Polar machines

An active cathode (direct polarity machining) or active anode (reverse polarity machining) [63] can be used as a tool, of which the use of the former is most popular. As the discharge activity, and especially the discharge mechanism, differs for an active cathode and anode, the machining performances will also be different. 

Neumann M and Steinhauser O 1980 The influence of boundary conditions used in machine simulations on the structure of polar systems Mol. Phys. 39 437-54... 

Flexible polyethylene separators have facilitated a novel cell construction the separator material, supplied in roll form, is wound so that it meanders around electrodes of alternating polarity (Fig. 23), requiring ribs in the cross-machine direction such profiles are available commercially [60],... 

Polar wrap machine with swinging fiber delivery arm desirable for high-speed winding. Helical machine with programmed cross-feed will wind polar wraps more slowly. 

Polar wrap machine can be used where geodesic (non-slipping) path is in a plane. 

Normal incidence transmission IRLD measurements are used to study thin films (typically 100 pm thickness and less, depending on the molar extinction coefficient of the bands) with in-plane uniaxial orientation. Two spectra are recorded sequentially with the radiation polarized parallel (p) and perpendicular (s) to the principal (machine) direction of the sample. The order parameter of the transition moment of the studied vibration is calculated from either the dichroic ratio (R — Ap/As) or the dichroic difference (AA = Ap—As) as ... 

Paper made on a paper machine exhibits quite different properties in the x and y directions (the machine and cross machine directions), an example of which is a difference in stiffness which can be demonstrated by plotting the specific elastic stiffness in the x-y plane as a function of the machine direction and cross machine direction co-ordinates in the form of a polar diagram (Figure 4.7). 

NOTE Several possibilities for the drawn circle not including the origin of the polar chart are operator error during balancing, a faulty balancing machine pickup or cable, or the balancing machine is not sensitive enough. 

Step 4 Transfer. Paper is passed between the drum and the transfer corona, which has a polarity that is the opposite of the charge on the toner. The toner image is transferred by a combination of pressure and electrostatic attraction from the drum to the paper. On many color and high-speed machines, it is common to replace the transfer corona with one or more charged bias transfer rollers (BTRs), which apply greater pressure and a higher quality image. 

One very common beneficial interaction involving an excipient is the interaction between magnesium stearate and the metal of tablet punches and dies, or the equivalent parts on a powder encapsulation machine. Magnesium stearate is an example of a boundary lubricant. As such it has a polar head and a fatty acid tail. It is believed that the polar head of the magnesium stearate is oriented toward the die wall or tablet punch face. In these ways it is able to reduce the ejection force (the force required to eject the tablet from the die after compaction) and prevent sticking to the punch faces. The other boundary lubricants, e.g., calcium stearate and sodium stearyl fumarate, will also function in a similar manner. However, the so-called liquid film lubricants function in a very different manner (19). 

Nevertheless, several issues have still to be addressed and improved, such as the ability of the solvent mixture to dissolve polar and heavy compounds, the entire washing and rinsing cycle to maximize stain removal, the machine s cost compared to the conventional machines. 

---