Evaluación de daños ambientales por minería a cielo abierto en un lecho fluvial en Colombia, usando imágenes multiespectrales

Maestría en Tecnologías de la Información Geográfica, Facultad de ciencias e ingeniería.El presente trabajo tiene el objetivo de proponer una metodología e implementarla para la determinación del daño ambiental causado por la minería a cielo abierto, empleando imágenes ópticas satelitales y aéreas. Este análisis incluye la cuantificación del daño ambiental y las transformaciones de las superficies por la explotación de las fuentes hídricas, así como el establecimiento de actividades antropogénicas en las zonas, usando imágenes con resolución submétrica. El análisis de las imágenes ópticas de gran y pequeña escala incluyó procesos de corrección de errores geométricos, topográficos y geográficos. Con el fin de detectar zonas afectadas por excavaciones y posible contaminación del agua. Así mismo, se efectuó la asignación de clases por superficies terrestres observadas, la identificación de perfiles espectrales de cada clase y la clasificación de la imagen empleando algoritmos de decisión para la agrupación de pixeles, por las características morfológicas del objeto captado y su nivel digital. Los resultados incluyeron la cuantificación del daño ambiental generado en superficies mineras a cielo abierto en zonas de difícil acceso, tomando como estudio de caso el lecho fluvial del Rio Nechí, ubicado en los municipios de Nechí, El Bagre y Caucasia del departamento de Antioquia. Las conclusiones de este trabajo proporcionarán a las entidades control del país una herramienta para la toma de decisiones a diferentes niveles para la recuperación y conservación del ecosistema

Gestión de recursos humanos y prevención de fenómenos sísmicos en las insituciones educativas integradas de Pamplona Alta del distrito de San Juan de Miraflores, 2013

El presente trabajo de investigación tuvo como problema general: ¿Cuál es la relación que existe entre la gestión de Recursos Humanos y la prevención de Fenómenos Sísmicos en las instituciones educativas integradas de Pamplona Alta del distrito de San Juan de Miraflores 2013? y el objetivo general fue determinar la relación entre la gestión de recursos humanos y la prevención de fenómenos sísmicos en las instituciones educativas integradas de Pamplona Alta del distrito de San Juan De Miraflores, 2013 El tipo de investigación fue básica de naturaleza descriptiva- correlacional, el diseño fue no experimental de corte transversal – correlacional. La muestra estuvo conformada por 90 docentes de las instituciones educativas integradas. Se aplicó la técnica de la encuesta con cuestionario tipo escala de Likert para ambas variables. En la investigación se ha encontrado que existe una alta correlación de r=0.899 entre la gestión de recursos humanos y la prevención de fenómenos sísmicos de las instituciones educativas integradas de Pamplona Alta en el distrito de San Juan de Miraflores, con un nivel de significancia de a=0,05 y p=0,001. La población está constituida por los docentes de las instituciones educativas Nº 6038-Ollantay, Nº6041 - Alfonso Ugarte y Nº7035 – Leoncio Prado; que en su totalidad representa 270 docentes, de los cuales se ha implementado una muestra de 90 docentes. La sistematización de estos datos se ha realizado a través de una encuesta para responder a la primera variable “gestión de recursos humanos” en relación al desarrollo de sus actividades en sus instituciones educativas, y en la aplicación de la segunda variable sobre “la prevención de fenómenos sísmicos” en relación a su conocimiento y capacitación en acciones de prevención

Optical and electrical characterization of AgInS2 thin films deposited by spray pyrolysis.

Silver indium sulfide (AgInS2) thin films have been prepared by spray pyrolysis (SP) technique using silver acetate, indium acetate, and N, N-dimethylthiourea as precursor compounds. Films were deposited onto glass substrates at different substrate temperatures (Ts) and Ag:In:S ratios in the starting solutions. Optical transmission and reflection as well as electrical measurements were performed in order to study the effect of deposition parameters on the optical and electrical properties of AgInS2 thin films. X-ray diffraction measurements were used to identify the deposited compounds. It was found that different compounds such as AgInS2, Ag2S, In2O3, and In2S3 can be grown only by changing the Ag:In:S ratio in the starting solution and Ts. So that, by carefully selecting the deposition parameters, single phase AgInS2 thin films can be easily grown. Thin films obtained using a molar ratio of Ag:In:S = 1:1:2 and Ts = 400 ◦C, have an optical band gap of 1.9 eV and n-type electrical conductivity with a value of 0.3 −1 cm−1 in the dark

