Role of element solubility on the kinetics of element partitioning: In situ observations and a thermodynamic kinetic model

2003 ◽  
Vol 108 (B3) ◽  
Author(s):  
Ralf Dohmen ◽  
Sumit Chakraborty ◽  
Herbert Palme ◽  
Werner Rammensee
Keyword(s):  
Kinetic Model ◽  
Element Partitioning ◽  
In Situ Observations ◽  
Kinetics Of

scholarly journals Phosphorylation of GAPVD1 Is Regulated by the PER Complex and Linked to GAPVD1 Degradation

2021 ◽  
Vol 22 (7) ◽  
pp. 3787
Author(s):  
Hussam Ibrahim ◽  
Philipp Reus ◽  
Anna Katharina Mundorf ◽  
Anna-Lena Grothoff ◽  
Valerie Rudenko ◽  
...  
Keyword(s):  
Circadian Clock ◽  
Transcriptional Repression ◽  
Small Gtpase ◽  
Main Role ◽  
Interacting Proteins ◽  
Casein Kinase 1 ◽  
Bona Fide ◽  
Kinetics Of

Repressor protein period (PER) complexes play a central role in the molecular oscillator mechanism of the mammalian circadian clock. While the main role of nuclear PER complexes is transcriptional repression, much less is known about the functions of cytoplasmic PER complexes. We found with a biochemical screen for PER2-interacting proteins that the small GTPase regulator GTPase-activating protein and VPS9 domain-containing protein 1 (GAPVD1), which has been identified previously as a component of cytoplasmic PER complexes in mice, is also a bona fide component of human PER complexes. We show that in situ GAPVD1 is closely associated with casein kinase 1 delta (CSNK1D), a kinase that regulates PER2 levels through a phosphoswitch mechanism, and that CSNK1D regulates the phosphorylation of GAPVD1. Moreover, phosphorylation determines the kinetics of GAPVD1 degradation and is controlled by PER2 and a C-terminal autoinhibitory domain in CSNK1D, indicating that the regulation of GAPVD1 phosphorylation is a novel function of cytoplasmic PER complexes and might be part of the oscillator mechanism or an output function of the circadian clock.

In situ synchrotron XRD analysis of the kinetics of spodumene phase transitions

2018 ◽  
Vol 20 (16) ◽  
pp. 10753-10761 ◽  
Author(s):  
Radhika L. Moore ◽  
Jason P. Mann ◽  
Alejandro Montoya ◽  
Brian S. Haynes
Keyword(s):  
Phase Transitions ◽  
Kinetic Model ◽  
Xrd Analysis ◽  
Kinetics Of ◽  
Synchrotron Xrd

A kinetic model for the decomposition of α-spodumene and γ-spodumene is derived using in situ XRD to monitor the transitions.

Effect of pH on the Grain Size Dependence of Magnesium Corrosion

CORROSION ◽  
2012 ◽  
Vol 68 (6) ◽  
pp. 507-517 ◽  
Author(s):  
K. D. Ralston ◽  
G. Williams ◽  
N. Birbilis
Keyword(s):  
Grain Size ◽  
Corrosion Rate ◽  
Anodic Polarization ◽  
Localized Corrosion ◽  
Anodic Reaction ◽  
Left Behind ◽  
Kinetics Of ◽  
Electrode Technique

Prior works show that grain size can play a role in the corrosion of a metal; however, such works are nominally executed in a single electrolyte/environment at a single pH. In this work, the anodic and cathodic reaction kinetics of pure Mg specimens with grain sizes ranging from approximately 8 μm to 590 μm were compared as a function of pH in 0.1 mol dm−3 sodium chloride (NaCl) electrolytes using anodic polarization experiments and an in situ scanning vibrating electrode technique (SVET). Anodic polarization experiments showed that grain size is important in determining overall electrochemical response, but the environment dictates the form of the grain size vs. corrosion rate relationship (i.e., pH is the overall controlling factor). Consequently, the role of grain size upon corrosion cannot be fully assessed unless a variation in environment is simultaneously studied. For example, the anodic reaction, which dictates active corrosion, also dictates passivation, so the corrosion rate vs. grain size relationship has been shown to “flip” depending on pH. Further, SVET analysis of unpolarized Mg immersed in 0.1 mol dm−3 NaCl electrolyte at neutral pH showed that breakdown of passivity of cast Mg occurred after ~1 h immersion, giving filiform-like corrosion tracks. The front edges of these corrosion features were revealed as intense local anodes, while the remainder of the dark-corroded Mg surface, left behind as the anodes traversed the surface, became cathodically activated. In contrast, grain-refined Mg samples were significantly less susceptible to localized corrosion, and breakdown was not observed for immersion periods of up to 24 h.

