High gradient directional solidification furnace

A high gradient directional solidification furnace is disclosed which includes eight thermal zones throughout the length of the furnace. In the hot end of the furnace, furnace elements provide desired temperatures. These elements include Nichrome wire received in a grooved tube which is encapsulated y an outer alumina core. A booster heater is provided in the hot end of the furnace which includes toroidal tungsten/rhenium wire which has a capacity to put heat quickly into the furnace. An adiabatic zone is provided by an insulation barrier to separate the hot end of the furnace from the cold end. The old end of the furnace is defined by additional heating elements. A heat transfer plate provides a means by which heat may be extracted from the furnace and conducted away through liquid cooled jackets. By varying the input of heat via the booster heater and output of heat via the heat transfer plate, a desired thermal gradient profile may be provided

General purpose rocket furnace

A multipurpose furnace for space vehicles used for material processing experiments in an outer space environment is described. The furnace contains three separate cavities designed to process samples of the widest possible range of materials and thermal requirements. Each cavity contains three heating elements capable of independent function under the direction of an automatic and programmable control system. A heat removable mechanism is also provided for each cavity which operates in conjunction with the control system for establishing an isothermally heated cavity or a wide range of thermal gradients and cool down rates. A monitoring system compatible with the rocket telemetry provides furnace performance and sample growth rate data throughout the processing cycle

Macroeconomic fluctuations in Europe: demand or supply, permanent or temporary?

We use generalized method of moments to estimate a rational expectations aggregate demand-aggregate supply macroeconomic model for five European economies. Our aim is to examine whether supply or demand shocks have predominated in the major European economies during the post-war era and whether shocks of either type have been primarily temporary or permanent in nature. The estimation procedure is an alternative to estimating and interpreting vector autoregressions under restrictions either of the Bernanke-Sims variety or the Blanchard-Quah variety or to performing calibration exercises. ; We find that all four types of shocks (permanent supply, permanent demand, temporary supply, and temporary demand) are needed to account for the data on output and inflation. Permanent or temporary demand shocks have been the dominant source of variance in output growth in four of the five countries, but there is no consistent pattern for inflation.Business cycles ; Econometric models ; Europe ; Macroeconomics

Evaluation of a composite mobile holographic nondestructive test system

A simplified theoretical model for the interpretation of the double-exposure holographic interference fringe loci due to the general three-dimensional displacements was derived for the specific composite mobile holographic nondestructive test system. The model, representing a good approximation to a more tedious theoretical result, predicts that a combination of in-plane and out-of-plane displacements of the surface will produce concentric circular-shaped fringe patterns with locations of their center affected by the displacements. Appropriate experiments were designed and carried out for the test of the validity of the theory. These experiments include the taking of double-exposure holograms of in-plane translations and combined in-plane and out-of-plane translations. The simplified model agreed quite well with the experimental results. Experimentally observed effects due to the curvature of the test plate and the variations of the angles of incidence of the laser light suggest that in order for the simplified model to be able to predict the test results more accurately, incidence and reflection of the laser light should be chosen as nearly perpendicular to the surface of the tested object as possible

Macroeconomic fluctuations in Europe: demand or supply, permanent or temporary?

We use generalized method of moments to estimate a rational expectations aggregate demand-aggregate supply macroeconomic model for five European economies. Our aim is to examine whether supply or demand shocks have predominated in the major European economies during the post-war era and whether shocks of either type have been primarily temporary or permanent in nature. The estimation procedure is an alternative to estimating and interpreting vector autoregressions under restrictions either of the Bernanke-Sims variety or the Blanchard-Quah variety or to performing calibration exercises. ; We find that all four types of shocks (permanent supply, permanent demand, temporary supply, and temporary demand) are needed to account for the data on output and inflation. Permanent or temporary demand shocks have been the dominant source of variance in output growth in four of the five countries, but there is no consistent pattern for inflation