A Method for Calculating Surface Mechanical Stresses in Axisymmetric Magnetic Systems

SummaryHuman platelets exposed to hypotonicity undergo regulatory volume decrease (RVD), controlled by a potent, yet labile, lipoxygenase product (LP). LP is synthesized and excreted during RVD affecting selectively K+ permeability. LP is assayed by its capacity to reconstitute RVD when lipoxygenase is blocked. Centrifugation for preparing washed platelets (1,550 × g, 10 min) is sufficient to express LP activity, with declining potency in repeated centrifugations, indicating that it is not readily replenish-able. When platelet suspension flows in a vinyl tubing (1 mm i.d.), at physiological velocity, controlled at 90–254 cm/s, LP formation increases as a function of velocity but declines as result of increasing the tubing length. Stirring the platelets in an aggregometer cuvette for 30 s, yields no LP unless the stirring is intermittent. No associated platelet lysis or aggregation are observed following the mechanical stress applications. These results demonstrate that although mechanical stresses result in LP production, the mode of its application plays a major role. These results may indicate that LP is synthesized under pathological conditions and could be of relevance to platelets behavior related to arterial stenosis.

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Dynamical chaos in magnetic systems

Uspekhi Fizicheskih Nauk ◽

10.3367/ufnr.0162.199207b.0081 ◽

1992 ◽

Vol 162 (7) ◽

pp. 81 ◽

Cited By ~ 6

Author(s):

K.N. Alekseev ◽

G.P. Berman ◽

V.I. Tsifrinovich ◽

A.M. Frishman

Keyword(s):

Dynamical Chaos ◽

Magnetic Systems

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Direct observation of oscillations of RKKY-interaction in layered magnetic systems

Uspekhi Fizicheskih Nauk ◽

10.3367/ufnr.0162.199204g.0158 ◽

1992 ◽

Vol 162 (4) ◽

pp. 158-163

Author(s):

S.O. Demokritov

Keyword(s):

Direct Observation ◽

Rkky Interaction ◽

Magnetic Systems

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Role of Mechanical Stresses at Ion Implantation of CdHgTe Solid Solutions

Ukrainian Journal of Physics ◽

10.15407/ujpe58.09.0872 ◽

2013 ◽

Vol 58 (9) ◽

pp. 872-880 ◽

Cited By ~ 4

Author(s):

Smirnov A.B. Smirnov A.B. ◽

◽

Lytvyn O.S. Lytvyn O.S. ◽

Morozhenko V.A. Morozhenko V.A. ◽

Savkina R.K. Savkina R.K. ◽

...

Keyword(s):

Ion Implantation ◽

Solid Solutions ◽

Mechanical Stresses

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On the method of ultrasonic control of mechanical stresses

Industrial laboratory Diagnostics of materials ◽

10.26896/1028-6861-2018-84-7-62-66 ◽

2018 ◽

Vol 84 (7) ◽

pp. 62-66

Author(s):

K. V. Kurashkin

Keyword(s):

Elastic Wave ◽

Orientation Distribution ◽

Elastic Wave Velocity ◽

Mechanical Stresses ◽

Material Structure ◽

Stress Determination ◽

Welded Steel ◽

Ultrasonic Control ◽

Cubic Crystallites ◽

Proportional Relationship

A method of ultrasonic control of the mechanical stresses which takes into account the heterogeneity of the material structure and does not require unloading of the structure or using reference samples is considered. The procedure is based on echo-method of measuring time of the bulk elastic wave propagation and determination of the relative values ν31 and ν32 related to the material structure and mechanical stresses. It is shown that stresses violate the linearity of the relationship observed between the parameters in the absence of the mechanical stresses in the rolled material. This effect formed a basis for developing a method of the deviator stress determination. The purpose of the study is to demonstrate the main advantages of the developed method against the known ultrasonic techniques used for evaluation of the mechanical stresses, give theoretical grounds to the effect which allows taking into account the heterogeneity of the material structure, and also to exemplify the procedure. An analytical expression is derived using bulk elastic wave velocity in an orthotropic material composed of cubic crystallites and an assumption on the existence of simple proportional relationship between the coefficients of the orientation distribution function in rolled metal. Presented results of the mathematical modeling confirm the experimentally observed linear dependence between the parameters ν31 and ν32 in the absence of mechanical stresses. The results of evaluating residual stresses in a welded steel plate are presented as an example of the applicability of the developed procedure. Data of ultrasonic technique and data of strain gage measurements are compared. The features of the described method of stress determination are marked and the applicability limits are specified.

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