ETC research at Soreq NRC, Israel
An overview of the electro-thermal-chemical launcher (ETC) research program at the Propulsion Physics Laboratory, Soreq NRC, Israel is presented. The main avenue explored is a detailed study of solid propellant ETC (SPETC) performance and optimization. A better knowledge of the physical phenomena taking place inside the device and in parallel efforts to tackle the engineering aspects of specific weapon systems based on the SPETC concept. Theoretical and experimental tools have been developed. Permanent efforts towards developing optimal and efficient components for such systems are invested. A second avenue is the design and the construction of a small caliber ETC demonstrator, as an answer for present military demands for urban combat conditions. All system options are dealt with including a novel inductive pulse power supply.
A theoretical model for the physical processes in the confined high pressure discharges of electrothermal launchers
Different physical processes in confined high-pressure discharges are analyzed. The energy transport inside the discharge tube yields a radial temperature profile which has sharp gradients only near the tube walls. The regime at which such discharges can operate at a steady state is determined. For a given discharge ablation rate and plasma pressure, the tube length is limited. An analytical model is developed for confined high-pressure discharges operating in a quasi-steady-state in which the resulting plasma jet characteristics are steady at hydrodynamic timescales. This model allows the calculation of all the discharge parameters, such as ablation rate plasma temperature, resistivity, density and pressure as functions of the slowly varying current and the tube dimensions. The scaling laws obtained in this model are important for determining the impedance matching between the discharge and the power source and upgrading the discharge energy in electrothermal launchers to hypervelocities. Good agreement is obtained between the analytical model and experimental results at energies up to 100 kJ. >
Adsorption of immunoglobulin Y in supermacroporous continuous cryogel with immobilized Cu(2+) ions.
The influence of temperature, pH and ionic strength on the adsorption of Immunoglobulin Y (IgY) in IDA-Cu(2+) cryogel system was studied by batch equilibrium measurements. The adsorptive equilibrium data were obtained at 17 and 27°C, pH 5.0 and 6.5, and at ionic strength of 50 and 200mmolL(-1) NaCl. Langmuir, Freundlich and Langmuir-Freundlich models were fitted to equilibrium data, while the enthalpy of adsorption of IgY in IDA-Cu(2+) cryogel system was calculated through Van't Hoff analysis. The binding of IgY on cryogel was stronger at 27°C and lowest pH and ionic strength values, with apparent maximum adsorption capacity of 27mgg(-1). The adsorption of protein in the resin was spontaneous in all analyzed cases. The results provide valuable information to enable the improvement of IgY purification processes.