Dispersed Oil Research Articles

Sandwich-like tribofilm induced highly effective lubrication for MoDTP coupled with hydroxy-magnesium silicate (MSH)

In the field of lubrication enhancement, nanomaterials are becoming increasingly important. However, the issue of their stable dispersion in lubrication oil remains a persistent challenge. To address this issue, we synthesized two distinct morphologies of MSH nanomaterials, subsequently modifying them with alkylsilane (OTMS) to enhance their dispersion stability. Particularly, the 1.0 wt% of OTMS-modified laminar MSH (LMSH@OTMS) combined with 0.3 wt% molybdenum dialkyldithiophosphate (MoDTP) exhibited remarkable lubricating performance in PAO10. The result indicate there is a synergistic effect between two components, resulting in the formation of a main sandwich-like tribofilm. The tribofilm is comprised of two distinct layers: a lubricating layer derived from MoDTP and an anti-wear layer stemming from LMSH@OTMS. These findings offer significant potential for enhancing durability of mechanical systems.

New surfactants based on soybean oil triglycerides, hexamethylenediamine and alkyl dihalides

The interaction of soybean oil triglycerides with hexamethylenediamine resulted in a nonionic surfactant – hexamethyleneamide of a mixture of soybean oil acids, which was then modified using alkyl dihalides (1,2-dibromoethane, 1,3-dibromopropane, and 1,5-dibromopentane). These reactions synthesized ionic surfactants. The composition and structure of the resulting amidoamine and its modifications with alkyl dihalides were identified using infrared spectroscopy. The obtained products were characterized by key physicochemical parameters. Conductometric measurements of aqueous solutions of the obtained salts with varying concentrations were also performed. It was found that with increasing concentration, the specific conductivity value increases, and these values are significantly higher than the specific conductivity of distilled water, indicating the ionic structure of the obtained substances. Surface activity was measured with a tensiometer using the Du Nouy ring method at the air-water interface. According to the determined surface tension values, surface tension isotherms were constructed. The stabilization of surface tension values for the nonionic surfactant occurs at 35.2 mN/m, while for the ionic surfactants, it occurs at values of 34.2, 34.0, and 33.2 mN/m, respectively. The colloid-chemical properties of the synthesized surfactants were studied, their adsorption characteristics were experimentally determined, and the most important colloid-chemical parameters were calculated, such as the critical micelle concentration, surface tension, maximum adsorption, minimum cross-sectional area of the molecule, surface pressure, adsorption efficiency, and the change in Gibbs free energy of the micellization and adsorption processes. Under laboratory conditions, the relative oil-collecting and oil-dispersing abilities of the obtained products were investigated using thin films (thickness <1 mm) of Balakhani oil on the water surface with different levels of salinity (seawater, freshwater, and distilled water). The synthesized surfactants were used in undiluted form and as 5% aqueous solutions. It was found that in seawater, the maximum oil dispersion coefficient, which indicates the degree of cleaning the water surface, is 91.1%. It is worth noting that transitioning from nonionic to ionic surfactants increases the duration of the reagents’ action.

Modeling of electromagnetic wave reflection from wet soil taken into account of dispersion, heterogeneity and surface roughness

Background. Taking into account temperature, soil composition, surface roughness and the dependence of effective dielectric constant on frequency allows a more accurate assessment of soil moisture and other important parameters, which can be used in various fields such as agriculture, geology, ecology and hydrology. Aim. In this work, we calculate the reflection of a linearly polarized electromagnetic wave from wet soil, taking into account such physical factors as heterogeneity of soil structure, surface roughness and dispersion. Methods. Based on a heterogeneous mathematical model of wet soil, taking into account the dispersion of the dielectric constant of water and surface roughness, expressions are derived for the complex reflection coefficients of electromagnetic waves of vertical and horizontal polarization. Results. The model of loose wet soil with the standard deviation of roughness on the surface was chosen as the object of study. An analysis of the frequency and angular characteristics of the modules of the reflection coefficients was carried out at a fixed level of soil moisture. Conclusion. The data obtained as a result of the calculations is a valuable tool for further improving methods of remote sensing of the Earth and contributes to the development of new technologies for monitoring soil parameters using unmanned aerial vehicles, which opens up prospects for more accurate and efficient analysis of the state of land resources and ecosystems.

