Enhancement of the adsorption of hexacyanoferrate (III) ion on granular activated carbon by the addition of cations: a promissory application to mining wastewater treatment

The influence of the addition of cations on the adsorption of [Fe(CN)6] 3− on granular activated carbon (GAC) was evaluated. The tests were performed at three pH values (3, 8.2, and 13) to determine the repulsion or electrostatic affinity between the adsorbent and adsorbate. Afterward, the cations (K+, Ca2+, and Al3+) at three pollutant-cation molar ratios (1:1, 1:10, and 1:50) were added to the system, and the influence of those was identified by the changes in the adsorption efficiency. The results show that the higher removal (%) was obtained at pH 13 without neither the presence of iron precipitates nor the liberation of HCN. The adsorption of [Fe(CN)6] 3- was enhanced by the addition of K + at 1:10 and 1:50 mol ratio since higher removals were achieved (75.27 % and 76.81 % respectively) than those obtained in the absence of cations (64.18 %) or in the presence of Ca2+ (67.58 %) and Al3+ (65.13 %) at a 1:10 mol ratio. The behavior in adsorption in the presence of cations shows that the ion-pair adsorption mechanism can describe the physical phenomenon, showing an increase in the fraction removed and the rate of adsorption with increasing cation charge. The adsorption kinetics using K+ with a 1:10 pollutant-cation molar ratio was fitted to the Lagergren pseudo-first-order model. The GAC adsorption capacity describes the pollutant adsorption rate with the predominance of physical interactions. The experimental data were fitted by the Langmuir and Freundlich isotherms, indicating a monolayer adsorption phenomenon consistent with the previously proposed ion-pair adsorption mechanism

Rheological analysis to predict and improve the hydraulic behavior in well drilling

The prediction of the well pressure loss and the standpipe pressure (real value of the system pressure loss) are values that differ in the well drilling operation. The methodology that was elaborated in this study has the goal todecrease that difference using a comparative analysis of rheological models finding the best model to describe the hydraulic behavior and with this, achieve the optimization of simulated value. The methodology was implemented in each section of the well ANH-PATÍA-1-ST-P, and the results could be applied in projects of the same area.  La predicción de las pérdidas de presión en un pozo y la presión del Stand pipe (valor real de las pérdidas de presión del sistema) son valores que difieren en la perforación de un pozo. La metodología elaborada en este estudio busca disminuir dicha diferencia por medio de un análisis comparativo de los modelos reológicos existentes con el fin de encontrar el modelo que mejor se ajusta al comportamiento hidráulico del pozo y con esto optimizar el valor encontrado en la simulación. Dicha metodología fue aplicada al pozo ANH-PATÍA-1-ST-P, en cada una de las secciones del pozo y sus resultados podrán ser utilizados en proyectos del área. &nbsp

Gemini near infrared field spectrograph observations of the Seyfert 2 galaxy Mrk 573 : in situ acceleration of ionized and molecular gas off fueling

We present near-infrared and optical emission-line and stellar kinematics of the Seyfert 2 galaxy Mrk 573 using the Near-Infrared Field Spectrograph (NIFS) at Gemini North and Dual Imaging Spectrograph at Apache Point Observatory, respectively. By obtaining full kinematic maps of the infrared ionized and molecular gas and stellar kinematics in a ∼700×2100pc2 circumnuclear region of Mrk573, we find that kinematics within the Narrow- Line Region are largely due to a combination of both rotation and in situ acceleration of material originating in the host disk. Combining these observations with large-scale, optical long-slit spectroscopy that traces ionized gas emission out to several kpcs, we find that rotation kinematics dominate the majority of the gas. We find that outflowing gas extends to distances less than 1 kpc, suggesting that outflows in Seyfert galaxies may not be powerful enough to evacuate their entire bulges

Diseño acueducto y alcantarillado asentamiento urbano Francisco primero en el municipio de San José de Cúcuta, Norte de Santander

El proyecto de investigación tiene como finalidad diseñar las redes del sistema de acueducto y alcantarillado para el sector francisco primero en la ciudad de san José de Cúcuta. Para ello, se elabora un trabajo dirigido que consiste en el desarrollo por parte del estudiante y bajo la dirección de un profesional en el área de conocimiento a la que es inherente el trabajo. La población corresponde a los habitantes de la ciudad de San José de Cúcuta. Se toma como muestra los usuarios del sistema de distribución y recolección de agua del asentamiento francisco primero de la ciudad de san José de Cúcuta. En los resultados se realiza el estudio de topografía. Seguidamente, se cuantifica la población a ser beneficiada por las redes de acueducto y alcantarillado. Igualmente, se diseña la red de distribución de agua potable. Se diseña el sistema de alcantarillado sanitario. Finalmente, se presupuesta el costo de obra civil.PregradoIngeniero(a) Civi

Feasibility Study For The Improvement Of The Urban Road Network Of The Municipality Of Convención, Colombia

