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To our knowledge, this is the first study examining the effect of three different treatments [descending to lower altitude (from 3,900 m to 1,050 m), nocturnal oxygen supply, and administration of acetazolamide] on changes in hemoglobin mass in patients experiencing chronic mountain sickness (CMS). We report that descent to low altitude is a fast-acting measure for the treatment of excessive erythrocytosis in patients with CMS, reducing Hbmass by 16% within 3 wk. Nighttime oxygen supplementation and daily acetazolamide administration are also effective, but reduce Hbmass by only 6%. In all three treatments, the underlying mechanism is a reduction in plasma erythropoietin concentration due to higher oxygen availability.

The role of architects in urban design is quite unknown in society and the significance of architecture is relegated, in most cases, to the building. Fundamental aspects such as the width of the streets, the vegetation, the height of the buildings or the pavement seem alien to architecture. Even its impact on energy efficiency and user comfort, not only on public roads but also inside buildings, is often ignored. This idea of separation between architecture and efficient urban design is also that of those who start the degree in Architecture. Therefore, the objective of this teaching experience is to provoke a critical reflection of the students on these issues prior to the start of the degree, carrying out a workshop in the Zero Course in Architecture in which the active participation of the student is encouraged. El papel de arquitectos y arquitectas en el diseño urbano es bastante desconocido en la sociedad y el alcance de la arquitectura queda relegado, en la mayoría de los casos, al edificio. Aspectos fundamentales como el ancho de las calles, la vegetación, la altura de los edificios o el pavimento parecen ajenos a la arquitectura. Incluso su repercusión en la eficiencia energética y el confort de los usuarios, no solo en la vía pública sino también en el interior de edificios, es ignorada en muchas ocasiones. Esta idea de separación entra arquitectura y diseño urbano eficiente es también la de aquellos que inician el grado en Arquitectura. Por tanto, el objetivo de esta experiencia docente es provocar una reflexión crítica del alumnado sobre estos temas previa al inicio del grado, realizando para ello un taller en el Curso Cero en Arquitectura en el que se fomenta una participación activa del estudiantado.

Natural light exposure both in flux and spectrum is essential to human health due to its direct relationship with circadian rhythms. Given that light affects visual performance and circadian rhythms differently, metrics need to assess them independently. The aim of this research is to present a new parametric workflow to integrate metrics quantifying the effect of light on circadian rhythm. CircaLight is a new open-source tool for Rhino environment developed as a plugin for Grasshopper. This software enables the calculation of different metrics that quantify the effect of light, both natural and electric, on circadian rhythms, considering the influence of the spectral reflectance of inner surfaces. The CircaLight components can be integrated into Grasshopper plugins such as Solemma or Ladybug tools providing information about the Circadian Stimulus, the Equivalent Melanopic Lux and the Melanopic Photopic ratio, all of which provide current metrics related with circadian rhythms. This research evaluates the reliability of the software presented, quantifying its accuracy by means of other validated software. The results show the accuracy of this new parametric tool with an error under ±10% even in the most unfavorable scenarios.

En este capítulo se presenta un Ciclo de Mejora en el Aula aplicado en la asig- natura de Acondicionamiento e Instalaciones 3 del grado en Fundamentos de Arquitectura, concretamente en la docencia de los Sistemas Hidrónicos. La alta carga técnica y especialización de dicha asignatura complejiza el aprendizaje de los estudiantes. Además, a eso se le une el fuerte carácter transmisivo de la parte teórica en la que el alumno se convierte la mayoría de las veces en un sujeto pasivo. Por ello es fundamental la aplicación de este CIMA para la mejora de la docencia. El objetivo principal de esta experiencia docente es mejorar el aprendi- zaje de los estudiantes convirtiéndolos en sujetos activos, promoviendo un razo- namiento crítico en contra de la memorización y repetición mecánica. Palabras clave: Acondicionamiento e instalaciones 3, grado en fundamentos de arquitectura, docencia universitaria, desarrollo profesional docente, ciclo de mejora en el aula.

