scholarly journals Evolution of the Size Distribution of Oil-droplets Over Time in Oil-in-water Emulsions

2015 ◽  
Vol 16 (3) ◽  
pp. 231-234 ◽  
Author(s):  
Kazutaka KATSUKI ◽  
Yayoi MIYAGAWA ◽  
Ryuichi MATSUNO ◽  
Shuji ADACHI
Keyword(s):  
Size Distribution ◽  
Oil Droplets ◽  
Oil In Water ◽  
Over Time

Active motion of multiphase oil droplets: emergent dynamics of squirmers with evolving internal structure

Soft Matter ◽  
2021 ◽  
Author(s):  
Xin Wang ◽  
Rui Zhang ◽  
Ali Mozaffari ◽  
Juan J. de Pablo ◽  
Nicholas L. Abbott
Keyword(s):  
Internal Structure ◽  
Oil Droplets ◽  
Active Motion ◽  
Over Time ◽  
Emergent Dynamics

Self-propelled motions of active droplets can be programmed by transforming their internal morphologies over time.

Experimental Measurement of Oil Droplets Size and Velocity Above the Rotor/Stator in a Rotary Compressor

2021 ◽  
Author(s):  
Puyuan Wu ◽  
Jun Chen ◽  
Paul E. Sojka ◽  
Yang Li ◽  
Hongjun Cao
Keyword(s):  
Size Distribution ◽  
Droplet Size ◽  
Outer Region ◽  
Droplet Size Distribution ◽  
Rotary Compressor ◽  
Discharge Process ◽  
Oil Droplets ◽  
Lower Cavity ◽  
Lubricant Oil ◽  
Rolling Piston

Abstract Hundreds of millions of Air conditioning (AC) systems are produced each year. Many of them, especially small AC appliances, use rotary compressors as the system’s heat pump due to their simple structure and high efficiency in a small system. Lubricant oil is used in the rotary compressor to lubricate the moving parts, such as the crankshaft and the rolling piston, and to seal the clearance between the sliding parts, e.g., the clearance between the rolling piston and the cylinder, and the vane and the cylinder. As the compressed refrigerant vapor is discharged from the cylinder through the discharge port, part of lubricant oil in the cylinder would be carried by the vapor and atomize into small droplets in the lower cavity during the discharge process, which is complicated and highly-coupled. Some of these oil droplets would ultimately be exhausted from the compressor and enter other parts in the system, reducing the compressor reliability and deteriorating the heat transfer of the condenser and the evaporator in the system. Our previous research studied the atomization of the lubricant oil during the discharge process in the compressor’s lower cavity. However, the oil droplets’ behavior downstream of the lower cavity is unknown. Thus, studying the oil droplets’ behavior after passing through the rotor/stator can help understand how the rotor/stator would affect the droplet size distribution and movement, thus controlling the flow rate of escaped oil droplets. In this study, a hot gas bypass test rig is built to run a modified rotary compressor with sapphire windows right above the rotor/stator. The oil droplets’ size distribution and movement along the radial direction are obtained at the shaft’s rotating frequency of 30 and 60 Hz by shadowgraph. It is found that droplet size at 30 and 60 Hz varies little in the inner region of the rotor/stator clearance and would increase sharply above the clearance and keep increasing in the outer region of the clearance. More importantly, droplet velocity has a downward velocity component at the inner region and an upward velocity component at the outer region of the rotor/stator clearance. With the result of droplet size distribution and droplet velocity above the rotor/stator, we propose the model of the oil droplet’s path above the rotor/stator, which can be understood as the coupling of a swirling jet and a rotating disk.

scholarly journals Comparative study of properties of different pesticide formulations of the same active ingredient

2008 ◽  
Vol 23 (3) ◽  
pp. 201-206
Author(s):  
Slavica Gasic ◽  
Zlatko Oreskovic
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Comparative Study ◽  
Size Distribution ◽  
Active Ingredient ◽  
Oil In Water ◽  
Pesticide Formulations ◽  
Final Estimate ◽  
New Formulation ◽  
Emulsion Oil

