The kinetics of Ge lateral overgrowth on SiO2

MRS Advances ◽  
2015 ◽  
Vol 1 (23) ◽  
pp. 1703-1708 ◽  
Author(s):  
M. Yako ◽  
N. J. Kawai ◽  
Y. Mizuno ◽  
K. Wada
Keyword(s):  
Growth Kinetics ◽  
Growth Rates ◽  
Growth Process ◽  
Theoretical Calculations ◽  
Film Formation ◽  
Lateral Overgrowth ◽  
Flat Film ◽  
The Difference ◽  
Kinetics Of

ABSTRACTThe kinetics of Ge lateral overgrowth on SiO2 with line-shaped Si seeds is examined. The growth process is described by the difference between the growth rates of Ge on (100) planes (GR100) and <311> facets (GR311). The theoretical calculations well reproduce the growth kinetics. It is shown that narrowing the line-seeds helps Ge coalescence and flat film formation.

Model for Epitaxial growth of Cobalt on CU(100)

1989 ◽  
Vol 160 ◽  
Author(s):  
Dimitri D. Vvedensky ◽  
Shaun Clarke
Keyword(s):  
Epitaxial Growth ◽  
Growth Kinetics ◽  
Solid Model ◽  
Free Energies ◽  
Diffusion Parameters ◽  
The Difference ◽  
Kinetics Of

AbstractThe epitaxial growth kinetics of Co on Cu(100) are investigated with a kinetic solid-on-solid model. Two effects are found to dominate the growth of this system reflecting the difference in surface free energies betweenthe two materials: the difference of diffusion parameters, and the inability of Co to wet Cu(100) at lower temperatures.

scholarly journals In-Depth Analysis of the Effect of Fragmentation on the Crystallization-Driven Self-Assembly Growth Kinetics of 1D Micelles Studied by Seed Trapping

Polymers ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 3122
Author(s):  
Gerald Guerin ◽  
Paul A. Rupar ◽  
Mitchell A. Winnik
Keyword(s):  
Growth Kinetics ◽  
Self Assembly ◽  
Growth Process ◽  
Elevated Temperatures ◽  
Polymer Chains ◽  
Exponential Law ◽  
Depth Analysis ◽  
Protein Fibrils ◽  
Polymer Fractionation ◽  
Kinetics Of

Studying the growth of 1D structures formed by the self-assembly of crystalline-coil block copolymers in solution at elevated temperatures is a challenging task. Like most 1D fibril structures, they fragment and dissolve when the solution is heated, creating a mixture of surviving crystallites and free polymer chains. However, unlike protein fibrils, no new nuclei are formed upon cooling and only the surviving crystallites regrow. Here, we report how trapping these crystallites at elevated temperatures allowed us to study their growth kinetics at different annealing times and for different amounts of unimer added. We developed a model describing the growth kinetics of these crystallites that accounts for fragmentation accompanying the 1D growth process. We show that the growth kinetics follow a stretched exponential law that may be due to polymer fractionation. In addition, by evaluating the micelle growth rate as a function of the concentration of unimer present in solution, we could conclude that the micelle growth occurred in the mononucleation regime.

scholarly journals Growth Kinetics of Hyphomicrobium and Thiobacillus spp. in Mixed Cultures Degrading Dimethyl Sulfide and Methanol

2010 ◽  
Vol 76 (16) ◽  
pp. 5423-5431 ◽  
Author(s):  
Alexander C. Hayes ◽  
Steven N. Liss ◽  
D. Grant Allen
Keyword(s):  
Growth Rate ◽  
16S Rrna ◽  
16S Rrna Gene ◽  
Specific Growth Rate ◽  
Growth Kinetics ◽  
Growth Rates ◽  
Dimethyl Sulfide ◽  
Specific Growth ◽  
Rrna Gene ◽  
Kinetics Of