The significance of facilities in Architecture is quite unknown in the society in which we live, even for future architecture students. Relegating the facilities to the background is habitual and it causes operation problems, visually pollution and it affects inhabitants’ comfort. Furthermore, basic aspects for users’ health such as indoor air quality are not usually included in the architectural process. Can this be avoided by making the students aware of the importance of integrating the facilities and the aspects they cover? Is the root of the problem in the way of teaching these subjects? To give an answer to these questions, the Architecture Zero Course has been used to force a first critical reflection on these issues, using gamification and ICT. This experience results are key to focus teaching in the facilities subjects of the degree. El alcance de las Instalaciones en la Arquitectura es bastante desconocido en la sociedad en la que nos encontramos, incluso para los futuros estudiantes de Arquitectura. Lo habitual es relegar las instalaciones a un segundo plano causando problemas de funcionamiento, contaminando visualmente y afectando al confort de los habitantes. Además, aspectos fundamentales para la salud del usuario como la calidad del aire no suelen incluirse en el proceso arquitectónico. ¿Se puede evitar esto concienciando previamente a los estudiantes de la importancia de la integración de las instalaciones y de los aspectos que abarcan? ¿Está la raíz del problema en la docencia de estas asignaturas? Para responder a estas preguntas se ha utilizado el Curso Cero de Arquitectura para forzar una primera reflexión crítica sobre estos temas, usando la gamificación y las TIC. Los resultados de esta experiencia son claves para enfocar la docencia en las asignaturas de Instalaciones del Grado.

Este proyecto de investigación tiene como finalidad realizar un análisis de la gastronomía en la Cuenca de México, específicamente en los municipios de Tizayuca y Villa de Tezontepec pertenecientes al Estado de Hidalgo, para identificar los productos y platillos característicos de los municipios antes mencionados, con el fin de implementar una actividad turística enfocada en la gastronomía regional, de tal manera que tenga un impacto positivo para las comunidades receptoras generando empleos para los habitantes de los dos municipios y lugares aledaños; y al mismo tiempo activar la economía mediante la derrama de capital que genera el turismo mediante la afluencia de visitantes de diferentes partes del país y de ser posible, del extranjero; además se pretende que los municipios en cuestión lleguen a ser reconocidos dentro de los lugares recomendados por la industria turística.

Litter on beaches is one of the most difficult problems in coastal management and every year, much efforts and public money are invested to try to alleviate and solve the problem. Cigarette butts (CB) are among the most widespread abandoned personal items in the world. In Spain, they are found on all types of beaches, where they are discarded by beach users; however, rivers and streams can also deposit CB on shores. This paper analyses the abundance of CB on different beaches in Southern Spain in order to address and better understand this relevant environmental problem and propose sound solutions to decrease or eliminate their presence. The main factors favouring CB accumulation were identified, namely the seasonality and number of beach users, beach typology (remote, rural, village or urban sites), type of beach sediment and methods and frequency of cleaning operations. Mean and median CB abundance values per 100 m of beach length, calculated from all the data used in this study, were 159 and 68 items, respectively. The largest number of CB were observed at urban sites, followed by village, rural and remote beaches. Further, sand beaches registered higher values of CB than cobble or pebble beaches. This research was funded by Andalusia PAI Research Group RNM-328.

