scholarly journals Time-resolved X-ray stress measurement by PSPC method during cyclic loading.

1989 ◽  
Vol 38 (430) ◽  
pp. 847-853
Author(s):  
Shin'ichi OHYA ◽  
Shozaburo OHTA
Keyword(s):  
Cyclic Loading ◽  
Stress Measurement ◽  
Time Resolved ◽  
X Ray

Time-Resolved X-ray Stress Measurement During Cyclic Loading

1989 ◽  
Vol 33 ◽  
pp. 335-340
Author(s):  
Shin'ichi Ohya ◽  
Shozaburo Ohta
Keyword(s):  
Residual Stress ◽  
Cyclic Loading ◽  
Static Loading ◽  
Stress Measurement ◽  
Fatigue Behavior ◽  
Residual Stress Distribution ◽  
X Rays ◽  
Time Resolved ◽  
X Ray ◽  
Actual Stress

X-ray stress analysis is widely used in the measurement of residual stress or stress under static loading. If it is possible to measure actual stress at any applied stress level during cyclic loading by using x-rays, it will be of much help in investigating dynamical fatigue behavior such as crack closure and change of residual stress distribution.

Time-Resolved X-Ray Stress Measurement During Cyclic Loading

1990 ◽  
pp. 335-340
Author(s):  
Shin’ichi Ohya ◽  
Shozaburo Ohta
Keyword(s):  
Cyclic Loading ◽  
Stress Measurement ◽  
Time Resolved ◽  
X Ray

scholarly journals Time-Resolved X-Ray Stress Analysis by Single Exposure Technique during Cyclic Loading.

1991 ◽  
Vol 40 (454) ◽  
pp. 825-831 ◽  
Author(s):  
Shin-ichi OHYA ◽  
Shozaburo OHTA ◽  
Ken-ichi HASEGAWA ◽  
Shigekazu MISONO
Keyword(s):  
Cyclic Loading ◽  
Stress Analysis ◽  
Single Exposure ◽  
Time Resolved ◽  
X Ray ◽  
Exposure Technique

Estimation of Residual Stress Change due to Cyclic Loading by Classical Elastoplasticity Model and Subloading Surface Model

2016 ◽  
Vol 725 ◽  
pp. 281-286 ◽  
Author(s):  
Ryota Higuchi ◽  
Kazuo Okamura
Keyword(s):  
Residual Stress ◽  
Cyclic Loading ◽  
Stress Measurement ◽  
Kinematic Hardening ◽  
Bending Test ◽  
Surface Model ◽  
Material Function ◽  
X Ray ◽  
Before And After ◽  
Good Agreement

The subloading surface model has been formulated and applied to the prediction of cyclic loading behavior. The material function prescribing elastic-plastic transition in the original subloading surface model has been extended so as to describe the inverse and reloading behavior and the strain accumulation in cyclic loading more accurately for steel. In the present paper, the extended subloading surface model was applied to the prediction of the change of the residual stress due to cyclic loading. The four-point cyclic bending test was performed for the specimen that had initial residual stress. The distributions of the residual stress before and after cyclic loading were measured by the X-ray stress measurement method. The simulation to the experiment was performed by the extended subloading surface model. The stress distribution after cyclic loading simulated by the extended subloading surface model was in good agreement with measured one, and was more accurate than that by the nonlinear isotropic/kinematic hardening model.

Microtubule nucleation sequence studied by time-resolved x-ray scattering and electron microscopy

1983 ◽  
Vol 41 ◽  
pp. 766-767
Author(s):  
Eva-Maria Mandelkow ◽  
Eckhard Mandelkow ◽  
Joan Bordas
Keyword(s):  
Electron Microscopy ◽  
Dynamic Equilibrium ◽  
Time Resolved ◽  
X Ray ◽  
Additional Information ◽  
X Ray Scattering ◽  
Low Concentrations ◽  
Microtubule Growth ◽  
Ray Patterns ◽  
Ray Scattering

When a solution of microtubule protein is changed from non-polymerising to polymerising conditions (e.g. by temperature jump or mixing with GTP) there is a series of structural transitions preceding microtubule growth. These have been detected by time-resolved X-ray scattering using synchrotron radiation, and they may be classified into pre-nucleation and nucleation events. X-ray patterns are good indicators for the average behavior of the particles in solution, but they are difficult to interpret unless additional information on their structure is available. We therefore studied the assembly process by electron microscopy under conditions approaching those of the X-ray experiment. There are two difficulties in the EM approach: One is that the particles important for assembly are usually small and not very regular and therefore tend to be overlooked. Secondly EM specimens require low concentrations which favor disassembly of the particles one wants to observe since there is a dynamic equilibrium between polymers and subunits.

