Photoluminescence of ZnO Nanowires: A Review

One-dimensional ZnO nanostructures (nanowires/nanorods) are attractive materials for applications such as gas sensors, biosensors, solar cells, and photocatalysts. This is due to the relatively easy production process of these kinds of nanostructures with excellent charge carrier transport properties and high crystalline quality. In this work, we review the photoluminescence (PL) properties of single and collective ZnO nanowires and nanorods. As different growth techniques were obtained for the presented samples, a brief review of two popular growth methods, vapor-liquid-solid (VLS) and hydrothermal, is shown. Then, a discussion of the emission process and characteristics of the near-band edge excitonic emission (NBE) and deep-level emission (DLE) bands is presented. Their respective contribution to the total emission of the nanostructure is discussed using the spatial information distribution obtained by scanning transmission electron microscopy−cathodoluminescence (STEM-CL) measurements. Also, the influence of surface effects on the photoluminescence of ZnO nanowires, as well as the temperature dependence, is briefly discussed for both ultraviolet and visible emissions. Finally, we present a discussion of the size reduction effects of the two main photoluminescent bands of ZnO. For a wide emission (near ultra-violet and visible), which has sometimes been attributed to different origins, we present a summary of the different native point defects or trap centers in ZnO as a cause for the different deep-level emission bands

Análisis de la satisfacción académica de los estudiantes de la Facultad de Administración, Contaduría y Derecho en Piedras Negras, Coahuila.

Es muy importante valorar la satisfacción estudiantil de una institución educativa de nivel licenciatura en cuanto a los servicios educativos que de ella obtiene, en esta ocasión nos adentramos en la Facultad de Administración, Contaduría y Derecho, en lo que a educación se refiere, tanto del contenido de lo aprendido como del  cumplimiento, la metodología y servicios disponibles como los salones de clase, canchas deportivas, espacios abierto y el cuidado de las mismas, servicios de la institución, desarrollo de los docentes y el aprovechamiento de los estudiantes. La población está conformada por 322 estudiantes de los cuales participaron 148 estudiantes de las distintas carreras de la universidad referida. El tipo de investigación es de carácter descriptivo. Se realizó una encuesta a los estudiantes sobre los servicios que en ella se ofrecen para conocer el grado de satisfacción de los estudiantes que en esta institución estudian utilizando la escala de Likert para conocer dichos aspectos. Dichos resultados del cuestionario son de gran beneficio para mejorar la calidad académica y la permanencia de la institución educativa. Los resultados de este análisis permiten identificar los puntos débiles ya que se establecen criterios traducidos en mejoras en el proceso de enseñanza aprendizaje. Así mismo, concederán a la Facultad elaborar un plan acción estratégico que permita mejorar la satisfacción de los estudiantes en las diferentes carreras

"SANTUARIOS DEL AGUA (SA) COMO POLÍTICA AMBIENTAL EN EL ESTADO DE MÉXICO, HACIA UNA PROTECCIÓN DE LOS RECURSOS HÍDRICOS, CASO DE ESTUDIO: ÁREA NATURAL PROTEGIDA PARQUE ESTATAL (SA) "PRESA CORRAL DE PIEDRA"

El recurso "agua" es considerada como un factor estratégico para el desarrollo del país, por lo cual el gobierno mexicano identifico áreas de captación de agua, como lo es la cuenca Valle de Bravo-Amanalco que dentro de esta se encuentra el "(SA) Presa Corral de Piedra", cuyo objetivo es preservar las condiciones naturales que permitan la continuidad del ciclo hidrológico. Ante este tipo de políticas ambientales es necesario el análisis de su establecimiento, saber si cumplen con la función de protección, que llegue a integrar los factores sociales y económicos, a la par con el ambiente.El recurso "agua" es considerada como un factor estratégico para el desarrollo del país, por lo cual el gobierno mexicano identifico áreas de captación de agua, como lo es la cuenca Valle de Bravo-Amanalco que dentro de esta se encuentra el "(SA) Presa Corral de Piedra", cuyo objetivo es preservar las condiciones naturales que permitan la continuidad del ciclo hidrológico. Ante este tipo de políticas ambientales es necesario el análisis de su establecimiento, saber si cumplen con la función de protección, que llegue a integrar los factores sociales y económicos, a la par con el ambiente

