Ti-silicalite as catalyst for gas-phase ammoximation of cyclohexanone with molecular oxygen

The catalyst behaviour of titanium silicalite, which was found the most active and selective catalyst for liquid-phase ammoximation of cyclohexanone to the corresponding oxime with hydrogen peroxide, was investigated in the gas-phase ammoximation with molecular oxygen in and compared with those of pure silicalite and samples of vanadium and chromium silicalites. The results showed that Ti-silicalite is a selective catalyst not only in the reaction with hydrogen peroxide but also in the reaction with molecular oxygen. However, a big limitation was found in the poor activity of the silicalites which do not allow to reach high oxime yields.     

TCAD and SPICE modeling help solve ESD protection issues in analog CMOS technology

The number of circuit design iterations due to electrostatic discharge (ESD) failures increases with the complexity of VLSI technologies and their shrinking. In this paper, we show how TCAD and ESD SPICE modeling can be used to solve ESD protection issues in an analog CMOS technology.     

An analytical expression for the power coefficient of an ideal horizontal-axis wind turbine

The paper shows that an analytical evaluation of the power coefficient C_p for an ideal horizontal-axis wind turbine can be made via an expression giving the direct relationship of C_p and the axial induction factor a. The results obtained agree closely with those obtained numerically from the usual integral expression involving several variables.     

Quantification of Three Cholesterol Oxidation Products in Raw Meat and Chicken

Raw veal, beef, pork, and chicken muscle tissues were extracted by a modified dry column procedure in which silicic acid was incorporated in the trap of the column. This method separated cholesterol derivatives from the bulk of neutral lipids, phospholipids and cholesterol. Isolation of sterols by preparative thin layer chromatography followed by quantification by direct on-column capillary gas chromatography permitted measurement of 7-ketocholesterol, cholesterol 5α, 6α-epoxide, and cholesterol 5β 6β-epoxide at concentrations less than 1 ppm. All muscle tissues contained the three cholesterol products in measurable quantities. 7-Ketocholesterol constituted more than 50% of the oxidation products in all samples.     

Learning and convergence analysis of neural-type structurednetworks

A class of feedforward neural networks, structured networks, has recently been introduced as a method for solving matrix algebra problems in an inherently parallel formulation. A convergence analysis for the training of structured networks is presented. Since the learning techniques used in structured networks are also employed in the training of neural networks, the issue of convergence is discussed not only from a numerical algebra perspective but also as a means of deriving insight into connectionist learning. Bounds on the learning rate are developed under which exponential convergence of the weights to their correct values is proved for a class of matrix algebra problems that includes linear equation solving, matrix inversion, and Lyapunov equation solving. For a special class of problems, the orthogonalized back-propagation algorithm, an optimal recursive update law for minimizing a least-squares cost functional, is introduced. It guarantees exact convergence in one epoch. Several learning issues are investigated.