Porosity of talc and cellulose filter cake during mechanical dewatering was investigated using a non-invasive technique namely electrical resistance tomography (ERT). Appling the ERT in mechanical dewatering is stateof-the-art technique with promising outcomes. This work showed the potential of this technique in characterizing the structure of filter cakes. An inverse problem was solved to reconstruct the distribution of electrical conductivity in the filter cake. If the electrical current is carried by the interstitial solution, filling the pores, the image obtained is thus considered as a representation of the porous structure of the tested material. It was found that, at constant pressure, the porosity of cellulose and talc filter cakes decreases over time. The spatial porosity distribution at the end of compression was calculated. At 4 mm of the filter media, the porosity values estimated by the ERT technique were compared to those calculated experimentally at the end of the compression phenomenon.

This paper presents an experimental comparative study of three passive solar distillers tested under the arid climate of Kairouan, Tunisia. The first is a conventional double slope solar still (DSSS). The second is a single slope double absorber solar still (DASS), in which a perforated plate equipped with cotton wicks enhances evaporation by capillary effect. The third is a novel double condensation solar still (DCSS), featuring an asymmetric cover design combined with a dual-basin configuration and an external cooling strategy to simultaneously enhance evaporation and condensation. Daily productivity and thermal behaviour are experimentally determined and compared for the three systems. Results demonstrate that the DCSS achieves the highest daily productivity with an improvement of x% over the DSSS, followed by the DASS with an enhancement of $\mathrm{x} \%$ over the same distiller.

In response to the increasing demand for energy-efficient housing in Tunisia, this study applies Design Builder simulations to investigate the effectiveness of passive and hybrid ventilation strategies in a representative dwelling situated in three distinct climate zones: temperate Mediterranean (Tabarka), Mediterranean (Sousse), and hot arid (Tozeur). The scenarios explored include optimized natural ventilation (based on window operation, scheduling, and opening temperature), phase change materials (PCMs), a solar chimney, reflective roofing, and a hybrid ventilation system, all evaluated against a conventional mechanical ventilation baseline. Results indicate that optimized natural ventilation is particularly effective, reducing annual energy consumption by 38.4-42.6 % and lowering COQ emissions by 6-10.8 %, depending on the region. While the hybrid ventilation system increased energy use by 14-16 %, it significantly improved thermal comfort, as reflected by enhanced PMV and PPD indices and by raising the proportion of comfortable occupied hours to nearly 76 %. Economically, optimized natural ventilation achieved the greatest savings, reaching 42.96 TD/m2 in Tozeur, compared with 28.71 TD/m2 for the hybrid approach. These findings highlight the substantial potential of climate-responsive passive and hybrid strategies to advance sustainable, cost-effective, and environmentally responsible residential buildings in Tunisia.

This study presents a numerical investigation of coupled heat and mass transfer during drying in deformable packed beds subjected to humid-air and superheated-steam drying conditions. Unlike conventional rigid-bed approaches, the solved governing equations using the finite volume method under transient conditions, combines macroscopic transport equations with the evolution of bed structural properties; including porosity, particle diameter, specific surface area and bed height, which vary as a consequence of shrinkage during drying. Model validation was performed by comparing numerical predictions with independent experimental data available in the literature. The proposed model reproduces the evolution of moisture content during drying under identical operating conditions. Statistical analysis showed moderate agreement between numerical and experimental results (R² = 0.74, MAPE = 25.1

Freshwater productivity by solar desalination offers promising solutions for using clean energy, reducing environmental pollution and being cost-effective. However, solar stills require energy storage and evaporation rate improvement to overcome global water demand. In this article, a case study in Kairouan city (Tunisia) is presented: the impact of incorporating hollow-red-bricks into the basin area of single-slope-solar-stills to improve sensible energy storage capacity and water evaporation area by capillarity action was investigated. The study specifically analyses the effect of varying the bricks height over the basin. Therefore, four identical solar distillers were designed and constructed: three systems called modified solar stills integrating hollow bricks with 4 cm, 6 cm and 8 cm heights, and a conventional system. This work included an in-depth examination of energy, exergy, economic and to environmental aspects for both systems. Thus, the use of red-bricks significantly improved water production by 33.84 %, 29.1 % and 28.87 % for MSS-6cm, MSS-4cm and MSS-8cm in comparison to that of the conventional case. Furthermore, the net repayment period and the carbon credit earned were also calculated. The results revealed that 6 cm was the optimal brick height giving a maximum energy payback period of about 100 days and could mitigate 94.26 tons of CO2 emission during its 10 years lifetime.

