Nanotechnologies of Strength Control of Materials

2021 ◽  
Vol 1040 ◽  
pp. 101-108
Author(s):  
Victor V. Nosov ◽  
Egor V. Grigoriev ◽  
Sabina A. Peretyatko ◽  
Artem P. Artyushchenko
Keyword(s):  
Multilevel Model ◽  
Fatigue Tests ◽  
Scale Level ◽  
Specific Product ◽  
Standard Material ◽  
Before And After ◽  
Ae Signal ◽  
Control Technologies ◽  
Determination Of Parameters

The strength of materials is determined by their atomic molecular structure and the process of decay of atomic molecular bonds, which must be taken into account when optimizing materials strength control technologies. The fracture photomicrograph of metal microdamage of welded joint at various moments of time, a multilevel model of flow of acoustic emission signals of materials are presented. The physical meaning, the scale level of parameters included in the model are revealed. The structure of the mathematical model of the flow of AE signals with components of its informative elements of different scale level by strength characteristics of structural materials and resource of technical objects is shown. The multilevel model of the AE signal flow is hierarchically structured, obtained by generalizing deterministic-statistical variability. It describes the process of randomly recording deterministic accumulated damages in the material both before and after the formation of a crack at the stage of waiting for its next leap. It is shown that the proposed nanotechnology of strength control of materials is reduced to non-destructive determination of parameters of prognostic homogeneous destruction, identification of which is based on multilevel modeling of time dependence of micro-crack formation, formulation of criterion of strength homogeneity, registration of AE parameters related to the model of a specific product, which can be automated processing of registration results and determination of universal strength nanoconstants from already published reference data of fatigue tests of standard material samples.

Determination of Parameters of Endurance Limit Distribution Law of Material by the Methods of Nonparametric Statistics and Kinetic Theory of High-Cycle Fatigue

2017 ◽  
Vol 736 ◽  
pp. 52-57 ◽  
Author(s):  
Ksenia Syzrantseva ◽  
Vladimir Syzrantsev
Keyword(s):  
Kinetic Theory ◽  
Distribution Density ◽  
Endurance Limit ◽  
Nonparametric Statistics ◽  
Fatigue Tests ◽  
Distribution Law ◽  
Distribution Density Function ◽  
Life Tests ◽  
Determination Of Parameters

The paper considers the first developed algorithm of processing the data of specimen life tests based on the kinetic theory of mechanical fatigue and methods of nonparametric statistics. It makes it possible to determine the distribution density function of the material endurance limit. Implementation of the algorithm is illustrated on example of processing the data obtained in fatigue tests of steel 50 specimens.

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.

Determination of parameters of short circuit of power transformer by means of mathematical modeling

2017 ◽  
Vol 26 (102) ◽  
pp. 110-119
Author(s):  
D. S. Yarymbash, ◽  
◽  
S. T. Yarymbash, ◽  
T. E. Divchuk, ◽  
D. A. Litvinov
Keyword(s):  
Mathematical Modeling ◽  
Power Transformer ◽  
Short Circuit ◽  
Determination Of Parameters

FRACTIONAL DETERMINATIONS OF URINARY 17-KETOSTEROIDS IN HYPEREMESIS GRAVIDARUM

1962 ◽  
Vol 41 (1) ◽  
pp. 123-128 ◽  
Author(s):  
Pentti A. Järvinen ◽  
Sykkö Pesonen ◽  
Pirkko Väänänen
Keyword(s):  
Hyperemesis Gravidarum ◽  
First Trimester ◽  
Control Group ◽  
Before And After ◽  
Daily Urine ◽  
First Trimester Of Pregnancy ◽  
The Difference

ABSTRACT The fractional determination of 17-ketosteroids in the daily urine was performed in nine cases of hyperemesis gravidarum and in four control cases, in the first trimester of pregnancy both before and after corticotrophin administration. The excretion of total 17-KS is similar in the two groups. Only in the hyperemesis group does the excretion of total 17-KS increase significantly after corticotrophin administration. The fractional determination reveals no difference between the two groups of patients with regard to the values of the fractions U (unidentified 17-KS), A (androsterone) and Rest (11-oxygenated 17-KS). The excretion of dehydroepiandrosterone is significantly higher in the hyperemesis group than in the control group. The excretion of androstanolone seems to be lower in the hyperemesis group than in the control group, but the difference is not statistically significant. The differences in the correlation between dehydroepiandrosterone and androstanolone in the two groups is significant. The high excretion of dehydroepiandrosterone and low excretion of androstanolone in cases of hyperemesis gravidarum is a sign of adrenal dysfunction.

DETERMINATION OF BLOOD CORTICOIDS USING THE IN VITRO RESIN UPTAKE OF 3H-PREDNISOLONE

1968 ◽  
Vol 57 (1) ◽  
pp. 23-32 ◽  
Author(s):  
Hironori Nakajima ◽  
Mitsunori Murala ◽  
Masumitsu Nakata ◽  
Takeshi Naruse ◽  
Seiji Kubo
Keyword(s):  
Thyroid Function Test ◽  
Normal Subjects ◽  
Adrenal Function ◽  
Function Test ◽  
Before And After ◽  
Adrenal Response ◽  
Suppression Test

ABSTRACT The in vitro resin uptake of 3H-prednisolone was used for the determination of blood cortisol after addition of radioactive prednisolone followed by Amberlite CG 400 Type 1 to the test serum, and incubation of the mixture. The radioactivity of the supernatant was compared before and after the addition of the resin. The principle of this method is similar to that of the 131I-triiodothyronine resin uptake for the thyroid function test. The tests for the specificity, reproducibility and sensitivity gave satisfactory results. The mean basal value ± SD of the 3H-prednisolone resin uptake was 35.3 ± 9.2% in normal subjects, and 27.1 ± 4.8% in pregnant women. This method was valid in various adrenal function tests, i. e. the adrenal circadian rhythm, corticotrophin (ACTH) test, dexamethasone suppression test and the adrenal response to lysine-8-vasopressin. It proved to be a sensitive indicator of the adrenal function. These results suggest that this method should be useful for a routine adrenal function test.

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