Weighing, effect

Figure 2. Risk premium weighing effect (a = 0 - 3) on the optimal design in the simplified TMP case with different number of years for depreciation (a) number of refiners and (b) storage tank volume.

The table which follows gives the values of k (buoyancy reduction factor), which is the correction necessary because of the buoyant effect of the air upon the object weighed the table is computed for air with the density of 0.0012 m is the weight in grams of the object when weighed in air weight of object reduced to in vacuo = m + m/1000. 

Buoyant Effect of Air. Weighing operations performed m vacuo are not affected by buoyancy forces. An object in air, however, is subject to a buoyancy force that is equal and opposite to the gravitational force on the mass of air the object displaces (10). If the equal arm balance of Figure 1 is in balance with a test weight of mass, in one pan, and material of mass, m, in the other, m = m if they have the same density. If the densities are different, then the buoyancy forces acting on each pan affect the result. Taking moments about the center pivot point gives... 

Electrostatic and Magnetic Effects. These two effects are generally small but may be significant in laboratory weighing. 

As a vessel is loaded, it moves downward because of deflection of the load cells and support stmcture. Pipes rigidly attached to a vessel restrict its free movement and assume some portion of the load that cannot be measured by the load cells. This is very detrimental to scale accuracy. Deflection of the load cell is unavoidable deflection of the vessel support stmcture should be minimized. Anything which increases vessel deflection, eg, mbber pads used for shock protection, must be avoided. The total number of pipes should be minimized and be of the smallest diameter, thinnest wall possible. Pipe mns to weigh vessels must be horizontal and the first pipe support should be as far as possible from the vessel. Alternatively, a section of mbber hose or flexible bellows should be used to make the final connection to the vessel. The scale should be caUbrated using weights, not by means of an electrical simulation method, which cannot account for the effects of the piping or test the correct functioning of the scale. 

It may be necessary to contain dust by enclosing a weigh hopper and using dust seals or flexible connections to seal openings. Figure 19 shows an arrangement where the top of the hopper is fixed to the stmcture, and the hopper must have an effective vent which minimizes even transient pressure... 

Twice-daily sc injection of 10 or 20 p.g human GRF (hGRF)(l-44)NH2/kg BW for 36 days in barrows weighing 78 kg improved feed conversion efficiency and lean content of the ham (102). However, treatment with hGRF was less effective than pST injection of 20 or 40 Fg/kg BW at the same frequency (103). 

SoHd carbon dioxide is produced ia blocks by hydrauHc presses. Standard presses produce blocks 25 x 25 x 25 cm, 50 x 25 x 25 cm, or 50 X 50 X 25 cm. A 25-cm cube of dry ice weighs 23 kg, allowiag for about 10% sublimatioa loss duriag storage and shipment (some 27-kg blocks are also produced). Dry ice is about 1.7 times as dense as water ice, whereas its net refrigerating effect on a weight basis is twice that of water ice. Automation and improved operating cycles have iacreased dry-ice press capacities so that one 50 x 50 x 30 cm press can produce more than thirty metric tons of dry-ice blocks per day (42). 

Whatever treatment is used to clean specimens after a corrosion test, its effect in removing metal should be determined, and the weight loss should be corrected accordingly. A blank specimen should be weighed before and after exposure to the cleaning procedure to estabhsh this weight loss. 

This procedure is particularly time-saving when scrap platinum or spent catalyst is used for the preparation of platinum oxide, for after conversion to chloroplatinic acid a purification is conveniently effected by precipitating the ammonium salt, and the direct fusion of this with sodium nitrate eliminates the tedious process of reconversion to chloroplatinic acid. Furthermore ammonium chloroplatinate is not hygroscopic and can he accurately weighed. The amount of catalyst obtained is almost exactly half the weight of the ammonium salt employed. 

Stirring and boiling are continued until complete solution is effected. This requires about 6 minutes (Note 16). The stirrer is withdrawn and the beaker is removed from the hot plate for a few minutes. Finally, the solution is stirred and cooled first in a warm water bath and then in an ice bath. After 30 minutes the gray-brown solid is collected by suction filtration and washed with hexane. The product is suspended in 250 ml. of hexane, filtered, and washed with hexane. After drying, the crude gray-colored 3-hydroxyquinoline weighs 57-63 g. (79-87%), m.p. 175-191° (cor.). 

In weighing the pros and cons of inside staff versus outside contractors, the most useful determinant is long-range cost-effectiveness. It s easy to underestimate the true cost of using employee resources, since these expenses are "buried" within ongoing business. 

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