Thermodynamic and Kinetic Properties of Prebiological Open Systems

1996 ◽  
pp. 239-247
Author(s):  
L. N. Moiseeva
Keyword(s):  
Open Systems ◽  
Kinetic Properties

Chromatographic Isolation of the LDH-Isoenzymes of Human Blood Platelets and an Investigation of Their Enzyme Kinetics

1968 ◽  
Vol 20 (03/04) ◽  
pp. 301-313 ◽  
Author(s):  
W Schneider ◽  
K Schumacher ◽  
B Thiede ◽  
R Gross
Keyword(s):  
Human Blood ◽  
Blood Platelets ◽  
Deae Cellulose ◽  
Order Reaction ◽  
Kinetic Properties ◽  
Ldh Isoenzymes ◽  
Kinetic Investigations ◽  
Substrate Concentrations ◽  
Chromatographic Isolation ◽  
Human Blood Platelets

SummaryThe LDH-isoenzymes of human blood platelets show a distinct predominance of the isoenzymes 2 and 3 upon chromatography on DEAE-cellulose. Small amounts of LDH-1 are also present, while only traces of LDH-4 and -5 can be detected.Enzyme kinetic investigations of the principal isoenzymes LDH-1, -2 and -3 clearly show that the differences in inhibition constants with pyruvate as substrate which are demonstrable at 25° largely disappear at 37°. On the other hand, the differences among the isoenzymes in their affinity for pyruvate and lactate as substrate as well as in with respect to the optimal substrate concentrations of pyruvate are more marked at 37° than at 25°. Also, the type of inhibition found with lactate as substrate is increasingly the expression of a higher order reaction in going from LDH-1 to LDH-3. A dependence of the LDH distribution pattern upon the metabolism of the cell is discussed. A comparison of our results with thrombocytes with those of other workers with erythrocytes and leucocytes makes it unlikely that the LDH pattern is directly dependent upon the existence of an oxidative metabolism. Rather, the redox potential of the cell could be of importance for the nature of the pattern of isoenzymes and for their differing kinetic properties.

MODELLING AND CONTROL OF OPEN SYSTEMS

2016 ◽  
Vol 7 (1) ◽  
pp. 1-19
Author(s):  
Neto José Alves da Silva ◽  
◽  
Giacaglia Giorgio Eugenio Oscare ◽  
Lamas Wendell de Queiroz ◽  
Bargos Fabiano Fernandes ◽  
...  
Keyword(s):  
Open Systems ◽  
And Control

Phase equilibria in partially open systems under pressure: the decomposition of stoichiometric GeO2 oxide

2003 ◽  
Vol 173 (12) ◽  
pp. 1359 ◽  
Author(s):  
Vadim V. Brazhkin ◽  
Roman N. Voloshin ◽  
A.G. Lyapin ◽  
Svetlana V. Popova
Keyword(s):  
Phase Equilibria ◽  
Open Systems

Effect of CeO$lt;inf$gt;2$lt;/inf$gt;-based Solid Solutions on Hydrogen Storage Kinetic Properties of Mg$lt;inf$gt;2$lt;/inf$gt;Ni Alloy

2014 ◽  
Vol 29 (12) ◽  
pp. 1241
Author(s):  
ZHANG Guo-Fang ◽  
ZHANG Yang-Huan ◽  
LIU Zhuo-Cheng ◽  
XU Jian-Yi ◽  
ZHANG Yin
Keyword(s):  
Hydrogen Storage ◽  
Solid Solutions ◽  
Kinetic Properties ◽  
Ni Alloy

Thermal Decomposition Kinetics of Torrefied Oil Palm Empty Fruit Bunch Briquettes

2016 ◽  
Vol 10 (3) ◽  
pp. 325-328 ◽  
Author(s):  
Bemgba Nyakuma ◽  
◽  
Arshad Ahmad ◽  
Anwar Johari ◽  
Tuan Abdullah ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Oil Palm ◽  
Decomposition Kinetics ◽  
Thermal Decomposition Kinetics ◽  
Kinetic Properties ◽  
Tg Analysis ◽  
Empty Fruit Bunches ◽  
Thermal Lag ◽  
Profile Characteristics ◽  
Kinetics Of

