Cytochrome c-552 from gram-negative alkaliphilic Pseudomonas alcaliphila AL15-21T alters the redox properties at high pH

A soluble class I cytochrome c of an alkaliphile was purified and characterized, and its primary structure was determined. This is the first example of a soluble class I cytochrome c in alkaliphiles. Cells the alkaliphilic gram-negative bacterium Pseudomonas alcaliphila AL15-21(T) grown at pH 10 had a soluble cytochrome c content that was more than twofold that of strain AL15-21(T) cells grown at pH 7 under air-limited conditions. Cytochrome c-552, a soluble cytochrome c with a low molecular weight, was purified from strain AL15-21(T) cells grown at pH 10 under air-limited conditions. Cytochrome c-552 had a molecular mass of 7.5 kDa and exhibited an almost fully reduced state in the resting form, which exhibited absorption maxima at wavelengths of 552, 523 and 417 nm. In the oxidized state, it exhibited an absorption maximum at 412 nm when it was oxidized by ferricyanide, its isoelectric point (pI) was 4.3 and it contained one heme c as a prosthetic group. Cytochrome c-552 was autoreduced at pH 10, and the autoreduction was reproducible. On the other hand, the autoreduction of cytochrome c-552 was not observed at pH 7.0. When pH was increased from 7.0 to 8.3, its midpoint redox potentials (E(m) values) increased from +228 mV to +276 mV as determined by redox titrations, and from +217 mV to +275 mV as determined by cyclic voltammetric measurements. The amino acid sequence deduced by cytochrome c-552 gene analysis revealed that the sequence consists of 96 residues, including 19 residues as an amino-terminal signal peptide. A phylogenetic tree based on amino acid sequence indicated that the protein belongs to group 4, cytochrome c(5) in class I cytochrome c.     

Practical studies on rockfall simulation by DDA

In this paper,simulations of real rockfall by discontinuous deformation analysis (DDA) are conducted.In the simulations,the energy losses of rockfall are categorized into three types,i.e.the loss by friction,the loss by collision,and the loss by vegetation.Modeling of the energy loss using absolute parameters is conducted by the DDA method.Moreover,in order to verify the applicability and validity of the proposed DDA,field tests on rockfall and corresponding simulations of rockfall tests by DDA are performe...     

Dual-LED imaging for finger liveliness detection and its evaluation with replicas

Unattended fingerprint identification systems need to reject input attempts by a replica. Previously, we proposed detecting the color changes of a finger during an input action as a signature of liveliness. To improve its reliability, a dual-LED imaging system is investigated. It employs two LEDs with peak emissions at 530 and 630 nm to cover the spectral ranges where live fingers show characteristic changes. Using nine types of replicas and the live fingers of 42 participants, we have recorded and analyzed 153 input trials. The two groups of data are successfully separated by some defined criteria.     

Strong rhodium–niobia interaction in Rh/Nb2O5, Nb2O5–Rh/SiO2 and RhNbO4/SiO2 catalysts: Application to selective CO oxidation and CO hydrogenation

The extent of Rh–niobia interaction in niobia-supported Rh (Rh/Nb₂O₅), niobia-promoted Rh/SiO₂ (Nb₂O₅–Rh/SiO₂) and RhNbO₄/SiO₂ catalyst after H₂ reduction has been investigated by H₂ and CO chemisorption measurements. These catalysts have been applied to selective CO oxidation in H₂ (CO+H₂+O₂) and CO hydrogenation (CO+H₂), and the results are compared with those of unpromoted Rh/SiO₂ catalysts. It has been found that niobia (NbO_x) increases the activity and selectivity for both the reactions.     

PIXE spectrum analysis taking into account bremsstrahlung spectra

Continuous background appearing over the wide region of X-ray energy in the PIXE spectrum is very troublesome presence in the peak fitting. In the usual manner, the spectrum of continuous background is predicted as a function of polynomial and is subtracted from the X-ray spectrum. However, the parameters of the polynomial are determined with difficulty in the case that the continuous background exists under many peaks of characteristic X-rays. We calculated the production cross sections of continuous X-rays for several elements on the basis of the theories of quasi-free electron bremsstrahlung (QFEB), secondary electron bremsstrahlung (SEB) and atomic bremsstrahlung (AB), and obtained the continuous X-ray spectrum as a function of atomic number and X-ray energy. X-ray spectra of a standard sample and of a bovine liver sample were analyzed by a pattern analysis method assuming the reference spectra consisting of characteristic X-rays and continuous X-rays for each element. The results of analysis are quite satisfactory. By the present method, the PIXE spectra can be analyzed under little influence of the background subtraction, and it enables us a full auto-analysis of PIXE spectrum.     