Dispersion Stability and Oil Displacement Effect of Modified Black Nanosheet

Dispersion Stability and Oil Displacement Effect of Modified Black Nanosheet

Aureobasidium pullulans formulations: evaluation of the effectiveness against grey mould of table grape

Antagonism against Botrytis cinerea is often carried out using yeast as direct antagonists. Aureobasidium pullulans strain AP1 was tested in two different formulations: wettable powder (WP) and oil dispersion (OD). By in vitro assays, the viability of the strain cells was constantly evaluated for seven months and the OD formulation ensured the highest cells viability. The efficacy of the formulations was assayed by evaluating the production of volatile and non-volatile metabolites. Results showed that the formulation affected the non-volatile less than the volatile metabolites. Both AP1 WP and AP1 OD non-volatile metabolites displayed almost 50% of mycelial pathogen inhibition. Comparing the two products, the lowest EC50 value (518.15 mg L− 1) was detected for the AP1 OD formulation that was thus chosen for postharvest in vivo assays. The preventative treatments (200, 400, 800 mg L− 1) were active in reducing the pathogen incidence on table grape on average by 52%. Instead, in the curative application assay, the highest concentration (800 mg L− 1) reduced grey mold incidence by 86%. The present study reported the potential of two new formulations to use against the postharvest grey mold of table grape for a possible further commercial product development.

Effects of synthetic site water on bentonite-concrete system for a potential nuclear waste repository

In high-level nuclear waste (HLW) repositories, concrete and compacted bentonite are designed to be employed as buffer materials, which may raise a problem of interactions between concrete and bentonite. These interactions would lead to mineralogy transformation and buffer performance decay of bentonite under the near field environment conditions in a repository. A small-scale experimental setup was established to simulate the concrete-bentonite-site water interaction system from a potential nuclear waste repository in China. Three types of mortars were prepared to correspond to the concrete at different degradation states. The results permit the determination of the following: (1) The macro-properties of Gaomiaozi (GMZ) bentonite (e.g. swelling pressure, permeability, the final dry density, and water content of reacted samples); (2) The composition evolution of fluids from the synthetic site water-concrete-bentonite interaction systems; (3) The sample characterization including Fourier transform infrared spectroscopy (FTIR) and X-ray powder diffraction (XRD). Under the infiltration of the synthesis Beishan site water (BSW), the swelling pressure of bentonite decreases slowly with time after reaching its second swelling peak. The flux decreases with time during the infiltrations, and it tends to be stable after more than 120 d. Due to the cation exchange reactions in the BSW-concrete-bentonite systems, the divalent cations (Ca and Mg) were consumed, and the monovalent cations (Na and K) were released. The dissolution of minerals in the bentonite such as albite causes Si increasing in the pore water. It was concluded that the hydro-mechanical property degradation of bentonite takes place when it comes into contact with concrete mortar, even under low-pH groundwater conditions. The soil dispersion, the uneven water content, and the uneven dry density in bentonite samples may partly contribute to the swelling decay of bentonite. Therefore, the direct contact with concrete has an obvious effect on the performance of bentonite.

Study on the Flow Characteristics of Heavy Oil-Water Two-Phase Flow in the Horizontal Pipeline.

Aiming at the problem of transportation for heavy oil during the middle-later development stages of the Lvda oilfield, based on the self-developed design of a visual circulating flow experimental apparatus for heavy oil-water two-phase flow-the flow regime characteristics and corresponding drag properties of the two-phase flow of Lvda viscous oil, which is simulated by 500# industrial white oil and water in a horizontal pipeline are investigated experimentally. According to the Kelvin-Helmholtz instability theory, the flow pattern transition criteria from stratified flow to annular flow (AF) are proposed. The effects of 0.11-0.90 m/s oil superficial velocities, 0.06-1.49 m/s water superficial velocities, and 0.09-0.93 input water cuts on the drag reduction effect of different flow regimes are analyzed. The experimental results indicated that with the increase of mixing velocity and water volume fraction, stratified flow, AF, oil plug flow, and dispersed oil lump flow are successively observed in the horizontal heavy oil-water two-phase flow, in which AF is the main flow pattern. As the Froude number increases to 4.0, the input water volume fraction does not change any more and remains at about 10% of the total flow rate in the process of converting from stratified flow to AF. The four delivery approaches can archive the reduction of transportation resistance for heavy oil at different degrees, in which the transportation of heavy oil surrounded by a water ring has the best effect of drag reduction. At the optimal working conditions of 0.61 m/s oil superficial velocity, 0.07 m/s water superficial velocity, and 0.10 input water cut, the pressure drop of water annulus conveying for heavy oil is only 1/62.54 of that of separate transport for pure heavy oil under the same oil flow rate.

