Effects of Temperature and Charge Depletion on the Spin Density in Hydrogenated Amorphous Silicon

1991 ◽  
Vol 219 ◽  
Author(s):  
J.-K. Lee ◽  
E. A. Schiff
Keyword(s):  
Spin Density ◽  
Negative Charge ◽  
Temperature Dependent ◽  
Defect Model ◽  
Depletion Width ◽  
Initial Charge ◽  
Effects Of Temperature ◽  
Hydrogenated Amorphous ◽  
Spin Densities ◽  
Charge Depletion

ABSTRACTThe dependence of the spin density upon temperature and charge depletion is calculated based on the standard defect model in a-Si:H of a D-center with positive, neutral, and negative charge states. The results are compared with recent measurements of depletion width modulated spin densities and temperature-dependent spin densities. It is shown that the initial charge density assumed for the defect system substantially affects conclusions regarding electronic correlation energies drawn from the measurements.

1/f Noise in Mott Variable Range Hopping Conduction in p-type Amorphous Silicon

2015 ◽  
Vol 1770 ◽  
pp. 25-30 ◽  
Author(s):  
V.C. Lopes ◽  
A.J. Syllaios ◽  
D. Whitfield ◽  
K. Shrestha ◽  
C.L. Littler
Keyword(s):  
Electrical Conductivity ◽  
Amorphous Silicon ◽  
Chemical Vapor ◽  
Variable Range Hopping ◽  
Temperature Dependent ◽  
Noise Component ◽  
Variable Range ◽  
Noise Measurements ◽  
P Type ◽  
Hydrogenated Amorphous

ABSTRACTWe report on electrical conductivity and noise measurements made on p-type hydrogenated amorphous silicon (a-Si:H) thin films prepared by Plasma Enhanced Chemical Vapor Deposition (PECVD). The temperature dependent electrical conductivity can be described by the Mott Variable Range Hopping mechanism. The noise at temperatures lower than ∼ 400K is dominated by a 1/f component which follows the Hooge model and correlates with the Mott conductivity. At high temperatures there is an appreciable G-R noise component.

scholarly journals Global dynamics of a Huanglongbing model with a periodic latent period

2021 ◽  
Vol 0 (0) ◽  
pp. 0
Author(s):  
Yan Hong ◽  
Xiuxiang Liu ◽  
Xiao Yu
Keyword(s):  
Reproduction Number ◽  
Threshold Value ◽  
Transmission Model ◽  
Threshold Dynamics ◽  
Global Dynamics ◽  
Temperature Dependent ◽  
Candidatus Liberibacter ◽  
Effects Of Temperature ◽  
Disease Free ◽  
The Basic Reproduction Number

<p style='text-indent:20px;'>Huanglongbing (HLB) is a disease of citrus that caused by phloem-restricted bacteria of the Candidatus Liberibacter group. In this paper, we present a HLB transmission model to investigate the effects of temperature-dependent latent periods and seasonality on the spread of HLB. We first establish disease free dynamics in terms of a threshold value <inline-formula><tex-math id="M1">\begin{document}$ R^p_0 $\end{document}</tex-math></inline-formula>, and then introduce the basic reproduction number <inline-formula><tex-math id="M2">\begin{document}$ \mathcal{R}_0 $\end{document}</tex-math></inline-formula> and show the threshold dynamics of HLB with respect to <inline-formula><tex-math id="M3">\begin{document}$ R^p $\end{document}</tex-math></inline-formula> and <inline-formula><tex-math id="M4">\begin{document}$ \mathcal{R}_0 $\end{document}</tex-math></inline-formula>. Numerical simulations are further provided to illustrate our analytic results.</p>

scholarly journals Emission Characteristics of Fluorescent Labels with Respect to Temperature Changes and Subsequent Effects on DNA Microchip Studies

2005 ◽  
Vol 71 (10) ◽  
pp. 6453-6457 ◽  
Author(s):  
Wen-Tso Liu ◽  
Jer-Horng Wu ◽  
Emily Sze-Ying Li ◽  
Ezrein Shah Selamat
Keyword(s):  
Melting Curve ◽  
Melting Curve Analysis ◽  
Emission Characteristics ◽  
Fluorescent Labels ◽  
Temperature Dependent ◽  
Temperature Changes ◽  
Formamide Concentration ◽  
Effects Of Temperature ◽  
Microarray Studies ◽  
Texas Red

ABSTRACT The effects of temperature, salt concentration, and formamide concentration on the emission characteristics of commonly used fluorescent labels were evaluated on DNA microchips. The emission intensities of different fluorophores without hybridization were observed to vary, each to a different extent, to mainly temperature changes. Rhodamine red, TAMRA (tetramethylrhodamine), and dyes from the carbocyanide group exhibited the largest variations, and Texas Red and Oregon Green exhibited the smallest variations. This temperature dependency was shown to affect results obtained during melting curve analysis in DNA microarray studies. To minimize the bias associated with the temperature-dependent emission of different fluorescent labels, a normalization step was proposed.

