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In light of current high and volatile energy and food prices, we examine the daily dynamics of the conditional variance-covariance matrix and price discovery in European vegetable oils. We find that energy prices chiefly influence vegetable oil trends, while stock-to-use ratios significantly impact variance-covariance dynamics when considering their specific cold filter plugging point (CFPP). This technical detail robustly demonstrates interplays among vegetable oils based on economic principles of complementarity and substitutability, even amid the pandemic and the Russian-Ukrainian conflict. Moreover, both marginal distributions and volatility dependence structures relate to distinct economic fundamentals, enhancing our understanding of the market's complexity. [ABSTRACT FROM AUTHOR]

The tribological properties of lubricants containing the same additives often vary with varying hardness and composition of the frictional parts. This means that, in terms of the effectiveness of lubricant additives, most of current researches using GCr15 steel to assemble the frictional pair could not be directly cited by the moving parts made of other materials. Aiming at verifying if RNS‐1A‐PIBSA (referring to amino‐functionalized silica nanoparticle [RNS‐1A] after secondary surface‐capping by polyisobutylene succinic anhydride [PIBSA]) is suitable for multiple frictional parts made of different materials with varying hardness and composition, herein we investigate its applicability an additive in poly‐alpha‐olefin 6 (PAO6) base oil to three types of sliding pairs constructed from GCr15 steel, #45 steel, and ductile iron with much different hardness and composition by SRV‐5. A series of analyses of worn surface morphology and composition demonstrate that, independent of the composition and hardness of the frictional pairs, RNS‐1A‐PIBSA added in PAO6 base oil can form silica deposition film on the rubbed surfaces of the three kinds of sliding pairs, thereby effectively reducing friction and wear. Besides, we also examine the effect of RNS‐1A‐PIBSA on the thermal stability of the PAO6 base oil, and found the nano‐additive RNS‐1A‐PIBSA can delay the thermal decomposition of PAO6 base oil to some extent, which is favourable for its application in lubrication engineering. [ABSTRACT FROM AUTHOR]

In the realm of lubrication, nanoparticles play a pivotal role in enhancing the tribological efficacy of lubricating oils. Unveiling a critical need, the research underscores the necessity for a predictive model capable of anticipating these performance characteristics. This research endeavors to fill this gap by introducing an artificial neural network (ANN) tailored specifically for predicting the behavior of nanolubricants. The optimized neural network structure, at 5 × 8 × 2, attains a remarkable minimum mean square error of 0.00046667, with R-values hovering at impressive proximity to unity (0.99828). During the confirmation phase, the neural network's predictions demonstrate a deviation of 7.51% (negative) and 2.87% (negative) for COF, alongside 0.50% and 1.80% for WSD, further affirming its predictive capacity in assessing lubricant performance characteristics. [ABSTRACT FROM AUTHOR]

In order to ensure the accuracy of oilfield development dynamic data, the author starts from analyzing the characteristics of development dynamic data, and conducts in-depth research on the characteristics of development dynamic data, the algorithm set for accuracy detection of development dynamic data, and comprehensive analysis methods. Firstly, in response to the spatiotemporal heterogeneity in developing dynamic data, combined with the design concept of a multi detector combination algorithm based on spatiotemporal mixed patterns, the accuracy detection algorithm is evaluated and selected. Based on this, the author proposes a development dynamic data accuracy detection method that considers the influence of multiple factors (FAGTN); Secondly, ARIMA, MGLN, STGCN, and FAGTN algorithms were selected as the algorithm sets for developing dynamic data accuracy detection, in order to complete the data accuracy detection based on monthly oil well data as the research object; Then, a combined weighting based analysis method was proposed to comprehensively analyze the accuracy detection results of dynamic data development, and the results showed: The dynamic data accuracy detection method based on ARIMA has the worst performance, with detection accuracy below 70% in different detection attributes, which is relatively not high enough; The development of dynamic data accuracy detection method based on MGLN achieved an accuracy rate of 80.53% when detecting sleeve pressure, but the accuracy rate did not reach 80% when detecting oil pressure, dynamic liquid level, monthly oil and water production, and the detection effect was relatively unstable; The accuracy of developing dynamic data accuracy detection methods based on STGCN fluctuates around 80%; Realize comprehensive evaluation of detection results; Finally, the experiment and evaluation of the comprehensive detection method for developing dynamic data accuracy were completed using real sample data. [ABSTRACT FROM AUTHOR]

Deep eutectic solvents (DESs) are acknowledged as a novel class of functional liquid. DESs share similar physical properties with ionic liquids (ILs) and have the potential to be a novel class of lubricants. In this study, two DESs, namely tetrabutylammonium chloride-decanoic acid DES (C4-DES) and methyl tricaprylmethylammonium chloride-decanoic acid DES (C8-DES), were synthesized, and their physico-chemical properties and tribological performances were evaluated. Post-analysis of the rubbing surfaces used multiple techniques to gain insights into the lubrication mechanisms. Results show that the coefficient of friction (COF) and wear were reduced by approximately 29% and 91% for the C4-DES, and 36% and 94% for the C8-DES, compared to an ester base oil. The friction reduction behavior of the DESs is attributed to the monolayer adsorption of the polar group in the decanoic acid (DEAC), whose effectiveness is affected by the component of the ammonium salts in the DESs and the operating temperatures. In addition to the adsorbed film, worn surface analysis revealed that an ultra-thin tribochemical film with a thickness of 3–7 nm was formed on the surfaces lubricated with the C8-DES. The composition of the film was studied, and the lubrication mechanisms of the two DESs were discussed. [ABSTRACT FROM AUTHOR]

AbstractThe experimental study assessed the impact of choline chloride cation-based ionic liquid (IL), on the dispersion stability and wear characteristics of copper (II) oxide (CuO) nanoparticles (NPs) in synthetic base oil (PAO 10). CuO NPs, averaging 50 nm in size, underwent surface modification using varying concentrations of the IL (0.25%, 0.5%, 0.75%, and 1% by weight). The formulations were subjected to sliding wear tests to evaluate their wear behavior. Analysis of the worn surfaces utilized scanning electron microscopy, energy-dispersive x-ray spectroscopy, and atomic force microscopy. The results indicated that the combination of 0.75% IL and 1% CuO NPs provided optimal dispersion and exhibited effective surface mending, enhancing wear protection by 21.1% than that of PAO 10. The formulation containing 1% IL and 1% CuO NPs demonstrated the highest load carrying capacity among all tested compositions. In terms of wear behavior, the nanolubricant formulations with 0.75% and 1% IL outperformed the lubricant formulation containing 1 wt% of the commercial antiwear additive Zinc dialkyldithiophosphates (ZDDP). [ABSTRACT FROM AUTHOR]

Oleogels are semi-solid materials that consist primarily of liquid oil immobilized in a network of organized structural molecules, which provide stability and maintain the oil in the desired shape. Due to their structure, oleogels can stabilize large amounts of liquid, making them excellent carriers for active substances, both lipophilic and hydrophilic. This study presents the synthesis methodology and investigations of olive oil-based oleogels, which are among the healthiest and most valuable vegetable fats, rich in unsaturated fatty acids and antioxidants such as vitamin E. Two types of surfactants were used: TWEEN 80, which lowers surface tension and stabilizes emulsions, and SPAN 80, which acts in oil-dominated phases. The oleogels were enriched with lidocaine, an active substance commonly used as a pain reliever and local anesthetic. This research characterized the obtained oleogels regarding their medical applications, paying particular attention to the influence of surfactant type and amount as well as the active substance on their physicochemical properties. Structural analyses were also conducted using Fourier transform infrared (FTIR) spectroscopy, alongside rheological and sorption studies, and the wettability of the materials was evaluated. The stability of the obtained oleogels was verified using the MultiScan MS20 system, allowing for an assessment of their potential suitability for long-term pharmaceutical applications. The results indicated that SPAN-stabilized oleogels exhibited better stability and favorable mechanical properties, making them promising candidates for medical applications, particularly in pain relief formulations. [ABSTRACT FROM AUTHOR]

