2018 Research & Innovation Day Program

A one day showcase of applied research, social innovation, scholarship projects and activities.https://first.fanshawec.ca/cri_cripublications/1005/thumbnail.jp

A Non-Newtonian Magnetohydrodynamics (MHD) Nanofluid Flow and Heat Transfer with Nonlinear Slip and Temperature Jump

The velocity and thermal slip impacts on the magnetohydrodynamics (MHD) nanofluid flow and heat transfer through a stretched thin sheet are discussed in the paper. The no slip condition is substituted for a new slip condition consisting of higher-order slip and constitutive equation. Similarity transformation and Lie point symmetry are adopted to convert the derived governed equations to ordinary differential equations. An approximate analytical solution is gained through the homotopy analysis method. The impacts of velocity slip, temperature jump, and other physical parameters on flow and heat transfer are illustrated. Results indicate that the first-order slip and nonlinear slip parameters reduce the velocity boundary layer thickness and Nusselt number, whereas the effect on shear stress is converse. The temperature jump parameter causes a rise in the temperature, but a decline in the Nusselt number. With the increase of the order, we can get that the error reaches 10 − 6 from residual error curve. In addition, the velocity contours and the change of skin friction coefficient are computed through Ansys Fluent

Spatiotemporal Evolution Characteristics and the Climatic Response of Carbon Sources and Sinks in the Chinese Grassland Ecosystem from 2010 to 2020

With the increase in global carbon dioxide emissions, China has put forward the goals of a carbon peak and carbon neutrality (double carbon) and formulated an action plan to consolidate and enhance the carbon sink capacity of the ecosystem. The Chinese grassland ecosystem (CGE) is widely distributed and is the key link for China to achieve the double carbon objectives. However, there is a relative lack of research on carbon sources and sinks in the CGE, so it is urgent to integrate and analyze the carbon sources and sinks in the grassland ecosystem on the national scale. Based on the refined grid data, the net ecosystem productivity (NEP) of the CGE was estimated by coupling the vegetation production model and soil respiration model. The results showed that the cumulative carbon sequestration of the CGE was 14.46 PgC from 2010 to 2020. In terms of spatial distribution, this shows that the differentiation characteristics are high in the northwest of China and low in the southeast of China, which strongly corresponds with the 400 mm isohyet and 0 °C isotherm of China. The results of the correlation analysis showed that the NEP of the CGE was positively correlated with precipitation and negatively correlated with temperature; that is, precipitation mainly promotes the accumulation of NEP, and temperature mainly inhibits it. The coupling effect of temperature and precipitation jointly affects the spatial change of carbon sources and sinks of the CGE. This study can provide a scientific basis for government departments to formulate targeted policies to deal with climate change, which is of great significance for China to improve ecosystem management, ensure ecological security and promote the realization of China’s double carbon goal

Spatiotemporal Evolution Characteristics and the Climatic Response of Carbon Sources and Sinks in the Chinese Grassland Ecosystem from 2010 to 2020

With the increase in global carbon dioxide emissions, China has put forward the goals of a carbon peak and carbon neutrality (double carbon) and formulated an action plan to consolidate and enhance the carbon sink capacity of the ecosystem. The Chinese grassland ecosystem (CGE) is widely distributed and is the key link for China to achieve the double carbon objectives. However, there is a relative lack of research on carbon sources and sinks in the CGE, so it is urgent to integrate and analyze the carbon sources and sinks in the grassland ecosystem on the national scale. Based on the refined grid data, the net ecosystem productivity (NEP) of the CGE was estimated by coupling the vegetation production model and soil respiration model. The results showed that the cumulative carbon sequestration of the CGE was 14.46 PgC from 2010 to 2020. In terms of spatial distribution, this shows that the differentiation characteristics are high in the northwest of China and low in the southeast of China, which strongly corresponds with the 400 mm isohyet and 0 °C isotherm of China. The results of the correlation analysis showed that the NEP of the CGE was positively correlated with precipitation and negatively correlated with temperature; that is, precipitation mainly promotes the accumulation of NEP, and temperature mainly inhibits it. The coupling effect of temperature and precipitation jointly affects the spatial change of carbon sources and sinks of the CGE. This study can provide a scientific basis for government departments to formulate targeted policies to deal with climate change, which is of great significance for China to improve ecosystem management, ensure ecological security and promote the realization of China’s double carbon goal

