Influence of the porosity gradient in cement paste matrix on the mechanical behavior of mortar

This paper is devoted to the study of the influence of the microstructure of mortar on its mechanical behavior. For this purpose, mechanical tests have been carried out on mortars and a mathematical model, the (n + 1)-phase model, has been used to take into account three variable parameters of the microstructure of mortar (the thickness of the interfacial transition zone, the porosity gradient in the cement paste matrix and the nature of the constituents of the Interfacial Transition Zone) for some given parameters (volume fraction of aggregates, porosity of the mortar and mechanical behavior of the aggregates and the cement paste). By fitting some measured moduli to the model predictions, we can estimate in a non-destructive manner, the possible distribution of porosity within the Interfacial Transition Zone. Our results provide information on the data such micromechanical models can deal with in order to predict the elastic behavior of mortars.     

Effect of Novel AKT Inhibitor Vevorisertib as Single Agent and in Combination with Sorafenib on Hepatocellular Carcinoma in a Cirrhotic Rat Model

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related mortality worldwide. The AKT pathway is often activated in HCC cases, and a longer exposure to tyrosine kinase inhibitors such as sorafenib may lead to over-activation of the AKT pathway, leading to HCC resistance. Here, we studied the efficacy of a new generation of allosteric AKT inhibitor, vevorisertib, alone or in combination with sorafenib. To identify specific adverse effects related to the background of cirrhosis, we used a diethylnitrosamine (DEN)-induced cirrhotic rat model. Vevorisertib was tested in vitro on Hep3B, HepG2, HuH7 and PLC/PRF cell lines. Rats were treated weekly with intra-peritoneal injections of DEN for 14 weeks to obtain cirrhosis with fully developed HCC. After that, rats were randomized into four groups (n = 7/group): control, sorafenib, vevorisertib and the combination of vevorisertib + sorafenib, and treated for 6 weeks. Tumor progression was followed by MRI. We demonstrated that the vevorisertib is a highly potent treatment, blocking the phosphorylation of AKT. The tumor progression in the rat liver was significantly reduced by treatment with vevorisertib + sorafenib (49.4%) compared to the control group (158.8%, p < 0.0001). Tumor size, tumor number and tumor cell proliferation were significantly reduced in both the vevorisertib group and vevorisertib + sorafenib groups compared to the control group. Sirius red staining showed an improvement in liver fibrosis by vevorisertib and the combination treatment. Moreover, vevorisertib + sorafenib treatment was associated with a normalization in the liver vasculature. Altogether, vevorisertib as a single agent and its combination with sorafenib exerted a strong suppression of tumor progression and improved liver fibrosis. Thus, results provide a rationale for testing vevorisertib in clinical settings and confirm the importance of targeting AKT in HCC.     

Calculation of CO_2, CH_4 and H_2S Solubilities in Aqueous Electrolyte Solution at High Pressure and High Temperature

INTRODUCTIONPhasebehaviourinaqueouselectrolytesystemsisofinterestfornumerousindustrialapplicationssuchasscaleformationprediction,hydrometallurgy,distil-lation,gasstorage,waterpollutioncontrol.Becauseofeconomical,technicalandecologicalconsiderations,accuratepredictionofgassolubilitiesinelectrolyteso-latinnsoverawiderangeoftemperatures,pressures,andionicstrengthisneeded.Duringnilgration,production,transportandstock-ing,petroleumfluidsareincontactwithsaltedwa-ter(i.e.formationwater,seawateror…     

Chlorination of phenols: kinetics and formation of chloroform

The kinetics of chlorination of several phenolic compounds and the corresponding formation of chloroform were investigated at room temperature. For the chlorination of phenolic compounds, second-order kinetics was observed, first-order in chlorine, and first-order in the phenolic compound. The rate constants of the reactions of HOCl with phenol and phenolate anion and the rate constant of the acid-catalyzed reaction were determined in the pH range 1-11. The second-order rate constants for the reaction HOCl + phenol varied between 0.02 and 0.52 M(-1) s(-1), for the reaction HOCl and phenolate between 8.46 x 10(1) and 2.71 x 10(4) M(-1) s(-1). The rate constant for the acid-catalyzed reaction varied between 0.37 M(-2) s(-1) to 6.4 x 10(3) M(-2) s(-1). Hammett-type correlations were obtained for the reaction of HOCl with phenolate (log(k) = 4.15-3.00 x sigma sigma) and the acid-catalyzed reaction of HOCl with phenol (log(k) = 2.37-4.26 x sigma sigma). The formation of chloroform could be interpreted with a second-order model, first-order in chlorine, and first-order in chloroform precursors. The corresponding rate constants varied between k > 100 M(-1) s(-1) for resorcinol to 0.026 M(-1) s(-1) for p-nitrophenol at pH 8.0. It was found that the rate-limiting step of chloroform formation is the chlorination of the chlorinated ketones. Yields of chloroform formation depend on the type and position of the substituents and varied between 2 and 95% based on the concentration of the phenol.     

