Deposition velocities of aerosol on building and monument vertical surfaces have scarcely been documented and modeled so far. A methodology is proposed based on simultaneous measurements of artificial aerosol tracer fluorescein emissions, concentrations and depositions, and of high frequency turbulent variables. The results are compared to year-long deposition of 7Be, a naturally produced airborne radioactive particle tracer. A three-dimensional simulation of the turbulent flow and concentration fields in the vicinity of the wall specifies the flow structure responsible for deposition on the facade. It also allows comparison of the measured fluorescein deposition velocities with two semi-empirical models.

The emissivity of coated glazing is commonly determined from spectral reflectance measurements using a specular reflectance accessory or other suitable reflectance attachment. As part of the ongoing EU Thermes RTD project, a 19 laboratory intercomparison was undertaken in 2003 to establish the state-of-the-art of infrared reflectance measurement accuracy and uncertainty and to identify any needs for improvement. Six test samples were selected to provide samples with low, medium and high infrared reflectance. In addition, bare gold mirrors were prepared for distribution to each participant to serve as the reference material. Both the reference mirrors and the round robin samples were calibrated and evaluated prior to delivery to enable closely characterised and similar sample sets to be prepared. A measurement procedure requiring a sequence of 18 measurements undertaken in a strict order was developed. The outcome of the exercise is very encouraging. Participants have performed the work using a wide range of experimental conditions but the final results are in excellent agreement. This is because of the adherence to the required measurement procedure and the use of reference mirrors with known reflectance values. The analysis indicates uncertainties in the final results which are less than +/- 0.01. Factors such as instrument resolution, number of scans and time of acquisition do not appear to have been significant in affecting measurement accuracy. (c) 2005 Elsevier B.V. All rights reserved.

Venoms from Viperidae, Crotalidae, some Australian Elapidae and few Colubridae are a mixture of enzymes which impact on blood coagulation in several ways. These proteins can be classified as haemorragins which induce disorders of the capillary permeability disintegrins and related proteins which disturb the clotting time while acting on plate adhesion, and proteases which cleave peptides. Venoms contain molecules directed against several targets of the coagulation system. The same molecule may present different activities. Components of snake venoms are used in diagnostic coagulation tests, fundamental research and as drugs against infectious agents, cancer or haematological disorders. The structural differences between proteins from snake venoms and natural coagulation factors and the target diversity of the venom components explain why it remains illusory to treat bleedings when acting just at symptom level. Conversely, antivenom, whose components are directed against the venom proteins, is the only aetiological therapy effective against snake envenomations.

Faced with an envenomation, the problem is to take sufficiently rapidly the decision to administer the only effective treatment--immunotherapy--, to know which antivenom to choose and how long to administrate it. If the snake is not identified, symptoms and initial development give information on the type of venom. It is convenient to classify the symptoms according to four clinical types: i) the cobra syndrome with a potentially fatal evolution within two to ten hours and which resembles an Elapid bite, ii) the viper syndrome associating bleeding and inflammation, which can be due either to a viper, pit viper or, in Australia, to Elapids, iii) disturbance of blood circulating functions and iv) disturbance of other live functions. Between the third to the half of snakebite victims present no envenomation. Severe envenomations must be monitored in an intensive care unit, with experience in emergency management and monitoring of patients with major life-threatening conditions. Throughout the world, snakebites induce more than 100,000 deaths every year. Schematically, the emergency may be considered in terms of seconds for blood circulation disorders, minutes for respiratory paralysis, and hours for the coagulopathy.

Venoms from Viperidae, Crotalidae, some Australian Elapidae and few Colubridae are a mixture of enzymes which impact on blood coagulation in several ways. These proteins can be classified as haemorragins which induce disorders of the capillary permeability, disintegrins and related proteins which disturb the clotting time while acting on plate adhesion, and proteases which cleave peptides. Venoms contain molecules directed against several targets of the coagulation system. The same molecule may present different activities. Components of snake venoms are used in diagnostic coagulation tests, fundamental research and as drugs against infectious agents, cancer or haematological disorders. The structural differences between proteins from snake venoms and natural coagulation factors and the target diversity of the venom components explain why it remains illusory to treat bleedings when acting just at symptom level. Conversely, antivenom, whose components are directed against the venom proteins, is the only aetiological therapy effective against snake envenomations.