Characteristics of two formulations of trifluralin, an emulsifiable concentrate (EC) and emulsion, oil in water (EW), the latter being a new formulation of our design, were investigated and compared. Attention was focused on particle size distribution and aspects of the two aqueous dilute formulations as the most characteristic and comparable parameters. The results show that the trifluralin EW formulation has certain advantages over the EC formulation, but a final estimate will be possible only after testing biological efficacy of the new formulation (EW).

scholarly journals Communication: On the Stability and Necessary Electrophoretic Mobility of Bare Oil Nanodroplets in Water

2020 ◽  
Author(s):  
Saranya Pullanchery ◽  
Sergey Kulik ◽  
halil okur ◽  
Hilton. B. de Aguiar ◽  
Sylvie Roke
Keyword(s):  
Electrophoretic Mobility ◽  
Dlvo Theory ◽  
Air Bubbles ◽  
Oil Droplets ◽  
Cleaning Procedure ◽  
Charged Droplets ◽  
Oil In Water ◽  
The Creation ◽  
The Stability ◽  
The 19Th Century

Hydrophobic oil droplets, particles and air bubbles can be dispersed in water as kinetically stabilized dispersions. It has been established since the 19th century that such objects harbor a negative electrostatic potential roughly twice larger than the thermal energy. The source of this charge continues to be one of the core observations in relation to hydrophobicity and its molecular explanation is still debated. What is clear though, is that the stabilizing interaction in these systems is understood in terms of electrostatic repulsion via DLVO theory. Recent work [Carpenter et al., PNAS 116 (2019) 9214] has added another element into the discussion, reporting the creation of bare near-zero charged droplets of oil in water that are stable for several days. Key to the creation of the droplets is a rigorous glassware cleaning procedure. Here, we investigate these conclusions and show that the cleaning procedure of glassware has no influence on the electrophoretic mobility of the droplets, that oil droplets with near-zero charge are unstable, and provide an alternative possible explanation for the observations involving glass surface chemistry.

Preparation of a synergistically stabilized oil-in-water paraffin Pickering emulsion for potential application in wood treatment

Holzforschung ◽  
2018 ◽  
Vol 72 (6) ◽  
pp. 489-497 ◽  
Author(s):  
Jun Jiang ◽  
Jinzhen Cao ◽  
Wang Wang ◽  
Haiying Shen
Keyword(s):  
Mechanical Properties ◽  
Cell Wall ◽  
Size Distribution ◽  
Droplet Size ◽  
Surface Hardness ◽  
Pickering Emulsion ◽  
Silica Particles ◽  
Morphological Properties ◽  
Pickering Emulsions ◽  
Oil In Water

AbstractPickering emulsions (emulsions stabilized by solid-state additives) are attractive as they have strong similarities with traditional surfactant-based emulsions. In this study, an oil-in-water (O/W) paraffin Pickering emulsion system with satisfying stability and small droplet size distribution was developed by hydrophilic silica particles and traditional surfactants as mixed emulsifiers. The droplet morphology and size distribution were observed by optical microscopy and a laser particle analyzer. The emulsion stability was improved and the droplet size was reduced after addition of a suitable amount of silica particles. The silica concentration of 1% showed the optimal effect among all the levels observed (0.1, 0.5, 1 and 2%). Wood was impregnated with the prepared emulsion, and the chemical and morphological properties of the product were investigated by Fourier-transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM) combined with energy-dispersed X-ray analysis (SEM-EDXA). Moreover, the hydrophobicity, thermal properties, surface hardness, axial compression strength (CS) and dynamic mechanical properties were tested. The silica was evenly distributed in the wood cell wall and thus there was a synergistic positive effect from the paraffin and silica in the cell wall leading to better hydrophobicity, improved surface hardness and mechanical properties including the thermal stability.

scholarly journals The NCAR–FAA Snow Machine: An Artificial Snow-Generation System

