16,099 research outputs found
Search for the Next Silver Bullet : A Review of Literature
We present a review on the application of silver containing compounds that have been incorporated in the surfaces of a large variety of medical devices including vascular, urinary, and peritoneal catheters, endotracheal tubes, sutures, and fracture fixation devices, as well as other materials such as plastics in kitchen appliances and fabrics. We found renewed and rising interest in silver-containing materials due to their antimicrobial, including antiviral and antifungal, properties, their good toxicology and environmental record. Silver-containing compounds could be used against bacterial strains that are known to be resistant to antibiotics. More research is necessary to determine safe levels and particle-size of silver for use in human
Search for the Next Silver Bullet : A Review of Literature
We present a review on the application of silver containing compounds that have been incorporated in the surfaces of a large variety of medical devices including vascular, urinary, and peritoneal catheters, endotracheal tubes, sutures, and fracture fixation devices, as well as other materials such as plastics in kitchen appliances and fabrics. We found renewed and rising interest in silver-containing materials due to their antimicrobial, including antiviral and antifungal, properties, their good toxicology and environmental record. Silver-containing compounds could be used against bacterial strains that are known to be resistant to antibiotics. More research is necessary to determine safe levels and particle-size of silver for use in human
Blade loss transient dynamics analysis. Volume 3: User's manual for TETRA program
The users manual for TETRA contains program logic, flow charts, error messages, input sheets, modeling instructions, option descriptions, input variable descriptions, and demonstration problems. The process of obtaining a NASTRAN 17.5 generated modal input file for TETRA is also described with a worked sample
Possible Observational Criteria for Distinguishing Brown Dwarfs from Planets
The difference in formation process between binary stars and planetary
systems is reflected in their composition as well as their orbital
architecture, particularly orbital eccentricity as a function of orbital
period. It is suggested here that this difference can be used as an
observational criterion to distinguish between brown dwarfs and planets.
Application of the orbital criterion suggests that with three possible
exceptions, all of the recently-discovered substellar companions discovered to
date may be brown dwarfs and not planets. These criterion may be used as a
guide for interpretation of the nature of sub-stellar mass companions to stars
in the future.Comment: LaTeX, 11 pages including 2 figures, accepted for publication in the
Astrophysical Journal Letter
Magnetoresistance of proximity coupled Au wires
We report measurements of the magnetoresistance (MR) of narrow Au wires
coupled to a superconducting Al contact on one end, and a normal Au contact on
the other. The MR at low magnetic field is quadratic in , with a
characteristic field scale determined by phase coherent paths which
encompass not only the wire, but also the two contacts. is essentially
temperature independent at low temperatures, indicating that the area of the
phase coherent paths is not determined by the superconducting coherence length
in the normal metal, which is strongly temperature dependent at low
temperatures. We identify the relevant length scale as a combination of the
electron phase coherence length in the normal metal and the coherence
length in the superconductor
Influence of temperature dependent inelastic scattering on the superconducting proximity effect
We have measured the differential resistance of mesoscopic gold wires of
different lengths connected to an aluminum superconductor as a function of
temperature and voltage. Our experimental results differ substantially from
theoretical predictions which assume an infinite temperature independent gap in
the superconductor. In addition to taking into account the temperature
dependence of the gap, we must also introduce a temperature dependent inelastic
scattering length in order to fit our data
Structure, bonding and morphology of hydrothermally synthesised xonotlite
The authors have systematically investigated the role of synthesis conditions upon the structure and morphology of xonotlite. Starting with a mechanochemically prepared, semicrystalline phase with Ca/Si=1, the authors have prepared a series of xonotlite samples hydrothermally, at temperatures between 200 and 250 degrees C. Analysis in each case was by X-ray photoelectron spectroscopy, environmental scanning electron microscopy and X-ray diffraction. The authors’ use of a much lower water/solid ratio has indirectly confirmed the ‘through solution’ mechanism of xonotlite formation, where silicate dissolution is a key precursor of xonotlite formation. Concerning the role of temperature, too low a temperature (~200 degrees C) fails to yield xonotlite or leads to increased number of structural defects in the silicate chains of xonotlite and too high a temperature (>250 degrees C) leads to degradation of the xonotlite structure, through leaching of interchain calcium. Synthesis duration meanwhile leads to increased silicate polymerisation due to diminishing of the defects in the silicate chains and more perfect crystal morphologies
New nickel-base wrought superalloy with applications up to 1253 K (1800 F)
Alloy possesses combination of high tensile strength at low and intermediate temperatures to 1033 K with good rupture strength at high temperatures to 1255 K. Alloy has promise for turbine disk application in future gas turbine engines and for wrought integrally bladed turbine wheel; thickness and weight of disk portion of wheel could be reduced
Loss of quantum coherence due to non-stationary glass fluctuations
Low-temperature dynamics of insulating glasses is dominated by a macroscopic
concentration of tunneling two-level systems (TTLS). The distribution of the
switching/relaxation rates of TTLS is exponentially broad, which results in
non-equilibrium state of the glass at arbitrarily long time-scales. Due to the
electric dipolar nature, the switching TTLS generate fluctuating
electromagnetic fields. We study the effect of the non-thermal slow fluctuators
on the dephasing of a solid state qubit. We find that at low enough
temperatures, non-stationary contribution can dominate the stationary (thermal)
one, and discuss how this effect can be minimized.Comment: 4 page
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