Oxygen production using solid-state zirconia electrolyte technology

High purity oxygen is required for a number of scientific, medical, and industrial applications. Traditionally, these needs have been met by cryogenic distillation or pressure swing adsorption systems designed to separate oxygen from air. Oxygen separation from air via solid-state zirconia electrolyte technology offers an alternative to these methods. The technology has several advantages over the traditional methods, including reliability, compactness, quiet operation, high purity output, and low power consumption

SUPPLY RESPONSE TO TECHNOLOGICAL CHANGE AND REGULATION: THE CASE OF MECHANICALLY DEBONED POULTRY

Research and Development/Tech Change/Emerging Technologies,

Method of producing ceramic distribution members for solid state electrolyte cells

A solid state electrolyte cells apparatus and method of producing is disclosed. The apparatus can be used for separating oxygen from an oxygen-containing feedstock or as a fuel cell for reacting fluids. Cells can be stacked so that fluids can be introduced and removed from the apparatus through ceramic distribution members having ports designed for distributing the fluids in parallel flow to and from each cell. The distribution members can also serve as electrodes to membranes or as membrane members between electrodes, The distribution member design does not contain any horizontal internal ports which allows the member to be thin. A method of tape casting in combination with an embossing method allows intricate radial ribs and bosses to be formed on each distribution member. The bosses serve as seals for the ports and allow the distribution members to be made without any horizontal internal ports

Ceramic distribution members for solid state electrolyte cells and method of producing

A solid state electrolyte cells apparatus and method of producing is disclosed. The apparatus can be used for separating oxygen from an oxygen-containing feedstock or as a fuel cell for reacting fluids. Cells can be stacked so that fluids can be introduced and removed from the apparatus through ceramic distribution members having ports designed for distributing the fluids in parallel flow to and from each cell. The distribution members can also serve as electrodes to membranes or as membrane members between electrodes. The distribution member design does not contain any horizontal internal ports which allows the member to be thin. A method of tape casting in combination with an embossing method allows intricate radial ribs and bosses to be formed on each distribution member. The bosses serve as seals for the ports and allow the distribution members to be made without any horizontal internal ports

Effects of Corn Crop Residue Grazing on Soil Physical Properties and Subsequent Soybean Production in a Corn–Soybean Crop Rotation

For three years beginning in 1999, a 96-acre field near Atlantic, Iowa was used to study the effects of corn residue grazing by beef cows on soil characteristics and soybean yields in subsequent years. Each winter, cows were allowed to graze corn crop residues inside selected paddocks in four sub-fields over five monthly periods. To compare the effects of grazing, one paddock was left as an ungrazed control. At the end of grazing in the spring, soil bulk density, moisture content, and penetration resistance were measured inside and 15 ft outside twelve grazing exclosures in each paddock. Soil surface roughness, texture, and type were also measured in twelve locations in each paddock. Corn crop residues were collected for yield, cover, and composition at the initiation, middle and termination of grazing. Precipitation and soil temperature also were recorded throughout the grazing season. Each following year, soybeans were planted in replicated subfields with disking or no tillage and harvested using a combine equipped with a yield monitor and global positioning system (GPS). Cattle grazing corn crop residue has shown no effect on soil bulk density, but there has been a measurable effect on penetration resistance in paddocks grazed in October and November (P\u3c 0.05). There is an increase in soil surface roughness during certain periods of cattle grazing where 75% of the variation can be contributed to increase in the amount of time soil temperature is above freezing. Cattle grazing had no effect on soybean plant population. However, 36 and 38% of the variation in soybean yield can be attributed to penetration resistance and soil surface roughness

Aqueous Alteration on Mars

Aqueous alteration is the change in composition of a rock, produced in response to interactions with H2O-bearing ices, liquids, and vapors by chemical weathering. A variety of mineralogical and geochemical indicators for aqueous alteration on Mars have been identified by a combination of surface and orbital robotic missions, telescopic observations, characterization of Martian meteorites, and laboratory and terrestrial analog studies. Mineralogical indicators for aqueous alteration include goethite (lander), jarosite (lander), kieserite (orbiter), gypsum (orbiter) and other Fe-, Mg-, and Ca-sulfates (landers), halides (meteorites, lander), phyllosilicates (orbiter, meteorites), hematite and nanophase iron oxides (telescopic, orbiter, lander), and Fe-, Mg-, and Ca-carbonates (meteorites). Geochemical indicators (landers only) for aqueous alteration include Mg-, Ca-, and Fe-sulfates, halides, and secondary aluminosilicates such as smectite. Based upon these indicators, several styles of aqueous alteration have been suggested on Mars. Acid-sulfate weathering (e.g., formation of jarosite, gypsum, hematite, and goethite), may occur during (1) the oxidative weathering of ultramafic igneous rocks containing sulfides, (2) sulfuric acid weathering of basaltic materials, and (3) acid fog (i.e., vapors rich in H2SO4) weathering of basaltic or basaltic-derived materials. Near-neutral or alkaline alteration occurs when solutions with pH near or above 7 move through basaltic materials and form phases such as phyllosilicates and carbonates. Very low water:rock ratios appear to have been prominent at most of the sites visited by landed missions because there is very little alteration (leaching) of the original basaltic composition (i.e., the alteration is isochemical or in a closed hydrologic system). Most of the aqueous alteration appears to have occurred early in the history of the planet (3 to 4.5 billion years ago); however, minor aqueous alteration may be occurring at the surface even today (e.g., in thin films of water or by acid fog)

