scholarly journals A Comprehensive Approach from Interfacial to Bulk Properties of Legume Protein-Stabilized Emulsions

Fluids ◽  
2019 ◽  
Vol 4 (2) ◽  
pp. 65 ◽  
Author(s):  
Manuel Félix ◽  
Alberto Romero ◽  
Cecilio Carrera-Sanchez ◽  
Antonio Guerrero
Keyword(s):  
Rheological Properties ◽  
Size Distribution ◽  
Droplet Size ◽  
Electrostatic Interactions ◽  
Ph Value ◽  
Droplet Size Distribution ◽  
Interfacial Properties ◽  
Industrial Applications ◽  
Droplet Sizes ◽  
Legume Protein

The correlation between interfacial properties and emulsion microstructure is a topic of special interest that has many industrial applications. This study deals with the comparison between the rheological properties of oil-water interfaces with adsorbed proteins from legumes (chickpea or faba bean) and the properties of the emulsions using them as the only emulsifier, both at microscopic (droplet size distribution) and macroscopic level (linear viscoelasticity). Two different pH values (2.5 and 7.5) were studied as a function of storage time. Interfaces were characterized by means of dilatational and interfacial shear rheology measurements. Subsequently, the microstructure of the final emulsions obtained was evaluated thorough droplet size distribution (DSD), light scattering and rheological measurements. Results obtained evidenced that pH value has a strong influence on interfacial properties and emulsion microstructure. The best interfacial results were obtained for the lower pH value using chickpea protein, which also corresponded to smaller droplet sizes, higher viscoelastic moduli, and higher emulsion stability. Thus, results put forward the relevance of the interfacial tension values, the adsorption kinetics, the viscoelastic properties of the interfacial film, and the electrostatic interactions among droplets, which depend on pH and the type of protein, on the microstructure, rheological properties, and stability of legume protein-stabilized emulsions.

Influence of Composition of Emulsifier Blends on the Rheological Properties of Salad Dressing-Type Emulsions

2003 ◽  
Vol 9 (1) ◽  
pp. 53-63 ◽  
Author(s):  
M. A. Riscardo ◽  
J. M. Franco ◽  
C. Gallegos
Keyword(s):  
Rheological Properties ◽  
Size Distribution ◽  
Droplet Size ◽  
Physical Stability ◽  
Droplet Size Distribution ◽  
Egg Yolk ◽  
Tween 20 ◽  
Binary Blends ◽  
Sorbitan Monolaurate ◽  
Salad Dressing

This paper deals with the influence that composition of emulsifier blends exerts on the rheological properties of low-in-fat salad dressing-type emulsions. Binary blends of egg yolk and different types of amphiphilic molecules (low-molecular weight and macromolecules) were used in several proportions to stabilize emulsions by keeping constant the total amount of emulsifier. The different emulsifiers added to egg yolk were pea protein, sodium caseinate, polyoxyethylene(20)-sorbitan monolaurate (Tween 20) and sucrose distearate. Steady state flow tests and small-amplitude oscillatory measurements within the linear viscoelasticity region were carried out. Rheological tests were complemented with droplet size distribution measurements and observation of physical stability against creaming of these emulsions. It was pointed out that rheological properties, droplet size and physical stability of the emulsions studied depended on the weight ratio of emulsifiers in the binary blends, although the emulsifier total concentration remained constant, as well as the nature of the substance blended with egg yolk. These results have been explained on the basis of the relationship among rheological properties, droplet size distribution, continuous phase characteristics and interactions among different emulsifier molecules.

Modeling Subsurface Dispersant Applications for Response Planning and Preparation

2014 ◽  
Vol 2014 (1) ◽  
pp. 933-948 ◽  
Author(s):  
Deborah Crowley ◽  
Daniel Mendelsohn ◽  
Nicole Whittier Mulanaphy ◽  
Zhengkai Li ◽  
Malcolm Spaulding
Keyword(s):  
Interfacial Tension ◽  
Water Column ◽  
Size Distribution ◽  
Droplet Size ◽  
Droplet Size Distribution ◽  
Relative Volume ◽  
Modeling Tools ◽  
Droplet Sizes ◽  
Oil Water ◽  
The Relationship

