Experimental and Numerical Studies on a Centrifugal Pump with 2D-Curved Blades in Cavitating Condition

In the presented study a special test-pump with 2D curvature blade geometry in cavitating and non-cavitating conditions was investigated using different experimental techniques and a 3D numerical model of cavitating flows. Experimental and numerical results concerning pump characteristics and performance breakdown were compared at different flow conditions. Appearing types of cavitation and the spatial distribution of vapour structures within the runner were also analysed

The brezis-ekeland-nayroles minimization principle with mixed finite element method for elastoplastic dynamic problems

We propose a modification of the Hamiltonian formalism which can be used for dissipative systems, the Brezis-Ekeland-Nayroles principle. The formalism is specialized to the standard plasticity in small strains and dynamics. We apply it to solve the classical problem of a thin tube in plane strain subjected to an internal pressure. The continuum is discretized with mixed finite elements

Challenges of modeling current very large lahars at Nevado del Huila Volcano, Colombia

Nevado del Huila, a glacier-covered volcano in the South of Colombia's Cordillera Central, had not experienced any historical eruptions before 2007. In 2007 and 2008, the volcano erupted with phreatic and phreatomagmatic events which produced lahars with flow volumes of up to about 300 million m3 causing severe damage to infrastructure and loss of lives. The magnitude of these lahars and the prevailing potential for similar or even larger events, poses significant hazards to local people and makes appropriate modeling a real challenge. In this study, we analyze the recent lahars to better understand the main processes and then model possible scenarios for future events. We used lahar inundation depths, travel duration, and flow deposits to constrain the dimensions of the 2007 event and applied LAHARZ and FLO-2D for lahar modeling. Measured hydrographs, geophone seismic sensor data and calculated peak discharges served as input data for the reconstruction of flow hydrographs and for calibration of the models. For model validation, results were compared with field data collected along the Páez and Simbola Rivers. Based on the results of the 2007 lahar simulation, we modeled lahar scenarios with volumes between 300 million and 1 billion m3. The approach presented here represents a feasible solution for modeling high-magnitude flows like lahars and allows an assessment of potential future events and related consequences for population centers downstream of Nevado del Huil

Hydrogeology, geology & engineering aspects of surficial materials on the Lake Michigan shore in Illinois

Other titles: Geologic, Hydrogeologic, and engineering aspects of surficial materials on the Lake Michigan shore in IllinoisOpe

Lombalgie chronique, COTOREP et reclassement professionnel en Moselle

Objectifs : Décrire les caractéristiques, la prise en charge, les résultats et le coût d\u27un reclassement professionnel concernant les assurés mosellans lombalgiques chroniques bénéficiant d’un accord de la Commission technique d\u27orientation et de reclassement professionnel (COTOREP). Méthodes : Etude descriptive menée entre août 2000 et mars 2001 dans le cadre d\u27un partenariat avec la COTOREP de Moselle intégrant 48 lombalgiques chroniques pour lesquels la COTOREP a donné en 1995 un accord de pré-orientation ou de reclassement professionnels. Résultats : Le lombalgique pris en charge était un homme jeune, de faible niveau scolaire et professionnel, en rupture avec le milieu du travail et souffrant d\u27une pathologie lombaire invalidante. Sur 32 formations suivies, 24 candidats ont réussi leur examen mais seuls dix diplômés ont trouvé un emploi. Huit diplômés ont trouvé un emploi conforme à la formation apprise. Le taux de reprise du travail était semblable pour les diplômés (10/24) et pour les autres lombalgiques (11/24). Le coût global pour l\u27assurance maladie variait de 25 000 en externat à 39 000 en internat. Conclusion : Devant la faible valeur ajoutée du reclassement professionnel que nous avons constatée, il paraît souhaitable de maintenir le lombalgique chronique dans son emploi en restaurant son rachis, en aménageant son poste de travail et, surtout, en gérant ses peurs et croyances liées au couple lombalgietravail

Spherical similarity explorer for comparative case analysis

Comparative Case Analysis (CCA) is an important tool for criminal investigation and crime theory extraction. It analyzes the commonalities and differences between a collection of crime reports in order to understand crime patterns and identify abnormal cases. A big challenge of CCA is the data processing and exploration. Traditional manual approach can no longer cope with the increasing volume and complexity of the data. In this paper we introduce a novel visual analytics system, Spherical Similarity Explorer (SSE) that automates the data processing process and provides interactive visualizations to support the data exploration. We illustrate the use of the system with uses cases that involve real world application data and evaluate the system with criminal intelligence analysts

The impact of epilepsy surgery on sex hormones and the menstrual cycle in female patients

AbstractWe investigated the impact of temporal lobe epilepsy surgery on sex hormones and menstrual cycles. Sixteen female patients with temporal lobe epilepsy were investigated prior to surgery and 3, 6, and 12 months after surgery. The patients received carbamazepine (CBZ) as monotherapy (10 patients ) or in combination with other antiepileptic drugs (six patients ). Antiepileptic drugs were maintained after surgery. During the 1-year follow-up after surgery eight patients (50%) remained completely free of seizures. In another four patients (25%) only rare disabling seizures occurred. There were no significant differences between pre-surgical and post-surgical serum concentrations of testosterone, free testosterone, prolactin, dehydroepiandrosterone sulfate, growth hormone, cortisol and sex hormone binding globulin. There was, however, a significant increase in serum androstenedione concentration 6 months post-surgically (P< 0.02). Documentation of menstrual cycles in addition to laboratory parameters revealed individual post-surgical changes of the menstrual cycle in eight patients . Four patients had a change in menstrual periodicity: two patients with complete seizure control had regular cycles instead of oligomenorrhoea and two patients with incomplete seizure control had oligomenorrhoea instead of regular cycles. These data indicate that at least in some patients with temporal lobe epilepsy surgical treatment influences menstrual periodicity

Psychological structure and neuroendocrine patterns of daily stress appraisals

Threat and challenge are two fundamental appraisal concepts of psychological stress theories, determined by the mismatch between demands and resources. Previous research has predominantly investigated the neuroendocrine correlates of stress appraisal in laboratory contexts during acute demanding situations. We tested whether the psychoneuroendocrinology of stress appraisals can also be investigated in naturalistic trans-contextual everyday life settings. Forty-two participants produced five daily saliva samples and provided concurrent questionnaire data on subjective stress, demands, resources, and the threat-challenge continuum over the course of five days (69% female; mean age = 22.8, range = 18-30 years). Momentary salivary cortisol and alpha amylase were predicted with three-level autoregressive linear mixed models. We found that both momentary cortisol and alpha amylase were elevated during higher subjective stress. In contrast, cortisol was not significantly related to a bipolar threat-challenge indicator. Moreover within-person response surface analyses showed no effect of the mismatch between demands and resources on either physiological stress indicator, but confirmed theoretically proposed effects on subjective threat-challenge, which was replicated in another intensive longitudinal (N = 61) and a large cross-sectional sample (N = 1194). In sum, our study (a) suggests robust relations between subjective stress and HPA/SAM axis activity on a moment-to-moment basis and (b) confirms theoretical predictions concerning stress appraisal and the mismatch between demands and resources on a psychological level. In contrast, no neuroendocrine patterns of threat-challenge were found, suggesting that neuroendocrine patterns might be context-specific and do not apply to a general demand-resource imbalance in everyday life. (DIPF/Orig.