Structures resistance

The justification for the use of the lognormal is the modified Central Limit Theorem (Section 2.5.2.5). However, if the lognormal distribution is used for estimating the very low failure frequencies associated with the tails of the distribution, this approach is conservative because the low-frequency tails of the lognormal distribution generally extend farther from the median than the actual structural resistance or response data can extend. 

Reduction of 3,5-dimethylisoxazolo[5,4-h]pyridine over 5% Pd-on-C proceeded with loss of the aromatic system to give 3-(l-aminoethyliden)-5-methyl-2-oxopiperidine (94). The product is a vinylogous amide, a type of structure resistant to further hydrogenation (118). 

Ludzack FJ, Ettinger MB. 1960. Chemical structures resistant to aerobic biochemical stabilization. J Water Pollut Control Fed 32 1173-1200. 

Shape-memory alloys (e.g. Cu-Zn-Al, Fe-Ni-Al, Ti-Ni alloys) are already in use in biomedical applications such as cardiovascular stents, guidewires and orthodontic wires. The shape-memory effect of these materials is based on a martensitic phase transformation. Shape memory alloys, such as nickel-titanium, are used to provide increased protection against sources of (extreme) heat. A shape-memory alloy possesses different properties below and above the temperature at which it is activated. Below this temperature, the shape of the alloy is easily deformed due to its flexible structure. At the activation temperature, the alloy can be changed by applying a force, but the structure resists this deformation and returns back to its initial shape. The activation temperature is a function of the ratio of nickel to titanium in the alloy. In contrast with Ni-Ti, copper-zinc alloys are capable of a two-way activation, and therefore a reversible variation of the shape is possible, which is a necessary condition for protection purposes in textiles used to resist changeable weather conditions. 

As described in Section 4.2, the sub-pressure drop measured between Points B and C or between Points B and C, -ApBC or -APb o is the sum of the pressure drop across the impingement zone, —Apim, and the structural resistance -A/ ds, but not any individual one of them. Such a measuring arrangement is not only because the pressure fluctuation frequently occurs round the impingement zone, making accurate measurement difficult, but also because both sub-pressure drops are too small (< 10 Pa) to be measured separately. To obtain the values for these sub-pressure drops, Eq. (4.17) can be specified for the impinging stream contactor studied here as... 

With fire losses increasing as they have been for the past decade, there is urgent need for a true paint which will render homes and other structures resistant to fire. 

Pressure solution can cause major alterations in carbonate rock structures on megascopic to microscopic scales. Numerous papers and reviews deal with this topic (e.g., Bathurst, 1975 Choquette and James, 1987). We feel that one of the best attempts to bring an orderly picture out of the many complex features that are observed was that by Wanless (1979), who also emphasized the importance of pressure solution for subsurface dolomitization (see next section). Figure 8.12 presents his general model for the characteristics and controls on pressure solution types in limestones. The primary variables that Wanless considered were the clay content of the limestone, the concentration of structurally resistant elements, and variations between different units or beds. Temperature, pressure and fluid composition are also likely to play an important role in determining the timing and extent of pressure solution. 

Tissues that contain high molecular weight HA are unusually resistant to invasion and penetration.49 Blood vessels are unable to penetrate joint synovium, cartilage, and the vitreous of the eye. It is also unusual for tumor metastases to develop in these structures. It may be the large size of the HA polymer that also protects such structures from invasion by parasites. The mechanism by which such high molecular weight structures resist hyaluronidase degradation, and avoid the rapid HA turnover characteristic of the rest of the body is not known. Potent hyaluronidase inhibitors may be involved, a class of molecules about which little is known. 

Excessive pretreatment destroys the polymer surface and therefore reduces adhesion. In addition to the adhesion, the surface of the substrate affects the growth, and thus the structure, resistance, and barrier properties, of the metal layer. 

An important characteristic of zeolites, determining to a large extent their efficiency as catalysts, adsorbents, and ion exchangers, is their structural resistance to various factors, including thermal, chemical, and mechanical ones. Different theoretical aproaches are now being applied to this problem. Although quantum-chemical methods are only now coming into use in this field, certain results have already been obtained and some of them are summarized below. 

Hooke realized that a material or structure resists a load by pushing back with an equal and opposite force (Newton s third law). He also noted that this force is generated by deflections—an object under a load changes its shape. Crucially, he also realized that not only does a structure change shape when it is stretched or compressed, so does the mate-rial pom which it is constructed. It is such material properties that concern us here. 

Some crops, animals, and structures resist pests better than others. Some varieties of crops, wood, and animals are immune to certain pests. Use of resistant types helps keep pest populations below harmful levels by making the environment less favorable for the pests. Host resistance works in two main ways ... 

Helicenes are polycyclic aromatic compounds in which the helical structure is a consequence of a steric repulsion of the terminal aromatic nuclei. The conformation and chirality of helicenes have attracted the attention of many researchers over the years [39]. We chose to enlist helicenes as both pawls and springs because (1) they have an inherent helicity that we thought would favor the unidirectional rotation and (2) their relatively rigid structures resist deformation. That resistance to deformation is also a characteristic of springs. 

In vivo protection experiments with DMS that is able to transfer a methyl group to the N7 position of guanines enabled us to demonstrate that telomestatin engages the telomeric overhang in vivo in a DNA structure resistant to action of DMS. These experiments represent the first proof of the existence of G-quadruplexes at the telomeric G-overhang under the effect of the treatment by a G-quadruplex ligand. 

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