Experiments and DFT study on modified CaO-based adsorbents for enhanced CO2_{{2}} capture

CaO-based adsorbents for carbon capture represent a promising technology for reducing carbon emission. In this study, we prepare metal oxide-doped multifarious CaO-based adsorbents using the hydration method. We investigate the effect of various working conditions, such as temperature and carbonation time, on different adsorbents in a fixed-bed reactor under multiple carbonation–calcination cycles. We examine the behavior of different metal oxides-doped synthetic adsorbents using density functional theory calculation based on experiments. The results prove that 5 wt% ZrO2-doped adsorbents show excellent CO2 adsorption efficiency, which reaches up to 38.4% after 20 carbonation–calcination cycles at 700 °C with 15 vol% CO2. The adsorbents doped with other metal oxides are also useful for CO2 capture to varying degrees. The adsorption energy of CO2 molecules on modifiequationed adsorbents is higher than that on pure CaO, especially for Zr, where the adsorption energy reached 2.37 eV. The calculation results are in good agreement with the experimental data

Experiments and DFT study on modified CaO-based adsorbents for enhanced CO2_{{2}} capture

CaO-based adsorbents for carbon capture represent a promising technology for reducing carbon emission. In this study, we prepare metal oxide-doped multifarious CaO-based adsorbents using the hydration method. We investigate the effect of various working conditions, such as temperature and carbonation time, on different adsorbents in a fixed-bed reactor under multiple carbonation–calcination cycles. We examine the behavior of different metal oxides-doped synthetic adsorbents using density functional theory calculation based on experiments. The results prove that 5 wt% ZrO2-doped adsorbents show excellent CO2 adsorption efficiency, which reaches up to 38.4% after 20 carbonation–calcination cycles at 700 °C with 15 vol% CO2. The adsorbents doped with other metal oxides are also useful for CO2 capture to varying degrees. The adsorption energy of CO2 molecules on modifiequationed adsorbents is higher than that on pure CaO, especially for Zr, where the adsorption energy reached 2.37 eV. The calculation results are in good agreement with the experimental data

Perception and Behavioral Intention of Cycling Space on Urban Greenway

To explore the spatial power and spatial relationship of urban greenway sports cultural memory, using literature data induction analysis method, questionnaire survey method, interview method, and other research methods, the connotation of urban greenway sports cultural memory is analyzed, and the urban greenway sports are explained. Using Lefebvre’s ternary dialectics to study the production process of Guangzhou greenway’s sports cultural memory space, its spatial practice is in the interpretation of Guangzhou’s Greenway sports cultural memory. The government is the leading force in the memory of greenway sports culture. It is a necessary prerequisite for the cultural memory of greenway sports, and the public is the main body of the cultural memory of greenway sports. The spatial representation is in the context of the cultural memory of greenway sports, sorting out the hard memory and soft memory in the memory field of Guangzhou Greenway Sports Culture. The representational space is the sports cultural memory space experienced by the greenway activists, space directly “lived” by the greenway activists, and the internalization of the cognition, experience, and spatial representation of the sport’s cultural memory of the greenway activists

The Production and Motivation Mechanism of Sports Cultural Memory Space in Urban Greenway

To study the relationship between urban greenway cycling space perception and cycling behavior intention, factor analysis, correlation analysis, and regression analysis were used to conduct a questionnaire survey of 411 college students to discover the advantages and disadvantages of urban greenway cycling factor, to achieve the comparison of related indicators and dimensions. The results show that the dimensions of Guangdong urban greenway sports space perception include accessibility perception, supporting perception, service perception, and environmental spatial characteristics; Guangdong college students’ greenway cycling space perception is highly correlated with cycling behavior intention, and there is a positive correlation. Among them, the environmental spatial characteristics are the most influential factors. Greenway accessibility, supporting services, cycling landscapes, etc. can stimulate college students’ greenway cycling behavior intentions. Improving the perception of urban greenway cycling space is an effective strategy to improve college students’ greenway sports behaviour and greenway cycling behaviour

