Cooling weathering

Unless a thermostatic expansion valve is very tightly rated, the system will operate satisfactorily at a lower condensing condition in cool weather, with a gain in compressor duty and lower power input. A growing awareness of energy economy is leading to more careful application of this component. Suppliers are ready to help with advice and optimum selections. 

Since acetic melts at 62 F, shipping pure grades poses a special problem. Cool weather can cause freezing, expansion, and container rupture. 

Protection H Dosage, ag>ain/a] Hot and Huaid Heather, Teap. above 80°F, Sweating Skin Dosages of Wans Weather, Tenp. 60-8OOF, Skin not Wet with Sweat H Vapor for Production Cool Weather, Dry, Tenp. 40-60°F, Skin Cool and Dry of Injuries in Man Ffee t Disability Tine Lo Onset Dural ion of Etfeci... 

It may polymerise with violence on melting at 86°C [1], The concentrated aqueous solutions of commerce will crystallise in cool weather. The usual industrial technique for softening raw materials, applying a steam hose to the bottom of the container, to which crystals have fallen, will create domains of molten, unstabilised, monomer, initiating polymerisation of the whole, then rupturing containers through steam pressure. Rather, the liquid at the top should be warmed and circulated. Photoinitiation seems involved, black plastic containers give less problem than translucent ones. Best do not store below 15°C [2],... 

Powdery mildew form cleistothecia, the overwintering structures of the organism. Cleistothecia are 90 to 135 pm in diameter and have numerous unbranched appendages. Development of cleistothecia is stimulated by cool weather, and they are seen as black, pinhead-sized dots scattered over the surface of the leaves. Cleistothecia are found on infested stubble, which acts as an inoculum, providing conidia or ascospores that infect new plants the following season. 

Because glacial acetic acid freezes at about 16°C, exceptional care must be taken for melting tke product in cool weather. Electrical or steam heaters may be employed Tank cars or tank wagons must be fitted witk heating coils, which can be attacked to a steam line and trap. Tank vents must be traced with electrical or steam lines to prevent crystallization. Acetic acid sublimes so that a single, large crystal can appear and completely fill an otherwise adequate vent. 

Planting Time—Cool-weather crops, such as spinach, peas, and some turfgrass, are subject to attack by certain diseases if planted when the temperatures are warmer. They often emerge and establish poorly under such conditions. Conversely, beans, melons, and many flowers should be planted under warm conditions to avoid disease. 

Safflower seed that is produced in areas with late summer rains or cool weather cycles that interfere with maturation can produce dark-colored or greenish oils that are often higher in FFA as well. If the seed has sprouted before or during harvest or has been attacked by Alternaria, Pseudomonas, or other head-rot diseases, the resulting oil can be quite difficult to refine and extremely difficult to bleach. 

When guayule is in an active growth phase, it produces little or no rubber, but if the plants are stressed, such as in cool weather or because of reduced moisture supply, biomass growth slows and the photosynthetic products are diverted to rubber production. The rubbers are not metabolized by the plant, even when it is deprived of all carbohydrates and other energy sources, and continue to accumulate for at least 10 years. The resins, which include terpenes, sesquiterpenes, diterpenes, glycerides, and low-molecular-weight polyiso-prenes, are found in resin ducts throughout the plant they constitute 10-15 dry wt % of the plant. 

Foxgloves enjoy a shady site with rich, moist, well-drained, slightly acidic soil. Plants tolerate full sun, but favor cool weather and need shade in extreme summer heat. Water regularly to maintain soil moisture. Stake tall cultivars to support flower spikes plant in a sheltered site. Remove foxgloves after they have set seed and self-sown next year s crop. Cutting flowers before they set seed promotes second-year blooms, but flowering is reduced the second year. 

Fruit gnarled and malformed with dry scars near the blossom end. Cause Cold injury. Cat-facing, as this symptom is also called, is caused by prolonged cool weather during blossoming. Poor pollination may be partially responsible. Protect plants with row cover until nights remain above 55°E... 

Prevention and Control Verticillium and Fusarium wilt fungi cause similar symptoms. Verticillium wilt is more common in cool weather in temperate areas of the country. 

Cold, or in some cases cool temperatures, also damages herbaceous plants. If you plant com or beans too early, these heat-loving plants suffer during extended cool weather, even though the temperature never dips below freezing. Sub-freezing weather in the spring... 

The Brazilian Wandering Spider has another well known common name. Banana Spider. The spider was given the name Banana Spider because there have been many cases where these spiders unintentionally hitched a ride on the banana boats heading for the United States and other countries. Though they can only survive a short time in cool weather. They thrive in the temperatures of the Southern United States and Mexico. 

Figure 5 shows the variation of time to failure (5% oxidation) with temperature. The decrease in lifetime with no stabilizer is more or less as expected, ranging from a few months in hot tropical weather, 310K (100°F), to almost two years in cool weather, 280K (45°F). An attempt at a typical Arrhenius plot (Figure 6) shows an "apparent net activation energy" of 10-16 kcal/mol near atmospheric temperatures (280-310K). Experimental values of 16-35 kcal/mol for the dependence of the induction period in polyethylene oxidation have been reported by Wilson (29) and Blum et al. (30) at temperatures above 380 K. For thick films the observed value is as low as 10 kcal/mol (31). 

In principle, the computational approach to the kinetics of the complex photooxidation process can give meaningful insight into the effects of outdoor weathering of hydrocarbon polymers. For clear amorphous linear polyethylene, the model suggests that the optimum stabilizer would be a molecularly dispersed additive in very low concentration which could trap peroxy radicals. An additive which decomposes hydroperoxides would also be effective but would require higher concentrations. The useful lifetime of unstabilized polyethylene is predicted to vary from a few months in hot weather (100°F) to almost two years in cool weather (45°F), which correlates well with experimental results and general experience. 

---