Mechatronics

There are theories related to the time dependence of the speed of light that predict that the speed of light is not constant but depends on the time. But they are not verifiable or demonstrable physically or mathematically with concrete results. In this study, based on simple assumptions on the microwave background and thermal electrons, a model of the time varying speed of light is presented, which is fully compatible with currently accepted results for the speed of light and the Hubble constant theories.

There are theories related to the time dependence of the speed of light that predict that the speed of light is not constant but depends on the time. But they are not verifiable or demonstrable physically or mathematically with concrete results. In this study, based on simple assumptions on the microwave background and thermal electrons, a model of the time varying speed of light is presented, which is fully compatible with currently accepted results for the speed of light and the Hubble constant theories.

La norma UNE 25-460-90 especifica en las instalaciones eléctricas en edificios la elección e instalación de los materiales eléctricos en la puesta a tierra con los conductores de protección adecuados. El factor K surge en la norma como una formula que especifica la relación entre la intensidad y la sección del cable. Como se obtiene esta fórmula?

La ley de relación del transformador es una ley propiamente electromagnética, que surge como consecuencia de la aplicación de la inducción electromagnética entre el circuito eléctrico primario y el circuito eléctrico secundario. En este articulo proponemos una nueva demostración de la relación del transformador sin necesidad de recurrir a la inducción electromagnética e incluso sin recurrir a principios electromagnéticos. Deducimos la ley a partir de principios mecánicos fundamentales, como es la ley de conservación del momento angular. Con todo esto demostramos que la ley del transformador es consecuencia de un fenómeno inercial.

Una de las formas de entender como se propaga una epidemia es utilizando un modelo matemático. En 1927 el bioquímico William Ogilvy Kermanck y el teniente coronel Anderson Gray McKendrick [1] idearon un modelo para interpretar las características de una epidemia, es la base del modelo SIR. Es un modelo sencillo, pero nos bastara para entender cuales son los factores decisivos a tener en cuenta ante una pandemia. El modelo considera que toda la población reacciona de la misma manera ante la enfermedad o infección, es decir, no se dice nada sobre el carácter genético individual. Considera ademas que todos los individuos tienen la misma tasa de transmisión de la enfermedad. El objetivo de este análisis es determinar que parámetro es fundamental para caracterizar el proceso infeccioso de una pandemia. Siguiendo un esquema sencillo y asequible a cualquier persona interesada con unos mínimos conocimientos matemáticos. Para así conocer cuales son las condiciones que indiquen de que manera los contagiados por la infección disminuirá o bien aumentara y se convertirá en una pandemia.

There are theories related to the time dependence of the speed of light that predict that the speed of light is not constant but depends on the time. But they are not verifiable or demonstrable physically or mathematically with concrete results. In this study, based on simple assumptions on the microwave background and thermal electrons, a model of the time varying speed of light is presented, which is fully compatible with currently accepted results for the speed of light and the Hubble constant theories. I. Energy density of space Based on the idea of space as a continuum, the speed of light can be considered as a disturbance in this space, the same way as a wave is considered a disturbance on a rope. If we associate the concept of speed of light as the speed on a stretched string of length l and mass m, we can establish the following c = √ F μ = √ F m l = √ Fl m = √ E m = √ ρm Obviously, the following relationship is also obtained: E = mc2 The energy density of space depends on t...

The aim of this work is to produce a classification system to assess cervical injury from a multi-sensor database. This is a database that has never been gathered before, with data coming from three different sensors: inertial, EEG, and thermography. How well these sensors help to build a good model and which right features influence the response variable are key to a better understanding of the link between sensor data and the presence of a cervical injury. There is an additional data set related to the user/patient (a survey) that will provide us with a different view and a baseline to compare with the sensor data. Both data sets are characterized by few observations and many variables, such that feature selection or feature engineering is crucial to success in building a good classification system. The approach used with both data sets is penalized logistic regression. This type of models helps in the selection of the best features and also prevents overfitting by adding a penalized term over the coefficients in the objective function. To verify the ability of each data set, a k-fold cross-validation was carried out with promising results for both the sensor and survey data sets. Results demonstrate an accuracy of up to 70%, which gives a good starting point to encourage increasing the size of the database with more patients. A final discussion highlights the importance of never underestimating the information provided by the patients.

