Highly solar active Fe(III) immobilised alumina for the degradation of Acid Violet 7

The hetero-Fenton catalyst Fe(III)-Al₂O₃ was prepared and characterised by ICP-AES, FT-IR and SEM-EDX. A detailed investigation of photocatalytic degradation of Acid Violet 7 (AV 7) using this Fenton immobilised Al₂O₃ catalyst was carried out. The optimal reaction conditions for the photodegradation of AV 7 with this catalyst are reported. Higher efficiency of the catalyst in solar light than in UV light makes this heterophoto-Fenton degradation, a green technological process. The catalyst is found to be stable and reusable. The completion of degradation has also been confirmed by chemical oxygen demand (COD) measurements.     

Improvements in Noise Suppression for I/O Circuits Using Embedded Planar Capacitors

The performance of embedded planar capacitors in noise suppression of input/output (I/O) circuits and improvements in board impedance profile have been investigated in this paper. Simultaneous switching noise (SSN) is a critical issue in today's systems and this paper shows performance improvements by introducing thin planar embedded capacitors in the board stack up. Measurement and modeling results by including the effects of transmission lines and the power ground plane pairs in the board stack up in the gigahertz range quantify the performance of the embedded capacitors.     

Tensile flow and fracture behaviour of a superplastic Al-Ca-Zn alloy

The tensile flow behaviour in the range 275 to 550 ° C of an ultra-fine-grained superplastic Al-Ca-Zn alloy is reported. Under certain conditions of temperature and strain rate, superplastic ductility could be established. Fracture surfaces of tensile specimens tested in the above temperature range were examined by scanning electron microscopy and a correlation could be obtained between the ductility, as revealed by the tension tests, and the fracture behaviour. The fractographic studies also suggested a transition in the deformation process from grain deformation (mainly slip) at the lower temperatures to grain-boundary deformation (predominantly grain-boundary sliding) in the vicinity of 425 ° C.     

Effects of load ratio and temperature on the near-threshold fatigue crack propagation behavior in a CrMoV steel

The influence of temperature in the range of 24 to 260 °C and load ratio on the near-threshold fatigue crack growth rate behavior of a CrMoV steel was characterized. At all temperatures investigated, the threshold stress intensity range, ΔK _th, for fatigue crack growth decreased with increasing load ratio. The near-threshold crack growth rates increased significantly at 149 °C when compared with the rates at room temperature. However, the crack growth rates at 260 °C were comparable to those at 149 °C. These observations are rationalized in terms of the concepts of roughness and oxide-induced crack closure. Extensive fracture surface characterization using SEM, oxide thickness measurements by Auger spectroscopy, and roughness measurements by light-section-microscopy were conducted to substantiate the explanations.     

Studies on a vegetable protein mixture based on peanut and soya flours

A vegetable protein mixture made up of 50% edible peanut flour and 50% full-fat soya flour and fortified with 1% each of 1-lysine and dlmethionine and adequate amts of essential vitamins and minerals has been developed. Two formulations, 1) unseasoned and 2) seasoned have been developed for use in sweet and savoury preparations; both the formulations keep well for more than 9 months at 37C when stored in hermetically sealed cans. The protein mixture contains 49.2% protein which possesses a PER of 2.80 and NPU of 72.3; these values compare favourably with those for skim milk powder. Growth studies on albino rats and feeding trials on school children have shown that the protein mixture has a significant supplementary value to poor cereal-based diets. The mixture fortified with methionine alone is equally effective as skim milk powder for the treatment of kwashiorkor.     

Inverse radiation problem to retrieve hydrometeors from satellite microwave radiances

This study presents a new hybrid method that combines regression analysis with genetic algorithms for the retrieval of hydrometeors (cloud liquid water, ice and rain) in the atmosphere, from satellite microwave radiances. A three layered atmosphere model (divided into 30 sub-layers) is used to generate simulated profiles of hydrometeors. The equation governing the transfer of radiation is solved using the finite volume method to obtain radiances (brightness temperatures) in the microwave region. This is known as the forward problem and is solved repeatedly to create a database with which regression equations are developed for the monochromatic microwave radiances, for six typical frequencies ranging from 6.6 to 85 GHz. The regression is done using nonlinear parameter estimation techniques. The inverse problem of retrieving the hydrometeors characteristics from microwave radiances is accomplished by posing the parameter estimation problem as an optimization problem, wherein, minimization of the sum of squares of residuals between the estimated and known radiances, for the above mentioned six typical frequencies, is done. In this study, genetic algorithms have been used for solving the minimization problem.     

Experimental determination of low order structure factors in the intermetallic compound TiAl

Rocking curves from several low order reflections in TiAl were recorded in digitized form using energy-filtered convergent beam electron diffraction in a transmission electron microscope. The low order reflections studied were 001, 002, 200, 111, 110, 220, 202, 113, and 311. These experimental rocking curves were simulated using computations based on the dynamic theory of electron diffraction. From these simulations, values of the X-ray structure factors for these reflections were deduced, and then used to determine charge difference maps for varioius plane sections in TiAl. These charge difference maps were compared with theoretical predictions, and it was found that there is a considerable degree of agreement between theory and experiment.