3D‐Architected Alkaline‐Earth Perovskites

3D ceramic architectures are captivating geometrical features with an immense demand in optics. In this work, an additive manufacturing (AM) approach for printing alkaline-earth perovskite 3D microarchitectures is developed. The approach enables custom-made photoresists suited for two-photon lithography, permitting the production of alkaline-earth perovskite (BaZrO 3, CaZrO 3, and SrZrO 3) 3D structures shaped in the form of octet-truss lattices, gyroids, or inspired architectures like sodalite zeolite, and C 60 buckyballs with micrometric and nanometric feature sizes. Alkaline-earth perovskite morphological, structural, and chemical characteristics are studied. The optical properties of such perovskite architectures are investigated using cathodoluminescence and wide-field photoluminescence emission to estimate the lifetime rate and defects in BaZrO 3, CaZrO 3, and SrZrO 3. From a broad perspective, this AM methodology facilitates the production of 3D-structured mixed oxides. These findings are the first steps toward dimensionally refined high-refractive-index ceramics for micro-optics and other terrains like (photo/electro)catalysis.</p

LOS IMAGINARIOS SOCIALES Y EL TURISMO: CONCEPTOS Y APLICACIONES

Libro en formato pdfLa difusión y aceptación progresiva de lo relacionado con los imaginarios y representaciones sociales en el entorno académico mexicano, han conllevado a la adhesión de destacados académicos a esa línea de trabajo así como a la formación continua de jóvenes investigadores que buscaron aplicar los temas correspondientes a estudios de caso. Por lo mismo, la publicación se divide en dos partes: la primera presenta las aportaciones conceptuales de autores de varias latitudes de la geografía del país, reuniendo textos de conocidos(as) académicos(as) entre los estudiosos de las representaciones y los imaginarios como (citados en el orden de la publicación) Lidia Girola, Martha de Alba González, Milton Aragón Palacios, Daniel Hiernaux-Nicolás, Ilia Alvarado-Sizzo, Álvaro López López y Víctor Fernando Zamora Águila. La segunda parte que intitulamos simplemente “Aplicaciones” integra los textos de Rosa Adriana Vázquez Gómez, Maribel Osorio García, Carlos Rogelio Virgen Aguilar, Alfonso Zepeda Arce, Mario Alberto Velázquez García, Helene Balslev Clausen y Eloy Méndez Sainz. El lector notará a primera vista la variedad de los casos de aplicación: además del ya citado estudio sobre jóvenes estudiantes, se integra un trabajo sobre Vallarta, otro sobre el nuevo imaginario del pulque y, una reflexión interesante que muestra el potencial de la literatura para analizar el paisaje de pueblo.Universidad Panamericana, Red de Investigación Turística (RIT) y Red Iberoamericana de Investigación en Imaginarios y Representaciones Sociales (RIIR

Middle East - North Africa and the millennium development goals : implications for German development cooperation

          Closed-loop controlled combustion is a promising technique to improve the overall performance of internal combustion engines and Diesel engines in particular. In order for this technique to be implemented some form of feedback from the combustion process is required. The feedback signal is processed and from it combustionrelated parameters are computed. These parameters are then fed to a control process which drives a series of outputs (e.g. injection timing in Diesel engines) to control their values. This paper’s focus lies on the processing and computation that is needed on the feedback signal before this is ready to be fed to the control process as well as on the electronics necessary to support it. A number of feedback alternatives are briefly discussed and for one of them, the in-cylinder pressure sensor, the CA50 (crank angle in which the integrated heat release curve reaches its 50% value) and the IMEP (Indicated Mean Effective Pressure) are identified as two potential control variables. The hardware architecture of a system capable of calculating both of them on-line is proposed and necessary feasibility size and speed considerations are made by implementing critical blocks in VHDL targeting a flash-based Actel ProASIC3 automotive-grade FPGA

Chlorine in NiO promotes electroreduction of CO2 to formate

We report the exceptional finding that NiO, a known electroactive catalyst for the reduction of CO2 to CO, can be tuned to become an active electrocatalyst for CO2 reduction to formate when chlorine is synthetically incorporated into NiO. The CO2 reduction reaction (CO2RR) is carried out on chlorine-containing NiO octahedral particles made by a solid-state synthesis method yielding a Faradaic efficiency (FE) of 70 % for formate production at -0.8 V vs. RHE with a partial current density of 14.7 mA/cm2. XPS confirms the presence of Ni3+ and Ni2+ species, indicating the existence of uncoordinated Ni. The Ni3+/Ni2+ ratio increases with the Cl concentrations on NiO. Cl concentrations are also confirmed with STEM-EDX. DFT modeling provides insights into the thermodynamic stability and CO2RR mechanism over the Cl-containing NiO surface. It is suggested that Cl can occupy the defective sites created by oxygen vacancies on the NiO model with Cl (O-alpha+Cl). The surface Pourbaix diagrams constructed from DFT indicate the preferred surface terminations favorable at the operating conditions for the CO2RR, which closely agrees with the experimental findings. The O-alpha+Cl has been found to promote CO2RR to formate. Our results create new possibilities in the development of earth-abundant electrocatalysts for selective CO2RR.</p