Monitoring Drying Conditions

By monitoring the H MAS spectra, it has been suggested that the loss of water from bone tissue is an irreversible process under air drying conditions.38 It has been shown that CP transfer within an isolated heteronuclear spin pair will exhibit a characteristic oscillation, from which the dipolar coupling constant can be accurately determined.197 The technique of LG-CPMAS can probe this oscillation pattern due to a dominating 31P-1H interaction in a dipolar coupled network, if any. However, such oscillation is seldom observed in 31P 1H CPMAS measurements of biominerals because of the damping effect of the homonu-clear dipole-dipole interaction. Thus, it is rather remarkable that the buildup curve of 31P 1H LG-CPMAS obtained for a sample of powdered femoral cortical bone, which is partially hydrated, shows a distinctive... 

Other equipment, working at lower velocities and with a flat contact, does not imitate aquaplaning and is more suitable under dry conditions. The be.st known example is the Tortus apparatus designed by British Ceram Research Ltd. and described by Brough et al. [26]. This is a four-wheeled trolley electrically propelled across the floor. A cylindrical rubber piece contacts the floor, and the frictional resistance is monitored via a spring assembly coupled to a transducer. The FSC 2000 [27] is very. similar. Portable equipment of this type is useful in that it enables tests to be made on installed floors, but in the laboratory different tests are sometimes used. 

An inherent problem is the location of the sensors. It is not possible to locate the sensors inside the packages which are to be sterilized. Electromechanical instmmentation is, therefore, capable of providing information only on the conditions to which the packages are exposed but cannot detect failures as the result of inadequate sterilization conditions inside the packages. Such instmmentation is considered a necessary, and for dry and moist heat sterilization, a sufficient, means of monitoring the sterilization process. 

Precipitated Calcium Carbonate. Precipitated calcium carbonate can be produced by several methods but only the carbonation process is commercially used in the United States. Limestone is calcined in a kiln to obtain carbon dioxide and quicklime. The quicklime is mixed with water to produce a milk-of-lime. Dry hydrated lime can also be used as a feedstock. Carbon dioxide gas is bubbled through the milk-of-lime in a reactor known as a carbonator. Gassing continues until the calcium hydroxide has been converted to the carbonate. The end point can be monitored chemically or by pH measurements. Reaction conditions determine the type of crystal, the size of particles, and the size distribution produced. 

Implementation of advanced performance degradation models, necessitate the inclusion of advanced instrumentation and sensors such as pyrometers for monitoring hot section components, dynamic pressure transducers for detection of surge and other flow instabilities such as combustion especially in the new dry low NO combustors. To fully round out a condition monitoring system the use of expert systems in determining fault and life cycle of various components is a necessity. 

Pharmaceuticals for injection must be presented in a sterile form. Sterility may be achieved by filtration through 0.22 pm filters under aseptic conditions, or by steam, dry heat, radiation or gas sterilisation methods, which may be applied to packaged products. Irrespective of the method, the process must be validated and monitored to assure its effectiveness. As discussed in Chapter 2, this is an example of a process that cannot be assured by verification testing because of its destructive nature. 

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