159 research outputs found
Sesión Extraordinaria conmemorativa del Bicentenario del nacimiento de Justus von Liebig (1803-1873)
Extraordinary commemorative session of the Bicentenary of the birth of Justus von Liebig (1803-1873)Sesión Extraordinaria conmemorativa del Bicentenario del nacimiento de Justus von Liebig (1803-1873
Aporte martensíticos en la soldadura de aceros 9%Cr
Los aceros 9% en cromo son utilizados en plantas de producción de energía eléctrica debido a su elevada resistencia a la corrosión, buenas propiedades mecánicas y resistencia a la termofluencia. Estos aceros presentan una estructura completamente martensítica. Sin embargo, la realización de uniones soldadas los hace susceptibles a la aparición en la zona fundida de ferrita delta, que reduce sus propiedades de termofluencia y tenacidad. Este trabajo analiza la microestructura del metal de aporte producido durante la soldadura manual con electrodo consumible (SMAW) utilizando aportes con diferentes composiciones en cromo y otros elementos de aleación como molibdeno, wolframio, cobre y cobalto. El objetivo ha sido el análisis de consumibles con diferente composición química con los cuales se obtengan zonas fundidas con estructuras martensíticas libres de ferrita delta en la soldadura de aceros 9%Cr
¿Es posible un cambio de actitudes hacia un modelo de desarrollo sostenible?
En la presente investigación se pretende conseguir que unos estudiantes que, en líneas generales, siguen las líneas de un desarrollismo o de un conservacionismo, modifiquen su actitud hacia un modelo más cercano al desarrollo sostenible; para ello se realizan actividades basadas en un taller ambiental y en conocimientos que fomentan el desarrollo sostenible, obteniendo resultados diversos que combinan los conocimientos sobre ciencias sociales y economía con los ambientales. Para realizarlo, seleccionamos estudiantes de distintas etapas de secundaria con características y contextos diferentes. Surge así una idea del desarrollo sostenible múltiple según las situaciones y contextos
Subjective symptoms related to GSM radiation from mobile phone base stations : a cross-sectional study
Objectives: We performed a reanalysis of the data from Navarro et al., 2003, in which health symptoms related to microwave exposure from mobile phone base stations (BS) were explored, including data obtained in a retrospective inquiry about fear of exposure from BS. Design: Cross-sectional study. Setting: La Ñora (Murcia), Spain. Participants: Participants with known illness in 2003 were subsequently disregarded: 88 participants instead of 101 (in 2003) were analysed. Since weather circumstances can influence exposure, we restricted data to measurements made under similar weather conditions. Outcomes and methods: A statistical method indifferent to the assumption of normality was employed: namely, binary logistic regression for modelling a binary response (e.g. suffering fatigue (1) or not (0)), and so exposure was introduced as a predictor variable. This analysis was carried out on a regular basis and bootstrapping [95% percentile method] was used to provide more accurate confidence intervals. Main outcome measures Results: The symptoms most related to exposure were: lack of appetite [odds ratio (OR)] = 1.58, 95% confidence interval (95%CI) = 1.23-2.03; lack of concentration [OR = 1.54, 95% CI = 1.25- 1.89]; irritability [OR = 1.51, 95% CI = 1.23-1.85]; and trouble sleeping [OR = 1.49, 95% CI = 1.20-1.84]. Changes in -2 log likelihood showed similar results. Concerns about the BS were strongly related with trouble sleeping [OR = 3.12, 95% CI = 1.10-8.86]. The exposure variable remained statistically significant in the multivariate analysis. The bootstrapped values were similar to the asymptotic confidence intervals. Conclusion: This study confirms our preliminary results. We observed that the incidence of most of the symptoms was related to exposure levels ¿ independently of the demographic variables and some possible risk factors. Concerns about adverse effects from exposure, despite being strongly related with sleep disturbances, do not influence the direct association between exposure and sleep
MMP-2 and sTNF-R1 variability in patients with essential hypertension: 1-year follow-up study
The aim of this study is to analyze MMP-2 and sTNF-R1 variability, potent predictors of cardiovascular events, in stable hypertensive patients during a 12-month followup. 234 asymptomatic patients (age
6 0 ± 1 3
, 136 male) out of 252 patients with essential hypertension were followed up. MMP-2 and sTNF-R1 were measured at baseline and after 12 months (stage I). To compare MMP-2 and sTNF-R1 levels over time interval, we used the statistical method of Bland-Altman. MMP-2 and sTNF-R1 reproducibility was good in our patients for the two intervals with a coefficient of reproducibility of 8.2% and 11.3%, respectively. The percentages of patients within 1.96 × standard deviation of the mean were 93.6% and 92.7%. An elevated coefficient of correlation was obtained for MMP-2, basal versus stage I
Bienestar psicológico, personalidad y actividad física. Un estilo de vida para la vida adulta
