Water diffusion is widely believed to be a driving factor in the breakdown of corrosion protection by polymer coatings. However, in the epoxy-phenolic system examined, water absorption into more cured, electrically resistive coatings is shown to increase, contradicting the common perception that hydrophobic coatings yield improvements in corrosion protection. Water uptake into epoxy-phenolic coatings was estimated as a function of time using the dielectric and resistive properties of the coating measured using electrochemical impedance spectroscopy (EIS). Bulk water uptake through the coating surface and the localised nature of corrosive failure was then confirmed using localised electrochemical impedance (LEIS). This technique also allowed comparison of resistance for coatings with different curing degrees. The greater degree of water absorption into highly cured coatings was attributed to diffusion into the polymer free volume, which increases with prolonged crosslinking. Evidence for this mechanism was found in the decreasing density of epoxy-phenolic coatings as a function of cure time. The effect of coating volume was therefore evaluated with respect to the dry coating dielectric properties. Cathodic delamination of the epoxy-phenolic coatings was achieved on tinplated steel substrates, whereas this was not possible from tin-free steel (ECCS). The electrochemical behaviour of these two substrates was examined under the same NaCl concentration, their surfaces were analysed by XPS prior to immersion, and XRD after potentiostatic polarisations. The electrochemical behaviour of the bare substrates was found to be unchanged by heating to the coating cure temperature (within the accuracy of polarisation tests carried out). Nonetheless, the delamination rate of epoxy-phenolic coatings deposited on them was dependent on the coating crosslinking (cure time). The reason coating adhesion selectively failed on tinplate substrates is believed to be the lower concentration of hydroxides on its relatively flat surface, allowing less bonding to take place at the interface with the coating. The impact of the substrate on coating resistivity was further investigated by volume resistivity measurements in the presence and absence of a metallic substrate. The resistivity of free standing films was tested in permeation cells, and showed a direct correlation between the polymer resistivity and the resistivity of the solution in which it was immersed. In comparison, attached films remained highly resistive at all examined concentrations. To conclude, the results presented here demonstrate that water uptake is not as critical to the breakdown in the protection offered by epoxy-phenolics as bonding at the metal-polymer interface. These results suggest that the complex interaction between these two dissimilar materials determines the overall coating electrochemical behaviour.

ITC/USA 2013 Conference Proceedings / The Forty-Ninth Annual International Telemetering Conference and Technical Exhibition / October 21-24, 2013 / Bally's Hotel & Convention Center, Las Vegas, NV / Constrained codes also known as modulation codes are a key component in the digital magnetic recording systems. The constrained codes forbid particular input data patterns which lead to some of the dominant error events or higher media noise. In data recording systems, a concatenated approach toward the constrained code and error-correcting code (ECC) is typically used and the decoding is done independently. In this paper, we show the improvement in combining the decoding of the constrained code and the ECC using generalized belief propagation (GBP) algorithm. We consider the performance of a combined modulation constraints and the ECC on a binary symmetric channel (BSC). We show that combining demodulation and decoding results in a superior performance compared to concatenated schemes. Furthermore, we compute the capacity of the joint ECC and modulation codes for 1-D and 2-D constraints.

Made available in DSpace on 2014-10-09T12:45:15Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:56:53Z (GMT). No. of bitstreams: 0 / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

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Made available in DSpace on 2014-10-09T12:45:15Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:56:53Z (GMT). No. of bitstreams: 0 / Neste trabalho são apresentados resultados experimentais, de um circuito operando em circulação natural, que permitem analisar o comportamento de um sistema de resfriamento de emergência quando é aberta uma linha de desvio entre a fonte quente e a fonte fria. O trabalho tem ainda a importância de documentar os testes de caracterização hidráulica do circuito experimental, fornecendo inclusive os fatores de perda de pressão específicos para o circuito. Observou-se que, para uma mesma potência, quando é aberta a linha de desvio, a temperatura na saída da fonte quente aumenta substancialmente. Esse aumento ocorre porque a vazão através do aquecedor diminui. A vazão através do trocador de calor (fonte fria) aumenta ligeiramente, sendo sempre a soma das vazões na linha de desvio e no aquecedor. O trabalho mostra ainda que a posição de conexão da linha de desvio com a perna quente determina o sentido de escoamento, podendo ocorrer a inversão a partir de uma determinada cota. Para comprovar a possibilidade de simulação precisa dos experimentos foi ainda desenvolvido um modelo numérico das equações de conservação, utilizando o programa “Engineering Equation Solver” (EES). Esse modelo foi utilizado para reproduzir os experimentos de circulação natural pelo circuito externo. / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

