Silicon Substitution for Aluminum in Calcium Silicate Hydrates

²⁷Al MAS and multiquantum (MQ) MASNMR (magic-angle spinning nuclear magnetic resonance) spectroscopy were used to study the substitution of silicon by aluminum in calcium silicate hydrates (C-S-H), which are the main component of hydrated portland cement. Synthetic C-S-H samples were prepared, and their chemical stability was studied. Two-dimensional 3Q-MASNMR spectra revealed the chemical shift and quadrupolar parameters (delta_iso, nu_Q) that labeled aluminum sites in the C-S-H. Tetrahedral aluminum was observed in the bridging and nonbridging sites of the silicate chains.     

Removal of NOx: Part II. Species formed during the sorption/desorption processes on barium aluminates

The formation of various species formed during the adsorption of NO_x issued from a synthetic lean-burn exhaust gas upon barium aluminates was studied using FTIR and TGA. The results have been systematically compared to those obtained with bulk BaO. Two factors are responsible for the difference observed during adsorption/desorption tests on the two solids. On one hand, stable carbonates are formed on BaO whereas no carbonate is formed on barium aluminate. On the other hand, the structure of the nitrates formed on these two compounds is very different, an N-bounded nitrate is formed on barium aluminate and not on bulk BaO.     

Exposure levels to brominated compounds in seawater swimming pools treated with chlorine

Despite evidence of formation of brominated compounds in seawater swimming pools treated with chlorine, no data about exposure levels to these compounds have been reported. To address this issue, a survey has been carried out in four establishments (representing 8 pools) fed with seawater and devoted to relaxing and cure treatments (thalassotherapy centres located in Southeast of France). Carcinogenic and mutagenic brominated disinfection byproducts (trihalomethanes -THM- and halogenated acetic acids -HAA-) were quantified at varying levels, statistically related to organic loadings brought by bathers, and not from marine organic matter, and also linked to activities carried out in the pools (watergym vs swimming). Bromoform and dibromoacetic acid, the most abundant THM and HAA detected, were measured at levels up to 18-fold greater than the maximum contaminant levels of 60 and 80 μg/L fixed by US.EPA in drinking waters. The correlations between these disinfection byproducts and other environmental factors such as nitrogen, pH, temperature, free residual chlorine, UV₂₅₄, chloride and bromide concentrations, and daily frequentation were examined. Because thalassotherapy and seawater swimming pools (hotels, cruise ships,…) are increasing in use around the world and because carcinogenic and mutagenic brominated byproducts may be produced in chlorinated seawater swimming pools, specific care should be taken to assure cleanliness of users (swimmers and patients taking the waters) and to increase water circulation through media filters to reduce levels of brominated byproducts.     

An Automatic Correction of Ma’s Thinning Algorithm Based on <Emphasis Type="Italic">P</Emphasis>-simple Points

The notion of P-simple points was introduced by Bertrand to conceive parallel thinning algorithms. In ‘A 3D fully parallel thinning algorithm for generating medial faces’ (Pattern Recogn. Lett. 16:83–87, 1995), Ma proposed an algorithm for which there are objects whose topology is not preserved. In this paper, we propose a new application of P-simple points: to automatically correct Ma’s algorithm.     

Thermal behavior of an electrical motor through a reduced model

The aim of this study is to obtain quickly thermal information on some sensitive components of an electrical motor in a short lapse of time. The thermal behavior of this complex system is modeled and validated. The corresponding detailed model leads to the resolution of a linear system of differential equations of high order, but is not easy to handle for control purposes, due to long CPU time. In order to compute faster, two model reduction techniques are used: the Eitelberg method and the reduction by modal identification. The reduced models effectively give good temperature accuracy on the critical points of the motor with very fast computation time     

Comparative resistance of food proteins to adult and infant in vitro digestion models

