Deposition of BaTiO3 thin films by plasma MOCVD

Barium titanium trioxide (BaTiO₃) thin films were deposited on fused silica or silicon wafer substrate from barium dipivaloylmethanate (II) (Ba(dpm)₂) and titanium tetraisopropoxide (IV) (TTIP) used as precursors in an oxygen microwave plasma. The substrates were dielectrically heated and the substrate temperatures were around 900 K during the film deposition. The deposition was performed for 15 min and the deposits were identified as BaTiO₃ by means of X-ray diffraction, X-ray photoelectron spectroscopy, infrared spectroscopy, and ellipsometry. Oxygen and barium atoms and TiO and CO molecules were identified in the plasma. These species would produce higher deposition rates at lower substrate temperatures than those did in the usual thermal metalorganic chemical vapor deposition (MOCVD). The dielectric constant of the BaTiO₃ thin film that was directly deposited on the silicon wafer substrate was as low as 10¹ order of magnitude. Because the deposit reacted with the substrate and an interdiffusional layer was formed, the platinum layer was coated on the silicon wafer substrate in order to prevent the formation of an interdiffusional layer. The dielectric constant then increased to 10³ order of magnitude.     

Theoretical studies on VPI-5. 3. The MS-Q force field for aluminophosphate zeolites

Aluminophosphate zeolite is an artificial material which shows strange hydrophilicity. We have been investigating the reason by quantum mechanics, and found that the hydrophilicity of this zeolite depended on the local geometric deformation, and speculated that the site-specific hydrophilicity might be explained by differences in the stiffness of the local deformation determined by the location with the pore structure. In order to test these ideas, we construct a reliable force field based on the new MS-Q approach developed by Demiralp, Cagin, and Goddard. Our force field well reproduces the experimental structure of VPI-5.     

Replication of Microstructures by Roll-to-Roll UV-Curing Embossing

The characteristics of pattern replication and releasing in a roll-to-roll ultraviolet- (UV) curing embossing process were investigated. The roll embossing system was designed for large-area continuous embossing, with employment of a fast curing resin, a heat damage protector, and a surface energy reducing coating. A 60° V-groove pattern with a groove period of 30 µm was embossed. It was found that the replication quality was profoundly influenced by the pattern geometry, the pattern direction, and the mold surface energy. In particular, the pattern direction significantly affected the edge sharpness and the surface topography of replicated features. In the parallel groove mode, a significant amount of tearing and sliding occurred, whereas in the transverse groove mode, biting marks were observed on the side wall of the V-groove. A simple mechanical model was used to explain the difference in pattern releasing with different pattern layouts. The replication quality was found to be significantly improved with the application of a fluorinated coating on the roll mold.     

THE EXTRACTION OF NEPTUNIUM(V) BY METHYLTRIOCTYLAMMONIUM CHLORIDE AND 1-PHENYL-3-METHYL-4-BENZOYL-5-PYRAZOLONE

The synergistic effect of methyltrioctylammonium chloride (QCI) on the extraction of Np(V) by 1-phenyl-3-methyl-4-benzoyl-pyrazolone(HP) in benzene is studied over the pH range 2-6. This system extracts Np(V) better than any previously reported. The interaction of the extractants and monomer-dimer equilibria affect the distribution behavior of Np(V) in a complicated manner. Analysis of the results suggests that NpO₂ ⁺ (M⁺) is extracted as mixed dimers, (QMP₂QCl)_o and (QMP₂QP)_o.     

Analysis of a manipulator in relation to collision between a link and an object

In this article, equations of motion of a manipulator are derived after consideration of the characteristics of the driving source. By considering a collision between a link and an object, and considering the active motion to absorb the kinetic energy of the object, the trajectories for saving energy are calculated by the iterative dynamic programming (IDP) method. The dynamic characteristics of manipulator control based on the trajectory for saving energy are also analyzed theoretically and investigated experimentally.     

Hydrogen-bonded polymer complexes of macrocycles containing a pyridyl moiety and carboxyl-functionalized polystyrenes An approach to H-bonded rotaxanes

Summary Copolystyrenes complexed with macrocyclic compounds through hydrogen bonding have been synthesized by the copolymerization of styrene with the complex of 4-vinylbenzoic acid and crown ethers containing a 2,6-pyridyl moiety. The glass transition temperatures of the copolymeric complexes are significantly lower than that of the simple copolymer, which shows that the carboxylic acid groups in the polymer backbone do not intermolecularly dimerize. The UV absorption spectra of polymeric complexes suggest that they have complex structures similar to that of the low-molecular-weight complexes of 4-ethylbenzoic acid and the crown ethers. Received: 31 March 1999/Accepted: 27 April 1999     

A local demand forecast by NN method for distributed autonomous voltage and reactive power control system

The paper describes required technological innovation for voltage control of power systems under deregulation of power supply industries and presents a new concept of an autonomous control system for the voltage and reactive power of power systems. Installation of distributed generation connected to distribution networks will significantly increase the short circuit capacity of distribution lines. Therefore, GIS underground substations in the center of a large city are required to enable replacement of circuit breakers with ones of greater capability and to reform GIS bus configurations. Furthermore, a more detailed forecast of local demand and operation data of distributed generators are required for the stable control of voltage and reactive power. This paper presents methods of on‐line autonomous forecasting for short circuit capacity and demand of local transmission and distribution lines, which are indispensable for voltage and reactive control under deregulation of electric power supply industries. © 2007 Wiley Periodicals, Inc. Electr Eng Jpn, 159(4): 27–37, 2007; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20450     

A Foundation of Quantum Channels with Super Additiveness for Shannon Information

This paper presents a review and some results on problems of super additiveness in quantum channel for Shannon information. Especially, how to investigate concrete systems showing super additiveness is discussed. It is verified that the concept of the conventional error correction scheme does not play an important role to demonstrate, at least, the super additiveness of quantum channel, and that rather one can apply them to only selection of code word states with desirable Hamming distance. Finally, some properties of quantum reliability function are given, which are useful to discuss the general property of coding with super additiveness. Received: September 29, 1998; revised version: July 9, 1999