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No / The objective of this study was to evaluate the effect of corrosion level on shear behavior of engineered cementitious composite (ECC) beams. Reinforced normal concrete (R-NC) specimens with compressive strength equal to the ECC specimens were also used for control purposes. Ten reinforced concrete beams (five ECC and five NC) with dimensions of 150 x 220 x 1400 mm (5.91 x 8.66 x 55.12 in.) were manufactured for the study. Using accelerated corrosion through the application of a constant current of 1 ampere, four levels of corrosion were established at 5%, 10%, 15%, and 20% of mass loss of the reinforcing bars. To ensure the highest probability of shear failure mode, all beams were tested under a four-point loading system with a shear span-effective depth ratio of 2.5. General structural behavior, strength, stiffness, failure mode, and energy absorption capacities of ECC and R-NC beams subjected to different corrosion levels were evaluated and compared. Experimental results showed a high correlation between calculated mass loss and measured mass loss in reinforcing bars due to accelerated corrosion. Compared to NC, ECC beams exhibited significantly higher strength, stiffness, and energy absorption capacity, along with superior performance in terms of the restriction of damage caused due to corrosion. The increase in corrosion level negatively influenced the structural behavior of the ECC beams tested.

Background The growth of global e-commerce along with technology and information adoption has driven the international expansions of retail firms. Even though e-commerce companies (ECCs) are changing the way businesses operate and generally have fewer physical barriers to new markets, they still face numerous challenges while internationalizing. Dynamic capabilities are found to have an impact on the internationalization process of ECCs, where exploitative and explorative dynamic capabilities will be the focus of this study. This topic is particularly relevant for the fashion industry since the industry has the characteristics of being highly dynamic, global and complex. Therefore, this paper will focus on the internationalization process of ECCs in the fashion industry. Purpose Due to limited research regarding the internationalization process of ECCs, the purpose of this study is to seek a deeper understanding concerning the internationalization process of fashion ECCs. In particular, in what way exploitative and explorative dynamic capabilities affect the internationalization process of fashion ECCs and how they use these capabilities. Method This is a qualitative study with an abductive research approach. Furthermore, the empirical data was collected from semi-structured in-depth interviews with six international fashion ECCs. Conclusion One main conclusion that can be drawn from this study is that all the ECCs use both exploitative and explorative dynamic capabilities in their internationalization, and hence, ambidexterity is achieved. Moreover, language, logistics and payment method are three major factors used in both activities and could be an explanation for how fashion ECCs use their exploitative and explorative dynamic capabilities when internationalizing.

E-commerce is an arguably new way of trading goods or services for monetary values through electronic means. It has increased in volume over the past years and it is not predicted to stop increasing in Sweden. The Swedish market holds a substantial amount of internet users who are in fact e-consumers. The European Union has taken a series of measures to harmonize the legislation regarding e-commerce in order to increase cross border e-commerce between the member states. The authors aimed to investigate the effect of the Swedish legislation on foreign companies’ establishment process on the Swedish e-commerce market. In order to achieve this, two in-depth interviews were conducted, one with a lawyer with considerable competence regarding e-commerce and the other one was in association with our case study on a French company that recently entered the Swedish e-commerce market. The research resulted in the notion that the Swedish legislation does differ from the European legal standards and that foreign ECCs have to adapt to the Swedish legislation. Another important finding is that European legislation is different between nations due to the variations in the interpretations of the same law text incorporated into the national legislations in the member states of the European Union. The resource based model of entry was also re-interpreted to facilitate the internationalization process of the companies.

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