Kinetics of heterogeneous bubble nucleation in rhyolitic melts: implications for the number density of bubbles in volcanic conduits and for pumice textures

2008 ◽  
Vol 156 (6) ◽  
pp. 745-763 ◽  
Author(s):  
N. Cluzel ◽  
D. Laporte ◽  
A. Provost ◽  
I. Kannewischer
Keyword(s):  
Bubble Nucleation ◽  
Number Density ◽  
Kinetics Of

Spectrochemical Behavior of Carcinogenic Polycyclic Aromatic Hydrocarbons in Biological Systems. Part II: A Theoretical Rate Model for BaP Metabolism in Living Cells

1996 ◽  
Vol 50 (11) ◽  
pp. 1352-1359 ◽  
Author(s):  
Ping Chiang ◽  
Kuang-Pang Li ◽  
Tong-Ming Hseu
Keyword(s):  
Rate Constant ◽  
Living Cells ◽  
Rate Model ◽  
Number Density ◽  
Order Process ◽  
Irreversible Reaction ◽  
First Order ◽  
Metabolism Rate ◽  
Polycyclic Aromatic ◽  
Kinetics Of

An idealized model for the kinetics of benzo[ a]pyrene (BaP) metabolism is established. As observed from experimental results, the BaP transfer from microcrystals to the cell membrane is definitely a first-order process. The rate constant of this process is signified as k1. We describe the surface–midplane exchange as reversible and use rate constants k2 and k3 to describe the inward and outward diffusions, respectively. The metabolism is identified as an irreversible reaction with a rate constant k4. If k2 and k3 are assumed to be fast and not rate determining, the effect of the metabolism rate, k4, on the number density of BaP in the midplane of the microsomal membrane, m3, can be estimated. If the metabolism rate is faster than or comparable to the distribution rates, k2 and k3, the BaP concentration in the membrane midplane, m3, will quickly be dissipated. But if k4 is extremely small, m3 will reach a plateau. Under conditions when k2 and k3 also play significant roles in determining the overall rate, more complicated patterns of m3 are expected.

Modeling the Kinetics of Bubble Nucleation in Champagne and Carbonated Beverages

2006 ◽  
Vol 110 (42) ◽  
pp. 21145-21151 ◽  
Author(s):  
Gérard Liger-Belair ◽  
Maryline Parmentier ◽  
Philippe Jeandet
Keyword(s):  
Bubble Nucleation ◽  
Carbonated Beverages ◽  
Kinetics Of

Study on Crystallization Kinetics of Gypsum Prepared by Bittern under 30oC and Different Stirring Speed

2014 ◽  
Vol 962-965 ◽  
pp. 731-735
Author(s):  
Bi Jun Luo ◽  
Dan Wu ◽  
Hai Hong Wu ◽  
Tao Wang ◽  
Xi Ping Huang
Keyword(s):  
Experimental Data ◽  
Crystallization Kinetics ◽  
Calcium Sulfate ◽  
Particle Number ◽  
Particle Number Density ◽  
Crystal Growth Rate ◽  
Number Density ◽  
Relationship Of ◽  
The Relationship ◽  
Kinetics Of

Crystallization kinetics experiment of calcium sulfate dehydrates, which is prepared by bittern under 30oC and different stirring speed conditions, is carried out. According to the results of the experimental data, the relationship of nucleus particle-number density n0 and crystal growth rate G with the residence time, temperature and the stirring speed is summarized. Also, the crystallization kinetics formula under 30oC and different stirring speed is given.

scholarly journals Surface precipitation of supersaturated solutes in a ternary Fe–Au–W alloy and its binary counterparts

2020 ◽  
Vol 56 (8) ◽  
pp. 5173-5189
Author(s):  
Y. Fu ◽  
C. Kwakernaak ◽  
J. C. Brouwer ◽  
W. G. Sloof ◽  
E. Brück ◽  
...  
Keyword(s):  
Free Surface ◽  
Ternary System ◽  
Number Density ◽  
Free Surfaces ◽  
Interior Surface ◽  
Surface Precipitation ◽  
Weight Percentage ◽  
Internal Surfaces ◽  
Creep Loading ◽  
Kinetics Of

Abstract The precipitation of supersaturated solutes at free surfaces in ternary Fe–3Au–4W and binary Fe–3Au and Fe–4W alloys (composition in weight percentage) for different ageing times was investigated at a temperature of 700 °C. The time evolution of the surface precipitation is compared among the three alloys to investigate the interplay between the Au and W solutes in the ternary system. The Au-rich grain-interior surface precipitates show a similar size and kinetics in the Fe–Au–W and Fe–Au alloys, while the W-rich grain-interior surface precipitates show a smaller size and a higher number density in the Fe–Au–W alloy compared to the Fe–W alloy. The kinetics of the precipitation on the external free surface for the ternary Fe–Au–W alloy is compared to the previously studied precipitation on the internal surfaces of the grain-boundary cavities during creep loading of the same alloy. Graphical abstract

Glass Formation and Nanostructure Development in Al-Based Alloys

1999 ◽  
Vol 581 ◽  
Author(s):  
R. I. Wu ◽  
G. Wilde ◽  
J. H. Perepezko
Keyword(s):  
Metallic Glasses ◽  
Glass Formation ◽  
Amorphous Matrix ◽  
Particle Density ◽  
Number Density ◽  
Scanning Calorimetry ◽  
Cold Rolled ◽  
Fe Alloys ◽  
Rate Limiting ◽  
Kinetics Of

ABSTRACTAl-Sm and Al-Y-Fe alloys with a high number density of nanocrystalline fcc-Al homogeneously dispersed within the amorphous matrix have been synthesized by devitrifying the precursor metallic glasses produced by rapid solidification. The kinetics of metallic glass formation and the development of the nanostructure during devitrification are discussed in terms of the rate limiting mechanism. The glass transition temperature of the two metallic glasses has been successfully assessed with the application of the modulated-temperature differential scanning calorimetry (DDSC). In addition, the formation of quenched-in nuclei was investigated by a comparison study on the cold-rolled and melt-spun Al92Sm8 amorphous samples. Furthermore, the enhancement of the particle density of the fcc-Al nanocrystals in the amorphous matrix after devitrification has been demonstrated by the incorporation of nanosize Pb particles.

