Social awareness and duopoly competition

Human actions are often guided both by individual rationality and by social norms. In this paper we explore how duopoly market competition values the variants of a product, when these variants embody at different levels the requirements derived from some social norm. In a model where preferences of consumers depend partially on the levels of compliance of the variants with the social norm, we characterize the equilibrium path along which firms choose sequentially their level of compliance and their pric

Influence of temperature and applied potential on the permeability of polyphenol films prepared on vitreous carbon in acid and alkaline media

The electrochemical polymerization of phenol is known to rapidly produce a thin insulating film at the anode surface. This film generally blocks further polymerization. The objective of this study is to show that, depending on the operating conditions, polymeric films resulting from phenol oxidation present different properties and that certain films can be so porous that they allow the oxidation of phenol to continue. The deposition of polyphenol films with improved permeability could be attractive in the removal of phenol from polluted solutions. Polyphenol films were prepared in aqueous solution on a vitreous carbon anode either by cyclic voltammetry or by electro-oxidation at constant potential. The apparent permeability P (%) of the films prepared by these techniques was evaluated by monitoring changes in the electrode response towards phenol and potassium ferricyanide at 25 and 85°C and as a function of the potential applied during electropolymerization performed either in acidic (1 mol L-¹H₂SO₄) or in alkaline (1 mol L-¹ NaOH) aqueous solution. It was shown that: (1) the polyphenol film electrosynthesized in alkaline medium was more permeable than that prepared in acidic medium, (2) the apparent permeability was higher when the polyphenol film was electrosynthesized with simultaneous oxygen evolution and (3) the use of a high temperature in the polyphenol film preparation, especially in the presence of a concomitant oxygen evolution, significantly enhanced its apparent permeability (P ≥ 100 %). These results are interpreted in terms of a mixed-transport mechanism involving both pore and membrane diffusion. The effect of the permeability of the polymeric film on the removal of phenol from aqueous solution by electropolymerization is discussed

Influence of temperature and applied potential on the permeability of polyphenol films prepared on vitreous carbon in acid and alkaline media

The electrochemical polymerization of phenol is known to rapidly produce a thin insulating film at the anode surface. This film generally blocks further polymerization. The objective of this study is to show that, depending on the operating conditions, polymeric films resulting from phenol oxidation present different properties and that certain films can be so porous that they allow the oxidation of phenol to continue. The deposition of polyphenol films with improved permeability could be attractive in the removal of phenol from polluted solutions. Polyphenol films were prepared in aqueous solution on a vitreous carbon anode either by cyclic voltammetry or by electro-oxidation at constant potential. The apparent permeability P (%) of the films prepared by these techniques was evaluated by monitoring changes in the electrode response towards phenol and potassium ferricyanide at 25 and 85°C and as a function of the potential applied during electropolymerization performed either in acidic (1 mol L-¹H₂SO₄) or in alkaline (1 mol L-¹ NaOH) aqueous solution. It was shown that: (1) the polyphenol film electrosynthesized in alkaline medium was more permeable than that prepared in acidic medium, (2) the apparent permeability was higher when the polyphenol film was electrosynthesized with simultaneous oxygen evolution and (3) the use of a high temperature in the polyphenol film preparation, especially in the presence of a concomitant oxygen evolution, significantly enhanced its apparent permeability (P ≥ 100 %). These results are interpreted in terms of a mixed-transport mechanism involving both pore and membrane diffusion. The effect of the permeability of the polymeric film on the removal of phenol from aqueous solution by electropolymerization is discussed

Regular paper Modeling, Control and Analyze of Multi-Machine Drive Systems using Bond Graph Technique

JES Journal of Electrical Systems In this paper, a system viewpoint method has been investigated to study and analyze complex systems using Bond Graph technique. These systems are multimachine multi-inverter based on Induction Machine (IM), well used in industries like rolling mills, textile, and railway traction. These systems are multi-domains, multi-scales time and present very strong internal and external couplings, with non-linearity characterized by a high model order. The classical study with analytic model is difficult to manipulate and it is limited to some performances. In this study, a "systemic approach" is presented to design these kinds of systems, using an energetic representation based on Bond Graph formalism. Three types of multimachine are studied with their control strategies. The modeling is carried out by Bond Graph and results are discussed to show the performances of this methodology

Electrochemical polymerisation of phenol in aqueous solution on a Ta/PbO2 anode

This paper deals with the treatment of aqueous phenol solutions using an electrochemical technique. Phenol can be partly eliminated from aqueous solution by electrochemically initiated polymerisation. Galvanostatic electrolyses of phenol solutions at concentration up to 0.1 mol dm−3 were carried out on a Ta/PbO2 anode. The polymers formed are insoluble in acidic medium but soluble in alkaline. These polymers were filtered and then dissolved in aqueous solution of sodium hydroxide (1 mol dm−3). The polymers formed were quantified by total organic carbon (TOC) measurement. It was found that the conversion of phenol into polymers increases as a function of initial concentration, anodic current density, temperature, and solution pH. The percentage of phenol polymerised can reach 15%

Toksikološke metode otkrivanja opojnih droga u tragovima: kromatografska, spektroskopska i biološka karakterizacija derivata ecstasyja

