Model thermodynamics and the role of free-carrier energy at high temperatures: Nitrogen and boron pairing in diamond

2009 ◽  
Vol 80 (5) ◽  
Author(s):  
R. M. MacLeod ◽  
S. W. Murray ◽  
J. P. Goss ◽  
P. R. Briddon ◽  
R. J. Eyre
Keyword(s):  
High Temperatures ◽  
Free Carrier ◽  
Carrier Energy

scholarly journals Molecular Dynamics of Chloroplast Membranes Isolated from Wild-Type Barley and a Brassinosteroid-Deficient Mutant Acclimated to Low and High Temperatures

Biomolecules ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 27
Author(s):  
Iwona Sadura ◽  
Dariusz Latowski ◽  
Jana Oklestkova ◽  
Damian Gruszka ◽  
Marek Chyc ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Temperature Stress ◽  
High Temperatures ◽  
Biological Membrane ◽  
Hydrophobic Core ◽  
Wild Type ◽  
Chloroplast Membranes ◽  
Paramagnetic Resonance ◽  
Photosynthetic Membranes

Plants have developed various acclimation strategies in order to counteract the negative effects of abiotic stresses (including temperature stress), and biological membranes are important elements in these strategies. Brassinosteroids (BR) are plant steroid hormones that regulate plant growth and development and modulate their reaction against many environmental stresses including temperature stress, but their role in modifying the properties of the biological membrane is poorly known. In this paper, we characterise the molecular dynamics of chloroplast membranes that had been isolated from wild-type and a BR-deficient barley mutant that had been acclimated to low and high temperatures in order to enrich the knowledge about the role of BR as regulators of the dynamics of the photosynthetic membranes. The molecular dynamics of the membranes was investigated using electron paramagnetic resonance (EPR) spectroscopy in both a hydrophilic and hydrophobic area of the membranes. The content of BR was determined, and other important membrane components that affect their molecular dynamics such as chlorophylls, carotenoids and fatty acids in these membranes were also determined. The chloroplast membranes of the BR-mutant had a higher degree of rigidification than the membranes of the wild type. In the hydrophilic area, the most visible differences were observed in plants that had been grown at 20 °C, whereas in the hydrophobic core, they were visible at both 20 and 5 °C. There were no differences in the molecular dynamics of the studied membranes in the chloroplast membranes that had been isolated from plants that had been grown at 27 °C. The role of BR in regulating the molecular dynamics of the photosynthetic membranes will be discussed against the background of an analysis of the photosynthetic pigments and fatty acid composition in the chloroplasts.

The role of acetic acid in FeCO3 scale deposition on CO2 corrosion of API X65 carbon steel under high temperatures

2021 ◽  
pp. 1-12
Author(s):  
Bernardo Augusto Farah Santos ◽  
Rhuan Costa Souza ◽  
Maria Eduarda Dias Serenario ◽  
Eugenio Pena Mendes Junior ◽  
Thiago Araujo Simões ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Carbon Steel ◽  
High Temperatures ◽  
Co2 Corrosion ◽  
Scale Deposition

Conduction and Hall measurements ofBa2YCu3O6+δfilms at high temperatures: The role of oxygen

1988 ◽  
Vol 38 (4) ◽  
pp. 2828-2831 ◽  
Author(s):  
A. Davidson ◽  
P. Santhanam ◽  
A. Palevski ◽  
M. J. Brady
Keyword(s):  
High Temperatures ◽  
Hall Measurements

The Role of Leaf Epicuticular Wax in the Adaptation of Wheat ( Triticum aestivum L.) to High Temperatures and Moisture Deficit Conditions

Crop Science ◽  
2018 ◽  
Vol 58 (2) ◽  
pp. 679-689 ◽  
Author(s):  
Suheb Mohammed ◽  
Trevis D. Huggins ◽  
Francis Beecher ◽  
Chris Chick ◽  
Padma Sengodon ◽  
...  
Keyword(s):  
Triticum Aestivum ◽  
High Temperatures ◽  
Triticum Aestivum L ◽  
Epicuticular Wax ◽  
Moisture Deficit ◽  
Leaf Epicuticular Wax

