Low Viscosity Mineral Oil Research Articles

Emulsification of low viscosity oil in alkali-activated materials

This research aims to understand the mechanisms enhancing the fixation of low viscosity mineral oils, including tailings, in reactive inorganic matrices, by emulsification. To this purpose, significant amounts of a model low viscosity pure mineral oil (20%vol) are immobilized in alkali-activated materials (AAM), either based on metakaolin or blast furnace slag. In such case, Portland cement-based matrices are not adequate (emulsification delicate to manage and excessive setting retardation). Various surfactants are used to ease the oil emulsion.Visual observation and rheology evidence two distinct groups of surfactants. One contributes to structuring the oil/AAM fresh mix, with greater viscosity than without surfactant; the other includes non-structuring surfactants, without change in viscosity. Each group depends on the AAM considered.Whatever the AAM and the surfactant, the oil droplet size decreases significantly, without consistent correlation with the interfacial tension between oil/activating solution (AS). Interfacial tension alone does not explain the reduction in oil droplet size. Characterization of diluted ternary suspensions (solid particles – oil – AS) relates the structuring effect to interactions between oil and solid particles, through the surfactant polar head groups and non-polar hydrocarbon tails. A detailed mechanism explaining the oil stabilization and the mix structuring is discussed.

Experimental study of the rheological properties and stability of highly-concentrated oil-based emulsions

This study presents a systematic investigation of viscosity and rheological properties of several dozen emulsions and nanoemulsions. The concentration by volume of the oil in emulsions varied from 20% to 80%. Low-viscosity mineral oils were used for emulsion formation and an aqueous solution of calcium chloride was used as the second medium. The volumetric concentration of emulsifiers varied from 1.5% to 4.5%. Three types of mineral oil, as well as various emulsifiers, are considered. The effect of the volumetric content and base oil type, the emulsifier type and concentration and the ultrasonic treatment duration on colloidal stability, rheological properties and droplet size of the resulting emulsion has been studied. It is shown that emulsions are considered to be non-Newtonian fluids with apparent elastic properties at oil concentration less than 35 vol%. All other things being equal, the average droplet size in the emulsion increases with an increase in the base oil viscosity. The use of ultrasonic treatment makes it possible to reduce the average droplet size in the emulsion by 4.5 times and to reduce its viscosity by 1.5 times.

Experimental investigation of flow and pressure drop characteristics of air-oil slug flow in a horizontal tube

This study examines two-phase flow and pressure drop characteristics associated with slug flow in a tube with an inner diameter of 4 cm. Experiments are conducted using air and low viscosity mineral oil as working fluids at atmospheric pressure and two different oil temperatures, 25 and 45°C. The superficial gas and liquid velocities are in the range of 0.33–2.43 m/s and 0.20–1.20 m/s, respectively. Flow visualization images and temporal records of pressure drop oscillation are presented for different gas and liquid superficial velocities. The relevant flow parameters associated with slug flow, such as the elongated bubble velocity, elongated bubble length, liquid slug length, and liquid film thickness, are measured, and the relationship between the slug flow parameters and the superficial gas and liquid velocities is investigated. The measured pressure gradient data are also compared to predictions of previous homogeneous equilibrium models and semi-empirical correlations for two-phase frictional pressure gradient. A theoretical slug flow model for predicting the total pressure gradient of slug unit is presented using empirical correlations for the slug flow parameters. The new model accurately predicts the experimental pressure gradient data, evidenced by an overall mean absolute error of 19.3%.

Towards the direct validation of computational lubrication modelling of hip replacements

This study attempted to provide insights into validating computational lubrication modelling of hip replacements. Direct comparisons between experimental measurements and numerical simulations were conducted for the central film thickness in a CoCr-on-glass hip bearing pair. A low-viscosity mineral oil and a 25% bovine serum were used as lubricants, respectively. Results indicated that for the low-viscosity lubricant case, the film thicknesses predicted by the computational model were comparable to the experimental measurements. For the bovine serum case, the computational results did not agree with those measured by experiments due to the viscosity model adopted in the computational models. A new effective viscosity equation was proposed to accurately predict the lubrication performance of hip replacements for protein-containing lubricants under transient conditions.

