Effects of freshness on ATP-related compounds in retorted chub mackerel Scomber japonicus

To examine the usefulness of measurement of adenosine triphosphate (ATP)-related compounds for estimation of the quality of canned and/or retorted fishes, we investigated the ATP-related compounds, in sashimi (for raw-eating)-grade and for-cooking-grade chub mackerel Scomber japonicus before and after retort process (121 °C for 30 min) by HPLC method. By the deterioration (storage time) and retort process, inosine monophosphate (IMP), an umami-taste compound, was decreased and inosine (HxR), hypoxantine (Hx) and the K-value, an index of fish freshness defined as the ratio of the sum of HxR and Hx to the sum of ATP-related compounds, were increased. By the retorting, the K-values of sashimi-grade, for-cooking-grade and unacceptable-grade meats were increased from 9.9%, 26.6% and 70% to 36%, 46% and 81%, respectively. These results suggest that the measurement of ATP-related compounds in retorted fish products may estimate the freshness in raw materials, the product quality and/or the good manufacture practices.     

Characterization of N-linked oligosaccharides attached to recombinant human antithrombin expressed in the yeast Pichia pastoris

We studied the structures of four N-linked oligosaccharide chains of the recombinant human antithrombin (rAT) expressed in the yeast Pichia pastoris. rAT was fully glycosylated at Asn 96 and Asn 155, whereas the glycosylation on Asn 135 and Asn 192 was partial. The glycosylation level on Asn 135 was only 12% and this reduction is assumed to be one of the reasons for a higher heparin-binding affinity of rAT than plasma-derived human antithrombin (pAT). In order to determine the sizes and electrostatic charges of the N-linked oligosaccharides, rAT was treated with PNGase F, and the reduced ends were labelled by pyridylamination followed by analysis using anion exchange and amide adsorption columns. The N-linked oligosaccharides were 78% neutral and 22% phosphomannosylated. The neutral oligosaccharides were thought to be Man(9-12)GlcNAc(2) as their major components. The phosphomannosylated oligosaccharides were then subjected to mild acid hydrolysis and/or digestion with alkaline phosphatase, and their charge shifts were analysed by the affinity to an anion exchange column. Among phosphomannosylated oligosaccharides, monophosphate diester type was predominant, whereas negatively charged diphosphate diester and monophosphate monoester types were minor components. The mannose residues at the non-reducing end(s) of Man(9-12)GlcNAc(2) were phosphomannosylated or phosphorylated and these are the major components. Because rAT is less negatively charged than pAT, which has disialyl biantennary N-glycans, it might be less repulsive to pentasaccharide-bearing anticoagulantly active heparan sulphate proteoglycan molecules exposed on the surface of the damaged vascular vessels.     

A Fluorescence‐Based Method for Cyanate Analysis in Ethanol/Water Media: Correlation between Cyanate Presence and Ethyl Carbamate Formation in Sugar Cane Spirit

Based on the fluorescence properties of 2,4‐(1H,3H)‐quinazolinedione, a product of the reaction between cyanate and 2‐aminobenzoic acid, a simple, sensitive, selective, and reproducible method for the cyanate analysis in aqueous ethanolic media is proposed. In this method, λ_exc and λ_em are 310 and 410 nm, respectively, and the limits of detection and quantification are 2.2 × 10^?7 and 6.7 × 10^?7 mol/L, respectively. Under optimal conditions (pH = 4.5, 40% ethanol), a concentration of 5.0 × 10^?6 mol/L cyanate can be determined in a single measurement, at a 95% level of confidence, with an uncertainty of ± 0.13 × 10^?6 mol/L. Cyanide, thiocyanate, chloride, nitrate, and sulfate ions, as well as urea and urethane in concentrations 1 × 10³ higher than that of cyanate do not interfere with the measurement. The methodology was applied to cyanate analyses in the different fractions of the sugarcane distillate and the data strongly suggest a correlation between the presence of urea in wine, and the cyanate and ethyl carbamate concentrations in the spirit.     

Preparation and electrochemical characteristics of LiNi1/3Mn1/3Co1/3O2 coated with metal oxides coating

LiNi_1/3Mn_1/3Co_1/3O₂ prepared by a spray drying method exhibited poor cyclic performance when it was operated at rates of 0.5C and 2C in 3–4.6 V. A metal oxide (ZrO₂, TiO₂, and Al₂O₃) coating (3 wt%) could effectively improve its cyclic performance at both 0.5C and 2C. Electrochemical impedance spectroscopy (EIS) studies suggested that both the surface resistance and the charge transfer resistance of the bare LiNi_1/3Mn_1/3Co_1/3O₂ significantly increase after 100 cycles, whose origin is mainly related to the change in both the particle surface and electrode morphologies. The presence of a thin metal oxide layer could remarkably suppress the increase in the total resistance (sum of the surface resistance and the charge transfer resistance), which was attributed to the improvement in good cyclic performances.     

