COMPETITION BETWEEN TWO MICROORGANISMS IN THE CHEMOSTAT WITH GENERAL VARIABLE YIELDS AND GENERAL GROWTH RATES

2008 ◽  
Vol 01 (04) ◽  
pp. 463-474 ◽  
Author(s):  
JIANMEI LUO ◽  
SANLING YUAN ◽  
WEIGUO ZHANG
Keyword(s):  
Asymptotic Behavior ◽  
Continuous Culture ◽  
Growth Rates ◽  
Local Stability ◽  
Nutrient Concentration ◽  
Yield Coefficient ◽  
General Growth ◽  
Oscillatory Coexistence

A model of competition between two organisms in the chemostat is studied in this paper, where it is assumed that the yield coefficients and growth rates are general functions of the nutrient concentration. We give a characterization of the outcome of this competition in terms of the relevant parameters in hyperbolic cases: conditions of the existence and local stability of the rest points are obtained, and the global asymptotic behavior of the solutions is analyzed. In contrast to the corresponding model with constant yields rate, it is demonstrated that the variability of the yield coefficient may lead to oscillatory coexistence of two microorganisms in continuous culture.

A Competition Chemostat with General Variable Yield and Growth Rates in the Presence of a Internal Inhibitor

2011 ◽  
Vol 110-116 ◽  
pp. 285-293
Author(s):  
Jian Mei Luo ◽  
Yu Ming Feng
Keyword(s):  
Hopf Bifurcation ◽  
Qualitative Analysis ◽  
Limit Cycles ◽  
Growth Rates ◽  
Local Stability ◽  
Nutrient Concentration ◽  
The Other ◽  
Global Asymptotical Stability ◽  
Variable Yield ◽  
Increasing Function

This paper considered two organisms competing for a nutrient in the chemostat in the presence of an inhibitor, where the yields and growth rates are general increasing function of the nutrient concentration. The inhibitor is produced by one organisms and is lethal to the other organism. By the theory of qualitative analysis for ordinary equations, first, conditions of the existence and local stability of the rest points are obtain; then the global asymptotical stability, the existence of limit cycles and Hopf bifurcation are discussed.

Characterization of β-Ga2O3 homoepitaxial films and MOSFETs grown by MOCVD at high growth rates

2021 ◽  
Author(s):  
Marko J. Tadjer ◽  
Fikadu Alema ◽  
Andrei Osinsky ◽  
Michael Mastro ◽  
Neeraj Nepal ◽  
...  
Keyword(s):  
Growth Rates ◽  
High Growth

scholarly journals Electromagnetic Gauge Choice for Scattering of Schrödinger Particle

2019 ◽  
Vol 20 (11) ◽  
pp. 3633-3650
Author(s):  
Andrzej Herdegen
Keyword(s):  
Asymptotic Behavior ◽  
External Electromagnetic Field ◽  
Asymptotic Completeness ◽  
Free Evolution ◽  
Wave Operators ◽  
Radiation Fields ◽  
Mechanical Evolution ◽  
Scattering Wave ◽  
Free Fields

Abstract We consider a Schrödinger particle placed in an external electromagnetic field of the form typical for scattering settings in the field theory: $$F=F^\mathrm {ret}+F^\mathrm {in}=F^\mathrm {adv}+F^\mathrm {out}$$ F = F ret + F in = F adv + F out , where the current producing $$F^{\mathrm {ret}/\mathrm {adv}}$$ F ret / adv has the past and future asymptotes homogeneous of degree $$-3$$ - 3 , and the free fields $$F^{\mathrm {in}/\mathrm {out}}$$ F in / out are radiation fields produced by currents with similar asymptotic behavior. We show that with appropriate choice of electromagnetic gauge the particle has ‘in’ and ‘out’ states reached with no further modification of the asymptotic dynamics. We use a special quantum mechanical evolution ‘picture’ in which the free evolution operator has well-defined limits for $$t\rightarrow \pm \infty $$ t → ± ∞ , and thus the scattering wave operators do not need the free evolution counteraction. The existence of wave operators in this setting is established, but the proof of asymptotic completeness is not complete: more precise characterization of the asymptotic behavior of the particle for $$|\mathbf {x}|=|t|$$ | x | = | t | would be needed.

Growth and Characterization of bulk GaN by Ga Vapor Transport

2004 ◽  
Vol 831 ◽  
Author(s):  
Phanikumar Konkapaka ◽  
Huaqiang Wu ◽  
Yuri Makarov ◽  
Michael G. Spencer
Keyword(s):  
Growth Rates ◽  
Vapor Transport ◽  
Spiral Growth ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Bulk Gan ◽  
Diffraction Patterns

ABSTRACTBulk GaN crystals of dimensions 8.5 mm × 8.5 mm were grown at growth rates greater than 200μm/hr using Gallium Vapor Transport technique. GaN powder and Ammonia were used as the precursors for growing bulk GaN. Nitrogen is used as the carrier gas to transport the Ga vapor that was obtained from the decomposition of GaN powder. During the process, the source GaN powder was kept at 1155°C and the seed at 1180°C. Using this process, it was possible to achieve growth rates of above 200 microns/hr. The GaN layers thus obtained were characterized using X-Ray diffraction [XRD], scanning electron microscopy [SEM], and atomic force microscopy [AFM]. X-ray diffraction patterns showed that the grown GaN layers are single crystals oriented along c direction. AFM studies indicated that the dominant growth mode was dislocation mediated spiral growth. Electrical and Optical characterization were also performed on these samples. Hall mobility measurements indicated a mobility of 550 cm2/V.s and a carrier concentration of 6.67 × 1018/cm3

