Viscoelastic interpretations of erosion performance of short aramid fibre reinforced vinyl ester resin composites

Short aramid fibre reinforced vinyl ester resin based isotropic composites are fabricated with varying fibre weight fractions (20–50 wt%). The composites were evaluated for their erosion performance under a dynamic set of variables such as impingement angle (30°–90°), impact velocity (43–76 m/s), erodent size (250–600 μm) and stand-off distance (55–85 mm) following design of experiments (DOE) based on Taguchi analysis approach. The thermo-mechanical attributes such as storage modulus, loss modulus and damping properties as viscoelastic responses of the composites were investigated in the temperature range of 0–180 °C for their possible interpretations regarding reinforcement efficiency and energy dissipation aspects relevant to erosion process. An interrelation between the full-width half-maxima (FWHM) of loss modulus peak and erosion rate has emerged indicating the erosion to be mainly controlled by the fibre–matrix interfacial characteristics. The eroded surface morphology investigation by scanning electron microscopy (SEM) revealed the nature of wear-craters, material damage mode and other qualitative attributes responsible in facilitating erosion of the composites.     

BFCNet: a CNN for diagnosis of ductal carcinoma in breast from cytology images

Pattern Analysis and Applications - Fine Needle Aspiration Cytology (FNAC) is a quick and minimally invasive technique used to diagnose breast cancer, specifically ductal carcinoma. The incidence...     

Synthesis,Optimal Fabrication,and Physico-Mechanical Property Evaluation of PCL-b-PLLA Diblock Copolymer-Based Nanoscale Roughness Textured Electrospun Mats

Poly(ɛ-caprolactone)-block-poly(L-lactide) (PCL-b-PLLA) diblock copolymer and its electrospun mats (EMs) are characterized for their microstructural, thermal, and physico-mechanical properties. The EMs of synthesized copolymer exhibiting the optimal level of average fiber diameter (Co-FD) and diameter variation (Co-SD) are obtained following Taguchi's design of experiments (DOE). Electrospinning process parameters such as solution concentration, DMF content in CF/DMF solvent mixture, and applied voltage are varied at three different levels (L₉). Analysis of variance (ANOVA) indicated DMF content to be the major influencing factor on FD and SD of EMs with ∼95% confidence. Regression model indicated ∼88% accuracy in predicting the FD of the copolymer-based EMs. The physico-mechanical properties of the optimized EMs are evaluated vis-à-vis the influence of FD and SD on the mechanical properties. Atomic force microscopy revealed solvent evaporation induced radial inconsistencies, desirable in terms of nanoscale surface roughness, which is higher for Co-SD (∼600 nm) than in Co-FD (∼400 nm). The swelling and weight loss showed marked improvement in PCL-b-PLLA based EMs reiterating the possibility of their enhanced compatibility as biomedical materials.     

Technology adoption to reduce the harvesting losses and wastes in agriculture

Clean Technologies and Environmental Policy - In general, the harvesting of paddy is carried out through manual or mechanical approach of cutting the crop, and then collecting and bundling them....     

Correction to: Technology adoption to reduce the harvesting losses and wastes in agriculture

Clean Technologies and Environmental Policy - A correction to this paper has been published: https://doi.org/10.1007/s10098-021-02114-y     

Structural, dielectric and ferroelectric properties of multilayer lithium tantalate thin films prepared by sol-gel technique

Multilayer lithium tantalate thin films were deposited on Pt-Si [Si(111)/SiO₂/TiO₂/Pt(111)] substrates by sol-gel process. The films were annealed at different annealing temperatures (300, 450 and 650 °C) for 15 min. The films are polycrystalline at 650 °C and at other annealing conditions below 650 °C the films are in amorphous state. The films were characterized using X-ray diffraction, atomic force microscopy (AFM) and Raman spectroscopy. The AFM of images show the formation of nanograins of uniform size (50 nm) at 650 °C. These polycrystalline films exhibit spontaneous polarization of 1.5 μC/cm² at an application of 100 kV/cm. The dielectric constant of multilayer film is very small (6.4 at 10 kHz) as compared to that of single crystal.     

Effect of boric acid sintering aid on densification of barium ferrite

Boric acid has been added in 0.1-0.6% range for studying the densification characteristics of solid state sintered barium hexaferrite. Sintering studies have been carried out at three different temperatures. Physical properties like density and porosity have been studied for all compositions. The phase identification and microstructural investigation on the fractured surface have been carried out to understand the effect of sintering aid on the densification characteristics.     

Erosion Wear Response of Glass Microsphere Coatings: Parametric Appraisal and Prediction Using Taguchi Method and Neural Computation

This article presents an analysis of the erosion wear response of borosilicate glass microsphere (BGM)-coated metal specimens subjected to reproducible erosive situations. The coatings are deposited on metal substrates by a plasma spraying route using an atmospheric plasma spray setup working on a nontransferred arc mode. The response of these coatings to solid particle erosion for different test parameters is studied. The erosion test schedule is planned as per Taguchi's experimental design and is carried out under controlled laboratory conditions using an air jet–type erosion tester. The analysis of test results reveals that the impact velocity is the most significant among various factors influencing the erosion wear rate of these coatings. A prediction tool based on artificial neural networks (ANNs) is then implemented to predict the triboperformance of such coatings in regard to their erosion rates under different test conditions. ANN is a technique that takes into account the training, testing, and validation protocols using the database generated from experimentation. This technique helps in saving time and resources for a large number of experimental trials and it is seen in this work that it can successfully predict the wear rate of the coatings for test conditions both within and beyond the experimental domain.     

Comparison of the Mechanical and Thermo-Mechanical Properties of Unfilled and SiC Filled Short Glass Polyester Composites

This paper presents a comparison between particulate filled (SiC particles) and unfilled glass polyester composites on the basis of their mechanical and thermo-mechanical properties. The results show that particulate filled composites have a decreasing trend in mechanical properties when compared to the unfilled glass polyester composites. In particulate filled composites, the tensile and flexural strength of the composites decrease with the addition of 10 wt.-% SiC particles but increase with 20 wt.-% SiC particles. In the case of the unfilled glass polyester composite, the tensile and flexural strength of the composites increase with an increase in the fiber loading. However, higher values of tensile strength and flexural strength of particulate filled glass polyester were found than that of the unfilled glass polyester composite. In the case of thermo-mechanical and thermal properties, the particulate filled composites show better dynamical and thermal properties when compared to the unfilled glass polyester composites. The mechanical and thermal properties (i.e. thermal conductivity) are also calculated using FE modeling (ANSYS software) and the results from this simulation shows good agreement with the experimental results.