Experimental method, testing

The experimental unit, shown on the previous page, is the simplest assembly that can be used for high-pressure kinetic studies and catalyst testing. The experimental method is measurement of the rate of reaction in a CSTR (Continuous Stirred Tank Reactor) by a steady-state method. 

Experimental methods coming from laboratory-based studies of worst-case testing of simulated workplace conditions. 

There are several other comparable rheological experimental methods involving linear viscoelastic behavior. Among them are creep tests (constant stress), dynamic mechanical fatigue tests (forced periodic oscillation), and torsion pendulum tests (free oscillation). Viscoelastic data obtained from any of these techniques must be consistent data from the others. 

This section deals with the experimental determination of the rate of oil solubilization in aqueous solutions of AOS and IOS [70]. The experimental method [71] consists of injecting 25 pi of n-hexadecane (containing 5 wt % Dobanol 45-3 as an emulsifier) into 50 ml water this produces a turbid macroemulsion upon vigorous stirring. At the start of the experiment, a concentrated solution of the surfactant under test is injected and the decrease in turbidity is followed with a photometer. The time elapsed to reach 90% of the initial turbidity is recorded (t ) and the pseudo rate constant of oil solubilization is calculated from... 

As the value of these two new chemicals for insecticides became more evident, the need for extended experimental and test work was definitely established. It was necessary to determine chemical formulas, work out analytical methods, obtain knowledge of various physical and chemical characteristics, and complete evaluation of insecticidal action as well as toxicity and effect of residues. Toxicity was concerned with not only insects but humans and other warm-blooded animals. Residual studies included information on persistence and type and amount of residue. This information, once accumulated, must be correlated with similar information on other insecticides. 

Experimental methods which yield precise and accurate data are essential in studying diffusion-based systems of pharmaceutical interest. Typically the investigator identifies a mechanism and associated mass transport model to be studied and then constructs an experiment which is consistent with the hypothesis being tested. When mass transport models are explicitly involved, experimental conditions must be physically consistent with the initial and boundary conditions specified for the model. Model testing also involves recognition of the assumptions and constraints and their effect on experimental conditions. Experimental conditions in turn affect the maintenance of sink conditions, constant surface area for mass transport, and constant and known hydrodynamic conditions. 

Freitag, D., Ballhom, L., Geyer, H., Korte, F. (1985) Environmental hazard profile of organic chemicals. An experimental method for the assessment of the behaviour of organic chemicals in the ecosphere by means of simple laboratory tests with 14C labelled chemicals. Chemosphere 14, 1589-1616. 

However, the use of this interesting approach remains to be tested by experimental methods and from a philosophical position. ... 

Turner, B. C., "The Time/Pressure Test, Part I, Design and Experimental Method," EM2 Branch, RARDE, London, England (1973). 

The presence of clay in the ore has a detrimental effect on copper oxide flotation. Results from experimental development test conducted on various clay containing ore types using AQ depressants showed that in the presence of these depressants, the results improved markedly using the sulphidization flotation method. 

Experimental methods exist to determine a critical value for any one of these factors when the others are held constant. However, parameters such as pH, concentration of inhibiting ions (e.g., SO4"), dissolved gas, test area, flow rate, and surface finish influence the resistance to pitting. ... 

Two somewhat different types of null hypotheses are tested, one during the development and validation of an analytical method and the other each time the method is used for one purpose or another. They are stated here in general form but they can be made suitably specific for experimentation and testing after review and specification of the physical, chemical and biochemical properties of the analyte, the matrix, and any probable interfering substances likely to be in the same matrix. Further, the null hypotheses of analytical chemistry are cast and tested in terms of electronic signal to noise ratios because modern analytical chemistry is overwhelmingly dependent on electronic instrument responses which are characterized by noise. 

Fig. 6. Determination of the critical protein concentration. (A) Plot of protein in the supernatant fluid after quantitatively sedimenting polymer from a polymerized solution of tubules and tubulin at steady state. The critical concentration, Ko, is determined from the value of the y axis intercept, and the fraction of active protein, y, from the slope. (B) The conventionally used experimental method for estimating the critical concentration. Note that the x axis intercept is actually Ko/y, instead of Kj,. Interpretation of the slope from such plots requires knowledge of the ratio of polymer weight concentradon to turbidity (given here as a). Data from experiments such as those in A may be used in conjunction with this plot to obtain the cridcal concentration, and this can serve as an internal test for self-consistency of the data.

Mikos A., and Peppas, N.A., Bioadhesive analysis of eontrolled-release systems. IV. An experimental method for testing the adhesion of microparticles with mucus, J. Control. Rel, 12 31-37 (1990). 

As mentioned previously, there are no test guideline methods for respiratory irritation. Good data, often clearly related to exposure levels, can be obtained on respiratory and mucous membrane irritation, from well-designed and well-reported inhalation studies in animals. Also the Alarie test (Alarie 1973, 1981), an experimental animal test assessing the concentration that results in a 50% reduction of the breathing frequency, may provide useful information on sensory irritation of the upper respiratory tract and the results may be used for hazard identification. 

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