Immersion testing principles

The test principle is such that the extraction of migratable substances from a sample of the plastics is determined as the mass of non-volatile residue after evaporation of the solvent following immersion. Test specimens of at least 1 dm2 (single side considered) are immersed in the extraction solvent at the specified test conditions and then... 

Plaque assays, at present, apply to only a very limited number of viruses, e.g. poliovirus, herpes virus, human rotavirus. The principle ofthese assays is as follows test virus is dried on to coverslips which are immersed in various concentrations oftest disinfectant... 

If we consider Ni as an active site for Ni-based materials, changing the environment in which the ion is immersed is expected to influence its electronic properties. This is in principle the reason for testing a series of alloys or intermetallic compounds of Ni. On the other hand, on changing the environment, bond lengths will also be modified and this will modify the actual concentration of active sites, in turn determining the active surface area. A few examples can better illustrate these concepts. 

The so-called tail suspension test applies a similar principle (Steru et id., 1985 Fujishiro et ah, 2001). Instead of being immersed in water the animal (usually a mouse) is suspended by its tail. Following an initial period of struggling, untreated (control) animals remain predominantly in an immobile posture whereas animals treated immediately before the experiment with an antidepressant drug show a reduction in the time spent immobile. 

The same plasma polymer deposited in a closed-system reactor has a graded elemental composition with a carbon-rich top surface, and the oligomer content is much lower [10], both of which increase the level of adhesion. The adhesion of the same water-borne primer is excellent and survives 8 h immersion in boiling water. When this surface is treated with O2 plasma, the adhesion does not survive 1 h of boiling, while the dry tape test still remains at the level of 5. The water-sensitivity of adhesion depends on the chemical nature of the top surface as depicted by XPS data shown in Figure 28.12. Water-insensitive tenacious adhesion, coupled with good transport barrier characteristics, provides excellent corrosion protection, as supported by experimental data [1-4], and constitutes the basic principle for the barrier-adhesion approach. 

If successful the Circulatum should have a peculiar penetrating odour and a sharp corrosive taste. The test is as follows Cut up fresh green leaves from an aromatic herb like mint and immerse them in the matter. The liquid will cloud as tiny drops of oil form and rise to the surface. Eventually the exhausted dregs fall to the bottom. The oil contains the combined Principles of the plant. This oil can be separated and the remaining Circulatum redistilled from the vessel and stored for future use. 

The operating principle of the YR-1 Rheometer is to drive a spindle through a calibrated spiral spring connected to a motor drive shaft (see Fig. 3). The vane spindle is immersed in the test materiaJ. The resistance of the material to movement is measured by observing increasing torque values as the YR-1 motor rotates. The amount of shaft rotation is measured by the deflection of the calibrated spiral spring inside the instrument. Spring deflection is measured with a rotary transducer. 

The probe-modified electrode is then immersed into a solution of target DNA to test its nucleotide sequence. When the sequence of target DNA exactly matches that of the probe DNA (based on the complementarity principle stating that A pairs with T and G with G), a hybrid (probe-target) duplex DNA is formed at the electrode surface. The following sections will focus on two most important steps in the detection of the DNA nucleotide sequence the formation of the DNA recognition layer and hybrid duplex DNA, and the transformation of the latter event into an electrical signal. 

Section HI covers Types of Tests (H. Hack, Section Editor) includirrg laboratory-accelerated tests, field tests, and service tests. The chapters in this section provide basic principles, describe test techniques and specific considerations such as specimen preparation, test duration and acceleration factors, and cite pertinent standards. Chapters included under laboratory tests are electrochemical, cabinet, immersion, high temperature, and high pressure. Field Tests chapters include atmospheric exposure, seawater, fresh water, and soil. Under service tests are industrial applications and high temperature environments. 

Fig. 23 schematically shows the principle of the method of using a circular cylinder as the test solid. S, L, and V in the figure indicate solid, liquid, and vapor phases, respectively. The cylinder held horizontally is first immersed and then slowly drawn from the liquid bath. We can see a pair of two-dimensional menisci formed under the cylinder, as shown in Fig. 23a. As the cylinder is raised to a certain critical height, the waists of the two meniscus curves contact each other and the liquid breaks off from the solid surface. The geometry of the two-dimensional meniscus can be determined from the Laplace equation (11) and the contact angle as a boundary condition, as mentioned in Section I. Hence we could calculate the contact angle using the...

In principle, an improvement of rust corrosion rates in low-alloyed steels is possible as well in the tidal and immersion zone, but expectations should not be too high. The significant improvements frequently cited in the literature and patent registrations are usually based on tests in the laboratory and cannot be confirmed in practical applications or only in reduced form. It must also be noted that in the low-alloyed steels shallow pit corrosion or pitting corrosion is frequently observed in addition to uniform surface corrosion. Examples can be cited in which certain alloying elements reduce the uniform surface corrosion, only to cause increased pitting at the same time. 

Consider a process in a system that we will call the test tube, immersed in a heat bath. The system need not be a real test tube in a water jacket. It could be molecules in a solvent or air in the atmosphere. Heat bath refers to any surroundings of a system that hold the temperature of the system constant. This arrangement controls the temperature T, not the energy U, at the boundary around the subsystem. If the test tube plus heat bath are isolated from the greater surroundings, equilibrium will be the state of maximum entropy for the total system. However, we are not interested in the state of the total system. We are interested in what happens in the test tube itself. We need a new extremum principle that applies to the test tube, where the independent variables are (T,V,N). 

The tea bag is to contain a polymer sample and be immersed in the test solution. In principle, it is made of nylon cloth with hole size of 57 pm (255 mesh), and is 10 cm wide and 40 cm in length. As shown in Fig. 1, the longer side is folded and both sides are heat sealed to make a bag. 

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