Size analysis reduction

At a first glance, a very promising procedure for speeding up LC/MS analysis without compromising peak capacity of the separation would involve (1) reduction of particle size, (2) reduction of... 

As is shown in Table 1 and Table 2, both H2 chemisorption and the EXAFS Pt-Pt coordination number indicate some variations in the final metal particle size after reduction. The Pt/LTL [1.04], Pt/LTL [1.53] and Pt/HT [IE] have similar particle sizes and Pt/HT [IM] show somewhat larger particles. The EXAFS analysis after evacuation at 200°C (Table 2) showed a similar trend. 

I he gross sample can be reduced to a laboratory sample of about 10 g, using a Vezin type sampler for example, and finally to a measurement sample of about 1 g using a rotary riffler. If the particle size analysis is carried out on less than I g the final reduction is usually effected by dispersing the powder in a liquid and pipetting out the required aliquot. 

In the absence of any flocculation, the coalescence of an emulsion results in a reduction of its viscosity. At any given volume fraction of oil, an increase in droplet size will result in a reduction of viscosity, and this is particularly the case for concentrated emulsions. Thus, by following the decrease in emulsion viscosity with time, information may be obtained on its coalescence. However, care should be exercised when applying simple viscosity measurements, particularly if flocculation occurs simultaneously (as this results in an increased viscosity). It is possible - at least in principle - to predict the extent of viscosity reduction on storage by combining the results of droplet size analysis (or droplet number) as a function of time with the reduction in viscosity during the first few weeks. 

In any case, the size constraints for this DARPA commissioned research far exceed those of NeSSI s (New Sampling and Sensing Initiative) modular and standardized micro-analytic elements, so that these sensors will easily fit on a NeSSl substrate for even further application possibilities. The drastic reduction in size, analysis time, cost, and energy consumption, ease of implementation and maintenance, and compliance with NeSSl standards make this technology highly marketable to the civilian sector. 

Dignard-Balley, L., M.L. Trudeau, A. Joly, R. Schulz, G. Lalande, D. Guay, and J.P. Dodelet (1994). Graphitization and particle size analysis of pyrolyzed cobalt phthalocyanine/carbon catalysts for oxygen reduction in fuel cells. J. Mater. Res. 9, 3203-3209. 

The results are different from the 15 and 30 sample sizes analysis. Now the reduction of the expected fatigue limit is 3.6 % for the 99.9 % probability of survival and 4 % for the 99.99 % probability of survival that passes, this last, from 241.7 MPa to just 231.9 MPa. 

The heat capacity decreases with the size at fixed temperature (except for A1 nanowires measured at room temperature, where the heat capacity is very close to the bulk Cy value obtained when A] > 15 and increases slightly with decreasing size). For a given size, the reduction in the heat capacity is more significant at lower temperatures or larger m values. In this analysis, we set Tq — T. If Tq is assumed 0 K, the general trend of heat capacity is preserved, but the reduction in heat capacity is more pronounced. 

Take the results for questions 4 and 5 and do a comparative cost analysis. First go the the Web and find suitable equipment suppliers that will provide the equipment in the size ranges you have calculated. Obtain some vendor quotes (rough ones will do). Then perform the fowllowing analysis (a) What are the comparative costs between the two oprions for energy use (b) What are the comparative costs between the two options in terms of maintanance and labor costs (c) Can you combine both equipment options into a single process, and if so, can you justify this and how Assume in the above that the reduction in solids concentration must meet the 1 % weirht criteria described in question 4. 

---