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In order to study the microstructural evolution of cascade and interaction between cascade and He, the irradiations were carried out using ion accelerator to introduce the cascade and a high resolution high voltage electron microscope (1250 kV) to irradiate with electrons and for in situ observation. A lot of small cascades were introduced by Ni+-ion irradiation at room temperature, and due to following electron irradiation at higher temperature interstitial type dislocation loops were nucleated from the interstitials rich zone and grew. On the other hand the cascades transferred to SFTs during annealing above 623 K. When He atoms were previously implanted, He bubbles were formed at cascades. Also segregation of solutes and precipitates were induced at cascades during electron irradiation.

The effect of installing an escape vent on catch and size of the mud crab Scylla olivacea (Herbst) in collapsible pots was investigated. Initially, the escape behavior of crabs was observed in a pond in the laboratory when the rectangular-shaped escape vents were located at five different positions on the pot; the aim being to determine the most suitable position for escape vents. The study also included field trials to assess the effect of different sizes of escape vents (3 cm × 4 cm, 3 cm × 4.5 cm, 3 cm × 5 cm, 3 cm × 5.5 and 3 cm × 6 cm) and was carried out in a commercial fishing ground in Klong Ngao mangrove swamp, Ranong Province, Thailand (latitude 9°51′ to 9°56′N and longitude 98°31′ to 98°37′E). The escape vent located at the bottom on the side panel of the pot produced the highest number of escapees. The selectivity curve of the 3 cm × 6 cm escape vent allowed more small crabs to escape than other vent sizes. Further, the percentage of non-target species catches decreased as the size of the escape vent increased. The 3 cm × 6 cm escape vent was the most effective for releasing undersized S. olivacea . The vents did not affect the rate of mud crab entry into the pot.

Oxygen consumption and ammonia excretion rates of three abalone species, Haliotis discus discus, H. gigantea, H. madaka and their hybrids were measured at 20 °C by incubating for 3 h under dark and light (N = 9–13 for each species and hybrid). Animals were fasted before and during the experiment and measurements were made first under dark followed by light on the next day. The rates increased with the increase in body weight and were higher under light than dark. On average, H. discus discus had higher oxygen consumption (DD; dark = 0.039, light = 0.04 ml/g/h) than H. gigantea (G; D = 0.033, L = 0.036) and H. madaka (M; D = 0.034, L = 0.035); the hybrids had varied patterns with respect to their parental species [DD × M (D = 0.032, L = 0.038); M × DD (D = 0.03, L = 0.038); G × DD (D = 0.035, L = 0.04) and DD × G (D = 0.03, L = 0.034), mother first]. M (0.261, 0.298 μmol/g/h) had the highest ammonia excretion rate while G (0.162; 0.264) and DD (0.229; 0.232) had the lowest under dark and light, respectively. The hybrids had varied patterns in comparison with their parents (DD × M = 0.247, 0.32;M × DD= 0.177, 0.28; DD × G = 0.249, 0.364 and G × DD = 0.116, 0.155). The O/N ratios under both conditions in all species and hybrids indicated that they had carbohydrate dominated metabolism. Results demonstrated physiological variability among the species and hybrids indicating necessity of different strategies for their management and aquaculture.

The Japanese bitterling Tanakia tanago (Cyprinidae) is on the verge of extinction in the wild, placing great importance on captive breeding programs for current conservation of the species. However, the loss of genetic diversity during captive breeding is an ongoing matter of concern. Since some captive populations have been almost monomorphic in mitochondrial DNA (mtDNA), this hampers assessments of their genetic diversity during captive breeding. To more accurately assess their genetic diversity, one wild and three captive populations were examined using amplified fragment length polymorphism (AFLP) markers. Estimates of average heterozygosity and nucleotide diversity ranged 0.0479–0.1920 and 0.0023–0.0088, respectively, enabling comparison of genetic diversity among the wild and captive populations, and among year-classes of captive populations. Significant differences in numbers of amplified fragments and proportions of polymorphic fragments were observed among year-classes of all populations. The indices of genetic diversity calculated from AFLP seemed to be, however, less sensitive to weak bottlenecks. No continuous decrease in genetic diversity in nuclear DNA was detected in presently captive populations. This supports the possibility of re-introduction of the captive populations into the original habitats, although survival and reproductive ability in the wild must be taken into consideration.

Pulsed spallation neutron sources for the materials structure science are severely influenced by beam impact and radiation damage. We have developed the materials strong to these influence since 2004. In this paper, recent topics are described concerning the development of intergranular corrosion (IGC)-resistant austenitic stainless steel for target vessel and window, radiation-resistant ultra-fine grained tungsten materials (W–TiC) for a solid target, CrN film on a tungsten target by means of a molten-salt method, surface treatment of stainless steel for pitting damage in mercury target. Bubble behavior at the interface of mercury and window glass was also observed to clarify the phenomenon of the pitting damage.

