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Adopting an advanced microscopic model of the Au–graphite interaction, a systematic study of Au nanoclusters (up to sizes of 11 238 atoms) on graphene and on graphite is carried out to explore their structure and energy landscape. Using parallel tempering molecular dynamics, structural distribution as a function of temperature is calculated in the entire temperature range. Low‐energy structures are identified through a combination of structural optimization and Wulff–Kaischew construction which are then used to explore the energy landscape. The potential energy surface (PES), which is energy as a function of translation and rotation, is calculated for a few Au nanoclusters along specific directions on carbon lattice. Minimum‐energy pathways are identified on the PES indicating a reduced barrier for pathways involving simultaneous rotation and translation. Diffusion simulations of Au233 on graphite show that diffusion mechanism is directly related to the PES, and the information of the cluster pinning events is already present in the PES. Finally, a comparison of various interaction models highlights the importance of reasonably correct Au–C interactions which is crucial for studying the energy landscape and cluster sliding. [ABSTRACT FROM AUTHOR]

Copyright of Bearing is the property of Bearing Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Insufficient hole cleaning, cutting suspension, clay swelling, and filtrate invasion of the formation might result from inadequate drilling mud properties. For effective drilling and wellbore stability, water-based mud (WBM) rheology, lubricity, filtration, and shale inhibition must be optimized and controlled. WBMs react with clays and cause time-dependent borehole issues, which is their principal drawback. Moreover, prolonged exposure destroys certain WBM components, resulting in minimal mud properties. These indicate the need for multifunctional additives to improve WBMs. Thus, this study developed WBM systems employing graphene nanoplatelets (GNPs) and locally acquired discarded coconut shells to overcome severe drilling challenges. By adding triton-X100 to coconut shell-based graphene (GN-CS), a greater dispersion of modified graphene (GN-TX) particles was produced. Characterization, rheology, lubricity, inhibition, and filtration tests were performed on these GN-CS and GN-TX at concentrations of 0.125, 0.25, 0.375, and 0.50 wt%. Furthermore, biotoxicity, biodegradability, and heavy metal content experiments were performed to study the environmental impact of GN-CS and GN-TX. The results showed that GN-TX had good thermal resistance up to 300 °C with only a 10% loss in weight. Both EDX and FTIR tests showed that the epoxy, carboxyl, and hydroxyl groups are in the GNP-based materials' basal plane. The GN-CS and GN-TX had better fluid properties, including better lubricity, rheology, filtration, and inhibition over the base mud, and the optimal rheological model of the drilling muds was the Herschel Buckley model. The GN-TX (modified) decreased the fluid loss to 20.6–14.3 mL from 24.6 mL at 353 K, whereas the GN-CS (unmodified) reduced it to 21.3–16.7 mL. GN-TX and GN-CS decreased the coefficient of friction of WBM from 0.47 to 0.55 to 0.25–0.41 and 0.33–0.44, respectively, from 298 to 353 K. In addition, 0.50 wt% of GN-CS and GN-TX reduced the shale pellet swelling height to 5.4% and 5.6%, respectively, from 8.8%. Moreover, the EC50 values for GN-CS and GN-TX were about 54,000 mg/L and the BOD/COD ratio was about 47%. These results show that the GNP-based products are safe and biodegradable. The GNP-based materials have promising prospects for drilling in environmentally sensitive formations.

Diesel engines commonly suffer from oil contamination by fuel and other chemicals during operation and maintenance. This contamination alters the oil's lubricating properties, leading to increased wear, corrosion, and other potential problems. Therefore, it is crucial to understand how oil degrades and becomes contaminated due to different replacement strategies is crucial for both engine operators and manufacturers. This study focuses on the impact of fuel dilution on specific properties of engine oil under real-world operating conditions in a marine diesel engine. Oil samples were collected regularly from the crankcase of the engine fuel injection pump and tribological tests were performed. These tests aimed to assess how marine gas oil affects the oil lubricity performance and how it maintains its useful life. The results confirm that diesel dilution primarily affects the oil lubricating abilities as well as overall performance. [ABSTRACT FROM AUTHOR]

This study prepared carbon nanoparticles (CNPs) by precipitating a soluble carbon material (SCM) solution synthesized from phloroglucinol. To this end, an SCM was dissolved in N,N-dimethylformamide (DMF) and deionized water, which was used as a poor solvent. After tuning the initial concentration of the SCM-DMF solution (0.5–10 wt. %), the CNPs prepared from SCM (SCMCNPs) dispersions demonstrated changeable particle sizes (18–110 nm). Scanning electron microscopy observations revealed that the primary SCMCNPs had a spherical shape, and Raman analysis confirmed that the SCMCNPs had G and D bands, further confirming that they were carbon materials. Moreover, the SCMCNPs, whose zeta potential was − 42.1 mV at pH 7.16, was dispersed in a stable and uniform manner in water, and Tyndall effect was observed. The lubricating properties of the SCMCNP dispersions were evaluated. A smaller coefficient of friction was observed for larger particle sizes. Therefore, the largest SCMCNPs exhibited the best lubricity with a kinetic friction coefficient of 0.3. The SCMCNPs also exhibited rolling lubrication properties because of their spherical shape. Thus, this study demonstrates that size-adjustable SCMCNPs can be synthesized using simple and environment-friendly methods and can be used in aqueous systems. [ABSTRACT FROM AUTHOR]

Experience shows that dilution of lubricating oil with diesel oil is unfavorable to the engine, causing issues including deterioration of engine performance, shortening of oil life, and reduction in engine reliability and safety. This paper presents the verification of the hypothesis that the changes in lubricity, friction coefficient, and decreasing oil film thickness (using a relative approach, given as a percentage) are similar for lubricating oil and diesel mixtures prepared from fresh lubricating oil and used lubricating oil. To validate this hypothesis, an experiment is conducted using a high-frequency reciprocating rig (HFFR), in which the lubricity is determined by the corrected average wear scar WS1.4, the coefficient of friction μ, and the percentage relative decrease in oil film thickness r. A qualitative visual assessment of the wear scars on the test specimens is also performed after the HFFR tests. The testing covers mixtures of SAE 30 grade Marinol CB-30 RG1230 lubricating oil with Orlen Efecta Diesel Biodiesel. The used lubricating oil is extracted from the circulating lubrication system of a supercharged, trunk-piston, four-stroke ZUT Zgoda Sulzer 5 BAH 22 engine installed in the laboratory of ship power plants of the Maritime University of Szczecin. Mixtures for the experiment are prepared for fresh lubricating oil with diesel oil and used lubricating oil with diesel oil. Mixtures of these lubricating oils with diesel oil are examined for diesel oil concentrations in the mixture equal to 1, 2, 5, 10, 15, and 20% m/m. The results of the experiment confirm the hypothesis, proving that, for up to 20% m/m diesel oil concentration in lubricating oil, the changes in the lubricity of used lubricating oil diluted with diesel oil can be evaluated based on reference data prepared for mixtures of diesel oil with fresh lubricating oil. The linear approximation of μ and r trends is made with a certain margin of error we estimated. The experiment also confirms the results of previous studies which state that oil aging products in small quantities contribute to improved lubricity. [ABSTRACT FROM AUTHOR]

