Search results for "Rash"
showing 10 items of 377 documents
Urban structure changes and environmental factors of Valencian Community towns as potentital drivers of the House Sparrow decline
2021
El gorrión común Passer domesticus (Linnaeus, 1758) se encuentra en declive en gran parte de Europa. En España, destaca el caso de la Comunidad Valenciana, área de estudio de esta tesis, con descensos superiores al 95% en zonas rurales y al 70% en zonas urbanas. Las causas del declive en zonas urbanas no son claras. En los pueblos y ciudades de la Comunidad Valenciana se están produciendo importantes procesos de transformación de la estructura urbana que afectan a la disponibilidad y adecuación del hábitat para la especie. El objetivo de la tesis fue explorar esos cambios como potenciales impulsores del declive del gorrión común. La tesis se distribuye en 8 capítulos. El capítulo 1 contiene…
La apicultura valenciana: Un aprovechamiento agrario tradicional
1988
LA APICULTURA VALENCIANA ES UNA ACTIVIDAD TRADICIONAL Y MUY ARRAIGADA EN LA COMUNIDAD VALENCIANA QUE COLOCA A ESTA REGION EN LA CABEZA NACIONAL. ELLO SE DEBE A UNAS IDONEAS CONDICIONES CLIMATICAS Y BOTANICAS QUE LA HACEN ESPECIALMENTE APTA PARA EL DESARROLLO DE ESTE APROVECHAMIENTO AGRARIO. ADEMAS, AQUI COINCIDEN LA MAYOR PARTE DE LAS INDUSTRIAS Y ACTIVIDADES RELACIONADAS CON LA MIEL. LA EXPLOTACION APICOLA VALENCIANA SE CARACTERIZA POR DOS ASPECTOS FUNDAMENTALES: UN TALANTE ECONOMICO COMPLEMENTARIO QUE PROPORCIONA INGRESOS ADICIONALES A UNA AGRICULTURA INSUFICIENTE, Y LA TRASHUMANCIA, ORIENTACION PRODUCTIVA QUE REALIZA IMPORTANTES DESPLAZAMIENTOS TERRITORIALES EN BUSCA DE DIVERSAS FLORACIO…
La trashumancia ibérico-valenciana en la Edad Moderna
1990
La trashumancia de rebaños desde las altas sierras de Albarracín, Gúdar y Javalambre hasta las llanuras litorales valencianas es un hecho poco conocido a pesar de la gran importancia que ha tenido para mantener durante siglos la alta productividad de nuestra agricultura y para explicar relaciones de migración y dependencia que llegan a nuestros días.
Mathematical modeling of a vehicle crash test based on elasto-plastic unloading scenarios of spring-mass models
2011
Published version of an article in the journal: The International Journal of Advanced Manufacturing Technology. Also available from the publisher on SpringerLink: htp://dx.doi.org/10.1007/s00170-010-3056-x This paper investigates the usability of spring which exhibit nonlinear force-deflection characteristic in the area of mathematical modeling of vehicle crash. We present a method which allows us to obtain parameters of the spring-mass model basing on the full-scale experimental data analysis. Since vehicle collision is a dynamic event, it involves such phenomena as rebound and energy dissipation. Three different spring unloading scenarios (elastic, plastic, and elasto-plastic) are covered…
Investigation of vehicle crash modeling techniques: theory and application
2013
Published version of an article in the journal: The International Journal of Advanced Manufacturing Technology. Also available from the publisher at: http://dx.doi.org/10.1007/s00170-013-5320-3 Creating a mathematical model of a vehicle crash is a task which involves considerations and analysis of different areas which need to be addressed because of the mathematical complexity of a crash event representation. Therefore, to simplify the analysis and enhance the modeling process, in this work, a brief overview of different vehicle crash modeling methodologies is proposed. The acceleration of a colliding vehicle is measured in its center of gravity—this crash pulse contains detailed informati…
The performance investigation of viscoelastic hybrid models in vehicle crash event representation
2011
Aurthor's version of a chapter published in the book: Proceedings of the 18th IFAC World Congress 2011. Also available from the publisher at: http://dx.doi.org/10.3182/20110828-6-IT-1002.00284 This paper presents application of physical models composed of springs, dampers and masses joined together in various arrangements to simulation of a real car collision with a rigid pole. Equations of motion of those systems are being established and subsequently solutions to obtained differential equations are formulated. We start with a general model consisting of two masses, two springs, and two dampers, and illustrate its application to represent fore-frame and aft-frame of a vehicle. Hybrid model…
Reproduction of kinematics of cars involved in crash events using nonlinear autoregressive models
2012
Vehicle crashworthiness can be assessed by the variety of methods - the most common and direct one is a vehicle crash test. Visual inspection and obtained measurements, such as car acceleration, are used to examine impact severity of an occupant and overall car safety. However, those experiments are complex, time-consuming, and expensive. We propose a method to reproduce car kinematics during a collision using a feedforward neural network to estimate the system by use of nonlinear autoregressive (NAR) models. Specifically, feasibility of applying neural networks with an NAR model to the analysis of experimental data is explored by application to measurements of a vehicle crash test. This mo…
Ultrafast Dynamics of Dansylated POPAM Dendrimers and Energy Transfer in their Dye Complexes
2009
We have studied internal dynamics of dansylated poly(propyleneamine) dendrimers of different generations in solution and excitation energy transfer from dansyl chromophores to xanthene dyes that form van der Waals complexes with the dendrimers
Ultrafast stimulated Raman parallel adiabatic passage by shaped pulses
2009
We present a general and versatile technique of population transfer based on {\it parallel adiabatic passage} by femtosecond shaped pulses. Their amplitude and phase are specifically designed to optimize the adiabatic passage corresponding to parallel eigenvalues at all times. We show that this technique allows the robust adiabatic population transfer in a Raman system with the total pulse area as low as 3 $\pi$, corresponding to a fluence of one order of magnitude below the conventional stimulated Raman adiabatic passage process. This process of short duration, typically pico- and subpicosecond, is easily implementable with the modern pulse shaper technology and opens the possibility of ul…
All-optical extinction-ratio enhancement of a 160 GHz pulse train by a saturable-absorber vertical microcavity
2006
International audience; A vertical-access passive all-optical gate has been used to improve the extinction ratio of a 160 GHz pico-second pulse train at 1555 nm. An extinction ratio enhancement of 6 dB is observed within an 8 nm bandwidth. Such a device is a promising candidate for low-cost all optical reamplication and reshaping (211) regeneration at 160 Gbits/s.