998 resultados para charge air
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What do we know about the effectiveness of various treatments of alcoholism? This review of literature shows that lack--or weaknesses--of published studies make it impossible to draw definite conclusions. Rigorous controlled studies show high rates of spontaneous remission and important uncertainties about specialised treatments of alcoholism. However, except for severe dependence that may well require a different approach, brief interventions conducted by non-specialists have proved highly effective for at-risk alcohol drinkers: based on minimal medical advice, they increase the chances of lowering alcohol consumption. General practitioners may thus represent on important link in the therapeutic chain.
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During the first hours after release of petroleum at sea, crude oil hydrocarbons partition rapidly into air and water. However, limited information is available about very early evaporation and dissolution processes. We report on the composition of the oil slick during the first day after a permitted, unrestrained 4.3 m(3) oil release conducted on the North Sea. Rapid mass transfers of volatile and soluble hydrocarbons were observed, with >50% of ≤C17 hydrocarbons disappearing within 25 h from this oil slick of <10 km(2) area and <10 μm thickness. For oil sheen, >50% losses of ≤C16 hydrocarbons were observed after 1 h. We developed a mass transfer model to describe the evolution of oil slick chemical composition and water column hydrocarbon concentrations. The model was parametrized based on environmental conditions and hydrocarbon partitioning properties estimated from comprehensive two-dimensional gas chromatography (GC×GC) retention data. The model correctly predicted the observed fractionation of petroleum hydrocarbons in the oil slick resulting from evaporation and dissolution. This is the first report on the broad-spectrum compositional changes in oil during the first day of a spill at the sea surface. Expected outcomes under other environmental conditions are discussed, as well as comparisons to other models.
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This paper estimates a model of airline competition for the Spanish air transport market. I test the explanatory power of alternative oligopoly models with capacity constraints. In addition, I analyse the degree of density economies. Results show that Spanish airlines conduct follows a price-leadership scheme so that it is less competitive than the Cournot solution. I also find evidence that thin routes can be considered as natural monopolies
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RJ 2.2.5 is a human B cell line that has lost the capacity to express MHC class II genes. The human class II-positive phenotype is restored in somatic cell hybrids between RJ 2.2.5 and mouse spleen cells. By karyotype and molecular studies of an informative family of hybrids we have now shown that the reexpression of human class II gene products, as well as the maintenance of the mouse class II-positive phenotype, correlates with the presence of mouse chromosome 16. Thus, the existence on this mouse chromosome of a newly found locus, designated by us aIr-1, that determines a trans-acting activator function for class II gene expression, is established. Possible implications of this finding are discussed.
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The role of the bridging ligand on the effective Heisenberg coupling parameters is analyzed in detail. This analysis strongly suggests that the ligand-to-metal charge transfer excitations are responsible for a large part of the final value of the magnetic coupling constant. This permits us to suggest a variant of the difference dedicated configuration interaction (DDCI) method, presently one of the most accurate and reliable for the evaluation of magnetic effective interactions. This method treats the bridging ligand orbitals mediating the interaction at the same level than the magnetic orbitals and preserves the high quality of the DDCI results while being much less computationally demanding. The numerical accuracy of the new approach is illustrated on various systems with one or two magnetic electrons per magnetic center. The fact that accurate results can be obtained using a rather reduced configuration interaction space opens the possibility to study more complex systems with many magnetic centers and/or many electrons per center.
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The character of the electronic ground state of La0.5Ca0.5MnO3 has been addressed with quantum chemical calculations on large embedded clusters. We find a charge ordered state for the crystal structure reported by Radaelli et al. [Phys. Rev. B 55, 3015 (1997)] and Zener polaron formation in the crystal structure with equivalent Mn sites proposed by Daoud-Aladine et al. [Phys. Rev. Lett. 89, 097205 (2002)]. Important O to Mn charge transfer effects are observed for the Zener polaron.
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A cleft can be labial, labial-maxillary, unilateral or bilateral labial-maxillary-palatal, or isolated palatal. A multidisciplinary team includes several specialists who will handle the diverse problems of children born with a cleft. This team will follow the child through each developmental stage and assemble an optimal treatment plan, thus reducing the onus on the family. Depending on the type of cleft and the age of the child, feeding, speech, ORL, dental, orthodontic, esthetic and possibly also psychological problems will be taken care of. This is why cleft treatment starts at the time it is diagnosed, before or after birth, and ends when the child is fully grown. It requires a complete interdisciplinary team and the collaboration with obstetricians and geneticians.
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En 36 chapitres, concis et efficaces, cet ouvrage propose des repères pour la prise en charge des patients adultes en médecine générale et en médecine interne ambulatoire. Les thèmes ont été choisis en fonction des besoins exprimés par les médecins en formation. Chaque chapitre propose une stratégie diagnostique et thérapeutique dans une perspective d'usage rationnel des ressources du système de santé, en tenant compte des données les plus récentes de la médecine basée sur les preuves. Ce livre confirme que la pratique de la médecine reste un subtil assemblage des connaissances scientifiques, de l'expertise clinique et des valeurs du patient.
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Underfeeding causes a significant increase of postoperative complications, particularly respiratory and infectious complications. Thoracic surgery is frequently required in patients suffering wasting diseases (cancer, COPD, cystic fibrosis), which increase the risk of malnutrition. The most important risk factors are preoperative hypoalbuminemia and BMI < 20. The deleterious effects of underfeeding may be corrected by a preoperative nutritional support for 7 to 15 days using oral supplements or enteral feeding: respiratory muscle strength is improved, immunity is restored, and overall complications are reduced. Therefore preoperative diagnosis of underfeeding is of utmost importance. In case of emergency surgery, the nutritional assessment on admission enables the introduction of early postoperative artificial feeding.
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Concrete will suffer frost damage when saturated and subjected to freezing temperatures. Frost-durable concrete can be produced if a specialized surfactant, also known as an air-entraining admixture (AEA), is added during mixing to stabilize microscopic air voids. Small and well-dispersed air voids are critical to produce frost-resistant concrete. Work completed by Klieger in 1952 found the minimum volume of air required to consistently ensure frost durability in a concrete mixture subjected to rapid freezing and thawing cycles. He suggested that frost durability was provided if 18 percent air was created in the paste. This is the basis of current practice despite the tests being conducted on materials that are no longer available using tests that are different from those in use today. Based on the data presented, it was found that a minimum air content of 3.5 percent in the concrete and 11.0 percent in the paste should yield concrete durable in the ASTM C 666 with modern AEAs and low or no lignosulfonate water reducers (WRs). Limited data suggests that mixtures with a higher dosage of lignosulfonate will need about 1 percent more air in the concrete or 3 percent more air in the paste for the materials and procedures used. A spacing factor of 0.008 in. was still found to be necessary to provide frost durability for the mixtures investigated.
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Giant cell arteritis (GCA) is a subacute/chronic vasculitis and represents the most common form of systemic vasculitis in people over the age of 50 years. The absence of clear and specific diagnostic criteria with the highly variable clinical presentation is a diagnostic challenge requesting a multidisciplinary approach. Yet, GCA is an emergency and the treatment must be initiated very rapidly due to the risk of blindness. This article presents a review of GCA as well as the diagnostic and therapeutic institutional guidelines of the University Hospital of Lausanne.