FFCAEs: An efficient feature fusion framework using cascaded autoencoders for the identification of gliomas

Intracranial tumors arise from constituents of the brain and its meninges. Glioblastoma (GBM) is the most common adult primary intracranial neoplasm and is categorized as high-grade astrocytoma according to the World Health Organization (WHO). The survival rate for 5 and 10 years after diagnosis is under 10%, contributing to its grave prognosis. Early detection of GBM enables early intervention, prognostication, and treatment monitoring. Computer-aided diagnostics (CAD) is a computerized process that helps to differentiate between GBM and low-grade gliomas (LGG), using the perceptible analysis of magnetic resonance (MR) of the brain. This study proposes a framework consisting of a feature fusion algorithm with cascaded autoencoders (CAEs), referred to as FFCAEs. Here we utilized two CAEs and extracted the relevant features from multiple CAEs. Inspired by the existing work on fusion algorithms, the obtained features are then fused by using a novel fusion algorithm. Finally, the resultant fused features are classified with the Softmax classifier to arrive at an average classification accuracy of 96.7%, which is 2.45% more than the previously best-performing model. The method is shown to be efficacious thus, it can be useful as a utility program for doctors.     

Falling ball method for determining zero shear and shear-dependent viscosity of polymeric systems: Solutions,melts, and composites

The falling ball method (FBM) is one of the well-established techniques for measuring the viscosity of Newtonian liquids at the room as well as at elevated temperatures and pressures. Owing to its simplicity and low cost, the possibility of extending its range of application to non-Newtonian systems including virgin and filled polymer melts, composites, polymer-solutions, and so forth, is explored here, In this work, theoretical results for the flow of power-law fluids past a sphere have been used to extract the values of the zero-shear viscosity and shear-dependent viscosity in the low-shear rate limit. The theoretical scheme outlined here has been validated by presenting comparisons with experimental results for scores of polymer solutions for which both falling sphere and rheological data are available in the literature. Indeed, the good correspondence obtained between these two independent data is encouraging and it is thus possible to use the FBM for shear-thinning systems when the resulting Reynolds numbers are such that the flow is viscosity-dominated, and the inertial effects are negligible. This implies that the Reynolds number should be ≤ ~1 for shear-thinning fluids and ≤ ~10⁻⁵ for shear-thickening fluids.     

Design,Synthesis, in vitro and in silico Characterization of 2-Quinolone-L-alaninate-1,2,3-triazoles as Antimicrobial Agents

Due to the ever-increasing antimicrobial resistance there is an urgent need to continuously design and develop novel antimicrobial agents. Inspired by the broad antibacterial activities of various heterocyclic compounds such as 2-quinolone derivatives, we designed and synthesized new methyl-(2-oxo-1,2-dihydroquinolin-4-yl)-L-alaninate-1,2,3-triazole derivatives via 1,3-dipolar cycloaddition reaction of 1-propargyl-2-quinolone-L-alaninate with appropriate azide groups. The synthesized compounds were obtained in good yield ranging from 75 to 80 %. The chemical structures of these novel hybrid molecules were determined by spectroscopic methods and the antimicrobial activity of the compounds was investigated against both bacterial and fungal strains. The tested compounds showed significant antimicrobial activity and weak to moderate antifungal activity. Despite the evident similarity of the quinolone moiety of our compounds with fluoroquinolones, our compounds do not function by inhibiting DNA gyrase. Computational characterization of the compounds shows that they have attractive physicochemical and pharmacokinetic properties and could serve as templates for developing potential antimicrobial agents for clinical use.     

Transient natural convective heat transfer and fluid flow in an undulated cavity: Effects of localized heat sources

The purpose of this research work is to investigate two-dimensional transient natural convective heat transfer and fluid flows in an undulated cavity by placing solid objects with isolated heated surfaces on the bottom wall. We discretize the coupled nonlinear transport equations using a higher-order compact finite-difference scheme. First, we test our scheme using existing experimental and numerical data. Then, we analyze the transient and steady-state natural convective flow phenomena for distributed heat sources on corrugations on the lower wall for a range of the Rayleigh number $\left(Ra=10^3-10^6\right)$ and Prandtl number $\left(Pr=0.71\right)$. These simulated outcomes are presented in the form of central-line velocity $\left(u,v\right)$, local $(N{u}_h^{*},N{u}_v^{*})$ and averaged $(\overline{N{u}_h^{*}},\overline{N{u}_v^{*}})$ Nusselt numbers, streamlines $\left(\psi \right)$, dispersion of isotherms $\left(T\right)$, and so forth. It is found that the transient fluid flow behavior is more magnificent than the steady-state solutions and shows the dominant behavior of the prominent primary cells over secondary cells, where it influences the heat transfer rates inside the entire enclosure. In steady states, at high Rayleigh numbers; convection dominates, formation of thermal boundary layers, compression of isotherms, and stratification of isotherms are significantly observed. Our results show many interesting flow phenomena that have not been analyzed previously.     

