Non-uniform

When the grey level dynamic range in the image processed is small, usually because of a poor illumination or a non uniform lighting, it s possible to increase this dynamic range by a histogram transformation. This transformation affect the intensity distributions and increase the contrast. 

Chapman S and Cowling T G 1970 The Mathematical Theory of Non-uniform Gases 3rd edn (London Cambridge University Press)... 

Percus J K 1982 Non uniform fluids The Liquid State of Matter Fluids, Simple and Complex ed E W Montroll and J L Lebowitz (Amsterdam North-Holland)... 

Weeks J D, Vollmayr K and Katsov K 1997 Intermolecular forces and the structure of uniform and non uniform fluids Physice A 244 461... 

Weeks J D, Katsov K and Vollmayr K 1998 Roles of repulsive and attractive forces in determining the structure of non uniform liquids generalized mean field theory Phys. Rev. Lett. 81 4400... 

As noted above, one of the goals of NAMD 2 is to take advantage of clusters of symmetric multiprocessor workstations and other non-uniform memory access platforms. This can be achieved in the current design by allowing multiple compute objects to run concurrently on different processors via kernel-level threads. Because compute objects interact in a controlled manner with patches, access controls need only be applied to a small number of structures such as force and energy accumulators. A shared memory environment will therefore contribute almost no parallel overhead and generate communication equal to that of a single-processor node. 

In 1971 the Protein Data Bank - PDB [146] (see Section 5.8 for a complete story and description) - was established at Brookhaven National Laboratories - BNL -as an archive for biological macromolccular cr7stal structures. This database moved in 1998 to the Research Collaboratory for Structural Bioinformatics -RCSB. A key component in the creation of such a public archive of information was the development of a method for effreient and uniform capture and curation of the data [147], The result of the effort was the PDB file format [53], which evolved over time through several different and non-uniform versions. Nevertheless, the PDB file format has become the standard representation for exchanging inacromolecular information derived from X-ray diffraction and NMR studies, primarily for proteins and nucleic acids. In 1998 the database was moved to the Research Collaboratory for Structural Bioinformatics - RCSB. 

Figure 5.20 (a) The predicted non-uniform exit flow distribution in a co-extrusion die. 

Two of the most severe limitations of the harmonie oseillator model, the laek of anharmonieity (i.e., non-uniform energy level spaeings) and laek of bond dissoeiation, result from the quadratie nature of its potential. By introdueing model potentials that allow for proper bond dissoeiation (i.e., that do not inerease without bound as x=>°o), the major shorteomings of the harmonie oseillator pieture ean be overeome. The so-ealled Morse potential (see the figure below)... 

It should be emphasized that the value of tf resulting from use of (1.49) or (1.50) applies to a particular value of n,. Because of the joint effects of the energetic non-uniformity of the adsorbent surface and the interaction of adsorbate molecules in the adsorbed film itself, the heat of adsorption in general varies significantly with the amount adsorbed. It is therefore essential to repeat the calculation of (f for a succession of values of n, and thereby obtain the curve of against n,. 

This section is devoted to the relationship between the specific surface of particulate solids and some parameter or parameters which characterize the particle size. Attention will be restricted to particles of simple shapes, but non-uniformity of particle size will be considered. 

Figure 5 shows conduction heat transfer as a function of the projected radius of a 6-mm diameter sphere. Assuming an accommodation coefficient of 0.8, h 0) = 3370 W/(m -K) the average coefficient for the entire sphere is 72 W/(m -K). This variation in heat transfer over the spherical surface causes extreme non-uniformities in local vaporization rates and if contact time is too long, wet spherical surface near the contact point dries. The temperature profile penetrates the sphere and it becomes a continuum to which Fourier s law of nonsteady-state conduction appfies. 

A low tan S will mean a high degree of resin cure. Most insulation systems are composites of many materials. In practice, they almost always contain small voids. Consider a coil side with a single void. The voltage distribution across the insulation will be non-uniform, due to different permittivities of air and insulation. When a low voltage is applied, a proportion of this will appear across the... 

Alluvial soil formed of a number of layers of non-uniform non-homogeneous soil of different stratifications... 

The ground resistance is a function of the area occupied by the grounding station and the stratification of the soil. The stratification of the soil is usually of a non-uniform nature and may vary the resistivity of soil vertically as well as horizontally, thus varying the resistance of soil. The minimum value of ground resistance (resistance of the grounding station) at a certain depth h from the ground surface may be expressed by... 

S. Chapman and T.G. Cowling. Mathematical Theory of Non-uniform Gases, 2nd ed, Cambridge University Piess (1951). 

Finally, the combustion zone does not always proceed at a uniform rate, but oscillates in time, slowing down and dren advancing rapidly. This effect is probably due to die non-uniform packing and distribution of die reactants in the compact. Also visual observation shows that the zone is not uniformly distributed around the periphety of the compact, and the observed movement of a hot spot around the periphery is usually refeiTed to as spin combustion. 

The simple model given above does not take account of the facts that industrial refractories are poly crystalline, usually non-uniform in composition, and operate in temperature gradients, both horizontal and vertical. Changes in the coiTosion of multicomponent refractories will also occur when there is a change in the nature of tire phase in contact with the conoding liquid for example in Ca0-Mg0-Al203-Cf203 refractories which contain several phases. 

This formula is another variation on the Affinity Laws. Monsieur s Darcy and VVeisbach were hydraulic civil engineers in France in the mid 1850s (some 50 years before Mr. H VV). They based their formulas on friction losses of water moving in open canals. They applied other friction coefficients from some private experimentation, and developed their formulas for friction losses in closed aqueduct tubes. Through the years, their coefficients have evolved to incorporate the concepts of laminar and turbulent flow, variations in viscosity, temperature, and even piping with non uniform (rough) internal. surface finishes. With. so many variables and coefficients, the D/W formula only became practical and popular after the invention of the electronic calculator. The D/W forntula is extensive and eomplicated, compared to the empirieal estimations of Mr. H W. 

Non-uniformity may be caused by other reasons, like non-uniformity in catalyst activity, etc. Finally, uniformity is not always desirable. In a reactor containing several thousand tubes, for example, uniform runaway in all the tubes at the same time would result in a heat load impossible to control. Disaster would follow. 

Turbomaehinery bearing systems are normally designed for radial loads eorresponding to the weight of the rotor. Non-uniform pressure distribution around the wheel(s) of a turbomaehine may also eontri-bute to the magnitude of gas dynamie radial load, oeeasionally ealled side load. The sourees of gas dynamie radial loads on the eom-pressor wheel are different from those at the expander wheel. 

In a eompressor with a vaned diffuser followed by a typieal easing, the non-uniform, eireumferential flow resistanee aeross the diffuser walls induees an asymmetrie gas pressure around the wheel. Non-uniform peripheral gas pressure results in unbalaneed loading on the wheel and, henee, a radial bearing load. 

On the expander side, the expander wheel is surrounded by the nozzle vanes. The nozzle vanes, in turn, reeeive gas from a toroidal spaee that is eonneeted to tlie expander inlet piping. Any non-uniformity in the torus spaee and/or in the nozzle vane design may result in a non-uniform pressure distribution around the expander wheel. Non-uniform gas pressure around the expander wheel will result in a non-uniform load and, henee, produee a gas dynamie radial load on the bearing. In the expander ease, however, the nozzle throat flow resistanee is mueh larger than the easing peripheral pressure nonuniformity. The latter aets as a buffer making the expander wheel eireumferential pressure variations smaller than those of the eompressor side. This smaller pressure variation produees mueh less radial load when eompared to that of the eompressor side. 

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