Stream discharge and water quality data for East Fork Poplar Creek beginning 2012     

Scott C. Brooks  Ami L. Riscassi  Kenneth A. Lowe 《水文研究》2021,35(3):e14103

This data note describes 15-min discharge and in situ water quality data at two locations along East Fork Poplar Creek in east Tennessee, USA. Data records include temperature, gauge height, water surface elevation above mean sea level, and volumetric discharge. Water quality measurements include temperature, specific conductance, pH, dissolved oxygen (percent saturation and concentration), turbidity, and less extensive fDOM data at one site. The data records begin in 2012 at one site and 2015 at the second site; monitoring at both sites is ongoing (as of 2021). The goal of this data collection is to improve understanding of watershed functions, hydrologic dynamics, and material flux. The data will contribute to site conceptual and numerical models, exposure and risk evaluation, remediation selection and design, and performance monitoring. The data are publicly available and can be accessed via unique url or DOI.  相似文献   

Mesoscale modeling of water penetration into concrete by capillary absorption   总被引：3，自引：0，他引：3  

Licheng Wang  Tamon Ueda 《Ocean Engineering》2011,38(4):519-528

Water penetration into concrete by capillary absorption plays a very important role in the ingress of contaminative substances when the structures are built in aggressive environments. In the present paper the lattice network model is proposed based on the unsaturated flow theory to predict the water penetration into concrete. On the mesocale level, concrete is treated as a three-phase composite. By means of the Voronoi diagram meshing strategy, the lattice network model of concrete with different types of lattice elements is developed. The corresponding transport properties are assigned to the lattice elements in the network falling in different phases. As a result, the lattice elements are idealized as conductive “pipes” in which uni-directional flow can be realized between the two nodes of the elements. Parameters in the lattice network model, such as the sorptivity and porosity of the mortar and the ITZs are quantitatively determined. With help of the approach, the water content distribution within a concrete sample after any elapsed time, especially the penetration depth of water frontier, can be easily predicted. The cumulative water absorption calculated by the lattice network model is shown to be well agreed with the experimental results.  相似文献   

Assessment of shallow groundwater in Lake Nyos catchment (Cameroon,Central-Africa): implications for hydrogeochemical controls and uses   总被引：1，自引：0，他引：1  

Brice T. Kamtchueng  Wilson Y. Fantong  Akira Ueda  Edwige R. Tiodjio  Katsuro Anazawa  Mengnjo J. Wirmvem  Joseph O. Mvondo  Luc S. Nkamdjou  Minoru Kusakabe  Takeshi Ohba  Gregory Tanyileke  Joseph V. Hell 《Environmental Earth Sciences》2014,72(9):3663-3678

In 1986, carbon dioxide gas exploded from Lake Nyos and killed about 1,800 people. After that disaster, various administrative and research activities have been conducted to mitigate subsequent disasters. However, none of those endeavors have characterized the groundwater chemistry to identify hydrogeochemical processes that control the water chemistry, and the quality of the water for domestic and agricultural uses that support the lives of un-official resettlers around Lake Nyos. Conventional hydrochemical techniques coupled with statistical and graphical analysis were therefore employed to establish the baseline hydrochemical conditions, assess processes controlling solutes distribution in shallow groundwater in the Lake Nyos catchment and explore its usability. Groundwater samples were analyzed for their physical and chemical properties. The wide ranges of electrical conductivity and total dissolved solid values reveal the heterogeneous distribution of groundwater within the watershed. The relative abundance of major dissolved species was Ca > Mg > Na > K for cations and HCO₃ >>> Cl > SO₄ > NO₃ for anions. Piper diagram classified almost all water samples into mixed CaMg–HCO₃ water type. Major ion geochemistry reveals that, in addition to silicates weathering (water–rock interaction), ion exchange processes regulate the groundwater chemistry. Principal component analysis supports the occurrence of water rock interaction. Hierarchical cluster analysis showed that the chemistry of groundwater in the study area is controlled by three main factors, and suggests no hydraulic connectivity between deep lake water and groundwater in the catchment. The quality assessment of the groundwater showed that groundwater parameters are within the acceptable limit of the World Health Organization and Nigeria guidelines for drinking and domestic uses, and water found to be good for irrigation.  相似文献   