The European Union ADOPT project has been concerned with the accurate determination of the optical properties of coated glass products, describing reliable procedures for angle-dependent measurements and the development of predictive algorithms to enable accurate angle-dependent performance characterisation based upon near-normal values only. An essential element of the ADOPT project was the inter-laboratory comparison of transmittance and reflectance measurements for commercially available glazings. Thirteen European and three USA laboratories participated. The selected samples represent major categories of coated glass products used in buildings. Each participant received a set of samples and measured the angle-dependent spectral transmittance and reflectance under appropriate polarisation conditions for incident wavelengths within the solar spectral distribution. Calibrated mirrors were also provided for reference purposes. This paper presents the results of the inter-comparison which show that near-normal solar, visible and spectral transmittance and reflectance can be measured with an uncertainty of better than ±0.02. The inter-comparison illustrates the difficulties still experienced in making accurate oblique incidence measurements. The predictive algorithms, which require near-normal input data only, are capable of predicting the angle-dependent transmittance, reflectance and total solar energy transmittance for double and triple glazed windows to an accuracy which enables reliable calculation of the annual solar heat gain through windows.

In the first part of this paper, the mechanisms of heat transfer through insulating materials are presented Expanded PolyStyrene (EPS) foam is investigated in more details. As observed by optical an electron microscopy EPS exhibits a double-scale microstructure. it can be considered as a dense packing of cellular beads with three phases : the macropores between beads, the shell and the core of the pellets.Heat transfer is modelled laking into account conduction and radiation within cells and through cell-walls according to the model of Glicksman (I). Heat transfer through the packing of cellular pellets is described using the model of De Vries (2).Results taking into account the effect of foam density, cell-size and proportion of each phases are presented.The thermal conductivity of cellular materials exhibits an optimum value with regards to the cell sizes and the density: Actually as the cell struts act as barriers to radiation, when smaller cells are built with the same amount of polymer, the size of the struts are shrunk and they are no more efficientThe model of De Vries is also applied to lightweight concrete (Concrete + EPS beads).In the second part, heat transfer through a very low conductivity material is studied : monolithic organic aerogel. This material has a lower thermal conductivity than all other thermal insulants at ambient conditions (3) : around 0.023 W/mK without using any heavy gas. This low conductivity originates in :very high porosity (95 - 98 %) and thus small solid conductivity;extremely small pore size (10 - 100 nm, lower than the mean free path of air), that causes very low gaseous thermal conductivity due to Knudsen effectMoreover, the gas conductivity can be minimized by lowering the gas pressure within the aerogel. A typical thermal conductivity of 0.008 W/mk can be reached at 0.05 hPa.At low temperature, the radiation is minimized and a value of 0.002 W/mK was obtained at 110 K and 0.05 hPa.

Les auteurs relatent la première série française concernant une intoxication collective oxycarbonée, ayant nécessité le déclenchement d'un plan de secours pour de nombreuses victimes intoxiquées par un produit chimique non persistant. Une population de plus de 500 personnes a été ≪ triée ≫ et 162 victimes intoxiquées symptomatiques prises en charge. L'organisation des secours médicaux fut adaptée à une situation de catastrophe à effets limités, où les moyens diagnostiques et thérapeutiques ont été initialement insuffisants. Les moyens de détection, de dosage du monoxyde de carbone et de traitement sont abordés, et la relation symptômes/taux de carboxyhémoglobine analysée.

