We present a systematic study of the DO 22 -structure trialuminide intermetallic alloys using 27 Al NMR spectroscopy. The quadrupole splittings, Knight shifts, and spin-lattice relaxation times on Al 3 Ti, Al 3 V, Al 3 Nb, and Al 3 Ta have been identified. Knight-shift tensors were isolated by observation of quadrupole satellite lines and fitting to the central-transition powder patterns. The results are associated with the local electronic density of states for each crystallographic site. Universally small isotropic Knight shifts and long T 1 's are consistent with low Fermi-surface densities of states indicating the importance of Fermi-surface features for the phase stability of these alloys. Larger anisotropic Knight shifts occurring at aluminum site I indicate strong hybridization at this site, and the electric-field-gradient tensors confirm the strong ab plane bonding configuration. Local-moment magnetism is found in Al 3 V, yet electrically this material appears very similar to the other DO 22 aluminides. ͓S0163-1829͑98͒07112-4͔

We give solutions for spin-lattice relaxation in NOR due to magnetic interactions, generalized for non-axial crystal fieldswith q # 0. We find analyticexpressions for I = f and give numerical solutions for I = 3, Z and 4. We find that the relaxation curves change considerably with q , Specificresultsarederivedfor relaxationdue toFermicontactinmetals andotherelectronic hyperfineinteractions. We alsodesaibechangesinduced by the addition of a magnetic field, indicating fields at which standard NMR results break down.

We have performed NMR studies on an aligned, multicrystalline NbSe3 sample at various temperatures. We find conclusive evidence of field-induced Fermi-surface changes at low temperatures, and associate these changes with charge-density-wave (CDW) enhancement mainly localized on the yellow crystallographic site, contrary to expectations, since the low-temperature CDW is mainly localized on the orange site.

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To keep the water supply safe and to ensure a swift and accurate response to a water supply contamination event, rapid and robust methods for microbial testing are necessary. Current technologies are complex, lengthy and costly and there is a need for rapid, reliable, and precise approaches that can readily address this fundamental security and safety issue. T2 Biosystems is focused on providing solutions to this problem by making breakthroughs in nanotechnology and biosensor techniques that address the current technical restrictions facing rapid, molecular analysis in complex samples. In order to apply the T2 Biosystems nucleic acid detection procedure to the analysis of nucleic acid targets in unprocessed water samples, Bacillus thuringeinsis was selected as a model organism and local river water was selected as the sample matrix. The initial assay reagent formulation was conceived with a manual magnetic resonance reader, was optimized using a high throughput system, and transferred back to the MR reader for potential field use. The final assay employing the designed and manufactured instruments was capable of detecting 10 CFU/mL of B. thuringiensis directly within the environmental water sample within 90 minutes. Further, discrimination of two closely related species of Bacilli was accomplished using the methods of this project; greater than 3-fold discrimination between B. cereus and B. thuringiensis at a concentrations spanning 10 CFU/mL to 10 5 CFU/mL was observed. 2.0 Performance against Goals and Objectives T2 Biosystems (T2Bio) has achieved the goals and objectives of DOE project DE-SC0001821. As set out in the original proposal, the goals of this project were the following: Goal 1: Develop a qualified test for the detection of a microbial pathogen that validates that an MR system can detect the presence of pathogens in water samples. Goal 2: Develop a prototype MR instrument that can be used for the detection of a microbial pathogen in water samples. To achieve these goals, the project was approached from T2Bio's integrated engineering and assay development programs, and the corresponding objectives were the following: Objective 1: Engineer a portable magnetic resonance detection device to robustly measure T 2 relaxation time. The system was an all-in-one design, incorporating a permanent magnet, computer, and spectrometer components into a single, compact and ergonomic enclosure for use with specifically designed assays, as in this funded project, pathogen detection in contaminated water. Objective 2: Develop reagents and assay formats that optimize analysis from unprocessed water samples. Nucleic acid targets of a specific pathogen were identified and detected using magnetic relaxation switches in contaminated water. As described below, all of the goals and objectives of the project were met. As partial fulfillment of this project, several data sets have been collected on the portable bench top magnetic resonance unit T2 Biosystems DOE project DE-SC0001821

We have studied ordered and disordered Cu-Au alloys via 63Cu NMR, probing local electronic structure in the bulk and near anti-phase boundaries in CuAuII. A line-shape model has provided good agreement for disordered and partially ordered alloys, and we thus have obtained a measure of local site symmetries, and Knight shifts and local densities of states within the alloys. We have combined Knight shift and relaxation measurements to obtain detailed local information. We report effects of the ordering process in Cu3Au, CuAu, and CuAu3 intermetallics. We find enhanced susceptibility at the CuAuII anti-phase boundary which is heavily anti-site populated. We compare these results to other measurements of these properties.