Development of multianode photomultiplier tube

We have developed a multianode photomultiplier tube (MAPMT) which has a sensitive cathode diameter of 36 mm and an anode with 88 segments. The position sensitivity of the tube was studied by using light from a LED and scintillation light from a scintillation-fiber bundle. We observed particle tracks for the first time by using a single photomultiplier tube.     

Phase Relationships and Physical Properties of Homologous Compounds in the Zinc Oxide-Indium Oxide System

Equilibrium phase relationships in the ZnO-In₂O₃ system were determined between 1100° and 1400°C using solid-state reaction techniques and X-ray diffractometry. In addition to ZnO and In₂O₃, nine homologous compounds, Zn _k In₂O _{k +3} (where k = 3, 4, 5, 6, 7, 9, 11, 13, and 15), were observed. Electrical conductivity and diffuse reflectance of the k = 3, 4, 5, 7 and 11 members were measured before and after annealing at 400°C for 1 h under forming gas (4%₂-96% N₂). Room-temperature conductivity increased as k decreased, because of increased carrier concentration as well as increased mobility. In general, transparency in the wavelength range of 450-900 nm increased as k increased. Reduction in forming gas resulted in increased conductivity and reduced transparency for all compounds measured. The highest room-temperature conductivity measured, 270 S/cm, was that of reduced Zn₃In₂O₆.     

Accumulation of pyrraline-modified albumin in phagocytes due to reduced degradation by lysosomal enzymes

Previous studies suggested that the interaction between proteins modified by advanced glycation end products (AGEs) and cells, such as macrophages, may be involved in diabetic angiopathy. Pyrraline is one of the AGEs and known to be elevated in plasma of diabetic rats and humans, and is present in vascular lesions of diabetic and elderly subjects. We examined whether modification of albumin by pyrraline influences its degradation by macrophage-like cell line, P388D1 cells. Degradation of pyrraline-modified albumin by these cells was diminished, causing accumulation of the albumin in these cells. The susceptibility of pyrraline-modified albumin to lysosomal proteolytic enzymes was reduced by approximately 40% in vitro, while lysosomal activity in the cells per se was not affected. This phenomenon was also observed when human monocytes were used instead of P388D1 cells. Our results suggest that accumulation of pyrraline-modified albumin in P388D1 cells is due to the reduced susceptibility of the protein to lysosomal enzymatic degradation. Such alterations in the interaction between AGEs-modified protein and phagocytes may contribute to angiopathy in elderly subjects and patients with diabetes.     

Capacitance-voltage characteristics of Semiconductor-Insulator-Semiconductor (SIS) structure

The ideal low- and high-frequency capacitance-voltage curves of a semiconductor(2)-insulator-semiconductor(1) (SIS) structure were first calculated with the insulator thickness, conductivity types and doping concentrations in semiconductor(1) and semiconductor(2) as parameters. The effects of fixed oxide charge and interface trap charge on the low and high frequency capacitance-voltage curves were also calculated. It was found that the fixed oxide sheet charge density with its centroid and the order estimation of the interface trap charge density with its effective type in addition to the insulator thickness, conductivity types and doping concentrations in semiconductor(1) and semiconductor(2) could be estimated from measured low and high frequency capacitance-voltage curves of an SIS structure.     

Ceramic Dental Molds for the Precision Casting of Titanium and Titanium Alloys: I, Relationship between Particle-Size Distribution of Aggregates and Mold Expansion

A new ceramic dental mold can cast excellent Ti restoratives by controlling expansion due to the oxidation of additive metal particles. The packing structure of the metal and aggregate particles in the mold can be considered a function of the size distribution of the aggregate grains. An investigation of the expansion mechanism reveals three different relationships of void fraction versus linear thermal expansion for the molds at the high temperature under which oxidation of the metal particles occurs. Room-temperature casting, favorable for making high-quality Ti restoratives, can also be achieved by precisely controlling both the amount of additive metal powder and the compositional distribution of aggregate grain sizes in the mold.     

