Sharad Sinha

This study investigates the heat-transfer and flow characteristics of a Williamson fluid in a converging–diverging channel. The analysis focuses on steady, incompressible, two-dimensional radial flow bounded by two symmetrically inclined vertical walls that may stretch or shrink. The momentum and energy equations, incorporating viscous dissipation, are expressed in polar coordinates and recast into a dimensionless framework to clarify the influence of governing parameters such as the Weissenberg number, viscosity ratio, Eckert number, and channel inclination. Because an exact analytical treatment is impractical, the resulting boundary value problem is solved numerically using Matlab's bvp4c routine, which provides reliable solutions through adaptive mesh refinement. The results show that higher Weissenberg numbers and viscosity ratios cause moderate velocity enhancement under stretching wall conditions, yielding changes of approximately 13% in convergent channels and up to about 115% in divergent configurations, while temperature variations remain below about 3% for most cases and increases noticeably (approximately 20% to 27%) for higher Prandtl and Eckert numbers. Overall, the study enhances understanding of non-Newtonian transport in non-parallel channels and offers useful insights for applications including polymer extrusion, blood flow near arterial bifurcations, microfluidic heat-exchange devices, and lubrication or wedge-bearing systems.

Sequences derived from organisms sharing common evolutionary origins exhibit similarity, while unique sequences, absent in related organisms, act as good diagnostic marker candidates. However, the approach focused on identifying dissimilar regions among closely-related organisms poses challenges as it requires complex multiple sequence alignments, making computation and parsing difficult. To address this, we have developed a biologically inspired universal ^NAUniSeq algorithm to find the unique sequences for microorganism diagnosis by traveling through the phylogeny of life. Mapping through a phylogenetic tree ensures a low number of cross-contamination and false positives. We have downloaded complete taxonomy data from Taxadb database and sequence data from National Center for Biotechnology Information Reference Sequence Database (NCBI-Refseq) and, with the help of NetworkX, created a phylogenetic tree. Sequences were assigned over the graph nodes, k-mers were created for target and non-target nodes and search was performed over the graph using the depth first search algorithm. In a memory efficient alternative NoSQL approach, we created a collection of Refseq sequences in MongoDB database using tax-id and path of FASTA files. We queried the MongoDB collection for the target and non-target sequences. In both the approaches, we used an alignment free sliding window k-mer–based procedure that quickly compares k-mers of target and non-target sequences and returns unique sequences that are not present in the non-target. We have validated our algorithm with target nodes Mycobacterium tuberculosis, Neisseria gonorrhoeae, and Monkeypox and generated unique sequences. This universal algorithm is a powerful tool for generating diagnostic sequences, enabling the accurate identification of microbial strains with high phylogenetic precision.

Aim of the paper is to investigate the effects of thermal radiation and velocity slip on steady MHD slip flow of viscous incompressible electrically conducting fluid over a permeable stretching cylinder saturated in porous medium in the presence of external magnetic field. The governing nonlinear partial differential equations are transformed into ordinary differential equations by suitable similarity transformation and solved numerically using Runge-Kutta fourth order method with shooting technique. Effect of various physical parameters on fluid velocity, temperature, skin –friction coefficient and Nusselt number are presented through graphs and discussed numerically.

A viscous electrically conducting fluid is considered and its steady mixed convective flow along a vertical stretching cylinder is investigated. It is assumed that the cylinder is embedded in a porous medium and, external magnetic field, heat source/sink are also taken into account. Suitable similarity transformations are used to reduce the governing equations and associated boundary conditions into a system of nonlinear ordinary differential equations. This system along with the boundary conditions is solved by fourth order Runge-Kutta method with shooting technique. Variations in fluid velocity and temperature due to various physical parameters such as heat source/sink parameter, mixed convection parameter, magnetic parameter are presented through graphs. Effect of these parameters on dimensionless shear stress and rate of heat transfer are discussed numerically through tables.