The ongoing uranium mining activities coupled with mines development in SOMAIR open pit mine at Arlit led to the discovery of a new prospect called Tamari prospect endowed with a potential uranium ore deposit and have been subjected to a very few scientific studies but their characteristics still need to be examined in further detail investigation in order to determine the mineralogical composition, ore genesis and geochemical characteristics of the deposit. Based on detailed studies using optical microscopy, backscattered electron imaging, electron-microprobe and high resolution elemental mapping, the authors have established that detrital, authigenic and uranium ore-stage minerlization are associated with the deposit. Previous studies on the deposits documented two stages of uranium deposits one close to 190 Ma and the other close to 150 Ma. The dominant uranium ore minerals occur as uraninite. Pyrite and galena are the most dominant sulfide minerals associated with the uranium mineralization and therefore, chemical composition analysis shows that pyrite contains an average U concentration up to of 7.62 wt% and galena has an average of 27.16 wt%. The association U–Zr–Pb present in the zircon and monazite indicates that the geochemical environment responsible for this correlation should be that with a large association with lithophile elements which occur in monazite and zircon minerals that could possibly be the potential source of uranium. The impregnation of organic matter with U–Ti oxide indicates a synsedimentary or early source of uranium. Uraninite contains a high concentration of Zr (av. 5.77 wt%) suggesting a probable succession of fluid circulation that would allow either the deposition of two generations of uraninites or mineralization leaching. The excellent positive correlation of U, Fe, Ca and Mn in the mineralized pole of U–Ti oxides is related to the presence of high concentrations of complexing ligands such as carbonate, oxalate, hydroxide, fulvic and humic acids in the deposits. Uranium mineralization occurs as Iriginite (U–Mo) and the powellite (Pb–MoO4) cemented the quartz grains and kaolinite highlights a late fluid circulation.

Hydrogeological active zones found in mine waste (tailings) dumping sites are a major source of concern that threatens the safety of the environment and groundwater, especially in karstic areas. Therefore, detecting and identifying these regions correctly will help in selecting the appropriate sites for tailings disposal and avoid consequential environmental problems. In this study, electrical resistivity imaging (ERI) surveys with high-resolution data were carried out to detect hydrogeological active zones in an area proposed as a settling pond for mining tailings accumulated from El Mochito mine property, located in the north-western section of Honduras. Two-dimensional (2-D) inversion results of thirty-four survey lines revealed several zones of low resistivity. These zones indicate water-/clay-bearing regions that are structurally weak. However, some survey lines, the limestone beneath the surface is entirely compacted; as such, it is considered to be an ideal site for tailings pond construction. In addition, on the eastern side of the valley, there is a large chunk limestone layer that is compacted and can be considered for tailings pond construction. The ERI method provided insight and developed an informative subsurface map to detect the hydrogeological active zones, thus proving it as a beneficial tool used for selecting disposal sites for mining tailings in karstic areas.

Solar energy industries require an accurate estimation of global solar irradiation particularly on inclined planes. This improves the accuracy of the sizing procedures and optimizes the performance of the solar energy platforms as photovoltaic modules and flat-plate solar collectors. A variety of the transposition models have been developed and reportedly determine incidences of solar irradiance on an inclined surface. However, there is a gap in the literature regarding identifying the most promising transposition model, particularly for the Middle East and North Africa region (MENA). Therefore, this article serves two main objectives. Firstly, it compares comprehensively 24 different transposition models. Several statistical methods are used to quantify the performance of the tilted surface transposition models. Furthermore, the transposition models are compared with real, hourly measured time-series data for several Palestinian cities to identify the promising and most accurate model. The analysis was carried out on three bases: annually, monthly, and a clearness index. The transposition models prove their ability to represent the measured data during the annual and monthly analyses, but they all failed to achieve complacency in the clearness index (K_tK_t) for the clear sky condition (K_t > 0.78). Secondly, the article advises a reliable and accurate transposition model for the area of the MENA for clear sky conditions. The proposed model was tested for the sites under investigation, and it produces significantly better performance than the candidate transposition models.

