Quantification of Aquatic Nano Particles after Different Steps of Bodensee Water Purification with Laser‐induced Breakdown Detection (LIBD)     

Tobias Bundschuh  Roger Knopp  Rudi Winzenbacher  Jae Il Kim  Rainer Kster 《洁净——土壤、空气、水》2001,29(1):7-15

The laser‐induced breakdown detection (LIBD) is a very sensitive method for the direct detection of colloids based on the plasma generation on single particles by a focused, pulsed laser beam and the detection of the produced shock wave or plasma light emission. For the determination of colloid sizes the light emission of single plasmas is detected by a microscope CCD‐camera system. With known mean particle diameter and breakdown probability the particle concentration can be calculated. The application of the LIBD to monitor the change of colloid concentration and size during the purification steps of drinking water at the Bodensee (Lake Constance, Germany) water purification plant is shown. The breakdown probability, correlating to colloid number density, decreases with every purification step. By addition of FeCl₃ as a precipitating agent and with an additional filtration step, not only suspended matter, but also colloids are effectively removed. After this process a remaining particle concentration of 50 ng/L and a mean particle diameter of 27 nm are found.  相似文献   

Paleozoic sedimentation and tectonics in Korea: A review   总被引：11，自引：1，他引：11  

Yong Il Lee  Jae Il Lee 《Island Arc》2003,12(2):162-179

Abstract The geological history of the Korean Paleozoic is recorded in lower and upper Paleozoic strata, mostly distributed in two relatively large sedimentary basins, the Taebaeksan and Pyeongnam basins. The lower Paleozoic sedimentary rocks are exclusively of marine origin, dominated by shallow platform carbonate rocks with minor interbedded siliciclastic rocks. The development of the lower Paleozoic sequence was mostly controlled by eustatic changes, having cyclic sedimentation of various temporal scales. During the early Paleozoic the Korean Peninsula was located in a low‐latitude tropical region and experienced frequent storm activities. The upper Paleozoic sequence comprises paralic to non‐marine rocks with minor limestone intercalations in the lower part of the sequence. Upsection changes in sandstone composition and mudrock geochemistry of the upper Paleozoic Pyeongan Supergroup in the Samcheok coalfield indicate that sediments may have been derived from the continued uplift and unroofing of a collisional orogen source. There exists a great unconformity between the lower and upper Paleozoic strata, which spans the geological time from the Late Ordovician to Early Carboniferous. The unconformity period is conventionally thought to be of non‐deposition, but a recent study suggests that it is characterized by continuous sedimentation and significant removal (>1 km thick) of sediments by erosion. No Paleozoic tectonic history has been addressed so far, and thus it needs further study to elucidate geological events during the middle–late Paleozoic in the Korean Peninsula. Tectonostratigraphic correlation of the Korean Peninsula with neighboring Chinese blocks has been a hot issue for a long time. Although the eastward extension of the Chinese collision belt has been recently suggested to be the Imjingang belt located in the middle of the peninsula, further studies are needed to test this hypothesis because results of recent paleontological, sedimentological and stratigraphic studies on Paleozoic sediments are not in agreement with this possibility.  相似文献   

Diagenesis of the Lower Cretaceous Kanmon Group sandstones, SW Japan     

Kyung Hwan Sur  Yong Il Lee  Ken-ichiro Hisada 《Journal of Asian Earth Sciences》2002,20(8)

The Kanmon Group (Lower Cretaceous) is a non-marine sequence in the Inner Zone of southwest Japan and is divided into the lower Wakino (lacustrine) and the upper Shimonoseki (fluvial) subgroups. Major diagenetic changes in this group are compaction, iron-oxide cementation, calcite cementation and grain replacement, quartz overgrowth and pore-fill cementation, illite authigenesis, chlorite pore-fill cementation and grain replacement, albitization of feldspar, and grain replacement by pyrite. Two subgroups of the Kanmon Group present no significant differences in general diagenetic features, paragenetic sequence, or the degree of diagenetic changes despite differences in depositional environments (lacustrine vs. fluvial) and stratigraphic positions. However, some differences are recognized in the content and chemistry of authigenic minerals caused by different sandstone framework compositions. The content of authigenic clay minerals is higher in sandstones of the Shimonoseki Subgroup containing abundant volcanic rock fragments. In addition, the composition of chlorite, the most abundant authigenic clay mineral in Kanmon sandstones, is Mg-rich in the volcanoclastic Shimonoseki sandstones, compared to an Fe-rich variety in Wakino sandstones. The original sandstone composition played a significant role in pore-water composition and diagenetic reactions.The Wakino sandstones lost most of its porosity by compaction, whereas Shimonoseki sandstones are only compacted in the vicinity of the basin-bounding fault. The weakly compacted Shimonoseki sandstones, instead, were largely cemented by pore-filling calcite during early diagenesis; cementation prevented compaction during further burial. The Kanmon Group sediments were heated to about 300 °C based on illite crystallinity values.  相似文献   

Conditions of formation of ferromanganese nodules in the bottom sediments of lakes in the Baltic shield     

V. A. Dauval’ter  B. P. Il’yashuk 《Geochemistry International》2007,45(6):615-619

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Laboratory Modeling of the Rotation of Jets Ejected from Young Stellar Objects at Studies the Azimuthal Structure of an Axial Jet at the PF-3 Facility     

Krauz  V. I.  Mitrofanov  K. N.  Kharrasov  A. M.  Il’ichev  I. V.  Myalton  V. V.  Anan’ev  S. S.  Beskin  V. S. 《Astronomy Reports》2021,65(1):26-44

