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In recent years, the investment in the wind energy sector has increased in the context of producing green electricity and saving the environment. The installation of small wind turbines (SWTs) represents an actual strategy for meeting energy needs for off-grid systems and certain specialized applications. SWTs are more expensive per kilowatt installed as compared to large-scale wind turbines. Therefore, the main objective of this study is to produce an economical technology for the wind power market offering low-cost SWTs. The idea consists of considering a simple structure of the wind turbine using direct-drive permanent magnet synchronous generator (DDPMSG). DDPMSGs are the most useful machines in the wind energy field thanks to several advantages, such as elimination of noise and maintenance cost due to suppression of the gearbox and absence of the rotor circuit excitation barriers by the presence of the permanent magnets (PMs). Their major downside is the high cost of active materials, especially the PMs. Thus, the improvement of the generator design is treated as being the main component of the considered chain to assure active materials’ mass and cost reduction. The methodology studied aims to explain the approach of the design integrated by optimization of the considered system. It is based on the elaboration of analytical models to find a feasible structure for the system, taking into account the multi-disciplinary analysis. The relevance of these models is validated by the finite element method using 2D MATLAB-FEMM simulation. The models are integrated to elaborate the optimization problem based on a genetic algorithm to improve the cost of the proposed generator by minimizing the mass of its active constructive materials. As an outcome, an optimal solution is offered for the wind generators market, providing a 16% cost reduction.
Henda Agrebi; Naourez Benhadj; Mohamed Chaieb; Farooq Sher; Roua Amami; Rafik Neji; Neil Mansfield. Integrated Optimal Design of Permanent Magnet Synchronous Generator for Smart Wind Turbine Using Genetic Algorithm. Energies 2021, 14, 4642 .
AMA StyleHenda Agrebi, Naourez Benhadj, Mohamed Chaieb, Farooq Sher, Roua Amami, Rafik Neji, Neil Mansfield. Integrated Optimal Design of Permanent Magnet Synchronous Generator for Smart Wind Turbine Using Genetic Algorithm. Energies. 2021; 14 (15):4642.
Chicago/Turabian StyleHenda Agrebi; Naourez Benhadj; Mohamed Chaieb; Farooq Sher; Roua Amami; Rafik Neji; Neil Mansfield. 2021. "Integrated Optimal Design of Permanent Magnet Synchronous Generator for Smart Wind Turbine Using Genetic Algorithm." Energies 14, no. 15: 4642.
This study investigates the effects of tillage tools on the structural changes and CO2 emissions of a sandy loam soil, in the region of Sousse, Central East of Tunisia. Four treatments were tested: no-tillage, minimum tillage (0–10 cm), medium tillage (10–20 cm), and conventional deep plowing (20–30 cm). Under each tillage treatment, soil bulk density and carbon dioxide emissions were monitored for a period of 40 days. Experimental results have shown that conventional tillage leads to high CO2 emissions and a low soil compaction, indicated by low bulk density values. On the other hand, reduced tillage techniques are characterized by a significant reduction in CO2 emissions and a more compact soil, indicated by high soil bulk density values.
Roua Amami; Khaled Ibrahimi; Abdelhamid Znouda; Khaoula Abrougui; Chehaibi Sayed. Influence of Tillage Systems on Soil Bulk Density and Carbon Dioxide Emissions in the Mediterranean Context. Soil and Recycling Management in the Anthropocene Era 2021, 977 -984.
AMA StyleRoua Amami, Khaled Ibrahimi, Abdelhamid Znouda, Khaoula Abrougui, Chehaibi Sayed. Influence of Tillage Systems on Soil Bulk Density and Carbon Dioxide Emissions in the Mediterranean Context. Soil and Recycling Management in the Anthropocene Era. 2021; ():977-984.
Chicago/Turabian StyleRoua Amami; Khaled Ibrahimi; Abdelhamid Znouda; Khaoula Abrougui; Chehaibi Sayed. 2021. "Influence of Tillage Systems on Soil Bulk Density and Carbon Dioxide Emissions in the Mediterranean Context." Soil and Recycling Management in the Anthropocene Era , no. : 977-984.
