Planar waveguides were generated in samples of rutile crystal (TiO2) by bombarding with two types of ion: silicon and carbon. Rutile is used because of its anisotropic properties, particularly its birefringence. The guide is generated due to damage caused by the ions in the crystal which change its index of refraction. Three parameters were used: the implantation ion energy, the implantation fluence, and the orientation of the crystallographic planes. The refractive index profile of the irradiated sample was calculated and together with the value of the optical barrier the comparison was made between the different waveguides generated.

Cocoa plant (Theobroma cacao L.) is native from South America and it represents one of the most significant "bio-cultural" resources of Mesoamerica, since it is a region where it was domesticated and had a relevance as ritual drink and as currency in many pre-hispanic cultures until the arrival of the Spaniards who spread its use worldwide, and became it one of the most consumed commodity goods. Through this research, an alternative is proposed to address the problem of cultivars through the introduction of a wide variety of cocoa plants in traditional agroforestry systems, in synergy with the inoculation of nitrogen-fixing and insoluble phosphor solubilizing edaphic bacterial consortia. Four cultivars of improved grafted cocoa plants were introduced in a traditional agroforestry plot and three fertilization treatments were applied: application of biofertilizer, application of chemical fertilizer and control. Measurements of height, stem diameter, number of leaves and branches were recorded at 2 and 12 months after planting and rhizosphere microbial populations were characterized. Growth results showed good potential for all studied cultivars and it was observed that biofertilization foresees significant effects in some of the growth indicators of cocoa plant. Thereby, plant associations in an agroforestry system could be favorable to promote fruit development and resistance to pests and diseases.

El cacao (Theobroma cacao L.) es nativo de América del Sur y representa uno de los recursos «bioculturales» más significativos de Mesoamérica, ya que es una región donde se domesticó y tuvo relevancia como bebida ritual y como moneda en muchas culturas prehispánicas hasta la llegada de los españoles, quienes difundieron su uso en el mundo y lo convirtieron en una de las mercancías «commodity» más consumidas. Mediante este trabajo se propone una alternativa para atender la problemática de las plantaciones a través de la introducción de una diversidad amplia de cultivares de cacao en sistemas agroforestales tradicionales, en sinergia con la inoculación de bacterias edáficas fijadoras de nitrógeno y solubilizadoras de fósforo insoluble. En una parcela agroforestal tradicional se introdujeron plantas de cacao injertadas de cuatro cultivares y se dispusieron 3 tratamientos: aplicación de biofertilizante, aplicación de fertilizante químico y testigo. Se registraron la altura, el diámetro basal, el número de hojas y el número de ramas a los 2 y 12 meses, y se caracterizó la población de microorganismos asociada alrededor del tallo bajo la copa de las plantas. Los resultados de crecimiento muestran un buen potencial para los 4 cultivares estudiados y se observó que la biofertilización generó efectos significativos en algunos de los indicadores de crecimiento de las plantas de cacao. Así, las asociaciones vegetales en un sistema agroforestal podrían ser favorables para potenciar el desarrollo de frutos y resistencia a plagas y enfermedades.

Introduction: The aim of our study was to analyze the relationship of the rs9939609 FTO gene polymorphism with insulin resistance and serum adipokine levels. Material and methods: A population of 610 patients with obesity was analyzed in a cross sectional design. Weight, blood pressure, basal glucose, c-reactive protein (CRP), insulin, insulin resistance (HOMA), lipid profile and adipocytokines (leptin, adiponectin, resistin, TNF alpha, and interleukin 6) levels were measured. Results: Insulin (122.2 ± 101.8 pmol/L vs. 104.5 ± 61.5 pmol/L vs. 112.1 ± 74.3 pmol/L: p < 0.05) and HOMA-IR values (4.76 ± 4.4 vs. 3.71 ± 2.5 vs. 3.76 ± 3.1; p < 0.05) were higher in TT group than AT and AA groups. Triglycerides values were higher in TT group than AA group (1.42 ± 0.71 mmol/L vs. 1.39 ± 0.69 mmol/L vs. 1.23 ± 0.64 mmol/L; p < 0.05). Adiponectin levels were lower in TT genotype group than AA genotype group (35801.2 ± 35,912.3 ng/L vs. 26,718.1 ± 36,323.1 ng/L vs. 21,112.3 ± 25,623.1 ng/L p < 0.05). Conclusion: The FTO gene polymorphism, rs9939609, was found to be associated with insulin resistance, insulin, triglyceride and adiponectin levels in obese patients with TT variant.