Research on the Package Feature Selection of Talent Attracting Factors in International Trade in Guangdong-Hong Kong-Macao Greater Bay Area

This paper designs a survey questionnaire based on the Guangdong-Hong Kong-Macao Greater Bay Area’s demand for talents in international trade, adds job types, filters through package features, and performs feature filtering with the error filter criteria set in this paper, and conducts logistic regression analysis on talent types, so as to realize the classification and dynamic analysis of talents. The dynamic needs of various types of talents in international trade in the Guangdong-Hong Kong-Macao Greater Bay Area are drawn, and specific measures such as increasing salaries and benefits, reducing living costs, providing housing subsidies, solving children's employment problems, and ensuring quality of life are proposed for the development of international trade talents. Reducing the cost of talent migration can promote them to make more contributions to the Guangdong-Hong Kong-Macao Greater Bay Area. This will help the Guangdong-Hong Kong-Macao Greater Bay Area government to attract outstanding international trade talents and formulate detailed and feasible strategies, which has certain reference significance

Boiling Heat Transfer Characteristics of Porous Microchannel with Pore-Forming Agent

Traditional microchannel needs to face the flow-reversal difficulty in high heat fluxes due to limited space. It results in large pressure and temperature fluctuation. Porous microchannels arouse more interest to provide a new solution to this problem. Flow boiling experiments in porous microchannels with PFA were investigated. Porous microchannels were sintered by 10 μm (or 30 μm) spherical copper particles with pore-forming agent (Na2CO3, 60–90 μm). Porous microchannels were composed of 23 parallel porous microchannels with 600 μm in width and 1200 μm in depth.The addition of PFA (pore-forming agent) could increase the sample porosity. For Q10 series, sample porosities increase from 20.4% to 52.9% with the PFA percentage change from 0% to 40%, while for the Q30 series they increase from 26.6% to 47.5%. Experimental results showed the boiling heat transfer coefficient (HTC) reached the maximum at the moderate porosity for both Q10 and Q30 series. Too large or too small porosity would degrade boiling heat transfer performance. It demonstrated that there existed an optimal range of PFA content for sintered microchannels. PFA content has a minor effect on the average pressure drop and would not cause the rapid increase in flow resistance. Visual observation disclosed that the sample porosity would affect the pressure instability significantly. The sample with moderate porosity showed periodic pressure fluctuation and could establish rhythmical boiling. Particle size also exerted a certain influence on the boiling heat transfer performance. Q30 series could achieve higher HTC and CHF (Critical heat flux) than Q10 series. This is attributed to the larger ratio of layer-thickness-to-particle-size (δ/d) for Q10-series samples

The effect and mechanism of highland barley β-glucan in improving liver regeneration after partial hepatectomy

Studies have shown the beneficial effect of highland barley β-glucan (HBBG) on multiple acute and chronic liver diseases, however, whether it can improve liver regeneration following 2/3 partial hepatectomy (PH) is yet unknown. This study investigated the positive effect of β-glucan on liver regeneration in acute liver injury after PH. Before PH or CCl4 administration, mice were fed either a chow diet or that containing 5 or 10% HBBG for two weeks. The experimental mice were weighed on days 0, 1, and 2 after PH or CCl4 treatment, and the serum and liver tissue were collected. qRT-PCR, Western blotting, TUNEL staining, and immunostaining analysis were performed to measure the associated indices of proliferation and apoptosis of hepatocytes. We found that 5% HBBG promoted hepatocyte proliferation and liver regeneration and increased the liver/body weight ratio at 1 and 2 days after PH in mice. Mechanistically, HBBG activated the STAT3-CyclinD1 signaling pathway to increase hepatocyte proliferation, accelerating their transition from the G0 to S phase. Additionally, the HBBG intervention decreased hepatocyte apoptosis in the CCl4-induced liver injury model of mice. Concisely, HBBG can promote hepatocyte proliferation and liver regeneration via the STAT3-CyclinD1 signaling pathway in acute liver injury or PH

