Deep fat frying characteristics of chickpea flour suspensions

Chickpea ( Cicer arietinum ) (Bengal gram) flour suspensions are widely used in the preparation of oriental traditional snacks and sweets. We investigated the frying characteristics of small and large boondi , a traditional product made by deep fat frying the droplets of chickpea flour suspensions. The rate of water loss during frying was much higher than that of oil uptake. Towards the end of frying, the bulk densities of small and large boondis were similar and remained constant. The analysis of microstructure of the product indicated that there were large pores and vacuoles inside, whereas the outer surface remained fairly smooth with fewer smaller pores. The colour changes during frying were described in terms of tristimulus values (brightness, hue and chroma) and yellowness, of which brightness decreased markedly; the colour of the product changed from bright yellowish orange (raw batter) to dull orange (finished product).     

System-Level Specification Testing Of Wireless Transceivers

This paper presents an efficient system-level manufacturing test methodology for wireless transceiver systems. Conventional system-level testing procedures incur large test times and require the use of multiple test hardware configurations for measuring frequency and modulation-domain performance specifications, e.g., system-gain, nonlinearity, noise-figure, channel power, adjacent-channel power-ratio, error vector magnitude, modulation signal-to-noise ratio and bit error rate. The proposed test methodology addresses these problems by simplifying the test stimulus application and test response capture/analysis procedures. In addition, the number of test hardware configurations needed to measure all the performance specifications is minimized and fewer as well as shorter tests are used to determine all the test specification values of interest. Test accuracy is achieved by optimizing the test stimulus so that the observed response has strong statistical correlation with the target test specification values. Experimental results show significant testing time reduction and was validated on 1.575 GHz and 900 MHz wireless transceiver prototypes.     

Investigation of the interface region produced by molecular beam epitaxial regrowth

The interface region generated by molecular beam epitaxial regrowth has been studied in detail. Regrowth was carried out on epitaxial GaAs after a variety of realistic device processing steps. Combinations of wet chemical etching and ion milling with and without annealing were used with the objective of establishing the best procedure for integrated technologies during regrowth. Capacitance voltage measurements showed perturbations in the carrier profile corresponding to depletion and accumulation regions at the interface which are directly related to interface states at and around the regrowth interface. The measured concentration of the interface states are in the range 1.2 × 10¹⁰ to 7.05 × 10¹¹ cm⁻². The former is one of the lowest reported till date. The concentration of deep traps in the regrown layer and interface, observed by deep level transient spectroscopy, is much lower than the interface state density. Their contribution to carrier perturbation is insignificant, except in one case where an electron trap has a rather high concentration. Results of secondary ion mass spectroscopy indicate that the presence of carbon at the regrown interface is not principally responsible for creating the high resistivity interface region. Our data favor the concept of a disordered region created at the interface during regrowth. Interface state density and trap densities are much larger in the wet chemically etched samples, which is further supported by the results of temporal photoresponse measurements on junction photodiodes. The overall characteristics of the dry etched regrowth interfaces seem to be much more promising than the wet chemical etched ones. On leave from the Institute of Radiophysics and Electronics, The University of Calcutta, Calcutta 700 009, India.     

Nature of growth inhibitors for Trogoderma granarium Everts (Coleoptera: Dermestidae) in lentil (Lens esculenta Moench.) and French bean (Phaseolus vulgaris L.)

Steaming of lentil (Lens esculenta Moench.) and French bean (Phaseolus vulgaris L.) made them suitable for Trogoderma granarium Everts. Addition of glucose, casein, cholesterol, lard, nucleic acid, McCollum salt mixture, vitamins of the B group and -methionine indicated that the poor food value of lentil was due to the presence of heat labile inhibitor and dietary deficiency of cholesterol. But in the case of French bean heating probably facilitated, apart from destruction of heat labile inhibitor, the release of an assimilable form of carbohydrate needed for proper growth and development. The possibility of the presence of qualitatively and/or quantitatively different types of inhibitors in these pulses was suspected.     

A comparative study of YBCO powders prepared by different processes

Abstracts are not published in this journal This revised version was published online in November 2006 with corrections to the Cover Date.     

Transistor-level optimization of digital designs with flex cells

The flex-cell approach, either alone or in combination with standard cells, provides an optimally tuned set of building blocks for integrated circuit design when optimality is measured using accepted and quantifiably definable metrics such as clock speed, die size, and power consumption.     

CMOS implementation of a multiple-valued logic signed-digit fulladder based on negative-differentiaI-resistance devices

This paper presents a fully integrated implementation of a multivalued-logic signed-digit full adder (SDFA) circuit using a standard 0.6-μm CMOS process. The radix-2 SDFA circuit, based on two-peak negative-differentiaI-resistance (NDR) devices, has been implemented using MOS-NDR, a new prototyping technique for circuits that combine MOS transistors and NDR devices. In MOS-NDR, the folded current-voltage characteristics of NDR devices such as resonant-tunneling diodes (RTDs) are emulated using only nMOS transistors. The SDFA prototype has been fabricated and correct function has been verified. With an area of 123.75 by 38.7 μm² and a simulated propagation delay of 17 ns, the MOS-NDR prototype is more than 15 times smaller and slightly faster than the equivalent hybrid RTD-CMOS implementation     

Effect of post-deposition annealing on microstructural and optical properties of barium strontium titanate thin films deposited by r.f. magnetron sputtering

The effect of post-deposition annealing on the structural and optical properties of barium strontium titanate, Ba_0.8Sr_0.2TiO₃ film has been investigated. The films have been deposited on oxidized p-silicon substrates by r.f. magnetron sputtering followed by annealing in O₂ atmosphere at different temperatures. In situ deposition has also been carried out at 550 °C for comparison. The nature of the variation of refractive index and extinction coefficient with annealing temperature and wavelength has been studied. Absorption band edges shift towards lower photon energy values as the temperature is increased causing a reduction in the optical band gap energy. Infrared absorption bands show a cubic symmetry at lower frequency and are found to be broadened and even split at higher frequency.     

Characteristics of a photonic bandgap single defect microcavityelectroluminescent device

A microcavity surface-emitting coherent electroluminescent device operating at room temperature under pulsed current injection is described. The microcavity is formed by a single defect in the center of a 2-D photonic crystal consisting of a GaAs-based heterostructure. The gain region consists of two 70-Å compressively strained In_0.15Ga_0.85As quantum wells, which exhibit a spontaneous emission peak at 940 nm. The maximum measured output power from a single device is 14.4 μW. The near-field image of the output resembles the calculated TE mode distribution in a single defect microcavity. The measured far-field pattern indicates the predicted directionality of a microcavity light source. The light-current characteristics of the device exhibit a gradual turn-on, or a soft threshold, typical of single- or few-mode microcavity devices. Analysis of the characteristics with the carrier and photon rate equations yields a spontaneous emission factor β≈0.06