Preparation of open microcellular polylactic acid foams with a microfibrillar additive using coreback foam injection molding processes

2018 ◽  
Vol 54 (4) ◽  
pp. 765-784 ◽  
Author(s):  
Shota Ishihara ◽  
Yuta Hikima ◽  
Masahiro Ohshima
Keyword(s):  
Injection Molding ◽  
Polylactic Acid ◽  
Bubble Nucleation ◽  
Number Density ◽  
Cell Content ◽  
Open Cell ◽  
Cooling Conditions ◽  
Nucleation Sites ◽  
Fast Cooling ◽  
Foam Injection Molding

Open microcellular polylactic acid foams with a fibrous polytetrafluoroethylene additive were prepared by a coreback foam injection molding technique. The effects of this fibrous additive on the foam cell structure were investigated. Fibrous polytetrafluoroethylene forms a network structure in polylactic acid in metering and mixing processes. The fibrous polytetrafluoroethylene network increased the viscoelasticity of polylactic acid and provided polylactic acid with a strain-hardening property. The network also provided heterogeneous bubble nucleation sites for physical foaming. However, because of the slow crystallization rate of polylactic acid, the fibrous polytetrafluoroethylene additive did not promote the nucleation of polylactic acid crystals under fast cooling conditions. During fast cooling, such as injection molding cooling conditions, the crystals induced by the fibrous polytetrafluoroethylene network could not behave as bubble nucleation sites. Thus, changes in rheological properties and the increased number of heterogeneous sites contributed to the decrease in cell size, the increase in the number density of cells and the increase in the open cell content. As the number density of cells increased, the cell walls with the fibrous polytetrafluoroethylene fibrous additive became so thin that they could be easily fibrillated by a stretching operation during the coreback operation, while their strain-hardening property prevented the walls from complete breakage. Synergistically conducting cell reduction and stretching (coreback) operations, high expansion ratio foams with high open cell content were prepared. When we adjusted the foaming temperature and holding time, five-fold expansion (i.e. 80% void ratio) foams with cell diameters less than 25 µm and open cell contents (OCC) higher than 80% were produced.

The effect of nanolites on degassing of silica-rich magma

2020 ◽  
Author(s):  
Francisco Cáceres ◽  
Fabian Wadsworth ◽  
Bettina Scheu ◽  
Mathieu Colombier ◽  
Claudio Madonna ◽  
...  
Keyword(s):  
Ambient Pressure ◽  
Volcanic Eruptions ◽  
Bubble Nucleation ◽  
Magma Ascent ◽  
Explosive Eruptions ◽  
Initial Water Content ◽  
Primary Control ◽  
Number Density ◽  
Bubble Number ◽  
Bubble Number Density

<p>Magma degassing dynamics play an important role controlling the explosivity of volcanic eruptions. Some of the largest explosive eruptions in history have been fed by silica-rich magmas in volcanic systems with complex dynamics of volatiles degassing. Degassing of magmatic water drives bubble nucleation and growth, which in turn increases magma buoyancy and results in magma ascent and an eventual eruption. While micro- to milli-meter sized crystals are known to cause heterogeneous bubble nucleation and to facilitate bubble coalescence, the effects of nanolites remains mostly unexplored. Nanolites have been hypothesized to be a primary control on the eruptive style of silicic volcanoes, however the mechanisms behind this control remains unclear.</p><p>Here we use an experimental approach to show how nanolites dramatically increase the bubble number density in a degassing silicic magma compared to the same magma without nanolites. The experiments were conducted using both nanolite-free and nanolite-bearing rhyolitic glass with different low initial water content. Using an Optical Dilatometer at 1 bar ambient pressure, cylindrical samples were heated at variable rates (1-30 °C min<sup>-1</sup>) to final temperatures of 820-1000 °C. This method allowed us to continuously monitor the volume, and hence porosity evolution in time. X-ray computed microtomography (µCT) and Scanning Electron Microscope (SEM) analyses revealed low and high bubble number densities for the nanolite-free and nanolite-bearing samples respectively.</p><p>Comparing vesicle number densities of natural volcanic rocks from explosive eruptions and our experimental results, we speculate that some very high naturally occurring bubble number densities could be associated with nanolites. We use a magma ascent model with P-T-H<sub>2</sub>O starting conditions relevant for known silicic eruptions to further underpin that such an increase in bubble number density caused driven by the presence of nanolites can feasibly turn an effusive eruption to an eventually explosive behavior.</p>

Excitation Kinetics of Oxygen O(1D) State in Low-Pressure Oxygen Plasma and the Effect of Electron Energy Distribution Function

2017 ◽  
Vol 20 (2) ◽  
Author(s):  
Junya Konno ◽  
Atsushi Nezu ◽  
Haruaki Matsuura ◽  
Hiroshi Akatsuka
Keyword(s):  
Distribution Function ◽  
Numerical Model ◽  
Energy Distribution ◽  
Electron Energy ◽  
Electron Energy Distribution Function ◽  
Oxygen Plasma ◽  
Energy Distribution Function ◽  
Number Density ◽  
Pressure Oxygen ◽  
Kinetics Of

AbstractWe develop numerical model to discuss the number density and excitation kinetics of O(

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