Diffusion Deposition on Model Fibrous Filters with Intermediate Porosity

Theoretical and experimental studies of the diffusional deposition of aerosols on model niters of intermediate packing density are reported. At low Reynolds number (Re« 1) and intermediate porosity (0.01 < α < 0.4), the Kuwabara flow field is applicable for parallel staggered model filters, and the diffusional deposition efficiency can be expressed as A = 2.92 n [(l-a)/k]^1/3 Pe ^?2/3. By applying a correction factor based on the ratio of pressure drops to this equation, the deposition efficiency for a fan model filter is n = A Pe ^?2/3, where A has a value of 2.4–2.6 for α = 0.05–0.4. The efficiency increases with the fiber solidity, α for the parallel staggered filter, but is essentially independent of a for the fan model filter. Experimental results of diffusional deposition of ultrafine aerosols on wire screens which is used as a fan model filter has been performed. Summary data on screens and the fan model filter reported in the literature show that the single fiber efficiency is independent of the solid volume fraction and can be expressed as n = 2.7 Pe ^?2/3 where Pe is the Peclet number (over the range of 0.02 < a < 0.35). The small difference between the experimental data and theory can be explained by the approximate nature of the flow field used in the theory.     

基于蒸汽炉物煅烧氧化铋构成复合物自由引导压电材料性能的研究

由于环境污染问题，取代传统的基于引导的PZT自由引导压电材料得到了发展。其中CaBi4Ti4O15由于其多极性显示出铁和压电特性。在早期研究中，Ca-Bi-Ti合成醇盐的旋转涂层薄膜作为一个前期方案，通过钙、铋的氧化物和锑的异丙氧化物在酒精和2-甲氧基乙氧基混合物中的化学反应已经很好地合     

Miniaturization design method and performance evaluation of prototype permanent‐magnet synchronous motor optimally designed by thermomagnetic field coupling analysis

This paper reports on the results of the miniaturization design of a permanent magnet synchronous motor, for which an optimal design technique based on thermomagnetic field coupling analysis is used. We derived the optimal solution for various motor flatness ratios and determined the relationship between the motor size and the flatness ratio. For motors with different flatness ratios, we calculated the speed–torque characteristics by considering the voltage, temperature rise, and demagnetization limits and compared them. Moreover, we manufactured and tested the smallest designed motor. The measured temperature rises demonstrated the high accuracy of the proposed miniaturization design. © 2013 Wiley Periodicals, Inc. Electr Eng Jpn, 183(2): 58–66, 2013; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/eej.22279     

Construction of simulation model for spray flash desalination system

This paper describes a simulation model for a spray flash desalination system which makes fresh water from sea water by using the temperature difference between warm surface sea water and cool deep sea water. The spray flash desalination system can be modeled by using the energy conservation law and the mass conservation law. Simulation results of the model are compared with the experimental results and show the accuracy of the proposed simulation model. © 2009 Wiley Periodicals, Inc. Electr Eng Jpn, 170(4): 9–17, 2010; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20975     

Chain stiffness and chain conformation of poly(α-methylene-γ-butyrolactone) in dilute solutions

The chain stiffness and local chain conformation of atactic poly(α-methylene-γ-butyrolactone) (PMBL), which is a side chain cyclic structural analog of poly(methyl methacrylate) (PMMA), with a weight-average molecular weight (M_w) ranging from 2.8 × 10³ to 2.6 × 10⁶ in N,N-dimethylformamide (DMF) and γ-butyrolactone (GBL) were characterized by size exclusion chromatography with a multi-angle light-scattering detector (SEC-MALS) and synchrotron radiation small-angle X-ray scattering (SAXS). Based on the Kratky-Porod worm-like chain model, the scattering functions and the M_w dependence of z-average root-mean-square radius of gyration <S²>_z^1/2 yielded the Kuhn segment lengths λ⁻¹, the diameter of the PMBL chains d, and the excluded-volume strengths in DMF and GBL. The local conformation of atactic PMBL in DMF and GBL were slightly larger than those of atactic PMMA, due to the presence of the conformationally rigid lactone ring structure.     

