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Hindered rotational energy levels of a linear ion in octahedral and tetrahedral cystalline fields J. Chem. Phys. 68, 3222 (1978); 10.1063/1.436123 Hindered rotational energy levels of a tetrahedron in an orthorhombic crystalline fieldThe electron.ic en:rgy levels. determined from absorption spectra of UH in crystals containing UCI62complexes are Identl1ied as to Irreducible ~epresentation and the resulting set of levels used to determine the le~st-squares best values of Slater Fk mtegrals, spin-orbit 1;5j, and fourth-and sixth-degree crystalline potenti~l par~meters A (r4) and B (r6). It was necessary to diagonalize within the 5f2 configuration all these mteractlOns simultaneously. The values are F2= 191.4, F.=33.83, F6=3.98, 1;5,= 1796, A (r4)=912, B (r6)= 56.5. New data on the spectra of the UBr62-complex are presented.

Magnesium composites containing nano‐size SiC particulates were synthesized using powder metallurgy technique incorporating microwave assisted rapid sintering. Microstructural characterization revealed minimal porosity and the presence of a continuous network of nano‐size SiC particulates decorating the particle boundaries of the metal matrix. Mechanical characterization revealed that the addition of nano‐size SiC particulates lead to a simultaneous increase in microhardness, 0.2% yield strength, ultimate tensile strength and ductility of the matrix.

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Improving energy efficiency has been identified as the cheapest, fastest and most environmentally friendly way to meet the increasing demand in energy by the International Energy Agency (IEA). [1] This can be achieved through innovation, the adoption of new cost-effective technologies and a better use of existing energy-efficient technologies. One of the key areas targeted by IEA for improved energy efficiency lies in buildings, industry and transport. For industry, it was highlighted that there is huge potential to reduce energy consumption and CO 2 emission through increased energy recovery in materials-production processes and the adoption of new and more advanced processes and materials. Similarly in the transport sector, the use and development of lighter materials can reduce fuel consumption leading to improved energy efficiency.Magnesium is the lightest of all engineering metals with a density of 1.74 g/cm 3 which is lighter than aluminum (2.7 g/ cm 3 ) and steel (∼ 7.87 g/cm 3 ) and in close comparison with plastics (0.92-2.17). [2] Magnesium is the 6 th most abundant element in the earth crust (2 mass%) and the 3 rd most dissolved mineral in seawater (1.1 kg/m 3 ). [3] Currently, the use of magnesium and its alloys are still limited to niche applications and aluminum alloys remains the preferred choice amongst materials where lightweight properties are desired. Other advantages of magnesium include comparable strength value with aluminum, high damping capacity, recyclable, most easily machinable of all structural metals and less energy required in the production of magnesium compared to aluminum. [3][4] The major limiting factors for the limited use of magnesium and its alloys include its low stiffness and ductility, limited strength and creep resistance at elevated temperatures and low electrical potential making it prone to corrosion. These limitations are often circumvented by the addition of stiffer and stronger ceramic and/or metallic reinforcements. However, the addition of micron-size reinforcements generally deteriorates the intrinsic limited ductility of magnesium. In recent studies, it has been observed that the addition of nano-size reinforcements such ceramic oxides, SiC and carbon nanotubes can lead to a simultaneous increase in strength and ductility of magnesium. [5][6][7] Accordingly, the aim of this study was to develop lightweight and high performance Mg/Al 2 O 3 nanocomposites through the use of a cost-effective and energy efficient microwave sintering technique. Characterization studies were conducted following hot extrusion to evaluate the physical, microstructural and mechanical properties of the synthesized materials. Particular emphasis was placed to highlight the cost-effectiveness and energy efficiency of microwave sintering over conventional sintering and to correlate the addition of nano Al 2 O 3 particulates on the physical, microstructural and mechanical properties of pure magnesium. Results and Discussion Macrostructural CharacteristicsMacrostructural characterization con...