scholarly journals ABOUT THE FEATURES OF THE PROCESS OF CIRCULAR PLASTIC COMPRESSION STRANDS

2020 ◽  
pp. 41-46
Author(s):  
L. M. Gurevich ◽  
V. F. Danenko
Keyword(s):  
Plastic Deformation ◽  
Outer Surface ◽  
Outer Layer ◽  
Plastic Compression ◽  
Local Areas ◽  
Selective Formation

A simulation of the process of circular plastic compression of a strand of construction 1+6 by stretching in four pairs of rollers is carried out. It is established that the wires of the outer layer of the strand swell before entering the first pair of rollers, as well as selective formation of local areas of sharply increased plastic deformation on the outer surface of the wires.

The Lipid Layer: The Outer Surface of the Ocular Surface Tear Film

2001 ◽  
Vol 21 (4) ◽  
pp. 407-418 ◽  
Author(s):  
James P. McCulley ◽  
Ward E. Shine
Keyword(s):  
Water Vapor ◽  
Fatty Acid ◽  
Outer Surface ◽  
Outer Layer ◽  
Tear Film ◽  
Polar Phase ◽  
Lipid Layer ◽  
Water Vapor Transmission ◽  
Aqueous Layer ◽  
Alcohol Composition

The outer layer of the tear film—the lipid layer—has numerous functions. It is a composite monolayer composed of a polar phase with surfactant properties and a nonpolar phase. In order to achieve an effective lipid layer, the nonpolar phase, which retards water vapor transmission, is dependent on a properly structured polar phase. Additionally, this composite lipid layer must maintain its integrity during a blink. The phases of the lipid layer depend on both lipid type as well as fatty acid and alcohol composition for functionality. Surprisingly, the importance of the composition of the aqueous layer of the tear film in proper structuring of the lipid layer has not been recognized. Finally, lipid layer abnormalities and their relationship to ocular disease are beginning to be clarified.

Investigation of Properties of Coated Hollow Mini-Spheres

2019 ◽  
Vol 799 ◽  
pp. 26-30
Author(s):  
Viktors Mironovs ◽  
Alexey Tatarinov ◽  
Ervins Blumbergs ◽  
Irina Boiko
Keyword(s):  
Electrical Conductivity ◽  
Adsorption Capacity ◽  
Outer Surface ◽  
Outer Layer ◽  
Cellular Structures ◽  
Light Weight ◽  
Structured Materials ◽  
Low Weight ◽  
Lower Porosity ◽  
High Level

Metal hollow mini-spheres (MHMS) present a basis for the creation of new structured materials due to their low weight and energy adsorption capacity. Typically, MHMS are made of steel with a high level porosity in the sphere’s wall 80-110 microns thick. Modification of the outer surface by copper coating of 20-30 microns imposed by vacuum sputtering provides several times higher electrical conductivity, lower porosity of the outer layer and smoother surface, preserving light weight and flotation properties. This modification will provide better possibilities for spheres’ consolidation by means of sintering and electric brazing and creation of new cellular structures.

scholarly journals The Ligament of the Lucinacea (Eulamellibranchia)

1960 ◽  
Vol s3-101 (53) ◽  
pp. 25-36
Author(s):  
J. A. ALLEN
Keyword(s):  
Outer Surface ◽  
Outer Layer ◽  
Intermediate Stage ◽  
Basic Structure ◽  
Adductor Muscle

The basic structure of the opisthodetic ligament of the Lucinacea consists primarily of inner layer, anterior and posterior outer layers, and periostracum. This is secondarily extended by fused periostracum and fusion layer. Fused periostracum extends as far as the posterior adductor muscle and, except in the Ungulinidae, to the anterior adductor. The fusion layer covers the posterior outer layer and a little beyond. Only in Loripes lucinalis is the fusion layer to be found anteriorly. Below the umbos the inner layer, posterior outer layer, and overlying fusion layer are split. This split can be explained in terms of the growth and form of the shell. The anterior outer layer fills the split and extends to the anterior limit of the lunule. The ligament, external in the Ungulinidae, becomes progressively more internal. At the same time the posterior limit of the outer layer becomes modified as a result of the elongation of the outer surface of the outer mantle fold between the pallial lobes in the depth of the posterior mantle embayment. The Lucinidae are most specialized in this respect where, in L. lucinalis, a tongue of tissue divides much of the ligament horizontally. The Thyasiridae, the remaining family of the group, occupies an intermediate stage in this specialization.