Radio imaging of the Subaru/XMM–Newton Deep Field – I. The 100-μJy catalogue, optical identifications, and the nature of the faint radio source population     

Chris Simpson  Alejo Martínez-Sansigre  Steve Rawlings  Rob Ivison  Masayuki Akiyama  Kazuhiro Sekiguchi  Tadafumi Takata  Yoshihiro Ueda  Mike Watson 《Monthly notices of the Royal Astronomical Society》2006,372(2):741-757

We describe deep radio imaging at 1.4 GHz of the 1.3-deg² Subaru/ XMM–Newton Deep Field (SXDF), made with the Very Large Array in B and C configurations. We present a radio map of the entire field, and a catalogue of 505 sources covering 0.8 deg² to a peak flux density limit of 100 μJy. Robust optical identifications are provided for 90 per cent of the sources, and suggested identifications are presented for all but 14 (of which seven are optically blank, and seven are close to bright contaminating objects). We show that the optical properties of the radio sources do not change with flux density, suggesting that active galactic nuclei (AGN) continue to contribute significantly at faint flux densities. We test this assertion by cross-correlating our radio catalogue with the X-ray source catalogue and conclude that radio-quiet AGN become a significant population at flux densities below 300 μJy, and may dominate the population responsible for the flattening of the radio source counts if a significant fraction of them are Compton-thick.  相似文献   

Simultaneous observations of meteors with the radar and TV systems     

Y. Fujiwara  M. Ueda  T. Nakamura  M. Tsutsumi 《Earth, Moon, and Planets》1995,68(1-3):277-282

We have carried out a simultaneous observation of radar and optical meteors with the MU radar (Middle and Upper Atmosphere Radar), Shigaraki and TV camera systems. We usually obtained about 20 meteors per an hour with 85 mm lens, but very small part of them are simultaneously observed by the MU radar (< 5%), suggesting the significance of rectangular scatterring. We have analyzed about 20 simultaneous meteors with magnitudes from 0 to +5.5, most of which are overdense meteors. For Geminid meteors, a linear relation between the logarithm of the echo duration and the absolute magnitude of the TV meteor, was deduced.  相似文献   

Television meteor radiant mapping     

M. Ueda  Y. Fujiwara 《Earth, Moon, and Planets》1995,68(1-3):585-603

We have carried out double-station TV meteor observations between 1990 and 1994. The orbits of 326 meteors have been determined from doubly observed meteors, and radiant distributions are studied. The mean magnitude of the observed meteors was as faint as +4.7, since I.I. (Image Intensifier) and Video cameras were used. Radiants were widely distributed over the celestial sphere. The velocity distribution showed some similarity with the distribution predicted by the theoretical radiant distribution from comets rather than that from asteroids. In all 13 showers including both major and minor meteor showers were detected from radiant distributions of the observed meteors; from the orbital elements and meteor velocities as well as from the radiant directions.  相似文献   

Tectonic accretion of a subducted intraoceanic remnant arc in Cretaceous Hokkaido, Japan, and implications for evolution of the Pacific northwest     

Hayato  Ueda  Sumio  Miyashita 《Island Arc》2005,14(4):582-598

Abstract   An accretionary complex, which contains fragments of a remnant island arc, was newly recognized in the Cretaceous accretionary terranes in Hokkaido, Japan. It consists of volcanics, volcanic conglomerate, intermediate to ultramafic intrusive rocks with island-arc affinity including boninitic rocks, accompanied by chert and deformed terrigenous turbidites. Compared with the results of modern oceanic surveys, the preserved sequence from island-arc volcanics to chert, via reworked volcanics, is indicative of intraoceanic remnant arc, because the sequence suggests an inactive arc isolated within a pelagic environment before its accretion. The age of a subducting oceanic crust can be discontinuous before and after a remnant-arc subduction, resulting in abrupt changes in accretion style and metamorphism, as seen in Cretaceous Hokkaido. Subduction of such an intraoceanic remnant arc suggests that the subducted oceanic plate in the Cretaceous was not an extensive oceanic plate like the Izanagi and/or Kula Plates as previously believed by many authors, but a marginal basin plate having an arc–back-arc system like the present-day Philippine Sea Plate.  相似文献   