In this paper, the effect of random permeability is considered for the real fracture reservoir, hence a stochastic dual-porosity-Navier-Stokes model with random permeability is proposed to simulate shale oil problem based on superhydrophobic material modification. Finite element method and Monte Carlo method are used to deal with discrete physical space and probability space, respectively. The decoupled finite element method with backward-Euler temporal discretization is presented, which allows the coupling problem to be divided into three subproblems in a non-iterative manner. Furthermore, the stability analysis and error estimation of the corresponding partition scheme are given. 2D/3D numerical experiments verify the validity of the theoretical analysis and prove the reliability and applicability of the scheme. [ABSTRACT FROM AUTHOR]

The aim of this study is to evaluate the lubricating performance of various base oils in a hydrogen-enriched environment. Experiments were conducted wherein base oils were emulsified with meticulously calibrated hydrogen concentrations, followed by a series of friction and wear measurements. Elemental analysis was performed on the worn surfaces, providing further insight into the wear mechanism. The findings of this study highlight the pronounced effect of hydrogen on the lubrication of pure water emulsions of Class IV 4 base oils, with the Class V 5-1 base oils showing optimal lubricating performance in hydrogen-enriched conditions. SEM images at high magnification scanning revealed the presence of a protective friction film on the surfaces of the wear scars in each sample. X-ray photoelectron spectroscopy (XPS) identified traces of metal sulfide within the friction film, which may play a role in reducing friction. The formation of this friction film is likely a contributing factor to the enhanced lubricating performance of the base oil. These findings contribute a substantial foundation for the development of standards for evaluating the performance of hydrogen internal combustion engine oils. [Display omitted] • Study on water emulsification of oil in hydrogen internal combustion engine. • The participation of hydrogen plays an anti-wear and anti-friction effect. • The lubrication effect of hydrogen on class IV emulsion is significantly improved. • The lubrication effect of class V emulsion is the best in hydrogen environment. • The participation of hydrogen contributes to the formation of metal sulfide films. [ABSTRACT FROM AUTHOR]

The environmental concerns associated with mineral oil lubricants have led to the exploration of vegetable oil‐based lubricants as a more sustainable and benign alternative. Nanolubricants have emerged as one of the innovative solution for producing improved friction reduction as well as better thermal and tribological performances. This research investigates the potential of karanja oil as a base lubricant, improved with copper oxide (CuO) nanoparticles as additives. Different amounts of CuO (ranging from 0.01% to 0.1% w/w) were introduced to karanja oil to form nanobiolubricants. These formulations were subsequently evaluated for their physiochemical and tribological properties, such as thermal stability by thermogravimetric analysis (TGA), kinematic viscosity, viscosity index, pour point, and anti‐wear characteristics following ASTM standards. Remarkably, even at low nanoparticle loadings, significant improvements in anti‐wear performance were observed. The study aims to elucidate the lubricating behavior of karanja oil when combined with CuO nanoparticles, revealing that these nanobiolubricants exhibit enhanced physicochemical and tribological properties, as well as improved thermal stability. These results emphasize the key role of nanoparticle concentration in optimizing the effectiveness of formulations. [ABSTRACT FROM AUTHOR]

Purpose: Due to the environmental issues caused by petroleum lubricants used in lubrication, the concept of creating various bio-lubricants requires research globally. Thus, this study aims to develop, characterize and test the base ficus carica oil (fig oil) for its ethylene vinyl acetate copolymer (EVA) and sodium dodecylbenzene sulfonate (SDBS) content. Design/methodology/approach: The sample characterization was done using the Fourier transmission infrared spectrum, whereas the morphologies of the EVA, SDBS particles and lubricated surfaces were carried out under scanning electron microscope equipment. To ensure the homogeneity of the solution (base oil and additives), the formulations were subjected to the sonication process. The anti-friction and anti-wear properties of EVA and SDBS particles as lubricant additives were investigated using a ball on a flat high-frequency reciprocating rig tribo-tester. Findings: According to the findings, the base oil's anti-friction and anti-wear capabilities can be greatly enhanced by the additions. revealed that the best results were obtained when 1.2% EVA + 2% SDBS was applied for the examination of wear (597.8 µm) and friction coefficient (0.106). Commercial references were used, nevertheless, and the results were excellent. This is because the particles in the contact area during lubrication have strong solubility and quickly penetrate the contact zone. The lubricating mechanisms were explained by a tribological model of the EVA + SDBS and SDBS particles. Research limitations/implications: The coefficient of friction and wear reduction caused by the use of the additives will certainly enhance system performance and protect the machine components from excessive wear that could cause damage or failure. Originality/value: The originality and uniqueness of this work are officially affirmed by the authors. The authors' autonomous and original contribution to the development of sustainable lubrication is represented in this work. To the best of the authors' knowledge, no other study has been published or made publicly available that duplicates the precise scope and goals of our research, and this conclusion is based on a thorough literature assessment. [ABSTRACT FROM AUTHOR]

Objectives: To address the poor efficacy and percutaneous penetration of grape seed oil, ionic liquids and nanotechnology were combined to prepare a grape seed oil emulsion. Methods: A novel Menthol-CoQ10 ionic liquid and ionic liquid based grapeseed oil emulsion were prepared and confirmed. Results: The average size of the grapeseed oil emulsion was 218 nm, and its zeta potential was −33.5 mV. The ionic liquid-based grape seed oil emulsion exhibited a transdermal penetration effect 4.63-fold higher than that of ordinary grape seed oil emulsion. Ionic liquid also displayed enhanced efficiency both in vitro and in vivo. It significantly inhibited the production of DPPH free radicals and tyrosinase, inhibited melanin and matrix metalloproteinase-1 (MMP-1) produced by cells, and promoted type I collagen expression in fibroblasts. After 28 days of continuous use, the grapeseed oil emulsion improved the water content of the stratum corneum and the rate of transepidermal water loss, enhanced the firmness and elasticity of the skin, and significantly improved the total number and length of under-eye lines, tail lines, nasolabial folds, and marionette lines on the face. Conclusions: Menthol-CoQ10 ionic liquid is a promising functional excipient for both transdermal delivery increase and efficient enhancement. Ionic liquid and nanotechnology for grape seed oil facial mask displayed significantly enhanced efficacy and permeability. [ABSTRACT FROM AUTHOR]

