An experimental investigation of minimum fluidization velocity at elevated temperatures and pressures

Minimum fluidization data at elevated temperatures and pressures are relatively scarce in the literature. This study was undertaken to provide some new data under these conditions. Minimum fluidization velocities at temperatures up to 800°K and pressures up to 5 MPa were measured for uniformly-sized glass beads with diameters between 0.2 mm and 4 mm in beds ranging in diameter from 30 mm to 50 mm. The experimental results are compared with a number of empirical correlations from the literature to determine the validity of the correlations under these elevated temperature and pressure conditions.     

Feasibility study on the applicability of a diffusion-welded compact intermediate heat exchanger to next-generation high temperature gas-cooled reactor

The development of an intermediate heat exchanger (IHX) transferring high temperature heat to a process heat application is of prime importance for a next-generation high temperature gas-cooled reactor (HTGR). The IHX needs high structural integrity and reliability over 900°C for a long duration. A plate fin type compact heat exchanger (PFCHX) has a large heat transfer area per heat exchanger volume and is expected to be used as the IHX. However, the brazing for connecting fins and plate is not reliable when existing PFCHXs are used in a high temperature condition for a long time. We have proposed a concavo-convex plate type compact heat exchanger (CPCHX) which consists of concavo-convex plates (CPs) welded by solid state diffusion and made of nickel-based superalloy Hastelloy XR. In our study, first, an optimized condition for the solid state diffusion welding between the CPs of the CPCHX was found by experiments using test pieces made of Hastelloy XR. Second, small-scale diffusion-welded CPCHXs were designed, manufactured and installed in a test loop to investigate the reliability of the diffusion welding. As a result of leakage tests, it was confirmed that the reliability of the solid state diffusion welding between the CPs of the small-scale CPCHX is sufficient. A thermal performance test revealed that the thermal conductance of the small-scale CPCHX was better than calculated. In addition, a design study for the CPCHX was performed to investigate the feasibility of the diffusion-welded CPCHX to the IHX in a next-generation HTGR.     

Pulse‐width modulation with current uniformization for AM‐OLED micro‐displays on Si LSI chips

We have developed pulse‐width modulation (PWM) with current uniformization for active‐matrix organic light‐emitting diode (AM‐OLED) micro‐displays on Si large‐scale integration (LSI) chips. This driving method can simultaneously solve luminance unevenness and image sticking due to characteristic deviations and degradations of driving transistors and OLEDs. With the use of circuit simulation, it is verified that the PWM with current uniformization (PWM‐CU) can simultaneously achieve precise gray scale and exceedingly improve luminance uniformity. Moreover, an actual panel is designed and fabricated, where the OLEDs are layered on the Si LSI chip. It is found that the luminance uniformity can be improved within 2% to 3%. It is meaningful that the correct images can be displayed using the PWM‐CU for the first time for AM‐OLED micro‐displays on Si LSI chips.     

Scalability and homogeneity of slot die‐coated metal oxide semiconductor for TFTs

An indium oxide‐based precursor solution has been developed by spin coating method. In order to apply this material to mass production, material, process, and equipment optimizations for slot die coating have been implemented. Slot die coating is a cost‐effective and scalable process and already applied to photoresist materials in the display industry. The indium oxide‐based precursor solution has been coated on bare glasses and thin‐film transistor substrates by a mass production‐type slot die coater. Mobility of over 10 cm²/Vs is achieved for the first time for a large area at an annealing temperature of 350 °C. The homogeneity of the film will be presented.     

Refractive Index Dispersion of Sodium Magnesium Silicate Glasses for Ultralow-Loss Fibers

The refractive index dispersion and infrared (IR) reflection spectra of soda magnesium silicate glasses with low Rayleigh scattering were measured to evaluate their potential for use in fabricating ultralow-loss fibers. The zero-material dispersion wavelength (λ₀) was found to be around 1.5 μm, which is one of the key wavelengths in the present telecommunication system. The compositional dependence of λ₀ was found to relate to the population of nonbridging oxygen. Since the oscillation strength and frequency of the Si—O stretching vibrations of the glasses were found to be smaller than those of silica glass, their IR absorption loss was considered to be less than that of silica glass. The minimum loss due to the intrinsic factors, Rayleigh scattering and IR absorption, was estimated to be 0.06 dB/km at 1.6μm.     