Over the years, cultivation using sustainable tillage practices has gained significant importance, but the impact of tillage on soil water infiltration is still a concern for landowners due to the possible effects on crop yield. This study investigates the impact of different tillage managements on the infiltration rate of sandy clay loam soil under a semiarid environment. Field experiments were conducted in Chott Mariem Sousse, Tunisia. The tillage practices consisted of three treatments, including a tine cultivator (TC, 16 cm), moldboard plows (MP, 36 cm) and no-tillage (NT). Three infiltration models, Kostiakov, Philip and Horton, were applied to adjust the observed data and evaluate the infiltration characteristics of the studied soils. Comparison criteria, including the coefficient of determination (R2), along with the root mean square error (RMSE) and mean absolute error (MAE), were used to investigate the best-fit model. The results showed that moldboard plowing enhanced soil infiltration capacity relative to tine cultivation and no-tillage treatments. The mean saturated hydraulic conductivity was highest under MP, while it was lowest in NT, with 33.4% and 34.1% reduction compared to TC and MP, respectively. Based on the obtained results, Philip’s model showed better results with observed infiltration due to a higher R2 (0.981, 0.973 and 0.967), lower RMSE (3.36, 9.04 and 9.21) and lower MAE (1.46, 3.53 and 3.72) recorded, respectively, for NT, MP and TC. Horton’s model had a low regression coefficient between observed and predicted values. It was suggested that the Philip two-term model can adequately describe the infiltration process in the study area.
Roua Amami; Khaled Ibrahimi; Farooq Sher; Paul Milham; Hiba Ghazouani; Sayed Chehaibi; Zahra Hussain; Hafiz Iqbal. Impacts of Different Tillage Practices on Soil Water Infiltration for Sustainable Agriculture. Sustainability 2021, 13, 3155 .
AMA StyleRoua Amami, Khaled Ibrahimi, Farooq Sher, Paul Milham, Hiba Ghazouani, Sayed Chehaibi, Zahra Hussain, Hafiz Iqbal. Impacts of Different Tillage Practices on Soil Water Infiltration for Sustainable Agriculture. Sustainability. 2021; 13 (6):3155.
Chicago/Turabian StyleRoua Amami; Khaled Ibrahimi; Farooq Sher; Paul Milham; Hiba Ghazouani; Sayed Chehaibi; Zahra Hussain; Hafiz Iqbal. 2021. "Impacts of Different Tillage Practices on Soil Water Infiltration for Sustainable Agriculture." Sustainability 13, no. 6: 3155.
In agricultural systems, soil carbon dioxide emissions and physical properties are thought to depend largely on management practices. This field study was carried out in a semi-arid region of eastern Tunisia to evaluate the effects of tillage management on soil carbon dioxide emissions and related physical properties; bulk density (BD), penetration resistance (PR), total porosity (TP) and air-filled porosity (AFP). Tillage management treatments included plowing with a moldboard plow or a disk plow to different depths, described here as shallow (10 cm), medium (15 cm) and deep (25 cm). No-tillage was also considered as a control plot. Correlation analysis was used to explore how soil carbon dioxide emissions (CO2) were related to the other studied properties. The results showed higher carbon dioxide (CO2) emissions (p < .05) from tilled soil compared to no-till (NT), regardless of the tillage management. No significant differences in carbon dioxide (CO2) emissions were found between moldboard and disk plow tillage at the same tillage depth. Soil carbon dioxide release was the highest after deep tillage (moldboard = 0.101 t ha−1 and disk plow = 0.107 t ha−1) suggesting that deeper tillage to 25 cm promoted higher carbon dioxide (CO2) emissions. Significant differences with tillage were observed in bulk density (BD) and penetration resistance (PR) compared to no-tillage. Correlations of carbon dioxide emissions to soil physical properties across all the tillage treatments indicated significant negative relationships between carbon dioxide (CO2) emissions and soil bulk density (BD) and penetration resistance (PR) and significant positive relationships between carbon dioxide (CO2) and total porosity (TP) and air-filled porosity (WFP) suggesting that these soil attributes are important controlling factors of carbon dioxide (CO2) emissions.
Roua Amami; Khaled Ibrahimi; Newton La Scala Júnior; Amira Hmila; Khaoula Abrougui; Sayed Chehaibi. Soil Physical Properties, Carbon dioxide Emissions and Their Relationships under Different Management Systems in Semi-arid Region of Eastern Tunisia. Communications in Soil Science and Plant Analysis 2021, 52, 1689 -1705.
AMA StyleRoua Amami, Khaled Ibrahimi, Newton La Scala Júnior, Amira Hmila, Khaoula Abrougui, Sayed Chehaibi. Soil Physical Properties, Carbon dioxide Emissions and Their Relationships under Different Management Systems in Semi-arid Region of Eastern Tunisia. Communications in Soil Science and Plant Analysis. 2021; 52 (14):1689-1705.
Chicago/Turabian StyleRoua Amami; Khaled Ibrahimi; Newton La Scala Júnior; Amira Hmila; Khaoula Abrougui; Sayed Chehaibi. 2021. "Soil Physical Properties, Carbon dioxide Emissions and Their Relationships under Different Management Systems in Semi-arid Region of Eastern Tunisia." Communications in Soil Science and Plant Analysis 52, no. 14: 1689-1705.