Integrating phase change materials (PCMs) into building envelopes offers a powerful method for enhancing thermal mass and reducing heating, ventilation, and air conditioning energy demand. This study provides a comprehensive analysis of combining PCMs with various roof designs (flat, gable, and domed) and shading strategies in a Mediterranean climate to optimize residential building performance. Through a 3E (energetic, environmental, and economic) assessment and computational fluid dynamics (CFD) modeling, we determined that the use of PCM23 significantly enhances occupant comfort, improving the predicted mean vote by 17% and enhancing overall thermal comfort by 14%. The most effective configuration, a gable roof with integrated PCMs, outperformed a flat roof by reducing annual energy consumption by 20% (1103 kWh). This optimal design also yielded substantial economic and environmental benefits, including a 16.2 TD/m2 reduction in annual energy costs, a short investment payback period, and a 4% decrease in operational CO2 emissions. These results highlight the significant potential of pairing PCMs with passive architectural features to create more energy-efficient, cost-effective, and comfortable living environments.

Wind power was a renewable energy source that harnessed natural airflow to produce electricity. Advanced wind capture systems, such as the one studied here, aimed to improve efficiency to maximize energy conversion. This paper presented a numerical study of the influence of the number of inlets or the number of fins of the wind collector on the performance of the system, focusing on maximizing the wind speed in the cylindrical part. We started by simulating different configurations with varying numbers of fins, analyzing how this affected the wind capture ability of the system. We then examined how this wind capture capacity related to the amplification coefficient, which measured the increase in wind speed through the system. By conducting this study, we determined the optimal number of blades to maximize wind capture efficiency and wind speed amplification compared to the baseline system. This allowed us to optimize the system design for optimal performance in various wind conditions

In this study, the Monte Carlo method was applied to estimate the concentrated solar radiation along the perimeter of the receiver in a solar dish system. This approach aids in creating solar heat flux distributions for various solar system structures. The effect of several parameters is examined to determine the most efficient solar parabolic dish configuration.The effect of positioning the receiver at varying distances from the dish vertex has been simulated. Six different distances D are tested: $\mathrm{D}=1.8 \mathrm{~m}; \mathrm{D}=1.81 \mathrm{~m}; \mathrm{D}=1.82$; $\mathrm{D}=1.84 \mathrm{~m}; \mathrm{D}=1.85 \mathrm{~m}$ and $\mathrm{D}=1.86 \mathrm{~m}$, respectively. It has been demonstrated that the distribution of solar radiation rises as the receiver placement decreases.Furthermore, the influence of the solar receiver’s diameter on the concentrated flux distribution has been investigated. The parameter is studied in the following ranges: diameter of the receiver from 0.5 to 3 m. The findings indicate that the concentrated solar flux grows as the diameter of the receiver decreases.

In solar energy concentration systems, the receiver configuration affects how effectively the concentrated sunlight can be converted into usable thermal energy. Therefore, careful consideration and optimization of the receiver geometry shape are essential to improve the efficiency of the solar-thermal energy conversion process. In this article, the impact of inserting disc in the cylindrical absorber is studied numerically using Ansys Fluent. Performance assessment is carried out for various numbers of discs. As the number of discs increases from 0 to 8, both the working fluid outlet temperature and the solar receiver thermal efficiency rise. The results demonstrate a significant enhancement in these two parameters, with increases of 12.08 % and 29.14 %, respectively, as the discs number rises from 0 to 8.Haut du formulaire This study represents the first detailed investigation of a disc receiver, making it a novel contribution to the field of parabolic solar collectors.

