Assumption of homogeneous elasticity in theories of lamellar texture of polymers

1974 ◽  
Vol 9 (1) ◽  
pp. 155-155 ◽  
Author(s):  
R. G. C. Arridge
Keyword(s):  
Lamellar Texture ◽  
Homogeneous Elasticity

Chromic Acid Etching of Polyethylene

1973 ◽  
Vol 31 ◽  
pp. 72-73
Author(s):  
J. D. Muzzy ◽  
R. D. Hester ◽  
J. L. Hubbard
Keyword(s):  
Chromic Acid ◽  
Low Cost ◽  
Acid Etching ◽  
Crystalline Morphology ◽  
Bulk Specimen ◽  
Morphological Studies ◽  
Perfect Form ◽  
Molecular Length ◽  
Lamellar Texture ◽  
Cost Studies

Polyethylene is one of the most important plastics produced today because of its good physical properties, ease of fabrication and low cost. Studies to improve the properties of polyethylene are leading to an understanding of its crystalline morphology. Polyethylene crystallized by evaporation from dilute solutions consists of thin crystals called lamellae. The polyethylene molecules are parallel to the thickness of the lamellae and are folded since the thickness of the lamellae is much less than the molecular length. This lamellar texture persists in less perfect form in polyethylene crystallized from the melt.Morphological studies of melt crystallized polyethylene have been limited due to the difficulty of isolating the microstructure from the bulk specimen without destroying or deforming it.

Elasticity Solution for a Radially Nonhomogeneous Hollow Circular Cylinder

1999 ◽  
Vol 66 (3) ◽  
pp. 598-606 ◽  
Author(s):  
Xiangzhou Zhang ◽  
Norio Hasebe
Keyword(s):  
Circular Cylinder ◽  
Continuous Functions ◽  
Variable Coefficients ◽  
Circular Cylinders ◽  
Explicit Solutions ◽  
Elasticity Solution ◽  
First Order ◽  
Hollow Circular Cylinder ◽  
Homogeneous Elasticity ◽  
Ordinary Differential Equation Systems

An exact elasticity solution is developed for a radially nonhomogeneous hollow circular cylinder of exponential Young’s modulus and constant Poisson’s ratio. In the solution, the cylinder is first approximated by a piecewise homogeneous one, of the same overall dimension and composed of perfectly bonded constituent homogeneous hollow circular cylinders. For each of the constituent cylinders, the solution can be obtained from the theory of homogeneous elasticity in terms of several constants. In the limit case when the number of the constituent cylinders becomes unboundedly large and their thickness tends to infinitesimally small, the piecewise homogeneous hollow circular cylinder reverts to the original nonhomogeneous one, and the constants contained in the solutions for the constituent cylinders turn into continuous functions. These functions, governed by some systems of first-order ordinary differential equations with variable coefficients, stand for the exact elasticity solution of the nonhomogeneous cylinder. Rigorous and explicit solutions are worked out for the ordinary differential equation systems, and used to generate a number of numerical results. It is indicated in the discussion that the developed method can also be applied to hollow circular cylinders with arbitrary, continuous radial nonhomogeneity.

Paleomagnetism of the Triassic Nikolai Greenstone, McCarthy Quadrangle, Alaska

1977 ◽  
Vol 14 (11) ◽  
pp. 2578-2592 ◽  
Author(s):  
J. W. Hillhouse
Keyword(s):  
British Columbia ◽  
High Temperature ◽  
North America ◽  
Vertical Axis ◽  
Upper Triassic ◽  
Present Position ◽  
Stable Component ◽  
South Central ◽  
Early Mesozoic ◽  
Lamellar Texture

Paleomagnetic evidence indicates that the extensive early Mesozoic basalt field near McCarthy, south-central Alaska, originated far south of its present position relative to North America. Results obtained from the Middle and (or) Upper Triassic Nikolai Greenstone suggest that those basalts originated within 15° of the paleoequator. This position is at least 27° (3000 km) south of the Upper Triassic latitude predicted for McCarthy on the basis of paleomagnetic data from continental North America. The Nikolai pole, as determined from 50 flows sampled at 5 sites, is at 2.2° N, 146.1° E (α95 = 4.8°). The polarity of the pole is ambiguous, because the corresponding magnetic direction has a low inclination and a westerly declination. Therefore, the Nikolai may have originated near 15° N latitude or, alternatively, as far south as 15° S latitude. In addition to being displaced northward, the Nikolai block has been rotated roughly 90° about the vertical axis. A measure of the reliability of this pole is provided by favorable results from the following tests: (1) Within one stratigraphic section, normal and reversed directions from consecutive flows are antipolar. (2) Consistent directions were obtained from sites 30 km apart. (3) Application of the fold test indicated the magnetization was acquired before the rocks were folded. (4) The magnetizations of several pilot specimens are thermally stable up to 550 °C. The stable component is probably carried by magnetite with lamellar texture, a primary feature commonly acquired by a basalt at high temperature during initial cooling of the magma. Geologic and paleomagnetic evidence indicates that the Nikolai is allochthonous to Alaska and that, together with associated formations in southern Alaska and British Columbia, it is part of a now disrupted equatorial terrane.