Physiological and morphological effects of climate change

2019 ◽  
pp. 120-133 ◽  
Author(s):  
Andrew E. McKechnie
Keyword(s):  
Climate Change ◽  
Body Mass ◽  
High Temperatures ◽  
Arid Zone ◽  
Future Research ◽  
Long Term Effects ◽  
Adaptation To Climate Change ◽  
Heat Events

The direct impacts of higher temperatures on birds are manifested over timescales ranging from minutes and hours to years and decades. Over short timescales, acute exposure to high temperatures can lead to hyperthermia or dehydration, which among arid-zone species occasionally causes catastrophic mortality events. Over intermediate timescales of days to weeks, high temperatures can have chronic sub-lethal effects via body mass loss or reduced nestling growth rates, negatively affecting sev eral fitness components. Long-term effects of warming manifested over years to decades involve declining body mass or changes in appendage size. Key directions for future research include elucidating the role of phenotypic plasticity and epigenetic processes in avian adaptation to climate change, examining the role of stress pathways in mediating responses to heat events, and understanding the consequences of higher temperatures for species that traverse hot regions while migrating.

Critical role of nanoinclusions in silver selenide nanocomposites as a promising room temperature thermoelectric material

2019 ◽  
Vol 7 (9) ◽  
pp. 2646-2652 ◽  
Author(s):  
Khak Ho Lim ◽  
Ka Wai Wong ◽  
Yu Liu ◽  
Yu Zhang ◽  
Doris Cadavid ◽  
...  
Keyword(s):  
Seebeck Coefficient ◽  
Room Temperature ◽  
Opposite Effect ◽  
Critical Role ◽  
Free Carrier ◽  
Silver Selenide ◽  
Band Bending ◽  
Seebeck Coefficients ◽  
Electrical Conductivities

The introduction of nonmetal nanoinclusions within Ag2Se results in an interphase band bending that promotes electron filtering and increase Seebeck coefficient. Similar loading of metal nanoinclusions provided an opposite effect-modulating free carrier concentration, as characterized by superior electrical conductivities and lower Seebeck coefficients.

The Ultrafast Carrier Dynamics in Semiconductors: The Role of Defects

1995 ◽  
Vol 378 ◽  
Author(s):  
P. M. Fauchet ◽  
G. W. Wicks ◽  
Y. Kostoulas ◽  
A. I. Lobad ◽  
K. B. Ucer
Keyword(s):  
Low Temperature ◽  
Amorphous Silicon ◽  
Point Defects ◽  
Free Carrier ◽  
Carrier Dynamics ◽  
Ultrafast Laser ◽  
Ultrafast Laser Spectroscopy ◽  
Ultrafast Carrier ◽  
Scattering Time

AbstractThe presence of point defects is expected to influence the properties of free carrier in semiconductors. We have used the techniques of ultrafast laser spectroscopy to characterize the dynamics of photoinjected carriers in several III–V semiconductors grown at low temperature. The initial scattering time and the lifetime of the carriers become very short at low growth temperatures. Results obtained with low-temperature grown III–Vs are compared to those obtained with III–Vs grown at normal temperatures and amorphous silicon.

Examining the Role of Free Carrier Concentration on the Phonon Lifetimes in GaN Using Raman Spectroscopy

2007 ◽  
Author(s):  
Thomas Beechem ◽  
Samuel Graham
Keyword(s):  
Raman Spectroscopy ◽  
Thermal Performance ◽  
Uncertainty Relation ◽  
Free Carrier ◽  
Optical Phonons ◽  
Time Uncertainty ◽  
Longitudinal Phonon ◽  
Optical Modes ◽  
Carrier Interaction

The lifetimes of polar optical phonons are known to affect the electrical and thermal performance of gallium nitride (GaN) based devices. Utilizing the energy-time uncertainty relation, this study investigates these lifetimes using Raman spectroscopy for a series of samples having free carrier concentrations ranging from 1.24e18 to 3e17 cm−3. By measuring across the typical operating temperatures of these devices, the mechanisms responsible for scattering of 5 separate optical modes are elucidated. It is found that phonon-carrier interaction directly determines the lifetime of the polar optical A1(LO) mode while indirectly influencing the modes into which this longitudinal phonon decays, namely, E1 and A1(TO). Thus understanding the entire phonon energy cascade is vital both for management of the so called “hot phonon” effect as well as modeling of carrier-phonon interactions.

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