Characterization of the surface-active exopolysaccharide produced by Halomonas sp TGOS-10: Understanding its role in the formation of marine oil snow.

In this study, we characterize the exopolymer produced by Halomonas sp. strain TGOS-10 -one of the organisms found enriched in sea surface oil slicks during the Deepwater Horizon oil spill. The polymer was produced during the early stationary phase of growth in Zobell's 2216 marine medium amended with glucose. Chemical and proton NMR analysis showed it to be a relatively monodisperse, high-molecular-mass (6,440,000 g/mol) glycoprotein composed largely of protein (46.6% of total dry weight of polymer). The monosaccharide composition of the polymer is typical to that of other marine bacterial exopolymers which are generally rich in hexoses, with the notable exception that it contained mannose (commonly found in yeast) as a major monosaccharide. The polymer was found to act as an oil dispersant based on its ability to effectively emulsify pure and complex oils into stable oil emulsions-a function we suspect to be conferred by the high protein content and high ratio of total hydrophobic nonpolar to polar amino acids (52.7:11.2) of the polymer. The polymer's chemical composition, which is akin to that of other marine exopolymers also having a high protein-to-carbohydrate (P/C) content, and which have been shown to effect the rapid and non-ionic aggregation of marine gels, appears indicative of effecting marine oil snow (MOS) formation. We previously reported the strain capable of utilising aromatic hydrocarbons when supplied as single carbon sources. However, here we did not detect biodegradation of these chemicals within a complex (surrogate Macondo) oil, suggesting that the observed enrichment of this organism during the Deepwater Horizon spill may be explained by factors related to substrate availability and competition within the complex and dynamic microbial communities that were continuously evolving during that spill.

ON DEVELOPMENT OF OIL FIELDS

Using a literature review, the article concludes that the displacement of oil by surfactants affects interrelated factors: by affecting the surface tension at the oil-water-rock interface, SAM adsorption occurs on the surface of pore channels, rock surface water and oil wetting changes, the oil layer is broken up and washed from the rock surface, the dispersion of oil in water stabilizes, the phase permeability of the porous medium changes, and finally, the forced displacement of oil by the water phase occurs. Keywords: gravity, elastic, capillary forces, adhesion, adsorption.

Calcium ions and calcium carbonate: key regulators of the enzymatic mineralization for soil dispersivity control

Calcium ions and calcium carbonate: key regulators of the enzymatic mineralization for soil dispersivity control

Effects of metakaolin and zeolite on the dispersion properties and shear strength of dispersive clay soil

ABSTRACT The current study used metakaolin and zeolite either separately or in combination at 0%, 2%, 4%, 6% and 8% of the soil weight to improve dispersive clay soil at optimal humidity levels. The samples were tested to determine the extent of change in the dispersion potential, as well as improvements in the shear strength of dispersive clay soil. The dispersive soil was obtained near the city of Ardakan in Iran and the extent of change in its soil dispersion potential was evaluated after 7 days of curing. The results of the pinhole test indicated that the addition of 2% zeolite plus 8% metakaolin to the soil considerably decreased the dispersion potential. Uniaxial testing after 7, 14 and 28 days of curing revealed that the UCS of the samples increased. The greatest increase was observed in samples containing 2% zeolite and 8% metakaolin after 28 days of curing. The direct shear test was carried out after 7, 14 and 28 days of curing on the unmodified soil and soil modified with optimal percentages of metakaolin and zeolite. The combined addition of zeolite and metakaolin was found to increase the shear strength parameters of the samples.

Impact of wave action on the entrainment rate and droplet size of oil

Oil dispersed on the water surface undergoes fragmentation into droplets, subsequently entering the water column under wave action. The oil entrainment rate and the droplet size distribution (DSD) significantly influence the subsequent migration and transformation of oil in the water column. A wave tank system was employed to investigate the impact of wave action on oil entrainment rate and DSD. The experimental results revealed that increased wave height and wave frequency facilitated the entry of oil into the water column and fragmented it into dispersed droplets. Relationships between oil entrainment rate and energy dissipation, as well as DSD, were established and supported by mathematical regression analyses. Non-linear regression analysis indicated that the cumulative frequency distribution of DSD adhered to the Log-Normal and Rosin-Rammler distributions. These findings contribute to a comprehensive understanding of natural oil dispersion and subsea transport, valuable for estimating the origin of oil spills.

