Photoinduced Magnetization in a Thin Fe-CN-Co Film

The magnetization of a thin Fe-Co cyanide film has been investigated from 5 K to 300 K and in fields up to 500 G. Upon illumination with visible light, the magnetization of the film rapidly increases. The original cluster glass behavior is further developed in the photoinduced state and shows substantial changes in critical temperature and freezing temperature.Comment: 2 pages, 2 figures, 1 table, International Conference on Magnetism 200

Field repair of coated columbium Thermal Protection System (TPS)

The requirements for field repair of coated columbian panels were studied, and the probable cause of damage were identified. The following types of repair methods were developed, and are ready for use on an operational system: replacement of fused slurrey silicide coating by a short processing cycle using a focused radiant spot heater; repair of the coating by a glassy matrix ceramic composition which is painted or sprayed over the defective area; and repair of the protective coating by plasma spraying molybdenum disilicide over the damaged area employing portable equipment

Temperature measurements behind reflected shock waves in air

A radiometric method for the measurement of gas temperature in self-absorbing gases has been applied in the study of shock tube generated flows. This method involves making two absolute intensity measurements at identical wavelengths, but for two different pathlengths in the same gas sample. Experimental results are presented for reflected shock waves in air at conditions corresponding to incident shock velocities from 7 to 10 km/s and an initial driven tube pressure of 1 torr. These results indicate that, with this technique, temperature measurements with an accuracy of + or - 5 percent can be carried out. The results also suggest certain facility related problems

Magnetic Properties of a Two-Dimensional Mixed-Spin System

Using a Langmuir-Blodgett (LB) synthesis method, novel two-dimensional (2D) mixed-spin magnetic systems, in which each magnetic layer is both structurally and magnetically isolated, have been generated. Specifically, a 2D Fe-Ni cyanide-bridged network with a face-centered square grid structure has been magnetically and structurally characterized. The results indicate the presence of ferromagnetic exchange interactions between the Fe$^{3+}$ ($S=1/2$) and Ni$^{2+}$ (S=1) centers.Comment: 2 pages, 3 figs., submitted 23rd International Conference on Low Temperature Physics (LT-23), Aug. 200

Analytic theory of orbit contraction

The motion of a satellite in orbit, subject to atmospheric force and the motion of a reentry vehicle are governed by gravitational and aerodynamic forces. This suggests the derivation of a uniform set of equations applicable to both cases. For the case of satellite motion, by a proper transformation and by the method of averaging, a technique appropriate for long duration flight, the classical nonlinear differential equation describing the contraction of the major axis is derived. A rigorous analytic solution is used to integrate this equation with a high degree of accuracy, using Poincare's method of small parameters and Lagrange's expansion to explicitly express the major axis as a function of the eccentricity. The solution is uniformly valid for moderate and small eccentricities. For highly eccentric orbits, the asymptotic equation is derived directly from the general equation. Numerical solutions were generated to display the accuracy of the analytic theory

The Plasma Interaction Experiment (PIX) description and test program

The plasma interaction experiment (PIX) is a battery powered preprogrammed auxiliary payload on the LANDSAT-C launch. This experiment is part of a larger program to investigate space plasma interactions with spacecraft surfaces and components. The varying plasma densities encountered during available telemetry coverage periods are deemed sufficient to determine first order interactions between the space plasma environment and the biased experimental surfaces. The specific objectives of the PIX flight experiment are to measure the plasma coupling current and the negative voltage breakdown characteristics of a solar array segment and a gold plated steel disk. Measurements will be made over a range of surface voltages up to plus or minus kilovolt. The orbital environment will provide a range of plasma densities. The experimental surfaces will be voltage biased in a preprogrammed step sequence to optimize the data returned for each plasma region and for the available telemetry coverage

Communication Gear Shift

At 8:30 A.M. the telephone rang. It was the signal that telephone communication had been established between the international trainees at TVA and Gardner Advertising Co., St. Louis

Detergent Extraction of a Presumptive Gating Component from the Voltage-Dependent Sodium Channel

A physiologically characterized radiolabeled neurotoxin complex obtained from venom of the scorpion Leiurus quinquestriatus has been used to identify detergent-solubilized presumptive sodium channel components in sucrose gradients. This toxin-binding component is found in extracts prepared from three sources of excitable membrane but appears to be absent from similar extracts prepared from nonexcitable membrane or from Torpedo californica membrane. Procedures that destroy the physiological activity of the Leiurus neurotoxin lead to a corresponding loss of toxin binding to the putative sodium channel component. The major component recognized by the Leiurus toxin sediments at 6.5 S. Scatchard analysis of quantitative binding experiments carried out in sucrose gradients shows approximately linear plots and indicates that the toxin recognizes a relatively small number of sites with a dissociation constant near 10 nM. Once formed, the channel element--toxin complex is quite stable. Experiments show diphasic dissociation kinetics with half-times near 70 hr and greater than 200 hr