Avoidance of Density Anomalies as a Structural Principle for Semicrystalline Polymers: The Importance of Chain Ends and Chain Tilt

2017 ◽  
Vol 50 (4) ◽  
pp. 1521-1540 ◽  
Author(s):  
Keith J. Fritzsching ◽  
Kanmi Mao ◽  
Klaus Schmidt-Rohr
Keyword(s):  
Semicrystalline Polymers ◽  
Structural Principle ◽  
Chain Tilt

Beckett's Broken Circle: A Literary Fractal

2020 ◽  
Vol 29 (2) ◽  
pp. 196-215
Author(s):  
Luke Connolly
Keyword(s):  
Dynamic Chaos ◽  
Geometric Form ◽  
Self Similarity ◽  
Collision Point ◽  
Stable Order ◽  
Structural Principle ◽  
Recent Interest ◽  
Viable Solution ◽  
Specific Shape

This essay proposes that the picture of a broken circle encountered by Watt during the second part of his tale marks a crucial collision point between Beckett's literary and mathematical interests and triggers a process of fractal scaling self-similarity. Building on recent interest concerning the role of the mathematics and mathematical forms found in Beckett's work, I argue that the broken circle depicted in the picture from Watt is a geometric form which (re)appears within at least three interlocking scales throughout Beckett's novel-length prose: (i) its moment of arrival in the picture from Watt, (ii) a macroscopic reinscription in the names of the protagonists populating the five novels spanning Watt through to The Unnamable and (iii) buried within the narratological depths of How It Is. As a structural principle, the interminable irregularity of fractals offered Beckett a viable solution for what he considered the defining task of the modern artist: ‘to find a form to accommodate the mess’. Moreover, the specific shape selected for his fractal is shown to contain within its geometry one of Beckett's most universal and pressing concerns: the inevitable insufficiency of language. Therefore, although this essay restricts itself to examining Beckett's novel-length prose, the idea of a broken circle fractal promises to provide a valuable heuristic through which to reassess the author's other generic avenues. Fractals thus offer a means through which one can bind together the length and breadth of Beckett's oeuvre without ever reducing dynamic chaos to stable order.

ZUR SUBMIKROSKOPISCHEN STRUKTUR DER RATTENSCHILDDRÜSE ELEKTRONENMIKROSKOPISCHE UNTERSUCHUNGEN AN DER BASIS DES SCHILDDRÜSENFOLLIKELS

1960 ◽  
Vol XXXV (III) ◽  
pp. 334-350 ◽  
Author(s):  
U. Waller
Keyword(s):  
Endothelial Cells ◽  
Basement Membranes ◽  
The Other ◽  
Small Vesicle ◽  
Thyroid Follicle ◽  
Basal Secretion ◽  
Structural Principle ◽  
Thyroid Epithelial Cell ◽  
Endocrine Organs ◽  
Subendothelial Space

ABSTRACT This is a description of ultramicroscopic structures at the base of the thyroid follicle. The structural principle of the subendothelial or interfollicular space, namely basement membranes closely following both the endothelial cells of the capillaries and the epithelial cells of the thyroid, corresponds to that described by other authors in the other endocrine organs. Especially shown are small vesicle like decreases of intensity in the subendothelial space, causing bulges in both the subepithelial basement membrane and the membrane covering the endothelial cell pores thereby forming pseudopores. This membrane is in several parts a double one. The possible role played by the above mentioned structures in the basal secretion of the thyroid epithelial cell is discussed.

NEWEST TECTONICS OF THE VISTULA SPIT AREA

2017 ◽  
Author(s):  
Nikolay Dunaev ◽  
Nikolay Dunaev ◽  
Nadezhda Politova ◽  
Nadezhda Politova
Keyword(s):  
Baltic Sea ◽  
Coastal Zones ◽  
Structural Principle ◽  
Modern Landscape ◽  
Tectonic Pattern

The interests of forecasting of the area’s development simulate to take more attention to the study of its newest tectonics. The most informative tectonic pattern for the studies of coastal zones is neotectonic one, based on the structural principle, which shows the newly formed and inherited dislocations, reflected in the modern landscape and exodynamics of the earth's surface. The question of the manifestations of newest tectonics by way on the example of the Vistula Spit (Baltic Sea) is discussed.

Study of Transcrystallization in Polymer Composites

1989 ◽  
Vol 170 ◽  
Author(s):  
Benjamin S. Hsiao ◽  
J. H. Eric
Keyword(s):  
Thermal Conductivity ◽  
Free Energy ◽  
Carbon Fiber ◽  
Plasma Treatment ◽  
Polymer Composites ◽  
High Performance ◽  
Interfacial Strength ◽  
Fiber Surface ◽  
Semicrystalline Polymers ◽  
First Case

AbstractTranscrystallization of semicrystalline polymers, such as PEEK, PEKK and PPS, in high performance composites has been investigated. It is found that PPDT aramid fiber and pitch-based carbon fiber induce a transcrystalline interphase in all three polymers, whereas in PAN-based carbon fiber and glass fiber systems, transcrystallization occurs only under specific circumstances. Epitaxy is used to explain the surface-induced transcrystalline interphase in the first case. In the latter case, transcrystallization is probably not due to epitaxy, but may be attributed to the thermal conductivity mismatch. Plasma treatment on the fiber surface showed a negligible effect on inducing transcrystallization, implying that surface-free energy was not important. A microdebonding test was adopted to evaluate the interfacial strength between the fiber and matrix. Our preliminary results did not reveal any effect on the fiber/matrix interfacial strength of transcrystallinity.

A Positron Annihilation Lifetime Study of Poly(Bisphenol-a Carbonate)

1986 ◽  
Vol 82 ◽  
Author(s):  
P. L. Jones ◽  
A. J. Hill ◽  
G. W. Pearsall ◽  
J. H. Lind
Keyword(s):  
Bisphenol A ◽  
Positron Annihilation ◽  
Thermal History ◽  
Thermal Response ◽  
Semicrystalline Polymers ◽  
Glass Transitions ◽  
Thermal Dependence ◽  
Positron Annihilation Lifetime ◽  
Ductile To Brittle Transition ◽  
Increasing Temperature

ABSTRACTPositron annihilation lifetime spectroscopy has proven to be sensitive to glass transitions and other free volume dependent phase transitions in amorphous and semicrystalline polymers. The thermal dependence of the lifetime spectra of positrons in compression-molded poly(bisphenol-A carbonate) has been measured from 253K to 323K, then modelled using a three component fit. The longest-lived component lifetime τ3 was found to vary linearly with increasing temperature independent of thermal history. The corresponding component intensity I3 was found to vary in a non-linear fashion with increasing temperature, exhibiting a significant dependence on thermal history. The observed thermal response of τ3 and I3 is discussed in terms of both molecular relaxation and the ductile-to-brittle transition behavior of poly(bisphenol-A carbonate).

Sign in / Sign up

Export Citation Format

Share Document