• Title/Summary/Keyword: surface accumulation

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Copper and Lead Concentrations in Water, Sediments, and Tissues of Asian Clams (Corbicula sp.) in Bung Boraphet Reservoir in Northern Thailand (2008)

  • Netpae, Tinnapan;Phalaraksh, Chitchol
    • Environmental Engineering Research
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    • v.15 no.1
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    • pp.35-40
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    • 2010
  • Bung Boraphet is the largest freshwater reservoir in Thailand. This study examined the accumulation of copper (Cu) and lead (Pb) in water, sediment and tissues of Asian clams (Corbicula sp.) within Bung Boraphet to assess the possible polluting effect of soil erosion and the dissolution of water soluble salts from the Nan River. Samples were collected from 12 study sites within Bung Boraphet between February and December 2008. The physicochemical parameters of the water including temperature, pH, turbidity, ammonia nitrogen, nitrate nitrogen, orthophosphates, biochemical oxygen demand, dissolved oxygen, Cu, and Pb were measured. The water in Bung Boraphet was found to be medium clean according to the surface water quality standard of Thailand. The levels of Cu and Pb in the water were low but heavy metals were detected at higher levels in the sediment and tissues of Corbicula sp. In the near future, management practices and regulator approaches for Cu and Pb contamination will be needed to protect the water in Bung Boraphet.

A bibliographic study on the external therapy of Acute Mastitis(乳癰Yu-ong) (유선염(乳腺炎) 의 한방(韓方) 외치법(外治法)에 대한 문헌적고찰(文獻的考察))

  • Chang, Sung-Hwan
    • Korean Journal of Korean Medical Institute of Dermatology and Aesthetics
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    • v.1 no.1
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    • pp.177-197
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    • 2005
  • Acute Mastitis(急性乳腺炎=乳癰) is an acute suppurative disease appearing in the breast. It is mostly caused by galactostasis, the stagnation of liver-qi(肝鬱) and stomach-heat(胃熱). It is mostly found in breast feeding women, mostly in primiparae. It usually appears in the third and the fourth weeks of postpartum. At the beginning in the chest there appear induration, distending pain, galactostasis, inversion to cold with fever followed by the enlargement of the masses, burning red, megalgia, not subduing of chills and fever, the accumulation of it to form pus. In the early phase it is advisable to follow the therapeutic principles of soothing the liver and clearing away heat, promoting lactation and subduing swelling. After the formation of pus it is advisable to cut radially and drain the pus. External Therapy(外治法) generally refers to all the methods to treat various diseases and symptoms with application of drugs and manipulation or together with proper instruments on the body surface except the method of taking medicine orally Acute Mastitis has been regarded as surgery or the method of taking medicine orally But, based on many bibliographies, acute mastitis was treated by external therapy. Thus through the historical bibliographic studies of external therapy about acute mastitis, this study was made to help the expanding of the methods of treating acute mastitis.

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Leakage Current of Hydrogenated Amorphous Silicon Thin-Film Transistors (수소화된 비정질규소 박막트랜지스터의 누설전류)

  • Lee, Ho-Nyeon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.8 no.4
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    • pp.738-742
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    • 2007
  • The variations in the device characteristics of hydrogenated amorphous thin-film transistors (a-Si:H TFTs) were studied according to the processes of pixel electrode fabrication to make active-matrix flat-panel displays. The off-state current was about 1 pA and the switching ratio was over $10^6$ before fabrication of pixel electrodes; however, the off-state current increased over 10 pA after fabrication of pixel electrodes. Surface treatment on SiNx passivation layers using plasma could improve the off-state characteristics after pixel electrode process. $N_2$ plasma treatment gave the best result. Charge accumulation on the SiNx passivation layer during the deposition of transparent conducting layer might cause the increase of off-state current after the fabrication of pixel electrodes.

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Eliminating Method of Estimated Magnetic Flux Offset in Flux based Sensorless Control Algorithm of Surface Mounted PM Synchronous Motor (표면부착형 영구자석 동기전동기의 자속기반 센서리스 제어 알고리즘의 추정자속 옵셋 제거 기법)

  • Kim, Hack-Jun;Cho, Kwan-Yuhl;Kim, Hag-Wone;Lee, Kwang-Woon
    • The Transactions of the Korean Institute of Power Electronics
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    • v.22 no.3
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    • pp.216-222
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    • 2017
  • The rotor position of a PM synchronous motor is commonly estimated from the mathematical model for the sensorless control without rotor position sensors. For the magnet flux-based rotor position estimator in the stationary reference frame, the magnet flux estimator for estimating rotor position and speed includes the integrator. The integrator in the magnet flux estimator may accumulate the offset of the current sensors and the voltage drift. This continuous accumulation of the offset may cause the drift and overflow in the integrator, such that the estimated rotor position and speed may fail to track the real rotor position and speed. In this paper, the magnet flux estimator without integrator is proposed to avoid overflow in the integrator. The proposed rotor position and speed estimator based on magnet flux estimator are verified through simulation and experiment.

TSV Formation using Pico-second Laser and CDE (피코초 레이저 및 CDE를 이용한 TSV가공기술)

  • Shin, Dong-Sig;Suh, Jeong;Cho, Yong-Kwon;Lee, Nae-Eung
    • Laser Solutions
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    • v.14 no.4
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    • pp.14-20
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    • 2011
  • The advantage of using lasers for through silicon via (TSV) drilling is that they allow higher flexibility during manufacturing because vacuums, lithography, and masks are not required; furthermore, the lasers can be applied to metal and dielectric layers other than silicon. However, conventional nanosecond lasers have disadvantages including that they can cause heat affection around the target area. In contrast, the use of a picosecond laser enables the precise generation of TSVs with a smaller heat affected zone. In this study, a comparison of the thermal and crystallographic defect around laser-drilled holes when using a picosecond laser beam with varing a fluence and repetition rate was conducted. Notably, the higher fluence and repetition rate picosecond laser process increased the experimentally recast layer, surface debris, and dislocation around the hole better than the high fluence and repetition rate. These findings suggest that even the picosecond laser has a heat accumulation effect under high fluence and short pulse interval conditions. To eliminate these defects under the high speed process, the CDE (chemical downstream etching) process was employed and it can prove the possibility to applicate to the TSV industry.

