Surface Oil Research Articles

The Effect of Surface Oil on Ocean Wind Stress

This study provides, to the best of our knowledge, the first detailed analysis of how surface oil modifies air–sea interactions in a two-way coupled model, i.e., the coupled–ocean–atmosphere–wave–sediment–transport (COAWST) model, modified to account for oil-related changes in air–sea fluxes. This study investigates the effects of oil on surface roughness, surface wind, surface and near-surface temperature differences, and boundary-layer stability and how those conditions ultimately affect surface stress. We first conducted twin-coupled modeling simulations with and without the influence of oil over the Deepwater Horizon (DWH) oil spill period (20 April to 5 May 2010) in the Gulf of Mexico. Then, we compared the results by using a modularized flux model with parameterizations selected to match those selected in the coupled model adapted to either ignore or account for different atmospheric/oceanic processes in calculating surface stress. When non-oil inputs to the bulk formula were treated as being unchanged by oil, the surface stress changes were always negative because of oil-related dampening of the surface roughness alone. However, the oil-related changes to 10 m wind speeds and boundary-layer stability were found to play a dominant role in surface stress changes relative to those due to the oil-related surface roughness changes, highlighting that most of the changes in surface stress were due to oil-related changes in wind speed and boundary-layer stability. Finally, the oil-related changes in surface stress due to the combined oil-related changes in surface roughness, surface wind, and boundary-layer stability were not large enough to have a major impact on the surface current and surface oil transport, indicating that the feedback from the surface oil to the surface oil movement itself is insignificant in forecasting surface oil transport unless the fractional oil coverage is much larger than the value found in this study.

Underwater Acoustic Technology-Based Monitoring of Oil Spill: A Review

Acoustic monitoring is an efficient technique for oil spill detection, and the development of acoustic technology is conducive to achieving real-time monitoring of underwater oil spills, providing data references and guidance for emergency response work. Starting from the research background of oil spills, this review summarizes and evaluates the existing research on acoustic technology for monitoring underwater oil spills. Underwater oil spills are more complex than surface oil spills, and further research is needed to investigate the feasibility of acoustic technology in underwater oil spill monitoring, verify the accuracy of monitoring data, and assess its value. In the future, the impact mechanism and dynamic research of acoustic technology in oil spill monitoring should be explored, and the advantages and differences between acoustic technology and other detection techniques should be compared. The significance of auxiliary mechanisms combined with acoustic technology in oil spill monitoring should be studied. Moreover, acoustic research methods and experimental techniques should be enriched and improved to fully tap into the future value of acoustic technology.

Application and prospects of multi-phase pipeline simulation technology in empowering the intelligent oil and gas fields

This paper reviews the application of multiphase flow simulation technology for constructing intelligent oil and gas fields. By utilizing the theoretical multiphase flow simulation model and solution algorithm, the practical engineering application of this technology in various oil and gas gathering and transportation system scenarios, including subsea production systems in offshore oil and gas fields, well site gathering and transportation production systems in onshore gas fields, and platform gathering and transportation production systems, was assessed and described. In addition, the role of multiphase flow simulation technology in intelligent oilfield surface production was discussed from the perspective of surface oil and gas pipeline networks and intelligent oilfield operations. Moreover, the future development prospects of multiphase pipeline transport simulation technology were proposed, providing a reference for improving related research and constructing intelligent oilfields.

Oxidative stability of physiologically functional oil microencapsulated by spray drying

Edible oils with physiological functions, such as fish oil and krill oil, which contain polyunsaturated fatty acids (PUFAs), are highly unstable to heat and oxygen. One of the methods for improving the shelf life of these oils is microencapsulation of the oils through spray drying. This mini-review describes the effects of the surface–oil ratio, oil location within the microcapsules, and oil-droplet diameter on the oxidative stability of functional oils in microcapsules prepared through spray drying. The surface–oil ratio, s, can be expressed through the ratio of the average oil-droplet diameter to the average powder diameter, E, by s = 1 − (1 − 2E)3. Additionally, the effects of oil-droplet size and storage temperature on the stability of the encapsulated oil were examined using squalene as a model functional oil. The activation energy E a of the squalene degradation rate constant of the Avrami equation can be correlated with the average oil-droplet diameter d e. The release behavior of the microencapsulated flavors is also discussed because spray drying is also used for the microencapsulation of flavors. The flavor release rate constant of the Avrami equation is related to the oxygen diffusion coefficient of the wall material.