Copyright of Energy Chemical Industry is the property of Energy Chemical Industry Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Despite the extensive use of intermittent catheters (ICs) in healthcare, various issues persist for long-term IC users, such as pain, discomfort, infection, and tissue damage, including strictures, scarring and micro-abrasions. A lubricous IC surface is considered necessary to reduce patient pain and trauma, and therefore is a primary focus of IC development to improve patient comfort. While an important consideration, other factors should be routinely investigated to inform future IC development. An array of in vitro tests should be employed to assess IC's lubricity, biocompatibility and the risk of urinary tract infection development associated with their use. Herein, we highlight the importance of current in vitro characterisation techniques, the demand for optimisation and an unmet need to develop a universal 'toolkit' to assess IC properties. [ABSTRACT FROM AUTHOR]

Adopting an advanced microscopic model of the Au–graphite interaction, a systematic study of Au nanoclusters (up to sizes of 11 238 atoms) on graphene and on graphite is carried out to explore their structure and energy landscape. Using parallel tempering molecular dynamics, structural distribution as a function of temperature is calculated in the entire temperature range. Low‐energy structures are identified through a combination of structural optimization and Wulff–Kaischew construction which are then used to explore the energy landscape. The potential energy surface (PES), which is energy as a function of translation and rotation, is calculated for a few Au nanoclusters along specific directions on carbon lattice. Minimum‐energy pathways are identified on the PES indicating a reduced barrier for pathways involving simultaneous rotation and translation. Diffusion simulations of Au233 on graphite show that diffusion mechanism is directly related to the PES, and the information of the cluster pinning events is already present in the PES. Finally, a comparison of various interaction models highlights the importance of reasonably correct Au–C interactions which is crucial for studying the energy landscape and cluster sliding.

Polyimide (PI) is a special engineering plastic, widely involved in mechanical components, instruments, and petrochemicals. However, single PI material is inevitably subject to wear and tear in practice, which leads to weakened material properties. In this work, Ti3C2Tx@SiO2 was prepared to enhance the wear resistance and lubrication properties of PI by intercalating SiO2 into the interlayer of Ti3C2Tx sheets. Ti3C2Tx@SiO2/PI composites were fabricated in two steps to test the tribological performances. SiO2 particles change the form of interfacial friction from sliding to rolling, thus relieving direct friction between material and steel ball. So, the composites have a minimum COF (COF = 0.33) when the content of Ti3C2Tx@SiO2 is 0.80 wt%. Moreover, the average value of wear rate was 0.24 × 10−5 mm3/(N·m) when Ti3C2Tx@SiO2 content was 1.60 wt%, which was 91.0% lower compared to the PI matrix. During the friction process, the abrasive chips of the material migrate to the surface of the steel ball to form a transfer film, which protects the material and thus reduces the wear rate. Therefore, the hybrids Ti3C2Tx@SiO2 are effective and important wear‐resistant agents and solid lubricants to improve the wear resistance and lubricity of PI or other polymer materials. Highlights: SiO2 insert Ti3C2Tx is a key factor in changing sliding friction into rolling friction, effectively reducing the COF.The average wear rate was 91.0% lower than that of the polyimide matrix when Ti3C2Tx@SiO2 content was 1.60 wt%.The minimum COF of Ti3C2Tx@SiO2/PI composites reached 0.33 when the content of Ti3C2Tx@SiO2 was 0.80 wt%.The transfer film effectively reduces further wear of the material during friction. [ABSTRACT FROM AUTHOR]

Stick-slip in drilling happens when the drill bit and assembly repeatedly stop and slide due to factors like friction and torque. Using better lubricants in the drilling mud can help reduce friction, lessening stick-slip issues. Nanotechnology has improved drilling mud, making it more resistant to heat and enhancing its viscosity and friction properties. This research extensively investigates the use of nanofluids in drilling processes through thorough lab tests. It examines the impact of introducing NanoSiO2 into two types of drilling mud—freshwater bentonite (FWB) and polymer-based mud—at concentrations of 0.04%, 0.08%, 0.15%, and 0.31% under higher temperatures. The study also explores two methods of dispersing NPs using ultrasonic and solvent techniques. The results show that SiO2 nanoparticles notably improve the flow and filtering abilities of FWB mud but have negative effects on polymer-based mud. A 0.05% addition of NanoSiO2 significantly reduces friction by 52% in FWB mud. In FWB mud, all NanoSiO2 concentrations lead to a 25% decrease in mud cake thickness. Furthermore, adding NanoSiO2 to FWB mud decreases torque, with the most substantial reduction of 40% observed at 0.09% concentration (0.35 gm). On the contrary, incorporating NanoSiO2 into polymer-based mud increases fluid loss volume for all concentrations, reaching up to 36% compared to the base mud. Additionally, filter cake thickness increases eightfold, while lubricity factor doubles. This study offers insights into the advantages of using SiO2 nanoparticles in drilling mud and their impact on the fluid properties during drilling. [ABSTRACT FROM AUTHOR]

The smooth functioning of the machinery demands good lubricants. Today mineral oils are extensively used to lubricate machine parts, which are not environmentally friendly. The increased environmental pollution and depletion of crude oil reserves triggered the search for eco-friendly alternate sources of lubricating oils. The bio-lubricants derived from plants and vegetable sources are renewable and environmentally friendly. An in-depth exploration of their potential to replace petroleum-based lubricants is essential. In the present work, the tribological characteristics of Pongamia oil blended with neem oil and enriched with SiO2 nanoparticles (NPs) are investigated. The SiO2 NPs are fabricated via sol–gel methodology and characterized by numerous analytical techniques. A ring-on-block concept is used to measure the lubricity of the oils and to understand the influence of SiO2 NPs on the lubricating regimes, which underlines the novelty of this research work. The rheological properties are studied under rotational shear mode. The results show that the SiO2 NPs extend the mixed lubrication regime of the Pongamia oil by reducing 8.69% of the average coefficient of friction. The antioxidant property was carried out using DPPH analysis and found a maximum of 74.38% at the highest concentration (700 µg/mL). [ABSTRACT FROM AUTHOR]

