Representation of Water Particle Velocity of Breaking Waves on Beaches by Dean's Stream Function

Experimental values of water particle velocity of breaking waves on uniformly sloping beaches differ considerably from the theoretical values of Stokes waves of the third order and cnoidal waves of the second approximation. In this paper, Dean's stream functions are calculated by giving simultaneously measured time variations of the water level of the breaking waves. Vertical distributions of horizontal water particle velocity at the crest phase, calculated by using these stream functions, are compared with experimental distributions in order to discuss the applicability of Dean's stream function method. These theoretical distributions can explain the experimental results well, although this stream function method assumes permanent waves in uniform depth. Dean's stream function can express an asymmetric wave profile as that of breaking waves on sloping beaches, while the Stokes wave theory has a symmetric wave profile. It is suggested that the breaking wave profile dominates the water particle velocity field of breaking waves

精管に沿って発生した精索平滑筋腫の1例

67歳男, 腫瘤の形成はなく, 精管に沿って発生した精索平滑筋腫の1例.精索に発生した平滑筋腫でこのような特異な形態を呈した症例は文献上報告がなく, 本症例が最初の報告であるWe report an unusual case of a leiomyoma of the spermatic cord. The tumor did not present as a mass but presented as a hard structure along the spermatic cord. To our knowledge, this is the first case report of a leiomyoma of the spermatic cord with such an unusual appearance

Syn-metamorphic B-bearing fluid infiltrations deduced from tourmaline in the Main Central Thrust zone, Eastern Nepal Himalayas

Mode of occurrence and chemical composition of tourmaline in pelitic schists from the Main Central Thrust (MCT) zone of the Lesser Himalayan Sequences (LHS) are described in detail with the aim of deducing the chemical characteristics of tourmaline formed through B-bearing fluid infiltration and of estimating the composition of the syn-metamorphic fluids. Metasomatic tourmalines from the tourmalinized wall rocks show significant increases in XCa [=Ca/(Ca + Na)] at almost constant XMg [=Mg/(Mg + Fe²⁺)] from the cores or mantles to the rims. Tourmaline in tourmaline-rich (> 1.0 vol%) pelitic schists from the biotite zone to the kyanite zone also show marked increase in XCa at almost constant XMg, and are interpreted as a product of B-bearing fluid infiltration. Abundant margarite and anorthite formed in the pelitic schists intercalated with the metadolostone layers suggesting that the B-rich fluid became Ca enriched as it interacted with metadolostone layers, and metasomatically introduced Ca into the pelitic schists. Infiltration of such B- and Ca-rich fluids into pelitic schists likely resulted in production of abundant tourmaline with the compositional trend of increasing XCa at almost constant XMg. Most of the tourmaline in tourmaline-rich pelitic schists are in equilibrium with plagioclase, suggesting that the fluid composition was buffered by the pelitic schists. Composition of tourmaline in the pelitic schists with <1 vol% tourmaline mostly show increase in XCa and wider range of XMg values, reflecting its growth during prograde metamorphism. The composition of fluids that coexisted with tourmaline is estimated by applying experimentally-determined fluid/tourmaline chemical relationships to the composition of tourmaline from veins associated with tourmalinization, pelitic schists with <1 vol% tourmaline and tourmaline-rich pelitic schists. Assuming coexisting anion to be Cl, the salinity estimated for these rock types was ~0.44–0.59 mol/l NaCl + CaCl₂ that is similar to or slightly lower than the present-day seawater. Veins associated with tourmalinization and tourmaline-rich pelitic schists are sporadically distributed in the MCT zone of the LHS, suggesting that the syn-metamorphic, B-bearing saline fluid infiltrations took place widely in the MCT zone, and the fluid pathways were localized and channeled. Our observation supports the scenario whereby infiltration of fluid into the High Himalayan Crystallines (HHC) caused vapor-saturated partial melting of the HHC to give tourmaline leucogranite melts contemporaneous with inverted metamorphism in the MCT zone

Denudation Process of Crystalline Nappes in a Continental Collision Zone Constrained by Inversion of Fission‐Track Data and Thermokinematic Forward Modeling: An Example From Eastern Nepalese Himalaya

Thermochronological methods were applied to the Higher Himalayan Crystalline (HHC) nappe and the underlying Lesser Himalayan Sequences (LHS) to elucidate the denudation process for the middle- and upper-crust of eastern Nepal over millions of years. Thermochronological inverse modeling was undertaken for new results of fission-track (FT) age and FT length data of zircon and apatite in order to reconstruct the time-temperature (t-T) paths in the temperature range of 60–350°C. Eight t-T paths calculated along the across-strike section show that the cooling process of the HHC nappe in this study area is characterized by the following three aspects: (a) gradual cooling followed by rapid cooling and subsequent gradual cooling, (b) northward-younging of the timing of the rapid cooling, and (c) gradual cooling followed by <2 Myr rapid cooling in the frontmost part of the HHC nappe. The observed FT ages and t-T paths were then compared with those predicted by forwarding thermokinematic modeling. The results of the thermokinematic modeling for the “Flat-Ramp-Flat MHT model”, in which the HHC and the underlying LHS are denudated in direct proportion to the uplift of rocks transported along the Main Himalayan Thrust (MHT), reproduced the observed t-T paths and FT ages in eastern Nepal. This indicates that the observed FT ages and t-T paths reflect a denudation process driven by the movement of the MHT with a flat-ramp-flat geometry and that the denudation rate and its spatial distribution have roughly been constant in eastern Nepal since ca. 9 Ma