Twelve beaches located in Ceuta (Spain) were studied from February to April 2019 to assess litter amounts (expressed as number of items), categories and temporal distribution. At each beach, three surveys were conducted, i.e., one per month (i.e., 36 in total). Selected beaches covered urban (7), rural (2) and remote (3) bathing areas. Plastic represented the dominant material, i.e., 35.2% of all debris, followed by glass (18.2%), pottery/ceramics (14.6%), wood (11.4%), metal (11.4%), paper/cardboard (4.8%), cloth (3.5%), rubber (0.7%), organic (0.3%) and other materials (0.1%). The Clean Coast Index was calculated to classify beaches in five categories for evaluating the cleanliness level of the coast observed at each survey: “Very Clean” (7 surveys), “Clean” (10), “Moderately Dirty” (8), “Dirty” (2) and “Extremely Dirty” (9). Litter occurrence was assessed by the Litter Grade methodology, which allowed to classify beaches in four grades: “A”: very good (0), “B”: good (4), “C”: fair (7), and “D”: poor (25). In a few surveys, some beaches were considered “good”, but their management should not be ignored because in other surveys those beaches reached fair and poor scores. Several potentially harmful litter items were related to beach users. Severe eastern storms removed litter at many of the beaches investigated and favored accumulation at others. Data analysis shows significant differences in litter abundance with respect to site, beach typology and the presence of cleaning operations but no important differences between the studied months. Rural beaches recorded the most litter, followed by urban and remote beaches. All beaches require immediate and more appropriate management actions to improve their environmental status.

This article reports the preparation and characterization of nanofluids based on the heat transfer fluid (HTF) commonly used in concentrating solar power (CSP) plants. Nanofluids were prepared with commercial Ag nanoparticles and synthesized Au nanoparticles which were dispersed into a base fluid composed by a eutectic mixture of two stable compounds: diphenyl oxide and biphenyl. Both sets of nanofluids were characterized attending to its physical and chemical stability and the possible improvement on thermal properties respect to base fluid. Moreover, a theoretical analysis was achieved by Molecular Dynamics simulations to obtain a greater knowledge about this kind of systems through the study of the different interactions between the metal and the molecules of the base fluid. The results showed that the incorporation of Ag nanoparticles into a base fluid improves significantly thermal properties such as isobaric specific heat and thermal conductivity, giving an enhancement of its heat transfer coefficient. Theoretical analysis revealed that the arrangement of molecules of base fluid around the Ag nanoparticle favors the improvement of thermal properties. On his part, addition of Au nanoparticles into the base fluid did not produce any increment of thermal properties with regard to base fluid, and the theoretical analysis showed a minor participation of diphenyl oxide molecules in a first layer of Au nanoparticle.

Photodegradation processes are of great interest in a range of applications, one of which is the photodecomposition of pollutants. For this reason, analysing nanoparticles that improve the efficiency of these processes under solar radiation are very necessary. Thus, in this study, TiO2 was doped with Mo and Cu using low-temperature hydrolysis as the method of synthesis. Pure TiO2 and x%MoS2/Cu/TiO2 nanoparticles were prepared, where x is the theoretical quantity of MoS2 added (0.0%, 1.0%, 5.5%, 10.0%), setting the nominal quantity of Cu at 0.5 wt.%. The samples obtained were characterized by X-ray diffraction, Raman spectroscopy, X-ray electron spectroscopy and UV-Vis spectroscopy in diffuse reflectance mode. The results suggest that the TiO2 structure was doped with the Mo6+ and Cu2+ ions in the position of the Ti4+. The x%MoS2/Cu/TiO2 samples presented lower band gap energy values and greater optical absorption in the visible region than the pure TiO2 sample. Lastly, the photocatalytic activity of the samples was assessed by means of the photodegradation of methylene blue under visible light. The results show that when the quantity of Mo in the co-doped samples increased (x%MoS2/Cu/TiO2) there were significant increases of up to 93% in the photocatalytic activity.

This study presents a combined experimental and theoretical analysis of the stability of NiO nanofluid systems based on a base fluid composed of the eutectic mixture of diphenyl oxide and biphenyl in presence of surfactants. The base fluid is used as a heat transfer fluid in concentrated solar energy and the surfactants were used to analyse the stability of the nanofluids: Benzalkonium Chloride (BAC) and 1-Octadecanethiol (ODT). The stability was analysed experimentally by using UV–vis spectroscopy, particle size and ζ potential measurements. The experimental results indicate that the presence of BAC as surfactant enhance the stability of the nanofluids. Molecular dynamic calculations were performed for three systems (75% BAC, 75% ODT and 75% BAC-75% ODT) to understand the behaviour of both surfactants in the stability of the nanofluid. The analysis of the radial distribution functions (RDFs) and spatial distribution functions (SDFs) revealed a competition of ODT with both base fluid and NiO nanoparticles that explains why the BAC surfactant favoured the formation of stable NiO nanofluid over that with ODT.

