Article
Engineering, Chemical
Siou Pei Ng, Yih Phing Khor, Hong Kwong Lim, Oi Ming Lai, Yong Wang, Yonghua Wang, Chin Ping Tan
Summary: The addition of sucrose stearate as a nonionic emulsifier to POL-DAG oil significantly reduced its thermal properties and hardness, resulting in shear-thinning behavior and low apparent viscosity. This simple method of adding an emulsifier resolves the solidification issue of POL-DAG oil and is highly applicable for the fats and oils industries.
Article
Chemistry, Physical
Arshia Dehghani, S. Sadra Mohammad Nafari, Naeimeh Bahri-Laleh, Leila Moballegh, Samahe Sadjadi, Mehrsa Emami, Montserrat Rodriguez-Pizarro, Albert Poater
Summary: In this research, nano-scaled halloysite-supported imidazolium based dicationic ionic liquids (ILs) with different electronic features were prepared and used in the oligomerization of 1-octene monomer. The resulting polyalphaolefins (PAOs) showed lower molar masses but comparable performance to commercial counterparts, indicating a more sustainable and greener polymerization procedure.
JOURNAL OF MOLECULAR LIQUIDS
(2023)
Article
Engineering, Mechanical
Oscar A. Aguilar-Rosas, Jorge A. Alvis-Sanchez, Bernardo Tormos, Benjamin M. Marin-Santibanez, Jose Perez-Gonzalez, Leonardo I. Farfan-Cabrera
Summary: In this investigation, a polyalphaolefin oil (PAO4) containing graphene nanoplatelets (GnPs) was tested as a potential nanolubricant for electrified environments. The GnPs enhanced the thermal and rheological properties of PAO4, reduced the dielectric strength, and improved the tribological performance under electrified conditions. This suggests that GnPs can be effective additives to improve the properties of low-viscosity oils in aggressive electrical environments.
TRIBOLOGY INTERNATIONAL
(2023)
Article
Engineering, Mechanical
Andreas Conrad, Annika Hodapp, Bernhard Hochstein, Norbert Willenbacher, Karl-Heinz Jacob
Summary: According to ASTM D97, the pour point is the temperature below which petroleum products cease to flow. The study investigated the crystallization, melting temperature, and low-temperature flow behavior of mineral and synthetic lubricating oils, leading to the classification of three groups based on their behavior. The pour point correlates well with the crystallization temperature and viscosity behavior of the oils.
Article
Green & Sustainable Science & Technology
Madhavi Perera, Jinyong Yan, Li Xu, Min Yang, Yunjun Yan
Summary: In recent years, vegetable oils and their derivatives have gained attention as environmentally friendly lubricants due to their biodegradability, renewable nature, and superior lubrication performance compared to fossil commercial lubricants. This review examines the zero-waste approach of enzymatic conversion for bio-lubricant production using non-edible oil and agro-industrial waste, while also exploring the use of lipase as a biocatalyst in place of chemically mediated transesterification processes. The article provides information on the types of lipases used, their optimal reaction conditions, and the maximum product yields, as well as highlights the physicochemical properties and enhanced application fields of bio-lubricants.
JOURNAL OF CLEANER PRODUCTION
(2022)
Article
Chemistry, Physical
Huaigang Su, Qin Zhao, Yanan Wang, Qilong Zhao, Cheng Jang, Yongfang Niu, Wenjing Lou, Yanxing Qi
Summary: A new composite material SnO@GO was fabricated by depositing nanosized SnO on graphene oxide using a hydrothermal technique, showing excellent catalytic performance in esterifying fatty acids and trimethylolpropane with a yield of up to 99%, and can be recycled for 6 cycles without deactivation. This outstanding catalytic performance is attributed to the active Lewis acid of SnO and the increase in specific surface area due to the loading of SnO onto GO.
CATALYSIS COMMUNICATIONS
(2022)
Article
Food Science & Technology
Eun-Ae Chu, Da-Gyun Park, Eun-Ji Oh, Yeon-Su Lim, Na-Hyeon Kim, Yeong-Min Lee, Kyeong Sik Jin, Jonghoon Choi, Hee-Young Lee
Summary: Edible oleogels can be created using lecithin and D-sorbitol as gelators, with potential applications in the food industry. The formation of the oleogels was studied, and the gelation mechanism was identified through various techniques. The results suggest that this method is simple and reproducible, and can be used for mass production of marketable consumer products.