Análise do Parâmetro Numérico N na Transformada Inversa de Laplace Segundo o Algoritmo Talbot-Racional

This article investigates the numerical inversion of the Laplace Transform by the Rational-Talbot method and analyzes the influence on the variation of the free parameter N established by the technique when applied to certain functions. The set of elementary functions, for which the method is tested, has exponential and oscillatory characteristics. Based on the results obtained, it was concluded that the Rational-Talbot method is e cient for the inversion of decreasing exponential functions. At the same time, to perform the inversion process effectively for trigonometric forms, the algorithm requires a greater amount of terms in the sum. For higher values of N, the technique works well. In fact, this is observed in inverting the functions transform, that combine trigonometric and polynomial factors. The method numerical results have a good precision for the treatment of decreasing exponential functions when multiplied by trigonometric functions.Neste artigo investiga-se a inversão numérica da Transformada de Laplace pelo método Talbot-Racional e analisa-se a influência da variação do parâmetro livre N, estabelecido pela técnica, quando aplicado a certas funções. O conjunto de funções elementares, para o qual o método é testado, possui características exponencial e oscilatória. Com base nos resultados obtidos, concluiu-se que o método Talbot-Racional é eficiente para a inversão de funções exponenciais decrescentes. No entanto, para realizar o processo de inversão de forma eficaz para formas trigonométricas, o algoritmo requer uma quantidade maior de termos na soma. Para valores mais elevados de N, a técnica funciona bem. Isso é observado, de fato, na inversão das transformadas de funções que combinam fatores trigonométricos e polinomiais. Os resultados numéricos do método possuem boa precisão para o tratamento de funções exponenciais decrescentes quando multiplicados por funções trigonométricas

AC plasma induced modifications in Sb2S3thin films

Sb2S3 thin films, deposited by the chemical bath deposition method, were treated with N2 plasma at 3.0 Torr during several minutes. The as-prepared Sb2S3 thin films and films treated with N2 plasma have been characterized using several techniques. X-ray diffraction studies have shown that plasma treatment induced recrystallization on the as-prepared Sb2S3 thin films. The band gap values decreased from 2.37 to 1.82 eV after plasma treatment, and the electrical conductivity increased from 10 to 10 ( cm) due to the annealing effect

Propuesta de supply chain management y logística para la empresa marcegaglia carbón steel co.

El siguiente trabajo presenta la aplicación de conceptos en logística y cadena de suministro incorporados en una empresa con el fin de lograr que los productos o servicios lleguen al mercado de manera eficiente y eficaz. Por lo tanto, se implementa las bases teóricas de Supply Chain Management con el fin de proponer estrategias de control a lo largo de la cadena de suministros y procesos logísticos para la empresa Marcegaglia Carbón Steel en Colombia. La configuración de la red de suministro para la empresa permitió analizar los miembros de la red actual a la cual pertenece la empresa, establecer las dimensiones estructurales de la red y tipos de vínculos de los procesos en la empresa. Seguidamente se identificó para Marcegaglia Carbón Steel Colombia los procesos estratégicos según el enfoque de Global Supply Chain Forum, gestión de inventarios, gestión de almacén, gestión de transportes, efecto látigo, aprovisionamiento en la empresa , procesos logísticos de distribución es decir medios de transportes utilizados por la empresa. Finalmente, se obtiene que la aplicación de cada una de las técnicas y/o estrategias propuestas desde Supply Chain Management mejora los procesos corporativos logísticos y de transporte, pronostica demanda, prevé materiales, capital humano y herramientas requeridas para atender los requerimientos de venta en el momento oportuno.The following work presents the application of concepts in logistics and supply chain incorporated in a company in order to ensure that products or services reach the market efficiently and effectively. Therefore, the theoretical bases of Supply Chain Management are implemented in order to propose control strategies throughout the supply chain and logistics processes for the company Marcegaglia Carbon Steel in Colombia. The configuration of the supply network for the company allowed to analyze the members of the current network to which the company belongs, to establish the structural dimensions of the network and the types of links of the processes in the company. Next, strategic processes were identified for Marcegaglia Carbon Steel Colombia according to the Global Supply Chain Forum approach, inventory management, warehouse management, transport management, bullwhip effect, supply in the company, distribution logistics processes, that is, means of transport used. by the company. Finally, it is obtained that the application of each of the techniques and/or strategies proposed from Supply Chain Management improves corporate logistics and transportation processes, forecasts demand, foresees materials, human capital and tools required to meet sales requirements in the market. opportune moment

