This study investigates the relationship between renewable energy, fossil fuel consumption, economic growth, urbanization and CO2 emissions in China via the commonly used Autoregressive Distributed ...Lag (ARDL) model under the Environmental Kuznets Curve (EKC) hypothesis examining the period from 1990 to 2020. The aim of this work is to test the role of long- and short-term dynamics of renewable energy consumption in reducing CO2 emissions in China. The findings strongly support the existence of an inverted U-shaped relationship between CO2 emissions and GDP per capita, both in the long and short term. Not surprisingly, fossil fuel use increases the level of CO2 emissions in China. We show that a 1% increase in fossil fuel consumption per capita increases the CO2 emission per capita by 0.235% in the long term. The role of renewable energy consumption in reducing CO2 emissions might result from a cumulative effect. A 1% increase in renewable energy consumption per capita decrease the CO2 emissions per capita by 0.259% in the long run, while our findings reveal that the rapid development of the renewable energy industry in China contemporarily increases CO2 emissions and 1% renewable energy consumption increase the CO2 emissions by 0.285% to 0.288% in the short term. Our conclusions suggest that China‘s energy policy should further encourage the use of renewable power sources in the energy mix and further increase awareness of the increased short-term levels of carbon emissions associated with the rapid development of the renewable energy industry in China.
China has set itself the ambitious goal of becoming carbon-neutral by 2060. This work explores the long- and short-run relationships between CO2 emissions, real GDP, clean energy, fossil fuel ...consumption, and trade openness in China covering the period of 1992–2020. 1992 is suggested as the starting year as China’s economy transferred to a market-oriented open economy starting in that year. The findings verified that long-run equilibrium cointegration existed among the analyzed variables. The hypothetical environmental Kuznets curve (EKC) could further be verified. Besides, clean energy use potentially improves environmental quality measured by the long-run impact on CO2 emissions. A 1% increase in clean energy consumption significantly decreases the CO2 emissions by 0.68% in the long run. In contrast, CO2 emissions are dramatically influenced by per capita income, fossil fuel consumption, and trade openness. It is suggested that environmental policies should be reinforced, and clean energy consumption be encouraged as a practical solution to reducing CO2 emissions to reach China’s carbon neutrality target. This work specifically highlights the important benefits of nuclear energy and hydropower in supporting carbon neutrality in the long run, and suggests that China (1) continues to invest in its clean energy industry and (2) encourages less energy-intensive, clean production processes that have the potential to reach carbon neutrality in the long term. Both suggestions will help reaching the carbon-neutrality target by 2060.
This investigation assessed the relationship between clean energy consumption, GDP, trade openness, urbanization, and CO2 emissions in the G7 economies from 1979 to 2019. The specific goal of this ...work is to scrutinize the long- and short-run dynamics of clean energy consumption, trade openness, and urbanization in CO2 emissions reduction in G7 economies. Panel Autoregressive Distributed Lag (ARDL) is used to illustrate the long-run and short-run dynamics between CO2 emissions, clean energy consumption, trade openness and urbanization after testing slope heterogeneity, cross-section dependence, and long-run cointegration. The empirical findings verify the existence of the Environmental Kuznets Curve (EKC) in the long run. A 1% increase in clean energy consumption on the other hand decreased CO2 emissions by 0.099% in the long run and 0.33% in the short run. In addition, the results support the thesis that trade openness increases CO2 emissions and increased urbanization decreases CO2 emissions. This study intensifies the use of nuclear energy, hydropower and renewables to improve sustainable energy production and the quality of the environment. The results are limited to a certain region and a certain period of time, but provide quantitative analysis that may be of interest to policy makers everywhere.
India is facing challenges on its pursuit to carbon neutrality and energy security. This paper analyzes the long- and short-run dynamics of clean energy, coal consumption, trade openness, and ...urbanization on CO2 emissions in India. The findings suggest that: (1) the Environmental Kuznets Curve (EKC) hypothesis can be verified for India in the time period from 1990 to 2020, and the long-run elasticities for per capita income on CO2 emissions have strengthened compared to previous studies. (2) The long-run coal consumption increased CO2 emissions by 0.75%–0.78%, while clean energy consumption potentially decreases long-run CO2 emissions by 0.08%–0.14%. (3) Urbanization and trade openness seem to have an adverse impact on CO2 emissions. The study suggests that India, to reach net-zero carbon emissions in 2070 can (1) accelerate the utilization of higher efficiency and low CO2 emissions technology in coal-fired plants, increase the share of hydropower and nuclear energy use, which would help alleviate the current tradeoff between energy security and carbon neutrality, (2) seek more opportunities for cooperation with countries that are further ahead in the deployment of clean energy technologies, such as China, to accelerate clean energy technology utilization and thus achieve mutual benefits, (3) Lastly it is suggested that India’s carbon trading market should be further developed to allow for carbon pricing in practice.
Similar and dissimilar material joints of AISI grade 304 (1.4301) and AISI grade 316 (1.4401) austenitic stainless steel by solid state diffusion bonding and transient liquid phase (TLP) bonding are ...of interest to academia and industry alike. Appropriate bonding parameters (bonding temperature, bonding time, and bonding pressure) as well as suitable surface treatments, bonding atmosphere (usually high vacuum or protective gas) and interlayers are paramount for successful bonding. The three main parameters (temperature, time, and pressure) are interconnected in a strong non-linear way making experimental data important. This work reviews the three main parameters used for solid state diffusion bonding, TLP bonding and to a smaller degree hot isostatic pressing (HIP) of AISI grade 304 and AISI grade 316 austenitic stainless steel to the aforementioned materials (similar joints) as well as other materials, namely commercially pure titanium, Ti-6A-4V, copper, zircaloy and other non-ferrous metals and ceramic materials (dissimilar joints).
