Numerical study of hydrodynamic characteristics of gas liquid slug flow in vertical pipes

Multiphase flows occur in wide applications including; nuclear, chemical, and petroleum industries. One of the most important flow regime encountered in multiphase flow is the slug flow which is often encountered in oil and gas production systems. The slugging problems may cause flooding of downstream processing facilities, severe pipe corrosion and the structural instability of pipeline and further induce the reservoir flow oscillations, and a poor reservoir management. In the present study, computational fluid dynamics simulation is used to investigate two phase slug flow in vertical pipe using the volume of fluid (VOF) methodology implemented in the commercial code ANSYS Fluent. Theviscous, inertial, and interfacial forces have the significant effect on the hydrodynamic characteristics of two-phase slug flow. These forces can have investigated by introducing a set of dimensionless numbers, namely; inverse viscosity number, Nf, Eotvos number, Eo, and Froude number, FrTB. The simulation accounts for the hydrodynamic features of two phase slug flow including; the shape of Taylor bubble, bubble profile, velocity and thickness of the falling film, wake flow pattern, and wall shear stress distribution. The CFD simulation results are in good agreement with previous experimental data and models available in literature

Análisis de las Negociaciones de Mercado de Carbono en la Bolsa de Valores en Ecuador

El presente ensayo  apunta, en primera instancia, a describir el funcionamiento y razón de ser del mercado de carbono, realizando un análisis de las implicaciones del Protocolo de Kioto mediante sus   tres mecanismos, cuyo objetivo principal es ofrecer medios para recortar los Gases de Efecto Invernadero, responsables del Cambio Climático; estos mecanismos son: Mecanismo para un Desarrollo Limpio (MDL), Mecanismo de Implementación Conjunta (IC) y el Comercio de Derechos de Emisión. A continuación, se realiza una descripción simplificada de cada uno de ellos, con el fin de conocer sus alcances, limitaciones y aplicabilidad en el Ecuador.   Finalmente, se analizará la Bolsa de Valores de Quito, su importancia, caracterí­sticas, quienes participan y su función económica.Con los elementos analizados anteriormente, se realizará entonces un análisis del Mercado de Carbono en la Bolsa de Valores de Ecuador así­   como la creación de un mercado de valores que promueva la Responsabilidad Social Empresarial (RSE), describiendo claramente lo que es el mercado de valores social y ambientalmente responsable, la estrategia de la Bolsa de Valores en el marco de la RSE, así­ como la promoción del Mercado de Carbono en Ecuador con todas y cada una de las estrategias a seguir.En otras palabras, la idea central de este ensayo  es analizar la   posibilidad de aprovechamiento de compraventa de certificados de carbono por medio de la Bolsa de Valores, motivando a las empresas del Ecuador para que participen en los procesos de negociación en los mercado de carbono y así­ generar una seguridad jurí­dica, lo que nos permite tener una visión más amplia de un emprendiendo en el   desarrollo social y económico del paí­s y al   mismo tiempo apostar a tecnologí­as limpias lo que conlleva a una gradual transición hacia una economí­a pos petrolera

Inspiratory muscle warm-up does not improve cycling time-trial performance

Purpose: This study examined the effects of an active cycling warm-up, with and without the addition of an inspiratory muscle warm-up (IMW), on 10-km cycling time-trial performance

Estudio de la relación curricular entre el bachillerato y el 1er año de la carrera de Administración Pública de la Universidad Central del Ecuador.

El presente estudio busca establecer estratégicamente la relación existente entre la currí­cula del bachillerato y su articulación con los componentes de la Carrera de Administración Pública de la Universidad Central, en lo que al primer año se refiere; Para lo cual se determina las inexactitudes en las diferentes áreas del conocimiento a fin de proporcionar las competencias necesarias para que el bachiller tenga la sapiencia y habilidades requeridas para cumplir con las exigencias que el primer año de universidad lo requiere.Los cambios realizados en las polí­ticas educativas del paí­s hacen ineludible estudiar las necesidades de la Licenciatura en Administración Pública de la Facultad de Ciencias Administrativas de la Universidad Central del Ecuador, respecto a la relación curricular entre el bachillerato y el primer año de Universidad. Para este efecto se determinaron    las inexactitudes en las diferentes áreas del conocimiento a fin de proporcionar las competencias necesarias para que el bachiller tenga la sapiencia y habilidades requeridas para cumplir con las exigencias que el primer año de bachillerato las requiere.Se aplicó el método de investigación   deductivo, y  se realizó  un   enfoque cuantitativo y cualitativo que permitió efectuar un estudio exploratorio analizar la importancia de una formación académica en el ámbito de la Administración Pública, con pensamiento crí­tico y argumentativo.

