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Search Results: 1 - 10 of 324978 matches for " Sánchez Sánchez "
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Calculation of the Fine-Structure Constant  [PDF]
Jesús Sánchez
Journal of High Energy Physics, Gravitation and Cosmology (JHEPGC) , 2018, DOI: 10.4236/jhepgc.2018.43029
Abstract: The fine-structure constant α [1] is a constant in physics that plays a fundamental role in the electromagnetic interaction. It is a dimensionless constant, defined as: \"\" (1) being q the elementary charge, ε0 the vacuum permittivity, h the Planck constant and c the speed of light in vacuum. The value shown in (1) is according CODATA 2014 [2]. In this paper, it will be explained that the fine-structure constant is one of the roots of the following equation: \"\" (2) being e the mathematical constant e (the base of the natural logarithm). One of the solutions of this equation is: \"\" (3) This means that it is equal to the CODATA value in nine decimal digits (or the seven most significant ones if you prefer). And therefore, the difference between both values is: \"\" (4) This coincidence is higher in orders of magnitude than the commonly accepted necessary to validate a theory towards experimentation. As the cosine function is periodical, the Equation (2) has infinite roots and could seem the coincidence is just by chance. But as it will be shown in the paper, the separation among the different solutions is sufficiently high to disregard this possibility. It will also be shown that another elegant way to show Equation (2) is the following (being i the imaginary unit): \"\" (5) having of course the same root (3). The possible meaning of this other representation (5) will be explained.
How to Check If a Number Is Prime Using a Finite Definite Integral  [PDF]
Jesús Sánchez
Journal of Applied Mathematics and Physics (JAMP) , 2019, DOI: 10.4236/jamp.2019.72028
Abstract: In the history of mathematics different methods have been used to detect if a number is prime or not. In this paper a new one will be shown. It will be demonstrated that if the following equation is zero for a certain number p, this number p would be prime. And being m an integer number higher than (the lowest, the most efficient the operation). \"\" . If the result is an integer, this result will tell us how many permutations of two divisors, the input number has. As you can check, no recurrent division by odd or prime numbers is done, to check if the number is prime or has divisors. To get to this point, we will do the following. First, we will create a domain with all the composite numbers. This is easy, as you can just multiply one by one all the integers (greater or equal than 2) in that domain. So, you will get all the composite numbers (not getting any prime) in that domain. Then, we will use the Fourier transform to change from this original domain (called discrete time domain in this regards) to the frequency domain. There, we can check, using Parseval’s theorem, if a certain number is there or not. The use of Parseval’s theorem leads to the above integral. If the number p that we want to check is not in the domain, the result of the integral is zero and the number is a prime. If instead, the result is an integer, this integer will tell us how many permutations of two divisors the number p has. And, in consequence information how many factors, the number p has. So, for any number p lower than 2m?- 1, you can check if it is prime or not, just making the numerical definite integration. We will apply this integral in a computer program to check the efficiency of the operation. We will check, if no further developments are done, the numerical integration is inefficient computing-wise compared with brute-force checking. To be added, is the question regarding the level of accuracy needed (number of decimals and number of steps in the numerical integration) to have a reliable result for large numbers. This will be commented on the paper, but a separate study will be needed to have detailed conclusions. Of course,
The Origin of Piketty’s Inequality r > g Considered in a General Framework  [PDF]
Alberto Benítez Sánchez
Theoretical Economics Letters (TEL) , 2018, DOI: 10.4236/tel.2018.810115
Abstract: This paper studies the origin of Piketty’s inequality between the profit rate (r) and the growth rate of the national income (g) by focusing on the growth rate (γ) of the r / g ratio in an economy that grows gradually along a succession of production cycles. It is shown that, given a succession of three production cycles, the value of γ in the last cycle is determined by the equation 1+γ=(1+v)(1+k) where v is the growth rate of the profit share (α) in the last cycle while κ is a function of three variables: the income/capital ratio of the last cycle, the values of the savings rate in the first two cycles and those of the growth rate of the income/capital ratio in the last two. The equation just presented is also relevant for a succession of more than three production cycles for which the yearly values of r, g and α are known. Indeed, in this case it is possible to calculate the average values of γ and v from the empirical data, which then can be used in the equation to determine the average value of κ. Once the three variables are known,
La vacuna contra la hepatitis B, un reto al cáncer hepático
Sánchez Sánchez,Mercedes;
Vaccimonitor , 2000,
Abstract: in geographical regions where the hepatitis b virus (hbv) has high prevalence, liver cancer is the most common neoplasm. infection control is becoming more complex because of the considerable amount of asymptomatic carriers that exist in the world now. nevertheless, with the discovery and production of a vaccine against hepatitis b virus and its subsequent inclusion in the expanded program for immunization, this situation could change, by reducing the number of new cases and carriers in the future. this should in consequence reduce the mortality by virus-caused liver carcinoma.
