Swelling problems

Eastern coal conversion development may come to be favored because of market proximity, water availability, and coal sources which, because of their high sulfur content, are currently unuse-able and, hence, largely decoupled from other energy prices. Proximity reduces transport costs and allows an increased use of low and medium Btu syngas processes. Reactivity and swelling problems may be overcome by technology. 

In solid-phase synthesis the standard conditions used in solution resulted in an incomplete reaction probably due to a swelling problem of the resin in MeOH. In this case the use of DMF in place of MeOH results in an approximately complete reaction. 7 It has been shown that the introduction of a reduced amide linkage between Phe and Pro residues, by reductive alkylation of the Pro nitrogen with Boc-Phe-H in the presence of NaBH3CN under acidic conditions leads to epimerization of the Phe residue. 57 This problem of racemization is... 

Figure 16. The peripheral stream tube and its mapped computational domain in the extrudate swell problem...

Base o-ring swelling measurements were conducted on petroleum-derived and F-T diesel and jet fuels to determine the extent of swelling problems that might be encountered in moving from a petroleum-derived fuel to a synthetic fuel. The results are reported in Table I. As expected, the petroleum-derived... 

In the case of negative resists, molecular weights greater than one million are unfavorable because of swelling problems during development processes. 

The swelling problem in the negative resist can be avoided if the differential solubility between exposed and unexposed area does not totally rely on the crosslinking of the exposed resist (4), or a dry development process, such as plasma development, is used. 

Thus, the initial swelling problem for a plane layer is reduced to a boundary value problem for diffusion equation [6.1.3] with boundary conditions of Eqs. [6.1.6], [6.1.7], [6.1.17] and [6.1.18]. The solution to this problem provides a full description of swelling processes in the plane layer. In other words, using Eqs. [6.1.1 ], [6.1.2], [6.1.10] and [6.1.15] we can define a current distribution of a liquid fluough the layer and calculate the stress-strain state of the material. 

There have been many useful attempts made to classify separation technologies. Supercritical fluids are applicable with both intra-phase and inter-phase separations. Due to the ease and flexibility in which a new phase can be formed for regeneration of the solvent, inter-phase is the more common. Furthermore, material solubility and swelling problems, particularly with organic-component based membranes, limit inter-phase separations. This is due to the enhanced solubility of these components in supercritical solvents. 

It can be easily appreciated that, compared to a conventional cation-exchange resin, the diffusion path length is reduced because the unreacted, hydrophobic resin core restricts analyte cations to the resin surface. This results in faster mass transfer of the cations and consequently in improved separations. Also, because of the rigidity of the resin core, there is less tendency for the bead to compress. This means that higher flow rates (at relatively low back pressures) can be used than would be possible with conventional resins. Superficially functionalized resins are stable over the pH range of 1 to 14 and swelling problems are minimal. The selectivity of the superficial cation-exchange resins for ions is similar to that observed for conventional resins. 

Let us consider the case of extrusion from a channel with an aspect ratio of 4 shown schematically in Fig. 7. The same algorithm used to solve the above square-die swell problem is used. The final shape attained by the extrudate in this case is shown in Fig. 8 for several values of Reynolds number,... 

Considerable progress has been made in the development of ceramic fuels. The swelling problems of the dense fuels (alloys, carbide and nitride) which prevented their application as LMFBR fuels in the early sixties have in principle been solved. The solution consists of two parts. The first is common to all three fuels and consists of... 

Kim and coworkers prepared polyimide (PI)-based film microreactors by ArF excdmer laser or UVlasertreatment The PI microreactor (ArF-SH type) was successfully operated in extremely strong acidic conditions without any leaking and swelling problems [11]. The Beckman rearrangement of cyclohexanone oxime to -caprolactam by sulfuric add at 130 °C proceeded in 0.9 s residence time with 46% yield, which is much more effident than the results obtained from the corresponding batch reaction (28%, 1 h). 

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