Increasing Storage Modulus, Contact Angle and Surface Tension of Airway Mucus Increases Clearance by Simulated Cough Through a Model Trachea

2010 ◽  
Author(s):  
Anpalaki J. Ragavan ◽  
Cahit A. Evrensel ◽  
Peter Krumpe
Keyword(s):  
Surface Tension ◽  
Contact Angle ◽  
Storage Modulus ◽  
Surface Properties ◽  
Respiratory Diseases ◽  
Interactive Effects ◽  
Altered Surface ◽  
Human Trachea ◽  
Tension Increase ◽  
And Storage

Altered surface and viscoelastic material properties of mucus during respiratory diseases have a strong influence on its clearance by cilia and cough. Combined effects of the surface properties (contact angle and surface tension) and storage modulus with relatively unchanged viscosity on displacement of the simulated mucus aliquot during simulated cough through a model adult human trachea is investigated. For the mucus simulants used in this study contact angle and surface tension increase significantly as storage modulus increase while viscosity remains practically unchanged. Displacement of mucus simulant aliquots increased significantly with increasing storage modulus (and contact angle) at a given cough velocity in the range between 5 meters/second (m/s) and 30 m/s with duration 0.3 s. Results suggest that the interactive effects of elasticity and surface properties may help facilitate mucus displacement at low cough velocities.

Interactive Effect of Surface Tension and Viscosity on Displacement of Airway Mucus Inside a Rigid Model Adult Trachea During Cough

2012 ◽  
Author(s):  
Anpalaki J. Ragavan ◽  
Cahit A. Evrensel ◽  
Peter Krumpe
Keyword(s):  
Surface Tension ◽  
Capillary Number ◽  
Interactive Effect ◽  
Interactive Effects ◽  
Chronic Obstructive ◽  
Obstructive Pulmonary Disease ◽  
Altered Surface ◽  
Rigid Model ◽  
Human Trachea ◽  
Airway Mucus

Altered surface and viscoelastic properties of mucus during respiratory diseases have a strong influence on its clearance by cilia and cough. Combined effect of the surface tension and viscosity with relatively unchanged storage modulus of simulated airway mucus (simulant) considered as the capillary number on displacement of 0.3mL simulant aliquot during simulated cough through a model adult human trachea at relatively low cough velocity (15±0.5m/s) of 0.3s duration was investigated. Displacement of simulant aliquots decreased significantly with capillary number (p<0.0001). The interactive effects of viscosity and surface properties may give insight into understanding mucus displacement at low cough velocities in patients with chronic obstructive pulmonary disease (COPD), cystic fibrosis (CF) and asthma.

scholarly journals Experimental study on the influence of coal powders on the performance of water-based polymer drilling fluid

2020 ◽  
Vol 38 (5) ◽  
pp. 1515-1534
Author(s):  
Lei Zhang ◽  
Xiaoming Wu ◽  
Shuaifeng Lyu ◽  
Penglei Shen ◽  
Lulu Liu ◽  
...  
Keyword(s):  
Surface Tension ◽  
Contact Angle ◽  
Coalbed Methane ◽  
Drilling Fluid ◽  
Wellbore Stability ◽  
Filtration Loss ◽  
Water Based ◽  
Natural Degradation ◽  
Tension Increase ◽  
Powder Content

Coal powders, as cuttings, invade the drilling fluid along a coal seam during coalbed methane development, thereby changing the properties of the drilling fluid. Therefore, this work aims to investigate the influence of coal powders on drilling fluid performance. The powders of lignite, anthracite, and contrasting shale were added to a water-based polymer drilling fluid. Then, the rheology, filtration, lubricity, and adhesiveness were measured, and the natural degradation, as well as the wettability were further evaluated. The results show that some parameters of the drilling fluid, including viscosity, lubrication coefficient, adhesion coefficient, contact angle, and surface tension, increase after adding coal powders, while other parameters, such as filtration loss and natural degradation, decrease. Compared with lignite and shale, anthracite powders, with the lowest mineral content, exhibit the smallest change in the rheological property, lubricity, adhesion, and natural degradation of the drilling fluid. Moreover, the content and size of the coal powders generally have opposing effects on the drilling fluid. When the coal powder content reaches 3 wt.%, the surface tension and contact angle of the drilling fluid show more evident changes than other parameters. Based on the analysis of the stress intensity factor, the drilling fluid with coal powders exceeding 100 mesh can reduce the capillary force in microfractures, and in combination with other factors (such as reduced filtration loss and sealing and supporting of the microfractures), improves wellbore stability. Therefore, coal powders with suitable particle sizes and concentration levels are expected to become a new drilling fluid material to protect coal field reservoirs.

