BiCMOS adjustable linear current mirror

Two novel BiCMOS adjustable gain linear current mirrors are presented. Variable gain is achieved by introducing a DC voltage into the control loop. Simulation and experimental results indicate that the gain is linear over several decades of signal current. The circuits are designed for maximum voltage swing with cascoded output to provide high output resistance     

Equivalence of the angular forces in the lattice dynamics of fcc metals

The expressions for the Clark, Gazis and Wallis type of angular forces are rederived in the caseof fcc metals. These expressions are now foundtobe equivalent to the deLauney type of angular forces.     

Electrical conductivity studies of cobalt-precipitation in RbCl crystals

The results of electrical conductivity measurements in heavily doped RbCl:CoCl₂ crystals with 2500 and 6000 ppm of cobalt are being reported in this paper. The different regions of the conductivity plots for the crystals with the two concentrations of cobalt have been explained and relevant energy parameters determined. The crystals with 6000 ppm of cobalt have been found to contain two types of precipitates one of these being of the same type as that existing in RbCl crystals with 2500 ppm of cobalt while the other being of a different composition. Further, it has been found that the crystals appear blackened after heating during measurements. The blackening has been attributed to the expulsion of cobalt from the bulk of the crystal which forms an oxide at the surface.     

A simple method of photomask yield optimization by defect inspection

The quality of the photomask set decides to a large extent the quality and quantity of the device that will be produced. In order to ensure the quality of the photomasks, several sophisticated instruments are commercially available. However, in a research type of environment, the cost of such equipment can be prohibitive. In this paper, we propose a simple method of multiple master mask preparation with subsequent matching of defective die locations to optimize the master mask set. The advantage here is that a very good master mask set can be chosen so that minimum number of dies on the photomask set itself contribute to low wafer yield. The method is based on manual inspection of individual dies on photomasks and can be practically used for a complexity of up to 500 components.     

Cost function analysis of a 3-state reparable system

This paper presents the cost function analysis of a system with 3 states: good, degraded and failed. The system suffers from two types of failure: partial and catastrophic. The partial and catastrophic failures bring the system to degraded and failed state respectively. There is only one server, which is always available. The failure and repair times for the system follow exponential and general distributions respectively. Laplace transforms of various probability states are obtained along with steady-state behaviour of the system. A numerical example has also been discussed to highlight the important results.     

Reliability analysis of a three-state multi-component warm standby redundant complex system with waiting for repair

Investigations have been carried out with the help of Laplace transforms and supplementary variable techniques for the evaluation of reliability analysis of a three-state multi-component warm standby redundant complex system suffering three types of failures, namely minor, major, and human due to critical human errors incorporating the concept of waiting for repair.     

Stochastic quantization and regularization

In this paper the method of stochastic quantization introduced by Parisi and Wu is extended to field theories that include fermions and are supersymmetric. A new non-perturbative regulator based on stochastic quantization is introduced. This regulator preserves all the symmetries of the lagrangian, including gauge, chiral, and supersymmetries, at the expense of introducing non-locality.     

Holographic interferometry of non-sinusoidal vibrations

In this paper, the techniques of extended pulse stroboscopic holography and holographic subtraction have been applied to the study of periodic, non-sinusoidal vibrations represented by a Jacobian elliptic function. Fringe irradiance distribution in reconstructed images has been evaluated for the two cases. For this purpose we make use of an expression for the characteristic fringe function derived from considerations of the effect of motion on the coherence. It is shown that the above-mentioned techniques are more advantageous for the measurement of periodic, non-sinusoidal vibrations than in the case of pure sinusoidal vibrations.     

Radiation resistance of a square loop in a warm plasma

A linearised hydrodynamic theory has been used to calculate the radiation resistance of a square-loop antenna in a warm plasma. It is suggested that cosinusoidal currents of two different propagation coefficients and amplitudes are simultaneously and independently present. Comparisons of the theoretical results with the measured values of the radiation resistance of a square-loop antenna on Ariel 3 satellite gives the ratio of the amplitudes of the currents in the two modes, for various values of the ratio of plasma to measuring frequency.     

Phase transition and its pressure dependence in polyethylene

The cell model for diffusion transition has been applied to study first order phase transition and its pressure dependence in polyethylene. The experimental data of Matsuoka have been utilized. The agreement with experimental curves gets progressively better at higher pressure values because of the accompanied crystallisation.