A key issue for nano‐additive to effectively exert tribological function is to ensure its entrance to and adhesion on the frictional contact surfaces. But the adhesion of nano‐additive on the rubbed surfaces under oil lubrication faces the challenge of the competitive adsorption of lubricant base oil thereon. In this study, oleic acid–modified ultra‐small cerium oxide (OA‐CeO2) nanoparticle was synthesised by one‐pot liquid‐phase surface‐modification method in the presence of OA as the surface modifier. The susceptibility of non‐polar poly–alpha olefin 6 (PAO6) and polar diisooctyl sebacate (DIOS) base oils to the as‐prepared OA‐CeO2 nano‐additive was investigated, and the effect of the OA‐CeO2 nano‐additive on the friction‐reducing and anti‐wear abilities of the two kinds of base oils towards a steel–steel sliding contact was investigated with four‐ball friction and wear tester. Furthermore, the tribological mechanism of the adsorption and deposition of the OA‐CeO2 nano‐additive on the surface of friction steel and the competitive adsorption of base oil were discussed. Characterisations by scanning electron microscopy, transmission electron microscopy and Fourier transform infrared spectroscopy demonstrate that the as‐prepared OA‐CeO2 nanoparticle is of a spherical shape and has an ultra‐small average size of 1.2 nm. As the lubricant additive in PAO6 and DIOS base oils, the OA‐CeO2 nano‐additive exhibits different tribological properties, which is attributed to the difference in the base oils' polarity. Namely, the CeO2 nanoparticle in the non‐polar PAO6 base oil is more easily adsorbed on the rubbed surface of the steel–steel sliding contact, thereby forming the CeO2 deposition film to improve the tribological properties of the base oil. However, the CeO2 nanoparticle added in polar DIOS base oil is difficult to form the CeO2 deposition film, because of the competitive and preferential adsorption of the polar base oil on the rubbed steel surface. Therefore, it is imperative to select the base oils with proper polarity to better exert the friction‐reducing and anti‐wear functions of the OA‐CeO2 nano‐additive. [ABSTRACT FROM AUTHOR]

In the present work we have investigated the oligomerization process of Fischer-Tropsch synthesis products - gasoline (C5-C10) and diesel (C11-C18) hydrocarbon fractions with a total olefin content (consisting mainly olefins with a branched isomeric chain) of 79.3 and 31.8 wt.%, respectively. Oligomerization was carried out by radical initiation method using azobisisobutyronitrile, benzoyl peroxide, dicumyl peroxide and methyl ethyl ketone peroxide (Butanox M-50) as initiators. It was established that the yield of the oligomerization process depending on the initiator used decreases in the following order: azobisisobutyronitrile > benzoyl peroxide > dicumyl peroxide > Butanox M-50. It was determined that when the oligomerization is carried out in polar solvents such as acetone and dichloromethane the yield of product increases by ~2.1 and ~1.7 times, respectively, while at the same time adding a non-polar solvent such as tetrachloromethane to the reaction mixture decreases the product yield by ~2.0 times. The optimal technological parameters for carrying out oligomerization process of synthetic gasoline and diesel fractions were determined: where azobisisobutyronitrile, content 0.5 wt.%., is used as an initiator, acetone as solvent, with reaction temperature of 200 °C, and duration of 12 hrs. under inert atmosphere. The product yield from the diesel fraction is 39.5 %, and from the synthetic gasoline fraction - 36.0 %. At the same time, in terms of characteristics, the oligomerization product of the diesel fraction showed properties similar to commercially available Base oil 3cSt (Group III), and the gasoline fraction showed properties on par with the commercially produced PAO-2 (Group IV). [ABSTRACT FROM AUTHOR]

Anti-wear and anti-oxidation abilities are two key properties of lubricants that play a crucial role in ensuring long-term stable equipment operation. In this study, we aimed to develop a base oil with good anti-oxidation and anti-wear properties for use under extreme pressure. The as-prepared metallocene polyalphaolefin (mPAO) was chemically modified using the trifluoromethanesulfonic acid (TfOH) catalysis through an alkylating reaction with triphenyl phosphorothioate (TPPT). During the experiments, when the reaction temperature exceeded 70 °C or the concentration of TfOH exceeded 2.67%, the β -scission reaction in the alkylation process became significantly more pronounced. The physical and chemical properties of TPPT-modified mPAO (T-mPAO) were evaluated by nuclear magnetic resonance spectroscopy, Fourier trans-form infrared spectroscopy, gel–permeation chromatography, and ASTM standards. T-mPAO showed significantly improved antioxidant capacity, with the initial oxidation temperature increasing by 32 °C compared to the base oil, and it exhibited the slowest increase in acid number in the 96-h oven oxidation test. The tribological tests showed that T-mPAO had the lowest friction coefficient, wear track, and wear rate (72.7% lower than that of mPAO) as well as the highest PB (238 kg) and PD (250 kg) among all tested samples. Compared to mPAO, the average friction coefficient of TPPT-modified mPAO in the four-ball friction test was reduced by 30.5%, and by 16.4% in the TE77 reciprocating friction test. Based on the experimental results, T-mPAO had strong anti-oxidation ability and excellent lubricating performance.The successful synthesis of multifunctional mPAO has enabled lubricant base oil additization, making it possible to use it in more demanding work scenarios, greatly broadening its application scope and making lubricant formulation blending more flexible. [ABSTRACT FROM AUTHOR]

When a transformer is in a long-term heavy load operation state, the oil temperature reaches the alarm temperature; if a slight fault occurs inside the transformer, traditional inverse time current protection and other protections that react to phase current may not operate due to insufficient sensitivity or they may operate for too long. Based on this, this article proposes a new principle of accelerating inverse time overcurrent protection based on transformer oil temperature. The proposed method uses transformer oil temperature to accelerate the action time of traditional inverse-time overcurrent protection, then introduces the transformer oil temperature factor and acceleration index to optimize the inverse time characteristic curve, and establishes a mathematical model to optimize the adjustment for the complexity of adjustment of the protection action equation and the risk of mismatch of the protection after the acceleration of oil temperature. The existing theoretical analysis and simulation verification results show that the proposed new overcurrent protection scheme based on the transformer oil temperature acceleration inverse time can effectively improve the protection of the rapidity and sensitivity, providing a new research idea for the combination of non-electrical and electrical quantity protection. [ABSTRACT FROM AUTHOR]

A series of Ni-W bimetallic catalysts were prepared by Ni2O3 and WO3 on porous materials and used in a fixed bed reactor for the hydrogenation of poly alpha-olefin base oil synthesis. The catalysts were characterized by N2 adsorption–desorption, XRD, H2-TPR, H2-TPD, XPS, TEM and ICP-OES to investigate the catalytic activity and explore the possible deactivation mechanism. Under the optimal reaction conditions of 250℃, 4 MPa, LHSV = 3 h−1 and H2: PAO = 200, the Ni5W1/Clay catalyst with 5% nickel and 1% tungsten loading can make the hydrogenation conversion rate as high as 100%, and the catalyst deactivation is not obvious within 8 h. The addition of W led to the reduction of the metal particle size as well as the formation of more dispersed active sites, thus improve its catalytic activity. [ABSTRACT FROM AUTHOR]