IgE‐mediated allergy to milk and egg is widespread in industrialised countries and mainly affects infants and young children. It may be connected to an incomplete digestion of dietary proteins causing an inappropriate immune response in the gut. In order to study this, a biochemical model of infant gastroduodenal digestion has been developed, which has reduced levels of protease (eightfold for pepsin and tenfold for trypsin and chymotrypsin), phosphatidylcholine and bile salts, compared with the adult model. This model has been used to study the behaviour of three characterised food‐relevant proteins (bovine β‐lactoglobulin (β‐Lg), β‐casein (β‐CN) and hen's egg ovalbumin), all of which are relevant cows' milk and hens' egg allergens. Digestion products were characterised using electrophoresis, immunochemical techniques and MS. These showed that ovalbumin and β‐CN were digested more slowly using the infant model compared with the adult conditions. Resistant fragments of β‐CN were found in the infant model, which correspond to previously identified IgE epitopes. Surprisingly, β‐Lg was more extensively degraded in the infant model compared with the adult one. This difference was attributed to the tenfold reduction in phosphatidylcholine concentration in the infant model limiting the protective effect of this phospholipid on β‐Lg digestion.     

Adaptive IPTV services based on a novel IP Multimedia Subsystem

Heterogeneous communication devices are emerging and changing the way of communication. Innovative multimedia applications are now accessible through these embedded systems. The 3GPP IP Multimedia Subsystem (IMS) provides a basic architecture framework for the Next Generation Network (NGN) supporting the convergence platform for service provisioning in heterogeneous networks. ETSI TISPAN standardization effort focuses on delivering IPTV services on such platform. Nevertheless, IPTV on IMS standardization suffers from a lack of efficient user-centric network management mechanisms as the end-user may consume IPTV service from different access networks, on different mobile devices, at anytime. User’s Perceived Quality of Service (PQoS) or Quality of Experience (QoE) of IPTV service may also suffer from wireless access network impairments. This paper introduces new functionalities in IPTV over IMS architecture which optimize satisfaction of the end-user and resource utilization of the operator’s networks. A context-sensitive User Profile (UP) model is used to deliver IPTV streams adapted to the user’s environment. In order to optimize the operator network usage, the impact of spatiotemporal dynamics of the video content on the deduced perceptual quality is considered. A Multimedia Content Management System (MCMS) is proposed to perform dynamic cross-layer adaptation of the IPTV stream based on PQoS measurements at the end-user side.     

Mechanical Behavior of Nanostructured and Microstructured Explosives

Nanostructured hexolites (40/60), (60/40), (80/20) and microstructured hexolite (60/40) powders are pressed by uniaxial compression to obtain explosive charges. This kind of composition is often used for the synthesis of detonation nanodiamonds. The morphology, density and cohesion of the resulting pellets are analyzed in the light of the different used compression parameters. This study allows optimizing the compression parameters to obtain well suited explosive charges from nanostructured explosive components. A good cohesion of the nanostructured explosive pellets could be obtained with increasing the temperature used for the compression. Another very important point is that the nanostructuring of the composites is maintained for every compression.     

Case Study: Retrofitting Large Bridge Piers on the Nakdong River, South Korea

The Gupo Bridge crosses the Nakdong River near the city of Busan, South Korea. During Typhoon Maemi in 2003, the old Gupo Bridge collapsed due to excessive pier scour. More recently, the highway construction on the left-bank floodplain required right-bank channel widening to restore the channel flood-carrying capacity. This 7?m deep floodplain excavation is expected to cause significant local scour around the 8–10?m wide and 3?m thick spread footings of Piers 11 and 12 of the Subway Bridge and Piers 15 and 16 of the Gupo Bridge. Three design options are examined for retrofitting floodplain bridge piers with massive spread footings. A solution with sheet piles and riprap was recommended in 2006 as the most appropriate design, but Plan III with a conical riprap structure around the footings was ultimately constructed in 2007 for economic reasons. Laboratory experiments also highlight the need to place gravel and synthetic filters under the designed riprap.