Article
Polymer Science
Vasile Cojocaru, Doina Frunzaverde, Calin-Octavian Miclosina, Gabriela Marginean
Summary: Polylactic acid (PLA), due to its low melting temperature and carbon footprint advantages, is widely used in additive manufacturing, particularly fused filament fabrication (FFF). The research conducted by the authors of this paper systematically reviews the influence of process parameters on the mechanical properties of PLA specimens additively manufactured by FFF, focusing on six process parameters: layer thickness, printing speed, printing temperature, build plate temperature, build orientation, and raster angle. The mechanical behavior of the specimens was evaluated using tensile, compressive, and bending tests.
Article
Polymer Science
Wenli Gao, Zhidan Wang, Fei Song, Yu Fu, Qingrong Wu, Shouxin Liu
Summary: A novel type of dual responsive nanogels were synthesized through physical crosslinking, showing temperature and reduction dual stimulation responsiveness, stability, and targeting ability. Results indicate that adjusting the polymerization degree of polylactic acid can alter the properties of nanogels.
Article
Materials Science, Composites
Khaled Benfriha, Mohammad Ahmadifar, Mohammadali Shirinbayan, Abbas Tcharkhtchi
Summary: This study investigates the effect of key process parameters on the temperature evolution and mechanical behavior of PA6 reinforced with chopped carbon fibers produced by FFF. Results indicate the relationship between parameters and mechanical properties of parts. The measurement of temperature profiles reveals the impact of process parameters on cooling and filament bonding.
POLYMER COMPOSITES
(2021)
Article
Chemistry, Physical
Marie Bayart, Marie Dubus, Sebastien Charlon, Halima Kerdjoudj, Nicolas Baleine, Samira Benali, Jean-Marie Raquez, Jeremie Soulestin
Summary: Scaffolds with specific features help cells to attach, proliferate, and differentiate. In this study, PLA and PLA/HA scaffolds were produced and the effect of HA particles on the scaffolds was investigated. The presence of HA induced faster and more complete polymer biodegradation, while PLA scaffolds did not degrade during conditioning.
Article
Chemistry, Multidisciplinary
Paul Palmay, Melissa Mora, Diego Barzallo, Joan Carles Bruno
Summary: This study determined the thermodynamic parameters of Polylactic Acid (PLA) under conditions of thermal degradation and found that as the heating rate increases, the degradation temperature also increases, while the activation energy, enthalpy and pre-exponential factor decrease. The results suggest that PLA has significant potential to be used as a raw material to produce bioenergy/biofuels.
APPLIED SCIENCES-BASEL
(2021)
Article
Computer Science, Interdisciplinary Applications
Maurizio Galetto, Elisa Verna, Gianfranco Genta
Summary: The research uses a Design of Experiments approach to study the effects of FDM process parameters on PLA component production, optimizes response outputs through mathematical models, and verifies the optimizations through experiments.
The results show that different parameter settings can lead to different goals in terms of part quality and process efficiency.
This method can help designers determine the optimal process parameter settings to enhance both part quality and process efficiency.
COMPUTERS & INDUSTRIAL ENGINEERING
(2021)
Article
Polymer Science
Chil-Chyuan Kuo, Jia-You Chen, Yuan-Hao Chang
Summary: This study investigated the feasibility of recycling PLA waste plastic and re-extruding it into new PLA filaments. It was found that it was possible to fabricate PLA filament using recycled PLA waste plastic at a production cost that is only 60% of the commercially available PLA filament. The tensile strength of the developed PLA filament is approximately 1.1 times that of the commercially available PLA filament, and the optimal process parameters for fabricating PLA filament were determined through a design of experiments approach.
Article
Materials Science, Ceramics
Yue Hu, Degeng Xia, Huizhen Shen, Jinxuan Nan, Ning Ma, Zuoxing Guo, Xiaolong Wang, Quan Jin
Summary: Hydroxyapatite is commonly used as a bone substitute material, but its brittleness and low fatigue strength make it challenging to meet the long-term requirements of implants. This study developed a drug-loaded hydroxyapatite-polylactic acid composite through cold sintering process at 80 degrees Celsius, which achieved high densification, improved mechanical properties, and in-situ drug loading capability.
