Kinetics of U(VI) reduction by a dissimilatory Fe(III)-reducing bacterium under non-growth conditions

1997 ◽  
Vol 55 (3) ◽  
pp. 490-496 ◽  
Author(s):  
Michael J. Truex ◽  
Brent M. Peyton ◽  
Nancy B. Valentine ◽  
Yuri A. Gorby
Keyword(s):  
Growth Conditions ◽  
Kinetics Of

scholarly journals The kinetics of chromosome transfer in Escherichia coli: a mathematical treatment

1962 ◽  
Vol 3 (2) ◽  
pp. 273-281 ◽  
Author(s):  
N. Symonds
Keyword(s):  
Escherichia Coli ◽  
Minimal Medium ◽  
Growth Conditions ◽  
Mathematical Treatment ◽  
Female Cell ◽  
Transfer Delay ◽  
Maximum Delay ◽  
Effective Contact ◽  
Kinetics Of ◽  
Good Agreement

A mathematical treatment has been presented of the ideas of de Haan & Gross concerning transfer delay and chromosomal withdrawal during conjugation In Escherichia coli. The calculations involve three parameters: (i) the maximum delay, λ, which can occur between the formation of effective contact in mating pairs and the initiation of chromosomal transfer, (ii) the probability, b, that mating pairs separate with the withdrawal of that segment of the Hfr chromosome which has entered the female cell, and (iii) the probability, c, that mating pairs separate with the breakage of the Hfr chromosome at the point where it enters the female cell, leaving the injected fragment in the female.A comparison of the theory with the experimental results of de Haan & Gross obtained when chromosomal transfer occurs either in minimal medium or in broth shows good agreement under the following conditions:(i) the value of λ is the same under both growth conditions,(ii) the value of b is the same under both growth conditions,(iii) the value of c is much greater during transfer in broth than it is in minimal medium.

Growth of Nonpolar (1100) Films and Heterostructures by Plasma-Assisted Molecular Beam Epitaxy

2004 ◽  
Vol 831 ◽  
Author(s):  
Oliver Brandt ◽  
Yue Jun Sun ◽  
Klaus H. Ploog
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Surface Segregation ◽  
Multiple Quantum Well ◽  
Growth Conditions ◽  
High Energy ◽  
Growth Direction ◽  
Desorption Kinetics ◽  
Multiple Quantum ◽  
Kinetics Of

ABSTRACTWe discuss the growth of M-plane GaN films and (In, Ga)N/GaN multiple quantum well (MQW) structures on LiAlO2(100) substrates by plasma-assisted molecular beam epitaxy. The adsorption and desorption kinetics of Ga on M-plane GaN is studied by reflection high-energy electron diffraction, allowing us to identify the optimum growth conditions with regard to surface morphology. Furthermore, we investigate the compositional profile of M-plane (In, Ga)N/GaN MQWs grown under conditions resulting in comparatively abrupt interfaces. The results demonstrate that significant In surface segregation occurs for the case of M-plane (In, Ga)N. The dependence of the transition energies of the M-plane MQWs on the actual well thickness reveals, however, that the structures are indeed free of electrostatic fields along the growth direction.

Molecular Dynamics Studies of Impurity Segregation and Trapping.

1991 ◽  
Vol 237 ◽  
Author(s):  
G. H. Gilmer ◽  
Christopher Roland ◽  
R. P. U. Karunasiri
Keyword(s):  
Molecular Dynamics ◽  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Crystal Surface ◽  
Growth Conditions ◽  
Impurity Atoms ◽  
Impurity Segregation ◽  
Kinetics Of

ABSTRACTThe ability to make highly doped δ-layers in semiconductors depends on the rate of interchange of atoms between layers at the crystal surface. We have simulated molecular beam epitaxy on a silicon (100) surface covered with a monolayer of impurity atoms. The kinetics of impurity segregation to the surface was examined for various growth conditions and segregation energies. We find that segregation is facilitated by appreciable inter-layer diffusion of atoms in the top several layers. The amount of diffusion is much greater during deposition than it is when the beam is off.

Effect of the Crystallinity of V6O13 Films on the Electrochemical Behavior of Lithium Microbatteries

1994 ◽  
Vol 369 ◽  
Author(s):  
A. Gorenstein ◽  
A. Khelfa ◽  
J.P. Guesdon ◽  
C. Julien
Keyword(s):  
Thin Films ◽  
Growth Conditions ◽  
Electrochemical Characteristics ◽  
X Ray Diffraction ◽  
Flash Evaporation ◽  
Deposition Parameters ◽  
Evaporation Technique ◽  
Kinetics Of ◽  
Post Deposition ◽  
Discharge Curves

AbstractElectrochemical characteristics of Li/V6O13 microbatteries are evaluated in relation with the crystallinity and morphology of thin-film cathodes. Thin films of V6O13 were prepared using the flash evaporation technique. Amorphous and polycrystalline samples were characterized by X-Ray diffraction, Raman spectroscopy and conductivity measurements. The effect of either deposition parameters or post-deposition treatment are presented in this work. Thermodynamics and kinetics of lithium insertion were studied in V6O13 thin films obtained with various growth conditions. Discharge curves present different types of behavior depending on the cathode morphology. Diffusion coefficients and enhancement factors were calculated as a function of the degree of lithium intercalation.

