37 resultados para SURFACTANT FILMS
Resumo:
Pd1-xInx thin films (0.4 < x < 0.56) were prepared by radio frequency sputtering from a multi-zone target. The properties of these Hume-Rothery alloys were studied by X-ray diffractometry, electron probe microanalysis and scanning tunneling microscopy. The diffraction spectra were analyzed to obtain the intensity ratio of the (100) superlattice line to the (200) normal line, together with the variations of the lattice constant. The results ape explained quantitatively by a model based on point defects, i.e. Pd vacancies in In-rich films and Pd antisite atoms in Pd-rich films. In-rich films grow preferentially in the [100] direction while Pd-rich films grow preferentially in the [110] direction. The grains in indium-rich sputtered films appear to be enclosed in an atomically thick, indium-rich layer. The role of texture and the influence of point defects on electrical resistivity is also reported. (C) 1996 Elsevier Science Limited.
Resumo:
Peut-on se réclamer du « cinéma » tout en prétendant rendre compte d'une « vérité »? Quelles sont les limites éthiques du dévoilement d'un individu face à une caméra ? Un cinéaste peut-il être pleinement « auteur » d'une oeuvre construite à partir de fragments de réel? Voilà quelques-unes des questions posées au début des années soixante par la sortie des films qui se revendiquent ou sont associés au « cinéma-vérité ». Proposée en 1960 par Edgar Morin, cette notion controversée sert durant quelques années de bannière à un mouvement cinématographique supposé renouveler les rapports entre film et réalité par une approche plus directe, un dispositif d'interactions avec les protagonistes, ou une démarche autoréflexive qui interroge en son sein le projet du film. Chronique d'un été de Jean Rouch et Edgar Morin, Les Inconnus de la terre et Regard sur la folie de Mario Ruspoli, les travaux de Richard Leacock pour la Drew Associates, Le Chemin de la mauvaise route de Jean Herman, Hitler, connais pas de Bertrand Blier, La Punition de Jean Rouch ou encore Le Joli Mai de Pierre Lhomme et Chris Marker : tous ces « films-vérité » renouvellent les débats et construisent de nouveaux clivages dans la cinéphilie française. Sans chercher à se positionner sur le contenu des polémiques, le présent ouvrage retrace pour la première fois l'histoire du mouvement « cinéma-vérité » en s'intéressant aux films (contexte de production, tournages, innovations techniques) et aux discours (articles, débats, tables rondes) qui les ont précédés, accompagnés et traversés. Grâce à de nombreuses sources inédites, Cinéma-vérité, films et controverses met au jour un phénomène d'une importance méconnue dans l'histoire du cinéma en France.
Resumo:
Endotoxin causes an inflammation at the bronchial and alveolar level. The inflammation-induced increase in permeability of the bronchoalveolar epithelial barrier is supposed to cause a leakage of pneumoproteins. Therefore, their concentrations are expected to increase in the bloodstream.This study aimed at examining the association between occupational exposure to endotoxin and a serum pneumoprotein, surfactant protein A, to look for nonoccupational factors capable of confounding this association, and examine the relation between surfactant protein A and spirometry. There were 369 control subjects, 325 wastewater workers, and 84 garbage collectors in the study. Exposure to endotoxin was assessed through personal sampling and the Limulus amebocytes lysate assay. Surfactant protein A was determined by an in house sandwich enzyme-linked immunosorbent assay (ELISA) in 697 subjects. Clinical and smoking history were ascertained and spirometry carried out according to American Thoracic Society criteria. Multiple linear regression was used for statistical analysis. Exposure was fairly high during some tasks in wastewater workers but did not influence surfactant protein A. Surfactant protein A was lower in asthmatics. Interindividual variability was large. No correlation with spirometry was found. Endotoxin has no effect on surfactant protein A at these endotoxin levels and serum surfactant protein A does not correlate with spirometry. The decreased surfactant protein A secretion in asthmatics requires further study.
Resumo:
MoS(x) lubricating thin films were deposited by nonreactive, reactive, and low energy ion-assisted radio-frequency (rf) magnetron sputtering from a MoS2 target. Depending on the total and reactive gas pressures, the film composition ranges between MoS0.7 and MoS2.8. A low working pressure was found to have effects similar to those of low-energy ion irradiation. Films deposited at high pressure have (002) planes preferentially perpendicular to the substrate, whereas films deposited at low pressure or under low-energy ion irradiation have (002) mainly parallel to it. Parallel films are sulfur deficient (MoS1.2-1.4). Their growth is explained in terms of an increased reactivity of the basal surfaces, itself a consequence of the creation of surface defects due to ion irradiation. The films exhibit a lubricating character for all compositions above MoS1.2. The longest lifetime in ball-on-disk wear test was found for MoS1.5.
Resumo:
The present study discusses the effect of iron doping in TiO2 thin films deposited by rf sputtering. Iron doping induces a structural transformation from anatase to rutile and electrical measurements indicate that iron acts as an acceptor impurity. Thermoelectric power measurement shows a transition between n-type and p-type electrical conduction for an iron concentration around 0.13 at.%. The highest p-type conductivity at room temperature achieved by iron doping was 10(-6) S m(-1).
Film Propaganda and the Balance between Neutrality and Alignment: Nazi Films in Switzerland, 1933-45
Resumo:
Two common lung-related complications in the neonate are respiratory distress syndrome, which is associated with a failure to generate low surface tension at the air-liquid interface because of pulmonary surfactant insufficiency, and bronchopulmonary dysplasia (BPD), a chronic lung injury with reduced alveolarization. Surfactant phosphatidylcholine (PC) molecular species composition during alveolarization has not been examined. Mass spectrometry analysis of bronchoalveolar lavage fluid of rodents and humans revealed significant changes in surfactant PC during alveolar development and BPD. In rats, total PC content rose during alveolarization, which was caused by an increase in palmitoylmyristoyl-PC (16:0/14:0PC) concentration. Furthermore, two animal models of BPD exhibited a specific reduction in 16:0/14:0PC content. In humans, 16:0/14:0PC content was specifically decreased in patients with BPD and emphysema compared with patients without alveolar pathology. Palmitoylmyristoyl-PC content increased with increasing intrinsic surfactant curvature, suggesting that it affects surfactant function in the septating lung. The changes in acyl composition of PC were attributed to type II cells producing an altered surfactant during alveolar development. These data are compatible with extracellular surfactant 16:0/14:0PC content being an indicator of alveolar architecture of the lung.