Length, effective

FIGURE 28 6 The effective length of DNA is reduced by coiling around the surface of histones to form nucleo somes The histone proteins are represented by the spheres and the DNA double helix by the ribbon... 

Section 28 9 Within the cell nucleus double helical DNA adopts a supercoiled terti ary structure m which short sections are wound around proteins called histones This reduces the effective length of the DNA and maintains it m an ordered arrangement... 

The methods described above are used widely in the synthesis of dyes with new heterocycHc residues such as tropjlium (25) [76430-96-1] (102), 2,4-diphen5lpyryHum and its heteroanalogues (26) with a high effective length (103,104), or exotic systems (27) with long-wavelength local electron transitions (105) (Fig. 7). 

Frequently cost savings for cylindrical shells can result from reducing the effective length-to-diameter ratio and thereby reducing shell thickness. This can be accomplished by adding circumferential stiffeners to the shell. Rules are included for designing and locating the stiffeners. 

Electrophoretic condition 60 cm (effective length of 50 cm)x75 p.m I.D. fused capillary column, run buffer borate buffer pH 9,0, P-cyclodextrin, electrophoresis voltage 20 kV, detection at 254 nm. 

It is easy to see that, under normal circumstances, the characteristic distance is much shorter than the effective length of the precipitation system. 

Effective length, duct The dimension that a straight duct contributes to the length of an air distribution installation. 

For high-speed flames, which are usually accompanied hy a pressure rise, an array of apertures must have sufficient pressure drop to decelerate the flame, and sufficient length to achieve the heat loss needed to quench the flame. Thus, the diameter criterion is not sufficient and the effective length of the passageway must meet the following criterion (Wilson and Attalah 1975) ... 

One challenge in the design of U-tube heat exchangers is to determine the effective length of the tubes. For example, when U-tube bundles are fabricated from 12-ft tubes, the maximum length tube in the bundle is 12 ft which is in the outside tube row. The inside tube is the shortest and is less than 12 ft long. 

Pressure drops from Dowtherm A heat transfer media flowing in pipes may be calculated from Figure 10-137. The effective lengths of fittings, etc., are shown in Chapter 2 of Volume 1. The vapor flow can be determined from the latent heat data and the condensate flow. With a liquid system, the liquid flow can be determined using the specific heat data. 

There are three ways to measure V-belt length outside circumference (OC), datum length (DL) and effective length (EL). 

Effective length The effective length is measured on a length-inspection machine. The machine consists of two parallel shafts on movable centers with a scale to accurately measure the center distance between shafts. Inspection pulleys of equal diameter and grooved in accordance with industry standards are mounted on these shafts. A belt is mounted on these pulleys and tensioned to a specified force. The belt is rotated through at least three complete revolutions to ensure that the tension is equalized around the belt and that the belt is properly seated in the grooves. 

The effective length is defined as the measured center distance plus the outside circumference of one of the inspection pulleys. This measurement method accounts for the modulus of elasticity, or stretch ability, and dimensional variations among belts with the same cross-section. 

Hp = Power, horsepower L = Effective length of key, inches RPM = Revolutions per minute Ss = Shear stress, psi Sc = Compressive stress, psi... 

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