2018 ◽  
Vol 35 (11) ◽  
pp. 2159-2168
Author(s):  
Scott D. Landolt ◽  
Roy M. Rasmussen ◽  
Alan J. Hills ◽  
Warren Underwood ◽  
Charles A. Knight ◽  
...  
Keyword(s):  
Mass Balance ◽  
Size Distribution ◽  
Liquid Water ◽  
Generation System ◽  
Fall Velocity ◽  
Atmospheric Research ◽  
Controlled Conditions ◽  
Precipitation Gauge ◽  
Cold Chamber ◽  
Over Time

AbstractThe National Center for Atmospheric Research (NCAR) developed an artificial snow-generation system designed to operate in a laboratory cold chamber for testing aircraft anti-icing fluids under controlled conditions. Flakes of ice are produced by shaving an ice cylinder with a rotating carbide bit; the resulting artificial snow is dispersed by turbulent airflows and falls approximately 2.5 m to the bottom of the device. The resulting fine ice shavings mimic snow in size, distribution, fall velocity, density, and liquid water equivalent (LWE) snowfall rate. The LWE snowfall rate can be controlled using either a mass balance or a precipitation gauge, which measures the snowfall accumulation over time, from which the computer derives the LWE rate. LWE snowfall rates are calculated every 6 s, and the rate the ice cylinder is fed into the carbide bit is continually adjusted to ensure that the LWE snowfall rate matches a user-selected value. The system has been used to generate LWE snowfall rates ranging from 0 to 10 mm h−1 at temperatures from −2 to −30°C and densities of approximately 0.1–0.5 g cm−3. Comparisons of the snow-machine fluid tests with the outdoor fluid tests have shown that the snow machine can mimic natural outdoor rates under a broad range of conditions.

scholarly journals Impact of effervescent atomization on oil drop size distribution of atomized oil-in-water emulsions

2011 ◽  
Vol 1 ◽  
pp. 138-144 ◽  
Author(s):  
Jewe Schröder ◽  
Fabian Werner ◽  
Volker Gaukel ◽  
Heike P. Schuchmann
Keyword(s):  
Size Distribution ◽  
Drop Size ◽  
Drop Size Distribution ◽  
Oil In Water

SHORELINE CLEANSING BY INTERACTIONS BETWEEN OIL AND FINE MINERAL PARTICLES

1995 ◽  
Vol 1995 (1) ◽  
pp. 219-227 ◽  
Author(s):  
James R. Bragg ◽  
Edward H. Owens
Keyword(s):  
Potential Role ◽  
Sea Water ◽  
Field Studies ◽  
Low Energy ◽  
Oil Removal ◽  
Oil Droplets ◽  
Mineral Particles ◽  
Treatment Techniques ◽  
Oil In Water ◽  
Flocculation Process

ABSTRACT Interactions of fine mineral particles with oil stranded on shorelines following spills has been shown to be an important natural cleansing process, capable of accelerating oil removal in most environments, and particularly in low energy environments where wave action and abrasion are negligible. This process involves formation of solids-stabilized oil-in-water emulsions by flocculation of micron-sized mineral fines with oil droplets in the presence of water containing ions (such as sea water). Once flocculated, the oil droplets do not coalesce, and the oil no longer adheres strongly to shoreline sediments, facilitating its removal and dispersion by waves and tidal currents. The importance of the flocculation process to the rate of oil removal from sediments, the conditions needed for the process to occur, and the properties of the resulting floe have been studied in detail for the Exxon Valdez spill. Its potential role in shoreline cleansing also has been studied for other recent spills: Metula (1974, Chile), Arrow (1970, Nova Scotia), BIOS test spill (1981, Cape Hatt, Northwest Territories), Nosac Forest (1993, Tacoma, Washington), and Fred Bouchard (1993, Tampa, Florida). This paper summarizes the various laboratory and field studies and discusses the findings within the contexts of natural shoreline cleansing, and the use of certain treatment techniques.

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