Bursting of shielded pressure vessels subject to hypervelocity impact

During the 30-year lifetime of the Space Station, NASA is concerned that a large piece of orbital debris could strike one of the inhabited or laboratory modules. The modules are basically cylindrical pressure vessels, 4.3 meters in diameter and 9.1 meters long, made of Al 2219-T87. There is a potential for unstable crack growth (“unzipping”) in these pressure vessels if a sufficiently-long crack were formed in the pressure vessel wall. The ragged hole generated when debris strikes an exterior shield and impulsively loads the pressure vessel wall could lead to such a crack. The central concern of this research is quantifying the minimum crack length (critical crack length) to initiate unstable crack growth. This paper reports on a two-part investigation into this problem: 1) fracture experiments and analyses aimed at determining the fracture resistance and critical crack length of the module walls, and 2) examination of impact data to determine the impact conditions that could cause the critical crack length to be exceeded. Al 2219-T87 was found to be a modestly rated sensitive material, exhibiting an increase in both ultimate strength and fracture toughness at high strain rates. The results of the conservative linear elastic fracture mechanics analyses indicate critical cracks at least 22.9 cm in length are required for unzipping (3.17-mm thick wall), and 45.7-cm length (for 4.83-mm thick wall). The dynamic analysis results indicate that the critical crack lengths are even longer, about 48.3 to 61.0 cm in length. Examination of the rather limited experimental database indicates that the dynamic analysis values are more realistic, and that under certain conditions of projectile size, wall stress, and shield design the critical crack length can be exceeded.     

Body area network for wireless patient monitoring

Patient data monitoring is a key issue for health and disease management. The use of wireless sensors within a body area network (BAN) makes this task seamless and easy. A BAN system is presented, which allows the connectivity of a wide range of heterogeneous body sensors to a portable hub device that is connectable to external networks (IEEE 802.11, GPRS). This BAN is based on the use of Zigbee/IEEE 802.15.4 standard technology and off-the-shelf modules. It is currently being used at the European level for the detection and the prediction of the human physiological state in relation to wakefulness, fatigue, and stress applications in which users carrying out daily activities are monitored in an unobtrusive and comfortable way. Characterised by its low power consumption, low cost, and ability to connect a wide range of heterogeneous sensors, this system can substantially improve the performance of different services, especially those that are health related.     

Microwave photonic photorefractive smart filters

This paper reviews our past and current work on microwave photonic photorefractive smart filters (MWP-PSFs). These devices rely on the generation of dynamic Bragg gratings inside InP:Fe 1.55-/spl mu/m photorefractive crystals. First, we concentrate on the applications of MWP-PSFs to optical measurements. We report a 15-pm resolution optical spectrum analyzer without mechanical tuning and a 0.2-nm passive wavelength spaced controller. Secondly, we describe the extension of the MWP-PSF concept to the radio modulation frequency control of fiber-wireless systems. Then, we outline the recent proposal of a wavelength self-tunable single-sideband (WST-SSB) filter in order to compensate for the effects of fiber chromatic dispersion in fiber-radio systems. The performance of the latter device is extensively examined in a fiber-radio 140-Mbit/s data transmission employing binary phase-shift keying modulation at 16 GHz without intermediate frequency. Finally, possible future developments such as the InGaAsP integration of MWP-PSFs and the use of a new photorefractive material are discussed.     

Nature,mass and preferential sites of coarse woody debris deposits in the lower ain valley (Mollon reach), France

Coarse woody debris (CWD) has been examined in a section of the Ain, a sixth order piedmont river with an actively meandering channel and a wooded floodplain. The spatial distribution of CWD, its mass and forms of accumulation are controlled by the hydrodynamics and the retention capacity of the forest. A typology shows the relative importance of woody debris in the mosaic of patches and the essential role of the ecotonal zones. The mass of debris varies from 0001 t ha^?1, to more than 200t ha^?1, but is lower than those observed in certain American rivers. Most of the material is deposited in the margins and forms a narrow debris line. The restocking in woody debris is recent in Europe and tends to diversify the environment. This affects the researcher and the planner. The first considers this transit of material as a useful hydromorphodynamic and biodynamic tool which is easy to evaluate, and the second considers it as a restoring and generative vector, the ecological functions of which are recognized. Its effect is stronger today as the watershed area tends to be subjected to a decrease in agricultural activity.