Dense Pattern

The production of flat-panel cathode ray tubes (CRTs) is essentially a fabrication issue. The basic principle of operation is the same as a standard CRT. Electrons are emitted from a hot cathode. These are guided by a magnetic field to the glass screen coated in a layer of phosphorescent material. Upon impact the energy of the electron is transferred to the phosphor and light is emitted. A regular pattern of red, green and blue phosphors creates a dense pattern of... 

Figure 5, crazes I and II can clearly be distinguished, the large and isolated crazes I and the dense pattern of very fine crazes II. The axes of both coincide with the draw axis. Other examples of the coexistence of two distinct types of crazes, whose axes however do not coincide, may be found in the literature 09,ii5,n6) Unfortunately, the phenomena reported in these publications are not very well understood. 

Tokyo Gas Company, 246, 381 Topsoe Dense Pattern Flexible Distribution Tray, 241... 

Particle Diameter Because plastic deformation depends on stress concentration in the whole volume between particles and not directly on the stress at the particles, D is not of primary importance. The only precondition is that for a given particle volume content, the particles must be small enough to ensure that A is less than the critical value according to equation 1. Therefore, the most important function of particles is to produce a dense pattern of microvoids. Recently, an increase of the toughness of modified PA with increasing tendency to form microvoids inside the particles (with decreasing stress to crack the particles or with decreasing cavitation strain) was found (6). The cavitation stress of an elastomer is dependent on its modulus (27). 

Loading can also occur at the microscopic feature scale microloading). It has been observed, for example, that isolated features etch faster than dense patterns. This is due to local reactant depletion over the dense pattern caused by greater consumption of the reactant (greater etchable surface area exposed by the dense pattern). 

Figure 17.5 Top-down SEM images of (a) 160-nm dense patterned contact holes that were not irradiated with electron beam, (b) same size contact holes as in (a) after irradiation with electron beam of 20-KeV accelerating voltage, 4-mA current, and dose of 750 pC/cm, and (c) same size contact holes as in (a) after irradiation with electron beam of 20-KeV accelerating voltage, 5-mA current, and dose of 1000 pC/cm. ...

Fig. 4.13 Irran left to right template layout to fabricate ctanplex patterns consisting of design patterns of posts. Each color represents the pattern templated by each arrangement SEM images of the templates of posts to fabricate dense patterns of bends and temninations SEM images of the PDMS patterns formed on the template shown on the left SCFT simulation result showing the constant 50 % density smface of PDMS cylinders assembled with the template on the left. Scale bars are 50 nm. Adapted by permission from Macmillan Publishers Ltd Nature Comm. 2014, 5, 3305 (ref. [112]), copyright 2014...

The typical micromechanical behavior of this material at room temperature is shown in Figure 10. The lower magnification in Figure 10a shows a dense pattern of cavitated and elongated rubber particles and plastically deformed matrix material between the particles. The matrix deformation occurs mainly in the form of homogeneous shear deformation zones and a small number of short and relatively thin fibrillated crazes (40). 

A fine entanglement network with small meshes deforms in a dense pattern of small stretched meshes in a homogeneous manner (Fig. 1.10(b)) [13]. There are several criteria for craze initiation and growth, reviewed in [5, 13,17]. 

Spheres can actually compact in a very dense pattern to a minimum void ratio of 0.215, but Cheremisinoff (1984) indicated that the average void ratio from thickeners was 0.6. For nonspherical and coarse particles, the situation becomes more complex because of the shape factor (discussed in Chapter 3), and it is the norm to conduct s imentation tests on samples of the slurry before designing the thickener. 

The improvement in vapor-liquid contact can enhance the performance of distillate hydrotreaters. As an example, in testing of an improved vapor-liquid distributor in commercial use, Haldor-Topsoe and Phillips Petroleum found that the new Topsoe Dense Pattern Flexible Distribution Tray (installed in 1996 to replace a chimney type distributor installed in 1995 in a refiney) allowed a 30% higher sulfur feed to be processed at 25°C lower temperatures, while reducing the sulfur content of the product from 500 to 350 ppmw . Albemarle estimates that an improved vapor-liquid distributor can reduce the temperature necessary to meet a 50 ppmw sulfur level by 10 °C, which in turn would increase catalyst life and allow an increase in cycle length from 10 to 18 months. Based on the above data from Haldor-Topsoe, if temperature were maintained, the final sulfur level could be reduced by 50%. Maintaining temperature should have allowed an additional reduction in sulfur of more than two-thirds. Thus, ensuring adequate vapor-liquid contact can have a major impact on final sulfur levels. 

Li, W.-D.D., Wu, W., Stanley Williams, R., 2012. Combined helium ion beam and nanoimprint lithography attains 4 nm half-pitch dense patterns. J.Vac. Sci.Technol., B Micro-electron. Nanometer Struct. 30 (6), 06F304. 

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