Article
Chemistry, Physical
Bingyu Shi, Man Liu, Jiangang Chen
Summary: Derivatives of 2,4-dimethyldihydrocyclopentadiene were prepared and characterized by NMR spectroscopy. These derivatives were applied in the oligomerization of 1-decene. A two-step activation method using both triisobutylaluminium (TIBA) and methyl aluminoxane (MAO) was developed for N-doped ligand catalyst. The N-doped catalyst showed high polymerization conversion and the obtained oligomers had high viscosity index, making them promising catalysts for high quality lubricant base oils.
Article
Agronomy
Indrek Keres, Maarika Alaru, Reine Koppel, Illimar Altosaar, Tiina Tosens, Evelin Loit
Summary: The study found that the application of mineral N can increase the gluten content and dough quality, while the quality of dough in organic treatments is more variable.
Review
Geosciences, Multidisciplinary
Shengsi Sun, Yunpeng Dong, Yixi Li, Yihai Yang, Chao Cheng, Bo Hui, Bin Zhang, Rutao Zang
Summary: This paper provides a comprehensive review of the current research progress in rock rheology, including the rheological mechanisms and seismic properties of main rock-forming minerals at different depths of continental lithosphere. It introduces the latest advances in high-pressure and high-temperature experiments and natural deformation observations, and discusses the application of rock rheology in interpreting seismic anisotropy data.
SCIENCE CHINA-EARTH SCIENCES
(2023)
Article
Engineering, Multidisciplinary
Joyce Jacob, P. Preetha, T. K. Sindhu, U. Mohan Rao
Summary: In this study, it is found that natural ester nanofluids exhibit better dielectric and thermal properties compared to non-biodegradable mineral oil. After 1200 hours of thermal aging, the AC breakdown voltage, thermal conductivity, and tensile strength of cellulose impregnated with natural ester are significantly higher than those impregnated with mineral oil. Furthermore, the AC breakdown voltage, thermal conductivity, and tensile strength of cellulose impregnated with natural ester nanofluid are also higher than those impregnated with mineral oil nanofluid. These findings suggest a potential for extended service life of solid insulation in liquid filled high voltage transformers.
Article
Polymer Science
Manuela Machado, Sergio Cruz Sousa, Luis Miguel Rodriguez-Alcala, Manuela Pintado, Ana Maria Gomes
Summary: This study aimed to develop novel bigels to protect bioactive fatty acids in vegetable oils during digestion. The bigels, composed of monoglycerides-vegetable oil oleogel and carboxymethyl cellulose hydrogel, demonstrated solid-like behavior and effectively protected fatty acids against degradation. The proportions of oleogel played a crucial role in the viscosity of the final formulation. These results suggest that bigels can be used as an important strategy for delivering bioactive fatty acids in food applications.
Article
Food Science & Technology
Laura Principato, Daniele Carullo, Andrea Bassani, Alice Gruppi, Guillermo Duserm Garrido, Roberta Dordoni, Giorgia Spigno
Summary: In this study, oleogels were prepared using rice bran wax and bamboo fiber in olive oil and sunflower oil, and the effects of fiber addition and cooling temperature on the thermal and structural parameters of the gels were investigated. It was found that decreasing cooling temperature and adding low-granulometry fiber had a negative impact on network formation, but the negative effects could be partially recovered by the addition of low-granulometry fiber.
Article
Energy & Fuels
Anastasiya Y. Yadykova, Sergey O. Ilyin
Summary: This article studies and analyzes the morphological features, thermophysical properties, and rheology of bio-oil in comparison with light and heavy crude oils. The study demonstrates that bio-oil is a water-in-oil emulsion, light crude oil is a suspension of paraffin waxes in oil medium, and heavy crude oil is a homogeneous liquid. The article also explores the blends of bio-oil with fossil oils and their miscibility, showing that macroscopically compatible blends are formed only when heavy crude oil is mixed with bio-oil at a low content of the latter.
Review
Environmental Sciences
Georgia Baliota, Christos G. Athanassiou
Summary: Paraffin oils derived from petroleum have insecticidal properties and have been widely used, but their potential phytotoxic effects have limited their research and application in agriculture. However, there is growing interest in petroleum-based pesticides due to their compatibility with integrated pest management programs. This study aims to provide an overview of the current status of petroleum oils in agriculture, including their insecticidal properties, factors influencing their efficacy and phytotoxicity, commercial aspects, and toxicological profile to non-target organisms.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2023)
Article
Engineering, Mechanical
Pedro M. T. Marques, Joao D. M. Marafona, Ramiro C. Martins, Jorge H. O. Seabra
Summary: A continuous analytical model is presented in this work for estimating mesh stiffness, load sharing, and friction torque in parallel axis involute spur and helical gears. The model allows for a continuous description of gearing phenomena without using functions by domains. The influence of model parameters on mesh stiffness, load sharing, and friction torque is evaluated by comparing three gears of different types.
