aqt
Administrator
member is offline
![[avatar]](http://img1.jurko.net/avatar_1947.png "[avatar]")
Joined: Jan 2009
Gender: Female 
Posts: 4,720
Karma: 1 | |
aqt
Administrator
member is offline
Joined: Jan 2009
Gender: Female
Posts: 4,720
Karma: 1 | |
aqt
Administrator
member is offline
Joined: Jan 2009
Gender: Female
Posts: 4,720
Karma: 1 | |
skyship
Top Member
member is offline
Joined: Jan 2009
Gender: Female
Posts: 6,966
Karma: 3 |  | Re: Silica
« Reply #3 on Jun 22, 2012, 2:18am » | ![[Quote]](http://images.proboards.com/buttons/quote.gif "[Quote]") |
bumping up the page.
| |
|
skyship
Top Member
member is offline
Joined: Jan 2009
Gender: Female
Posts: 6,966
Karma: 3 | | Re: Silica
« Reply #4 on Jul 13, 2012, 3:26am » | |
Silica crystalloid material?
Archeocytes? formaminiferans
Archaeocytes (from Greek archaios "beginning" and kytos "hollow vessel") or amoebocytes are amoeboid cells found in sponges. They are totipotent ]and have varied functions depending on the species.
Location
Archaeocytes are located in the mesohyl, an acellular gelatinous matrix, along with other specialized sponge cells including collencytes and structural elements called spicules. They move about within the mesohyl with amoeba-like movements performing a number of important functions.
Functions
Cellular differentiation is an essential function of the archaeocyte. All specialized cells within the sponge have its origins with the archaeocyte. This is especially important in reproduction as the sex cells of the sponge in sexual reproduction are formed from these amoeboid cells. Similarly in asexual reproduction amoebocytes result in the formation of gemmules which are cyst-like spheres containing more amoebocytes as well as other sponge cells including the phylum specific choanocyte. These cells move within the walls of a sponge and form spicules.
http://en.wikipedia.org/wiki/Archaeocyte
====================
sponges have silica
diatoms have silica
mmmmmmm
"growing a silica cyrstalloid"
================
Process of silication.
http://ars.els-cdn.com/content/image/1-s2.0-S0065288106520012-gr37.jpg
Conduction system?
As the most ancient extant metazoans, glass sponges (Hexactinellida) have attracted recent attention in the areas of molecular evolution and the evolution of conduction systems but they are also interesting because of their unique histology: the greater part of their soft tissue consists of a single, multinucleate syncytium that ramifies throughout the sponge. This trabecular syncytium serves both for transport and as a pathway for propagation of action potentials that trigger flagellar arrests in the flagellated chambers. The present chapter is the first comprehensive modern account of this group and covers work going back to the earliest work dealing with taxonomy, gross morphology and histology as well as dealing with more recent studies.
The structure of cellular and syncytial tissues and the formation of specialised intercellular junctions are described.[color=Maroon] Experimental work on reaggregation of dissociated tissues is also covered, a process during which histocompatibility, fusion and syncytialisation have been investigated, and where the role of the cytoskeleton in tissue architecture and transport processes has been studied in depth. The siliceous skeleton is given special attention, with an account of discrete spicules and fused silica networks, their diversity and distribution, their importance as taxonomic features and the process of silication
http://www.sciencedirect.com/science/article/pii/S0065288106520012
================================
optical fibers are made of silica> wonder if it comes from sponges or diatoms?
"An optical fiber (or optical fibre) is a flexible, transparent fiber made of glass (silica) or plastic, slightly thicker than a human hair. It functions as a waveguide, or “light pipe”,[1] to transmit light between the two ends of the fiber.[2] The field of applied science and engineering concerned with the design and application of optical fibers is known as fiber optics."
https://en.wikipedia.org/wiki/Optical_fiber
===================
glass silica? or plastic?
All-silica fiber, or silica-silica fiber, is an optical fiber whose core and cladding are made of silica glass. The refractive index of the core glass is higher than that of the cladding. These fibers are typically step-index fibers. The cladding of an all-silica fiber should not be confused with the polymer overcoat of the fiber.