La demografía de Albacete en los a os noventa. Persistencia de los procesos de despoblamiento en las áreas rurales
José Sánchez Sánchez
Papeles de Geografía , 2003,
Abstract: El freno a la gran emigración desde principios de los a os ochenta, la política comunitaria de apoyo al medio rural y el aumento de la inmigración en Espa a han sido factores que, en principio, parecían poder influir en la recuperación económica y demográfica de las áreas rurales en crisis. Aunque así ocurrió en algunas de ellas, no ha sucedido lo mismo en las extensas áreas rurales de la Espa a interior que han continuado el proceso de regresión demográfica iniciado en los a os cincuenta. Este trabajo analiza la evolución de la población en los municipios de la provincia de Albacete en los a os noventa. El estudio concluye poniendo de manifiesto la persistencia de los procesos de despoblamiento en la mayor parte del espacio rural albacete o, en fuerte contraste con la polarización del crecimiento en unos pocos núcleos urbanos.
La vacuna contra la hepatitis B, un reto al cáncer hepático
Mercedes Sánchez Sánchez
Vaccimonitor , 2000,
Abstract: El cáncer hepático es el tipo de neoplasia más difundido en las regiones donde el virus de la hepatitis B (VHB) tiene alta prevalencia. Actualmente existe en el mundo una cantidad onsiderable de portadores asintomáticos, lo que hace que sea cada vez más complejo el control de la infección. Sin embargo, con el advenimiento de la vacuna contra el virus de la hepatitis B y su inclusión en el Programa Ampliado de Inmunización, esta situación pudiera cambiar, e ir reduciendo en el futuro el número de nuevos casos y los portadores, lo que traería como consecuenciauna disminución de la mortalidad por cáncer hepático como secuela de este virus.
Migrantes culiacanenses en California: Diversidad en sus redes migratorias
Ernesto SáNCHEZ SáNCHEZ
Migraciones internacionales , 2012,
Abstract: Es un hecho la dinámica extraordinaria que tienen los lugares de reciente migración, ya sea como lugares de origen o destino. El estado de Sinaloa se suma a esta dinámica en la cual aparecen ahora sus tres principales zonas urbanas --Culiacán, Mazatlán y Ahome-- dentro de su mapa migratorio. Sin embargo la migración, como proceso social, implica una serie de interrelaciones formadas tiempo atrás. éstas repercuten en la conformación de las nuevas redes migratorias. No obstante, durante décadas, las principales zonas de expulsión en Sinaloa han sido rurales y siguen teniendo un papel esencial en las actuales relaciones sociales de los migrantes provenientes de Culiacán.
Seminarios Hispano-Húngaros (1990-2001): encuentros en torno a problemas regionales de Espa a y Hungría
Sánchez Sánchez, José
Estudios Geográficos , 2005,
Abstract:
Coevolución genética de la interacción parásito-hospedero
Hermilo Sánchez Sánchez
Ciencia Ergo Sum , 2005,
Abstract: La evolución de la interacciónparásito-hospedero es un proceso dinámicoque implica cambios en la composicióngenética de las especies involucradas. Loscambios pueden observarse en los genes delos individuos mediante el modelo gen porgen, o en la estructura genética de lapoblación mediante el modelo del mosaicogeográfico.
A Decomposition of the Atkinson Index through the Shapley Value  [PDF]
Joss Sánchez-Pérez
Theoretical Economics Letters (TEL) , 2012, DOI: 10.4236/tel.2012.25100
Abstract: This paper studies the economic inequality as a phenomenon resulting from two variables: The variable of responsibility which depends on the agents’ performance in the economy, and the variable of opportunity which is independent of the individuals’ performance in the economy. Identifying the contribution of the inequality of opportunity in the total inequality as the problem to be measured, we propose a decomposition of the Atkinson inequality index, by using one of the central solution concepts of cooperative game theory, called the Shapley value.
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