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Building retrofitting plays a key-role in energy saving and a growing interest is focused on insulating materials that allow a reduction in heat loss from envelopes with low thickness, by a process of reducing heating and cooling demand. In this context, a complete characterization of the physical properties of Moroccan natural gypsum materials was carried out. Basic information on the mineralogical, microstructure, thermal, mechanical, and acoustic characteristics of the rocks sampled from two Moroccan regions is provided. It was found that mineralogy, porosity, and water content are the main factors governing the development of the structure and the strength of the samples. The measured values of the porosity were 8.94%, the water content varied between 2.5–3.0% for the two studied typologies, coming from Agadir and Safi, respectively. Gypsum powder was used for fabricating samples, which were investigated in terms of thermal and acoustic performance. Thermal properties were measured by means of a hot disk apparatus and values of conductivity of 0.18 W/mK and 0.13 W/mK were obtained for Agadir and Safi Gypsum, respectively. The acoustic performance was evaluated in terms of absorption coefficient and sound insulation, measured by means of a Kundt’s Tube (ISO 10534-2). The absorption coefficients were slightly higher than the ones of conventional plasters with similar thickness. A good sound insulation performance was confirmed, especially for Safi Gypsum, with a transmission loss-value up to about 50 dB at high frequency.

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Nowadays energy storage seems to be a vital point in any new energy paradigm. It has become an important and strategic issue, to ensure the energetic sufficiency of humanity. Indeed, hydrogen storage in solids has been proved and revealed as clean and efficient energy storage. Moreover, it can be thought as a seriously considered solution to enable renewable energy to be a part of our quotidian life. To achieve storing hydrogen in solid form, the present study aimed to concepts and simulates a solid-state hydrogen storage reactor (tank). An investigation of the parameters influencing the hydrogen storage performance is carried out. Meanwhile, to understand the physical phenomenon taking place during the storage of hydrogen, a 2D numerical modelling for a metal hydrides-based in hydrogen reactor is presented. A strong coupling between energy balance, kinetic law, as well as a mass momentum balance at sorbent bed temperature under a non-uniform pressure was resolved based on finite element method. The temporal evolutions of pressure, the raising temperature in the bed during the hydriding process as well as the impact of the hydrogen supply pressure within the tank are analysed and validated by comparison with the experimental work in literature, a good agreement is obtained. From an industrial point of view, this study can be used to design and manufacture an optimal solid-state hydrogen storage reactor.

We report on thermally assisted flux flow in YBa2Cu3O7-delta superconductor. The resistivity measurements rho(T,B) for many values of the magnetic field up to 14T in two directions with a dc weak transport current density were investigated in order to determine the activation energy and then understand the vortex dynamic phenomena and therefore deduce the vortex phase diagram. The apparent activation energy U0(T) is calculated using an Arrhenius relation. The measured results of the resistivity were adjusted to the modified thermally assisted flux flow model accounting for the temperature-field dependence of the activation energy U(T,B). The obtained values from the thermally assisted activation energy, exhibit a behavior similar to the one showed with the Arrhenius model, albeit larger than the apparent activation energy. The vortex glass model was used to obtain the vortex-glass transition temperature from linear fitting of [dLn(Rho)/dT]^-1 plots. In the course of this work thanks to the resistivity measurements we could locate the upper critical magnetic field Hc2(T), the irreversibility line Hirr(T) and the crossover field Hcrossover(T) . These three parameters allowed us to establish a phase diagram of the studied material where limits of each vortex phase are sketched in order to optimize its applicability as a practical high temperature superconductor used for diverse purposes.

The aim of this paper is to provide a theoretical analysis on the mechanical power of the mass spring's system. Some tests are conducted to experimentally evaluate the theoretical analysis and to investigate the mechanical energy ability of this concept. The authors suggest a system used for applications of energy harvesting from roads. The system is able to transform the kinetic energy produced by the passage of vehicles on the road for electrical energy based on the mass-spring using two technologies. The hybrid system has two goals. First, supply the entourage by a mechanism to produce significant electrical power used mainly for public lighting. A device is also provided for storing electrical energy for later use, for home lighting at night or in the case of bad weather. Second, the piezoelectric subsystem controls the spring's health through analyzing the amplitude and shape of the voltage generated by a piezoelectric material. Finally, an experimental validation of the designed smart speed bump is presented.