CERAMICS INTERNATIONAL
(2023)
Article
Multidisciplinary Sciences
Masoud Zarei, Sayed Shahab Sayedain, Amirhossein Askarinya, Mobina Sabbaghi, Reza Alizadeh
Summary: This study utilized in-situ cold argon plasma treatment combined with a fused deposition modeling printer to enhance the physio-mechanical and biological behavior of 3D-printed polylactic acid (PLA) scaffolds for bone tissue engineering. The plasma treatment resulted in a rougher surface and improved interlayer bonding of the modified scaffold. It also significantly improved the tensile properties, water wettability, and degradation rate of the PLA scaffolds, while promoting cell viability and proliferation.
SCIENTIFIC REPORTS
(2023)
Article
Thermodynamics
Shaotao Xu, Xiaoshu Lue, Youhong Sun, Wei Guo, Qiang Li, Lang Liu, Shijie Kang, Sunhua Deng
Summary: A temperature optimization strategy for the Huadian oil shale autothermal pyrolysis in-situ conversion process (ATS) was proposed by investigating the reaction characteristics of various semi-cokes. The calorific value of semi-coke showed three different stages of increase, decrease, and flattening with increasing pyrolysis temperature, peaking at around 330 degrees C. The combustion characteristics of semi-coke formed at different temperatures were similar, but decreased at about 330 degrees C due to pore blockage caused by bitumen. A reasonable strategy for temperature parameter screening was proposed, providing crucial guidance for practical engineering applications.
Article
Polymer Science
R. A. Ilyas, M. Y. M. Zuhri, H. A. Aisyah, M. R. M. Asyraf, S. A. Hassan, E. S. Zainudin, S. M. Sapuan, S. Sharma, S. P. Bangar, R. Jumaidin, Y. Nawab, A. A. M. Faudzi, H. Abral, M. Asrofi, E. Syafri, N. H. Sari
Summary: This article presents the research progress and characteristics of polyactic acid (PLA) and its natural fiber-based green composites. PLA, as a thermoplastic polymer, has wide potential in replacing traditional polymers. Green composites, with advantages such as degradability, recyclability, high strength, and low toxicity, have been extensively used in fields like packaging and medicine. The article also discusses the research issues, challenges, and future development directions of PLA-based green composites.
Article
Polymer Science
Markos Petousis, Nectarios Vidakis, Nikolaos Mountakis, Emmanuel Karapidakis, Amalia Moutsopoulou
Summary: This study introduces multi-objective optimization of material deployment, 3D printing flexural response, and energy consumption in MEX AM with Polylactic Acid (PLA). The impact of control parameters on these responses was evaluated using the Robust Design theory, and it was found that infill density, raster deposition angle, and layer thickness have the greatest influence on printing time, material weight, flexural strength, and energy consumption.
Article
Biochemistry & Molecular Biology
Yujing Tang, Zhuolun Li, Shihong Chen, Xiangdong Wang
Summary: Fully degradable poly (lactic acid) foam with green environmental protection characteristics can help alleviate the shortage of petroleum resources caused by plastic applications. This study successfully prepared PLA microcellular foam with ultra-high expansion ratio and small cell size by introducing PTFE nanofibers and self-assembled nucleator TMC-300.
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
(2022)
Article
Biochemistry & Molecular Biology
Qiming Wang, Xinyi Chen, Shaohua Zeng, Pengpeng Chen, Ying Xu, Wangyan Nie, Ru Xia, Yifeng Zhou
Summary: A polycondensate-coated cellulose nanofiber (CNF) hybrid was designed and used as a nanofiller for fabricating CNF-reinforced polylactic acid (PLA) composites. The polycondensate coatings effectively promoted the dispersion of CNFs and enhanced the interfacial compatibility between CNFs and PLA. The resulting composites exhibited significant improvements in processing, mechanical, and thermal properties.
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
(2023)
Article
Biochemistry & Molecular Biology
Bingbing Cheng, Song Yan, Wenpeng Chu, Shiwen Yang, Long Zheng, Yeqiang Tan, Xianze Yin
Summary: Enhancing the toughness of biodegradable polylactic acid (PLA) blends while preserving their thermomechanical properties is achieved through the in situ mixing of PLA with cellulose nanocrystals (CNC) and cellulose nanocrystal nanofluids (CNCfs). The addition of CNCfs@CNC significantly reduces the zero-shear viscosity and storage modulus of the PLA/CNCfs blends, while retaining the storage modulus of the PLA/CNCfs@CNC blends compared to pure PLA. The optimized PLA/CNCfs@CNC blends demonstrate excellent melt processing performance, increased elongation at break, and enhanced toughness, while maintaining a high modulus.
