785 research outputs found
Expression of Interest ICES/KIS-3 : Thema 4: Hoogwaardig Ruimtegebruik Speerpunt 6
Hoofddoel van dit speerpunt is om zowel de Nederlandse overheid als het bedrijfsleven uit te rusten met een operationele kennisinfrastructuur die toegesneden is op de relatie tussen (antropogene en natuurlijke) klimaatverandering en meervoudig ruimtegebrui
Microscopic aspects of crack propagation along PET-glass and PET-Al interfaces
This paper reports microscopic investigations of the propagation of cracks along polymer-glass and polymer-metal interfaces. The experimental methods include an asymmetric double cantilever beam in an optical microscope, and bire-fringence and atomic force microscopy of the crack faces. The crack fronts propagate inhomogeneously in space and time by way of forward bursts that spread laterally along the front over a certain distance. Experimental indications for correlation between crack propagation and interface roughness and for the occurrence of shear-bands in front of the propagating interface cracks are discussed. (c) 2006 Elsevier Ltd. All rights reserved
Синтетические и растительные лекарственные средства с эстрогеноподобной активностью
Описаны синтетические и растительные соединения с эстрогеноподобной активностью. Рассмотрены механизмы их действия и возможности клинического применения.Описано синтетичні й рослинні сполуки з естрогеноподібною активністю. Розглянуто механізми їх дії та можливості клінічного використання.Synthetic and herbal compounds with estrogen-like activity are described. The mechanisms of their action and possibility of clinical application are discussed
Local delamination on heavily deformed polymer-metal interfaces:evidence from microscopy
In this work the microstructure of interfaces present in heavily bi-axially deformed polymer-coated metal is studied. Cross sections of deformed polymer-coated steel are prepared using several polishing strategies, including the use of focused ion beam, and are imaged using optical microscopy and scanning electron microscopy. We find that the interfaces show significant details right down to the smallest scale observable with the preparation techniques used of about similar to 10 nm. Local delamination events at these deformed interfaces are observed and are found to be preferentially associated with overhanging parts on the interface. Overhanging parts are frequently observed, but only below a certain length-scale on the interfaces that are otherwise found to be self-affine up to a certain correlation length. The smallest detail includes the tail of the size distribution of the overhanging features. Together this suggests that the physical mechanisms determining the formation of critical features for adhesion operate at sub-grain level as well as at grain level
General purpose models for intravenous anesthetics, the next generation for target-controlled infusion and total intravenous anesthesia?
PURPOSE OF REVIEW: There are various pharmacokinetic-dynamic models available, which describe the time course of drug concentration and effect and which can be incorporated into target-controlled infusion (TCI) systems. For anesthesia and sedation, most of these models are derived from narrow patient populations, which restricts applicability for the overall population, including (small) children, elderly, and obese patients. This forces clinicians to select specific models for specific populations. RECENT FINDINGS: Recently, general purpose models have been developed for propofol and remifentanil using data from multiple studies and broad, diverse patient groups. General-purpose models might reduce the risks associated with extrapolation, incorrect usage, and unfamiliarity with a specific TCI-model, as they offer less restrictive boundaries (i.e., the patient "doesn't fit in the selected model") compared with the earlier, simpler models. Extrapolation of a model can lead to delayed recovery or inadequate anesthesia. If multiple models for the same drug are implemented in the pump, it is possible to select the wrong model for that specific case; this can be overcome with one general purpose model implemented in the pump. SUMMARY: This article examines the usability of these general-purpose models in relation to the more traditional models.</p
Exploring high-end climate change scenarios for flood protection of the Netherlands
This international scientific assessment has been carried out at the request of the Dutch Delta Committee. The "Deltacommissie" requested that the assessment explore the high-end climate change scenarios for flood protection of the Netherlands. It is a state-of–the art scientific assessment of the upper bound values and longer term projections (for sea level rise up to 2200) of climate induced sea level rise, changing storm surge conditions and peak discharge of river Rhine. It comprises a review of recent studies, model projections and expert opinions of more than 20 leading climate scientists from different countries around the North Sea, Australia and the US
Quantitative measurement of sliding friction dynamics at mesoscopic scales: The lateral force apparatus
We describe an apparatus designed to quantitatively measure friction dynamics at the mesoscopic scale. This lateral force apparatus, LFA, uses double parallel leaf springs in leaf-spring units as force transducers and two focus error detection optical heads, optical heads, to measure deflections. The design of the leaf-spring units is new. Normal spring constants are in the range of 20–4000 N/m, and lateral spring constants are 7–1000 N/m. The optical heads combine a 10 nm sensitivity with a useful range of about 100 µm. The proven range of normal forces is 400 nN–150 mN. The leaf-spring units transduce friction and normal forces independently. Absolute values of normal and friction forces are calibrated. Typical errors are less than 10%. The calibration is partly in situ, for the sensitivity of the optical heads, and partly ex situ for the normal and lateral spring constants of the leaf-spring units. There is minimal coupling between the deflection measurements in the lateral and normal directions. This coupling is also calibrated in situ. It is typically 1% and can be as low as 0.25%. This means that the displacements of the tip can be measured accurately in the sliding direction and normal to the surface. Together, these characteristics make the LFA, well suited for quantitative study of friction dynamics at mesoscopic scales. Furthermore the design of the leaf-spring unit allows exchange of tips which may be fabricated (e.g., etched) from wire material (d0.4 mm) and can have customized shapes, e.g., polished flat squares. The ability of the LFA to study friction dynamics is briefly illustrated by results of stick-slip measurements on soft polymer surfaces
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Climate Change and Extreme Weather Events
The report of the Intergovernmental Panel on Climate Change of 1995 has been taken as a starting point. Since 1995 many new observations and reports have become available. Much of the information on observations and studies on climate change and its impacts can be found through the Internet. Where possible we have made references, such that the reader can easily verify and review our sources. This study addresses three main questions: To what extent can the human influence on the climate system presently be measured? What can we expect for the short term and long-term future? To what extent will measures to reduce net greenhouse gas emissions affect the future climate
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