The relation between moisture content and moulding in cured hay.
Samples of cured hay have been stored in closed containers at relative humidities of 0–95% at temperatures varying from 5 to 25° C. A curve relating equilibrium moisture content to relative humidity of the store has been constructed and the incidence of first mould growth noted. An explanation has been suggested to account for the apparent discrepancy between earlier published work concerning the onset of moulding and conditions normally prevailing on the farm. In laboratory storage experiments temperature conditions are relatively constant, whereas with hay stacked in the open air the high atmospheric humidity in winter is offset by a lowered temperature, and the higher summer temperature is accompanied by a lower moisture content in the hay.
Preservation of moist hay in miniature bales treated with propionic acid
Abstract In 2 experiments, propionic acid was applied by hand-sprayer to partly dried hay which was made into miniature bales of about 1 kg. In an experiment in which the hay moisture content was 51%, acid was applied at 0%, 1%, 2%, 4%, 6% and 8% by weight. Bales with less than 4% acid showed severe heating, moulding, and losses of dry matter and nutrient content within a few weeks. Bales with 4% acid or more were still well preserved after 3 months. In a second experiment hays of 32% and 41% moisture showed moulding at 0.5% and 1.0% acid respectively, but slight or no moulding at 1.0% and 1.5% acid. At 48%, 59% and 76% moistures the lowest acid levels used, 2%, 3% and 3.5% respectively, all prevented moulding. It was concluded that acid treatments of 1%, 1%–1.5%, and 2% for hays of 30%, 40% and 50% moisture respectively were on the margin between being effective and ineffective in the preservation of hay stored under experimental conditions.
Investigations of dielectric gratings using electrodynamic models based on volume integral equations
Eigenmodes of planar and cylindrical dielectric gratings (DGs) and electromagnetic wave scattering from multiplayer DGs are investigated. The DG characteristics are calculated using numerical-analytical solution of integral equations (IEs).