Phenomenological level density model with hybrid parameterization of deformed and spherical state densities

A phenomenological level density model that has different level density parameter sets for the state densities of the deformed and the spherical states and the optimization of the parameters using experimental data of the average s-wave neutron resonance spacing are presented. The transition to the spherical state from the deformed one is described using the parameters derived from a microscopic nuclear structure calculation. The nuclear reaction calculation has been performed by the statistical model using the present level density. Resulting cross sections for various reactions with the spherical, deformed, and transitional target nuclei show a good agreement with the experimental data, which indicates the effectiveness of the present model. The role of the rotational collective enhancement in the calculations of those cross sections is also discussed.     

Quantification of ammonia-oxidizing bacteria populations in full-scale sewage activated sludge systems and assessment of system variables affecting their performance.

This study carried out quantification of ammonia-oxidizing bacteria (AOB) populations in 12 full-scale sewage activated sludge systems that were different in ammonia removals and treatment processes during three different seasons. Experiment was divided into 3 parts: 1) analysis of AOB communities by PCR-DGGE-cloning-sequencing of 16S rRNA genes; 2) development of four real-time PCR primer sets for quantification of the particular AOB of interest; and 3) quantification of AOB populations by using the newly developed real-time PCR primer sets. The results suggested that all the primer sets gave good reproducibility and specificity for PCR amplification with the detection limits of 10(2) copies/PCR reaction. Although the 12 systems were different in several aspects, one of the identified sequence types of Nitrosomonas oligotropha cluster was the dominant AOB in every system and every season studied. However, the other sequence type of this cluster was not significantly involved in ammonia removals in the systems. The occurrence of N. communis cluster in the systems seemed to depend on the remaining oxygen concentrations in the sludge floc and thus the activity of aerobic heterotrophs in the aeration tanks. N. europaea-Nitrosococcus. mobilis solely existed in one A20 system of which the influent contained twice the chloride concentrations than those of other systems.     

Changes in riparian forests in the Kushiro Mire,Japan, associated with stream channelization

The Kushiro Mire, the largest mire in Japan, presently faces the serious problem of turbid water flooding. Shortening of stream channels associated with agricultural development is a major cause of streambed aggradation. This aggradation reduces the carrying capacity of the channel, resulting in sediment laden water spilling over the wetlands in a flood event. Sedimentation progresses with repeated inundation by turbid water, which significantly alters the edaphic conditions, and thereby the composition and structure of marsh forests. Aggradation of the geomorphic surfaces with sedimentation lowers the water level, and increases soil particle size and nutrient status. This situation was clearly displayed in an ordination of canonical correspondence analysis. Among the environmental variables, water level was related most strongly to the pattern of a forest community. Salix species dominated the flood areas, which were characterized by a low water level, coarse sediment, and high electrical conductivity. Alnus japonica, the most common tree species in the Kushiro Mire, favors soil conditions represented by high water table and organic content. A. japonica adapts to a higher water level by developing lenticels with hypertrophied and adventitious roots, multiple sprouting and regenerates vegetatively. Basal areas (BAs) of A. japonica, however, seem to be limited by high fluctuations in water levels, which are amplified by channelization. This raises serious concerns for the integrity of the Kushiro Mire. It is important to implement a conservation plan from a watershed perspective because most problems originate in upper basins. Creating riparian buffer strips, sediment‐filtering wetlands, and restoring the original meandering course may slow down sedimentation in the mire, and thus help to restore the natural hydrological regime. Copyright © 2002 John Wiley & Sons, Ltd.     

Distribution of ammonia-oxidizing bacteria in sewage activated sludge: analysis based on 16S rDNA sequence.

This study carried out analysis of ammonia-oxidizing bacteria (AOB) communities in 12 sewage activated sludge systems standing in eight sewage treatment plants located in Tokyo. The systems were different in the treatment process configuration: anaerobic/anoxic/aerobic (A20), anaerobic/aerobic (AO), and conventional activated sludge (AS) processes. AOB communities were analyzed by sequences of 16S rDNA amplicons, which were separated by denaturing gradient gel eletrophoresis (DGGE) after specific polymerase chain reaction (PCR) amplification. The results demonstrated that low ammonium concentrations in the influents of the 12 sewage activated sludge systems resulted in the dominance of Nitrosomonas oligotropha-like sequences. Further, Nitrosomonas europaea- and Nitrosomonas cryotolerans-like sequences were recovered from only one A20 system of which the influent contained higher ammonium and chloride concentrations than those of other systems. Nitrosomonas communis-like sequences were found in every A20 and AO system, but mostly not found in every AS system. In summary, influent characteristics and treatment process configuration affected the AOB communities in the 12 sewage activated sludge systems.     