Nanofluids could be a promising alternative to the typical heat transfer fluids (HTF) used in concentrating solar power. This study analyses nanofluids based on a typical HTF for concentrating solar power (CSP) applications and NiO nanoparticles. The optimum nanoparticle concentration was determined by analysing the stability of the nanofluids. Some of their properties, such as density, viscosity, isobaric specific heat and thermal conductivity, were characterized to evaluate their performance. Their thermal conductivity increased by up to 96% and the heat transfer coefficient by 50%. Molecular dynamics calculations were performed to explain from a molecular perspective how the presence of equal proportions of two surfactants, benzalkonium chloride (BAC) and 1-Octadecanethiol (ODT), enhanced the thermal properties of the NiO nanofluid. The isobaric specific heat and thermal conductivity values followed the same experimental tendency. The analysis of the radial distribution functions (RDFs) and spatial distribution functions (SDFs) revealed an inner layer of base fluid and surfactant molecules around the NiO cell. This first layer contained BAC molecules at all the temperatures, while ODT was only incorporated at higher temperatures. The exchange of surfactant and base fluid molecules around the NiO as the temperature increases may play an important role in the enhancement of the thermal properties.

The nano-colloidal suspension of nanomaterials in a base fluid, typically named a nanofluid, is a promising system that shows interesting properties, such as those related to heat transfer processes. Obtaining nanofluids with high stability is a priority challenge for this kind of system. So, a rationalization of the preparation of nanofluids is clearly needed. Thus, this study presents a methodology based on liquid phase exfoliation that makes it possible to prepare stable nanofluids and control the morphology of the nanostructures, which is defined by the surfactant used. Two stable nanofluids were prepared based on MoS2 nanosheets and MoS2 nanowires and a typical heat transfer fluid (HTF) used in high temperature applications. Periodic-Density Functional Theory (periodic-DFT) calculations were performed to rationalize why different nanostructures were obtained according to the surfactant used. Finally, enhancements in thermal properties were found, being up to 57% for thermal conductivity and up to 7.5% for isobaric specific heat. Therefore, these nanofluids are a promising alternative to the typical HTF used, which is a eutectic mixture of biphenyl and diphenyl oxide. Also, to our knowledge, controlling the nanostructures obtained and the rationalization of the methodology for the preparation of stable nanofluids is reported for the first time. This leads to highly stable nanofluids with improved thermal properties, promising for application in concentrating solar power.

One of the possible research lines for improving the Concentrated Solar Power (CSP) technology is the enhancement of the thermophysical properties of the Heat Transfer Fluids (HTF) used. This enhancement leads to reduce costs for producing electricity using this technology. So, this study presents the preparation of nanofluids in which Ag nanoparticles were added to a base fluid composed of a eutectic mixture of diphenyl oxide and biphenyl. The base fluid is a heat transfer fluid commonly used in concentrating solar power plants. The nanofluids were shown to have improved thermal properties, the heat transfer coefficient increasing by up to 6% compared with the base fluid. Thus, their use could lead to enhancements in the overall efficiency of CSP plants. Accordingly, nanofluids were prepared with varying nanoparticle concentrations and their properties were characterized, including their physical and chemical stability, viscosity, isobaric specific heat and thermal conductivity. In addition, molecular dynamic calculations were performed to reach a better understanding of the nanofluid system at a molecular level. The isobaric specific heat and thermal conductivity values followed the same experimental tendency. An analysis of the radial distribution functions (RDFs) and spatial distribution functions (SDFs) shows that there is a first layer of base fluid molecules around the metal in which the oxygen atoms play an important role. This first layer encourages the directionality of the movement in the heart of the nanofluid, which leads to enhanced thermal properties.

