Estudio de la resistencia mecánica de compósitos basados en hidroxiapatita, aluminio reforzados con cuasicristal icosaedral i-Al64Cu23Fe13

Se presenta un estudio de la resistencia mecánica de dos tipos de compósito de matrices: (i) matriz cerámica de hidroxiapatita (HAp) y (ii) matriz metálica de aluminio (Al), reforzados con la aleación cuasicristalina iAl64Cu23Fe13 (Cc). La síntesis de la matriz de HAp se realizó por coprecipitación química; mientras que la matriz de aluminio fue adquirida comercialmente. La síntesis del cuasicristal (Cc) se realizó por la técnica de horno de arco con un posterior tratamiento térmico. La caracterización estructural y química de las muestras se realizó mediante las técnicas de difracción de rayos X, microscopía óptica, microscopía electrónica de barrido, espectroscopía infrarroja por transformada de Fourier y espectroscopía Raman por transformada de Fourier. El estudio de las propiedades mecánicas se realizó mediante ensayos de dureza Vickers y ensayos de compresión. Los resultados de los análisis corroboraron la alta calidad estructural y química obtenida en la síntesis de HAp y i-Al64Cu23Fe13, obteniéndose compuestos cristalinos monofásicos. Asimismo, los ensayos mecánicos mostraron incremento en la resistencia de ambos compósitos al aumentar el refuerzo cuasicristalino. Los compósitos HAp/Cc mejoraron su límite elástico y módulo de Young en ~42% y ~20%, respectivamente, al añadir apenas 10% de refuerzo; mientras que los compósitos Al/Cc mejoraron su dureza Vickers en ~13% con también apenas 10% de refuerzo. Se propone este método de preparación de compósitos como alternativa de bajo costo y alta eficiencia para aplicaciones biomédicas e industriales con alta potencialidad de escalabilidad, siendo clave para la solución de problemas en la ciencia e ingeniería de materiales.Perú. Consejo Nacional de Ciencia y Tecnología. Fondo Nacional de Desarrollo Científico y Tecnológico (Fondecyt). CONV-000011-2014-FONDECYTTesi

Estudio del efecto del tamaño de grano sobre la dureza del cuasicristal i-Al64Cu23Fe13

Los cuasicristales son materiales con propiedades interesantes y anómalas, como baja conductividad térmica, alta resistividad eléctrica, bajo coeficiente de fricción, buena resistencia a la corrosión y baja densidad. Estas propiedades se atribuyen a su estructura aperiódica sin simetría de traslación. En esta tesis se estudia la influencia del proceso de nanoestructuración sobre la dureza del cuasicristal i-Al64Cu23Fe13. La aleación se sintetizó mediante horno de arco y el proceso de nanoestructuración se llevó a cabo mediante molienda mecánica de alta energía (razón de carga de 7:1). Las probetas de nanocuasicristal se prensaron por extrusión en frío a 25 MPa y se sinterizaron a 500° C. La caracterización estructural, morfológica, elemental y mecánica se llevó a cabo por difracción de rayos X (DRX), microscopía electrónica de barrido (MEB), fluorescencia de rayos X (FRX) y ensayos de dureza Vickers (HV), respectivamente. EL resultado más relevante de este trabajo es que la fase cuasicristalina redujo su tamaño de grano de 270 nm a 13 nm después de 5 horas de molienda. Además, mediante el proceso de sinterizado se modificó el tamaño de grano del cuasicristal, formándose a la vez una fase cúbica β tipo CsCl por activación térmica. La dureza aumentó de acuerdo con la relación HallPetch hasta 2.57 GPa a un tamaño de grano crítico de ~41 nm. Por debajo de este tamaño, el material se comporta según un modelo de ablandamiento por frontera twin que reduce su dureza.Perú. Universidad Nacional Mayor de San Marcos. Vicerrectorado de Investigación y Posgrado. Proyecto Multidisciplinario. PMI2014L01Tesi

Good or excellent? Factors determining online hotel ratings. A spatial approach.

In a competitive environment, where hotel demand is lower than market supply, it is of interest to determine what factors explain how excellence differentiates certain hotels from others. Using spatial quantile regression, this research investigates the effect of locational factors as well as those related to the management of human capital investment in Spanish hotels rated on Booking.com. The study shows that human capital investment in hotels can significantly increase guest delight. As regards location, hotels in protected natural areas that are far from large cities obtain higher guest review scores. Additionally, a spatial spillover effect due to reputation transfer among nearby hotels with median scores is found. However, this effect is not observed for hotels with very high scores. These results can serve to rationalize the available resources and inform hotel owners and managers about the factors required to achieve high scores.Grant PID2019-110941RB-I00 funded by MCIN/AEI/10.13039/501100011033 and Junta de Andalucía and FEDER funds with the project B-SEJ-381-UGR1

Biotecnología

El ejercicio profesional del Médico Veterinario Zootecnista esta relacionado con muchos procesos biotecnológicos. La biotecnología en su definición más amplia, incluye la idea del uso de organismos biológicos con la finalidad de facilitar o mejorar la obtención de productos derivados de ellos, podríamos decir que ésta ha acompañado al hombre desde los inicios de la civilización y que ha alcanzado a diversas áreas de interés humano como son los alimentos, la medicina, procesos industriales, la agricultura y la medicina veterinaria y la zootecnia. Por lo que el presente curso pretende dar al alumno un panorama generadle algunos de los aspectos más relevantes de la biotecnología que tienen un impacto en el área del conocimiento profesional de un médico Veterinario Zootecnista, con un enfoque teórico práctico en algunas áreas, y teórico en otras; tales como la ingeniería genética, Proteómica, inmunología, la reproducción y producción animal y diagnóstico de enfermedades infecciosas y genéticas. Así como, los aspectos bioéticos esenciales en la manipulación y manejo sanitario de los animales de laboratorio

