scholarly journals Long-term physical ageing in vitreous arsenic selenides

2006 ◽  
Vol 10 (1) ◽  
pp. 35-38
Author(s):  
R. Ya. Golovchak ◽  
A. Kozdras ◽  
M. V. Shpotyuk ◽  
O. I. Shpotyuk
Keyword(s):  
Physical Ageing ◽  
Arsenic Selenides

On the Kinetics Description of Below-Tg Structural Relaxation in Network Glass Formers

2013 ◽  
Vol 200 ◽  
pp. 162-167 ◽  
Author(s):  
Valentina Balitska ◽  
Roman Golovchak ◽  
Oleh Shpotyuk
Keyword(s):  
Structural Relaxation ◽  
Chalcogenide Glasses ◽  
Glassy Matrix ◽  
Physical Ageing ◽  
Exponential Behavior ◽  
First Order ◽  
First Order Kinetics ◽  
Network Glass ◽  
Arsenic Selenides

Phenomenological description of below-Tg structural relaxation known as long-term natural physical ageing in network glass formers exemplified by chalcogenide glasses of binary arsenic selenides was adequately developed within formalism of first-order kinetics. This kinetics was shown to obey a character stretched exponential behavior being treated as sequence of aligning-shrinkage stages throughout glassy matrix.

scholarly journals The influence of physical ageing on the in-plane shear creep compliance of 5HS C/PPS

2019 ◽  
Vol 24 (2) ◽  
pp. 197-220
Author(s):  
E. R. Pierik ◽  
W. J. B. Grouve ◽  
M. van Drongelen ◽  
R. Akkerman
Keyword(s):  
Creep Compliance ◽  
Superposition Principle ◽  
Woven Fabric ◽  
Tensile Creep ◽  
Physical Ageing ◽  
Creep Response ◽  
Structural Applications ◽  
Term Creep ◽  
Over Time

Abstract Thermoplastic polymer-matrix composites, such as carbon woven fabric reinforced poly(phenylene sulphide) (C/PPS), are increasingly used in the aircraft industry. Primary structural applications, however, are limited due to uncertainty concerning the long-term behaviour. Recent work indicated a progressive creep response over time, which would render these materials unusable for such applications. However, the effect of physical ageing was neglected, which is well known to alleviate the creep behaviour and hence physical ageing is rigorously included in this study on the long-term creep response of C/PPS. Short-term tensile creep tests in the bias direction were performed at temperatures of 50, 60, 65, 70, 75 and 80$^{\circ}\mbox{C}$ C ∘ to obtain a master curve using the time–temperature superposition principle. Ordinary horizontal shifting failed to produce a smooth curve and therefore three alternative approaches were used and compared. The physical ageing rate was, however, characterised with horizontal shifting only at 50$^{\circ}\mbox{C}$ C ∘ and was implemented by means of the effective time theory (Struik, 1977) to correct the momentary master curves for the influence of physical ageing. The resulting predictions are more realistic and demonstrate that the structural changes in a material reduce the creep rate over time. Hence, the long-term creep compliance tends to increase asymptotically towards a finite value, in contrast to the unbounded momentary response.

Physical ageing effects in vitreous arsenic selenides

2006 ◽  
Vol 137 (1-2) ◽  
pp. 67-69 ◽  
Author(s):  
R.Ya. Golovchak ◽  
Cz. Gorecki ◽  
A. Kozdras ◽  
O.I. Shpotyuk
Keyword(s):  
Physical Ageing ◽  
Ageing Effects ◽  
Arsenic Selenides

Theorising about ageing, family and immigration

2011 ◽  
Vol 31 (7) ◽  
pp. 1180-1201 ◽  
Author(s):  
LYNN MCDONALD
Keyword(s):  
Theory Building ◽  
Structural Level ◽  
Physical Ageing ◽  
Social Psychological ◽  
Fine Grained ◽  
The Social ◽  
Cursory Examination ◽  
Multiple Levels ◽  
Interdisciplinary Theory

ABSTRACTThis article critically reviews the ways in which theories in social gerontology have been used to explain the influence of ethnicity and immigration on older adults. The purpose of this cursory examination is to explore how these theories can be used for further theory advancement without serious modifications to existing theories. Current theories do not have the capacity to capture the effects of immigration at the structural level and its link to the social, psychological and family levels, let alone the physical ageing of individuals or societies. The overriding complexity of ageing and immigration requires at minimum, a long-term view and an integrating framework with multiple levels that can accommodate a variety of theoretical interests. The conclusions are that a lifecourse perspective, in conjunction with existing theories, can be employed in two different ways to further this theoretical agenda. A lifecourse perspective provides scaffolding for other theories where seemingly incommensurate epistemological positions can be easily accommodated and the principles of the lifecourse can be integrated into existing theories for a more fine-grained analysis of ethnicity and immigration. These approaches leave the theoretical door open to everyone including the positivists, the constructionists and critical and postmodern scholars with the possibility for interdisciplinary theory building to advance the understanding of the lives of immigrant families.

Long-term physical ageing in As–Se glasses with short chalcogen chains

2008 ◽  
Vol 20 (24) ◽  
pp. 245101 ◽  
Author(s):  
R Golovchak ◽  
O Shpotyuk ◽  
A Kozdras ◽  
M Vlček ◽  
B Bureau ◽  
...  
Keyword(s):  
Physical Ageing
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