See also
Hard-clad silica optical fiber
Plastic-clad silica fiber
Plastic optical fiber
Silica fiber
https://en.wikipedia.org/wiki/All-silica_fiber
=============
For an optical fiber, a step-index profile is a refractive index profile characterized by a uniform refractive index within the core and a sharp decrease in refractive index at the core-cladding interface so that the cladding is of a lower refractive index. The step-index profile corresponds to a power-law index profile with the profile parameter approaching infinity. The step-index profile is used in most single-mode fibers and some multimode fibers.
https://en.wikipedia.org/wiki/Step-index_fiber
mmmmmmm
| |
|
skyship
Top Member
member is offline
Joined: Jan 2009
Gender: Female
Posts: 6,966
Karma: 3 | | Re: Silica
« Reply #5 on Jul 13, 2012, 3:56am » | |
fiber glass and glass silica:
Fiberglass (or fibreglass) (also called glass-reinforced plastic, GRP,[1] glass-fiber reinforced plastic, or GFRP[2]), is a fiber reinforced polymer made of a plastic matrix reinforced by fine fibers of glass. It is also known as GFK (for German: Glasfaserverstärkter Kunststoff).
Fiberglass is a lightweight, extremely strong, and robust material. Although strength properties are somewhat lower than carbon fiber and it is less stiff, the material is typically far less brittle, and the raw materials are much less expensive. Its bulk strength and weight properties are also very favorable when compared to metals, and it can be easily formed using molding processes.
The plastic matrix may be epoxy, a thermosetting plastic (most often polyester or vinylester) or thermoplastic.
Common uses of fiberglass include boats, automobiles, baths, hot tubs, water tanks, roofing, pipes, cladding, casts and external door skins.
https://en.wikipedia.org/wiki/Fiberglass
==============
Vinylesters?????????????????? mmmmmm
"Vinyl Ester, or Vinylester, is a resin produced by the esterification of an epoxy resin with an unsaturated monocarboxylic acid. The reaction product is then dissolved in a reactive solvent, such as styrene, to a 35 - 45 percent content by weight."....
https://en.wikipedia.org/wiki/Vinylester
=======
Ah yes.............the bundled filaments, fibers, strands and colors.!
http://www.chem1.com/acad/webtext/states/polymer-images/kabelkugel2.jpg
Shapes of polymer molecules: think "spaghetti"!
Don't be misled by chemical formulas that depict polymers such as polyethylene as reasonably straight chains of substituted carbon atoms. Free rotation around C—C bonds allows long polymer molecules to curl up and and tangle very much like spaghetti. Thus polymers generally form amorphous solids. There are, however, ways in which certain polymers can be partially oriented.
Amorphous and crystalline polymers
The spaghetti-like entanglements of polymer molecules tend to produce amorphous solids, but it often happens that some parts can become sufficiently aligned to produce a region exhibiting crystal-like order, so it is not uncommon for some polymeric solids to consist of a random mixture of amorphous and crystalline regions. As might be expected, shorter and less-branched polymer chains can more easily organize themselves into ordered layers than can long chains. Hydrogen-bonding between adjacent chains also helps, and is very important in fiber-forming polymers both synthetic (Nylon 6.6) and natural (cotton cellulose).
http://www.chem1.com/acad/webtext/states/polymers.html
| |
|
skyship
Top Member
member is offline
Joined: Jan 2009
Gender: Female
Posts: 6,966
Karma: 3 | | Re: Silica
« Reply #6 on Jul 16, 2012, 5:53pm » | |
Jumper bumper
| |
|
![[Home]](http://images.proboards.com/menu/home.gif "[Home]")
![[New Topics]](http://images.proboards.com/menu/topics.png "[New Topics]")
![[Help]](http://images.proboards.com/menu/help.gif "[Help]")
![[Search]](http://images.proboards.com/menu/search.gif "[Search]")
![[Login]](http://images.proboards.com/menu/login.gif "[Login]")
![[Register]](http://images.proboards.com/menu/register.gif "[Register]")
![[Live Chat]](http://images.proboards.com/menu/chat.gif "[Live Chat]")
![[Search This Thread]](http://images.proboards.com/search2.gif "[Search This Thread]")
![[Reply]](http://images.proboards.com/buttons/reply.gif "[Reply]")
![[Share Topic]](http://images.proboards.com/new/buttons/share.png "[Share Topic]")
![[Print]](http://images.proboards.com/buttons/print.gif "[Print]")
Author
Logged