ABSTRACT Thermal stratification is important because it naturally suppresses or enhances buoyancy‐driven flow, directly controlling heat transfer efficiency in applications such as thermal energy storage, atmospheric flows, and heat exchangers. Therefore, the aim of this study is to explore the impact of a thermally stratified medium on heat transfer that arises from the flow of non‐Newtonian fluids along a slender cylinder. This is achieved by constructing an algebraic framework that reduces the flow topology of the proposed problem to a set of coupled nonlinear equations. The necessary non‐dimensional scaling variables convert the formulated partial differential equations to the appropriate form for integration. The primitive form of partial differential equations is integrated. The coefficient matrix of arbitrary variables governing the flow model is computed via the Gaussian elimination technique and the computer program Laher Fortran‐95. To show the results graphically, the obtained data have been uploaded to Techplot‐360. The non‐Newtonian behaviour index, , thermal stratification parameter, , and Prandtl number, , are main physical parameters that regulate fluid flow in terms of heat transfer rate and local skin friction. It has been noted that an increase in the thermal stratification parameter weakens the buoyancy force, thereby reducing the fluid velocity, temperature profile, and heat transfer rate. Additionally, it is also observed that a decrease in the power‐law index significantly affects the velocity profile, which becomes steeper near the wall for and attains higher values compared to dilatant fluids () and Newtonian fluids (). The innovative aspect of the present investigation lies in its slender cylinder geometry and the use of non‐Newtonian fluid, which has wide industrial and real‐life applications.
ABSTRACT The fundamental objective of this study is to investigate the thermal transport of mixed convective flow over a thermally conducting vertical cone with combined effects of Joule heating and variable magnetic permeability. The principal novelty of this work is the incorporation of Joule heating effect into mixed convection flow over a thermally conducting cone with variable magnetic permeability, a combined consideration that has not been previously explored in this configuration. This research gap motivates an extensive investigation of the combined effects of variable magnetic permeability and Joule heating on flow and heat transfer characteristics. The governing partial differential equations are formulated into primitive variables and the steady, real and imaginary primitive components are evaluated using implicit finite difference methodology and the Gaussian elimination technique. The resulting numerical solutions provide the fluid velocity, temperature and magnetic‐field profiles, which are further used to examine the oscillatory skin friction, heat transfer rate and current density for different appropriate dimensionless parameters, including the modified magnetic Prandtl number, Joule heating parameter, mixed convection parameter, magnetic force parameter and conductivity variation parameter. The results are graphically presented using FORTRAN software and display these results on Tech Plot. It was observed that the velocity and temperature distributions show a visible increase as the value of the Joule heating parameter rises and the magnetic field profile decreases with higher values of . Also, an increase in the Joule heating parameter enhances skin friction and magnetic transfer rates, whereas the heat transfer rates exhibit a declining response. The parametric analysis further demonstrates that magnetic diffusion plays a significant role in regulating the coupled flow and thermal characteristics of the magnetised cone.
ABSTRACT Bletilla striata glucomannan (BSG) is a natural polysaccharide exhibiting inherent thickening, gelling and bioadhesive properties, alongside diverse pharmacological activities, making it a promising functional biopolymer for novel vaginal drug delivery systems (VDDS). However, data regarding the vaginal mucosal safety of BSG, particularly following repeated exposure, are lacking; such data represent a critical prerequisite for clinical translation. In this work, BSG was isolated from the traditional Chinese medicine Bletilla striata and characterised. The biopolymer exhibited a weight average molecular weight (M w ) of about 11.108 kDa, a linear molecular backbone of (1→4)‐linked mannose (Man) and glucose (Glu) in a molar ratio of 2.7:1, and a moderate polydispersity (Mw/Mn = 2.54). Crucially, the molecular structure and natural origin of BSG enable it to degrade into monosaccharide fragments under physiological conditions. Moreover, owing to its inherent anti‐inflammatory effects, BSG did not elicit immunogenicity or inflammatory responses in vaginal mucosal tissues. Furthermore, the BSG demonstrated excellent hemocompatibility and no cytotoxicity to vaginal epithelial cells; conversely, it promoted cell proliferation and protected cells from damage. This work provides the first toxicological basis for BSG as a biodegradable, short‑term locally tolerable biopolymer, filling a previously unaddressed safety gap for BSG‑based VDDS applications.
ABSTRACT Photo‐assisted transfection is a method to physically inject genes into cells and induce their expression using short‐pulsed lasers. However, its application to plant cells has been limited because the cell wall and turgor pressure prevent the injection. In this study, we performed the transfection on plant protoplasts under controlled turgor pressure. In particular, as the light source for the transfection, we employed an intense picosecond microchip laser. This centimetre‐sized laser provides a compact, robust, and simple platform accessible to biological laboratories. When laser pulses are focused into the medium near the targeted cells, cavitation bubbles are generated through explosive evaporation induced by the pulse. We demonstrated that the impact of the bubbles allowed photo‐assisted transfection into tobacco BY‐2 protoplasts and induced expression of the enhanced green fluorescent protein plasmid. When laser pulses with an energy of 2.5 µJ were scanned at a speed of 100 µm/s and an interval of 0.2 mm, a maximum molecular delivery efficiency of 7.2% was achieved for the introduction of fluorescein isothiocyanate–dextran into the cytoplasm. Based on this result, the gene expression efficiency was estimated to be ∼5% among plasmid‐delivered protoplasts. Our results highlight the potential of this approach as a feasible method for the transfection of plant cells.
Plant-derived nanomaterials have traditionally been recognised as green alternatives for the management of plant diseases and insect pests. The present study has been designed to evaluate the bio-efficacy of the Paulownia plant extract as a reducing agent for silver nanoparticle (AgNP) synthesis in addition to its bioactivity against Fusarium basal rot (FBR) and onion thrips. Biosynthesised AgNPs were well-characterised by UV-Vis spectroscopy, X-ray diffraction, Fourier transform infrared, energy-dispersive X-ray spectroscopy, and scanning electron microscopy. Although there was very little efficacy from the use of Paulownia extracts alone, which resulted in inhibition levels of 12.8% against Fusarium oxysporum and 12.22% against thrips at 50 & micro;g/mL, the biosynthesised AgNPs were highly active against F. oxysporum, exhibiting a 32.8%-100% inhibition of growth, and had an insecticidal effect that ranged up to 98%. Further, AgNPs suppressed FBR by 86.67%-88.42%, improved onion bulb quality, and significantly enhanced both bulb number and weight, 191.53 kg total, compared with untreated infected plants showing the lowest yield (76.4 kg). Thus, the present outcomes have emphasised that Paulownia-based AgNPs are an efficient and eco-friendly nanobiotechnological approach towards improving plant health and crop yields.