Nanofluids are considered a promising alternative to the classic fluids used in heat transfer processes. One interesting application of nanofluids is their use as heat transfer fluid in thermosolar plants, such as those using concentrating solar power (CSP) technology. In turn, graphene oxide is an interesting nanomaterial for preparing nanofluids for solar thermal applications due to its appealing properties, such as high thermal conductivity, easy exfoliation and high black coloration. Therefore, this study presents the preparation by means of a liquid phase exfoliation (LPE) process of nanofluids based on graphene oxide in a typical fluid used in CSP plants. The efficiency of the LPE process and the stability of the nanofluids were analysed using UV–Vis spectroscopy, particle size measurements and transmission electron microscopy. Thermal properties were also measured, improvements of up to 6.6% and 45.5% being found for isobaric specific heat and thermal conductivity, respectively. Finally, strong-colored nanofluids were obtained and their optical properties were therefore characterized. Due to the strong coloration of the nanofluids, they can be used for designing Direct Absorption Solar Collectors (DASC).

Nanofluids are colloidal suspensions of nanomaterials in a fluid which exhibit enhanced thermophysical properties compared to conventional fluids. The addition of nanomaterials to a fluid can increase the thermal conductivity, isobaric-specific heat, diffusivity, and the convective heat transfer coefficient of the original fluid. For this reason, nanofluids have been studied over the last decades in many fields such as biomedicine, industrial cooling, nuclear reactors, and also in solar thermal applications. In this paper, we report the preparation and characterization of nanofluids based on one-dimensional MoS2 and WS2 nanosheets to improve the thermal properties of the heat transfer fluid currently used in concentrating solar plants (CSP). A comparative study of both types of nanofluids was performed for explaining the influence of nanostructure morphologies on nanofluid stability and thermal properties. The nanofluids prepared in this work present a high stability over time and thermal conductivity enhancements of up to 46% for MoS2-based nanofluid and up to 35% for WS2-based nanofluid. These results led to an increase in the efficiency of the solar collectors of 21.3% and 16.8% when the nanofluids based on MoS2 nanowires or WS2 nanosheets were used instead of the typical thermal oil.

Aiming for the introduction of stability requirements in nanofluids processing, an interface-based three-step method is proposed in this work. It is theory-based design framework for nanofluids that aims for a minimum tension at the solid-liquid interface by adjusting the polar and dispersive components of the base fluid to meet those of disperse nanomaterial. The method was successfully tested in the preparation of aqueous nanofluids containing single-walled carbon nanotubes that resulted to be stable and to provide good thermal properties, i.e. thermal conductivity increases by 79.5% and isobaric specific heat by 8.6% for a 0.087 vol.% load of nanotubes at 70 °C. Besides, a system for these nanofluids was modelled. It was found to be thermodynamically consistent and computationally efficient, providing consistent response to changes in the state variable temperature in a classical Molecular Dynamics environment. From an analysis of the spatial components of the heat flux autocorrelation function, using the equilibrium approach, it was possible to elucidate that heat conduction through the host fluid is enhanced by phonon propagation along nanotubes longitudinal axes. From an analysis of the structural features described by radial distribution functions, it was concluded that additional heat storage arises from the hydrophobic effect.

