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DPC visible between concrete foundation and brickwork. Damp proofing is defined by the American Society for Testing and Materials (ASTM) as a material that resists the passage of water with no hydrostatic pressure. [1] Waterproof is defined by the ASTM as a treatment that resists the passage of water under pressure. [1]
Download as PDF; Printable version; In other projects Wikidata item; ... data are given for materials in their standard state ... (3,5-DCP) is a chlorinated ...
For example, pharmaceuticals that pick up more than 5% by mass, between 40 and 90% relative humidity at 25 °C, are described as hygroscopic, while materials that pick up less than 1%, under the same conditions are regarded as non-hygroscopic. [32] The amount of moisture held by hygroscopic materials is usually proportional to the relative ...
The relationship between water content and equilibrium relative humidity of a material can be displayed graphically by a curve, the so-called moisture sorption isotherm. For each humidity value, a sorption isotherm indicates the corresponding water content value at a given temperature. If the composition or quality of the material changes, then ...
A common use for desiccators is to protect chemicals which are hygroscopic or which react with water from humidity. The contents of desiccators are exposed to atmospheric moisture whenever the desiccators are opened. It also requires some time to achieve a low humidity.
Removing water with good drainage will remove any form of dampness. Once done, and dampness remains, the next step is to look for the presence of a damp-proof course. [14] If a damp-proof course is present, it is likely to be functioning, as the materials from which damp proof courses are manufactured tend to have a long lifespan.
Many natural building materials are hygroscopic, that is they can absorb (water condenses) and release water (water evaporates). The process is thus: Condensation (gas to liquid) ΔH<0; enthalpy decreases (exothermic process) gives off heat. Vaporization (liquid to gas) ΔH>0; enthalpy increases (endothermic process) absorbs heat (or cools).
The moisture sorption properties of pharmaceutical materials such as excipients, drug formulations and packaging films are recognized as critical factors in determining their storage, stability, processing and application performance. [1] [2] Further, vapor sorption experiments can be used to study hydrate [3] and solvate [4] formation.