Effects of carbon fibers on consumer products

The potential effects of carbon fibers on consumer products such as dishwashers, microwave ovens, and smoke detectors were investigated. The investigation was divided into two categories to determine the potential faults and hazards that could occur if fibers should enter the electrical circuits of the selected appliances. The categories were a fault analysis and a hazard analysis. Hazards considered were fire, flood, physical harm, explosion, and electrical shock. Electrical shock was found to be a possible occurrence related to carbon fibers. Faults were considered to be any effect on the performance of an appliance which would result in complaint or require service action

Exchange coupling between silicon donors: the crucial role of the central cell and mass anisotropy

Donors in silicon are now demonstrated as one of the leading candidates for implementing qubits and quantum information processing. Single qubit operations, measurements and long coherence times are firmly established, but progress on controlling two qubit interactions has been slower. One reason for this is that the inter donor exchange coupling has been predicted to oscillate with separation, making it hard to estimate in device designs. We present a multivalley effective mass theory of a donor pair in silicon, including both a central cell potential and the effective mass anisotropy intrinsic in the Si conduction band. We are able to accurately describe the single donor properties of valley-orbit coupling and the spatial extent of donor wave functions, highlighting the importance of fitting measured values of hyperfine coupling and the orbital energy of the $1s$ levels. Ours is a simple framework that can be applied flexibly to a range of experimental scenarios, but it is nonetheless able to provide fast and reliable predictions. We use it to estimate the exchange coupling between two donor electrons and we find a smoothing of its expected oscillations, and predict a monotonic dependence on separation if two donors are spaced precisely along the [100] direction.Comment: Published version. Corrected b and B values from previous versio

Cyclization of W-tertiary Butyl Uramido Benzoic Acid

This 13 page thesis investigates the cyclization of w-tertiary butyl uramido benaoic acid and establishes the equation for the resulting reaction

Global nonlinear optimization of spacecraft protective structures design

The global optimization of protective structural designs for spacecraft subject to hypervelocity meteoroid and space debris impacts is presented. This nonlinear problem is first formulated for weight minimization of the space station core module configuration using the Nysmith impact predictor. Next, the equivalence and uniqueness of local and global optima is shown using properties of convexity. This analysis results in a new feasibility condition for this problem. The solution existence is then shown, followed by a comparison of optimization techniques. Finally, a sensitivity analysis is presented to determine the effects of variations in the systemic parameters on optimal design. The results show that global optimization of this problem is unique and may be achieved by a number of methods, provided the feasibility condition is satisfied. Furthermore, module structural design thicknesses and weight increase with increasing projectile velocity and diameter and decrease with increasing separation between bumper and wall for the Nysmith predictor

Surface code architecture for donors and dots in silicon with imprecise and nonuniform qubit couplings

A scaled quantum computer with donor spins in silicon would benefit from a viable semiconductor framework and a strong inherent decoupling of the qubits from the noisy environment. Coupling neighbouring spins via the natural exchange interaction according to current designs requires gate control structures with extremely small length scales. We present a silicon architecture where bismuth donors with long coherence times are coupled to electrons that can shuttle between adjacent quantum dots, thus relaxing the pitch requirements and allowing space between donors for classical control devices. An adiabatic SWAP operation within each donor/dot pair solves the scalability issues intrinsic to exchange-based two-qubit gates, as it does not rely on sub-nanometer precision in donor placement and is robust against noise in the control fields. We use this SWAP together with well established global microwave Rabi pulses and parallel electron shuttling to construct a surface code that needs minimal, feasible local control.Comment: Published version - more detailed discussions, robustness to dephasing pointed out additionall

Rapid and robust spin state amplification

Electron and nuclear spins have been employed in many of the early demonstrations of quantum technology (QT). However applications in real world QT are limited by the difficulty of measuring single spins. Here we show that it is possible to rapidly and robustly amplify a spin state using a lattice of ancillary spins. The model we employ corresponds to an extremely simple experimental system: a homogenous Ising-coupled spin lattice in one, two or three dimensions, driven by a continuous microwave field. We establish that the process can operate at finite temperature (imperfect initial polarisation) and under the effects of various forms of decoherence.Comment: 5 pages, 2 figure

Making Heads or Tails out of Selecting Problem-Solving Strategies

When solvers have more than one strategy available for a given problem, they must make a selection. As they select and use different strategies, solvers can learn the strengths and weaknesses of each. W e study how solvers learn about the relative success rates of two strategies in the Building Sticks Task and what influence this learning has on later strategy selections. A theory of how people learn from and make such selections in an adaptive way is part of the ACT-R architecture (Anderson, 1993). W e develop a computational model within ACT- R that predicts individual subjects' selections based on their histories of success and failure. The model fits the selection behavior of two subgroups of subjects: those who select each strategy according to its probability of success and those who select the more successful strategy exclusively. W e relate these results to probability matching, a robust finding in the probability?learning literature that occurs when people select a response (e.g., guess heads vs. tails) a proportion of the time equal to the probability that the corresponding event occurs (e.g., the coin comes up heads vs. tails)

Solving the brachistochrone and other variational problems with soap films

We show a method to solve the problem of the brachistochrone as well as other variational problems with the help of the soap films that are formed between two suitable surfaces. We also show the interesting connection between some variational problems of dynamics, statics, optics, and elasticity.Comment: 16 pages, 11 figures. This article, except for a small correction, has been submitted to the American Journal of Physic

EC82-1738 Tree Planting Guide

Site Preparation Proper site preparation is essential to your tree planting operation, and varies with the different climates and soil types. Chemical Control: On sandy soils, rough terrain, or other highly erodible sites, tillage is not recommended. Chemical weed and/or grass killers may be applied to the site in the fall or before planting in the spring. Summer Fallow: This practice is recommended on heavy soil in western Nebraska to conserve soil moisture. This may be accomplished with the aid of occasional disking, subsurface tillage, or chemicals to control weeds. Fall Tillage: In the eastern areas of the state fall plowing is recommended for grassland sites. Cropland may need no fall tillage. All sites should then be disked before spring planting