Relevance of porosity and surface chemistry of superactivated carbons in capacitors

We show, through some examples, that chemical activation by alkaline hydroxides permits the preparation of activated carbons with tailored pore volume, pore size distribution, pore structure and surface chemistry, which are useful for their application as electrodes in supercapacitors. Examples are presented discussing the importance of each of these properties on the double layer capacitance, on the kinetics of the electric double-layer charge-discharge process and on the pseudo-capacitative contribution from the surface functional groups or the addition of a conducting polymer.

A new betweenness centrality measure based on an algorithm for ranking the nodes of a network

We propose and discuss a new centrality index for urban street patterns represented as networks in geographical space. This centrality measure, that we call ranking-betweenness centrality, combines the idea behind the random-walk betweenness centrality measure and the idea of ranking the nodes of a network produced by an adapted PageRank algorithm. We initially use a PageRank algorithm in which we are able to transform some information of the network that we want to analyze into numerical values. Numerical values summarizing the information are associated to each of the nodes by means of a data matrix. After running the adapted PageRank algorithm, a ranking of the nodes is obtained, according to their importance in the network. This classification is the starting point for applying an algorithm based on the random-walk betweenness centrality. A detailed example of a real urban street network is discussed in order to understand the process to evaluate the ranking-betweenness centrality proposed, performing some comparisons with other classical centrality measures.

Analyzing the commercial activities of a street network by ranking their nodes: a case study in Murcia, Spain

Urban researchers and planners are often interested in understanding how economic activities are distributed in urban regions, what forces influence their special pattern and how urban structure and functions are mutually dependent. In this paper, we want to show how an algorithm for ranking the nodes in a network can be used to understand and visualize certain commercial activities of a city. The first part of the method consists of collecting real information about different types of commercial activities at each location in the urban network of the city of Murcia, Spain. Four clearly differentiated commercial activities are studied, such as restaurants and bars, shops, banks and supermarkets or department stores, but obviously we can study other. The information collected is then quantified by means of a data matrix, which is used as the basis for the implementation of a PageRank algorithm which produces a ranking of all the nodes in the network, according to their significance within it. Finally, we visualize the resulting classification using a colour scale that helps us to represent the business network.

The relevance of harmonising the technical level of social housing with the urban level of the neighbourhood through the example of the 500 dwellings in Albacete

The Architecture and Household Trade Union built nearly 2,000 subsidized dwellings in Albacete from 1941 to 1971. It was the responsible entity from the end of the Civil War until the beginning of Democracy of the social policy programs in Spain. Later on, and together with the National Housing Institute, were responsible for the construction activity. Its limited budget, scarcity of technical and human resources and an urgent need for new housing developments, constituted the basis for producing a vast housing market of low construction qualities. However, thanks to the true architectonic expertise of some of the professionals, some of the developments were designed with a clear urban strategy and in direct relation with the city, which characterizes them to be studied and conserved. This is the case for the selected development for the analysis, the urban complex of the 500 dwellings in Albacete, the Hermanos Falcó Neighborhood. Designed and built between 1963, Alfonso Crespo and Adolfo Gil architects, and 1977 second reformed project by the architect Fernando Rodríguez. It is characterized by its layout on the territory, its controlled relation with the city and its different types of open blocks. Above all, its spatial and human scale strengths, directly related to the European post-war proposals, have to be emphasized; although its technical deficiencies affect the interior quality of the houses. This paper examines its virtues and failures and proposes, using current tools, its renovation. This proposal main aims are to extend its lifetime and develop the particular and urban sustainability levels.