10,226 research outputs found
Reusable Augmented Concrete System: Accessible Method for Formwork Manufacturing through Holographic Guidance
Reinforced concrete has been one of the essential materials for modern architecture for the last hundred years. Its use is entirely global, having been adopted by all cultures and styles since its invention in the late 19th century. Although its value is excellent due to its low cost, durability and adaptability, its environmental impact is significant, being, in fact, one of the most polluting industries in the world (Babor et al. 2009). This experimental project will research a more sustainable use of concrete, exploring a new form of reusable concrete formwork that will ideally reduce the CO2 footprint by removing wood waste in the casting process and replacing it with adaptable metal components. The modular part-based system for the concrete casting also attempts to simplify one of the current complexities for concrete construction, the Skilled-Labour shortage. (Yusoff et al. 2021). To mitigate this problem, the project also proposes using an Augmented Assembly logic for the casting parts to guide the ensemble and dismantle the formwork through an optimised algorithmic logic. The use of Augmented Reality as a replacement for traditional paper instructions will facilitate access to more workers to this construction art and potentially improve access to optimised use of concrete in developing communities with restricted building technological resources
Structure, morphology, and mechanical properties of polysiloxane elastomer composites prepared by in situ polymerization of zinc dimethacrylate
Methyl vinyl silicone rubber/zinc dimethacrylate (VMQ/ZDMA) composites were prepared through in situ polymerization of ZDMA monomers during the peroxide curing. The polymerization conversion of ZDMA and morphology of the VMQ/ZDMA composites were studied. The results showed that most of the ZDMA monomers participated in the in situ polymerization during the cross-linking of the VMQ matrix and uniform nanophases were formed in the composites. The ‘dissolving-diffusion’ model was used to explain the micro-nano transformation of ZDMA. According to the model, a uniform nano-dispersed structure could be obtained through the in situ reaction even though the initial dispersion of ZDMA in the blends was poor. In addition, tensile tests of VMQ/ZDMA composites showed that ZDMA had a significant reinforcement on the mechanical properties of VMQ, and the best mechanical properties were obtained when the amounts of peroxide and ZDMA were 5 and 40 phr, respectively. The gross crosslink density and ionic crosslink density increased as the amount of ZDMA increased, but the covalent crosslink density decreased slightly. These results indicated that the ionic crosslink structure had a significant effect on the mechanical properties of VMQ/ZDMA composites
Bandwidth and Electron Correlation-Tuned Superconductivity in RbFe(SeS)
We present a systematic angle-resolved photoemission spectroscopy study of
the substitution-dependence of the electronic structure of
RbFe(SeS) (z = 0, 0.5, 1), where
superconductivity is continuously suppressed into a metallic phase. Going from
the non-superconducting RbFe(SeS) to
superconducting RbFeSe, we observe little change of the Fermi
surface topology, but a reduction of the overall bandwidth by a factor of 2 as
well as an increase of the orbital-dependent renormalization in the
orbital. Hence for these heavily electron-doped iron chalcogenides, we have
identified electron correlation as explicitly manifested in the quasiparticle
bandwidth to be the important tuning parameter for superconductivity, and that
moderate correlation is essential to achieving high
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Effects of soilâstructure interaction on the design of tuned mass damper to control the seismic response of wind turbine towers with gravity base
This paper studies the effect of soilâstructural interaction (SSI) on gravityâbased wind turbine towers equipped with tuned mass dampers (TMDs) subjected to earthquake loading. A smallâscale shaking table test of wind turbine towers with TMD was conducted, and the results showed that using TMD designed considering SSI resulted in larger vibration suppression. A simplified analytical numerical model was developed for SSI analysis considering TMD. The effect of soil site class and the earthquake intensity on the response reduction efficiency of the TMD was also discussed using the simplified model. It is concluded that the TMD efficiency depends not only on the soil stiffness but also on the characteristics of the applied ground motions, both of which are affected by the site classes and earthquake intensity levels. Moreover, the peak acceleration ratio (PAR), the root mean square acceleration ratio (RAR), the peak displacement ratio (PDR), and the root mean square displacement ratio (RDR) of the top of the wind turbine tower were obtained with and without TMD for different earthquake intensities and sites. These parameters can be used as references for the rational selection of TMD parameters considering SSI
