Chiral recognition ability of oligopeptide derivatives consisting of glutamyl residues

The effect of the constituting amino acid residue [Glu(OBzl)] number on the chiral recognition ability was investigated. Chiral recognition sites were prepared from oligopeptide derivatives (constituting amino acid residue number = three–five) by adopting alternative molecular imprinting. It was made clear that with a constituting amino acid residue number of four, the tetrapeptide derivative of Glu(OBzl) is the best candidate material to generate a chiral recognition site among eight types of oligopeptide derivatives in the study. The affinity constant between Ac‐L ‐Trp and a chiral recognition site ranged from 3.4 × 10³ to 1.08 × 10⁴ mol^?1 dm³, depending on the number of Glu(OBzl) residues in an oligopeptide derivative. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 95: 1302–1309, 2005     

Position sensorless control of interior permanent magnet synchronous motor using extended electromotive force

Driving a permanent magnet synchronous motor (PMSM) requires the rotor position information to control the motor torque, and this is generally detected by mechanical position sensors such as an encoder or a resolver. However, these sensors increase the machine size and the cost of the drive, and reduce reliability of the system. Therefore, many papers about position sensorless drive method of PMSM have been published. This paper presents a position sensorless control of interior permanent magnet synchronous motor (IPMSM). A mathematical model of IPMSM using the extended electromotive force (EMF) in the rotating reference frame is utilized to estimate the rotor speed and position. This model has a simple structure integrating position information into the extended EMF term. Therefore, the sensorless control based on the mathematical motor model can be implemented simply. The estimation method proposed is based on the principle that the error of the current is proportional to that of extended EMF. This method was carried out using a 6‐pole, 400‐W, 1750 r/min test motor system. It was found that sensorless speed control was achieved from 80 r/min to 1800 r/min under 0 to 100%loads. © 2007 Wiley Periodicals, Inc. Electr Eng Jpn, 161(3): 41–48, 2007; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20406     

Convergence acceleration of the rational Runge-Kutta scheme for the Euler and Navier-Stokes equations

An efficient method-of-lines approach is presented for the Euler and Navier-Stokes equations. The governing equations are spatially discretized by a central finite-difference approximation. The rational Runge-Kutta scheme is used for the time integration. Attention is focused on improving the efficiency and accuracy of the solution. A remarkable improvement in the efficiency is achieved by adopting a combination of the present scheme with the residual averaging and multigrid (M.G.) techniques. The M.G. method and the high suitability of the present scheme to a vector computer partly reduce the computational load imposed on a numerical simulation with a finer grid. The steady-state convergence obtained with the scheme is comparable with those of diagonalized implicit approximate factorization schemes for inviscid and viscous flow equations. The reliability and accuracy of the scheme have also been improved by adopting the artificial dissipation terms scaled down to the minimum level required for stability. The facilities of the scheme are demonstrated in a series of numerical experiments for two- and three-dimensional transonic flows.     

Hyper-Kloosterman Sums and their Applications to the Coding Theory

The dual code of the Melas code is called the Kloosterman code. The weights of its codewords can be expressed by the Kloosterman sums, and are uniformly distributed with respect to the Sato-Tate measure. In this paper, the hyper-Kloosterman code C _m (q), a generalization of the Kloosterman code is defined, and the uniform distribution property is deduced using the hyper-Kloosterman sums when m is even and p− 1|m. Finally we discuss doubly-evenness for the weights in the binary case. It shows that we can construct infinitely many doubly-even codes in a non-trivial way. Received: October 30, 2000; revised version: February 28, 2001     

Rapid sensing of trace ionic substances with the novel porous monolith type ion exchanger

Biological and chemical sensor with a rapid response in microlevel test is required for health and environmental monitor. A novel sensing due to porous ion exchanger with three-dimensional acceptor has been first attempted to develop a high-performance sensor. This porous monolith type ion exchanger has an open-cellular monolith structure with 5–50-μm diameter pores. The trace amount of inorganic ions dissolved in aqueous solutions can be quantitatively determined with the impedance given by the monolith, which attracts and adsorbs the ions rapidly. We have succeeded in detecting ions with a concentration as low as 10⁻⁷ mol. The porous ion exchanger has a potentiality as a high-performance device for biological and chemical sensing. POLYM. ENG. SCI., 47:1666–1670, 2007. © 2007 Society of Plastics Engineers     

In situ hybridization studies of matrix metalloproteinase-3, tissue inhibitor of metalloproteinase-1 and type IV collagen in diabetic nephropathy

The effects of UV radiation on humans and animals are receiving increasing attention and much interest has recently been focused on the environmental effects of UV A and UV B. This study compares the in vitro effects of UV A and UV B on the clonogenic survival of two human skin keratinocyte cell lines, HaCaT which are immortal but not tumorigenic and HPV-G transfected keratinocytes which form non malignant tumours in nude mice. The effects were also studied on an EPC fish cell line. The aim of the work was to establish if similar initial and delayed survival responses occurred in both species. The cells were exposed to ultraviolet lamps emitting maximally at 365 nm (UV A) and 302 nm (UV B). Clonogenic survival was determined at appropriate times post exposure. Results for the initial survival curves show that the HaCaT and HPV-G cells did not show any appreciable difference in their response to UV A but the EPC cells were more sensitive at doses < 3000 Jm-2. The EPC cells were more sensitive to UV B at doses < 200 Jm-2 in comparison to the human HaCaT and HPV-G cells with the HPV-G cells showing the most sensitivity to UV B at doses > 200 Jm-2. The possible contribution of lethal mutations (delayed cell death) to the UV radiation response in the HaCaT and EPC cell lines was examined. The results showed that lethal mutations were expressed in the HaCaT cells following exposure to UV A and UV B but no lethal mutations were expressed in the EPC cells.     