ABSTRACT The increase in oil and gas development activity at increasing water depths has highlighted the need for modeling tools to evaluate the unique aspects of accidental deepwater releases, one aspect being the need to assess the impact of subsurface dispersant application to a deepwater blowout. In response to this need, the effect of subsurface dispersant application has been implemented within RPS ASA's blowout model OILMAPDeep. OILMAPDeep was developed to simulate deepwater blowout releases; it predicts the evolution and characteristics of the subsurface plume and estimates the oil droplet size distribution associated with the release. The droplet size distribution dictates the vertical transport of oil within the water column, and impacts the relative volume anticipated to either surface or remain trapped in the water column. Droplet sizes are primarily a function of the energy of the release and the oil-water interfacial tension. The energy of the release is characterized by a reference velocity, typically the exit velocity, and the oil-water interfacial tension as a function of the oil properties. Dispersants mixed with oil reduce the oil-water interfacial tension, which in turn reduces the droplet sizes associated with treated releases serving to delay or eliminate surfacing oil. The present model implementation takes advantage of recent studies that have quantitatively assessed the relationship between the dispersant to oil ratio and surface tension. Here we present a background of the OILMAPDeep module, the governing physical processes of droplet formation, and the relationship between dispersant-to-oil ratio (DOR) and droplet size formation as characterized in the model. A description of the model implementation including model inputs and outputs are provided. Furthermore a set of scenarios are presented that demonstrate the model's capabilities for planning and preparing response activities in the event of a potential oil well blowout. This paper shows how the implementation of subsurface dispersant application within OILMAPDeep provides an effective means of evaluating potential response activities associated with subsurface dispersant application to a deepwater blowout. This includes evaluating the effect of subsurface dispersant application on droplet size distribution, and the ultimate impact on the timing, location and the relative volume of surfacing oil.

scholarly journals Chemical composition and droplet size distribution of cloud at the summit of Mount Tai, China

2017 ◽  
Author(s):  
Jiarong Li ◽  
Xinfeng Wang ◽  
Jianmin Chen ◽  
Chao Zhu ◽  
Weijun Li ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Size Distribution ◽  
Droplet Size ◽  
Atmospheric Aerosols ◽  
Ph Value ◽  
Inorganic Ions ◽  
Droplet Size Distribution ◽  
Dilution Effect ◽  
Water Soluble ◽  
Cloud Droplets

Abstract. Chemical composition of 39 cloud samples and droplet size distribution in 24 cloud events were investigated at the summit of Mt. Tai from July to October 2014. Inorganic ions, organic acids, metals, HCHO, H2O2, sulfur(IV), organic carbon, element carbon as well as pH and electrical conductivity were analyzed. The acidity of the cloud water significantly decreased from a reported value of pH 3.86 in 2007–2008 (Guo et al., 2012) to pH 5.87 in the present study. The concentrations of nitrate and ammonium were both increased since 2007–2008, but the overcompensation of ammonium led to the increase of the mean pH value. The microphysical properties showed that cloud droplets were smaller than 26.0 μm and the most were in the range of 6.0–9.0 μm. The maximum droplet number concentration (Nd) was associated with droplet sizes of 7.0 μm. Cloud droplets exhibited a strong interaction with atmospheric aerosols. High PM2.5 level resulted in higher concentrations of water soluble ions and smaller sizes with more numbers of cloud droplets, and further gave rise to relatively high acidity. High degrees of relative humidity facilitated the formation of large cloud droplets and led to high liquid water contents under low PM2.5 level. The cloud droplets to wet deposition acted as an important sink of soluble material in the atmosphere and the dilution effect of the water content should be considered when estimating concentrations of soluble components in the cloud phase.

Influence of pH value on microstructure of oil-in-water emulsions stabilized by chickpea protein flour

2018 ◽  
Vol 24 (7) ◽  
pp. 555-563 ◽  
Author(s):  
Manuel Felix ◽  
Nadia Isurralde ◽  
Alberto Romero ◽  
Antonio Guerrero
Keyword(s):  
Size Distribution ◽  
Droplet Size ◽  
Protein Concentration ◽  
Ph Value ◽  
Droplet Size Distribution ◽  
Laser Scanning Microscopy ◽  
Plant Proteins ◽  
Small Amplitude Oscillatory Shear ◽  
Oil In Water ◽  
Influence Of Ph

