Testing generally

The sensitivity test on nickel-chromium test blocks show that products which give bad results to over washing tests generally do not give good results to sensitivity tests. 

In these tests it is to be determined if iron inclusions with a mass greater than a minimum value are present and, if yes, at what location within the disk. The large thickness of the disk is a special challenge. While eddy current and ultrasonic test generally fail we operate as follows. 

There is hardly a metal that cannot, or has not, been joined by some welding process. From a practical standpoint, however, the range of alloy systems that may be welded is more restricted. The term weldability specifies the capacity of a metal, or combination of metals, to be welded under fabrication conditions into a suitable stmcture that provides satisfactory service. It is not a precisely defined concept, but encompasses a range of conditions, eg, base- and filler-metal combinations, type of process, procedures, surface conditions, and joint geometries of the base metals (12). A number of tests have been developed to measure weldabiHty. These tests generally are intended to determine the susceptibiHty of welds to cracking. 

Corrodkote corrosion test General rules for stationary outdoor exposure corrosion tests... 

Metals and alloys removal of corrosion products from corrosion test specimens Metals and alloys atmospheric corrosion testing general requirements for held tests Corrosion of metals and alloys. Classification of corrosivity of atmospheres Corrosion of metals and alloys. Guiding values for the corrosivity categories of atmospheres... 

The tests generally involve some form of maze but the simplest is the passive avoidance test. In this the animal learns that in a certain environment it will be punished with an electric shock for some particular action, like stepping onto a special part of the floor of the test chamber. The test of memory is how long the rat avoids (remains passive to) making the movement that will initiate the shock. Of course, drugs that reduce the animal s anxiety also modify the response. Using a maze in its simplest T shape, the animal is placed at the base of the vertical arm and a food reward at the end of one of the horizontal arms. Clearly the animal has to learn which arm contains the reward. Memory is assessed by the time taken for a food-deprived animal to reach the reward and the number of false arm entries. This simple system can be made more complex by introducing many more arms and branches but the principle is the same. 

It is pertinent, then, to seek a dependence of substitution rates on (/) leaving group, (ii) solvent, Hi) steric crowding, iv) charge, v) nature of non-labile substituents including stereochemistry, consistent with this picture of the activation mode. If these tests generally support d modes it will be desirable to examine rate laws closely to attempt a distinction between D and 7j stoichiometric pathways. 

A quantity sufficient to carry out the required tests, generally in duplicate, are filled into the containers. Most substances for which there are no concerns for either toxicity or stability are filled by weighing the appropriate quantity into antibiotic vials in a horizontal laminar flow work station. These operations are carried out in a self-contained cubicle to avoid cross-contamination. The vials are then closed with butyl rubber stoppers and sealed with an aluminium crimp seal using an automatic crimping and labelling machine. 

Screening (continuous, commercial) and sieving (batch, laboratory test generally confined for size determination) are essentially mechanical separations of particles based on size, accomplished by using a perforated surface that serves as a go-no-go gauge. Both processes, like all other separation processes, have the drawback that a complete separation is seldom obtained, and some potential oversize/undersize particles are always left in the undersize/oversize fraction. 

The storage temperature of a specimen influences the results of coagulation tests. Generally, when plasma is stored in contact with cells and maintained at4°C for up to 7 hours, the PT is not artifactually shortened (103). However, beyond 7 hours factor VII is activated, thereby shortening the PT (104). At room temperature (25°C), provided the specimen container is well stoppered, the PT has been shown to be stable for up to 48 hours (104). Even freezing plasma at — 20°C and at - 70°C did not activate factor VII. Both PT and APTT results were shown to be stable in plasma frozen at —20°C for 10 days and at -70°C for 21 days (104). 

When large quantities of a substance are handled, sensitivity of the material to heating under confinement may need to be considered to demonstrate the effect on the stored/handled, and probably confined, substance in the event of an external heat load. Tests such as the steel sleeve test or Koenen test [24, 137], the Dutch pressure vessel test (DPVT) [143], and the United States pressure vessel test (US-PVT) [143] may be applicable. These tests are used mostly for transportation considerations. The tests generally subject the sample substances to very high energy inputs under confined conditions, and thus are more severe than the deflagration and autoclave tests previously discussed in Section 2.3.3.2. As an example, the Koenen test, used mainly in Europe, is illustrated in Figure 2.32. 

Endurance burn testing generally implies that the ignited gas mixture and flow rate are adjusted to give the worst-case heating (based on temperature observations on the protected side of the element surface), that the burn continues for a specified duration, and flame penetration does not occur. Continuous flame testing implies a gas... 

POLYMERS AND BIOLOGICAL SAFETY TESTING GENERAL AND SPECIFIC RISK ASSESSMENT Baldrick P... 

Oral contraceptives are subject to special testing requirements. These have recently been modified so that in addition to those preclinical safety tests generally required, the following are also required (Berliner, 1974) ... 

ISO 9370, Plastics - Instrumental determination of radiant exposure in weathering tests - General guidance and basic test method, 1997. 

The Demo II tests generally confirmed the performance and efficacy of the GPCR process for the treatment of the waste streams from the process. However, problems with the agent detection method hampered a full evaluation of the process, and some concerns were raised about the selection of materials of construction for the processing agent. 

The Demo II tests generally confirmed the performance and efficacy of the GPCR process for the... 

Low-temperature impact tests cooled samples are subjected to a conventional impact test. Generally, the temperatures most often used are -20°C, -30°C or -40°C. 

One final point deserves emphasis. The astute reader may already have considered a "higher" level of detection — i.e., detection of deviations from the ideal assumptions via appropriate test statistics (x F,. ..) or independent measurements. Unfortunately, unless there are severe deviations or large numbers of degrees of freedom, such tests generally lack sufficient power to signal significant (unanticipated) error. 

D. Berek, Repeatability and apparent reproducibility of molar mass values for homopolymers determined by size exclusion chromatography, lUPAC Round Robin Test, General Assembly of lUPAC, Brisbane, Australia, 2001. 

Inspection and testing requirements are covered in detail. Most vessels are required to be hydrostatic-tested (generally with water) at 1.3 times the maximum allowable working pressure. Some enameled (glass-lined) vessels are permitted to be hydrostatic-tested at lower pressures. Pneumatic tests are permitted and are carried to at least IV4 times the maximum allowable working pressure, and there is provision for proof testing when the strength of the vessel or any of its parts cannot be computed with satisfactory assurance of accuracy. Pneumatic or proof tests are rarely conducted. 

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