Studies on the Chironomid Midges Collected on the Shore of Shimanto River in April, 1998. : Part 1. Description of Species of the Subfamily Chironominae

Collection of "yusurika", or insects of the family Chironomidae, were conducted during the period from April 25 to 27, 1998, at 10 localities along Shimanto River in western Shikoku, Japan by daytime collections with insects net, and night collections with a light trap. The specimens collected were preserved in 70% alcohol, and were individually mounted on slides in gum-chloral medium after dissected. A total of 320 male specimens have so far been examined, and 144 among them were found to be belonging to the subfamily Chironominae, and the rests to Orthocladiinae and Tanypodinae. Those belonging to the first subfamily were further classified into 42 species, among which as many as 24 are described in this paper as new species. It should especially been noted that the species belonging to the 3 genera of Tribe Tanytarsini, Cladotanytarsus, Micropsectra and Tanytarsus, are classified into 10 species, among which Tanytarsus oyamai Sasa, 1979, is the only one previously recorded, and the rests 9 were the new species. It has again been demonstrated that the Shimanto River basin is very rich in the insect fauna and many new species were collected at the present survey

Studies on the Chironomid Midges Collected on the Shore of Shimanto River in April 1998. : Part 2. Description of Additional Species Belonging to Orthocladiinae, Diamesinae and Tanypodinae.

Collection of adult chironomid midges were conducted during 3 day period from April 25 to 27, 1998, in areas along Shimanto River, western Shikoku Island, Japan, in night time with light traps at the town of Nakamura and Hiromi, and in daytime by sweeping with insect net at 8 localities along the main stream of the river and its branches, from near the mouth to the upstream portions. The chironomid specimens were preserved in 70% ethanol, and first examined under a stereomicroscope for classification, and those considered necessary for detailed examinations were dissected and mounted individually on slides in gum-chloral medium. By examination of 240 slide mounted specimens, 74 were identified as belonging to 42 different species of the subfamily Chironomidae, and 24 among them were described as new species in our previous paper. The rest specimens were classified into 36 species belonging to the subfamily Orthocladiinae, including 19 new species and 5 species new or rare to Japan, 1 species of subfamily Diamesinae new to Japan, and 9 species including 3 new species and 3 species new to Japan are belonging to the subfamily Tanypodinae, or a total of 46 species, including 22 new species and 9 species new to Japan, are recorded this time as members of these 3 subgenera. It was again demonstrated that the areas along Shimanto River are very rich in the chironomid fauna, and such large numbers of new species or species new to Japan were collected and identified this time

Individual shape and composition analysis of urban atmospheric aerosols using FIB-TOF-SIMS

Minute solid or liquid particles suspended in air are called aerosols. Aerosols can be of natural origin, such as yellow sand, or of anthropogenic origin, such as railroad wear dust. Bulk analysis has been used for the chemical analysis of aerosols with such various sources. However, bulk analysis can only determine the average chemical composition of a group of particles and cannot, in principle, analyze the chemical composition of individual particles. In our group, we have developed an FIB-TOF-SIMS (Focused Ion Beam Time-of-Flight Secondary Ion Mass Spectrometer) to analyze the compositional distribution of individual particles . Our investigations have revealed that there is a certain correlation between particle composition (source) and particle shape. In addition, it is important to understand the composition and shape of particles originating from urban areas because the traffic volume is relatively high in urban areas and there is concern about the emission of large amounts of aerosols and their health effects on human health. In this study, we sampled aerosols in Shinjuku area and analyzed them using FIB-TOF-SIMS. In this presentation, we will report the component analysis of urban atmospheric aerosols and the shape characteristics of the particles

Safe and minimally invasive laminoplastic laminotomy using an ultrasonic bone curette for spinal surgery: technical note

Background: Ultrasonic surgical aspirators have been used mainly for removing brain tumors. Because of their longitudinal and torsional tip, they are used for cutting the bone structures in spinal surgery installing a scalpel-type tip. The purpose of this report is to describe the effectiveness and surgical pitfalls of an ultrasonic bone curette in laminoplastic laminotomy and hemilaminotomy. Methods: We present 12 patients who underwent laminoplastic laminotomy and hemilaminotomy. We used a SONOPET UST-2001 ultrasonic bone curette with HB-05S handpieces (M and M Co, Ltd, Tokyo, Japan). After a tumor was removed, titanium plates were used for the laminoplastic laminotomy and hemilaminotomy. The technical advantage of an ultrasonic bone curette and procedure-related complication were examined. Results: There were no major procedure-related complications such as cord injury. Wound infection and subcutaneous fluid collection caused by cerebrospinal fluid leakage did not occur for reconstruction of posterior bony structure. In 1 patient with calcified dura mater associated with tumor, dural tear occurred. The width of the tip was narrow enough for resected laminae to be fused postoperatively, and spinal instability did not occur in all cases. Conclusion: The scalpel-type ultrasonic bone curette is useful for cutting bone and effective for reconstruction of the laminae. Laminotomy with an ultrasonic bone curette is safe and minimally invasive. To prevent dural tear, we recommend drilling laminae to make the bone thin as the first step, followed by cutting the remaining laminae using a bone curette especially in cases with calcified or tense dura mater.ArticleSURGICAL NEUROLOGY. 72(5):470-475 (2009)journal articl