Relationship between static bending and compressive behaviour of particle-reinforced cement composites

Innovative particle-reinforced materials made of alumina particles and cement-based matrix were designed, manufactured and tested to evaluate the potential use of ceramic aggregates in concretes. These particle-reinforced composites were tested in three-point bending and uniaxial compression conditions to determine the influence of the shape and size of the ceramic inclusions, and the addition of silica fume on the mechanical properties. A specific methodology combining post-mortem observations with a statistical analysis of tensile failure stresses (average strength and Weibull modulus) was conducted to deduce the origin of failure for each cement-based composite (porosity or ceramic particles/matrix decohesion). A remarkable correlation is observed between bending failure stress level and the average strength measured under uniaxial compression loading. As main conclusion, addition of alumina particles in a mortar appears to strengthen or to weaken the composite depending on whether silica fume is used in the cementitious matrix.     

Effect of processing conditions on proteolysis and taste of dry-cured sausages

 This paper deals with the influence of industrial practices such as use of starters (Lactobacillus sake and Staphylococcus carnosus), preripening (3 days at 5°C) and drying temperatures (8 and 16°C) on proteolysis, ammonia production and the taste of “salchichón”, a traditional Spanish dry-cured sausage lacking surface mould. pH dropped more sharply in the presence of a starter and at a high drying temperature (16°C); preripening did not affect the pH. The highest value for non-protein nitrogen (NPN), 16% of total nitrogen, was observed to occur in samples with the lowest pH (4.7–4.8). Total volatile basic nitrogen (TVBN) increased during drying due to the deaminase activity of internal microbial flora, which was not great (0.5–1.0% of total nitrogen) enough to affect the pH, and significantly in samples showing a larger decrease of pH. The greater proteolysis in samples with starter did not affect the assessors’ taste preference. Assessors clearly preferred those samples without starter that were dried at low temperature (8°C); however, samples with starter showed excellent commercial appearance since they dried more homogeneously. An equilibrium point must be found between acid production and taste. Received: 12 February 1996/Revised version: 24 May 1996     

Bitumen modification with a low-molecular-weight reactive isocyanate-terminated polymer

A low-molecular-weight polyethyleneglycol functionalized with a polymeric MDI (4,4′-diphenylmethane diisocynate) was used as a modifying agent for a 60/70 penetration grade bitumen. The rheological properties of the resulting modified binder, at both low and intermediate temperatures, before and after curing at room temperature were studied and compared with those corresponding to a SBS modified bitumen. The analysis showed that the addition of a small quantity of this reactive polymer leads to enhanced rheological properties mainly at high in-service temperature (50 °C). However, modification was found to be rather slow during binder curing at room temperature. Moreover, storage stability analysis showed that phase separation did not take place after bitumen storage at 163 °C, though storage at high temperature affects the modification capability of the reactive polymer. Atomic force microscopy measurements showed that the reactive polymer addition leads to asphaltene-rich regions with lower thermal susceptibility, which are present even at high temperature, yielding an improved bitumen viscosity in this range of in-service temperatures.     

Integral numerical technique for the study of axially symmetricresonant devices

A numerical technique is proposed which is based on the coupling of Kirchhoff's integral formulation and the moment method and is suitable for application to the study of a wide class of axially symmetric resonant devices. Numerical results are presented and compared with corresponding theoretical data for two systems which allow an analytical treatment. The results confirm the validity of the method and its broad applicability. The simplicity and generality of the formulation allow such problems as unbound systems to be tackled, something that is difficult with other techniques. The complexity of the numerical procedure is not excessive, and the consideration of a low number of intervals in the boundary partition leads to quite accurate results, errors in frequency being less than 1%     

Electrochemical and morphological characterization of poly(12-pyrrol-1′-yl dodecanoic acid)

12-Pyrrol-1′-yl dodecanoic acid was prepared and electrochemically polymerized on ITO electrodes by three different methods. The electrochemical and morphological properties of poly(12-pyrrol-1′-yl dodecanoic acid) films were investigated by cyclic voltammetry, galvanostatic charge–discharge curves and AFM, which characteristics varied as function of deposition method. Films deposited by potentiodynamic and galvanostatic methods showed capacitive properties and are promising for application in polymeric capacitors.     

Chihuahua: a water reuse case in the desert.

Water supply for all kind of uses in Chihuahua is mainly groundwater. During the last decade this city has been damaged with a heavy hydrologic crisis because of a persistent drought. This came up with the overexploitation of groundwater aquifers; therefore a deficit between demand and offer was done. To minimize this problem the government authorities have started an integral plan of optimizing hydrologic resources which considers the treatment of wastewater and the use of reclaimed water. The secondary wastewater treatment facility of the city treats about 30,000 m3/d of a wastewater with high organic contents, and produces an effluent with low concentration of suspended solids, organic matter, fats, detergents, and metals. Reclaimed water is conveyed toward strategic sites for the irrigation of great green areas in sport clubs, educational institutions and industrial zones, besides of its utilization on some manufacturing processes, road service, and also over construction industry. The potential reuse of this water goes farther from those activities; the treatment of the secondary effluent until the required levels of the water-bearing recharge criteria are met for drinking water supply is considered as the next step to achieve through a suitable planning strategy for the best integral resource advantage.     

Combined FRM and GDFT filter bank designs for improved nonuniform DSA channelisation

Multistandard channelisation for base stations is a big application of generalised discrete Fourier transform modulated filter banks (GDFT‐FBs) in digital communications. For technologies such as software‐defined radio and cognitive radio, nonuniform channelisers must be used if frequency bands are shared by different standards. However, GDFT‐FB‐based nonuniform channelisers can suffer from high filter orders when applied to wideband input signals. In this paper, various combinations of GDFT‐FB with the frequency response masking technique are proposed and evaluated for both uniform and nonuniform channelisation applications. Results show that the proposed techniques achieve savings in both the number of filter coefficients and the number of operations per input sample. Copyright © 2015 John Wiley & Sons, Ltd.     

Urban regeneration policies and mental health in a context of economic crisis in Andalusia (Spain)

Literature suggests that urban regeneration policies might contribute towards improving mental health of residents, but to date there is a lack of empirical research on how these policies and downward social mobility can interact and influence health outcomes. The current study aims to explicitly test whether regeneration policies implemented in deprived Andalusian urban places (southern Spain) moderate the use of anxiolytics and/or antidepressants, taking into consideration families’ downward social mobility during the recent period of economic crisis in Spain. We designed a post intervention survey to retrospectively compare the evolution of psychotropic drug consumption in target and comparison areas. We observe a general increase in the use of anxiolytics and/or antidepressants from 2008 to 2015, specifically for people in whose families the economic crisis had the greatest impact (odds ratio?=?2.18; p value?<?0.001). However, better evolution is observed among residents of the target areas compared with residents of similar urban areas where this kind of polices have been not in force (odds ratio?=?0.50; p value?<?0.05). Therefore, urban regeneration policies might act as moderators of the risk of mental health, particularly when people are subject to the loss of individual/family resources in urban vulnerable contexts.