Elastic-Plastic State of Inhomogeneous Soil Array with a Spherical Cavity

2013 ◽  
Vol 842 ◽  
pp. 462-465 ◽  
Author(s):  
Vladimir I. Andreev ◽  
Anatoliy S. Avershyev ◽  
Stanislaw Jemiolo
Keyword(s):  
Plastic Deformation ◽  
Outer Surface ◽  
Spherical Cavity ◽  
Plastic Material ◽  
Plastic State ◽  
Cavity Model ◽  
Limit Loads ◽  
Elastic Plastic ◽  
Perfectly Plastic ◽  
Elastic Perfectly Plastic

The article deals with the elastic-plastic state of inhomogeneous array with a spherical cavity. Model is used thick-walled ball of an elastic-perfectly plastic material (Prandtl diagram). It is shown that in the inhomogeneous material, depending on the inhomogeneity functions describing the change of the modulus of elasticity and yield stress of soil plastic deformation may appear on both the inner and outer surface of the ball and inside it. Are found values of the limit loads, displacement diagrams are constructed in an array.

scholarly journals Memoirs: Note on Eggs and Embryos of the South African Myxinoid, Bdellostoma (Heptatretus) hexatrema, Müll

1918 ◽  
Vol s2-63 (249) ◽  
pp. 141-159
Author(s):  
J.D. F. GILCHRIST
Keyword(s):  
South African ◽  
Outer Surface ◽  
Outer Layer ◽  
General Structure ◽  
Lower Surface ◽  
The Body ◽  
The South ◽  
Early Stages ◽  
Definite Structure ◽  
Excretory Organs

(1) Five naturally deposited eggs of the Cape Bdellostoma have been found, two containing well-advanced embryos. (2) The eggs are larger than those of other species, the anchor-filaments are shorter, and there are two polar rings. (3) The general structure of the shell is similar to that described for other species, and there are numerous small projections on its surface, as in some species. These consist of the columns of the columnar layer modified at the apex of the projection. (4) There are numerous small fissures in the shell, probably respiratory apertures. (5) The polar rings have a definite structure, differing from that of the rest of the shell, in that the inner layer becomes greatly enlarged, and the outer layer much reduced. (6) The anchor-filaments are not homogeneous in their structure, but consist of all the layers of the shell, the chief modification being that the heads of the columns of the columnar layer becomes drawn out so as to appear as striations. (7) The anchors' consist of the modified columnar layer and the stratified layer. On their outer surface the heads of the columns of the columnar layer appear as disconnected dark dots, while their lower surface consists of the same elements as the surface of the filament. (8) In the embryo the segmental duct occurs at the distal end of the last tubule of the pronephros, but, though having a lumen, does not open into it. It is found also at the distal end of the second last tubule, where, however, it becomes solid, and disappears. It was not found extending further into the pronephros. (9) The tubules of the mesonephros are not strictly segmentally arranged, in that there are six tubules in three segments of the body behind the pronephros, though there is one tubule for each succeeding segment, as far as the mesonephros extends. I am greatly indebted to Prof. Bashford Dean for his generous assistance in literature on the early stages of Bdellostoma and allied subjects. As a pioneer in this work, he is deeply interested in the finding of the eggs of the Cape Bdellostoma. Prof. Price has also kindly sent me reprints of his important papers on the development of the excretory organs. I have also to express my obligations to Mr. P. MacManus, who has redrawn for me figs. 2 and 10.

Sem Examinations of Glass Knives

1970 ◽  
Vol 28 ◽  
pp. 282-283
Author(s):  
J. Temple Black
Keyword(s):  
Plastic Deformation ◽  
Tensile Loading ◽  
Resultant Force ◽  
Stress Concentrations ◽  
Edge Chipping ◽  
Surface Flaws ◽  
Edge Defects ◽  
Microscopic Surface

There are two types of edge defects common to glass knives as typically prepared for microtomy purposes: 1) striations and 2) edge chipping. The former is a function of the free breaking process while edge chipping results from usage or bumping of the edge. Because glass has no well defined planes in its structure, it should be highly resistant to plastic deformation of any sort, including tensile loading. In practice, prevention of microscopic surface flaws is impossible. The surface flaws produce stress concentrations so that tensile strengths in glass are typically 10-20 kpsi and vary only slightly with composition. If glass can be kept in compression, wherein failure is literally unknown (1), it will remain intact for long periods of time. Forces acting on the tool in microtomy produce a resultant force that acts to keep the edge in compression.

A scanning electron microscopic study on dissolving process of cholesterol gallstones by chenodeoxycholic acid (CDCA)

1978 ◽  
Vol 36 (2) ◽  
pp. 522-523
Author(s):  
T. Kanetaka ◽  
M. Cho ◽  
S. Kawamura ◽  
T. Sado ◽  
K. Hara
Keyword(s):  
Electron Microscope ◽  
Chenodeoxycholic Acid ◽  
Outer Surface ◽  
Electron Microscopic ◽  
Cholesterol Gallstones ◽  
The Core ◽  
Scanning Electron Microscopic Study ◽  
Scanning Electron Microscopic ◽  
Acceleration Voltage ◽  
Scanning Electron

The authors have investigated the dissolution process of human cholesterol gallstones using a scanning electron microscope(SEM). This study was carried out by comparing control gallstones incubated in beagle bile with gallstones obtained from patients who were treated with chenodeoxycholic acid(CDCA).The cholesterol gallstones for this study were obtained from 14 patients. Three control patients were treated without CDCA and eleven patients were treated with CDCA 300-600 mg/day for periods ranging from four to twenty five months. It was confirmed through chemical analysis that these gallstones contained more than 80% cholesterol in both the outer surface and the core.The specimen were obtained from the outer surface and the core of the gallstones. Each specimen was attached to alminum sheet and coated with carbon to 100Å thickness. The SEM observation was made by Hitachi S-550 with 20 kV acceleration voltage and with 60-20, 000X magnification.