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•The functionalized biochar-clay composite (FBKC) was successfully synthesized.•FBKC exhibited specific surface area of 221.04 m2/g compared to 47.02 m2/g for BC.•Synergistic sorption ...mechanisms were confirmed for NFX and CVD sorption by FBKC.•FBKC showed a maximum column bed capacity of 37.90 (NFX) and 53.98 mg/g (CVD).•The cost estimation of FBKC was precisely presented, indicating a rate of 5.72 €/kg.
This study investigated the successful synthesis of functionalized algal biochar-clay composite (FBKC). Subsequently, the sorption performance of FBKC towards norfloxacin (NFX) antibiotic and crystal violet dye (CVD) from water was extensively assessed in both batch and continuous flow systems. A series of characterization techniques were carried out for FBKC and the utilized precursors, indicating that the surface area of FBKC was increased thirty-fold with a well-developed pore structure compared to the original precursors. FBKC demonstrated a maximum sorption capacity of 192.80 and 281.24 mg/g for NFX and CVD, respectively. The suited fitting of the experimental data to Freundlich and Clark models suggested multi-layer sorption of NFX/CVD molecules. The mechanistic studies of NFX/CVD sorption onto FBKC unveiled multiple mechanisms, including π-π interaction, hydrogen bonding, electrostatic attraction, and surface/pore filling effect. The estimated cost of 5.72 €/kg and superior sorption capacity makes FBKC an efficient low-cost sorbent for emergent water pollutants.
Oxidase and peroxidase enzymes have attracted attention in various biotechnological industries due to their ease of synthesis, wide range of applications, and operation under mild conditions. Their ...applicability, however, is limited by their poor stability in harsher conditions and their non-reusability. As a result, several approaches such as enzyme engineering, medium engineering, and enzyme immobilization have been used to improve the enzyme properties. Several materials have been used as supports for these enzymes to increase their stability and reusability. This review focusses on the immobilization of oxidase and peroxidase enzymes on metal and metal oxide nanoparticle-polymer composite supports and the different methods used to achieve the immobilization. The application of the enzyme-metal/metal oxide-polymer biocatalysts in biosensing of hydrogen peroxide, glucose, pesticides, and herbicides as well as blood components such as cholesterol, urea, dopamine, and xanthine have been extensively reviewed. The application of the biocatalysts in wastewater treatment through degradation of dyes, pesticides, and other organic compounds has also been discussed.
Diffusion bonding is a solid-state welding technique used to join similar and dissimilar materials. Relatively long processing times, usually in the order of several hours as well as fine polished ...surfaces make it challenging to integrate diffusion bonding in other production processes and mitigate widespread use of the technology. Several studies indicate that varying pressure during diffusion bonding in contrast to the traditionally applied constant load may reduce overall processing- and bonding times. Such processes are referred to as impulse pressure-assisted diffusion bonding (IPADB) and they are, for the first time, reviewed in this work using the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analysis) methodology. Results of the review indicate that varying pressure can indeed reduce bonding times in diffusion bonding and reduce the requirements for pre-bond surface preparation. Additional research is required and should go beyond small and simple sample geometries to concentrate on making IPADB accessible to industrial applications.
Phosphate rock, pre-concentrated phosphate ore, is the primary raw material for the production of mineral phosphate fertilizer. Phosphate rock is among the fifth most mined materials on earth, and it ...is also mined and processed to fertilizers in East Africa. Phosphate ore can contain relevant heavy metal impurities such as toxic cadmium and radiotoxic uranium. Prolonged use of phosphate rock powder as a fertilizer and application of mineral fertilizers derived from phosphate rock on agricultural soils can lead to an accumulation of heavy metals that can then pose an environmental risk. This work assesses the uranium concentrations in four major phosphate rocks originating from East Africa and four mineral phosphate fertilizers commonly used in the region. The concentration measurements were performed using energy-dispersive X-ray fluorescence spectrometry. The results showed that the uranium concentration in phosphate rock ranged from as low as 10.7 mg kg
−1
(Mrima Hill deposit, Kenya) to as high as 631.6 mg kg
−1
(Matongo deposit, Burundi), while the concentrations in phosphate fertilizers ranged from 107.9 for an imported fertilizer to 281.0 mg kg
−1
for a local fertilizer produced from Minjingu phosphate rock in Tanzania. In this context, it is noteworthy that the naturally occurring concentration of uranium in the earth crust is between 1.4 and 2.7 mg kg
−1
and uranium mines in Namibia commercially process ores with uranium concentrations as low as 100–400 mg kg
−1
. This study thus confirms that East African phosphate rock, and as a result the phosphate fertilizer produced from it can contain relatively high uranium concentrations. Options to recover this uranium are discussed, and it is recommended that public–private partnerships are established that could develop economically competitive technologies to recover uranium during phosphate rock processing at the deposits with the highest uranium concentrations.
This study examines the dynamic connectedness and hedging opportunities between CSI300 (China Security Index 300) and copper, gold, PTA (purified terephthalic acid), and soybean in China from January ...09, 2008, to June 30, 2023. A TVP-VAR and cDCC-FIAPARCH modeling framework was used for the empirical investigation. The results show that the total connectedness index can effectively capture cross-asset information transmission in China’s financial markets. Copper returns are the dominant volatility transmitters, while CSI300, gold, and soybean returns are net recipients. The Russian–Ukraine war reinforced the safe-haven role of gold. Finally, investors with CSI300 long positions may benefit from prioritizing gold for hedging, while those with CSI300 short positions profit more from allocating gold to PTA. Portfolio managers and investors can use the findings to track the dynamics of systemic risk and adjust their long/short positions when investing in China's stock and commodity markets.
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