Cold damage

Geraldine Warner, Hot Water Could Protect Trees from Cold Damage. Good Fruit Grower, February 15,1997. 

Trees and shrubs that are fertilized too late in summer, or overfertilized with nitrogen at any time, do not harden off with the approach of cold weather in autumn. Pruning or ovcrwatcring too late in the summer can also cause a late flush of succulent growth. In the winter, insufficiently hardened plants may experience cold damage and subsequent disease problems, such as Cytospora canker, also known as Valsa canker, of peach trees. 

Secondly, if LNG spills, or sprays, out of the vents, beware of (a) cold bums to personnel, (b) asphyxiation by displacement of breathing air by dense cold vapour and (c) cold damage to carbon steel structures and wet concrete pavings. 

Urea resin adhesives, by the use of the proper hardener, may be set either by heat or at room temperature. For room temperature curing, the hardener may be ammonium chloride, together with basic materials like calcium phosphate to neutralize excess acid that might damage the wood. Cold set or room temperature set adhesives are those that set satisfactorily at 20 —30°C, whereas a hot set adhesive generally means one that is set above 99 °C. 

Coils may be sloped to facihtate drainage. When it is impossible to do so and remain close enough to the bottom to get proper remelting, the coils should be blown out after usage in cold weather to avoid damage by freezing. 

Examination of the microstructure of the cavitated surface will commonly disclose evidence of deformation such as twins (Neumann hands) in carbon steel and general cold working in other metals (Case History 12.6). Damage from cavitation can be differentiated from attack by a strong mineral acid, which can produce a similar surface appearance, by observing the highly specific areas of attack characteristic of cavitation. Acid attack is typically general in its extent (Case History 12.6). 

Injury to plants and vegetation is caused by a variety of factors, of which air pollution is only one. Drought, too much water, heat and cold, hail, insects, animals, disease, and poor soil conditions are some of the other causes of plant injury and possible plant damage (3). Estimates suggest that less than 5% of total crop losses are related to air pollution. Air pollution has a much greater impact on some geographic areas and crops than others. Crop failure can be caused by fumigation from a local air pollution source or by more widespread and more frequent exposure to adverse levels of pollution. 

Core damage can result most likely from heat imbalance. Figure 6.3-3 is an example from the Indian Point PRA that uses heat imbalance to approach completeness. This diagram shows that cote damage may result from either a loss of cooling or excess power (or both). The direct causes of insufficient heat removal may be loss of flow, makeup water, steam flow, or heat extraction by the turbine. Indirect causes are reactor trip or steam line break inside or outside of containment. Cau.ses of excess power production are rod withdrawal, boron removal, and cold water injection. 

Repairs to the coating are made with either hot-melt polyethylene sticks or polyethylene sheet patches with mastic profiling compounds for small damaged areas. Large repair areas are best treated as for field weld joint coating, where either heat-shrink crosslinked polyethylene sleeves or cold-applied self-adhesive laminate tapes are employed. 

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