Study on Regional Differences and Convergence of Green Development Efficiency of the Chemical Industry in the Yangtze River Economic Belt Based on Grey Water Footprint

Grey water footprint is included in the green development efficiency evaluation index system of the chemical industry. From 2002 to 2016, the super efficiency Slack Based Measure (SBM) model was used to measure the green development efficiency of the chemical industry in the Yangtze River Economic Belt. Dagum Gini coefficient and its decomposition method were used to decompose the regional differences of green development efficiency of the chemical industry in the Economic Belt, and the coefficient of variation method and panel data regression model were used to test the convergence characteristics. The following results were obtained. (1) The total grey water footprint of the chemical industry in the Yangtze River Economic Belt showed a fluctuating downward trend from 2002 to 2016. (2) The green development efficiency of the chemical industry in the Yangtze River Economic Belt was significantly improved, and the spatial differentiation law of gradient decline in the upper, middle, and lower reaches of the Economic Belt was shown. (3) The regional difference of green development efficiency of the chemical industry in the Yangtze River Economic Belt initially showed an expanding trend and then a narrowing trend. Regional differences in the upper reaches of the Yangtze River increased while those in the middle reaches first increased and then decreased, whereas those in the lower reaches decreased significantly. The variance in green development efficiency of the chemical industry is the main cause of regional differences. (4) From 2012 to 2016, the Yangtze River Economic Belt had obvious convergence in its whole region, middle reaches, and lower reaches and an inconspicuous convergence in the upstream area. Regional difference of green development efficiency of the chemical industry in the Economic Belt was the combined effect of the results of environmental regulation, industrial structure, foreign investment intensity, and scientific and technological advancements. Our results have high theoretical reference values and practical guiding significance for implementing the green efficiency promotion strategy of the chemical industry in Yangtze River Economic Belt by region and classification

Poly (Vinyl Alcohol) Composite Membrane with Polyamidoamine Dendrimers for Efficient Separation of CO2/H-2 and CO2/N-2

Although polyvinyl alcohol (PVA) membranes are commonly used for CO2 separation, there is still large development space in mechanical properties and high selectivity of the gas separation process. In this study, the gas separation performance and mechanical properties of the (PVA/Cu2+) substrate membranes were improved by introducing polyamidoamine (PAMAM). PAMAM had an important effect on the gas adsorption and separation performance of the membrane. In addition, the gas adsorption and separation properties of the PVA/Cu2+/PAMAM membrane (PPCm) were analyzed and studied when the inlet gas pressure and the species of mixed gases were variable. The results showed that the crystallinity and mechanical properties of the membrane with the PAMAM had been significantly improved. Young's modulus of PPCm with 30% PAMAM was 132% higher than that of the PVA/Cu2+ composite membrane without PAMAM. In addition, efficient separation efficiency and high selectivity of the gas separation process were observed. The separation factors of the PPCm for CO2/H-2 and CO2/N-2 were about three times higher than that of the PVA/Cu2+ substrate membranes. These results suggested that the introduction of PAMAM was promising for CO2 separation and permeance

Poly (Vinyl Alcohol) Composite Membrane with Polyamidoamine Dendrimers for Efficient Separation of CO2/H-2 and CO2/N-2

Although polyvinyl alcohol (PVA) membranes are commonly used for CO2 separation, there is still large development space in mechanical properties and high selectivity of the gas separation process. In this study, the gas separation performance and mechanical properties of the (PVA/Cu2+) substrate membranes were improved by introducing polyamidoamine (PAMAM). PAMAM had an important effect on the gas adsorption and separation performance of the membrane. In addition, the gas adsorption and separation properties of the PVA/Cu2+/PAMAM membrane (PPCm) were analyzed and studied when the inlet gas pressure and the species of mixed gases were variable. The results showed that the crystallinity and mechanical properties of the membrane with the PAMAM had been significantly improved. Young's modulus of PPCm with 30% PAMAM was 132% higher than that of the PVA/Cu2+ composite membrane without PAMAM. In addition, efficient separation efficiency and high selectivity of the gas separation process were observed. The separation factors of the PPCm for CO2/H-2 and CO2/N-2 were about three times higher than that of the PVA/Cu2+ substrate membranes. These results suggested that the introduction of PAMAM was promising for CO2 separation and permeance