Genetic, biological and structural hierarchies during sponge spicule formation: from soft sol–gels to solid 3D silica composite structures

Soft Matter ◽  
2012 ◽  
Vol 8 (37) ◽  
pp. 9501 ◽  
Author(s):  
Xiaohong Wang ◽  
Heinz C. Schröder ◽  
Kui Wang ◽  
Jaap A. Kaandorp ◽  
Werner E. G. Müller
Keyword(s):  
Composite Structures ◽  
Sponge Spicule ◽  
Silica Composite ◽  
Spicule Formation

ChemInform Abstract: Genetic, Biological and Structural Hierarchies During Sponge Spicule Formation: from Soft Sol-Gels to Solid 3D Silica Composite Structures

ChemInform ◽  
2012 ◽  
Vol 43 (46) ◽  
pp. no-no
Author(s):  
Xiaohong Wang ◽  
Heinz C. Schroeder ◽  
Kui Wang ◽  
Jaap A. Kaandorp ◽  
Werner E. G. Mueller
Keyword(s):  
Composite Structures ◽  
Sponge Spicule ◽  
Silica Composite ◽  
Spicule Formation

scholarly journals Memoirs: Studies in Spicule Formation

1908 ◽  
Vol s2-52 (205) ◽  
pp. 139-157
Author(s):  
W. WOODLAND
Keyword(s):  
Thin Film ◽  
Single Cells ◽  
Siliceous Sponge ◽  
Sponge Spicule ◽  
Calcareous Sponges ◽  
Stage Of Development ◽  
Spicule Formation

1. The earliest stages in development of the Hexactinellid spicule are at present unknown, but there exist reasons for supposing that it originates as a granule enclosed by a spherical syncytium in which cell-outlines are absent, and that the six rays of the hexact grow out from this granule. 2. The earliest stage of development yet discovered is the small hexact, the rays of which do not extend to the periphery of the enveloping syncytium. 3. The rays of the hexact elongate, causing the spherical syncytium at first "to present a more or less octahedral shape, with somewhat concave surfaces and with rounded corners" (Ijima). 4. The rays at length extend beyond the spherical contour of the syncytium (the scleroblast mass), the scleroplasm of which, however, persistently adheres to the rays as a thin film, which occasionally includes nuclei. 5. The peripheral growth of the megasclere type of spicule causes the spherical syncytium enveloping the point of junction of the six rays to dwindle and finally to disappear on account of the distension involved. The whole of the microsclere, with the exception of the terminals, remains permanently enveloped by the spherical syncytium. 6. All tetractinellid and monactinellid spicules originate as granules contained within single cells. In a few instances the spicule arises from several granules within the cell and then consists of separate parts (dragmata, for example). 7. All growth is accretionary. There is no well-authenticated instance of a siliceous sponge-spicule being formed by the fusion of at-first-separate parts--such as occurs in calcareous sponges, for example. 8. With the exception of very large spicules, the nucleus of the distended scleroblast remains single throughout growth. 9. It is a significant fact that spicule formation proceeds on very different lines in each of the three great groups of sponges--the Tetraxonida, Triaxonida, and Calcarea.

In Situ microscopy of the anodic etching of silicon

1995 ◽  
Vol 53 ◽  
pp. 232-233
Author(s):  
Frances M. Ross ◽  
Peter C. Searson
Keyword(s):  
Composite Structures ◽  
High Surface ◽  
High Surface Area ◽  
Chemical Properties ◽  
Selective Etching ◽  
Silicon On Insulator ◽  
Second Phase ◽  
Porous Layers ◽  
New Class ◽  
Porous Semiconductors

Porous semiconductors represent a relatively new class of materials formed by the selective etching of a single or polycrystalline substrate. Although porous silicon has received considerable attention due to its novel optical properties1, porous layers can be formed in other semiconductors such as GaAs and GaP. These materials are characterised by very high surface area and by electrical, optical and chemical properties that may differ considerably from bulk. The properties depend on the pore morphology, which can be controlled by adjusting the processing conditions and the dopant concentration. A number of novel structures can be fabricated using selective etching. For example, self-supporting membranes can be made by growing pores through a wafer, films with modulated pore structure can be fabricated by varying the applied potential during growth, composite structures can be prepared by depositing a second phase into the pores and silicon-on-insulator structures can be formed by oxidising a buried porous layer. In all these applications the ability to grow nanostructures controllably is critical.

A Numerical and Experimental Approach for Modeling Porosity Due to Entrapped Air and Volatiles Off-gassing During Manufacturing of Composite Structures

2019 ◽  
Author(s):  
Curtis Hickmott ◽  
Alireza Forghani ◽  
Victoria Hutten ◽  
Evan Lorbiecki ◽  
Frank Palmieri ◽  
...  
Keyword(s):  
Composite Structures ◽  
Experimental Approach ◽  
Entrapped Air

Torsional Analysis of a Steel Cord-Rubber Tire Belt Structure

1996 ◽  
Vol 24 (4) ◽  
pp. 339-348 ◽  
Author(s):  
R. M. V. Pidaparti
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Composite Structures ◽  
Three Dimensional ◽  
Element Model ◽  
Torsional Stiffness ◽  
Element Analysis ◽  
Rubber Belt ◽  
Steel Cord ◽  
Torsional Analysis

Abstract A three-dimensional (3D) beam finite element model was developed to investigate the torsional stiffness of a twisted steel-reinforced cord-rubber belt structure. The present 3D beam element takes into account the coupled extension, bending, and twisting deformations characteristic of the complex behavior of cord-rubber composite structures. The extension-twisting coupling due to the twisted nature of the cords was also considered in the finite element model. The results of torsional stiffness obtained from the finite element analysis for twisted cords and the two-ply steel cord-rubber belt structure are compared to the experimental data and other alternate solutions available in the literature. The effects of cord orientation, anisotropy, and rubber core surrounding the twisted cords on the torsional stiffness properties are presented and discussed.

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