Laser patterning and morphology of two-dimensional planar ferroelastic rare-earth molybdate crystals on the glass surface

The laser-induced crystallization method is applied to pattern two-dimensional planar crystals consisting of ferroelastic β′-(Sm,Gd)₂(MoO₄)₃ crystals (designated here as SGMO crystals) on the surface of Sm₂O₃–Gd₂O₃–MoO₃–B₂O₃ glass. By scanning Yb:YVO₄ fiber lasers (wavelength: 1080 nm) continuously with a small pitch (0.7 μm) between laser irradiated parts, planar SGMO crystals with periodic domain structures showing different refractive indices are patterned successfully, and a high orientation of SGMO crystals is confirmed from micro-Raman scattering spectrum and second harmonic intensity measurements. It is found that the crystal growth direction is perpendicular to the laser scanning direction. This relation, i.e., the perpendicular relation, is a different from the behavior in discrete crystal line patterning, where the crystal growth direction is consistent with the laser scanning direction. The present study proposes the possibility of the control of crystal growth direction in laser-induced crystallization in glasses.     

The effect of sample size for estimating Rasch/IRT parameters with dichotomous items

Thirteen samples were randomly drawn from the normative database for the latest edition of Knox's Cube Test-Revised (KCT-R). Parameter estimates for the Rasch model and two and three parameter logistic models were derived and compared. Sample size influenced these estimates as might be expected. Rasch parameter estimates consistently showed the smallest values by sample size using a goodness of fit index.     

Molecular properties of mycelial aggregate-specific lectin of Pleurotus cornucopiae

By cloning and sequencing cDNA, the primary structure of a mycelial aggregate-specific lectin of Pleurotus cornucopiae was determined. The amino acid sequence was novel and elucidated unique properties of this lectin: It was composed of 373 amino acids, 33 of which constitute a signal sequence. The sequence of the mature lectin consisted of two homologous regions having five glycosylation recognition signals and six cysteine residues. However, the distribution of these elements in the two regions was biased. Expression of cDNA in Escherichia coli and Pichia pastoris revealed the requirement of glycosylation to produce the functional lectin. Gel filtration followed by gel electrophoretic analyses of the purified lectin showed that the active component moved faster than the bulk of the protein, suggesting that the most active lectin formed an oligomer of subunits through disulfide bonds. From these observations, a model for the structure of the active form of this lectin is proposed. Southern hybridization using the cDNA as a probe revealed the presence of several genes. The lectin gene was composed of five exons and five introns.     

Tracking control for an object in pushing operation

In this paper, we consider the problem of making a manipulator push an object on a flat floor with a point of contact to a desired position. A manipulator control method for the object to follow a planned trajectory is proposed. First, using the given distribution of frictional forces between the object and the floor, we find a particular point, named pseudo center, on which the motion of the pushed object can be approximated by the motion of a wheeled mobile robot on its center. Then, a control rule for the pushing operation is derived by applying a tracking control rule for a nonholonomic mobile robot at the pseudo center. This method makes it possible for the robot to perform the tracking control in the pushing operation. A simulation result shows the effectiveness of the proposed method. Finally, we present an approach for using a mobile manipulator to realize the pushing operation. Experimental verification of the proposed method was performed and the result is described. ©1997 John Wiley & Sons, Inc.     

Metals by Micro‐Scale Additive Manufacturing: Comparison of Microstructure and Mechanical Properties

Many emerging applications in microscale engineering rely on the fabrication of 3D architectures in inorganic materials. Small‐scale additive manufacturing (AM) aspires to provide flexible and facile access to these geometries. Yet, the synthesis of device‐grade inorganic materials is still a key challenge toward the implementation of AM in microfabrication. Here, a comprehensive overview of the microstructural and mechanical properties of metals fabricated by most state‐of‐the‐art AM methods that offer a spatial resolution ≤10 μm is presented. Standardized sets of samples are studied by cross‐sectional electron microscopy, nanoindentation, and microcompression. It is shown that current microscale AM techniques synthesize metals with a wide range of microstructures and elastic and plastic properties, including materials of dense and crystalline microstructure with excellent mechanical properties that compare well to those of thin‐film nanocrystalline materials. The large variation in materials' performance can be related to the individual microstructure, which in turn is coupled to the various physico‐chemical principles exploited by the different printing methods. The study provides practical guidelines for users of small‐scale additive methods and establishes a baseline for the future optimization of the properties of printed metallic objects—a significant step toward the potential establishment of AM techniques in microfabrication.     

1000MW单轴多缸汽轮发电机组的开发

为优化化石燃料电厂的建设投资,在保证高可靠性和高效率的同时,设备的布置应更加合理。因此１０００ＭＷ化石燃料汽轮发电机组的布置趋向于从双轴布置改为单轴置。本文介绍了日立公司开发的１０００ＭＷ单轴多缸汽轮发电机组部件技术的情况,目前,末级叶片分别为１０１６ｍｍ及１０９２．２ｍｍ的单轴多缸４排汽汽轮机已分别应用到６０Ｈｚ和５０Ｈｚ发电机上。