• This paper investigates innovative cooling techniques for gas turbine combustor walls, crucial for maintaining durability and functionality in high-temperature conditions. Focusing on the combustor liner, the study examines the progression from traditional cooling methods such as louver and splash cooling to advanced techniques like transpiration cooling, which significantly reduces cooling air requirements by up to 50%. Using Computational Fluid Dynamics (CFD) analysis, the research evaluates convection cooling in ducts with 5 mm and 10 mm gap configurations, testing various inlet velocities. The results demonstrate that the narrower 5 mm gap offers a slightly higher cooling efficiency, achieving approximately 70% optimal cooling effectiveness. The study underscores the effectiveness of (CFD) in predicting temperature distributions and optimizing turbine design.

Vortex airflow-assisted melt differential electrospinning for preparing superfine fiber yarns was proposed. This method with solvent-free exhibits a higher yield of 20 ± 5.17 m/min compared to the range of 0–5 m/min achieved by solution electrospinning with organic solvents. Simulation and high-speed photography show that the fibers are aggregated by suction airflow and twisted into yarns by vortex airflow. Polylactic acid (PLA) superfine fiber yarns exhibit fine fiber diameters ranging from 0.96 to 5.57 μm, a yarn diameter of 211.7 ± 40.8 μm, and a high tensile strength of 39.4 ± 3.12 MPa. Furthermore, these PLA melt electrospun yarns can be woven into fabric with a water contact angle of 120.1° and triboelectric voltage of 7.41 V, demonstrating their potential in self-cleaning textiles and flexible smart textiles. Moreover, this method is generally applicable to thermoplastic polymers including polyethylene …

A design of a geothermal heat pump heating, ventilating, and air conditioning system has been done for XYZ Indianapolis School by using renewable energy. Geothermal energy is one of the important energies that has proved itself in air conditioning systems all over the world. The design was classified in three points as follows. Using borehole heat exchanger (BHEs) vertical type, heat pump and all its equipment such as mechanical room, pipes, and fitting design to cover the total load of the school the results were 20 boreholes and a total flow rate of 60 gpm (3 gpm/bore) of 20 % propylene solution, and spacing 20 ft with 1.1 Hp and 6.5 in impeller size. For individual borehole design, the results were 15 boreholes and a total power consumption 1.1 kW. For the ventilation design, the peak load for heating is 42779 Btu/hr, and for cooling, it is 47779 Btu/hr. There are 4 boreholes, a 0.5 hp electric pump with a flow rate of 10 gpm a 40ft of H2O pressure drop, and a 10 hp fan integrated with a water-to-water heat pump. The total load we assumed for the heating supply in class 6 and the corridor are 10% and 25 %, respectively. The thermal resistance was calculated for each case according to the fluid flow rate. The ventilation load of the school is designed separately from the heating and cooling loads and connected to a water-water heat pump that will make the system work with high efficiency. Finally, we designed this project using Geothermal Energy, which is cleaner than conventional energy.

Solar energy, known for its abundance and sustainability, stands out as a preferred renewable energy source. Net-zero energy buildings (NZEBs) technology for an elementary school in Dayton, Ohio, was implemented using the f-chart, phi method, photovoltaic system, and the CombiSystem TRNSYS executable. The solar fraction achieved for the system was 56% utilizing the f-chart and phi method. The project required 181 collectors for heating and cooling loads and 578 photovoltaic collectors for electricity generation. Using the f-chart and phi method, the simple payback period was calculated to be 5 years. The optimal storage tank design was determined to be a 120-60 gallon configuration, achieving a solar fraction of 62.45%. The photovoltaic system generated energy valued at $191,135 annually, meeting the requirements for a net-zero energy building. This design provides clean energy without environmental pollution or CO₂ emissions. The total project cost amounted to $275,393.99, making it the most cost-effective design compared to alternative designs incorporating photovoltaic systems for cooling loads. 

Electrospun fibers membrane is considered an efficient drug carrier for transdermal drug delivery due to its breathability and high drug loading percentage, compared with coating film. However, pollution and safety risk caused by the use of organic solvents during the solution electrospinning process limit its industrialization and direct application in the biomedical field. Herein, a fiber membrane containing tandospirone was prepared using the melt electrospinning process and to be used for sustained drug release. The process of fiber preparation is an eco‐friendly and safe process due to the characteristics of solvent‐free. The in vitro drug release results showed that the fiber membranes containing tandospirone had slower initial drug release and higher end drug release compared with coating film containing tandospirone. The sustained‐release property can be attributed to the crystalline structure of fibers and …

The electrospun yarn for sutures has gained worldwide attention due to its fine fibers that resemble the extracellular matrix and its abundant functional sites. However, the use of a large number of toxic solvents poses safety risks and environmental pollution during production, making it challenging to directly apply electrospun yarn in the biomedical field. In this study, an environmentally friendly and safe method without toxic solvents was proposed for preparing antibacterial PLA ultrafine fiber sutures. This method involves melt electrospinning, hot‐stretching, low‐temperature plasma treatment, and chitosan grafting. The PLA ultrafine fiber sutures exhibit a high tensile strength which is 2.04 N before knotting and 1.57 N after knotting. The suture diameter is 118.7 μm and average fiber diameter is 1.72 μm. Chitosan grafted on the fiber surface provides excellent antibacterial properties for the sutures, with …

Engineering education has a crucial role in the economic and social development of society; this paper aims to investigate the most significant factors that contributing in improving the quality of the engineering education. Furthermore, identify the factors affecting the students’ academic performance. The study was conducted by using statistical Design of Experiments (DOE) approach to investigate the main effects of lecture delivery, assessment, engagement, communication, and interaction with instructors. Minitab software is implemented to perform statistical analysis to identify the significance of each factor, and degree by which each factor influences the students’ academic achievement. Results showed that the students’ academic performance is affected by the availability of course materials, and communications with instructors.

This paper addresses a bi-criteria optimization problem to minimize total flow time and makespan simultaneously for a cellular flowshop with Sequence Dependent Setup Times (FMCSP with SDSTs); A multi-objective Particle Swarm Optimization (MPSO) and a Multi-objective Simulated Annealing (MOSA) Algorithm are proposed to solve the proposed problem. furthermore, an improved algorithm (named as IMPSO-TA), where MPSO is combined with Threshold Acceptance (TA) algorithm to improve the convergence of the obtained Pareto Fronts. The proposed algorithms are evaluated using several Quality Indicators (QI) measures for multi-objective optimization problems. Results showed that proposed algorithms can generate approximated Pareto Fronts in a reasonable CPU time. Furthermore, quality of Pareto fronts generated by IMPSO-TA is better than Pareto fronts found by MPSO and MOSA based on the test problems that are used in this research at the cost of CPU time. Further, the proposed IMPSO-TA performs as best available algorithms in the literature for small and medium test problems with a very minor deviation for best results for large test problems.

Oil spills are an unavoidable risk during exploration, production, and transportation. In the event of an accident, the environmental impact is often severe and may even harm the local environment for decades. Therefore, there is a need to find a method and device that minimizes damage to the environment. Oil spill cleanup and remedy are still a challenge and raise global concern because of the many environmental complications associated with it. This chapter reviews existing methods and devices for oil spill cleanup, particularly the wetting phenomenon for oil absorption and membrane filtration methods for oil spill cleanup, and focuses on the properties of nanofiber materials and their use for manufacturing oil absorbents and cross-flow filtration membranes. In particular, this chapter discusses the performance, effectiveness, and applications of nanofibrous materials fabricated by the solution and hot melt …