Food industry is highly interested in the development of healthier formulations of oil-in-water emulsions, stabilized by plant proteins instead of egg or milk proteins. These emulsions would avoid allergic issues or animal fat. Among other plant proteins, legumes are a cost-competitive product. This work evaluates the influence of pH value (2.5, 5.0 and 7.5) on emulsions stabilized by chickpea-based emulsions at two different protein concentration (2.0 and 4.0 wt%). Microstructure of chickpea-based emulsions is assessed by means of backscattering, droplet size distributions and small amplitude oscillatory shear measurements. Visual appearances as well as confocal laser scanning microscopy images are obtained to provide useful information on the emulsions structure. Interestingly, results indicate that the pH value and protein concentration have a strong influence on emulsion microstructure and stability. Thus, the system which contains protein surfaces positively charged shows the highest viscoelastic properties, a good droplet size distribution profile and non-apparent destabilization phenomena. Interestingly, results also reveal the importance of rheological measurements in the prediction of protein interactions and emulsion stability since this technique is able to predict destabilization mechanisms sooner than other techniques such as backscattering or droplet size distribution measurements.

scholarly journals Aerosol Transmission of SARS-CoV-2: Physical Principles and Implications

2020 ◽  
Vol 8 ◽  
Author(s):  
Michael C. Jarvis
Keyword(s):  
Size Distribution ◽  
Droplet Size ◽  
Aerosol Particles ◽  
Droplet Size Distribution ◽  
Research Areas ◽  
Droplet Sizes ◽  
The Mean ◽  
Uv Lamps ◽  
Physical Principles ◽  
Aerosol Form

Evidence has emerged that SARS-CoV-2, the coronavirus that causes COVID-19, can be transmitted airborne in aerosol particles as well as in larger droplets or by surface deposits. This minireview outlines the underlying aerosol science, making links to aerosol research in other disciplines. SARS-CoV-2 is emitted in aerosol form during normal breathing by both asymptomatic and symptomatic people, remaining viable with a half-life of up to about an hour during which air movement can carry it considerable distances, although it simultaneously disperses. The proportion of the droplet size distribution within the aerosol range depends on the sites of origin within the respiratory tract and on whether the distribution is presented on a number or volume basis. Evaporation and fragmentation reduce the size of the droplets, whereas coalescence increases the mean droplet size. Aerosol particles containing SARS-CoV-2 can also coalesce with pollution particulates, and infection rates correlate with pollution. The operation of ventilation systems in public buildings and transportation can create infection hazards via aerosols, but provides opportunities for reducing the risk of transmission in ways as simple as switching from recirculated to outside air. There are also opportunities to inactivate SARS-CoV-2 in aerosol form with sunlight or UV lamps. The efficiency of masks for blocking aerosol transmission depends strongly on how well they fit. Research areas that urgently need further experimentation include the basis for variation in droplet size distribution and viral load, including droplets emitted by “superspreader” individuals; the evolution of droplet sizes after emission, their interaction with pollutant aerosols and their dispersal by turbulence, which gives a different basis for social distancing.

scholarly journals A New Mechanism of Droplet Size Distribution Broadening during Diffusional Growth

2013 ◽  
Vol 70 (7) ◽  
pp. 2051-2071 ◽  
Author(s):  
Alexei Korolev ◽  
Mark Pinsky ◽  
Alex Khain
Keyword(s):  
Size Distribution ◽  
Droplet Size ◽  
Initial Conditions ◽  
Droplet Size Distribution ◽  
Cloud Base ◽  
Diffusional Growth ◽  
Cloud Droplets ◽  
Droplet Concentration ◽  
Droplet Sizes ◽  
Precipitation Formation

Abstract A new mechanism has been developed for size distribution broadening toward large droplet sizes. This mechanism may explain the rapid formation of large cloud droplets, which may subsequently trigger precipitation formation through the collision–coalescence process. The essence of the new mechanism consists of a sequence of mixing events between ascending and descending parcels. When adiabatically ascending and descending parcels having the same initial conditions at the cloud base arrive at the same level, they will have different droplet sizes and temperatures, as well as different supersaturations. Isobaric mixing between such parcels followed by further ascents and descents enables the enhanced growth of large droplets. The numerical simulation of this process suggests that the formation of large 30–40-μm droplets may occur within 20–30 min inside a shallow adiabatic stratiform layer. The dependencies of the rate of the droplet size distribution broadening on the intensity of the vertical fluctuations, their spatial amplitude, rate of mixing, droplet concentration, and other parameters are considered here. The effectiveness of this mechanism in different types of clouds is discussed.

