2,778 research outputs found
Correction to: BRG1 regulation by miR-155 in human leukemia and lymphoma cell lines.
No full textFollowing the publication of the original article the author listed as Antonio Herrera contacted the Publisher to state that his correct and full name is Antonio Herrera-Merchan. Antonio Herrera-Merchan has agreed to the publication of this erratum
A novel experimental model and a drag-optimal allocation method for variable-pitch propellers in multirotors
No full textThis paper proposes a new mathematical model to map the rotational speed and angle of attack (pitch) of small-size propellers typically used in multirotors and the aerodynamic thrust force and drag moment produced by the propeller itself. The new model is inspired by standard models using the blade-element and momentum theories, which have been suitably modified in order to allow for explicit fast computation of the direct and inverse map (useful for high-frequency control) and obtain a better adherence to experimental data. The new model allows and captures all the main nonlinear characteristics of the thrust/drag generation. An extensive experimental comparison shows that the prediction capability of the proposed model outperforms the most commonly used models at date. In the second part of the paper, two optimization methods are proposed in order to exploit the redundancy of the inputs of variable-pitch propellers to decrease the power consumption due to the drag dissipation. The first method deals with the optimal allocation for thrust generation on a single propeller, while the second method is aimed at solving the optimal allocation of the rotational speed and pitch of all the propellers in a multi-rotor with any number of propellers. Simulations results show the viability and effectiveness of the proposed methods
[Lectionarium officii]
No full textEl nombre del impresor consta en colofónSignaturas: [ ]4, A-Z6, 2A-2N6, 2O4, A-D6, E2Texto a dos columnasPortada con orla tipográfica y grabado calcografiadoPortada y texto a dos tintasIllustraciones calcografiada
La opción solidaria y la práctica empresarial de la gestión comercializadora de camarón
No full textInicio de Cmari (1.981-1.986). Funcionamiento de Camari. Vision de los sectores vinculados a Camari. Fortalezas y deblidades de Camari. Conclusiones y Recomendaciones. Bibliografia y Anexos
Model of preventive maintenance plan for the valorcon company volleyfront fleet *
No full textEl Modelo de Plan de Mantenimiento Preventivo que se presenta, busca ser una ayuda valiosa y un inicio fundamental mejores prácticas de mantenimiento dentro de la organización, se entiende que el mantenimiento preventivo pretende mantener en un mejor estado los equipos mediante acciones programadas buscando siempre anticiparse a fallos o paradas de equipos por desperfectos repentinos que pueden ser anticipados, todo lo anterior incide directamente en dos factores fundamentales que se desean afectar positivamente. 1. Reducir los costos de mantenimiento, este es el factor principal a tener en cuenta con la presentación del modelo de mantenimiento preventivo, trabajando sobre cada uno de los actores que interviene en el incremento innecesario de este rubro. 2. Conservación de los equipos en buen estado, un valor significativo de los activos de la empresa está representado en sus más de 600 equipos, de ahí la importancia de mantener su condición de la mejor forma posible a partir de adecuadas prácticas de mantenimiento reduciendo al máximo posible su depreciación por condición. Se pretende que el modelo presentado sea específico para las necesidades de VALORCON S.A, de fácil aplicación y que pueda utilizar la experiencia de más de 30 años del grupo de mantenimiento acoplando medios y métodos más actuales con mayor trazabilidad, con el fin de hacer mucho más eficientes y eficaces los procedimientos, siempre teniendo en cuenta las directrices y recomendaciones de los fabricantes de los equipos. *Monografía de grado ** Facultad de Ingenierías Fisicomecánicas. Escuela de Ingeniería Mecánica. Especialización en Gerencia de Mantenimiento. Ing. Samuel Rodriguez MerchanEspecializaciónEspecialista en Gerencia de MantenimientoThe Model of Preventive Maintenance wants to be a valuable help and a start fundamentals better practice of Maintenance in the organization, we understood that Preventive Maintenance looking keep the equipment in a better condition by means of programmed actions, always seeking to anticipate failures or equipment stops due to sudden damage like that can be anticipated, all of the above impact direct on two fundamental factors that we wish to affect in a way positive. 1. Reduce Maintenance cost, this is the most important factor to take in the Model of Preventive Maintenance, working with all actors involved in the unnecessary increase of this item. 2. f the company is represented in all equipment, there is more than 600, this is the most important way to make an appropriate Maintenance practices by reducing the maximum possible depreciation for condition. We intend that the model presented to specific apply and implement their experience because is more than 30 years of experience on Maintenance group coupling ways and methods whit greater traceability, we find to be more efficient and effective in procedures, choose always the guidelines and recommendations of the equipment manufacturers. *Monograph: Faculty of Physicomechanical Engineering. School of Mechanical Engineering. Specialization in Maintenance Management. Ing. Samuel Rodrigue
Tractado de las causas y curacion de las fiebres con secas pestilenciales que han oprimido à Valladolid, y otras ciudades de España ...
No full textCopia digital : Google BooksColofónMarca tip. en portSign.: []\p8\s, []\p8\s, A-R\p8\s, S\p6\sHojas impresas por ambas cara
Alkylation of camphor and pinanone imines of 2-(aminomethyl)thiazole. Enantioselective synthesis of 2-(1-amino alkyl)thiazoles
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A Theoretical Study of the Low-Lying Excited States of trans- and cis-Urocanic Acid
No full textA multiconfigurational second-order perturbation theory (CASPT2) study of the lowest lying states in the gas-phase electronic spectra of trans- and cw-urocanic acid is presented. Geometries of both isomers have been optimized at the MP2/6-31G(d) and jr-CASSCF/ANO-L(4s3pld, 2s) levels of theory. The geometries are found to differ considerably between the two levels. The vertical and 0-0 excitation spectra were calculated for each isomer. Both singlet and triplet states are described for each, including the lowest lying noπ* excitations and the noπ* excitations. Remarkably, in the trans spectrum, it is found that the noπ* state has a higher vertical excitation energy than the lowest ππ* (5.12 vs 4.93 eV), but a lower band origin (4.10 vs 4.66 eV). Thus, the ππ* and noπ* surfaces cross at a coordinate between that of the ground-state structure and the equilibrium excited state structure. The trans vertical spectrum consists of three intense (nn) electronic transitions at 4.93, 5.40, and 6.00 eV, whereas the cis spectrum is dominated by a single intense transition at 4.15 eV and a weaker one at 5.85 eV. The wave functions of the excitations typically show a multiconfigurational character, with the weighting of doubly excitated configurations exceeding 20% in a number of instances. The lowest lying Rydberg states (π3s) were found at 5.47 and 5.67 eV for the trans and cis isomers, respectively. © 1999 American Chemical Society
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