Influence of an Agatha flax fibre location in a stem on its mechanical,chemical and morphological properties

The mechanical properties of flax fibres are analysed as a function of their biochemical and morphological characteristics. The fibres, from the Agatha variety, have been selected from either the top, the middle or the bottom of the stems. The results of each analysis are discussed according to the position of the fibre in the stem and compared among themselves. Considering a flax fibre as a natural composite, this study underlines the complexity of its structure and shows that many parameters intervene in its deformation behaviour.     

Electrochemical studies on Sr doped LaMnO<Subscript>3</Subscript> and LaCoO<Subscript>3</Subscript> layers synthesised in a low-pressure plasma reactor equipped with a convergent nozzle

The aim of this work was to synthesise and deposit a perovskite (La_1-x Sr _x MnO₃ or La_1-x Sr _x CoO₃) cathode on an SOFC electrolyte (8% Yttria Stabilised Zirconia – YSZ). The recombination of atomic oxygen on Sr doped LaMnO₃ was performed in order to study the properties of perovskite for the adsorption of oxygen. The electrical resistance of the layers was measured as a function of the chemical composition. Impedance measurements on different samples were performed in order to analyse the electrochemical response of the cathode – electrolyte stack as a function of temperature and nature of the atmosphere. Moreover, the Faradaic impedance representing the electrochemical processes at the cathode – electrolyte interface was calculated from the global impedance in various conditions.     

Aluminum multiple implantations in 6H–SiC at 300 K

A complete study was driven in order to elaborate a p⁺–n junction in 6H–SiC. The chosen techniques were aluminum multiple implantations, followed with high-temperature furnace annealings. First, we had to configure the furnace geometry aiming at optimizing the annealed material characteristics. We evidenced the beneficial effects of a SiC plate inside the furnace reactor on the surface stoichiometry of the annealed sample, and also on its crystal reordering velocity. Then, the fivefold aluminum implantation necessary for the 0.5 μm depth p⁺-region creation has been studied, especially the energy order influence on the junction steepness. It was found that the increasing energy order implantations lead to a channeling effect less important, a deeper amorphized zone, and a defect interface at volume more abrupt. After an annealing performed with the optimized furnace, the best electrical activation obtained equated the degree of ionization even though the as-implanted material was totally amorphized up to 0.25 μm. Moreover, the three different multiple implantations investigated during this study induced different amorphized layer depths, despite they all have the same total aluminum dose with the same highest energy value. All along the paper, we propose to explain this fact. This is probably due to distinct mechanisms involved in the amorphization phenomena, which were tentatively estimated with a specific Monte Carlo simulator recently developed.     

Dopamine D1 and D2 antagonist effects on response likelihood and duration.

Experimentally induced and parkinsonian disruptions in dopamine (DA) transmission are associated with motor abnormalities that include a reduced likelihood of behavioral response initiation and an increased duration of executed responses. Here we investigated the dopamine receptor subtypes involved in regulating these two aspects of behavior. We examined the effects of D1 family (D1/D5) antagonist R(+)-7-chloro-8-hydroxy-3-methyl-1-phenyl-2,3,4,5-tetrahydro-1H-3-benzazepine hydrochloride (SCH23390; 0, 0.04, 0.08, or 0.16 mg/kg) and D2/D3 antagonist 3,5-dichloro-N-(1-ethylpyrrolidin-2-ylmethyl)-2-hydroxy-6-methoxybenzamide (+)-tartrate salt (raclopride; 0, 0.2, or 0.4 mg/kg) on the likelihood and duration of a cued Pavlovian approach and a cued operant lever-press response. While the high doses of the D1 and D2 antagonists produced similar levels of overall locomotor suppression, only the D2 antagonist increased the duration of time that animals’ heads remained in the food compartment during both Pavlovian and operant task performance. In contrast, D1 antagonist SCH23390 decreased the proportion of trials in which animals executed both the Pavlovian approach and operant lever-press, while raclopride did not. The results suggest that D2 receptor blockade preferentially increases response duration, and, under the simple discrete-trial procedures employed here, D1 receptor blockade preferential reduces Pavlovian and operant response likelihood. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Performance evaluation of a WDM metropolitan network: A virtual prototyping approach

We present a generic low-cost and flexible metropolitan area network optical ring architecture and evaluate its performance using optical transmission simulation software. We describe a specific design method that can be used to extract relevant parameters, such as the ber and osnr for different channels at any ring network node. We show the possibility offered by a personal computer in the physical modeling of a complex system consisting of numerous components with many parameters. The design method that we describe can be considered as an efficient virtual prototyping method, offering cost and timesavings to network planners.     

Optimal dimensioning of the WDM unidirectional ECOFRAME optical packet ring

To efficiently support the high rate and the high dynamicity of the traffic in metro networks, an optical packet-switched WDM ring, named ECOFRAME, is proposed. The key features of the proposed ring are optical transparency and statistical multiplexing of optical packets on parallel WDM channels. Such features can be exploited by properly allocating wavelengths and receivers. This paper aims to optimally dimension the unidirectional ECOFRAME rings. The dimensioning at minimum cost (i.e., for wavelengths and receivers) is modeled with an mixed-integer linear programming formulation. An heuristic algorithm is also proposed, and its performance is compared against the optimal solutions and bounds. When considering the receiver and wavelength cost, results indicate that trading the wavelengths for receivers allows cost saving of up to 75% with respect to WDM optical packet rings with a single dedicated wavelength per node (i.e., single receiver at each node).     

Phospholipid Profiles of Oleaginous Pressed Cakes Using NMR and Gas Chromatography

Camelina, flaxseed, hemp, sesame, and walnut cakes were analyzed for their phospholipid (PL) content and composition using ³¹P and ¹H nuclear magnetic resonance and gas chromatography. The data evidenced variations between the sources in terms of (1) total lipid content and PL concentration, camelina cake being the richest source of PLs, (2) PL composition, phosphatidylcholine being the most abundant phospholipid in sesame and hemp cakes, whereas phosphatidylinositol represented about 25% of the total PLs in most cakes, and (3) fatty acid composition of the PLs, camelina cake being the richest source of omega 3 polyunsaturated fatty acids. These data may be useful to diversify the PL sources available and to provide PL fractions with specific nutritional or functional properties.