A simple method for the production of fuel and fuel additives from renewable low-viscosity mineral oils (Number-10 oil) and their mixtures

In this study, the production of fuel and fuel additives from low-viscosity waste renewable mineral oils, called number-10 oil in Turkey, and also of their mixtures, was investigated in detail. The direct addition of these oils and their blends to diesel cause clogging of the fuel pumps of the vehicles due to the crystallization of the waxes present in them, especially at low temperatures. Because of this congestion in the pump, the fuel cannot be pumped to the injectors properly at a constant pressure; this results in incomplete combustion of the fuel, which causes environmental pollution. This problem was solved by developing a simple, economical and environmentally friendly process. It was achieved by blending these oils or their mixtures with suitable solvents and by setting the total oil/total solvent ratio to be at least 1/3 (w/w). Once these oils were blended with suitable solvents or their mixtures, and when the total oil/total solvent ratio was adjusted to be at an optimum, it was noticed that there was no wax crystallization even at very low temperatures down to −35 °C. If these mixtures are prepared using these guidelines, they can be used as fuel or fuel additives in diesel- or gasoline-consuming vehicles without causing air pollution and without reducing the performance of the vehicles, while providing fuel savings up to 15%.

Application of waste polypropylene bags as filter media in coalescers for oily water treatment

The polypropylene fibers have been used in bed coalescers for separation of micro-sized oil droplets from water for a long time. Possibilities of applying different forms of polypropylene as filter beds are still being in the focus of many researches. The possibility of applying waste polypropylene bags used for packing vegetables (PPDJ) was investigated in this paper. The results are compared with results obtained by applying waste polypropylene fibers from carpet production (PP). It is well known that there are difficulties to separate the oils of low viscosity by polymer fiber beds. Due to the above mentioned, the presented research refers to separation of low viscosity mineral oil from water. The obtained experimental results confirm that the material PPDJ could be efficiently used as a bed material for coalescers. The critical velocity of 50 m h-1 could be reached at using both polypropylene forms that is from bags PPDJ and from the carpet industry PP, when the adequate bulk density of materials is used.

Mineral oil viscosity affects the osmotic pressure of human embryonic culture medium microdrops in non-humidified incubators

Humidified incubators are widely used for culturing human embryos. However, the use of non-humidified benchtop incubators is becoming more common due to their smaller size and lower risk of fungal contamination. We previously reported that the osmotic pressure of culture media increased more than 20 mOsm/kg after continuous culture for five days in non-humidified incubators. Microdrops of culture medium are typically covered with mineral oil, which prevents changes in the medium's osmotic pressure, pH and temperature. Although several types of mineral oils are commercially available, it is unknown how the different types affect culture conditions. In this study, we examined how different mineral oil viscosities influenced the osmotic pressure of culture media in non-humidified incubators. Basic Clinical Study. We prepared 18 culture dishes containing six 50-μl microdrops of single-step medium (265 ± 10 mOsm/kg). Dishes were divided into three groups: A, light oil (10.8 mPa/sec at 37°C); B, heavy oil (36.5 mPa/sec at 37°C); and C, washed oil (10.4 mPa/sec at 37°C), and placed in a non-humidified benchtop incubator for six days. The osmotic pressure of one dish per group was measured daily using an osmometer. Student t-tests were used for statistical analyses. The osmotic values for each group are expressed as the mean ± S.D. In group A, the osmotic pressure increased from 268.4 ± 0.5 mOsm/kg (day 0) to 280.5 ± 0.5 mOsm/kg (day 3), and then 300.7 ± 2.4 mOsm/kg (day 6). The osmotic pressure in group B rose from 267.6 ± 0.5 mOsm/kg (day 0) to 275.6 ± 1.1 mOsm/kg (day 3), and then 286.8 ± 1.3 mOsm/kg (day 6). As with group B, the osmotic pressure in group C elevated from 267.6 ± 0.5 mOsm/kg (day 0) to 276.8 ± 0.8 mOsm/kg (day 3), and then 287.8 ± 0.4 mOsm/kg (day 6). These results showed that the osmotic pressure of microdrops covered by light oil significantly increased on day 3 onwards compared to that of microdrops covered by heavy oil (P < 0.01). Elevations in osmotic pressure are minimized by using heavy or washed mineral oils. Low-viscosity mineral oil significantly increased the osmotic pressure of culture medium after three days in a non-humidified incubator. However, our results also showed that the osmotic pressure of culture media will inevitably increase in non-humidified incubators regardless of the viscosity of the mineral oil. Therefore, depending on the types of mineral oil, culture media, culture period and incubators used, it may be possible for the osmotic pressure of culture media to exceed the optimal culture environment threshold for human embryos. Although in vitro culture is essential for ART programs, this system is unstable and insufficient compared to the in vivo situation. To more closely align the ART in vitro culture environment to that found in vivo, we must focus on optimizing the materials available to us.

