Cylinders transfer

Heating the Tube.—When cold, the tube is placed in an iron protecting cylinder with a screw cap and the cylinder transferred to a tube furnace, where it is heated according to the directions given on p. 43. The temperature and duration of heating depend on the resistance of the substance towards decomposition. With many compounds that oxidise easily,... 

Flat Card n The type of card used for cotton fibers and for cotton-system processing. It is named for the flat wire brushes called flats that are assembled on an endless chain that partially surrounds the main cylinder. The staple is worked between the flats and cylinder, transferred to a doffer roll, and peeled off as a web that is condensed into a sliver. (Vincenti R (ed) (1994) Elsevier s textile dictionary. Elsevier Science and Technology Books, New York). Also see Flat. 

Prepare four standard solutions consisting of 2.00 ml of the dilute nitrite solution (measured with a 2.00-ml graduated pipette) made to a volume of 50 ml in a graduated flask or 50-ml measuring cylinder. Transfer the solutions to four dry 125-ml Erlenmeyer flasks and place 50 ml of distilled water in two more flasks to act as blanks. Carry out the nitrite determination as described in Section F, paragraphs 2-3. 

Never transfill cylinders. Transferring the contents from one cylinder to another must never be done. Cylinder filling requires special equipment and training, and laboratory... 

Meanwhile, prepare a pellet of the substance, using a pellet press of the type shown in Fig. 78 (p. 431), but having the cylinder C of about 3 mm. internal bore to enable a pellet of 20-50 mg. to be compressed and then ejected. (Do not compress the pellet more than is necessary for manipulation, otherwise it may dissolve too slowly in the boiling solvent.) Transfer the pellet to a watch-glass, which preferably should be kept in a small desiccator before and after weighing. 

The apparatus depicted in Fig. 11,34, 1, intended for advanced students, may be used for the filtration of a small quantity of crystals suspended in a solvent either a Hirsch funnel or a glass funnel with Witt filter plate is employed. The mixture of crystals and mother liquor is filtered as usual through the funnel with suction. Rotation of the three-way tap wifi allow air to enter the filter cylinder, thus permitting the mother liquor to be drawn oflF by opening the lower tap. The mother liquor can then be applied for rinsing out the residual crystals in the vessel, and the mixture is again filtered into the cylinder. When all the crystals have been transferred to the funnel and thoroughly drained, the mother liquor may be transferred to another vessel the crystals may then be washed as already described (Section 11,32). 

To prepare the solution we use a graduated cylinder to transfer 80 mb of glacial acetic acid to a container that holds approximately 2 b, and we then add sufficient water to bring the solution to the desired volume. 

Calculate the molar concentration of NaCl, to the correct number of significant figures, if 1.917 g of NaCl is placed in a beaker and dissolved in 50 mF of water measured with a graduated cylinder. This solution is quantitatively transferred to a 250-mF volumetric flask and diluted to volume. Calculate the concentration of this second solution to the correct number of significant figures. 

A standard solution of Mn + was prepared by dissolving 0.250 g of Mn in 10 ml of concentrated HNO3 (measured with a graduated cylinder). The resulting solution was quantitatively transferred to a 100-mL volumetric flask and diluted to volume with distilled water. A 10-mL aliquot of the solution was pipeted into a 500-mL volumetric flask and diluted to volume, (a) Express the concentration of Mn in parts per million, and estimate uncertainty by a propagation of uncertainty calculation, (b) Would the uncertainty in the solution s concentration be improved... 

RoUer-top cards have five to seven sets of workers and strippers to mix and card the fibers carried on the cylinder. The multiple transferring action and re-introduction of new groupings of fibers to the carding zones provides a doubling effect which enhances web uniformity. Stationary-top cards have strips of metallic clothing mounted on plates positioned concavely around the upper periphery of the cylinder. The additional carding surfaces thus estabhshed provide expanded fiber alignment with minimum fiber extraction. 

Sheet Drying. At a water content of ca 1.2—1.9 parts of water per part of fiber, additional water removal by mechanical means is not feasible and evaporative drying must be employed. This is at best an efficient but cosdy process and often is the production botdeneck of papermaking. The dryer section most commonly consists of a series of steam-heated cylinders. Alternate sides of the wet paper are exposed to the hot surface as the sheet passes from cylinder to cylinder. In most cases, except for heavy board, the sheet is held closely against the surface of the dryers by fabrics of carefuUy controUed permeabiHty to steam and air. Heat is transferred from the hot cylinder to the wet sheet, and water evaporates. The water vapor is removed by way of elaborate air systems. Most dryer sections are covered with hoods for coUection and handling of the air, and heat recovery is practiced in cold climates. The final moisture content of the dry sheet usually is 4—10 wt %. 

Letterpress is printed directly by the rehef method from cast metal or plates on which the image or printing areas are raised above the nonprinting areas. Ink rollers apply ink to the surface of the raised areas, which transfer it directly to paper. Flat-bed cylinder presses are available but most letterpress is printed on rotary presses. 

Shipment and Storage. Liquid sulfur dioxide is commonly shipped in North America using 55- and 90-t tank cars, 20-ton tank tmcks, 1-ton cylinders, and 150-lb cylinders. Cylinders made of specified steel are affixed with the green label for nonflammable gases. The DOT classification is Poison Gas, Inhalation Ha2ard. Purchasers of tank-car quantities are required to have adequate storage faciUties for prompt transfer. 

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