| 1. |
- Bartocci, Pietro, et al.
(author)
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Bioenergy with Carbon Capture and Storage (BECCS) developed by coupling a Pressurised Chemical Looping combustor with a turbo expander: How to optimize plant efficiency
- 2022
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In: Renewable and Sustainable Energy Reviews. - : Elsevier BV. - 1879-0690 .- 1364-0321. ; 169
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Research review (peer-reviewed)abstract
- Carbon Capture and Storage is a technology of paramount importance for the fulfillment of the Sustainable Development Goal 7 (Affordable and Clean Energy) and the Sustainable Development Goal 5 (Climate Action). The European Union is moving rapidly towards low carbon technologies, for instance via the Energy Union Strategy. Coupling biofuels and carbon capture and storage to decarbonize the power and the industrial sector can be done through the development of BECCS (Bioenergy with Carbon Capture and Storage). Chemical Looping combustion is one of the cheapest way to capture CO2. A Chemical Looping Combustion (CLC) plant can be coupled with a turbo expander to convert energy to power, but it has to work in pressurised conditions. The effect of pressure on the chemical reactions and on fluidised bed hydrodynamics, at the moment, is not completely clear. The aim of this review is to summarize the most important highlights in this field and also provide an original method to optimize power plant efficiency. The main objective of our research is that to design a pressurised Chemical Looping Combustion plant which can be coupled to a turbo expander. To achieve this we need to start from the characteristics of the turbo expander itself (eg. the Turbine Inlet Temperature and the compression ratio) and then design the chemical looping combustor with a top down approach. Once the air and the fuel reactor have been dimensioned and the oxygen carrier inventory and circulation rate have been identified, the paper proposes a final optimization procedure based on two energy balances applied to the two reactors. The results of this work propose an optimization methodology and guidelines to be used for the design of pressurised chemical looping reactors to be coupled with turbo expanders for the production of power with carbon negative emissions.
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| 2. |
- Lu, P. F., et al.
(author)
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Closing the bandgap for III-V nitrides toward mid-infrared and THz applications
- 2017
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In: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322 .- 2045-2322. ; 7:1, s. Art. no 10594-
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Journal article (peer-reviewed)abstract
- A theoretical study of InNBi alloy by using density functional theory is presented. The results show non-linear dependence of the lattice parameters and bulk modulus on Bi composition. The formation energy and thermodynamic stability analysis indicate that the InNBi alloy possesses a stable phase over a wide range of intermediate compositions at a normal growth temperature. The bandgap of InNBi alloy in Wurtzite (WZ) phase closes for Bi composition higher than 1.5625% while that in zinc-blende (ZB) phase decreases significantly at around 356 meV/%Bi. The Bi centered ZB InNBi alloy presents a change from a direct bandgap to an indirect bandgap up to 1.5625% Bi and then an oscillates between indirect bandgap and semi-metallic for 1.5625% to 25% Bi and finally to metallic for higher Bi compositions. For the same Bi composition, its presence in cluster or uniform distribution has a salient effect on band structures and can convert between direct and indirect bandgap or open the bandgap from the metallic gap. These interesting electronic properties enable III-nitride closing the bandgap and make this material a good candidate for future photonic device applications in the mid-infrared to THz energy regime.
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| 3. |
- Luo, H., et al.
(author)
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Applicability analysis of insulation in different climate zones of China
- 2017
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In: Energy Procedia. - : Elsevier BV. - 1876-6102. ; 142, s. 1835-1841
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Journal article (peer-reviewed)abstract
- In this paper we evaluated the applicability of the widely-used passive design strategy i.e., insulation, in three typical climate zones of China. Software IES VE was used for modelling and simulation of performance of insulation in a residential house. The practical behavior patterns of Chinese family from survey were utilized for analyzing the thermal characteristics of the house. Four parameters of the results were selected for analyzing the performance of insulation in three cities of China. The conditions varying in time periods and locations were compared on the basis of the simulation.
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| 4. |
- Lu, Yu, et al.
(author)
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Electroless deposition of high-uniformity nickel microbumps with ultrahigh resolution of 8 μm pitch for monolithic Micro-LED display
- 2024
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In: Materials Science in Semiconductor Processing. - 1369-8001. ; 175
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Journal article (peer-reviewed)abstract
- Micro-light-emitting diode (Micro-LED) displays have attracted growing attention due to their unsurpassed properties that satisfy the requirements of reality/virtual reality (AR/VR) displays. A crucial procedure of monolithic integration technology in high-density microdisplays is the interconnection process, which is intimately associated with the quality of the display device. Microfluidic electroless interconnection (MELI), an innovative low-temperature and pressure-free chip-stacking approach that eliminates the warpage-induced issues and cracking damage of the chip caused by thermo-compression bonding (TCB), holds great promise as a technology for establishing interconnections between the CMOS driver and Micro-LED. However, the requirement for the consistency of the microbump arrays and the risk of creating bridges is significantly intensified with smaller gaps in stacked chips, which restricts the application range of MELI to high-density interconnects. This paper analyzes the feasibility of further lowering the stand-off height of stacked chips in ultrafine pitch interconnects by optimizing the bump preparation process. The plasma modification time and surfactant concentration during the bump preparation process have been investigated. The result indicated that microbump arrays with a uniformity of less than 3% could be successfully manufactured by employing a 7-min plasma treatment and incorporating optimal surfactants, which catalyzes the implementation of the subsequent vertical interconnection process and eventually enhances yields of Micro-LEDs.
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| 5. |
- Sun, Xun, et al.
(author)
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Can experiment determine the stacking fault energy of metastable alloys?