scholarly journals Surfactant-Induced Reconfiguration of Urea-Formaldehyde Resins Enables Improved Surface Properties and Gluability of Bamboo

Polymers ◽  
2021 ◽  
Vol 13 (20) ◽  
pp. 3542
Author(s):  
Lulu Liang ◽  
Yu Zheng ◽  
Yitian Wu ◽  
Jin Yang ◽  
Jiajie Wang ◽  
...  
Keyword(s):  
Surface Tension ◽  
Contact Angle ◽  
Surface Properties ◽  
High Efficiency ◽  
Urea Formaldehyde ◽  
Production Costs ◽  
Spreading Area ◽  
Uf Resin ◽  
Development And Utilization ◽  
Application Fields

The high-efficiency development and utilization of bamboo resources can greatly alleviate the current shortage of wood and promote the neutralization of CO2. However, the wide application of bamboo-derived products is largely limited by their unideal surface properties with adhesive as well as poor gluability. Herein, a facile strategy using the surfactant-induced reconfiguration of urea-formaldehyde (UF) resins was proposed to enhance the interface with bamboo and significantly improve its gluability. Specifically, through the coupling of a variety of surfactants, the viscosity and surface tension of the UF resins were properly regulated. Therefore, the resultant surfactant reconfigured UF resin showed much-improved wettability and spreading performance to the surface of both bamboo green and bamboo yellow. Specifically, the contact angle (CA) values of the bamboo green and bamboo yellow decreased from 79.6° to 30.5° and from 57.5° to 28.2°, respectively, with the corresponding resin spreading area increasing from 0.2 mm2 to 7.6 mm2 and from 0.1 mm2 to 5.6 mm2. Moreover, our reconfigured UF resin can reduce the amount of glue spread applied to bond the laminated commercial bamboo veneer products to 60 g m−2, while the products prepared by the initial UF resin are unable to meet the requirements of the test standard, suggesting that this facile method is an effective way to decrease the application of petroleum-based resins and production costs. More broadly, this surfactant reconfigured strategy can also be performed to regulate the wettability between UF resin and other materials (such as polypropylene board and tinplate), expanding the application fields of UF resin.

Surface Properties of Molten Bismuth-Bismuth Chloride in Contact with Uranium Dioxide

1961 ◽  
Vol 14 (3) ◽  
pp. 409 ◽  
Author(s):  
DH Bradhurst ◽  
AS Buchanan
Keyword(s):  
Surface Tension ◽  
Contact Angle ◽  
Surface Properties ◽  
Uranium Dioxide ◽  
Surface Active Agent ◽  
Active Agent ◽  
Effective Surface ◽  
Liquid Bismuth ◽  
Surface Active ◽  
Bismuth Chloride

The wetting of uranium dioxide by liquid bismuth has been investigated by means of measurements of surface tension of the liquid and contact angle of the liquid on the solid. Bismuth chloride in low concentration was found to be a very effective surface active agent in improving the wetting of the solid by the metal.

Herbicidal Ionic Liquids with 2,4-D

Weed Science ◽  
2012 ◽  
Vol 60 (2) ◽  
pp. 189-192 ◽  
Author(s):  
Tadeusz Praczyk ◽  
Przemysław Kardasz ◽  
Ewa Jakubiak ◽  
Anna Syguda ◽  
Katarzyna Materna ◽  
...  
Keyword(s):  
Surface Tension ◽  
Contact Angle ◽  
Ionic Liquids ◽  
Winter Wheat ◽  
Surface Properties ◽  
Field Conditions

Three herbicidal ionic liquids (HILs)—alkyldi(2-hydroxyethyl)methylammonium (2,4-dichlorophenoxy)acetate, dialkyldimethylammonium (2,4-dichlorophenoxy)acetate, and alkyltrimethylammonium (2,4-dichlorophenoxy)acetate—were synthesized and their activity against broad-leaved weeds was investigated under field conditions. HILs as [cation][2,4-D] used in winter wheat were much more active compared to 2,4-D-dimethylammonium salt and demonstrated efficacy similar to 2,4-D 2-ethylhexyl ester. HILs exhibited desirable surface properties such as low contact angle of droplets and low surface tension. Moreover, the HILs may be safer to operators and neighboring plants due to their nonvolatile nature. HILs at 450 g ha−1 of 2,4-D did not injure wheat.