Introducción: el objetivo de nuestro estudio fue analizar la relación del polimorfismo rs9939609 del gen FTO con la resistencia a la insulina y los niveles de adipocitoquinas séricas. Material y métodos: se analizó una población de 610 pacientes con obesidad en un diseño transversal. Se registraron los valores de peso, presión arterial, glucosa basal, proteína C-reactiva (PCR), insulina, resistencia a la insulina (HOMA), perfil lipídico y adipocitoquinas (leptina, adiponectina, resistina, TNF alfa y la interleucina 6). Resultados: los niveles de insulina circulante (104,5 + /l vs. / L 112.1 ± 74,3 pmol 61,5 pmol 122,2 ± 101,8 pmol/l vs.: p < 0,05) y HOMA-IR (4,76 ± 4,4 vs. 3,71 + 2,5 vs. 3,76 ± 3,1; p < 0,05) fueron mayores en el grupo TT que en el grupo AT+ AA. Los valores de triglicéridos fueron mayores en el grupo TT que AA (1,42 ± 0,71 mmol/l vs. 1,39 + 0,69 mmol/l vs. 1,23 ± 0,64 mmol/l; p < 0,05). Los niveles de adiponectina fueron menores en el grupo con genotipo TT que en el grupo con genotipo AA (35.801,2 ± 35.912,3 ng/l vs. 26.718,1 ± 36.323,1 ng/l vs. 21.112,3 ± 25.623,1 ng/l p < 0,05). Conclusión: el polimorfismo del gen FTO, rs9939609, está asociado con los niveles de resistencia a la insulina, insulina, triglicéridos y de adiponectina en pacientes obesos con variante TT.

Mesoamerican agrosystem ‘milpa’ is the association of maize, beans (Phaseolus sp.) and squash (Cucurbits sp.) in the same space and time. It is characterized by the production of a large diversity of species in small areas, but currently its use tends to decrease because of technological introductions of monocultures. In this work, the yield and productive efficiency of the association maize, beans and squash, intercropped with fruit tree rows were evaluated in two locations from Puebla, Mexico, through 32 experimental treatments clustered in three agrosystems. They were: triple associations of maize-beans-squash intercropped with fruit trees, double associations maize-beans without fruit trees, and monocultures with and without intercropped fruit trees, all distributed under a randomized complete block design with three replications. Significant differences (P<0.05) were detected in the analysis of variance for locations of evaluation, agrosystems and experimental treatments based on associations and monocultures, for grain yields and land equivalent ratio. For the comparative index of area yield, there were just significant differences among agrosystems. In these cases, the agrosystems with triple and double associations difered significantly from the monocultures. These agroecosystems surpassed the yields per unit area by two or three times, and had greater productive efficiencies, in comparison to the monocultures. In relation with the performance of genotype-agrosystems, the triple interactions in alternate rows of ‘Tropical’ or ‘Niebla’® maize, ‘Negro’ or‘Amarillo’ beans and ‘Huejotzingo’ or ‘Moxolahuac’ squash, presented the highest yields (7.13 to 10.1 kg/8 m²) and productive efficiencies (>2.0). The intercropped row of fruit trees conferred a particular microenvironment, and complemented the agrosystem productivity. This was because the production of the fruit trees was significantly and positively associated (r>0.3) with the production of the most efficient and productive triple associations, both in San Andres Calpan with apple trees and in San Lorenzo Chiautzingo with peach trees.

