The Twisted Pair

Fig. 6.65. The twisted-pairs technique for reducing inductive coupling...

Ethernet repeaters are invaluable with point-to-point media. As pointed out earlier, a network with only two nodes is of limited use. A twisted pair repeater allows several point-to-point segments to be joined into one network. One end of the point-to-point link is attached to the repeater and the other is attached to the computer with a transceiver. If the repeater is attached to a backbone, then all computers at the end of the twisted pair segments can communicate with all the hosts on the backbone. 

STP (shieid twisted-pair) Cabling that has a braided foil shield around the twisted pairs of wire to decrease electrical interference. 

Get to know your own DNA. Just as deoxyribonucleic acid (DNA) forms human cells with twisted strands of polymers forming a double helix, each item has its own DNA. You can only master the supply chain when you know each item s DNA. The twisted pairs or long polymers in the DNA cell makeup are replaced by demand and supply strands (representing the rhythms and cycles of demand and supply) in the supply chain. The processes of supply can only be effectively designed outside-in with a goal in mind (e.g., supply chain strategy). 

Find the heavily insulated black "primary" wires of the transformer (see pages 3 and 8). Make sure the insulation is stripped off the ends of the wires. Hold one power cord and one transformer primary wire, end-facing-end, and with the bare metal wires overlapping and next to each other. With your fingers, twist the bare wires around each other, but do not include any insulated parts. Put some cardboard or heavy paper on the table top, to protect it from damage. Arrange the twisted pair of wires so it is suspended an inch or so above the cardboard or paper, and it can later be touched from underneath by the hot soldering iron. 

The communication between the units is performed through a local ring network, based on twisted pair wire as shown in the figure below. 

Data Communication Wires. Electronic cables such as data communication wires employ three basic designs coaxial, twisted pair, and fiber optics (3,4) (Eig. 1). Coaxial cables are so named because the axis of curvature of its outer conductor is concentric to its inner central wire. The metal braiding wrapped around the insulated center wire acts as the return current conductor in addition to shielding the wire from various interferences. 

The twists of twisted pair cable act as a shield against radio frequency interference (REI), and electromagnetic interference (EMI), and against the cross talk interference that a wire exerts on nearby wires the more twist the less interference. Telephone wires can use large numbers of pairs. In most cases the pairs are not shielded with braiding or foil, as shown in Eigure lb for data communication wire. Data communication wires work at very high... 

Signal Transmission and Conditioning. A wide variety of physical and chemical phenomena are used to measure the many process variables required to characteri2e the state of a process. Because most processes are operated from a control house, these values must be available there. Hence, the measurements are usually transduced to an electronic form, most often 4 to 20 m A, and then transmitted to the control house or to a remote terminal unit and then to the control house (see Fig. 6). Wherever transmission of these signals takes place in twisted pairs, it is especially important that proper care is taken so that these measurement signals are not cormpted owing to ground currents, interference from other electrical equipment and... 

The first teehnique that enhanees eoupling between windings is twisted pair winding. This oeeurs when two or more wires are twisted together and then... 

Examine AT pair and GC pair, adenine-thymine and guanine-cytosine base pairs, respectively. Identify the hydrogen bonds in each. Are they the same as those you sketched Are the base pairs flat as normally drawn in textbooks, or are they significantly puckered or twisted ... 

The structures of phases such as the chiral nematic, the blue phases and the twist grain boundary phases are known to result from the presence of chiral interactions between the constituent molecules [3]. It should be possible, therefore, to explore the properties of such phases with computer simulations by introducing chirality into the pair potential and this can be achieved in two quite different ways. In one a point chiral interaction is added to the Gay-Berne potential in essentially the same manner as electrostatic interactions have been included (see Sect. 7). In the other, quite different approach a chiral molecule is created by linking together two or more Gay-Berne particles as in the formation of biaxial molecules (see Sect. 10). Here we shall consider the phases formed by chiral Gay-Berne systems produced using both strategies. 

The exact nature of the lesion in DNA is unknown, and so is the type of DNA that is attacked. Recent X-ray crystallographic studies, as well as other physicochemical studies, have made it clear that DNA is not simply a polynucleotide, folded as Watson and Crick (106) proposed. There are three main conformational types of DNA they each keep the hydrogen-bonded bases in the center of the helix, but may tilt them by a "propellor twist," may slide them from the center of the helix in the plane of the base pairs, and may vary the amount of rotation from one base pair to the next up the helical axes. 

The matrix can be taken away by HN03 except at the ends of the wire, to allow easy soldering. Below IK, the electrical contact can be done also by squeezing the wires to be connected inside a thin A1 tube (see, for example, Section 12.4). For low-level signals, shielded twisted pairs or cryogenic coaxial cables are used. When thousands of wires are necessary, as in large experiments, Kapton strips with deposited conductors [3] or woven wires [4] are used. 

Fig. 10.2. Twisted pair suppresses magnetically coupled interference because it tends to null out the effects of...

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