9,885 research outputs found

    Disaggregating Market Definition: \u3ci\u3eAmEx\u3c/i\u3e and a Plural View of Market Definition

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    The orthodox view of market definition in antitrust cases is that the same principles of market definition should apply at all stages of an antitrust analysis, and, in particular, that markets should be defined for virtually all purposes by reference to demand-side substitutability. Commentators have struggled to reconcile the Supreme Court’s recent decision in Ohio v. American Express Co.—in which the majority combined services to cardholders and services to merchants into a single antitrust market, despite the evident lack of substitutability between them—with that familiar view. In this short Article, we suggest that this effort at reconciliation may be unnecessary, and perhaps even undesirable. Against the orthodox view, we claim that market definition should be “disaggregated” such that the correct approach to market definition may vary depending on the element of the antitrust analysis for which it is being used. Thus, while market definition based on substitutability is an appealing tool for the assessment of market power, it may not be appropriate for the evaluation of competitive effects in all cases under Section 1 of the Sherman Act. The majority opinion in AmEx can (and perhaps should) be understood as an implicit—albeit cryptic—endorsement of a disaggregated approach to market definition. I. Introduction II. The AmEx Majority Opinion ... A. Overview ... B. Market Definition ... C. Analysis of Competitive Effects III. AmEx and a “Plural View” of Market Definition ... A. The Unitary View ... B. The Plural View IV. AmEx and the Integrity Principle V. Conclusio

    Diagnostic in TCOs CVD processes by IR pyrometry

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    Infra red pyrometry is a sensitive, simple and low-cost technique commonly used for the measurement of the deposition temperature in CVD processes. We demonstrate in this work that this optical technique can be used as diagnostic tool to provide fruitful informations during the growth under atmospheric pressure of TiO2 films on various substrates chosen as an example of transparent oxide. Significant variations of the pyrometric signal were observed during the deposition of TiO2 thin films due to interferences in the growing film resulting from multi-reflections at the interfaces and scattering induced by the surface roughness. Modeling of the time dependence of the IR pyrometric signal allows simultaneously the determination of the layer thickness, the growth rate, surface roughness and refractive index of the thin films under the growth conditions. This diagnostic technique can be used for various transparent thin films grown on opaque substrates and is well adapted to control CVD processes operating either under atmospheric or low pressure and more generally any thermal treatment processes

    TiOxNy coatings grown by atmospheric pressure metal organic chemical vapor deposition

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    Titanium oxynitride coatings were deposited on various substrates by an original atmospheric pressure metal organic chemical vapor deposition (MOCVD) process using titanium tetra-iso-propoxide as titanium and oxygen precursors and hydrazine as a nitrogen source. The films composition was monitored by controlling the N2H4 mole fraction in the initial reactive gas phase. The variation of the N content in the films results in significant changes in morphological, structural and mechanical properties. When a large excess of the nitrogen source is used the resulting film contains ca 17 at % of nitrogen and forms dense and amorphous TiOxNy films. Growth rates of these amorphous TiO1.5N0.5 coatings as high as 14 μm/h were obtained under atmospheric pressure. The influence of the deposition conditions on the morphology, the structure, the composition and the growth rate of the films is presented. For the particular conditions leading to the growth of amorphous TiO1.5N0.5 coatings, first studies on the mechanical properties of samples grown on stainless steel have revealed a high hardness, a low friction coefficient, and a good wear resistance in unlubricated sliding experiments against alumina which make them very attractive as protective metallurgical coatings

    N-doped TiO2 coatings grown by atmospheric pressure MOCVD for visible light-induced photocatalytic activity

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    N-doped TiO2 films were deposited by atmospheric pressure CVD from titanium tetra-isopropoxide (TTIP) and N2H4 as reactive gas in the temperature range 400–500 °C on various substrates. The films grown at 400 °C are amorphous and exhibit a compact structure and a smooth surface morphology. Increasing the deposition temperature first leads to the crystallization in the anatase structure (temperature range 410–450 °C) and then to the formation of rutile, so that an anatase-rutile mixture is observed in the temperature range 450–500 °C. Correlation between the structure, the morphology, optical properties, hydrophilicity and photocatalytic activity of the thin films both under UVand VIS light are presented and discussed in relation with deposition conditions

