Underwater manipulation of oil droplets and bubbles on superhydrophobic surfaces via switchable adhesion

2019 ◽  
Vol 55 (23) ◽  
pp. 3394-3397 ◽  
Author(s):  
Dejun Gao ◽  
Jian Cao ◽  
Zhiguang Guo
Keyword(s):  
Uv Light ◽  
Superhydrophobic Surfaces ◽  
Bubble Motion ◽  
Oil Droplets ◽  
Oil Droplet ◽  
Underwater Manipulation

UV light-responsive reversible switching of oil droplet and bubble adhesion underwater is realized to manipulate oil droplet or bubble motion and transportation.

Numerical Simulation of Oil-Droplet Cleavage by Surfactant

1996 ◽  
Vol 118 (2) ◽  
pp. 201-209 ◽  
Author(s):  
Xiaoyi He ◽  
Micah Dembo
Keyword(s):  
Experimental Data ◽  
Numerical Simulation ◽  
Surface Tension ◽  
Large Deformation ◽  
Concentration Gradient ◽  
Surface Tension Gradient ◽  
Oil Droplets ◽  
Numerical Computations ◽  
Oil Droplet ◽  
Pure Surface

We present numerical computations of the deformation of an oil-droplet under the influence of a surface tension gradient generated by the surfactant released at the poles (the Greenspan experiment). We find this deformation to be very small under the pure surface tension gradient. To explain the large deformation of oil droplets observed in Greenspan’s experiments, we propose the existence of a phoretic force generated by the concentration gradient of the surfactant. We show that this hypothesis successfully explains the available experimental data and we propose some further tests.

Visual pigments and oil droplets in diurnal lizards

2002 ◽  
Vol 205 (7) ◽  
pp. 927-938 ◽  
Author(s):  
Ellis R. Loew ◽  
Leo J. Fleishman ◽  
Russell G. Foster ◽  
Ignacio Provencio
Keyword(s):  
Visual Pigment ◽  
Visual Pigments ◽  
Anolis Carolinensis ◽  
Visual Cell ◽  
Oil Droplets ◽  
Oil Droplet ◽  
Long Wavelength ◽  
Apparent Color ◽  
Vitamin A2 ◽  
Insight Into

SUMMARY We report microspectrophotometric (MSP) data for the visual pigments and oil droplets of 17 species of Caribbean anoline lizard known to live in differing photic habitats and having distinctly different dewlap colors. The outgroup Polychrus marmoratus was also examined to gain insight into the ancestral condition. Except for Anolis carolinensis, which is known to use vitamin A2 as its visual pigment chromophore, all anoline species examined possessed at least four vitamin-A1-based visual pigments with maximum absorbance (λmax) at 564, 495,455 and 365 nm. To the previously reported visual pigments for A. carolinensis we add an ultraviolet-sensitive one withλ max at 365 nm. Five common classes of oil droplet were measured, named according to apparent color and associated with specific cone classes — yellow and green in long-wavelength-sensitive (LWS) cones,green only in medium-wavelength-sensitive (MWS) cones and colorless in short-wavelength-sensitive (SWS) and ultraviolet-sensitive (UVS) cones. MSP data showed that the colorless droplet in the SWS cone had significant absorption between 350 and 400 nm, while the colorless droplet in the UVS cone did not. The pattern for Polychrus marmoratus was identical to that for the anoles except for the presence of a previously undescribed visual cell with a rod-like outer segment, a visual pigment with a λmaxof 497 nm and a colorless oil droplet like that in the UVS cones. These findings suggest that anoline visual pigments, as far as they determine visual system spectral sensitivity, are not necessarily adapted to the photic environment or to the color of significant visual targets (e.g. dewlaps).