Storage Stability of Spray- and Freeze-Dried Chitosan-Based Pickering Emulsions Containing Roasted Coffee Oil: Color Evaluation, Lipid Oxidation, and Volatile Compounds

Drying Pickering o/w emulsions has been considered as a promising strategy to produce oil microcapsules, as long as their quality parameters can be preserved over storage. In this sense, it is shown as an interesting alternative to preserve the quality of roasted coffee oil, a valuable agroindustrial byproduct. Thus, freeze- and spray-dried chitosan-based Pickering emulsions of roasted coffee oil were evaluated over 30 days of storage at 25 °C together with the non-encapsulated oil as a control. Water sorption isotherms were determined, whereas color, oxidative stability (peroxide value and conjugated dienes) and volatile compounds were assessed over the storage period. Type II isotherms and Guggenheim–Anderson–Boer (GAB) model parameters showed that water binding was impaired by the surface oil in freeze-dried samples. Oxidation was maintained under acceptable values over the storage for all samples, with slightly higher protection also observed for volatile compounds in the spray-dried particles. The powdered emulsions were able to suitably preserve the oil’s quality over 30 days of storage, enabling its commercialization and application as a food ingredient and potential flavoring.

Coupled effects of misalignment and viscoelastic deformation on dynamically loaded journal bearings

Numerous studies on the lubrication characteristics of journal bearings with existing journal misalignment and bearing elastic deformation have demonstrated that both significantly affect the lubrication performance. Recent studies have also indicated that viscoelastic deformation is more useful than elastic deformation for determining the effects of strong impact loads caused by internal combustion engine detonation. However, studies involving the coupled effects of misalignment and viscoelastic deformation have not been reported yet. Therefore, this study proposes a novel transient lubrication model that couples the influences of journal misalignment and bearing viscoelastic deformation, considering the contact surface morphology and oil film cavitation effects. Based on the numerical model, the evolution of lubrication performance under transient time-varying dynamic load was revealed. The coupled influences of misalignment and viscoelastic deformation on the lubrication performance of dynamically loaded journal bearings were systematically investigated. The results show that the coupling of journal misalignment and viscoelastic deformation increases the probability of metal-to-metal contact. The difference in the coupling of misalignment and elastic deformation is exhibited in the distribution, amplitude, and occurrence phases of the performance parameters. Increasing the journal speed and applied load significantly enhances the coupled effects of journal misalignment and viscoelastic deformation on the lubrication performance. Under high speeds, heavy loads, and large and rapidly changing impact loads, the analysis considering the coupled effects of misalignment and viscoelastic deformation will be more accurate and realistic.

An Experimental Study of Surface Damage on Rolling Bearings in Low Lambda Conditions

In order to better understand the occurrence of surface damage in low lambda, Λ, conditions, an experimental study was conducted. The surface damage investigations have been made based on the relationship between Λ values and surface roughness. In this study, the ball roughness, rotational speed, and oil viscosity were varied to obtain a specific Λ value which ranges from 0.10 to 0.90. It was found that three different surface damage modes, namely wear, micro-pitting, and no damage occurred depending on the ball roughness and Λ value. Morphological cross-sectional of each damage mode were observed, and surface fatigue characteristics were identified. The experimental results have shown that surface fatigue, including plastic flow thickness and crack angle, are related to contact conditions, which are influenced by surface roughness and oil film thickness.

