Existing structure conditions

The thickness of the HMA overlay is determined according to the existing structural condition of the pavement and the required number of years the pavement will be of service in the future. 

Existing structures (their condition, type of construction, etc.) ... 

Estimate of current required The surface area of the structure is calculated and the current density required for the particular environment is selected (Table 10.26). In the case of an existing structure the condition of the coating may be unknown and the application of a temporary cathodic-protection system may be necessary to determine the amount of current required for protection, as established by the potential. Such a test to determine the... 

A patented water injection system has been devised for extinguishing oil and gas well fires in case of a blowout. The "Blowout Suppression System" (BOSS) consist of finely atomized water injected to the fluid stream of a gas and oil mixture before it exits a release point. The added water lowers the flame temperature and flame velocities thereby reducing the flame stability. In the case where the flame cannot be completely dissipated, the fire intensity is noticeably deceased, preserving structural integrity and allowing manual intervention activities. A precaution in the use of such a device is that, if a gas release fire is suppressed but the flow is not immediately isolated, a gas cloud may develop and exploded that would be more destructive that the pre-existing fire condition. 

Existing structures, facilities, and conditions not legally in existence at the time of adoption of the relevant IFC edition. 

As discussed above, monomer molecules are capable of functioning either as it-electron donors and n-electron acceptors (e.g. C=C double bond containing compounds), respectively, or as n-electron donors (e.g. epoxides). Therefore, their ground or excited states can interact with donor or acceptor molecules, which are unable to polymerize. For that interaction the general Scheme 3 holds, too. Clearly, in these cases only a homopolymerization of the monomer used takes place. The mechanism of that reaction depends on the electronic properties existing (e.g. monomer acts as donor or acceptor), and on the structural conditions in both molecules. Again, in some cases a proton transfer reaction could occur. 

However, we have shown that the novel bond formation between phenol and acetonitrile plays a role on increasing the concentration of the acetonitrile. By postulating its existence under conditions in which phenol interacts with two acetonitrile molecules, we were able to explain the experimental data that have seemed to be rather unclear during the last four decades. Moreover, we have predicted the existence of another structure formed from phenol and two molecules of acetonitrile, which is characterized by a significant downshift by 244 cm of the v(OH) stretching mode of phenol, never observed experimentally in phenol-acetonitrile complexes. We have suggested that it is likely to exist in the gas phase and non-polar solvents at lower temperatures and showed its fingerprints in order to facilitate its possible experimental detection. 

A substance is said to be polymorphous when it is capable of existing in two or more forms with different crystal structures. We have already encountered numerous instances of this phenomenon as, for example, carbon, selenium, some of the metallic elements, zinc sulphide, ferric oxide, silica, and many others. In some of these examples one form alone is found under a given set of physical conditions and a reversible transition between forms is brought about by a change in these conditions, in which case the forms are said to be enantiotropic. Thus iron has the cubic close-packed structure between the temperatures 906 and 1401 °C, and the cubic body-centred structure at temperatures outside this range. Even so, the rate at which the transition takes place may vary between wide limits at the one extreme it may be virtually instantaneous and at the other it may be so slow that a form is capable of indefinite existence under conditions in which it is, strictly speaking,... 

For existing structures the carbonation depth of any part of the structure can be measured after a given period of time and thus the value of K and its spatial variation can be calculated. By assuming that the average exposure conditions will not change in the future, these values of K may be utilised to extrapolate the carbonation depth to a later point in time. 

While this factor is easy to visualise in the case of free-field sites, its estimation is more involved when liquefaction below foundations of existing structures is being considered primarily as it involves the calculation of initial effective stress cr. The range of r varies from 0 to 1 i.e. no excess pore pressures generated to full liquefaction condition. When the value of r reaches... 

Micro piles (a.k.a. mini piles) of diameter 150-300 mm are used especially for underpinning of existing structures in distress, as well as support for structures (buildings and bridges) in difficult ground conditions, particularly in shallow karsts limestone formations, boulders in granite formations as well as soft ground over shallow hard formation (Ooi et al. 2004). 

Until now there was no obvious correlation found between the monomer structure and the resulting pol qner phase. No.theorr retical structural conditions were described which would result in a liquid crystalline polymer with a definite ordered phase e.g. with a nematic a smectic or a cholesteric phase as in conventional liquid crystals. Although previous examples have established (8 9) the existence of enantiotropic liquid crystalline side chain polymers additional considerations are in order for a systematic synthesis of such polymers. 

During pavement maintenance or rehabilitation, it is also recommended that the case of simultaneous pavement strengthening be examined. However, pavement strengthening may be decided at any time regardless of the need for maintenance or rehabilitation of the pavement. In any case, the thickness of the strengthening overlay is determined after examining the structural condition of the existing pavement. 

Carry out a condition survey of existing structure, with particular attention to foimdation conditions, undermining or scour and impact/collision damage. 

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