Liquid metal (LM) with good room-temperature fluidity and high-temperature stability is an ideal base fluid for extreme high-temperature hydraulic transmission medium. However, the low viscosity and high density of LMs are not conducive to the sealing and lubrication performance of hydraulic components. Using Ga68.5In21.5Sn10 as the base fluid and SiC nanoparticles and graphene with good self-lubricity as a dispersed phase through homogenization and grinding, the novel LM-based SiC/Graphene binary hybrid nanofluid were prepared. The basic physical properties, rheological properties and lubricity at 25–200 °C of LM-based SiC/Graphene binary hybrid nanofluid at 0% 5 vol. %, 10 vol. %, 20 vol. % and 30 vol. % of nanoadditives were also explored. Compared with existing high-temperature hydraulic medium, LM-based SiC/Graphene binary hybrid nanofluid has excellent thermal stability, excellent heat dissipation performance, smaller temperature-viscosity changes, and good high-temperature lubricating performance. We selected 20 vol. % of the samples with the most suitable rheological and lubricating properties for hydraulic transmission medium and evaluated the volumetric efficiency and wear of the gear pump by introducing the samples into a hydraulic system. The results show that compared to pure LM, 20 vol. % of the sample can improve the volumetric efficiency of the gear pump and demonstrate good anti-wear performance. [ABSTRACT FROM AUTHOR]

A significant increase of energy demands all over the world and production decline from available oil and gas reservoirs have led the industry to invest in major offshore petroleum resources. However, drilling operations in offshore environments are usually restricted by environmental constraints. Therefore, recent studies are devoted to the development of environmentally compatible fluids with adequate technical properties. Glycerine is a non-toxic, lubricating, colorless, odorless substance with a higher density than water. Due to the properties of glycerine, it can be used as the base of drilling fluid to formulate synthetic-based fluids. This research aimed to review the studies on the applications of glycerine in the composition of drilling fluid. Based on the results, glycerine-based fluids can be considered as an environmentally compatible fluid with sufficient technical properties to replace other drilling fluids. However, there is a lack of experimental studies on the glycerine fluid properties for a reliable decision. For the application of glycerine fluids, an economic feasibility study is mandatory for both pure and crude glycerine. Also, the thermal stability of glycerine fluids is an important aspect, which should be covered in future research studies.

Drilling mud is a major concerning element due to its high operational and economic impact on the drilling process. Various additives are introduced to enhance the efficiency of drilling fluid, but none of them could perfectly achieve their proposed efficacy in drilling operations. Researchers conceived several nanoparticles (NPs) in drilling fluid to dissolve this issue. In a singular instance, commercial tin oxide (SnO2) nanoparticles were utilized to analyze the influence of NPs on the rheological and filtration properties of inorganic KCl salt-based drilling fluid. However, the effect of SnO2 NPs on mud lubricity characteristics is not studied previously. However, due to the hazardous behavior of KCl, its use is very limited. Thus, we consider a KCl-free bentonite water-based mud to avoid any environmental damages from drilling operations. We also use SnO2 NPs that is synthesized in our laboratory by co-precipitation method. In addition to rheological and filtration properties, we also investigate the effect of NPs on mud's lubricity that was not considered in the previous study. Drilling fluid properties are measured at five different NPs concentrations of 0.10, 0.25, 0.50, 0.75 & 1.0 wt%, and at six different temperatures of 30, 40, 50, 60, 70, and 80 °C, while filtration properties are measured using API low-pressure low temperature (LPLT) condition. The addition of 0.1 wt% SnO2 NPs increases plastic viscosity, yield point, 10 s gel strength, and 10 min gel strength by 10%, 63%, 20%, and 14%, respectively. The maximum reduction in lubricity coefficient is found to be 14% at NPs concentration of 1.0 wt%. The NPs concentration of 0.5 wt% yielded a reduction in fluid loss and mud cake thickness by 8.1% and 34%, respectively. The study suggests that SnO2 NPs can be employed as an additive to improve the rheology, lubricity, and filtration properties of KCl-free bentonite water-based drilling mud.

With the growth of deep drilling and the complexity of the well profile, the requirements for a more complete and efficient exploitation of productive formations increase, which increases the risk of various complications. Currently, reagents based on modified natural polymers (which are naturally occurring compounds) and synthetic polymers (SPs) which are polymeric compounds created industrially, are widely used to prevent emerging complications in the drilling process. However, compared to modified natural polymers, SPs form a family of high-molecular-weight compounds that are fully synthesized by undergoing chemical polymerization reactions. SPs provide substantial flexibility in their design. Moreover, their size and chemical composition can be adjusted to provide properties for nearly all the functional objectives of drilling fluids. They can be classified based on chemical ingredients, type of reaction, and their responses to heating. However, some of SPs, due to their structural characteristics, have a high cost, a poor temperature and salt resistance in drilling fluids, and degradation begins when the temperature reaches 130 ℃. These drawbacks prevent SP use in some medium and deep wells. Thus, this review addresses the historical development, the characteristics, manufacturing methods, classification, and the applications of SPs in drilling fluids. The contributions of SPs as additives to drilling fluids to enhance rheology, filtrate generation, carrying of cuttings, fluid lubricity, and clay/shale stability are explained in detail. The mechanisms, impacts, and advances achieved when SPs are added to drilling fluids are also described. The typical challenges encountered by SPs when deployed in drilling fluids and their advantages and drawbacks are also discussed. Economic issues also impact the applications of SPs in drilling fluids. Consequently, the cost of the most relevant SPs, and the monomers used in their synthesis, are assessed. Environmental impacts of SPs when deployed in drilling fluids, and their manufacturing processes are identified, together with advances in SP-treatment methods aimed at reducing those impacts. Recommendations for required future research addressing SP property and performance gaps are provided. [ABSTRACT FROM AUTHOR]