Sodium alginate edible coating to reduce oil absorption of French fries with maintaining overall acceptability: Based on a water replacement mechanism

The effect of sodium alginate (SA) coating on the oil content and quality of fries was evaluated, and the inhibitory mechanism of SA on oil absorption was analyzed based on the water replacement theory. Compared to uncoated samples, the penetrated surface oil (PSO), structure oil (STO), and total oil (TO) contents, a*, and b* of coated fries decreased, whereas moisture content, L* and hardness increased with no significant difference revealed by sensory evaluation of all samples. The water contact angle of the films correlated negatively with the water content and hardness of the fries. In contrast, it correlated positively with PSO, STO, and TO contents. The TO content of fries with 1 % SA film which had a compact microstructure, was the lowest, reduced by 52.5 % compared to the control sample. SA coating reduces the pores and roughness on the fries' surface, which inhibits the oil from penetrating into the samples. SA coating decreased the T21, T22, and pores of the starch, and increased the P2b, P21, relative crystallinity, and ΔH significantly (P < 0.05). Therefore, SA coating inhibits the oil absorption in fries by reducing water evaporation which is attributed to the increase in double helices and crystallinity of starch.

Physicochemical, Structural Structural and Functional Properties of Non-Waxy and Waxy Proso Millet Protein.

The physicochemical, structural and functional properties of proso millet protein from waxy and non-waxy proso millet were investigated. The secondary structures of proso millet proteins consisted mainly of a β-sheet and ɑ-helix. The two diffraction peaks of proso millet protein appeared at around 9° and 20°. The solubility of non-waxy proso millet protein was higher than that of waxy proso millet protein at different pH values. Non-waxy proso millet protein had a relatively better emulsion stability index (ESI), whereas waxy proso millet protein had a better emulsification activity index (EAI). Non-waxy proso millet protein showed a higher maximum denaturation temperature (Td) and enthalpy change (ΔH) than its waxy counterpart, indicating a more ordered conformation. Waxy proso millet exhibited higher surface hydrophobicity and oil absorption capacity (OAC) than non-waxy proso millet, suggesting that the former may have potential applications as a functional ingredient in the food industry. There was no significant difference in the intrinsic fluorescence spectra of different waxy and non-waxy proso millet proteins at pH 7.0.

Buried and surface oil degradation – Evaluating bioremediation to increase PAHs removal through linear mathematical models

A bioremediation approach with tide simulation for buried and surface oil degradation was tested for removal of two, three and four rings polycyclic aromatic hydrocarbons (PAHs). Linear models depicted degradation constants of individual PAH as simple additive function of their initial concentrations (C0) in contaminated sand, hydrophobicity, sampling layer and treatment conditions. For all PAHs and treatment conditions, the degradation of oil in buried layers was faster than at the surface. Naturally-occurring microorganisms proved to be efficient for bioremediation of PAHs and were stimulated by fertilizer addition (biostimulation, BS). Bioaugmentation (BA) by addition of a slurry of a native oil-degraders pre-stimulated consortium did not show faster PAH degradation than BS. Degradation was more rapid for PAH present at low C0 and with intermediate hydrophobicity. Bioremediation of beach sand either with surface or buried crude oil is a cost-effective strategy to clean-up different hydrocarbon families, including persistent ones, such as PAHs.

Co-encapsulation of resveratrol in fish oil microcapsules optimally stabilized by enzyme-crosslinked whey protein with gum Arabic

O/W emulsion and its spray-dried microcapsule contain the oil phase and the protein matrix, providing the potential to co-encapsulate different antioxidants. However, antioxidants were generally encapsulated in the oil phase of microcapsule, its protein matrix is rarely used. It is first to prove the possibility to encapsulate resveratrol in the emulsified oil droplets at high wall/core ratios. The optimal microcapsule with 1.75% surface oil was fabricated with 15% transglutaminase-crosslinked WPI (TGase-WPI) and 5% gum Arabic (GA). Resveratrol mainly located in the protein matrix of initial emulsion and reconstituted microcapsule. The effects of TGase-WPI/GA microcapsule and resveratrol co-encapsulation on DHA/EPA and lipid hydroperoxides/TBARS were different. The interfacial protein, the partition of resveratrol in the emulsified oil droplets and its storage stability and inhibitory effect on size change of reconstituted microcapsules increased as the polyphenol increased. These results expand the potential use of spray-dried microcapsules as co-encapsulation carriers.