Estuaries are nutrient-rich environments characterized by a gradient in salinity due to the mixing of freshwater and seawater. These bodies of water play vital functions in nature and provide a wide variety of essential ecosystem services. In general, many natural and/or man-made activities have strongly stressed the Egyptian Nile estuarine habitats, as has the water shortage that was expected after the construction of the Grand Ethiopian Renaissance Dam. In recent decades, the Nile Delta has been considered to be one of the most important productive oil-producing petroleum regions due to onshore and offshore gas discoveries alongside gasoline and base oil generation. Up-to-date systematic reviews of the Egyptian estuarine habitats (Rosetta and Damietta) are missing, and the review reported here was undertaken to fill this gap. In this review, we consider the physical, chemical, geological, pollution, and biological parameters of Egyptian Nile estuaries. In this context, our aim is to contribute to a broader understanding of the Egyptian estuarine habitat; moreover, we provide potential warning signals that may aid in estuarine environmental protection. We found that most of the previous studies had focused on the two branches of the Nile or on the marine waters adjacent to these branches, and that only a few studies focused on the estuarine habitats themselves. In most of these previous studies, the salinity gradient of water was reported to be a significant factor in the distribution of the different measured parameters while, in contrast, more recent investigations confirm the importance of potential effluent sources in affecting the distribution of these parameters. We highly recommend that the data reported here be updated in future studies on different environmental aspects. [ABSTRACT FROM AUTHOR]

Machine learning models that are used for the prediction and control of production can improve quality and yield. However, developing models that are highly accurate and reflective of real-world processes is challenging. We propose a feedforward neural network model specifically designed for continuous Multistage Manufacturing Processes (MMPs) without intermediate outputs. This model, which is termed "MMP Net," can accurately represent the control mechanism of continuous MMPs. Whereas existing studies on learning MMPs assume an intermediate output data, the MMP Net does not require such an unrealistic assumption. We use the MMP Net to develop prediction models for the lubricant base oil production process of a world-leading lubricant manufacturer. Evaluation results show that the MMP Net is superior to other deep neural network and machine learning models. Consequently, the MMP Net was actually implemented in a real factory in 2022 and is expected to save 900,000 dollars per year for each production line. We believe that our work can serve as a basis to develop customized machine learning solutions for improving continuous MMPs. [ABSTRACT FROM AUTHOR]

In boundary lubrication, adsorbed molecular films formed by lubricant additives on the metal surfaces of sliding parts effectively reduce friction and wear. A method is presented for simultaneously measuring friction and the gap at a metal-lubricant interface under boundary lubrication conditions using atomic force microscopy. In this method, line-and-space patterns are microfabricated in Cu films on Si substrates, and the gap is evaluated from the step height change when scanning in base oil and in base oil with an additive. Neutron reflectometry showed that whereas both stearic acid and stearyl alcohol formed molecular film about 2 nm thick on Cu film in a static state, the gap increased only with stearic acid due to maintaining a molecular film on the Cu film. This demonstrates the feasibility of the proposed method as means for visualizing the gap and shows that there is a difference between the two additives in their film-forming ability in a static state and their durability against friction. The proposed method for simultaneously measuring friction and the gap at a metal-lubricant interface is thus an effective way to investigate the tribological performance of additives under boundary lubrication conditions. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the characteristics of different varieties of camellia oils and their diacylglycerol (DAG)-enriched derivatives in terms of triacylglycerol (TAG) species, bioactive components, volatile compounds, and antioxidant activity. Six types of camellia oils, including C. oleifera (C.O), C. semiserrata (C.S), C. gauchowensis (C.G), along with commercially refined C. oleifera oil (C-C.O) and its DAG-enriched counterparts (at 40% and 80% enrichment), were analyzed and compared. Unique patterns of TAG profiles, fatty acid distributions on different glycerol backbones, tocopherol, squalene, total polyphenols, and volatile compounds were observed, suggesting that these characteristics can be utilized as a criterion to differentiate them. DAG-enriched oils exhibited increased levels of unsaturated fatty acids (UFAs) compared to C-C.O, albeit with decreased contents of tocopherol, squalene, and total polyphenols. Moreover, diverse volatile compounds were identified across all types of camellia oils, among which the DAG-enriched oils had distinct distribution characteristics compared with their crude oils, indicating the influence of the enrichment process on volatile compounds. Furthermore, DAG-enriched oils demonstrated reduced antioxidant activity abilities compared to their counterparts, with the highest activity observed in C.O, followed by C.G. Additionally, strong correlations were observed between antioxidant activity and tocopherol, as well as squalene content. [ABSTRACT FROM AUTHOR]

The purpose of this study is to investigate the physical and mechanical properties of local carbon materials and the warm compaction method in the production of current collectors for light rail transit (LRT) applications. The problem here is that the current collectors used by the railway industry in Malaysia for the LRT are still imported from foreign countries which is very costly. Furthermore, the production method of commercial current collectors, namely C-Cu composites, is compact and sintered, which also results in relatively high costs. Therefore, this study focuses on replacing the old materials and methods of commercial current collector production with new materials and methods. This study used a local carbon, which is the kernel shell of oil palm as the main carbon for the production of current collectors. The compact and sintered production methods are then replaced by warm compaction and post-heating methods. The current collectors that had been produced are then cut into several samples to allow them to be tested in a number of physical and mechanical tests. Based on the test results, when using these new materials and methods, the density and hardness were observed to be slightly lower at 1.81 g/cm³ and 122.6 HRR compared to the commercial current collectors, which have a density of 2.2 g/cm³ and 126.9 HRR. Meanwhile, in the transverse rupture strength (TRS) and resistivity tests, the warm compaction method based on oil palm kernel shell demonstrated higher values of 175.1 MPa and 1631 Ω-cm, respectively, compared to the commercial current collectors which showed values of 58.71 MPa and 598.77 Ω-cm. In conclusion, there are various advantages and disadvantages between the new current collectors and the commercial current collectors in terms of mechanical as well as physical characteristics. Therefore, various improvements and suggestions need to be made in order to produce physically and mechanically better current collectors to be used in LRT applications. [ABSTRACT FROM AUTHOR]

Waste plastics bring about increasingly serious environmental challenges, which can be partly addressed by their interconversion into valuable compounds. It is hypothesized that the porosity and acidity of a zeolite‐based catalyst will affect the selectivity and effectiveness, enabling a controllable and selective conversion of polyethylene (PE) into gas‐diesel or lubricating base oil. A series of embryonic, partial‐ and well‐crystalline zeolites beta with adjustable porosity and acidity are prepared from mesoporous SBA‐15. The catalysts and catalytic systems are studied with nuclear magnetic resonance (NMR), X‐ray diffraction (XRD), and adsorption kinetics and catalytic reactions. The adjustable porosity and acidity of zeolite‐beta‐based catalysts achieve a controllable selectivity toward gas‐diesel or lubricating base oil for PE cracking. With a catalyst with mesopores and appropriate acid sites, a fast escape and reduced production of cracking of intermediates are observed, leading to a significant fraction (88.7%) of lubricating base oil. With more micropores, a high acid density, and strong acid strength, PE is multiply cracked into low carbon number hydrocarbons. The strong acid center of the zeolite is confirmed to facilitate significantly the activation of hydrogen (H2), and, an in situ ammonia poisoning strategy can significantly inhibit hydrogen transfer and effectively regulate the product distribution. [ABSTRACT FROM AUTHOR]

In order to solve the problem of remote oil level measurement for unmanned transformers, this paper proposes an online monitoring technology for transformer oil level based on ultrasonic sensors. Subsequently, a finite element model and experimental testing platform were constructed to analyse and verify the influencing factors of the transformer oil level sensors. The results indicated that there is a lower measurement error at 140 kHz in the ultrasonic frequency range of 20–320 kHz, which can be selected as the recommended frequency. The impurities in the oil and the thickness of the tank wall have a slight impact on the accuracy of oil level measurement, and can lead to a decrease in the signal‐to‐noise ratio of the echo. Furthermore, as the speed of sound increases by about 4 m/s, for every 1°C increase in oil temperature, it is necessary to calibrate the measurement results based on the oil temperature. The test results of actual experimental transformers showed that the designed online monitoring device can achieve high‐precision monitoring of transformer oil level, with a relative error generally less than 3%. [ABSTRACT FROM AUTHOR]

