THREE-DIMENSIONAL ANALYSIS OF TURBINE ROTOR FLOW INCLUDING TIP CLEARANCE

A 3D Navier-Stokes investigation of a high pressure turbine rotor blade including tip clearance effects is presented. The 3D Navier-Stokes code developed at ONERA solves the three-dimensional unsteady set of mass-averaged Navier-Stokes equations by the finite volume technique. A one step Lax-Wendroff type scheme is used in a rotating frame of reference. An implicit residual smoothing technique has been implemented, which accelerates the convergence towards the steady state. A mixing length model adapted to 3D configurations is used. The turbine rotor flow is calculated at transonic operating conditions. The tip clearance effect is taken into account. The gap region is discretized using more than 55,000 points within a multi-domain approach. The solution accounts for the relative motion of the blade and casing surfaces. The total mesh is composed of five sub-domains and counts 710,000 discretization points

Recommendations for active correction of hypernatremia in volume-resuscitated shock or sepsis patients should be taken with a grain of salt: A systematic review

Background: Healthcare-acquired hypernatremia (serum sodium >145 mEq/dL) is common among critically ill and other hospitalized patients and is usually treated with hypotonic fluid and/or diuretics to correct a “free water deficit.� However, many hypernatremic patients are eu- or hypervolemic, and an evolving body of literature emphasizes the importance of rapidly returning critically ill patients to a neutral fluid balance after resuscitation. Objective: We searched for any randomized- or observational-controlled studies evaluating the impact of active interventions intended to correct hypernatremia to eunatremia on any outcome in volume-resuscitated patients with shock and/or sepsis. Data sources: We performed a systematic literature search with studies identified by searching MEDLINE, Embase, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, ClinicalTrials.gov, IndexCatalogue of the Library of the Surgeon General’s Office, DARE (Database of Reviews of Effects), and CINAHL and scanning reference lists of relevant articles with abstracts published in English. Data synthesis: We found no randomized- or observational-controlled trials measuring the impact of active correction of hypernatremia on any outcome in resuscitated patients. Conclusion: Recommendations for active correction of hypernatremia in resuscitated patients with sepsis or shock are unsupported by clinical research acceptable by modern evidence standards.ECU Open Access Publishing Support Fun

Familial hypercholesterolaemia in children and adolescents from 48 countries: a cross-sectional study

Background Approximately 450 000 children are born with familial hypercholesterolaemia worldwide every year, yet only 2·1% of adults with familial hypercholesterolaemia were diagnosed before age 18 years via current diagnostic approaches, which are derived from observations in adults. We aimed to characterise children and adolescents with heterozygous familial hypercholesterolaemia (HeFH) and understand current approaches to the identification and management of familial hypercholesterolaemia to inform future public health strategies. Methods For this cross-sectional study, we assessed children and adolescents younger than 18 years with a clinical or genetic diagnosis of HeFH at the time of entry into the Familial Hypercholesterolaemia Studies Collaboration (FHSC) registry between Oct 1, 2015, and Jan 31, 2021. Data in the registry were collected from 55 regional or national registries in 48 countries. Diagnoses relying on self-reported history of familial hypercholesterolaemia and suspected secondary hypercholesterolaemia were excluded from the registry; people with untreated LDL cholesterol (LDL-C) of at least 13·0 mmol/L were excluded from this study. Data were assessed overall and by WHO region, World Bank country income status, age, diagnostic criteria, and index-case status. The main outcome of this study was to assess current identification and management of children and adolescents with familial hypercholesterolaemia. Findings Of 63 093 individuals in the FHSC registry, 11 848 (18·8%) were children or adolescents younger than 18 years with HeFH and were included in this study; 5756 (50·2%) of 11 476 included individuals were female and 5720 (49·8%) were male. Sex data were missing for 372 (3·1%) of 11 848 individuals. Median age at registry entry was 9·6 years (IQR 5·8–13·2). 10 099 (89·9%) of 11 235 included individuals had a final genetically confirmed diagnosis of familial hypercholesterolaemia and 1136 (10·1%) had a clinical diagnosis. Genetically confirmed diagnosis data or clinical diagnosis data were missing for 613 (5·2%) of 11 848 individuals. Genetic diagnosis was more common in children and adolescents from high-income countries (9427 [92·4%] of 10 202) than in children and adolescents from non-high-income countries (199 [48·0%] of 415). 3414 (31·6%) of 10 804 children or adolescents were index cases. Familial-hypercholesterolaemia-related physical signs, cardiovascular risk factors, and cardiovascular disease were uncommon, but were more common in non-high-income countries. 7557 (72·4%) of 10 428 included children or adolescents were not taking lipid-lowering medication (LLM) and had a median LDL-C of 5·00 mmol/L (IQR 4·05–6·08). Compared with genetic diagnosis, the use of unadapted clinical criteria intended for use in adults and reliant on more extreme phenotypes could result in 50–75% of children and adolescents with familial hypercholesterolaemia not being identified. Interpretation Clinical characteristics observed in adults with familial hypercholesterolaemia are uncommon in children and adolescents with familial hypercholesterolaemia, hence detection in this age group relies on measurement of LDL-C and genetic confirmation. Where genetic testing is unavailable, increased availability and use of LDL-C measurements in the first few years of life could help reduce the current gap between prevalence and detection, enabling increased use of combination LLM to reach recommended LDL-C targets early in life. Funding Pfizer, Amgen, Merck Sharp & Dohme, Sanofi–Aventis, Daiichi Sankyo, and Regeneron

