Water in wood

Skaar, C. (1972). Water in Wood. Syracuse University Press, New York. 

Skaar, C. "Water in Wood" Syracuse Univ. Press., Syracuse,... 

Figure 21. Diagram showing the relative energy levels, in terms of Q, for water vapor, liquid water, ice, and bound water in wood at different moisture contents, (Reproduced with permission from Ref. 10. Copyright 1972, Syracuse University Press.)...

Figure 24 shows curves of Qi, AG, and TAS plotted against wood moisture content. All energy terms are negative (heat is given off) when wood takes up water from the liquid state. The decrease in entropy indicates that bound water is more ordered than liquid water, in analogy to the greater order of water in ice compared with the liquid state. As the moisture content approaches fiber saturation the distinction between liquid water and water in wood decreases toward zero. However, even above fiber saturation the water in cell cavities may be different from ordinary liquid water because of capillary forces and/or dissolved materials. 

Water in wood is rarely in static equilibrium. It is continually adjusting to changes in its environment. The most dramatic change occurs when green wood is first dried. However, even in use wood is exposed to cycles of changing humidity, both daily and seasonally. 

Skaar, C. Water in Wood Syracuse Univ. Press Syracuse, 1972. 

Water in wood ean exist as either absorbed (also called free water) in the cell lumens and intereellular spaees or as adsorbed (also called bound water) within the cell walls. When wood dries water first evaporates from the lumens and intercellular spaees. The fibre saturation point is defined as the moisture content at which all the absorbed water has been removed but at which the cell walls are still fully saturated. This oeeurs at a moisture eontent of 25 to 35%. In most instances it is adequate to presume the fibre saturation point to be 30% moisture content. 

Any change in one of the variables (temperature in this case) that determines the state of a system in equilibrium (adsorbed water in wood in equilibrium with water vapour in the surrounding environment) causes a shift in the position of equilibrium in a direction that tends to counteract the change in the variable under consideration. 

Araujo CD, MacKay AL, Whittall KP and Hailey JRT (1993) A diffusion model for spin-spin relaxation of compartmentalized water in wood. Journal of Magnetic Resonance Series B, 101 248-61... 

Rietz RC (1972) A calendar for air-drying lumber in the upper midwest. USDA, Forest Service, Forest Products Laboratory, Research Note FPL-0224 Riggin MT, Sharp AR, Kaiser R and Schneider MH 1979 Transverse NMR relaxation of water in wood. Journal of Applied Polymer Science, 23 3147-54 Rimpi PK (1983) Chemical recovery in the first SAP-market pulp producing mill. Proceedings 1983 Pulping Conference, Houston. TAPPl Press, Atlanta, Georgia, Vol. 1 59-61... 

Skaar, Christen Water in Wood Syracuse University Syracuse, NY, 1972. 

Water in Wood Sorbed and Capillary Water, and Shrinkage.804... 

Sorbed water in the cell wall has a lower enthalpy than liquid water. However, contrary to other forms of water, such as solid, the enthalpy of bound water increases with increasing moisture content up to FSP. Above this value, the enthalpy of water in wood is essentially the same as that of liquid water. 

Anonymous (1954). Ernest A. Moritz. Who s who in the West 483. Marquis Chicago. Anonymous (1974). Ernest A. Moritz celebrates 92 birthday. Henderson News (9/10) 7. P Anonymous (1981). Moritz, Ernest A. Who was who in America 7 414. Marquis Chicago. Etcheveny, B.A. (1915). Irrigation practice and engineering. McGraw-Hill New York. Moritz, E.A. (1911). Experiments on the flow of water in wood stave pipe. Trans. ASCE 74 411-482. 

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