scholarly journals MODELING OF THE STANDARD MACHINE TO REPRODUCE FIELDS OF MECHANICAL STRESSES

2021 ◽  
Vol 31 (2) ◽  
pp. 52-65
Author(s):  
I. V. Andronov ◽  
◽  
A. A. Lobashev ◽  
A. Yu. Petrov ◽  
S. N. Tropkin ◽  
...  
Keyword(s):  
Numerical Modeling ◽  
Nondestructive Testing ◽  
Mechanical Stresses ◽  
Practical Measurement

The paper concerns the problem of practical measurement of mechanical stresses in industrial objects. The signal dependencies of different nondestructive testing devices on the stresses are discussed. Results of numerical modeling of the mechanical stresses that can be reproduced by the suggested standard machine are presented. A number of questions that should be solved to turn nondestructive testing into the measurements of mechanical stresses is discussed.

Nondestructive Testing with Ultrasound: Numerical Modeling and Imaging

1996 ◽  
pp. 757-764 ◽  
Author(s):  
R. Marklein ◽  
K. J. Langenberg ◽  
R. Bärmann ◽  
K. Mayer ◽  
S. Klaholz
Keyword(s):  
Numerical Modeling ◽  
Nondestructive Testing

Erosion-Resistant Electrode Coatings of Vacuum and Gas-Discharge Switching Devices

MRS Advances ◽  
2015 ◽  
Vol 1 (17) ◽  
pp. 1177-1182
Author(s):  
Sergey Karabanov ◽  
Dmitry Suvorov ◽  
Gennady Gololobov ◽  
Victor Gurov ◽  
Evgeny Slivkin ◽  
...  
Keyword(s):  
Numerical Modeling ◽  
Electric Current ◽  
Gas Discharge ◽  
Mechanical Stresses ◽  
Local Temperature ◽  
Interlayer Thickness ◽  
Thermal Fields ◽  
Efficiency Assessment ◽  
Intermediate Layers ◽  
Switching Devices

ABSTRACTThe paper presents the results of numerical modeling of thermomechanical stresses and thermal fields for conditions of erosion-resistant electrode coatings of vacuum and gas discharge switching devices with W-Ti-Cu and W-Mo-Cu structures at local temperature and electric current influence in axially symmetrical approximation. The efficiency assessment of intermediate layers introduction by comparison of interlaminar mechanical stresses is carried out. It is shown that introduction of titanium interlayer in the coating with W Cu structure results in considerable (more than two times) decrease of internal thermomechanical stresses between layers that increases coating resistance to delamination. The optimum value of interlayer thickness at which the minimum thermomechanical stresses are provided is determined.

Human Platelets Exposed to Mechanical Stresses Express a Potent Lipoxygenase Product

1992 ◽  
Vol 68 (05) ◽  
pp. 589-594 ◽  
Author(s):  
Alon Margalit ◽  
Avinoam A Livne
Keyword(s):  
Regulatory Volume Decrease ◽  
Human Platelets ◽  
Mechanical Stresses ◽  
Arterial Stenosis ◽  
Platelet Suspension ◽  
Suspension Flows ◽  
Lipoxygenase Product ◽  
Pathological Conditions ◽  
K Permeability ◽  
Volume Decrease

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.

Sign in / Sign up

Export Citation Format

Share Document