Managing deepsea oil spills through a systematic modeling approach

Offshore oil exploration and production in deepwater are associated with environmental risks to marine ecosystems. This research introduces DWOSM (Deep Water Oil Spill Model), a three-dimensional Lagrangian model, which is developed to simulate the transport and fate of oil spills resulting from subsea blowouts. DWOSM comprises three interconnected modules: DWOSM-DSD, which predicts the oil droplet size distribution from a blowout release; DWOSM-NearField, simulating plume dynamics and tracking oil droplets within the plume region; and DWOSM-FarField, modeling the evolution of dispersed oil beyond the near-field. Compared to other oil spill models, this integrated approach improves the transition between near and far fields using a near-field particle tracking algorithm. It also employs the thermodynamic models to enable the prediction of oil properties under varying deep water pressure and temperature. To gauge the reliability and efficacy of DWOSM, a hypothetical case situated within a North American context is employed for model testing. The DWOSM and its each module are juxtaposed with other established oil spill models. The outcomes indicate that DWOSM yields comparable results to these models by providing reasonable predictions of a deepwater blowout. The model's verification through case scenario testing and comparison underscores its potential as a decision tool for assessing and managing the potential environmental impacts of offshore petroleum activities.

The role of soil dispersivity and initial moisture content in splash erosion: Findings from consecutive single-drop splash tests

Dispersive soil is commonly associated with hydraulic erosion due to its tendency to disperse when in contact with water. Nevertheless, the erosion process of dispersive soil remains poorly understood. This study aims to explore the influence of dispersivity and initial moisture content on the splash erosion of dispersive soil, which is a crucial stage of hydraulic erosion. Consecutive single-drop splash tests were conducted on artificially prepared dispersive soil (made by adding sodium carbonate to the soil) with varying dispersivity levels and moisture contents. A high-speed and a single-lens reflex (SLR) camera were employed to capture the process of erosion in exquisite detail. The results demonstrated the significant influence of dispersivity on splash erosion. At moisture content below 20%, increased dispersivity weakened the splash erosion effect, leading to reduced infiltration, splashed soil mass, crater volume, and depth. Conversely, when the initial moisture content reached 20% or saturation, intensified dispersivity exacerbated splash erosion. Dispersivity also increased the sensitivity of the soil splash process to changes in moisture content. Dispersive soil exhibited greater sensitivity compared to non-dispersive soil, affecting the mass of splashed soil, soil-water mixture droplets area, water-soil mass ratio, and particle ejection distance. Dispersivity also caused splashed particles to fragment, resulting in more soil-water mixture droplets and a greater splash distance. Furthermore, dispersivity reduced infiltration ratio and increased runoff yield after erosion events, indicating a higher risk of transporting splashed soil particles through runoff. These insights contribute to erosion models and have practical applications in managing dispersive soil.

Analysis of Dispersibility and Mechanical Properties of Lignin Modified Dispersive Soil

Dispersive soil is a kind of special soil with water sensitivity, which is easy to produce ravages such as gully and piping when encountering water in engineering. In order to improve the poor engineering properties of dispersive soil, a kind of lignin was selected to improve the dispersibility and mechanical properties of dispersive soil in western Jilin Province. Pinhole test, fragment test, unconfined compressive strength test and resistivity test were carried out on the improved soil samples with different lignin content. The results showed that lignin could significantly reduce the dispersibility of dispersive soil. With the increasing of curing time, the unconfined compressive strength of the improved soil samples increased gradually. With the increase of lignin content, the unconfined compressive strength of the improved soil first increased and then decreased, and the peak strength appeared when the lignin content was 3%. In the resistivity test, the resistivity of the improved soil decreased gradually with the increase of lignin content. Through microscopic analysis of lignin improved soil samples, it can be concluded that lignin fibers play a stereograin-like bridging role in soil, which promotes the formation of larger aggregates, weakens the dispersion of single soil particles, and thus reduces the dispersion of soil mass and improves the strength of soil mass. This study can provide a basis for the improvement of dispersive soil in seasonal freezing area and has practical engineering significance.

Rapid Investigation of Oil Pollution in Water-Combined Induced Fluorescence and Random Sample Consensus Algorithm

