Sample preparation irradiated length

Some problems developed in sample preparation and irradiation because of the variety of sample matrices submitted for INAA. Some samples were particulates (coal, fly ash, bottom ash, ore), some were volatile hydrocarbons (gasoline, jet fuel, etc.), some were aqueous, and some were solids. Our methods of sample preparation were refined to provide all samples in sealed quartz and polyethylene vials for irradiation (see Figure 1). Depending on the contents of the quartz vials, the length of irradiation was varied from 3-12 hrs to minimize vial breakage from... 

Electron irradiation (100 keV) of the sample, heated to 800°C, yields MWCNTs (20-100 nm in length) attached to the surface. Such nanotube growth does not take place if natural graphite, carbon nanoparticles or PTFE are subjected to electron irradiation. The result implies that the material may be a unique precursor for CNTs and may constitute a new preparation method. 

The irradiated samples were tested for mechanical properties such as Young s modulus at room temperature using the ASTM D638 specification. Samples were prepared in a dog-bone shape of initial dimensions corresponding to gauge length of 10 mm and width of 2.8 mm. An Instron... 

Samples were prepared, stretched, and irradiated as previously described. The temperature of stretching, transportation to the cobalt source, and irradiation were 0, -15, and -15 C for Polymer B, and 0, -15, and -lO C for Polymer C, respectively. In the stretching procedure at 0 u, the chosen elongation was reached in about 30 sec and the sample was quenched to -15 C for exactly 3 min after the stretch was begun, so the extent of entanglement relaxation was carefully controlled. Meanwhile the sample was attached to a steel band on which it remained during irradiation, so its length in the strained state could be measured accurately. 

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