States Dynamic

Yoshizawa FI, McGuiggan P and Israelaohvili J N 1993 Identification of a second dynamic state during stick-slip motion Science 259 1305-8... 

In the surrounding atmosphere, a blast wave is experienced as a transient change in gas-dynamic-state parameters pressure, density, and particle velocity. Generally, these parameters increase rapidly, then decrease less rapidly to sub-ambient values (i.e., develop a negative phase). Subsequently, parameters slowly return to atmospheric values (Figure 3.7). The shape of a blast wave is highly dependent on the nature of the explosion process. 

If the combustion process within a gas explosion is relatively slow, then expansion is slow, and the blast consists of a low-amplitude pressure wave that is characterized by a gradual increase in gas-dynamic-state variables (Figure 3.7a). If, on the other hand, combustion is rapid, the blast is characterized by a sudden increase in the gas-dynamic-state variables a shock (Figure 3.7b). The shape of a blast wave changes during propagation because the propagation mechanism is nonlinear. Initial pressure waves tend to steepen to shock waves in the far field, and wave durations tend to increase. 

The similarity solution for a flow field in front of a steady piston is a special case from a much larger class of similarity solutions in which certain well-defined variations in piston speed are allowed (Guirguis et al. 1983). The similarity postulate for variable piston speed solutions, however, sets stringent conditions for the gas-dynamic state of the ambient medium. These conditions are unrealistic within the scope of these guidelines, so discussion is confined to constant-velocity solutions. 

Once the piston-driven flow field is known, the flame-driven flow field is found by fitting in a steady flame front, with the condition that the medium behind it is quiescent. This may be accomplished by employing the jump conditions which relate the gas-dynamic states on either side of a flame front. The condition that the reaction products behind the flame are at rest enables the derivation of expressions for the density ratio, pressure ratio, and heat addition... 

Monomeric actin binds ATP very tightly with an association constant Ka of 1 O M in low ionic strength buffers in the presence of Ca ions. A polymerization cycle involves addition of the ATP-monomer to the polymer end, hydrolysis of ATP on the incorporated subunit, liberation of Pi in solution, and dissociation of the ADP-monomer. Exchange of ATP for bound ADP occurs on the monomer only, and precedes its involvement in another polymerization cycle. Therefore, monomer-polymer exchange reactions are linked to the expenditure of energy exactly one mol of ATP per mol of actin is incorporated into actin filaments. As a result, up to 40% of the ATP consumed in motile cells is used to maintain the dynamic state of actin. Thus, it is important to understand how the free energy of nucleotide hydrolysis is utilized in cytoskeleton assembly. 

Equilibrium is a dynamic state. Although there is no net change in the concentration of substrates or products, individual substrate and product molecules are continually being interconverted. 

High purity products require the careful control of the column because of its dynamic state. 

Because batch processes are in a dynamic state, it can be difficult to maintain the required product specification throughout the batch. Thus, storage can help to dampen out variations in product quality for fluid products. Variations in the outlet properties from the storage are reduced compared with variations in the inlet properties for fluid products. As long as the mean quality is within specifications, all of the product can be sold. 

Only in the last decades has the thermodynamics of open systems been treated intensively and successfully. The thermodynamics of irreversible systems was studied initially by Lars Onsager, and in particular by Ilya Progogine and his Brussels school both studied systems at conditions far from equilibrium. Certain systems have the capacity to remain in a dynamic state far from equilibrium by taking up free energy as a result, the entropy of the environment increases (see Sect. 9.1). 

It is also evident that this phenomenological approach to transport processes leads to the conclusion that fluids should behave in the fashion that we have called Newtonian, which does not account for the occurrence of non-Newtonian behavior, which is quite common. This is because the phenomenological laws inherently assume that the molecular transport coefficients depend only upon the thermodyamic state of the material (i.e., temperature, pressure, and density) but not upon its dynamic state, i.e., the state of stress or deformation. This assumption is not valid for fluids of complex structure, e.g., non-Newtonian fluids, as we shall illustrate in subsequent chapters. 

Collier, N., and Schelsinger, M. J. (1986). The dynamic state of heat shock proteins in chicken embryo fibroblasts. J. Cell Biol. 103, 1495—1507. 

The total classical energy E = H. The Schrodinger equation for the wave function. .. rn,t) which describes the dynamical state of the system is obtained by defining E and p as the differential operators... 

The rate of rewarming is especially critical. One has to differentiate between quasistatic situations, which are independent of time and all other dynamic states, in which the history of the present situation and the rate of the further changes play an important role. 

The multichannel procedure introduces an alternative approach to the problem of dynamic state-parameter estimation. The decoupling of the state estimator from... 

In HPLC, the mobile phase is constantly passing through the column at a finite rate. The sample injections are made rapidly in the dynamic state in the form of a narrow band or plug (see Fig. 15.1), which provides a significant advantage over older stop-flow injection techniques in HPLC. After a sample has been injected as a narrow band, the separation can then be envisioned as a three-step process shown in the figure ... 

If 15N ammonium citrate was administered, and glutamate, aspartate, and glycine isolated from liver and intestinal wall protein, all showed 15N uptake. From the results of labeling studies, Schoenheimer finished his Edward K.Dunham lectures in Harvard in 1941 with the phrase— the structural materials [of the body] are in a steady state of flux. The classical picture must thus be replaced by one which takes account of the dynamic state of body structure —an idea which has become an integral part of biochemistry since that time, and which was almost totally dependent on the introduction of isotopes for its discovery. 

Schoenheimer, R. (1942). The Dynamic State of Body Constituents. (Republished 1964). Hafner Publishing, New York. 

D. Jourd heuil, K. Hallen, M. Feelisch, M. B. Grisham, Dynamic State of S-Nitroso-thiols in Human Plasma and Whole Blood , Free Radical Biol. Med. 2000, 28, 409-417. 

Schoenheimer s concept of the dynamic state of body proteins did not remain unchallenged. In 1955, Monod and co-workers studied the origin of amino acids utilized for the synthesis of newly induced j8-galactosidase in growing E. coli [4]. 

Robert Hecht-Nielsen, the inventor of one of the first commercial neurocomputers, defined [17] a neural network as a computing system made up of a number of simple, highly interconnected processing elements, which process information by its dynamic state response to external inputs. ... 

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