- 2021
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In: Materials & design. - : Elsevier Ltd. - 0264-1275 .- 1873-4197. ; 199
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Journal article (peer-reviewed)abstract
- Stacking fault energy (SFE) plays an important role in deformation mechanisms and mechanical properties of face-centered cubic (fcc) metals and alloys. In many concentrated fcc alloys, the SFEs determined from density functional theory (DFT) calculations and experimental methods are found having opposite signs. Here, we show that the negative SFE by DFT reflects the thermodynamic instability of the fcc phase relative to the hexagonal close-packed one; while the experimentally determined SFEs are restricted to be positive by the models behind the indirect measurements. We argue that the common models underlying the experimental measurements of SFE fail in metastable alloys. In various concentrated solid solutions, we demonstrate that the SFEs obtained by DFT calculations correlate well with the primary deformation mechanisms observed experimentally, showing a better resolution than the experimentally measured SFEs. Furthermore, we believe that the negative SFE is important for understanding the abnormal behaviors of partial dislocations in metastable alloys under deformation. The present work advances the fundamental understanding of SFE and its relation to plastic deformations, and sheds light on future alloy design by physical metallurgy.
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| 6. |
- Wang, Shu Min, 1963, et al.
(author)
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Phosphorus and Nitrogen Containing Dilute Bismides
- 2019
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In: Springer Series in Materials Science. - Singapore : Springer Singapore. - 2196-2812 .- 0933-033X. ; 285, s. 97-123
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Book chapter (other academic/artistic)abstract
- Phosphorus and nitrogen containing dilute bismides differ from arsenic and antimony containing bismides in that the anions have large differences in atomic size and electronegativity, offering rich potentials for strain as well as bandgap engineering. In this chapter, we show theoretical modeling, epitaxy and characterizations of III-PBi and III-NBi and their quaternary alloys.
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| 7. |
- Xue, Haiyang, et al.
(author)
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Understanding and Constructing AKE via Double-Key Key Encapsulation Mechanism
- 2018
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In: Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics). - Cham : Springer International Publishing. - 1611-3349 .- 0302-9743. ; 11273 LNCS, s. 158-189
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Conference paper (peer-reviewed)abstract
- Motivated by abstracting the common idea behind several implicitly authenticated key exchange (AKE) protocols, we introduce a primitive that we call double-key key encapsulation mechanism (2-key KEM). It is a special type of KEM involving two pairs of secret-public keys and satisfying some function and security property. Such 2-key KEM serves as the core building block and provides alternative approaches to simplify the constructions of AKE. To see the usefulness of 2-key KEM, we show how several existing constructions of AKE can be captured as 2-key KEM and understood in a unified framework, including widely used HMQV, NAXOS, Okamoto-AKE, and FSXY12-13 schemes. Then, we show (1) how to construct 2-key KEM from concrete assumptions, (2) how to adapt the classical Fujisaki-Okamoto transformation and KEM combiner to achieve the security requirement of 2-key KEM, (3) an elegant Kyber-AKE over lattice using the improved Fujisaki-Okamoto technique.
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| 8. |
- Lei, Qiyun, et al.
(author)
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Broadband transparent and flexible silver mesh for efficient electromagnetic interference shielding and high-quality free-space optical communication
- 2023
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In: Optical Materials Express. - : Optica Publishing Group. - 2159-3930. ; 13:2, s. 469-483
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Journal article (peer-reviewed)abstract
- A broadband transparent and flexible silver (Ag) mesh is presented experimentally for the first time for both efficient electromagnetic interference (EMI) shielding in the X band and high-quality free-space optical (FSO) communication. High transmission is achieved in a broad wavelength range of 0.4-2.0 mu m. The transmittance of the Ag mesh relative to the substrate is around 92% and the sheet resistance is as low as 7.12 ohm/sq. The Ag mesh/polyethylene (PE) achieves a high average EMI shielding effectiveness (SE) of 28.8 dB in the X band with an overall transmittance of 80.9% at 550 nm. High-quality FSO communication with small power penalty is attributed to the high optical transmittance and the low haze at 1550 nm, superior to those of the Ag NW networks. With a polydimethylsiloxane (PDMS) coating, the average EMI SE is still up to 26.2 dB and the overall transmittance is increased to 84.5% at 550 nm due to antireflection. The FSO communication does not change much due to the nearly unchanged optical property at 1550 nm. Both the EMI shielding performance and the FSO communication function maintain after 2-hour chemical corrosions as well as after 1000 bending cycles and twisting. Our PDMS/Ag mesh/PE sandwiched film can be self-cleaned, suitable for outdoor applications.
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| 9. |
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| 10. |
- Liang, D., et al.
(author)
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Electronic and excitonic properties of two-dimensional and bulk InN crystals
- 2017
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In: RSC Advances. - : Royal Society of Chemistry (RSC). - 2046-2069. ; 7:67, s. 42455-42461
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Journal article (peer-reviewed)abstract
- Motivated by potential extensive applications in nanoelectronics devices of III-Vmaterials, we calculate the structural and optoelectronic properties of two-dimensional (2D) InN as well as its three-dimensional (3D) counterparts by using density functional theory (DFT). Compared with the 3D form, the In-N bonding in the 2D InN layer is stronger in terms of the shorter bond length, and the formation of the 2D one is higher in terms of the lower cohesive energy. The bandgap of monolayer InN is 0.31 eV at PBE level and 2.02 eV at GW(0) level. By many-body GW(0) and BSE within RPA calculations, monolayer InN presents an exciton binding energy of 0.12 eV. The fundamental bandgap increases along with layer reduction and is converted from direct (0.7-0.9 eV) in bulk InN to indirect (2.02 eV) in monolayer InN. Under biaxial compressive strain, the bandgap of 2D-InN can be further tuned from indirect to direct.
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