Field Monitoring of X-Disease Leafhopper Vectors (Homoptera: Cicadellidae) and Infected Chokecherry in Michigan Peach and Cherry Orchards

Populations of leafhopper vectors of X-disease, a major disease problem of the Michigan peach industry, were monitored by yellow sticky board traps and sweepnet samples during 1985 and 1986. Abundance of known leafhopper vectors varied throughout the stone fruit belt of Michigan, with Paraphlepsius irroratus common in the southwest Lower Peninsula, but representing 73.1 % of all known vectors found. Other commonly found vectors included Scaphytopius acutus (22%), Colladonus clitellarius (1.5\u27k). and Norvellina seminuda (3.4%). Yellow sticky boards were the best monitoring method used. accounting for 90.3% of all vectors captured. The appearance of X-disease symptoms on chokecherry throughout the survey area indicated transmission between wild hosts was occurring in areas where X-disease is not yet a major problem to growers

Inertial energy storage hardware definition study (ring rotor)

Rotor analysis, interference stresses, fabrication/assembly, failure analysis, ring tolerances, stren plots, and drawings are discussed

The effect of support flexibility and damping on the dynamic response of a single mass flexible rotor in elastic bearings

The dynamic unabalance response and transient motion of the single mass Jeffcott rotor in elastic bearings mounted on damped, flexible supports are discussed. A steady state analysis of the shaft and the bearing housing motion was made by assuming synchronous precession of the system. The conditions under which the support system would act as a dynamic vibration absorber at the rotor critical speed were studied. Plots of the rotor and support amplitudes, phase angles, and forces transmitted were evaluated by the computer and the performance curves were plotted by an automatic plotter unit. Curves are presented on the optimization of the support housing characteristics of attenuate the rotor synchronous unbalance response

Transient journal bearing analysis

Transient response of fluid film journal bearin

Transforming a 4th year Modern Optics Course Using a Deliberate Practice Framework

We present a study of active learning pedagogies in an upper division physics course. This work was guided by the principle of deliberate practice for the development of expertise, and this principle was used in the design of the materials and the orchestration of the classroom activities of the students. We present our process for efficiently converting a traditional lecture course based on instructor notes into activities for such a course with active learning methods. Ninety percent of the same material was covered and scores on common exam problems showed a 15 % improvement with an effect size greater than 1 after the transformation. We observe that the improvement and the associated effect size is sustained after handing off the materials to a second instructor. Because the improvement on exam questions was independent of specific problem topics and because the material tested was so mathematically advanced and broad (including linear algebra, Fourier Transforms, partial differential equations, vector calculus), we expect the transformation process could be applied to most upper division physics courses having a similar mathematical base.Comment: 31 page

Magnetically suspended flywheel system study

A program to study the application of a graphite/epoxy, magnetically suspended, pierced disk flywheel for the combined function of spacecraft attitude control and energy storage (ACES) is described. Past achievements of the program include design and analysis computer codes for the flywheel rotor, a magnetically suspended flywheel model, and graphite/epoxy rotor rings that were successfully prestressed via interference assembly. All hardware successfully demonstrated operation of the necessary subsystems which form a complete ACES design. Areas of future work include additional rotor design research, system definition and control strategies, prototype development, and design/construction of a UM/GSFC spin test facility. The results of applying design and analysis computer codes to a magnetically suspended interference assembled rotor show specific energy densities of 42 Wh/lb (92.4 Wh/kg) are obtained for a 1.6 kWh system

