A novel approach for modeling bubbling gas–solid fluidized beds

A phenomenological discrete bubble model is proposed to help in the design and dynamic diagnosis of bubbling fluidized beds. An activation region mechanism is presented for bubble formation, making it possible to model large beds in a timely manner. The bubbles are modeled as spherical-cap discrete elements that rise through the emulsion phase that is considered as a continuum. The model accounts for the simultaneous interaction of neighboring bubbles by including the trailing effects due to the wake acceleration force. The coalescence process is not irreversible and therefore, the coalescing bubble pair is free to interact with other rising bubbles originating the splitting phenomena. To validate the model, the simulated dynamics are compared with both experimental and literature data. Time, frequency, and state space analysis are complementarily used with a multiresolution approach based on the empirical method of decomposition to explore the different dynamic scales appearing in both the simulated time series and those obtained from experimental runs. It is concluded that the bubble dynamics interactions play the main role as the driver of the resulting bed dynamics, matching the main features of measured bubble dynamics. Exploding bubble phenomena have been identified by establishing a direct relation between the bubble generation, interaction and eruption, and the measured signalsProjects DPI2009-10518 (MICINN) and CARDENER-CM (S2009ENE-1660)Publicad

Sistema difuso de alerta de sueño al volante utilizando algoritmo de Viola Jones

El uso de sistemas de monitoreo que notifican el nivel de atención del conductor se constituye en una herramienta importante en la prevención de accidentes relacionados al estado de vigilia. El presente trabajo integra el enfoque de visión por computador, la Raspberry Pi, los componentes electrónicos necesarios, en conjunto con la inteligencia artificial y el reconocimiento de patrones, para implementar una solución no intrusiva para detección del nivel de somnolencia y distracciones del conductor, además de brindar una alternativa accesible para instalar el sistema en cualquier tipo de vehículo. Se presenta un prototipo sencillo para detección de somnolencia y distracciones, en el cual el método de Viola-Jones es utilizado para el reconocimiento de rostros y un clasificador tipo cascada que utiliza una base de datos de imágenes para su entrenamiento. Se cuenta la cantidad de detección de ojos, tanto abiertos como cerrados, y los cambios en la boca, para el conteo de bostezos en una secuencia continua de imágenes para luego utilizar los datos captados y medir el nivel de somnolencia del conductor por medio de Lógica Difusa dando una salida de alerta en caso de que el nivel de somnolencia lo amerite. Además, este método permite detectar distracciones, utilizando como parámetros rostro y ojos. Resultados de pruebas demuestran que el sistema mide con eficiencia parámetros mencionados y detecta estado de somnolencia como también distracciones por medio del método de Viola-Jones.Fil: Mendieta Zárate, Hugo Enrique. Universidad Nacional del Este (Paraguay)Fil: Fornerón Acosta, Juan Pablo. Universidad Nacional del Este (Paraguay)Fil: Almeida Delgado, Carlos Domingo. Universidad Nacional del Este (Paraguay

Dense-phase velocity fluctuation in a 2-D fluidized bed

This work presents an investigation of the perturbations induced by the bubbles in a 2-D fluidized bed. A combination of Digital Image Analysis (DIA) and Particle Image Velocimetry (PIV) techniques was developed to characterize the dense and bubble phases. The analysis of the mean and the instantaneous fluctuations of the velocity of the dense phase, together with the solid movement around bubbles, allowed for themeasurement of the influence region, distinguishing an upwardmoving dense phase in the nose and thewake of the bubble (drift) and a downward moving dense phase in the sides of the bubble. For an isolated bubble, we measured the drift area within the total influence region and related the size of these regions to the equivalent diameter of the bubble. This work also presents results on the volumetric dissipation of kinetic energy, wherewe concluded that the energy dissipation in the dense phase is proportional to the square of the bubble velocityPublicad

Circulating microRNAs in sera correlate with soluble biomarkers of immune activation but do not predict mortality in ART treated individuals with HIV-1 infection: A case control study

Introduction: The use of anti-retroviral therapy (ART) has dramatically reduced HIV-1 associated morbidity and mortality. However, HIV-1 infected individuals have increased rates of morbidity and mortality compared to the non-HIV-1 infected population and this appears to be related to end-organ diseases collectively referred to as Serious Non-AIDS Events (SNAEs). Circulating miRNAs are reported as promising biomarkers for a number of human disease conditions including those that constitute SNAEs. Our study sought to investigate the potential of selected miRNAs in predicting mortality in HIV-1 infected ART treated individuals. Materials and Methods: A set of miRNAs was chosen based on published associations with human disease conditions that constitute SNAEs. This case: control study compared 126 cases (individuals who died whilst on therapy), and 247 matched controls (individuals who remained alive). Cases and controls were ART treated participants of two pivotal HIV-1 trials. The relative abundance of each miRNA in serum was measured, by RTqPCR. Associations with mortality (all-cause, cardiovascular and malignancy) were assessed by logistic regression analysis. Correlations between miRNAs and CD4+ T cell count, hs-CRP, IL-6 and D-dimer were also assessed. Results: None of the selected miRNAs was associated with all-cause, cardiovascular or malignancy mortality. The levels of three miRNAs (miRs -21, -122 and -200a) correlated with IL-6 while miR-21 also correlated with D-dimer. Additionally, the abundance of miRs -31, -150 and -223, correlated with baseline CD4+ T cell count while the same three miRNAs plus miR- 145 correlated with nadir CD4+ T cell count. Discussion: No associations with mortality were found with any circulating miRNA studied. These results cast doubt onto the effectiveness of circulating miRNA as early predictors of mortality or the major underlying diseases that contribute to mortality in participants treated for HIV-1 infection

100 años investigando el mar. El IEO en su centenario (1914-2014).