For the purpose of the prediction of casting structures, heterogeneous nucleation rate in the undercooled melt of solififying Al-Si alloys were evaluated by comparing experimentally observed macrostructures of solidified ingots with numerically simulated ones. Molten alloys were unidirectionally solidified in an adiabatic mold from a steel chill block located at the bottom of the mold. In the experiment, columnar to equiaxed transition (CET) was observed. A numerical simulation for grain structure formation of the sample ingots was carried out using a cellular automaton (CA) method, and heterogeneous nucleation rate in the solidifying alloys were evaluated by producing the similar structures to experimental ones. An attempt was made to predict the grain structure of conventionally cast ingots using the evaluated heterogeneous nucleation rate. However, the simulation could not predict the structure of ingot with low superheat due to crystal multiplication near the mold wall. The crystal multiplication mechanism, so-called "Big Bang mechanism", was introduced into the simulation and the simulation could predict the grain macrostructure composed of columnar and equiaxed crystals that were similar to experimentally observed one.

Atomic and electronic structures of interfaces in an internally oxidized Pd/ZnO system were studied by high-resolution transmission electron microscopy (HRTEM) and electron energy-loss spectroscopy (EELS). {0001}ZnO polar planes tend to be parallel to the interface. A ZnO precipitate was terminated by an oxygen surface at one end of the precipitate and by a zinc (0001) surface at the other end of the precipitate. A pre-edge peak was detected only in O-K energy-loss near-edge spectra (ELNES) acquired from the oxygen-terminated interface. Ab initio calculations indicated that the origin of the pre-edge peak could be attributed to the strong chemical bonding and hybridization of Pd-d and O-p orbitals at the oxygen-terminated polar interface.

Hybridization among abalone species has been suggested as a possible means to increase their growth rates for aquaculture. As a first step to test the usefulness of the hybrids of Japanese abalone species (Haliotis discus discus, Haliotis gigantea and Haliotis madaka) for aquaculture, we characterized the genetic background and gonad development of hybrids that were produced by artificial insemination. The hybrid status of the resulting offspring was confirmed by assaying 14 allozymes and by RFLP analysis of the 16s rRNA and cytochrome oxidase I (COI) regions of mtDNA using 13 restriction enzymes. Histological examination of the gonads of the hybrids was conducted in comparison with those of the parental species. Cross-breeding among the three species was conducted successfully in all combinations although with lower fertilization rates (means of 1.3-60.8%) than the parental species (34.3-90%). Crosses between H. discus discus and H. madaka had higher fertilization rates (22.4-60.8%) than those involving H. gigantea (1.3-19.9%). The hybrids were ascertained by the presence of both parental genotypes at the LDH-A, ME-A, MDH-A and GPI loci. The maternal origin of the hybrid mtDNA was confirmed by digestion with DdeI, TaqI, HpaII of the COI region. No polymorphism was observed in the 16S rRNA region. The hybrids had gonadal development and maturity stages similar to the parental species up to fully mature oocytes and sperm. They spawned upon stimulation and produced viable offspring with high fertilization rates and successful development to the juvenile stage in back- and homologous hybrid crosses.

The effects of fast neutron irradiation conditions have been investigated by focusing on the mechanical properties of 11Cr-0.5Mo-2W, Nb, V ferritic/martensitic (F/M) stainless steel (PNC-FMS) and 10.5Cr-1.5Mo, Nb, V F/M stainless steel (HT9M) claddings, especially tensile and transient burst properties. These two F/M claddings were irradiated at temperatures from 693 to 833K to 42.5 dpa (displacement per atom) in the experimental fast reactor JOYO using the PFB090 fuel test subassembly. Post-irradiation tensile and temperature-transient-to-burst tests were carried out for defueled cladding specimens. The results of mechanical tests for the PNC-FMS cladding showed that there was no significant degradation in tensile and transient burst strengths even after fast neutron irradiation. On the other hand, the strength of the HT9M cladding tended to shift to lower values than those of as-received specimens. The differences in tensile and transient burst strengths between the two claddings were attributed to mart...

The formation process of intermetallic compound under Ni+ion implantation into pure Al was studied at lower temperature below room temperature. Ion implantation was carried out using 250KeV ion accelerator. Cascade damage was introduced Ni+ions implantation at 223K without new phase nucleation. However, when Ni+ions were implanted at room temperature, the grown larger plate-like phases were observed during implantation up to 1x1017 Ni+/cm2. Ni concentration in Al matrix and newly formed phase were 0.3-0.5 and 8.5-13.3at%,respectively. It was identified that the formed phases were close to the ordered orthorhombic structure of Al3Ni type. It was also confirmed from observation with high resolution HVEM that these phases grew with continuous ion implantation. Thus it was clarified that cascades act as preferential nucleation site for intermetallic compound, and the phases nucleated at cascades coalesce in the growth process of each phase during continuous implantation through ion irradiation enhanced diffusion.