El agrosistema mesoamericano ‘milpa’ es la asociación de maíz, frijol (Phaseolus sp.) y calabaza (Cucurbita sp.) en el mismo espacio y tiempo. Dicho sistema se caracteriza por la producción de una gran diversidad de especies en pequeñas extensiones, y su uso tiende a decrecer por efecto de introducciones tecnológicas de monocultivos. En este trabajo se evaluó el rendimiento y efciencia productiva de la asociación de maíz, frijol y calabaza intercalada con frutales en dos localidades de Puebla, México, a través de 32 tratamientos agrupados en tres agrosistemas: asociaciones triples maíz-frijol-calabaza intercaladas con frutales, asociaciones dobles maíz-frijol sin frutales, y monocultivos con y sin frutales intercalados, distribuidos en bloques al azar con tres repeticiones. En el análisis de varianza se detectaron diferencias significativas (P<0,05) en rendimiento de grano y razón equivalente de terreno entre localidades de evaluación, agrosistemas y tratamientos basados en asociaciones y monocultivo. En índice comparativo de rendimiento área solo hubo diferencias significativas entre agrosistemas. En estos casos, los agrosistemas de asociaciones triples y dobles difrieron significativamente de los sistemas de monocultivos, hasta el punto de duplicar o triplicar los rendimientos por unidad de área y presentar mayores eficiencias productivas que los monocultivos. En el comportamiento de genotipos-agrosistemas, las interacciones triples en surcos alternos de maíz ‘Tropical’ o ‘Niebla’®, frijol ‘Negro’ o ‘Amarillo’, y calabaza ‘Huejotzingo’ o ‘Moxolahuac’ presentaron los mayores rendimientos (7,13 a 10,1 kg/8 m²) y eficiencias productivas (>2,0). La hilera de frutales intercalados generó un microambiente particular y complementó la productividad del agrosistema, debido a que se asoció de manera significativa y positiva (r>0,3) con las asociaciones triples más eficientes y de mayor eficiencia productiva, tanto en la localidad de San Andrés Calpan con manzana como en San Lorenzo Chiautzingo con durazno.

Abstract: Introduction: The appearance of patellofemoral pain after a knee arthroplasty, particularly in rheumatic diseases, resulted in the incorporation of the substitution of the patellar component in all designs. The replacement of the patella became a standard part of knee arthroplasty, but the controversy over whether to restore it or not continues among orthopedists that perform knee arthroplasties. Objective: To analyze the incidence of anterior knee pain in patients who underwent primary knee arthroplasty with or without replacement of the patellar component. Material and methods: Observational, retrospective, descriptive and transversal study from January 2011 to December 2013. Results: A total of 54 patients were included, 12 men (with an average age of 63 years) and 42 women (with an average age of 71 years), totaling 64 knees that were surgically intervened. Conclusion: This study found no significant difference in anterior knee pain and in the function of the patellofemoral joint and the knee in the groups of patients who were tested with the different scales.

Resumen: Introducción: La aparición de dolor patelofemoral postoperatorio en la artroplastía de rodilla, sobre todo en pacientes reumáticos, resultó en la incorporación de la sustitución del componente patelar en la mayoría de los diseños. Esta se convirtió en una parte estándar de la artroplastía total de rodilla; la controversia sobre si restituir o no el componente patelar continúa siendo debatida por los cirujanos ortopedistas que realizan artroplastías de rodilla. Objetivo: Realizar un análisis de la incidencia de dolor anterior de rodilla en pacientes sometidos a artroplastía primaria de rodilla con o sin remplazo del componente patelar. Material y métodos: Estudio observacional, retrospectivo, descriptivo y transversal de Enero de 2011 a Diciembre de 2013. Resultados: 54 individuos, 12 hombres (con un promedio de edad de 63 años) y 42 mujeres (con un promedio de edad de 71 años), que dieron un total de 64 rodillas intervenidas quirúrgicamente. Conclusión: No se encontró diferencia significativa en cuanto al dolor anterior de rodilla, en la función de la articulación patelofemoral y de la rodilla en los grupos de sujetos que fueron analizados con las diferentes escalas.