La comunicación que se presenta al VII Congreso de Ciudades Creativas consiste en reflejar la importancia del evento tradicional como potenciador económico y creador de nuevos nichos de mercado –cuestión que forma parte de la tesis doctoral sobre el evento tradicional, que en la actualidad está redactando una de las autoras- centrado en el caso de las Fiestas de la Magdalena de Castellón de la Plana, festividades que celebran la fundación de esta ciudad española de alrededor de 180.000 habitantes. La proyección de la marca territorio enriquece el evento tradicional y complementa la oferta para un público que llega a la ciudad para visitarla y disfrutar del mismo y que contribuye a la sostenibilidad económica, vinculándolo al desarrollo local y provincial a través del aeropuerto, sí como otros medios de transporte como el tren. Es importante unir el desarrollo económico con la marca ciudad y el evento tradicional. La metodología será el método hipotético deductivo. Revisión de la teoría sobre el evento tradicional, territorio y marca y aplicar la investigación a la repercusión de estos en el potenciador económico. Por lo que se refiere a las aportaciones, es importante esta investigación para unir a la marca de la ciudad, al evento tradicional aparejado al desarrollo económico de Castellón. Amplía la oferta y atrae a un tipo de turismo específico y de calidad que puede contribuir al crecimiento de la ciudad.

International audience; Nowadays, the use of nanofluids as alternative to commonly-used industrial heat transfer fluids is a topic of increasing interest. Analysing the improved efficiency of heat transfer processes according to advanced nanomaterials and obtaining stable nanofluids is one of the most interesting challenges. This paper presents a study of nanofluids based on boron nitride nanotubes and using an aqueous solution of Triton X-100 (which acts as a surfactant) as the base fluid. UV-vis spectroscopy, particle size measurements (size between 150 and 170 nm) and potential (at about 25 mV) showed that stable nanofluids were obtained. Surface tension measurements were also performed. The surface tension of water was weakly affected by the presence of any amount of nanoparticles and was mainly governed by the presence of surfactant. The rheological properties of the fluids were also analysed, as were their isobaric specific heat and thermal conductivity values. A Newtonian behaviour was observed for the base fluid and the nanofluids, with no significant increase in viscosity. The isobaric specific heat increased by 8% and thermal conductivity by 10% compared with the base fluid. Thus, the results obtained are interesting because while thermal properties improved with nanoparticle content, rheological behaviour did not change. Consequently, the nanofluids studied in the current paper do not raise the pressure drop and pumping power significantly and may therefore be a good option for thermal system applications.

This paper presents the preparation of Au nanoparticles in a non-polar medium, which is a fluid composed of the eutectic mixture of biphenyl and diphenyl oxide commonly used in Concentrating Solar Power (CSP) plants. The nanofluids prepared showed enhanced thermal properties, presenting thermal conductivity values 70% higher than those of base fluids, and isobaric specific heat values up to 10% higher. In turn, an increase of up to 36% was observed in their heat transfer coefficient, which is their efficiency as a heat transfer fluid (HTF). Also, the stability of the nanofluids was analysed using UV-vis spectroscopy, and particle size and ζ potential. The nanofluids with lower concentrations agglomerate slowly, which is considered stable for this application. Thus, these nanofluids are a promising, interesting alternative to the HTF often used in CSP plants. Also, molecular dynamics calculations were performed to better understand how the Au-nanofluid behaves in the presence of a surfactant within a temperature range between 50 and 600 K. The isobaric specific heat and thermal conductivity values followed the same experimental tendency. The analysis of the radial distribution functions (RDFs) and spatial distribution functions (SDFs) showed that, as the temperature rose, an exchange took place between the surfactant and diphenyl oxide molecules in the first layer of molecules around the metal. This movement incorporated a directionality that may play a part in the enhanced thermal properties. The surfactant participates as an active component within the Au-nanofluid, contributing to efficient heat transfer processes.