An atomistic study of radiation-induced amorphization in the NiTi intermetallic compound was performed by using in-situ high-resolution high-voltage electron microscopy and molecular dynamics in conjunction with image simulations. Both theoretical and experimental results show that metastable nanometer-size inherent atomic clusters form and disappear during irradiation, so that a spatiotemporal fluctuation under amorphization is induced. The random formation and annihilation of such inherent nanoclusters are believed to be responsible for these fluctuations, which appear to be related to transitions between the ideal glass state and metastable, unrelaxed states in an energy-dissipative system under irradiation.

A species of squat lobster, Munidopsis kermadec new to science is described and illustrated from a hydrothermal vent area in Brothers Seamount, Kermadec Volcanic Arc, Southwest Pacific Ocean. It is distinguished from the allied Munidopsis lauensis, by the shape of rostrum, the erectness of eye spines, structure of the sixth abdominal segment and dactyl morphology of P2-4. This new record increases the number of species of Munidopsis reported from Southwest Pacific vent fields to five. A key is provided to distinguish the vent associated Munidopsis. New records of M. lauensis and M. sonne from Brothers Seamount are also reported here and this extends their distribution further south to the western Pacific. The habitat of the new species is briefly described. A note on the Munidopsis diversity in West Pacific vent fields is also provided.

Stocking of exogenous, hatchery-reared white-spotted charr Salvelinus leucomaenis has been conducted throughout much of their range in Honshu Island, Japan, to increase angling opportunities. Although the native char populations are thought to have declined because of hybridization with introduce fish, their distribution and genetic status have been uncertain. Fine population structures of charr in the upper Tone River drainage were examined using mitochondrial DNA and microsatellite analyses so as to clarify the presence of native populations. One common mtDNA haplotype was detected in all populations in the Ohashi River and Watarase River, and four and one tributary populations were monomorphic for such haplotypes, respectively. However, several haplotypes, considered to have originated from stocked hatchery fish, were observed in the stocked and the remaining populations. Judging from the genetic integrity over a fine geographic scale, the former were considered as indicative of native populations and the latter as admixtures with hatchery fish. Comparisons of genetic diversity, deviations from the Hardy-Weinberg equilibrium, principal component analysis, and relatedness estimations based on microsatellite DNA can also provide evidence for distinguishing native populations from those influenced by hatchery fish.

Sexual maturity, morphological sexual dimorphism, and reproduction of the goneplacid crab Carcinoplax vestita were investigated in Tokyo Bay, Japan, from November 2002 to October 2003. The puberty molt in males was evidenced by changes in the relative size of the chelipeds and merus of the walking legs, and was estimated to occur at a size range of 13.20–18.85 mm carapace length. Post-pubertal females were identified by the relative size of the abdomen and puberty was estimated to occur at a size range of 12.81–15.46 mm carapace length. Sexual dimorphism in C. vestita was observed in all features that showed secondary sexual characteristics. Monthly changes of gonad index in males, and of seminal receptacle index and occurrence of sperm plugs in females were synchronized, and indicated that mating was intense in spring. Ovaries began developing in March. Ovigerous females were found in all months except December, but were clearly more abundant between August and October. Fecundity ranged from 7800 to 57 000 mature oocytes per female per batch and was highly correlated with body size. The results suggest that some females may spawn more than one batch per year.

The natural diet of Plagusia dentipes de Haan was studied in Tateyama Bay, Japan, between June 2004 and May 2005. A total of 389 specimens were collected for analysis of stomach content during the period, with sizes ranging between 7.1 and 63.1 mm in carapace width. The major dietary item was rhodophycean algae (mostly articulated coralline algae), which was ingested by 91.8% of the crabs and accounted on average for 55.6% (points) of the volume of stomach contents. Chlorophycean algae (mostly Ulvaceae, 39.1% and 8.1 points) and crustaceans (mostly amphipods, 38% and 3 points) came next in feeding frequency and volume. Minor dietary items also included other algae such as Phaeophyceae and animals such as mollusks (bivalves, gastropods), annelids (polychaetes), other crustaceans (caprellids, isopods), and echinoids. Significant seasonal dietary differences were observed and, in general, the diet in spring contained more food items, particularly more animals, compared to other seasons. Feeding of Rhodophyceae was highest and lowest in winter and summer, respectively. The total volume of food consumed was also lowest in summer and likely reflected reduced availability of the main food item in this season. There were no differences in dietary items between male and female crabs. In conclusion. P. dentipes is a primarily herbivorous crab with incidental or opportunistic feeding on animal items, and it is suggested that seasonal shifts in consumption may be related to growth, molting, and reproductive activity.

