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581.
Masood S. Alivand Rebecca V. McQuillan Arash Momeni Ali Zavabeti Geoffrey W. Stevens Kathryn A. Mumford 《Small (Weinheim an der Bergstrasse, Germany)》2023,19(30):2300150
Direct removal of carbon dioxide (CO2) from the atmosphere, known as direct air capture (DAC) is attracting worldwide attention as a negative emission technology to control atmospheric CO2 concentrations. However, the energy-intensive nature of CO2 absorption-desorption processes has restricted deployment of DAC operations. Catalytic solvent regeneration is an effective solution to tackle this issue by accelerating CO2 desorption at lower regeneration temperatures. This work reports a one-step synthesis methodology to prepare monodispersed carbon nanospheres (MCSs) using trisodium citrate as a structure-directing agent with acidic sites. The assembly of citrate groups on the surface of MCSs enables consistent spherical growth morphology, reduces agglomeration and enhances water dispersibility. The functionalization-assisted synthesis produces uniform, hydrophilic nanospheres of 100–600 nm range. This work also demonstrates that the prepared MCSs can be further functionalized with strong Brønsted acid sites, providing high proton donation ability. Furthermore, the materials can be effectively used in a wide range of amino acid solutions to substantially accelerate CO2 desorption (25.6% for potassium glycinate and 41.1% for potassium lysinate) in the DAC process. Considering the facile synthesis of acidic MCSs and their superior catalytic efficiency, these findings are expected to pave a new path for energy-efficient DAC. 相似文献
582.
Mahshid Farzanehsa Liam C. Vaughan Arash Zamyadi Stuart J. Khan 《Water and Environment Journal》2023,37(4):633-643
Applications of advanced oxidation processes (AOPs) in water and wastewater treatment have been the subject of growing interest throughout the last decade. Although UV/hydrogen peroxide (UV-H2O2) is the most established technology among the UV-AOPs, UV-chlorine (UV-Cl) is emerging as a reliable and potentially more cost-effective alternative. Recent studies have indicated that UV-Cl processes may be more efficient and economically favourable for the degradation of some chemicals of emerging concern from contaminated water. Moreover, in terms of the formation of disinfection by-products (DBPs), UV-H2O2 seems to have no superiority over UV-Cl. This said, more investigation in the assessment of genotoxicity and cytotoxicity of DBPs is required. Additionally, more pilot-scale and full-scale studies are required to establish UV-Cl as a reliable alternative to UV- H2O2. This paper compares UV-Cl and UV-H2O2 AOPs for the degradation of intractable chemicals from water and wastewater based on the practical considerations of efficiency, cost, DBP formation, kinetics and sensitivity to water matrix variability. Finally, various modelling approaches to UV-Cl have been reviewed. This review showed that UV-Cl is superior to UV-H2O2 in terms of degradation efficiency and cost effectiveness and can be a robust alternative in many UV-AOPs applications. 相似文献
583.
Erfan Lotfi-Khojasteh Hassan Elmkhah Meisam Nouri Omid Imantalab Arash Fattah-Alhosseini 《International Journal of Applied Ceramic Technology》2023,20(5):2874-2887
The present study investigated the wear and electrochemical behaviors of CrN/AlCrN multilayered coatings post-annealed at 300, 450, and 600°C temperatures. The cathodic arc evaporation technique has been utilized to deposit the coatings. Scanning electron microscope, field emission SEM, energy-dispersive X-ray, grazing incidence X-ray diffraction, and Rockwell-C indenter methods were used to characterize the coatings and to investigate the interdiffusion between the multilayered CrN/AlCrN and the H13 base metal. The results showed that the sharp interface of the CrN and AlCrN layers was blurred by the annealing process supporting the interdiffusion of the layers. The reciprocating wear test and the microhardness tester were used to evaluate the coatings’ mechanical behavior. The hardness and roughness of the coatings were increased by increasing the post-annealing temperature. The smallest wear rates were observed for the samples treated at 300 and 450°C, which were approximately 17 times and 12 times smaller than the wear rate of the sample annealed at 600°C. Electrochemical testing was used to study the corrosion behavior of the coatings. The results showed that by increasing annealing temperature, corrosion resistances of the coatings are improved. As a result, the corrosion current density of the 600°C annealed coating was approximately 434 times smaller than as-deposited coatings. 相似文献
584.
