Diseño y cálculo de un reductor de velocidad para una cinta transportadora

El projecte de final de grau que s’ha realitzat a continuació consisteix a dissenyar i calcular un reductor de velocitat per la seva aplicació a una cinta transportadora de cereal.Primerament, s’han valorat les necessitats prèvies de la cinta com son lasevavelocitat de funcionament, el pes màxim de carrega que arrossega y la potència necessària per complir tots aquests requeriments. A continuació, s’ha començat el disseny i càlcul de les diferents parts que conformen el reductor. Començant per la relació de transmissió, les característiques i dimensions dels engranatges cilíndrics rectes, el lubricant utilitzat, disposició i mida dels eixos, les unions a torsió i els altres elements necessaris pel funcionament del reductor.En tercer lloc, per a la confecció dels plànols i diferents comprovacions, s’ha simulat amb el programa CAD i CAE de SolidWorks el reductor de velocitat i tots els seus elements.Per últim, s’ha confeccionat un plec de condicions per aclarir les clàusules i execució del projecte. Així com un pressupost per concloure el cost total i de cada una de les parts del reductor de velocitat

La situación laboral de la mujer salvadoreña en calidad de inmigrante irregular en El Estado de California de los Estados Unidos de América. Periodo 2010-2017.

Causa del posicionamiento laboral y salarial de la inmigrante irregular salvadoreña en el Estado de California de los Estados Unidos de América –Impacto del posicionamiento laboral y salarial de la inmigrante irregular salvadoreña en el Estado de California de los Estados Unidos de América – Importancia de la participación activa del Estado de El Salvador en la mejora laboral y salarial de las inmigrantes irregulares salvadoreñas, radicadas en el Estado de California de los EUA

Luminescent Downshifting by Photo-Induced Sol-Gel Hybrid Coatings: Accessing Multifunctionality on Flexible Organic Photovoltaics via Ambient Temperature Material Processing

A novel high-durability multifunctional organic-inorganic hybrid coating material is presented in this work as luminescent down-shifting (LDS) host matrix system for flexible organic photovoltaic (OPV) devices. Such new LDS coating is obtained by incorporating a convenient fluorescent organic dye in an appropriately functionalized fluoropolymeric resin that can be readily crosslinked by means of a dual-cure mechanism with a single-step ambient-temperature photo-induced sol-gel process. Due to its peculiar characteristics, the newly proposed system may be readily implemented in heat-sensitive flexible devices. By carefully tuning the amount of organic fluorophore in the hybrid coating material, a maximum increase in power conversion efficiency exceeding 4% is achieved on devices incorporating the new LDS layer with respect to control systems. This represents the highest efficiency enhancement reported to date on flexible OPVs by means of a polymer-based LDS layer. In addition, long-term accelerated weathering tests (>550 h) highlight the excellent stability of LDS-coated OPV devices, which can retain 80% of their initial performance, as opposed to the dramatic efficiency decay experienced by control uncoated devices. The approach presented here opens the way to the straightforward incorporation of versatile multifunctional light-managing layers on flexible OPV systems for improved device efficiency and lifetime

Self-mixing interferometry and its applications in noninvasive pulse detection

Abstract This thesis describes the laser Doppler technique based on a self-mixing effect in a diode laser to noninvasive cardiovascular pulse detection in a human wrist above the radial artery. The main applications of self-mixing interferometry described in this thesis in addition to pulse detection are arterial pulse shape and autonomic regulation measurements. The elastic properties of the arterial wall are evaluated and compared to pulse wave velocity variation at different pressure conditions inside the radial artery. The main advantages of self-mixing interferometry compared to conventional interferometers are that the measurement set up is simple, because basically only one optical component, the laser diode, is needed. The use of fewer components decreases the price of the device, thus making it inexpensive to use. Moreover, an interferometer can be implemented in a small size and it is easy to control because only one optical axis has to be adjusted. In addition, an accuracy, which corresponds to half of the wavelength of the light source, can be achieved. These benefits make this technique interesting for application to the measurement of different parameters of the cardiovascular pulse. In this thesis, measurement of three different parameters from cardiovascular pulsation in the wrist is studied. The first study considers arterial pulse shape measurement. It was found that an arterial pulse shape reconstructed from the Doppler signal correlates well to the pulse shape of a blood pressure pulse measured with a commercial photoplethysmograph. The second study considers measurement of autonomic regulation using the Doppler technique. It was found that the baroreflex part of autonomic regulation can be measured from the displacement of the arterial wall, which is affected by blood pressure variation inside the artery. In the third study, self-mixing interferometry is superimposed to evaluate the elastic properties of the arterial wall. It was found that the elastic modulus of the arterial wall increases as blood pressure increases. Correlations between measurements and theoretical values were found but deviation in measured values was large. It was noticed that the elastic modulus of the arterial wall and pulse wave velocity behave similarly as a function of blood pressure. When the arterial pressure increases, both the elastic modulus and pulse wave velocity reach higher values than in lower pressure