Effect of Base Oil Composition on the Low-Temperature Properties of Polyurea Greases

The influence of the base oil composition on the low-temperature properties of polyurea grease has been studied. Low-viscosity mineral, hydrotreated, and synthetic polyalphaolefin base oils have been used as a dispersion medium for polyurea grease samples. The fractional and group compositions of these base oils have been determined. The effect of the fractional and group compositions on the thickening power of the polyurea thickener and on the low-temperature and tribological properties of the lubricating greases has been examined.

Influence of the ultrafine oil additives on friction and vibration in journal bearings

In order to study the influence of ultrafine additives on hydrodynamic lubrication in journal bearings, this paper combines experimental and simulative approaches. The lubricants׳ samples were obtained by means of adding the fullerene black, fullerenes, molybdenum disulfide and fluoropolymer in quantity no higher than 0.05% of the mass in base low-viscosity mineral oil. The experiment was made during the run-down of the rotor, and we measured the friction coefficient in the journal bearing and the vibrations of its housing. The simulation model based on the developed methodology of setting and solving of the variational problem, allowed to explain and reproduce the results of the experiment. Ultrafine additives significantly decreased the load-carrying capacity and the friction coefficient in the journal bearing, as well as the vibration level in the bearing. The rate of lowering of friction and vibration directly depended on the level of pseudoplastic properties of the sample. The best results were shown by samples with fullerene black and fluoropolymer.

Experimental investigation of deep drawing of C-rail benchmark using various lubricants

This paper deals with the deep drawing of C-rail experimental benchmark, which has a complex deformation path. The influence of various lubricants, including the dry friction, low and high viscosity mineral oil, semisolid grease and PTFE film on the drawability of dual-phase steel sheets, was performed. The digital image correlation technique was applied for component tests as well as the deformation analysis. The drawability was experimentally assessed by comparing surface roughness, thickness reduction, and springback of drawn component. The experimental results indicate that the interfacial lubrication between tools and work-piece plays an important role on the drawability of advanced high strength steel sheets. The quality of component was improved obviously by using PTFE film compared to the other lubricants.

Comparative toxicokinetics of low-viscosity mineral oil in Fischer 344 rats, Sprague–Dawley rats, and humans – Implications for an Acceptable Daily Intake (ADI)

Oral repeated-dose studies with low-viscosity mineral oils showed distinct species and strain differences, which are hypothesized to be due to differences in bioavailability, with Fischer 344 rats being more susceptible than Sprague–Dawley rats or dogs.Sensitive analytical methodology was developed for accurate measurement of low levels of mineral hydrocarbons and applied in single-dose toxicokinetics studies in rats and humans. Fischer 344 rats showed a 4-fold higher AUC0–∞ and consistently higher blood and liver concentrations were found than Sprague–Dawley rats. Hepatic mineral hydrocarbon concentration tracked the blood concentration in both strains, indicating that blood concentrations can serve as functional surrogate measure for hepatic concentrations. In human volunteers receiving 1mg/kg body weight of low-viscosity white oil, all blood concentrations of mineral hydrocarbons were below the detection limit. Comparison with threshold blood concentrations associated with NOAELs in both rat strains, indicate that the margin-of-exposure is at least 37-fold. Using an internal dose metric rather than applied dose reduces the uncertainty around the temporary ADI considerably since it intrinsically accounts for intra- and inter-species differences. The current data support replacement of the temporary ADI of 0.01mg/kg/day by a (permanent) ADI of at least 1.0mg/kg/day for low- and medium-viscosity mineral oils.

5219 鉱油潤滑条件下におけるボールねじの油膜形成状態と玉の運動挙動(S65-5 潤滑膜計測技術,S65 トライボロジーの基礎と応用)

Using an electric resistance method, the authors measured the states of oil film formation during one stroke of the improved type ball screw which incorporates resin retaining pieces between balls. As lubricating oil, two kinds of mineral oil with much different viscosity were used. The screw shaft is rotated in the range of 120rpm〜950rpm. The results were compared with the experimental results in the grease lubricated condition. In the case of the high viscosity mineral oil, the oil film between balls and raceways was formed sufficiently even at a lower shaft speed of N=120rpm. On the other hand, the oil film formation with the low viscosity mineral oil or with the grease was influenced by the rotating speed of screw shaft. Using a magnetized ball and hall elements, the ball motion in ball screw was also measured, and the relationship between the ball motion and the oil film formation was discussed.