Meeting public health objectives and supporting the resumption of tourist activity through COVID-19: a triangular perspective

This work was supported by FEDER/Junta de AndalucAa-ConsejerAa de TransformaciA3n EconA3mica, Industria, Conocimiento y Universidades [grant number Project CV20-09357].Non-pharmaceutical interventions (NPIs) implemented during the COVID- 19 pandemic (and previous health crises) have included measures to restrict interaction between people and minimize non-essential mobility. Therefore, tourism travel is one of the main areas affected by the restrictions. Even when the majority of the population is vaccinated, some risk of infection will remain, and governments are obliged to consider NPI measures that balance the health risk of outbreaks against the economic and social benefits of resuming tourist activity. This study analyzes the effect of each of four categories of NPIs (Social Distancing; Public Healthcare-System Improvements; Tourist Controls; and Capacity and Opening-Hours Regulation) on three major objectives (the resumption of tourism activity; tourist travel intention; and the minimization of public health risk), taking a triangular perspective (destination managers, domestic tourists, and public healthcare managers, respectively). While it is difficult to fulfil public healthcare objectives while simultaneously responding to the economic interests of tourism-industry stakeholders, the study finds that, under vaccinatedpopulation conditions, tourist controls (e.g. COVID Certificate) alongside improvements to the public healthcare system (e.g. adequate resourcing and an efficient epidemiological monitoring system) could constitute a viable combination of measures.FEDER/Junta de AndalucAa-ConsejerAa de TransformaciA3n EconA3mica, Industria, Conocimiento y Universidades CV20-0935

Influence of the initiative “New7Wonders” on image and intention to visit the city

This project has been funded with support from the European Commission. This publication reflects the views only of the author, and the Commission cannot be held responsible for any use which may be made of the information contained therein.The publication was co-funded by Culture programme of the European Union as a part of Campus Culturae project (grant No. 2011-1177/001-001)

Determinants of the Likelihood of Tourist Spending in Cultural Micro-Destinations: Type, Timing, and Distance of the Activity as Predictors

Although tourism expenditure has long been a pertinent topic in studies dealing with cultural tourism, its importance in recent years has become even more marked due to the consequences of low-cost tourism that many destinations are suffering. This need has been further aggravated by the impact of the ongoing Coronavirus pandemic. Now, the only sustainable means of increasing destination revenue is to generate greater financial profitability of tourism-related activities, as opposed to increasing tourist volumes. The present study analyzes the determinants of the likelihood of tourist spending in an urbancultural destination whose economic sustainability is being threatened by low-cost tourism. To this end, all the tourism activities of the sample (672 in total) were recorded in real time during the stay via a purpose-designed mobile application. Given the nested structure of the sample, multilevel modeling was used: the characteristics of the different tourism activities were used as predictor variables, while characteristics of the tourist were used as control variables. Regarding the former, the results suggest that spending is more likely at the beginning of the stay and in relation to non-cultural tourism activities (restaurants, shopping, transport, etc.). An interaction effect between activity location and timing (beginning vs. end of stay) was also demonstrated: at the beginning of the stay, the greater likelihood of spending was related to services or attractions outside the city center; and, toward the end, spending patterns become more static, based close to the city center. The aim is to explain the probability of tourist expenditure at each spending opportunity, thus contributing to the current knowledge of total tourist spending. Knowledge of tourist expenditure patterns is a prerequisite for raising profitability-per-tourist when increasing visitor volumes is not an option.State Research Agency PID2019-110941RB-I00/SRAJunta de Andalucia B-SEJ-381-UGR18European Commission B-SEJ-381-UGR1

What shapes tourists’ visit intention in different stages of public health crises? The influence of destination image, information-literacy self-efficacy, and motivations

This empirical study aims to identify the components of destination image and tourist motivation that help explain tourist visit intention during different stages of a major public health crisis. It also seeks to determine how tourists’ information-literacy self-efficacy influences that image. The research focuses on two stages of the COVID-19 pandemic: 1) tourist behavior before the alleviating effect of a public vaccination program is felt among the general public and 2) tourist behavior after the alleviating effect has reached most individuals. The results show that, in stage 1, visit intention is shaped by a “safe and secure” destination image, affective image, and tourists’ stimulus-avoidance motivation. In stage 2, visit intention is influenced by both cognitive and affective image and by intellectual, social, competence, and stimulus-avoidance motivations. Information-literacy self-efficacy influences destination image in both stages. These findings enable tourism managers to develop mechanisms to lessen the adverse effects of health crises

Experience moderation effect on the relationship between usefulness, ease of use and website acceptance

The modelling of acceptance behaviour of new information technologies is of great utility to managers who need to evaluate the probability of success in the introduction of these technologies. The present study empirically tests the capacity of Fishbein and Ajzen´s Theory of Reasoned Action (TRA) (1975) and Davis´s Technology Ac-ceptance Model (TAM) (1989) to help understand the determinants of the intention to revisit a website – ease of use and perceived usefulness – focusing on the experience moderation effect. The findings show that a combination of both theories explains the acceptance of a website by Internet users. Furthermore, within the effect of each of the elements of TAM, the user’s experience of the website plays a moderating role. In this regard, ease of use is a more important factor in determining a furure revisit to a website in the case of the less experienced users, while perceived usefulness is a more influential factor in the case of the high experience users