scholarly journals Chemical composition and droplet size distribution of cloud at the summit of Mount Tai, China

2017 ◽  
Vol 17 (16) ◽  
pp. 9885-9896 ◽  
Author(s):  
Jiarong Li ◽  
Xinfeng Wang ◽  
Jianmin Chen ◽  
Chao Zhu ◽  
Weijun Li ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Size Distribution ◽  
Droplet Size ◽  
Ph Value ◽  
Inorganic Ions ◽  
Droplet Size Distribution ◽  
Dilution Effect ◽  
Cloud Water ◽  
Water Soluble ◽  
Cloud Droplets

Abstract. The chemical composition of 39 cloud samples and droplet size distributions in 24 cloud events were investigated at the summit of Mt. Tai from July to October 2014. Inorganic ions, organic acids, metals, HCHO, H2O2, sulfur(IV), organic carbon, and elemental carbon as well as pH and electrical conductivity were analyzed. The acidity of the cloud water significantly decreased from a reported value of pH 3.86 during 2007–2008 (Guo et al., 2012) to pH 5.87 in the present study. The concentrations of nitrate and ammonium were both increased since 2007–2008, but the overcompensation of ammonium led to an increase in the mean pH value. The microphysical properties showed that cloud droplets were smaller than 26.0 µm and most were in the range of 6.0–9.0 µm at Mt. Tai. The maximum droplet number concentration (Nd) was associated with a droplet size of 7.0 µm. High liquid water content (LWC) values could facilitate the formation of larger cloud droplets and broadened the droplet size distribution. Cloud droplets exhibited a strong interaction with atmospheric aerosols. Higher PM2. 5 levels resulted in higher concentrations of water-soluble ions and smaller sizes with increased numbers of cloud droplets. The lower pH values were likely to occur at higher PM2. 5 concentrations. Clouds were an important sink for soluble materials in the atmosphere. The dilution effect of cloud water should be considered when estimating concentrations of soluble components in the cloud phase.

Effects of Varying Liquid Fuel and Air Co-Flow Rates on Spray Characterisation of an Annular Co-Flow Spray Burner

2019 ◽  
Author(s):  
R. A. Alsulami ◽  
S. Nates ◽  
W. Wang ◽  
S. H. Won ◽  
Bret Windom
Keyword(s):  
Size Distribution ◽  
Droplet Size ◽  
Liquid Fuel ◽  
Air Flow ◽  
Droplet Size Distribution ◽  
Droplet Breakup ◽  
Flame Stability ◽  
Flow Rates ◽  
Droplet Sizes ◽  
The Impact

Abstract Development of efficient and clean combustion systems requires the understanding of all the processes experienced by a complex liquid fuel in IC engines, such as atomization, vaporization, turbulent mixing, and combustion. Many of these processes are interconnected; the atomization process, which leads to various droplet sizes can enhance or diminish the vaporization rate of the liquid fuel and consequently impact the energy conversion process. Furthermore, the combustion/flame stability of liquid-fueled gas turbine can be influenced by the fuel and the air co-flow rates delivered in the engine. Increasing the fuel and/or air flow rates can enhance droplet breakup and the turbulence of the flow, and as a result sway the droplet size distribution of the spray. This work focuses on investigating the impact of varying the fuel and air flow rates on the spray atomization (e.g. droplet size distribution) of an Annular Co-Flow Spray Burner. This was explored by measuring droplet sizes and velocities of the spray at different radial and axial positions of n-heptane fuel under nonreacting conditions. In addition, the turbulence intensity and the liquid spray droplet distribution were quantified for different fuel and air flow rate conditions. The measurements were obtained by using a Phase Doppler Particle Analyzer/Laser Doppler Velocimeter (PDPA/LDV) at P = 1 atm and T = 298 K. Moreover, the Sauter Mean Diameters for different flow conditions are predicted, using an established correlations, and compared to PDPA/LDV measurements. The results provided a fair understanding of the influence of varying the fuel and air flow rates on the droplet sizes, velocity, and turbulent intensity. Furthermore, the results presented here will support future work that will focus on unraveling the role of phase change on flame stability.

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