COMPARISON FOR STEADY AND UNSTEADY SIMULATIONS FOR HIGH PRESSURE TURBINE

For the new generation of advanced aero-engines, the turbine design is a key issue to most of the critical engine related factors, such as fuel consumption, component life, weight, duration and cost of the development program. For many years, an important effort has been devoted at Snecma Moteurs to the development, the validation and the industrialization of methods for the prediction of aerothermal phenomena in multi-stage turbines. The purpose of this contribution is to report on the recent advances of Snecma Moteurs CFD tools for aerodynamic turbine design and analysis. Three approaches, based on 3D Navier-Stokes calculations, each of them corresponding to a different level of complexity, are presented for the prediction of the aerodynamic behavior of high pressure turbines, showing the degree of accuracy and maturity that the turbine aerothermal methods of Snecma Moteurs, have now reached. Firstly, two types of steady stage simulation are considered. The first one uses the mixing plane method in order to transfer the flow information between adjacent blade rows, while the second one uses the average passage method proposed by Adamczy

Metabolic Acidosis during Treatment of Mushroom Poisoning: A Diagnostic Pitfall

Metabolic acidosis is a frequently encountered acid-base disturbance in hospitalized patients that occasionally develops in the course of treatment with medications used in everyday clinical practice, including propylene glycol-containing drugs (lorazepam, diazepam, etomidate, pentobarbital). Disruption of enterohepatic circulation with activated charcoal is a common practice for several intoxications, including mushroom poisoning. Herein, we present a patient who was hospitalized due to mushroom intoxication and developed severe metabolic acidosis as a treatment side effect rather than from the mushroom poisoning..o the best of our knowledge, this is the first report on propylene glycol-containing activated charcoal-induced metabolic acidosis

Unsteady Euler and Navier-Stokes flow simulations with an implicit Runge-Kutta method

Communication to : 2th European conference - ECOMAS 94, Stuttgart (Germany), September 5-8, 1994Available at INIST (FR), Document Supply Service, under shelf-number : 22419, issue : a.1994 n.119 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueSIGLEFRFranc

3-D turbomachinery Euler and Navier-Stokes calculations with a multidomain cell-centered approach

Communication to : AIAA/SAE/ASME/ASEE 29th Joint Propulsion Conference and Exhibit, Monterey, CA (USA), June 28-30, 1993Available at INIST (FR), Document Supply Service, under shelf-number : 22419, issue : a.1993 n.106 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueSIGLEFRFranc

Transonic and supersonic flow calculations around aircraft using a multidomain Euler code

Extrait de : 13th International Conference on Numerical Methods in Fluid Dynamics, Rome (Italy), July 6-10, 1992SIGLEAvailable at INIST (FR), Document Supply Service, under shelf-number : 22419, issue : a.1992 n.137 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc