Engineers from the University of Sheffield have developed a way to significantly reduce the volume of some higher-activity nuclear wastes, which should reduce the cost of interim storage and final disposal. The researchers mixed plutonium-contaminated waste with blast furnace slag and turned it into glass, reducing its volume by 85–95%. The process effectively locks in the radioactive plutonium, creating a stable end product. Current treatment for non-compactable, plutonium-contaminated wastes involves cement encapsulation, which typically increases overall volume. A key element of the research was to show that a single process and additive could be used to treat the expected variation of wastes produced to ensure the technique would be cost-effective. The scientists are now working on optimizing the vitrification process to support full-scale demonstration.
(Business Standard) Next-generation lithium-ion batteries made with iron oxide nanoparticle electrodes could extend the range of electric cars and improve battery life in many applications, according to scientists at the ASTAR Institute of Materials Research and Engineering, Singapore, and Fudan University, China. The researchers say their Fe2O3 nanoparticle electrode material is inexpensive, suitable for large-scale manufacturing and can store higher charge densities than conventional Li-ion battery electrodes. They made 5-nm particles of α-Fe2O3 by heating iron nitrate in water, then mixed them with carbon black, bound them together with polyvinylidene fluoride, and coated the mixture onto copper foil to fabricate the anodes. After 230 charge/discharge cycles, the anode’s efficiency remained at 97% with a capacity almost three times greater than that of commercial graphite anodes.
Researchers at Columbia University have developed a new approach to designing novel nanostructured materials through an inverse design framework using genetic algorithms. The study is said to be the first to demonstrate the application of this methodology to the design of self-assembled nanostructures. Using an algorithm they developed, the researchers designed DNA-grafted particles that self-assembled into the crystalline structures they wanted. They built upon their earlier work to develop what they call an evolutionary framework for the automated discovery of new materials. The researchers plan to continue exploring the design of potential colloidal nanostructures, improve their models, and bring in more advanced machine learning techniques.
From graphite to diamond to Buckminster fullerenes, nanotubes and graphene, carbon can display in a range of structures. But the search for a stable three-dimensional form of carbon that is metallic under ambient conditions, including temperature and pressure, has remained an ongoing challenge for scientists in the field. Now a theoretical 3D form of carbon that is metallic under ambient temperature and pressure has been discovered by an international team of researchers from Peking University, Virginia Commonwealth University, and Shanghai Institute of Technical Physics. The scientists used simulation to show it is possible to manipulate carbon to form a 3D metallic phase with interlocking hexagons. According to one researcher, the hexagonal arrangement introduces metallic character, and the interlocking form with tetrahedral bonding provides stability. The team hopes to move their initial findings from theory to the experimental phase.
The new convention center at Cole Polytechnique Fédérale De Lausanne (Switzerland) is being equipped with a dye solar cell façade said to be the first architectural integration of the technology. Transparent, colored solar panels are being installed on the west façade of EPFL’s SwissTech Convention Center, which is scheduled to open in April, 2014. The 1,400 solar modules, each one 35 × 50 cm, will combine for a total surface area of 300 m2. The translucent panels are unaffected by light angle of incidence and can be deployed vertically with no loss of efficiency. Funded by Romande Energie, the installation is scheduled to be operational in December.