scholarly journals Experimental and numerical investigations on resonant characteristics of a single-layer piezoceramic plate and a cross-ply piezolaminated composite plate

2006 ◽  
Vol 119 (3) ◽  
pp. 1476-1486 ◽  
Author(s):  
Chien-Ching Ma ◽  
Hsien-Yang Lin ◽  
Yu-Chih Lin ◽  
Yu-Hsi Huang
Keyword(s):  
Composite Plate ◽  
Single Layer ◽  
Piezoceramic Plate ◽  
Numerical Investigations

Progressive Collapse of Single-Layer Braced Domes

1996 ◽  
Vol 11 (3) ◽  
pp. 291-306 ◽  
Author(s):  
K. Abedi ◽  
G.A.R. Parke
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Progressive Collapse ◽  
Single Layer ◽  
Central Point ◽  
Loading Conditions ◽  
Element Analysis ◽  
Numerical Investigations ◽  
Dynamic Propagation

Progressive collapse may be defined as the “widespread propagation of instability following damage to a portion of a structure”. In this paper, the dynamic propagation of local snap-through in single-layer braced domes is discussed. Dynamic snap-through and simultaneous multi-snap-through are described. Loading conditions for the occurrence of local snap-through have also been presented and a procedure for modelling this phenomenon using finite element analysis is developed. The central point in the proposed procedure is that the effect of dynamic snap-through is represented by providing appropriate initial velocities at the nodes in which snap-through as occurred. Using this procedure, the likelihood of progressive collapse is evaluated. In addition, some numerical investigations have also been presented.

scholarly journals Study on a Cracked Single-Layer 2D Woven Composite Plate: Fracture Mode and Damage Analysis

2018 ◽  
Vol 50 (5) ◽  
pp. 800-806
Author(s):  
Y. Q. Wang ◽  
P. Cheng ◽  
X. S. Liu ◽  
Y. J. Bao ◽  
H. Gao
Keyword(s):  
Fracture Mode ◽  
Composite Plate ◽  
Single Layer ◽  
Damage Analysis ◽  
Woven Composite ◽  
Plate Fracture

Crystalline order to a resolution of 4.7 A in the sheath of Methanospirilium hungatii: A cross-beta structure

1984 ◽  
Vol 42 ◽  
pp. 214-215
Author(s):  
Murray Stewart ◽  
T.J. Beveridge ◽  
D. Sprott
Keyword(s):  
Cell Wall ◽  
Single Layer ◽  
Uranyl Acetate ◽  
Optical Diffraction ◽  
Tube Axis ◽  
Basic Subunit ◽  
Beta Structure ◽  
Diffraction Patterns ◽  
Protein Treatment ◽  
General Appearance

The archaebacterium Methanospirillum hungatii has a sheath as part of its cell wall which is composed mainly of protein. Treatment with dithiothreitol or NaOH released the intact sheaths and electron micrographs of this material negatively stained with uranyl acetate showed flattened hollow tubes, about 0.5 μm diameter and several microns long, in which the patterns from the top and bottom were superimposed. Single layers, derived from broken tubes, were also seen and were more simply analysed. Figure 1 shows the general appearance of a single layer. There was a faint axial periodicity at 28.5 A, which was stronger at irregular multiples of 28.5 A (3 and 4 times were most common), and fine striations were also seen at about 3° to the tube axis. Low angle electron diffraction patterns (not shown) and optical diffraction patterns (Fig. 2) from these layers showed a complex meridian (as a result of the irregular nature of the repeat along the tube axis) which showed a clear maximum at 28.5 A, consistent with the basic subunit spacing.

Differentiation Processes of the Ocellar Retina of the Honeybee (Apis Mellifera L.)

