Filamentary structure

Stephen W. Tsai, Strength Theories of Filamentary Structures, in Fundamental Aspects of Fiber Reinforced Plastic Conposites, Conference Proceedings, R. T. Schwartz and H. S. Schwartz (Editors), Dayton, Ohio, 24-26 May 1966, Wiley interscience. New York, 1966, pp. 3-11. 

Type I, He- and N-rich, with bipolar filamentary structure. These are thin-disk objects, with young, relatively massive central stars. 

By studying the X-ray line of iron at 6.7 keV, we will greatly improve our understanding of the progressive synthesis of metals, and more generally, the chemical evolution of the cosmos. The composition, mass and temperature of the true intergalactic medium, which seems to be dominated by a very hot gas with filamentary structure, should also be revealed by XEUS, a marvellous balcony looking out across the Universe. May we relish the prospect ... 

Under the microscope, the dye is seen to form long filamentary structures in the solute. If the dye is allowed to aggregate on a surface, it will form a "liquid crystalline" structure. This structure will exhibit the unique absorption region at long wavelengths and may or may not fluoresce depending on other conditions related to the liquid crystal and its relation to the substrate. 

Bond orbitals are constructed ft om s/r hybrids for the simple covalent tetrahedral structure energies are written in terms of a eovalent energy V2 and a polar energy K3. There are matrix elements between bond orbitals that broaden the electron levels into bands. In a preliminary study of the bands for perfect crystals, the energies for all bands at k = 0 arc written in terms of matrix elements from the Solid State Tabic. For calculation of other properties, a Bond Orbital Approximation eliminates the need to find the bands themselves and permits the description of bonds in imperfect and noncrystalline solids. Errors in the Bond Orbital Approximation can be corrected by using perturbation theory to construct extended bond orbitals. Two major trends in covalent bonds over the periodic table, polarity and metallicity, arc both defined in terms of parameters from the Solid State Table. This representation of the electronic structure extends to covalent planar and filamentary structures. 

Planar and filamentary structures are of interest in their own right, but understanding their electronic structure and properties seems to depend upon a combination of concepts applicable also to other, more general systems rather than upon a unique set of concepts. We will not undertake a special study of them, therefore, but will carry them along as illustrative examples at the end of each chapter. 

The surface motion of the sea takes place on a variety of scales from mm capillary waves to mesoscale eddies. At low wind conditions it seems that there are some scales that dominate with regard to slick-formation. They give rise to long filamentary structures observed on optical- as well as SAR-images of the sea surface, where they have a transverse dimension of the order of 100 m and longitudinal coherence for several kilometres (Scully-Powers 1986). 

Figure 3.29. Fine-scale structure of a tracer in the vicinity of the polar vortex from 6 January to 16 January 1992 on the 850 K isentropic surface. The calculation made with NMC-analyzed winds show that, as a result of Rossby wave breaking, air is ejected from the polar vortex as long filamentary structures. This process transfers vortex air into mid-latitudes. From Waugh et al.( 1994).

Transport from the troposphere to the stratosphere occurs primarily in the tropics and is associated with the upward branch of the Brewer-Dobson circulation. Folkins et al. (1999) argue that the top of the tropospheric Hadley circulation in the tropics occurs at 14 km, he., well below the tropopause, and that a barrier to vertical mixing therefore exists in the tropical tropopause layer (TTL) 2 or 3 km below the thermal tropopause. Air injected above this barrier subsequently participates in generally slow vertical ascent into the stratosphere. Small-scale exchanges also take place at mid-latitudes through filamentary structures that are drawn poleward in relation with anticyclonic circulation in the upper troposphere (Chen, 1995). 

The second point of interest relates to the electronic structure of ordered (macroscopic) arrays of small particles which are themselves, individually metallic. By the controlled synthesis of such arrays in one, two, or three dimensions, one can hope to engineer significant electron tunneling and transport between neighboring metallic particles or metallic filamentary structures the resulting electron wave-function can ultimately be completely delocalized over macroscopic distances. We now review just some of the key literature in relation to the SIMIT in individual particles and clusters, and the complementary subject of the metal-insulator transition in connected arrays of metallic particles. 

As first proposed by Alfven, sheets and ropes of electric current crisscross the universe, giving rise to the formation of large-scale cellular and filamentary structures. The increasing number of galactic clusters and superclusters that show up on maps of deep space may be evidence of precisely such filamentary connections (Lerner, 1991). 

Tsai SW. Strength theories of filamentary structures. In Schwartz RT, Schwartz HS, editors. Fundamental aspects of fiber reinforced plastic composites. New York, USA Wiley Interscience 1968. pp. 3—11. 

With an understanding of the gross behavior of a filamentary structure, a proper assessment of the mechanical and geometric properties of the constituent materials is possible. In particular, the use of fiber strength, the binding resin matrix, and the interface may be placed in a perspective based on the results of a mathematical analysis. They provide accurate guidelines for the design of RPs. 

Geodesic isotensoid A filamentary structure in which there exists a constant stress in any given filament at all points in its path, laac MD, Ishal O (2005) Engineering mechanics of composite materials. Oxford University Press, UK. 

Determining the porosity or void fiaction of die alloy occupied by electrolyte following a dissolution simulation are more relevant to selective dissolution simulations in which at least one noble component of the alloy does not dissolve so that a coarsened filamentary structure results. As noted earlier, in the case of dissolution of a single component sample, there is no porous structure at the completion of the simulation. Porosity as a function of depth can be used to characterize different t5rpes of attack and to determine how uniform the dissolution was throughout the sample. One approach to determine void fraction is to extract metal atom position information from cross sections through the sample and color code the cross... 

---