To obtain high production rate with less oil and gas wells, The Qinghai oilfield decided to drill five long open hole horizontal wells in the Fengxi structure which is located in the Dafengshan area in Qaidam Basin. Water-based and oil-based drilling fluids were to be used to drill these wells, and the results be compared to improve and perfect the technical prototype for future drilling and completion of long open hole and long horizontal section horizontal wells in the same area. This paper summarizes the field engineering of a high-quality compound saltwater drilling fluid on the well Fengxi IH1-5 and analyses are briefly conducted on the application, control of the engineering parameters, rheology and sand carrying capacity of the drilling fluid. The well Fengxi IH1-5, which is 5,487 m in depth, has a length of horizontal section of 2,541 m, the longest horizontal section in the Qinghai oilfield. This well has broken several records in this oilfield, such as penetrating the highest percentage of pay zones (100%), the longest footage (1,566 m) drilled in a single bit run, the longest horizontal section (1,000 m) in which short trips were performed, as well as the first application of casing floatation technology in casing running etc. The success of the drilling operation has milestone significance in applying the ultralong horizontal section well drilling technology in the Qinghai oilfield. Compared with the drilling operation of the offset wells drilled with oil-based drilling fluids, the use of this high-quality compound saltwater drilling fluid has gained better results in drilling than the oil-based drilling fluids previously used in other wells. The success gained in applying the water-based drilling fluid has provided a good guidance for optimizing the properties of water-based drilling fluids for horizontal wells with long open hole and long horizontal sections. [ABSTRACT FROM AUTHOR]

Copyright of Rudarsko-Geolosko-Naftni Zbornik is the property of Faculty of Mining, Geology & Petroleum Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

With the continuous exploration of deep reservoirs in the oil and gas industry, the performance of drilling fluid has become increasingly demanding. The addition of nanoparticles can meet the requirements of optimizing the specific performance of high temperature and high-pressure drilling fluid. Compared with traditional drilling fluid additives, nanoparticles can effectively improve the rheology of drilling fluid, reduce filtration loss, improve thermal stability and lubricity to cope with high-temperature and high-pressure reservoir conditions. Based on the excellent thermal, mechanical and chemical properties of nanoparticles, as well as their compatibility with base fluids, the applications of metal nanoparticles, carbon-based nanoparticles and silica nanoparticles in high-temperature and high-pressure drilling fluids were reviewed. At the same time, the influence of nanoparticles on the performance of drilling fluid under high temperature and high pressure was discussed, and it was stated that the shape, size and concentration of nanoparticles were the key factors affecting their performance. The use of nanoparticles as additives in high-temperature and high-pressure drilling fluids also puts forward new ideas for research on reducing their environmental impact and production costs. [ABSTRACT FROM AUTHOR]

Based on the characteristics of aluminum alloy and the demanding requirements of high-gloss machining quality，a polyether polyol ester lubricant was synthesized using castor oil acid and methoxy polyethylene glycol as raw materials， and a new type of synthetic high-gloss cutting fluid was developed using a maleic anhydride composite of boric acid and ternary carboxylic acid as rust inhibitors.Comparative studies were conducted on the lubrication performance， corrosion resistance to aluminum alloy， rust prevention， defoaming， and hard water resistance of this synthetic high-gloss cutting fluid against commonly available imported and domestic cutting fluids on the market.Results showed that compared with imported and domestic cutting fluids，the maximum non jamming load PB value of high-gloss cutting fluid was 735 N，which was better than imported cutting fluid (686 N) and domestic cutting fluid (588 N).The threading torque value of the high-gloss cutting fluid was the lowest， followed by the imported and then the domestic diluted cutting fluid， suggesting superior lubrication of the high-glosscutting fluid.The 24 h corrosion test showed that the corrosion resistance of high-gloss cutting fluid to aluminum alloy was grade A， which reached the level of imported cutting fluid and is better than domestic cutting fluid.Additionally， the high-gloss cutting fluid exhibited commendable rust prevention， excellent defoaming， and favorable hard water resistance.

Poly(acrylamide-co-acrylic acid) (P(AAm-co-AA)) hydrogels are highly tunable and pH-responsive materials frequently used in biomedical applications. The swelling behavior and mechanical properties of these gels have been extensively characterized and are thought to be controlled by the protonation state of the acrylic acid (AA) through the regulation of solution pH. However, their tribological properties have been underexplored. Here, we hypothesized that electrostatics and the protonation state of AA would drive the tribological properties of these polyelectrolyte gels. P(AAm-co-AA) hydrogels were prepared with constant acrylamide (AAm) concentration (33 wt%) and varying AA concentration to control the amount of ionizable groups in the gel. The monomer:crosslinker molar ratio (200:1) was kept constant. Hydrogel swelling, stiffness, and friction behavior were studied by systematically varying the acrylic acid (AA) concentration from 0-12 wt% and controlling solution pH (0.35, 7, 13.8) and ionic strength (I = 0 or 0.25 M). The stiffness and friction coefficient of bulk hydrogels were evaluated using a microtribometer and borosilicate glass probes as countersurfaces. The swelling behavior and elastic modulus of these polyelectrolyte hydrogels were highly sensitive to solution pH and poorly predicted the friction coefficient (µ), which decreased with increasing AA concentration. P(AAm-co-AA) hydrogels with the greatest AA concentrations (12 wt%) exhibited superlubricity (µ = 0.005 ± 0.001) when swollen in unbuffered, deionized water (pH = 7, I = 0 M) and 0.5 M NaOH (pH = 13.8, I = 0.25 M) (µ = 0.005 ± 0.002). Friction coefficients generally decreased with increasing AA and increasing solution pH. We postulate that tunable lubricity in P(AAm-co-AA) gels arises from changes in the protonation state of acrylic acid and electrostatic interactions between the probe and hydrogel surface.

Diesel engines commonly suffer from oil contamination by fuel and other chemicals during operation and maintenance. This contamination alters the oil’s lubricating properties, leading to increased wear, corrosion, and other potential problems. Therefore, it is crucial to understand how oil degrades and becomes contaminated due to different replacement strategies is crucial for both engine operators and manufacturers. This study focuses on the impact of fuel dilution on specific properties of engine oil under real-world operating conditions in a marine diesel engine. Oil samples were collected regularly from the crankcase of the engine fuel injection pump and tribological tests were performed. These tests aimed to assess how marine gas oil affects the oil lubricity performance and how it maintains its useful life. The results confirm that diesel dilution primarily affects the oil lubricating abilities as well as overall performance.

