Overview of energy consumption and GHG mitigation technologies in the building sector of Japan

This paper outlines the energy consumption and greenhouse gas emission trends in the residential and commercial sectors in Japan. The results showed that the increase in residential energy consumption in Japan is mainly caused by the widespread use of heating equipment, hot water supply apparatus, and other household electrical appliances. On the other hand, it was indicated that the increase in commercial energy use is mainly due to the increase of the floor area of buildings, particularly hotels, hospitals, and department stores. The paper also describes political measures to promote energy conservation, including the building energy conservation standard, Comprehensive Assessment System for Building Environmental Efficiency, top runner programs, financial incentives, and the dissemination of the Cool Biz concept. Finally, the projections of CO₂ emissions until 2050 are presented.

Novel polymerization of divinyl monomer to polyester catalyzed with organocobaloxime

The polymerization of ethylene bis(-ethylacrylate) to polyester was catalyzed with benzyl(bisdimethylglyoximato)(pyridine)cobalt(III). Although the -ethylacrylic ester does not radically homopolymerize, radical addition to the carbon-carbon double bond yields the corresponding radical. This radical readily reacts with the cobalt(II) complex involved to form a carbon-cobalt bond. Dissociation of the generated bond accompanying fast -hydrogen elimination results in a new carbon-carbon double bond and the cobalt hydride which rapidly adds to the ethylacrylate moiety to form a carbon radical which may react with the cobalt(II) complex. Through the sequence of these reactions, the novel polyester linkage was expected to be formed. Actually, the cobaloxime catalyzed reaction competed with radical propagation, and the polymer consisted of the polyester linkage (32%) and the consecutive ethylacrylate units with two types of unsaturated pendant groups (68%).     

A 513‐ppi FFS‐mode LCD using technique for changing part of active layer of oxide semiconductor to transparent electrode

We have established a technique for changing part of an active layer of an oxide semiconductor (OS) to a transparent electrode in order to achieve an aperture ratio of 50% or higher and a bezel width of 1 mm in an fringe field switching (FFS) mode LCD panel with a high resolution of 513 ppi. Furthermore, we have prototyped an LCD panel by examining a driving mode that enables low‐frequency driving.     

Solid Solubility of Aluminum in O'-SiAlON

Energy -dispersive X-ray spectroscopy(EDXS) analysis was used to investigate the solid solubility of aluminum ( X value) in O -SiAlONs (Si_2-xAl_xO_1+xN_2-x)using transmission electron microscopy in the scanning transmission electron microscopy mode. Lattice parameter a of the O -SiAlONs increased with increased X value =0.16. The X value of 0.16 was the maximum of the X value in SiAlONs precipitated from a Si-Al O-N melt which was sasturated with aluminum and nitrogen at 1700^oC.The X value of O -SiAlONs measured by EDXS were smaller than those calculated on the assumption that the Si₂N₂O structure accommodated the total amount of the doped Al₂O₃ . This result suggested that a considerable amount of Al₂O₃ remained in grain boundaries as secondary phases.     

Surface Finishing of Alumina Ceramics by Means of Abrasive Jet Machining

Abrasive jet machining (AJM) is proposed as a new approach to surface finishing of structural ceramics. The effect of AJM on the material removal behavior of a commercially available alumina ceramic, and its effect on mechanical properties, was characterized and compared with identical material subjected to conventional finishing processes. Conventional grinding of the ceramic resulted in a surface that was dominated by intergranular fracture, whereas, during AJM, impact by the abrasives led to material removal in a manner resembling ductile behavior, and the resulting surface appearance was much smoother. A significant improvement in flexural strength was attained, compared with the strength of both the ground and lapped samples, because of an induced compressive residual stress.     

Synthesis of Porous Silicon Nitride with Unidirectionally Aligned Channels Using Freeze-Drying Process

Porous silicon nitride with macroscopically aligned channels was synthesized using a freeze-drying process. Freezing of a water-based slurry of silicon nitride was done while unidirectionally controlling the growth direction of the ice. Pores were generated subsequently by sublimation of the columnar ice during freeze-drying. By sintering this green body, a porous silicon nitride with high porosity (over 50%) was obtained and its porosity was controllable by the slurry concentration. The porous Si₃N₄ had a unique microstructure, where macroscopically aligned open pores contained fibrous grains protruding from the internal walls of the Si₃N₄ matrix. It is hypothesized that vapor/solid phase reactions were important to the formation mechanism of the fibrous grains.     

Fabrication of Elongated α-SiAlON via a Reaction-Bonding Process

A reaction-bonding process, which offers low sintering shrinkage and is a low-cost process, was applied to fabricate Y–α-SiAlON ceramics. The green compacts composed of Si, Y₂O₃, Al₂O₃, and AlN were nitrided and subsequently postsintered. Dense single-phase Y–α-SiAlON with elongated grain morphology could be achieved in the specimen postsintered at 1900°C. The material exhibited high hardness (1850 HV10) and high fracture toughness (5.1 MPa·m^1/2).     

Improvement of Mechanical Properties and Corrosion Resistance of Porous β-SiAlON Ceramics by Low Y2O3 Additions

Addition of Y₂O₃ as a sintering additive to porous β-SiAlON (Si_{6− z} Al _z O _z N_{8− z} , z = 0.5) ceramics has been investigated for improved mechanical properties. Porous SiAlON ceramics with 0.05–0.15 wt% (500–1500 wppm) Y₂O₃ were fabricated by pressureless sintering at temperatures of 1700°, 1800°, and 1850°C. The densification, microstructure, and mechanical properties were compared with those of Y₂O₃-free ceramics of the same chemical composition. Although this level of Y₂O₃ addition did not change the phase formation and grain size, the grain bonding appeared to be promoted, and the densification to be enhanced. There was a significant increase in the flexural strength of the SiAlON ceramics relative to the Y₂O₃-free counterpart. After exposure in 1 M hydrochloric acid solution at 70°C for 120 h, no remarkable weight loss and degradation of the mechanical properties (flexural and compression strength) was observed, which was attributed to the limited grain boundary phase, and with the minor Y₂O₃ addition the supposed formation of Y-α-SiAlON.     

Wind tunnel experiment for predicting a visible plume region from a wet cooling tower

We developed a new method for a wind tunnel experiment to predict a visible plume region from a wet cooling tower. The diffusion of water vapor and heat emitted from a cooling tower in a wind tunnel is estimated using a tracer gas. The instantaneous concentration of the tracer gas is measured using high-response flame ionization detectors. A moist plume-induced fog is assumed to be generated whenever the instantaneous specific humidity predicted from the concentration of the tracer gas at measured points is larger than the inferred saturation specific humidity. To confirm the validity of the present method, the results in the wind tunnel experiments are roughly compared with the observations obtained at the mechanical-draft cooling tower of the Benning Road plant. The results show that the visible plume length and height are nearly in agreement with observations and the present method has the capability to predict the visible plume region from the cooling tower.