Plans for wind energy system simulation

A digital computer code and a special purpose hybrid computer, were introduced. The digital computer program, the Root Perturbation Method or RPM, is an implementation of the classic floquet procedure which circumvents numerical problems associated with the extraction of Floquet roots. The hybrid computer, the Wind Energy System Time domain simulator (WEST), yields real time loads and deformation information essential to design and system stability investigations

Development Of A Piezo-Mechanical Battery

The piezo-mechanical battery is designed to store energy in a flat spiral spring and harvest the kinetic energy of the unwinding spring using piezoelectric unimorph cantilever beams. The system, initially proposed on a micro scale, was designed to function on a macro scale. The power spring of the system was designed to deliver enough torque to run the system and provide enough force to the escapement mechanism to excite the cantilever beams. The gear system is designed as a compound epicyclic gear system with a gear ratio of 55:1. The cantilever beams were designed to act as springs as well as harvesters in the system. The runtime of the system was estimated to be 220 seconds. The proposed design was tested numerically as well as experimentally to prove that the system integration works. Experiments to prove the power output from a piezoelectric cantilever beam were also carried out. The maximum torque delivered by the spring is 0.08Nm and the dimensions of the escapement mechanism translates the output torque to 0.37N of force on the cantilever beams. The final assembly of the device is 4 inches tall and 7 inches across and so the objective of portability was somewhat achieved

Petrographic Studies of Rocks from The Chesapeake Bay Impact Structure (USA): Implication for Moderate Shock Pressures in Sedimentary Breccias

Shock petrographic investigations were carried out on samples collected from drill cores from the Chesapeake Bay impact structure (USA). The late Eocene Chesapeake impact structure is, at 85 km diameter, currently the largest impact structure known in the United States, buried at shallow to moderate depths beneath continental margin sediments underneath southeastern Virginia. To better define the variety of the samples collected from the shallow drill cores and the shock degrees experienced by the target rocks and breccias in the Chesapeake impact crater, thin section analyses were conducted on more than 50 samples from the various zones of the impact structure. The study involves measurements of the orientations of planar deformation features (PDFs) using a universal stage attached to a petrographic microscope. The aim of this study is to determine the shock pressures of various clasts in the shallow breccia fill of the crater. As a result, we note that the overwhelming numbers of shocked grains, which are now present in the sedimentary breccia, are derived from the basement granitoids. Our studies involved samples from four shallow drill cores (Exmore, Windmill Point, Kiptopeke, and Newsport News).The breccia fill is termed the Exmore breccia, which is dominated by particulates of silt, shocked and unshocked granitic fragments, shale, clay, and free shocked quartz grains. The Kiptopke and Windmill Point samples contained rare fragments showing a variety of different shock effects, whereas the Newporte News samples, show several fragments and impact melt with the evidence shock metamorphism was noted. The most abundantly observed shock indicators are shock fracturing, indicative of shock pressures of less than about 10 GPa, as well as 1-2 sets of PDFs in quartz grains, which is indicative of moderate shock pressures of up to about 20 or 25 GPa. Key words: Chesapeake Bay Crater, PDFs, Shock pressure, Universal stage, Impact structure

In-source laser spectroscopy with the laser ion source and trap: first direct study of the ground-state properties of Po-217,Po-219

D. A. Fink et al.; 15 págs.; 17 figs.; 3 tabs.; Open Access funded by Creative Commons Atribution Licence 3.0A Laser Ion Source and Trap (LIST) for a thick-target, isotope-separation on-line facility has been implemented at CERN ISOLDE for the production of pure, laser-ionized, radioactive ion beams. It offers two modes of operation, either as an ion guide, which performs similarly to the standard ISOLDE resonance ionization laser ion source (RILIS), or as a more selective ion source, where surface-ionized ions from the hot ion-source cavity are repelled by an electrode, while laser ionization is done within a radiofrequency quadrupole ion guide. The first physics application of the LIST enables the suppression of francium contamination in ion beams of neutron-rich polonium isotopes at ISOLDE by more than 1000 with a reduction in laser-ionization efficiency of only 20. Resonance ionization spectroscopy is performed directly inside the LIST device, allowing the study of the hyperfine structure and isotope shift of 217Po for the first time. Nuclear decay spectroscopy of 219Po is performed for the first time, revealing its half-life, α- to-β-decay branching ratio, and α-particle energy. This experiment demonstrates the applicability of the LIST at radioactive ion-beam facilities for the production and study of pure beams of exotic isotopes. Published by the American Physical SocietyThis work was supported by the Bundesministerium für Bildung und Forschung (BMBF, Germany) within the Wolfgang- Gentner programme as well as through the consecutive project fundings of 06Mz9181I, 06Mz7177D, and 05P12UMCIA, by FWO-Vlaanderen (Belgium), by GOA/2010/010 (BOF-KULeuven), by the IUAP-Belgian State Belgian Science Policy (BRIX network P7/12), by the U.K. Science and Technology Facilities Council (STFC), by the European Union within FP7 (ENSAR No. 262010), by the Slovak Research and Development Agency (Contract No. APVV-0105-10), by the Slovak grant agency VEGA, and the Reimei Foundation of JAEA (Contract No. 1/0576/13). T. E. C. was supported by STFC Ernest Rutherford Grant No. ST/J004189/1.Peer Reviewe