The efficiency of traditional solar stills in producing distilled water is relatively low. By integrating heat storage materials, these systems can achieve notable improvements in performance. This study explores the desalination of brackish water using a passive solar still combined with thermal storage materials. The proposed system, which utilizes heat storage in both sensible and latent forms, offers a viable solution for arid and semi-arid regions facing severe water shortages and abundant brackish water supplies.

Energy conservation in buildings has been the focus of many studies since nearly one-third of global energy consumption is due to buildings. Phase change material (PCM) technology promises to be an attractive solution for energy saving in buildings since it is a passive and effective technology, as demonstrated in the literature. Therefore, this study focuses on the energy-saving performance of PCM-integrated buildings located in a Mediterranean climate to reveal their energy-saving potential. PCM is integrated both in external or internal south walls and roofs of buildings under four different climatic conditions. EnergyPlus, which is a well-known building simulation software, is adopted for building thermal analyses. The effects of melting temperature, location of PCM layer in the wall, thickness of PCM layer, type of envelope (wall or roof), and PCM double-layer system in the wall are investigated. The corresponding energy savings and CO2 emission reductions are obtained for the considered cases. The results showed that up to 41.6% reduction in energy demand can be obtained depending on the PCM application. Besides, PCM with a low melting temperature (21 °C) favored heating energy savings, while PCM with a high melting temperature (29 °C) favored cooling energy savings. Moreover, the double-layer PCM system provided higher energy savings than the single-layer PCM system, especially in warm and arid regions (Sousse and Tozeur).

Wind energy is a key driver for the transformation towards a sustainable energy system. From a certain point of view, the main parameter is to increase the turbines' height and the rotor's size to improve the economic aspect and performance. On the other hand, 'ducted wind turbines', which can significantly improve the performance of smaller wind turbines, are attracting much attention. The objective is to create system compatible with urban environments and at the same time improve the efficiency of ducted wind turbines. This article studies a configuration, namely a wind turbine equipped with a wind catcher system, by studying it both experimentally and numerically. First, the tests are carried out on the system without inserting the wind rotor. Then the results of the developed model are compared via experimental tests, showing that it is possible to accept wind from all directions and from different heights by using the wind collector system and the cones. The results also show that the maximum wind speed increases by 2.5 times in the middle of the cylindrical part where the turbine is planned to be placed. Finally, the effects of inserting a vertical axis wind turbine inside the cylindrical part of the system on its power coefficient are studied. The results show that the system significantly improves the maximum power coefficient of the turbine.

Phase change material (PCM) is considered as a promising solution for reducing heating and cooling energy consumption by integrating them into the building envelope, which in turn reduces CO2 emissions. In this paper numerical simulations were carried out to evaluate the energy performance based optimization of envelope building integrated PCM. The effect of several parameters (PCM melting temperature, PCM layer combined with insulation, PCM layer and insulation layer thickness, double PCM layer system in the double external wall, and air layer interaction with PCM in roof) on energy savings in two typical models of residential buildings in Tunisia are investigated. Results show that energy demand reduction of 73.81% and 76.46% can be achieved under the optimal conditions of application of the PCM integrated in simple wall and double wall buildings respectively. This is associated with significant reduction of CO2 emission. Moreover, PCM layer performance is improved by increasing its thickness with an optimal value of 6 cm. Two PCM layers located in the middle of the double wall involve higher energy saving than a simple PCM layer.

This work studied the effect of external conditions on the drying kinetics of a thin layer of corn during convective drying. The density and the specific volume of the corn grain were reported and the desorption isotherms of the corn were determined at three temperatures and for a water activity from 0.1 to 0.9 using the static gravimetric method. Initially, a thin layer of corn about 7 mm thick with an initial moisture content of 45% (d.b) was investigated, and the external conditions were tested. Afterwards, a comparison between the experimental convective drying of a packed bed and a thin layer was performed under the same conditions. Finally, the values of equilibrium moisture contents, water activities and temperatures obtained were fitted using seven sorption models. It was found that the experimental desorption data exhibited type II behavior, according to Brunauer’s classification. The GAB model was found as the most suitable semi-empirical model which was well suited to represent the desorption equilibrium moisture content of corn kernels in the suggested ranges of temperature and water activity. It can be concluded from the entropy–enthalpy compensation theory that the desorption process of the corn kernels is controlled by the enthalpy mechanism.

