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This study focuses on formulating the most sustainable concrete by incorporating recycled concrete aggregates and other products retrieved from construction and demolition (C&D) activities. Both recycled coarse aggregates (RCA) and recycled fine aggregates (RFA) are firstly used to fully replace the natural coarse and fine aggregates in the concrete mix design. Later, the cement rich ultrafine particles, recycled glass powder and mineral fibres recovered from construction and demolition wastes (CDW) are further incorporated at a smaller rate either as cement substituent or as supplementary additives. Remarkable properties are noticed when the RCA (4–12 mm) and RFA (0.25–4 mm) are fully used to replace the natural aggregates in a new concrete mix. The addition of recycled cement rich ultrafines (RCU), Recycled glass ultrafines (RGU) and recycled mineral fibres (RMF) into recycled concrete improves the modulus of elasticity. The final concrete, which comprises more than 75% (wt.) of recycled components/materials, is believed to be the most sustainable and green concrete mix. Mechanical properties and durability of this concrete have been studied and found to be within acceptable limits, indicating the potential of recycled aggregates and other CDW components in shaping sustainable and circular construction practices. The authors wish to acknowledge the financial support from EU Horizon 2020 Project VEEP ‘‘Cost-Effective Recycling of C&DW in High Added Value Energy Efficient Prefabricated Concrete Compo-nents for Massive Retrofitting of our Built Environment” (No.723582).

Co-deposition of carbon atoms with hydrogen isotopes and hydrogenated carbon radicals and molecules is recognized as the main mechanism for tritium retention in the graphite walls of the previous tokamak fusion devices. Significant tritium retention would be a serious concern for safe and economic long-term operation of future fusion test reactors and fusion energy systems. Similar deposits are observed on the surface of the engineered components in a tritium-producing assembly, known as a Tritium-Producing Burnable Absorber Rod (TPBAR). Characterization of the deposits can help understand the tritium transport, accumulation history and distribution in TPBARs. This study reports our recent results from the carbonaceous deposits formed on an aluminide-coated cladding in the lower plenum of a TPBAR following thermal neutron irradiation. The observed deposits are amorphous in nature, consisting of flakes of interconnected nanoscale features. They contain primarily double-bonded carbon (e.g., alkene) and carbonyl carbon, as well as a minor fraction of aliphatic carbon, all of which are likely tritiated. A similar co-deposition process that occurred in previous fusion devices is responsible for the formation and growth of the carbonaceous deposits.

Developing high capacity yet stable cathodes is key to advancing Li-ion battery technologies. Now, a new metal oxide cathode that is rich in Li with a gradient in Li concentration is shown to be stable to O2 release leading to long cycle life and high capacity.

Abstract A numerical simulation program, based upon a finite difference nodal network, was used to simulate two Los Alamos test cells (one single and one multi-room cell) and a typical residence — all of which were exposed to intense insolation and large changes in ambient weather conditions. For the test cells, the predicted surface and globe temperatures are in good agreement with the measured values and indicate the acceptability of thermal modeling. The program was used to predict the behavior of a residential structure. The process of refining these predictions, guided by observations, led to the development of a stepwise simulation methodology. The insights gained as a result of this interdisciplinary involvement have been stimulating and instructive. The importance of recognizing the differences in the thought processes and the work styles of the several professions has been demonstrated. The most effective simulation methodology was that based upon human comfort, which appeared to be a common perception amongst all the program users.

Owing to its amorphous structure, a chalcogenide glass exhibits a thermal conductivity k approaching the theoretical minimum of its composition, called the Einstein’s limit. In this work, this limit is beaten in an amorphous solid consisting of glassy particles joined by nanosized contacts. When amorphous particles are sintered below the glass transition temperature under a high pressure, these particles can be mechanically bonded with a minimized interfacial thermal conductance. This reduces the effective k below the Einstein’s limit while providing superior mechanical strength under a high pressure for thermal insulation applications under harsh environments. The lowest room temperature k for the solid counterpart can be as low as 0.10 W/m·K, which is significantly lower than k≈0.2 W/m·K for the bulk glass.

This work has been published in Solar Energy Materials & Solar Cells 215 (2020) 110603 (DOI: 10.1016/j.solmat.2020.110603). Antimony selenide (Sb2Se3) based solar cell technology has experienced rapid development with demonstrated cell efficiency reaching ̴ 9.2% for devices with substrate configuration, hence necessitating more intense research investigation for further progress. Though the effect of crystallographic orientation in this non-cubic material on device performance is now well understood, the influence of composition and intrinsic defects remains debatable. In this work we describe the fabrication and device characteristics of Sb2Se3 solar cells designed in the substrate configuration of (SLG/Mo/Sb2Se3/CdS/i-ZnO+ITO). Notably, Sb2Se3 absorber layers with predominant (hk0) orientation were deposited in a single step by e-beam evaporation of pre synthesized bulk source material. As grown precursor Sb2Se3 thin films were subjected to reactive thermal annealing (RTA) treatment in the presence of Se source at different temperatures for enhancing their crystalline quality and balancing their stoichiometry. Analysis of the completed solar cells indicated improved efficiencies post RTA process, with the best performing devices exhibiting a power conversion efficiency (η) of ~ 4.34% for an absorber annealed at a temperature of 350 °C. The improved efficiency is ascribed to the observed changes in chemical composition of the absorber layer and the possible formation of related beneficial antisite defects. This project has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 712949 (TECNIOspring PLUS)" and the Government of Catalonia's Agency for Business Competitiveness(ACCIÓ). This research was also supported by the Spanish Ministry of Science, Innovation and Universities under the WINCOST (ENE2016-80788-C5-1-R) project, and by the European Regional Development Funds (ERDF, FEDER Programa Competitivitat de Catalunya 2007-2013). Authors from IREC and the University of Barcelona belong to the SEMS (Solar Energy and Materials Systems) Consolidated Research Group of the 'Generalitat de Catalunya' (Ref. 2017 SGR 862). Ministry of New and Renewable Energy (MNRE) is very well acknowledged for funding the research activities at SRM IST through the project "Development of Lithium Ion Batteries and Computational Studies for Solar Absorber Layers, (Grant No. 31/03/2014-15/PVSE-R&D).

Abstract Research on biofuels has been focused on improving yield of the conversion process while reducing the capital cost. Currently, 88% of the US ethanol production capacity and 96% of the planned expansion of capacity utilizes a dry milling process, which has a higher ethanol yield and a lower capital cost per gallon capacity than a wet milling process. However, the fact that all the corn ethanol plants that were bankrupted or idled during the 2008 economy recession used dry milling processes while all the plants that used wet milling processes had survived suggests that the efficiency driven approach may be flawed. This paper compares the economic performances of a typical dry milling plant with those of a typical wet milling plant under scenarios when market conditions are favorable or unfavorable to the corn ethanol production. The results show that the wet milling plant exhibits better performance under both scenarios due to its operational flexibility (e.g. having starch, high fructose corn syrup, gluten meal, gluten feed, and corn oil in its product portfolio). It is argued that the development of biofuel technologies should take operational flexibility into consideration in order to absorb disruptions from unexpected feedstock supply and volatile market conditions.

Abstract This paper presents a comparison of commercially used German and Russian reactor pressure vessel steels from the positron annihilation spectroscopy (PAS) point of view, having in mind knowledge obtained also from other techniques from the last decades. The second generations of Russian RPV steels seems to be fully comparable with German steels and their quality enables prolongation of NPP operating lifetime over projected 40 years. The embrittlement of CrMoV steel is very low due to the dynamic recovery of radiation-induced defects at reactor operating temperatures.