Techno-Economic Analysis of Hydrogen and Electricity Production by Biomass Calcium Looping Gasification

Combined cycle, biomass calcium looping gasification is proposed for a hydrogen and electricity production (CLGCC–H) system. The process simulation Aspen Plus is used to conduct techno-economic analysis of the CLGCC–H system. The appropriate detailed models are set up for the proposed system. Furthermore, a dual fluidized bed is optimized for hydrogen production at 700 °C and 12 bar. For comparison, calcium looping gasification with the combined cycle for electricity (CLGCC) is selected with the same parameters. The system exergy and energy efficiency of CLGCC–H reached as high as 60.79% and 64.75%, while the CLGCC system had 51.22% and 54.19%. The IRR and payback period of the CLGCC–H system, based on economic data, are calculated as 17.43% and 7.35 years, respectively. However, the CLGCC system has an IRR of 11.45% and a payback period of 9.99 years, respectively. The results show that the calcium looping gasification-based hydrogen and electricity coproduction system has a promising market prospect in the near future

Impacts of selenium supplementation on soil mercury speciation, and inorganic mercury and methylmercury uptake in rice (Oryza sativa L.)

Rice grain is known to accumulate methylmercury (MeHg) and has been confirmed to be the major pathway of MeHg exposure to residents in mercury (Hg) mining areas in China. Selenium (Se) supplementation has been proven to be effective in mitigating the toxicity of Hg. To understand how Se supplementation influences soil Hg speciation, a wide range of Se (0-500 mg/kg) was applied to Hg polluted paddy soils in this study, which decreased MeHg concentration in soil from 2.95 +/- 0.36 to 0.69 +/- 0.16 mu g/ kg (or 77%). After Se addition, humic acid state Hg (F4) was transformed into strong-complexed state Hg (F5), indicating that Hg bound up to the non-sulfur functional groups of humic acid (non-RSH) was released and reabsorbed by strong binding Se functional group (F5). As a result, inorganic Hg (IHg) was reduced by >48%, 18%, and 80% in root, stem, and grain, respectively, however, the reduction was not apparent in leaf. Substantial reductions were also found for MeHg in grain and root, but not in stem and leaf. Soil is suggested to be the main source of both MeHg and IHg in rice grain. Such a finding may provide an idea for improving Hg-polluted paddies through controlling soil IHg and MeHg. Further research on the molecular structure of the strong-complexed Hg in F5 should be conducted to elucidate the mechanism of Hg-Se antagonism. (C) 2019 Elsevier Ltd. All rights reserved

Weir building: A potential cost-effective method for reducing mercury leaching from abandoned mining tailings

To mitigate mercury (Hg) pollution and reduce Hg downstream transportation, a weir was designed by a river system that had been inflicted by leachate from the slagheap of the Yanwuping Hg mine in Wanshan Hgmining area. A whole yearmonitoring of Hg species was conducted, and the efficiency of Hg reduction by the weir application was evaluated. The Hg concentrations in the river waterwere significantly higher in the wet season than in the dry season. Waterflow was confirmed to be the main driving factor for Hg mobilization and transportation, and an episode study revealed that most Hg was released in times of storms. Increased monitoring and preventive maintenance measures need to be taken on barriers in advance of storms. A large proportion of the total Hg (THg) and methylmercury (MeHg) is associated to particles. During the study period, approximately 412 g THg and 4.04 g total MeHg (TMeHg) were released from the YMM slagheap, of which 167 g THg and 1.15 g TMeHg were retained by the weir. Annually, 40.4% THg and 38.4% TMeHg was retained by the weir. Weir construction is considered as a potential cost-effective measure tomitigate Hg in riverwater and should be promoted and extended in the future after optimization. (C) 2018 Elsevier B.V. All rights reserved