Determination of Diffusivity From Steady-state Mass Transfer Measurements in a Continuous Dialyzer Under Conditions of Non-zero Solution Flux Through a Membrane

2009 ◽  
Vol 32 (12) ◽  
pp. 1909-1915 ◽  
Author(s):  
Z. Palatý ◽  
H. Bendová
Keyword(s):  
Mass Transfer ◽  
Steady State ◽  
Zero Solution

Comparison of methods for the determination of KLaO2 for respirometric measurements

2004 ◽  
Vol 50 (11) ◽  
pp. 153-161 ◽  
Author(s):  
S. Pratt ◽  
R. Zeng ◽  
Z. Yuan ◽  
J. Keller
Keyword(s):  
Mass Transfer ◽  
Steady State ◽  
Recovery Period ◽  
Process Conditions ◽  
Comparison Of Methods ◽  
Steady State Method ◽  
Mass Balancing ◽  
State Method ◽  
The Given

The mass transfer coefficient for oxygen in water (KLaO2) is an important parameter for respirometric studies. But determination of KLaO2 in process conditions is not straightforward. In this paper, two distinct procedures for determining KLaO2 in process conditions are outlined and tested. The off-gas method relies on a gas mass balance over a bioreactor while the non-steady state methods rely on analysing DO recovery after perturbation. Various means for inducing perturbation are tested and compared. KLaO2 values for a bioreactor are determined by the listed methods. It was found that the off-gas method resulted in the highest KLaO2 for the given reactor, while the non-steady state method, whereby perturbation is caused by exogenous activity on acetate, resulted in the lowest KLaO2. It is shown that the gas mass balancing technique is robust to unexpected exogenous activity (caused by for example, the oxidation of storage polymers formed or nitrite accumulated), while the non-steady state methods that involve inducing perturbations by exogenous activity appear susceptible to such continued exogenous activity in the DO recovery period.

STEADY-STATE DETERMINATION OF FUEL-BOND NITROGEN IN DIESEL AND INDUSTRIAL GAS OIL

Clean Air ◽  
2007 ◽  
Vol 8 (4) ◽  
pp. 359-371
Author(s):  
A. Medeiros ◽  
R. Edenhofer ◽  
K. Lucka ◽  
H. Kohne
Keyword(s):  
Steady State ◽  
Gas Oil ◽  
State Determination

Calcium Budgets for Catchments as Interpreted by Strontium Isotopes

1989 ◽  
Vol 20 (2) ◽  
pp. 85-96 ◽  
Author(s):  
Gunnar Jacks ◽  
Göran Åberg ◽  
P. Joseph Hamilton
Keyword(s):  
Steady State ◽  
Forest Ecosystem ◽  
Coniferous Forest ◽  
Strontium Isotopes ◽  
Runoff Water ◽  
Weathering Rate ◽  
Weathering Rates ◽  
Exchangeable Calcium

Strontium isotopes in precipitation, soil and runoff water can be used to establish a ratio of wet plus dry deposited Sr to Sr released by weathering. This ratio is especially enhanced in areas with old acid Proterozoic rocks (0.6-2.5 Ga) and Archean rocks (>2.5 Ga). Since Sr and Ca behave in an analogous way in the coniferous forest ecosystem the results for Sr can be used for the determination of Ca. If the deposition of calcium can be calculated reasonably accurately the weathering rate can also be estimated. Five catchments have been investigated using this approach. Three of them seem to be close to a steady state, wherein the losses and gains of calcium to the system are equal. In the two southern-most catchments there seems to be an ongoing loss of exchangeable calcium. The loss by runoff occurs with sulphate being the dominant anion. Weathering rates of 1.5 to 4.8 kg Ca/ha year have been estimated.