In this paper, the optimum coordination of an energy hub system, fed with multiple fuel options (natural gas, wood chips biomass, and electricity) to guarantee economically, environmentally friendly, and reliable operation of an energy hub, is presented. The objective is to lessen the total operating expenses and CO₂ emissions of the hub system. Additionally, the effect of renewable energy sources as photovoltaics (PVs) and wind turbines (WTs) on energy hub performance is investigated. A comparison of various configurations of the hub system is done. The proper planning of the hub elements is determined by a multi-objective particle swarm optimization (PSO) algorithm to achieve the lowest level of the gross running cost and total system emissions, simultaneously. The outcomes show that the natural gas turbine (NGT) is superior to the biomass generating unit in lowering the gross operating expenses, while using the biomass wood chips plant is most effective in lessening the total CO₂ emissions than the NGT plant. Furthermore, the combination of the natural gas turbine, biomass generator, photovoltaics, and wind turbines enhances the operation of the hub infrastructures by lessening both the gross operating cost and overall CO₂ emission simultaneously.

This paper deals with the numerical simulation of the dynamic failure of an aluminium plate under air-blast loading. Constitutive modelling based on the fractional viscoplasticity is used. The material model is non-local due to the properties of the applied fractional differential operator and is implemented as user material in the engineering finite element computation code ABAQUS. It is important that the numerical simulations are contrasted with experiments. Numerical outcomes clearly show the applicability of the adopted modelling for the description of salient stages of dynamic structural failure.

In this paper, a system dynamics approach is introduced for the macro-planning of the selection of new product families in the consumer electronics industry in developing countries. A decision methodology structure is built that includes the impact factors of rapid technology changes and uncertainty. System dynamics models are designed to select the product family's planning strategy, considering the different variables in marketing, product design, supply chain, and manufacturing method. The developed model is validated for a real case study of television manufacturing in Egypt. The results reveal that using system dynamics reflects the dynamics of the consumer electronics industry and can be used for its strategic planning.

Fused deposition modeling (FDM) is one of the most additive manufacturing techniques that adopted to produce prototypes and/or final parts, particularly under geometrical complexity restrictions. One of the most challenging aspects of FDM technology is the attainable roughness. In this paper, a hot-air jet was applied simultaneously during the printing process of FDM products to investigate the effect of its factors on surface roughness. Experimentally, a test rig was utilized to evaluate the effect of these factors on surface roughness. Two main factors were addressed: air jet temperature; and nozzle translational velocity over the part surface and investigated their effect on the roughness. Statistically, ANOVA and regression analysis were conducted to study the contribution of the individual factors to the process response and to introduce regression model to predict the resulting surface roughness in terms of different …

The large number of interdigitated electrodes (IDEs) in a macro fiber composite (MFC) piezoelectric actuator dictates using a very fine finite element (FE) mesh that requires extremely large computational costs, especially with a large number of actuators. The situation becomes infeasible if repeated finite element simulations are required, as in control tasks. In this paper, an efficient technique is proposed for modeling MFC using a finite element method. The proposed technique replaces the MFC actuator with an equivalent simple monolithic piezoceramic actuator using two electrodes only, which dramatically reduces the computational costs. The proposed technique was proven theoretically since it generates the same electric field, strain, and displacement as the physical MFC. Then, it was validated with the detailed FE model using the actual number of IDEs, as well as with experimental tests using triaxial rosette strain gauges. The computational costs for the simplified model compared with the detailed model were dramatically reduced by about 74% for memory usage, 99% for result file size, and 98.6% for computational time. Furthermore, the experimental results successfully verified the proposed technique with good consistency. To show the effectiveness of the proposed technique, it was used to simulate a morphing wing covered almost entirely by MFCs with low computational cost

In rural and remote areas, solar photovoltaic energy (PV) water pumping systems (SPWPSs) are being favored over diesel-powered water pumping due to environmental and economic considerations. PV is a clean source of electric energy offering low operational and maintenance cost. However, the direct-coupled SPWPS requires inventive solutions to improve the system’s efficiency under solar power variations while producing the required amount of pumped water concurrently. This paper introduces a new quadratic V/f (Q V/f) control method to drive an induction motor powered directly from a solar PV source using a two-stage power converter without storage batteries. Conventional controllers usually employ linear V/f control, where the reference motor speed is derived from the PV input power and the dc-link voltage error using a simple proportional–integral (PI) controller. The proposed Q V/f-based system is compared with the conventional linear V/f control using a simulation case study under different operating conditions. The proposed controller expectedly enhances the system output power and efficiency, particularly under low levels of solar irradiance. Some alternative controllers rather than the simple PI controller are also investigated in an attempt to improve the system dynamics as well as the water flow output. An experimental prototype system is used to validate the proposed Q V/f under diverse operating conditions.