Processing of solids

The actual process of solid phase peptide synthesis outlined m Figure 27 15 begins with the attachment of the C terminal ammo acid to the chloromethylated polymer m step 1 Nucleophilic substitution by the carboxylate anion of an N Boc protected C terminal... 

R. A. McKay,M Study of Selected Parameters in S olid Propellant Processing,]et Propulsion Lab, Pasadena, Calif., Aug. 1986 J. L. Brown and co-workers. Manufacturing Technologyfor SolidPropellantIngredients/Preparation Reclamation, Morton Thiokol, Inc., Brigham City, Utah, Apt. 1985 W. P. Sampson, Eow Cost Continuous Processing of Solid Rocket Propellant, Al-TR-90-008, Astronautics Laboiatoiy/TSTR, Edwards AEB, Oct. 1990. 

Because many of the techniques, especially those associated with the recovery of materials and energy and the processing of solid hazardous wastes, are in a state of flux with respect to application and design criteria, the objective here is only to introduce them to the reader. If these techniques are to be considered in the development of waste-management systems, current engineering design and performance data must be obtained from consultants, operating records, field tests, equipment manufacturers, and available literature. 

Ayazi Shamlou P (1993) Processing of solid-liquid suspensions. Butterworth Heine-mann, London... 

MR Bolhuis, CF Lerk. Film forming of tablet lubricants during the mixing process of solids. Acta Pharm Technol 23 13-20, 1977. 

Levenspiel, O., Kunii, D., and Fitzgerald, T., The Processing of Solids of Changing Size in Bubbling Fluidized Beds, Powder Tech., 2 87 (1968)... 

Solid-phase organic synthesis (SPOS) exhibits several shortcomings, due to the nature of the heterogeneous reaction conditions. Nonlinear kinetic behavior, slow reactions, solvation problems, and degradation of the polymer support due to the long reaction times are some of the problems typically experienced in SPOS [2], Any technique which is able to address these issues and to speed up the process of solid-... 

Properly simulating a dissolution process of solid particles in a stirred vessel operated in the turbulent-flow regime urges for a very detailed simulation of the turbulent-flow field itself. Just reproducing the overall flow pattern by means of... 

However, despite those positive reports, the authors would not recommend precalcination of the starting NiO-YSZ powder mixture as a necessary step in the processing of solid oxide fuel cells for the following reasons. First, the mechanism for the enhanced electrochemical performance for anodes when the NiO-YSZ precalcinated together has not been explained clearly. The phenomenon is actually counterintuitive because it has been shown that coarsening of NiO or YSZ alone leads to lower anode... 

This review defines the thermochemical conversion processes of solid fuels in general and biofuels in particular that is, what they are (drying, pyrolysis, char combustion and char gasification) and where they take place (in the conversion zone of the packed bed) in the context of the three-step model. 

The reaction of solids is not regarded as a traditional aspect of chemical reaction engineering, which usually concerns mostly fluids (gases and liquids). However, chemical processing of solids represents an increasingly important part of reaction engineering. The material in this chapter also introduces gas-liquid and liquid-liquid processes because similar geometries are involved. 

Solidification of the particles may not be the final step in the formation process of solid lipid particles. Lipidic materials exhibit rich polymorphism [69,70], which may also occur in the dispersed state. In nanoparticles, the polymorphic behavior of the matrix lipids may, however, differ distinctly from that in the bulk material. Polymorphic transitions are usually accelerated in the nanoparticles compared with the bulk lipids [2,62]. In some cases, polymorphic forms not observable in the corresponding bulk materials were detected in lipid nanoparticles [1,65]. Because polymorphism can affect pharmaceutically relevant properties of the particles, such as the drug incorporation capacity [65], corresponding investigations should also be included in the characterization process. As long as polymorphic or other crystalaging phenomena have not terminated, the particle matrix cannot be regarded as static, and alterations of the particle properties may still occur. 

Most authors who have studied the consolidation process of solids in compression use the basic model of a porous medium having point contacts which yield a general equation of the mass-and-momentum balances. This must be supplemented by a model describing filtration and deformation properties. Probably the best model to date (ca 1996) uses two parameters to define characteristic behavior of suspensions (9). This model can be potentially applied to sedimentation, thickening, cake filtration, and expression. 

The nature and sizing of equipment depends on the economic values and proportions of the phases as well as certain physical properties that influence relative movements of liquids and particles. Pressure often is the main operating variable so its effect on physical properties should be known. Table 11.1 is a broad classification of mechanical processes of solid-liquid separation. Clarification is the removal of small contents of worthless solids from a valuable liquid. Filtration is applied to the recovery of valuable solids from slurries. Expression is the removal of relatively small contents of liquids from compressible sludges by mechanical means. 

Figure 19.12. Batch parametric processing of solid-liquid interactions such as adsorption or ion exchange. The bottom reservoir and the bed interstices are filled with the initial concentration before pumping is started, (a) Arrangement of adsorbent bed and upper and lower reservoirs for batch separation, (b) Synchronization of temperature levels and directions of flow (positive upward), (c) Experimental separation of a toluene and n-hcptane liquid mixture with silica gel adsorbent using a batch parametric pump. (Reprinted from Wilhelm, 1968, with permission of the American Chemical Society), (d) Effect of cycle time t on reservoir concentrations of a closed system for an NaCl-H20 solution with an ion retardation resin adsorbent. The column is initially at equilibrium with 0.05M NaCl at 25°C and a = 0.8. The system operates at 5° and 55°C. [Sweed and Gregory, AIChE J. 17, 171 (1971)J.

York, P. (1983). Solid-state properties of powders in the formulation and processing of solid dosagirfbrms,... 

The dissolution process of solids consists of two steps. First, the molecules at the solid-liquid interface are solvated and detached from the... 

Kargel (2001), Thomson and Delaney (2001), and O Brien et al. (2002) have hypothesized that a Europan ocean could become thermally and com-positionally stratified. Disturbance and overturning of this ocean could lead to exsolution of gases and a massive thermal flux to the surface via cryo-volcanism (Fig. 5.21). Such massive fluxes, if frequent enough, could play an important role in cycling oxidants compared with the presumably slower process of solid-phase convective flow in the soft ice. There may also be hydrothermal vents in a Europan ocean. If massive enough, these vents could... 

Di Felice, R. Solid Suspension in Liquid Fluidized Beds in Processing of Solid-Liquid Suspensions, Shamlou, P.A. (Ed.), Butterworfh-Heinemann Boston, 1993, pp. 246-272. 

Shamlou, P.A. (Ed.) Processing of Solid-Liquid Suspensions, Butterworth-Heinemann Boston, 1993. 

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