ABSTRACT The growth kinetics of Hyphomicrobium spp. and Thiobacillus spp. on dimethyl sulfide (DMS) and methanol (in the case of Hyphomicrobium spp.) in an enrichment culture created from a biofilter cotreating DMS and methanol were studied. Specific growth rates of 0.099 h−1 and 0.11 h−1 were determined for Hyphomicrobium spp. and Thiobacillus spp., respectively, growing on DMS at pH 7. These specific growth rates are double the highest maximum specific growth rate for bacterial growth on DMS reported to date in the literature. When the pH of the medium was decreased from pH 7 to pH 5, the specific growth rate of Hyphomicrobium spp. decreased by 85%, with a near 100-fold decline in the yield of Hyphomicrobium 16S rRNA gene copies in the mixed culture. Through the same pH shift, the specific growth rate and 16S rRNA gene yield of Thiobacillus spp. remained similar. When methanol was used as a substrate, the specific growth rate of Hyphomicrobium spp. declined much less over the same pH range (up to 30%) while the yield of 16S rRNA gene copies declined by only 50%. Switching from an NH4 +-N-based source to a NO3 −-N-based source resulted in the same trends for the specific growth rate of these microorganisms with respect to pH. This suggests that pH has far more impact on the growth kinetics of these microorganisms than the nitrogen source. The results of these mixed-culture batch experiments indicate that the increased DMS removal rates observed in previous studies of biofilters cotreating DMS and methanol are due to the proliferation of DMS-degrading Hyphomicrobium spp. on methanol at pH levels not conducive to high growth rates on DMS alone.

scholarly journals Effect of Environmental Factors on Growth Kinetics of Biocontrol Agent Bacillus thuringiensis Bacterium using 2L and 5L A+ Sartorius Stedim Biostat® Fermentation Systems

2020 ◽  
Vol 2 (6) ◽  
Author(s):  
C. S. Richardson ◽  
D. Upadhyay ◽  
S. Mandjiny ◽  
L. Holmes
Keyword(s):  
Growth Rate ◽  
Bacillus Thuringiensis ◽  
Growth Kinetics ◽  
Growth Rates ◽  
Environmental Conditions ◽  
Doubling Time ◽  
Specific Growth ◽  
Optimal Conditions ◽  
Specific Growth Rates ◽  
Kinetics Of

Bacillus thuringiensis (Bt) is a soil-dwelling, Gram-positive bacterium that is used as a biological pesticide and used to genetically engineer plants due to the toxic proteins it produces. B. thuringiensis was studied in batch cultures to determine the specific growth rates and doubling times. The purpose of this experiment was to research the growth kinetics of Bacillus thuringiensis in a 2L bioreactor and a 5L bioreactor containing growth media at different environmental conditions. Fermentation parameters were controlled by utilizing a Sartorius Stedim Biostat® A+ bioreactor system for bacterial growth. The environmental conditions included temperature, agitation, and aeration. The specific growth rates of B. thuringiensis were determined. The optimal conditions for the 2L bioreactor were 200 RPM, 30°C, 1.5 VVM, and with the highest specific growth rate 0.30 hr and the shortest doubling time 2.3 hr. For the 5L bioreactor, the optimal conditions were 150 RPM, 30°C, 1.5 VVM, and with the highest specific growth rate 1.2 hr and the fastest doubling time 0.6 hr.

scholarly journals Kinetics of Perchlorate- and Chlorate-Respiring Bacteria

2001 ◽  
Vol 67 (6) ◽  
pp. 2499-2506 ◽  
Author(s):  
Bruce E. Logan ◽  
Husen Zhang ◽  
Peter Mulvaney ◽  
Michael G. Milner ◽  
Ian M. Head ◽  
...  
Keyword(s):  
Growth Kinetics ◽  
Growth Rates ◽  
Maximum Growth ◽  
Electron Acceptors ◽  
Electron Donors ◽  
Aerobic Growth ◽  
Batch Tests ◽  
Reducing Conditions ◽  
Biomass Yields ◽  
Kinetics Of