Liquid Vortex Shielding for Fusion Energy Applications

Swirling liquid vortices can be used in fusion chambers to protect their first walls and critical elements from the harmful conditions resulting from fusion reactions. The beam tube structures in heavy ion fusion (HIF) must be shielded from high energy particles, such as neutrons, x-rays and vaporized coolant, that will cause damage. Here an annular wall jet, or vortex tube, is proposed for shielding and is generated by injecting liquid tangent to the inner surface of the tube both azimuthally and axially. Its effectiveness is closely related to the vortex tube flow properties. 3-D particle image velocimetry (PIV) is being conducted to precisely characterize its turbulent structure. The concept of annular vortex flow can be extended to a larger scale to serve as a liquid blanket for other inertial fusion and even magnetic fusion systems. For this purpose a periodic arrangement of injection and suction holes around the chamber circumference are used, generating the layer. Because it is important to match the index of refraction of the fluid with the tube material for optical measurement like PIV, a low viscosity mineral oil was identified and used that can also be employed to do scaled experiments of molten salts at high temperature.

軸受鋼ローラの転がり疲れ : TEHL理論による検討(OS13-2 一般講演(II))

Using a two-roller testing machine, the rolling contact fatigue life of bearing steel rollers with mirror-like smooth surfaces was examined. A pair of rollers were driven under the rolling with sliding condition of s=-3.2%, and a maximum Hertzian stress in the range of PH=3.0GPa〜4.0GPa was applied in point contact condition. As lubricant, a low viscosity synthetic traction oil with viscosity grade of ISO VG 32 was used, and the test results were compared with those obtained using a low viscosity mineral oil with almost the same viscosity grade. Consequently, the fatigue life with a low viscosity traction oil was shorter than that with a low viscosity mineral oil, and this tendency appeared more distinctly under higher stress conditions above PH=3.4GPa. Based on the numerical calculation results of the thermal EHL, the authors discuss the mechanism which causes such a difference in the fatigue life.

Viscosity and binder composition effects on tyrosinase-based carbon paste electrode for detection of phenol and catechol

The systematic study of the effect of binder viscosity on the sensitivity of a tyrosinase-based carbon paste electrode (CPE) biosensor for phenol and catechol is reported. Silicon oil binders with similar (polydimethylsiloxane) chemical composition were used to represent a wide range of viscosities (10–60 000 mPa s −1 at 25°C) while minimizing polarity effects. The highest response for both phenol and catechol was achieved using a silicon oil binder of intermediate viscosity (100 mPa s −1). The binder viscosity showed no appreciable effect on the direct oxidation of phenol and catechol using a plain CPE, suggesting the involvement of diffusion kinetics in the binder matrix for the enzyme-based CPE. The effect of the relative binder concentration in the carbon paste was measured over the range of 30–70%. Optimal results were obtained using 40% silicon oil. For comparison of the viscosity effects observed with the carbon paste electrode (CPE) containing silicon oil, other low and high viscosity mineral oils and paraffin waxes were also examined.

The States of Oil Film Formation and Running Performance of Deep Groove Ball Bearings under Combined Loads.

Using an electric resistance method, the authors monitored continuously the state of oil film formation during operation of the type 6008 deep groove ball bearing under variously combined radial and axial loads. As lubricants, two kinds of mineral oils with nuch different viscosity grade were used. As a result of calculation, it was found that the extent of the loading zone and the increase in the normal load become remarkable in the case of a deep groove ball bearing as the axial load increases. In the running tests, it was shown that the increase of axial load has a large effect on the state of oil film formation of the deep groove ball bearing. Furthermore, it was recognized that the extent of the loading zone has a close relation to the coefficient of friction and the slip ratio of separator. When a low viscosity mineral oil was used, the load distribution had a significant effect on the state of oil film formation and on the running performance under the combined loads as compared with a higher viscosity mineral oil.

