Phenomena of the Mechanical Deformation of Rubber

1931 ◽  
Vol 4 (1) ◽  
pp. 54-63
Author(s):  
H. Mark ◽  
E. Valko
Keyword(s):  
Mechanical Properties ◽  
Single Crystal ◽  
Mechanical Deformation ◽  
The Other ◽  
Considerable Progress ◽  
Organic Substances ◽  
Normal Position ◽  
Regular Lattice ◽  
Other Hand ◽  
Crystalline System

Abstract It is only during recent years that it has become possible by the use of new technic to detect molecular phenomena produced in the mechanical deformation of substances. As far as metallic substances are concerned, and crystalline substances in particular, the problem has already been solved for the most part. On the other hand, in spite of considerable progress during recent years the study of the deformation of organic substances and of fibers in particular, in which group rubber is included, has not yet been carried on. The mechanical properties of a crystalline system vary according to whether there is a single crystal or an aggregate of crystals. However, in both cases the extensibility of the products originates in a displacement of parallel layers, i. e., a sliding of the parts of the crystal along definite crystalline planes, this phenomenon of sliding being irreversible in these substances. In fact, in these cases the reversible part of the elongation is very weak, and amounts to only a few thousandths of the entire phenomenon. In brief, the phenomena of hardening brought about by deformation (sometimes observable) are due to disturbances of the regular lattice. In particular, the displacement of the atom and the change from its normal position can cause the appearance of irregularities on the surface of sliding.

Morphology and mechanical properties of transcrystalline isotactic polypropylene

e-Polymers ◽  
2003 ◽  
Vol 3 (1) ◽  
Author(s):  
Koh-hei Nitta ◽  
Yoshikazu Yamamoto
Keyword(s):  
Mechanical Properties ◽  
Isotactic Polypropylene ◽  
Mechanical Energy ◽  
Supermolecular Structure ◽  
The Other ◽  
Morphological Properties ◽  
Spherulitic Morphology ◽  
Other Hand ◽  
Morphology And Mechanical Properties ◽  
Yielding Process

Abstract We examined mechanical and morphological properties of fully transcrystalline polypropylene grown from the surface of poly(tetrafluoroethylene) sheets. Comparison of mechanical properties between transcrystalline and spherulitic polypropylenes demonstrated that Young’s modulus is dependent on the crystallinity and independent of the supermolecular structure. On the other hand, the mechanical yielding process was predominantly affected by the supermolecular structure, and the mechanical energy required for yielding of transcrystalline sheets was greater than that of the spherulitic morphology. In addition, it was found that mechanical necking is required for the alignment of lamellae in the stretching direction. This means that the unfolding process of lamellae orienting in the stretching direction is associated with necking and ductility.

Mechanisms of Ciliary Co-Ordination in Ctenophores

1973 ◽  
Vol 59 (1) ◽  
pp. 231-245
Author(s):  
SIDNEY L. TAMM
Keyword(s):  
Experimental Analysis ◽  
Mechanical Deformation ◽  
The Other ◽  
Mechanical Forces ◽  
Mechanical Interaction ◽  
Conduction Process ◽  
Other Hand

1. An experimental analysis of ciliary metachronism was performed on ctenophores of two types: those with a continuation of the ciliated groove running between adjacent comb plates (lobates), and those in which the ciliated grooves end at the first plate of each comb row (cydippids and beroids). 2. The results showed that the comb plates of cydippids and beroids are co-ordinated by mechanical forces arising from the movement of the plates themselves. Only along the ciliated grooves and at their junctions with the comb rows is a neuroid conduction process likely in this group of ctenophores. 3. Ctenophores with an interplate ciliated groove, on the other hand, do not depend on mechanical interaction between active plates for co-ordination. Instead, the lobates use neuroid conduction at the junction between the interplate ciliated groove and the comb plate, at the junction between adjacent interplate ciliated grooves, and probably along the ciliated grooves and interplate ciliated grooves as well. Ciliary co-ordination may therefore be entirely neuroid in lobate ctenophores. 4. In both types of ctenophores the comb plates may be triggered to beat by depolarization of the comb-plate cells. Electiical excitation of a plate could be caused by mechanical deformation of its base arising from the motion of the preceding plate (in cydippids and beroids), or by a neuroid process at the interplate ciliated groove-comb plate junction (in lobates). 5. These findings resolve a long-standing controversy over the mechanism of ciliary co-ordination in ctenophores.

