No abstract

Amid rising environmental concerns, Industry 4.0 and blockchain technology (BCT) are transforming circular economy (CE) practices and prevailing business models. Recognize the same; this study examines the role of blockchain technology in circular CE practices and their impact on eco-environmental performance, which influences organizational performance. The study collects data from 404 enterprises located in Chinese and Pakistani territories, involved in cross-border supply chain operations. Both countries' sample has great relevance due to the China Pakistan Economic Corridor (CPEC), which possesses several positive fallouts in terms of technology spillovers across firms. Using the partial least squares structural equation modeling (PLS-SEM) modeling framework, this study provides three key findings. First, BCT significantly improves the circular economy practices (circular procurement, circular design, recycling, and remanufacturing). Second, CE practices help improve firms'environmental performance and stimulate their financial performance. Third, higher eco-environmental performance significantly boosts organizational performance. This study sets out the foundations for participating countries/firms that simultaneously achieve financial and sustainable goals by integrating blockchain technology in circular economy practices.

Atomic oxygen, formed in Earth's thermosphere, interacts readily with many materials on spacecraft flying in low Earth orbit (LEO). All hydrocarbon based polymers and graphite are easily oxidized upon the impact of ∼4.5 eV atomic oxygen as the spacecraft ram into the residual atmosphere. The resulting interactions can change the morphology and reduce the thickness of these materials. Directed atomic oxygen erosion will result in the development of textured surfaces on all materials with volatile oxidation products. Examples from space flight samples are provided. As a result of the erosive properties of atomic oxygen on polymers and composites, protective coatings have been developed and are used to increase the functional life of polymer films and composites that are exposed to the LEO environment. The atomic oxygen erosion yields for actual and predicted LEO exposure of numerous materials are presented. Results of in-space exposure of vacuum deposited aluminum protective coatings on polyimide Kapton indicate high rates of degradation are associated with aluminum coatings on both surfaces of the Kapton. Computational modeling predictions indicate that less trapping of the atomic oxygen occurs, with less resulting damage, if only the space-exposed surface is coated with vapor deposited aluminum rather than having both surfaces coated.

The present study investigated whether osteoblasts could attach to a culture substratum through a surface texture-dependent mechanism. Four test groups were used: (A) untextured, and three texture groups with maximum feature sizes of (B) <0.5 microm, (C) 2 microm, and (D) 4 microm, respectively. All surfaces were coated with the nonadhesive protein bovine serum albumin (BSA). Osteoblasts were allowed to adhere in serum-free medium for either 1 or 4 h, at which time nonadherent cells were removed. At 4 h, untextured surface A exhibited no cell attachment, while textured surfaces B, C, and D exhibited 9%, 32%, and 16% cell adhesion, respectively. At 16 h of incubation, adherent osteoblasts on textured surface C exhibited focal adhesion contacts and microfilament stress-fiber bundles. These results indicate that microtextured surfaces in the absence of exogenous adhesive proteins can facilitate osteoblast adhesion.