Two new species ofMunidopsisfrom the hydrothermal vent area, Kairei Field, Central Indian Ridge in the Indian Ocean and Forecast Vent Field, Mariana Back Arc Basin in the west Pacific are described and illustrated. Their affinities to closely related species are discussed. The number ofMunidopsisspecies associated to hydrothermal vents in the world oceans has increased to 16. The habitat of new species is briefly described and the pattern of abundance of vent associatedMunidopsisis briefly discussed.

Phase transformation behaviors of the austenitic 301 stainless steel was studied under Fe + , Ti + and Ar + ions implantation at room temperature with 100, 200 and 300 keV up to fluence of 1 x 10 21 ions/m 2 and the microstructures were observed by means of transmission electron microscopy (TEM). The plane and cross-sectional observations of the implanted specimen showed that the induced-phases due to implantation from the y matrix phase were identified as a' martensite phases with the orientation relationship of (110) α //(111) γ and [111] α // [011] γ close to the Kurdjumov-Sachs (K-S). The ion implantation induced phases nucleated near the surface region and the depth position of the nucleation changed depending on the ion accelerating energy and ion species. It was also found that the induced marten sites phases nucleate under the influence of the stress distribution, which is introduced due to the concentration of implanted ions, especially due to the stress gradient caused by the corresponding concentration gradient.

The developmental time and thermal threshold for temperature-dependent sex determination (TSD), gender differences in temperature sensitivity, the fertility of thermally sex reversed fish, and the effect of temperature on the expression of two major sex determination/differentiation genes (DMY/DMRT1bY and DMRT1) were examined in the Hd-rR strain of medaka, Oryzias latipes. Fertilized eggs were exposed from either shortly after fertilization (8–16 cells; embryonic stages 5–6) or from middle embryogenesis (heart development stage; stage 36) until hatching to temperatures ranging from 17°C to 34°C. Secondary sexual characteristics, gonadal histology, progeny testing, sex-linked body coloration and gene expression were used to determine phenotypic and genotypic sex. Sex determination was unaffected by low or high temperatures in genotypic (XY) males. In contrast, genotypic (XX) females treated from stages 5–6 showed increasing rates of sex reversal into phenotypic males at temperatures above 27°C up to 100% at 34°C. Thermal manipulation of sex was ineffective after stage 36, indicating that gonadal fate in medaka is determined considerably earlier than histological differentiation (stage 39). High temperature induced DMRT1 expression in genotypic females, which was observed already from stage 36. Sex-reversed males had histologically normal testes, were capable of sexual courtship and, with the exception of fish from 34°C, sired viable progeny when mating with fertile females. These results clarify the pattern of TSD in medaka and provide important clues to understand the mechanism of sex determination in this species. They also suggest that a brief exposure to high temperature early in life could impair the fertility of medaka as adults.

Summary The morphometrical and meristic features of the carapace, cephalic appendages (antenna, antennule), mouthparts (maxillule, maxilla, first-third maxillipeds), sternum, pereiopods, abdomen, and pleopods of juveniles and the onset of morphological sexual dimorphism were described for the xanthid crab Leptodius exaratus (H. Milne Edwards, 1834), based on laboratory-reared and wild adult specimens collected from Tateyama Bay, Japan. First instar juveniles shared some of the features of adults (e.g. gross appearance of the carapace and cheliped propodus proportions), but differed from adults on almost all other morphological parameter examined. Morphological development was still not complete at the ninth instar; extrapolation from the rate of morphological changes between instars 1–9 suggests that L. exaratus requires about 13 ecdyses to transform into adults, including development of reproductive structures. Differences in the number and morphology of pleopods and abdomen width allowed early distincti...

{112} Σ3 CSL grain boundary in silicon was investigated by high-resolution transmission electron microscopy (HRTEM) and ab-initio calculation. A {112} Σ3 CSL boundary consisted of two segments which differed in atomic structure. The segment near the connected corner to {111} Σ3 CSL boundary showed symmetric structure and the other long segment, being distant region from the corner, showed asymmetric structure. It was shown that the asymmetric structure is more stable than the symmetric one. In the symmetric segment a 5-fold coordinated atom presented, which elevated the structure energy of the boundary and produced a new state in the band gap.

Luminescent silicon nanoparticles have attracted considerable attention for their potential uses in various applications. Many approaches have been reported to protect the surface of silicon nanoparticles and prevent their easy oxidation. Various air-stable luminescent silicon nanoparticles have been successfully prepared. However, the effect of interactions of the π-electron system with the silicon surface on the excited state properties of silicon nanoparticles is unclear. In this study, we have successfully prepared silicon nanoparticles protected with three organic compounds (styrene, 1-decene, and 1-vinyl naphthalene) and have examined their photophysical properties. The ligand π-electron systems on the silicon surface promoted the light harvesting ability for the luminescence through a charge transfer transition between the protective molecules and silicon nanoparticles and also enhanced the radiative rate of the silicon nanoparticles.