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
(2023)
Article
Engineering, Mechanical
Van-Thang Nguyen, Cheikh Brahim Abed, Amelie Danlos, Florent Ravelet, Richard Paridaens, Michael Deligant, Sofiane Khelladi, Farid Bakir
Summary: This study presents the design and performance analysis of a low pressure-ratio centrifugal compressor with two counter-rotating rotors, called a counter-rotating centrifugal compressor (CRCC). The geometric parameters of the rotors were determined using a design method based on the loss model. The results showed that the CRCC achieved a 4.6% increase in pressure ratio and a 3.5% increase in efficiency compared to a single rotor centrifugal compressor (SRCC) at the same tip-speed. Additionally, the CRCC demonstrated better efficiency over a wide range of flow rates.
JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER-TRANSACTIONS OF THE ASME
(2022)
Article
Thermodynamics
M. N. Hamlaoui, A. Smaili, I. Dobrev, M. Pereira, H. Fellouah, S. Khelladi
Summary: The wake flow characteristics downstream from the rotor blade of small Horizontal Axis Wind Turbine (HAWT) were investigated using both experimental and simulation methods. The study revealed that the performance of the rotor blade and the nacelle have different effects on the flow field characteristics at varying distances from the rotor.
Article
Environmental Sciences
Riadh Ouzani, Zineddine Alloui, Sofiane Khelladi, Mathieu Specklin
Summary: This study numerically investigates the evolution of salt finger double-diffusive convection and analyzes the effects of buoyancy ratio and thermal Rayleigh numbers on the structure evolution and mixing properties.
ENVIRONMENTAL FLUID MECHANICS
(2022)
Article
Engineering, Mechanical
Petar Tomov, Loic Pora, Richard Paridaens, Theodore Magne, Mohamed Kebdani, Sofiane Khelladi, Farid Bakir
Summary: This study experimentally investigates the performance of two axial inducers at low flow rates in cavitating and noncavitating regimes, using water with and without dissolved CO2. The research finds that adding dissolved CO2 gas does not change the inducers' performance in noncavitating regime, and the geometrical parameters of the inducers have an impact on their cavitating performance.
JOURNAL OF FLUIDS ENGINEERING-TRANSACTIONS OF THE ASME
(2022)
Article
Engineering, Chemical
Embarek Douroum, Amar Kouadri, Antar Tahiri, Mostefa Brihmat, Sofiane Khelladi
Summary: It is evident that the flow kinematic parameters play a significant role in generating secondary flows and affecting the hydrodynamic behavior of fluid mixing. These parameters can be used to represent vortex zones in the flow field. The study shows that secondary flows in a specific micromixer can enhance the mixing efficiency.
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2022)
Article
Energy & Fuels
Michael Deligant, Moritz Huebel, Tchable-Nan Djaname, Florent Ravelet, Mathieu Specklin, Mohamed Kebdani
Summary: This paper discusses the design and system simulation of Concentrated Solar Power (CSP) plants, with a focus on the performance prediction of the radial turbine expander. The study finds that adjusting the rotational speed and inlet guide vane angle can improve the system's performance under different load conditions.
Article
Polymer Science
Salah-Eddine Ouassil, Anouar El Magri, Hamid Reza Vanaei, Sebastien Vaudreuil
Summary: This study evaluates the effects of nozzle temperature, printing speed, and specimen state on the porosity percentage and tensile properties of 3D printed PEI parts in the Z-direction. The results show that printing speed is the most influential process parameter and should be adjusted along with other printing parameters. The state of the specimens does not have a notable influence, as the amorphous nature of PEI is less receptive to annealing. The best printing conditions obtained through optimization are a printing temperature of 360 degrees C and a printing speed of 30 mm/s, followed by heat treatment.
JOURNAL OF APPLIED POLYMER SCIENCE
(2023)
Article
Chemistry, Physical
Sebastien Vaudreuil, Salah-Eddine Bencaid, Hamid Reza Vanaei, Anouar El Magri
Summary: The AlSi7Mg0.6 alloy is commonly used in LPBF for aerospace engineering parts with complex geometries. This study evaluated the influence of laser parameters on mechanical properties and identified an optimal processing region. Results showed that laser power and scanning speed had a significant impact on mechanical properties, while the laser strategy had limited influence. Surface plots revealed a region of higher mechanical properties when using specific energy densities. Optimal performance was achieved by combining mid-speed and power within this region.