Thermal-Mechanical Contact of a Sphere on a Layered Surface

2010 ◽  
Author(s):  
Wenping Song ◽  
Andrey Ovcharenko ◽  
Guangyu Zhang ◽  
Frank E. Talke
Keyword(s):  
Layer Thickness ◽  
Coating Thickness ◽  
Temperature Rise ◽  
Material Properties ◽  
Mechanical Deformation ◽  
The Other ◽  
Mechanical Contact ◽  
Other Hand ◽  
Transient Thermal

The effect of coating thickness is investigated during transient thermal-mechanical contact between a sphere and a layered surface. The range of coating thicknesses studied was from 0.001≤t/R≤0.1, where t is the coating thickness and R is the radius of the contacting sphere. It was found that for the range of coating thickness and material properties investigated, the coating thickness has only a small effect on the mechanical deformation of the interface. On the other hand, the layer thickness has a large effect on the temperature rise of the interface.

Fructose-Permeable Liquid Membranes Containing Boronic Acid Carriers

2004 ◽  
Vol 57 (4) ◽  
pp. 291 ◽  
Author(s):  
Peter J. Duggan
Keyword(s):  
Boronic Acid ◽  
Potential Application ◽  
Transport Process ◽  
Boronic Acids ◽  
The Other ◽  
Environmentally Benign ◽  
Considerable Progress ◽  
Liquid Membranes ◽  
Other Hand ◽  
Careful Investigation

Liquid membranes that contain boronic acids have potential application in environmentally benign industrial D-fructose production. This review describes our efforts to develop boronic acid carriers that promote high fluxes, that are resistant to leaching, and that are highly selective for fructose over other sugars. Considerable progress has been made with multidentate boronic acid carriers. Initial attempts to transport D-fructose as macrocyclic β-D-fructopyranose diesters appeared to suffer from competitive transport of macrocyclic α-D-glucofuranose diesters, and did not lead to high D-fructose selectivity. On the other hand, carriers that can bind multiple equivalents of D-fructose as tridentate β-D-fructofuranose esters have been much more effective. Unfortunately, D-fructose selectivity is still apparently limited by a competitive and boronic acid-independent non-selective ‘mobile fixed site relay’ transport process. However, further progress will be possible through improved carrier design, careful investigation of the various stages of the transport process, and the use of more industrially useful membrane configurations.

Effect of Weld Side Combination on Mechanical Properties of Double Sided Friction Stir Welded 5083 Aluminum Alloy

2014 ◽  
Vol 699 ◽  
pp. 169-174
Author(s):  
Achmad Zubaydi ◽  
Nurul Muhayat ◽  
Budie Santosa ◽  
Dony Setyawan
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloy ◽  
Tensile Properties ◽  
Welded Joints ◽  
Welding Process ◽  
The Other ◽  
Butt Welds ◽  
Friction Stir ◽  
Other Hand ◽  
5083 Aluminum Alloy

Double sided friction stir butt welds on 6 mm thick of 5083 aluminum alloy were produced. Two variants of the weld side combination, different weld side (DS) and same weld side (SS), have been made to investigate the effect of the weld side on mechanical properties.The SS is a double sided welding process that produces advancing side in one plate and retreating side in the other one. On the other hand, the DS is a double sided welding process that causes advancing side and retreating side in each plate. Tensile properties of the joints were evaluated and correlated with macrostructure and hardness. The weld side influenced the macrostructure and mechanical properties of welded joints. The different weld side (DS) had better mechanical properties than the same weld side (SS).

Variable-temperature neutron diffraction studies of the short, strong N...O hydrogen bonds in the 1:2 co-crystal of benzene-1,2,4,5-tetracarboxylic acid and 4,4'-bipyridyl

2003 ◽  
Vol 59 (6) ◽  
pp. 794-801 ◽  
Author(s):  
John A. Cowan ◽  
Judith A. K. Howard ◽  
Garry J. McIntyre ◽  
Samuel M.-F. Lo ◽  
Ian D. Williams
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Neutron Diffraction ◽  
Single Crystal ◽  
Variable Temperature ◽  
Intermediate Position ◽  
The Other ◽  
Tetracarboxylic Acid ◽  
Other Hand

The 1:2 adduct of benzene-1,2,4,5-tetracarboxylic acid and 4,4′-bipyridyl at 100 K has been studied by single-crystal neutron diffraction at 20, 200 and 296 K. The structure contains two short, strong N...O hydrogen bonds: one O—H...N hydrogen bond [O...N 2.6104 (17) Å at 20 K] and one short N—H...O hydrogen bond [N...O 2.5220 (17) Å at 20 K]. The N—H distance in the N—H...O hydrogen bond changes from 1.207 (3) Å at 20 K to 1.302 (4) Å at 296 K and the N...O distance increases to 2.5315 (16) Å at 296 K. At 200 K the H atom lies in an intermediate position 1.251 (6) Å from the N atom with an N...O separation of 2.520 (4) Å. The O—H...N hydrogen bond, on the other hand, does not change with temperature.