Size Distribution of Mist Generated During Metal Machining

Mist generated by machining processes is formed by three mechanisms: impaction, centrifugal force, and evaporation/condensation. This study characterized the size distribution of soluble and mineral oil mists that resulted from these formation mechanisms. Salient parameters influencing the particle size distributions also were identified. Variables investigated included metalworking fluid and machining characteristics. The size distribution of the mist generated on a small lathe by each mechanism was measured using an Aerosizer LD. For impaction, only the mineral oil viscosity influenced the mass median diameter of the mist. No parameter affected the geometric standard deviation. High-viscosity mineral oil mist had a mass median diameter of 6.1 microns and a geometric standard deviation of 2.0. Low-viscosity mineral oil mist had a mass median diameter of 21.9 microns and a geometric standard deviation of 2.2. The mass median diameter of the mist generated by centrifugal force depended on the type of metalworking fluid, fluid flow, and rotational speed of the lathe. Mass median diameters for low-viscosity mineral oil mist ranged from 5 to 110 microns. Mass median diameters for soluble oil mist varied between 40 and 80 microns. The average geometric standard deviation was 2.4, and was not affected by any parameter. The mass median diameter and geometric standard deviation of the mist generated by evaporation/condensation varied with the type of metalworking fluid. The mineral oil mist and soluble oil mist mass median diameters were 2.1 microns and 3.2 microns, respectively. No machining or fluid parameter was important because the mist size distribution depended on the rate of condensation, coagulation processes, and the dynamics of the apparatus. Using the size distribution data from all three mechanisms, the estimated inhalable, thoracic, and respirable fractions of the total mass generated for each metalworking fluid were 60 percent, 12 percent, and 8 percent, respectively. To minimize exposure to the inhalable mass fraction, the amount of mist generated by centrifugal force must be reduced or the size of the drops generated must be increased. Altering the machining or fluid parameters did not change the mist size distribution and reduce exposure to the respirable mass fraction.

Surface preparation for the LDH test

The present work is aimed at developing a surface preparation technique that reduces or eliminates random variations often found in the limiting dome height (LDH) test without diminishing the ability of the test to discriminate between different batches of material. Degreasing with a nonpolar solvent (mineral spirits) followed by the application of a low viscosity mineral oil (mineral seal oil) gave the best results and was adopted as a standard. With this preparation, the LDH was as low as with sheets degreased with chlorinated solvents, while scatter was reduced. Surfaces prepared by wiping with a clean towel gave higher LDH values, corresponding to a surface coated with SAE 30 oil. None of the preparation methods could completely eliminate or mask residual films left by oils compounded with boundary or EP additives. Day-to-day variations were evident with all preparation techniques employed over a period of three months. However, when all LDH means were plotted as a function of sheet location in the coil, the means defined a curve which—within the limited coil length represented by the total sample quantity available—had a period of about 15 m (45 ft). Thus, random variations observed in the laboratory and press shop can be attributed to small variations in mechanical properties, revealed by the great sensitivity of the LDH test and not necessarily detectable by tensile tests. Surface preparation may contribute to random variations but such contribution can be eliminated by the standard preparation technique.

Cell transformation and promoter activity of insulation oils in the Syrian hamster embryo cell and in the C3H/10T1/2 mouse embryo fibroblast test systems.

The ability of mineral-oil-based and synthetic cable insulating fluids to transform and promote transformation of mammalian cells in vitro have been studied. In experiments with the Syrian hamster embryo cell transformation assay, it was found that C15-C18 alkylbenzenes were the most potent inducers of transformation, followed by low-viscosity and residual mineral oils. No activity and low cytotoxicity were found for a low-viscosity polyisobutylene-based oil. In the two-stage transformation assay of C3H/10T1/2 cells, promoter activity was obtained with all fluids tested. A blend of residual and low-viscosity mineral oils showed the highest activity. This oil possessed a low cytotoxicity and was tested at a relatively high concentration. The alkylbenzenes were more potent than the polyisobutylene-based fluid. The alkylbenzenes were also found to possess initiating activity in the two-stage assay, when 12-O-tetradecanoylphorbol 13-acetate (TPA) was used as promoter. All the fluids showed low potency compared to benzo[a]pyrene and the tumor promoter TPA.

Effect of lubricant fluid on plastic metal flow in sliding contact

Plastic metal flow in surface layers, especially “abnormal metal flow”, in which the direction of metal flow in the inner surface layer is different from that in the layer nearer the surface, in sliding contacts between a pin of cemented carbide and a ring of steel under lubrication is discussed in this paper. Low viscosity mineral oil is used as a base oil. Sulphide and chloride extreme pressure additives are also mixed with the base oil. Such a lubricant has a great influence on the plastic metal flow of a ring. While base oil produces severe plastic metal flow, the sulphide additive causes the plastic metal flow to be very mild. In contrast, a lubricant containing a chloride additive causes abnormal metal flow, where cracks can be seen. Conditions for and causes of abnormal metal flow are investigated.