A SEM and Light Microscope Study of the Epidermal Leaf Structures of the Carnivorous Plant, Sarracenia purpurea, L.

1971 ◽  
Vol 29 ◽  
pp. 358-359
Author(s):  
B. J. Panessa ◽  
J. F. Gennaro
Keyword(s):  
Methylene Blue ◽  
Toluidine Blue ◽  
Outer Surface ◽  
Microscope Study ◽  
Light Microscope ◽  
Carnivorous Plant ◽  
Sarracenia Purpurea ◽  
Inner Surface

Tissue from the hood and sarcophagus regions were fixed in 6% glutaraldehyde in 1 M.cacodylate buffer and washed in buffer. Tissue for SEM was partially dried, attached to aluminium targets with silver conducting paint, carbon-gold coated(100-500Å), and examined in a Kent Cambridge Stereoscan S4. Tissue for the light microscope was post fixed in 1% aqueous OsO4, dehydrated in acetone (4°C), embedded in Epon 812 and sectioned at ½u on a Sorvall MT 2 ultramicrotome. Cross and longitudinal sections were cut and stained with PAS, 0.5% toluidine blue and 1% azure II-methylene blue. Measurements were made from both SEM and Light micrographs.The tissue had two structurally distinct surfaces, an outer surface with small (225-500 µ) pubescent hairs (12/mm2), numerous stoma (77/mm2), and nectar glands(8/mm2); and an inner surface with large (784-1000 µ)stiff hairs(4/mm2), fewer stoma (46/mm2) and larger, more complex glands(16/mm2), presumably of a digestive nature.

Stereo Electron Microscopy Applied to High Resolution Freeze-Etch Replicas

1970 ◽  
Vol 28 ◽  
pp. 306-307
Author(s):  
L. Andrew Staehelin
Keyword(s):  
Electron Microscopy ◽  
Plastic Deformation ◽  
High Resolution ◽  
Smooth Surfaces ◽  
Small Particles ◽  
Membrane Surfaces ◽  
Wide Acceptance ◽  
New Information ◽  
Number Of Particles ◽  
Small Holes

Freeze-etched membranes usually appear as relatively smooth surfaces covered with numerous small particles and a few small holes (Fig. 1). In 1966 Branton (1“) suggested that these surfaces represent split inner mem¬brane faces and not true external membrane surfaces. His theory has now gained wide acceptance partly due to new information obtained from double replicas of freeze-cleaved specimens (2,3) and from freeze-etch experi¬ments with surface labeled membranes (4). While theses studies have fur¬ther substantiated the basic idea of membrane splitting and have shown clearly which membrane faces are complementary to each other, they have left the question open, why the replicated membrane faces usually exhibit con¬siderably fewer holes than particles. According to Branton's theory the number of holes should on the average equal the number of particles. The absence of these holes can be explained in either of two ways: a) it is possible that no holes are formed during the cleaving process e.g. due to plastic deformation (5); b) holes may arise during the cleaving process but remain undetected because of inadequate replication and microscope techniques.

Plastic Deformation in Microtomed Sections

1971 ◽  
Vol 29 ◽  
pp. 458-459
Author(s):  
J. Temple Black
Keyword(s):  
Plastic Deformation ◽  
Plastic Strain ◽  
Applied Stress ◽  
Elastic Strain ◽  
High Strain ◽  
Tool Material ◽  
Cutting Edge ◽  
Material Structure ◽  
Geometrical Constraints

The output of the ultramicrotomy process with its high strain levels is dependent upon the input, ie., the nature of the material being machined. Apart from the geometrical constraints offered by the rake and clearance faces of the tool, each material is free to deform in whatever manner necessary to satisfy its material structure and interatomic constraints. Noncrystalline materials appear to survive the process undamaged when observed in the TEM. As has been demonstrated however microtomed plastics do in fact suffer damage to the top and bottom surfaces of the section regardless of the sharpness of the cutting edge or the tool material. The energy required to seperate the section from the block is not easily propogated through the section because the material is amorphous in nature and has no preferred crystalline planes upon which defects can move large distances to relieve the applied stress. Thus, the cutting stresses are supported elastically in the internal or bulk and plastically in the surfaces. The elastic strain can be recovered while the plastic strain is not reversible and will remain in the section after cutting is complete.

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