scholarly journals Kinematics of formation and cessation of type B deformation bands during the Portevin-Le Chatelier effect in an AlMg alloy

2019 ◽  
Vol 12 ◽  
pp. 867-869 ◽  
Author(s):  
M.A. Lebyodkin ◽  
D.A. Zhemchuzhnikova ◽  
T.A. Lebedkina ◽  
E.C. Aifantis
2009 ◽  
Vol 508 (1-2) ◽  
pp. 156-160 ◽  
Author(s):  
A. Chatterjee ◽  
A. Sarkar ◽  
P. Barat ◽  
P. Mukherjee ◽  
N. Gayathri

Fractals ◽  
2010 ◽  
Vol 18 (03) ◽  
pp. 319-325 ◽  
Author(s):  
A. SARKAR ◽  
P. BARAT ◽  
P. MUKHERJEE

The complexity of the Portevin-Le Chatelier effect in Al-2.5%Mg polycrystalline samples subjected to uniaxial tensile tests is quantified. Multiscale entropy analysis is carried out on the stress time series data observed during jerky flow to quantify the complexity of the distinct spatiotemporal dynamical regimes. It is shown that for the static type C band, the entropy is very low for all the scales compared to the hopping type B and the propagating type A bands. The results are interpreted considering the time and length scales relevant to the effect.


2019 ◽  
Vol 61 (2) ◽  
pp. 296
Author(s):  
А.А. Шибков ◽  
А.А. Денисов ◽  
М.Ф. Гасанов ◽  
А.Е. Золотов ◽  
М.А. Желтов

AbstractIt has been established that the Portevin–Le Chatelier effect in the AlMg6 aluminum–magnesium alloy deformed in an aqueous medium is accompanied by an intermittent electrochemical response, such as the negative jumps of the electrode potential of the sample, which occur simultaneously with the jumps of the mechanical stress on the deformation curve. Statistical and fractal analyses of the stepwise component of the electrode potential indicate the presence of long-term correlations in the structure of the electrochemical response, which are typical for the state of self-organized criticality. A possible mechanism of the appearance of jumps of the electrode potential, which is associated with the dynamics of deformation bands, is discussed.


2021 ◽  
Vol 15 (58) ◽  
pp. 434-441
Author(s):  
Tatyana Viсtorovna Tretyakova ◽  
Mikhail Tretyakov ◽  
Evgeniia Chechulina

The aim of this work is to solve the methodological issues of the experimental study of the nucleation and propagation of deformation bands due to the Portevin-Le Chatelier effect under conditions of complex loading. It is of interest to determine the boundaries of unstable plastic deformation of the AMg6 alloy under complex loading conditions. A technique for controlling the loading process with a given rate of deformation intensity of materials has been worked out. The results showed that short-term stops and unloading during loading influence on the value of critical deformation, at which the manifestation of the jerky flow begins. The evolution of inhomogeneous strain fields and local strain rates under conditions of manifestation of jerky flow during tension with torsion tests of Al-Mg alloy samples.


Author(s):  
S. Fujinaga ◽  
K. Maruyama ◽  
C.W. Williams ◽  
K. Sekhri ◽  
L. Dmochowski

Yumoto and Dmochowski (Cancer Res.27, 2098 (1967)) reported the presence of mature and immature type C leukemia virus particles in leukemic organs and tissues such as lymph nodes, spleen, thymus, liver, and kidneys of SJL/J strain mice with Hodgki's-like disease or reticulum cell neoplasm (type B). In an attempt to ascertain the possibility that this neoplasia may be of viral origin, experiments with induction and transmission of this neoplasm were carried out using cell-free extracts of leukemic organs from an SJL/J strain mouse with spontaneous disease.It has been possible to induce the disease in low-leukemia BALB/c and C3HZB strain mice and serially transfer the neoplasia by cell-free extracts of leukemic organs of these mice. Histological examination revealed the neoplasia to be of either reticulum cell-type A or type B. Serial transfer is now in its fifth passage. In addition leukemic spleen from another SJL/J strain mouse with spontaneous reticulum cell neoplasm (type A) was set up in tissue culture and is now in its 141st serial passage in vitro. Preliminary results indicate that cell-free material of 39th tissue culture passage can reproduce neoplasia in BALB/c mice.


Author(s):  
P. F. Flicker ◽  
V.S. Kulkarni ◽  
J. P. Robinson ◽  
G. Stubbs ◽  
B. R. DasGupta

Botulinum toxin is a potent neurotoxin produced by Clostridium botulinum. The toxin inhibits release of neurotransmitter, causing muscle paralysis. There are several serotypes, A to G, all of molecular weight about 150,000. The protein exists as a single chain or or as two chains, with two disulfide linkages. In a recent investigation on intracellular action of neurotoxins it was reported that type B neurotoxin can inhibit the release of Ca++-activated [3H] norepinephrine only if the disulfide bonds are reduced. In order to investigate possible structural changes in the toxin upon reduction of the disulfide bonds, we have prepared two-dimensional crystals of reduced type B neurotoxin. These two-dimensional crystals will be compared with those of the native (unreduced) type B toxin.


2004 ◽  
Vol 10 ◽  
pp. 37-38
Author(s):  
Lisa C. Moore ◽  
Archana Sadhu ◽  
Dorothy Martinez ◽  
Robin Kate Kelley
Keyword(s):  

Sign in / Sign up

Export Citation Format

Share Document