Hydrogen production through dry reforming of biogas using a porous electrochemical cell: Effects of a cobalt catalyst in the electrode and mixing of air with biogas

This paper reports the performance of porous Gd-doped ceria (GDC) electrochemical cells with Co metal in both electrodes (cell No. 1) and with Ni metal in the cathode and Co metal in the anode (cell No. 2) for CO₂ decomposition, CH₄ decomposition, and the dry reforming reaction of a biogas with CO₂ gas (CH₄ + CO₂ → 2H₂ + 2CO) or with O₂ gas in air (3CH₄ +?1.875CO₂ +?1.314O₂ → 6H₂ +?4.875CO +?0.7515O₂). GDC cell No. 1 produced H₂ gas at formation rates of 0.055 and 0.33?mL-H₂/(min?m²-electrode) per 1?mL-supplied gas/(min?m²-electrode) at 600?°C and 800?°C, respectively, by the reforming of the biogas with CO₂ gas. Similarly, cell No. 2 produced H₂ gas at formation rates of 0.40?mL-H₂/(min?m²) per 1?mL-supplied gas/(min?m²) at 800?°C from a mixture of biogas and CO₂ gas. The dry reforming of a real biogas with CO₂ or O₂ gas at 800?°C proceeded thermodynamically over the Co or Ni metal catalyst in the cathode of the porous GDC cell. Faraday's law controlled the dry reforming rate of the biogas at 600?°C in cell No. 2. This paper also clarifies the influence of carbon deposition, which originates from CH₄ pyrolysis (CH₄ → C + 2H₂) and disproportionation of CO gas (2CO → C + CO₂), on the cell performance during dry reforming. The dry reforming of a biogas with O₂ molecules from air exhibits high durability because of the oxidation of the deposited carbon by supplied air.     

Oxidation of doped europium in BaMgAl10O17 by annealing studied by x‐ray‐absorption fine‐structure measurements

Abstract— We studied the influence of annealing in air on doped europium in BaMgAl₁₀O₁₇ by performing x‐ray absorption fine‐structure measurements. We determined the oxidation of doped divalent europium by annealing in air at over 500°C. The interatomic distance between the europium and the surrounding oxygen atoms was compressed by oxidation. It also appears that the oxidation process of europium is determined by the diffusion of oxygen into BaMgAl₁₀O₁₇.     

Photoinduced Formation of Small Gold Particles in Silica Gels

AuCl⁻₄ ions in sol-gel-derived silica gels (Au/silica gels) were photoreduced by ultraviolet light irradiation at room temperature. In the presence of ethylene glycol in the silica gels, small Au particles were effectively formed by the irradiation. When the storage temperature of the gels was increased in the dark after the irradiation, the surface plas-mon resonance absorption peak of the Au particles was shifted to longer wavelengths, indicating that the Au particles became large. At a storage temperature below 9°C, Au particles could not be observed in the silica gels. The apparent activation energy of Au particle formation was estimated to be 17. 3 kcal·tmol⁻¹.     

A 160-kDa Protein Is Essential for Hemocyanin-derived Melanosis of Prawn

ABSTRACT A purified 160-kDa protein, isolated from the cuticle of kurama prawn and named melanosis collaborating factor (MCF), was a key factor in promoting melanosis by a cooperative reaction with hemocyanin-derived phenoloxidase but hemocyanin itself was incapable of producing black pigment. The enzymatic activity of MCF in the body of the prawn was very stable against the process of freezing and thawing; the enzyme maintained more than 80% of its activity after 3 mo of storage at −2 5 °C. These results indicated that MCF, acting in conjunction with hemocyanin-derived phenoloxidase, played a crucial role in postharvest melanogenesis in prawn.     

2D Image Construction from Low Resolution Response of a New Non‐invasive Measurement for Medical Application

This paper presents an application of digital signal processing to data acquired by the radio imaging method (RIM) that was adopted to measure moisture distribution inside the human body. RIM was originally developed for the mining industry; we are applying the method to a biomedical measurement because of its simplicity, economy, and safety. When a two‐dimensional image was constructed from the measured data, the method provided insufficient resolution because the wavelength of the measurement medium, a weak electromagnetic wave in a VHF band, was longer than human tissues. We built and measured a phantom, a model simulating the human body, consisting of two water tanks representing large internal organs. A digital equalizer was applied to the measured values as a weight function, and images were reconstructed that corresponded to the original shape of the two water tanks. As a result, a two‐dimensional image containing two individual peaks corresponding to the original two small water tanks was constructed. The result suggests the method was applicable to biomedical measurement by the assistance of digital signal processing. This technique may be applicable to home‐based medical care and other situations in which safety, simplicity, and economy are important.     

Wake and aerodynamics loads in multiple bodies—application to turbomachinery blade rows

Two-dimensional, unsteady flow around bodies of complex geometry (or multiple bodies) at high Reynolds number is simulated using the vortex method. This method is modified to take into account the sub-grid scale phenomena through a second order velocity structure function model adapted to the Lagrangian scheme. The dynamics of the body wake is computed using the convection-diffusion splitting algorithm; the convection process is carried out with a Lagrangian Adams-Bashforth time-marching scheme and the diffusion process is simulated using the random walk method. The pressure distribution is obtained using an integral equation derived from the pressure Poisson equation, which was first developed for a single body. Results for the numerical simulation around a linear cascade of airfoils are presented. As the flow is periodic in the y direction, the discrete vortex shedding need only be considered for a reference airfoil. The flow characteristics around the NACA 65-410 series airfoils are calculated and comparisons are made with results available in the literature.     

Role of nitric oxide in rat nephrotoxic nephritis: comparison between inducible and constitutive nitric oxide synthase

Nitric oxide (NO), generated by inducible NO synthase (iNOS) in migrating macrophages, is increased in glomerulonephritis. This study investigates the effect of NO inhibition on rat nephrotoxic nephritis (NTN) to clarify the role of NO production in glomerular damage. NTN was induced in Sprague Dawley rats by an injection of an anti-glomerular basement membrane (GBM) antibody. Urinary nitrite excretion and nitrite release from kidney slices (5.47 +/- 1.19 versus 2.15 +/- 0.73 nmol/mg protein, NTN versus Control, P < 0.05) were increased in NTN on day 2. Glomerular macrophage infiltration and intercellular adhesion molecule (ICAM)-1 expression increased from day 2. iNOS expression was increased in interstitial macrophages. Glomerular endothelial cell NOS (ecNOS) expression evaluated by counting immunogold particles along GBM was suppressed (0.06 +/- 0.02 versus 0.35 +/- 0.04 gold/micron GBM, P < 0.0001). Glomerular damage developed progressively. NG-nitro-L-arginine methyl ester (L-NAME), which inhibits both iNOS and ecNOS and aminoguanidine (AG), a relatively selective inhibitor for iNOS, equally suppressed nitrite in urine and renal tissue. Glomerular ICAM-1 expression and macrophage infiltration were reduced by L-NAME, but not by AG. Expression of ecNOS was significantly increased by L-NAME (0.91 +/- 0.08, P < 0.0001 versus NTN), but slightly by AG (0.18 +/- 0.04). AG significantly and L-NAME slightly attenuated the glomerular damage at day 4. In conclusion, suppression of iNOS prevents glomerular damage in the early stage of NTN. Treatment by L-NAME reduces macrophage infiltration by suppression of ICAM-1 expression, which may be explained by an increase in ecNOS expression.