Aerodynamic design optimization of wind turbine airfoils under aleatory and epistemic uncertainty

This paper presents different approaches to optimize wind turbine airfoils in an uncertain scenario. The approaches are specifically applied to the aerodynamic design optimization of a wind turbine airfoil accounting for the uncertainty in setting up the XFOIL's NCRIT constant: a parameter that is considered affected by a chain of aleatory and epistemic uncertainty. Subject to a set of aerodynamic and structural constraints, the uncertain response of the airfoil is optimized by means of both probability- and imprecise probability-based approaches. These solutions are compared with a reference airfoil optimized with a conventional design approach, in which the treatment of uncertainty is carried out in a simplistic fashion. Once evaluated in the probabilistic scenario, the airfoil designed with the conventional approach still achieves the largest aerodynamic efficiency mean. This airfoil is however affected by the largest performance sensitivity to NCRIT variations. The airfoils optimized by means of uncertainty-based approaches instead achieve larger performance robustness and reliability than the airfoil optimized with the conventional approach

Monitoring alkylphenols in water using the polar organic chemical integrative sampler (POCIS): determining sampling rates via the extraction of PES membranes and Oasis beads

Polar organic chemical integrative samplers (POCIS) have previously been used to monitor alkylphenol (AP) contamination in water and produced water. However, only the sorbent receiving phase of the POCIS (Oasis beads) is traditionally analyzed, thus limiting the use of POCIS for monitoring a range of APs with varying hydrophobicity. Here a “pharmaceutical” POCIS was calibrated in the laboratory using a static renewal setup for APs (from 2-ethylphenol to 4-n-nonylphenol) with varying hydrophobicity (log Kow between 2.47 and 5.76). The POCIS sampler was calibrated over its 28 day integrative regime and sampling rates (Rs) were determined. Uptake was shown to be a function of AP hydrophobicity where compounds with log Kow < 4 were preferentially accumulated in Oasis beads, and compounds with log Kow > 5 were preferentially accumulated in the PES membranes. A lag phase (over a 24 h period) before uptake in to the PES membranes occurred was evident. This work demonstrates that the analysis of both POCIS phases is vital in order to correctly determine environmentally relevant concentrations owing to the fact that for APs with log Kow ≤ 4 uptake, to the PES membranes and the Oasis beads, involves different processes compared to APs with log Kow ≥ 4. The extraction of both the POCIS matrices is thus recommended in order to assess the concentration of hydrophobic APs (log Kow ≥ 4), as well as hydrophilic APs, most effectively. © 2017 Elsevier Lt

Intrahepatic persistent fetal right umbilical vein: a retrospective study

Introduction: To appraise the incidence and value of intrahepatic persistent right umbilical vein (PRUV). Methods: This was a single-center study. Records of all women with a prenatal diagnosis of intrahepatic PRUV were reviewed. The inclusion criteria were women with gestational age greater than 13 weeks of gestation. Exclusion criteria were fetuses with situs abnormalities, due to the hepatic venous ambiguity, and extrahepatic PRUV. The primary outcome was the incidence of intrahepatic PRUV in our cohort. The secondary outcomes were associated malformations. Results: 219/57,079 cases (0.38%) of intrahepatic PRUV were recorded. The mean gestational age at diagnosis was 21.8 ± 2.9 weeks of gestations. PRUV was isolated in the 76.7%, while in 23.3% was associated with other major or minor abnormalities. The most common associated abnormalities were cardiovascular abnormalities (8.7%), followed by genitourinary abnormalities (6.4%), skeletal abnormalities (4.6%), and central nervous system abnormalities (4.1%). Within the cardiovascular abnormalities, the most common one was ventricular septal defect (six cases). Conclusion: In most cases PRUV is an isolated finding. Associated minor or major malformations are presented in the 23.3% of the cases, so this finding should prompt detailed prenatal assessment of the fetus, with particular regard to cardiovascular system

Biostratigraphy of the upper Bajocian-middle Callovian (Middle Jurassic), South America

