Due to the COVID-19 epidemic, biomedical waste management has overwhelmed both developed and developing nations. It is now a critical issue that has to be addressed with minimal possible adverse impact on the environment. This study introduced a technique of recycling face masks into polypropylene fibers for use in concrete. This proposed recycling process provides complete disinfection of contaminated clinical waste and offers the opportunity to transform the characteristics of an end product. Microfibers manufactured from recycled medical masks were subjected to testing. According to the results, polypropylene is the primary component of this research program. Two batches of concrete were made, one with the inclusion of masks as polypropylene fibers and another that performed as a control mix. The modified mortar was compared to the control mix in split tensile, flexure, compressive strength, and water absorption. Compressive strength was found to be improved by about 17%, and tensile strength to be increased by around 22% when mask fibers were incorporated. This research introduced a novel approach for disposing of waste masks and established the preliminary viability of upcycling trash face masks towards mortar concrete production.

The land use and land cover change dynamics is in par with the increasing growth of urban developments and associated sprawl. The objective of the study is to quantify such land cover changes caused due to the urban expansion along the outer ring road using Remote Sensing and GIS. The land cover maps are created for four segments namely Chikkarayapuram, Nazarathpettai, Meppur, and Perungalathur for the years of 2009, 2012, and 2016, respectively. The land cover maps are analyzed for changes among seven classes, namely agriculture, barren land, residential units, industry, water body, other vegetation, and marshland (swamp). Further, the land cover maps of the four segments are analyzed for changes in terms of spatiotemporal aspects (area-based land cover change), environmental aspects (green cover change), and economical factors. The urban growth of the Chikkarayapuram, Nazarathpettai, Meppur, and Perungalathur segment along the outer ring road corridor in the years 2009, 2012, and 2016 are (5.16%, 20.10%, 7.14%, and 12.63%), (14.31%, 30.62%, 13.9%, and 22.18%), and (19.67%, 33.1%, 23.22%, and 40.27%), respectively. The urban areas have increased from 2009 to 2016 by 20, 76,530 sq. m. The agriculture regions have been reduced from 2009 to 2016 by 12, 62,700 sq. m. Besides, using the MOLUSCE plugin in open-source GIS (QGIS), simulated maps for the year 2022 were created based on the land cover maps of the three years (2009, 2012, and 2016) which are then validated with the ground-truth points obtained from Google Earth. The scope of the study utilization of Google Earth Engine (GEE) and automated feature extraction algorithms for predictive analysis.

This article is focused on the study of the contribution of aramid fibers in a hybrid carbon–aramid fiber twill weave used to reinforce epoxy resin. To evaluate the influence of the aramid fibers, a comparative study between carbon and carbon–aramid woven–reinforced composites, considering the mechanical behavior of both materials under several loading conditions, is performed. The tests used in this study are meant to analyze the effect of aramid reinforcements on the composite stiffness, strength, impact, and fracture performance. Higher values of energy absorption and fracture toughness were exhibited by the carbon–aramid composite. The mechanical tests performed indicated that the aramid phase present in the hybrid carbon–aramid composite induced an important enhancement on the impact (37.9% in energy absorption) and fracture resistance (12.7% for fracture initiation and 43% for steady state regime), compared to small reductions on the material stiffness. In addition, the ultimate strain and the through thickness compression strength were favorably affected, with an increase up to 19.5% and 8.3%, respectively, by the presence of aramid fiber that presents a more ductile response with respect to the carbon reinforcement.

Woven fabrics used in composite materials are designed to fulfill specific manufacturing or structural requirements. Knowledge of the influence of the weave structure on the mechanical properties of the composite is essential to properly optimize the design of structural components. The focus of this work is to investigate the influence of the type of weave used for fabric reinforcement in polymers particularly on the in-plane shear mechanical performance. The selected materials are carbon fibers and epoxy resin. The laminates are manufactured by vacuum infusion. Three woven structures are selected for manufacturing the composite laminates: (a) a plain weave with unidirectional orientation in the warp direction, (b) a plain weave with balanced properties in the warp and weft directions and (c) a 2/2 twill weave with balanced properties in the warp and weft directions. The laminates are tested according to the ASTM D 4255 standard by a two-rail shear test under quasi-static monotonic and cyclic loading conditions. The resulting stress–strain curves are used to study the initial in-plane shear modulus and its evolution (which directly correlates with material damage) and the hardening produced by plastic strain. The results show that for vacuum infusion manufacturing, the weave structure has an influence on the resulting fiber and void volume fractions and, consequently, on the mechanical performance. However, for similar fiber volumes, the weave structure is found to have little effect on the experimental results.