Steady state and transient transport in a-Si, Ge : H, F alloys

During the last two decades the macroscopic formulation of moisture transport in wood below the fiber saturation point has motivated many research efforts. From experiments the difference in steady-state and transient transport processes is well known, but could not be explained in a fully physically motivated manner. In the following article, first the microstructure of wood is depicted, followed by a description of the physical background of steady-state and transient transport processes in wood, and thereon based mathematical formulations. For a correct macroscopic description of transient transport processes, three coupled differential equations have to be solved in parallel, which is done using the finite element method. The validation of the whole model by comparison of model predictions with experimentally derived values is currently in progress and will be published in near future.

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Ultrafast dynamics of carriers and phonons of photoinjected double-plasma in aluminium nitride

Revista Mexicana de Física ◽

10.31349/revmexfis.67.318 ◽

2021 ◽

Vol 67 (2 Mar-Apr) ◽

pp. 318

Author(s):

C. Gonçalves Rodrigues ◽

R. Luzzi

Keyword(s):

Steady State ◽

Aluminum Nitride ◽

Electric Fields ◽

Scientific Community ◽

Theoretical Study ◽

Operator Method ◽

Ultrafast Dynamics ◽

Transient Transport ◽

Nonequilibrium Temperature ◽

Statistical Operator

Aluminum nitride is attracting great interest of the industry and scientific community due to its interesting properties. In this paper is performed a theoretical study on the ultrafast transient transport properties of photoinjected carriers in wurtzite AlN subjected to electric fields up to 80 kV/cm. For this, the Nonequilibrium Statistical Operator Method was used. The evolution towards the steady state of drift velocity of carriers (electrons and holes) and nonequilibrium temperature (carriers and phonons) subpicosecond scale were determined.

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How changes in the crystal temperature and the doping concentration impact upon bulk wurtzite zinc oxide’s electron transport response

MRS Advances ◽

10.1557/adv.2019.225 ◽

2019 ◽

Vol 4 (50) ◽

pp. 2673-2678

Author(s):

Poppy Siddiqua ◽

Walid A. Hadi ◽

Michael S. Shur ◽

Stephen K. O’Leary

Keyword(s):

Monte Carlo ◽

Steady State ◽

Electron Transport ◽

Drift Velocity ◽

Doping Concentration ◽

Electron Drift ◽

Crystal Temperature ◽

Transient Transport ◽

Transport Response ◽

The Impact

ABSTRACTThe role that changes in the crystal temperature and the doping concentration play in shaping the character of the steady-state and transient transport response of electrons within bulk wurtzite zinc oxide will be examined. Monte Carlo electron transport simulations are drawn upon for the purposes of this analysis. We find that both the crystal temperature and the doping concentration greatly influence the character of the steady-state and transient electron transport response. In particular, for the case of steady-state electron transport, the peak drift velocity decreases by 30% as the crystal temperature is increased from 100 to 700 K, this decrease in velocity being only 20% as the doping concentration is increased from 1015 to 1019 cm-3. The impact on the transient electron drift velocity is not as acute.

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Monte Carlo study of steady-state and transient transport in wurtzite InN

physica status solidi (c) ◽

10.1002/pssc.200564146 ◽

2006 ◽

Vol 3 (3) ◽

pp. 598-601 ◽

Cited By ~ 6

Author(s):

V. M. Polyakov ◽

F. Schwierz ◽

D. Fritsch ◽

H. Schmidt

Keyword(s):

Monte Carlo ◽

Steady State ◽

Monte Carlo Study ◽

Transient Transport

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Steady-state and transient transport studies of gas permeation through dense membranes using on-line mass spectrometry

Separation and Purification Technology ◽

10.1016/j.seppur.2017.12.026 ◽

2018 ◽

Vol 197 ◽

pp. 18-26 ◽

Cited By ~ 5

Author(s):

Sofia C. Fraga ◽

Maria A. Azevedo ◽

Isabel M. Coelhoso ◽

Carla Brazinha ◽

João G. Crespo

Keyword(s):

Mass Spectrometry ◽

Steady State ◽

Gas Permeation ◽

Transient Transport ◽

Transport Studies ◽

Line Mass ◽

On Line

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Studies on Water in the Hydration Chamber of a Modified Electron Microscope

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100069715 ◽

1970 ◽

Vol 28 ◽

pp. 544-545

Author(s):

R. C. Moretz ◽

G. G. Hausner ◽

D. F. Parsons

Keyword(s):

Thin Film ◽

Thin Films ◽

Electron Microscope ◽

Steady State ◽

Room Temperature ◽

Small Mass ◽

Equilibrium Pressure ◽

Biological Objects ◽

Mechanical Pump ◽

Differential Pumping

Use of the electron microscope to examine wet objects is possible due to the small mass thickness of the equilibrium pressure of water vapor at room temperature. Previous attempts to examine hydrated biological objects and water itself used a chamber consisting of two small apertures sealed by two thin films. Extensive work in our laboratory showed that such films have an 80% failure rate when wet. Using the principle of differential pumping of the microscope column, we can use open apertures in place of thin film windows.Fig. 1 shows the modified Siemens la specimen chamber with the connections to the water supply and the auxiliary pumping station. A mechanical pump is connected to the vapor supply via a 100μ aperture to maintain steady-state conditions.

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Continuous hydrogenolysis of acetal-stabilized lignin in flow

Green Chemistry ◽

10.1039/d0gc02928a ◽

2021 ◽

Author(s):

Wu Lan ◽

Yuan Peng Du ◽

Songlan Sun ◽

Jean Behaghel de Bueren ◽

Florent Héroguel ◽

...

Keyword(s):

Steady State ◽

Challenges And Opportunities

We performed a steady state high-yielding depolymerization of soluble acetal-stabilized lignin in flow, which offered a window into challenges and opportunities that will be faced when continuously processing this feedstock.

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