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Sustainability has become of great interest in many fields, especially in production systems due to the continual increase in the scarcity of raw materials and environmental awareness. Recent literature has given significant attention to considering the three sustainability pillars (i.e., environmental, economic, and social sustainability) in solving production planning problems. Therefore, the present study conducts a review of the literature on sustainable production planning to analyze the relationships among different production planning problems (e.g., scheduling, lot sizing, aggregate planning, etc.) and the three sustainability pillars. In addition, we analyze the identified studies based on the indicators that define each pillar. The results show that the literature most frequently addresses production scheduling problems while it lacks studies on aggregate production planning problems that consider the sustainability pillars. In addition, there is a growing trend towards obtaining integrated solutions of different planning problems, e.g., combining production planning problems with maintenance planning or energy planning. Additionally, around 45% of the identified studies considered the integration of the economic and the environmental pillars in different production planning problems. In addition, energy consumption and greenhouse gas emissions are the most frequent sustainability indicators considered in the literature, while less attention has been given to social indicators. Another issue is the low number of studies that have considered all three sustainability pillars simultaneously. The finidings highlight the need for more future research towards holistic sustainable production planning approaches.

The wind turbine blades are the main part of the rotor. Extraction of energy from wind depends on the design of the blade. In this paper, a design method based on Blade Element Momentum (BEM) theory is explained for small horizontalaxis wind turbine model (HAWT) blades. The method was used to optimize the chord and twist distributions of the wind turbine blades to enhance the aerodynamic performance of the wind turbine and consequently, increasing the generated power. A Fortran program was developed to use (BEM) in designing a model of Horizontal-Axis Wind Turbine (HAWT). NACA 4412 airfoil was selected for the design of the wind turbine blade. Computational fluid dynamics (CFD) analysis of HAWT blade cross section was carried out at various blade angles with the help of ANSYS Fluent. Present results are compared with other published results. Power generated from wind turbine increases with increasing blade angle due to the increase in airvelocity impact on the wind turbine blade. For blade angle change from 20° to 60°, the turbine power from wind has a small change and reaches the maximum when the blade angle equals to 90°. Thus, HAWT power depends on the blade profile and its orientation.

Renewable energy attracts many researchers as the non-renewable one has negative environmental impacts and limited availability. One of the main types of renewable energy is the blue energy where electricity is generated by water waves using triboelectric nanogenerators (TENGs). Thin films play an important role in the performance and therefore the efficiency of TENGs as they represent the electrodes between which electrons move producing electricity. In order to increase the generated electricity from TENGs, the properties of these electrodes should be modified. Therefore, in this paper, nano- and micro-size thin films are fabricated and characterized by measuring the geometrical parameters and electrical properties. Thin films are fabricated using aluminum with thicknesses 0.5 μm and 1.5 μm on acrylic substrate and 0.5 μm copper film on different types of dielectric materials including PVC and polystyrene. Atomic force microscopy is used to measure the geometrical parameters of the fabricated films including thickness and surface roughness. Also, Gwyddion software is used for the grain size evaluation. On the other hand, Keithley is used for measuring the electrical properties including electrical conductivity and sheet resistance. It is found that the electrical conductivity of aluminum films is inversely proportional to the thickness. The corresponding measured values of the electrical conductivity of the fabricated thinner and thicker aluminum films equal 1.7 x 107 (Ω.m)-1 and 1.4×107 (Ω.m)-1, respectively. Whereas, the electrical conductivity of the fabricated copper film equals 8.8×107 (Ω.m)-1. In addition, the temperature effects on the electrical conductivity are studied. Finally, simulation of a TENG using COMSOL software is accomplished in order to evaluate the electrical outputs of potential, charge, and energy.

The metal rolling industry is in continuous demand for increasing the efficiency of the process. A new method of partitioning the consumed power in plate rolling into its constituent parts is presented. The proposed model takes into consideration the spread of workpiece, making it applicable to more general situations where the height to length ratio is equal to or larger than one. A mathematical model is proposed to calculate the consumed power and calculate different losses in the rolling operation. The method is easy and computationally efficient, which makes it attractive to industrial application.