Article
Thermodynamics
Cheikh Brahim Abed, Van-Thang Nguyen, Sofiane Khelladi, Michael Deligant, Amelie Danlos, Farid Bakir
Summary: The use of counter-rotating rotors in turbomachines improves performance and reduces size and weight compared to multistage configurations. This study demonstrates another advantage of counter-rotating rotors: expanding the operating range of centrifugal compressors towards extremely low flow rates through active control methods. Experimental results show that reducing the rotation speed of the upstream rotor while fixing the speed of the downstream rotor pushes instability towards lower mass flow rates, decreasing pressure rise and efficiency. The use of co-rotating mode further extends the stable region towards low mass flow rates, resulting in a significant increase in the operating range.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART A-JOURNAL OF POWER AND ENERGY
(2023)
Article
Engineering, Mechanical
Belkacem Manser, Sofiane Khelladi, Michael Deligant, Haroun Ragueb, Idir Belaidi, Farid Bakir
Summary: This study investigates the effects of textured liner and shear-thinning lubricants on the performance of finite-length journal bearing. The nonlinear Rabinowitsch-Reynolds PDE system is solved using the finite difference method combined with Elrod's algorithm. Results show that texturing the converging area of the bearing enhances load-carrying capacity and reduces friction coefficient, while using lubricants with pronounced shear-thinning behavior and/or elastic liner reduces performance. An optimal arrangement of textures, determined using particle swarm optimization, improves load capacity by 10%.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART J-JOURNAL OF ENGINEERING TRIBOLOGY
(2023)
Article
Environmental Sciences
Fatima Zohra Fourar, Ali Fourar, Omar Khanfouf, Sofiane Khelladi, Fawaz Massouh, Abdellatif Zeroual
Summary: The objective of this research is to experiment with the effects of the rough bottom on the dynamic behaviour of flows carrying solid particles of varying size, to study the behaviour of solid transport under the influence of certain easily accessible parameters, and to describe the interactions between the solid particles and the water flow. Experimental studies are necessary to overcome the complexities in the equations governing the dynamics of particles in turbulence, especially when the particle Reynolds number is very high. The study compares experimental and simulated results to evaluate the impact of flows on the materials constituting the bottom of natural channels.
MODELING EARTH SYSTEMS AND ENVIRONMENT
(2023)
Article
Thermodynamics
Riadh Ouzani, Sofiane Khelladi
Summary: Numerical simulations were used in this study to investigate the influence of density inversion on the dynamics and mixing process of finger structures. A numerical methodology based on the finite volume method and high accuracy schemes was utilized to solve the two-dimensional Navier-Stokes equations for high buoyancy ratio and moderate thermal Rayleigh number. The density was assumed to depend quadratically on temperature and linearly on salinity. The results showed that density inversion significantly affected the flow pattern and asymmetric motions were observed as the nonlinear parameter increased. In the nonlinear cases, the sinking fingers rapidly evolved and increased due to enhanced buoyancy force. The density inversion played a significant role in the mixing process, with an increase in the nonlinear parameter enhancing mixing dynamics in the lower layer.
THERMAL SCIENCE AND ENGINEERING PROGRESS
(2023)
Review
Energy & Fuels
Hamid Reza Vanaei, Sofiane Khelladi, Ivan Dobrev, Farid Bakir, Rania M. Himeur, Amrid Mammeri, Kamel Azzouz
Summary: Cross-Flow Fans (CFFs) have been widely used in various industries and there have been efforts to optimize and improve their performance by enhancing their structural, aerodynamic, and acoustic properties. This review aims to provide an overview of the research in this field, summarizing the critical factors that play a significant role in studying CFFs' performance.
Article
Mechanics
Abdelhak Megdoud, Belkacem Manser, Idir Belaidi, Farid Bakir, Sofiane Khelladi
Summary: Machine component design and analysis of bearing systems have gained significant attention in recent years. This paper explores the lubricant behavior of dynamically loaded journal bearings using the Proper Generalized Decomposition (PGD) approach, demonstrating its accuracy and efficiency.
COMPTES RENDUS MECANIQUE
(2022)