The biostratigraphic division of the upper Bajocian-middle Callovian of South America is based on ammonites from different sections of the following provinces and regions: Neuquén, Mendoza, and San Juan in Argentina; Malleco, Linares, Talca, Atacama, Antofagasta, and Tarapacá in Chile. The complete upper Bajocian-middle Callovian succession includes the following biostratigraphic units: the Megasphaeroceras magnum assemblage zone, lowermost upper Bajocian; the Cadomites-Tulitidae mixed assemblage, (?lower) middle and upper Bathonian; the Steinmanni zone, index Lilloettia steinmanni (Spath), uppermost Bathonian, with two local horizons — Stehnocephalites gerthi horizon (Argentina) and Choffatia jupiter horizon (northern Chile); the Vergarensis zone, index Eur y cep halites vergarensis (Burck.), near the Bathonian-Callovian boundary; the Bodenbenderi zone, index Neuquenicerás (Frickites) bodenbenderi (Tornq.), lower Callovian; the Proximum zone, index Hecticoceras proximum Elmi, uppermost lower Callovian; and the Rehmannia (Loczyceras) patagoniensis horizon, middle Callovian.La división bioestratigráfica del Bajociano superior-Caloviano inferior de América del Sur esté basada en la fauna de amonites proveniente de diferentes secciones de las provincias/regiones de Neuquén, Mendoza, San Juan (Argentina), Malleco, Linares, Talca, Atacama, Antofagasta, y Tarapacá (Chile). La sucesión del Bajociano superior-Caloviano medio incluye las siguientes unidades bioestratigráfícas: zona de asociación de Megasphaeroceras magnum, Bajociano superior bajo; asociación de mezcla de Cadomites- Tulitidae, Bathoniano (?inferior) medio y superior; zona de Steinmanni, fósil guía Lilloettia steinmanni (Spath), Bathoniano superior alto, con dos horizontes locales — horizonte con Stehnocephalites gerthi (Argentina) y horizonte con Choffatia jupiter (norte de Chile); zona de Vergarensis, fósil guía Eurycephalites vergarensis (Burck.), aproximadamente límite Bathoniano-Caloviano; zona de Bodenbenderi, fósil guía Neuquenicerás (Frickites) bodenbenderi (Tornq.), Caloviano inferior; zona de Proximum, fósil guía Hecticoceras proximum Elmi, Caloviano inferior alto; horizonte con Rehmannia (Loczyceras) patagoniensis, Caloviano medio.Facultad de Ciencias Naturales y Muse

Biostratigraphy of the upper Bajocian-middle Callovian (Middle Jurassic), South America

The biostratigraphic division of the upper Bajocian-middle Callovian of South America is based on ammonites from different sections of the following provinces and regions: Neuquén, Mendoza, and San Juan in Argentina; Malleco, Linares, Talca, Atacama, Antofagasta, and Tarapacá in Chile. The complete upper Bajocian-middle Callovian succession includes the following biostratigraphic units: the Megasphaeroceras magnum assemblage zone, lowermost upper Bajocian; the Cadomites-Tulitidae mixed assemblage, (?lower) middle and upper Bathonian; the Steinmanni zone, index Lilloettia steinmanni (Spath), uppermost Bathonian, with two local horizons — Stehnocephalites gerthi horizon (Argentina) and Choffatia jupiter horizon (northern Chile); the Vergarensis zone, index Eur y cep halites vergarensis (Burck.), near the Bathonian-Callovian boundary; the Bodenbenderi zone, index Neuquenicerás (Frickites) bodenbenderi (Tornq.), lower Callovian; the Proximum zone, index Hecticoceras proximum Elmi, uppermost lower Callovian; and the Rehmannia (Loczyceras) patagoniensis horizon, middle Callovian.La división bioestratigráfica del Bajociano superior-Caloviano inferior de América del Sur esté basada en la fauna de amonites proveniente de diferentes secciones de las provincias/regiones de Neuquén, Mendoza, San Juan (Argentina), Malleco, Linares, Talca, Atacama, Antofagasta, y Tarapacá (Chile). La sucesión del Bajociano superior-Caloviano medio incluye las siguientes unidades bioestratigráfícas: zona de asociación de Megasphaeroceras magnum, Bajociano superior bajo; asociación de mezcla de Cadomites- Tulitidae, Bathoniano (?inferior) medio y superior; zona de Steinmanni, fósil guía Lilloettia steinmanni (Spath), Bathoniano superior alto, con dos horizontes locales — horizonte con Stehnocephalites gerthi (Argentina) y horizonte con Choffatia jupiter (norte de Chile); zona de Vergarensis, fósil guía Eurycephalites vergarensis (Burck.), aproximadamente límite Bathoniano-Caloviano; zona de Bodenbenderi, fósil guía Neuquenicerás (Frickites) bodenbenderi (Tornq.), Caloviano inferior; zona de Proximum, fósil guía Hecticoceras proximum Elmi, Caloviano inferior alto; horizonte con Rehmannia (Loczyceras) patagoniensis, Caloviano medio.Facultad de Ciencias Naturales y Muse