This paper discusses a method of finish turning Inconel 718 alloy to compare machining performance of a naturally aged and used metalworking fluid (MWF), which had been conventionally managed through its life cycle, with the same new unaged product. The MWF concentrate was a new-to-market bio-ester oil, diluted with water to produce an emulsion. In the experiments, 50 mm diameter bars were turned down with multiple passes at a 250 μm depth of cut to reach a tool flank wear of 200 μm. The machining was interrupted at several stages to measure the flank wear and compare the chip forms for the aged and unaged MWF. The method of finish turning used a small tool nose radius and a small depth of cut that was found to be sensitive in detecting a difference in the flank wear and chip forms for the aged and unaged MWF. On the chemistry, the findings suggest that higher total hardness of the aged MWF was the cause of reduced lubricity and accelerated flank wear. This paper discusses the state of the art with the insights that underpin the finish turning method for the machinability assessment of MWFs. The findings point to stabilization of the MWF chemistry to maintain machining process capability over an extended sump life. [ABSTRACT FROM AUTHOR]

为考察二聚酸抗磨剂对加氢精制航空煤油润滑性的改善作用，同时验证不同二聚酸抗磨剂的改善效果，分别采用桐油、棉籽油及妥尔油酸为原料进行了二聚酸的合成与精制，利用液相色谱仪、红外光谱仪、核磁共振波谱仪等验证了桐油基、棉籽油基及妥尔油酸基二聚酸的分子结构，采用球柱润滑性评定仪（BOCLE）法和高频往复试验机（HFRR）法考察了3种不同原料来源的二聚酸对航空煤油润滑性的改善作用，用显微镜分析试验球的磨痕形貌，并提出抗磨机制。结果表明：随着二聚酸添加量的不断增大，磨痕直径、表面划痕及深度不断减小；在BOCLE法中，当二聚酸添加量为20 mg/L时，3种二聚酸均可使航空煤油润滑性磨痕直径从0.92 mm降到0.65 mm以下，满足GB 6537—2018《3号喷气燃料》要求；在HFRR法中，当二聚酸添加量为50 mg/L时，3种二聚酸均可使润滑性磨痕直径降到550 μm 以下，平均摩擦系数降到0.265以下，平均成膜率达到24%以上，且平均摩擦系数和平均成膜率的变化规律与二聚酸对航空煤油润滑性改善规律一致；制备的二聚酸均具有长碳链和羧基官能团，羧基通过强电负性吸附在金属表面，羧基之间的氢键以及非极性端通过范德华力等使二聚酸分子形成平行分子簇，进而在金属表面形成有效的润滑膜，阻止两摩擦副之间发生直接接触与摩擦。综上，3种二聚酸的润滑能力相当，均显示出良好的润滑性能。 In order to investigate the improvement of lubricity of dimer acid antiwear agents on jet fuel and verify the improvement effects of different dimer acids antiwear agents,dimer acids were synthesized and refined from tung oil, cottonseed oil and tall oil fatty acids, respectively, and their molecular structures were verified by liquid chromatography, FT-IR spectrometer and NMR spectrometer. The effects of cottonseed oil-based dimer acid, tung oil-based dimer acid and tall oil fatty acids-based dimer acid on the lubricity of jet fuel were investigated by BOCLE and HFRR tests. The wear scar morphology of the test ball was analyzed by measuring microscope and the antiwear mechanism was proposed. The results showed that with the increase of the dosage of dimer acid, the wear scar diameter, surface scratch and depth decreased. In BOCLE test, 20 mg/L dosage of dimer acids from three different raw materials could reduce the wear scar diameter of jet fuel from 0.92 mm to less than 0.65 mm ,meeting the requirement of GB 6537-2018 No.3 jet fuel. In HFRR test, when the dosage of three dimer acids was 50 mg/L, the wear scar diameter of lubricity and the average friction coefficient could be reduced below 550 μm and 0.265 respectively, and the average film formation rate could reach above 24%. The variation of the average friction coefficient and average film formation rate was consistent with the improvement rule of dimer acid on the lubricity of jet fuel. The dimer acids prepared had long carbon chains and carboxyl functional groups. The carboxyl group was adsorbed on the metal surface through strong electronegativity, the hydrogen bond with carboxyl groups and the non-polar end through Van Der Waals force made the dimer acid molecules form parallel molecular clusters, and then formed an effective lubrication film on the metal surface to prevent direct contact and friction between the two friction pairs. In conclusion, the three dimer acids have the uniform lubrication ability, and show good lubrication performance.

Experience shows that dilution of lubricating oil with diesel oil is unfavorable to the engine, causing issues including deterioration of engine performance, shortening of oil life, and reduction in engine reliability and safety. This paper presents the verification of the hypothesis that the changes in lubricity, friction coefficient, and decreasing oil film thickness (using a relative approach, given as a percentage) are similar for lubricating oil and diesel mixtures prepared from fresh lubricating oil and used lubricating oil. To validate this hypothesis, an experiment is conducted using a high-frequency reciprocating rig (HFFR), in which the lubricity is determined by the corrected average wear scar WS1.4, the coefficient of friction μ, and the percentage relative decrease in oil film thickness r. A qualitative visual assessment of the wear scars on the test specimens is also performed after the HFFR tests. The testing covers mixtures of SAE 30 grade Marinol CB-30 RG1230 lubricating oil with Orlen Efecta Diesel Biodiesel. The used lubricating oil is extracted from the circulating lubrication system of a supercharged, trunk-piston, four-stroke ZUT Zgoda Sulzer 5 BAH 22 engine installed in the laboratory of ship power plants of the Maritime University of Szczecin. Mixtures for the experiment are prepared for fresh lubricating oil with diesel oil and used lubricating oil with diesel oil. Mixtures of these lubricating oils with diesel oil are examined for diesel oil concentrations in the mixture equal to 1, 2, 5, 10, 15, and 20% m/m. The results of the experiment confirm the hypothesis, proving that, for up to 20% m/m diesel oil concentration in lubricating oil, the changes in the lubricity of used lubricating oil diluted with diesel oil can be evaluated based on reference data prepared for mixtures of diesel oil with fresh lubricating oil. The linear approximation of μ and r trends is made with a certain margin of error we estimated. The experiment also confirms the results of previous studies which state that oil aging products in small quantities contribute to improved lubricity.

This study represents the first investigation into the potential of Spirulina algae proteins as drilling fluid constituents to address the problems of the environmental impacts of the petroleum industry. Algae protein is a common waste product from many bioprocessing operations including biofuel production, so this work also presents a solution to a waste utilization problem for bioprocessing industries. As such, this technology could create an important coproduct for bioprocessing industries while providing more sustainable and environmentally-benign drilling fluids for the petroleum industry. Algae biomass was hypothesized to serve as a bentonite replacement or as an additive that could improve drilling fluid performance by reducing fluid loss via permeation, and/or improvement of lubricity via reduction in coefficient of friction. Measurements were taken in accordance with API RP 13B-1 using an OFITE viscometer, OFITE 4-Unit HTHP Filter Press, and OFITE extreme pressure and lubricity tester. The rheological tests include viscosity, yield stress, and gel strength. Key findings include a friction reduction of up to 27% and a standard fluid loss as low as 13.5 mL. The biomass was able to increase the viscosity of the drilling fluids and exhibited a shear-thinning rheology with yield points exceeding 40 lbf/ft2. The rheology was fitted to the Bingham plastic model and the Herschel-Bulkley model. These findings have potential impacts in the fields of petroleum, chemical, environmental, and material engineering. It is concluded that Spirulina biomass is a good potential additive for decreasing fluid loss and improving the lubricity of drilling fluids, but it will not suffice as a bentonite replacement.