A dual reciprocity boundary face method for 3D non-homogeneous elasticity problems

2012 ◽  
Vol 36 (9) ◽  
pp. 1301-1310 ◽  
Author(s):  
Fenglin Zhou ◽  
Jianming Zhang ◽  
Xiaomin Sheng ◽  
Guangyao Li
Keyword(s):  
Boundary Face ◽  
Elasticity Problems ◽  
Homogeneous Elasticity

On Uniqueness in Nonlinear Homogeneous Elasticity

2003 ◽  
pp. 119-137 ◽  
Author(s):  
Robin J. Knops
Keyword(s):  
Homogeneous Elasticity

Ferroelasticity of SrCo0.8Fe0.2O3–δperovskite-related oxide with mixed ion–electron conductivity

2015 ◽  
Vol 48 (1) ◽  
pp. 179-188 ◽  
Author(s):  
I. Belenkaya ◽  
A. Matvienko ◽  
A. Nemudry
Keyword(s):  
Phase Transition ◽  
Theoretical Analysis ◽  
Mechanical Load ◽  
Electron Conductivity ◽  
Transmission Electron ◽  
Lamellar Texture ◽  
The Common ◽  
Common Nature ◽  
Means Of Transmission ◽  
Group Theoretical Analysis

A group-theoretical analysis was carried out to determine the possible orientation states of domains formed as a result of the `perovskite–brownmillerite' phase transition in SrCo0.8Fe0.2O2.5oxide with mixed ion–electron conductivity (MIEC). The results of the theoretical analysis agree with the experimental data obtained in the study of the SrCo0.8Fe0.2O2.5microstructure by means of transmission electron microscopy. Brownmillerite SrCo0.8Fe0.2O2.5(BM) has a lamellar texture composed of 90° twins 60–260 nm in size; the 〈010〉BMand 〈101〉BMdirections are linked through twinning in accordance with the predictions of the group-theoretical analysis. The presence of twins and their switching under mechanical load provide evidence that the perovskite–brownmillerite phase transition in SrCo0.8Fe0.2O2.5is ferroelastic. Comparative analysis of the phenomena observed for ferroelectrics and MIEC oxides indicates their similarity based on the common nature of ferroelectricity and ferroelasticity, and allows us to suppose that nonstoichiometric SrCo0.8Fe0.2O3−δwith compositional disorder may be considered (in terms of its microstructural features) a `relaxor ferroelastic'.

Phase Orientation of a TiC-TiB2-SiC Ternary Eutectic Composite Prepared by An FZ Method

2007 ◽  
Vol 534-536 ◽  
pp. 1057-1060 ◽  
Author(s):  
Rong Tu ◽  
Wenjun Li ◽  
Takashi Goto
Keyword(s):  
Eutectic Composition ◽  
Ternary Eutectic ◽  
Growth Direction ◽  
Floating Zone ◽  
Eutectic Composite ◽  
Zone Method ◽  
Floating Zone Method ◽  
Specific Relationship ◽  
Lamellar Texture

The TiC-TiB2-SiC system was a ternary eutectic, whose eutectic composition was 34TiC-22TiB2-44SiC (mol%). A TiC-TiB2-SiC ternary eutectic composite were synthesized via the floating zone method using TiC, TiB2 and SiC powders as starting materials. The TiC-TiB2-SiC eutectic composite showed a lamellar texture. TiC(022), TiB2(010) and SiC(111) of the eutectic composite were perpendicular to the growth direction. The TiC-TiB2-SiC ternary eutectic composite had a specific relationship among the crystal planes: TiC[011]//TiB2[010]//SiC[112], TiC(200)// TiB2(001)//SiC( 402 ) and TiC(111)//TiB2(101)//SiC( 220 ).

PARAMETERS AFFECTING LAMELLAR FORMATIONS IN ER FLUIDS: AN ALTERNATIVE MODEL FOR ER ACTIVITY

2001 ◽  
Vol 15 (06n07) ◽  
pp. 686-694 ◽  
Author(s):  
F. E. FILISKO ◽  
S. HENLEY
Keyword(s):  
Electric Field ◽  
Alternative Model ◽  
Particle Concentration ◽  
Electrode Gap ◽  
Present Information ◽  
Complex Functions ◽  
Lamellar Texture ◽  
Chain Breaking ◽  
Static Conditions ◽  
Er Fluids

Under static conditions, ER suspensions form columns under electric field. However under the combined stimulii of a shear and electric field, the particles assemble into lamellar structures. The morphology of these structures are complex functions of electric field, shear rate, time of shear, electrode gap, particle concentration, and others. In this paper we present information regarding the field dependence, the concentration dependence, and the sequence of application of the electric and shear fields. A alternative model for ER activity, other than chain breaking, is presented which incorporates this lamellar texture.

The elastic moduli of anisotropic polymers having a lamellar texture

1973 ◽  
Vol 251 (2) ◽  
pp. 117-122 ◽  
Author(s):  
V. B. Gupta
Keyword(s):  
Elastic Moduli ◽  
Lamellar Texture

scholarly journals Lamellar Texture of Isotactic Polypropylene Spherulites

1968 ◽  
Vol 25 (276) ◽  
pp. 241-253 ◽  
Author(s):  
Morio Kojima
Keyword(s):  
Isotactic Polypropylene ◽  
Lamellar Texture
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