Knife-edge method

Nonstabilized foams are referred to as froths froth-bonded fabrics are similar in properties to some saturation-bonded nonwovens. Typical foams used as nonwoven binder solutions have a consistency similar to shaving cream. AppHcation methods include knife-edge layering onto a horizontal web surface followed by vacuum penetration, and saturation and penetration of a vertical web surface using a horizontal-nip pad. Drying and curing is carried out in ovens, dmm dryers, or steam cans. 

Due to diffraction effects of micron-sized mirrors in a regular array, commonly used techniques for surface characterization based on interferometry are inefficient. To overcome the diffraction effects we have developed a novel surface characterization method with an incoherent light source, based on the Foucault s knife-edge test (Zamkotsian and Dohlen, 1999). Since Leon Foucault introduced the knife-edge test in the last century (Foucault, 1859), it has been widely used for testing optical surfaces (see Ch. 3). The test offers a simple way of obtaining easily understandable, qualitative information of the surface shape. 

Diffraction theory of the knife edge test and its improved form, the phase contrast method. Roy. Astron. Soc. M. N. 94, 377 (1934). 

In the Knudsen effusion method a substance is enclosed in a sealed container into which a very small hole is drilled. This hole must be knife-edged and the mean free path of the vapour must be 10 times the diameter of the hole. In its simplest form an experiment proceeds as follows. The Knudsen cell, with sample in it, is carefully weighed and then heated in a vacuum at the requisite temperature for a set time. The cell is then re-weighed and the weight loss is measured. However, it is now more usual to continuously measure the weight of the cell. If the molecular weight and surface area of the sample is known the vapour pressure can be found. 

Attack the Adam s apple with the knife edge of your hand (fig. 10), A severe blow can result in death by severing the windpipe. A lesser blow is painful and causes your opponent to gag. The Adam s apple is also vulnerable to attack with the fist, toe, or knee, depending upon your opponent s position. Squeezing it or pulling it outward with the fingers and thumb is another method you can use. 

The unsymmetrical, or Straumanis, method of film loading is shown in Fig. 6-5(c) and Fig. 3-12. Two holes are punched in the film so that it may be slipped over both the entrance collimator and the beam stop. Since it is possible to determine from measurements on the film where the incident beam entered the film circle and where the transmitted beam left it, no knife-edges are required to make the film-shrinkage correction. The point X (20 = 180°), where the incident beam entered, is halfway between the measured positions of lines 4,4 similarly, the point Y (20 = 0°), where the transmitted beam left, is halfway between lines 1,1. The difference between the positions of X and Y gives W, and 0 is found by proportion ... 

Methods for the production of rubber bonded components have to be established and firmly founded within strict limits of the many parameters for the control of quality. It is in the initial stages of the development of the production process that the use of suitable bond tests is vital. The test values will allow the manufacturer to discover the operational limits for all process variables and ensure that the set conditions for production do not allow a knife-edge situation where small changes can produce large variations in the quality of the bond. This is best achieved through the use of factorial experiment design and statistical regression analysis of the results. 

---