Visual pigments, oil droplets and cone photoreceptor distribution in the european starling (Sturnus vulgaris)

1998 ◽  
Vol 201 (9) ◽  
pp. 1433-1446 ◽  
Author(s):  
N S Hart ◽  
J C Partridge ◽  
I C Cuthill
Keyword(s):  
Visual Pigment ◽  
Sturnus Vulgaris ◽  
European Starling ◽  
Visual Pigments ◽  
Double Cone ◽  
Temporal Region ◽  
Oil Droplets ◽  
Tetrazolium Chloride ◽  
Oil Droplet ◽  
Single Cone

Microspectrophotometric measurements of retinal photoreceptors from the European starling (Sturnus vulgaris) revealed four classes of single cone, containing visual pigments with wavelengths of maximum absorbance (<IMG src="/images/symbols/lambda.gif" WIDTH="8" HEIGHT="12" ALIGN="BOTTOM" NATURALSIZEFLAG= "3">max) at 563, 504, 449 and close to 362 nm. The two longer-wave-sensitive single cones contained brightly coloured oil droplets which cut off light below 572 and 514 nm, respectively. The 449 nm <IMG src="/images/symbols/lambda.gif" WIDTH="8" HEIGHT="12" ALIGN="BOTTOM" NATURALSIZEFLAG="3">max pigment was associated with a 'colourless' oil droplet with peak measured absorptance below 400 nm. The ultraviolet-sensitive visual pigment was paired with a transparent oil droplet which showed no significant absorption above 350 nm. A single class of double cone was identified, both members of which contained the longwave-sensitive (<IMG src="/images/symbols/lambda.gif" WIDTH="8" HEIGHT= "12" ALIGN="BOTTOM" NATURALSIZEFLAG="3">max 563 nm) visual pigment. The principal member of the double cone contained an oil droplet with a topographically variable cut-off wavelength below 471 nm; the oil droplet found in the accessory member was only measured in the ventral retina and displayed three distinct peaks of absorption at approximately 430, 450 and 480 nm. Rod photoreceptors had a <IMG src="/images/symbols/lambda.gif" WIDTH="8" HEIGHT="12" ALIGN="BOTTOM" NATURALSIZEFLAG="3">max at 503 nm. A new polynomial for fitting visual pigment templates to ultraviolet-sensitive visual pigment data is given. Topographic density measurements of the different cone classes were made using Nitroblue-tetrazolium chloride to label selectively bleached photoreceptors. The two classes of shortwave-sensitive single cone were more abundant in the dorsal retina, and longwave-sensitive single cones were notably less abundant in the dorso-temporal region of the retina, which subserves binocular vision.

scholarly journals Emulsification of Surfactant on Oil Droplets by Molecular Dynamics Simulation

Molecules ◽  
2020 ◽  
Vol 25 (13) ◽  
pp. 3008
Author(s):  
Yaoshuang Cheng ◽  
Shiling Yuan
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Heavy Oil ◽  
Molecular Level ◽  
Sodium Dodecyl ◽  
Mean Square Displacement ◽  
Dynamics Simulation ◽  
Oil Droplets ◽  
Hydration Layer ◽  
Oil Droplet

Heavy oil in crude oil flooding is extremely difficult to extract due to its high viscosity and poor fluidity. In this paper, molecular dynamics simulation was used to study the emulsification behavior of sodium dodecyl sulfonate (SDSn) micelles on heavy oil droplets composed of asphaltenes (ASP) at the molecular level. Some analyzed techniques were used including root mean square displacement, hydrophile-hydrophobic area of an oil droplet, potential of mean force, and the number of hydrogen bonds between oil droplet and water phase. The simulated results showed that the asphaltene with carboxylate groups significantly enhances the hydration layer on the surface of oil droplets, and SDSn molecules can change the strength of the hydration layer around the surface of the oil droplets. The water bridge structure between both polar heads of the surfactant was commonly formed around the hydration layer of the emulsified oil droplet. During the emulsification of heavy oil, the ratio of hydrophilic hydrophobic surface area around an oil droplet is essential. Molecular dynamics method can be considered as a helpful tool for experimental techniques at the molecular level.

scholarly journals Analysis of Oil Droplet Deposition Characteristics and Determination of Impact State Criterion in Aero-Engine Bearing Chamber

Processes ◽  
2020 ◽  
Vol 8 (6) ◽  
pp. 741
Author(s):  
Fei Wang ◽  
Lin Wang ◽  
Guoding Chen
Keyword(s):  
Impact Velocity ◽  
Incident Angle ◽  
Droplet Diameter ◽  
Oil Droplets ◽  
Oil Droplet ◽  
Spreading Width ◽  
The Impact ◽  
State Criterion ◽  
Maximum Spreading