Nanofluids are systems with several interesting heat transfer applications, but it can be a challenge to obtain highly stable suspensions. One way to overcome this challenge is to create the appropriate conditions to disperse the nanomaterial in the fluid. However, when the heat transfer fluid used is a non-polar organic oil, there are complications due to the low polarity of this solvent. Therefore, this study introduces a method to synthesize TiO2 nanoparticles inside a non-polar fluid typically used in heat transfer applications. Nanoparticles produced were characterized for their structural and chemical properties using techniques such as X-ray Diffraction (XRD), Raman spectroscopy, Transmission Electron Microscopy (TEM), Fourier Transform Infrared (FTIR) spectroscopy, and X-ray photoelectron spectroscopy (XPS). The nanofluid showed a high stability, which was analyzed by means of UV-vis spectroscopy and by measuring its particle size and &zeta, potential. So, this nanofluid will have many possible applications. In this work, the use as heat transfer fluid was tested. In this sense, nanofluid also presented enhanced isobaric specific heat and thermal conductivity values with regard to the base fluid, which led to the heat transfer coefficient increasing by 14.4%. Thus, the nanofluid prepared could be a promising alternative to typical HTFs thanks to its improved thermal properties and high stability resulting from the synthesis procedure.

Photodegradation processes are of great interest in a range of applications, one of which is the photodecomposition of pollutants. For this reason, analysing nanoparticles that improve the efficiency of these processes under solar radiation are very necessary. Thus, in this study, TiO

This study presents the incorporation of thulium oxide onto the surface of TiO2 nanoparticles, which were used as the photoelectrode in dye-sensitized solar cells. The Tm-TiO2-based semiconductors were widely characterized using techniques such as atomic emission spectroscopy, X-ray diffraction, Raman spectroscopy, UV–Vis spectroscopy, and X-ray photoelectron spectroscopy. The presence of a Tm oxide on the surface was confirmed, and neither the crystalline phases present nor the band gap of TiO2 were affected. In turn, the presence of Tm3+ resulted in new electronic transitions, which led to luminescence processes in the Tm-TiO2 semiconductors. Furthermore, the use of these semiconductors as photoelectrodes in DSSCs led to an increase in open-circuit voltage of up to 6 %. This increase can be reasonably explained by the negative shift of the flat-band potential of the photoelectrodes.

This study presents the incorporation of Al-(hydr)oxide species onto the surface of TiO 2 nanoparticles used as photoelectrodes in dye-sensitized solar cells. The semiconductors prepared were comprehensively characterized by means of atomic absorption spectroscopy, X-ray diffraction, Fourier transform infrared spectroscopy, Raman spectroscopy, and UV–vis spectroscopy. The percentages of Al incorporated onto the TiO 2 surface were obtained, the maximum being 6.45 wt.% (Al/TiO 2 ). The presence of Al-(hydr)oxides in the samples was also determined, and was shown not to affect the crystalline phases present, as well as affecting the amount of dye that the semiconductors were able to absorb. These results are evidence of the presence of Al-(hydr)oxide species on the surface. Furthermore, the use of the semiconductors prepared as photoelectrodes in DSSCs led to an increase in open-circuit voltage of up to 16%.

XRD reveals that the doping delays the transition Anatase to Rutile to high temperature. XRD pattern of 5%W-TiO2 treated at 900 °C exhibits the appearance of new phase (H). Photocatalytic study shows an important activity in visible light of doped samples thermally treated at 700 and 900 °C. Appearing new phase enhances the photocatalytic reactivity of Rutile in visible light. The percentage of doping affects the photocatalytic activity.

This paper presents the synthesis of the organic–inorganic hybrid perovskite, CH3NH3PbI3, doped in the Pb2+ position with Sn2+, Sr2+, Cd2+ and Ca2+. The incorporation of the dopants into the crystalline structure was analysed, observing how the characteristics of the dopant affected properties such as the crystalline phase, emission and optical properties. XRD showed how doping with Sn2+, Sr2+ and Cd2+ did not modify the normal tetragonal phase. When doping with Ca2+, the cubic phase was obtained. Moreover, DR-UV-Vis spectroscopy showed how the band gap decreased with the dopants, the values following the trend Sr2+ Cd2+ > Sr2+ for the tetragonal structure and Pb2+ > Ca2+ for the cubic phase. The electron localization function (ELF) analysis showed similar electron localizations for undoped and Sn2+-doped tetragonal structures, which were different from those doped with Sr2+ and Cd2+. Furthermore, when Cd2+ was incorporated, the Cd–I interaction was strengthened. For Ca2+ doping, the Ca–I interaction had a greater ionic nature than Cd–I. Finally, an analysis based on the non-covalent interaction (NCI) index is presented to determine the weak-type interactions of the CH3NH3 groups with the dopant and I atoms. To our knowledge, this kind of analysis with these hybrid systems has not been performed previously.

