Papers

In the recent years, reversible logic has emerged as a promising technology having its applications in low power CMOS, Quantum Computing, Nanotechnology and Optical Computing. Mostly in every Computing Systems bit information is either erased or changes its status every time it performs a logic operation. This erasure is done very inefficiently and heat is dissipated in each bit of erasing. Energy efficient digital circuits used in computing systems are being developed using Reversible Logic Technique. In this paper concepts of various reversible logic gate has been described which may be used as building blocks of digital circuits used in computing system.

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The need of the hour in places where portable water is scarce is solar distillation. In the present work, a comparative study on the thermal performance .of the step type solar still and wick type solar still is carried out. Numerical analysis has been carried out by making use of temperatures of water, glass, basin and ambient and the performances of both the stills are compared. Efficiency of the still is found to be in the range of 10-25 % (wick type) and 20-40 % (step type). Physical and chemical analysis of the water samples have been done. Cost-benefit analysis has been carried out and found that the amount spent on the system could be recovered in three years. The distilled output is found to vary from 47-817ml (wick type) and 82-1258ml (step type). Step type still is found to be better in performance than the wick type still.

The vibrational analyses of 2-halopropenes are carried out by Redington's method The vibrational analysis comprises the solving of 14 x 14 and an 7x 7 inverse vibrational problems to determine the force field. The force field thus obtained is utilized to evaluate the other molecular constants such as the mean square amplitudes of vibration. The results are compared with those obtained by the earlier workers.

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Inclusion of effects of disturbances behind the shock waves moving in uniform and non-uniform medium modifies the approximate method used to investigate their propagation. Using modified CCW Method an attempt has been made to study the propagation of strong cylindrical shock waves including the effect of disturbances behind the shock through an ideal and rotating gas at permissible shock front locations for an arbitary initial density distribution of the form, say, p₀= p1 og(1+lr), where is the density at the axis of symmetry and l is non-dimensionalyzing constant.The numerical estimate of the flow variables have been computed at only on those values of propagation distance r which are permitted by the entropy distribution condition. The result obtained has been presented through graph and compared with the earlier work.

Ultrasonic velocity (U), density (r) and viscosity (h) have been measured for three amino acids viz., L-serine, L-leucine and L-histidine in aqueous magnesium chloride solution at 298.15 K. Using the experimental values, the adiabatic compressibility (β), hydration number (n_H), apparent molal compressibility (Ø_k), apparent molal volume (Ø_v), limiting apparent molal compressibility (Ø_k⁰), limiting apparent molal volume  and their constant (S_K,S_V ), transfer volume () and viscosity A and B coefficients of Jones-Dole equation were calculated for all the ternary systems. All these results have been interpreted in terms of solute- co-solute and ion-solvent interactions in the given solution.

Differential amplifiers play an important role in the analog circuit design because of their excellent performance as input amplifiers and the straightforward application with the possibility of feedback to the input. The differential amplifier circuit characterized in terms of self-bias capability, common-mode rejection, voltage gain, and the gain-bandwidth product. In this paper a new model for high performance low voltage CMOS differential amplifier has been proposed. This model is simulated using SPICE simulator and optimized device parameter with .25 micron CMOS technology.

Ultrasonic velocity has proved to be useful in understanding the physicochemical behaviour of the particular system. . Study of Borassus flabellifier (toddy) and different type of wine is important due to its wide range of applications in medicine and industries . Toddy (natural liquid of palm tree Borassus flabellifier) is chemically alcoholic behaviour on fermentation. Borassus flabellifier (Toddy) is used medicinally as a detersive astringent in intestinal troubles. We have measured ultrasonic velocity, Viscosity Density, Surface tension of Borassus flabellifier first time then calculated adiabatic compressibility b, acoustical impendence Z, intermolecular free length L_f, viscous relaxation time t, Gibb's free energy DG. We have reported Ultrasonic velocity, of absolute alcohol, different type of wine (i.e. Rum, Dry Gin, and Whiskey), Toddy with compare to distil water at temperature 313.15K and 2M.Hz.

The electrical conductivity (s) and Seebeck coefficient (S) of trivalent Nickel and Chromium zirconates are measured in the temperature range 500-1200K. It has been concluded that chromium zirconate undergoes a phase transition at 790 and nickel zirconate at 750K. In certain temperature ranges log s and S depend linearly on T^-1. It is shown that conduction mechanism in these solids is essentially band type with O^2- : 2p and M³⁺ : 4s (transition metal 4s) bands as valence and conduction band. Energy band gap and mobility of the charge carriers have also been evaluated.

Darlington pair amplifier in CC/CE configuration is a useful amplifier circuits for low voltage signals. First time we have proposed two distinct modifications in CC/CE Darlington pair amplifier by replacing one of the BJT of pair from FET and by including an extra biasing resistance R_P. We observed that one amplifier produce high voltage gain with improved bandwidth while another produces extremely wide bandwidth with consistent voltage gain. Such amplifiers with distinct behavior may be very useful for amplification of small signals in mid frequency or wide frequency bands.

The pulsing hiss emissions recorded during daytime in the frequency range of 50 Hz - 15 kHz at low latitude station Jammu (geomag. lat. = 22^o 26^/ N; L = 1.17) are reported. The reported pulsing VLF emissions is a rare phenomena at low latitudes and the spectrograms of pulsing VLF hiss emissions clearly show band limited spectrums regularly pulsing with almost equal period of the order of few seconds in the frequency range of ~ 3 to 8 kHz. Generation and propagation mechanism of these emissions are briefly discussed.