The main technical challenge of drilling fluid in deep oil and gas drilling is that the treatment agent fails at high temperatures. The shortcomings of emulsifiers used in oil-based drilling fluids under high temperature conditions included high dosage and susceptibility to failure. An oligomeric emulsifier SSRH-1 with high temperature resistant was prepared through the reaction of organic acids and organic amines and the product yield exceeded 93%. Using SSRH-1, a high temperature oil base drilling fluid was formulated with organophilic clay, xc. The density of this oil base drilling fluid was adjustable between 1.2 and 2.1 g/cm3. The oil base drilling fluid had the characteristics of good rheological performance and low filtration rate at 220°C. [ABSTRACT FROM AUTHOR]

Aiming at the problem of high failure rate and inconvenient maintenance of wind turbine gearboxes, this paper establishes a stochastic differential equation model that can be used to fit the change of gearbox oil temperature and adopts an iterative computational method and Markov-based modified optimization to fit the prediction sequence in order to realize the accurate prediction of gearbox oil temperature. The model divides the oil temperature change of the gearbox into two parts, internal aging and external random perturbation, adopts the approximation theorem to establish the internal aging model, and uses Brownian motion to simulate the external random perturbation. The model parameters were calculated by the Newton–Raphson iterative method based on the gearbox oil temperature monitoring data. Iterative calculations and Markov-based corrections were performed on the model prediction data. The gearbox oil temperature variations were simulated in MATLAB, and the fitting and testing errors were calculated before and after the iterations. By comparing the fitting and testing errors with the ordinary differential equations and the stochastic differential equations before iteration, the iterated model can better reflect the gear oil temperature trend and predict the oil temperature at a specific time. The accuracy of the iterated model in terms of fitting and prediction is important for the development of preventive maintenance. [ABSTRACT FROM AUTHOR]

High internal phase emulsions (HIPEs) are commonly stabilized by a large amount of surfactants that should be removed after the polymerization of the continuous phase, and the resulting polyHIPEs from W/O HIPEs are usually brittle and chalky. Herein we report on an amphiphilic polymerizable polyurethane (PPU) macromolecular surfactant synthesized by polyaddition reaction of diisocyanates and polyols, which can well stabilize up to 88% internal phase volume of W/O HIPE with a content of only 5 wt% based the oil phase. Compared with the HIPEs stabilized by traditional surfactant Span 80, HIPEs stabilized by PPU at either room temperature or 70 °C are much more stable owing to the increased viscosity which can inhibit droplet coalescence. Moreover, the resulting polyHIPEs not only have several times higher mechanical properties than those stabilized by Span 80 but also have higher elasticity. The effects of concentration of PPU on the morphology and mechanical properties of the resulting polyHIPEs were investigated. It was found that with the increase of PPU content, the average void and window sizes decreased, while the compression strength increased. Cyclic compression tests were performed to examine reversible compressibility and durability of these polyHIPEs. The polymerizable polyurethane macromolecular surfactant (PPU) synthesized through the polyaddition reaction of diisocyanates and polyols can solely stabilize high internal phase emulsions (HIPEs), and highly interconnected macroporous polymer produced by the polymerization of HIPE stabilized with PPU, known as polyHIPE, can withstand large deformation compression with no visible cracks. [ABSTRACT FROM AUTHOR]

Purpose. Detailed substantiation of the geological structure of the eastern edge of the Northern Ustyurt, clarification of modern geological and geophysical data, as well as highlighting the mainstages of evaluating the results of exploration work to confirm the oil and gas potential and subsequent exploitation of the fields. Methodology. The authors used the following scientific methods: generalization – to systematize scientific provisions; analogy and comparison – to characterize deflection in different periods; analysis and synthesis – to substantiate geological and geophysical data; algorithmmization – to determine conceptual provisions regarding the assessment of the oil and gas bearing capacity of the trough. Findings. In order to achieve the goals, the indicators of oil and gas capacity in the areas of the eastern side of the Northern Ustyurt of different geological ages were substantiated. The geological and geophysical features of the basin dating back to 2010 compared to modern refinement of geological data were characterized. The productive and unproductive structures of the eastern side of the Northern Ustyurt are characterized, taking into account the showing of oil and gas based on deposits of different geological ages. The importance of conducting geological exploration and creating corresponding cartographic materials is justified, followed by the design of predictive graphical models, geological sections, and a detailed plan of the territory. Originality. The influence of high hydro carbon generation rates on the further identification of “oil windows” has been substantiated for the first time. The hierarchical levels of predicting the oil and gas content of the trough are identified. The necessity of improving the mechanisms for assessing oil and gas content is substantiated. Practical value. The substantiation of the features of the assessment of the oil and gas content of the of the eastern edge of the Northern Ustyurt, which should be based on forecasting promising areas of prospecting, is the key to distinguishing between productive and unproductive objects, determining their real scale and directing investment flow precisely to promising areas with minimal environmental and economic losses. [ABSTRACT FROM AUTHOR]

In this study, MoS2 nanosheets have been prepared and treated ultrasonically with silver ammonia solutions. The MoS2/Ag precursor was reduced using dopamine (DA) as reducing and linking agent at room temperature, and it was subjected to a hydrothermal treatment to produce MoS2/Ag nanocomposites (denoted as MoAg). The MoAg samples were functionalized with N-oleoylethanolamine to improve dispersion in the base oil component of additives. Use of the functionalized MoAg (denoted as Fc-MoAg) as a lubricant additive for steel balls resulted in effective friction reduction and anti-wear. This work avoids ion exchange during exfoliation, and the Ag+ has been reduced to nano-silver particles by dopamine to enlarge the layer spaces of MoS2. Taking the case of lubrication with base oil containing Fc-Mo0.6Ag15, the wear scar diameters and coefficients of friction of the steel balls were 0.428 and 0.098 mm, respectively, which were about three-fifths base oil. In addition, MoS2/Cu and MoS2/Ni nanocomposites were synthesized and the tribological properties associated with steel/steel balls assessed. The results demonstrate that all MoS2/metal composites exhibit enhanced tribological behavior in the steel/steel pair tests. Both nanocomposite synergy and the tribofilm containing sulfide, oxide, carbide, and other compounds play important roles in achieving reduced friction and improved anti-wear. The friction and wear properties of base oil containing Fc-MoAg and commercial additives were evaluated using a four-ball wear tester with steel/steel, steel/zirconia and zirconia/zirconia pairs. The base oil containing Fc-MoAg delivered smaller coefficients of friction (COFs) and/or scarring groove depths than those observed with the use of pure base oil and base oil containing commercial additives. [ABSTRACT FROM AUTHOR]

Efficient cooperative lubrication can be achieved via the introduction of core-shell structure lubricant additives with hard core and soft shell, for obtaining the expected anti-wear performance from the structural changes in the friction process. In this study, C@Ag microspheres with a core-shell structure were prepared by the redox method with carbon spheres as the core and Ag nanoparticles as the shell. Their tribological behaviors as base oil (G1830) additive with different concentrations were investigated in detail. Compared with base oil, the addition of C@Ag particles at 0.5 wt% can reduce the coefficient of friction (COF) and wear volume (Wv) up to 15.5% and 88%, respectively. More importantly, C@Ag particles provide superior lubrication performance to single additive (like carbon sphere (CS) and Ag nanoparticle). C@Ag core-shell particles contribute to the formation of tribo-film by melt bonding of flexible Ag and carbon sphere (CS) toward excellent self-repair performance and high-efficiency lubrication. Hence, core-shell structural nanoparticles with hard-core and soft-shell hold bright future for high-performance lubrication application. [ABSTRACT FROM AUTHOR]