Single Crystal Wurtzitic Aluminum Nitride Growth on Silicon Using Supersonic Gas Jets

1995 ◽  
Vol 395 ◽  
Author(s):  
S. A. Ustin ◽  
L. Lauhon ◽  
K. A. Brown ◽  
D. Q. Hu ◽  
W. Ho
Keyword(s):  
Aluminum Nitride ◽  
Growth Rates ◽  
High Energy ◽  
X Ray Diffraction ◽  
Rutherford Back Scattering ◽  
X Ray ◽  
Supersonic Molecular Beam ◽  
Supersonic Beams ◽  
Wide Range

ABSTRACTHighly oriented aluminum nitride (0001) films have been grown on Si(001) and Si (111) substrates at temperatures between 550° C and 775° C with dual supersonic molecular beam sources. Triethylaluminum (TEA;[(C2H5)3Al]) and ammonia (NH3) were used as precursors. Hydrogen, helium, and nitrogen were used as seeding gases for the precursors, providing a wide range of possible kinetic energies for the supersonic beams due to the disparate masses of the seed gases. Growth rates of AIN were found to depend strongly on the substrate orientation and the kinetic energy of the incident precursor; a significant increase in growth rate is seen when seeding in hydrogen or helium as opposed to nitrogen. Growth rates were 2–3 times greater on Si(001) than on Si(111). Structural characterization of the films was done by reflection high energy electron diffraction (RHEED) and x-ray diffraction (XRD). X-ray rocking curve (XRC) full-width half-maxima (FWHM) were seen as small as 2.5°. Rutherford back scattering (RBS) was used to determine the thickness of the films and their chemical composition. Films were shown to be nitrogen rich, deviating from perfect stoichiometry by 10%–20%. Surface analysis was performed by Auger electron spectroscopy (AES).

Isolation and Physiological Characterization of Thiothrix sp.

1994 ◽  
Vol 29 (7) ◽  
pp. 261-269 ◽  
Author(s):  
V. Tandoi ◽  
N. Caravaglio ◽  
D. Di Dio Balsamo ◽  
M. Majone ◽  
M. C. Tomei
Keyword(s):  
Growth Yield ◽  
Maximum Growth ◽  
Maximum Growth Rate ◽  
Yield Coefficient ◽  
Simultaneous Presence ◽  
Mixotrophic Growth ◽  
Physiological Characterization ◽  
South Italy ◽  
Mixotrophic Conditions

Thiothrix CT3 was isolated in pure culture by micromanipulation technique. The growth of this microorganism was analyzed in autotrophic, heterotrophic and mixotrophic conditions, in a bicarbonate-containing mineral medium supplemented with thiosulphate and/or acetate. Thiothrix CT3 was able to grow in all the conditions examined: the maximum growth rates estimated were 1.8, 2.5 and 2.5 d−1 respectively. The capacity of this organism to grow autotrophically, as supposed by Winogradsky in 1888, is a strong advantage over the other bacteria present in activated sludge, when sulphides are produced or carried by the sewer. Both the maximum growth rate and growth yield coefficient shown during heterotrophic and mixotrophic growth were comparable, indicating that the simultaneous presence of two substrates (acetate and a reduced sulphur compound) does not give it any particular advantage. The strong presence of Thiothrix spp. in many plants located in South Italy can be explained by the wide nutritional versatility of this filamentous bacterium.

scholarly journals On a New Characterization of Some Class Nonlinear Eigenvalue Problem

2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
Lutfi Akin
Keyword(s):  
Asymptotic Behavior ◽  
Eigenvalue Problem ◽  
Nonlinear Eigenvalue Problem ◽  
Normal Mode Analysis ◽  
Mode Analysis ◽  
Electrical System ◽  
Eigenvalues And Eigenfunctions ◽  
Complete Study ◽  
Nonlinear Eigenvalue

A normal mode analysis of a vibrating mechanical or electrical system gives rise to an eigenvalue problem. Faber made a fairly complete study of the existence and asymptotic behavior of eigenvalues and eigenfunctions, Green’s function, and expansion properties. We will investigate a new characterization of some class nonlinear eigenvalue problem.

Asymptotic behavior of near-critical multitype branching processes

1991 ◽  
Vol 28 (03) ◽  
pp. 512-519 ◽  
Author(s):  
Fima C. Klebaner
Keyword(s):  
Asymptotic Behavior ◽  
Population Size ◽  
Discrete Time ◽  
Growth Rates ◽  
Branching Processes ◽  
Sufficient Conditions ◽  
Limiting Distribution ◽  
Size Dependent ◽  
Generalized Gamma ◽  
Multitype Branching Processes

Sufficient conditions for survival and extinction of multitype population-size-dependent branching processes in discrete time are obtained. Growth rates are determined on the set of divergence to infinity. The limiting distribution of a properly normalized process can be generalized gamma, normal or degenerate.

scholarly journals Characterization of Virulent Bacteriophage Infections of Escherichia coli in Continuous Culture

Science ◽  
1971 ◽  
Vol 172 (3981) ◽  
pp. 405-405 ◽  
Author(s):  
M. J. B. Paynter ◽  
H. R. Bungay ◽  
M. T. Horne
Keyword(s):  
Escherichia Coli ◽  
Continuous Culture
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