Exact boundary controllability of the second-order Maxwell system: Theory and numerical simulation

The exact controllability of the second order time-dependent Maxwell equations for the electric field is addressed through the Hilbert Uniqueness Method. A two-grid preconditioned conjugate gradient algorithm is employed to inverse the H.U.M. operator and to construct the numerical control. The underlying initial value problems are discretized by Lagrange finite elements and an implicit Newmark scheme. Two-dimensional numerical experiments illustrate the performance of the method.     

Global assessment of El Ni?o's disaster burden

BACKGROUND: Natural disasters have profound effects on health and require medical intervention as part of relief operations. The world's populations are becoming increasingly vulnerable to extreme weather events, which are responsible for most natural disasters. The El Ni?o Southern Oscillation (ENSO) is the most prominent global climate system associated with year-to-year weather variability and extreme events. We have estimated the burden on human health of natural disasters associated with ENSO. METHODS: We used time-series regression analysis of the relation between El Ni?o years and the annual rates of persons affected by natural disasters per 1000 population during 1964-93, globally and also by region and disaster type. Correlations between sea-surface temperature (SST) anomalies (index of ENSO) and the rates of persons affected by natural disasters per 1000 population were determined globally, by region and by disaster type. FINDINGS: The rate of persons affected by natural disasters worldwide is strongly associated with ENSO; rates are greater during the first El Ni?o year (p = 0.05) and the following year (p = 0.01) than in the pre-Ni?o year. The correlation between rates of persons affected by natural disasters and SST anomalies in the Eastern Pacific (a key ENSO indicator) is highest in the last quarter of the previous year (r = 0.53, p < 0.01). These associations are strongest in South Asia, the region where more than 50% of all disaster victims live. Worldwide, rates of persons affected by drought/famine (half of all disaster victims) and by volcanic eruptions show significant associations with the ENSO cycle, being highest in the post-Ni?o year and El Ni?o year, respectively, and being significantly associated with SST anomalies. INTERPRETATION: The strong relation between ENSO and populations affected by natural disasters can be described as a "natural disaster cycle". Determining the phase in this cycle, using SST from the Eastern Equatorial Pacific, could benefit disaster preparedness on a global scale, for South Asia in particular, and for all populations affected by drought/famine and volcanic disasters.     

Interactions between volatiles and lipids in complex systems

Partition equilibria of three aroma compounds in three different biphasic systems were studied by a liquid/liquid partition technique to investigate interactions that occur between volatiles and lipids in biphasic solutions. The lipids used were linoleic acid and ricinoleic acid and tetradecane as a model. The three aroma compounds were ethyl acetate, 2,5-dimethylpyrazine, and oct-1-en-3-ol. The results showed that the intermolecular forces involved were weak. Infrared spectroscopy was then performed on binary systems (tetradecane and linoleic acid or aroma compound) and on ternary systems (tetradecane, linoleic acid, and aroma compound) to determine the nature of the interactions. This method confirmed the presence of hydrogen bonds between linoleic acid and 2,5-dimethylpyrazine or oct-1-en-3-ol and also between molecules of oct-1-en-3-ol when the latter are present at high concentrations in lipids. The observations provided sufficient information to explain the behavior of oct-1-en-3-ol in biphasic solutions, but further work is needed to fully elucidate the nature of interactions between ethyl acetate or 2,5-dimethylpyrazine and lipids and also to explain the behavior of these compounds in biphasic solutions.     

The sensitivity and impact of dye structure and fibre micronaire on the increased dyeability of bioengineered cotton fibres

Previous research reported on a screening method to assess the functionalisation of bioengineered cotton fibres through the absorption of CI Acid Orange 7. The aim of the present paper is to extend this study to different dye classes. Thus the dye absorption of bioengineered cotton fibres containing oligochitin is studied for a series of dye classes. Statistically significant differences were found between cotton lines designed to produce oligochitin in the fibre and their respective controls for all tested dyes, confirming previous results with CI Acid Orange 7. Further, although variations in micronaire influenced dye absorption, it was confirmed for all dyes tested as well as for CI Acid Orange 7 that the oligochitin production had a larger impact on the exhaustion values than the differences in micronaire. The method described in this paper can be applied as a screening tool to meet the challenge of working with small quantities of fibrous materials. Moreover it shows the potential that the incorporated oligochitin has for increasing dyeability with a wide range of dyes and creating fibres with more versatile reactivity.     