The research of oil/air two-phase flow and heat transfer is the fundamental work of the design of lubrication and heat transfer in aero-engine bearing chamber. The determination of impact state criterion of the moving oil droplets with the wall and the analysis of oil droplet deposition characteristics are important components. In this paper, the numerical analysis model of the impact between the moving oil droplet and the wall is established by using the finite volume method, and the simulation of oil droplet impingement on the wall is carried out. Then the effects of oil droplet diameter, impact velocity, and incident angle on the characteristic parameters of impact state are discussed. The characteristic parameters include the maximum spreading length, the maximum spreading width, and the number of splashing oil droplets. Lastly the calculation results are verified through comparing with the experimental results in the literature. The results show as follows: (1) The maximum spreading width of oil droplet firstly increases and then slows down with the incident angle and the oil droplet diameter increasing; (2) when the oil droplet diameter becomes small, the influence of the incident angle on the maximum spreading length of oil droplet is obvious and vice versa; (3) with the impact velocity and diameter of oil droplet increasing, the maximum spreading width of oil droplet increases firstly and then slows down, and the maximum spreading length increased gradually; (4) the number of splashing oil droplets increases with the incident angle and impact velocity increasing; and (5) compared with the experimental data in literature, the critical dimensionless splashing coefficient K c proposed in this paper can better distinguish the impact state of oil droplet.

Numerical Study on Evaporation of Lubricating Oil Droplets Under Natural Gas Engine Conditions

2018 ◽  
Author(s):  
Liyan Feng ◽  
Zixin Wang ◽  
Ping Yi ◽  
Weixin Gong ◽  
Jingchen Cui ◽  
...  
Keyword(s):  
Liquid Phase ◽  
Natural Gas ◽  
Methane Concentration ◽  
Evaporation Rate ◽  
Carbon Number ◽  
Droplet Evaporation ◽  
Lubricating Oil ◽  
Oil Droplets ◽  
Oil Droplet ◽  
Natural Gas Engines

The distribution of lubricating oil droplets in cylinder is one of main causes of abnormal combustion of natural gas engines. The evaporation of lubricating oil droplet is one of the key sub-processes controlling its auto-ignition event. The components of lubricating oil with different carbon number (16–50) shows significantly different evaporation and ignition characteristics from gasoline and diesel fuels. Even though there are many evaporation models focusing on the evaporation behaviors of multi-component droplets, most of them are limited to the liquid fuels, which are composed by more volatile hydrocarbons. Therefore, understanding the evaporation characteristics of lubricating oil droplets is very important for investigating the mechanism of abnormal combustion of natural gas engines. In this study, a multi-component evaporation model for lubricating oil was developed, which considers several key characteristics in the droplet evaporation process, including the finite heat conduction and limited mass diffusion in liquid phase, multi-component diffusion in gas phase, real vapor-liquid equilibrium at the droplet interface, as well as the nitrogen quantity dissolved in liquid phase. The simulation results by this model were compared with experimental results, and good agreements have been achieved. Then, this model was used to study the evaporation behaviors of different hydrocarbon droplets, including lubricating oil droplet. The influences of ambient temperatures and pressures, as well as methane concentration on evaporation characteristics (namely the heat up period, average evaporation rate, and droplet lifetime) were investigated. The results show that both heat up period and evaporation rate of lubricating oil droplets increase as the methane concentration increases. Besides, the droplet lifetime monotonically decreases as the ambient pressure decreases. This is different from the diesel and gasoline droplets, for which the effects of pressure on the droplet evaporation behaviors are depended on the ambient temperature.

