Advantages, small-scale testing

Advantages, Possibilities, and Limitations of Small-Scale Testing of Catalysts for Fixed-Bed Processes... 

There can be clear advantages to using a centrifuge over a filter, such as a drier product or a more effective separation. This will be dependent upon the application. However, there can be applications where a nutsche or even several types of centrifuges appear, from small scale testing, to yield similar product quality results. Ultimately, the decision will depend upon operability, that is installation, maintenance, and day-to-day operation. For these purposes, it is strongly recommended that the plant invest the time and relatively small capital costs for a rental unit to run an in-plant test on the product. 

In situ measurements of stratospheric reactive trace gas abundances provide an opportunity to test the fundamental photochemical mechanisms (3). The advantage of such measurements is that they are local, so the simultaneous measurements of trace gases place a true constraint on the possible photochemical mechanisms. These measurements are also able to resolve small-scale spatial and temporal structure in the trace constituent fields. The disadvantage of in situ measurements is that they do not capture the global or perhaps even seasonal view of photochemical transformations because they are seldom done frequently enough or in enough places to provide that information. Another disadvantage of in situ measurements is that they must be made from platforms in the stratosphere, and these remote observational outposts have their liabilities. 

The development model presented here may differ from some formulation research programs in that biostudies may not be performed on small-scale batches. The major advantage of early biostudies is the potential for early IVIVC and subsequent surrogate use of dissolution testing in further work. Scale-up and pilot-plant roles in formulation changes, while not covered thoroughly here, are reviewed by Racz. ... 

Test experiments on a small scale with pure alcohol had shown that when ammonium bromide separated in quantity in the early stage of the process, the formation of triethylamine was promoted when the reaction was prolonged. The reason is fairly obvious when the probable mechanism of the process is considered, hence it was found advantageous to use alcohol containing 10 percent water. 

In Fig. 2.1-1, the general arrangement of an environmental test chamber is shown. Basically, two types of environmental test chambers can be distinguished small scale chambers with volumes ranging from a few litres to a few cubic metres, and room-size large scale chambers of the walk-in type. Both types of chambers have advantages as well as disadvantages (see Table 2.1-1) (EC, 1989). 

More sophisticated suction controlled tests which explore the behaviour of the bentonite under specific stress and suction paths are described in the references given above. Tests on small scale cells involving simultaneous hydration and heating were also performed. They are boundary value problems and their analysis may provide a refined evaluation of constitutive parameters. Some of the research groups participating in the reBEX benchmark test have used this information to their advantage. Their analysis is published elsewhere. 

Another very important advantage of miniaturized bioreactors is that scale-up takes on a different form. The scale-up procedure for standard bioreactors and miniaturized bioreactors is compared in Figure 10.5. The scale-up procedure for standard bioreactors involves a complicated iteration processes. A laboratory bioreactor is designed as a proof-of-concept. Next, an experimental-scale bioreactor is designed to ensure production viability. After a few iterations, a small-scale pilot plant is constracted to test and finalize the production process, equipment placement, and economic viability. Once this step is accomplished, a large-scale... 

The biodegradation tests performed in field show the advantage to obtain data that represent the real conditions where the polymers will be biodegraded. However, the laboratorial tests show many advantages, as the facihty to work in a small scale, shorter time of test, and better reproducibility and control of conditions. 

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