Bone tissue engineering (BTE) holds promise for treating bone defects, and 3D-printed porous scaffolds are pivotal for tissue regeneration.This study explores the impact of material extrusion 3D printing (ME3DP) process parameters (i.e., layer height and extrusion temperature) on 3D-printed porous scaffolds made of polyetherimide (PEI) material for BTE.The intricate relationships shaping scaffold dimensional accuracy, residual stresses, and warpage tendencies were unveiled using comprehensive numerical simulations.Our findings reveal that higher layer heights enhance dimensional stability, especially at lower printing temperatures, reducing maximum displacements.Consequently, lower layer heights lead to higher warpage critical values.This insight is instrumental in optimizing the material extrusion 3D printing (ME3DP) process, vital for precise net shape in BTE applications.Furthermore, residual stresses also revealed a correlation between higher printing temperatures and increased residual stresses.These findings emphasize the necessity of balancing material flow, printing temperature, and layer height for scaffold quality.Therefore, the right balance between precision and mech. stability is critical for producing high-quality scaffolds that meet BTE requirements.

2024-05-01·Process Safety and Environmental Protection

Challenges and opportunities in biogas conversion to microbial protein: A pathway for sustainable resource recovery from organic waste

作者: Rasool, Kashif ; Shahzad, Hafiz Muhammad Aamir ; Shahzad, Asif ; Almomani, Fares ; Mahmoud, Khaled A.

A review.Addressing global food security is a paramount challenge that necessitates a shift towards enhanced food self-sufficiency.The escalating demand for animal-derived proteins, such as meat and dairy, underscores the critical role of livestock farming in meeting the nutritional needs of the global population.To sustain this, protein-rich feed, essential for livestock production, consumes a considerable share of agricultural resources.Concurrently, urban expansion significantly increases organic waste, undermining both economic and environmental sustainability.This highlights the urgent need for innovative waste management solutions that bolster sustainability.Microbial protein (MP), produced by methane-oxidizing bacteria (MOB), presents a promising solutionIt offers a land-independent method for producing feed for livestock and aquaculture, potentially alleviating the pressure on agricultural lands.Despite its advantages, reliance on natural gas for MP production raises sustainability concerns when compared to traditional feeds like fishmeal and soybean meal.Recent research focuses on valorizing waste materials using high-protein microorganisms for animal feed production, thereby addressing these concerns.Aerobic fermentation of methane to produce MP, utilizing methanotrophic microbes, showcases distinct advantages.These microbes produce a protein-rich biomass, containing over 75% protein, offering a viable alternative to conventional protein sources.This review explores the potential of urban biowaste valorization for MP production through the integration of anaerobic digestion (AD) and subsequent fermentation of biogas.It delves into the valorization mechanisms of biogas from AD to MP, highlighting methane's value in MP production for environmental and economic sustainability.Despite advancements, challenges such as inefficient fermenters, MOB inhibition, and safety issues hinder large-scale MP productionFurther investigation into the life cycle assessment (LCA) and techno-economic anal. (TCA) of these integrated technologies is essential for enhancing and establishing a sustainable MP production system.

2024-04-01·Advanced Industrial and Engineering Polymer Research

Product, process, property, and performance (PPPP) relationship of 3D-Printed polymers and polymer composites: Numerical and experimental analysis

作者: Koc, Muammer ; Al Rashid, Ans ; Khan, Shoukat Alim

Understanding the external and internal factors during an additive manufacturing (AM) process is crucial, as they can significantly affect the final product′s performance.Efforts have been made to unwind the product, process, property, and performance (PPPP) relationships.The conventional exptl. approaches can lead to boundless runs, resulting in exorbitant costs for research and development.Hence, developing, adapting, and validating numerical models is essential to achieving the desired performance of 3D-printed products with lesser resource utilization.In this study, numerical and exptl. techniques were used to perform the PPPP relationship assessment on material extrusion 3D-printed parts.Three infill designs (rectangular, triangular, and hexagonal), with layer heights (0.1 mm, 0.125 mm, and 0.2 mm), and three different materials (carbon fiber-reinforced polyamide-6 (PA6-CF), polyamide-6 (PA6), and acrylonitrile butadiene styrene (ABS)), were selected for the investigation.Taguchi′s design of experiments (DOE) method was used to limit the number of numerical simulations and exptl. runs.A thermomech. numerical model was utilized to perform the material extrusion process simulations and mech. performance prediction of the specimens.Subsequently, the samples were 3D-printed and tested mech. to validate the numerical simulation results.The dimensional, distortion, and mech. anal. performed on numerical simulation results agreed well with the exptl. observations.

100 项与 Qatar Foundation Endowment SPC 相关的药物交易

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100 项与 Qatar Foundation Endowment SPC 相关的转化医学

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