Developments in bilateral air service agreements

This dissertation deals with international transport law and looks at the development of bilateral air service agreements governing international scheduled flights from their inception after the Chicago Conference of 1944 until the present day. The Chicago Conference left a legacy of separation in airline services. Scheduled and nonscheduled flights came into existence and bilateral agreements are needed to regulate international scheduled services. The relationship between the state and its designated airline forms the pivot of the bilateral relationship. However, the aviation relationship between state and airline and between states inter se face challenges as globalisation and development take place in the air transport industry. New methods of cooperation now exist which need to be adapted to suit the needs of individual countries and airlines. South Africa has accepted the challenges of development and undertaken modern methods of cooperation such as code-sharing.LawLL.M

Electrochemical synthesis of polypyrrole doped with graphene oxide and its electrochemical characterization as membrane material

Polypyrrole (PPy) doped with graphene oxide (GO) has been electrochemically obtained by potentiostatic synthesis and its electrochemical behavior as membrane material has been studied for the first time. Fourier transform infrared spectroscopy with attenuated total reflection showed the formation of the hybrid material due to presence of PPy and GO bands. Field emission scanning electron microscopy micrographs showed the effective incorporation of GO sheets and the formation of a 3-D porous material with high surface area. Scanning electrochemical microscopy of PPy/GO films showed positive feedback close to the ideal conducting behavior, indicating a good electroactivity. Electrochemical impedance spectroscopy (EIS) was employed to measure the electrochemical properties of the coatings by two-, three-, and four-electrode configurations. The electronic conductivity of PPy/GO film, measured between two metallic conductors, was 4.7·10−6 S/cm. Its ionic conductivity was superior (1.6·10−3 S/cm) due to the high porosity of the material as demonstrated by cyclic voltammetry and EIS measurements, where the PPy/GO film was employed as a free-standing membrane. The diffusion-migration rate of tetramethylammonium chloride was very similar to sodium chloride when present in the same concentration, which indicated no influence of the size of the electrolyte conductor due to the high porosity. © 2016 Elsevier B.V. All rights reserved.Authors wish to thank the Spanish Ministerio de Ciencia e Innovacion (contract CTM2011-23583) for the financial support. J. Molina is grateful to the Conselleria d'Educacio, Formacio i Ocupacio (Generalitat Valenciana) for the Programa VALi+D Postdoctoral Fellowship (APOSTD/2013/056). A.I. del Rio is grateful to the Spanish Ministerio de Ciencia y Tecnologia for her FPI fellowship. Electron Microscopy Service of the UPV (Universitat Politecnica de Valencia) is gratefully acknowledged for help with FESEM and EDX characterization.Molina Puerto, J.; Bonastre Cano, JA.; Fernández Sáez, J.; Del Río García, AI.; Cases Iborra, FJ. (2016). Electrochemical synthesis of polypyrrole doped with graphene oxide and its electrochemical characterization as membrane material. Synthetic Metals. 220:300-310. https://doi.org/10.1016/j.synthmet.2016.06.028S30031022

Sensing and Tactile Artificial Muscles from Reactive Materials

Films of conducting polymers can be oxidized and reduced in a reversible way. Any intermediate oxidation state determines an electrochemical equilibrium. Chemical or physical variables acting on the film may modify the equilibrium potential, so that the film acts as a sensor of the variable. The working potential of polypyrrole/DBSA (Dodecylbenzenesulfonic acid) films, oxidized or reduced under constant currents, changes as a function of the working conditions: electrolyte concentration, temperature or mechanical stress. During oxidation, the reactive material is a sensor of the ambient, the consumed electrical energy being the sensing magnitude. Devices based on any of the electrochemical properties of conducting polymers must act simultaneously as sensors of the working conditions. Artificial muscles, as electrochemical actuators constituted by reactive materials, respond to the ambient conditions during actuation. In this way, they can be used as actuators, sensing the surrounding conditions during actuation. Actuating and sensing signals are simultaneously included by the same two connecting wires

Spectroelectrochemical study of the influence of anions on the formation and on the behaviour of poly(N-vinylcarbazole) films

Poly(N-vinylcarbazole) (PVCz) films were prepared by potentiostatic deposition onto indium tin oxide-coated glass (ITO) electrodes from acetonitrile solutions containing the monomer. Two different supporting electrolyte solutions, LiClO4 and LiBF4, were used. The electrochemical behaviour of the polymer-coated electrodes was studied in solutions containing successively, both electrolytes, by means of in situ UV-vis spectrophotometry. The experimental results obtained in both electrolytes at the same analytical concentration could not be interpreted completely by considering only the influence of the size of the electrolyte anion. Spectroelectrochemical measurements performed in electrolyte solutions of the same conductivity have shown the importance of the specific interactions which may exist between the anions and the oxidized polymer sites.info:eu-repo/semantics/publishe