Search results for "visual_art"
showing 10 items of 2987 documents
The response of Trissolcus basalis to footprint contact kairomones from Nezara viridula females is mediated by leaf epicuticular waxes.
2009
Chemical footprints left behind by true bugs are perceived as contact kairomones by scelionid egg parasitoids. Female wasps encountering a contaminated artificial substrate display a characteristic arrestment posture, holding the body motionless and antennating the surface. In the system Nezara viridula (L.) and its egg parasitoid Trissolcus basalis (Wollaston), previous studies have shown that the kairomone mediating such behavior is part of N. viridula's cuticular hydrocarbons (CHC) and furthermore that the wasp's ability to discriminate host male and female footprints is mainly based on the presence/absence of nonadecane (nC(19)). In this study, the effect of epicuticular waxes of leaves…
Experimental Survey on Dry Asphalt Rubber Concrete for Sub-ballast Layers
2012
This paper presents the results of an experimental survey on the potential application of DARC (dry asphalt rubber concrete) in rail superstructure, within sub-ballast layers by measuring its damping and mechanical properties. Based on the environmental friendly point of view the DARC has the significant advantage as the backfill material of sub-ballast layer because the rubber comes from the waste tires of truck and its usage can results a significant recycling of non-biodegradable wastes. After a preliminary mix-design of several DARCs, with different rubber content that confirmed by using the Marshall test, the stiffness modulus and damping ratio both of a standard bituminous mixture and…
Application of textile fibres from tire recycling in asphalt mixtures
2022
The tire rubber obtained from end-of-life car and truck tires has been successfully recycled, among other applications, in the asphalt industry by providing a mean to get asphalt mixtures with superior performance. Textile fibres are another component derived from tire recycling typically disposed of in landfills or used in energetic valorisation. This paper wants to re-ignite interest in this secondary product by evaluating its use as a valuable resource in asphalt mixtures. Indirect tensile tests, dynamic modulus, fatigue resistance, and permanent deformation tests were performed on a series of AC14 asphalt mixtures manufactured with two binders, namely 50/70 and 35/50 pen, using several …
Dioxomolybdenum(VI) and -tungsten(VI) complexes with tetradentate aminobis(phenol)s
2006
Abstract Aminobis(phenol) ligands (H2Ln) carrying either a dimethylamino, a pyridyl or a methoxy sidearm donor were used in the preparation of new tungsten and molybdenum complexes. Treatment of [W(eg)3] (eg = 1,2-ethanediolate dianion) with H2Ln under hydrolytic conditions in a CHCl3–MeOH mixture gave the cis-dioxotungsten(VI) complexes [WO2(Ln)] in good yields. The corresponding molybdenum complexes [MoO2(Ln)] were prepared from [MoO2(acac)2] and respective ligands. The solid-state structures of two molybdenum and one tungsten compounds were determined by single crystal X-ray diffraction, which revealed that the dianionic aminobis(phenolate) backbones of the ligands have coordinated to th…
From tungsten hexacarbonyl adsorption on TiO2(1 1 0) surface to supported tungsten oxide phases.
2008
Abstract Synchrotron-based photoemission spectroscopies were used to study the adsorption of tungsten hexacarbonyl on (1 1 0) TiO 2 surfaces: experiments using W4f and Ti2p intensities variations show that, at 140 K, the hexacarbonyl growth proceeds via a layer-by-layer mode. Moreover, it was evidenced using both core levels and valence band experiments that, after back to room temperature, W(CO) 6 desorbs without significant decomposition. However, low energy (500 eV) ion (Ar + ) irradiation can allow partial decomposition of tungsten hexacarbonyl molecules leading to sub-carbonyl tungsten molecules. The bonding of sub-carbonyl species to the TiO 2 surface was then stronger than the one of…
The selective oxidative dehydrogenation of ethane over hydrothermally synthesised MoVTeNb catalysts
2002
Mo–V–Te–Nb metal oxide catalysts prepared by hydrothermal synthesis and heat-treated in N2 at high temperatures (600–700 °C) show high activity and selectivity for the oxidative dehydrogenation of ethane to ethene. Yields of ethene of 75% have been obtained at 400 °C on the best catalysts. Dejoz Garcia, Ana Maria, Ana.M.Dejoz@uv.es
Heavy metal ion induction of adhesion molecules and cytokines in human endothelial cells: the role of NF-kappaB, I kappaB-alpha and AP-1.
1997
We analyzed the influence of heavy-metal ions on human umbilical vein endothelial cells (HUVEC) in comparison to proinflammatory cytokines (TNF-alpha, IL-1beta) and lipopolysaccharide (LPS). Adhesion molecule and cytokine expressions are upregulated by heavy-metal exposure. Expression of E-selectin on the cell surface was strongly induced by 1-mM concentrations of NiCl2 and CoCl2, whereas ZnCl2 and CrCl3 had no influence. Furthermore, it is shown that NiCl2 induces mRNA expression of E-selectin, intercellular adhesion molecule-1, IL-6 and IL-8 in a 1-mM concentration. The transcription factor NF-kappaB is known to be involved in the regulation of adhesion molecule expression in endothelial …
Low-Grade Mylonites
2009
The temperature range for these mylonites is thought to be roughly between 250 and 500 °C. There is a gradual transition between cataclasites and low-grade mylonites. Whereas many feldspar porphyroclasts in low-grade mylonites still show fracturing by cataclasis, the quartz is usually deformed by crystal-plastic processes as shown by its change in shape and by undulose extinction. At increasing temperature bulging recrystallisation starts to manifest itself along the lobate contacts and eventually recrystallisation by subgrain rotation takes over (Chapter 10).
Micromechanisms of load transfer in a unidirectional carbon fibre-reinforced epoxy composite due to fibre failures: Part 3. Multiscale reconstruction…
2008
International audience; This third article describes a multiscale process which takes into account the most important microscopic phenomena associated with composite degradation, including fibre fractures and interfacial debonding, overloading of fibres neighbouring a fibre break as well as viscoelastic behaviour of the matrix. The results have been used to accurately predict the macroscopic failure of unidirectional carbon fibre-reinforced epoxy and quantify damage accumulation in pressure vessels made of the same material. The approach described has allowed the acoustic emission activity resulting from fibres breaks to be evaluated and shown how the residual lifetimes of such vessels, whe…
Evaluation of bond strength of orthodontic brackets without enamel etching
2015
Background: to compare the shear bond strength of brackets with and without enamel etching. Material and Methods: In this study, 60 sound premolars were randomly divided into four different groups: 1- TXE group: Enamel etching + Transbond XT adhesive + Transbond XT composite. 2- TXS group: Transbond plus self-etch adhesive + Transbond XT composite. 3- PQ1E group: Enamel etching + PQ1 adhesive + Transbond XT composite. 4- PQ1 group: PQ1 adhesive + Transbond XT composite. The shear bond strengths of brackets were evaluated using universal testing machine at cross head speed of 0.5 mm/ min. The Adhesive Remnant Index (ARI) was also measured. One-way ANOVA, Tukey’s post hoc, Kruskal-wallis and …