The electrochemical characteristics of commercial aluminium alloy electrodes for Al/air batteries

To develop new materials for Al/air batteries, the evaluation and characterisation of commercial aluminium alloys, namely, Al2000, Al2000Clad and Al7000, as anodes in alkaline electrolyte batteries has been performed. Their self-corrosion rate, hydrogen evolution rate and electrochemical properties, including open circuit potentials, polarisation characteristics and potentiodynamic measurements, were examined in a 4 M KOH solution. Among the tested alloys, Al2000 was found to be the most promising because it exhibits a high open circuit potential, a good anode efficiency and a minimum corrosion rate. Al2000/NiOOH and Al2000/air batteries were tested. Electrolyte concentrations between 0.01 and 4 M KOH were studied, and discharge currents between 0.8 and 20 mA cm^?2 were imposed to analyse the evolution of the E_cell. Conversely, the Al7000 alloy exhibited the highest corrosion rate and H₂ evolution compared to the other alloys.     

Staphylococcus aureus survival, staphylococcal enterotoxin production and shelf stability of country-cured hams manufactured under different processing procedures

Fresh hams were inoculated with Staphylococcus aureus, cured, equalized, cold smoked or non-smoked, and aged. Initial S. aureus populations of 8.57 and 8.12 Log(10) CFU/cm(2) for salt and salt+NO(2)hams decreased to below the levels of detection after the fourth month of aging. S. aureus was detected following enrichment for 75% of the inoculated and 62% of the control hams at the end of the aging period. Staphylococcal enterotoxin was detected in 40% of the inoculated and 50% of the control hams following the aging period. The NaCl content of these hams with or without nitrite were 4.45/3.37% and a(w) values 0.94/0.91. Country-cured ham products obtained from retail stores in Kentucky were all negative for S. aureus enterotoxin. These results indicate that higher salt content and lower a(w) values on country-cured hams play an important role in controlling the growth and toxin production of S. aureus.     

On the performance and improvement of alias resolution methods for Internet core networks

The Internet is a huge interconnection of thousands of networks with different technologies, equipment, configurations, and administrative owners. This, added to the lack of public information about those individual infrastructures, makes it a difficult task to provide a so-called Internet map: a topological map with information of routers, interconnections between routers, and IP addressing configuration. Traditional topology discovery methods based on traceroutes only provide IP addresses in the path between end-nodes. Some of those IP addresses can belong to the same router, and this identification is made by alias resolution methods. Therefore, alias resolution allows to provide router-level map of the Internet with important applications in network simulation, protocol design, network management, network security, network service design, and geolocation. In this paper, alias resolution methods are analyzed in Internet core networks (GlobalNOC, Canet4, and Geant). This allows to identify peculiar behaviors in these core networks, improving alias resolution methods. Simultaneously, reduction methods are used to decrease the number of probing packets in alias resolution methods.     

New Light and Highly-Damped Bonded Structures for Noise and Vibration Reduction

The current trend with machine tool structures is the reduction of weight of their moving parts. The present paper looks at a method for achieving this, namely that of bonding rigid materials, whether or not of metal. Special emphasis is laid on achieving structures with a high damping ratio. The method makes it possible to combine materials and thicknesses, and produce closed, ribbed sections. To assess the behaviour of these structures it was necessary to develop a tool that adds to the features of a finite-element system. With this tool it is possible to assess not only rigidity and mass, but also damping. Various glues were tested, so that those providing optimum rigidity and damping may be used. The prototypes demonstrate the validity of the technology of bonding and of the method of verification.     

The material optimization and reliability characterization of an indium-solder thermal interface material for CPU packaging

Developing new thermal interface materials (TIMs) is a key activity to meeting package thermal performance requirements for future generations of microprocessors. Indium solder is capable of demonstrating end-of-line performance to meet current technology targets due to its inherent high thermal conductivity. However, improving its reliability performance, particularly in temperature cycling, is a challenge. This study describes the failure mechanisms and reliability performance of indium solder TIM as a function of integrated heat spreader metallization thickness, TIM bond line thickness, and die size. Also studeited were the steps taken to improve its temperature cycle performance. Analyses were performed using thermal resistance measurements, scanning-electron microscopy, scanning-acoustic microscopy, and transmission-electron microscopy to characterize the solder TIM thermal performance, interfacial microstructure, and failure mechanisms.     