Cadmium transport by a Cd2+-sensitive and a Cd2+-resistant strain of Bacillus subtilis

1986 ◽  
Vol 32 (7) ◽  
pp. 539-542 ◽  
Author(s):  
Brian E. Burke ◽  
Robert M. Pfister
Keyword(s):  
Bacillus Subtilis ◽  
Temperature Sensitivity ◽  
Resistant Strain ◽  
Resistant Mutant ◽  
Growth Conditions ◽  
Growth Media ◽  
Saturation Kinetics ◽  
Cadmium Transport ◽  
Energy Dependent ◽  
Kinetics Of

Cadmium uptake by a Cd2+-sensitive (1A1) and a Cd2+-resistant mutant (1A1r) strain of Bacillus subtilis was investigated. Uptake of 109Cd2+ was determined for cells of both strains grown in tryptone broth and in broth containing tryptone, yeast extract, and glucose (TYG). The extent of 109Cd2+ uptake by cells of 1A1r was less than by cells of 1A1 under both growth conditions. In both growth media, 109Cd2+ uptake by 1A1 cells demonstrated saturation kinetics and was energy dependent. In both TYG and tryptone broth, 109Cd2+ uptake by 1A1 cells was inhibited by the addition of unlabeled Mn2+. Although lower in magnitude, the kinetics of 109Cd2+ uptake by 1A1r cells were similar to those of 1A1 cells when grown in tryptone broth. However, no obvious saturation kinetics, energy dependence, temperature sensitivity, or inhibition of 109Cd2+ uptake by the addition of unlabeled Mn2+ was observed in 1A1r cells grown in TYG. Differential Mn2+ accumulation by 1A1r cells in TYG and tryptone broth correlated with differential 109Cd2+ uptake by 1A1r cells in these media.

scholarly journals Self-consistent modeling of MBE self-catalyzed GaAs nanowire growth

2021 ◽  
Vol 2086 (1) ◽  
pp. 012008
Author(s):  
S V Fedina ◽  
A A Koryakin ◽  
V V Fedorov ◽  
G A Sapunov ◽  
I S Mukhin
Keyword(s):  
Molecular Beam ◽  
Growth Conditions ◽  
Nanowire Growth ◽  
Material Transport ◽  
Evaporation Coefficient ◽  
Catalyst Droplet ◽  
Gaas Nanowires ◽  
Gaas Nanowire ◽  
The Given ◽  
Kinetics Of

Abstract Self-catalyzed GaAs nanowires are synthesized by molecular beam epitaxy at various arsenic fluxes and growth temperatures. The growth of GaAs nanowires is simulated considering the kinetics of material transport inside the catalyst droplet. The re-evaporation coefficient of arsenic is estimated for the given growth conditions. Calculated nanowire growth rate is in satisfactory agreement with the experimental data.

scholarly journals Cathodoluminescence of Diamond: Features of Visualization

Crystals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1522
Author(s):  
Evgeny Vasilev ◽  
Dmitry Zedgenizov ◽  
Dmitry Zamyatin ◽  
Igor Klepikov ◽  
Anton Antonov
Keyword(s):  
Steady State ◽  
Growth Conditions ◽  
Optical Microscope ◽  
Nitrogen Vacancy ◽  
Hydrogen Atoms ◽  
Vacancy Defects ◽  
Factors Affecting ◽  
Natural Diamonds ◽  
Versus Color ◽  
Kinetics Of

Zonal and sectorial heterogeneities in natural diamonds provide information on the growth conditions and post-growth changes. Cathodoluminescence (CL) microscopy revealed these heterogeneities in a very detailed manner with high spatial resolution. In this study, factors affecting the CL images of two natural diamonds were analyzed and the results of cathodoluminescence studies in steady-state (SS-CL) and scanning modes were compared. SS-CL was observed using an optical microscope, and scanning mode was evaluated via SEM (SEM-CL). It was demonstrated that the relative brightness of the <111> and <100> growth sectors in diamond crystals depends on the nature of defects in them and on the method of image detection (steady-state/scanning versus color/panchromatic). The differences between SS-CL and SEM-CL images can be attributed to the kinetics of luminescence and spectral sensitivity of the detectors. It was established that the nature of lattice defects around small inclusions can be changed (e.g., the intensity of blue luminescence from nitrogen-vacancy defects (N3V) decreases due to their transformation into nitrogen–hydrogen defects (N3VH). The hydrogen disproportion between the sectors is caused by different growth mechanisms. Hydrogen atoms in the diamond matrix can affect the kinetics of transformation of the defects by transforming a part of N3V to N3VH.

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