Impact of mercury emissions from incineration of automobile shredder residue in Japan     

Fumitake Takahashi  Mitsuo Yamagata  Kenji Yasuda  Akiko Kida 《Applied Geochemistry》2008

Mercury emissions from the incineration of automobile shredder residues (ASRs) were investigated. Continuous monitoring of elemental and reactive gaseous Hg in flue gas was performed in lab-scale and plant-scale ASR incineration. Results of continuous monitoring agreed with those obtained using the JIS K0222 method and Ontario-Hydro method. Before cleaning by air pollutant control devices (APCDs), reactive Hg was the dominant form of that element in both lab-scale and plant-scale results. Emission factors of reactive Hg before APCDs estimated from monitoring results showed large differences between plant-scale and lab-scale emissions. The emission factor in the plant scale was more than 10 times larger than that in the lab-scale, which is explainable by the different Hg contents of ASR. Based on plant-scale monitoring at the stack, emission factors after APCDs were estimated as 0.79 mg-Hg/Mg-ASR for elemental Hg and 6.8 mg-Hg/Mg-ASR for reactive Hg. Using these emission factors, total Hg emissions from ASR incineration were estimated as 2.2 kg/a. An ASR incineration plant investigated in this study used highly effective APCDs. Consequently, these emission factors might result in underestimation of national Hg emissions from ASR incineration. Emission factors estimated from lab-scale monitoring at a fabric filter outlet side might be more appropriate. However, even if emission factors calculated from plant-scale or the lab-scale monitoring are used, estimated emissions are still less than 1.0% of total Hg emissions in Japan. Therefore, Hg emissions from ASR incineration can be evaluated as insignificant. Unless Hg contents of ASR increase extremely, ASR incineration would be a minor source of Hg atmospheric emission in Japan, even if all ASRs were incinerated.  相似文献   

Physical oceanography   总被引：2，自引：0，他引：2  

K. Yoshida  K. Takano  T. Teramoto  Y. Toba  Y. Nagata  K. Kajiura  T. Nan'nichi  N. Iwata  T. Takahashi  M. Chaen  T. Tabata 《Journal of Oceanography》1971,27(6):248-264

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Simultaneous multifrequency observations of an eruptive prominence at millimeter wavelengths     

Yoshihisa Irimajiri  Toshiaki Takano  Hiroshi Nakajima  Kiyoto Shibasaki  Yoichiro Hanaoka  Kiyoshi Ichimoto 《Solar physics》1995,156(2):363-375

Radio images and spectra of an eruptive prominence were obtained from simultaneous multifrequency observations at 36 GHz, 89 GHz, and 110 GHz on May 28, 1991 with the 45-m radio telescope at Nobeyama Radio Observatory (NRO), the National Astronomical Observatory, Japan (NAOJ). The radio spectra indicated that the optical depth is rather thick at 36 GHz whereas it is thin at 89 and 110 GHz. The H data, taken at Norikura Solar Observatory, NAOJ, suggest that the eruption of an active region filament was triggered by an H flare. The shape and position of the radio prominence generally coincided with those of H images. The radio emission is explained with an isothermal cool thread model. A lower limit for the electron temperature of the cool threads is estimated to be 6100 K. The range of the surface filling factors of the cool threads is 0.3–1.0 after the H flare, and 0.2–0.5 in the descending phase of the eruptive prominence. The column emission measure and the electron number density are estimated to be of the order of 10²⁸ cm^–5 and 10¹⁰ cm^–3, respectively. The physical parameters of a quiescent prominence are also estimated from the observations. The filling factors of the eruptive prominence are smaller than those of the quiescent prominence, whereas the emission measures and the electron densities are similar. These facts imply that each cool thread of the prominence did not expand after the eruption, while the total volume of the prominence increased.  相似文献   

Lithology and palynology of Neogene sediments on the narrow edge of the Kitakami Massif (basement rocks), northeast Japan: Significant change for depositional environments as a result of plate tectonics     

