A combined electrochemical quartz-crystal microbalance probe beam deflection (EQCM-PBD) study of solvent and ion transfers at a poly[Ni(saltMe)]: modified elecrode during redox switching

The oxidative polymerization of the complex2,3-dimelhyl-N,N-bis( salicylidene)butane-2,3-diaminatonickel( n), [Ni(saltMe)], was monitored by the electrochemical quartz microbalance (EQCM) and crystal impedance techniques. Polymerisation efficiency was maintained throughout deposition of a film, which behaved rigidly, on the electrode

Electrochemical behavior of a new precursor for the design of poly[Ni(salen)]-based modified electrodes

Wedescribe the potentiodynamic preparation and subsequent characterization of poly[Ni(3-MeOsaltMe)] films (surface concentration, 3 < ¡/nmol cm-2 < 350) in acetonitrile media. Coulometric and gravimetric (electrochemical quartz crystal microbalance, EQCM) data allow one to monitor the deposition process and show that the resultant films are physically and chemically stable

Universal current-potential relationship for mass-transfer through Formal Graph approach

International audienceThe Formal Graph theory, a new language able to model graphically instead of algebraically most of basic equations used in physics and chemistry, is applied to mass-transfer occurring in electrochemical reactions. The integral admittance used in electrodynamics is generalized to all domains where energy is defined. Associated with the concept of energy coupling, this leads to very simple relationships between variables and operators describing processes in a system containing several energy varieties. The paradox of two different forms for the electric capacitance, linear in electrostatics and exponential in electrified materials, is treated and understood. The concept of energetic path brings physical meaning into mathematical models by attributing to each link a role in the conservation or dissipation of the energy. Normal transient diffusion, featured by an exponent 1/2, conserves half of energy, while anomalous diffusion, featured by an exponent p different from 1/2, conserves only 100 p%. The principle of every electrochemical measurement is represented in a simple and clear way by associating two Formal Graphs. The use of a mass-transfer operator generalizing all kinds of mass-transfer (diffusion, convection, thin layer, etc.) and for all geometric situations, allows the characterization of unknown process without previous knowledge of an algebraic model

Are Our Basic Concepts, such as Activity and Equilibrium Laws, Necessarily based on Statistics?

International audienceLewis' relationship defining the activity is demonstrated from scratch without using any statistical argument and is generalized to every domain in which energy exists. A general and simple theory of influence is developed based on the Formal Graph approach and on the analogy with radiation transmission through an absorbing medium. This new approach explains that the electric capacitance can be represented by an exponential function in some materials when more than one energy variety is present and why equilibrium laws in chemistry can be verified with very small numbers of molecules (typically enzymes, proteins ...). Applicability of Nernst's law to immobilized species onto an electrode, out of the validity domain of Boltzmann's statistic, is also establishe

Introduction to Formal Graphs, a new approach of the classical formalism

International audienceThe creation of a purely graphic language called Formal Graphs for modelling many physical and physico-chemical systems is described. It represents an improvement over traditional equivalent circuits used for modelling systems made of individual components and over bond graphs used mainly in physico-chemistry. In contradistinction with these graphs, which represent graphically only mounting equations and maintain algebraic equations for describing components behaviour, a formal graph is an oriented graph incorporating all the information contained in a usual algebraic model. Combination of paths considerably extends use to domains that were not accessible to quantitative graphs, such as relaxation processes, chemical reactivity or mass-transfer. Moreover, inclusion of space derivation allows representing graphically every physical law describing a process involving energy conservation or dissipation, such as particle diffusion. Physical meaning can be deduced from paths in a graph that can be followed by processes, as illustrated by the exponent of fractional derivation, which appears as bearing the information on the proportion of conserved versus dissipated energy. The numerous examples given in this introduction address several domains, electrodynamics, mechanics, thermodynamics, and physico-chemistry. They show common graph structures that reveal a striking unity of our classical formalism, bringing transversal insight and opening a new route towards unification. Differences also appear that are subjects of interrogation

A New Graph Language for Representing the Macroscopic Formalism in Physico-chemistry and Physics.

International audienc

Opinions de nos lecteurs

Un vieil instituteur. Opinions de nos lecteurs. In: Manuel général de l'instruction primaire : journal hebdomadaire des instituteurs. 71e année, tome 40, 1904. p. 337

L'art de la peinture sur verre et de la vitrerie

En el lomo: Descripti des arts, Tomo XXVITit. y mencion tomados de la portFecha del pie consta en el colofonAntepTexto a 2 colTexto con apostillas marginalesSign.: A-3P(2), 3Q(1)Las h. de lam. son grab. xilContiene: I-III parti

ETUDE ET CARACTERISATION PAR TECHNIQUES IN SITU DE COUCHES ELECTROACTIVES DESTINEES A L'HYBRIDATION DE L'ADN POUR L'ELABORATION DE CAPTEURS ET DE BIOPUCES

GRENOBLE1-BU Sciences (384212103) / SudocSudocFranceF

L'art de la peinture sur verre et de la vitrerie

Pertenece a: "Descriptions des arts et mètiers faites ou approuvées par ... L'Académie Royale des Sciences". Paris: chez Desaint & Saillant, 1761-1789 (Brunet, 10217)Datos de imp. tomados del colofón, p. 239Sign.: [ ]\p1\s, a-c\p2\s, A-Z\p2\s, 2A-2Z\p2\s, 3A-3P\p2\s, 3Q\p1\sLas h. de grab. son calc."De La Gardette del. et sculp.", alusivas al tema del tratad