Hardening electronic devices against very high total dose radiation environments

The possibilities and limitations of hardening silicon semiconductor devices to the high neutron and gamma radiation levels and greater than 10 to the eighth power rads required for the NERVA nuclear engine development are discussed. A comparison is made of the high dose neutron and gamma hardening potential of bipolar, metal insulator semiconductors and junction field effect transistors. Experimental data is presented on device degradation for the high neutron and gamma doses. Previous data and comparisons indicate that the JFET is much more immune to the combined neutron displacement and gamma ionizing effects than other transistor types. Experimental evidence is also presented which indicates that p channel MOS devices may be able to meet the requirements

Heuristic Refinement Method for the Derivation of Protein Solution Structures: Validation on Cytochrome B562

A method is described for determining the family of protein structures compatible with solution data obtained primarily from nuclear magnetic resonance (NMR) spectroscopy. Starting with all possible conformations, the method systematically excludes conformations until the remaining structures are only those compatible with the data. The apparent computational intractability of this approach is reduced by assembling the protein in pieces, by considering the protein at several levels of abstraction, by utilizing constraint satisfaction methods to consider only a few atoms at a time, and by utilizing artificial intelligence methods of heuristic control to decide which actions will exclude the most conformations. Example results are presented for simulated NMR data from the known crystal structure of cytochrome b562 (103 residues). For 10 sample backbones an average root-mean-square deviation from the crystal of 4.1 A was found for all alpha-carbon atoms and 2.8 A for helix alpha-carbons alone. The 10 backbones define the family of all structures compatible with the data and provide nearly correct starting structures for adjustment by any of the current structure determination methods

Developing Health Information Literacy in Disadvantaged and Dependent Circumstances: The Everyday Role of Family Nurses

This paper examines the challenges of developing health information literacy (HIL) amongst disadvantaged and dependent populations from the perspective of non-information professionals occupying everyday support roles. Our participants were a team of UK Family Nurses providing outreach support to vulnerable young mothers from areas of multiple deprivations. Our data collection methods were observation, interviews, and focus groups. Our participants all believe that they have an important role in developing HIL in clients but are unfamiliar with fundamental overarching information literacy (IL) concepts and models. Consequently, their confidence in their own ability to develop HIL skills in clients is limited. We discuss that to extend primary healthcare practices beyond HIL support to HIL education requires not only IL training, but also an appropriate pedagogical approach adaptable to semi-structured problematic situations. We raise important questions regarding approaches to developing HIL in disadvantaged population

Environmental Impacts of Multi-Storey Buildings Using Different Construction Materials

The Research Goals and Objectives for this project were set out in the Ministry of Agriculture and Forestry (MAF) RFP POR/7811, April 2007. The University of Canterbury responded with a collaborative research programme ‘to fill the information gap about what is the greatest amount of wood that can be used in the construction and fit-out of commercial, large-scale buildings in New Zealand (and) …… to provide Life Cycle Assessment (LCA) information about the benefits of maximising the use of wood in sustainable buildings’. This research project modelled the performance of four similar office building designs – Concrete, Steel, Timber and TimberPlus – all based on an actual six-storey 4,200m2 building, to investigate the influence of construction materials on life cycle energy use and global warming potential (GWP). All four buildings were designed for a 60 year lifetime, with very similar low operational energy consumption. The Concrete and Steel buildings employed conventional structural design and construction methods. The Timber buildings were designed with an innovative post-tensioned timber structure using laminated veneer lumber (LVL). The TimberPlus design further increased the use of timber in architectural features such as exterior cladding, windows and ceilings. All timber materials are renewable and durable, sourced from sustainably managed forests. Predicted construction times for all four buildings are similar. The LCA study by Scion considered the full life cycle of the buildings including initial embodied energy of the materials, and maintenance, transport, operational energy and two endof- life scenarios, where deconstructed materials were either landfilled or reutilised. Increasing the amount of timber in the buildings decreased the initial embodied energy and GWP of materials and also decreased the total energy consumption and GWP over the 60 year lifetime. The TimberPlus design clearly had the lowest environmental impacts, whilst the Steel building had the highest impacts. A significant benefit could be obtained in the Steel, Concrete and Timber buildings by replacing high embodied energy components (especially aluminium windows and louvres) with timber. The final destination of deconstruction waste at the end of the 60 year life-cycle is extremely important. Landfilling of timber waste, with the permanent storage of most of the carbon in the timber, was slightly more beneficial than burning of wood waste for energy. The benefits of landfilling timber waste will increase as modern and future landfill construction and management capture and utilise more of the methane generated by decomposition. Recycling of steel and concrete is more beneficial than landfilling. It is important to note that looking at a single environmental indicator, such as GWP, could lead to unintended outcomes. For example, for the TimberPlus building the landfilling scenario would be slightly better in terms of climate change. However, looking at the energy results alongside the GWP results, the reutilisation scenario shows both an energy reutilisation benefit, as well as still being beneficial to climate change. Therefore, the use of multiple indicators may be necessary to inform the environmental decision-making process.An alternative end-of-life scenario which assumed permanent storage of carbon in wood materials showed that net total GWP for the materials in the TimberPlus building is negative, because the long-term storage of over 630 tonnes of carbon dioxide removed from the atmosphere more than cancels out all the greenhouse gases emitted in the manufacture of all the other building materials. In this scenario, the TimberPlus building could be considered to be ‘carbon-neutral’ for at least the first 12 years of its operation. With NZ-specific energy and GWP coefficients now available, a simple model can be developed for assessing the energy and GWP impacts of individual buildings. This study shows that the Green Star Office rating tool does not capture all the benefits of using more wood in buildings which are identified by the simple model or a full LCA study. Support of on-going research is essential to further develop the potential for Timber buildings to be more widely used in NZ, with subsequent reductions in greenhouse gas emissions