Assessment of Surface Properties of Silica-Bacterial Cell Complex: A Potential Application for Silicate Bioflotation Processes

2015 ◽  
Vol 1130 ◽  
pp. 515-518
Author(s):  
Edy Sanwani ◽  
Tri Wahyuningsih ◽  
Siti Khodijah Chaerun
Keyword(s):  
Surface Tension ◽  
Contact Angle ◽  
Surface Properties ◽  
Potential Application ◽  
Bacillus Pumilus ◽  
Binding Capacity ◽  
Hydrophobic Property ◽  
Water Contact ◽  
Cell Complexes ◽  
Silica Cell

The objective of the present work was to assess the surface properties of silica-cell complexes formed by Bacillus pumilus strain SKC-2 for bioflotation purposes. This bacterial strain was employed in this study because it is a Gram-positive, mixotrophic bacterium whose metal binding capacity extends to many different metals and circumstances as well as a biosurfactant producer. The strain was found to promote the formation of silica-cell complexes due to the generation of surface-active agents (i.e., extracellular polymeric substrances (EPS)) as represented by scanning electron microscopy equipped with energy dispersive X-ray spectroscopy (SEM-EDS) observation. Surface properties of the complexes was assessed by water contact angle and surface tension measurements, demonstrating that bacterial cells reduced the surface tension of the solutions and increased the contact angle of the silica surfaces, representing a larger hydrophobic property. Therefore, the findings of this study provide clear evidence for the potential application of the bacterium Bacillus pumilus strain SKC-2 for silicate bioflotation processes (i.e., as frother and collector).

scholarly journals Influence of moisture content on the contact angle and surface tension measured on birch wood surfaces

2021 ◽  
Author(s):  
Rami Benkreif ◽  
Fatima Zohra Brahmia ◽  
Csilla Csiha
Keyword(s):  
Surface Tension ◽  
Contact Angle ◽  
Moisture Content ◽  
Solid Wood ◽  
Contact Angles ◽  
Surface Moisture ◽  
Wood Coatings ◽  
The Relationship ◽  
Wood Surfaces

AbstractSurface tension of solid wood surfaces affects the wettability and thus the adhesion of various adhesives and wood coatings. By measuring the contact angle of the wood, the surface tension can be calculated based on the Young-Dupré equation. Several publications have reported on contact angle measured with different test liquids, under different conditions. Results can only be compared if the test conditions are similar. While the roles of the drop volume, image shooting time etc., are widely recognized, the role of the wood surface moisture content (MC) is not evaluated in detail. In this study, the effect of wood moisture content on contact angle values, measured with distilled water and diiodomethane, on sanded birch (Betula pendula) surfaces was investigated, in order to find the relationship between them. With increasing MC from approximately 6% to 30%, increasing contact angle (decreasing surface tension) values were measured according to a logarithmic function. The function makes possible the calculation of contact angles that correspond to different MCs.

scholarly journals Experimental Investigation of Coal Dust Wettability Based on Surface Contact Angle

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Gang Zhou ◽  
Han Qiu ◽  
Qi Zhang ◽  
Mao Xu ◽  
Jiayuan Wang ◽  
...  
Keyword(s):  
Surface Tension ◽  
Contact Angle ◽  
Specific Surface ◽  
Coal Dust ◽  
Single Point ◽  
Contact Angles ◽  
Critical Surface ◽  
Volume Percentage ◽  
Surface Areas ◽  
Specific Surface Areas

Wettability is one of the key chemical properties of coal dust, which is very important to dedusting. In this paper, the theory of liquid wetting solid was presented firstly; then, taking the gas coal of Xinglongzhuang coal mine in China as an example, by determination of critical surface tension of coal piece, it can be concluded that only when the surface tension of surfactant solution is less than 45 mN/m can the coal sample be fully wetted. Due to the effect of particle dispersity, compared with the contact angle of milled coal particle, not all the contact angles of screened coal powder with different sizes have a tendency to increase. Furthermore, by the experiments of coal samples’ specific surface areas and porosities, it can be achieved that the volume of single-point total pore decreases with the gradual decreasing of coal’s porosity, while the ultramicropores’ dispersities and multipoint BET specific surface areas increase. Besides, by a series of contact angle experiments with different surfactants, it can be found that with the increasing of porosity and the decreasing of volume percentage of ultramicropore, the contact angle tends to reduce gradually and the coal dust is much easier to get wetted.

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