Nucleation and Growth of Bubbles in Elastomers

1971 ◽  
Vol 44 (5) ◽  
pp. 1363-1379 ◽  
Author(s):  
Charles W. Stewart
Keyword(s):  
Surface Tension ◽  
Homogeneous Nucleation ◽  
Nucleation And Growth ◽  
Experimental Results ◽  
Dissolved Gas ◽  
Rate Of Growth ◽  
High Degree ◽  
Approximate Expressions ◽  
Temperature Surface

Abstract The theory of homogeneous nucleation of bubbles is combined with an expression, for their rate of growth in elastomers to obtain approximate expressions for calculating the number of bubbles formed under a high degree of supersaturation. Experimental results are given for several elastomers with argon as the dissolved gas under a variety of foaming conditions. The theory adequately describes the manner in which the number of bubbles formed depends on the temperature, surface tension of the polymer, and permeability of the dissolved gas.

Condensation of supersaturated vapours. Homogeneous nucleation of naphthalene and phthalic anhydride

1985 ◽  
Vol 50 (6) ◽  
pp. 1349-1358 ◽  
Author(s):  
Jiří Smolík ◽  
Jaroslav Vítovec
Keyword(s):  
Surface Tension ◽  
Thermal Diffusion ◽  
Classical Theory ◽  
Phthalic Anhydride ◽  
Homogeneous Nucleation ◽  
Corresponding States ◽  
Experimental Results ◽  
Critical Supersaturation ◽  
Fluid Behaviour ◽  
Good Agreement

The critical supersaturation required for the homogeneous nucleation of naphthalene and phthalic anhydride from their vapours has been measured using upward thermal diffusion cloud chamber. The results obtained are compared with the predictions of the classical theory of homogeneous nucleation (Volmer-Becker-Doring-Zeldovich) and the corresponding states correlation of homogeneous nucleation. The classical theory is found to be in excellent agreement with the experimental results on naphthalene but overpredicts the critical supersaturation of phthalic anhydride vapours by about 30%. In order to fit the experiment and theory, the new values of surface tension of phthalic anhydride were recalculated from the theory. Critical supersaturation of naphthalene plotted versus temperature reveals the same regular departure from single fluid behaviour as found for alkylbenzenes. The experimental results on phthalic anhydride were found to be in very good agreement with the corresponding states correlation.

scholarly journals Effect of dissolved-gas concentration on bulk nanobubbles generation using ultrasonication

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Jeong Il Lee ◽  
Byung-Seung Yim ◽  
Jong-Min Kim
Keyword(s):  
Surface Tension ◽  
Tensile Strength ◽  
Size Distribution ◽  
Ultrasonic Irradiation ◽  
Liquid Water ◽  
Bubble Growth ◽  
Nucleation And Growth ◽  
Dissolved Gas ◽  
Gas Concentration

Abstract In this study, the effects of dissolved-gas concentration in liquid water on the nucleation and growth of bubbles and nanobubble (NB) generation were investigated by measuring the concentration and size distribution of NBs. Three types of liquids with different dissolved-gas concentrations—undersaturated, saturated, and supersaturated deionized (DI) water—were prepared, and NBs were generated via ultrasonic irradiation. As the dissolved-gas concentration increased, a large number of bubbles with relatively large diameters (several tens of micrometers or more) were generated, but the NB concentration decreased. The surface tension decreased with an increase in the dissolved gas concentration, and thus, the tensile strength which required for bubble growth became lower. Therefore, there were barely any NBs in supersaturated conditions because of the accelerated nucleation and bubble growth.

The nucleation of cavities at grain boundaries

1987 ◽  
Vol 45 ◽  
pp. 288-291
Author(s):  
P. J. Goodhew
Keyword(s):  
Surface Tension ◽  
Surface Energy ◽  
Grain Boundaries ◽  
Radiation Damage ◽  
Impurity Concentration ◽  
Driving Force ◽  
Nucleation And Growth ◽  
Phase Boundaries ◽  
Cavity Nucleation ◽  
Spherical Bubble

Cavity nucleation and growth at grain and phase boundaries is of concern because it can lead to failure during creep and can lead to embrittlement as a result of radiation damage. Two major types of cavity are usually distinguished: The term bubble is applied to a cavity which contains gas at a pressure which is at least sufficient to support the surface tension (2g/r for a spherical bubble of radius r and surface energy g). The term void is generally applied to any cavity which contains less gas than this, but is not necessarily empty of gas. A void would therefore tend to shrink in the absence of any imposed driving force for growth, whereas a bubble would be stable or would tend to grow. It is widely considered that cavity nucleation always requires the presence of one or more gas atoms. However since it is extremely difficult to prepare experimental materials with a gas impurity concentration lower than their eventual cavity concentration there is little to be gained by debating this point.

