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This work proposes a practical and systematic model-based approach to identify the optimal operating conditions for a simulated moving bed reactor (SMBR). The SMBR operation is applied to an industrial case study for the continuous production of a solvent, propylene glycol methyl ether acetate (DOWANOL™ PMA), which is produced through an acid-catalyzed esterification reaction of 1-methoxy-2-propanol and acetic acid. The model-based approach is demonstrated by lab-scale SMBR experiments. A multi-objective optimization problem was formulated for developing an SMBR process to maximize the production rate of PMA and the conversion of the esterification reaction simultaneously. In this study, this optimization problem is solved using the epsilon-constrained method and a Pareto plot is presented. The solutions that corresponded to three different values of conversion, 70%, 80%, and 85%, are experimentally validated. The SMBR model that was developed from batch kinetic and single column chromatography experiments demonstrates reasonable agreement with the experimental results. Furthermore, the SMBR experimental data was used to correct the parameters in the model. A validation study at a higher conversion of 95% demonstrates improved predictability of the corrected parameters.

The full scale Soil Cement Mixing (SCM) wall was constructed to investigate viability of the wall. Long term behavior of the wall resulted in viability of the wall. However, design guidelines on SCM wall are limited due to its complex geometry. In this paper, the three dimensional finite element method is employed to study the influence of various design decisions for SCM wall. The numerical model is first calibrated with an instrumented case history. Then a parametric study is constructed. The results give information on the influence of the following factors on the wall behavior: size of column, column overlapping, column embedment, existence of relieving platform, and column strength. The implications in design are discussed.

A K-band low-power miniaturized planar-type hyperthermia system was developed to replace massive and expensive equipment. The system consists of a VCO with a buffer amplifier, a high-power amplifier module, a 20-㏈-coupled line coupler, a chip circulator and two power detectors for signal generation, amplification and power monitoring. All these components have been implemented in planar form on two module blocks. The total size of the hyperthermia system was less than 10×6.5×3 ㎤. In order to verify the system performance, ablations were carried out on nude mice xenografted with human breast cancer. Ablation results show performance comparable to the massive components-based system. This work shows the feasibility of a low-cost miniaturized hyperthermia system for practical clinical applications.

A planar bi-directional microwave heat applicator integrated with active circuits on a single platform is presented in this paper. K-band frequencies have been utilized to facilitate low-power hyperthermia and high-level integration. The active source module implemented with GaAs-based multichip monolithic microwave integrated circuits delivers 1.4 W at 20 GHz into the co-integrated planar applicator, which has three planar coaxial apertures on each side for wide-area bi-directional hyperthermia. The heating volume is further enhanced by employing switched heating, which effectively doubles the hyperthermic volume. The bio-heat equation is solved to find the optimum switching time, as well as to achieve uniform heating across the apertures. The effectiveness of the proposed applicator has been demonstrated by in-vitro heating experiments on the pork muscle, which showed 210.6- mm3 heating volume using only 1.4 W of on-board source power. The entire applicator was realized in a small form factor (5 mm times 50 mm times 0.524 mm) for minimally invasive interstitial insertion. The cost of the hyperthermia system can be drastically reduced by integrating active components on the applicator platform.

A bi-directional planar coaxial applicator with multiple apertures is presented in this paper. The applicator is optimized for uniform thermal distribution over large volume for low-power microwave hyperthermia. The proposed applicator can radiate microwaves in both up and down directions simultaneously, resulting in extended treatment volume. The power distribution into each aperture has been optimized to achieve uniform thermal profile by solving the bioheat equation. 3-D thermal profiles are measured on the surface of 4 mm-thick pork muscle using Infra-Red microscope from three orthogonal directions. The measured thermal profile confirms uniform thermal distribution and expanded heating volume.

In this study, the performance characteristics of electro-cyclone with different inlet shapes, such as helical, tangential and involute, were experimentally investigated. The range of particle size has 0.3 to 6 μm and the inlet velocities are 10, 15, 20, and 25 m/s. Particles used in this experiment are JIS Class 11 test powder which have the density of 1.9~2.1 g/cm3 and the mass median diameter of 2.3 μm. An electrocyclone has discharge wire which was inserted in the middle of vortex-finder. The length, diameter and material of discharge wire have 20 mm, 0.6 mm and SUS304, respectively. The discharge wire was applied with a voltage of 10 kV. The collection efficiency is calculated by the particle size distribution of the upstream and downstream using a laser optical particle counter. Pressure drops were measured between two pressure taps which were located at the inlet and outlet ducts of electrocyclone using a micromanometer. For the case of the involute type, due to a minimum turbulence, the retention time of particles becomes long in electrocyclone and particles have more chances to be charged. However, the experimental results show that a helical shape has a better collection effect than the other shapes. And the pressure drop of the involute shape for a given inlet velocity is smaller than the other shapes. The collection efficiency and the pressure drop with various inlet shapes and velocity changes in electrocyclone are graphically depicted.Copyright © 2005 by ASME