This work presents a comparative study of four drying processes of a porous media: superheated steam drying at atmospheric pressure (APSSD), humid air (HA), low pressure superheated steam drying (LPSSD) and vacuum drying (VD). A single porous particle model has been developed to simulate the four drying processes. The model is based on the method of averaging volume. Spherical porous particles of coal are used as the model material in this paper. The evaporation rates are equal for these processes in point called the inversion temperature. This temperature was calculated during the constant rate period (CRP) and the falling rate period (FRP). A variation in the values of inversion temperature was observed (363-503 K). The effect of drying parameters such as: particle radius, gas mass flux, permeability, porosity and operating pressure were investigated. Several researchers have reported the noticeable variation of the inversion temperature values according to the drying period used to calculate this key parameter. Our results are compared with those obtained from a front model reported in the literature. A good agreement is found.

Simultaneous heat and mass transfer inside a packed bed dryer between a fluid phase and corn kernels was studied. A developed two-phase model for evaluating the effect of bed shrinkage and non-constant physical properties on the drying efficiency was conducted. Experimental data were utilized to develop the governing equations of the bed shrinkage and structural parameters with moisture content inside the packed bed dryer. The developed model was verified by assessing predictions against experimentally obtained moisture content and temperature along the drying bed, as the standard errors of the experimental values compared to the model were found to be close to the accepted engineering accuracy of 5%. It has been concluded that the incorporation of bed shrinkage and alteration in properties within the operating model is capable of providing a more comprehensive and precise analysis of heat and mass transfer phenomenon in porous media drying, such as corn kernels.

This work represent the incorporation of information procurement (DAQ) equipment and programming to acquire information (LabVIEW) as well as real-time transport to show parameter appraises with regard to subsurface stream and transport issues. The main objective is to understand the mechanism of water and solute transfer in a sandy medium and to study the effect of some parameters on the transport of an inert tracer. In order to achieve this objective, a series of experiments were carried out on a soil column equipped with a tensiometer to monitor the state of saturation of the medium and by two four-electrode probes for measuring the electrical conductivity in the porous medium.

In the manufacturing field, a growing interest is being held to the environment, to sustainability and more precisely saving energy and time. Combining thermomechanical with pure mechanical processes is an eco-friendly and profitable technique. In this paper, it is proposed to combine grinding and ball-burnishing processes. Further from reducing time, energy and cost of the manufacturing operations, this original combination is imagined to take benefit from thermomechanical history occurring while grinding to optimise ball-burnishing process in order to enhance the workpiece surface integrity. In this paper, the impact of this newly developed process on the surface and subsurface behaviour is studied through experiments and 3D FEM simulations. It is shown that performing simultaneously grinding and ball-burnishing processes leads to a thick surface layer up to several millimetres with compressive residual stresses state. This is an interesting result to increase sustainability of metallic workpieces by enhancing wear resistance, fatigue strength and fatigue lifetime.

In this work, we investigated the morphological effect of dichloromethane (DCM) on alfalfa (Medicago sativa) plant. We studied in vitro the influence of its concentration on alfalfa germination. The plants were placed in pots for 15 weeks, and exposed to increasing concentrations of DCM (50 µg L-1 and 84 mg L-1). In addition, we examined the effect of two manures (cow and sheep), which were applied to a contaminated soil, on alfalfa plant growth. The effect of the presence of dichloromethane is obvious even in plant-soil manure system. In fact, in the event of contamination, the soil-cow manure mixture represents the best setting medium for the Alfalfa plant compared to other environments, regardless of the contamination level. Indeed, the presence of two types of manure does not allow the suppression of the inhibitory effect of dichloromethane on the mass of the dry matter of the aerial part which is 18.38% for the cow manure-amended soil and 13.96% for the sheep manure-amended soil.