El propósito de la investigación fue evaluar dos alternativas para la construcción de la malla vial de la carrera 10 entre calles 5 y 6 del municipio de Convención, Norte de Santander. Se tomó como objeto de estudio la comparación de pavimento flexible y rígido, con el fin de establecer la mejorar alternativa para la construcción de la vía. En los resultados se determinó la demanda de transito de la malla vial urbana y se realizó el análisis técnico de las alternativas de pavimentación de tipo rígido y flexible según los estándares internacionales y las especificaciones de INVIAS. Por último, se evaluaron financieramente las dos alternativas de pavimentación, haciendo un análisis de costo beneficio, tomando como base el APU (análisis precios unitarios) y el costo total de cada proyecto, el estudio de tránsito y el mejoramiento de la calidad de vida de la población beneficiaria. Se concluyó que la alternativa de pavimento flexible es la más factible, teniendo en cuenta criterios financieros, capacidad de servicio y demanda de transito de la comunidad.The purpose of the research was to evaluate two alternatives for the construction of the road network of Carrera 10 between streets 5 and 6 in the municipality of Convención, Norte de Santander. The object of study was the comparison of flexible and rigid pavement, in order to establish the best alternative for the construction of the road. In the results, the traffic demand of the urban road network was determined and the technical analysis of the rigid and flexible paving alternatives was performed according to international standards and INVIAS specifications. Finally, the two paving alternatives were evaluated financially, making a cost-benefit analysis, based on the APU (unit price analysis) and the total cost of each project, the traffic study and the improvement of the quality of life of the beneficiary population. It was concluded that the flexible pavement alternative is the most feasible, taking into account financial criteria, service capacity and community traffic demand

Análisis reológico para predecir y mejorar el comportamiento hidráulico durante la perforación de un pozo

The prediction of the well pressure loss and the standpipe pressure (real value of the system pressure loss) are values that differ in the well drilling operation. The methodology that was elaborated in this study has the goal todecrease that difference using a comparative analysis of rheological models finding the best model to describe the hydraulic behavior and with this, achieve the optimization of simulated value. The methodology was implemented in each section of the well ANH-PATÍA-1-ST-P, and the results could be applied in projects of the same area.La predicción de las pérdidas de presión en un pozo y la presión del Stand pipe (valor real de las pérdidas de presión del sistema) son valores que difieren en la perforación de un pozo. La metodología elaborada en este estudio busca disminuir dicha diferencia por medio de un análisis comparativo de los modelos reológicos existentes con el fin de encontrar el modelo que mejor se ajusta al comportamiento hidráulico del pozo y con esto optimizar el valor encontrado en la simulación. Dicha metodología fue aplicada al pozo ANH-PATÍA-1-ST-P, en cada una de las secciones del pozo y sus resultados podrán ser utilizados en proyectos del área

Early results after synchronous carotid stent placement and coronary artery bypass graft in patients with asymptomatic carotid stenosis

Background: The optimal management of patients with combined carotid and coronary artery disease requiring cardiac surgery is still unknown. Staged carotid endarterectomy and carotid artery stenting (CAS), each followed by coronary artery bypass graft (CABG), are options frequently employed. However, for patients with severe carotid artery disease in urgent need of open cardiac revascularization, staged operations may not be the most appropriate alternative. The aim of this study was to describe our experience using a synchronous CAS-CABG method with minimal interprocedural time. We used this synchronous combination of procedures in patients with combined carotid and coronary artery disease admitted for urgent CABG. Methods: Patients with concomitant severe carotid and coronary artery disease scheduled for synchronous CAS and urgent CABG between December 2006 and January 2010 were included in the study. All procedures were performed at a single center: the Cardiovascular Foundation of Colombia, in Floridablanca, Santander, Colombia. The study cohort was characterized according to demographic and clinical characteristics, which included degree of carotid stenosis, presence/absence of preoperative neurological symptoms, and cardiac operative risk profile. All patients underwent CAS under embolic protection devices and then CABG within the next 2 hours. Patients received aspirin pre- and postprocedure but were started on clopidogrel only after CABG. The primary end point of the study was the composite incidence rate of myocardial infarction, stroke, and death 30 days after CAS-CABG. Results: Fifteen patients with concomitant severe carotid and coronary artery disease underwent synchronous CAS-CABG. Most patients (60%) were men, and mean (+/- standard deviation) age was 65.2 (+/- 8.4) years. Most patients (93%) were neurologically asymptomatic. The median (interquartile range) ejection fraction and logistic European System for Cardiac Operative Risk Evaluation (EuroSCORE) for the cohort were 55% (36%-62%) and 9.7% (4.6%-14.8%), respectively. There were no deaths, major strokes, minor strokes, or myocardial infarctions during the procedure or within 30 days of CAS-CABG. One patient experienced neurological symptoms likely as a result of transient ischemic attack ipsilateral to the CAS procedure. None of the patients required cardiac or carotid reinterventdons, and there were no cases of postoperative bleeding requiring reoperation. Conclusions: Synchronous CAS-CABG, when CABG is performed within the 2 hours of the CAS procedure, may be a viable alternative to the more generally accepted staged combination, particularly among patients for whom CABG cannot be postponed. We hope that this strategy will be further evaluated in larger prospective studies and adequately powered randomized clinical trials. (J Vasc Surg 2013;57:58S-63S.

Digital Strategy For Uban Arts

D I S F R U T A se propone como una aplicación para web y dispositivos móviles que permita la convergencia entre el público y la programación de los escenarios de las Salas Concertadas de Bogotá. Una aplicación desde la cual se podrá acceder a experiencias artísticas completas: servicios de movilidad, rutas seguras, sugerencia de bares, restaurantes y tarifas especiales. Una aplicación que, además, generará una base de datos de actualización permanente, donde existan espacios para la opinión y crítica, con el fin de segmentar a los usuarios y las obras usando datos sobre sus preferencias en tendencias, gustos de consumo, intereses y posibilidades de acceso a las salas, tipos de espectáculos, formatos, tarifas, agendas y oferta de servicios complementarios.DISFRUTA is proposed as an application for web and mobile devices that allow convergence between the audience and scheduling of Salas concertadas of Bogota. An application from which you can access complete artistic experiences : mobility services , safe routes , suggestions of bars , restaurants and special rates . An application that also generate a database of continuous updating , where there are spaces for opinion and criticism , in order to segment users and works using data on their preferences trends, tastes consumer interests and possibilities access to Theater, types of shows , formats , fares, schedules and offer complementary services