A neolignoid feeding deterrent againstLuehdorfia puziloi larvae (lepidoptera: Papilionidae) fromHeterotropa aspera,a host plant of sibling species,L. japonica

A feeding deterrent against larvae of a papilionid butterfly,Luehdorfia puziloi (Parnassiinae), a specialist onAsiasarum plants (Aristolochiaceae), was isolated from another aristolochiaceous plant,Heterotropa aspera. Antifeedant activity was exhibited by then-hexane-soluble fraction that proved to contain at least two active components. One of the deterrents was identified as a neolignan compound, asatone. The concentration of asatone inH. aspera was estimated at approximately 225 ppm, and larval feeding ofL. puziloi was significantly deterred at concentrations over 90 ppm. By contrast, asatone was not detectable (< 1 ppm, if any) in its host plant,Asiasarum sieboldii.     

Solubility of butane and isobutane in molten polypropylene and polystyrene

The solubility of butane and isobutane in molten polypropylene (PP) and polystyrene (PS) was measured at pressures up to 3 MPa and along four isotherms from 438 to 483 K for PP and from 348 to 473 K for PS. The solubility increased with increasing pressure and decreasing temperature. At 438 K and 2 MPa, the solubilities of butane and isobutane in PP were 0.15 and 0.11 g‐gas/g‐polym, respectively. At 423 K and 2 MPa, the solubilities of butane and isobutane in PS were 0.08 and 0.05 g‐gas/g‐polym, respectively. Solubility could be correlated with the Sanchez‐Lacombe equation of state with temperature‐dependent binary interaction parameters to within 4.4% average relative deviation. Henry's constant for these gases in the PP and PS obtained in this work were used to determine correlation equations along with literature data. Polym. Eng. Sci. 44:2083–2089, 2004. © 2004 Society of Plastics Engineers.     

Microstructure and material properties of an Al–Cu alloy provided by the Ohno continuous casting technique

The specific objective in this work is an exploration of the material properties produced by a recently developed continuous casting technique. The study focuses on an Al–Cu alloy provided by the Ohno continuous casting process. The experimental approaches give rise to unusual microstructural characteristic in the cast samples, namely a fine lamellar eutectic structure with unidirectional growth along its axial direction together with a regularly oriented lattice structure. Such microstructural characteristics significantly increase the tensile and fatigue properties.     

New Members of the Pb-based 1222 Superconductor Containing Phosphorus: (Pb0.75P0.25)Sr2(Ln1.9?x Ce x Sr0.1)Cu2O z (Ln=Sm and Gd)

We previously reported on the synthesis of new Pb-based 1222 superconductor containing phosphorus in the (Pb_0.75P_0.25)Sr₂(Eu_1.9−x Ce _x Sr_0.1)Cu₂O _z system. Recently, we have discovered new members of the Pb-based 1222 superconductor containing phosphorus in the (Pb_0.75P_0.25)Sr₂(Ln_1.9−x Ce _x Sr_0.1)Cu₂O _z (Ln=Sm and Gd) systems. In each system, it is found that the samples of almost the single 1222 phase can be obtained for a wide composition area of 0.3≤x≤1.0. After annealing under 143 atm O₂ atmosphere at 400 °C, each sample of Ln=Sm and Gd with x=0.3 is found to show an onset of resistivity-drop at about 28 K and at about 24 K, respectively. Moreover, each samples of Ln=Sm and Gd is found to show an onset of diamagnetic signal at about 25 K and about 22 K, respectively. From these facts, these samples of Ln=Sm and Gd are found to be new members of the Pb-based 1222 superconductor containing phosphorus.