MAGNETRON SPUTTERED NANOCRYSTALLINE TiN THIN FILMS AND CORROSION PROPERTIES

In this report, TiN nanocrystalline thin films were deposited on glass and Ti-6Al-4V substrates using a DC-magnetron sputtering technique. The TiN films were sputtered using a pure Ti target (99.9%) with 40W of power in Ar/N2 gas mixture atmosphere. The structure of the TiN films was characterized by X-Ray diffraction, as prepared films exhibited a (200) preferred orientation, while film annealed at 500 °C shows the (111), (200) and (311). Polycrystalline, cubic, (111)-orientated TiN films were produced by annealing temperature of 500 °C. The effect of deposited temperature on the microstructural morphologies of the thin films was studied by Field Emission Scanning Electron Microscope (FESEM). The particle size of the sputtered TiN films ranged from 50 to 70 nm and was strongly influenced by annealing temperatures, the morphology of the films deposited before and after annealing has a characteristic agglomeration of particles. Potentiodynamic polarization analysis of the TiN films confirms the inverse relationship between polarization resistance and corrosion current. The biocorrosion measurements for TiN films deposited on the Ti-6Al-4V substrate in 3.5% NaCl solution have also been obtained. Clear improvement in the corrosion resistance was observed rather than for untreated, especially for thermally annealed (500 oC) TiN/Ti-6Al-4V samples. The corrosion rate was 0.1458 mm/y for the uncoated sample, while 2.68510-4 mm/y for TiN/Ti-6Al-4V in samples after annealing. The average corrosion potential calculated was - 0.117 V. The results confirmed that coated alloys with 500 °C thermally treated exhibited a better electrochemical behavior compare with uncoated and non-thermally treated alloys possibly due to the better cohesion degree of the coatings.

A Mathematical Study of Accessibility and Cohesion Degree in a High-Speed Rail Station Connected to an Urban Bus Transport Network

In the last twenty years, the implementation of High-Speed Rail (HSR) has been one of the major strategies for territorial structuring used by various countries. This model has enhanced the development of countries such as France, Spain, Germany and Japan. At present, the United States and China are also starting to implement this model. Nevertheless, the lack of social and economic profitability of several networks is being increasingly analysed. Many networks located in particular regions serve populations that are not large enough to recover the initial investment. For this reason, it is necessary to evaluate the population served by this transport mode, beyond the number of users. In this sense, it is essential to identify the deficiencies and potentials of implementing a network linked to other secondary networks in a specific territory which can compensate for the so-calledtunnel effect. This article proposes to apply a mathematical approach based on graph theory to measure the Degree Accessibility Node (DAN) in a constrained Geographic Information System (GIS) model. Hence, it would be possible to compare regions, especially medium-sized cities, where the implementation of HSR could represent a qualitative leap due to incorporation into large transport networks. The DAN function uses static and dynamic studies to evaluate the level of connection of stations to secondary transport networks—local public transport in this case. Thus, the impact of high-speed trains could be spread to greater territorial and population ranges. Four cases have been studied, two in Germany (one of them, Fulda, is analysed in depth throughout this article) and two in Spain. These two countries were selected since HSR was implemented in the same relative period of time, in comparison with other European countries. Results show relevant differences, suggesting a review of inappropriate policies of transport integration in a city that could weaken the expansion of the positive effects of HSR integration.

On Simulation of Multi-Particle Impact Interactions in the Cold Spray Process

The cold spray process consists of coating build-up by sequential impact, deformation and bonding of many particles. Therefore, formation and properties of a deposited layer are not only affected by the impact behavior of a single particle, but also by subsequent impact events. To investigate the material behavior under such conditions, impact of multiple particles in cold spray was studied here by the finite element method. Effects of high strain rates and temperature on material yield and failure criteria were considered. Particle conditions prior to impact were derived from fluid dynamics calculations. To predict sticking behavior of the particle, an interfacial cohesive strength parameter was defined between the particle and the substrate. The effects of temperature and particle positioning were examined for three particle impacts. In addition, simulations involving 100 consecutive particle impacts were carried out, and findings were compared with experimental observations. Results showed that subsequent impacts have a large effect on the previously impacted particles for cohesion, degree of deformation, and residual stresses.

Decomposition-Based Modularity Method for Product Collaborative Design

With the development of economic globalization, the union enterprises under the circumstance of inter-industry, inter-regional, inter-national have been making rapid development, which requires that the products R & D need implementing in the distributed heterogeneous environment. Modularity is the foundation of product collaborative design (PCD), and the decomposed modules are vital to improve the efficiency and performance of PCD. To meet the modularity requirements of PCD in the distributed heterogeneous environment, a new method of decomposition-based modularity for PCD is presented based on the combination of the heuristic analysis and the quantitative optimization. Firstly, on the basis of the incidence matrix of sub-task, the mathematic model based on multi-objective optimization is established in order to maximize the module cohesion degree and minimize the module coupling degree, while considering the module executable degree as the restrictions. Secondly, the mathematic model is optimized and simulated by the modified PSO, and the optimized modules are obtained. Finally, the rationality and effectiveness of this methodology is proved in an instance of collaborative design related to automobile body.

Consensus en oppositie in het Belgisch parlement tijdens een verkiezingsjaar : Onderzoek op basis van het stemgedrag in de Kamer van Volksvertegenwoordigers in 1985

This article describes the consensus and opposition in the Belgian Parliament (the Chamber) during 1985, a year of general elections. These phenomena are examined through the nature of voting patterns and the cohesion degree in the Chamber itself, between the ruling parties and between the parties in the opposition, as well as in the political parties itselves.The government vs. opposition gap is the dominant voting pattern. Unanimity counts for only 6 %, especially then in the final voting. VU and RAD/UDRT often join the majority vote.The dominant voting pattern is affirmed by the total Chamber cohesion degree: majority vs. opposition. The cohesion between the parties in opposition reaches lower than the majority cohesion degree. Cohesion in the fractions quotes higher in the smaller fractions, as well as in the fractions of the ruling parties.