Review on the Effect of Bottom Ash in Performance of Portland Cement Mortar

2015 ◽  
Vol 815 ◽  
pp. 164-169
Author(s):  
Ng Hooi Jun ◽  
Mohd Mustafa Al Bakri Abdullah ◽  
Kamarudin Husin ◽  
Soo Jin Tan ◽  
Mohd Firdaus Omar
Keyword(s):  
Mechanical Properties ◽  
Portland Cement ◽  
Mechanical Performance ◽  
Cement Mortar ◽  
Bottom Ash ◽  
The Other ◽  
Other Hand

Utilization and suitability of bottom ash in Portland cement have been increasing significantly in recent year. Bottom ash has substantial effects on mechanical properties with different composition of replacement in mixture of bottom ash and Portland cement. Bottom ash was used to determine the feasibility of the substitution as recycling product from industry depending on the percentage of the bottom ash. On the other hand, bottom ash offers a better solution for maintaining materials characteristic of Portland cement mortar and also provide beneficial mechanical performance. The result of using bottom ash in Portland cement mortar showed that it could make better the mechanical properties and hence disposed bottom ash wastes safely in technical, economic and environmental methods.

scholarly journals STUDY ON THE CLARIFYING ADDITIVES FOR HIGH DENSITY POLYETHYLENE

2018 ◽  
Vol 56 (2A) ◽  
pp. 63-68
Author(s):  
Le Thi Bang
Keyword(s):  
Mechanical Properties ◽  
Surface Morphology ◽  
High Density Polyethylene ◽  
High Density ◽  
The Other ◽  
Other Hand ◽  
Thermal Mechanical Properties ◽  
Cost Of Production ◽  
The Cost

Bis-3,4- dimethyldibenzylidene sorbitol (DMDBS); bis-p-methylbenzylidene sorbitol (MDBS) and the mixture of DMDBS/MDBS (50/50) were studied through optical, thermal, mechanical properties and surface morphology. With the same amount of additive (DMDBS/MDBS mixture and DMDBS) in the material, the results are similar. On the other hand, using an additive mix reduces the cost of production due to MDBS. Furthermore, the additive mixture is used without producing odours. Therefore, the mixture of DMDBS/MDBS (50/50) is chosen.

scholarly journals Success or Failure of Chiral Crystallization of Similar Heterocyclic Compounds

Molecules ◽  
2020 ◽  
Vol 25 (23) ◽  
pp. 5691
Author(s):  
Cyprian M. Chunkang ◽  
Iris E. Ikome ◽  
Emmanuel N. Nfor ◽  
Yuta Mitani ◽  
Natsuki Katsuumi ◽  
...  
Keyword(s):  
Hydrogen Bonds ◽  
Single Crystal ◽  
Single Crystals ◽  
Heterocyclic Compounds ◽  
Van Der Waals ◽  
Van Der Waals Forces ◽  
The Other ◽  
X Ray ◽  
Other Hand

Single crystals of two achiral and planar heterocyclic compounds, C9H8H3O(CA1) and C8H5NO2 (CA4), recrystallized from ethanol, were characterized by single crystal X-ray analysis, respectively, and chiral crystallization was observed only for CA1 as P212121 (# 19), whereas it was not observed for CA4 P21/c (# 14). In CA1, as a monohydrate, the hydrogen bonds were pronounced around the water of crystallization (O4), and the planar cyclic sites were arranged in parallel to slightly tilted positions. On the other hand, an anhydride CA4 formed a dimer by hydrogen bonds between adjacent molecules in the crystal, which were aggregated by van der Waals forces and placed in parallel planar cyclic sites.

The mechanism of cleavage in amphibian and sturgeon eggs

Development ◽  
1964 ◽  
Vol 12 (2) ◽  
pp. 247-262
Author(s):  
A. I. Zotin
Keyword(s):  
Cleavage Plane ◽  
Sea Urchins ◽  
Mechanical Deformation ◽  
The Other ◽  
Cleavage Furrow ◽  
Animal Cells ◽  
Mitotic Apparatus ◽  
Other Hand

The Cleavage plane in animal cells and eggs is known to be determined by the position of the mitotic apparatus (cf. Wilson, 1925). A displacement of the mitotic apparatus by centrifugation (Harvey, 1935), mechanical deformation of eggs (Rappaport, 1960, 1961) or by microsurgical operation (Carlson, 1952; Waddington, 1952; Kawamura, 1960; Chambers & Chambers, 1961; Dan & Kuno Kojima, 1963) results in a corresponding change in the location of the cleavage furrow. This shows that the position of the cleavage furrow is determined by the mitotic apparatus of the cell. On the other hand, the formation and position of the furrow in the eggs of amphibians (Waddington, 1952), sea urchins (Swann & Mitchison, 1953; Hiramoto, 1956; Chambers & Chambers, 1961) and in the neuroblasts of grasshopper (Carlson, 1952; Kawamura, 1960) depends upon the presence of the mitotic apparatus only up to the stage of late metaphase or anaphase.

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