Koji Yagishita  Akiko Obuse  Hiroshi Kurita 《Island Arc》2003,12(3):268-280

Abstract A controversial stratigraphic section, the Taneichi Formation, is exposed along the Pacific Coast of northeastern Honshu, the main island of the Japanese Archipelago. Although most sediments of the formation have long been dated as late Cretaceous, the northern section of it has been assigned to (i) the Upper Cretaceous; (ii) the Paleogene; or (iii) the Neogene. In the present report, we present the data of palynological and sedimentological studies, showing that the northern section should be assigned to the Neogene. A more important point in the present study is that we invoke some basic principles of fluvial sedimentology to resolve this stratigraphic subject. The lignite layers full of Paleogene–Miocene dinoflagellate cysts and pollen assemblages drape over the boulder‐sized (>40 cm in diameter) clasts in the northern section. However, the layers totally consist of aggregates of small lignite chips, indicating that the lignites are allochthonous materials. The mega‐clasts with derived microfossils in the lignites are thought to have been deposited as Neogene fluvial (flood) sediments in the newly formed Japanese Archipelago. Prior to the Miocene, the northern Honshu was part of the Eurasian Plate, thus the boulder‐sized clasts cannot be envisaged as long river flood deposits along the continental Paleogene Pacific Coast. Instead, the mega‐clasts with the draping lignites were probably derived from nearby Miocene highlands in the newly born island arc.  相似文献   

Bathymetric and geochemical investigation of Kawah Ijen Crater Lake, East Java, Indonesia     

B. Takano  K. Suzuki  K. Sugimori  T. Ohba  S. M. Fazlullin  A. Bernard  S. Sumarti  R. Sukhyar  M. Hirabayashi 《Journal of Volcanology and Geothermal Research》2004,135(4):299-329

A bathymetric survey of Kawah Ijen crater lake was conducted by acoustic sounding in 1996 to compare the lake morphology with those measured in 1922, 1925 and 1938, and to calculate the present lake volume. Even though the lake experienced several hydrothermal eruptions, the maximum depth became shallower (182 m) than before (200 m), resulting in a reduced lake volume (3.0×10⁷ m³).Fifty-two major and minor constituents including rare earth elements and polythionates (PT) of the lake waters at various depths were determined by ICP-AES, ICP-MS and HPLC, respectively. These ions except for several volatile elements are taken up by lake fringe through congruent dissolution of pyroclastics of Kawah Ijen volcano. Most ions are homogeneously distributed throughout the lake, although PT showed a considerable vertical variation. Rare earth elements (REE) in the Kawah Ijen water as well as those from other hyper-acidic crater lakes show distribution patterns likely due to the three rock dissolution (preferential, congruent and residual) types, and their logarithmic concentrations linearly depend upon the pH values of the lake waters.Using the PT degradation kinetics data, production rates of PT, injection rates of SO₂ and H₂S into the lake were estimated to be 114, 86 and 30 tons/day, respectively. Also travel time of the spring water at the Banyupahit Riverhead from Kawah Ijen was estimated to be 600–1000 days through the consideration of decreasing rates of PT. Molten sulfur stocks containing Sn, Cu, Bi sulfides and Pb-barite exposed on the inner crater slope were presumed to be extinct molten sulfur pools at the former lake bottom. This was strongly supported by the barite precipitation temperature estimated through the consideration of the temperature dependence of Pb-chlorocomplex formation.  相似文献   

Seafloor spreading, obduction and triple junction tectonics of the Mineoka Ophiolite, Central Japan     

Yujiro Ogawa  Akiko Takahashi 《Tectonophysics》2004,392(1-4):131

The Tertiary Mineoka ophiolite occurs in a fault zone at the intersection of the Honshu and Izu forearcs in central Japan and displays structural evidence for three major phases of deformation: normal and oblique-slip faults and hydrothermal veins formed during the seafloor spreading evolution of the ophiolite at a ridge-transform fault intersection. These structures may represent repeated changes in differential stress and pore-fluid pressures during their formation. The second series of deformation is characterized by oblique thrust faults with Riedel shears and no significant mineral veining, and is interpreted to have resulted from transpressional dextral faulting during the obduction of the ophiolite through oblique convergence and tectonic accretion. This deformation occurred at the NW corner of a TTT-type (trench–trench–trench) triple junction in the NW Pacific rim before the middle Miocene. The third series of deformation of the ophiolite is marked by contractional and oblique shear zones, Riedel shears, and thrust faults that crosscut and offset earlier structures, and that give the Mineoka fault zone its lenticular (phacoidal) fabric at all scales. This deformation phase was associated with the establishment and the southward migration of the TTT Boso triple junction and with the kinematics of oblique subduction and forearc sliver fault development. The composite Mineoka ophiolite hence displays rocks and structures that evolved during its complex geodynamic history involving seafloor spreading, tectonic accretion, and triple junction evolution in the NW Pacific Rim.  相似文献   

Efficient analysis of pile-group effect on seismic stiffness and strength design of buildings     

