General Experimental Suggestions

Regardless of the optical configuration chosen, the following suggestions may be helpful  

The prism used to couple the light into the system and the (usually disposable) slide or coverslip in which TIR takes place need not be matched exactly in refractive index. 

The prism and shde may be optically coupled with glycerol, cyclohexanol, or microscope immersion oil, among other liquids. Immersion oil has a higher refractive index (thereby avoiding possible TIR at the prism/coupling liquid interface at low incidence angles), but it tends to be more autofluorescent (even the extremely low fluorescence types). 

The TIR surface need not be specially polished the smoothness of a standard commercial microscope slide is adequate. 

Virtually any laser with a total visible output in the 0.5 W or greater range should be adequate. The most popular laser for cell biological work with a microscope appears to be a 3-W continuous-wave argon laser. 

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We also examined the effect of petuniolide C upon the brine shrimp, Artemia salina, in order to test the response of another class of arthropod toward this chemical. This crustacean has been suggested as a general experimental subject in toxicity determination of chemical substances toward invertebrates, and for the indication of cytotoxicity (21, 22). Solutions for the test were prepared by adding stock solutions of XVIII in ethanol to containers of artificial salt water (1% EtOH final concentration) with sonic agitation. Even with added ethanol, the solubility limit of the steroid was about 1.0 ppm. Newly hatched brine shrimp were added to these solutions, and controls were run using salt water and salt water containing 1% ethanol. After 24 hr., no mortality was observed for the EtOH controls, and no toxic effect was seen for petuniolide C at 1.0 ppm. 

The description of the polymer-surfactant interaction outlined above is based on the conception that the complex formation is a cooperative process of surfactant ions and reflects the general experimental finding, viz., the existence of a critical surfactant concentration for interaction. It also suggests a decrease of Cgp with increasing polymer concentration, which was experimentally found by many authors, as well as the appearance of two breakpoints in the different colligative properties vs. surfactant concentration curves. 

For advancement in scientific studies propositions must be identified with sensitivity. Many researchers make propositions about their studies and then try to verify these in rational or experimental ways. For instance, when metals are heated they expand is a proposition, which has been suggested after observation on several metals and then generalized to cover many others. It wiU remain true until someone with evidence falsifies this proposition. Up today no experimental evidence has been found for falsification and it is subject to falsification all the time. Some propositions can be set forth by rational or experimental suggestions... 

The approximate nature of the relationship in Equations (2.16) and (2.17) needs to be emphasized. Not only does the heat of adsorption q in the first layer vary, in general, with the coverage 0i, but theoretical considerations as well as analysis of experimental data suggest that the factor aiV2/ 2v, ( = ni. 

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