Spherical nano-MoS2 (S-MoS2) has excellent lubricating properties and potential application value in engine oil additives. Engine soot can enter the engine oil, so the tribological interaction between S-MoS2 and diesel combustion soot (DCS) should be investigated. In this study, DCS was used to simulate engine soot. The interaction was investigated in dioctyl sebacate (DOS), and the interaction mechanism was full characterized. Results showed that S-MoS2 and DCS had obvious antagonism effects on lubrication. The 0.5% S-MoS2 exhibited good lubricating properties in DOS, which could reduce friction by ∼22% and wear by ∼54%. However, after 0.5% S-MoS2 was added to the 0.5% DCS contaminated DOS, the lubrication performance was not improved and was even worse than that without S-MoS2. When S-MoS2 was added for DOS lubrication, a tribofilm containing MoS2 formed on the friction surface, but simultaneously adding 0.5% DCS resulted in the disappearance of the MoS2 tribofilm. Moreover, under the action of friction heat, DCS and S-MoS2 could form hard MoxCy, thereby increasing abrasive wear. Finally, a preliminary deantagonism method was provided. After 2.0% zinc isooctyl dithiophosphate was added to the above antagonistic system, the friction coefficient did not show visible changes, but the wear recovered to a level close to that when only S-MoS2 was added. The antiantagonism method is not very satisfactory and some more efficient methods need to be further explored. [ABSTRACT FROM AUTHOR]

Introducing an additive is a practical approach to improve the lubrication performance of base oil in the field of tribology. Herein, a series of sulfoximine derivatives was synthesized and incorporated into base oil A51 as additives. The tribological properties of these lubricants were evaluated at both room and high temperatures, and the result demonstrated that they displayed excellent friction reduction and wear resistance in the friction process under both test conditions. Moreover, the chemical composition of the worn scar surface was inspected using EDS, XPS and TOF-SIMS to explore the lubricating mechanism. It is reasonable to conclude that the synergistic interaction between the aromatic ring scaffolds and elements like N, F, and S facilitated the adsorption of lubricant on the steel block surfaces and forming a tribofilm during the friction process. This tribofilm has a dominant impact on the system's lubrication performance. This research provides novel oil-soluble lubricant additives, offering a facile approach to formulating high-quality lubricants. [ABSTRACT FROM AUTHOR]

A method for obtaining non-isocyanate polyurethane (NIPU) foams from cyclic carbonate (CC) based on soybean oil was developed. For this purpose, cyclic carbonate was synthesized from epoxidized soybean oil and CO2 using various ionic liquids (ILs) as catalysts. Among the tested ILs, the highest selectivity (100%) and CC yield (98%) were achieved for 1-ethyl-3-methylimidazolium ([emim]Br). Without any purification, the resulting cyclic carbonate was reacted directly with diethylenetriamine as a model crosslinking agent to produce NIPU foams. It was found that the soybean oil-based CC synthesized with bromide imidazolium ionic liquids exhibited significantly shorter gelling times (8 min 50 s for [emim]Br and 9 min 35 s for [bmim]Br) compared to those obtained with the conventional TBAB catalyst (26 min 15 s). A shorter gelling time is a crucial parameter for the crosslinking process in foams. The obtained foams were subjected to mechanical tests and a morphology analysis. [ABSTRACT FROM AUTHOR]

Approximately half of the lubricants sold globally find their way into the environment. The need for Environmentally Acceptable Lubricants (EALs) is gaining increased recognition. A lubricant is composed of a base oil and multiple functional additives. The literature has been focused on EAL base oils, with much less attention given to eco-friendly additives. This study presents the tribological performance and aquatic toxicity of four short-chain phosphonium-phosphate and ammonium-phosphate ionic liquids (ILs) as candidate anti-wear and friction-reducing additives for EALs. The results are benchmarked against those of four commercial bio-derived additives. The four ILs, at a mere 0.5 wt% concentration in a synthetic ester, demonstrated a 30–40% friction reduction and >99% wear reduction, superior to the commercial baselines. More impressively, all four ILs showed significantly lower toxicity than the bio-derived products. In an EPA-standard chronic aquatic toxicity test, the sensitive model organism, Ceriodaphnia dubia, had 90–100% survival when exposed to the ILs but 0% survival in exposure to the bio-derived products at the same concentration. This study offers scientific insights for the future development of eco-friendly ILs as lubricant additives. [ABSTRACT FROM AUTHOR]

Introduction: The traditional partial discharge localization improvement strategy mainly starts from the intelligent algorithm, but fails to consider the influence of core winding and oil temperature on partial discharge positioning. Methods: This paper also considers the influence of the iron core winding and oil temperature. Through finite element simulation, a transformer model was established to analyze the propagation characteristics of ultrasonic signals generated by partial discharge under the interference of gradient oil temperature and winding. The chaotic firefly-particle swarm hybrid algorithm is proposed, and through the calculation of Shubert's multi-peak function. Finally, a partial discharge defect platform based on gradient oil temperature was built to verify the chaotic firefly-particle swarm hybrid localization algorithm. Results: The ultrasonic velocity generated by partial discharge in transformers cannot be fixed, and it is suggested that ultrasonic sensors should be installed near the center of the top of the transformer. The proposed algorithm can be better optimized in the case of multiple local extreme points. Under gradient oil temperature experiments, the algorithm achieves positioning errors less than 100 and 55 mm for cases with and without winding obstruction, respectively, with average positioning errors of 74.2 and 35.2 mm. Discussion: The positioning method in this paper can provide a technical reference for the partial discharge positioning of transformers in actual operation. [ABSTRACT FROM AUTHOR]

Lubricant base oils, traditionally derived from non-renewable petroleum, contribute significantly to greenhouse gas emissions. In contrast, oils sourced from furfural and long-chain ketones through aldol condensation and hydrodeoxygenation present a renewable, cost-effective, and environmentally friendly alternative, offering superior cold flow properties. However, the production of long-chain ketones, a crucial component, currently relies on solvent dewaxing in refineries, which is costly and non-selective. One promising biobased approach involves self-ketonization of long-chain fatty acids derived from coconut or palm kernel oils. This method typically employs high boiling point solvents like dodecane or is done in a batch configuration, limiting its scale and industrial viability. This study addresses this bottleneck by eliminating solvents, transitioning to a continuous flow reactor, and achieving kilogram-scale production of long-chain ketones with exceptional selectivity (90%). The lab-scale setup can yield up to 25 kg of 12-tricosanone per month, utilizing earth-abundant MgO as a catalyst. The catalyst underwent slight deactivation due to carbonate formation. Catalyst stabilization, using mixed metal oxides, and regeneration via simple calcination in air are also discussed. Techno-economic analysis (TEA) indicates a 29% lower minimum selling price than the commercial synthetic poly alpha olefin (PAO). Life cycle assessment (LCA) evaluates the global warming potential (GWP) under different environmental assumptions. Under the carbon-neutral assumption for lauric acid production, an 8.9% reduction in GWP was achieved compared to petroleum-based lubricants. [ABSTRACT FROM AUTHOR]