Silicone oil droplets in repackaged anti–vascular endothelial growth factors for intravitreal injections: In search of the main source of contamination

2019 ◽  
Vol 30 (4) ◽  
pp. 774-779 ◽  
Author(s):  
José Luis Olea ◽  
María Gómez-Resa ◽  
María Mercedes Cervera-Peris ◽  
Juan Antonio Aragón
Keyword(s):  
Growth Factors ◽  
Silicone Oil ◽  
Average Frequency ◽  
Intravitreal Injections ◽  
Vascular Endothelial Growth Factors ◽  
Routine Practice ◽  
Vascular Endothelial ◽  
Oil Droplets ◽  
Oil Droplet ◽  
Endothelial Growth Factors

Introduction: Repackaging of anti–vascular endothelial growth factors in polypropylene syringes lubricated with silicone oil for intravitreal use is associated with the presence of intravitreal silicone oil droplets. The objective of this study is to assess how the use of silicone-free syringes (for storage and/or administration) would reduce the amount of silicone oil droplets in the product to be administered. Methods: Two 16 mL vials of bevacizumab were repackaged at the compounding pharmacy to obtain four sets of product, each consisting of three 1.2 mL tubes of the drug repackaged in different ways. Set A was repackaged according to routine practice, that is, the drug was placed into 1 mL siliconized syringes and 60 µL aliquots were extracted with 0.5 mL insulin siliconized syringes until reaching 1.2 mL. In set B, a 1-mL silicone-free syringe was used, followed by a 0.5 mL siliconized syringe. In set C, only 0.5 mL siliconized syringes were used. In set D, only the 1-mL silicone-free syringe was used. Micro-Flow Imaging technology was used for quantifying silicone oil droplet–like particles below 25 µm. Results: Silicone oil droplet–like particles were absent in set D. Set C had the highest average frequency of these particles, which was much lower in sets A and B. Set B had the lowest frequency. Conclusion: 0.5 mL insulin syringes with staked-in needles used for supplying the product seem to be the main source of silicone oil contamination in repackaged anti–vascular endothelial growth factors. Silicone-free insulin syringes with staked-in needles would be strongly recommended for supplying anti–vascular endothelial growth factor intravitreal injections from compounding pharmacies.

scholarly journals Owls lack UV-sensitive cone opsin and red oil droplets, but see UV light at night: Retinal transcriptomes and ocular media transmittance

2019 ◽  
Vol 158 ◽  
pp. 109-119 ◽  
Author(s):  
Julia Höglund ◽  
Mindaugas Mitkus ◽  
Peter Olsson ◽  
Olle Lind ◽  
Anna Drews ◽  
...  
Keyword(s):  
Uv Light ◽  
Light At Night ◽  
Oil Droplets ◽  
Cone Opsin ◽  
Ocular Media

scholarly journals Optics of cone photoreceptors in the chicken ( Gallus gallus domesticus )

2015 ◽  
Vol 12 (111) ◽  
pp. 20150591 ◽  
Author(s):  
David Wilby ◽  
Matthew B. Toomey ◽  
Peter Olsson ◽  
Rikard Frederiksen ◽  
M. Carter Cornwall ◽  
...  
Keyword(s):  
Outer Segment ◽  
Sensory Modality ◽  
Digital Holographic Microscopy ◽  
Cone Photoreceptors ◽  
Oil Droplets ◽  
Oil Droplet ◽  
Integrated Optical ◽  
Single Cone ◽  
Holographic Microscopy ◽  
Electromagnetic Models

Vision is the primary sensory modality of birds, and its importance is evident in the sophistication of their visual systems. Coloured oil droplets in the cone photoreceptors represent an adaptation in the avian retina, acting as long-pass colour filters. However, we currently lack understanding of how the optical properties and morphology of component structures (e.g. oil droplet, mitochondrial ellipsoid and outer segment) of the cone photoreceptor influence the transmission of light into the outer segment and the ultimate effect they have on receptor sensitivity. In this study, we use data from microspectrophotometry, digital holographic microscopy and electron microscopy to inform electromagnetic models of avian cone photoreceptors to quantitatively investigate the integrated optical function of the cell. We find that pigmented oil droplets primarily function as spectral filters, not light collection devices, although the mitochondrial ellipsoid improves optical coupling between the inner segment and oil droplet. In contrast, unpigmented droplets found in violet-sensitive cones double sensitivity at its peak relative to other cone types. Oil droplets and ellipsoids both narrow the angular sensitivity of single cone photoreceptors, but not as strongly as those in human cones.

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