Time-Resolved Cryo-Electron Microscopy of Oscillating Microtubules

1990 ◽  
Vol 48 (1) ◽  
pp. 502-503
Author(s):  
Eva-Maria Mandelkow ◽  
Ron Milligan
Keyword(s):  
Electron Microscopy ◽  
Dynamic Instability ◽  
Entire Solution ◽  
Reaction Scheme ◽  
Time Resolved ◽  
X Ray ◽  
X Ray Scattering ◽  
A Chain ◽  
Ray Scattering

Microtubules form part of the cytoskeleton of eukaryotic cells. They are hollow libers of about 25 nm diameter made up of 13 protofilaments, each of which consists of a chain of heterodimers of α-and β-tubulin. Microtubules can be assembled in vitro at 37°C in the presence of GTP which is hydrolyzed during the reaction, and they are disassembled at 4°C. In contrast to most other polymers microtubules show the behavior of “dynamic instability”, i.e. they can switch between phases of growth and phases of shrinkage, even at an overall steady state [1]. In certain conditions an entire solution can be synchronized, leading to autonomous oscillations in the degree of assembly which can be observed by X-ray scattering (Fig. 1), light scattering, or electron microscopy [2-5]. In addition such solutions are capable of generating spontaneous spatial patterns [6].In an earlier study we have analyzed the structure of microtubules and their cold-induced disassembly by cryo-EM [7]. One result was that disassembly takes place by loss of protofilament fragments (tubulin oligomers) which fray apart at the microtubule ends. We also looked at microtubule oscillations by time-resolved X-ray scattering and proposed a reaction scheme [4] which involves a cyclic interconversion of tubulin, microtubules, and oligomers (Fig. 2). The present study was undertaken to answer two questions: (a) What is the nature of the oscillations as seen by time-resolved cryo-EM? (b) Do microtubules disassemble by fraying protofilament fragments during oscillations at 37°C?

Time-resolved X-ray reciprocal space mapping of the crystal under external electric field

2018 ◽  
Vol 189 (02) ◽  
pp. 187-194 ◽  
Author(s):  
Nikita V. Marchenkov ◽  
Anton G. Kulikov ◽  
Ivan I. Atknin ◽  
Arsen A. Petrenko ◽  
Alexander E. Blagov ◽  
...  
Keyword(s):  
Electric Field ◽  
External Electric Field ◽  
Space Mapping ◽  
Reciprocal Space ◽  
Reciprocal Space Mapping ◽  
Time Resolved ◽  
X Ray

Monitoring Polymer-Assisted Mechanochemical Cocrystallisation Through in Situ X-Ray Powder Diffraction

2020 ◽  
Author(s):  
Luzia S. Germann ◽  
Sebastian T. Emmerling ◽  
Manuel Wilke ◽  
Robert E. Dinnebier ◽  
Mariarosa Moneghini ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Powder Diffraction ◽  
Reaction Rate ◽  
Polymer Additives ◽  
Time Resolved ◽  
X Ray

Time-resolved mechanochemical cocrystallisation studies have so-far focused solely on neat and liquid-assisted grinding. Here, we report the monitoring of polymer-assisted grinding reactions using <i>in situ</i> X-ray powder diffraction, revealing that reaction rate is almost double compared to neat grinding and independent of the molecular weight and amount of used polymer additives.<br>

In situ Time-Resolved Small-Angle X-ray Scattering Reveals the Formation Kinetics of Polyelectrolyte Complex Micelles

2019 ◽  
Author(s):  
Hao Wu ◽  
Jeffrey Ting ◽  
Siqi Meng ◽  
Matthew Tirrell
Keyword(s):  
Small Angle ◽  
Self Assembly ◽  
Electrostatic Interactions ◽  
Polyelectrolyte Complex ◽  
Time Resolved ◽  
X Ray ◽  
X Ray Scattering ◽  
Kinetics Of ◽  
Ray Scattering

We have directly observed the <i>in situ</i> self-assembly kinetics of polyelectrolyte complex (PEC) micelles by synchrotron time-resolved small-angle X-ray scattering, equipped with a stopped-flow device that provides millisecond temporal resolution. This work has elucidated one general kinetic pathway for the process of PEC micelle formation, which provides useful physical insights for increasing our fundamental understanding of complexation and self-assembly dynamics driven by electrostatic interactions that occur on ultrafast timescales.

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