Constructing The Non-stop,Self-healing T1 Network

Automatic protection switching that is integrated into a sensible backup scheme will keep T1 lines functioning even in the face of disaster.     

Molecular thermodynamics for fluid-phase equilibria in aqueous two-protein systems

With saline water as the continuous medium, a two-component McMillan-Mayer equation of state is used to describe liquid–liquid phase equilibria in a two-protein system. The equation of state is based on a hard-sphere reference with perturbations introduced through a potential of mean force to account for electrostatic forces and for attraction between protein particles. To illustrate the thermodynamic framework, one parameter each is fitted to experimental precipitation data for aqueous saline one-protein systems containing either lysozyme or ovalbumin. A lysozyme–ovalbumin interaction parameter is then introduced to calculate phase behavior in the aqueous two-protein system. These calculations are remarkably similar to classic vapor–liquid equilibrium calculations using an equation of state. For the aqueous two-protein system, calculations give the light-phase composition as well as the lysozyme and ovalbumin partition coefficients for a given dense-phase composition. Agreement with sparse experimental data is reasonable over a range of pH and high ionic strength provided by the common precipitant ammonium sulfate.     

Plasma-assisted co-evaporation of β-indium sulfide thin films

This paper describes the development of plasma-assisted co-evaporation (PACE) for the formation of β-In₂S₃ thin films. Indium was supplied by conventional thermal evaporation, while the chalcogen gas precursor (H₂S) was activated using an inductively coupled plasma (ICP) source. Using a combination of optical emission spectroscopy and mass spectrometry it was shown that the ICP effectively dissociated H₂S, producing atomic sulfur. Transport modeling was used to quantify the flux distributions of the co-evaporated metal and the plasma-generated species impinging the substrate. Model predictions were validated by measurements of deposition rate and film properties. Substantial improvements in both materials utilization and substrate temperature reduction were realized with respect to conventional co-evaporation. β-In₂S₃ was formed as low as 100 °C and it was observed that quality was a strong function of S/In ratio. The grain size decreased and the optical band gap increased as the substrate temperature was reduced.     

NOTE ON SECONDARY EXPANSION OF FLINT CLAY

Certain flint fire clays show a secondary expansion, which may amount to several per cent, at a temperature much below that at which dangerous expansion begins. Some specifications discriminate unjustly against brick containing fire clays of this the.     

Design and Expected Performance of GISMO-2, a Two Color Millimeter Camera for the IRAM 30 m Telescope

We present the main design features for the GISMO-2 bolometer camera, which we build for background-limited operation at the IRAM 30 m telescope on Pico Veleta, Spain. GISMO-2 will operate simultaneously in the 1 and 2 mm atmospherical windows. The 1 mm channel uses a \(32 \times 40\) TES-based backshort under grid (BUG) bolometer array, the 2 mm channel operates with a \(16 \times 16\) BUG array. The camera utilizes almost the entire full field of view provided by the telescope. The optical design of GISMO-2 was strongly influenced by our experience with the GISMO 2 mm bolometer camera, which is successfully operating at the 30 m telescope. GISMO is accessible to the astronomical community through the regular IRAM call for proposals.     

Fully Quantum Cross Second Virial Coefficients for the Three-Dimensional He–H_{2} Pair

A recent high-accuracy three-dimensional potential is used to compute the cross second virial coefficient \(B_{12}(T)\) between helium and molecular hydrogen. These calculations fully account for both quantum effects (with the path-integral Monte Carlo method) and the flexibility of the hydrogen molecule. The effect of flexibility is relatively small (only slightly larger than the expanded uncertainty of our results), but the full quantum mechanical approach is essential to obtain correct results at cryogenic temperatures. Values are calculated from 8 K to 2000 K; the uncertainty of the potential is propagated into uncertainties of \(B_{12}\) . Similar calculations are performed for He with the isotopologues D \(_{2}\) , T \(_{2}\) , HD, HT, and DT. Comparison is made with the experimental data for the He/H \(_{2}\) binary, and with the limited data available for He/D \(_{2}\) and He/HD. The calculated \(B_{12}(T)\) ’s are generally consistent with the experimental results, but have lower uncertainties.     

Operating Characteristics of Lithium Drift Detectors

A study of the operating characteristics of diffused window lithium drift silicon detector has revealed that the level of compensation is independent of depth. The compensation corresponds to a net impurity concentration of 5 × 1010 impurities per cubic centimeter and is approximately three order of magnitude poorer than that set by current flow through a diode. Using time stability studies it is possible to differentiate between stability of compensation in the bulk or main body of the detector and in the window (diffused type) area of the diode. By appropriate biasing a lithium distribution can be obtained in the window area which has good time stability. The stability of the compensation in the bulk of the diode is sufficiently high that the diffused window detector will provide many years of operation, even when the detector is left largely unbiased.     

Voltage controlled minority carrier collection—the exponentially retrograded photodiode

The large retarding field in an exponentially retrograded photodiode is shown to significantly reduce the base-generated photocurrent at low reverse-bias voltages. Increasing the reverse voltage on the diode reduces the length over which this retarding field is effective, thereby increasing the Photo-Transmission Coefficient of the diode. From avalanche breakdown considerations, the largest ratio of change in photocurrent caused by this effect is shown to be only a function of the resistivity and bulk-lifetime in the base of the diode. This voltage-controlled collection effect is observable only in diodes with high background resistivity (i.e. silicon > 25 Ω cm.). It is theoretically possible to obtain voltage-controlled collection ratios of better than 50:1 in, typically, a 10 V junction swing.

Experimental results compare well with theoretical models.