Slot, directional

The curve is symmetric from the middle of the slot. Hence the length of the defect is determined by the position of its edges at (x2+x3)/2 and -(x2+x3)/2 in the scanning direction of the probe. Of course this result is only true if we can distinguish the 5 zones on the curve. For other relative dimensions, for example a slot smaller than the probe (outer diameter), a curve like in set 1 is obtained, where the zones are confused. 

Flame Sources Atomization and excitation in flame atomic emission is accomplished using the same nebulization and spray chamber assembly used in atomic absorption (see Figure 10.38). The burner head consists of single or multiple slots or a Meker-style burner. Older atomic emission instruments often used a total consumption burner in which the sample is drawn through a capillary tube and injected directly into the flame. 

Sheet can be produced by melt extmsion, but in this case a three-roll stack of quenching roUs is generally used (Fig. 2). More than three roUs may be used where necessary. The roUs may be mounted vertically or horizontally. The web is extmded through a slot die in a thickness close to the desired final thickness. The die is in very close proximity to the first chill roU or chill-roll nip. The web may be cast horizontally directly onto the upper chill roU of the stack as shown (Fig. 2), or it may be extmded into the first nip directly. The roUs quench the sheet and provide the surface polish desired. In some applications, matte or embossed roUs maybe used to impart special surface characteristics for certain functions. Where the utmost in optical (glazing) quality is desired the trend has been to mount the roU stack horizontally. The hot melt is then extmded vertically down into the first nip. This avoids problems associated with sag of a horizontal hot melt no matter how short the distance between die and quench. 

Extmsion of polyethylene and some polypropylenes is usually through a circular die into a tubular form, which is cut and collapsed into flat film. Extmsion through a linear slot onto chilled rollers is called casting and is often used for polypropylene, polyester, and other resins. Cast, as well as some blown, films may be further heated and stretched in the machine or in transverse directions to orient the polymer within the film and improve physical properties such as tensile strength, stiffness, and low temperature resistance. 

Slot-die or extmsion coating involves the appHcation of molten polymer resin through a slot die directly onto the surface of a nonwoven. Upon extmsion, the resin is smoothed and quenched by a cooling roU. Coating weight is controlled by slot size and extmsion rate. 

There are two mechanisms by which arching can occur particle interlocking and cohesive strength. The minimum outlet size required to prevent mechanical interlocking of particles is directly related to the size of the particles. The diameter of a circular outlet must be at least six to eight times the particle size, and the width of a slotted outlet must be at least three to four times the particle size. These ratios normally only govern the outlet size of mass flow hoppers if the particles are at least 0.6 cm or larger. 

Mechanical Centrifugal Separators A number of collectors in which the centrifugal field is supphed by a rotating member are commercially available. In the typical unit shown in Fig. 17-45, the exhauster or fan and dust collector are combined as a single unit. The blades are especially shaped to direct the separated dust into an annular slot leading to the collec tion hopper while the cleaned gas continues to the scroll. 

The impulse test by means of a directly injected steep-fronted wave cannot be performed on a fully assembled machine as the bulk of the voltage, if the front of the wave is less than Ifls, will appear across the first few turns only. Also, in the event of a failure, the whole winding must be scrapped. The impulse test is therefore performed on completed individual resin-rich formed coils only after insertion into the slots. 

One slot was cut directly above the blade passage emplacement. The other slot was sealed off to prevent leakage. As the disc was lowered into close proximity to the blade tips, the blade passage was completed. The clearance between disc and blade was kept at 0.035 of an inch. The disc, when spun from above, acted as the rotating shroud. 

Total pressure surveys were made downstream of the stators in both the radial and circumferential directions to determine the effect of coolant on stator losses. The wake traces for the stator with discrete holes and the stator with trailing edge slots show that there is a considerable difference in total... 

The opening to the exhaust duct is either a horizontal rectangular exhaust opening facing down (with air direction upward) or one or more slots con nected to the exhaust duct. These slots should preferably also be placed horizontally, facing down, but could be at some angle to the horizontal plane. 

Linear air diffuser An air terminal device with single or multiple slots, each of which has an aspect ratio not less than 10 1. Each slot may consist of a number of separate elements and may or may not have an adjustable member, W hich allows the directions of the air delivered to the treated space to be varied. 

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