Above ground

This paper describes the construction and use of a diffusion tube for sampling NO2 from the atmosphere. Examples of its use include the determination of NO2 concentrations at various heights above ground level in an urban environment and through a tree s leaf canopy. 

Truck scales weigh highway vehicles they may be installed in a pit or above-ground with inclined approach ramps. A capacity of 100-t is typical. For monitoring axle weights, the scale deck can be broken into three scales, which are monitored independently the individual axle weights or total vehicle weight can be displayed by the indicator. 

Other above-ground continuous flow systems have been designed and operated for SCWO processes. A system developed by ModeU Development Corp. (Modec) uses a tubular reactor and can be operated at temperatures above 500°C. It employs a pressure letdown system in which soHd, Hquids, and gases are separated prior to pressure release. This simplifies valve design and material selection on the Hquid leg. 

Copper quinolinolate (oxine copper) is the chelate of divalent copper and 8-hydroxyquinoline and shares most of its market with copper naphthenate, which is a complex copper salt of mixed naphthenic acids. The principal uses are in wood treatments and some military textiles, where the green color is not objectionable. Copper naphthenate has an odor but is cheaper than oxine. Both copper naphthenate and 2inc naphthenate have performed well in environment tests, with exposure to soil above-ground, as well as concrete (33). 

Above-Ground Retorting. AGR processes can be grouped into DH or IH processes. Numerous design configurations as well as a variety of heat-transport mediums have been used in the indirect heated processes (Table 7). 

Generally, it is more economical to prevent explosive atmospheres ia rooms than to try to provide explosion-proof electrical equipment. Personnel should never be allowed to work ia a ha2ardous atmosphere. Where such an atmosphere cannot be avoided through control of flammable Hquids, gases, and dusts, access to the area iavolved should be limited and the area segregated by hoods or special ventilation. Electrical equipment on open, outdoor stmctures more than 8 m above-ground usually is considered free from exposure to more than temporary, local explosive mixtures near leaks (86). 

When the furnace is tilted toward the charging floor, which is on a platform above ground level, soHd scrap is dumped by an overhead crane into the mouth of the furnace. Scrap can form up to 30% of the charge unless it is preheated, when up to 45% may be used. The crane then moves away from the furnace and another crane carries a transfer ladle of molten pig iron to the furnace and pours the molten pig iron on top of the scrap. 

Important trends in this market include the 30% decrease of the new pool market over the past two years (1989—1990), and the trend toward printed above-ground liners with unique designs (39). 

A more recent development is the carbottom furnace, which is an above ground rectangular kiln the bottom is mounted on wheels and set on tracks so it is movable. The carbottom is isolated from the heating chamber by a water seal. These furnaces provide improved temperature and pressure control and better uniformity. 

A pieemeigence herbicide is used before emergence of seedbngs above ground. 

H,. Height of release above ground level, length... 

The puff model describes near-instantaneous releases of material. The solution depends on the total quantity of material released, the atmospheric conditions, the height of the release above ground, and the distance from the release. The equation for the average concentration for this case is (Growl and Louvar, 1990, p, 143) ... 

The center of the puff is located at x = ut. Here x is the downwind direction, y is the crosswind direction, and z is the height above ground level. The initial release occurs at a height above the ground point at x,y,z) = (0,0,0), and the center of the coordinate system remains at the center of the puff as it moves downwind. 

For releases at ground level, the maximum concentration occurs at the release point. For releases above ground level, the maximum ground concentration occurs downwind along the centerline. The location of the maximum is found using... 

The Phoenicians were building water ducts and pipelines of clay, stone, or bronze about 1000 B.c. and the construction of long-distance water pipelines flourished in imperial Roman times. The water supply lines of Rome had a total length of about 450 km, and consisted mainly of open or covered water ducts. The Roman writer Vitruvius gives a fairly accurate description of the manufacture of lead pipes [8]. The pipes were above ground and were often laid beside the roadway or in ducts inside houses [9]. 

Fig. 1-3 Oak water pipe over 200 years old laid above ground in the Wadgassen Abbey (Saarland) with cast iron clamps (photo Mannes-mann Archives).

Fig. 16 2. ConUmiiidul release decASion network. LOfildinmani ) above ground.

Fig. 17-15. Hodograph showing variation of wind speed and direction with height above ground. SFC = surface wind.

In such emergencies, it is most important to know the local wind direchon at the accident site, so that the area that should be immediately evacuated can be determined. The next important factor is the wind speed, so that the travel hme to various areas can be determined, again primarily for evacuation purposes. Both of these can be estimated on-site by simple means such as watching the drift of cigarette smoke. It would be well to keep in mind that wind speeds are higher above ground and that wind direction is usually different. 

If the variation in wind speed with height is well approximated with a power law wind profile having an exponent equal to 0.15, how much stronger is the wind at 100 m above ground than at 10 m ... 

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