Izuru Takewaki  Akiko Kishida 《Soil Dynamics and Earthquake Engineering》2005,25(5):355-367

A new efficient method is developed for the analysis of pile-group effects on the seismic stiffness and strength design of buildings with pile foundations. An efficient continuum model consisting of a dynamic Winkler-type soil element and a pile is used to express the dynamic behavior of the structure-pile-soil system with only a small numerical error. The pile-group effect is taken into account through the influence coefficients among piles which are defined for interstory drifts and pile-head bending moments. It is shown that, while the pile-group effect reduces the interstory drift of buildings in general, it may increase the bending moment of piles at the head. This means that the treatment without the pile-group effect results in the conservative design for super-structures and requires a revised member design for piles.  相似文献   

Grid‐size dependency of the meridional heat transport in a numerical model of an ocean     

Kenzo Takano 《大气与海洋》2013,51(3):258-267

Abstract

The meridional heat transport across a latitude circle in a model ocean is calculated by using a general circulation model with a coarse grid, a medium grid and a fine grid capable of resolving the mesoscale eddies in order to show to what extent this transport depends on grid size. Although the grid size strikingly affects the current velocities, it has almost no effect upon the meridional heat transport.  相似文献   

A diatom‐inferred record of lake variability during the last 900 years in Lützow–Holm Bay,East Antarctica          下载免费PDF全文

Rachel C. Rudd  Jonathan J. Tyler  John Tibby  Yusuke Yokoyama  Ines Tavernier  Elie Verleyen  Manabu Fukui  Yoshinori Takano 《第四纪科学杂志》2016,31(2):114-125

Decadal–centennial‐scale climate variability in coastal Antarctica remains poorly understood due to the limited number of highly resolved, well‐dated records. We present a 900‐year, decadal‐scale reconstruction based on sedimentary diatoms from Lake Abi in Lützow–Holm Bay, East Antarctica. Hydrological change is inferred from diatom ecological preferences in conjunction with an existing regional training set and implies that lake water specific conductivity, depth and nitrogen availability are the key drivers of diatom assemblage change. Lake Abi underwent a series of subtle environmental changes related to these environmental variables, possibly driven by changes in catchment snow melt and the duration of seasonal ice cover. Ordination is used to trace the major patterns of change in the diatom community, with notable shifts identified between 470 and 400 and at ～350 cal a BP (where present = CE 1950). The frequency of environmental variability at Lake Abi is broadly consistent with a record of the Interdecadal Pacific Oscillation during the last millennium, but contrasts with the apparent climate stability elsewhere in eastern Antarctica. Further research is required to constrain the limnological and ecological responses of lakes in coastal Antarctica to obtain more rigorous palaeoclimate reconstructions from these sites of immense potential.  相似文献   

Phylogenetic position and systematics of the wood‐associate limpet genus Caymanabyssia and implications for ecological radiation into deep‐sea organic substrates by lepetelloid gastropods          下载免费PDF全文

Yasunori Kano  Tsuyoshi Takano  Enrico Schwabe  Anders Warén 《Marine Ecology》2016,37(5):1116-1130

The gastropod superfamily Lepetelloidea represents an extremely diverse lineage in terms of their utilization of different deep‐sea organic substrates that include sunken wood, leaves, whale and fish bones, egg cases of sharks and rays, annelid tubes and detrital cephalopod beaks among others. They also inhabit cold seeps and hydrothermal vents, thus presenting an interesting case for the evaluation of such organic substrates as ‘stepping stones’ into these chemosynthetically nourished environments. Here we show the first molecular phylogeny of the Pseudococculinidae, a primarily wood‐dwelling family and the most speciose in Lepetelloidea. Special emphasis is placed on the genus Caymanabyssia, for which the only subfamily Caymanabyssiinae has been established, and a new species Caymanabyssia solis is described herein and compared with previously known taxa in order to reconsider the morphological characteristics of lepetelloids on wood. Bayesian and likelihood trees reconstructed using four‐gene sequences reveal that Pseudococculinidae sensu auctt. is a polyphyletic taxon that is grouped by shared plesiomorphic conditions of characters including the radula, a digestive organ, the morphology of which is often governed strongly by diet and feeding ecology. The newly reinterpreted families Pseudococculinidae and Caymanabyssiidae represent reciprocal sister clades as a basal radiation in Lepetelloidea. Sunken wood might thus have served as an ancestral habitat from which species on other substrates and vent and seep taxa were derived.  相似文献