Glassy materials investigated for nuclear reactor applications

Studies determine the feasibility of preparing fuel-bearing glasses and glasses bearing neutron-absorbing materials for use as crystalline fuel and control rods for reactors. Properties investigated were devitrification resistance, urania solubility, and density

Three-axis adjustable loading structure

A three axis adjustable loading structure for testing the movable surfaces of aircraft by applying pressure, is described. The device has three electric drives where the wall angle, horizontal position, and vertical position of the test device can be rapidly and accurately positioned

Innovative techniques for the production of energetic radicals for lunar materials processing including photogeneration via concentrated solar energy

The Department of Materials Science and Engineering (MSE) is investigating the use of monatomic chlorine produced in a cold plasma to recover oxygen and metallurgically significant metals from lunar materials. Development of techniques for the production of the chlorine radical (and other energetic radicals for these processes) using local planetary resources is a key step for a successful approach. It was demonstrated terrestrially that the use of UV light to energize the photogeneration of OH radicals from ozone or hydrogen peroxide in aqueous solutions can lead to rapid reaction rates for the breakdown of toxic organic compounds in water. A key question is how to use the expanded solar resource at the lunar surface to generate process-useful radicals. This project is aimed at investigating that question

Innovative techniques for the production of energetic radicals for lunar materials processing including photogeneration via concentrated solar energy

A technique for photo generation of radicals is discussed that can be used in the recovery of oxygen and metals from extraterrestrial resources. The concept behind this work was to examine methods whereby radicals can be generated and used in the processing of refractory materials. In that regard, the focus is on the use of sunlight. Sunlight provides useful energy for processing in the forms of both thermal and quantum energy. A number of experiments were conducted in the chlorination of metals with and without the aid of UV and near UV light. The results of some of those experiments are discussed

Aerosol studies in mid-latitude coastal environments in Australia

The results of the evaluation of several inversion procedures that were used to select one which provides the most accurate atmospheric extinction profiles for small aerosol extinction coefficients (that often predominate in the maritime airmass) are presented. Height profiles of atmospheric extinction calculated by a two component atmospheric solution to the LIDAR equation will be compared with corresponding in-situ extinction profiles based on the size distribution profiles obtained in Western Australia. Values of the aerosol backscatter to extinction ratio obtained from multi-angle LIDAR measurements will be used in this solution

Compression of Martian atmosphere for production of oxygen

The compression of CO2 from the Martian atmosphere for production of O2 via an electrochemical cell is addressed. Design specifications call for an oxygen production rate of 10 kg per day and for compression of 50 times that mass of CO2. Those specifications require a compression rate of over 770 cfm at standard Martian temperature and pressure (SMTP). Much of the CO2 being compressed represents waste, unless it can be recycled. Recycling can reduce the volume of gas that must be compressed to 40 cfm at SMTP. That volume reduction represents significant mass savings in the compressor, heating equipment, filters, and energy source. Successful recycle of the gas requires separation of CO (produced in the electrochemical cell) from CO2, N2, and Ar found in the Martian atmosphere. That aspect was the focus of this work

Bulk photonic metamaterial with hyperbolic dispersion

In this work, we demonstrate a self-standing bulk three-dimensional metamaterial based on the network of silver nanowires in an alumina membrane. This constitutes an anisotropic effective medium with hyperbolic dispersion, which can be used in sub-diffraction imaging or optical cloaks. Highly anisotropic dielectric constants of the material range from positive to negative, and the transmitted laser beam shifts both toward the normal to the surface, as in regular dielectrics, and off the normal, as in anisotropic dielectrics with the refraction index smaller than one. The designed photonic metamaterial is the thickest reported in the literature, both in terms of its physical size 1cm x 1cm x 51 mm, and the number of vacuum wavelengths, N=61 at l=0.84 mm.Comment: 6 pages, 4 figur

Non-diffusive transport in plasma turbulence: a fractional diffusion approach

Numerical evidence of non-diffusive transport in three-dimensional, resistive pressure-gradient-driven plasma turbulence is presented. It is shown that the probability density function (pdf) of test particles' radial displacements is strongly non-Gaussian and exhibits algebraic decaying tails. To model these results we propose a macroscopic transport model for the pdf based on the use of fractional derivatives in space and time, that incorporate in a unified way space-time non-locality (non-Fickian transport), non-Gaussianity, and non-diffusive scaling. The fractional diffusion model reproduces the shape, and space-time scaling of the non-Gaussian pdf of turbulent transport calculations. The model also reproduces the observed super-diffusive scaling

The effect of crop rotation and soil amendments on soil N bioavailability and N2O emissions

Non-Peer ReviewedThe majority of N2O emissions result from bacterial denitrification and to a lesser extent nitrification, occurring in agricultural soils. Therefore, the overall N economy of a system, along with soluble C and limited O2 are the key drivers in the release of N2O. Crop rotations and soil amendments readily add to or deplete the soil N economy depending on the C:N ratio of the biomass returned to the field. This paper synthesizes the results of three varied studies to further elucidate the role of management on key drivers of N2O release. Study one examined how N2O emissions during potato production are influenced by choice of preceding crop in two-year potato rotations. There was a significant effect of preceding crop (PC) on cumulative growing season N2O emissions from the potato crop. Preceding crops of red clover and Italian ryegrass (average of 1.7 kg N2O-N ha-1) produced significantly higher cumulative N2O emissions when compared to preceding crops of corn, canola, soybean, barley and potato (average of 0.8 kg N2O-N ha-1). A second study on potatoes conducted by Lynch et al. (2009) using Plant Root Simulator (PRS)™-probes found that a PC containing red clover increased soil N supply rates compared to a PC containing pea-oat-vetch. This increase in PRS™–N supply rates was associated with increased N2O emission during the five-year potato rotation. The use of by-products from biofuel processing as soil amendments and N2O emissions during canola production was assessed by Schoenau et al. (2009). Wet distillers’ grain and thin stillage resulted in the greatest N2O production compared with soil amendments of alfalfa powder and glycerol. PRS™–N supply rates were closely linked with these patterns of N2O emissions. These results suggest that selection of rotation crops and soil amendments can have significant effects on N2O emissions as affected by soil N bioavailability