Optical transmittance and reflectance of a translucent plastic PTFE him have been measured over the solar wavelength range using different integrating spheres. The same sample has been measured with small and large spheres and the total solar transmittance has been obtained from both broad band measurements and from integration of spectral data. The fact that the sum of reflectance and transmittance often exceeds 100% shows that all types of spheres tend to overestimate the transmittance of this highly scattering sample. This error can be attributed to the sphere geometry in combination with the light scattering properties of the sample, and unless proper correction of recorded data is carried out the error may be as large as 5-10%. Some specific errors are presented and an approximate correction procedure is suggested.These results show that there is a need for a transmittance standard which can be used to calibrate integrating spheres. Such a standard with negligible thickness would be especially useful for measurements with large, broadband integrating spheres, but would also be helpful for the correct handling of data from small spectral instruments. (C) 1998 Elsevier Science B.V. All rights reserved.

La cécité corticale est une perte de sensation visuelle liée à des lésions atteignant les voies optiques en arrière du corps genouillé latéral et plus particulièrement les cortex visuels primaires. Les connaissances sur le fonctionnement visuel ont connu une progression considérable ces vingt dernières années, en partie grâce à l’amélioration des techniques d’investigation mais surtout grâce à la convergence des données provenant des différentes approches: psychophysique, psychologie cognitive, neurophysiologie, et neuropsychologie. Cet enrichissement mutuel induit une meilleure compréhension des troubles neurovisuels complexes tels que la cécité corticale chez l’enfant et chez l’adulte, permet de mettre au point de nouvelles techniques de rééducation et d’en suivre la récupération grâce aux progrès de l’imagerie cérébrale fonctionnelle. En parallèle, l’étude de ces troubles, et la façon dont les processus visuels se désorganisent à la suite d’une lésion occipitale nous informent sur les processus cognitifs impliqués dans la perception visuelle à l’état normal.Cortical blindness refers to a visual loss induced by a bilateral occipital lesion. The very strong cooperation between psychophysics, cognitive psychology, neurophysiology and neuropsychology these latter twenty years as well as recent progress in cerebral imagery have led to a better understanding of neurovisual deficits, such as cortical blindness. It thus becomes possible now to propose an earlier diagnosis of cortical blindness as well as new perspectives for rehabilitation in children as well as in adults. On the other hand, studying complex neurovisual deficits, such as cortical blindness is a way to infer normal functioning of the visual system.

For various shock waves experiments, the integrity of the expanding free surface is required. However, different mechanisms contribute to the deterioration of the so called free surface. This experimental study is mainly concerned with such mechanisms induced by melting under shock loading. Free surface velocity measurements are performed by the well known D.L.I. technique. For optically polished surfaces, when a solid-liquid transition occurs on the release isentrope, the reflectivity drops drastically. Reflectivity variations and D.L.I. velocity time histories are related to initial microspalling of melted surfaces. In the case of rough surfaces, microjetting has been evidenced. Material ejection is quantitatively deduced by momentum transfer from ejecta to a thin foil whose velocity is recorded by D.L.I. A 400 kV X Ray pulsed generator gives an alternative possibility to reach the spatial density distribution of the ejecta near the free surface. By these methods it is possible to point out that the amount of ejected mass is strongly dependent on the capability for the material to melt during the microjet formation. Applications are made for Sn, Zn, Cu, Fe, Zr, Nb and Ta.

Detonics is the study of shock waves and the effects of shock waves on materials.

Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Twitter Facebook Reddit LinkedIn Tools Icon Tools Reprints and Permissions Cite Icon Cite Search Site Citation P. Andriot, P. Chapron, F. Olive; Ejection of material from shocked surfaces of tin, tantalum and lead‐alloys. AIP Conference Proceedings 1 April 1982; 78 (1): 505–509. https://doi.org/10.1063/1.33316 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAIP Publishing PortfolioAIP Conference Proceedings Search Advanced Search |Citation Search

We describe shock wave experiments using explosive generators and a two‐stage light‐gas gun. Experimental results are presented to illustrate the facilities, the diagnostics, and the measurement techniques.

An experimental method for studying material ejection mechanisms from a free surface due to strong shock wave reflection has been investigated. In this experiment the main phenomenon is momentum transfer from the ejecta to a thin foil whose distance to free surface is known. By measuring the thin foil velocity (0.3-300-µm foil thickness), we can determine the amount of matter ejected from the shocked sample.