Unexpected electronic properties of micrometer-thick supracrystals of Au nanocrystals

We investigated the electronic properties of highly ordered three-dimensional colloidal crystals of gold nanocrystals (7 ± 0.4 nm), called supracrystals. Two kinds of Au supracrystals with typical thicknesses of 300 nm and 5 μm, respectively, are probed for the first time with scanning tunneling microscopy/spectroscopy at 5 K revealing similar power law behavior and showing homogeneous conductance with the fingerprint of isolated nanocrystal. Potential applications evading the size-related risks of nanocrystals could be then considered.     

Géologie et barrages en béton compacté au rouleau (BCR)

RCC dams are often presented as an alternative to earth or rockfill embankments. They seem to be able to accept slightly greater deformation than ordinary concrete. The five examples quoted, recently built in France, show that RCC has been used for vertical upstream walling in a very varied range of soils, despite their traditional profiles.     

Negative supracrystals inducing a FCC-BCC transition in gold nanocrystal superlattices

The growth of nanocrystal superlattices of 5 nm single domain Au nanocrystals at an air-toluene interface induces formation of well-defined thin films （300--400 nm） with large coherence lengths. High-resolution electron microscopy showed that polyhedral holes （negative supracrystal） were formed on the nanocrystal superlattice surface. Formation of negative supracrystals is attributed to inclusion in the superlattice of organic molecules （dodecanethiol）, which are present in concentrated zones at the air-toluene interface. The coexistence of two supracrystalline structures （bcc/fcc） is attributed to diffusion of dodecanethiol molecules resulting in a Bain deformation of the nanocrystal array.     

Meshfree methods and boundary conditions

We perform here some meshfree methods to inhomogeneous Laplace equations. We prove the efficiency of those methods compared with classical ones, for one‐ or two‐dimensional case for numerics, and for one‐dimensional for theoretical results. Copyright © 2006 John Wiley & Sons, Ltd.     

Coherent 3-D echo detection for ultrasonic imaging

The purpose of the present paper is to present an ultrasonic processing set-up by which three-dimensional (3-D) echo location can be computed more efficiently than by other one-dimensional (1-D) methods. This set-up contains three successive tasks. The first one deals with a model for representing echoes. This model is based on a generic wavelet, which is a cosine function with variable amplitude and phase. To estimate the wavelet, we propose to use a spline representation of its complex envelope in order to reduce amplitude and phase dimension. The second task deals with 1-D detection and is conducted within a Bayesian framework. Using an Ascan decomposition on a family of wavelets resulting from the first task, we propose a specific procedure to carry on constrained least-squares in order to alleviate the bias inherent to this criterion. The third task deals with the spatial regularization of the detected echo location field resulting from the second task. We propose a Bayes-Markov model for removing isolated wrong detections and simultaneously improving, under regularization constraint, the spatial location of the detected echoes. In fact, this model deals with the general problem of nonorganized point approximation. All the proposed techniques are illustrated on real ultrasonic data.     

Association of proinsulin-like molecules with lipids and fibrinogen in non-diabetic subjects--evidence against a modulating role for insulin

Elevated concentrations of proinsulin-like molecules, other than insulin, may be associated with abnormalities of cardiovascular risk factors, promoting atherogenesis and thrombosis. Using specific assays we examined the relationship of levels of insulin, intact proinsulin and des-31,32 proinsulin to blood pressure, lipids, fibrinogen, factor VII and albumin excretion rate in 270 europids with normal glucose tolerance. After correcting for age and body mass index, fasting and 2-h insulin concentrations were significantly associated with those of total and LDL-cholesterol (r = 0.18-0.22), HDL-cholesterol (both r = -0.20) and triglycerides (r = 0.21 and 0.18), but not with blood pressure. Concentrations of intact and des-31,32 proinsulin showed significant associations with those of total and LDL-cholesterol (r = 0.20-0.23), HDL-cholesterol (r = -0.31 and -0.32) and triglycerides (r = 0.22 and 0.26). Fasting insulin and intact proinsulin concentrations were significantly associated with fibrinogen (r = -0.15 and 0.18). Concentrations of proinsulin-like molecules comprised less than 10% of all insulin-like molecules, and so were calculated not to influence previously described relationships between insulin concentrations and cardiovascular risk factors measured using non-specific assays. In multiple regression analyses des-31,32 proinsulin concentration was more strongly associated with those of HDL-cholesterol (negatively), LDL-cholesterol and triglycerides than fasting insulin concentrations, while intact proinsulin replaced insulin concentrations in their relationships with fibrinogen. Our results show correlations between dyslipidaemia and proinsulin-like molecules at concentrations at which biological, insulin-like, activity appears unlikely. We also show relationships between LDL-cholesterol and fibrinogen and the proinsulin-like molecules.(ABSTRACT TRUNCATED AT 250 WORDS)