Practice of physical activity is increasingly important for people both as a recreational activity as a health activity. Although it is difficult to find human behaviors that do not have any influence on the health and well-being, it´s possible to show conduct that are among the most important risk factors of major health problems today such as consumption alcohol, obesity and snuff. Regular healthy physical exercise following programmes or frequent and regular autonomous activities improves mental health, autonomy, memory, speed, body image and the feeling of wellbeing, while producing personal stability characterised by optimism, emotional clarity and mental flexibility, leading to a longer life and better health. This model of psychological wellbeing based on the development of human potential and physical exercise, indicates that some aspects of psychological wellbeing are perceived as being more important than others (e.g., self-acceptance, personal growth or life purpose) when studied in relation to autonomy or coping strategies. This study picks perceptions of subjective well-being of adults (N = 482) aged between 24 and 46 years using Scale psychological welfare Ryff's, self-efficacy indicators and persistence questionnaire, all corresponding to the Spanish poblation. The data analysis suggests a positive correspondence between the indices of psychological well-being perceived with the way personal of to oriente and perceive their physical activity. We see the importance of pedagogical transmission of physical activity as a model of psychological well-being as a basis for healthy behaviors in adulthood.ResumenLa práctica de la actividad física es cada vez más importante para las personas tanto como actividad recreativa, como actividad de salud. Aunque es difícil encontrar comportamientos humanos que no tienen ninguna influencia en la salud y el bienestar, es posible señalar conductas entre los factores de riesgo más importantes de los principales problemas de salud como el consumo de alcohol, la obesidad y el tabaco. Programas de ejercicio físico saludable regular o actividades autónomas regulares y frecuentes, mejoran la salud mental, la autonomía, la memoria, la velocidad, la imagen corporal y la sensación de bienestar, produciendo una estabilidad personal caracterizada por el optimismo, la claridad emocional y la flexibilidad mental, llevando a una vida más larga y con mejor salud. Este modelo de bienestar psicológico basado en el desarrollo del potencial humano y el ejercicio físico, indica que algunos aspectos del bienestar psicológico son percibidos como más importantes que otros (por ejemplo, la autoaceptación, el crecimiento personal o el propósito de la vida) cuando se estudian en relación con la autonomía o estrategias de afrontamiento. Este estudio recoge las percepciones del bienestar subjetivo de los adultos (N = 482) de entre 24 y 46 años utilizando la escala de bienestar psicológico de Ryff, los indicadores de autoeficacia y el cuestionario de persistencia, todos ellos correspondientes a la población española. El análisis de los datos sugiere una correspondencia positiva entre los índices de bienestar psicológico percibidos, con la forma personal de orientar y percibir su actividad física. Vemos la importancia de la transmisión pedagógica de la actividad física como un modelo de bienestar psicológico y favorecedor de comportamientos saludables en la edad adultaAbstractPractice of physical activity is increasingly important for people both as a recreational activity as a health activity. Although it is difficult to find human behaviors that do not have any influence on the health and well-being, it´s possible to show conduct that are among the most important risk factors of major health problems today such as consumption alcohol, obesity and snuff. Regular healthy physical exercise following programmes or frequent and regular autonomous activities improves mental health, autonomy, memory, speed, body image and the feeling of wellbeing, while producing personal stability characterised by optimism, emotional clarity and mental flexibility, leading to a longer life and better health. This model of psychological wellbeing based on the development of human potential and physical exercise, indicates that some aspects of psychological wellbeing are perceived as being more important than others (e.g., self-acceptance, personal growth or life purpose) when studied in relation to autonomy or coping strategies. This study picks perceptions of subjective well-being of adults (N = 482) aged between 24 and 46 years using Scale psychological welfare Ryff's, self-efficacy indicators and persistence questionnaire, all corresponding to the Spanish poblation. The data analysis suggests a positive correspondence between the indices of psychological well-being perceived with the way personal of to oriente and perceive their physical activity. We see the importance of pedagogical transmission of physical activity as a model of psychological well-being as a basis for healthy behaviors in adulthood
Diseño, desarrollo y fabricación de un medidor de CO2 de bajo coste con Wi-Fi.
