Ultrasonic, molecular and mechanical testing diagnostics in natural fibre reinforced, polymer-stabilised earth blocks

The aim of this research study was to evaluate the influence of utilising natural polymers as a form of soil stabilization, in order to assess their potential for use in building applications. Mixtures were stabilized with a natural polymer (alginate) and reinforced with wool fibres in order to improve the overall compressive and flexural strength of a series of composite materials. Ultrasonic pulse velocity (UPV) and mechanical strength testing techniques were then used to measure the porous properties of the manufactured natural polymer-soil composites, which were formed into earth blocks. Mechanical tests were carried out for three different clays which showed that the polymer increased the mechanical resistance of the samples to varying degrees, depending on the plasticity index of each soil. Variation in soil grain size distributions and Atterberg limits were assessed and chemical compositions were studied and compared. X-ray diffraction (XRD), X-ray fluorescence spectroscopy (XRF), and energy dispersive X-ray fluorescence (EDXRF) techniques were all used in conjunction with qualitative identification of the aggregates. Ultrasonic wave propagation was found to be a useful technique for assisting in the determination of soil shrinkage characteristics and fibre-soil adherence capacity and UPV results correlated well with the measured mechanical properties

A New Affordable Masonry System Based on Unfired Clay Sandwich Panel

Nowadays, construction is one of the main sectors that produces waste and consume more materials and energy, so there is a growing need for alternative construction technologies that allow us to modify this situation. In this context, this paper presents the development of an innovative proposal for an industrialized outdoor enclosure. This solution is based on a constructive system with prefabricated insulated sandwich panels, produced on the basis of a new eco-efficient composite material, based on raw stabilized clay. In this way, it is possible, prioritize environmental issues to significantly reduce the environmental impact generated during the manufacture of the piece. The use in the construction of buildings material such as stabilized raw clay can be an alternative to achieve buildings of nearly zero energy consumption. They are known both from a thermal comfort and ability to regulate temperature and humidity, as well as being materials that contain much less embodied energy. This study is a comparative analysis of building systems, as well, as a serie of selected patent systems and copyrighted materials. On the other hand, it also analyzes their enforcement against the values established by the Spanish building code

Chemical Oscillations out of Chemical Noise

The dynamics of one species chemical kinetics is studied. Chemical reactions are modelled by means of continuous time Markov processes whose probability distribution obeys a suitable master equation. A large deviation theory is formally introduced, which allows developing a Hamiltonian dynamical system able to describe the system dynamics. Using this technique we are able to show that the intrinsic fluctuations, originated in the discrete character of the reagents, may sustain oscillations and chaotic trajectories which are impossible when these fluctuations are disregarded. An important point is that oscillations and chaos appear in systems whose mean-field dynamics has too low a dimensionality for showing such a behavior. In this sense these phenomena are purely induced by noise, which does not limit itself to shifting a bifurcation threshold. On the other hand, they are large deviations of a short transient nature which typically only appear after long waiting times. We also discuss the implications of our results in understanding extinction events in population dynamics models expressed by means of stoichiometric relations

Ultrasonic, molecular and mechanical testing diagnostics in natural fibre reinforced, polymer-stabilised earth blocks

The aim of this research study was to evaluate the influence of utilising natural polymers as a form of soil stabilization, in order to assess their potential for use in building applications. Mixtures were stabilized with a natural polymer (alginate) and reinforced with wool fibres in order to improve the overall compressive and flexural strength of a series of composite materials. Ultrasonic pulse velocity (UPV) and mechanical strength testing techniques were then used to measure the porous properties of the manufactured natural polymer-soil composites, which were formed into earth blocks. Mechanical tests were carried out for three different clays which showed that the polymer increased the mechanical resistance of the samples to varying degrees, depending on the plasticity index of each soil. Variation in soil grain size distributions and Atterberg limits were assessed and chemical compositions were studied and compared. X-ray diffraction (XRD), X-ray fluorescence spectroscopy (XRF), and energy dispersive X-ray fluorescence (EDXRF) techniques were all used in conjunction with qualitative identification of the aggregates. Ultrasonic wave propagation was found to be a useful technique for assisting in the determination of soil shrinkage characteristics and fibre-soil adherence capacity and UPV results correlated well with the measured mechanical properties

Assessment of Perception in Lower Limb Amputees of Rehabilitative Physical Therapy Complemented with Virtual Reality

The present essay describes the perceptions and attitudes of a group of 111 lower limb amputees who have been on a physical therapy and rehabilitation program intended to achieve a final adaptation of a Lower limb prosthesis and accepted to add a virtual reality-supported therapy tool as a complementary reinforcement. The program started up attending an instructional training session based on a desktop non-immersive 360 virtual reality training video. In the video an avatar performs 5 series of 3 timed repetitions of the following routine: Kicking, Squatting, Cycling, March . At the end each participant filled a questionnaire of 5 items asking for perceptional attitudes as: Utility, Gratification, assimilability, Recommendability and understandability. the results found high rates of general acceptability and receptibility.  the bivariate analysis was found with no statistical significance

Walrasian prices in a market with consumption rights

In this paper we consider an exchange economy where there is an external restriction for the consumption of goods. This restriction is defined by both a cap on consumption of certain commodities and the requirement of an amount of rights for the consumption of these commodities. The caps for consumption are imposed exogenously due to the negative effects that the consumption may produce. The consumption rights are distributed among the agents. This fact leads to the possibility of establishing licence or consumption rights markets. These consumption rights do not participate in agents' preferences, however the individual's budgetary constraint may be modified, leading to a reassignment of resources. The aim of this paper is to show the existence of a Walrasian equilibrium price system linking tradable rights prices with commodity prices.competitive equilibrium, quotas, consumption rights, cap-and-trade program.

Cómo planear un programa de radio

La planificación en la producción radiofónica es básica para lograr un mayor impacto de los mensajes. Este artículo explica una manera de diseñar un programa o espacio de radio, que pueda transmitirse en una estación cultural como las emisoras de la Universidad de Costa Rica, o una comercial. Se destaca la importancia de la investigación para fundamentar las propuestas, así como los elementos principales de un proyecto de programa radiofónico, que podrán formular profesionales y estudiantes de Comunicación o de cualquier otra disciplina del conocimient