Forward and reverse creep of a physically nonlinear polymer material

1975 ◽  
Vol 9 (5) ◽  
pp. 696-703 ◽  
Author(s):  
A. F. Kregers ◽  
U. K. Vilks ◽  
M. Ya. Leitane

2013 ◽  
Vol 133 (4) ◽  
pp. 105-111
Author(s):  
Chisato Yoshimura ◽  
Hiroyuki Hosokawa ◽  
Koji Shimojima ◽  
Fumihiro Itoigawa


2006 ◽  
Vol 1 (1) ◽  
pp. 28-32 ◽  
Author(s):  
Kotaro Obata


2020 ◽  
Vol 23 (10) ◽  
pp. 51-54
Author(s):  
V.G. Semenov ◽  
◽  
V.G. Tyurin ◽  
N.N. Potyemkina ◽  
A.Yu. Sakharov ◽  
...  


2019 ◽  
Vol 59 ◽  
pp. 56-65
Author(s):  
Shiwei Ye ◽  
Satoru Takahashi ◽  
Masaki Michihata ◽  
Kiyoshi Takamasu ◽  
Hans Nørgaard Hansen ◽  
...  


2021 ◽  
Vol 11 (9) ◽  
pp. 4010
Author(s):  
Seon-Chil Kim

In the field of medical radiation shielding, there is an extensive body of research on process technologies for ecofriendly shielding materials that could replace lead. In particular, the particle size and arrangement of the shielding material when blended with a polymer material affect shielding performance. In this study, we observed how the particle size of the shielding material affects shielding performance. Performance and particle structure were observed for every shielding sheet, which were fabricated by mixing microparticles and nanoparticles with a polymer material using the same process. We observed that the smaller the particle size was, the higher both the clustering and shielding effects in the high-energy region. Thus, shielding performance can be improved. In the low-dose region, the effect of particle size on shielding performance was insignificant. Moreover, the shielding sheet in which nanoparticles and microsized particles were mixed showed similar performance to that of the shielding sheet containing only microsized particles. Findings indicate that, when fabricating a shielding sheet using a polymer material, the smaller the particles in the high-energy region are, the better the shielding performance is. However, in the low-energy region, the effect of the particles is insignificant.



Polymers ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 137
Author(s):  
Artur Andrearczyk ◽  
Bartlomiej Konieczny ◽  
Jerzy Sokołowski

This paper describes a novel method for the experimental validation of numerically optimised turbomachinery components. In the field of additive manufacturing, numerical models still need to be improved, especially with the experimental data. The paper presents the operational characteristics of a compressor wheel, measured during experimental research. The validation process included conducting a computational flow analysis and experimental tests of two compressor wheels: The aluminium wheel and the 3D printed wheel (made of a polymer material). The chosen manufacturing technology and the results obtained made it possible to determine the speed range in which the operation of the tested machine is stable. In addition, dynamic destructive tests were performed on the polymer disc and their results were compared with the results of the strength analysis. The tests were carried out at high rotational speeds (up to 120,000 rpm). The results of the research described above have proven the utility of this technology in the research and development of high-speed turbomachines operating at speeds up to 90,000 rpm. The research results obtained show that the technology used is suitable for multi-variant optimization of the tested machine part. This work has also contributed to the further development of numerical models.



2021 ◽  
pp. 197140092110291
Author(s):  
Thomas Mellemkjær ◽  
Ronil V Chandra ◽  
Lasse Speiser ◽  
Benedicte P Ulhøi ◽  
Claus Z Simonsen

As the neurointervention field grows, a new side effect emerges. Delayed leukoencephalopathy (DL) is believed to be an inflammatory or allergic reaction to polymer material that is shed from catheters during endovascular procedures. We present four cases of DL after aneurysm treatment in two patients, endovascular stroke treatment and diagnostic arteriography. We present our diagnostic process, including biopsy results in two patients, our anti-inflammatory treatment and outcomes together with a review of the literature. In our series, prognosis was variable with ongoing seizures in two patients. Our literature review reveals that asymptomatic shedding of polymer material is common, occurring in a third of endovascular stroke procedures, whereas symptomatic DL occurs in <0.5% of therapeutic neuroendovascular procedures. Clinicians should be aware of this rare complication, and oral glucocorticoids seem to be a reasonable first-line treatment strategy.





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