The study is aimed at investigating the thermal behavior and decomposition kinetics of torrefied oil palm empty fruit bunches (OPEFB) briquettes using a thermogravimetric (TG) analysis and the Coats-Redfern model. The results revealed that thermal decomposition kinetics of OPEFB and torrefied OPEFB briquettes is significantly influenced by the severity of torrefaction temperature. Furthermore, the temperature profile characteristics; Tonset, Tpeak, and Tend increased consistently due to the thermal lag observed during TG analysis. In addition, the torrefied OPEFB briquettes were observed to possess superior thermal and kinetic properties over the untorrefied OPEFB briquettes. It can be inferred that torrefaction improves the fuel properties of pelletized OPEFB for potential utilization in bioenergy conversion systems.

Catastrophe Theory in Explaining Price Dynamics on the Real Estate Market

2013 ◽  
Vol 21 (3) ◽  
pp. 51-61 ◽  
Author(s):  
Mirosław Belej
Keyword(s):  
Real Estate ◽  
Catastrophe Theory ◽  
Open Systems ◽  
Real Estate Market ◽  
Sensitivity Threshold ◽  
State Variables ◽  
The Real ◽  
The Real Estate ◽  
The Real Estate Market ◽  
External Stimuli

Abstract The real estate market is an open system, which implies that it is able to exchange signals with other open systems and dynamic systems. The evolution of a market system over time can be described mathematically. If the system's sensitivity threshold to external stimuli is exceeded, it becomes destabilized and moves from a near-balanced state to a state that is far from equilibrium. Those dynamic processes often induce key changes in the system's trajectory of evolution. In search of equilibrium, the system becomes transformed in a process of discontinuous and discrete changes in state variables. The above statement constitutes the research hypothesis in this article. In this study, an attempt was made to develop a mathematical model for visualizing the evolutionary path of the real estate market in the form of continuous changes interrupted by discontinuous changes. The qualitative transformation of the system will be evaluated with the use of the catastrophe theory.

Regioselective Gas-Phase n-Butane Transfer Dehydrogenation via Silica-Supported Pincer-Iridium Complexes

2020 ◽  
Author(s):  
Boris Sheludko ◽  
Cristina Castro ◽  
Chaitanya Khalap ◽  
Thomas Emge ◽  
Alan Goldman ◽  
...  
Keyword(s):  
Gas Phase ◽  
Active Site ◽  
Lower Cost ◽  
Open Systems ◽  
Iridium Complexes ◽  
Terminal Olefin ◽  
Molecular Precursors ◽  
Sterically Demanding ◽  
Olefin Production ◽  
Steam Cracking

<b>Abstract:</b> The production of olefins via on-purpose dehydrogenation of alkanes allows for a more efficient, selective and lower cost alternative to processes such as steam cracking. Silica-supported pincer-iridium complexes of the form [(≡SiO-<sup>R4</sup>POCOP)Ir(CO)] (<sup>R4</sup>POCOP = κ<sup>3</sup>-C<sub>6</sub>H<sub>3</sub>-2,6-(OPR<sub>2</sub>)<sub>2</sub>) are effective for acceptorless alkane dehydrogenation, and have been shown stable up to 300 °C. However, while solution-phase analogues of such species have demonstrated high regioselectivity for terminal olefin production under transfer dehydrogenation conditions at or below 240 °C, in open systems at 300 °C, regioselectivity under acceptorless dehydrogenation conditions is consistently low. In this work, complexes <a>[(≡SiO-<i><sup>t</sup></i><sup>Bu4</sup>POCOP)Ir(CO)] </a>(<b>1</b>) and [(≡SiO-<i><sup>i</sup></i><sup>Pr4</sup>PCP)Ir(CO)] (<b>2</b>) were synthesized via immobilization of molecular precursors. These complexes were used for gas-phase butane transfer dehydrogenation using increasingly sterically demanding olefins, resulting in observed selectivities of up to 77%. The results indicate that the active site is conserved upon immobilization.

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