MECHANISM AND MACHINE THEORY
(2021)
Article
Engineering, Mechanical
V Ripard, D. Goncalves, F. Ville, J. H. O. Seabra, J. Cavoret, P. Charles
Summary: The study analyzed lubrication starvation using the Starvation Degree parameter through tests with different operating conditions and types of greases to prevent damage such as scuffing.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART J-JOURNAL OF ENGINEERING TRIBOLOGY
(2022)
Article
Engineering, Mechanical
Lucas Fourel, Jean-Philippe Noyel, Etienne Bossy, Xavier Kleber, Philippe Sainsot, Fabrice Ville
Summary: A numerical model for rolling contact fatigue using finite element method and micromechanical model is developed, showing that mesoscopic consideration offers benefits over macroscopic approach in handling dented surfaces, while orthogonal shear stress computation on macroscopic model is legitimate for Hertzian contact. Mesoscopic modeling allows for life scatter on fatigue crack threshold, with initiation depths consistent with literature experiments.
TRIBOLOGY INTERNATIONAL
(2021)
Article
Engineering, Mechanical
Justino A. O. Cruz, Pedro M. T. Marques, Jorge H. O. Seabra, Jorge D. Castro
Summary: This study investigates the power loss in a real axle box gear transmission under no-load operating conditions. The research analyzes the contributions of different components and develops a numerical model for predicting power loss. The results highlight the significant impact of the tapered roller bearings in the overall power loss of the axle box.
JOURNAL OF TRIBOLOGY-TRANSACTIONS OF THE ASME
(2022)
Article
Nanoscience & Nanotechnology
Andre A. Ferreira, Ana R. Reis, Rui L. Amaral, Joao M. Cruz, Pedro C. Romio, Jorge O. Seabra, Manuel F. Vieira
Summary: This study investigated the mechanical and microstructural properties of a bulk produced by direct laser deposition (DLD) of a nickel superalloy (Inconel 625) on 42CrMo4 structural steel. The results demonstrated that a high-quality bulk was formed with structural integrity and mechanical properties similar to wrought Inconel 625. These findings contribute to the recognition of DLD as a suitable technique for the repair and remanufacturing of industrial components.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Materials Science, Coatings & Films
Nicolas Grenet-de Bechillon, Thomas Touret, Jerome Cavoret, Christophe Changenet, Fabrice Ville, Dhafer Ghribi
Summary: This paper investigates the strong coupling between friction power losses and film thickness, and proposes a new test method to study scuffing with film thickness as a key parameter. This method allows for film thickness variation with minimal friction losses and temperature changes, revealing the importance of film thickness in scuffing. The test results show that even in full film lubrication, asperity contact can be achieved potentially through the collapse of the oil film.
TRIBOLOGY-MATERIALS SURFACES & INTERFACES
(2022)
Article
Engineering, Chemical
Xavier Paredes, Jose M. Lineira del Rio, David E. P. Goncalves, Maria J. G. Guimarey, Maria J. P. Comunas, Jorge H. O. Seabra, Josefa Fernandez
Summary: The thermophysical and tribological properties of two new highly viscous biodegradable oils were investigated. The results showed that these oils have high viscosity under high pressure and high temperature conditions, which can affect the friction performance in different lubrication regimes and temperature variations.
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2022)
Article
Engineering, Mechanical
P. Navet, J. Cavoret, F. Ville, C. Changenet, D. Ghribi
Summary: This study conducts experiments to analyze starvation conditions for high slide-to-roll ratio, similar to those of gears. It proposes a new oil-off test procedure and highlights the positive effect of low viscosities of residual oil on starved conditions. Additionally, it introduces a new inverse method to estimate central oil film thickness during oil-off phases, which is consistent with existing models and suitable for severe starvation.
TRIBOLOGY TRANSACTIONS
(2023)
Article
Engineering, Mechanical
J. C. Poletto, C. M. C. G. Fernandes, L. Y. Barros, P. D. Neis, K. Pondicherry, D. Fauconnier, J. H. O. Seabra, P. De Baets, N. F. Ferreira
Summary: Visual inspection for identifying gear failure modes is subjective and biased, so it is important to design objective methods. This study used white light interferometry to measure the 3D topography of gears affected by different wear modes. Various roughness parameters were evaluated and a new parameter called surface motion orientation (Smo) was proposed. The combination of these parameters allowed for an objective classification of gear failure modes.
