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Sawing channel

Figure 18.2 shows schematically the situation in the sawing channel. The space between wire and crystal surface is filled with slurry and abrasive particles. The crystal is pushed against the wire web and causes a bow of the wire. The bow angle varies typically between 1-5°. The resulting force on the wire varies along the contact area. The forces are maximum directly below the wire and decrease towards the side faces (Fig. 18.3). Because of the observed transverse vibrations of the wire additional forces may be exerted sideward. The cutting process at the side faces is important because it determines the final surface quality of the sliced wafers. Figure 18.2 shows schematically the situation in the sawing channel. The space between wire and crystal surface is filled with slurry and abrasive particles. The crystal is pushed against the wire web and causes a bow of the wire. The bow angle varies typically between 1-5°. The resulting force on the wire varies along the contact area. The forces are maximum directly below the wire and decrease towards the side faces (Fig. 18.3). Because of the observed transverse vibrations of the wire additional forces may be exerted sideward. The cutting process at the side faces is important because it determines the final surface quality of the sliced wafers.
The space between the wire and the crystal surface is filled with slurry, which is transported into the sawing channel by the moving wire. The starting point to describe the slurry flow is the Reynolds equation. In the one-dimensional case under steady flow conditions one has... [Pg.462]

Considering the cross section of the sawing channel (Fig. 18.3) the pressure below a wire of radius R changes from a maximum value directly below the wire towards the side faces where the pressure must be zero at the free surfaces of the fluid bed. In the one-dimensional treatment here this is taken into account by an effective radius = aR. a has to be determined from a three-dimensional treatment of the problem but is assumed to be <1. [Pg.463]

The hydrodynamic pressure at the exit of the sawing channel must be zero, thus p(o) = 0. This yields the first boundary condition... [Pg.464]

The two plates were not manufactured via the same route and were not made of the same material [7]. Typically, rectangular channels in silicon are realized by sawing, whereas semi-circular channels are made in glass by wet-chemical etching. Such glass/silicon plates are joined by anodic bonding. [Pg.579]

In his work, Wallace [12] formed inkjet printheads from the rectangular blocks made of piezoelectric material. A diamond saw is used to create fluid channel grooves and channel actuator structures. These grooves are approximately 1 pm apart, 360 pm deep and 170 pm wide. Next, a cover plate is attached to the top of the grooves to form an enclosed rectangle channel for the working fluids. A polymer orifice plate (see Fig. 11.3) with many 40 pm diameter orifices is attached to the other end of the grooves. [Pg.339]

The field of gastrointestinal drugs saw the entry of Amitiza (lubiprostone), the first selective and locally acting CIC-2 chloride channel activator, for the... [Pg.508]

The 1950s saw the introduction of a completely new approach to automation, in the form of continuous flow analysis. This made a significant contribution to the advance of automated analysis and subsequent development has been in the form of flow injection analysis. The original instruments were single channel and capable of measuring only one constituent in each sample. Multichannel instruments were then developed which could simultaneously carry out several different measurements on each sample. These were useful in laboratories where many samples required the same range of tests. [Pg.211]

Fig. 21. A surface acoustic wave dual-delay line oscillator. The sensitise layer is placed in the propagation path of one of the two SAW devices. The differenee in Ireqnency (At) between the two channels provides a dtrecl result of the mass loading and electric field effects associated w ith the sensor layer... Fig. 21. A surface acoustic wave dual-delay line oscillator. The sensitise layer is placed in the propagation path of one of the two SAW devices. The differenee in Ireqnency (At) between the two channels provides a dtrecl result of the mass loading and electric field effects associated w ith the sensor layer...
The 1960s saw the discovery of a number of specific channel-blocking agents. Tetrodotoxin, for example, from the fugu puffer fish, specifically blocks voltagegated sodium channels. This provided very convincing confirmation that the sodium and potassium channels of nerve axons really are separate from each other. It also allowed potassium channels in nerves to be studied on their own, permitted estimates of channel densities in the membrane to be made, and ultimately proved crucial in the biochemical isolation of sodium channels. [Pg.254]

The 1960s and 1970s also saw increasingly sophisticated approaches to the investigation of ion channels in nerve and muscle. Armstrong used quaternary ammonium ions as blocking agents to probe the nature of potassium channels and Hille (1984) measured the permeability of channels to ions of different sizes, and so was able to estimate the minimum dimensions of the channel pore. These indirect... [Pg.254]

Drost et al. [129] developed an evaporator combined with a micro scale combustion chamber for homogeneous combustion of hydrocarbons (Figure 2.82). The main focus of the work was to maintain a stable combustion of the fuel avoiding NOx formation. Evaporation tests were carried out under isothermal conditions. Fifty-four parallel channels, 270 pm wide and 1 000 pm deep with a length of20.52 mm, were cut into a copper substrate with a diamond saw. [Pg.374]

By examining Eq. 6.4-1, as pointed out in Example 2.8, we see that at equal entrance and discharge pressures, the pressure profile exhibits a maximum at H = 2Hq/( 1 + 0), or at z/L = Cq(1 + Co), which for Co 2 is two-third of the way down the channel. This result focuses attention on the important difference between parallel plate and non-parallel plate geometries. In the former, equal inlet and outlet pressures imply no pressurization and pure drag flow in the latter it implies the existence of a maximum in pressure profile. Indeed, as we saw in Section 2.11, Example 2.9, this pressurization mechanism forms the foundation of hydrodynamic lubrication. [Pg.261]


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Sawing

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