Effects of geometric imperfections on stress distributions in cooling towers

The effect of geometric imperfections on the static stress distributions in cooling towers is investigated. The antisymmetric imperfections as well as the axisymmetric ones are assumed to be localized band imperfections at some height in a tower. Analyses are carried out for the self weight, seismic lateral load and wind load. Hoop stress and meridional bending moment are strongly influenced and the quantitative effects are summarized in simple figures.     

Development of 1 kW class solid oxide fuel cell stack using anode-supported planar cells

We have developed a 1 kW class solid oxide fuel cell (SOFC) stack composed of 50 anode-supported planar 120-mm-diameter SOFCs. Intermediate plates, which exhibited negligible deformation under operating conditions, were placed in the stack to cancel out the cumulative error related to the position and angle of the stack parts. The stack provided an electrical conversion efficiency of 54% (based on the lower heating value (LHV) of the methane used as a fuel) and an output of 1120 W when the fuel utilization, current density, and operating temperature were 67%, 0.28 A cm⁻², and 1073 K, respectively. The stack operated stably for almost 700 h.     

A monolithic field emitter array with a JFET

This paper proposes a novel structure of the conical Si field emitters monolithically incorporating a vertical-type junction field effect transistor (JFET) and demonstrates the emission control in field emission from the emitters. The proposal has many attractive advantages in the display application and reliable fabrication, because the structure needs neither additional area for the JFET nor additional process except ion implantation. The experimental results of the emitters show excellent controllability and stability in the emission current     

Thermodynamics of antimony and arsenic in BaO–BaF2 melts

Since the interest in removing tramp elements from steels is increasing, one of the authors has reported the thermodynamic behaviour of P, Sn, As, Sb, Bi, Pb and Cu in CaO–CaF₂ melts under strongly reducing conditions. In this investigation, the BaO–BaF₂ system, which is more basic than the CaO–CaF₂ system, was chosen as a flux and the thermodynamic behaviour of As and Sb in BaO–BaF₂ melts was studied at 1300°C under reducing conditions. The partition ratios of arsenic between Cu–As and BaO–BaF₂ melts and of antimony between Ag–Sb and BaO–BaF₂ melts were measured as functions of the flux composition and the partial pressure of oxygen. Both partition ratios increase with an increase in the BaO content of the flux and with a decrease in the partial pressure of oxygen. The reactions for the removal of arsenic and antimony have been identified. The partition ratios of arsenic and antimony between carbon saturated iron and BaO–BaF₂ melts are estimated and the possibility of the removal of tramp elements from molten iron by using a BaO–BaF₂ flux is discussed.     

Examination of gas desorption by B4C resin for use in neutron scattering experiment

Gas desorption rates for several types of B(4)C resins were investigated using a throughput method. The investigation was particularly focused on determining the out gas composition, effects of dry air, grain size (density) effects on the gas desorption rates. It is found that water is the main component of out gas and that dry air can effectively reduce gas desorption.