Histopathologic findings in malignant peripheral nerve sheath tumor predict response to radiotherapy and overall survival

BACKGROUND: Malignant peripheral nerve sheath tumor (MPNST) is an aggressive and poorly understood malignant neoplasm. Even in the setting of multimodal therapy, the clinical course of MPNST is frequently marked by metastatic conversion and poor overall prognosis, with optimal treatment paradigms for this rare tumor unknown. METHODS: We reviewed the medical records and histopathology of 54 consecutive patients who were treated at University of California San Francisco between 1990 and 2018. RESULTS: Our cohort consisted of 24 male and 30 female patients (median age 38 years). Fédération Nationale des Centres de Lutte Contre Le Cancer (FNCLCC) sarcoma grading criteria segregated patients into groups with differences in overall survival (OS) ( CONCLUSIONS: Our results lend support to the FNCLCC sarcoma grading criteria as a prognostic scheme for MPNST, although few cases of grade 1 were included. Further, we identify increased Ki-67 labeling as a strong predictor of poor OS from MPNST. Finally, we identify a subset of MPNSTs with a predictive immunohistochemical profile that has improved local control with adjuvant radiotherapy. These data provide insights into the grading and therapy for patients with MPNST, although further studies are needed for independent validation

CuInS2 thin films obtained through the annealing of chemically deposited In2S3–CuS thin films.

In this work, we report the formation of CuInS2 thin films on glass substrates by heating chemically deposited multilayers of copper sulfide (CuS) and indium sulfide (In2S3) at 300 and 350 ◦C in nitrogen atmosphere at 10 Torr. CIS thin films were prepared by varying the CuS layer thickness in the multilayers with indium sulfide. The XRD analysis showed that the crystallographic structure of the CuInS2 (JCPDS27-0159) is present on the deposited films. From the optical analysis it was estimated the band gap value for the CIS film (1.49 eV). The electrical conductivity varies from 3 × 10−8 to 3 −1 cm−1 depending on the thickness of the CuS film. CIS films showed p-type conductivity

Indium sulfide thin films as window layer in chemically deposited solar cells

Indium sulfide (In2S3) thin films have been synthesized by chemical bath deposition technique onto glass substrates using In(NO3)3 as indium precursor and thioacetamide as sulfur source. X-ray diffraction studies have shown that the crystalline state of the as-prepared and the annealed films is β-In2S3. Optical band gap values between 2.27 and 2.41 eV were obtained for these films. The In2S3 thin films are photosensitive with an electrical conductivity value in the range of 10−3 –10−7 (Ω cm)−1, depending on the film preparation conditions. We have demonstrated that the In2S3 thin films obtained in this work are suitable candidates to be used as window layer in thin film solar cells. These films were integrated in SnO2:F/In2S3/Sb2S3/PbS/C–Ag solar cell structures, which showed an open circuit voltage of 630 mV and a short circuit current density of 0.6 mA/cm2

Chemically deposited In2S3–Ag2S layers to obtain AgInS2 thin films by thermal annealing.

AgInS2 thin films were obtained by the annealing of chemical bath deposited In2S3–Ag2S layers at 400 ◦C in N2 for 1 h. According to the XRD and EDX results the chalcopyrite structure of AgInS2 has been obtained. These films have an optical band gap, Eg, of 1.86 eV and an electrical conductivity value of 1.2 × 10−3 ( cm)−1