DSpace at TTU: Recent submissions
Now showing items 21-40 of 46706
-
P-model v1.0: an optimality-based light use efficiency model for simulating ecosystem gross primary production
(Copernicus Publications, European Geosciences Union, 2020)Terrestrial photosynthesis is the basis for vegetation growth and drives the land carbon cycle. Accurately simulating gross primary production (GPP, ecosystem-level apparent photosynthesis) is key for satellite monitoring ... -
A reporting format for leaf-level gas exchange data and metadata
(Elsevier, 2021)Leaf-level gas exchange data support the mechanistic understanding of plant fluxes of carbon and water. These fluxes inform our understanding of ecosystem function, are an important constraint on parameterization of ... -
Assessing the role of trap-to-band impact ionization and hole transport on the dark currents of 4H-SiC photoconductive switches containing deep defects
(AIP, 2016)Simulation studies of the electrical response characteristics of 4H-SiC switches containing traps are reported in the absence of photoexcitation. The focus is on trap-to-band impact ionization and the role of hole injection ... -
Comparative evaluation of transmembrane ion transport due to monopolar and bipolar nanosecond, high-intensity electroporation pulses based on full three-dimensional analyses
(AIP, 2017)Electric pulse driven membrane poration finds applications in the fields of biomedical engineering and drug/gene delivery. Here we focus on nanosecond, high-intensity electroporation and probe the role of pulse shape (e.g., ... -
Model predictions for atmospheric air breakdown by radio-frequency excitation in large gaps
(AIP, 2017)The behavior of the breakdown electric field versus frequency (DC to 100 MHz) for different gap lengths has been studied numerically at atmospheric pressure. Unlike previous reports, the focus here is on much larger gap ... -
Monte Carlo analysis of field-dependent electron avalanche coefficients in nitrogen at atmospheric pressure
(AIP, 2017)Calculations of electron impact ionization of nitrogen gas at atmospheric pressure are presented based on the kinetic Monte Carlo technique. The emphasis is on energy partitioning between primary and secondary electrons, ... -
Calculations of secondary electron yield of graphene coated copper for vacuum electronic applications
(AIP, 2018)The suppression of secondary electron yield (SEY) which can possibly lead to multipactor is an important goal for several applications. Though some techniques have focused on geometric modifications to lower the SEY, the ... -
Model evaluations of surface modification by energetic incident carbon atoms on graphene coated copper electrodes
(AIP, 2019)Thin nanoscale coating of metal electrodes by graphene promises to be a useful approach for suppressing the secondary electron yield and potential multipactor. Recent calculations showed reductions by as much as 50% for ... -
Numerical evaluations of membrane poration by shockwave induced multiple nanobubble collapse in presence of electric fields for transport through cells
(AIP, 2019)Synergistic applications of an electric field combined with nanojet-based mechanical pressure, have recently been shown to help create larger pores and provide control of the aspect ratio in biological membranes. The ... -
Probing changes in secondary electron yield from copper electrodes due to surface defects and changes in crystal orientation
(AIP, 2019)There is considerable interest in mitigating secondary electron emission (SEE) from surfaces and electrodes produced by incident electrons, due to the deleterious effects of SEE in vacuum electron devices, accelerators, ... -
Rigorous theory based on transient Eigen expansion rectifying known integral analysis of unsteady viscous encroachment in capillary channels
(2015-08-10)The primary goal of my thesis is to investigate the well known fluid phenomenon of encroachment of a viscous liquid in a narrow channel due to capillary action. This has been achieved by determining the time-dependent ... -
Simulations of hydrogen outgassing and sticking coefficients at a copper electrode surface: Dependencies on temperature, incident angle and energy
(American Physical Society, 2021)Outgassing remains a pertinent issue as it typically is the first stage of possible plasma formation, and can lead to effects such as breakdown, surface flashover, and pulse shortening in high power systems. Here two ... -
Simulations of field emission from copper electrodes with inclusion of oxygen surface layer and work function changes based on first-principles calculations
(AIP, 2020)Analysis of field emission requires the inclusion of the internal potentials that shape the electronic wavefunctions and tunneling probabilities; details of the work function that are dependent on material quality and ... -
Electron emission from metal emitters subject to a high intensity laser in the presence of DC electric fields
(AIP, 2019)Electron emission driven by both a strong DC applied bias and a superimposed laser field is examined through numerical simulations. Heating at the electrode surface that creates a dynamic, nonequilibrium electron distribution ... -
Numerical evaluation of hydrogen outgassing from copper electrodes with mitigation based on a tungsten capping layer
(AIP, 2019)Outgassing remains a pertinent issue for high power applications and is exacerbated by the high field driven, localized heating environments commonly encountered. Here, molecular dynamics simulations are performed for a ... -
Lock-on physics in semi-insulating GaAs: Combination of trap-to-band impact ionization, moving electric fields and photon recycling
(AIP, 2018)The time-dependent photoconductive current response of semi-insulating GaAs is probed based on one-dimensional simulations, with a focus on the lock-on phenomenon. Our results capture most of the experimental observations. ... -
Dynamic analysis of material ejection from cathodic metal nano-tips due to local heating and field generated stress
(AIP, 2018)The potential for explosive cathode emission due to nanoprotrusions subjected to Maxwell stress and heating from strong electric fields is probed self-consistently based on non-equilibrium molecular-dynamics. The focus is ... -
Effect of Thermal Gradients Created by Electromagnetic Fields on Cell-Membrane Electroporation Probed by Molecular-Dynamics Simulations
(American Physical Society, 2017)The use of nanosecond-duration-pulsed voltages with high-intensity electric fields (∼100 kV/cm) is a promising development with many biomedical applications. Electroporation occurs in this regime, and has been attributed ... -
Particle-in-cell based parameter study of 12-cavity, 12-cathode rising-sun relativistic magnetrons for improved performance
(AIP, 2015)Particle-in-cell simulations are performed to analyze the efficiency, output power and leakage currents in a 12-Cavity, 12-Cathode rising-sun magnetron with diffraction output (MDO). The central goal is to conduct a parameter ... -
Asymmetric conduction in biological nanopores created by high-intensity, nanosecond pulsing: Inference on internal charge lining the membrane based on a model study
(AIP, 2015)Nanosecond, high-intensity electric pulses have been reported to open rectifying pores in biological cell membranes. The present goal is to qualitatively understand and analyze the experimental current-voltage (I-V) data. ...