Mutagenesis of Trichoderma reesei endoglucanase I: impact of expression host on activity and stability at elevated temperatures.

BackgroundTrichoderma reesei is a key cellulase source for economically saccharifying cellulosic biomass for the production of biofuels. Lignocellulose hydrolysis at temperatures above the optimum temperature of T. reesei cellulases (~50°C) could provide many significant advantages, including reduced viscosity at high-solids loadings, lower risk of microbial contamination during saccharification, greater compatibility with high-temperature biomass pretreatment, and faster rates of hydrolysis. These potential advantages motivate efforts to engineer T. reesei cellulases that can hydrolyze lignocellulose at temperatures ranging from 60-70°C.ResultsA B-factor guided approach for improving thermostability was used to engineer variants of endoglucanase I (Cel7B) from T. reesei (TrEGI) that are able to hydrolyze cellulosic substrates more rapidly than the recombinant wild-type TrEGI at temperatures ranging from 50-70°C. When expressed in T. reesei, TrEGI variant G230A/D113S/D115T (G230A/D113S/D115T Tr_TrEGI) had a higher apparent melting temperature (3°C increase in Tm) and improved half-life at 60°C (t1/2 = 161 hr) than the recombinant (T. reesei host) wild-type TrEGI (t1/2 = 74 hr at 60°C, Tr_TrEGI). Furthermore, G230A/D113S/D115T Tr_TrEGI showed 2-fold improved activity compared to Tr_TrEGI at 65°C on solid cellulosic substrates, and was as efficient in hydrolyzing cellulose at 60°C as Tr_TrEGI was at 50°C. The activities and stabilities of the recombinant TrEGI enzymes followed similar trends but differed significantly in magnitude depending on the expression host (Escherichia coli cell-free, Saccharomyces cerevisiae, Neurospora crassa, or T. reesei). Compared to N.crassa-expressed TrEGI, S. cerevisiae-expressed TrEGI showed inferior activity and stability, which was attributed to the lack of cyclization of the N-terminal glutamine in Sc_TrEGI and not to differences in glycosylation. N-terminal pyroglutamate formation in TrEGI expressed in S. cerevisiae was found to be essential in elevating its activity and stability to levels similar to the T. reesei or N. crassa-expressed enzyme, highlighting the importance of this ubiquitous modification in GH7 enzymes.ConclusionStructure-guided evolution of T. reesei EGI was used to engineer enzymes with increased thermal stability and activity on solid cellulosic substrates. Production of TrEGI enzymes in four hosts highlighted the impact of the expression host and the role of N-terminal pyroglutamate formation on the activity and stability of TrEGI enzymes

A Perspective on Livestock–Wolf Interactions on Western Rangelands

The reintroduction of wolves into their historical ranges in the North American Rocky Mountains and areas of the southwestern United States is possibly one of the most ambitious ecosystem restoration efforts of the recent past. This initiative has been controversial and has stimulated considerable debate among concerned stakeholders about the feasibility of harmonizing multiple land-use demands when preservation of a large predator becomes a central management goal. In many areas, ranching has taken center stage of this debate as ranchers and land managers seek to develop sustainable ways to manage livestock on landscapes with wolves. The challenges associated with wolf restoration programs vary regionally and depend on a myriad of interacting factors. Wolf population size and consequent regulatory and legal frameworks; site-specific, biophysical features; and local traditions, perceptions, and attitudes of urban vs. ranching communities are only a few of the issues driving the diversity of situations. Because of this complexity, “silver-bullet” approaches are unlikely to provide answers that will satisfy all stakeholders in all locations. In this context, our article seeks to 1) provide a science-based perspective to inform the wolf–livestock ongoing debate; and 2) suggest research approaches that could lead to locally relevant solutions. Of paramount importance is better understanding of direct and indirect effects of wolves on livestock, and development of effective methods for minimizing impacts while maintaining ecologically relevant wolf populations on the landscape. We argue that progress (i.e., optimizing coexistence or minimizing conflict) is most likely if multiple tools and techniques are used in a context-dependent fashion and integrated into a science based operation supported by producers