Effect of the temperature gradient,growth rate,and the interflake spacing on the microhardness in the directionally solidified Al-Si eutectic alloy

An alloy of composition Al-12.6 wt.% Si was prepared using metals of 99.99% purity. Weighed amounts of aluminium and silicon were melted in the vacuum-melting furnace. This irregular eutectic alloys were directionally solidified upward with a constant growth rate V (8.3×10⁻³ mm/s) and different temperature gradients G (2.0–7.8 K/mm) and also with a constant temperature gradient G (7.8 K/mm) and different growth rates V (8.3–498.7×10 ⁻³mm/s) in the directional solidification furnace. The interflake spacings λ and microhardness H_V were measured from both transverse section and longitudinal section of the specimen. The variations of H_V with respect to G, V, and λ have been determined by using the linear regression analysis method. It has been shown that H_V increases with the increasing values of G and V. On the other hand H_V values decreases with the increasing λ values. The Hall-Petch type relationships obtained in this work have been compared with the previous works.     

Game theory approach to use of noncommercial power plants undertime-of-use pricing

The authors use the game theory approach for evaluating the impact of the introduction of customer-owned noncommercial power plants (NCP) when time-of-use pricing is used. Various results from this analysis are derived, some of which are that the conflict between NCP customer and the supplier forces the supplier to reduce the price of NCP customers. Perception of the situation in which they are involved in plays an important role in this conflict. The game model analysis presented provides a detailed quantitative information on electricity prices and on the ways of using NCP     

A new technique for determining the capacitive couplingcoefficients in flash EPROMs

A method for determining the capacitive coupling coefficients of flash erasable programmable read only memories (EPROMs) is introduced. This technique relies on the Fowler-Nordheim erase measurements and source/drain junction leakage characteristics of the device to extract the control gate, source, and drain coupling coefficients. An advantage offered by this method is its use of an actual flash EPROM cell without requiring additional test structures     

Test of goodness of fit of impulse response model

A method for testing goodness of fit of an impulse response model of a dynamical system has been proposed. This method is also applicable after a slight modification to testing the hypothesis that the system is linear and autonomous. Hotelling's ,T²-test and the sign test are useful tools for these problems. Properties of the method are discussed with results of computer simulation runs.