Unprotected area

During stoving in convection-type box ovens, drying can be delayed (as it can on air drying when the ventilation is insufficient, e.g. in a ship s hold) if the vents are closed too far, or if the coated articles are too closely packed. In the latter case there may even be trouble caused by solvent wash, i.e. redissolution of the uncured film by stagnant solvent vapours, which occurs mostly on surfaces near the top of the oven. This can lead to the establishment of practically unprotected areas. 

Figure 11.2 Surface activity on the waterside of a condensate line, showing filmwise condensation of water on an unprotected area (a) and dropwise condensation on an area protected by a closely packed arrangement of filming amine molecules (b).

In male cats, peak concentrations of radioactivity in most tissues and fluids were observed 24 hours after application of 50 mg/kg [uniformly labeled 14C-phenyl]TOCP to unprotected areas of skin on the back of the neck (Nomeir and Abou-Donia 1986). Peak concentrations of radioactivity (reported in parentheses in... 

Fig. 1 Exploration pattern in a novel environment typically displayed by rodents. Placed in one corner of the environment, a rodent will first explore the protected area along the walls (thigmotaxis) before entering the unprotected area...

Fig. 3 Behavior of high (HAB) andlow(LAB) anxiety rats (see Sect. 2.1.2) after treatment with either vehicle or diazepam (1 mg/kg). While avoidance behavior towards an unprotected area remains unaffected, the number of stretched-attend postures is significantly reduced, indicating a high sensitivity of risk assessmentbehavior for anxiety-modulating drug effects. The lack of effects on locomotor activity shows that treatment with this relatively low dose of diazepam was not sedative...

Fig. 6 The modified hole board. In the center of the experimental box, i.e., in the unprotected area, a hole board is placed. The box is enlarged by an additional compartment, where the group-mates of the experimental animal are placed during testing...

Fig. 7 Results from behavioral testing in the modified hole board (see Sect. 2.2.5). While DBA/2 mice (DBA) display a more pronounced avoidance behavior towards an unprotected area as well as more risk assessment behavior than C57BL/6 (BL6) mice, no differences in term of general exploration and locomotion are found in these strains. Therefore, these strains can be considered to represent an interesting model for high and low anxiety...

Fig. 8. Avoidance behavior towards an unprotected area displayed by the offspring of mice treated with the mutagen ethyl-nitrosourea (ENU). The behavior of the offspring is compared to a mean value calculated from the genetic background strain. Mice differing more than 2.75 SDs from the mean value (indicated by circles) are considered to be potential mutants and, after confirmation of the phenotype, are selected as founders for a ENU-mutant line...

One must be wary of the use of anodic protection, in that any area that is not polarized completely into the passive region will dissolve at a high rate. The optimum protection range is shown in Fig. 16. Therefore anodic protection is more susceptible to the presence of crevices, deposits, or poor placement of polarizing electrodes than is cathodic protection. If a component is cathodically under protected, the maximum rate at which the unprotected area corrodes is the normal open circuit corrosion rate in anodic protection, underprotection results in high rate dissolution of the unprotected area and can therefore can lead to unexpected career changes. Understanding the manner in which current from an anodic protection system is distributed across a surface is important in such installations. The issues involved in current distribution are discussed in detail in Chapter 4. 

Anodic inhibitors reduce corrosion by polarizing the anodes rapidly. If insufficient anodic inhibitors are used, severe localized pitting will occur in the unprotected areas. Examples of anodic inhibitors are phosphates, silicates, nitrates, and chromates. ... 

The Ge-rich phase of the unprotected area is quickly dissolved, allowing the Se-rich columns to be attacked from the side as illustrated in Figure... 

Dermal Effects. Dermal effects have been documented in populations occupationally and non-occupationally exposed to coal tar and coal tar products. In patients medically treated with 5% coal tar, dermal applications induced a photosensitizing effect in all patients within 30 minutes of treatment. The Texas Department of Health documented an increased incidence of skin rashes among residents of a housing development built on contaminated land formerly occupied by a coal tar creosote wood treatment plant. The rashes were associated with contact with the soil in the housing area. In workers exposed to coal tar and coal tar products, the observed dermal effects appear to be generally limited to unprotected areas such as the hands, face, and neck, including the posterior part of the neck. There is also a report of... 

---