Strength macroscopic level

In spite of the presence of ECC, the sample exhibiting a domain structure remains unoriented on the macroscopic level. Figure 3 c shows a great difference in the structures obtained, if molecular orientation exists and if hydrostatic compression is applied. Although the method of hydrostatic compression of the melt is of paramount importance from the scientific view point just for samples crystallized under pressure it was possible to prove unequivocally the existence of ECC), it does not allow a direct preparation of oriented samples of high strength (they are brittle and readily crumble to powder under minimum strain). However, the material obtained in this way can probably serve as a semi-finished product for further technological treatment that would improve its mechanical properties. 

Van Santen [13] identifies three levels of research in catalysis. The macroscopic level is the world of reaction engineering, test reactors and catalyst beds. Questions concerning the catalyst deal with such aspects as activity per unit volume, mechanical strength and whether it should be used in the form of extrudates, spheres or loose powders. The mesoscopic level comprises kinetic studies, activity per unit surface area, and the relationship between the composition and structure of a catalyst and its... 

The macroscopic level of consideration takes into account fiber length and differences in cell growth such as earlywood, latewood, reaction wood, sapwood, heartwood, mineral content, resin content, etc. Difierences in growth chemistry can cause significant differences in the strength of wood. 

The failure of a ply depends on the loading and the strength of its constituents, the fibers, and matrix. At the macroscopic level, five different failure modes are recognized for a ply ... 

As in the case of macrophase separation, the two competing terms of enthalpic and entropic nature govern the thermodynamics of block copolymers. Similar to binary polymer bends the phase behavior of diblock copolymer melts is primarily controlled by the segregation strength and the volume fractions /a and /b = 1 - /a of the two blocks. Being covalently bonded, repulsive blocks are prevented from separating on a macroscopic level. Hence, the segregation into A- and B-rich domains... 

The Hooke law states that the strain of a body is proportional to the applied stress. The law is applicable at the macroscopic level of strength of a soUd (see Table 1.1, the characteristic length is greater than 0.01 m). Practically, the Hooke law holds within the elastic range of a material for relative small values of strain e (e 1). 

Two methods are used for determining the fabric-damaging properties of bleach systems tensile strength loss, on a macroscopic level, and the decrease in the degree of polymerization, on a microscopic level. Recently it was shown that there is only poor correlation between the resnlts of both test methods. To obtain reliable data, measnranent of tensile strength loss after 20 or 50 wash... 

Composite materials consist of two or more constituents mixed at a nano-, micro- or macroscopic level. These constituents are not soluble and form distinct phases. The reinforcing phase is embedded in the other phase, designated the matrix. Usually the reinforcing material is in the form of continuous or short fibres or particles. Actually, composites provide a more efficient way for using materials in structural applications. For example, they allow mass reduction without decreasing the stiffness and strength of components, by... 

The presence of the elastomer fragment either in the main chain of the reaction products or as a branch results in the increase in the macromolecule flexibility which determines at the macroscopic level the increase in the impact strength. A close correlation exists between the mechanical properties and the elastomer concentration in the mixture under processing (Figure 3.235), the impact strength improves with increasing concentration. 

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