Supercell thunderstorm charge structure variability and influences on spatial lightning flash relationships with the updraft

2021 ◽  
Author(s):  
Christopher J. Schultz ◽  
Daniel J. Cecil
Keyword(s):  
Negative Charge ◽  
Spatial Scales ◽  
Subsequent Development ◽  
Lightning Flash ◽  
Charge Structure ◽  
Kinematic Characteristics ◽  
Tennessee Valley ◽  
Initial Charge ◽  
Supercell Thunderstorm ◽  
Cloud Ice

Abstract Relationships between lightning flashes and thunderstorm kinematics and microphysics are important for applications such as nowcasting of convective intensity. These relationships are influenced by cloud electrification structures and have been shown to vary in anomalously electrified thunderstorms. This study addresses transitional relationships between active charge structure and lightning flash location in the context of kinematic and microphysical updraft characteristics during the development of an anomalously electrified supercell thunderstorm in the Tennessee Valley on 10 April 2009. The initial charge structure within the updraft was characterized as an anomalous dipole in which positive charge was inferred in regions of precipitation ice (i.e., graupel and hail) and negative charge was inferred in regions of cloud ice (i.e., aggregates and ice crystals). During subsequent development of the anomalous charge structure, additional minor charge layers as well as evidence of increasing horizontal complexity were observed. Microphysical and kinematic characteristics of the charge structure also evolved to include increasing observations of negative charge in precipitation ice regions, indicating the emergence of more prominent normal charging alongside dominant anomalous charging. Simultaneously, lightning flash initiation locations were also increasingly observed in regions of faster updrafts and stronger horizontal gradients in updraft speed. It is suggested that continuous variability in charging behavior over meso-gamma spatial scales influenced the evolution of lightning flash locations with respect to the updraft structure. Further work is necessary to determine how this variability may impact lightning flash relation-ships, including lightning flash rate, with bulk microphysical and kinematic characteristics and related applications.

EFFECTS OF TEMPERATURE-DEPENDENT COUPLING CONSTANT EVOLUTION ON THE UNIFICATION SCALE

1987 ◽  
Vol 02 (07) ◽  
pp. 479-485 ◽  
Author(s):  
K. ENQVIST ◽  
K. KAJANTIE
Keyword(s):  
Gauge Coupling ◽  
Coupling Constants ◽  
Thermal Bath ◽  
Coupling Constant ◽  
Temperature Dependent ◽  
Cosmological Context ◽  
Effects Of Temperature

We discuss how the evolution of gauge coupling constants is affected by a thermal bath, the existence of which is natural to assume in a cosmological context. The temperature dependent renormalization prescription induced by the thermal bath can cause sizeable effects, and the unification scale is shifted from the value computed from the coupling constant evolution in vacuum.

scholarly journals Shakedown Analysis of a Composite Cylinder With a Cross-Hole

2011 ◽  
Vol 133 (3) ◽  
Author(s):  
Haofeng Chen ◽  
Weihang Chen ◽  
Tianbai Li ◽  
James Ure
Keyword(s):  
Composite Cylinder ◽  
Temperature Dependent ◽  
Matching Method ◽  
Shakedown Analysis ◽  
Plasticity Limit ◽  
Material Discontinuities ◽  
Effects Of Temperature ◽  
Shakedown Limit ◽  
Composite Cylinders ◽  
Linear Matching Method

In this study, both the lower and upper bound shakedown limits of a closed-end composite cylinder with or without a cross-hole subject to constant internal pressure and a cyclic thermal gradient are calculated by the linear matching method. Convergence for the upper and lower bound shakedown limits of the composite cylinders is sought and shakedown limit interaction diagrams of the numerical applications identifying the regions of reverse plasticity limit and ratchet limit are presented. The effects of temperature-dependent yield stress, material discontinuities, composite cylinder thickness, and the existence of the cross-hole on the shakedown limits are discussed for different geometry parameters. Finally, a safety shakedown envelope is created by formulating the shakedown limit results of different composite materials and cylinder thickness ratios with different cross-hole sizes.

THE EFFECTS OF TEMPERATURE ON DIFFERENT LASER TRANSITIONS OF NEODYMIUM ORTHOVANADATE CRYSTAL

2016 ◽  
Vol 78 (3) ◽  
Author(s):  
Ganesan Krishnan ◽  
Noriah Bidin
Keyword(s):  
Laser Diode ◽  
Ground State ◽  
Phonon Scattering ◽  
Laser Crystal ◽  
Laser System ◽  
Temperature Dependent ◽  
Laser Transition ◽  
Level Laser ◽  
Effects Of Temperature ◽  
Terminal Level

The temperature dependence of Nd:YVO4 laser crystal pumped by laser diode emitting at 808 nm is studied within the range of 5 oC to 60 oC. The spectroscopy properties of quasi three level at 914 nm (4F3/2 - 4I 9/2) and four level at 1064 nm (4F3/2 - 4I 11/2) are characterized. The lineshape function of the transition lines were broadened as the temperature increases. The phenomenon is attributed to change in linewidth, lineshift and intensity. The linewidths for both laser transition of 914 nm and 1064 nm increases with temperature with the rate of 0.105 cm-1/oC and 0.074 cm-1/oC respectively. The peak of 914nm and 1064 nm lineshapes shifted to a longer wavelength with the rate of 3.0 pm/oC and 4.2 pm/oC respectively which correspond to same amount of lineshift. The lineshape broadening with respect to the temperature is due to one-phonon emission and Raman phonon scattering processes.  The intensities of 914 nm and 1064 nm transition lines are found to be decreased at the rate of 0.15 %/oC and 0.45 %/oC respectively due to non-radiative effects. Quasi three level laser transition is more temperature dependent because it terminal level is close to the ground state which suffers from higher phonon-ion interaction rather than four level laser system.

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