Specimen input area

On analyzers with several analytical modules (MODULAR, Architect, AU 5400 series), delivery of specimens from the specimen input area to the various modules is accomplished using either built-in conveyor tracks (MODULAR, AU 5400 series) or robotic handling of specimen carriers (Architect) (Figure 11-2). These devices will be discussed in more detail later. 

Specimen input area A holding area where bar code-labeled specimens are introduced into the system. 

Several additional, non-microstructural, inputs are required for the fracture model (i) Particle critical stress intensity factor, KIc. Here, the value determined in a previous study (Klc = 0.285 MPa in )[3] was adopted for all four graphites studied. This value is significantly less than the bulk Klc of graphites (typically -0.8-1.2 MPa rn). However, as discussed in the previous section, when considering fracture occurring in volumes commensurate in size with the process zone a reduced value of Klc is appropriate (ii) the specimen volume, taken to be the stressed volume of the ASTM tensile test specimens specimen used to determine the tensile strength distributions and (iii) the specimen breadth, b, of a square section specimen. For cylindrical specimens, such as those used here, an equivalent breadth is calculated such that the specimen cross sectional area is identical, i.e.,... 

The currently preferred method for the study of gas forming reactions as function of temp is DSC. Here the specimen and the ref sample are heated at programmed heating rates (in controlled atms, if desired) while the differential energy input to the specimens is recorded. Hence the pen movement is directly proportional to the heat capacity while the area under the curve represents the enthalpy change. New equipment is now on the market which can operate up to 1200° (Ref 79) and which is therefore adequate for expl and propint studies. Limitations on the use of DSC for kinetics studies of expls will be discussed under the entry Thermochemistry in this Vol... 

This procedure is similar to those given in ISO 2582 [35], DIN 52612 [36]. and ASTM C -177 [37], Two foam specimens of size 300 x 300 x 30-50 mm are placed in contact with the opposite faces of an electrically heated hot plate [33.38], The edges of the hot plate and the samples are guarded by heated collars that minimize heat loss from these areas. Steady-state conditions are established when the electrical input to the hot plate equals the heat flow through the specimen. The thermal conductivity is then calculated. 

The main value of electron microscopy in recent years has been to allow morphological features to be determined for small objects and visualization of structures down to the molecular level. For non-biologists, however, it should be pointed out that most electron microscopes are operated in hard vacuum which can produce artifacts due to desiccation. In addition, it is often necessary to stain features with materials that are electron dense in order to provide sufficient contrast in the field under examination, and this can occasionally result in mis-identification of structures or additional artifacts being produced in the specimen. Electron microscopy is therefore a fascinating and specialized area with its own challenges. However, here is another scientific discipline that could benefit from the input of experienced particle size analysts in... 

In an extension of the idea of Yates and West, above. Seah and Smith [62] introduced a scanning system inside the analyzer input lens, between the specimen and the transfer lens, to raster the virtual image of the analysis area. The spatial resolution available depends of course on the size of the aperture at the entrance to the CHA. The instrumental arrangement is shown in Fig. 20, from Ref. 6.. It forms the basis for the AXIS system marketed by Kratos Analytical. 

A specimen is heated by electrical self-resistance in vacuum. Total hemispherical emittance is determined from the Stefan-Boltzmann law of radiation, knowing the power input, the total surface area, and the temperature. By using a solar simulator, as in method 3, the difference in electric power required to maintain a given temperature with the solar simulator on and off determines the solar absorptance. 

In this Section it will be demonstrated that solutions with non-uniform deformations can also be found with the described model. For reasons of comparison, the input as used in the FE-calculation of the tensile experiment [2] is also taken as input for the model. The specimen dimensions are 250 60 50 mm, while two saw cuts reduced the critical cross-sectional area to 50 50 mm. In the first instance, 35 mm was taken for the depth of the fracture zone. This length is equal to the measuring length of the... 

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