| 1. |
- Wang, F., et al.
(författare)
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A comprehensive review on high-temperature fuel cells with carbon capture
- 2020
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Ingår i: Applied Energy. - : Elsevier Ltd. - 0306-2619 .- 1872-9118. ; 275
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Forskningsöversikt (refereegranskat)abstract
- High-temperature fuel cells and their hybrid systems represent one of the most promising technologies with high conversion efficiency. The configuration of such kind of system could facilitate an easy capture of CO2. Several novel CO2 capture strategies have been developed based on high-temperature fuel cells, such as solid oxide fuel cell (SOFC), molten carbonate fuel cell (MCFC) and direct carbon fuel cell (DCFC). However, related review which focus on their system integration and performance evaluation is still rare. The aim of this study is to improve interest in high-temperature fuel cell with CO2 capture by providing an overview of the status of such kind of cutting-edge technologies. To approach this goal, the major strategies and technologies for fuel cells and their hybrid system with CO2 capture have been reviewed. Simultaneously, the characteristics of fuel cell technologies are summarized and the technical and economic performance of the fuel cell with CO2 capture are explored and discussed as well. The existing challenges that required to be overcome in fuel cell with CO2 capture technology are highlighted with aspects on fuel cell module scale-up, cost, safety, reliability and capture energy, etc. Finally, opportunities for the future development of high-temperature fuel cell with CO2 capture technologies are discussed. The conclusion remarks of this investigation indicate that fuel cell integrating CO2 capture process is a promising route to sustainable future, and could even be more effective if fuel cell technology can be commercialized.
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| 2. |
- Wang, F., et al.
(författare)
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Current status and challenges of the ammonia escape inhibition technologies in ammonia-based CO2 capture process
- 2018
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Ingår i: Applied Energy. - : Elsevier Ltd. - 0306-2619 .- 1872-9118. ; 230, s. 734-749
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Tidskriftsartikel (refereegranskat)abstract
- CO2 capture using ammonia solvent is an alternative to the conventional amine-based CO2 capture technology. While ammonia escape is one of the main barrier limiting its implementation. The present work reviews the current status of ammonia escape mechanisms and its inhibition technologies. The chemistry of ammonia-based absorption and desorption are analyzed, and the mass transfer of the ammonia escape are presented and discussed. Most suppression approaches for ammonia slip are in lab- and bench-scale studies. The representative development of the pilot-scale tests involves NH3 abatement and recycling process and chilled ammonia process (CAP). Some other novel processes have been reported the potential to reduce ammonia slip significantly and relatively lower energy penalty, but some technical issues including the process modification and parameters optimization should be resolved to secure economic feasibility. Integration of different ammonia inhibition approaches is suggested for the future development of ammonia slip suppression process.
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| 3. |
- Zhang, H. W., et al.
(författare)
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Cellular automaton modelling of M7C3 carbide growth during solidification of Fe-C-Cr alloy
- 2020
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Ingår i: International conference on modelling of casting, welding and advanced solidification processes (MCWASP XV). - : IOP Publishing.
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Konferensbidrag (refereegranskat)abstract
- A microscopic cellular automaton combined with macroscopic heat and solute transport was developed to simulate the mutual growth and evolution of austenite and M7C3 carbide grains during Fe-C-Cr ternary alloy solidification process. The diffusion of solute C and Cr are contributed together to the constitutional undercooling, together with curvature undercooling, for obtaining the grain growth rate of austenite and M7C3 carbide. Results show that, the absorption of solute C and Cr by M7C3 grain and rejection by austenite grain promote the two grains' cooperative growth. Once they approach to each other, the austenite grain quickly overgrows towards the M7C3 grain till finally envelops it. The simulated solidification morphology of the Fe-4wt%C-17wt%Cr alloy, predicted averaged grain size of M7C3 carbides and C and Cr concentration in austenite grains agree with the experimental measurements and solidification path prediction. The predicted average liquid concentration curve fits with the LR, GS and PE prediction at the initial M7C3 precipitation regime and after austenite grains fully enveloping towards the M7C3 grains, returns to overlap the LR, GS and PE prediction curves.