We report a new production pathway for a variety of metal oxide nanocrystallites via submerged illumination in water: submerged photosynthesis of crystallites (SPSC). Similar to the growth of green plants by photosynthesis, nanocrystallites shaped as nanoflowers and nanorods are hereby shown to grow at the protruded surfaces via illumination in pure, neutral water. The process is photocatalytic, accompanied with hydroxyl radical generation via water splitting; hydrogen gas is generated in some cases, which indicates potential for application in green technologies. Together with the aid of ab initio calculation, it turns out that the nanobumped surface, as well as aqueous ambience and illumination are essential for the SPSC method. Therefore, SPSC is a surfactant-free, low-temperature technique for metal oxide nanocrystallites fabrication.

The Japanese and Spanish nuclear industries have conducted joint experimental programmes since early 1990's to address fuel performance issues such as fuel volume change and fission gas release. These efforts have produced large amount of valuable information on in-reactor performance of fuel materials representing current and potential future fuel designs. A large number of thoroughly characterised fuel rods composed of different materials have been irradiated in the Spanish PWR Vandellos II for up to five irradiation cycles achieving rod average burnup of up to 75 MWd/kgU. This paper looks into the fuel pellet performance at high burnup only based on the extensive PIE programme both on-site and in hot-cells carried out over this fuel and other related data on similar fuel rods thus supporting and enriching the conclusions.

The Japanese mitten crab Eriocheir japonica is a common grapsid species found throughout freshwater and estuarine regions in Japan. In order to obtain information on the genetic variation and population structure of this species, a polymerase chain reaction (PCR) restriction fragment length polymorphism (RFLP) analysis was conducted on the cytochrome oxidase subunit I (CCI) of mitochondrial DNA, on 666 individuals from 19 sample sites covering the three main geographic regions of Japan (Main Islands, Okinawa, and Ogasawara). Genetic analysis using seven restriction enzymes produced an array of 61 composite haplotypes. Three regional groups corresponding to the three geographic regions were clearly identified by cluster and molecular variance model (AMOVA) analyses. Each of the three groups showed dominant haplotypes that were almost completely absent in populations from the other geographic areas. Comparison with published information for other species indicates that the degree of genetic divergence between these three main groups is equivalent to the genetic distance between congeneric species. Thus, the population structure of the Japanese mitten crab, as inferred from mtDNA analysis, is formed by genetically distinct groups that closely reflect their geographic distribution in the Japanese archipelago as well as restricted gene flow.