Effect of Ti substitution on electrochemical properties of ZrNi alloy electrode for use in nickel-metal hydride batteries

Crystal structure and electrochemical properties of the Zr_1?xTi_xNi (0.05 ≤ x ≤ 0.5) alloys were investigated. X-ray diffraction spectra showed that the primary phase of all Zr_1?xTi_xNi alloys had the B33-type orthorhombic crystal structure, which was characteristic of ZrNi, and the unit cell volume of the primary phase linearly decreased with an increase in the x value. In the charge–discharge tests with the Zr_1?xTi_xNi alloy negative electrodes, the initial discharge curves for the alloys with x ≥ 0.3 had two plateaus. Both plateau potentials negatively shifted with an increase in the x value. The initial discharge capacity for the Zr_0.6Ti_0.4Ni alloy negative electrode was 349 mAh g^?1 at 25 mA g^?1 and 333 K, which was the highest in this study. The high-rate dischargeability and cycle performance were also improved by the partial replacement of Zr by Ti.     

Kinetic studies of thermally induced phase separation in polymer–diluent system

Thermally induced phase separation was studied by the light scattering in polypropylene/methyl salicylate system. Data could be well fitted with the linear Cahn theory for spinodal decomposition (SD) in the early stage of phase separation. Characteristic properties of the early stage of SD, such as an apparent diffusion coefficient and an interphase periodic distance, were obtained. The periodic distance ranged from 3 μm to 4 μm. The growth of the phase‐separated structure obeyed power‐law scaling in the later stage, and the structure factor could be scaled into a universal time‐independent form. Domain sizes obtained from the light‐scattering measurements were consistent with the optical microscope measurements. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 1028–1036, 2000     

Diffusive permeability of ionic solutes in charged chitosan membrane

The permeabilities of three kinds of solutes with similar sizes such as anionic benzenesulfonic acid, neutral styrene glycol, and cationic theophylline in the chitosan membrane were investigated. The chitosan membrane becomes cationic below its pKa value. Benzenesulfonic acid showed the highest permeability, whereas theophylline showed the lowest, although these solutes have almost the same size. This can be explained by the electrostatic attraction or repulsion between the solute and the membrane instead of the size exclusion effect. The permeabilities of benzenesulfonic acid and theophylline increased and decreased, respectively, with the decrease of pH from 7.4 to 4.0 because of the increase of the charge density of the membrane. Thus, the selectivity of benzenesulfonic acid to theophylline increased and reached about 30 at pH 4.0, in contrast to the selectivity of nearly unity in poly(vinyl alcohol) (PVA) membrane. The partition coefficients for three solutes showed the similar tendencies to those in the permeabilities. Contrary to the results of the permeabilities, the partition coefficients increased with the increase of the degree of the crosslinking in the membrane. This is probably due to the increase of the electrostatic interaction between the solute and the membrane brought about by the smaller mesh size and also due to the increase of the bound water fraction in the membrane. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 72: 397–404, 1999     

Generation of tree movement sound effects

This paper presents a method for automatically generating sound effects for an animation of branches and leaves moving in the wind. Each tree is divided into branches and leaves, and an independent sound effect generation process is employed for each element. The individual results are then compounded into one sound effect. For the branches, we employ an approach based on the frequencies of experimentally obtained Karman vortex streets. For the leaves, we use the leaf blade state as the input and assume a virtual musical instrument that uses wave tables as the sound source. All computations can be performed independently for each frame step. Therefore, each frame step can be executed on completion of the animation step. The results of the implementation of the approach are presented and it is shown that the process offers the possibility of real‐time operation through the use of parallel computing techniques. Copyright © 2005 John Wiley & Sons, Ltd.     

The role of ion-membrane interactions in fast and selective mono/multivalent ion separation with hierarchical nanochannels

Precise control over the nanofluid behavior of polyelectrolyte-based membranes is a primary step toward understanding the structure-morphology-property relationships to ultimately determine the mass transfer characteristics. In this study, a high-performance multistacked polyelectrolyte-based cation exchange membrane (CEM) with a heterogeneous structure and versatile surface chemistry was developed to achieve selective ion conductance. The self-assembled CEM can facilitate ion permeation with fluxes of 2.9 mol m⁻² h⁻¹ for K⁺ and 0.22 mol m⁻² h⁻¹ for Mg²⁺, reaching a mono/multivalent ionic selectivity of up to 13, outperforming mono/divalent fractionation when compared with state-of-the-art membranes. Molecular dynamic (MD) simulations illustrated the ionic transport trajectory in hierarchical channels with angstrom-scale cavities using multilayered CEMs. Both the experimental measurements and theoretical simulations indicated that ionic fractionation was associated with a large disparity in the energy barrier between mono/multivalent cations, which was the primary origin of the differences in the ion dehydration-rehydration processes in the angstrom-confinement membrane ion channels.