Investigation of the surface structure and activity of molybdenum oxide-containing catalysts : I. An infrared study of the surface structure of molybdena-alumina catalysts

A comparison has been made of the infrared spectra of alumina with molybdenum oxide-alumina in both the oxidized and reduced forms. In the case of molybdena-alumina prepared via adsorption of gaseous MoO2(OH)2, the spectra show that a practically complete monolayer of Mo6+ oxide covers the alumina. After reduction with hydrogen the hydroxyls of the carrier appear. From the reversibility of reduction and oxidation under mild conditions it has been established that the reduced oxide is present as an interrupted monolayer

Temperature anisotropy in a driven granular gas

When smooth granular material is fluidized by vertically shaking a container, we find that the temperature in the direction of energy input always exceeds the temperature in the other directions. An analytical model is presented which shows how the anisotropy can be traced back to the inelasticity of the interparticle collisions and the collisions with the wall. For a dilute granular gas, the model compares very well with molecular-dynamics simulations. It is concluded that any non-isotropic driving of a granular gas in a steady state necessarily causes anisotropy of the granular temperature

Een patiënt met Legionairsziekte in Nederland

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Modeling Transverse Cracking in Laminates With a Single Layer of Elements Per Ply

The objective of the present paper is to investigate the ability of mesolevel X-FEM models with a single layer of elements per ply to capture accurately all aspects of matrix cracking. In particular, we examine whether the model can predict the insitu ply thickness effect on crack initiation and propagation, the crack density as a function of strain, the strain for crack saturation, and the interaction between delamination and transverse cracks. Results reveal that the simplified model does not capture correctly the shear-lag relaxation of the stress field on either side of a crack, which leads to an overprediction of the crack density. It is also shown, however, that after onset of delamination many of the inserted matrix cracks close again, and that the density of open cracks becomes similar to the density predicted by the detailed model. The degree to which the spurious cracks affect the global response is quantified and the reliability of the mesolevel approach with a single layer of elements per ply is discussed

Spatially encoded light for Large-alphabet Quantum Key Distribution

Most Quantum Key Distribution protocols use a two-dimensional basis such as HV polarization as first proposed by Bennett and Brassard in 1984. These protocols are consequently limited to a key generation density of 1 bit per photon. We increase this key density by encoding information in the transverse spatial displacement of the used photons. Employing this higher-dimensional Hilbert space together with modern single-photon-detecting cameras, we demonstrate a proof-of-principle large-alphabet Quantum Key Distribution experiment with 1024 symbols and a shared information between sender and receiver of 7 bit per photon.Comment: 9 pages, 6 figures, Added references, Updated Fig. 1 in the main text, Updated Fig.1 in supplementary material, Added section Trojan-horse attacks in supplementary material, title changed, Added paragraphs about final key rate and overfilling the detector to result sectio

Auditen op basis van Dialoog

Zorginstellingen werken in toenemende mate samen binnen het publieke domein. Er ontstaan steeds meer samenwerkingsverbanden tussen zorg en onderwijs, arbeidstoeleidingen wonen. In de praktijk blijkt dat in deze samenwerkingsverbanden de kwaliteit van de zorg en de veiligheid van de cliënt niet goed geregeld zijn.Hoe kan dit

Ready for university? A cross national study on students' perceived preparedness for university

Students' preparedness for higher education is seen as one of the main factors affecting first-year attrition or study success. In this paper we report on a cross-national study in which students' preparedness for university was measured before students commenced their study at a university in New Zealand or in the Netherlands. This cross-national project provided a unique opportunity to compare students' perceptions of readiness for university where students are prepared for higher education in quite different secondary school systems. Departing from a transition framework, and comparing the results in both countries using logistic regression techniques to investigate which aspects of readiness could predict perceived preparedness, we discovered similarities in as well as differences between students' perceived readiness for university study. It could be argued that differences are caused by the different educational systems at secondary level. However, overall we can conclude that, in spite of differences between the educational systems in the two countries, many differences were not remarkable or very significant. This has clear implications for how we view the relative importance of secondary school preparation and tertiary induction. We can expect greater benefit from implementing first-year pedagogical practices in universities that would assist students to develop their academic skills, than from demanding that high schools prepare students better

Primaire biliaire cirrhose met sclerodermie en hypothyreoidie

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