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| 4. |
- Zaidi, A. A., et al.
(författare)
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A Preliminary Study on Waveform Candidates for 5G Mobile Radio Communications Above 6 GHz
- 2016
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Ingår i: IEEE Vehicular Technology Conference. - 1550-2252. ; 2016-July
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Konferensbidrag (refereegranskat)abstract
- This paper provides an overview and preliminary comparison of several multi-carrier and single-carrier waveforms that are potential candidates for future 5G mobile radio communications above 6 GHz. The waveforms are assessed primarily based on the established and known results as well as recent findings keeping in view the design requirements that are relevant to using frequencies above 6 GHz, especially the millimeter wave frequencies. The Key Performance Indicators and degrees of freedom in the design of different waveforms and their potential applications for mm-wave communications are discussed. Certain features that are particularly interesting for mm-wave communication and require further investigations are also highlighted. Furthermore, a common framework for synthesizing different waveform candidates has been developed. Finally, a preliminary qualitative comparison of different multicarrier and single carrier waveforms has been derived.
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| 5. |
- Zetterberg, P., et al.
(författare)
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Initial multi-node and antenna transmitter and receiver architectures and schemes; Deliverable D5.1
- 2016
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This deliverable provides the initial concepts and solutions from the technical work related to multi-antenna and multi-node transceiver schemes in millimetre wave (denoted as 6-100GHz) spectrum. It also briefly presents the use cases on which the work will be based and categorises the solutions in terms of their applicability to access, backhaul and relay deployments. Another important contribution from this report is the modelling of the hardware impairments in millimetre wave transceivers and the analysis of their impact on system performance.
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| 6. |
- Wang, Miao, et al.
(författare)
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Colloidal Ionic Assembly between Anionic Native Cellulose Nanofibrils and Cationic Block Copolymer Micelles into Biomimetic Nanocomposites
- 2011
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Ingår i: Biomacromolecules. - : American Chemical Society (ACS). - 1525-7797 .- 1526-4602. ; 12:6, s. 2074-2081
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Tidskriftsartikel (refereegranskat)abstract
- We present a facile ionic assembly between fibrillar and spherical colloidal objects toward biomimetic nanocomposites with majority hard and minority soft domains based on anionic reinforcing native cellulose nanofibrils and cationic amphiphilic block copolymer micelles with rubbery core. The concept is based on ionic complexation of carboxymethylated nanofibrillated cellulose (NFC, or also denoted as microfibrillated cellulose, MFC) and micelles formed by aqueous self-assembly of quaternized poly(1,2-butadiene)-block-poly(dimethylaminoethyl methacrylate) with high fraction of the NFC reinforcement. The adsorption of block copolymer micelles onto nanocellulose is shown by quartz crystal microbalance measurements, atomic force microscopy imaging, and fluorescent optical microscopy. The physical properties are elucidated using electron microscopy, thermal analysis, and mechanical testing. The cationic part of the block copolymer serves as a binder to NFC, Whereas the hydrophobic rubbery micellar cores are designed to facilitate energy dissipation and nanoscale lubrication between the NFC domains under deformation. We show that the mechanical properties do not follow the rule of mixtures, and synergistic effects are observed with promoted work of fracture in one composition. As the concept allows wide possibilities for tuning, the work suggests pathways for nanocellulose-based biomimetic nanocomposites combining high toughness with stiffness and strength.
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| 7. |
- Hwang, T., et al.
(författare)
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Green Radio
- 2015
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Ingår i: Green Communications. - Chichester, UK : Wiley-Blackwell. ; , s. 119-134
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- This chapter gives a comprehensive introduction to state-of-the-art energy-efficient communications, focusing on the physical (PHY) and medium access control (MAC) layers of wireless communication systems. The PHY layer consists of RF circuits, modulation, power control, and channel coding units, and so on and delivers data transmission as reliably as possible. The MAC layer ensures network-wide efficient resource management while maintaining quality of service (QoS) requirements of individual users. As wireless is a shared communication medium, with wireless communications, device energy consumption is not only affected by the designs of different layers of the point-to-point communicating link but also by the interactions of all links in the network. A system approach is therefore necessary for energy-efficient wireless communications system design. The focus of this chapter is on wireless system design, analysis, and optimization emphasizing energy efficiency enhancement while meeting given performance requirements. Since the design of all protocol layers impact energy consumption, this chapter introduces cross-layer energy-efficient techniques to reduce redundant message transfers and the associated energy consumption. Cross-layer techniques exploit interactions between different layers to significantly improve energy efficiency and adaptability to service, traffic, and environment dynamics.
