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Measurement of angular position of a rotating shaft is required in several industrial, medical, and aerospace applications. In this article, a simplified position measurement system using Tunneling Magneto-Resistance (TMR) sensing technique is proposed to cater this objective. The TMR-based rotary position-sensing system (TRPS) uses inherent merits of the TMR technology for shaft angle measurement. It processes the sensor signals, possessing sine–cosine behavior, and renders a linearly varying output. The TRPS is primarily designed and tested for angle measurement over full-circle range. However, a modified design, with lower component count, is also proposed and verified for half-circle range measurements. The circuit architecture of the TRPS and its operation are discussed in detail. Owing to its faster response, the TRPS can be used to track the angular position of the shaft, even at high speeds. The effects of non-idealities of sensor and circuit, on the TRPS output, are analyzed. Several simulation- and emulation-based tests are conducted to validate the suitability of the TRPS for static and dynamic inputs. The TRPS is found to be useful for angle measurement up to shaft speeds of 12000 rpm. A TRPS hardware is fabricated using AAT003-10E TMR integrated circuit (IC) as the sensor and tested. Experiments show that the TRPS output varies linearly for 360° range. Finally, a performance comparison study is carried out to highlight the achievements of the TRPS over the existing schemes.

An efficient approach of cancer classification using microarray expression data by vector-valued regularized kernel function approximation (VVRKFA) method is presented in a true computer aided diagnosis framework. A fast dimensionality reduction method based on maximum relevance minimum redundancy (MRMR) criteria is used to select very few genes so that both the classification accuracy and computational speed are enhanced. The experimental results are compared with support vector machines (SVM). It is observed that VVRKFA has achieved at least equal or better classification accuracy. This method also has the advantage that the separability of the data set can be observed in the label space.

Tea quality assessment is a difficult task because of the presence of innumerable compounds and their diverse contribution to tea quality. As a result, instrumental evaluation of tea quality is not practiced in the industry, and tea samples are assessed by experienced tea tasters. There had been a very few reports where an electronic tongue has been used for the discrimination of taste of tea samples. In this paper, a voltammetric electronic tongue instrument is described, which can declare tea-taster-like scores for black tea. The electronic tongue is based on the principle of pulse voltammetry and consists of an array of five working electrodes along with a counter and a reference electrode. The five working electrodes are of gold, iridium, palladium, platinum, and rhodium. The voltage equivalent of the output current from between the working electrode and the counterelectrode generated out of the tea liquor when excited with pulse voltage between the working electrode and the reference electrode has been considered for data analysis. First, the sampled data have been compressed using discrete wavelet transform (DWT) and are then processed using principal component analysis (PCA) and linear discriminant analysis (LDA) for visualization of underlying clusters. Finally, different pattern recognition models based on neural networks are investigated to carry out a correlation study with the tea tasters' score of five different grades of black tea samples obtained from a tea garden in India. The efficacy of the classifier has been established using tenfold cross-validation methods.

The existing energy-use pattern, based on the prevailing cultivation practices and the optimal energy-demand based on the optimal mechanization strategy for animal operated paddy farms of Assam (India) were assessed. Two categories of paddy farms, i.e. with and without the use of chemical fertilizers were identified. Lower yield (1976 kg/ha) associated with a lower energy-input (5681 MJ/ha) was the characteristic feature of farms not using fertilizer in contrast to the higher yield (3165 kg/ha) and energy input (9290 MJ/ha) of fertilizer-user farms. Human and animal (as also chemical fertilizer for fertilizer-user farms) were the major energy sources under the existing practices contributing to more than 70% of the total energy-input. The optimal demand of energy to achieve a potential paddy yield of 6000 kg/ha was estimated as 11,168 MJ/ha comprising human, animal, diesel, and fertilizers as the major energy sources. Though the overall energy demand increased, the introduction of improved tillage implements could reduce the future optimal demand of animal energy for animal-operated paddy farms in Assam.

The authors have continued their research in the area of assembly and reactivity of photochemical systems in zeolites and double layered metal hydroxides. Over the last year, the authors have focused on two issues, increasing the photochemical efficiency of charge separation in a triad system and the chemistry of Ru(bpy){sup 3+}{sub 3} in zeolites.

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This report summarizes work in the two areas of zeolites and layered double hydroxides. Results of studies on structural aspects of Ru(bpy){sub 3}{sup 2+}-zeolite Y are summarized. Photoinduced electron transfer between entrapped Ru(bpy){sub 3}{sup 2+} and methylviologen (MV) in neighboring supercages was examined. Benzylviologen was also used. Since molecules larger than 13 {angstrom} cannot be accomodated in zeolite cages, the layered double metal hydroxides (LDH) LiAl{sub 2}(OH){sub 6}{sup +}X{sup {minus}} is being investigated. Organized assemblies of hydrophobic domains are made by introducing into the interlayer long-chain carboxylic acids R(CH{sub 2}){sub n}COOH. Zinc tetraphenylporphyrin sulfonate (ZnTPPS) is introduced into myristate-LiAl-LDH; photolysis of ZnTPPS-AiAl-LDH with MV{sup 2+} in solution was examined.

Research continued on photochemically induced electron transfer in zeolites. Reactions and synthesis of Ru(bpy){sub 3}{sup 2+} are discussed. Also, the intercalation properties of LiAl{sub 2}(OH){sub 6}{sup +}-X{sup {minus}} are being pursued. 5 figs. (CBS)

To achieve the target of health for all by 2000 AD (HFA/2000), developing countries such as India need a proper perspective to implement health for all through a Primary Health Care approach and must develop a plan to achieve manpower needs. The present health institutional infrastructure is inadequate to meet this requirement. Distance education is a relatively new concept which not only has the ability to train a large number of health care workers in a short time in a cost effective way but can also attend to skills of health care without diluting the quality. The School of Health Sciences, IGNOU, is, at present, working on two health programs for nursing and medical personnel through distance education. Alternate models in distance education could also be envisioned to meet the immediate pressing needs.