An approach for the determination of the preconsolidation pressure in sensitive clays

1980 ◽  
Vol 17 (3) ◽  
pp. 446-453 ◽  
Author(s):  
S. Leroueil ◽  
J. P. LeBihan ◽  
F. Tavenas
Keyword(s):  
Pore Pressure ◽  
Theoretical Basis ◽  
Axial Stress ◽  
New Method ◽  
One Stage ◽  
Preconsolidation Pressure ◽  
Constant Rate ◽  
Constant Gradient ◽  
Oedometer Tests

The present methods for the determination of the preconsolidation pressure of clays are time consuming and expensive. A new method is proposed in which the clay is loaded in a "one-stage loading" to an axial stress in excess of the estimated preconsolidation pressure. The preconsolidation pressure is determined from the observation of the pore pressure dissipation within a few hours. The theoretical basis of this method is also used to discuss the method of interpreting constant rate of strain and constant gradient oedometer tests.

Theoretical Basis and Standardization of the One-Stage Lysis Time Method for Determination of Urokinase

1968 ◽  
Vol 19 (01/02) ◽  
pp. 169-177 ◽  
Author(s):  
W Berg ◽  
K Korsan-Bengtsen ◽  
J Ygge
Keyword(s):  
Theoretical Basis ◽  
One Stage ◽  
Lysis Time ◽  
The One ◽  
Standard Graph

SummaryThe theroretical basis for the use of a one-stage lysis time method for determination of urokinase is outlined. The calculations are based on experiments with purified plasminogen, fibrinogen, and thrombin preparations.The following correlation between the lysis time and the urokinase, plasminogen, and fibrinogen concentrations was found : This correlation is valid onyl for a certain range of plasminogen and urokinase concentrations. This validity has been verified experimentally.A method has been proposed for determination of urokinase in which the curve of the standard graph always is rectilinear and has the slope –0.5. The method is very sensitive and its accuracy is great.

scholarly journals Oedometer tests - an aid in determination of the geological load history?

1996 ◽  
Vol 43 ◽  
pp. 41-50
Author(s):  
Grete Thorsen
Keyword(s):  
Effect Of Temperature ◽  
Test Results ◽  
Load History ◽  
Ice Caps ◽  
Preconsolidation Pressure ◽  
Significant Difference ◽  
Model Set ◽  
Set Up ◽  
Oedometer Tests

The paper describes the results of oedometer tests carried out with samples from Eemian fresh-water deposits and the methods used to determine the preconsolidation pressure from the test results. The influence of creep in the material on the apparent preconsolidation pressure is estimated from a model set up by Moust Jacobsen in 1992. The test results do not show any significant difference in the determined values of the overconsolidation ratio (OCR) for the samples from Hollerup and SolsØ, east and west of the main stationary line for the last ice sheet in Weichselian, respectively. The results, however, te11 nothing about the kind of actions, which has caused the overconsolidation. The determined OCR-values might be due to previous ice caps but a big difference in the two values from Solso indicates a considerable influence from other actions. The sediments from Hollerup and SolsØ are not identical, and the effect of temperature, chemical and biological processes on the apparent preconsolidation pressure has not been evaluated.

scholarly journals Laboratory and field determination of preconsolidation pressures at Gloucester

1983 ◽  
Vol 20 (3) ◽  
pp. 477-490 ◽  
Author(s):  
S. Leroueil ◽  
L. Samson ◽  
M. Bozozuk
Keyword(s):  
Test Site ◽  
Test Methods ◽  
Strain Rate Effects ◽  
Oedometer Test ◽  
Undisturbed Samples ◽  
Preconsolidation Pressure ◽  
Constant Rate ◽  
Rate Effects

In recent literature several special test methods have been proposed to measure the preconsolidation pressure of a compressible clay soil. Five methods, in addition to the conventional oedometer test, were applied to the marine clays from the Gloucester test site. The preconsolidation pressures measured using these laboratory tests were compared with that mobilized in situ below the centre of a test embankment. The investigation showed that the preconsolidation pressure is directly related to the rate of strain and that special techniques such as constant rate of strain, controlled gradient, single-stage loading, and anisotropic triaxial consolidation tend to overestimate the in-situ preconsolidation pressure. The conventional oedometer test using a load increment ratio of 0.5 and a reloading schedule of 24 h applied to good-quality undisturbed samples produced preconsolidation pressures that compared best with the in-situ values. Keywords: preconsolidation pressure, laboratory, in situ, strain rate effects, disturbance.

A new method for the determination of nitrates

1960 ◽  
Vol 23 ◽  
pp. 227-232 ◽  
Author(s):  
P WEST ◽  
G LYLES
Keyword(s):  
New Method

A New Method for the Determination of Plasma Activators of Fibrinolysis

1977 ◽  
Vol 37 (02) ◽  
pp. 210-215 ◽  
Author(s):  
R Margalit ◽  
E Gidron ◽  
Y Shalitin
Keyword(s):  
New Method ◽  
Effective Activator

SummaryThe term “effective activator” of plasminogen is proposed, to denote the resultant of activator-antiactivator interaction, and a method for the determination of the level of these activators is described. By adding axcess plasminogen to the euglobulin fraction of plasma the influence of the level of endogenous plasminogen and of the antiplasmin is eliminated. It is shown that the level of fibrinogen has very little bearing on the results. An effective activator unit is defined as equal to 1 CTA unit of urokinase activity on a fibrinogen-plasminogen substrate.