This study, through an incubation experiment, evaluates the effect that different biomass ashes exert on the extractability of nutrients and some chemical parameters and dehydrogenase activity of a slightly acid soil. Three types of as were selected: two new ashes generated by the dry combustion of olive cake or by gasification of greenhouse vegetable wastes, and a third produced by wood combustion. The ash significantly increased the pH, electrical conductivity, and dehydrogenase activity of the soil. Dry olive-cake ash was the most effective in raising the levels of soil AB-DTPA extractable P, K, and Cu. By contrast, wood ash caused the greatest increases in soil AB-DTPA-extractable Zn. The three as he showed little effectiveness for increasing soil ABDTPA extractable Fe and Mn. Ash from dry olive cake could be used as a low-cost potassium fertilizer.

In a biopurification system such as a biobed, the rhizosphere of the grass layer may be a significant factor for promoting pesticide dissipation in the biomixture. The rhizosphere effect of a Lolium perenne, Festuca arundinacea and Trifolium repens mixture on the dissipation of a pesticide combination that was composed of atrazine, chlorpyrifos and isoproturon was studied. The assay was performed using glass pots divided into two separate compartments (root surface and root-free), each filled with an organic biomixture (oat husk, top soil and peat) and contaminated with the pesticide mixture at 5 mg kg-1.Non-planted and non-contaminated pots were also used as controls. The results indicated that there were high atrazine, chlorpyrifos and isoproturon dissipation in the planted pots compared with the unplanted pots. An inverse correlation was found throughout the assay between phenoloxidase activity and residual pesticide (0.684 to 0.952). Indeed, fungal biomass was positively correlated with phenoloxidase activity on day 1 (r =0.825) and day 30 (r =0.855). Besides, exudation of oxalic and malic acid in contaminated pots was higher than in the control without pesticides, associated with oxidation of the pesticide mixture in the biomixture of a bioded system. Therefore, the grass layer enhances pesticide removal in biobeds.

Growth curve analysis was used to explain the emergence of stems of two varieties (CP 65-357 y LCP 85-384) of healthy sugar cane seed obtained by two methodologies: micropropagation and hydrotermotherapy. The aim of this study was to model the effects of varieties, methodologies used and the interaction between them on the evolution of the number of stems per meter. Three replicates per variety and methodology were carry out and, for each replicate, the plot was considered as the test unit. From the descriptive analysis of the data, a logistic regression fit was selected. Initially, fixed models were applied, but due to the non-constant variance of the data nonlinear modeling with random effects for longitudinal data was applied where the plot was considered to be the unit or subject. Parameters corresponding to the horizontal asymptote and the average value of the horizontal asymptote were considered as random effects in order to reduce variability. The results showed significance in the logistic regression parameters. The horizontal asymptote and the number of days necessary to reach 50 % of maximum emergency were significant for variety, while the methodology and interaction were not significant. The assumptions of normality and constant variance on the residuals were analyzed and turned out to be adequate. As a conclusion, it can be proposed that the logistic regression model adequately explain the behavior of emergency data stems per meter.

