Enhanced electrochemical activity and long-term stability of Ni–YSZ anode derived from NiO–YSZ interdispersed composite particles

Nickel oxide–yttira stabilized zirconia (NiO–YSZ) interdispersed composite (IC) particles were prepared by a mechanochemical processing using NiO and YSZ nanoparticles. Transmission electron microscopy (TEM) revealed that primally particles of YSZ (75 nm) and NiO (160 nm) were presented alternatively in the composite particles. Specific surface area (SSA) decreased from 8.6 to 7.1 m²/g during the mechanochemical processing. The SSA reduction suggested that the chemically bound NiO/YSZ hetero-interfaces were formed during the processing. Scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDS) visualized that the anode made from the IC particles consisted of three-dimensional textured structure of fine Ni and YSZ networks (grain size of them was approximately 500 nm) with 34 vol% of porosity. The anode demonstrated not only low polarization of 152 mV at 1 A/cm² even under the operation at 700 °C but also long-term stability for 920 h.     

Three-dimensional analysis for multilayer wiring in sub-half-micron devices

We discuss the improvement on a three-dimensional analysis of multilayer wiring process failure. We have applied this technique to Al-plug multilayer wiring and have successfully confirmed the precise failure point three-dimensionally without causing any physical or electrical damage to the wiring. We used four-layered wiring sample but it is applicable to thicker samples. This technique also enables a multi-dimensional evaluation of the cover margin and void condition of the via-holes. This technique also make it possible to evaluate a lot of via-holes simultaneously. This technique therefore makes failure analysis and evaluation easier and provides quick feedback concerning the multi-layered process development.     

Catalytic Hydrogenation of Fullerenes in the Presence of Metal Catalysts in Toluene Solution

The catalytic hydrogenation of fullerenes was studied in the presence of various metal catalysts in toluene solution under several conditions. Fullerenes were found to be catalytically hydrogenated in toluene solution in the presence of the Ru/carbon, Pdharbon, NiDiatomaceous Earth or Ptharbon as the catalysts. The reactivity of catalytic hydrogenation of the Ru/C was the highest for the among the used metal catalysts.     

A Remark on Intramolecular Transfer of an Injected Electron in C60 and C70

A simple analysis on the intramolecular transfer of an injected electron into C₆₀ and C₇₀ has been performed based on the concept of orbital interaction. This analysis contains the partitioning of each fullerene into three parts and the examination of the frontier molecular orbital interaction for propagation of an injected electron into the whole Cgo or C70 molecule. This electron transfer process is shown to be “one-way” from energetical point of view.     

Anomalous structure and phonon dynamics in La1.85Sr0.15CuO4

We performed X-ray diffraction and neutron scattering experiments on high quality single crystals of La_1.85Sr_0.15CuO₄. We found a forbidden (1,0,0) peak, which develops below the HTT-LTO structural transition temperature, and an anomalous behavior of acoustic phonon at (2,2,0). These results indicate that the structural anomaly has a strong relation with an superconductivity.     

Freezing of a water droplet due to evaporation—heat transfer dominating the evaporation–freezing phenomena and the effect of boiling on freezing characteristics

One of the authors has proposed a novel transport/storage system for the waste cold from the gasification process of liquefied natural gas (LNG), which consists of an evaporator, a cold trap, and a pipeline. In order to estimate the performance of this system, one should know the pressure in the evaporator, in which evaporation–freezing of a PCM occurs, and in the cold trap, as well as the pressure drop of the pipeline due to the flow of low pressure vapor of the PCM. In this paper, the cooling/freezing phenomena of a water droplet due to evaporation in an evacuated chamber was experimentally examined, and the heat transfer dominating the evaporation-freezing phenomena was investigated in order to estimate the pressure in the evaporator. From the results, it was shown that the water droplet in the evacuated cell is effectively cooled by the evaporation of water itself, and is frozen within a few seconds through a remarkable supercooling state, and that the cooling rate of the water droplets were dominated by heat transfer within the droplet under the abrupt evacuation condition. The later result means that, in order to obtain an ice particle by evaporation–freezing, the surroundings of the water droplet should be evacuated at the pressure as low as the saturate pressure of water at the maximum supercooling temperature of the droplet.     

Characteristics of an induction motor with reduced turns of terminal coils

The use of PWM inverters with high switching characteristics for the adjustable speed drive system causes an overvoltage with steep‐fronted waveform on the motor terminals. As this steep‐fronted transient voltage in inverter drive loads heavily on the terminal coils of motor winding, the insulation failure in the motor winding occurs mostly on the terminal coils. Therefore, it is reasonable to reduce the turns of terminal coils only and to increase the dielectric strength of interturn insulation. This paper presents a comparison of measured characteristics of normal induction motors and induction motors with reduced turns of terminal coils and also a comparison of the results measured and calculated by equivalent circuit. The appropriate rate of reduced turns of terminal coils is about 20%. © 2002 Wiley Periodicals, Inc. Electr Eng Jpn, 142(3): 49–56, 2003; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.10093     

Structure, magnetic and thermal properties of Gd2MnTiO6

A new perovskite compound Gd₂MnTiO₆ was synthesized and its crystal structure, magnetic and thermal properties have been investigated. The XRD patterns were refined by the Rietveld method and the refined lattice parameters with the monoclinic space group P2₁/n (No. 14) were a=0.5398 (2), b=0.5704 (2), c=0.7767 (2) nm and β=89.68 (2)°. The antiferromagnetic behavior was observed below 16.0 K and λ-type heat capacity was measured near this temperature.     

Removal of phosphate,magnesium and calcium from swine wastewater through crystallization enhanced by aeration

In order to confirm the possibility of removing P04-P, Mg and Ca from swine wastewater through artificial crystallization by aeration, laboratory and pilot scale experiments were carried out using actual swine wastewater. The pH of swine wastewater increased up to approximately 8.5 with continuous aeration, and a large part of the soluble PO4-P, Mg and Ca was crystallized. The ingredients of the crystals were estimated as MAP and HAP according to their mole ratio of NH4-N, PO4-P, Mg and Ca. The sedimentation speed of crystals in swine wastewater was about 3 m h(-1), and over 90% of them had settled after standing 1 h. A pilot scale reactor with the dual functions of crystallization by aeration and settling was operated continuously using actual swine wastewater, with aeration conditions of HRT 4.1 h and 26m3 airh(-1) m(-2) cross section (18m3 air h(-1) m(-3) volume). During 50 days of operation, pH at the aeration column held stable at 8.0, and 65% of PO4-P, 51% of Mg, and 34% of Ca were removed.