Distribution of Trace Bioelements in the Subarctic North Pacific Ocean and the Bering Sea (the R/V Hakuho Maru Cruise KH-97-2)   总被引：2，自引：1，他引：2  

Yukiyo Fujishima  Kazumasa Ueda  Masahiro Maruo  Ehchiro Nakayama  Chikako Tokutome  Hiroshi Hasegawa  Masakazu Matsui  Yoshiki Sohrin 《Journal of Oceanography》2001,57(3):261-273

A column concentration-high resolution inductively coupled plasma mass spectrometry (ICP-MS) determination was applied to measure the total dissolved concentrations of Fe, Co, Ni, Cu and Zn in seawater collected from the subarctic North Pacific (~45°N) and the Bering Sea in July–September 1997. Total adsorbable Mn was determined on board by column electrolysis preconcentration and chemiluminescence detection. The vertical profiles for Fe, Ni and Zn were nutrient-like. The deep water concentration of Fe was ~0.5 nM in the northeast Pacific (18°-140°W) and increased to ~1 nM in the northwest Pacific (161°E) and ~2 nM in the Bering Sea (57°N, 180°E). The deep water concentrations for Ni and Zn in the Bering Sea were also 1.3–2 times higher than in the North Pacific. The profiles for Co and Cu were examined in the subarctic North Pacific, and results obtained were consistent with previous reports. There was a significant correlation between the concentrations of Co and Mn except for surface mixed layer. The profiles for total adsorbable Mn were similar to the reported profiles for total dissolvable Mn. The deep water concentration of Mn in the Bering Sea was also 4 times higher than in the North Pacific. Iron and zinc were depleted in surface water of the subarctic North Pacific. The relationship between these trace elements and nutrients suggests that these elements could be a limiting factor of phytoplankton productivity. In the Bering Sea, surface water contained ~0.3 nM of Fe. The Zn concentration, which was less than the detection limit in surface water, increased at shallower depths (~30 m) compared with the subarctic North Pacific. These results imply a higher flux of Fe and Zn to surface water in the Bering Sea. This in turn may cause the ecosystem in the Bering Sea characterized by a dominance of diatoms and high regenerated production.  相似文献   

Sulphide and oxide minerals from the Ohmine granitic rocks in Kii Peninsula,central Japan,and their primary paragenetic relations     

Mamoru Murata  Tetsumaru Itaya  Yoshio Ueda 《Contributions to Mineralogy and Petrology》1983,84(1):58-65

In the Ohmine granitic rocks of Kii Peninsula, central Japan, ilmenite, rutile, pyrrhotite, pyrite and chalcopyrite commonly occur, but no magnetite is present. Their primary paragenetic relations were confirmed by examining their mode of occurrences as inclusion species in major silicate minerals and the phase relations in the Cu-Fe-S system, though their parageneses changed in cooling of the rocks. This makes it possible to estimate the fugacities of oxygen and sulfur in the granitic rocks based upon their paragenetic relations, and to discuss the nature of volatiles in the granitic rocks. Significant subsolidus reactions for sulfide minerals continued until the rocks cooled below 300° C and took place in two types of mineral grains, in groundmass and as inclusions. The removal of sulfur and copper through the silicate crystals was too easy to preserve the chemistry of sulfides included in silicates.  相似文献   

Waveform characteristics of deep low-frequency earthquakes: time-series evolution based on the theory of the KM₂O-Langevin equation     

Minoru Takeo  Hiroko Ueda  Yasunori Okabe  Masaya Matsuura 《Geophysical Journal International》2006,165(1):87-107

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