Combined In Silico, In Vivo, and In Vitro Studies Shed Insights into the Acute Inflammatory Response in Middle-Aged Mice

We combined in silico, in vivo, and in vitro studies to gain insights into age-dependent changes in acute inflammation in response to bacterial endotoxin (LPS). Time-course cytokine, chemokine, and NO2-/NO3- data from "middle-aged" (6-8 months old) C57BL/6 mice were used to re-parameterize a mechanistic mathematical model of acute inflammation originally calibrated for "young" (2-3 months old) mice. These studies suggested that macrophages from middle-aged mice are more susceptible to cell death, as well as producing higher levels of pro-inflammatory cytokines, vs. macrophages from young mice. In support of the in silico-derived hypotheses, resident peritoneal cells from endotoxemic middle-aged mice exhibited reduced viability and produced elevated levels of TNF-α, IL-6, IL-10, and KC/CXCL1 as compared to cells from young mice. Our studies demonstrate the utility of a combined in silico, in vivo, and in vitro approach to the study of acute inflammation in shock states, and suggest hypotheses with regard to the changes in the cytokine milieu that accompany aging. © 2013 Namas et al

FCGR polymorphisms in the treatment of rheumatoid arthritis with Fc-containing TNF inhibitors

[EN] Objectives: Reproducible association of a functional polymorphism in FCGR2A with response to a TNF inhibitor (TNFi) in patients with rheumatoid arthritis (RA) led us to explore other Fc?R functional polymorphisms. Methods: Functional polymorphisms FCGR3A F158V, FCGR2B I223T and promoter VNTR in FCGRT were analyzed in up to 429 patients with RA. Response to TNFi was recorded during standard care at 3, 6 and 12 months of follow-up. Fixed effects meta-analysis of studies addressing FCGR3A F158V polymorphism, which is the most studied of these polymorphisms, was conducted with inverse variance weighting. Results: None of the functional polymorphisms were associated with change in DAS28. Meta-analysis of the seven studies (899 patients) with available data addressing association of FCGR3A F158V with response to TNFi in RA showed no association (OR: 1.11, 95% CI: 0.8-1.5; p = 0.5). Conclusion: None of the three functional polymorphisms in Fc?R genes showed association with response to TNFi in patients with RA. These negative results were obtained in spite of the larger size of this study relative to previous studies addressing the same polymorphisms. In addition, meta-analysis of FCGR3A F158V was also negative against the results provided by previous studies

Low-frequency cortical activity is a neuromodulatory target that tracks recovery after stroke.

Recent work has highlighted the importance of transient low-frequency oscillatory (LFO; <4 Hz) activity in the healthy primary motor cortex during skilled upper-limb tasks. These brief bouts of oscillatory activity may establish the timing or sequencing of motor actions. Here, we show that LFOs track motor recovery post-stroke and can be a physiological target for neuromodulation. In rodents, we found that reach-related LFOs, as measured in both the local field potential and the related spiking activity, were diminished after stroke and that spontaneous recovery was closely correlated with their restoration in the perilesional cortex. Sensorimotor LFOs were also diminished in a human subject with chronic disability after stroke in contrast to two non-stroke subjects who demonstrated robust LFOs. Therapeutic delivery of electrical stimulation time-locked to the expected onset of LFOs was found to significantly improve skilled reaching in stroke animals. Together, our results suggest that restoration or modulation of cortical oscillatory dynamics is important for the recovery of upper-limb function and that they may serve as a novel target for clinical neuromodulation

Gender-differences of in vitro colonic motility after chemo- and radiotherapy in humans.

Background: The aim of the present in vitro study was to investigate, in different genders, motor responses in surgical colonic specimens from patients with rectal cancer undergoing and not undergoing chemotherapy with capecitabine and radiotherapy. Methods: This in vitro study was conducted from October 2015 to August 2017 at the Experimental Pharmacology Laboratory at the National Institute “S. de Bellis” after collecting samples at the Department of Surgery. Segments of sigmoid colon were obtained from 15 patients (Male (M)/Female (F) = 8/7; control group, CG) operated on for elective colorectal resection for rectal cancer without obstruction and 14 patients (M/F = 7/7; study group, SG) operated on for elective colorectal resection for rectal cancer who also received chemotherapy, based on capecitabine twice daily, and radiotherapy. Isometric tension was measured on colonic circular muscle strips exposed to increasing carbachol or histamine concentrations to obtain concentration-response curves. The motor responses to electrically evoked stimulation were also investigated. Results: In males, carbachol and histamine caused concentration-dependent contractions in the CG and SG. An increased sensitivity and a higher response to carbachol and histamine were observed in SG than CG (P < 0.01). On the contrary, in females, the response to carbachol was not significantly different in CG from the SG and the maximal responses to carbachol were greater in CG than in SG (P < 0.001). The same applied to histamine for half-maximal effective concentrations and maximal response in that they were not significantly different in CG from the SG. Electrically evoked contractions were significantly more pronounced in males, especially in the SG (P < 0.05). Conclusions: This preliminary in vitro study has shown gender differences in motor responses of colonic circular muscle strips in patients who had received chemotherapy with capecitabine and radiotherapy

An Intelligent Decision Support System for the Detection of Meat Spoilage using Multispectral Images

In food industry, quality and safety are considered important issues worldwide that are directly related to health and social progress. The use of vision technology for quality testing of food production has the obvious advantage of being able to continuously monitor a production using non-destructive methods, thus increasing the quality and minimizing cost. The performance of an intelligent decision support system has been evaluated in monitoring the spoilage of minced beef stored either aerobically or under modified atmosphere packaging, at different storage temperatures (0, 5, 10, and 15 °C) utilising multispectral imaging information. This paper utilises a neuro-fuzzy model which incorporates a clustering pre-processing stage for the definition of fuzzy rules, while its final fuzzy rule base is determined by competitive learning. Initially, meat samples are classified according to their storage conditions, while identification models are then utilised for the prediction of the Total Viable Counts of bacteria. The innovation of the proposed approach is further extended to the identification of the temperature used for storage, utilizing only imaging spectral information. Results indicated that spectral information in combination with the proposed modelling scheme could be considered as an alternative methodology for the accurate evaluation of meat spoilage