Surface tension of sulfur nanoparticles as determined from homogeneous nucleation experiments

2016 ◽  
Vol 97 ◽  
pp. 1-21 ◽  
Author(s):  
A.A. Onischuk ◽  
S.V. Valiulin ◽  
S.V. Vosel ◽  
V.V. Karasev ◽  
V.D. Zelik ◽  
...  
Keyword(s):  
Surface Tension ◽  
Homogeneous Nucleation ◽  
Sulfur Nanoparticles

scholarly journals SEQUENCE-BASED PREDICTION OF PROTEIN B-FACTORS WITH DUAL SUPERVIZED LEARNING MODELS

2010 ◽  
Vol 22 (05) ◽  
pp. 385-391
Author(s):  
Yu-Cheng Liu ◽  
Shien-Ching Hwang ◽  
Yu-Feng Huang ◽  
Win-Li Lin ◽  
Yen-Jen Oyang ◽  
...  
Keyword(s):  
Correlation Coefficient ◽  
Prediction Accuracy ◽  
Active Sites ◽  
Pearson Correlation ◽  
Experimental Results ◽  
Structural Flexibility ◽  
Dual Model ◽  
Functional Sites ◽  
High Degree ◽  
Model Approach

The B-factor, which is also known as temperature factor or Debby–Waller factor, is an important structural flexibility index of the ground-state protein conformation. In particular, the B-factors associated with a segment of residues, reflect the local flexibility of the corresponding protein tertiary substructure. Recent studies have shown that, for certain families of proteins, there exists a high-degree of correlation between the B-factors and the protein functional sites, including antigenic regions, enzyme active sites, and nucleotide binding sites. This paper presents a sequence–based predictor of B-factors with a dual-model approach.  The design of the dual-model approach has been aimed at exploiting the bi-modal distribution of B-factors in order to achieve higher prediction accuracy. In this paper, the prediction accuracy is measured by Pearson correlation coefficient. Experimental results show that the dual-model predictor proposed in this article is capable of delivering superior correlation coefficient in comparison with two predictors reported in two latest papers.  Though experimental results show that the dual-model proposed in this paper really works more effectively than the conventional approach, it is of interest to continue investigating more advanced designs since there exists a strong correlation between B-factors and protein functional sites. In this respect, identifying additional physiochemical properties that are related to structural flexibility deserves a high-degree of attention.

Polymorphic Crystallization of Metal-Metalloid-Glasses above the Glass Transition Temperature

1990 ◽  
Vol 205 ◽  
Author(s):  
U. Köster ◽  
U. Schünemann ◽  
G.B. Stephenson ◽  
S. Brauer ◽  
M. Sutton
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Homogeneous Nucleation ◽  
Nucleation And Growth ◽  
Time Dependent ◽  
Nucleation Sites ◽  
Temperature Time ◽  
Initial Results ◽  
Temperature Crystallization

Crystallization of metal-metalloid glasses is known to proceed by nucleation and growth processes. Using crystallization statistics in partially crystallized glasses, at temperatures below the glass transition temperature, time-dependent heterogeneous nucleation has been found to occur at a number of quenched-in nucleation sites [1]. Close to the glass transition temperature crystallization proceeds so rapidly that partially crystallized microstructures could not be obtained. Initial results from fully crystallized glasses exhibit evidence for a transient homogeneous nucleation process at higher temperatures [1,2].

Ordering in clusters of uniaxial anisotropic particles during homogeneous nucleation and growth

2019 ◽  
Vol 150 (5) ◽  
pp. 054903 ◽  
Author(s):  
Takuma Nozawa ◽  
Paul E. Brumby ◽  
Sho Ayuba ◽  
Kenji Yasuoka
Keyword(s):  
Homogeneous Nucleation ◽  
Nucleation And Growth ◽  
Anisotropic Particles
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