Fortification of chocolate with microencapsulated fish oil: Effect of protein wall material on physicochemical properties of microcapsules and chocolate matrix

Protein stabilized fish oil microcapsules were incorporated into chocolates in order to design fortified product which could bear the nutritional claim “source of or high omega-3 fatty acids”. Protein wall material (soy, whey and potato) influenced microcapsules and chocolate performance. Soy protein resulted in the smallest microcapsules with the lowest content of surface oil. Peroxide values were low even after 14 days of microcapsules storage. Incorporation of microcapsules into chocolate led to increase in Casson viscosity and breaking force as well as decrease in melting enthalpy, due to prevalence of particle–particle over fat-fat interactions. Increase in microcapsules concentration resulted in chocolate with poorer snap and higher tendency to fat bloom formation. Whey protein microcapsules, having the largest diameter, resulted in chocolate with the lowest breaking force and melting enthalpy and the highest whitening index. In general, microcapsules addition did not require chocolate production modification and led to sensory acceptable product.

Tail-shake risks assessment &amp; mitigation by wind-tunnel tests on air-intake installation on a heavy-weight H/C configuration

AbstractIn this work, the key role of the upper-deck design including engine installation as a potential source of tail-shake is at focus. The work is based on a Wind-Tunnel Test (WTT) campaign performed at the Airbus Helicopters’ Marignane wind-tunnel facilities on a high-fidelity minibody fuselage at scale 1:3.5 representing a generic heavy-helicopter upper deck.Two different engine intake installations for a Power Unit (PU) have been investigated; in a first configuration, the air intake is implemented at the pylon-fairing trailing edge. The second configuration consists in positioning two air intakes on each side of the pylon fairing, close to the maximum cross-section location. Different measurement methods to evaluate aerodynamic interactions and wake sources are proposed: flow-separation assessments from surface oil flow visualisations, time-resolved Particle Image Velocimetry (PIV) measurements and unsteady skin-pressure measurements at the cowlings. Tail-shake-related indicators are then proposed. Basically, a configuration that produces strong vortices characterised by a broadband spectral signature is believed to gather all the conditions for tail-shake to emerge.The flow over the clean configuration is first analysed for various combinations of angle-of-attack and sideslip, highlighting four different areas of flow separation at the cowlings. The complex flow topology around the upper deck is then assessed, which includes a spectral analysis of the flow in the PIV planes. The influence of the air intakes (operating or not) is then evaluated. When located at the pylon-fairing trailing edge and operating, the air intake has a spectacular impact on the flow-field topology. It is responsible for the generation of an intense broadband wake interacting with the pylon-fairing lip vortices, which is believed to be a potential source of tail-shake. The second air-intake configuration is also not favourable, as it requires enlarging the pylon fairing by 100mm, which causes an intense wake similarly to a blunt body. At last, a mitigation mean is proposed for the first configuration. It demonstrates a significant reduction of the wake intensity and broadband signature at the source.

Encapsulation of Cumin (Cuminum cyminum L.) Seed Essential Oil in the Chickpea Protein-Maltodextrin Matrix.