A Graphical Method for Storage Coefficient Determination from Quasi-Steady State Flow Data

1996 ◽  
Vol 27 (4) ◽  
pp. 247-254 ◽  
Author(s):  
Zekâi Şen
Keyword(s):  
Steady State ◽  
Graphical Method ◽  
Pumping Test ◽  
Quasi Steady State ◽  
Flow Data ◽  
Steady State Flow ◽  
Storage Coefficient ◽  
State Flow ◽  
Aquifer Test

A simple, approximate but practical graphical method is proposed for estimating the storage coefficient independently from the transmissivity value, provided that quasi-steady state flow data are available from a pumping test. In the past, quasi-steady state flow distance-drawdown data have been used for the determination of transmissivity only. The method is applicable to confined and leaky aquifers. The application of the method has been performed for various aquifer test data available in the groundwater literature. The results are within the practical limits of approximation compared with the unsteady state flow solutions.

Operational Determination of the Activated Sludge Process Using Neural Networks

1992 ◽  
Vol 26 (9-11) ◽  
pp. 2461-2464 ◽  
Author(s):  
R. D. Tyagi ◽  
Y. G. Du
Keyword(s):  
Neural Network ◽  
Neural Networks ◽  
Steady State ◽  
Activated Sludge ◽  
Feedforward Neural Network ◽  
Training Data ◽  
Activated Sludge Process

A steady-statemathematical model of an activated sludgeprocess with a secondary settler was developed. With a limited number of training data samples obtained from the simulation at steady state, a feedforward neural network was established which exhibits an excellent capability for the operational prediction and determination.

scholarly journals Steady State Response of Linear Time Invariant Systems Modeledby Multibond Graphs

2021 ◽  
Vol 11 (4) ◽  
pp. 1717
Author(s):  
Gilberto Gonzalez Avalos ◽  
Noe Barrera Gallegos ◽  
Gerardo Ayala-Jaimes ◽  
Aaron Padilla Garcia
Keyword(s):  
Steady State ◽  
Linear Time ◽  
Direct Determination ◽  
The State ◽  
Steady State Response ◽  
State Variables ◽  
Linear Time Invariant ◽  
State Response ◽  
Time Invariant

The direct determination of the steady state response for linear time invariant (LTI) systems modeled by multibond graphs is presented. Firstly, a multiport junction structure of a multibond graph in an integral causality assignment (MBGI) to get the state space of the system is introduced. By assigning a derivative causality to the multiport storage elements, the multibond graph in a derivative causality (MBGD) is proposed. Based on this MBGD, a theorem to obtain the steady state response is presented. Two case studies to get the steady state of the state variables are applied. Both cases are modeled by multibond graphs, and the symbolic determination of the steady state is obtained. The simulation results using the 20-SIM software are numerically verified.

scholarly journals Steady state determination of sarcoplasmic reticulum ATPase intermediates. Their acid lability.

1981 ◽  
Vol 256 (7) ◽  
pp. 3399-3404
Author(s):  
G.L. Alonso ◽  
D.M. Arrigo ◽  
M.V. Soliz-Frieldmeier
Keyword(s):  
Steady State ◽  
Sarcoplasmic Reticulum ◽  
State Determination

Resistance to Outflow of Cerebrospinal Fluid Determined by Bolus Injection Technique and Constant Rate Steady State Infusion in Humans

Neurosurgery ◽  
1985 ◽  
Vol 16 (3) ◽  
pp. 336-340 ◽  
Author(s):  
Michael Kosteljanetz
Keyword(s):  
Cerebrospinal Fluid ◽  
Steady State ◽  
Bolus Injection ◽  
Point Of View ◽  
Injection Technique ◽  
Communicating Hydrocephalus ◽  
Constant Rate ◽  
High Degree ◽  
Infusion Technique

Abstract Two methods for the determination of resistance to the outflow of cerebrospinal fluid, the bolus injection technique and the constant rate steady state infusion technique, were compared. Thirty-two patients with a variety of intracranial diseases (usually communicating hydrocephalus) were studied. There was a high degree of correlation between the resistance values obtained with the two methods, but values based on the bolus injection technique were systematically and statistically significantly lower than those obtained with the constant rate infusion test. From a practical point of view. both methods were found to be applicable in a clinical setting.

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