2,273 research outputs found
Investigation of charge coupled device correlation techniques
Analog Charge Transfer Devices (CTD's) offer unique advantages to signal processing systems, which often have large development costs, making it desirable to define those devices which can be developed for general system's use. Such devices are best identified and developed early to give system's designers some interchangeable subsystem blocks, not requiring additional individual development for each new signal processing system. The objective of this work is to describe a discrete analog signal processing device with a reasonably broad system use and to implement its design, fabrication, and testing
Cosmological Implications of the Tetron Model of Elementary Particles
Based on a possible solution to the tetron spin problem, a modification of
the standard Big Bang scenario is suggested, where the advent of a spacetime
manifold is connected to the appearance of tetronic bound states. The metric
tensor is constructed from tetron constituents and the reason for cosmic
inflation is elucidated. Furthermore, there are natural dark matter candidates
in the tetron model. The ratio of ordinary to dark matter in the universe is
calculated to be 1:5.Comment: 23 page
Weight bearing after arthrodesis of the first metatarsophalangeal joint: A randomized study of 61 cases
We performed a prospective randomized study of 61 cases of arthrodesis of the first metatarsophalangeal joint in 56 patients. In the first group, full weight bearing was allowed after 2-4 days and in the second group at 4 weeks. Radiographic union of the arthrodesis in the two groups did not differ
Accelerating the LSTRS Algorithm
In a recent paper [Rojas, Santos, Sorensen: ACM ToMS 34 (2008), Article 11] an efficient method for solvingthe Large-Scale Trust-Region Subproblem was suggested which is based on recasting it in terms of a parameter dependent eigenvalue problem and adjusting the parameter iteratively. The essential work at each iteration is the solution of an eigenvalue problem for the smallest eigenvalue of the Hessian matrix (or two smallest eigenvalues in the potential hard case) and associated eigenvector(s). Replacing the implicitly restarted Lanczos method in the original paper with the Nonlinear Arnoldi method makes it possible to recycle most of the work from previous iterations which can substantially accelerate LSTRS
Aphid Feeding Behavior: Relationship to Barley Yellow Dwarf Virus Resistance in \u3ci\u3eAgropyron\u3c/i\u3e Species
The infectibility of various Agropyron species (wheatgrasses) was examined with respect to three isotates of barley yellow dwarf virus (BYDV) by infesting them with appropriate vector aphids, followed by testing by enzyme-linked immunosorbent assay. Feeding behavior of the vetors Rhopalosiphum padi and Sitobion avenae was also electronically monitored to determine their ability to inoculate phloem. The results indicated that resistance to BYDV infection occurs in several Agropyron species. For most species tested. resistance seemed due to failure in virus increase. but in some species a major constraint on infection \\\u27as the inability of vectors to locate phloem. Two potential approaches to breeding for reduced BYDV in wheat by crossing with Agropyron species may thus be: incorporating factors reducing or preventing virus production and incorporating factors reducing the ability of vectors to inoculate plants successfully
MOD-0A 200 kW wind turbine generator design and analysis report
The design, analysis, and initial performance of the MOD-OA 200 kW wind turbine generator at Clayton, NM is documented. The MOD-OA was designed and built to obtain operation and performance data and experience in utility environments. The project requirements, approach, system description, design requirements, design, analysis, system tests, installation, safety considerations, failure modes and effects analysis, data acquisition, and initial performance for the wind turbine are discussed. The design and analysis of the rotor, drive train, nacelle equipment, yaw drive mechanism and brake, tower, foundation, electricl system, and control systems are presented. The rotor includes the blades, hub, and pitch change mechanism. The drive train includes the low speed shaft, speed increaser, high speed shaft, and rotor brake. The electrical system includes the generator, switchgear, transformer, and utility connection. The control systems are the blade pitch, yaw, and generator control, and the safety system. Manual, automatic, and remote control are discussed. Systems analyses on dynamic loads and fatigue are presented
Lithosphere and upper-mantle structure of the southern Baltic Sea estimated from modelling relative sea-level data with glacial isostatic adjustment
Abstract. During the last glacial maximum, a large ice sheet covered Scandinavia, which depressed the earth's surface by several 100 m. In northern central Europe, mass redistribution in the upper mantle led to the development of a peripheral bulge. It has been subsiding since the begin of deglaciation due to the viscoelastic behaviour of the mantle. We analyse relative sea-level (RSL) data of southern Sweden, Denmark, Germany, Poland and Lithuania to determine the lithospheric thickness and radial mantle viscosity structure for distinct regional RSL subsets. We load a 1-D Maxwell-viscoelastic earth model with a global ice-load history model of the last glaciation. We test two commonly used ice histories, RSES from the Australian National University and ICE-5G from the University of Toronto. Our results indicate that the lithospheric thickness varies, depending on the ice model used, between 60 and 160 km. The lowest values are found in the Oslo Graben area and the western German Baltic Sea coast. In between, thickness increases by at least 30 km tracing the Ringkøbing-Fyn High. In Poland and Lithuania, lithospheric thickness reaches up to 160 km. However, the latter values are not well constrained as the confidence regions are large. Upper-mantle viscosity is found to bracket [2-7] × 10 20 Pa s when using ICE-5G. Employing RSES much higher values of 2 × 10 21 Pa s are obtained for the southern Baltic Sea. Further investigations should evaluate whether this ice-model version and/or the RSL data need revision. We confirm that the lower-mantle viscosity in Fennoscandia can only be poorly resolved. The lithospheric structure inferred from RSES partly supports structural features of regional and global lithosphere models based on thermal or seismological data. While there is agreement in eastern Europe and southwest Sweden, the structure in an area from south of Norway to northern Germany shows large discrepancies for two of the tested lithosphere models. The lithospheric thickness as determined with ICE-5G does not agree with the lithosphere models. Hence, more investigations have to be undertaken to sufficiently determine structures such as the Ringkøbing-Fyn High as seen with seismics with the help of glacial isostatic adjustment modelling
The MOD-OA 200 kilowatt wind turbine generator design and analysis report
The project requirements, approach, system description, design requirements, design, analysis, system tests, installation safety considerations, failure modes and effects analysis, data acquisition, and initial performance for the MOD-OA 200 kw wind turbine generator are discussed. The components, the rotor, driven train, nacelle equipment, yaw drive mechanism and brake, tower, foundation, electrical system, and control systems are presented. The rotor includes the blades, hub and pitch change mechanism. The drive train includes the low speed shaft, speed increaser, high speed shaft, and rotor brake. The electrical system includes the generator, switchgear, transformer, and utility connection. The control systems are the blade pitch, yaw, and generator control, and the safety system. Manual, automatic, and remote control and Dynamic loads and fatigue are analyzed
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