Enhanced amination and adsorption performance of functional copolymer synthesized <Emphasis Type="Italic">via</Emphasis> RAFT-mediated radiation grafting in emulsion

Grafted polymer substrates bearing diglycol amic acid (DA) ligands for Eu and Sm adsorption were prepared using a two-step post-grafting modification of polyethylene/polypropylene-g-poly(glycidyl methacrylate) (PE/PP-g-PGMA) that was synthesized through reversible addition-fragmentation chain transfer (RAFT)-mediated γ-radiation induced graft polymerization in emulsion phase. The PE/PP-g-PGMA prepared with RAFT mediation exhibited better reactivity towards amination reaction at 40 °C than the graft copolymers prepared without RAFT mediation, with the epoxide to amino group conversion of the former exceeding the latter by as much as 20%. The DA ligands were incorporated to the aminated graft copolymer by subsequent reaction with diglycolic anhydride to yield the DA-modified PE/PP-g-PGMA adsorbent. The effects of pH and competing ions on the uptake of Eu and Sm have been investigated. The DA-modified PE/PP-g-PGMA prepared with RAFT mediation showed higher Eu and Sm adsorption percentage than the DA adsorbent that was synthesized without RAFT mediation. The DA-modified PE/PP-g-PGMA exhibited higher affinity for Eu over Cu and Fe in acidic solutions.     

Nonlinear control for rotational movement of cart-pendulum system using homoclinic orbit

In this paper, we deal with the control method for rotational movements of a pendulum using a separatrix. We design a controller that attains a homoclinic motion or a heteroclinic motion of the pendulum and the asymptotic stability of the cart by using a kind of forwarding control design. First, we derive a controller that converges to a homoclinic orbit via a Lyapunov function of the pendulum subsystem. Next, we give a nonlinear stabilizing controller via another Lyapunov function of the cart subsystem. Moreover, using the third Lyapunov function and adding a complementary control input, we guarantee that the pendulum converges to the homoclinic orbit and the cart is stabilized. Finally, the simulation and the experiment using the rapid controller prototyping system based on MATLAB/Simulink are performed to demonstrate the forward upward circling and the giant swing of the pendulum.     

Evaluation of Young’s modulus of imprinted hydrogen silsesquioxane pillar after residual layer removal by reactive ion etching

Nanoimprint lithography has two basic steps. The first is the imprint step in which a mold with nanostructures on its surface is pressed into a resin film on a substrate, followed by removal of the mold. The second step is the residual layer removal by a reactive ion etching (RIE). There is no report whether the properties of the imprinted structure after RIE change or not. In this work, the authors evaluated the Young’s modulus of the imprinted pillar after residual layer removal by RIE. In this experiment, hydrogen silsesquioxane (HSQ), a type of spin-on-glass, was used as an imprint material. The residual layer was etched by RIE using CHF₃ gas. The Young’s modulus of imprinted pillar after RIE was measured via cantilever method. The Young’s modulus of HSQ pillar after RIE was twice as much as that of HSQ pillar before RIE. From the Fourier transform infrared measurement, it was founds the chemical structure of HSQ was changed by forming network structure due to heating by RIE plasma energy. These results indicate that the mechanical property of imprinted structure was changed in the residual layer removal step by using RIE.     

Tritium depth profile in matter using an imaging plate

A method to detect tritium non-destructively in regions deeper than the escape depth of beta rays is being developed using bremsstrahlung induced by beta rays with an imaging plate (IP). An IP made of europium-doped BaFBr(I), a photostimulated luminescence (PSL) material, is a two-dimensional radiation sensor. The bremsstrahlung energy spectrum is a continuum with photon energies, varying based on the atomic number and thickness of the target (or absorbing) material. When tritium migrates into matter, the bremsstrahlung energy spectrum distribution would change. The PSL intensity of the IP is affected by this energy spectrum variation. In order to quantify the amount of tritium in deeper regions with the IP technique, a tritium depth profile is required.In this study, a new method of obtaining a tritium depth profileusing the combined technique of the IP and thin absorbers is presented.     

Z-type jump in electrical conductivity of samarium manganite

The electrical conductivities of non-stoichiometric samarium manganites were measured as a function of temperature and the existence of a Z-type jump in the conductivity curve was found near 1300 K, and a heat anomaly was also observed by differential thermal analysis, which should reflect the same phase transition as in LaMnO₃.