either controlled by the use of flash traps or the part can be used as welded. Both internal flash and flash traps reduce internal volume and the conditions are not always acceptable. To address this short-coming, several innovative methods have been tested to determine their effect on flash control in inertia welding of hollow vessels. The methods include introduction of high pressure inert gas and incorporation of an expendable mandrel to divert the flash. Both gas and internal mandrels appear promising methods for diverting flash.

Recent modifications to the minimum energy efficiency requirements for residential water heaters have spurred an investigation into the variability in testing high-efficiency electric water heaters. While initial inter-laboratory comparisons showed excellent agreement between test results from different labs, subsequent inter-laboratory comparisons show differences between measured energy factors of up to 0.040. To determine the source of these differences, analyses of various parts of the test procedure are performed. For one case studied, the uncertainty in test results can be as high as +-0.028 if instrument accuracies reach the minimum level allowed in the test procedure. Other areas of the test procedure where variability is introduced are the optional use of pre-draws, the location of the lower tank temperature-measuring device, the use of insulation on tank fittings, and the use of a warm-up period before the simulated-use test commences. The implications of these issues on test results are provided.