Ionic liquid catalysts were synthesized using 1-vinyl-3-benzyl imidazolium chloride, 1-benzy 1-3- methyl imidazolium chloride, and 1-benzyl-3-ethyl imidazolium chloride as cations, with anhydrous aluminum chloride (AlCl3) serving as the anion. It was observed that the catalyst synthesized from 1-vinyl-3-benzyl imidazolium chloride and AlCl3 demonstrated enhanced selectivity. The influence of anion/cation molar ratio, reaction temperature, reaction time and catalyst dosage on PAO performance. When the catalyst's anion to cation molar ratio was maintained at 2:1, and the reaction conditions were set at a temper-ature of 80 °C, a duration of 3 h, and a catalyst loading of 7%, an outstanding catalytic performance was achieved. Under these conditions, the conversion rate of 1-decene surpassed 90%, resulting in the produc-tion of high viscosity index base oil. This oil exhibited a kinematic viscosity of 52.9 mm²/s at 40 °C and 8.7 mm²/s at 100 °C, along with a viscosity index of 142. [ABSTRACT FROM AUTHOR]

The present paper illustrates the results of an experimental study aimed at evaluating the effect of lubricant oil features on the emissive behaviour of a heavy duty spark ignition engine fuelled with methane. The activity was performed within a research project between CNR-STEMS and TotalEnergies in which oils with different formulations were characterized, focusing on their potentiality in particle emission reduction. Considering the ultralow particle emission level in the exhaust of gas engines, a specific testing procedure was designed to guarantee highly reliable and accurate results. In particular, the engine was operated under transient conditions, along the World Harmonized Transient Cycle in cold- and hot-start conditions. The results of the test campaign clearly highlight that the lubricant formulation is a key technology for the control of particles, revealing this as an important aspect in view of the upcoming severe regulation limits on particle emissions. The experimental findings show the capability of reformulated oils to drop down the total particle number to 60–70% with respect to a baseline standard oil. The interest in the present study also lies in providing information extendable to more sustainable fuels, like hydrogen or biomethane, nowadays of great interest as alternative energy sources. [ABSTRACT FROM AUTHOR]

Raman spectroscopy is a popular technology for material identification, but it encounters difficulties when distinguishing components with closely related substances by intuition and experience. The distinction of fats and oils is a typical example, which is significant in the food industry. In this work, the Raman spectroscopy and deep learning algorithm are combined to analyze closely related animal fats (lard, butter, mutton fat and chicken fat) and vegetable oils (soybean oil and peanut oil) in a dataset. A deep neural network founded on the VGG architecture with attention mechanism is developed, reaching an accuracy of 100% for fats and oils classification. By combining Raman spectroscopy with deep learning, this research provides a potent technique for tackling the identification of similar substances. In this work, the Raman spectroscopy and deep learning algorithm are combined to analyze closely related animal fats (lard fat, butter fat, mutton fat and chicken fat) and vegetable oils (soybean oil and peanut oil) in a dataset. A deep neural network founded on the VGG architecture with attention mechanism is developed, reaching an accuracy of 100% for fats and oils classification. [ABSTRACT FROM AUTHOR]

To achieve the goal of developing high-performance lubricant additives for industrial lubrication. Herein, tetradecylphosphonic acid (TDPA) modified Ti3C2TX and graphene oxide (GO) were used as nanohybrid lubricant additives in the polyalphaolefins base oil (PAO6). The high-speed reciprocating friction and wear test shows that TDPA–Ti3C2/GO is an efficient friction-reduction and antiwear additive. The base oil mixed with 0.05 wt%TDPA–Ti3C2/0.05 wt% GO exhibits the lowest coefficient of friction (COF) and wear rate with the value of 0.09 and 4.4 × 10–6 mm3/Nm, decreased by 54.5 and 90.0% compared with pure PAO6 oil, respectively. Detailed characterization analysis shows that the tribological film of the modified TDPA–Ti3C2/GO nanohybrids oil-lubricated surface was mainly composed of PAO6, TDPA, GO, and iron oxide. This indicates that the friction-reduction and antiwear mechanism of TDPA–Ti3C2/GO in base oil lies in the adsorption of the two nanomaterials and the formation of a self-lubricating film on the rubbing interface. This study provides a new approach to the design of nanohybrid lubricant additives and creates new prospects for the application of nanomaterials in tribology. [ABSTRACT FROM AUTHOR]

Film thickness in a grease-lubricated bearing is a critical bearing operation parameter, yet there are no models available to predict it. Our recent articles demonstrated that the relative film thickness ( h g / h ff ) can be predicted using the base oil viscosity ( η ), half contact width (b), and linear speed (u) for any axially loaded deep groove ball bearing. In this article, we extend this study to include radial loads and combined—axial and radial—loads. Radial load application causes an additional replenishment in the unloaded zone, introducing a new length variable z r and surface tension σ. A universal power-law relationship between the relative film thickness in a deep groove ball bearing and the nondimensional number (η bu) / ( z r σ) for all loading and grease lubrication conditions is presented for use in predicting film thickness. [ABSTRACT FROM AUTHOR]

Impact-sliding experiments were performed by using four self-made lithium-based greases, namely Yangtze Grease 1, Yangtze Grease 2, Yangtze Grease 3, and Yangtze Grease 4. The influence of base oil viscosity, thickener content, and morphology of thickener fiber clusters on the lubricating state were visually explored, combined with field-emission microscopy and two-light interference technology. The grease film distribution at the middle section was measured using Dichromatic Interference Intensity Modulation (DIIM) software. All experiments were executed in a completely flooded environment. The results show that among the components of grease, the base oil's viscosity has the greatest impact on the anti-wear performance of the grease. As the viscosity of the base oil increases, the grease exhibits better anti-wear performance. The grease film thickness under the condition of high-viscosity base oil is about 10 times higher than that under the condition of low-viscosity base oil. Secondly, the content of thickener in the grease needs to be controlled within a reasonable range. The experiments indicate that the effect of thickener content on the grease's film-forming properties becomes more pronounced at higher speeds. From the experiment using YG 4, it can be seen that a higher thickener content under high-speed conditions increases the thickness of the lubricating grease film by about 10 times. The dimensions of the thickener fibers and the density of their entanglement structure significantly influence the rheological properties and load-bearing capacity of the grease. Larger fiber sizes and higher entanglement densities result in reduced grease fluidity and recovery but enhance its load-bearing capabilities. In order to obtain the best anti-wear performance during impact-sliding motion, the size of the thickener fiber and the density of the entanglement structure need to be controlled within an appropriate range. [ABSTRACT FROM AUTHOR]

