Multimodal grades

Fig. 3. Types of optical fiber (a) multimode stepped index, (b) multimode graded index, and (c) single-mode stepped index.

In the case of heterophasic copolymers, the polymer from the gas-phase reactor is transferred into another, smaller gas-phase reactor where the rubbery copolymer is made. After this step, hydrocarbon residuals are removed, and the powder is transferred to the extrusion section. Polymerization conditions in each reactor can be independently controlled, enabling production of both standard uni-modal and broad molecular weight multimodal grades. The production rate ratios between the reactors can be adjusted to meet the targeted product properties. 

Figure 7.9 Refractive index profiles of three common types of optical glass fiber multimode step index, multimode graded index, and single mode.

Multimode step index Multimode graded index... 

Recommendation G.651, Characteristics of a 50/125 fxm multimode graded index optical fiber cable. International Telecommunications Union, 1998. 

Step-index Graded-index Multimode Multimode... 

Single-mode fibers have many advantages over multimode fibers. See Fig. 3. Compared to the 50 or 62.5 micron core diameter of typical graded-index multimode fibers, some single-mode fibers have a core diameter near... 

Figure 2.51. Cross-section image of an optical fiber. Shown is the propagation of Ught waves through an (a) step-index multimode fiber, (b) graded-index multimode fiber, and (c) single-mode fiber.

A graded size distribution, where fine particles fill the interstices between coarse particles as shown schematically in Fig. 4, will minimize the amount of void space that must be filled by fluid, and so will reduce the quantity of liquid needed to produce a flowable slurry. The best size distributions for this purpose have proven to be multimodal distributions, made up of several fairly narrow size fractions. An example of such a size distribution is shown in Table 1. To achieve such a multimodal size distribution, coal slurry production facilities are designed to generate several coal streams, which are each ground and sized to the desired particle sizes and then combined to give the proper size distribution. 

Single Mode Fiber (SMF) Graded Index Fiber (GIF) Careless Fiber(CF) Multimode Fiber(MMF)... 

Fig. 3. Gold nanoparticles are formed on the surface of (A) A fused MMF-CF-MMF structure and a fused SMF-GIF- CF-MMF structure, (B) Ray Tracing schematic of Structure B, which is an in-line fiber structure consisting of single mode, graded index, coreless, and multimode fibers to expand the Gaussian beam to the surface of the coreless fiber.

Denton JR, Moore EE, Coldwell DM (1997) Multimodality treatment for grade V hepatic injuries perihepatic packing, arterial embolization, and venous stenting. J Trauma 42 964-967 discussion 967-968... 

Graded index multimode fibers are far more complicated than their single mode counterparts. The relevant expressions are stated to permit insight into the relationships between material properties and fiber performance. The index profile as a function of radius r is given by Equation 4. For such a profile, the intermodal group delay may be approximated by... 

Feit, M. D., and Fleck, J. A., Calculation of dispersion in graded-index multimode fibers by a propagating-beam method, Appl. Opt, 18, 2843 (1979). 

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