The penicillate crabs, Hemigrapsus penicillatus and H. takanoi are two sympatric forms that were recently recognized as valid sibling species. In this study, we conducted a detailed examination of the morphology and pigmentation patterns of these two species and their distribution in Tokyo Bay, Japan. The presence or absence of dark spots on the mandible and the ventral side of the cephalothorax and abdomen were used as primary key characters for the identification of H. penicillatus and H. takanoi, respectively. Seventeen out of 750 crabs had unclear patterns unsuitable for identification, and 2 out of 400 males had a pigment pattern that conflicted with morphological features. Females of H. penicillatus had proportionally higher, but shorter chelae than those of H. takanoi. In males, only the ratio of the diameter of the patch of hair on the chela relative to the carapace width was different between the species. The ratio varied from 0.04 to 0.18 for pigmented (H. penicillatus) males and from 0.16 to 0.30 for unpigmented (H. takanoi) ones, with a 99% accurate cut-off value of 0.18. Three types of male first pleopods were identified. Pleopods with a slightly curved tip, showing a single slit, and setae curved along the tip, were found only in males of H. penicillatus, whereas those with a straight tip, with multiple slits, and setae that grow upright, were associated with males of H. takanoi. A third type of first pleopod with intermediate characteristics was found in 21% and 33% of the males of H. takanoi and H. penicillatus, respectively. Hemigrapsus takanoi was found to be distributed throughout Tokyo Bay, whereas H. penicillatus occurred predominantly in the central and outer sections of the bay. Crabs with unclear pigmentation patterns were found dispersed throughout the bay, whereas males with mixed characteristics and those with first pleopods of intermediate morphology where found in areas inhabited by both species. Die beiden Krabben Hemigrapsus penicillatus und H. takanoi kommen sympatrisch vor und sind kurzlich als valide Geschwisterarten erkannt worden. Bau und Pigmentierungsmuster dieser beiden Arten sowie ihre Verbreitung in der Tokyo Bucht, Japan, werden hier untersucht. Das Vorhandensein oder Fehlen dunkler Punkte auf der Mandibel und auf der Ventralseite von Cephalothorax und Pleon wurden als Haupmerkmale bei der Bestimmung beider Arten benutzt. Siebzehn von 750 Krabben hatten keine unzweideutigen Muster, so dass diese fur eine Bestimmung unbrauchbar waren. Zwei von 400 Mannchen hatten ein Pigmentierungsmuster, das im Widerspruch zu morphologischen Merkmalen steht. Bei Weibchen von H. penicillatus sind die Scheren verglichen mit denen von H. takanoi hoher, aber kurzer. Bei den Mannchen ergab sich ein Unterschied zwischen beiden Arten nur im Verhaltnis des Durchmessers eines Haarfeldes auf der Schere zur Carapaxbreite. Das Verhaltnis variierte zwischen 0,04 und 0,18 bei pigmentierten (H. penicillatus) Mannchen und zwischen 0,16 und 0,30 bei unpigmentierten (H. takanoi) Mannchen mit einem 99%-Schnittwert von 0,18. Es konnten drei Typen von ersten Pleopoden bei den Mannchen festgestellt werden. Solche mit einer leicht gebogenen Spitze mit einem einzigen Schlitz und mit um die Spitze gebogenen Borsten sind auf Mannchen von H. penicillatus beschrankt, wohingegen solche mit einer geraden Spitze mit mehreren Schlitzen und mit aufrecht abstehenden Borsten bei Mannchen von H. takanoi vorkommen. Ein dritter intermediarer Typ trat zu 21% bei Mannchen von H. takanoi und zu 33% bei denen von H. penicillatus auf. H. takanoi kommt in der gesamten Tokyo Bucht vor, wahrend H. penicillatus vornehmlich die zentralen und auseren Bereiche der Bucht besiedelt. Krabben mit einem Pigmentierungsmuster, das nicht unzweideutig ist, sind in der ganzen Bucht verbreitet, wahrend Mannchen mit Mischcharakteren und dem intermediaren Typ im Bau der ersten Pleopoden in Gebieten vorkommen, die von beiden Arten besiedelt werden.

The aerodynamic noise and drag are associated with the flow structures and the unsteady behavior of the vortex causes the wind noise. However, litter attention has been paid to the complex vortical structures around externally mounted car mirror from the measured data. In this paper the turbulent structure of mirror wake has been experimentally investigated. The instantaneous velocity fields were measured using PIV technique at Reynolds number of 5900. Then, the wavelet-based vector multiresolution analysis was applied to the postprocessing of PIV results for identifying the multiscale turbulent structures of a car mirror wake. The intermediate and small-scale vortices embedded within the large scale vortices were separated and visualized.

The adoption of an upright posture in abalones is essential to enable them to use their foot, and hence to be able to move and seek shelter, as well as to avoid exposure of soft parts and possible predation. In mass restocking programs for abalone, juveniles are released by divers near the seabed, but without control over their posture when they reach the bottom. Thus, the time to recover the upright posture is an important consideration in abalone restocking programs as the quicker they assume this posture the higher the likelihood of survival. This study reports significant differences in the speed of recovering the upright posture between juveniles of the abalones Haliotis discus discus, H. gigantea and H. madaka and between tests conducted under stagnant and flowing water conditions. Longer times were required for recovery in all species in stagnant than flowing water. On average, juveniles of H. discus discus (17.16 and 10.43 s) and H. gigantea (22.54 and 11.89 s) recovered faster than those of H. madaka (161.13 and 49.02 s) under stagnant and flowing water conditions respectively. These results suggest that different species require different levels of care and that water flow or current at the time of release may affect post-release survival.

Studies were conducted on growth and reproduction of the red frog crab, Ranina ranina (Linnaeus, 1758), in the Andaman Sea off Thailand from 1998 to 1999. Samples were collected from Ko Similan, Ko Surin and Thai-Myanmar boundary waters by gill net. Results showed that the relationship between carapace length (CL) and body weight (BW) for males (CL, 5.84–14.10 cm) was BW=0.2598 CL3.0931, and for females (CL, 5.35–10.97 cm) was BW=0.4280 CL2.8656. Growth in each gender showed allometric growth. The average CL of males was significantly larger than that of females. Average male and female crab sizes in 1999 were smaller than in 1998. The spawning season was found to be from November to February; maturing male crabs were abundant from September to December. Average sizes of CL at first maturity for males and females were 7.44 and 7.22 cm, respectively. Fecundity ranges of ovigerous female crabs were 74 600–167 900 eggs with an average egg diameter of 0.62 mm. The monthly sex ratios (male: female) varied between 1:0.56 and 1:2.77.