Introduction and identification of a foreign substance in fuels is a promising technology for monitoring adulteration and maintaining fuel quality. However, tagging substances with excellent fuel dispersion stability and detecting them by a simple procedure and device is an urgent need for monitoring fuel quality. Here, fluorescent carbon dots (CDs) are proposed as the tagging substance to identify the fuel product, monitor adulteration, and improve the lubricity of the fuel. We synthesized hydrophobic fluorescent CDs, where the presence of oleylamine on the surface of CDs provides excellent dispersion stability in fuels without any aggregation and changes in fluorescence properties. The distinct greenish yellow emission of CDs enables tagging of fuel and monitoring adulteration. Our study reveals that by adding CDs to fuels, detection and monitoring of adulteration can be done up to the level of 2% (v/v). In addition, CD dispersion gives the required lubricity to the fuel without addition of any traditional lubricity improvers. Furthermore, CDs-additized diesel and gasoline meet the required fuel specification, reduce harmful emission in exhaust gas, and improve fuel economy. All these results strongly indicate the potential application of CD dispersion as a multifunctional additive for tagging and monitoring adulteration and also as a lubricity improver for liquid fuels such as gasoline and diesel. [ABSTRACT FROM AUTHOR]

The rheological, ignition, and tribological properties of lubricating oils diluted with biodiesel were analyzed. The flash point tFP, calculated cetane index CCI, density ρ, coefficient of the temperature density change ε, kinematic viscosity ν, dynamic viscosity η, viscosity index VI, and lubricity during a High-Frequency Reciprocating Rig (HFFR) test (x, y, WSD, and WS1.4) and lubricating conditions during an HFFR test (oil film resistance FILM and friction coefficient μ) were determined. The test was performed for the oil mixtures of the lubricating oil of the SAE 30 and SAE 40 viscosity grades, which were diluted with the biodiesel blend (D93B7—diesel oil with 7% v/v fatty acid methyl esters, FAME) at concentrations of diesel oil in the mixture equal to 0% (pure lubricating oil), 1%, 2%, 5%, 10%, 20%, 30%, 50%, and 75% m/m, respectively. The experiment confirmed the existence of clear relationships between the increase in the dilution of lubricating oil with tested biodiesel blend and tFP, ρ, ε, ν, η, and VI, and the deterioration of lubrication conditions. It is recommended to take remedial action even in the case of low diesel oil concentration (<5% m/m) in the lubricating oil due to tFP, ν, and η changes. Simultaneously, the tests showed no significant effect on the lubricity and the CCI. The critical contamination of oil with fuel in the range of 2–5% by weight, as indicated in the literature, still allowed for a certain "safety margin" regarding these parameters. However, when the concentration of diesel fuel in the lubricating oil exceeded 5–8% m/m, the deterioration of the lubrication was expressed by a decrease in FILM and an increase in μ was observed; hence, such a contamination should be considered excessive. When the concentration of diesel fuel exceeds 10% by weight, there is a serious risk of engine damage during operation. [ABSTRACT FROM AUTHOR]

Fuel lubricity is an essential property that ensures the longevity end efficiency of diesel CI engines. Nanomaterials have been shown to have the potential to improve lubricity in many different lubricating substances, including fuels. Moreover, the combustion process has also been shown to improve with the introduction of nanomaterials. This study investigated a series of nanoparticles, including carbon nanoplates, carbon nanotubes, aluminum oxide, zinc oxide, and cerium oxide, as lubricity-enhancing additives for selected fuels. Conventional diesel fuel and rapeseed oil methyl ester, referred to as biodiesel, were chosen as base fuels for modification. The lubricity was evaluated according to the standard test method ASTM 6079 using the HFRR tribometer. The leading lubricity indicators were the wear scar diameter, wear volume, and coefficient of friction. In addition, the worn surface analysis was performed to elucidate the lubrication mechanism. The results show that the addition of nanoparticles can improve the lubricity of both investigated fuels. However, the effect differed among nanoparticles and fuels. In summary, carbon nanotubes could be a rational choice for both fuels. In addition, zinc oxide improved the lubricity of diesel fuel, while carbon nanoplatelets and aluminum oxide nanoparticles showed improvements in the lubricity of biodiesel. [ABSTRACT FROM AUTHOR]

This article gives an account of the work program within the framework of the Postdoctoral project to be developed around the question of the specificity of lubricity murder and its possible reading from the field of Psychoanalysis. In this sense, it delimits the variables that allow sifting the object of study, delineating the approach in the following terms: structural and economic perspective of the murder by lubricity. The present text briefly reviews the background of the subject and the question and objectives that allow the construction of the object of the research. [ABSTRACT FROM AUTHOR]

In an attempt to avoid serious problems that can affect the efficiency of refueling ground-operated vehicles and aircraft during military operations, the Armed Forces of the North Atlantic Treaty Organization (NATO) are introducing the use of a unique fuel for both air and land use. The fuel that has been selected is the F-34, similar to Jet A-1, which is used in civil aviation, in order to replace diesel fuel in many applications. It has to be mentioned that tests performed with this fuel, which is kerosene type on the high frequency reciprocating rig (HFRR) have shown that such fuel is responsible for severe wear. This very high wear is related to the very low lubricity of aviation fuel. Having the idea to improve the lubricity of aviation fuel to the level of fuels used in compression ignition engines (diesel fuel), seven N,N-Bis(2-ethoxyethyl) fatty acid amides were formulated from various vegetable oils (sunflower oil, soybean oil, cottonseed oil, olive oil, tobacco seed oil, coconut oil, used frying oil), and they were evaluated as lubricity improvers of the aviation fuel. The required tribological measurements for lubricity rating were carried out by employing ISO 12156-1 test method on an HFRR instrument. The test conditions during the measurements were in the range of 55% to 58% for the relative humidity and 24 °C for the temperature. The results from the tribological measurements showed that all N,N-Bis(2-ethoxyethyl) fatty acid amides used were rated as efficient in order to provide an acceptable mean wear scar diameter (below 460 μm) at concentrations from 150 to 300 ppm. Additive concentrations below 150 ppm did not improve the lubricity at the required level. The increase of N,N-Bis(2-ethoxyethyl) fatty acid amides at concentrations over 300 ppm did not have any significant decrease in the wear scar diameter. A comparison between the N,N-Bis(2-ethoxyethyl) fatty acid amides showed that those formulated by non-polyunsaturated oils like olive oil and coconut oil seem to have better lubricity improver characteristics.