The global issue of oil spreading in water poses a significant environmental challenge, emphasizing the critical need for the accurate determination and monitoring of oil content in aquatic environments to ensure sustainable development of the environment. However, the complexity arises from challenges such as oil dispersion, clustering, and non-uniform distribution, making it difficult to obtain real-time oil concentration data. This paper introduces a sophisticated system for acquiring induced fluorescence spectra specifically designed for the quantitative analysis of oil pollutants. The paper involved measuring the fluorescence spectra across 20 concentration gradients (ranging from 0 to 1000 mg/L) for four distinct oil samples: 92# Gasoline, Mobil Motor Oil 20w-40, Shell 10w-40 engine oil, and Soybean Oil. The research focused on establishing a relationship model between relative fluorescence intensity and concentration, determined at the optimal excitation wavelength, utilizing the segmented Random Sample Consensus (RANSAC) algorithm. Evaluation metrics, including standard addition recovery, average recovery, relative error, and average relative error, were employed to assess the accuracy of the proposed model. The experimental findings suggest that the average recovery rates for the four samples ranged between 99.61% and 101.15%, with the average relative errors falling within the range of 2.04% to 3.14%. These results underscore the accuracy and efficacy of the detection methodology presented in this paper. Importantly, this accuracy extends to scenarios involving heavier oil pollution. This paper exhibits exceptional sensitivity, enabling precise detection of diverse oil spills within the concentration range of 0~1000 mg/L in water bodies, offering valuable insights for water quality monitoring and sustainable development of the environment.

Prediction of characteristics of soil-concrete massifs created by injection of extremely finedispersed binders (microcements)

The urgency of the problem associated with the use of injection erection technology of soil cementation in various engineering and geological conditions is substantiated. Due to the peculiarities of cementation technologies under various modes of injection impregnation and the possibility of applying certain technical injection parameters for different types of soils, it is possible to improve various deformation characteristics of the soil mass when implementing the technology. Some results of the analysis of the work of injection cementation of soils in dispersed soils are presented and general patterns are established under which it is necessary to adjust the parameters of cementation. The theoretical prerequisites are considered in relation to experimental data, the effectiveness of the application of cementing technology in the injection impregnation mode is proved and the general applicability of the application of these cementing methods with an increase in the technical indicators of the fixed soils is established.

Priority sites for coral aquaculture in Kume Island based on numerical simulation

Global and local stresses such as increased water temperature and terrestrial sediment runoff significantly affect coral reef ecosystems. Over the past three decades, the increase in the intensity and frequency of coral bleaching has been a significant problem in tropical and subtropical coastal seas, and maintaining healthy coral reef ecosystems has long been a challenge. Coral cover in Shimajiri Bay on Kume Island, located in the Nansei Islands (Okinawa Prefecture, southern Japan), has declined due to exposure to high water temperatures, an outbreak of coral predators, and sediment (red soil) inflow from the land. From such a background, coral aquaculture has been implemented at a few stations in the bay. Therefore, it is essential to conduct aquaculture in suitable locations for coral growth and survival. This study aimed to select suitable locations for coral culture with high spatial resolution in an enclosed bay that was greatly affected by red soil runoff, mainly from a sugarcane field. A freshwater and red soil runoff model for the watershed was merged with a coastal hydrodynamic, red soil dispersal, and accumulation model at a spatial resolution of 75 m for Shimajiri Bay. The simulation results were validated using in situ continuous and routine observations. Simulations were conducted over ten years. Locations not subjected to high water temperature in the bay or river loading were selected based on topography, simulated water temperature, salinity, and red soil content of sea sediment. This coupled model enables us to evaluate the growth and survival conditions of cultured corals with high spatiotemporal resolution and quantitatively consider the reduction target of red soil runoff to realize robust coral growth and survival.

Revolutionizing Crop Nutrition: Exploring Nano Fertilizers in Agriculture

Revolutionizing Crop Nutrition: Exploring Nano Fertilizers in Agriculture

Analysis of the modification of piping channels on kaolinitic clayey samples in the pinhole test

Dispersivity is a severe pathology that occurs mainly in clay soils and is usually catastrophic in geotechnical structures susceptible to this damage. Hundreds of dams worldwide have failed due to quality problems, mainly by piping in the body, foundation, spillway, culvert, and other peripheral structures. The pinhole test is currently considered the most accurate test for detecting the dispersivity of clay soils. However, it presents problems when objectively evaluating the dispersivity of a material due to the qualitative nature of the estimation of results. In particular, the methodology for determining turbidity has been identified. This document studies different piping paths in the sample, which a priori may be more realistic than the single path in the current test. A kaolinitic clay, widely studied through index and mineralogical tests, is used as the base material. Regarding the detection of dispersivity, a specialized test package was used to reduce the uncertainty of the results. Natural samples were analyzed using ASTM D4647-13. A modification of the pinhole test was proposed based on the imposition of additional artificial channels. The results revealed that this modification can make the test more realistic because when the dispersive front advances in the soil, it does not travel along a single path but instead looks for different erosive paths. The details of this assertion are discussed throughout the paper.