We have developed a new model for radiation-induced grain boundary migration (RIGM) and radiation-induced segregation (RIS) for austenitic iron-chromium-nickel alloy system. It was assumed that the RIS was induced by diffusional and annihilation processes of excess point defects at the grain boundary, and the RIGM occurred due to rearrangement process of atoms on one of the interfacial planes by annihilation of point defects. The calculated results indicated that the region of RIS was enlarged by the RIGM and asymmetrical concentration profiles were observed around the migrated grain boundary. The present model could explain the RIS behavior with or without grain boundary migration as comparing with our previous experimental results.

The aerodynamic noise and drag are associated with the flow structures and the unsteady behavior of the vortex causes the wind noise. However, litter attention has been paid to the complex vortical structures around externally mounted car mirror from the measured data. In this paper the turbulent structure of mirror wake has been experimentally investigated. The flow structures of the mirror wake were first visualized by the smoke-wire technique. The shedding vortices that are produced by two side of the mirror edge were clearly visualized. Then the instantaneous velocity fields were measured using PIV technique at Reynolds number of 6300. Instantaneous and mean streamlines, vorticity contours and Reynolds stresses were examined. The separation bubble and the region of the reverse flow behind the mirror were observed.

実験池において，イワナとヤマメの体内に残留させた釣り鈎の動向を調査した。両種ともに，口腔に残留させた餌釣り用と毛鈎釣り用の鈎はいずれも 21 日以内にその多く（70.0～100%）が脱落した。口腔より奥に残留させた餌釣り用の鈎の体外への排出率は 21 日後に 0～16.7% であり，81 日後でも 15.0～50.0% であった。口腔より奥に残留させた鈎の多くは 81 日後には錆びていたが，崩壊したものは少なかった。以上の結果から，口腔に残留させた鈎は比較的短期間で脱落するが，口腔より奥に残留させた鈎は体外に排出されにくいことが明らかになった。

The vibration of car mirror is caused by fluid-dynamic force that is dominated by the flow structures and the unsteady behavior of the vortex when a car travels at high speed. In this paper, the turbulent structure of the car mirror with grooves wake was experimentally investigated. The instantaneous velocity fields were measured using PIV technique at a Reynolds number of 6300. By examining instantaneous and mean streamlines, vorticity contours and Reynolds stresses, the wake structure of the car mirror with grooves was compared to the car mirror without grooves. It is found that the region of the reverse flow, the size of vortex and Reynolds stress were reduced by grooves.

The two forms of Hemigrapsus penicillatus (de Haan, 1835), recently distinguished on the basis of electrophoresis and differences in the size of the setal patches on the male chelae, are here recognized as two distinct species. The individuals having smaller setal patches are H. penicillatus, whereas those with larger setal patches are described herein as a new species. Living and fresh material of the two species are also clearly separated by the size and distribution of dark spots on the cephalothorax, abdomen, third maxillipeds, and chelipeds. Morphology of the male first pleopod is different between the two species. Females of the two species are morphologically identical and cannot be easily separated once colour has faded.

The surfaces of athletic stadiums have improved since 1970. However, no classification has been made regarding the scars on surfaces. A standard of the surface was announced by the IAAF(International Association of Athletics Federations) in 1998. This standard consists of 10 properties such as force reduction, friction and modified vertical deformation. These properties and precedence studies are mostly in regard to vertical direction but few are related to the characteristics of level direction. The purposes of this study were to classify the scars on surfaces of athletic stadiums and to develop a wear test device. The characteristics of 3 kinds of track surfaces were investigated by using this device. Theresults are as follows;1) Scars on surfaces of the athletic stadiums were classified into three categories, a) abrasive wear (scratch damage), b) abrasive wear (brake damage), c) fatigue wear.2) The wear test device is able to simulate the contact phase of human running and can carry out various tests. This device detects the forces of spike pins and surface.3) It became clear that the vertical direction force is big on a hard surface.

To clarify hydrogen effects on mechanical properties of pure vanadium, two kinds of tensile tests were performed using hydrogen charged miniature specimens at room temperature. One is with hydrogen charging prior to testing, and the other is with hydrogen charging during testing with continuous or intermittent methods. The cathodic hydrogen charging was carried out electrolytically in various concentrations of H2SO4 with different current densities. The hydrogen charged specimens were tested to obtain stress–strain curves. The fractography was performed by SEM, and hydride formation and microstructural change were examined by TEM. Hydrogen-induced softening and hardening in vanadium resulted from hydrogen charging. The variations in mechanical property of specimens depended on the amount of dissolved hydrogen, that was determined by hydrogen diffusion and hydrogen desorption. Dislocation motion also plays a role in the variation of flow stress.