scholarly journals The role of DYNAMO in situ observations in improving NASA CERES-like daily surface and atmospheric radiative flux estimates

2017 ◽  
Vol 4 (4) ◽  
pp. 164-183 ◽  
Author(s):  
Hailan Wang ◽  
Wenying Su ◽  
Norman G. Loeb ◽  
Deepthi Achuthavarier ◽  
Siegfried D. Schubert
Keyword(s):  
Radiative Flux ◽  
In Situ Observations

Solubility and reaction kinetics of solution–solid reactions determined by in situ observations

Nature ◽  
1991 ◽  
Vol 351 (6328) ◽  
pp. 634-636 ◽  
Author(s):  
H. Ohmoto ◽  
K. Hayashi ◽  
K. Onuma ◽  
K. Tsukamoto ◽  
A. Kitakaze ◽  
...  
Keyword(s):  
Reaction Kinetics ◽  
In Situ Observations ◽  
Kinetics Of

scholarly journals Role of Convective Precipitation in the Relationship between Subdaily Extreme Precipitation and Temperature

2017 ◽  
Vol 30 (23) ◽  
pp. 9527-9537 ◽  
Author(s):  
In-Hong Park ◽  
Seung-Ki Min
Keyword(s):  
South Korea ◽  
Extreme Precipitation ◽  
Physical Effect ◽  
Convective Precipitation ◽  
Statistical Effect ◽  
Convective Process ◽  
In Situ Observations ◽  
The Relationship

On a subdaily time scale, the intensities of extreme precipitation are observed to increase with temperature at a rate exceeding water vapor constraints determined by the Clausius–Clapeyron (C-C) relationship. This so-called super C-C scaling has been suggested to occur as a result of 1) the statistical effect that involves the transition of precipitation types from stratiform to convective events and 2) the physical effect by which the convective process itself can overcome the thermodynamic limitation. This study examines these two mechanisms for the super C-C relationship using in situ observations in South Korea for a recent 35-yr period, focusing on the role of convective rainfall. Scaling results show that hourly extreme precipitation undergoes a transition from a C-C rate to a super C-C rate at around 20°C, supporting the statistical effect. The transition temperature observed in South Korea is, however, much higher than in European regions (12°C), which seems to be due to the climatologically lower frequency of convective events in South Korea than in Europe. Nevertheless, the threshold fraction of convective precipitation when the scaling transition starts to occur is found to very similar between two regions, around 0.2, indicating the important role of convective events in shaping the scaling. On the other hand, convective extreme precipitation alone exhibits a super C-C scaling, suggesting that the physical effect is also at work in South Korea. Also, the scaling shows a robust peaklike shape with maximum precipitation intensity near 24°C, which is closely linked with moisture limitation at high temperature, supporting the previous findings.

The Effect of Different Oxidizing Atmospheres on the Initial Kinetics of Copper Oxidation as Studied In Situ UHV-TEM

1999 ◽  
Vol 589 ◽  
Author(s):  
Mridula D. Bharadwaj ◽  
Anu Gupta ◽  
J. Murray Gibson ◽  
Judith C. Yang
Keyword(s):  
Water Vapor ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Solid State Reactions ◽  
Copper Oxidation ◽  
High Vacuum Condition ◽  
Ultra High Vacuum Condition ◽  
Kinetics Of

AbstractEffect of moisture on the oxidation of copper was studied using in situ UHV-TEM. The ultra high vacuum condition is required for minimum contamination effects. The initial observations show that the water vapor reduces the oxide as well as reduces the rate of oxidation if both oxygen gas and water vapor are simultaneously used. Based on these observations, we have speculated on the role of moisture in the solid state reactions involved in copper oxidation

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