Operating temperature of polystyrene from -200 to +85 C. Water absorption foam Unlike other materials Styrofoam is not hygroscopic. Even under water, it absorbs little moisture. Since the walls of the cells are impermeable to water, it can leak out only through the channels between the individual associated with each other between the cells. Water absorption is measured by the standard method. Test samples are squares with the surface of 200×200 mm and the corresponding thickness, immersed completely in water.
The water absorption is virtually independent of the bulk density. It is reached after 24 hours up to 2-3% in terms of volume. Water absorption during curing under water not only plays a significant role for most of the material and is of interest only in special situations. Since polystyrene does not dissolve or swells in water, and because no coherent structure containing air cells, almost does not absorb water. The water in the liquid phase can, in principle, to penetrate the labyrinth between the granules fused together, mainly due to capillary action, but can always leave the maze, without affecting long-term adverse effects on the mechanical strength, size, physical appearance or the insulating properties of the material. In addition, by increasing the degree of fusion between the granules through optimization of molding, the capture of water is minimized. Water vapor phase able to penetrate, and polystyrene, although at a density of 30 kg/m3 and above, the rate of displacement less than 1% compared to the speed of movement of water through the stable layer of air of the same thickness.
For it, the attachment behavior mother-baby would have appeared to guarantee safe proximity between adult and baby and is provoked by the baby since its initial gestures. It is important to leave clearly that the affective entailing is not only the automatic result of the physiology, therefore we are biological cultural beings. The attachment guarantees the protection of the baby, but it is the interaction between mother and son whom the construction of the affective bond guarantees. Minute inquiries of the behavior of small children have disclosed the presence of natural adaptations for the social interaction and the formation of affective entailings. The attachment is closely on to the parental investment, and of it cannot be dissociado, therefore it is from the signals emitted for the baby and of the reply of parents it who if forms the bond.
If he cannot think one without the other. As shown in the example above, one notices that the baby acts on the adult and this answers the baby of a form that goes increasing the affective entailing for the constant answers, therefore, according to John Bowlby, psychiatrist and English psychoanalyst, cited for Pliny Landmark of Toni, one of the determinative factors for the sprouting and maintenance of the attachment behavior it is the rapidity with that the adult answers to the baby and the intensity of the interaction. The attachment behavior, beyond the protection function, propitiates to the baby a series of social interactions that collaborate for a healthful development of the child, beyond providing chances to it to train its social behaviors and to perceive the modifications of it in the way. Thus, he is thanks to this proximity mother-baby who this will have chances to see and to explore the world in a safe way, and thus to develop its brain, to learn with the others of its species and to feel part of it insurance in it from the love of its parents.