This text describes the scientific medical atmosphere of Holland during century XVII, context in which the Cartesian model of body-machine is elaborated, and the intellectual relation that Descartes maintained with doctors and university professors (Harvey, among others). On the other hand, the text puts in evidence the traditional dualism attributed to Descartes, according to a detailed reading of his texts, in that the thesis of strict dualism is released by trialistic interpretations of authors like Monroy-Nasr. Este texto describe el ambiente médico científico de Holanda en el siglo XVII, contexto en el que se elabora el modelo de cuerpo-máquina cartesiano, y la relación intelectual que Descartes mantuvo con médicos y profesores universitarios (Harvey entre otros). Por otro lado, el texto pone en evidencia el tradicional dualismo atribuido a Descartes, según una lectura detallada de sus textos, en losque la tesis del dualismo estricto es sustituida por la tesis trialista, como la de Monroy-Nasr.

This is an experimental and theoretical study of thulium doped TiO2 nanoparticles. From an experimental perspective, a method was used to synthesize thulium-doped TiO2 nanoparticles in which Tm(3+) replaces Ti(4+) in the lattice, which to our knowledge has neither been reported nor studied theoretically so far. Different proportions of anatase and rutile phases were obtained at different annealing temperatures, and XRD and Raman spectroscopy also revealed the presence of a pyrochlore phase (Tm2Ti2O7) at 1173 K. Thus, the structure of the Tm-doped nanoparticles was thermally-controlled. Furthermore, XPS showed the presence of Tm(3+) in the samples synthesized, which produces oxygen vacancies to maintain the local neutrality in the lattice. The presence of Tm(3+) in the samples led to changes in the UV-Vis absorption spectra, so they showed photoluminescence properties and new states in the band gap, which produce a new lower energy electronic transition than the main TiO2 one. Periodic DFT calculations were performed to understand the experimentally produced structures. The production of oxygen vacancies was analysed and the changes generated in the structure were fully detailed. The DOS and PDOS analyses confirmed the experimental results obtained using UV-Vis spectroscopy, and showed that the new electronic states in the band gap are due to interactions of the f state of Tm and the p state of O. Likewise, the charge study and the ELF analysis indicate that when Tm is introduced into the TiO2 structure, the Ti-O bond around the oxygen vacancy is strengthened. Finally, an example of a photocatalytic application was developed to show the high efficiency of the samples due to the heterojunction in the interfaces of the phases in the samples, which improved the charge separation and the good charge carrier mobility due to the presence of the pyrochlore phase, as was also shown theoretically.

This study presents the experimental and theoretical study of highly internally Al-doped TiO2 nanoparticles. Two synthesis methods were used and detailed characterization was performed. There were differences in the doping and the crystallinity, but the nanoparticles synthesized with the different methods share common features. Anatase to rutile transformation occurred at higher temperatures with Al doping. X-ray photoelectron spectroscopy showed the generation of oxygen vacancies, which is an interesting feature in photocatalysis. In turn, the band-gap energy and the valence band did not change appreciably. Periodic density functional calculations were performed to model the experimentally doped structures, the formation of the oxygen vacancies, and the band gap. Calculation of the density of states confirmed the experimental band-gap energies. The theoretical results confirmed the presence of Ti(4+) and Al(3+) . The charge density study and electron localization function analysis indicated that the inclusion of Al in the anatase structure resulted in a strengthening of the TiO bonds around the vacancy.