Managing product/process knowledge in the concurrent/simultaneous enterprise environment

Innovation is a critical factor in the success of industrial companies, and just as important is the need to get innovative products to the market quickly. Therefore, it is important to talk about ‘management of product development time’ because, under this new paradigm, companies able of ‘mastering’ the development time will launch the product into the market just spending the planned time and resources and at the real moment. This will give back to the company higher market share and faster market penetration. The main objective of the project Acceleration of Innovative Ideas into the Market (AIM) is to provide the means of stimulating the creation of innovative ideas in general, and specifically on potential product/process improvements and on problem solving. These ideas are collected throughout the extended enterprise from people involved with the products and processes; this knowledge will be further developed into innovations in a project-basis process.     

Wave energy plants: Control strategies for avoiding the stalling behaviour in the Wells turbine

This study analyzes the problem of the stalling behaviour in Wells turbines, one of the most widely used turbines in wave energy plants. For this purpose two different control strategies are presented and compared. In the first one, a rotational speed control system is employed to appropriately adapt the speed of the double-fed induction generator coupling to the turbine, according to the pressure drop entry. In the second control strategy, an airflow control regulates the power generated by the turbine generator module by means of the modulation valve avoiding the stalling behaviour. It is demonstrated that the proposed rotational speed control design adequately matches the desired relationship between the slip of the double-fed induction generator and the pressure drop input, whilst the valve control using a traditional PID controller successfully governs the flow that modulates the pressure drop across the turbine.     

Tendencies in scientific output on carbon nanotubes and graphene in global centers of excellence for nanotechnology

A change has been taking place in the world of nanotechnologies since 2009, marking the beginning of a new era of end consumer goods related to these new technologies. In this article, our aim is to know the dominant tendencies observed in scientific output on carbon nanotubes at centres and poles from different countries and considered to be at the forefront of nanotechnologies research. We have selected a sample comprised of eight universities and locally coherent concentrations from different geographic areas: Europe, America and Asia. Based on this sample, we have used the Scopus database to analyse scientific output on carbon nanotubes in order to determine if there are significant differences in behaviour. We observe that dynamics of scientific output on nanotubes are similar in the universities and clusters analysed over time although a drop in publications was noted in 2009 in part of the organizations included in the sample. We have seen a large amount of publications on graphene in the last several years, due to the fact that researchers working in the field of carbon nanotubes gradually move towards the study of graphene, explained by the high expectations concerning the use of this element. The results lead us to conclude that advances in knowledge on carbon nanotubes and graphene will make it possible to meet the growing needs of a new and powerful market for products that are progressively including these new elements.     

Related variety and regional growth in Spain*

This paper investigates whether related variety, among other types of spatial externalities, affected regional growth in Spain at the NUTS 3 level during the period 1995–2007. We found evidence that related variety matters for growth across regions, especially when using two new methods that measure revealed relatedness between industries. The first method is based on Porter's cluster classification while the second method uses the proximity index proposed by Hidalgo et al. Our analyses show that Spanish provinces with a wide range of related industries tend to show higher economic growth rates, once we control for other determinants of growth. Este artículo investiga si la variedad relacionada, entre otros tipos de externalidades espaciales, afectó el crecimiento regional en España a nivel NUTS 3 durante el periodo 1995‐2007. Hallamos pruebas de que la variedad relacionada influye en el crecimiento entre regiones, especialmente al utilizar dos métodos nuevos que miden el grado de conexión manifiesto entre industrias. El primer método está basado en la clasificación de conglomerados de Porter, mientras que el segundo método utiliza el índice de proximidad propuesto por Hidalgo et al. Nuestros análisis muestran que las provincias españolas con un amplio rango de industrias relacionadas tienden a mostrar tasas de crecimiento económico más altas, una vez que se logra controlar otros factores determinantes del crecimiento.