Se realizó el modelado estadístico de la emergencia de tallos de dos variedades de caña de azúcar (CP 65-357 y LCP 85-384) provenientes de caña semilla saneada por dos metodologías: micro propagación e hidro termoterapia. El objetivo de este trabajo fue la modelación de curvas de crecimiento mediante el ajuste no lineal logístico para evaluar el efecto de las variedades, de las metodologías de saneamiento y de su interacción, sobre la evolución temporal del número de tallos. Se realizaron tres repeticiones por metodología y variedad para cada repetición se usó una parcela que se consideró como unidad experimental. A partir del análisis descriptivo de los datos se seleccionó el ajuste. Inicialmente se aplicó un modelo no lineal de efectos fijos, pero debido a la varianza no constante de los datos se aplicó modelación con efectos aleatorios para datos longitudinales donde la unidad o sujeto fue la parcela. Los parámetros correspondientes a la asíntota horizontal y al valor medio de crecimiento se consideraron como efectos aleatorios con el objeto de disminuir la variabilidad. Los resultados mostraron significación en algunas de las estimaciones de los parámetros de la regresión logística. La asíntota horizontal y el número de días necesarios, desde la plantación, para alcanzar el 50 % de la brotación máxima fueron significativas para variedad, mientras que la metodología y la interacción no resultaron significativas. Se analizaron los supuestos distribucionales de los residuos y de los efectos aleatorios que resultaron adecuados y se verificó la varianza constante de los residuos. Se concluye que el modelo propuesto explica adecuadamente el comportamiento de los datos del porcentaje de emergencia de tallos por metro.

En este trabajo se crecieron películas delgadas de AgInS2 con estructura tetragonal tipo calcopirita usando un procedimiento basado en la evaporación secuencial de precursores metálicos en presencia de azufre elemental, en un proceso en dos etapas. Se investigó el efecto de la temperatura de crecimiento y la proporción de la masa de Ag evaporada a la masa de In evaporada (mAg/mIn) sobre la fase y la homogeneidad en la composición química a través de medidas de difracción de rayos X y espectroscopía de electrones Auger. Estas medidas mostraron que las condiciones para preparar películas delgadas que contengan únicamente la fase AgInS2, crecidas con estructura tipo calcopirita tetragonal y buena homogeneidad de la composición química en todo el volumen son temperatura de 500 °C y proporción mAg/mIn 0.89. Las medidas de fotocorriente de transiente indicaron que el transporte eléctrico es afectado por procesos de recombinación, vía transiciones banda a banda y transiciones asistidas por trampas.

In this study, thin films of AgInS2 with chalcopyrite-type tetragonal structure were grown by means of a procedure based on the sequential evaporation of metallic precursors in presence of elemental sulfur in a two-stage process. The effect of the growth temperature and the proportion of the evaporated Ag mass in relation to the evaporated In mass (mAg/mIn) on the phase and homogeneity in the chemical composition were researched through X-ray diffraction measurements and Auger electrons spectroscopy. These measurements evidenced that the conditions for preparing thin films containing only the AgInS2 phase, grown with tetragonal chalcopyrite-type structure and good homogeneity of the chemical composition in the entire volume, are a temperature of 500 °C and a 0.89 mAg/mIn proportion. The transient photocurrent measurements indicated that the electricity transmission is affected by recombination processes via band-to-band transitions and trap-assisted transitions.

AnaPro is software that solves direct anaphora in Spanish, specifically pronouns: it finds the noun or group of words to which the pronoun refers. It locates in the previous sentences the referent or antecedent which the pronoun replaces. An example of a direct anaphora solved is the pronoun "he" in the sentence "He is sad." Much of the work on anaphora has been done for texts in English; thus, we specifically focus on Spanish documents. AnaPro directly supports text analysis (to understand what a document says), a non trivial task since there are different writing styles, references, idiomatic expressions, etc. The problem grows if the analyzer is a computer, because they lack "common sense" (which persons possess). Hence, before text analysis, its preprocessing is required, in order to assign tags (noun, verb, ) to each word, find the stems, disambiguate nouns, verbs, prepositions, identify colloquial expressions, identify and resolve anaphora, among other chores. AnaPro works for Spanish sentences. It is a novel procedure, since it is automatic (no user intervenes during the resolution) and it does not need dictionaries. It employs heuristics procedures to discover the semantics and help in the decisions; they are rather easy to implement and use limited knowledge. Nevertheless, its results are good (81% of correct answers, at least). However, more tests will give a better idea of its goodness.