Astronomy Reports - The paper presents the results of experiments for studying the dynamics and internal structure of an axial plasma jet at the PF-3 facility. Measurements of the azimuthal...  相似文献   

Correction factors for quantitative analysis of anchovy eggs and larval stages from the southern waters of Korea     

Jin Yeong Kim  Nancy C. H. Lo  Joo Il Kim 《Ocean Science Journal》2005,40(1):11-16

Correction factors based on the catch ratios of egg and larval densities in the southern waters of Korea were estimated for anchovyEngraulis japonica. This was undertaken in order to adjust ichthyoplankton data from different sampling methods, gear types and time. Samples were collected during ichthyoplankton surveys in Korean waters from 1983 to 1994. The ratios for egg densities obtained in vertical tows with a NORPAC net (ring Φ, 45 cm) compared to those obtained in oblique tows with a KOB net (ring Φ, 80 cm) were 0.86 (CV = 0.65), 1.22 (CV = 0.36), and 0.93 (CV = 0.42) for early, middle, and later developmental stages, respectively. The ratios for larval densities for vertical and oblique tows varied depending on size. For yolk-sac and small larvae (< 4 mm), the ratios were 3.08 (CV = 0.45) and 1.98 (CV = 1.34), while those of 4-6 mm, 6-8 mm, and 8-10 mm larvae were 0.44 (CV = 1.31), 0.45 (CV = 1.70), and 0.56 (CV = 2.50), respectively. Ratios of day/night densities for larvae of 4-10 mm lengths were lower (0.01-0.06) in offshore catches than values obtained in coastal areas (0.44-0.46) and similar values (0.16-0.04) for vertical and oblique tows. Our results indicated that vertical towing is more efficient for sampling early life stages (from eggs to larvae less than 4 mm long), while oblique towing is more efficient for larvae longer than 4 mm due to depth preferences for each developmental stage (e.g., changes in egg buoyancy and vertical migration of larvae).  相似文献   

Projected changes to high temperature events for Canada based on a regional climate model ensemble     

Dae Il Jeong  Laxmi Sushama  Gulilat Tefera Diro  M. Naveed Khaliq  Hugo Beltrami  Daniel Caya 《Climate Dynamics》2016,46(9-10):3163-3180

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Spillway discharges by modification of weir shapes and overflow surroundings     

Il Won Seo  Young Do Kim  Yong Sung Park  Chang Geun Song 《Environmental Earth Sciences》2016,75(6):496

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Holocene paleoclimate changes determined using diatom assemblages from Lake Long,King George Island,Antarctica     

Kyung Lee  Sook-Kyung Yoon  Ho Il Yoon 《Journal of Paleolimnology》2009,42(1):1-10

Formation of Lake Long, King George Island, Antarctica started about 4,000 years B.P., after which the diatom community changed in response to environmental shifts driven by climatic oscillations (warm/wet and cool/dry). Successive sequences of diatoms in a 7.5-m drill core were divided into 11 assemblage zones by cluster analysis. The most obvious change was an alternation of major dominants, Achnanthes minutissima, Fragilaria alpestris and Fragilaria pinnata v. antarctica according to the climatic oscillations in the late Holocene. Variations in diatom assemblages clearly reflect two warm periods, a single cool period, and three transition periods. The recent warm period (zones 2 and 1) has persisted for approximately 450 years, perhaps sufficiently long to suggest the imminent onset of a new transition period. A recent high TOC (total organic carbon) value in the core reflects a warm period in Antarctica during the late Holocene.  相似文献   

Sedimentological, geochemical and palaeontological evidence for a neoglacial cold event during the late Holocene in the continental shelf of the northern South Shetland Islands, West Antarctica     

Kyu-Cheul Yoo  Ho Il Yoon  Jin-Kyung Kim  & Boo-Keun Khim 《Polar research》2009,28(2):177-192

Two sediment cores obtained from the continental shelf of the northern South Shetland Islands, West Antarctica, consist of: an upper unit of silty mud, bioturbated by a sluggish current, and a lower unit of well-sorted, laminated silty mud, attributed to an intensified Polar Slope Current. Geochemical and accelerator mass spectrometry ¹⁴C analyses yielded evidence for a late Holocene increase in sea-ice extent and a decrease in phytoplankton productivity, inferred from a reduction in the total organic carbon content and higher C : N ratios, at approximately 330 years B.P., corresponding to the Little Ice Age. Prior to this, the shelf experienced warmer marine conditions, with greater phytoplankton productivity, inferred from a higher organic carbon content and C : N ratios in the lower unit. The reduced abundance of Weddell Sea ice-edge bloom species ( Chaetoceros resting spores, Fragilariopsis curta and Fragilariopsis cylindrus ) and stratified cold-water species ( Rhizosolenia antennata ) in the upper unit was largely caused by the colder climate. During the cold period, the glacial restriction between the Weddell Sea and the shelf of the northern South Shetland Islands apparently hindered the influx of ice-edge bloom species from the Weddell Sea into the core site. The relative increases in the abundance of Actinocyclus actinochilus and Navicula glaciei , indigenous to the coastal zone of the South Shetland Islands, probably reflects a reduction in the dilution of native species, resulting from the diminished influx of the ice-edge species from the Weddell Sea. We also document the recent reduction of sea-ice cover in the study area in response to recent warming along the Antarctic Peninsula.  相似文献