INDIACo m-2009 Co mputing For Nation Development

ABSTRAC

Two Bit Arithmetic Logic Unit (ALU) in QCA

Abstract –Quantum cellular automata (QCA) is a new technology in nanometre scale (<18nm) to support nano technology. QCA is very effective in terms of high space density and power dissipation and will be playing a major role in the development of the Quantum computer with low power consumption and high speed. This paper describes the design and layout of a 2-bit ALU based on quantum-dot cellular automata (QCA) using the QCADesigner design tool. The ALU design is based on combinational circuits which reduces the required hard-ware complexity and allows for reasonable simulation times. The paper aims to provide evidence that QCA has potential applications in future Quantum computers, provided that the underlying technology is made feasible. Design has been made using certain combinational circuits by using Majority gate, AND, OR, NOT, X-OR in QCA. 2 bit ALU needs the design of Logical Extender, Arithmetic Extender and the Full adder circuits using QCA. The QCA is a novel tool to realize Nano level digital devices and study and analyze their various parameters. To date, proof of concept QCA cells have been experimentally verified using a device which exploits the Coulomb blockade phenomenon [10], although the originally proposed cell is still beyond present fabrication capabilities. As a result, investigators are currently looking at creating QCA cells using single molecules [11]

Development of gravitational acceleration measurement set up based on laser beams

In this paper, using three parallel laser beams system we have calculated the value of gravitational acceleration (g) by deriving a simple equation, where there is no velocity term, is reported. The numerator of the equation is always positive irrespective of distances. The setup consists of commonly available three red laser light-emitting diodes and three sensors using very common fast transistors. A free-fall object intercepts the laser beams to produce three voltage pulses across the collector-emitters of three transistors. These voltage pulses are fed to a storage oscilloscope for measuring the two time-intervals between two subsequent gaps of three laser beams with millisecond resolutions. Time intervals are also measured by two-microsecond timers in microsecond resolution. The object may fall from any height above first laser beam, but the 'g' calculated remains the same. Measurements were done by letting an object fall from two different heights, six times from each height, and the average value of 'g' of 9.8036916315 meters per second squared is calculated using the data of two-microsecond timers, which has a 0.03% deviation from the standard value of 9.80665 meters per second squared. Results obtained using microsecond timers are more accurate than that obtained using oscilloscope millisecond data

Bharati Vidyapeeth's Institute of Computer Applications and Management

ABSTRAC