Penetrate Penetration

Other test media and techniques include post-emulsification penetrants, penetrants that form gels resistant to easy removal from entrapments, penetrants that concentrate dye constituents as their carrier Hquids evaporate during test processing, and penetrants that form strippable coatings in the developers. StiU other penetrant systems are formulated for use at abnormally low or high temperatures for special test appHcations. 

Figure 5.15(c) represents the case where there is a preference for penetrant-penetrant pairs to be formed, such that solubility increases with the concentration of penetrant in the polymer. This type of behavior is observed in systems where the polymer is strongly plasticized by the penetrant, and localized penetrant clusters form, into which additional penetrant molecules preferentially accumulate. 

Since the molecular weight of silicone resins is much greater than that of silanes or siloxanes, they are not very penetrative. Penetration of more than 0.1 mm is considered unlikely under site conditions. The use of this type of material is therefore declining (Stockdale, 1991). 

Type III behavior occurs when there is a preference for penetrant penetrant pairs to form. In this case, solubility increases with increasing pressure, and diffusion decreases with increasing concentration, because penetrant pairs or clusters are less mobile than isolated molecules. This type of behavior is also associated with swelling of the sample. 

Penetration—Penetration (1-efficiency) is used as a measure of performance and may be measured or calculated for specific particle size or size ranges. A series of empirical equations developed by Dennis and Klemm may be used for predicting the outlet concentration and penetration through a filter [18,41]. 

PMAA in water It is possible that the contraction of the PMAA membranes is not only related to the stability constant of the complexes, and to the extent of viscosity drop in solution, but also to a certain structural complementarity between the dissolved polymer and the membrane. If this is true, the contraction of the PMAA membranes should be discussed in terms of size and geometry of the polymers in solution and the chemical structure, both of which should influence the rate of penetration (penetration mechanism). The modest contraction observed with PVPdn, PVA, and PMVE seems to support this assumption. The penetration mechanism of the membrane contraction was proved experimentally and will be described in more detail in the paragraph of chemical valves (Section 3.4.1). 

Penetration. Penetration is an indicator of a grease s relative hardness or softness and not a criterion of quality. Measured on a penetrometer at 77°F (25°C), it is the depth of penetration (in tenths of mihimeters) into the grease of a standard 150-g cone. The softer the grease, the greater the penetration number will be. 

Penetration Penetration occurs when the liquid material enters a substrate. ... 

Penetration—Penetration (1-efficiency) is used as a measure of performance and may be measured or... 

The most commonly known way by which a chemical can pass through a protective barrier is through penetration. Penetration occurs through a pinhole, stitched seams between zipper teeth, a tear, a rip, or other imperfections of the material. The chemical simply flows through that imperfection. 

Pre-cellular Cellular penetration penetration rate in % rate in %... 

Fragmentation injuries to the eye can be either blunt or penetrating. Penetrating injury results in varying degrees of damage to the intraocular structures, with either an intra-ocular foreign body or further... 

X-rays may be detected either photographically or with an ionization counter. They have great penetrating power which increases with their frequency, and owing to this are used to photograph the interior of many solid objects, notably the human body and in monitoring for faults in construction. 

For optimum combustion, the fuel should vaporize rapidly and mix intimately with the air. Even though the design of the injection system and combustion chamber play a very important role, properties such as volatility, surface tension, and fuel viscosity also affect the quality of atomization and penetration of the fuel. These considerations justify setting specifications for the density (between 0.775 and 0.840 kg/1), the distillation curve (greater than 10% distilled at 204°C, end point less than 288°C) and the kinematic viscosity (less than 8 mm /s at -20°C). 

There are numerous tests for characterizing the mechanicai properties of iubricants cone penetration of greases, extreme pressure tests (as in the four-ball test), etc. 

The most widespread test is the penetration of a needle or cone. 

The standard NF T 65-001 gives a classification for bitumen as a function of their hardness. This is measured using a needle penetrability test, which measures the penetration depth of a weighted needle into the bitumen. Five grades have been defined. 

The standard NF T 65-004 classifies the types of composite bitumen it distinguishes three grades of bitumen-tars by their pseudo-viscosities and two grades of bitumen-coal tar pitch by their penetrabilities. 

The principal characteristics of bitumen are its softening point and its needle penetrability. In France the latter has always been the basis for bitumen classification and class designation. Yet, the former is more representative of a bitumen s capacity to deform when the service temperature increases. The other properties have more or less importance depending on the application. 

Penetrability is the depth, expressed in tenths of a millimeter, a standard steel needle penetrates into a bitumen sample at 25°C. The needle carries a weight of 100 g and the test is applied for five seconds. The corresponding test method is relatively difficult to carry out and is defined in France by the standard NF T 66-004, and in the USA by the method ASTM D 583. Penetration is related to the viscosity. 

Cone penetration (waxes) NFT 60-119 ISO/DIS 3986 ASTM D 937 Penetration of weighted cone... 

Needle penetration (bitumen) NF EN 1426 ISO/DIS 3997 ASTM D5 Penetration of weighted needle... 

The rate at which the drill bit penetrates the formation gives qualitative information about the lithology being drilled. For example, in a hard shale the rate of penetration ROP) will be slower than in a porous sandstone. 

As in the construction industry, piling of the conductor is done by dropping weights onto the pipe or using a hydraulic hammer until no further penetration occurs. In an offshore environment the conductor is either piled (e.g. on a platform) or a large diameter hole is actually drilled, into which the conductor is lowered and cemented. Once the drill bit has drilled below the conductor the well is said to have been spudded. 

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