AnaPro es un software que resuelve problemas con anáforas directas en español, especialmente pronombres: la herramienta encuentra el sustantivo o grupo de palabras al cual se refiere el pronombre. Localiza en oraciones previas la referencia o antecedente y lo reemplaza por el pronombre que le corresponde. Un ejemplo de anáfora directa resuelta es el pronombre "él", en la oración "Él está triste". AnaPro apoya directamente el análisis de textos (para entender lo que el documento dice), tarea no trivial ya que existen diferentes formas y estilos de escribir, referenciar, expresiones regionales (mexicanismos, argentinismos, etc.). Todavía se complica más si el analizador es una máquina porque no tiene "sentido común" (que cualquier persona puede tener). Así, antes de analizar el texto, se requiere pre-procesarlo para asignar etiquetas (sustantivos, y verbos, entre otros) a cada palabra, encontrar las derivaciones, desambiguar sustantivos, verbos, preposiciones, identificar expresiones coloquiales, identificar y resolver anáforas, entre otras tareas. AnaPro trabaja con oraciones en español. Es un proceso novedoso porque es totalmente automático (no requiere la intervención de un usuario) y tampoco necesita de diccionarios. Emplea un procedimiento heurístico para descubrir la semántica y apoyarse en las decisiones que debe de tomar. Ha resultado ser bueno (con un 81-100% de aciertos); sin embargo, más ejemplos nuevos darán mejor idea de su desempeño.

Background: Inflammation is a common phenomenon present in gastric mucosa of patients infected with H. pylori. Activation of the RAGE/multiligand axis is thought to be a relevant factor in cancer-mediated inflammation. RAGE is a membrane receptor, belonging to the immunoglobulin family, and the over-expression of RAGE has been associated with increased invasiveness and metastasis generation in different types of cancer, including gastric cancer. Furthermore recent experiences show that the use of its soluble form (sRAGE) or silencing of the gene coding for this receptor could provide therapeutic benefits in cancer. Aim: To evaluate the immunohistochemical expression of RAGE, MUC-1, β-Catenin free and phosphorylated, Cyclin-D1 and GSK3 in gastric biopsy specimens infected with H. pylori. Material and Methods: Immunohistochemical analysis was carried out in gastric biopsies from 138 patients: 55 with inflammatory injury (no atrophic gastritis), 42 with pre-cancerous conditions (atrophy or intestinal metaplasia) and 41 with dysplastic lesions or in situ adenocarcinoma. Results: There was a high rate of positive RAGE expression in the three groups of biopsies. Biopsies with dysplasia or in situ carcinoma had a significantly higher percentage of RAGE expression than the other groups of biopsies. Conclusions: The increased RAGE expression reported in both dysplasia and incipient cancer support the role of the multiligand/RAGE axis in gastric carcinogenesis.

Annual average of daily precipitation was used to group climatological stations into clusters using the k-means procedure and principal component analysis with varimax rotation. After a careful selection of the stations deployed in Mexico since 1950, we selected 349 characterized by having 35 to 40 complete years of observations. The clustering of stations was performed three times: firstly according to the amount of precipitation; secondly according to their anomalies from the mean, resulting in their standard deviations grouping; and thirdly using the standardized anomalies, which resulted in a clustering according to the features of the trend and the structural changes of the series over the observing period. We identified two clusters that occupy northwestern and north-central Mexico; another at the center of the territory, between Sierra Madre Oriental and Sierra Madre Occidental; the following over the Sierra Madre Oriental; and a last one in the southeast of the territory, the southern coast of the Pacific Ocean and the Yucatán Peninsula, that overlaps with Sierra Madre Oriental group. Some stations of Yucatán Peninsula show similar characteristics to the northwestern cluster. The groupings were compared with the results of previous studies. The comparison indicates that regions are invariant in time and space and independent of the method of agregation and the stations sampled.