UCLA Space-Time Area Law Model: A Persuasive Foundation for Hadronization

From the studies of rates and distributions of heavy quark mesons we have developed additional evidence that hadron formation is dominantly controlled by a Space-Time Area Law, an approach suggested by both non-perturbative QCD and Relativistic String Models.Comment: 37 pages, 12 figures, 2 tables, Accepted for publication in Eur. Phys. J.

Power-law random walks

We present some new results about the distribution of a random walk whose independent steps follow a $q-$Gaussian distribution with exponent $\frac{1}{1-q}; q \in \mathbb{R}$. In the case $q>1$ we show that a stochastic representation of the point reached after $n$ steps of the walk can be expressed explicitly for all $n$. In the case $q<1,$ we show that the random walk can be interpreted as a projection of an isotropic random walk, i.e. a random walk with fixed length steps and uniformly distributed directions.Comment: 5 pages, 4 figure

Magnetic Vortex Resonance in Patterned Ferromagnetic Dots

We report a high-resolution experimental detection of the resonant behavior of magnetic vortices confined in small disk-shaped ferromagnetic dots. The samples are magnetically soft Fe-Ni disks of diameter 1.1 and 2.2 um, and thickness 20 and 40 nm patterned via electron beam lithography onto microwave co-planar waveguides. The vortex excitation spectra were probed by a vector network analyzer operating in reflection mode, which records the derivative of the real and the imaginary impedance as a function of frequency. The spectra show well-defined resonance peaks in magnetic fields smaller than the characteristic vortex annihilation field. Resonances at 162 and 272 MHz were detected for 2.2 and 1.1 um disks with thickness 40 nm, respectively. A resonance peak at 83 MHz was detected for 20-nm thick, 2-um diameter disks. The resonance frequencies exhibit weak field dependence, and scale as a function of the dot geometrical aspect ratio. The measured frequencies are well described by micromagnetic and analytical calculations that rely only on known properties of the dots (such as the dot diameter, thickness, saturation magnetization, and exchange stiffness constant) without any adjustable parameters. We find that the observed resonance originates from the translational motion of the magnetic vortex core.Comment: submitted to PRB, 17 pages, 5 Fig

Testing the ΔS=ΔQ\Delta S=\Delta Q Rule with Exclusive Semi-Leptonic Kaon Decays

We consider the possibility of violations of the selection rule $\Delta S=\Delta Q$ at an appreciable level in {\it exclusive} semi-leptonic decays of Kaons. At $\Phi$-Factories, intense Kaon beams will be available and will probe among others, the semi-leptonic decays $K_{l4}$ and $K_{l3\gamma}$ in addition to $K_{l3}$ and could provide novel testing grounds for the $\Delta S=\Delta Q$ rule. In particular, the branching ratio of $K_{l3\gamma}$ is non-negligible and could be used to probe new phenomena associated with the violation of this selection rule. Furthermore, we modify certain di-lepton event rate ratios and asymmetries and time asymmetries that have been constructed by Dass and Sarma for di-lepton events from Beon decays to test the $\Delta B=\Delta Q$ at the $\Upsilon (4S)$, to the Kaon system at the $\phi(1020)$. We find that the large width of the $K_S$ relative to that of $K_L$ plays an important role in enhancing some of the time asymmetries.Comment: 10 pages, Plain Latex, To be run twice

Search for antiproton decay at the Fermilab Antiproton Accumulator

A search for antiproton decay has been made at the Fermilab Antiproton Accumulator. Limits are placed on thirteen antiproton decay modes. The results include the first explicit experimental limits on the muonic decay modes of the antiproton, and the first limits on the decay modes e- gamma gamma, and e- omega. The most stringent limit is for the decay mode pbar-> e- gamma. At 90% C.L. we find that tau/B(pbar-> e- gamma) > 7 x 10^5 yr. The most stringent limit for decay modes with a muon in the final state is for the decay pbar-> mu- gamma. At 90% C.L. we find that tau/B(pbar-> mu- gamma) > 5 x 10^4 yr.Comment: 20 pages, 8 figures. Submitted to Phys. Rev. D. Final results on 13 channels (was 15) are presente