Isoelectrically precipitated chickpea protein isolate (CPI) and its combination with maltodextrin (MD) were investigated for the ability to form and stabilize cumin seed oil emulsions. Solubility, net surface charge, emulsion activity/stability indices, and creaming stability of CPI at a pH of 3.0-9.0 were evaluated. Optimum conditions for minimum cream separation were identified as: 0.19% CPI and 6.83% oil concentrations. Cumin (Cuminum cyminum L.) seed essential oil was microencapsulated within the CPI-MD matrix via spray drying. Effects of CPI-MD matrix formulation on the physicochemical characteristics and volatile composition of the microencapsules were investigated. CPI-MD matrices had positive effects on microcapsule properties such as relatively lower surface oil, higher encapsulation efficiency (EE), and oil retention. Approximately 86.6-96.4% oil retention and 90.9-98.4% EE were achieved. Optimum conditions for maximized oil retention (92.9%) and EE (98.6%) were identified as: 2.1% CPI, 14.8% essential oil, and 35% MD. GC-MS analysis of microcapsules was carried out to determine the changes in volatile composition during spray drying. Cymene, α-pinene, β-pinene, sabinene, terpinene, terpineol, phellandrene, and cumin aldehyde were determined as the major components. Optimized design showed the highest EE and minimal changes in the volatile composition of cumin seed essential oil.

Thermosensitive Microfibril Cellulose/MnO2 Membrane: Dual Network Structure, Photothermal Smart Modulation for Switchable Emulsion Separation

Frequently occurring oil spill accidents have caused tremendous pollution of the ecological environment. Although various oil–water separation strategies have been developed, the design of efficient oil–water separation materials still remains a significant challenge. In this study, we report a controllable and scalable method for the fabrication of wettability-switchable membranes (MCPP) that achieved a smart temperature response and efficient emulsion separation. The pore structure of the membrane was precisely controlled by the amount of natural microfibril cellulose and MnO2 nanowires. The tensile strength of the membrane was significantly increased to 2.4 MPa with the introduction of poly(vinylidene difluoride). The temperature sensitivity of poly(N-isopropylacrylamide) resulted in a reversible wettability switch of the MCPP membrane, achieving temperature-controlled smart separation for emulsions. Interestingly, the excellent photothermal conversion properties of MnO2 nanowires realized the switch of membrane surface wettability and oil viscosity reduction, further increasing the emulsion separation performance. The MCPP membrane shows high separation permeance (O/W, 4300–5000 L m–2 h–1 bar–1; W/O, 5000–17000 L m–2 h–1 bar–1) and separation efficiency (>99.4%) for a variety of emulsions. The scalable preparation, smart temperature-sensitive wettability switch, excellent emulsion separation performance, and good reusability provide the basis for the practical application of this membrane in water purification fields.

Co-encapsulation of fish oil with essential oils and lutein/curcumin to increase the oxidative stability of fish oil powder

The oxidation-resistant and multi-functional fish oil powders were produced by co-encapsulating fish oil with essential oils, lutein, and curcumin. The ovalbumin/alginate complex was used as the wall, and the wall-to-oil ratio was fixed at 1:1 based on yield, oil recovery, and internalization efficiency (IE). Surface oil was removed to better understand the characteristics of the fish oil powders. Scanning electron microscopy (SEM) results indicated that the freeze-dried fish oil powders had irregular shapes with visible pores on the surface. Covalent bonds and electrostatic interactions within the ovalbumin/alginate complex were detected through FTIR. The garlic essential oil-added sample showed the strongest oxidative stability throughout the storage period (30 days). This work showed that fish oil had been encapsulated successfully and multi-functional fish oil powders could be produced by dissolving lipophilic bioactive compounds in fish oil before encapsulation.

