Higher College of Technology

About: Higher College of Technology is a based out in . It is known for research contribution in the topics: Computer science & Higher education. The organization has 369 authors who have published 379 publications receiving 729 citations.

Buoyant convective flow of different hybrid nanoliquids in a non-uniformly heated annulus

Abstract: A sealed annular geometry containing nanoliquids with differently heated boundaries aptly describes the geometrical structure of many important cooling applications. The present study reports the numerical investigation on the effect of axially varying temperature in the form of sinusoidal thermal profiles along the side walls of an annular enclosure containing different hybrid nanoliquids with insulated horizontal boundaries. An implicit FDM based approach is adopted to solve the transient and steady-state model equations and numerical simulations are presented to describe the qualitative flow behavior as well as the quantitative thermal transport rates. The prime objective of the analysis is to enhance the buoyant flow circulation strength as well as the associated thermal dissipation rates and is achieved by identifying a suitable combination of nanoparticle along with a proper choice of geometrical parameters. Numerical predictions revealed the buoyant motion and thermal dissipation rate could be effectively controlled by a proper selection of phase deviation. Further, the appropriate combination of nanoparticles is another crucial parameter in enhancing the thermal transport in the geometry.

A Multi-Layered Data Encryption and Decryption Scheme Based on Genetic Algorithm and Residual Numbers

Abstract: Over the years, Steganography and Cryptography have been complementary techniques for enforcing security of digital data. The need for the development of robust multi-layered schemes to counter the exponential grow in the power of computing devices that can compromise security is critical in the design and implementation of security systems. Therefore, we propose a new combined steganographic and cryptographic scheme using the operators of genetic algorithm (GA) such selection, crossover and mutation, and some properties of the residue number system (RNS) with an appropriate fusing technique in order to embed encrypted text within images. The proposed scheme was tested using MatLab ® R2017b and a CORE™i7 processor. Simulation results show that the proposed scheme can be deployed at one level with only the stego image containing the encrypted hidden message and at another level where the stego message is further encrypted. An analysis based on standard key metrics such as visual perception and statistical methods on steganalysis and cryptanalysis show that the proposed scheme is robust, is not complex with reduced runtime and will consume less power due to the use of residue numbers when compared to similar existing schemes.