    Pyrosol deposition of anatase TiO2 thin films starting from Ti(OiPr)4/acetylacetone solutions

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    TiO2 thin films were deposited on Si(100) and steel substrates by Pyrosol technique. The layer morphology depends on the concentration of titanium tetra-isopropoxide (TTIP) used as molecular precursor in solutions with acetylacetone (Acac). The concentration and, as a result, the viscosity of these TTIP/Acac starting solutions plays an important role on the efficiency of their nebulization and, consequently, on the microstructure and the growth kinetics of the TiO2 thin films. The correlations between the composition of the TTIP/Acac solutions and the structure, the morphology, optical properties and the deposition rate of the films are presented and discussed. Growth rates as high as 1.8 μm/min are obtained using pure TTIP without Acac solvent. The photocatalytic activity of these Pyrosol TiO2 thin films grown using TTIP with and without Acac solvent has been investigated and a negative effect of the solvent was found

    Multi-objective optimisation for battery electric vehicle powertrain topologies

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    Electric vehicles are becoming more popular in the market. To be competitive, manufacturers need to produce vehicles with a low energy consumption, a good range and an acceptable driving performance. These are dependent on the choice of components and the topology in which they are used. In a conventional gasoline vehicle, the powertrain topology is constrained to a few well-understood layouts; these typically consist of a single engine driving one axle or both axles through a multi-ratio gearbox. With electric vehicles, there is more flexibility, and the design space is relatively unexplored. In this paper, we evaluate several different topologies as follows: a traditional topology using a single electric motor driving a single axle with a fixed gear ratio; a topology using separate motors for the front axle and the rear axle, each with its own fixed gear ratio; a topology using in-wheel motors on a single axle; a four-wheel-drive topology using in-wheel motors on both axes. Multi-objective optimisation techniques are used to find the optimal component sizing for a given requirement set and to investigate the trade-offs between the energy consumption, the powertrain cost and the acceleration performance. The paper concludes with a discussion of the relative merits of the different topologies and their applicability to real-world passenger cars

    Growth of TiO2 thin films by AP-MOCVD on stainless steel substrates for photocatalytic applications

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    TiO2 thin films were deposited under atmospheric pressure by MOCVD in the temperature range 400–600 °C on stainless steel and Si(100) substrates. Titanium tetraisopropoxide (TTIP) was used as Ti and O source. Single-phased anatase and bi-phased (anatase/rutile) coatings with controlled composition have been deposited depending on the temperature and the TTIP mole fraction. The films grown on stainless steel at low temperature (b420 °C) and low TTIP mole fraction (b10−4) are constituted of pure anatase and they exhibit a high photocatalytic activity under UV light and a high hydrophilicity. In the temperature range 430–600 °C the rutile starts growing leading to anatase/rutile mixtures and subsequently to a progressive decrease of both photocatalytic activity and wettability. Correlations between functional properties and microstructure of the films are discussed

    Effect of H2 on the microstructure and properties of TiO2 films grown by atmospheric pressure MOCVD on steel substrates

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    TiO2 thin films were deposited under atmospheric pressure by MOCVD in the range 400-600 °C on various steel substrates under hydrogen ambiance. It is unusual to study the growth of functional oxide layers under H2 partial pressure, i.e. a reactive gas generally used as reductive atmosphere in CVD. Titanium tetra-isopropoxide was used as single source precursor of Ti and O. The growth rate of TiO2 layers grown under nitrogen increases with the temperature and reaches a maximum in the range 500-550 °C. At these temperatures the diffusion of substrate ions enhances the formation of rutile leading to a lower UV photocatalytic activity. Addition of H2 in the input gas phase during the deposition (i) reduces the formation of interface oxide layer, (ii) prevents the diffusion of cations from the steel substrate toward the TiO2 layer and (iii) favors the growth of anatase. This leads to an increase of photocatalytic efficiency under UV irradiation
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