Inmate Partner Violence Through Social Networks

The purpose of this research was to analyze the relationship between dating violence and the social media. A sample of 400 university students from both private and public institutions of Mexico City was selected. From these sample, 46.6% were men and 52.4% women, with an age range of 16-29. Two scales were used to evaluate, the first one corresponds to violence in dating and the second scale to violence in dating through social media. Both instruments are Likert scale with response options ranging from strongly disagree to strongly agree. A pilot test was used to evaluate the usefulness of the instrument and its validness and reliability. Statistical analysis of Chronback alpha and factor analysis of the scales were used. In the reliability analysis appropriate values for both scales were obtained, which means that there was an appropriate relationship between the reagents with the scales proposed in general. To analyze the relationship between intimate partner violence and intimate partner violence on social media crosstabs were performed with analysis chi square, the results showed significant differences between dating violence and intimate partner violence on social media on significance levels. Thus, the relationship between intimate partner violence and intimate partner violence on social media showed that in a low (high) level of violence there is also a low (high) level of violence in social media likewise in a severe level of intimate partner violence the level of violence involving social media is also severe

INNOVACION DE PRODUCTOS DE ALTO VALOR AGREGADO A PARTIR DE LA TUNA MEXICANA

In the world, Mexico is the major producer of prickly pears and also has the largest number in varieties. However, in addition to its highly seasonal production, prickly pears are consumed just by a small segment of the Mexican population. Therefore, the promotion of prickly pears consumption in the form of new derivative products by emphasizing its bioactive properties seems to be a possible solution to its low consumption. Recent studies from European and Asian laboratories showed that some prickly pears varieties have a significant antioxidant activity. In Mexico, prickly pears producers are looking for new ways of commercialization. In this regard, similar studies are underway surveying those varieties from the highly producing Mexican states with the goal to develop new functional products with high added value. In addition, the use of prickly pears as a raw material for the cosmetic and pharmaceutical industries is being considered and seems to be highly promising.Prickly pears, antioxidant activity, innovation, functional food., Agribusiness,

Evaluation of Microstructural and Mechanical Behavior of AHSS CP780 Steel Welded by GMAW-Pulsed and GMAW-Pulsed-Brazing Processes

Joints of complex phase 780 (CP-780) advanced high strength steel (AHSS) were carried out by using an ER-CuAl-A2 filler metal for the gas metal arc welding pulsed brazing (GMAW-P- brazing) process and the ER-80S-D2 for the GMAW-P process employing two levels of heat input. The phases in the weld bead and HAZ were analyzed, and the evaporation of zinc by means of scanning electron microscopy (SEM) was also monitored. The mechanical properties of the welded joints were evaluated by tension, microhardness and vertical impact tests. It was found that there was greater surface Zn evaporation in the joints welded with the GMAW-P process as compared to the GMAW-P-brazing process. The best results in tensile strength were observed in the joints welded with GMAW-P-brazing process, which increased by ~68% with respect to those of the GMAW-P. This behavior can be attributed to the formation of an intermetallic complex compound Cu-Al-Fe in the fusion line

Dignidad, Poder, Resistencia // Dignity, Power, Resistance

First To Go Abroad is a partnership between the Loyola Marymount University First To Go Program, LMU Study Abroad, and the Council on International Educational Exchange (CIEE), which seeks to increase study abroad opportunities for first-generation college students. In May 2017, fifteen first-gen students and two first-gen faculty mentors traveled together to Santiago, Dominican Republic, where they spent ten days exploring the country and learning about the local cultures, customs, and histories of the people who call the DR home. Travel is a privilege not all students have the same access to; for some students, this trip was the first time out of the United States. Like the first-generation college experience, the experience of international travel is marked by daily encounters with new spaces, people, and cultural practices that can be at once overwhelming and inspiring. This was a topic of exploration throughout the trip and the subject of the pages contained in this volume. The narratives published here are the product of a cross-institutional writing workshop, where students from LMU and the Pontificia Universidad Católica Madre y Maestra worked together to draft essays documenting their encounters with change that have pushed boundaries, broken down borders, and generated personal growth. We hope our readers around the world will appreciate these works, which showcase the transformative power of creative and collaborative global encounters