Se usaron los promedios anuales de la precipitación diaria y se agruparon las estaciones en conglomerados usando el procedimiento de k-medias y el de análisis de componentes principales con rotación varimax. Esto se realizó después de seleccionar cuidadosamente, entre las estaciones climatológicas de México, aquellas que tuvieran datos de precipitación a partir de 1950, y 35 a 40 años completos de observaciones. Hay 349 estaciones con estas características. El agrupamiento de estaciones se realizó tres veces: primero se agruparon según la cantidad de precipitación; después se emplearon las anomalías respecto a la media y se agruparon según su desviación estándar; por último se emplearon las anomalías estandarizadas y se agruparon según las características de tendencia y cambios estructurales de las series que ocurren a lo largo del periodo de observación. Se identificaron dos conglomerados en la parte noroeste y centronorte de México; otro en la parte central del territorio, entre la Sierra Madre Oriental y la Sierra Madre Occidental; uno más en la Sierra Madre Oriental, y un último agrupamiento en la parte sudoriental del territorio, la costa sur del Océano Pacífico y la Península de Yucatán, que se superpone al grupo de la Sierra Madre Oriental. Algunas estaciones de la Península de Yucatán muestran similitudes con las del agrupamiento noroeste. Los resultados se compararon con los de otros autores. El análisis muestra que las regiones son invariantes en el tiempo y el espacio, y son independientes del método de agrupamiento y de las estaciones muestreadas.

Neste trabalho, investigamos Zn(O;OH)S como substituto para ao CdS, que é convencionalmente usado como camada tamponante em células solares usando calcopirita. Filmes finos de Zn(O;OH)S foram depositados em banho químico de deposição (CDB), método que utiliza um banho químico contendo tiouréia, acetato de zinco, citrato de sódio e amônio. Filmes finos de CuGaSe2 (CGS) e vidro soda-cal foram utilizados como substratos. A equação de Avrami foi utilizada para estudar a taxa de crescimento de uma fina película de Zn(O;OH)S sobre ambos os substratos. A influência do tipo de subtrato, do tempo de síntese sobre a taxa de crescimento, as propriedades ópticas e morfológicas dos filmes finos crescidos como Zn(O;OH)S foram avaliadas com espectrofotometria e técnicas de microscopia de força atômica (AFM). Condições adequadas foram encontradas para síntese de filmes finos de Zn(O;OH)S para serem usadas como camadas tampão em celulas solares de CGS.

In this work, we investigated thin films of Zn(O;OH)S as substitute of thin films of CdS, which are conventionally used as buffer layer in chalcopyrite based solar cells. Thin films of Zn(O;OH)S were deposited by chemical bath deposition (CBD) method using a chemical bath containing thiourea, zinc acetate, sodium citrate and ammonium. Soda-lime glass and soda-lime glass covered with thin films of CuGaSe2 (CGS) were used as substrates in the deposition of thin films of Zn(O;OH)S. The Avrami equation was used to study the growth rate of thin film of Zn(O,OH)S on both substrates. The influence of the substrate kind and time of synthesis on the growth rate, optical and morphological properties of the as-grown thin films of Zn(O,OH)S have been carried out through spectrophotometry and atomic force microscopy (AFM) techniques. Finally, we found suitable conditions for synthesis of thin films Zn(O,OH)S to be used as buffer layer in CGS based solar cells.

From uvby -β photometry of the open clusters NGC 6811 (75 stars), and NGC 6830 (19 stars) we were able to determine membership of the stars to each cluster, and fix the age and reddening for each. Since several short period stars have recently been found, we have carried out a study of these variables.

A partir de la fotometría fotoeléctrica uvby - β de los cúmulos abiertos NGC 6811 (75 estrellas) y NGC 6830 (19 estrellas) realizamos la determinación de distancias y, por ende, la pertenencia de las estrellas a cada cúmulo. Asimismo, se determinaron la edad y el enrojecimiento de cada uno. Dado que recientemente se han determinado estrellas variables para el primero, realizamos un estudio de dichas variables.