In order to improve fuel economy to meet the standard for passenger car oil, a new formulation with good viscosity–temperature performance for gasoline engine oil is required. In this study, coal-to-liquid (CTL) base oil, with a high viscosity index and good low-temperature performance, was selected as the base oil to develop the gasoline engine oil. A systematic study on the molecular interaction between the CTL base oil and the viscosity index improver (VII), including three kinds of hydrogenated styrene diene copolymers (HSD-type) and four kinds of ethylene propylene copolymers (OCP-type), was conducted. It was found that in general, in CTL base oil, the HSD-type VII exhibited a much higher viscosity index, a significantly lower shear stability index, a higher thickening ability, and a lower cold-cranking simulator (CCS) viscosity than that of OCP-type VII. Moreover, when comparing CTL base oil with mineral oil 150N, the combination of CTL base oil and the VII displayed a lower CCS viscosity than that of mineral oil, suggesting it had better low-temperature performance and was able to quickly form a protective oil film on the surface, which was beneficial for the cold start. The functional group distribution state of the VII in base oil was analyzed using synchrotron radiation micro-infrared microscope (SR Micro-IR) technology, which revealed that HSD-1 had a better molecular interaction with CTL6 than 150N because of the better uniformity of the C=C group distribution. Based on this, a SP 0W-20 gasoline engine oil was developed by the combination of CTL base oil and the HSD-1 viscosity index improver, together with an additive package, a polymethacrylate pour point depressant, and a non-silicone defoamer, which showed excellent low-temperature performance, thermal oxidation stability, and detergency performance compared to the reference oil. [ABSTRACT FROM AUTHOR]

Within electrical contacts, poor electrical conductivity of lubricants can lead to triboelectric charging, causing electrostatic currents and thermal effects, which accelerate lubrication failure. This study aimed to address these challenges by producing and testing three greases with different base oils: ionic liquid ([Oley][Oleic]), synthetic oil (PAO4), and vegetable oil-based synthetic ester (trimethylolpropane oleate). Each grease was prepared with polytetrafluoroethylene powder as the thickener. The greases were tested using a custom-made tribometer, integrated with a grounded electrical current system, with friction tests conducted with up to a 2 A electrical current flow at a constant voltage supply of 4.5 V. Under triboelectric friction testing, [Oley][Oleic] grease outperformed a commercial perfluoropolyether grease by 27.7% in friction and 16.3% in wear. This grease also showed better performance than formulated lithium grease with extreme pressure additives. The study demonstrates that greases with low interfacial resistance can retain their lubrication capacity under triboelectric conditions. These results indicate that [Oley][Oleic] grease, with its ionic liquid base oil, offers a promising solution for applications involving electrical contacts. This study highlights the potential of using advanced base oils and thickeners to enhance the performance and sustainability of lubricants in demanding environments. [ABSTRACT FROM AUTHOR]

This work explores experimentally the effects of DC electrical currents on lubricant film thickness alteration in lubricated sliding steel contacts in the boundary and mixed regime as measured by ultrasound. The experiments were performed in a two-electrode cell-based pin-on-disk tester instrumented with ultrasonic transducers. Unelectrified and electrified tribological tests were conducted on steel flat-on-flat contacts under various speeds and loads using both a mineral base oil and a gear oil. Film thickness, coefficient of friction (CoF), and electrical contact resistance (ECR) were measured during short experiments (30 s) in unelectrified and electrified (1.5 and 3 A) conditions. The results suggest that film thickness, CoF, and all ECR are altered by passing DC currents through the contact. In particular, film thickness increased and decreased, respectively, by applying electricity at the different speeds and loads tested. These alterations were majorly ascribed to oil viscosity decrease by local heat and surface oxidation caused by electrical discharge and break down at the interface. [ABSTRACT FROM AUTHOR]

This paper demonstrates the potential of waste turbine oil (WTBO) as a base oil to substitute for mineral oil, which is usually used in grease formulations. This study will analyze the characteristics of used turbine oil, including its chemical composition and physical characteristics, including kinematic viscosity, viscosity index, moisture content, contamination, and density. The presence of antioxidants (butylated hydroxytoluene (BHT) and amine or phenyl-a-naphthylamine (PANA), anti-wear, and corrosion-inhibiting additives that can improve the formulated lubricating grease performance and lengthen service life are just a few of the useful remaining WTBO characteristics that can be used wisely as the base oil. It is crucial to create more environmentally friendly, economically sensible, and thrifty grease formulations to adhere to Malaysia's Green Technology Master Plan, which has outlined the strategic plans for developing green technologies. The new inventions must establish a resource- and carbon- efficient economy. The abundance of WTBO in the aviation industry and the unique characteristics of WTBO itself promise a reliable supply of base oil for lubricating grease in the future. [ABSTRACT FROM AUTHOR]

This paper presents the fabrication and characterization of plane capacitors utilizing magnetodielectric materials composed of magnetizable microfibers dispersed within a silicone oil matrix. The microfibers, with a mean diameter of about 0.94 μ m, comprise hematite (α -Fe2O3), maghemite (γ -Fe2O3), and magnetite (Fe3O4). This study investigates the electrical behavior of these capacitors under the influence of an external magnetic field superimposed on a medium-frequency alternating electric field, across four distinct volume concentrations of microfibers. Electrical capacitance and resistance measurements were conducted every second over a 60-s interval, revealing significant dependencies on both the quantity of magnetizable phase and the applied magnetic flux density. Furthermore, the temporal stability of the capacitors' characteristics is demonstrated. The obtained data are analyzed to determine the electrical conductance and susceptance of the capacitors, elucidating their sensitivity to variations in microfiber concentration and magnetic field strength. To provide theoretical insight into the observed phenomena, a model based on dipolar approximations is proposed. This model effectively explains the underlying physical mechanisms governing the electrical properties of the capacitors. These findings offer valuable insights into the design and optimization of magnetodielectric-based capacitors for diverse applications in microelectronics and sensor technologies. [ABSTRACT FROM AUTHOR]

Beam pumping is currently the broadly used method for oil extraction worldwide. A pumpjack shutdown can be incurred by failures from the load, corrosion, work intensity, and downhole working environment. In this study, the duration of uninterrupted pumpjack operation is defined as the pump inspection cycle. Accurate prediction of the pump inspection cycle can extend the lifespan, reduce unexpected pump accidents, and significantly enhance the production efficiency of the pumpjack. To enhance the prediction performance, this study proposes an improved two-layer stacking ensemble model, which combines the power of the random forests, light gradient boosting machine, support vector regression, and Adaptive Boosting approaches, for predicting the pump inspection cycle. A big pump-related oilfield data set is used to demonstrate the proposed two-layer stacking ensemble model can significantly enhance the prediction quality of the pump inspection cycle. [ABSTRACT FROM AUTHOR]

The concept of volume fracturing has revolutionized the conventional limits of low permeability, expanded the effective resource space, and significantly enhanced oil well production in tight oil reservoir development. This paper elucidates the mechanism of volume fracturing technology for tight sandstone reservoirs by considering multiple factors such as the initiation range of multi-fractures, influence of far-well horizontal principal stress on fracture initiation and propagation, degree of natural fractures development, and mechanical parameters of reservoir rock. Through simulation based on the mechanical parameters of reservoir rock, a comparative analysis was conducted between the model-calculated rock fracture pressure value and measured data from fracturing construction wells in the study area. The results revealed that there was a discrepancy within 10% between the model calculations and actual data. By simulating the effects of different injection volumes of fracturing fluid, pumping rates, and perforation methods on the fracture geometry, optimal design parameters for volume fracturing technology were obtained. Additionally, we propose optimization ideas and suggestions for construction parameters applicable to field operations. The simulation results indicate that a minimum recommended fluid volume scale exceeding 1800 m3 is advised for the reservoir. Based on frictional calculations, it is recommended to have an on-site construction rate not less than 18.0 m3/min along with 36–48 holes/section for perforation purposes. The numerical simulation research presented in this paper provides a theoretical reference basis and practical guidance for the application of fracturing network technology in tight sandstone reservoirs. [ABSTRACT FROM AUTHOR]