A new blind deconvolution algorithm based on the probability distribution method

Blind deconvolution is a method of recovering transmitted signals from only received signals. The probability distribution method is one of the blind deconvolution methods. This method has two problems: it has slower convergence and its reliability is lower. In this paper, we propose a new algorithm for solving these two problems. The proposed algorithm is as follows. (1) It is based on the adaptive processing with each sample. (2) Kurtosis is adaptively estimated by recovered signals with each sample. (3) Cost function is decided by kurtosis. (4) Transmitted signals are recovered by received signals using decided cost function on the sample time. We confirm the validity of the new algorithm by computer simulation. © 2007 Wiley Periodicals, Inc. Electr Eng Jpn, 162(1): 56–65, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20317     

The selective sorption of D,L-amino acids by chemically modified chitosan gels and its application to liquid chromatography

The sorption of D ,L -amino acids, DNP-L -amino acids and dipeptides by N-octanoyl- and N-benzoyl-chitosan gels was investigated under various conditions. The results indicate that optical resolution of D ,L -amino acids by liquid column chromatography has been achieved, using the chemically modified chitosan gels as a stationary phase.     

Proposal of a Simple Method for Assessing the Susceptibility of Naturally Deposited Clay Grounds to Large Long-Term Settlement due to Embankment Loading

A simple method that utilizes the results of laboratory tests has been proposed for determining the susceptibility of soft clay grounds to large residual consolidation settlement due to embankment loading. It was found that there is a possibility of large long-term settlement if the sensitivity and compression index ratios of the clay material that constitutes the ground are equal to or more than 8.0 and 1.5, respectively. The compression index ratio is defined in this paper as the ratio (Cc/Ccr) of the steepest gradient of the compression curve of an undisturbed sample to that of the remolded sample. Through the SYS Cam-clay model, an elasto-plastic constitutive model that describes the actions of the soil skeleton structure, it was found that clays with large sensitivity and compression index ratios are characterized by initially highly structured soils and that decay/upgradation of the structure can easily occur due to plastic deformation. In addition, by following Schmertmann's graphic method for in-situ compression curve (1953), this paper proposes a method of deducing the in-situ initial conditions from the results of laboratory consolidation tests on undisturbed samples. These investigations revealed not only that large delayed settlement is facilitated in clays, which have higher degrees of structure and faster rates of structural decay, but also that the Δe method and other simple methods of predicting settlement may underestimate the amount of settlement.     

Concentration-dependent response of estrone-degrading bacterial community in activated sludge analyzed by microautoradiography-fluorescence in situ hybridization

Inefficient removal of estrone (E1) in wastewater treatment plants (WWTPs) causes feminizing effects in male aquatic creatures. As E1 is mainly removed by biodegradation, investigation of E1 degradation is important to determine better removal strategies. Using microautoradiography-fluorescence in situ hybridization (MAR-FISH), we demonstrated that the structures of [³H]E1-incorporating bacterial communities were different at different E1 concentrations applied to activated sludge. At 200 μg/L E1, almost all [³H]E1-incorporating cells were associated with either Betaproteobacteria or Gammaproteobacteria (60% and 40% of MAR (+) cells, respectively). The proportion of Betaproteobacteria and Gammaproteobacteria in the total number of [³H]E1-incorporating cells decreased as the concentration of E1 decreased. In contrast, the proportion of Alphaproteobacteria in the total number of [³H]E1-incorporating cells increased as the concentrations of E1 decreased. At the lowest applied concentration (540 ng/L), almost all the [³H]E1-incorporating cells were Alphaproteobacteria (96%). The results of MAR-FISH applied to sludge samples collected from various plant locations and activated sludge processes, and during different seasons also demonstrated the high contribution of Alphaproteobacteria to the entire E1-degrading bacterial community (50.4 ± 11% of the total number of [³H]E1-incorporating cells) at 1 μg/L E1. Since the E1 concentration in domestic wastewater is at sub-μg/L levels, the key E1 degraders in activated sludge of domestic WWTPs are probably be Alphaproteobacteria. All [³H]E1-incorporating Alphaproteobacteria were hybridized with probe ALF968. Few MAR (+) cells were Sphingomonadales. An E1-degrading bacterial community at low E1 concentration appeared to consist of diverse bacterial groups of Alphaproteobacteria. This study suggested that substrate concentration is an essential factor for revealing E1-degrading bacteria in complex communities.