Ancient hydrocarbon slicks recorded by a coral atoll in the South China Sea

The intensifying oil slicks exert deleterious effects on coral reefs, hence attracting many investigations on coral's tolerance and resilience to anthropogenic oil pollution. We hypothesize that intense seafloor hydrocarbon seepages in the past could also produce oil slicks and subsequently contaminate coral reefs nearby, which may provide clues on their responses to natural oil contamination. Here, a long coral reef core (NK1) drilled in the isolated Meiji Atoll in the southern South China Sea is analyzed for aliphatic hydrocarbons to test this hypothesis. Two depth intervals, centered at 45–65 m and 95–110 m, corresponding to ages of ca. 0.3–0.6 Ma and 1.3–1.5 Ma, respectively, are characterized by geological-configured hydrocarbons indicative of ancient natural oil pollution. Because the Meiji Atoll stands on a volcanic seamount and in isolation in the sea, we deem that natural oils were incorporated into contemporary coral reefs by surface oil slicks, which were derived from hydrocarbon seepages at the seafloor of the adjacent petroliferous basins. The natural hydrocarbon seepages should result from regional tectonic movements that occurred extensively in the middle and late Pleistocene, likely in association with the arc-continent collision in the Taiwan region since 2 Ma. Albeit the two significant contamination events, it appears that they exerted insignificant disturbances on the growth and development of coral reefs, perhaps protected by certain holobiotic oil-degrading bacteria as indicated by excess production of bacterial branched fatty acids during the events. Our study thus suggests a high resilience of coral reefs to oil pollution under natural conditions, which, of course, does not mean that they would survive readily from the abrupt and intense anthropogenic pollution.

Research on flow pattern of low temperature lubrication flow field of rotating disk based on MPS method

Special vehicles often work in low temperature environment. Nevertheless, the lubrication flow field and oil distribution of gear in low temperature environment is still unclear. A visualized test bench for measuring the flow pattern of low temperature lubricating oil flow field is built. The transmission system component gear is simplified as rotating disk in the study. The variation rule of lubricating oil flow pattern with the disk speed at - 20 ℃ of the rotating disk are obtained. It is found that the lubricating oil flow pattern of the disk can be divided into coated, involute and reverse oil film flow pattern. The moving particle semi-implicit (MPS) numerical method can effectively simulate the flow pattern of the lubrication flow field of the disk. The mechanism of the change of oil film flow pattern of rotating disk at low temperature is revealed. The results show that the flow pattern of the oil film is greatly affected by centrifugal force. When the oil film flow pattern is involute, a clear separation point appears between the oil film and the disk. When the oil film flow pattern is reversed, the radial end face oil film of the disk disappears and there is less surface oil. It has theoretical guidance significance for the gear lubrication design under low temperature conditions, and provides a numerical calculation method of low temperature lubrication flow field.

Leading-edge tubercle modifications to the biomimetic wings

An experimental investigation was conducted to better understand the effects of the humpback whale flipper's tubercles on biomimetic models. Different configurations of tubercles were investigated for five biomimetic flipper models by performing force measurement experiments at the Reynolds number of 5.0 × 104, 8.0 × 104, and 1.2 × 105 and surface oil flow visualization at Re = 1.2 × 105. The experiments were carried out with five different test models: two baseline models, one having a smooth and one having a tubercle leading-edge (LE); two simply designed tubercle models with uniform distribution; and a proposed tubercle model having a more realistic approach. It is proposed to create a tubercle pattern of a flipper model by summing two wave functions. The results indicated that the models with LE tubercles improved lift, delayed stall angle, and reduced drag compared to the baseline model. Irrespective of the Reynolds number, the model C3, which was created with a more realistic approach, performs better compared to baseline and other tubercle models. It has been seen that the maximum improvement in lift coefficient is achieved by approximately 18% with the C3 model at Re = 5.0 × 104. According to flow visualization results, the laminar separation bubble formed in the smooth baseline model was replaced by a counter-rotating vortex pairs (CRVPs) in the tubercle models. The improvement of the aerodynamic characteristics is due to the CRVPs formed by the interaction of the LE tubercles with each other and wavelike trailing-edge flow separation pattern. One of the significant findings to emerge from this study is that a more realistic approach has the potential to obtain better performance than a model with a uniform distribution of tubercles.

ISWM: an information security system for water surface oil spill monitoring based on NB-IoT

ISWM: an information security system for water surface oil spill monitoring based on NB-IoT