72 research outputs found
Polymer-supported superbases for carbon dioxide adsorption
No full textWith the high demand to tackle climate change, direct air capture of CO2 has emerged as a potential technology. The choice of adsorbents significantly impacts the cost and efficiency of the process. The critical factor in this application is the stability and selectivity. Superbases are structurally stable and low-toxic compounds that contain amidine or guanidine groups. They have been identified as high-potential CO2 adsorbents due to their high CO2 capacity and fast kinetics. Despite the prevalent use of liquid sorbents containing superbases, solid adsorbents have received attention as well. In this master’s thesis, solid porous polymers combine with superbases by loading superbases on the polymer support through impregnation and covalent bonding methods to achieve high CO2 capacity and selectivity. The structure of the CO2 adsorbent was analyzed by attenuated total reflectance-Fourier transform infrared (FTIR) spectroscopy, nuclear magnetic resonance (NMR), and element analysis (EA). At the same time, the morphologies were characterized by Brunauer-Emmett-Teller/Barrett-Joyner-Halenda (BET/BJH) analyses and scanning transmission microscopy (SEM). CO2 adsorption properties were assessed using thermogravimetric analysis. Among these, hyper-crosslinked toluene (HCT)-impregnated superbase exhibited a CO2 capacity of 1.03 mmol/g and an amine efficiency of 33% under 14-vol% CO2/N2 dry conditions. After adsorption-desorption cycles, the adsorbent remains stable. A high amount of superbase impregnated with substrates can increase CO2 capacity. Conversely, superbase will aggregate on the porous polymer surface, clog pore cavities, and thus reduce the efficiency of CO2 diffusion. Therefore, in order to improve CO2 adsorption performance, emphasizing the mass ratio of substrate to superbase during impregnation and the choice of solvent is crucial. It is significant to achieve functionalization while maintaining a porous structure after impregnation
From Brand to Prosperity: The Impact of Agricultural Regional Public Brands on Local Economic Growth in China
No full textThis study evaluates the economic impact of Agricultural Regional Public Brands (ARPBs) using panel data from 2,725 Chinese counties (2000- 2020). A difference-in-differences (DID) approach with fixed effects identifies the causal impact of ARPB adoption. Results show that ARPBs significantly enhance county-level GDP, especially in livestock-oriented regions with stronger industrial linkages. Mechanism analyses reveal that ARPBs promote economic growth by upgrading employment structures, facilitating urban-rural integration, and encouraging agricultural modernization. Regional heterogeneity suggests that eastern and central regions benefit more than western ones, likely due to infrastructure and market access differences. The effects of reducing the urban-rural income gap are limited. These findings provide policy-relevant insights into how place-based branding can promote inclusive rural development
Operating Characteristics and Description of a Dual Fuel Engine for Diesel-Natural Gas Heavy-Duty Operation
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Naphthalene-Based Poly (arylene ether ketone) Copolymers Containing Sulfobutyl Pendant Groups for Proton Exchange Membranes
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Prediction condom usage intention : the role of protection motivation amongst homosexual and heterosexual males
No full textThe number of individuals infected with the HIV/AIDS continues to rise at an alarming rate in the world, as well as in Singapore. Sexual intercourse amongst heterosexual and homosexual males remains the main mode of transmission of the virus. Using the Protection Motivation Theory (Rogers, 1983), this research aims to understand the factors affecting condom usage intention amongst men in Singapore. We used self-administered surveys to gather data from 219 homosexual and 265 heterosexual men. Structural equation modeling found self-efficacy to be a significant predictor for both groups of men, together with perceived severity for homosexuals and response efficacy for heterosexuals. Following the empirical study, we content analyzed HIV-directed materials and found that the use of threat appeal themes is more common than the focus on promoting self-efficacy towards condom usage. Implications for policy makers, health and social marketing are discussed.Bachelor of Communication Studie
An assessment of sustainable wellbeing and coordination of mountain areas: A case study of Qinba Mountain Area in China
No full textOld economic development theories no longer adequately explain development issues as the world moves toward the Sustainable Development Goals (SDGs). The key to solving this problem lies in shifting from economic wellbeing with wealth at its core to sustainable wellbeing with equitable development at its core. However, there is a lack of systematic methods and applications for assessing sustainable wellbeing, which leaves policy makers unsure of how to optimize policies for sustainable wellbeing enhancement. Therefore, this research aims to establish a sustainable wellbeing measurement system connection with the SDGs, to value and index sustainable wellbeing, and to explore the progress of sustainable wellbeing in 46 counties in the Qinba Mountain Area from 2009 to 2020, taking the Qinba Mountain Area, which is the most concerned area in China. Methodologically, Genuine Progress Indicator (GPI), Ecosystem Services Vuale (ESV), and Life Satisfaction (LS) are valorized separately to represent economic capital, ecological capital, and social capital, thus valorizing sustainable wellbeing, and get the Sustainable Wellbeing Value (SWV). Based on this, we follow the principle of “the best system is one that achieves a simultaneously prosperous” advocated by the theory of sustainable wellbeing, and calculate the Sustainable Wellbeing Index (SWI) by the method of coupling coordination, so as to build up the interconnection of the three capital accounts of sustainable wellbeing: economic, ecological and social. We investigate the spatial and temporal dynamics dynamic changes of sustainable wellbeing in the Qinba Mountain Area based on the valuation and indexation of sustainable wellbeing. The results of the research show that, first, the value of sustainable wellbeing in the Qinba Mountain Area fluctuates upward, with economic capital contributing the most, ecological capital fluctuating the most, and social capital contributing most smoothly. Although economic capital is necessary for the development of all counties, it is obvious that developing counties rely on it more. The SWI in the Qinba Mountain Area fluctuates and rises, and it is overall in a stage of coordinated transition, showing strong social and economic capital and weak ecological capital. By county, the proportion of dysfunctional economic, ecological, and social capital interrelationships declined significantly in all counties. However, some counties still suffer from ecological lag, mainly stemming from an imbalance between human activities and the required ecosystem services. Therefore, it is crucial to clarify the functional territorial zoning of regions and promote the structural transformation of development. This research will provide a valuable reference for the refinement research of Sustainable Development Goals and the optimization of rural development policies in mountainous areas
The Design and Realization of the Expert System of Load/Unload Operation of Quayside Crane
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