Asim Bashir Khajwal Chih-Shen Cheng Arash Noshadravan 《Computer-Aided Civil and Infrastructure Engineering》2023,38(4):528-544
This study aims to facilitate a more reliable automated postdisaster assessment of damaged buildings based on the use of multiple view imagery. Toward this, a Multi-View Convolutional Neural Network (MV-CNN) architecture is proposed, which combines the information from different views of a damaged building, resulting in 3-D aggregation of the 2-D damage features from each view. This spatial 3-D context damage information will result in more accurate and reliable damage quantification in the affected buildings. For validation, the presented model is trained and tested on a real-world visual data set of expert-labeled buildings following Hurricane Harvey. The developed model demonstrates an accuracy of 65% in predicting the exact damage states of buildings, and around 81% considering ±1 class deviation from ground-truth, based on a five-level damage scale. Value of information (VOI) analysis reveals that the hybrid models, which consider at least one aerial and ground view, perform better. 相似文献
585.
In this paper, nanofiltration (NF) polymer membranes based on polyestersulphone (PES) were prepared by the phase inversion method. Polyethyleneimine (PEI) and zinc nitrate (Zn(NO3)2) as a surface modifier and glutealdehyde (GA) as cross-linker was used. Fourier transform infrared spectroscopy analysis (FTIR) was used to confirm the chemical composition on the membrane surface. Membranes were also characterized using field emission scanning electron microscopy (FESEM) and 3D surface images. Water contact angle, average pore size and porosity measurements, water flux, salt rejection, and membrane anti-fouling ability were discussed. Modified membranes showed a smoother surface than the original membrane. The amount of pure water flux decreased with increasing the concentration of modifiers at the surface, but the yield of Na2SO4 salt increased, 53% in virgin membrane and 83% in M3 membrane. Modified membranes had better anti-fouling and hydrophilicity properties than primary membranes. The lowest contact angle value was 26.2° for M4. Also, the best anti-clogging comparable properties were for the M3 membrane with FRR = 63.37%, Rr = 10.69%, Rir = 36.6%, and Rt = 47.3%. By increasing the concentration of modifiers, the removal of CuNO3− and CuSO4 improved that the M1 membrane (97.59%) had the highest Cu(NO3)2 separation and the M4 membrane (87.5%) had the most increased CuSO4 separation. 相似文献
586.
Arash Yahyazadeh Philip Boahene Tolu Emiola-Sadiq Ajay K. Dalai Lifeng Zhang 《加拿大化工杂志》2023,101(6):3132-3152
The kinetics of the Fischer–Tropsch (FT) reaction was evaluated through detailed experimentation with a KMo bimetallic promoted Fe catalyst supported on carbon nanotubes (CNTs). The kinetic tests were conducted in a fixed-bed reactor under operating conditions of P = 6.9–41.3 bar, T = 543–563 K, H2/CO = 1, gas hourly specific velocity (GHSV) = 2000 h−1. This study aimed to investigate the mechanism prevailing in CO activation and the rate equation for CO consumption during FT reactions over a 0.5K5Mo10Fe/CNTs catalyst. To evaluate the synergistic effects of Fe, Mo, and K phases on the catalyst activity, both fresh and spent catalysts were thoroughly characterized using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy and energy-dispersive spectroscopy (SEM-EDS), X-ray absorption near edge structure (XANES), and extended X-ray absorption fine structure (EXAFS) to ascertain the different phases (active sites) present and relevant interactions. Based on the adsorption of carbon monoxide and hydrogen, 22 possible mechanisms for monomer formation were proposed for FT synthesis in accordance with the Langmuir–Hinshelwood–Hougen–Watson (LHHW) and Eley–Rideal (ER) adsorption theories. The best fit kinetic model was identified through a multi-variable non-linear regression analysis. The selected mechanistic model was based on carbide formation approach, where H2-assisted adsorption of CO was considered for the derivation. Kinetic parameters such as activation energy, adsorption enthalpies of H2, and CO were estimated to be 65.0, −13.0, and −54.0 kJ/mol, respectively. Considering the developed kinetic model, the effects of reaction temperature and pressure were assessed on Fischer–Tropsch synthesis (FTS) product distribution. Additionally, the kinetic model was compared with the typical Anderson–Schulz–Flory model, suggesting the effects of water-gas-shift and the existence of additional formation pathway such as secondary re-adsorption of olefins for heavier hydrocarbons. 相似文献