ABSTRACT Ten chlorate-respiring bacteria were isolated from wastewater and a perchlorate-degrading bioreactor. Eight of the isolates were able to degrade perchlorate, and all isolates used oxygen and chlorate as terminal electron acceptors. The growth kinetics of two perchlorate-degrading isolates, designated “Dechlorosoma” sp. strains KJ and PDX, were examined with acetate as the electron donor in batch tests. The maximum observed aerobic growth rates of KJ and PDX (0.27 and 0.28 h−1, respectively) were only slightly higher than the anoxic growth rates obtained by these isolates during growth with chlorate (0.26 and 0.21 h−1, respectively). The maximum observed growth rates of the two non-perchlorate-utilizing isolates (PDA and PDB) were much higher under aerobic conditions (0.64 and 0.41 h−1, respectively) than under anoxic (chlorate-reducing) conditions (0.18 and 0.21 h−1, respectively). The maximum growth rates of PDX on perchlorate and chlorate were identical (0.21 h−1) and exceeded that of strain KJ on perchlorate (0.14 h−1). Growth of one isolate (PDX) was more rapid on acetate than on lactate. There were substantial differences in the half-saturation constants measured for anoxic growth of isolates on acetate with excess perchlorate (470 mg/liter for KJ and 45 mg/liter for PDX). Biomass yields (grams of cells per gram of acetate) for strain KJ were not statistically different in the presence of the electron acceptors oxygen (0.46 ± 0.07 [n = 7]), chlorate (0.44 ± 0.05 [n = 7]), and perchlorate (0.50 ± 0.08 [n = 7]). These studies provide evidence that facultative microorganisms with the capability for perchlorate and chlorate respiration exist, that not all chlorate-respiring microorganisms are capable of anoxic growth on perchlorate, and that isolates have dissimilar growth kinetics using different electron donors and acceptors.

The Ordered Phase Formation in Ti-Al-Ga Alloys

1970 ◽  
Vol 28 ◽  
pp. 440-441
Author(s):  
Shiro Fujishiro ◽  
Harold L. Gegel
Keyword(s):  
Thermal Stability ◽  
High Temperature ◽  
Titanium Alloys ◽  
Growth Kinetics ◽  
Stoichiometric Composition ◽  
Good Potential ◽  
Alpha Titanium ◽  
Cold Rolled ◽  
Kinetics Of ◽  
Thermal Stability Of

Ordered-alpha titanium alloys having a DO19 type structure have good potential for high temperature (600°C) applications, due to the thermal stability of the ordered phase and the inherent resistance to recrystallization of these alloys. Five different Ti-Al-Ga alloys consisting of equal atomic percents of aluminum and gallium solute additions up to the stoichiometric composition, Ti3(Al, Ga), were used to study the growth kinetics of the ordered phase and the nature of its interface.The alloys were homogenized in the beta region in a vacuum of about 5×10-7 torr, furnace cooled; reheated in air to 50°C below the alpha transus for hot working. The alloys were subsequently acid cleaned, annealed in vacuo, and cold rolled to about. 050 inch prior to additional homogenization

Growth Kinetics of Quantum Size ZnO Particles

1998 ◽  
Vol 536 ◽  
Author(s):  
E. M. Wong ◽  
J. E. Bonevich ◽  
P. C. Searson
Keyword(s):  
Growth Kinetics ◽  
Ostwald Ripening ◽  
Chemical Potential ◽  
Colloidal Suspensions ◽  
Green Emission ◽  
Blue Shift ◽  
Constant Current ◽  
Mass Model ◽  
Zno Particles ◽  
Kinetics Of

AbstractColloidal chemistry techniques were used to synthesize ZnO particles in the nanometer size regime. The particle aging kinetics were determined by monitoring the optical band edge absorption and using the effective mass model to approximate the particle size as a function of time. We show that the growth kinetics of the ZnO particles follow the Lifshitz, Slyozov, Wagner theory for Ostwald ripening. In this model, the higher curvature and hence chemical potential of smaller particles provides a driving force for dissolution. The larger particles continue to grow by diffusion limited transport of species dissolved in solution. Thin films were fabricated by constant current electrophoretic deposition (EPD) of the ZnO quantum particles from these colloidal suspensions. All the films exhibited a blue shift relative to the characteristic green emission associated with bulk ZnO. The optical characteristics of the particles in the colloidal suspensions were found to translate to the films.

Growth kinetics of boride layers formed on GGG 40.3 ductile iron

2016 ◽  
Vol 58 (5) ◽  
pp. 418-421
Author(s):  
Fatma Ünal ◽  
Ahmet Topuz
Keyword(s):  
Growth Kinetics ◽  
Ductile Iron ◽  
Kinetics Of
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