Although tillage is key in the control of soil CO2 emissions, data on its impact under Tunisian conditions are still lacking. A field study was carried out to evaluate the effects of various tillage systems on CO2 emission and on the structural changes of a sandy loam soil in the Sousse region in Central East Tunisia. There were four tillage treatments: no tillage (NT), shallow tillage (9 cm, ST), medium tillage (14 cm, MT), and deep tillage (25 cm, DT) established in a randomized block design. Treatments were replicated three times and the plots were 60 m2 (20 m × 3 m). The CO2 flux was measured after tillage using non-through-flow steady state chambers and bulk density (BD) was determined by the volumetric cylinder method. Under each tillage treatment, carbon dioxide emissions and soil BD were monitored for a period of 40 days. The greatest CO2 emissions occurred in the first 24 h after tillage and increased in the order NT (109 mg cm−2 h−1) < ST (113.97 mg cm−2 h−1) < MT (124.55 mg cm−2 h−1) < DT (136.08 mg cm−2 h−1). The BD decreased with increased tillage, e.g., NT (1.646 g cm−3) > DT (1.18 g cm−3). There was a significant negative correlation between CO2 emissions and BD (r = − 0.6; P < 0.01), showing that no tillage is an effective mitigation measure against carbon dioxide emission in the semiarid conditions.
Roua Amami; Khaled Ibrahimi; Abdelhamid Znouda; Khaoula Abrougui; Chehaibi Sayed. Influence of tillage systems on soil bulk density and carbon dioxide emissions in the Mediterranean context. Euro-Mediterranean Journal for Environmental Integration 2021, 6, 1 -9.
AMA StyleRoua Amami, Khaled Ibrahimi, Abdelhamid Znouda, Khaoula Abrougui, Chehaibi Sayed. Influence of tillage systems on soil bulk density and carbon dioxide emissions in the Mediterranean context. Euro-Mediterranean Journal for Environmental Integration. 2021; 6 (1):1-9.
Chicago/Turabian StyleRoua Amami; Khaled Ibrahimi; Abdelhamid Znouda; Khaoula Abrougui; Chehaibi Sayed. 2021. "Influence of tillage systems on soil bulk density and carbon dioxide emissions in the Mediterranean context." Euro-Mediterranean Journal for Environmental Integration 6, no. 1: 1-9.
The aim of this study was to investigate the effects of different tillage practices on bulk density, and the hydraulic properties of a sandy loam soil of eastern Tunisia. A replicated randomized complete block design with treatments consisting of (i) no-tillage (NT), (ii) tillage with moldboard plow at three level depths (SM=15cm, MM=20cm and DM=25cm), (iii) and tillage with disc plow at three level depths (SD=15cm, MD=20cm and DD=25cm) practices established at the Higher Institute of Agricultural Sciences of Sousse; Tunisia was used for the study. The soil bulk density and saturated hydraulic conductivity were determined for each of the treatments. The bulk density (BD) was determined at the depths of 5, 15 and 25 cm while the saturated hydraulic conductivity was determined on the surface (0-10 cm) soil. Experimental results showed that all the tillage practices were significantly different in their effects on soil density and was in the descending order of NT>SD> MD>DD>SM>MM>DM. The soil bulk density decreased with the degree of soil manipulation during tillage practices, with NT having the highest (1.76; 1.86 and 1.81g cm-3) and DD having the least (1.60; 1.56 and 1.59g cm-3) respectively for 5, 15 and 25cm depths. The greater mean value of Ksat was found in DD while the lowest was found in NT with 36% reduction than DD. The research concluded that the best Tillage Practices to be adopted in terms of improvement in physical and hydraulic properties is Shallow tillage practice.
Roua Amami; Khaled Ibrahimi; Khaoula Abrougui; Amira Hmila; Sayed Chehaibi. Comparative Study of Soil Tillage Practices Effects on Hydraulic Conductivity and Bulk Density of a Sandy Loam Soil in Tunisia. Aquademia 2019, 3, ep19013 .
AMA StyleRoua Amami, Khaled Ibrahimi, Khaoula Abrougui, Amira Hmila, Sayed Chehaibi. Comparative Study of Soil Tillage Practices Effects on Hydraulic Conductivity and Bulk Density of a Sandy Loam Soil in Tunisia. Aquademia. 2019; 3 (1):ep19013.
Chicago/Turabian StyleRoua Amami; Khaled Ibrahimi; Khaoula Abrougui; Amira Hmila; Sayed Chehaibi. 2019. "Comparative Study of Soil Tillage Practices Effects on Hydraulic Conductivity and Bulk Density of a Sandy Loam Soil in Tunisia." Aquademia 3, no. 1: ep19013.