While the methyl ester structure in biodiesel is responsible for lubrication improvement in base fuels with poor lubricity properties such as ultra-low sulfur diesel and non-upgraded HVO, relatively little is known about its effect on all-level blends, which would provide higher energy security for biodiesel utilization. In this study, binary blends of palm oil biodiesel (POB) with commercial petroleum diesel fuel (DF) and HVO at every 10%-v/v blend point were analyzed using a high-frequency reciprocating rig (HFRR) according to the standard method of ASTM D6079. It was found that the addition of POB successfully improved the lubricating properties of DF-CN48 and DF-CN51 and efficiently acted as a lubricity improver that showed a minimum friction coefficient and improved the specific wear rate. The adsorption of ester molecules on the metallic surfaces acted as a protective layer during the rubbing process, resulting in lubricity improvement for the diesel fuel. Interestingly, the 60–90%-v/v POB blend with HVO showed a lubricity capacity that competed determinatively and attractively, resulting in a non-ideal contribution to the changes in the friction coefficient, WSD formation, and specific wear rate. [ABSTRACT FROM AUTHOR]

During coal-based power generation, fuel oil is used to assist with ignition of pulverised coal. Fuel oil passes through several pieces of equipment on its way to the burner section of the boiler. In this article the focus is on the lubricity behaviour of three representative fuel oil types and on the potential blocking of filters and nozzles caused by the presence of unwanted components in these fuel oils. The high frequency reciprocating rig (HFRR) (ISO 12156-1) was used to determine the lubricity of these fuel oils at different temperatures. Results indicate that the presence of asphaltenes (components of heavy fuel oils with complex aromatic structures) changes the viscosities of fuel oils, which, in turn affect their lubricity behaviour. Medium wax-blend fuel oil (MFO) containing high molecular weight paraffins (wax), low concentrations of asphaltenes and solid particles caused less friction and wear (with coefficient of friction (COF) values below 0.1) and good high temperature performance. Crude-derived heavy fuel oil (HFO), containing high concentrations of asphaltenes and solid particles caused very high coefficients of friction (COF peaks above 0.3) and severe abrasive wear at high temperatures. Although the third fuel oil tested was a light cycle oil (LFO) and did not contain any asphaltenes, results indicated a sensitivity to oxidation, increasing with temperature, which can have an adverse effect on in situ performance. [ABSTRACT FROM AUTHOR]

Several problems have been encountered in the development of the Sulige gas field, for example, the caving and sloughing of the hard and brittle mudstones of the Shuangshi formation of the Permian system, borehole instability of the black mudstones as well as difficulties in exerting weight to the bit in horizontal slide drilling, to name but three. Environmental protection requirements have limited the use of conventional shale inhibitors. In previous drilling operation, long time reaming, sidetracking after plugging the abandoned hole have been the norm for some time. To deal with these problems, an environmentally friendly cellulose shale inhibitor CQYJZ-3 was developed through chemical modification of a hemicellulose derivative, and an environmentally friendly drilling fluid named HCG-1, which is suitable for through-casing sidetracking of horizontal wells in Sulige gas field, was developed. Laboratory experimental results show that HCG-1 drilling fluid has stable rheology and good properties such as inhibitive capacity, lubricity, contamination resistance and corrosion inhibition. It is a non-toxic easy-to-degrade drilling fluid. This drilling fluid has been successfully used on 10 wells in the Sulige gas field. Field operation showed that HCG-1 had stable properties, good inhibitive capacity and lubricity. Wireline logging was successful at the first try. No downhole troubles were encountered during drilling. The HCG-1 drilling fluid can be also recovered for re-use. Good application achievements were obtained with the use of the HCG-1 in the Sulige gas field. [ABSTRACT FROM AUTHOR]

In an attempt to avoid serious problems that can affect the efficiency of refueling ground-operated vehicles and aircraft during military operations, the Armed Forces of the North Atlantic Treaty Organization (NATO) are introducing the use of a unique fuel for both air and land use. The fuel that has been selected is the F-34, similar to Jet A-1, which is used in civil aviation, in order to replace diesel fuel in many applications. It has to be mentioned that tests performed with this fuel, which is kerosene type on the high frequency reciprocating rig (HFRR) have shown that such fuel is responsible for severe wear. This very high wear is related to the very low lubricity of aviation fuel. Having the idea to improve the lubricity of aviation fuel to the level of fuels used in compression ignition engines (diesel fuel), seven N,N-Bis(2-ethoxyethyl) fatty acid amides were formulated from various vegetable oils (sunflower oil, soybean oil, cottonseed oil, olive oil, tobacco seed oil, coconut oil, used frying oil), and they were evaluated as lubricity improvers of the aviation fuel. The required tribological measurements for lubricity rating were carried out by employing ISO 12156-1 test method on an HFRR instrument. The test conditions during the measurements were in the range of 55% to 58% for the relative humidity and 24 °C for the temperature. The results from the tribological measurements showed that all N,N-Bis(2-ethoxyethyl) fatty acid amides used were rated as efficient in order to provide an acceptable mean wear scar diameter (below 460 μm) at concentrations from 150 to 300 ppm. Additive concentrations below 150 ppm did not improve the lubricity at the required level. The increase of N,N-Bis(2-ethoxyethyl) fatty acid amides at concentrations over 300 ppm did not have any significant decrease in the wear scar diameter. A comparison between the N,N-Bis(2-ethoxyethyl) fatty acid amides showed that those formulated by non-polyunsaturated oils like olive oil and coconut oil seem to have better lubricity improver characteristics. [ABSTRACT FROM AUTHOR]

Fuel contamination of engine lubricating oil has been previously determined to arise from two independent phenomena: the effect on oil flash point, and the effect of changing lubrication conditions on tribological pairs. This paper combines these effects and holistically analyzes the consequences of fuel in the lubricating oil of a trunk piston engine on the risk of crankcase explosion. The author hypothesized that diesel fuel as an oil contaminant increases the risk of an explosion in the crankcase of an engine due to the independent interaction of two factors: (1) changes in the oil's combustible properties, and (2) deterioration of the lubrication conditions of the engine's tribological nodes, such as main bearings, piston pins, or crank bearings. An experiment was performed to evaluate the rheological, ignition, and lubrication properties of two oils (SAE 30 and SAE 40) commonly used for the recirculation lubrication of marine trunk piston engines for different levels of diesel contamination. The hypothesis was partially confirmed, and the results show that contamination of the lubricating oil with diesel fuel in an amount of no more than 10% does not significantly affect the risk of explosion in the crankcase. However, diesel concentrations above 10% call for corrective action because the viscosity index, lubricity, coefficient of friction and oil film resistance change significantly. Deterioration of the tribological conditions of the engine bearings, as seen in the change in viscosity, viscosity index, and lubricity of the oil, causes an increase in bearing temperature and the possibility of hot spots leading to crankcase explosion. [ABSTRACT FROM AUTHOR]