An assessment of spent nuclear fuel storage demands under uncertainty

This paper attempts to draw quantitative prospects of spent nuclear fuel (SNF) management in Japan, with emphasis on uncertainty of storage needs for SNF up to the year 2050. In a medium term up to the years 2020–2030, the storage need for SNF can be projected with relatively high accuracy as it steadily increases up to the level of 5000 tonnes of uranium (tU), which requires timely deployment of storage facilities accordingly. In a longer term up to 2050, a number of aspects may give influences on the SNF management strategy, which are analyzed in different sets of scenario assumptions. The results of quantitative simulation runs showed that the storage need for SNF will increase up to the level of 10,000 tonnes of heavy metals (tHM) in the Base Case, while it would further grow to 20,000–25,000 tHM in the Risk Management Cases. Careful attentions should be given to the point that not just quantity but characteristics of SNF to be stored will differ significantly among the simulation cases, such as from lower to higher burnup, uranium and MOX (mixed oxide) fuels. The results imply Japan's SNF management may require elaborate strategies, which consists of effective and timely measures into the future.     

Several Geotechnical Design and Construction Issues with Akashi Strait Bridge

The Akashi Kaikyo (Strait) Bridge, one of the major bridges of the Honshu-Shikoku bridge network connecting the main island and the Shikoku island, is the world's longest suspension bridge with a center span of about 2,000 m. The bridge was constructed over the Akashi Strait and opened to traffic in 1998 after a construction period of about 10 years. The granite stratum in the Akashi Strait was very deep, while the granite stratum provides the foundations for the other long span bridges which have been constructed in Japan. Three of the four foundations had to be constructed on either a weakly cemented gravelly soil deposit or a sedimentary soft rock layer. The geological structure was carefully investigated and the geotechnical properties, in particular the strength and deformation characteristics of these geomaterial types, were carefully evaluated. To this end, a comprehensive series of advanced triaxial compression (TC) tests were performed on rotary core tube samples of sedimentary soft rock after it was found that the due design was not possible based on unconfined compression tests. Both CD and CU TC tests and cyclic undrained triaxial tests were performed on rotary core tube samples (30 cm in dia.) of the gravelly soil. Based on the data, the long-term and seismic stabilities of the foundations were evaluated. The importance of strain- and pressure-dependent nonlinear stress-strain behaviour at small strains, as well as accurate strain measurements in the laboratory stress-strain tests, was confirmed by analyzing the full-scale behaviour of the foundation during and after construction and comparing the back-calculated stiffness values with those obtained from laboratory stress-strain tests, pressure-meter tests, plate loading tests and field shear wave velocity measurements.     

Oxide ionic conductivities of apatite-type lanthanum silicates and germanates and their possibilities as an electrolyte of lower temperature operating SOFC

Electrical properties of La_xM₆O_12+1.5x (M = Si, Ge) as an electrolyte for solid oxide fuel cell (SOFC) have been investigated. In La_xSi₆O_12+1.5x and La_xGe₆O_12+1.5x of x = 8–11, the highest conductivities were achieved at x = 9.7 (La_9.7Si₆O_26.55) and x = 9.0 (La_9.0(GeO₄)₆O_1.5), respectively. The conductivity of La_9.0(GeO₄)₆O_1.5 was higher than that of La_9.7Si₆O_26.55 in a temperature region higher than 700 °C, and the conductivity (2.4 × 10⁻³ S cm⁻¹) of La_9.7Si₆O_26.55 at 400 °C was higher than that (8.3 × 10⁻⁵ S cm⁻¹) of La_9.0(GeO₄)₆O_1.5. The power densities of SOFC (H₂ | Pt | electrolyte (thickness: 1 mm) | Pt | O₂) using La_9.0(GeO₄)₆O_1.5 as an electrolyte were 14.3 mW cm⁻² (700 °C) and 24.0 mW cm⁻² (800 °C). The corresponding SOFC using La_9.7Si₆O_26.55 was found to work even at lower temperatures of 400 and 500 °C with power densities of 0.011 and 0.12 mW cm⁻². The SOFC (H₂ | Ni–Sm_0.2Ce_0.8O_1.9 | electrolyte | Ba_0.5Sr_0.5Co_0.8Fe_0.2O_2.5 | air) using 0.3 mm thickness La_9.7Si₆O_26.55 electrolyte gave the 3.4 mW cm⁻² power density at 500 °C.     

Anisotropic corrosion of iron in pH 1 sulphuric acid

Anisotropic corrosion behaviour of a single grain of pure iron in 0.05 mol dm⁻³ sulphuric acid (pH 1) was investigated by a simple polarization technique. Both corrosion potential and corrosion current were found to be dependent on crystallographic orientation of the iron grain. A high corrosion current flowed on a grain showing a relatively noble corrosion potential, although both cathodic and anodic Tafel slopes were independent of the orientation. It was shown that cathodic hydrogen evolution reaction (HER) governed the corrosion reaction on the iron grain. Covalent bonding of Fe and H and coverage of H on Fe seem to play important roles in the HER and anisotropic corrosion behaviour of pure iron.