High-rate capable organic radical cathodes for lithium rechargeable batteries

Poly(2,2,6,6-tetramethyl-1-piperidinyloxy-4-yl methacrylate) (PTMA) is the most common active material with a stable radical molecular structure used for lithium rechargeable cells. Because it is an organic active material, PTMA can be dissolved easily in various solvents. Using a solution of active material in the electrode making process, we formed an extremely large surface area between the active material and the conducting additive. The electrode has excellent power capability and can be charged and discharged in 1 min. We believe that this cell can be used like an electric double layer capacitor. We also believe that the cell, whose cycle life is good, retaining 89% of original capacity after 1000 cycles, can be put into practical use.     

Development of a damping analysis program for multi-generator powersystems

A numerical damping analysis program (DAMP), based upon the frequency scanning method, for application to multi-generator power systems has been developed. This program permits the determination of electrical and mechanical torsional damping at arbitrary frequencies with respect to the individual generator under consideration within such a multi-machine system. Therefore, this allows the quantitative frequency domain analysis of power swing and torsional oscillation with due consideration for the effects of mutual interference among the generators. In this paper, first, the basic algorithm, modeling method, and validity of the new program are indicated. Next, the effectiveness of the program is demonstrated through SSR and other types of analyses for multi-machine systems     

Dry formation of a fatty acid crystallized thin film and application as an electron beam resist

A crystalline fatty acid film was formed by vacuum evaporation and evaluated as an electron beam resist. For an actual process, a double-layer dry resist process using evaporated fatty acid and aluminium was proposed for fine pattern fabrication. A pattern of 4 μm lines and spaces was successfully fabricated.     

Infrared spectra of poly(ethylene 2,6-naphthalate) and some related polyesters

Infrared spectra of some poly(methylene terephthalates) and some poly(methylene 2,6-naphthalates) were compared. To interpret the spectral changes during drawing and heat treatment, the concept of rotational isomerism of the ? O-(CH₂)_M-O? part, which was fairly successful in poly(ethylene terephthalate) (C₂T), was tried to apply to the polyesters other than C₂T. Also, the bands originated from a benzene ring and from a naphthalene ring were distinguished. Poly(ethylene 2,6-naphthalate) (C₂N) has some bands behaving differently from those of other polyesters. This would be due to the existence of certain intermolecular interactions arised from tight packing of the molecules in the crystal of C₂N.     

Structures and physical properties of sputtered amorphous SiC films

Optical and electrical properties have been measured for amorphous SiC films prepared by rf sputtering in a pure Ar atmosphere with a sintered 6H-SiC target. The absorption edge E₀ determined from the relation of αhΝ = B(hΝ-E₀)² ranged from 1.45 to 1.80 eV depending on the film thickness and the substrate temperature. The room temperature electrical conductivity is in the range of 5.4×10⁻¹¹ and 1.4×10⁻⁵ Ω⁻¹cm⁻¹. The absorption edge decreases and the conductivity increases with increasing film thickness. The absorption edge shifts to shorter wavelengths (blue shift) and the conductivity decreases during annealing below 400‡C for 60 min, whereas the absorption edge shifts to the longer wavelength side (red shift) and the conductivity increases during annealing at 800‡C It is proposed that the two annealing processes cause structural changes in amorphous SiC films, one of which involves removal of defects or voids while the other involves rearrangement or rebonding of the component atoms.     

Reactions in Au/Nb bilayer thin films

The interdiffusion and intermetallic compound formation of Au/Nb bilayer thin films annealed at 200–400 °C have been investigated. The bilayer thin films were prepared by electron beam deposition. The Nb film was 50 nm thick and the Au film was 50–200 nm thick. The interdiffusion of annealed specimens was examined by measuring the electrical resistance and depth-composition profile and by transmission electron microscopy. Interdiffusion between the thin films was detected at temperatures above 325 °C in a vacuum of 10^-4 Pa. The intermetallic compound Au₂Nb₃ and other unknown phases form during annealing at over 400 °C. The apparent diffusion constants, determined from the penetration depth for annealing at 350 °C, are 3.5 × 10⁻¹⁵ m² s⁻¹ for Nb in Au and 8.6 × 110^7minus;15 m² s⁻¹ for Au in Nb. The Au surface of the bilayer films becomes uneven after annealing at over 400 °C due to the reaction.     

Evaluation of aseismic integrity in HTTR core-bottom structure III. Structural integrity of core support post component

Component testing of the core support post for the high temperature engineering test reactor (HTTR) was carried out to verify its structural integrity using full-scale and -scale models. The compressive fracture load was measured at room temperature under the conditions of post inclination up to about 1 degree, cyclic load up to 200 times and oxidation up to about 30% of oxidation weight-loss.In this paper, the effects of post inclination angle, cyclic load and oxidation weight-loss of this component on the compressive fracture load were discussed and the fracture load was compared with the design load of the HTTR.     

Removal of aldehydes by amino acids and their salts in ambient air

The removal of gaseous aldehydes by amino acids and by their sodium salts and hydrochlorides was studied in ambient air with the relative humidity of 30% at 25°C. Amino acid sodium salts, diamino acids, sodium p-aminobenzoate (PABANa), and o-aminobenzoate (OABANa), and p-aminobenzoic acid (PABA) on sepiolite, both having a carboxylato functionality (? COO^?) together with an amino (? NH₂) group, were highly reactive with aldehydes. In contrast, PABA which has free carboxylic acid functionality (? COOH: dimeric) was not so reactive with aldehydes. Normal amino acids and their hydrochlorides having ammonio (? NH₂⁺) and ? COO^? or ? COOH (dimeric) groups were less reactive with aldehydes. The reactivity was closely related to the degree of dissociation of carboxylate anion; as the degree of dissociation increases, the compound becomes more reactive. p-Aminobenzoic acid hydrochloride (PABA · HCl), having ? NH₃⁺ and ? COOH (monomeric) groups, was the most reactive (with ethanal) of all the amino acids and their salts examined. Amino acid sodium salts, diamino acid, PABANa, OABANa, and PABA on sepiolite are proved to be excellent removers of aldehydes in ambient air. Among them, PABA · HCl is particularly good for ethanal.     

Model‐free recursive LQ controller design (learning LQ control)

A new data‐based iterative self‐optimizing approach to practical design (learning/adaptive process) of the infinite‐horizon LQ regulator is proposed. Optimality is given by a certain orthogonality condition of response signals, and the global convergence of feedback gain is proved for MIMO systems by an expansion of the Riccati equation. The design is applied to stabilizing control and steady state error‐less control of physical systems. Copyright © 2004 John Wiley & Sons, Ltd.