Effect of arc-shaped vertical control plate on heat and mass transfer in uniform flow past an isothermally heated circular cylinder

The current work investigates the effect of an arc-shaped vertical control plate on the heat and mass transfer in uniform flow past an isothermally heated circular cylinder. The control plate is positioned downstream at various distances from the circular cylinder's surface. The governing equations are discretized by the higher order compact (HOC) finite difference scheme, and then this system of discretized equations is solved by using a bi-conjugate gradient stabilized iterative method for Prandtl number $Pr=0.7$, Reynolds number $Re=150$. To investigate the effect of an arc-shaped control plate on heat and mass transfer, we consider a range of nondimensional distances between the circular cylinder and the control plate, $0.5\le d∕R_0\le 8$, where $d$ is the control plate's distance and $R_0$ is the cylinder's radius. The exact timing and location of the bifurcation points are calculated by using topological aspect-based structural bifurcation analysis. Significant effects of various locations of the control plate on periodic wake and heat transfer are observed. It is found that the increasing distance of the control plate from the cylinder delays the occurrence of the structural bifurcation and shifts the bifurcation points upwards in the upper half and downwards in the lower half of the cylinder. Our study shows that the specific location of the control plate can fully suppress the vortex shedding. Time-averaged total Nusselt number can be drastically reduced by increasing the distance between the control plate and the cylinder. With proper positioning, the vertical control plate can lessen the time-averaged drag force by up to $22.5\%$ when compared to a cylinder without a control plate. Overall, this work presents many new phenomena that have not been reported before.     

Performance evaluation of 67 denoising filters in ultrasound images: A systematic comparison analysis

Noise corrupts ultrasound images and degrades spatial and contrast resolutions. Hence, it is challenging to characterize the lesions precisely using ultrasound images. The present study aims to evaluate 67 denoising filters and select the best one for ultrasound image denoising. Seven test images were synthesized to evaluate the performance of filters at three different noise levels. Eleven full-reference quantitative image quality metrics (IQMs) were employed to evaluate the performance of the filters. A new filter evaluation method, Rank Analysis, was introduced and utilized at each noise level. The ten best filters with the smallest mean rank in all noise levels were defined for further analysis on real ultrasound images. The Rank Analysis was also employed for real ultrasound images, and filters were evaluated based on 14 IQMs (11 full-reference and three no-reference). Finally, the best filter was defined using the repeated measures analysis statistical test. According to the Rank Analysis results, the Spatial correlation (SCorr) filter obtained the best results with the mean rank scores±SD of 1 ± 0, which was significantly better than the other nine filters (p < 0.001). The second-best results were achieved by three filters, Bitonic, most homogeneous neighborhood, and Lee diffusion (p < 0.05). We concluded that SCorr is the best filter for ultrasound image denoising. It can be used in the pre-processing step before segmentation and diagnostic procedures. In addition, a new filter evaluation method, Rank Analysis, was introduced in this study, which is easy to use, fast, and provides reliable results. So, it can be used to evaluate newly developed filters in the future studies.     

Wholly thermoplastic composites from woven preforms based on nylon-11 fibers reinforced in situ with a hydroquinone-based liquid crystalline polyester

This work concerns a novel means to generate wholly thermoplastic composites based on low-melting thermoplastics reinforced with high-melting thermotropic liquid crystalline polymers (TLCPs). A novel dual extrusion process was employed to generate nylon-11 fibers that are reinforced with continuous fibrils of a hydroquinone-based liquid crystalline polyester (DuPont TLCP, HX8000). These composite fibers display tensile properties significantly higher than those predicted by composite theory. These fibers were subsequently woven into a fabric, which in turn serves as a composite preform. Several layers of the fabric preform were stacked and consolidated to yield a composite plaque. The consolidation was carried out at temperatures just high enough for nylon-11 to melt, but well below the melting temperature of HX8000. Fabric preform composites based on the composite fibers with ∼35 wt% HX8000 gave modulus values close to five and one half times that of nylon-11, and strength values approximately two and one half times that of nylon-11. The tensile and flexural properties of these composites are superior to continuous glass-fiber reinforced composites at comparable loadings on a volume basis. Moreover, as the reinforcing fibrils are already encapsulated by the matrix, fiber wetting and fabric impregnation issues that are critical in the fabrication of continuous glass and carbon fiber composites are eliminated.     

Synthesis and Characterization of ZnO/CuO Nanocomposites as an Effective Photocatalyst and Gas Sensor for Environmental Remediation

Journal of Inorganic and Organometallic Polymers and Materials - Current study delineates the synthesis and environmental applications of ZnO/CuO nanocomposite in photocatalysis and gas sensing....     

Critical thickness of polymer-derived ceramic coatings with particulate fillers

In this study, we demonstrate a novel environmental barrier coating processed from polymer-derived ceramics (PDCs) with homogeneously distributed sub-micrometer Y₂O₃ as the filler. Under suitable conditions, dense and crack-free coatings can be achieved for all the designed compositions with the volumetric content of Y₂O₃ varied from 45 to 93 vol%. To process the PDC SiC–Y₂O₃ composite coatings, Y₂O₃ particles and SiC liquid precursor were uniformly dispersed in hexane and then dip-coated on SiC substrates. After cross-linking at 250°C and heat-treated at 900°C in argon, dense and crack-free PDC SiC–Y₂O₃ composite coatings were formed. The effect of coating thickness and heat-treatment temperature on the formation of cracks due to constrained pyrolysis was studied. The critical thickness for realizing crack-free coatings of three compositions (i.e., 93, 77, and 45 vol% Y₂O₃) was studied for heat treatment from 1000 to 1300°C using atomic force microscope and scanning electron microscopy. As heat-treatment temperature increases, the critical coating thickness decreases for the same coating compositions due to enhanced shrinkage at higher temperature. With higher Y₂O₃ content, the critical thickness of the coating increased. The inert Y₂O₃ particles reduce the amount of polymer leading to reduction in the overall constrained shrinkage of the coating during heat treatment.