Effect of spectral irradiance distribution on the outdoor performance of amorphous Si//thin-film crystalline Si stacked photovoltaic modules

Effects of spectral irradiance distributions on the outdoor performance of amorphous Si//thin-film crystalline Si stacked photovoltaic (PV) modules installed at Shiga-prefecture in Japan have been investigated. Outdoor solar spectrum measurements revealed that more than 95% of annual total spectra were blue-rich compared to AM1.5 standard solar spectrum. The outdoor performance of the modules had a higher spectral dependence than that of polycrystalline Si modules. Also, the peak of the histogram of annual spectral indexes well corresponded to the peak of the outdoor performance. The results indicate that the actual spectral irradiance distribution is important in designing stacked PV modules.     

Solar photocatalytic decomposition of Probenazole in water with TiO2 in the presence of H2O2

The photocatalytic decomposition of Probenazole in water using TiO₂/H₂O₂ under sunlight illumination is studied. The addition of H₂O₂ is effective for the improvement of photocatalytic decomposition of Probenazole with TiO₂. Furthermore, the operating conditions, such as photocatalyst dosage, temperature, pH, sunlight intensity and illumination time are also optimized. The kinetics of photocatalytic decomposition follow a pseudo–first–order kinetic law, and the rate constant is 0.129 min^?1. The activation energy (E_a) is 11.34 kJ/mol. The photocatalytic decomposition mechanism is discussed on the basis of molecular orbital (MO) simulation for frontier electron density.     

A study on the preparation of supported metal oxide catalysts using JRC-reference catalysts. I. Preparation of a molybdena–alumina catalyst. Part 1. Surface area of alumina

This is the first report of a group study on the preparation of a MoO₃/Al₂O₃ catalyst to find predominant preparation parameters for better and reproducible catalyst preparations. Variously prepared MoO₃/Al₂O₃ catalysts possessing 13 wt% MoO₃ were subjected to multiprong characterizations and catalytic tests. It was found that the surface area of the support was the most predominant preparation parameter for the dispersion of Mo oxide species; the dispersion increased as the surface area of the support increased. The formation of crystalline MoO₃ was observed at a surface Mo concentration higher than 3.2 Mo nm⁻². With sulfided MoO₃/Al₂O₃, it was established that the dispersion of Mo sulfide species increased with increasing surface area of the support and was in proportion to that of Mo oxide precursor species. The hydrodesulfurization activity of sulfided MoO₃/Al₂O₃ was proportional to the NO adsorption capacity. It is suggested that a homogeneous distribution of Mo oxide species is attained by an equilibrium adsorption technique. However, it was revealed that the surface area of the catalyst and Mo distribution were considerably modified by preparation parameters, such as drying processes, other than the surface area.     

Sensorless rotor position estimation at standstill of cylindrical brushless dc motors using opened phase voltage change caused by eddy currents

A rotor position estimation of a cylindrical brushless dc motor at standstill has been difficult to obtain. Therefore, torque control of a motor has been difficult at starting of the motor, and realization of the position estimation at standstill has been sought. This paper proposes a simple processing of a rotor for which nonmagnetic materials are pasted on the rotor surface. This processing generates an eddy current on nonmagnetic materials and causes an opened phase voltage change according to rotor position. The experimental results using a microcomputer show that it is possible to estimate rotor position of the cylindrical motor despite a standstill by using the opened phase voltage change. ©�1998 Scripta Technica, Electr Eng Jpn, 126(1): 52–60, 1999     

Gait and foot trajectory planning for versatile motions of a six-legged robot

This article deals with the problem of planning and controlling a radially symmetric six-legged walker on an uneven terrain when a smooth time-varying body motion is required. The main difficulties lie on the planning of gaits and foot trajectories. As for the gaits, this article discusses the forward wave gait of a variable duty factor and a variable wave direction. With the commanded body motion, the maximum possible duty factor is computed using the speed limit of the leg swing motion. Guaranteeing this maximum duty factor contributes to obtain higher stability. We prove the “continuity” of this forward wave gait planning algorithm adds the versatility to gaits planned. The foot trajectory planning algorithm dynamically generates a smooth foot trajectory as a function of the instantaneous body motions by modifying standard leg motion templates. The robot can negotiate an uneven terrain by modifying a vertical leg motion by a signal of tactile sensors on the foot. The experiments prove that the robot can successfully track smooth curves with body rotations on an uneven terrain, and thus prove the robustness of the algorithms. © 1997 John Wiley & Sons, Inc.     

Spectral transmittance of water and sodium chloride water solution as working substance for a solar pond

The transmission properties of water and sodium chloride water solutions with various salt concentrations were investigated. This paper concerns the measurement of the spectral transmittance and the calculation of the total transmittance for water and NaCl water solutions. The spectral transmittance of the NaCl water solutions over the infrared and nearby regions increased with increasing salt concentration for constant specimen thickness and air mass. The spectral transmittance was found to be useful for precisely calculating the thermal performance of a solar pond, and by using an effective absorption coefficient, a five-partition method dividing the wavelengths into five bands by which the total transmittance up to a water depth of 3 m could be calculated, was found to be important as a practical method of solar pond technology. © 1997 Scripta Technica, Inc. Heat Trans Jpn Res, 26(1): 1–15, 1997