Fingermark Detection on Thermal Papers: Proposition of an Updated Processing Sequence

The detection of latent fingermarks on thermal papers proves to be particularly challenging because the application of conventional detection techniques may turn the sample dark grey or black, thus preventing the observation of fingermarks. Various approaches aiming at avoiding or solving this problem have been suggested. However, in view of the many propositions available in the literature, it gets difficult to choose the most advantageous method and to decide which processing sequence should be followed when dealing with a thermal paper. In this study, 19 detection techniques adapted to the processing of thermal papers were assessed individually and then were compared to each other. An updated processing sequence, assessed through a pseudo-operational test, is suggested

Diffuse Reflection Infrared Spectroscopy (Drifts): Application to the in Situ Analysis of Catalysts

Institut français du pétroleThe diffuse reflection infrared Fourier transform spectroscopy (DRIFTS) technique, less practiced than the transmission mode because of its limitations, is extremely useful, indeed indispensable, for non-transparent materials and/or for in situ measurements at elevated temperature. The authors describe the principles of this technique and its advantages over transmission infrared spectroscopy. The application of DRIFTS to the characterization of catalysts is illustrated by two studies conducted on the interaction of molybdenum with the precursor of fuel desulphurization catalysts, and on the in situ modifications under reactive gases of catalysts for reducing nitrogen compounds in exhaust gases

Analyse de risque et fiabilité des barrages - Application aux barrages-poids en béton

Dams are structures inducing a high risk. That is why the recent regulations in France on the safety of hydraulic plans to carry out hazard studies in which risk analysis approaches are required. Furthermore, methods of dependability and reliability have been important developments in recent years. This book proposes to address the issue of implementation of these methods to dam. It presents the context of risks and dam safety. He develops the main methods of Dependability and Reliability adapted in dams. Wealth of methods of risk analysis depends on the adequacy of the representation of input data. Proposals from the research are presented for the probabilistic modelling of hydraulic action and material properties of concrete gravity dams. Industrial applications from reproductive hazards are proposedLes barrages sont des ouvrages induisant de forts risques. C'est pourquoi la récente réglementation en France relative à la sûreté des ouvrages hydrauliques prévoit la réalisation d'études de dangers dans lesquelles les démarches d'analyse de risques sont requises. Par ailleurs, les méthodes de la Sûreté de Fonctionnement et de la Fiabilité ont fait l'objet de développements importants ces dernières années. Ce livre propose de traiter la question de la mise en ½uvre de ces méthodes au domaine des barrages. Il présente le contexte des risques et de la sécurité des barrages. Il développe les principales méthodes de la Sûreté de Fonctionnement et de la Fiabilité adaptées dans le domaine des barrages. La richesse des méthodes d'analyse de risques est conditionnée par la pertinence de la représentation des données d'entrée. Des propositions issues de la recherche sont présentées pour la modélisation probabiliste des actions hydrauliques et des propriétés des matériaux des barrages-poids en béton. Des applications industrielles issues d'études de dangers sont proposées

Effects of dietary 27-hydroxycholesterol on cholesterol metabolism and bile acid biosynthesis in the hamster

27-hydroxycholesterol (27OH-Chol) is an important endogenous oxysterol resulting from the action of sterol 27-hydroxylase (CYP27A1) on cholesterol in the liver and numerous extrahepatic tissues. It may act as a modulator of cholesterol and bile acid metabolism. The effects of 27OH-Chol on the main enzymes and receptors of cholesterol metabolism were investigated by feeding male hamsters a diet supplemented with 27OH-Chol (0.1% w/w) for 1 week. Intestinal scavenger class B, type I (SR-BI) protein level was decreased (-65%), but hepatic expression was increased (+34%). Liver 3β-hydroxy-3β -methyl glutaryl coenzyme A reductase (-58%), cholesterol 7α-hydroxylase (-54%), oxysterol 7α-hydroxylase (-44%), and sterol 12α-hydroxylase (-70%) activities were all decreased. Bile acid composition was changed (fourfold increase in the chenodeoxycholic/cholic acid ratio). This study demonstrates that dietary 27OH-Chol modulates major enzymes of cholesterol metabolism and alters the biliary bile acid profile, making it more hydrophobic, at least at this level of intake. Its effects on SR-BI protein levels are organ dependent. The properties of 27OH-Chol or its metabolites on cholesterol metabolism probably result from the activation of specific transcription factors

Zeolite beta catalysts for n-C7 hydroisomerization

Zeolite β with Si/2Al ratios of 60, 100, and 200 were synthesized using tetraethlammonium hydroxide (TEAOH) as the structure-directing agent (SDA) in the absence of alkali metal cations. Pt, Pd and Pt-Pd catalysts supported on the zeolite β samples were studied in n-heptane (n-C7) hydroisomerization. The Pt/β catalysts showed a higher catalytic activity than the Pd/β catalysts. For the Pt/β with a Si/2Al ratio of 100, its n-C7 conversion and selectivity of C7 isomers were observed to be 87.06% and 75.48% respectively at 250°C. The activity of n-C7 conversion was stable for at least 82 h. However, the selectivity of C7 isomers was gradually decreased with the reaction time. Experimental data also showed that the addition of Pd to catalyst Pt/β enhanced the n-C7 conversion, but lowered the selectivity of C7 isomers. Pd catalyst was also observed to minimize the formation of aromatics in comparison with Pt catalyst