Amniotic Fluid Surface Tension during Pregnancy

Neonatology ◽  
1976 ◽  
Vol 29 (1-2) ◽  
pp. 112-116 ◽  
Author(s):  
Firmino F. Rubaltelli ◽  
Mario Rondinelli ◽  
Carlo Zorzi ◽  
Sergio Saia
Keyword(s):  
Surface Tension ◽  
Amniotic Fluid ◽  
Fluid Surface

Amniotic Fluid Surface Tension Measurements versus Various Phospholipid Determinations in the Assessment of Fetal Lung Maturity

Respiration ◽  
1979 ◽  
Vol 37 (2) ◽  
pp. 114-121 ◽  
Author(s):  
A. Bichler ◽  
G. Daxenbichler ◽  
A. Ortner ◽  
H. Grill ◽  
W. Geir ◽  
...  
Keyword(s):  
Surface Tension ◽  
Amniotic Fluid ◽  
Fetal Lung ◽  
Fetal Lung Maturity ◽  
Fluid Surface ◽  
Lung Maturity

Measurement of Burst Pressure of Capillary Burst Valve

2010 ◽  
Author(s):  
Hong Chen ◽  
Toru Yamada ◽  
Mohammad Faghri
Keyword(s):  
Surface Tension ◽  
Solid Surface ◽  
Burst Pressure ◽  
Surface Tensions ◽  
Fluid Surface ◽  
Mechanical Components

Capillary burst valve (CBV), a counterpart to an elastomeric diaphragm microvalve, handles fluid in microchannels by capillarity. Thus, it avoids integration of mechanical components. We experimentally estimated the burst pressure, beyond which CBV cannot hold fluid, using fluids with distinct surface tensions in CBVs grafted with distinct surface constitutions in microchannels. We found that both the fluid surface tension and the solid surface constitution influence the burst pressure. The burst pressure reduces more significantly under the influence of the fluid surface tension.

The measurement of surface tension by means of a vertical-plate balance

1970 ◽  
Vol 23 (11) ◽  
pp. 2153 ◽  
Author(s):  
JE Lane ◽  
DO Jordan
Keyword(s):  
Surface Tension ◽  
Experimental Error ◽  
Gravitational Force ◽  
Vertical Plate ◽  
Infinite Plate ◽  
Arbitrary Cross Section ◽  
Finite Plate ◽  
Fluid Surface ◽  
Additional Force ◽  
Infinite Height

A thermodynamic analysis of the measurement of surface tension using plates with either horizontal or vertical grooves of arbitrary cross section is presented. An exact description of the behaviour of horizontal grooves in a plate of infinite width and of vertical grooves in a plate of infinite height is given. The behaviour of a plate of finite height with vertical grooves can be the same as for an infinite plate, but in most instances this is not true. An approximate analysis of a finite plate with vertical grooves is developed and the errors in the curvatures of the resulting liquid-fluid surface are evaluated. In general, it is found that a grooved plate partly immersed in liquid requires a greater force to balance it than a smooth plate of the same overall dimensions and mass and with zero contact angle against the liquid and fluid phases. The additional force required to balance the grooved plate is approximately independent of the groove orientation but increases with width (pitch) of the groove. It is shown that if the measurements are made with the bottom of the plate at the level of the liquid-fluid surface at an infinite distance from the plate, the additional force almost equals the gravitational force on the mass of liquid adhering to the plate after complete immersion and withdrawal from the liquid, the agreement improving as the groove pitch is decreased. This conclusion helps explain the good results obtained for surface tension measurements using roughened plates with scratched surfaces. The important results are checked experimentally and in most cases the agreement is within the experimental error. The only exceptions to this are the results for finite plates with vertical grooves but even then the agreement is nearly quantitative.

Phospholipid surface tension: the diagnostic utility of amniotic fluid and its lipid extract, an analysis of the value of precipitation with cold acetone.

1989 ◽  
Vol 35 (5) ◽  
pp. 800-803 ◽  
Author(s):  
J Ruiz Budría ◽  
J M Abbad Bara ◽  
E Fabre Gonzalez ◽  
M T Higueras Sanz ◽  
J L Serrano Ostáriz
Keyword(s):  
Surface Tension ◽  
Amniotic Fluid ◽  
Distress Syndrome ◽  
Biochemical Property ◽  
Fetal Lung ◽  
Lipid Extract ◽  
Biophysical Property ◽  
Three Samples ◽  
Cold Acetone ◽  
Lung Maturity

Abstract In prevention of the respiratory distress syndrome (RDS), measurements of surface tension values (a biophysical property) of amniotic-fluid samples are correlated with their lecithin/sphingomyelin (L/S) ratios (a biochemical property). According to some authors, precipitation of phospholipid with cold acetone is essential for determining the L/S ratio, because it separates surfactant and nonsurfactant phospholipidic fractions. Here we report the first study of the ability of three amniotic-fluid components to decrease surface tension: The complete lipid extract (without precipitation), and the fractions precipitated and (or) remaining soluble after addition of cold acetone. Addition of increasing aliquots of lipid extracts to these three samples showed that: (a) measurement of surface tension rapidly and reliably indicates fetal lung maturity, and (b) both precipitated and soluble phospholipid fractions decrease surface tension similarly, making it unlikely that the precipitation step in fact separates surfactant and nonsurfactant material.