It is a mistake to believe that the primitive experiments, known as the origin of the physical sciences, have been sufficiently studied and therefore it is impossible to extract from them some new and important knowledge. This view has contributed to the perpetuation of some misconceptions. The study of such experiments from other points of view, and applying new techniques, makes it possible to expand their meaning and understanding. Einstein must have thought this way since in 1905 decided to study the Faraday disk and, by doing so, discovered the theory of relativity, according to which the magnetic field is a consequence of the relative motion of different signs electric charges. The verifications of the theory of general relativity by cosmological experiments have led to the belief that the special relativity theory is irrelevant in terrestrial dimensions and speed. Therefore, it is important to correct this error by simple laboratory experiments, whose explanation is only poss...

Easy experiments carried out in the dawn of electromagnetism are still being a reason for scientific articles, because its functioning contradicts some laws and rules of electromagnetic theory. Although these experiments led Einstein to discover the relativistic electrodynamics and explained its working, the scientific community had not understood this. They see in these experiments a proof against relativity and prefer to look for the solution in the electromagnetics’ theory or accept that their are an exception. By means of a long and detailed experimental study with a new design in electromagnetic engines and improvements of these experiments that we call relativistic electrodynamics turbine, we managed to explain its working using relativistic electrodynamics. The revision of these experiments had taken us to discover the real law of induction, which does not have any exceptions. The explanation of the relativistic electrodynamics turbine led us to discard the Faraday induction ...

It is a mistake to believe that the primitive experiments, known as the origin of the physical sciences, have been sufficiently studied and therefore it is impossible to extract from them some new and important knowledge. This view has contributed to the perpetuation of some misconceptions. The study of such experiments from other points of view, and applying new techniques, makes it possible to expand their meaning and understanding. Einstein must have thought this way since in 1905 decided to study the Faraday disk and, by doing so, discovered the theory of relativity, according to which the magnetic field is a consequence of the relative motion of different signs electric charges. The verifications of the theory of general relativity by cosmological experiments have led to the belief that the special relativity theory is irrelevant in terrestrial dimensions and speed. Therefore, it is important to correct this error by simple laboratory experiments, whose explanation is only possible by using special relativity theory.

Los puntos de Lagrange son esencialmente puntos en el espacio con un determinado equilibrio. Donde pueden aparcarse satélites o telescopios de observación en una orbita más o menos estable. La determinación de estos puntos de Lagrange corresponde al problema gravitatorio de tres cuerpos, difícil de resolver de forma analítica. Sin embargo para los puntos L1 y L2  se puede asignar una formula determinada a partir de unas determinadas simplificaciones, que según las condiciones dadas en el sistema Sol-Tierra y Tierra-Luna dan lugar a un resultado aceptable.

Lagrangian points are essentially points in space with a certain equilibrium. Where satellites or observation telescopes can be parked in a stable orbit. The determination of these Lagrange points corresponds to the three-body gravitational problem, which is difficult to solve analytically. For points L1 and L2, however, a certain formula can be assigned on the basis of certain simplifications, which, depending on the given conditions in the Sun-Earth and Earth-Moon system, yields an acceptable result.

El propósito de esta publicación es comprobar que los fenómenos asociados al magnetismo son manifestaciones de la relatividad especial. No en vano, el magnetismo es una consecuencia de la velocidad de las cargas eléctricas, y la relatividad especial nos dice que la velocidad es relativa al sistema de referencia desde el cual se mide la velocidad.

The purpose of this publication is to verify that the phenomena associated with magnetism are manifestations of special relativity. Not in vain, magnetism is a consequence of the speed of electric charges, and special relativity tells us that speed is relative to the reference system from which speed is measured. In turn, the concept of relative speed is not as simple as it may seem today. Its origin must go back to the discovery and understanding of the movement of the Earth itself, which in turn is associated with the movement of the fixed stars. But well, leaving aside the historical origin of the relative speed, we will now focus on the purely electromagnetic aspects related to the movement of charges.

A new experiment on unipolar induction has been designed and built by topologically modifying the structure of the Faraday disk. The metamorphosis consists of replacing the magnet with a solenoid, with the same axis of rotation as the disc, and connected in series with a radial conductor, which replaces the disc. This resulting shape has been called G Coil, due to the shape similar to the letter G that the device forms. This experiment demonstrates the viability of a new electrical machine that works as a motor without the need for any external magnetic field. Working at low voltages and high currents.