We investigated the dependence of radiation-induced segregation (RIS) in austenitic stainless steels on grain boundary orientation by numerical calculations. A new rate equation model for RIS that incorporates the grain boundary sink strength for point defects was developed. The sink strength was determined as functions of misorientation angle and Σ values using interaction energies of vacancy near grain boundaries as determined by molecular dynamics (MD) and statics (MS). It was shown that the calculated results can reproduce the experimental data obtained by electron and proton irradiation experiments. The good agreement supports the validity of the present model.

The purpose of this study is to evaluate the synergistic effect of helium and hydrogen on Fe–Cr ferritic model alloys, to provide basic understanding concerning development of fusion reactor components. Single, dual and triple ion-beams consisting of Fe3+, He+ and H+ were used for irradiation, at temperatures 470–600 °C and dose to 50 dpa at 1 μm. The dual beam irradiation with He enhanced cavity nucleation extensively to swelling of about 0.4%, whereas the dual beam irradiation with H did not significantly affect the microstructure. In the case of triple ion irradiation, the synergistic effect of He and H was confirmed clearly; relative large void formation and enhanced swelling to almost 5%. The synergistic effect suggests that the role of H is important for void growth and dislocation bias.

Feeding habits of an exotic species, the Mediterranean green crab Carcinus aestuarii, in Tokyo Bay, Japan, were studied based on the analysis of stomach contents. Monthly samples were taken from May 2000 to October 2001 at stations near the Keihin Canal along the northern shore of Tokyo Bay. Stomach contents of 367 crabs (male n = 200, female n = 167) were examined. Carapace width ranged from 18.50 mm to 60.67 mm. Eleven food categories were identified: Bivalvia (mostly Mytilus galloprovincialis), other Mollusca, Cirripedia, Amphipoda, Brachyura, other Crustacea, Polychaeta, Pisces, unidentified animal materials, plant materials, and unidentified materials. The results showed that C. aestuarii is an omnivorous predator and that its diet depends greatly upon the availability of local prey species, especially in intertidal areas. Moreover, the analysis found no significant differences in the feeding habits of crabs of different sizes or sexes.

The eiects of salinity on haemolymph osmolality, oxygen consumption and ammonia excretion were investigated in adult kuruma shrimp, Marsupenaeus japonicus (Bate), at salinities of 20, 25, 30 and 35 g L � 1 . Haemolymph osmolality showed a positive linear relationship (r 2 50.9854) with medium osmolality. The isosmotic point calculated from this relationship was 1039 mOsm kg � 1 , which corresponds to a salinity of approximately 35 g L � 1 . The slope of the regression equation was very high (0.81), suggesting that M. japonicus adults are poor osmoregulators compared with the adults of other penaeids and to conspeci¢c young. The diierence between haemolymph and medium osmolality (DOP) was lowest at 35 g L � 1 and highest at 20 g L � 1 .T hus, the minimum DOP coincided with the isosmotic point of the shrimp. The respiration rate was signi¢cantly lower at 30 g L � 1 than at the other salinities. Ammonia excretion rates were inversely related with salinity and therefore were minimal at 35 g L � 1 . The results of this study suggest that the optimum salinity for adult kuruma shrimp is around 30^35 g L � 1 and that even minor (e.g. 5 g L � 1 ) deviations from this optimum cause signi¢cant physiological changes. Further, the observed increases in oxygen consumption and ammonia excretion during exposure to low salinities, which indicate higher energy expenditure and amino acid catabolism for osmoregulation, respectively, suggest that the growth e⁄ciency of M. japonicus adults may be severely compromised by hypohaline water in£ow into the rearing ponds.

一次元の養殖場分布モデルを用いてシミュレーションにより養殖場における伝染病の伝播を再現しリスク評価を行った。養殖場間の流通を (1) 隣接養殖場間の相互流通, (2) 隣接養殖場間の一方向的な流通, (3) ランダムな流通の3つのタイプに分け, 防疫策として3つの流通停止の方法を設定した。数値結果から流通 (3) を避ける事, および病死魚発見後は早期に流通を停止する事が有効であることが示された。流通の早期停止が不可能な場合は全養殖場間の流通停止, 未感染の養殖場間流通を先に停止することで伝播を抑制できることが明らかになった。

イワナ・ヤマメ養殖魚の小型魚と大型魚の釣獲放流後の死亡率と成長を実験池において調査した。餌釣り, 毛鈎釣りともに, 口腔にかかった鈎を除去した場合, いずれの魚種においても死亡率は低かった。餌釣りで口腔より奥にかかった鈎を除去した場合, イワナ小型魚とヤマメ大型魚では死亡率は高かった。口腔にかかった毛鈎を残留させた場合, イワナ大型魚では死亡率は高かった。死亡のほとんどが釣獲放流後14日以内に観察された。釣獲方法, 鈎がかりの部位, 鈎の処理方法は成長と肥満度に影響しなかった。