Two-Stage Procedure for the Quantitative Determination of Autoprothrombin III Concentration and Some Applications

1967 ◽  
Vol 18 (01/02) ◽  
pp. 198-210 ◽  
Author(s):  
Ronald S Reno ◽  
Walter H Seegers
Keyword(s):  
Prothrombin Time ◽  
Factor Vii ◽  
Two Stage ◽  
Pronounced Increase ◽  
One Stage ◽  
Assay Procedure ◽  
Bovine Plasma ◽  
The One ◽  
Autoprothrombin C

SummaryA two-stage assay procedure was developed for the determination of the autoprothrombin C titre which can be developed from prothrombin or autoprothrombin III containing solutions. The proenzyme is activated by Russell’s viper venom and the autoprothrombin C activity that appears is measured by its ability to shorten the partial thromboplastin time of bovine plasma.Using the assay, the autoprothrombin C titre was determined in the plasma of several species, as well as the percentage of it remaining in the serum from blood clotted in glass test tubes. Much autoprothrombin III remains in human serum. With sufficient thromboplastin it was completely utilized. Plasma from selected patients with coagulation disorders was assayed and only Stuart plasma was abnormal. In so-called factor VII, IX, and P.T.A. deficiency the autoprothrombin C titre and thrombin titre that could be developed was normal. In one case (prethrombin irregularity) practically no thrombin titre developed but the amount of autoprothrombin C which generated was in the normal range.Dogs were treated with Dicumarol and the autoprothrombin C titre that could be developed from their plasmas decreased until only traces could be detected. This coincided with a lowering of the thrombin titre that could be developed and a prolongation of the one-stage prothrombin time. While the Dicumarol was acting, the dogs were given an infusion of purified bovine prothrombin and the levels of autoprothrombin C, thrombin and one-stage prothrombin time were followed for several hours. The tests became normal immediately after the infusion and then went back to preinfusion levels over a period of 24 hrs.In other dogs the effect of Dicumarol was reversed by giving vitamin K1 intravenously. The effect of the vitamin was noticed as early as 20 min after administration.In response to vitamin K the most pronounced increase was with that portion of the prothrombin molecule which yields thrombin. The proportion of that protein with respect to the precursor of autoprothrombin C increased during the first hour and then started to go down and after 3 hrs was equal to the proportion normally found in plasma.

The Plasmin Inhibitors of Plasma

1964 ◽  
Vol 12 (01) ◽  
pp. 119-125 ◽  
Author(s):  
Y Shamash ◽  
A Rimon
Keyword(s):  
Human Plasma ◽  
New Method ◽  
Normal Amount ◽  
Caseinolytic Activity ◽  
Before And After ◽  
Plasmin Inhibitors

SummaryA new method for the assay of plasmin inhibitors in human plasma is described. The method consists of determination of the caseinolytic activity of a standard plasmin solution before and after incubation with the inhibitor, with lysine added to the mixture as a stabilizer of plasmin. Using this method, it was found that plasma contains enough inhibitors to inactivate 30 caseinolytic units of plasmin, or 10 times the normal amount of plasminogen in human plasma.

AGGLUTINATION INHIBITION REACTIONS FOR THE DETERMINATION OF GONADOTROPHINS

1969 ◽  
Vol 62 (1_Suppl) ◽  
pp. S95-S112 ◽  
Author(s):  
A. H. W. M. Schuurs
Keyword(s):  
Immune System ◽  
Quantitative Determination ◽  
Haemagglutination Inhibition ◽  
Latex Agglutination ◽  
Literature Survey ◽  
New Method ◽  
Test Fluid ◽  
Main Application ◽  
Test Systems

ABSTRACT Various techniques for sensitising erythrocytes and latex particles with gonadotrophins, particularly with HCG, are described. The haemagglutination inhibition reactions are generally interpreted by means of »erythrocyte settling patterns«. By a new method of evaluating these patterns a relatively precise quantitative determination is possible. Latex agglutination inhibition reactions on slides are particularly suitable as rapid qualitative tests. In cases where the maximum attainable sensitivity of the agglutination inhibition tests is insufficient, e. g. for determining LH concentrations in urine, the hormone in the test fluid has to be concentrated or extracted. An alternative method is a modified haemagglutination inhibition test for large volumes which is applicable to unconcentrated urine. Due to non-specific inhibitions the above-mentioned tests cannot be applied to unprocessed serum. Agglutination inhibition tests with HCG are already well advanced, pregnancy diagnosis being their main application. Now that highly purified HCG is available, a satisfactory specificity for these tests can be attained. If the immune system for HCG is used for estimating LH, it has to meet additional specificity requirements. Furthermore, the measure of cross-reaction and the choice of standard merit special attention. Finally, a literature survey is given of test systems in which LH and FSH were used as antigens.

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