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| 8. |
- Zhang, Pan, et al.
(författare)
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Nanochannel-Based Transport in an Interfacial Memristor Can Emulate the Analog Weight Modulation of Synapses
- 2019
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Ingår i: Nano letters (Print). - : AMER CHEMICAL SOC. - 1530-6984 .- 1530-6992. ; 19:7, s. 4279-4286
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Tidskriftsartikel (refereegranskat)abstract
- By exploiting novel transport phenomena such as ion selectivity at the nanoscale, it has been shown that nanochannel systems can exhibit electrically controllable conductance, suggesting their potential use in neuromorphic devices. However, several critical features of biological synapses, particularly their conductance modulation, which is both memorable and gradual, have rarely been reported in these types of systems due to the fast flow property of typical inorganic electrolytes. In this work, we demonstrate that electrically manipulating the nanochannel conductance can result in nonvolatile conductance tuning capable of mimicking the analog behavior of synapses by introducing a room-temperature ionic liquid (IL) and a KCl solution into the two ends of a nanochannel system. The gradual conductance-tuning mechanism is identified through fluorescence measurements as the voltage-induced movement of the interface between the immiscible IL and KCl solution, while the successful memorization of the conductance tuning is ascribed to the large viscosity of the IL. We applied a nanochannel-based synapse to a handwritten digit-recognition task, reaching an accuracy of 94%. These promising results provide important guidance for the future design of nanochannel-based neuromorphic devices and the manipulation of nanochannel transport for computing.
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| 9. |
- Dyakov, Sergey, et al.
(författare)
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Influence of the buffer layer properties on the intensity of Raman scattering of graphene
- 2013
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Ingår i: Journal of Raman Spectroscopy. - : Wiley. - 0377-0486 .- 1097-4555. ; 44:6, s. 803-809
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Tidskriftsartikel (refereegranskat)abstract
- Using a model of oscillating dipoles, we simulate the intensity of the G-band in the Raman signal from structures consisting of graphene, separated by an arbitrary buffer layer from a substrate. It is found that a structure with an optimized buffer layer refractive index and thickness exhibits a Raman signal which is nearly 50 times more intense than that from the same structure with a non-optimized buffer layer. The theoretical simulations are verified by Raman measurements on structures consisting of a layer of graphene on SiO2 and Al2O3 buffer layers. The optical contrast of the single graphene layer is calculated for an arbitrary buffer layer. It was found that both the Raman intensity and optical contrast can be maximized by varying the buffer layer thickness.
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| 10. |
- Feng, Yanyue, 1993, et al.
(författare)
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Applications of anodized TiO2 nanotube arrays on the removal of aqueous contaminants of emerging concern: A review
- 2020
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Ingår i: Water Research. - : Elsevier BV. - 0043-1354 .- 1879-2448. ; 186
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Forskningsöversikt (refereegranskat)abstract
- The presence of contaminants of emerging concern (CECs) in various water bodies and the associated threats to eco-system and human society have raised increasing concerns. To fight against such a problem, TiO2 photocatalysis is considered to be a powerful tool. In recent decades, TiO2 nanotube array (TNA) fabricated by electrochemical anodization emerged as a viable immobilized catalyst and its applications on CECs removal have gained a considerable amount of research interest. We herein present a critical review on the development of TNA and its applications on the removal of aqueous CECs. In this work, the CECs removal in different TNA based processes, the CECs removal mechanisms, the role of TNA properties, the role of operational parameters, and the role of water matrices are discussed. Moreover, perspectives on the current research progress are presented and recommendations on future research are elaborated.
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