A review on reversible logic gates

In recent years, reversible logic circuits have applications in the emerging field of digital signal processing, optical information processing, quantum computing and nano technology. Reversibility plays an important role when computations with minimal energy dissipation are considered. The main purpose of designing reversible logic is to decrease the number of reversible gates, garbage outputs, constant inputs, quantum cost, area, power, delay and hardware complexity of the reversible circuits. This paper reveals a comparative review on various reversible logic gates. This paper provides some reversible logic gates, which can be used in designing more complex systems having reversible circuits and can execute more complicated operations using quantum computers. Future digital technology will use reversible logic gates in order to reduce the power consumption and propagation delay as it effectively provides negligible loss of information in the circuit.   Keywords: Garbage output, Power dissipation, quantum cost, Reversible Gate, Reversible logic

Catalytic Influences of Dispersed copper Complex ion on Aquathermolysis of Heavy Crude Oil

Copper based catalyst Cu2+ was synthesized and characterised by X-ray diffraction (XRD) and Fourier transform infrared (FT-IR). Various concentrations of this catalyst was used to catalyse aquathermolysis of medium heavy crude oil (API gravity = 29.40o) at temperature of 200oC for three hours (3h). The oil sample(s) were characterised before and after aquathermolysis reaction using FT-IR. SARA analysis was carried out using column chromatography and the sulphur content, kinematic viscosity, density and API gravity were also determined. The original viscosity of the fresh crude oil was 9.8799 m2/s, after the reaction without catalyst; the viscosity was reduced to 8.8125 m2/s (10.80% reduction). When Cu2+ was used at optimum concentration, it was further reduced to 7.7339 m2/s (21.61% reduction).  The catalyst reduced the sulphur content by 4.37% and it was reduced by 2.77% when no catalyst was used. Also, API gravity was increased by 1.02% without catalyst while it was reduced by 2.72% when the catalyst was used. The results indicate that the percentage by weight of asphaltenes and resins were reduced due to cleavage on carbon to heteroatom bonds while that of aromatics and saturates were increased. The compared results with previous researches strongly confirmed that this catalyst possessed good catalytic activity owing to its strong viscosity reduction properties

Design of Key-shaped monopole antenna for UWB applications

In this paper key shaped monopole antenna with and without rectangular slot inserted on feeding strip is proposed for Ultra Wide Band (UWB). This UWB antenna is etched on a 30 x 30mm2 commercially available low cost substrate of Flame Recorded Grade 4 (FR4) with thickness of 1.6mm, relative dielectric constant ɛr = 4.4 and dielectric loss tangent = 0.02. One of the industry leading 3D EM software tools for radio frequency (RF) application known as High Frequency Structure Simulator (HFSS) was used to design this UWB antenna. The reflection coefficient S11 of the proposed antenna was found to be less than -10dB and Voltage Standing Wave Ratio (VSWR) is less than 2. It was found that the designed UWB antenna is operable over the entire 3.1GHz - 10.6GHz frequency range.KEYWORDS: Key-shaped monopole antenna, rectangular slot, HFSS software, UWB antenna, flame recorded grade

Review on the determination of turbulent flow in carbonate aquifers

No AbstractKeywords: Turbulent flow, Aquifer, Tracer tests, Spring discharge, Hydraulic conductivit