Lawns

The commercial use of 2,4-D has decreased substantially and (ca 1993) it has general use for home lawns to control broadleaved weeds it also is used on a limited basis to control broadleaved weeds in commercial moncotyledonous crops, eg, sugarcane. 2,4-D is used on citms when the fmit is 1/3 to 1 inch in diameter to increase fmit size and to limit fmit drop on trees more than six years old. It should not be appHed to trees that are in fliU flush. A further use includes treatment of harvested lemons at 500 mg/L to improve storage properties and to delay yeUowing (23). It is used in certain parts of the world to increase latex flow in old mbber tree plantations. 

Tuf Protection insects and weeds in lawns, parks, golf courses moles... 

Aluminum is used in the home as household foh (0.18 mm thick), cooking utenshs (the first commercial use of aluminum), refrigerators, air conditioners, appHances, insect screening, and hardware. It is also used for toys, sporting equipment, lawn furniture, lawn mowers, and portable tools. In many of these apphcations, anodized or colored coatings are employed for decorative purposes. 

Specialty Chemical Products, Product Bulletin, 5M 682 TGT, Lon2a Inc., Fair Lawn, N.J., 1987. 

Floor mats, carpet backing, and reHef mats have been traditional markets for ground mbber where the material adds resHiency at a lower cost compared to virgin compounds. Certain molded products have also been markets for ground mbber. An interesting use is the manufacture of lawn soaker... 

B. R. Lawn and T. R. Wilshaw, Fracture of Brittle Solids, Cambridge University Press, Cambridge, Mass., 1975. 

B. R. Lawn and R. J. Blau, eds.. Microindentation Techniques in Materials Science and Engineering, International Metakographic Society, ASTM STP 889, 1986. 

C. J. Lawn and co-workers. The Combustion of Heavy Fuels Oils, ia C. J. Lawn, ed.. The Principles of Combustion Engineering for Boilers, Academic Press, Inc., New York, 1987. 

The lawn-mowing analogy is also interesting in that up to a certain point there will be a linear speedup as mowers are added. This speedup occurs because the mowers do not interfere with each other s work and have efficient mechanisms for coordinating their efforts. The lawn-mowing problem exhibits very good data paraHeHsm. 

High product costs limit distribution to high value crop markets. This includes commercial ornamental production such as nurseries and greenhouses, citms production, and strawberry production. Limited amounts are sold to the consumer lawn and garden market. 

FIG. 27-42 Comp arison of the sizes and shapes of typical 500-MWg coal- and oil-fired boilers. Adapted with permission fixjm Lawn, Principles of Combustion Engineering for Boilers, Academic Press, London, 1987.)... 

Plate eolleetors were set at two heights above the ground, whieh may give an indieation of air eoneentration gradients. The two Broadbalk plots reeeived nitrogen fertilizers in the spring of eaeh year the lawn and parkland were unfertilized. 

Orowan (1949) suggested a method for estimating the theoretical tensile fracture strength based on a simple model for the intermolecular potential of a solid. These calculations indicate that the theoretical tensile strength of solids is an appreciable fraction of the elastic modulus of the material. Following these ideas, a theoretical spall strength of Bq/ti, where Bq is the bulk modulus of the material, is derived through an application of the Orowan approach based on a sinusoidal representation of the cohesive force (Lawn and Wilshaw, 1975). 

Ixt .s talk about the pump efficiency. Imagine a small pump connected to a garden hose squirting a stream of water across the lawn. You could direct the How from the ho.se up into the air at about a 45-degree angle, and the stream would arc upward and attain its best distance of reach from the nozzle or launch point. The stream of water would attain a specific height into the air and a specific distance. The efficiency curve of a pump is seen as the trajectory or arc of a stream of water. When squirted from a hose, the elevation that attains the be.st distance, when plotted onto the pump curve, is called the best efficiency point (RHP). On the pump curve, it is seen as in Figure 7. ... 

A mobile source of air pollution can be defined as one capable of moving from one place to another under its own power. According to this definition, an automobile is a mobile source and a portable asphalt batching plant is not. Generally, mobile sources imply transportation, but sources such as construction equipment, gasoUne-powered lawn mowers, and gasoline-powered tools are included in this category. 

Figure 6.12. Hertzian cone crack evolution and geometry (Lawn 1993).

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