Nanowire-structured titanate with anatase titania: Characterization and photocatalytic activity

Nanowire-structured titanate with titanium(IV) oxide (titania) was obtained by calcination of potassium ion-containing titanate nanowires prepared through alkali treatment of titania nanoparticles. The presence of potassium ions in the as-synthesized titanate nanowires was required for maintenance of the nanowire structure under the conditions of post-heat treatment. The crystallite structure, composition, morphology, specific surface area, pore volume distribution, and optical properties were found to be dependent on the temperature at which titanate nanowires were calcined. Photocatalytic activity was examined using three probe reactions: oxidative decomposition of acetic acid in an aqueous solution, oxygen liberation from an aqueous silver sulfate solution, and hydrogen liberation from an aqueous methanol solution in the presence of hexachloroplatinic acid as a precursor of photodeposition of platinum particles. Detailed characterization and results of photocatalytic activity tests revealed that titanate crystallites greatly contributed to the photocatalytic activities of the calcined nanowires except for photocatalytic hydrogen liberation. It was found that platinum was preferentially photodeposited on anatase crystallites rather than on titanate crystallites for hydrogen liberation.     

Leiomyoma of the bladder: report of two cases

We report 2 cases of leiomyoma of the urinary bladder. A 41-year-old female visited our hospital with the complaint of pollakisuria. A solid tumor of the urinary bladder was found by ultrasonography. A large shadow defect at the left-anterior wall was shown by drip infusion pyelography (DIP). Computed tomographic scan (CT) and magnetic resonance imaging (MRI) also revealed a large tumor. T1-weighted image revealed a homogeneous low intensity tumor and T2-weighted image disclosed heterogeneous low intensity tumor. Cystoscopy revealed a large submucosal tumor. Partial cystectomy was performed, and she has had neither recurrence nor metastasis for 36 months. A 32-year-old male was referred to our hospital with the complaint of macrohematuria. A solid tumor of the urinary bladder was found by ultrasonography. A shadow defect was not clearly detected by DIP. A large tumor was detected on the anterior wall by MRI. T1-weighted image showed a homogeneous low intensity tumor and T2-weighted image disclosed a high intensity tumor. Cystoscopy revealed a submucosal tumor on the anterior wall. Urine cytology did not suggest a malignancy. The biopsied specimens revealed only an inflammatory change in the mucosa. Partial cystectomy was carried out. He has had neither recurrence nor metastasis for 29 months. Histological diagnosis in both cases was leiomyoma of the urinary bladder.     

Numerical Analysis of Microcavities on Two-dimensional Photonic Crystals

We analyzed the frequency and quality factor of microcavities on a two-dimensional photonic crystal, using a Fourier series expansion method combined with perfectly matched layers (PMLs). Numerical examples are demonstrated and discussed to show that the resonant frequency and the quality factor Q values can be calculated by the present method using PMLs.     

Changes of trihalomethane formation potentials in the tone river

The changes of trihalomethane formation potentials (THMFPs) in the Tone River were examined. There were clear differences not in THMFPs but in THMFP loading (THMFP × flow rate) between the winter and the summer. The ratio of THMFP loading caused by artificial pollution was estimated. This ratio increased sharply with increases in watershed area and reached about 80% for a watershed area of about 2000 km² (with a population density of about 65 persons km²). Further, two formulas were obtained to estimate the THMFP and THMFP loading of the Tone River in the future.     

Robust Estimation of Three-Dimensional Motion Parameters from a Sequence of Image Frames Using Regularization

In this paper, we look at the issue of accurate estimation of the three-dimensional motion parameters of a rigid body from a sequence of synthetic images, and relate the effect of some parameters to the shape of an error function. We first consider the case where only a small set of corresponding points is identified and suggest that a technique called regularization improves the quality and stability of a solution. We then observe that, if more pairs of corresponding points are available, the error function becomes smooth and the solution stable. Finally, we try to improve the quality of estimation by considering more than two consecutive frames for a moving camera looking at a stationary scene, and summing the error functions obtained for any two consecutive frames. Surprisingly enough, this technique does not improve stability unless we use regularization again.     

Toxicity of Dangerous Prey: Variation of Tetrodotoxin Levels Within and Among Populations of the Newt Taricha granulosa

The ability to identify and accurately measure traits at the phenotypic interface of potential coevolutionary interactions is critical in documenting reciprocal evolutionary change between species. We quantify the defensive chemical trait of a prey species, the newt Taricha granulosa, thought to be part of a coevolutionary arms race. Variation in newt toxicity among populations results from variation in levels of the neurotoxin tetrodotoxin (TTX). Individual variation in TTX levels occurs within populations. Although TTX exists as a family of stereoisomers, only two of these (TTX and 6-epi-TTX) are likely to be sufficiently toxic and abundant to play a role in the defensive ecology of the newt.     

Numerical Analysis of Coupling between Two-Dimensional Conventional Dielectric Waveguides and Photonic Crystal Waveguide

A problem of coupling between conventional dielectric waveguides and a two-dimensional photonic crystal waveguide is analyzed, using the Fourier series expansion method combined with the absorbing boundary condition of a perfectly matched layer (PML). A novel structure for the input and output ends of the photonic crystal waveguide is proposed to increase the coupling efficiency. Numerical examples are demonstrated and discussed to validate the effectiveness of the proposed structure.     

Urban pedestrian mobility for mobile wireless network simulation

In order to perform precise evaluation of MANET applications in the real world, realistic mobility models are needed in wireless network simulation. In this paper, we propose a new method to create urban pedestrian flows (UPF) mobility scenarios, which reproduce the walking behavior of pedestrians in urban areas. From given densities of pedestrians observed at several points, our method derives a UPF mobility scenario that reproduces the walking behavior of pedestrians consistent with the observed densities, using linear programming techniques. We have developed a network simulator MobiREAL to design and evaluate MANET protocols and applications with this realistic mobility model. MobiREAL provides various functions and tools including a mobility model to describe the behavior of individual nodes, a GUI to assist with automatic generation of UPF mobility scenarios and a visualization tool. We have conducted some experiments using the MobiREAL simulator. Through the experiments, we have investigated the influence of node mobility on the performance of MANET protocols and have shown the usefulness of our method and the MobiREAL simulator.