Este TFG trata sobre el diseño, el desarrollo y la fabricación de un producto final como es nuestro medidor de CO2. La realización de este proyecto surge como consecuencia de los momentos que se están viviendo en la actualidad y para poder hacer frente a los problemas que se tienen en multitud de lugares frecuentados por mucha gente. Por estos motivos, se va a desarrollar un medidor de CO2 que sea capaz de medir la cantidad de CO2 que hay en una sala en la que se encuentre y este sea capaz de mostrar los datos a toda persona que acceda a esta. En una primera fase, se va a realizar una investigación sobre proyectos similares, sobre medidores de CO2 ya fabricados. Y en una segunda fase, se van a desarrollar todos los aspectos a los que ha tenido que ir haciendo frente a medida que se iba avanzando en el desarrollo del producto. Con la realización de este proyecto se desea conseguir que las personas que accedan a una sala, en la que se encuentre el medidor, tengan tranquilidad y seguridad de que es un espacio seguro y también, de que se sepa cuando es conveniente que se realice una ventilación de esta.<br /
Study of the corrosion behavior of magnesium alloy weldings in NaCl solutions by gravimetric tests
Evidence of topological superconductivity in planar Josephson junctions
Majorana zero modes are quasiparticle states localized at the boundaries of
topological superconductors that are expected to be ideal building blocks for
fault-tolerant quantum computing. Several observations of zero-bias conductance
peaks measured in tunneling spectroscopy above a critical magnetic field have
been reported as experimental indications of Majorana zero modes in
superconductor/semiconductor nanowires. On the other hand, two dimensional
systems offer the alternative approach to confine Ma jorana channels within
planar Josephson junctions, in which the phase difference {\phi} between the
superconducting leads represents an additional tuning knob predicted to drive
the system into the topological phase at lower magnetic fields. Here, we report
the observation of phase-dependent zero-bias conductance peaks measured by
tunneling spectroscopy at the end of Josephson junctions realized on a InAs/Al
heterostructure. Biasing the junction to {\phi} ~ {\pi} significantly reduces
the critical field at which the zero-bias peak appears, with respect to {\phi}
= 0. The phase and magnetic field dependence of the zero-energy states is
consistent with a model of Majorana zero modes in finite-size Josephson
junctions. Besides providing experimental evidence of phase-tuned topological
superconductivity, our devices are compatible with superconducting quantum
electrodynamics architectures and scalable to complex geometries needed for
topological quantum computing.Comment: main text and extended dat
Association between Opioid Receptor mu 1 (OPRM1) Gene Polymorphisms and Tobacco and Alcohol Consumption in a Spanish Population
Evidence gained from animals and humans suggests that the encephalic opioid system might be involved in the development of drug addiction through its role in reward. Our aim is to assess the influence of genetic variations in the opioid receptor mu 1 on alcohol and tobacco consumption in a Spanish population. 763 unrelated individuals (465 women, 298 men) aged 18-85 years were recruited between October 2011 and April 2012. Participants were requested to answer a 35-item questionnaire on tobacco and alcohol consumption, as well as to complete the AUDIT and Fagerström tests. Individuals were genotyped for three polymorphisms in the opioid receptor mu 1 (OPRM1) gene, using a TaqMan® protocol. In males, the rs10485057 polymorphism was associated with total pure ethanol intake and with the risk of being an alcohol consumer. Also, this polymorphism was significantly associated with higher Fagerström scores. Rs1799971 had a different influence on adaptive and maladaptive patterns of alcohol use. Despite the limited sample size, our study might enrich current knowledge on patterns of alcohol use, because it encompasses both extreme and adaptive phenotypes, providing thus a wider perspective on this subject
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