This article studies the tribological behavior of the lubricant film when the Q1-224 hydrostatic turntable is operated at constant cutting speed. First, the rotational speed equation of the worktable under the constraint of constant cutting speed is derived. Based on the lubrication mechanism of hydrostatic turntables, the flow-rate equation of the oil film, the temperature-rise equation of the oil film, and the bearing-capacity equation of the double rectangular cavity are deduced. Furthermore, the prediction model of the lubrication performance of hydrostatic turntable operating at constant cutting speed is established. Meanwhile the quasi-steady-state analysis is carried out by numerical simulation to obtain the change law for the lubricating oil film temperature, pressure, and other performance indicators with time under the different loads. Finally, these laws are verified by designed experiments. It is found that the load has a large effect on the change of oil film performance; it affects the temperature rise of the oil film by influencing the dissipation capacity, and there is a nonlinear relationship between the increase of the load and the average temperature rise of the oil film. [ABSTRACT FROM AUTHOR]

Maritime transport has a vital role in world economy. Its efficiency depends on the effective trade, transport facilitation, low cost of customs and the integration of new technologies for sustainable operation. However, the con-temporary demands have turned shipping industry into an emerging air pollutant with significant share to the global climate change problem. The industry is growing rapidly and it needs to lower greenhouse gas emissions in order to contribute towards the valuable effort for net zero emissions by 2050. A milestone to the ambitious strategy of decarbonization is the use of low or zero sulphur fuels that will contribute to the development of viable zero-emission vessels by 2030. Netherless the introduction of low-sulphur marine gasoils in the global fuel supply chain is accompanied by a huge range of side effects related to their storage, combustion, ignition and lubricity. The objective of the study is the evaluation of the lubricity of different marine distillate fuels with the High Frequency Reciprocating Rig (HFRR) test, either by following the primary conditions defined by ISO 12156-1 standard or by modifying them. The ultimate goal is the accurate and reliable assessment of their lubricating capacity so as to identify the challenges related to it, on time. [ABSTRACT FROM AUTHOR]

Highlights: Enhanced lubricity of biobased Metal Working Fluids (MWF) over mineral oil emulsions to machine titanium at low speed Method of soft synchronous tapping to evaluate MWFs on machine tool Method to calculate GHG Greenhouse Gas emission of MWFs Significant reduction in Greenhouse Gas emission for fully synthetic MWFs for cleaner manufacturing The paper discusses an instrumented tapping test method using a CNC machine tool to compare the lubricity of MWFs by cutting threads in a Ti-6Al-4V alloy at low speed. The method uses a spiral flute tap size typical of industrial practice. A soft synchronous tap holder and spindle mounted dynamometer were incorporated on the machine to measure torque and thrust force. The tapping test method was demonstrated on three groups of MWFs that were commercially available and classified by ASTM E2523-13:2018. The method developed stable results free of chip clogging in tool flutes which could otherwise mask their comparative lubricity. The fully synthetic (FS) group displayed the best lubricity and within this group the FS from renewables (FS-bio) was the best overall. The method was shown to be effective in mitigating biasing effects on lubricity performance due to the generous tool chamfer angle tolerance and was practical and economical to implement. The significance of the results is discussed enabling an understanding of friction effects in tapping using a soft synchronous tap holder. A life cycle assessment of each MWF group found total Greenhouse Gas emitted from the FS group was 17% of the hydrocarbon group whilst FS-bio emitted just 7%. [ABSTRACT FROM AUTHOR]

This paper discusses a method of finish turning Inconel 718 alloy to compare machining performance of a naturally aged and used metalworking fluid (MWF), which had been conventionally managed through its life cycle, with the same new unaged product. The MWF concentrate was a new-to-market bio-ester oil, diluted with water to produce an emulsion. In the experiments, 50 mm diameter bars were turned down with multiple passes at a 250 μm depth of cut to reach a tool flank wear of 200 μm. The machining was interrupted at several stages to measure the flank wear and compare the chip forms for the aged and unaged MWF. The method of finish turning used a small tool nose radius and a small depth of cut that was found to be sensitive in detecting a difference in the flank wear and chip forms for the aged and unaged MWF. On the chemistry, the findings suggest that higher total hardness of the aged MWF was the cause of reduced lubricity and accelerated flank wear. This paper discusses the state of the art with the insights that underpin the finish turning method for the machinability assessment of MWFs. The findings point to stabilization of the MWF chemistry to maintain machining process capability over an extended sump life.

Creaminess is a pleasant sensory attribute, generally associated with the fat components in food and closely related to the lubricating properties. Saliva plays a crucial role in oral lubrication. The interaction of salivary components with food compounds, especially fat/oil, could substantially influence creaminess. This review discusses the importance of saliva in food oral processing. The mechanisms of fat-producing creaminess perception in different types of food matrices have been discussed.

Copyright of Journal of Food Safety & Quality is the property of Journal of Food Safety & Quality Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The fatty acid methyl ester ethoxide (FMEE) has excellent emulsifying property for animal fat and clearing power of protein fouling. The introduction of PO group into the structure of FMEE can not only reduce the foaminess of FMEE, but also increase lubrication force of FMEE. In the wool washing process, FMEE with PO ends can form a lubricating film on the surface of wool scales, which can reduce the wool intertwine with each other. Using FMEE in PO block as the main component, the conditioner 6501, solvent ethylene glycol tert-butyl ether and osmotic agent sodium primary alkyl sulfonate were mixed to obtain a cleaning, felt-proof and balanced performance wool washing agent. The proportion of FMEE in PO block, conditioning agent 6501, ethylene glycol tert-butyl ether and sodium primary alkyl sulfonate was determined to be 3:2:1 to produce wool washing agent. It can not only remove the grease, protein fouling and metal soap deposited on the surface of wool, but also effectively protect the original elasticity, strength, color and other properties of wool, so that the washed wool is white and loose without felting. [ABSTRACT FROM AUTHOR]

Copyright of Lubrication Engineering (0254-0150) is the property of Editorial Office of LUBRICATION ENGINEERING and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)