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1.
Disaster Med Public Health Prep ; 17: e393, 2023 04 11.
Artículo en Inglés | MEDLINE | ID: covidwho-2320565

RESUMEN

According to the public data collected from the Health Commission of Gansu Province, China, regarding the COVID-19 pandemic during the summer epidemic cycle in 2022, the epidemiological analysis showed that the pandemic spread stability and the symptom rate (the number of confirmed cases divided by the sum of the number of asymptomatic cases and the number of confirmed cases) of COVID-19 were different among 3 main epidemic regions, Lanzhou, Linxia, and Gannan; both the symptom rate and the daily instantaneous symptom rate (daily number of confirmed cases divided by the sum of daily number of asymptomatic cases and daily number of confirmed cases) in Lanzhou were substantially higher than those in Linxia and Gannan. The difference in the food sources due to the high difference of the population ethnic composition in the 3 regions was probably the main driver for the difference of the symptom rates among the 3 regions. This work provides potential values for prevention and control of COVID-19 in different regions.


Asunto(s)
COVID-19 , Humanos , COVID-19/epidemiología , Pandemias/prevención & control , China/epidemiología
2.
Energy & Environment ; 2022.
Artículo en Inglés | Web of Science | ID: covidwho-2153252

RESUMEN

This study aims to analyze the risk spillover effects between the global crude oil market and the biofuel ethanol and corn markets in China, employing a DCC-GARCH-Copula-CoVaR model and basing the weekly price data from 2012 to 2021. The empirical results revealed that there were dynamic conditional correlations among international crude oil, China's biofuel ethanol, and corn markets. Following the COVID-19 outbreak, the CoVaR and Delta CoVaR changed, which caused a sharp increase in the mean values and volatility. Additionally, China's biofuel ethanol market is more vulnerable to the risk spillovers from the international crude oil market than China's corn market. However, China's markets do not appear to have obvious risk spillover effects on the global market. The implications of the results are discussed in financial market supervision, including the risk management and portfolio adjustment.

3.
Composites Part B: Engineering ; : 110463, 2022.
Artículo en Inglés | ScienceDirect | ID: covidwho-2149593

RESUMEN

Carbon fibre and carbon fibre reinforced polymer matrix composites (CFRPs) are important lightweight materials for aerospace, automotive, rail transport, infrastructure, and renewable energy applications. This paper provides a comprehensive review on the history of carbon fibres and carbon fibre composites, the current global CFRPs consumption, and trends for future developments in the aerospace, wind turbine, automotive, pressure vessels, sports and leisure, and construction sectors. The history of carbon fibres and CFRPs is discussed over four representative periods including their early development (1950–60's), growth of carbon fibre composites industry (1970–80's), major adoption of carbon fibre composites (the first wave, 1990–2000's), and expanded use of carbon fibre composites (the second wave, 2010's and beyond). Despite a 37% decline of carbon fibre consumption in the aerospace industry in 2021 caused by COVID-19, the global CFRP demand was around 181 kt which more than doubled its value in 2014. There is tangible projected increase over the next five years and the demand for CFRPs is expected to reach 285 kt in 2025, mainly attributed from the fast expansion of non-aerospace industries such as the wind energy sector. Lower cost carbon fibres (e.g., large tow) and associated manufacturing technologies are continually evolving. Finally, the implications of emerging materials and manufacturing methods in conjunction with recycling and reuse for carbon fibre composites are discussed.

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