Analysis often reveals variability in the composition of ecstasy pills from pure 3,4-methylenedioxymethamphetamine (MDMA) to mixtures of MDMA derivatives, amphetamine, and other unidentifi ed substances. For a comprehensive toxicological analysis one needs to know all steps to MDMA synthesis which may originate impurities. The aim of this study was to synthesise and determine the chemical-physical and in vitro biological properties of a series of MDMA derivatives. 3,4-methylendioxyphenyl-2-nitropropene (MDNP) was obtained by condensation of piperonal with an excess of nitroethane in the presence of ammonium acetate. MDNP was then reduced to methylenedioxyamphetamine (MDA) by LiAlH3. All compounds were analysed using HPLC and spectroscopic technique [Raman, nuclear magnetic resonance (NMR), or infrared (IR)] at all the steps of synthesis. In addition, we assessed the biological potentials of these compounds by measuring in vitro their (i) blood cell/whole blood partition coeffi cient, (ii) binding to plasmatic proteins (Fbp), and (iii) membrane adsorption. Chemical structure was determined with antibody fl uorescence polarisation immunoassay (FPIA). This study showed the presence of solid impurities, particularly of a neurotoxic compound of Al3+ in the fi nal products. FPIA identifi ed the aminoethane group close to the substituted benzene ring, but did not detect the two major precursors of MDMA: MDNP and piperonal. Raman spectroscopy is an attractive alternative technique to characterise ecstasy pills and it can identify stereoisomeric forms such as cis-MDNP and trans-MDNP, which exhibit signals at 1650 cm-1 and 1300 cm-1, respectively.Analize često otkriju neujednačenost sastava tableta ecstasyja od čistoga 3,4-metilendioksimetamfetamina (MDMA) do mješavina njegovih derivata, amfetamina i drugih neutvrđenih tvari. Stoga je za kvalitetnu toksikološku analizu potreban uvid u sve korake sinteze MDMA, s obzirom na to da se ondje vjerojatno kriju izvori nečistoće (prekursori, katalizatori). Cilj ovog ispitivanja bio je sintetizirati derivate MDMA te napraviti njihovu kemijsko-fi zikalnu i biološku in vitro karakterizaciju. 3,4-metilendioksifenil-2-nitropropen (MDNP) dobiven je kondenzacijom piperonala u suvišku nitroetana uz dodatak amonijeva acetata. Njegovom redukcijom s pomoću LiAlH3 dobiven je 3,4-metilendioksiamfetamin (MDA). Svi spojevi iz pojedinih koraka sinteze karakterizirani su s pomoću tekućinske kromatografi je visoke djelotvornosti (HPLC) i spektroskopskih tehnika [Ramanove spektroskopije, nuklearne magnetske rezonancije (NMR-a) te infracrvene spektroskopije (IR-a)]. Usto je ocijenjen i njihov biološki učinak in vitro mjerenjem (i) koefi cijenta raspodjele krvna stanica/puna krv, (ii) vezanja za bjelančevine u plazmi (Fbp) te (iii) adsorpcije na membranu. Kemijska je struktura utvrđena s pomoću fl uorescentnoga polarizacijskog imunokemijskog testa (FPIA). Analiza je u konačnim proizvodima utvrdila prisutnost krutih nečistoća, napose spojeva neurotoksičnog aluminija (Al3+). FPIA je prepoznao aminoetansku skupinu blizu supstituiranoga benzenskog prstena, ali ne i dva glavna prekursora za MDMA: MDNP i piperonal. Posebno je zanimljiva Ramanova spektroskopija budući da (i) pruža privlačnu alternativu za karakterizaciju sastava tableta ecstasyja te (ii) može otkriti stereoizomerne cis/trans-oblike spoja poput cis-MDNP-a odnosno trans-MDNP-a, čiji se signal vidi na 1650 cm-1 odnosno 1300 cm-1

UV-induced modification of stress distribution in optical fibers and its contribution to Bragg grating birefringence

This paper discusses the importance of stress-induced contributions to the photo-induced birefringence observed in fiber Bragg gratings. Optical tomography measurements are performed in exposed and unexposed fibers to extract the stress profiles induced by UV-writing of fiber Bragg gratings for various exposure levels. A photoelastic analysis and a high-order isoparametric finite elements method are then used to calculate the birefringence caused by stress profile modifications. The results are compared to the birefringence directly measured by spectral analysis of a chirped fiber grating with multiple phase-shifts. We can therefore estimate the fraction of the photo-induced birefringence due to stress-induced anisotropy following UV exposure. © 2008 Optical Society of America

Quantitative imaging of dielectric permittivity and tunability with a near-field scanning microwave microscope

We describe the use of a near-field scanning microwave microscope to image the permittivity and tunability of bulk and thin film dielectric samples on a length scale of about 1 micron. The microscope is sensitive to the linear permittivity, as well as to nonlinear dielectric terms, which can be measured as a function of an applied electric field. We introduce a versatile finite element model for the system, which allows quantitative results to be obtained. We demonstrate use of the microscope at 7.2 GHz with a 370 nm thick barium strontium titanate thin film on a lanthanum aluminate substrate. This technique is nondestructive and has broadband (0.1-50 GHz) capability. The sensitivity of the microscope to changes in relative permittivity is 2 at permittivity = 500, while the nonlinear dielectric tunability sensitivity is 10^-3 cm/kV.Comment: 12 pages, 10 figures, to be published in Rev. Sci. Instrum., July, 200