Se trata de un libro que pretende divulgar a la sociedad las principales investigaciones multidisciplinares llevadas a cabo por el Instituto Español de Oceanografía durante su primer siglo de vida, y dar a conocer la historia del organismo, de su Sede Central y de los nueve centros oceanográficos repartidos por los litorales mediterráneo y atlántico, en la península y archipiélagos.Kongsberg 20

Development and Validation of a Risk Score for Chronic Kidney Disease in HIV Infection Using Prospective Cohort Data from the D:A:D Study

Ristola M. on työryhmien DAD Study Grp ; Royal Free Hosp Clin Cohort ; INSIGHT Study Grp ; SMART Study Grp ; ESPRIT Study Grp jäsen.Background Chronic kidney disease (CKD) is a major health issue for HIV-positive individuals, associated with increased morbidity and mortality. Development and implementation of a risk score model for CKD would allow comparison of the risks and benefits of adding potentially nephrotoxic antiretrovirals to a treatment regimen and would identify those at greatest risk of CKD. The aims of this study were to develop a simple, externally validated, and widely applicable long-term risk score model for CKD in HIV-positive individuals that can guide decision making in clinical practice. Methods and Findings A total of 17,954 HIV-positive individuals from the Data Collection on Adverse Events of Anti-HIV Drugs (D:A:D) study with >= 3 estimated glomerular filtration rate (eGFR) values after 1 January 2004 were included. Baseline was defined as the first eGFR > 60 ml/min/1.73 m2 after 1 January 2004; individuals with exposure to tenofovir, atazanavir, atazanavir/ritonavir, lopinavir/ritonavir, other boosted protease inhibitors before baseline were excluded. CKD was defined as confirmed (>3 mo apart) eGFR In the D:A:D study, 641 individuals developed CKD during 103,185 person-years of follow-up (PYFU; incidence 6.2/1,000 PYFU, 95% CI 5.7-6.7; median follow-up 6.1 y, range 0.3-9.1 y). Older age, intravenous drug use, hepatitis C coinfection, lower baseline eGFR, female gender, lower CD4 count nadir, hypertension, diabetes, and cardiovascular disease (CVD) predicted CKD. The adjusted incidence rate ratios of these nine categorical variables were scaled and summed to create the risk score. The median risk score at baseline was -2 (interquartile range -4 to 2). There was a 1: 393 chance of developing CKD in the next 5 y in the low risk group (risk score = 5, 505 events), respectively. Number needed to harm (NNTH) at 5 y when starting unboosted atazanavir or lopinavir/ritonavir among those with a low risk score was 1,702 (95% CI 1,166-3,367); NNTH was 202 (95% CI 159-278) and 21 (95% CI 19-23), respectively, for those with a medium and high risk score. NNTH was 739 (95% CI 506-1462), 88 (95% CI 69-121), and 9 (95% CI 8-10) for those with a low, medium, and high risk score, respectively, starting tenofovir, atazanavir/ritonavir, or another boosted protease inhibitor. The Royal Free Hospital Clinic Cohort included 2,548 individuals, of whom 94 individuals developed CKD (3.7%) during 18,376 PYFU (median follow-up 7.4 y, range 0.3-12.7 y). Of 2,013 individuals included from the SMART/ESPRIT control arms, 32 individuals developed CKD (1.6%) during 8,452 PYFU (median follow-up 4.1 y, range 0.6-8.1 y). External validation showed that the risk score predicted well in these cohorts. Limitations of this study included limited data on race and no information on proteinuria. Conclusions Both traditional and HIV-related risk factors were predictive of CKD. These factors were used to develop a risk score for CKD in HIV infection, externally validated, that has direct clinical relevance for patients and clinicians to weigh the benefits of certain antiretrovirals against the risk of CKD and to identify those at greatest risk of CKD.Peer reviewe

Description of a Cohort of Type 1 Diabetes Patients: Analysis of Comorbidities, Prevalence of Complications and Risk of Hypoglycemia

Background: Despite major medical advances, Type 1 Diabetes (T1D) patients still have greater morbimortality than the general population. Our aim was to describe our cohort of T1D patients and identify potential risk factors susceptible to prevention strategies. Methods: Cross-sectional, observational study, including T1D patients treated at our center, from 1 March 2017 to 31 March 2020. Inclusion criteria: T1D, age > 14 years and signed informed consent. Exclusion criteria: diabetes other than T1D, age < 14 years and/or refusal to participate. Results: Study population n = 2181 (49.8% females, median age at enrollment 41 years, median HbA1c 7.7%; 38.24% had at least one comorbidity). Roughly 7.45% had severe hypoglycemia (SH) within the prior year. Macro/microvascular complications were present in 42.09% (5.83% and 41.14%, respectively). The most frequent microvascular complication was diabetic retinopathy (38.02%), and coronary disease (3.21%) was the most frequent macrovascular complication. The risk of complications was higher in males than in females, mainly macrovascular. Patients with SH had a higher risk of complications (OR 1.42; 1.43 in males versus 1.42 in females). Conclusions: Our T1D population is similar to other T1D populations. We should minimize the risk of SH, and male patients should perhaps be treated more aggressively regarding cardiovascular risk factors