Article
Chemistry, Physical
Nuno Miguel Ferreira, Maria Vila Pouca, Carlos Fernandes, Jorge Seabra, Grzegorz Lesiuk, Marco Parente, Abilio Jesus
Summary: This study used numerical simulation models to predict deformations and residual stresses in the gear repair process by directed energy deposition (DED). The model was validated using a case study from the National Institute of Standards and Technology (NIST), and a parametric study was conducted to examine the influence of DED parameters. The results demonstrated the model's accuracy in predicting deformations and residual stresses, and provided insights into the effects of printing parameters on the process.
Article
Engineering, Mechanical
Joao D. M. Marafona, Pedro M. T. Marques, Ramiro C. Martins, Jorge H. O. Seabra
Summary: In many gear stiffness models, the single tooth pair stiffness is often approximated as a symmetric curve with a parabolic shape along the contact path. However, this approach ignores the asymmetry and approximates the amplitude. In this study, a new analytical expression for the single tooth pair stiffness is proposed, based on a parabolic approximation of the tooth pair structural stiffness, considering the asymmetry, relative amplitude, and maximum value as a function of gear parameters. The accuracy and applicability of the proposed method are validated using a random sample of gears, showing the importance of including asymmetry and the improvements achieved with the new parameters.
MECHANISM AND MACHINE THEORY
(2023)
Article
Engineering, Mechanical
L. Darul, T. Touret, C. Changenet, F. Ville
Summary: This study presents a theoretical analysis of power losses in an oil-jet lubricated deep groove ball bearing. The model focuses on the physics of unloaded rolling elements and aims to solve the problem of estimating dissipation sources in the absence of applied load. The model is compared with global power loss models and shows that unloaded rolling elements can contribute up to 40% of the losses with a 5% applied radial load.
TRIBOLOGY TRANSACTIONS
(2023)
Article
Engineering, Mechanical
F. de Cadier de Veauce, L. Darul, Y. Marchesse, T. Touret, C. Changenet, F. Ville, L. Amar, C. Fossier
Summary: This article presents an experimental study on load-independent power losses in oil-jet lubricated deep-groove ball bearings. The influence of factors such as rotational speed, lubricant temperature, oil flow rate, and bearing dimensions on power losses were quantified through experiments. A load-independent power losses model for rolling element bearings, proposed in a previous article, was used to simulate the experiments, and the results were compared with measurements. Good agreement was found on the power losses in low-loaded deep-groove ball bearings.
TRIBOLOGY TRANSACTIONS
(2023)
Article
Engineering, Mechanical
Gabriel Lanaspeze, Berengere Guilbert, Lionel Manin, Fabrice Ville
Summary: A quasi-static chain drive model is proposed for simple two sprocket drives in single speed cycling application. Kinematics of the transmission is determined and both tensions into the links and contact forces are calculated. The results suggest that roller displacement should be considered in future studies on chain drive efficiency.
MECHANICS & INDUSTRY
(2022)
Article
Engineering, Mechanical
Huiyi Yang, Yang Xu, Chao Xu
Summary: This study focuses on the impact of dry friction interfaces on the dynamics of jointed structures, particularly on the statistics of contact pressure distribution. Through experimental and simulation analysis, it is found that surface roughness and contact load have significant effects on contact area, contact stiffness, and mean contact pressure.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART J-JOURNAL OF ENGINEERING TRIBOLOGY
(2024)
Article
Engineering, Mechanical
Guanglan Hu, Houfu Dai
Summary: The effect of metal coating on the machinability of cubic silicon carbide was investigated using molecular dynamics simulation. The results showed that the type of coating has a significant impact on cutting force, surface morphology, stress, and tool wear. Among the three metals studied, Cu coating had the greatest impact on improving cutting performance.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART J-JOURNAL OF ENGINEERING TRIBOLOGY
(2024)
Article
Engineering, Mechanical
Yunfan Liu, Guozheng Ma, Lina Zhu, Cuihong Han, Zhen Li, Bin Zhang, Haichao Zhao, Haidou Wang, Shuying Chen
Summary: The service performance of coated self-lubricating spherical plain bearings can be improved by applying self-lubricating coatings, especially double-sided coatings. The presence of a large-area and complete mixed friction transfer film on the contact surfaces can cause a signal downstage before the signal mutation stage.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART J-JOURNAL OF ENGINEERING TRIBOLOGY
(2024)
Article
Engineering, Mechanical
Yakup Artun, C. Oktay Azeloglu, Gokhan Taylan
Summary: This article investigates the tribological properties of polymer journal bearings, particularly focusing on radial journal bearings made from UHMWPE and POM materials with different surface qualities. The study examines the performance of these bearings under varying load and speed conditions, and analyzes the relationship between material and surface roughness in tribological performance.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART J-JOURNAL OF ENGINEERING TRIBOLOGY
(2024)
