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The production of aluminum metal-matrix composites (AMM) involves reinforcing aluminum and its alloys with various powders, with the addition of ceramic reinforcements expected to enhance the mechanical properties, corrosion resistance, and the wear resistance behaviour. However, suboptimal production techniques often result in reduced ductility and toughness when incorporating non-deformable ceramic reinforcements. To address this, friction stir processing (FSP) was employed as a novel surface modification process, using Ti–6Al–4V particles to reinforce 1100 Aluminum Alloy. Microstructures of the composites were analyzed through Scanning Electron Microscopy (SEM), revealing a mean particle size of 2.69 × 103μm for a one-pass FSP at X155 magnification. Notably, the two-pass sample with a particle size of 2.69 × 103μm displayed fewer spherical structures and more irregular structures, indicating a change in the flow mechanism. The three-pass sample exhibited a mean particle size of 1.36 × 103μm, indicating a more uniform distribution and significant size reduction compared to one and two passes.Additionally, a torque-based predicted heat-input analysis indicated that higher temperatures resulting from increased heat production rate and power input led to a decrease in the torque with rising rotational speed. The threaded taper tool generated more heat, potentially facilitating plastic deformation. Finite Element Analysis (FEA) using ABAQUS predicted how this heat affected composite quality, closely aligning with experimental data, with less than a 10 °C difference between processing temperatures in experimental and simulated data. The peak temperature increased as the tool rotated at various tool speeds in line with the projected temperature history of FSP. This study is a significant contribution to enhancing aluminium metal matrix composite through the FSP technology.

Most production methods of heavy oil involve thermal production. However, it is challenging to delineate the thermal-affected zone due to complex reservoir conditions. With steam injected, the heavy oil viscosity drops; the reservoir density and velocity decrease accordingly, causing changes to seismic impedance. Moreover, the oil-and-water viscosity ratio and permeability show the difference with changing temperature, indicating that the reservoir's ability to transmit seismic waves would also be temperature-dependent. Therefore, the seismic responses and attenuation characteristics of the steam chamber can be helpful to monitor the steam-affected zone. We introduce an improved viscoelastic model to approximate the heavy oil reservoir during thermal production, and use the frequency-space domain finite difference algorithm to simulate the seismic wave-fields. Numerical results demonstrate that this model is applicable to a wide temperature range, and can effectively reveal the seismic characteristics of the steam chamber. Through analyzing the propagation differences of seismic waves under different temperatures, it is concluded that the attenuation coefficient, root-mean-square amplitude difference and amplitude ratio of PP-wave and PS-wave under different conditions can reveal the temperature variation in the steam chamber, with which it is possible to detect the steam chamber spatial distribution. [ABSTRACT FROM AUTHOR]

Industrial Process Heat (IPH) represents a promising sector of application for solar concentration technologies – the Linear Fresnel Reflectors (LFR) as an alternative to the conventional source of thermal energy. Morocco is endowed with an abundant solar resource as other countries in the MENA region, with high level of DNI available over the year especially in the southeast, mid-south, and the south (Moroccan Sahara Desert). The main objective of this work is to assess the potential of solar thermal production of industrial process heat considering six different sites in Morocco. The evaluation has been done with respect to the Levelized Cost of Heat (LCoH), representing the whole production cost structure. This study includes as well a comparison of the same application in Stellenbosch (South Africa) and Andasol (Spain). The results show that the annual thermal production is 7.2 GWh-th/year in Zagora, 6.4 GWh-th/year in Missour, and around 6.3 GWh-th/year in Ben-Guerir and Erfoud. As expected, the Moroccan sites show, in general, higher thermal energy production with +1.4 GWh-th/year in Zagora compared to the Andasol site, and +2.9 GWh-th/year compared to Stellenbosch. The cheapest LCoH has been found to be 2.47 c$/kWh-th in Zagora, whereas it was 4.02 c$/kWh-th in Stellenbosch and 3.04 c$/kWh-th in Andasol, with a difference of +62.75% and +23.1% respectively.

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In highly polluted regions, it might be necessary to operate power plants enforcing appropriate emission limits to help ensuring air quality. If the air quality is low and pollutants are difficult to diffuse, few additional emissions should be allowed to avoid further deteriorating the air quality. Wind power helps reducing pollution levels as it substitutes polluting thermal production. However, wind and air pollution are generally anti‐correlated. Storage can be used to shift wind power production from hours when higher pollution levels are allowed to hours when lower pollution levels are allowed to help meeting emission constraints at critical hours. Storage availability also achieves a comparatively lower production cost for the system as a whole. To represent the stochastic nature of wind power production and weather‐dependent emission limits, the authors propose a two‐stage stochastic programming model to analyse the trade‐off emission versus cost in an electric energy system with storage facilities. The first stage represents the day‐ahead scheduling, while the second one represents the real‐time operation under different scenarios. The authors analyse the impact of emission limits and/or storage on generation scheduling by comparing different models using an illustrative example and a case study based on the IEEE 118‐node system. [ABSTRACT FROM AUTHOR]

Flexible nuclear power plants can adjust their electricity production to the predicted evolution of demand. Under certain conditions, flexible operation is necessary to ensure the stability of the electricity system. However, despite the potential advantages of nuclear energy including the flexibility of nuclear reactors, the social acceptance of nuclear has reduced after the Fukushima accident, leading some countries to reduce or even phase out nuclear (e.g. Germany). So, a question that arises is how flexible nuclear power plants have to be operated in order to maximize social welfare. The French nuclear fleet gives an illustration of flexible management while social acceptance of nuclear is questioned; this was reflected in the new French Energy Transition law. Theoretically and numerically, we found that the production behavior that maximizes social welfare is characterized by a constant thermal production and a totally flexible nuclear production given sufficient nuclear capacity. [ABSTRACT FROM AUTHOR]