Design of a windmill for a Romanian countriside home

El principal objetivo de este proyecto es diseñar un pequeño aerogenerador que proporcione suficiente suministro eléctrico para una familia. El proyecto está desarrollado en Rumania (Iasi) concretamente para una zona de población rural dentro de esta provincia, donde se puede encontrar a personas de avanzada edad con problemas en el suministro eléctrico o para favorecer el desarrollo de esta zona, dando acceso a personas sin recursos a algo tan básico como la electricidad. Incluso se puede encontrar en esta zona problemas con el suministro eléctrico, así lo asegura la unión europea, en un informe sobre las infraestructuras de este país, en el que asegura que no ha entrado aun en el nivel de la media Europa. Nos encontramos en una zona con mucho viento para instalar un pequeño aerogenerador conectado fuera de la red pública, que nos pueda solventar los problemas de suministro para poder desarrollar otras actividades, o en este caso vivir, lo cual nos haría resolver el problema energético. Hoy en día el coste de este aerogenerador no es muy caro y podría ser asumido por cualquier familia, como se demostrará en este proyecto. Para asegurarnos el funcionamiento y la estructura del aerogenerador, se ha realizado un exhaustivo análisis con ANSYS del eje, estructura, escaleras, y mecanismo del aerogenerador, asegurando que pueden resistir incluso en las peores condiciones de viento en Iasi, siguiendo datos del mapa de viento que proporciona en tiempo real la Unión Europea. Todo el modelo 3D de este aerogenerador así como los planos se ha realizado con CATIA V5 R20 dando la posibilidad, para que en el futuro se puedan mejorar componentes, materiales, en general el diseño, y incluso hacer un proyecto más rentable para el desarrollo de la sociedad. Como se podrá ver en el desarrollo del trabajo se encuentran multitud de problemas que se intentan solucionar eligiendo diversos materiales para cada parte del proyecto.En cualquier caso se asegura al menos una vida estimada de 18 años. Al final del proyecto se presenta un apartado económico muy importante hoy en dia, y unas conclusiones a tomar en cuenta.Departamento de Ciencias de los Materiales e Ingeniería Metalúrgica, Expresión Gráfica en la Ingeniería, Ingeniería Cartográfica, Geodesia y Fotogrametría, Ingeniería Mecánica e Ingeniería de los Procesos de FabricaciónGrado en Ingeniería Mecánic

Charge radii and electromagnetic moments of 195-211At

Hyperfine-structure parameters and isotope shifts of At195-211 have been measured for the first time at CERN-ISOLDE, using the in-source resonance-ionization spectroscopy method. The hyperfine structures of isotopes were recorded using a triad of experimental techniques for monitoring the photo-ion current. The Multi-Reflection Time-of-Flight Mass Spectrometer, in connection with a high-resolution electron multiplier, was used as an ion-counting setup for isotopes that either were affected by strong isobaric contamination or possessed a long half-life; the ISOLDE Faraday cups were used for cases with high-intensity beams; and the Windmill decay station was used for short-lived, predominantly α-decaying nuclei. The electromagnetic moments and changes in the mean-square charge radii of the astatine nuclei have been extracted from the measured hyperfine-structure constants and isotope shifts. This was only made possible by dedicated state-of-the-art large-scale atomic computations of the electronic factors and the specific mass shift of atomic transitions in astatine that are needed for these extractions. By comparison with systematics, it was possible to assess the reliability of the results of these calculations and their ascribed uncertainties. A strong deviation in the ground-state mean-square charge radii of the lightest astatine isotopes, from the trend of the (spherical) lead isotopes, is interpreted as the result of an onset of deformation. This behavior bears a resemblance to the deviation observed in the isotonic polonium isotopes. Cases for shape coexistence have been identified in At197,199, for which a significant difference in the charge radii for ground (9/2-) and isomeric (1/2+) states has been observed

Experimental and numerical flow analysis of low-speed fans at highly loaded windmilling conditions

This paper aims for the analysis of experimental and numerical results of windmilling flow topologies far from freewheeling condition. Two fans were investigated: a baseline design and an innovative one meant to reach good performance in both compressor and turbine modes. Experiments are conducted with global and local characterizations to determine energy recovery potential and local loss mechanisms. The numerical study is carried out with mixing plane steady simulations, the results of which are in fair agreement with experimental data. The difference of local topology between freewheeling and highly loaded windmill demonstrates that classical deviation rules such as Carter’s are not well-suited to highly loaded windmilling flows. Finally, under certain conditions, the minor influence of the stator on the rotor topology indicates that non rotating elements can be considered as loss generators

History of ball bearings

The familiar precision rolling-element bearings of the twentieth century are products of exacting technology and sophisticated science. Their very effectiveness and basic simplicity of form may discourage further interest in their history and development. Yet the full story covers a large portion of recorded history and surprising evidence of an early recognition of the advantages of rolling motion over sliding action and progress toward the development of rolling-element bearings. The development of rolling-element bearings is followed from the earliest civilizations to the end of the eighteenth century. The influence of general technological developments, particularly those concerned with the movement of large building blocks, road transportation, instruments, water-raising equipment, and windmills are discussed, together with the emergence of studies of the nature of rolling friction and the impact of economic factors. By 1800 the essential features of ball and rolling-element bearings had emerged and it only remained for precision manufacture and mass production to confirm the value of these fascinating machine elements