Effects of UHMWPE viscoelasticity on the squeeze-film lubrication of hip replacements
Many studies have been performed to analyse the lubrication of artificial joints since the pioneer work by the late Professor Duncan Dowson. However, the viscoelastic deformation of one of the most widely used bearing materials, ultra-high-molecular-weight polyethylene (UHMWPE), has only been considered recently. The described study attempted to investigate the effect of UHMWPE viscoelasticity on the elastohydrodynamic lubrication of such a soft artificial hip replacement under squeeze-film motion. A transient viscoelastic squeeze-film lubrication model of a typical hip implant was developed and solved to obtain the film thickness and pressure distributions. A boundary film thickness was adopted to consider the direct and indirect lubricant contact conditions. The results showed that the viscoelasticity had marked effects on the squeeze-film lubrication performance of UHMWPE artificial hip joints. The minimum film thickness in the viscoelastic model was smaller than that of the elastic model, causing an earlier direct contact. However, the film thickness within the central contact region in the viscoelastic model was greater than that of the elastic model due to the restricted flow of the lubricant, therefore enhancing the lubricating effect and particularly with a short relaxation time and mechanical loss factor
Embodied carbon emissions in China-US trade
China-US trade holds great significance for the worldâs political and economic landscape. Since 2018, the US government has imposed additional tariffs on Chinese exports on the grounds of the US trade deficit with China. However, the transfer of pollutants embodied in trade and the differences in environmental costs between China and the US have not been widely recognized. In this study, we quantify the embodied carbon emissions (the âvirtualâ emissions associated with trade and consumption) in China-US trade by constructing a carbon dioxide emissions inventory and a multiregional input-output model. The study shows that the US benefits from a trade surplus of environmental costs by importing energy-intensive and pollution-intensive products from China, which increases Chinaâs environmental pollution and abatement costs. In 2017, 288 Mt CO_{2} emissions were associated with products produced in China but finally consumed in the US, and only 46 Mt CO_{2} were associated with the US products that were consumed in China. From this perspective, China-US trade results in a net transfer of 242 Mt CO_{2} per year from the US to China, accounting for approximately 5% of the total CO_{2} emissions in the US. More importantly, for Chinese products exported to the US, the carbon emissions embodied in one unit of economic value amount to 0.92 kg/, which means China will incur environmental costs that are 74% higher than those of the US while enjoying the same economic benefits. This environmental trade deficit has burdened China with higher environmental costs thaneconomic benefits. To address this environmental trade deficit, China should actively promote further industrial upgrading and energy structure adjustment and increase investment in innovation and R&D, thereby increasing the value added per unit of export products and reducing the environmental cost of producing export products
Creating an Inter-hospital Resilient Network for Pandemic Response Based on Blockchain and Dynamic Digital Twins
This study proposes to develop new knowledge about how to configure digital information for pandemic
rapid response, which can use blockchain and digital-driven approaches to facilitate analyses and develop
a total solution. Developing and using the rich data implied by dynamic digital twins and blockchain is
relevant to manage both patients and medical resources (e.g., doctors/nurses, PPE, beds and ventilators etc.)
at the COVID-19 and post COVID period. This paper learns from the experiences of resources
deployment/redeployment and pandemic response from UK Hospitals to explore the blockchain solutions
for preparing healthcare systems ready for both efficient operation daily and in pandemic thorough (1) information integration of patient (privacy protected) flow and medical resource flow from healthcare and
medical records; (2) optimizing the deployment of such resources based on hospitals, regions and local
pandemic levels switching from normal to the outbreak. The main idea is to develop the novel framework
for creating an inter-hospital resilient network for pandemic response based on blockchain and dynamic
digital twin, which will set up innovative ways to best care for patients, protect NHS staff, and support
government scientific decisions to beat COVID-19 now and manage the crisis in the future
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