1990 ◽  
Vol 48 (3) ◽  
pp. 430-431
Author(s):  
Maria Anna Pabst
Keyword(s):  
Apis Mellifera ◽  
Distal Part ◽  
Cell Layer ◽  
Single Layer ◽  
Photoreceptor Cells ◽  
Distal Segment ◽  
Compound Eyes ◽  
Thin Sections ◽  
Ultrastructural Studies ◽  
Adult Worker

In addition to the compound eyes, honeybees have three dorsal ocelli on the vertex of the head. Each ocellus has about 800 elongated photoreceptor cells. They are paired and the distal segment of each pair bears densely packed microvilli forming together a platelike fused rhabdom. Beneath a common cuticular lens a single layer of corneagenous cells is present.Ultrastructural studies were made of the retina of praepupae, different pupal stages and adult worker bees by thin sections and freeze-etch preparations. In praepupae the ocellar anlage consists of a conical group of epidermal cells that differentiate to photoreceptor cells, glial cells and corneagenous cells. Some photoreceptor cells are already paired and show disarrayed microvilli with circularly ordered filaments inside. In ocelli of 2-day-old pupae, when a retinogenous and a lentinogenous cell layer can be clearly distinguished, cell membranes of the distal part of two photoreceptor cells begin to interdigitate with each other and so start to form the definitive microvilli. At the beginning the microvilli often occupy the whole width of the developing rhabdom (Fig. 1).

Characterization of a monolayer graphitic structure

1994 ◽  
Vol 52 ◽  
pp. 760-761
Author(s):  
X. Lin ◽  
X. K. Wang ◽  
V. P. Dravid ◽  
J. B. Ketterson ◽  
R. P. H. Chang
Keyword(s):  
Three Dimensional ◽  
Single Layer ◽  
Synthesis Process ◽  
Graphitic Structure ◽  
Positive Gaussian Curvature ◽  
Graphitic Sheet ◽  
Structural And Electronic Properties ◽  
New Material ◽  
Hexagonal Network

For small curvatures of a graphitic sheet, carbon atoms can maintain their preferred sp2 bonding while allowing the sheet to have various three-dimensional geometries, which may have exotic structural and electronic properties. In addition the fivefold rings will lead to a positive Gaussian curvature in the hexagonal network, and the sevenfold rings cause a negative one. By combining these sevenfold and fivefold rings with sixfold rings, it is possible to construct complicated carbon sp2 networks. Because it is much easier to introduce pentagons and heptagons into the single-layer hexagonal network than into the multilayer network, the complicated morphologies would be more common in the single-layer graphite structures. In this contribution, we report the observation and characterization of a new material of monolayer graphitic structure by electron diffraction, HREM, EELS.The synthesis process used in this study is reported early. We utilized a composite anode of graphite and copper for arc evaporation in helium.

The Continuous Single-Layer Anastomosis in the Gastrointestinal Tract

Swiss Surgery ◽  
2003 ◽  
Vol 9 (3) ◽  
pp. 114-120 ◽  
Author(s):  
Steinke ◽  
Leippold ◽  
Schweizer
Keyword(s):  
Gastrointestinal Tract ◽  
Single Layer

Über die Frage der besten oder "richtigen" Technik bei gastrointestinalen Anastomosen wird seit je diskutiert. Die Ansprüche an eine gute Anastomosentechnik sind: Gute Durchblutung, Wasserdichtigkeit, Spannungsfreiheit, Sicherheit, leichte Durchführbarkeit, wenig Unruhe und Verschmutzung im Operationsgebiet und geringe Kosten. Die Operationstechnik der extramukösen, fortlaufenden Anastomosentechnik im Gastrointestinaltrakt wird in Wort und Bild erläutert. Anhand einer Pilotstudie, einer randomisierten Vergleichsstudie, einer Schweizer Multizenterstudie und schliesslich einer 5-jährigen Qualitätskontrollstudie wird gezeigt, dass diese "Schweizer"-Technik allen Anforderungen zur Durchführung einer "idealen" Anastomose gerecht wird und an fast allen intestinalen Lokalisationen verwendet werden kann.

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