ASE® process

Here is the first book devoted completely to inorganic membrane separations and applications. It provides detailed information on all aspects of the development and utilization of both commercial and developmental inorganic membranes and membrano-t)ased processes, pointing out their key advantages and limitations as separation tools. 

The steps in the ASE process are shown in Figure 3.8. The sample is loaded into the extraction cell, and then the solvent is pumped in. Then the cell is heated to the desired temperature and pressure. The heat-up time can be 5 to 9 minutes (for up to 200° C). This is referred to as the prefill method. Alternatively, the sample can be heated before adding the solvent, which is known as the preheat method. However, the preheat method is prone to the loss of volatile analytes. Therefore, the prefill approach is generally preferred [46],... 

Bleich, J. Kleinebudde, P. Mueller, B. Influence of gas density and pressure on microparticles produced with the ASES process. Int. J. Pharm. 1994, 106, 77-84. 

The basic design of the devices used to develop an ASE process as reported in the first study using the Dionex" ASE 200 extractor [2,3], and also in some later investigations conducted using laboratory-built systems [1,18,77], is shown in Fig. 6.4. As can be seen, the equipment required to implement ASE consists of seven basic units, namely ... 

The PCA process is a slight modification of the ASES process. It is a one-step technique used to produce solvent free particles with a narrow size distribution at mild operating conditions [22]. It involves feeding SFCO into a precipitator so as to pressurize the precipitator to a desired value. The CO flow rate into the precipitator is then fixed. The solution of protein is fed into the precipitator through a nozzle. The antisolvent effect of the SECO leads to the precipitation of the protein particles. 

Three-photon active (SPA) materials have been studied extensively over the last few years owing to their potential applications in the fields of telecommunications and biophotonics [26-28, 30], Two major advantages of these materials—longer excitation wavelengths and much better spatial confinement—make them attractive in comparison with two-photon absorption (2PA) based materials [29], One of the most important applications of SPA materials is three-photon pumped frequency-upconversion cavity-less lasing [26, 30], Short infra-red (IR) pulses induce the ASE process via 3-photon absorption followed by fast non-radiative decay to a long-lived state which collects population. Conventional experiments with a pulsed longitudinal pump [27, 28, 30] show that stimulated emission occurs in both forward and backward directions with respect to the pump pulse. 

The ASE process is initiated by the spontaneously generated noise photons (SPs) with intensity... 

PRECIPITATION WITH A COMPRESSED FLUID ANTISOLVENT (PCA), A SUPERCRITICAL ANTISOLVENT (SAS), AND THE AEROSOL SOLVENT EXTRACTION SYSTEM (ASES) PROCESSES... 

Dozens of drugs have been recrystallized by means of the precipitation with a compressed fluid antisolvent (PCA) and the supercritical antisolvent (SAS) and aerosol solvent extraction system (ASES) processes. 

Steckel et al. (105) used the ASES process to micronize several steroids and particles with the required size were obtained. No chemical decomposition was observed. The wettability of the active products was improved upon addition of a physiological surfactant to the initial solution. This is advantageous for suspensions of the drug particles in water, hydrophilic solvents, or propellants. Some modifications were brought to the conventional process. First, once the organic solution spraying has been done, the antisolvent injection is stopped and a sedimentation phase is allowed to take place this phase is claimed to increase the yield. Second, the removal of the residual... 

Ruchatz F, Kleinebudde P, Muller BW. Residual solvents in biodegradable microparticles. Influence of process parameters on the residual solvent in microparticles produced by the aerosol solvent extraction system (ASES) process. J Pharm Sci 1997 86 101-105. 

Figure 11 Particle size distribution of inulin particles prepared by the ASES process at various scale plants XI (2g sample), XI0 (20g sample), and XI00 (200-g sample). (From Ref. 80.)...

In the following, the STS Multiplex ICP system and ASE process, etching performance and chemistry, and end point detection and experiment will be introduced for anisotropic plasma etching. 

Plasma Etching, Table 3 Typical characteristics of Si etching using the STS ASE process [3, 6]... 

The ASE process occurs in a gain medium whenever the optical confinement is superior, or the decoherence time is short (Section 22.2). The confinement can be described by the radiation leakage rate k, whereas the cooperation among chromophores may be quantified by the Arrechi-Courtens time [112] Tc, which is inversely proportional to the chromophore density in the medium. The value of (kTc) accounts for the relative number of photons emitted by the ASE process [96]. This happens in both polymer solutions (in a cuvette), or in neat polymer films of thickness 100 nm deposited on glass substrates due to optical confinement formed by the film waveguiding properties. 

ASE process [96]. Therefore, in the case of strong optical confinement, where kt < 1, ASE is the dominant radiation process. On the other hand, for weak optical confinement where kt > 1, cooperative... 

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