Experimental Study of Surface Tension Coefficient for Magnetic Fluid

2011 ◽  
Vol 492 ◽  
pp. 277-282
Author(s):  
Qing Lei Wang ◽  
De Cai Li ◽  
Fan Wang
Keyword(s):  
Surface Tension ◽  
Magnetic Fluid ◽  
Liquid Surface ◽  
Surface Tension Coefficient ◽  
Fluid Surface ◽  
Liquid Surface Tension ◽  
Experimental Apparatus ◽  
Different Temperatures ◽  
Increasing Temperature ◽  
The Relationship

The author measured surface tension coefficient for liquid with a new experimental apparatus, measured magnetic fluid surface tension coefficient at different temperatures and with different volume of surfactant. By the analysis of experimental data, we obtained that magnetic fluid surface tension coefficient decreases with the increasing temperature and increases with the addition of surfactant volume and reaches a certain stability value. We also obtained the expression of magnetic fluid surface tension coefficient and the temperature or surfactant. This paper discussed the relationship between the liquid surface tension coefficient and the temperature and surfactant from the view of thermodynamics.

scholarly journals Reminiscent capillarity in subnanopores

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Irena Deroche ◽  
T. Jean Daou ◽  
Cyril Picard ◽  
Benoit Coasne
Keyword(s):  
Surface Tension ◽  
Porous Materials ◽  
Adsorption Energy ◽  
Phenomenological Model ◽  
Chemical Potential ◽  
Nanoporous Materials ◽  
Simulation Data ◽  
Pore Sizes ◽  
Fluid Surface ◽  
Molecular Scale

Abstract Fluids in large and small pores display different behaviors with a crossover described through the concept of critical capillarity. Here we report experimental and simulation data for various siliceous zeolites and adsorbates that show unexpected reminiscent capillarity for such nanoporous materials. For pore sizes D exceeding the fluid molecule size, the filling pressures p are found to follow a generic behavior kBT ln p ∼ γ/ρD where γ and ρ are the fluid surface tension and density. This result is rationalized by showing that the filling chemical potential for such ultra-small pores is the sum of an adsorption energy and a capillary energy that remains meaningful even for severe confinements. A phenomenological model, based on Derjaguin’s formalism to bridge macroscopic and molecular theories for condensation in porous materials, is developed to account for the behavior of fluids confined down to the molecular scale from simple parameters.

Effect of intra-alveolar fluid on pulmonary surface tension properties

1964 ◽  
Vol 19 (4) ◽  
pp. 769-777 ◽  
Author(s):  
John W. C. Johnson ◽  
S. Permutt ◽  
John H. Sipple ◽  
El Sayed Salem
Keyword(s):  
Surface Tension ◽  
Amniotic Fluid ◽  
Lung Surfactant ◽  
Active Material ◽  
Isotonic Saline ◽  
Significant Negative Correlation ◽  
Surface Tensions ◽  
Tension Properties ◽  
Anesthetized Dogs ◽  
Surface Active Material

In 17 anesthetized dogs, 50–150 ml of isotonic saline or human amniotic fluid were instilled into a degassed lobe and after 2–6 hr of spontaneous or artificial ventilation, the lungs were excised. Static pressure-volume and extract surface tension values were then determined on a fluid- and a nonfluid-instilled lobe from each animal. When compared with nonfluid-instilled lobes the fluid-instilled lobes were found to have proportionately smaller volumes at maximum inflation ( P < .02) and during deflation ( P < .001) as well as regional areas with higher surface tension properties ( P < .001). It is proposed that the pressure-volume studies may furnish a useful means of assessing the anatomical extent of alterations in lung surface tension. There was a significant negative correlation between maximum inflation volumes and maximum surface tensions ( P < .001) as well as between the volumes during deflation and the minimum surface tensions ( P < .001). It is concluded that intra-alveolar fluid may inactivate or displace the surface-active material from the alveolar lining membrane. amniotic fluid; lung pressure-volume studies; lung surfactant Submitted on April 11, 1963

Experimental and theoretical investigation on Nano-fluid surface tension

2015 ◽  
Vol 27 ◽  
pp. 1806-1813 ◽  
Author(s):  
Hemat Ranjbar ◽  
Mohammad Reza Khosravi-Nikou ◽  
Amir Safiri ◽  
Samaneh Bovard ◽  
Ali Khazaei
Keyword(s):  
Surface Tension ◽  
Theoretical Investigation ◽  
Fluid Surface ◽  
Nano Fluid
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