Search results for "steady state"
showing 10 items of 173 documents
Nested MWC model describes hydrolysis of GroEL without assuming negative cooperativity in binding
2002
Folding assistance and ATPase activity of GroEL are based on the existence of different conformations. In order to characterise these conformations, published data on steady state ATPase activity in the absence of GroES were reanalysed simultaneously in terms of the Nested MWC model. This model is a hierarchical extension of the symmetry-model of Monod et al. [J. Mol. Biol. 12 (1965) 88]. An unique set of GroEL specific parameters was obtained. This set was supported by comparison of predictions arising from this set of values with experimental data for hydrolysis of ATP in the presence of ADP and ATPgammaS, binding of ATPgammaS and ADP to GroEL in the absence of ATP, and binding of ATP as …
Albumin clearance from human skeletal muscle during prolonged steady-state running.
2001
This study was designed to find out if the lymph flow, indicated as albumin clearance, from active skeletal muscle is maintained constant during a prolonged steady-state exercise. 99mTc-labelled albumin was injected bilaterally into the vastus lateralis muscles of eight endurance-trained men. The radioactivity at the injection site was monitored by a gamma-camera before, frequently during, and after a 2 h run at a controlled steady intensity of 69 +/- 4% of the maximal heart rate. The fractional clearance rate of albumin was calculated for each monitoring interval, and was expressed as percentage clearance per minute (% min(-1)). During the first 15 min of exercise the clearance rate was fi…
Does anaerobic threshold correlate with maximal lactate steady-state?
1992
The aim of this study was to compare the 'anaerobic threshold' (AnT) of subjects determined during a continuous 2-min incremental exercise test until exhaustion and the 'maximal lactate steady-state' (BLaSsmax) determined during prolonged exercise at constant loads corresponding to the subjects' AnT and/or 5-25% above and below it. Seventeen subjects performed an incremental exercise test and 1-5 prolonged exercise tests on a cycle ergometer until exhaustion at intervals of 1 week, and work rates, oxygen uptake (VO2) values and brachial venous blood lactate (BLa) levels were measured. It was proposed that when exercising at a constant workload below AnT, BLa would fall after having reached …
Soil organic carbon stocks under recommended management practices in different soils of semiarid vineyards
2019
The Intergovernmental Panel on Climate Change (IPCC) approach is widely used to estimate the C account through the use of standardized coefficients that are not site specific. For these reasons, the aim of the work was to define specific IPCC coefficient taking into account differences in pedological characteristics that affect soil C steady state. In a vineyard area of Sicily, the effectiveness of 5 years of recommended management practice (RMP) adoption on soil organic carbon (SOC) stock increases was evaluated by considering 100 paired sites distributed over four functional soil groups. Each site consisted of two neighbouring plots. The soil of one plot was managed with cover crops accor…
Adaptive discontinuous evolution Galerkin method for dry atmospheric flow
2014
We present a new adaptive genuinely multidimensional method within the framework of the discontinuous Galerkin method. The discontinuous evolution Galerkin (DEG) method couples a discontinuous Galerkin formulation with approximate evolution operators. The latter are constructed using the bicharacteristics of multidimensional hyperbolic systems, such that all of the infinitely many directions of wave propagation are considered explicitly. In order to take into account multiscale phenomena that typically appear in atmospheric flows nonlinear fluxes are split into a linear part governing the acoustic and gravitational waves and a nonlinear part that models advection. Time integration is realiz…
Numerical and experimental validation of a LiFePO<inf>4</inf> battery model at steady state and transient operations
2013
In the paper some of the battery models proposed in literature are analysed in order to predict the battery performance and, then, make sure that the Battery Management System (BMS) that is a key component to check and control the status of the batteries within their specified safe operating conditions, works in best conditions. In fact to reach an extended battery lifetime and increase the reliability of the system, is necessary to guarantee an accurate evaluation of the state of the whole stack of batteries to track their operations. Therefore, an accurate battery model that captures the dynamics of the battery is required. Lithium batteries are in particular considered because of their h…
Fuel cell modelling for power supply systems design
2008
Today academic and industrial research is addressed on fuel cell based power supply to replace current lithium-ion and similar rechargeable battery systems. For system simulation, fuel cell models are developed. Even if power electronics designers demand for a blackbox model to limit the knowledge of physical and chemical parameters, high performance in terms of model accuracy and portability is absolutely necessary. A steady state and dynamic fuel cell model oriented to power supply systems design is proposed and, as an example, the implementation on PSIM software is presented. Simulation and experimental results are compared and the model portability is discussed. ©2008 IEEE.
A steady state and dynamic fuel cell model including temperature effects
2009
In the last few years fuel cells have attracted much interest from both academic and industrial researchers to replace current lithium-ion and similar rechargeable battery systems. A wide variety of research areas benefit from fuel cell use: electro-chemical, stationary, transportation and portable electronics can be cited as an example. Potential applications range from few watts to megawatts systems. Even concerning quite different scientific areas, fuel cell modelling is a common requirement. The complexity of such a topic relies not only on the modelling approach but also in the model structure and implementation. In this paper a steady state and dynamic fuel cell circuital model includ…
Buckling and nonlinear dynamics of elastically coupled double-beam systems
2016
Abstract This paper deals with damped transverse vibrations of elastically coupled double-beam system under even compressive axial loading. Each beam is assumed to be elastic, extensible and supported at the ends. The related stationary problem is proved to admit both unimodal (only one eigenfunction is involved) and bimodal (two eigenfunctions are involved) buckled solutions, and their number depends on structural parameters and applied axial loads. The occurrence of a so complex structure of the steady states motivates a global analysis of the longtime dynamics. In this regard, we are able to prove the existence of a global regular attractor of solutions. When a finite set of stationary s…