Newly developed foam ceramic body shows promise as thermal insulation material at 3000 deg F

Optimized zirconia foam ceramic body shows promise for use as a thermal insulation material. The insulating media displays low density and thermal conductivity, good thermal shock resistance, high melting point, and mechanical strength

Physiological cost of walking in those with chronic fatigue syndrome

<b>Purpose:</b> To examine the physiological cost of walking in subjects with chronic fatigue syndrome (CFS) and a matched control group, walking at their preferred and at matched walking speeds. <b>Methods:</b> Seventeen people with CFS and 17 matched-controls participated in this observational study of physiological cost during over-ground gait. Each subject walked for 5 min at their preferred walking speed (PWS). Controls then walked for 5 min at the same pace of their matched CFS subject. Gait speed and oxygen uptake, gross and net were measured and oxygen uptake was expressed per unit distance ambulated. CFS subjects completed the CFS-Activities and Participation Questionnaire (CFS-APQ). <b>Results:</b> At PWS the CFS group walked at a slower velocity of 0.84 ± 0.21 m s<sup>-1</sup> compared to controls with a velocity of 1.19 ± 0.13 m s<sup>-1</sup> (p < 0.001). At PWS both gross and net oxygen uptake of CFS subjects was significantly less than controls (p = 0.023 and p = 0.025 respectively). At matched-velocity both gross and net physiological cost of gait was greater for CFS subjects than controls (p = 0.048 and p = 0.001, respectively). <b>Conclusion:</b> The physiological cost of walking was significantly greater for people with CFS compared with healthy subjects. The reasons for these higher energy demands for walking in those with CFS have yet to be fully elucidated

Populating the Galaxy with low-mass X-ray binaries

We perform binary population synthesis calculations to investigate the incidence of low-mass X-ray binaries and their birth rate in the Galaxy. We use a binary evolution algorithm that models all the relevant processes including tidal circularization and synchronization. Parameters in the evolution algorithm that are uncertain and may affect X-ray binary formation are allowed to vary during the investigation. We agree with previous studies that under standard assumptions of binary evolution the formation rate and number of black-hole low-mass X-ray binaries predicted by the model are more than an order of magnitude less than what is indicated by observations. We find that the common-envelope process cannot be manipulated to produce significant numbers of black-hole low-mass X-ray binaries. However, by simply reducing the mass-loss rate from helium stars adopted in the standard model, to a rate that agrees with the latest data, we produce a good match to the observations. Including low-mass X-ray binaries that evolve from intermediate-mass systems also leads to favourable results. We stress that constraints on the X-ray binary population provided by observations are used here merely as a guide as surveys suffer from incompleteness and much uncertainty is involved in the interpretation of results.Comment: 17 pages and 9 figures; accepted by MNRA

Bioengineering Lantibiotics for Therapeutic Success

peer-reviewedSeveral examples of highly modified antimicrobial peptides have been described. While many such peptides are non-ribosomally synthesized, ribosomally synthesized equivalents are being discovered with increased frequency. Of the latter group, the lantibiotics continue to attract most attention. In the present review, we discuss the implementation of in vivo and in vitro engineering systems to alter, and even enhance, the antimicrobial activity, antibacterial spectrum and physico-chemical properties, including heat stability, solubility, diffusion and protease resistance, of these compounds. Additionally, we discuss the potential applications of these lantibiotics for use as therapeutics.DF,CH,PC,RR are supported by the Irish Government under the National Development Plan, through a Science Foundation Ireland (SFI) Technology and Innovation Development Award (TIDA14/TIDA/2286) to DF, a SFI Investigator awards to CH and RR (10/IN.1/B3027),SFI-PIfunding(11/PI/1137) to PDC and the Alimentary Pharmabiotic Centre under Grant Number SFI/12/RC/2273

Notched impact behavior of polymer blends: Part 1: New model for particle size dependence

A model is proposed to explain the observed relationships between particle size and fracture resistance in high-performance blends, which typically reach maximum toughness at particle diameters of 0.2–0.4 μm. To date there has been no satisfactory explanation for the ductile–brittle (DB) transition at large particle sizes. The model is based on a recently developed criterion for craze initiation, which treats large cavitated rubber particles as craze-initiating Griffith flaws. Using this criterion in conjunction with Westergaard's equations, it is possible to map the spread from the notch tip of three deformation mechanisms: rubber particle cavitation, multiple crazing and shear yielding. Comparison of zone sizes leads to the conclusion that maximum toughness is achieved when the particles are large enough to cavitate a long way ahead of a notch or crack tip, but not so large that they initiate unstable crazes and thus reduce fracture resistance

Frio brine sequestration pilot in the Texas Gulf Coast

A field experiment to pioneer CO2 injection for sequestration in a brine-bearing sandstone-shale sequence in the Texas Gulf Coast, USA, is in the preinjection modeling and planning phase. Innovations in this experiment include (1) CO2 injection into high-volume highpermeability rocks that have storage capacity sufficient to impact greenhouse gas emissions, (2) injection into a setting lacking the complications introduced by hydrocarbons and perturbations resulting from production and secondary recovery, and (3) intensive pre-, syn-, and post-injection monitoring and modeling for validation of the effectiveness of sequestration. The experiment is designed to provide a rapid increase in information from a small-volume and short-duration injection.Bureau of Economic Geolog

Preliminary Checklist of the Fishes of the Illinois River, Arkansas

A survey of the fishes of the mainstream of the Illinois River in northwestern Arkansas produced 51 species representing 11 families. Four of these species, Ictiobus bubalus, smallmouth buffalo; Moxostoma carinatum, river redhorse; Lepomis gulosus, warmouth; and Percina phoxocephala, slenderhead darter, have not been recorded previously from the Arkansas part of the Illinois. Eleven additional species have been reported previously that were not collected during this survey, for a total of 62 species known in the Illinois River