Web assisted teaching: an undergraduate experience

The emergence of the Internet has created a number of claims as to the future of education and the possibility of dramatically changing the way in which education is delivered. Much of the attention has focussed on the adoption of teaching methods that are solely web-based. We set out to incorporate web-based teaching as support for more traditional teaching methods to improve the learning outcomes for students. This first step into web-based teaching was developed to harness the benefits of web-based teaching tools without supplanting traditional teaching methods. The aim of this paper is to report our experience with web-assisted teaching in two undergraduate courses, Accounting Information Systems and Management Accounting Services, during 2000. The paper evaluates the approach taken and proposes a tentative framework for developing future web-assisted teaching applications. We believe that web-assisted and web-based teaching are inevitable outcomes of the telecommunications and computer revolution and that academics cannot afford to become isolated from the on-line world. A considered approach is needed to ensure the integration of web-based features into the overall structure of a course. The components of the course material and the learning experiences students are exposed to need to be structured and delivered in a way that ensures they support student learning rather than replacing one form of learning with another. Therefore a careful consideration of the structure, content, level of detail and time of delivery needs to be integrated to create a course structure that provides a range of student learning experiences that are complimentary rather than competing. The feedback was positive from both extramural (distance) and internal students, demonstrating to us that web sites can be used as an effective teaching tool in support of more traditional teaching methods as well as a tool for distance education. The ability to harness the positives of the web in conjunction with more traditional teaching modes is one that should not be overlooked in the move to adopt web based instruction methods. Web-based teaching need not be seen as an all or nothing divide but can be used as a useful way of improving the range and type of learning experiences open to students. The Web challenges traditional methods and thinking but it also provides tools to develop innovative solutions to both distance and on campus learning. Further research is needed to determine how we can best meet the needs of our students while maintaining high quality learning outcomes

Mechanical capacitor

A new energy storage system (the mechanical capacitor), using a spokeless magnetically levitated composite ring rotor, is described and design formulas for sizing the components are presented. This new system is configured around a permanent magnet (flux biased) suspension which has active servo control in the radial direction and passive control in the axial direction. The storage ring is used as a moving rotor and electronic commutation of the stationary armature coils is proposed. There is no mechanical contact with the rotating spokeless ring; therefore, long life and near zero rundown losses are projected. A 7-kW h system is sized to demonstrate feasibility. A literature review of flywheel energy storage systems is also presented and general formulas are developed for comparing rotor geometries

Geological and geothermal investigations for HCMM-derived data

An attempt was made to match HCMM- and U2HCMR-derived temperature data over two test sites of very local size to similar data collected in the field at nearly the same times. Results indicate that HCMM investigations using resolutions cells of 500 m or so are best conducted with areally-extensive sites, rather than point observations. The excellent quality day-VIS imagery is particularly useful for lineament studies, as is the DELTA-T imagery. Attempts to register the ground observed temperatures (even for 0.5 sq mile targets) were unsuccessful due to excessive pixel-to-pixel noise on the HCMM data. Several computer models were explored and related to thermal parameter value changes with observed data. Unless quite complex models, with many parameters which can be observed (perhaps not even measured (perhaps not even measured) only under remote sensing conditions (e.g., roughness, wind shear, etc) are used, the model outputs do not match the observed data. Empirical relationship may be most readily studied

A simple reactive-transport model of calcite precipitation in soils and other porous media

Calcite formation in soils and other porous media generally occurs around a localised source of reactants, such as a plant root or soil macro-pore, and the rate depends on the transport of reactants to and from the precipitation zone as well as the kinetics of the precipitation reaction itself. However most studies are made in well mixed systems, in which such transport limitations are largely removed. We developed a mathematical model of calcite precipitation near a source of base in soil, allowing for transport limitations and precipitation kinetics. We tested the model against experimentally-determined rates of calcite precipitation and reactant concentration–distance profiles in columns of soil in contact with a layer of HCO3−-saturated exchange resin. The model parameter values were determined independently. The agreement between observed and predicted results was satisfactory given experimental limitations, indicating that the model correctly describes the important processes. A sensitivity analysis showed that all model parameters are important, indicating a simpler treatment would be inadequate. The sensitivity analysis showed that the amount of calcite precipitated and the spread of the precipitation zone were sensitive to parameters controlling rates of reactant transport (soil moisture content, salt content, pH, pH buffer power and CO2 pressure), as well as to the precipitation rate constant. We illustrate practical applications of the model with two examples: pH changes and CaCO3 precipitation in the soil around a plant root, and around a soil macro-pore containing a source of base such as urea