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Shell forms for egg-shaped concrete sludge digesters: A comparative study on structural efficiency

  • Zingoni, A.
    • Structural Engineering and Mechanics
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    • v.19 no.3
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    • pp.321-336
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    • 2005
  • The structural feasibility of a variety of non-conventional sludge digesters, in the form of thin shells of revolution constructed in concrete, has formed the subject of investigation of a recent programme of research at the University of Cape Town. Such forms are usually known in the literature as "egg-shaped", and the advantages of these over conventional digesters of the wide-cylindrical type are now well-recognised: superior mixing efficiency, less accumulation of deposits at the bottom, easier removal of bottom deposits and surface crust, reduced heat losses, and so forth. With the aim of exploring the structural feasibility of various non-conventional forms for concrete sludge digesters, and making available usable analytical data and practical guidelines for the design of such thin shell structures, a number of theoretical studies have recently been undertaken, and these have covered conical assemblies, spherical assemblies and parabolic ogival configurations. The purpose of the present paper is to bring together the different analytical approaches employed in each of these studies, summarise the main findings in each case, draw comparisons among the various studied configurations with regard to structural efficiency and functional suitability, and make appropriate conclusions and recommendations.

The Energy Flow and Mineral Cycles in a Zoysia japonica and a Miscanthus sinensis Ecosystem on Mt. Kwanak 8. The Cycles of Sulphur (관악산의 잔디와 억새 생태계에 있어서 에너지 흐름과 무기물의 순환 8.황의 순환)

  • 강경미;장남기
    • Asian Journal of Turfgrass Science
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    • v.11 no.4
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    • pp.281-288
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    • 1997
  • This study was performed to find out the mineral cycles of sulphur in dynamic grassland ecosystems in a steady state condition at the northwest side on Mt. Kwanak. The experimental results may be summarized on the communities of a Zoysia japonica and a Miscanthus sinensis as follows. As compared with some properties of the surface soils among two semi-natural grasslands, sulphur war greater quantity in a Miscanthus sinensis than in a Zoysia japonica on Mt. Kwanak . For the case of steady production and release, the raion of annual mineral production to the amount accumulated on the top of mineral soil in a steady state provides the estimates of release constant k. The release constants on sulphur of the litter were 0.54 in a Zoysia japonica and 0.36 in a Miscanthus sinensis grassland. The half times of S required for the release or accumulation of the litter on the grassland were 1.28 years in a Zoysia japonica and 1.93 years in a Miscauthus sinensis The amounts of annual cycles for sulphur in the grassland ecosystem under the steady-state conditions were 20.65g /$m^2$ in a Zoysia japonica and 26.28g /$m^2$ in a Miacanthus sinensis grassland. Key words: Zoysia japonica Miscanthus sinensis Mt. Kwanak, Sulphur, Mineral cycles.

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KATSTIC SINKHOLE SEDIMENTS OF DOLOSTONE IN THE UPPER MIDWEST'S DRIFTLESS AREA, USA

  • Oh, Jong-woo
    • Journal of the Speleological Society of Korea
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    • v.34 no.35
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    • pp.78-104
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    • 1993
  • Analysis of one sinkhole, the Dodgeville sinkhole, developed in Ordovician dolostones in the Driftless Area of Wisconsin in the Upper Midwest'd Driftless Area reveals homogenous clayey sediment fills reflecting a range of dissolutional processes during the Quaternary or Pre-Quaternary. Granulometric analysis, graphical moments statistics, carbonate minerals, ana sand grain lithology were used to differentiate sinkhole sediment sources and modes of accumulation. Sediments in the dolostone sinkholes developed by dissolution. Sediments contain two major types of sediments : residual redish clay( autogenic sediments) and aeolian silt (allogenic sediments). The massive clay is generated from the weathered dolostone bedrocks as a in situ materials. The loessial silt is mostly derived from transportation of the surrounding surface materials, with some evidences of penetrated deposition. Unlike the collapsed sandstone sinkholes (Oh et al., 1993), dolostone sinkholes reveal homogenous, autogenic clay materials, and a geochemical composition indicative of in situ autogenic karstification. Dolostone sinkhole si1ts (26.9%) and sands (34.9%) are derived from weathered Plattevi1le-Galena dolostones, and contain high carbonate(37.5%), chert (57.2%) and lead ore (3%). Graphical moments statistics for sorting, skewness, and kurtosis indicate that sand grains from dolostones were derived entirely from local bedrock by in situ dissolution. Upper sinkhole sediments are pedagogically very young as carbonate is unleashed. Materials of the sinkhole sediment are definitely inherited from internal dolostones by dissolution and weathering, because not only a granulomatric comparison of dolostone and sandstone sediments demonstrates that they have heterogeneous paticle size distributions, but also 1ithologic analyses displays they differ completely.

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Diffusion Simulation Using Envi-Met. in Urban Planetary Boundary Layer (Envi-Met.을 이용한 도심 대기경계층 내 확산장 변화 수치 모의)

  • Choi, Hyun-Jeong
    • Journal of Climate Change Research
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    • v.7 no.3
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    • pp.357-371
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    • 2016
  • Buildings in the city acts as a cause of distorted wind direction, wind speed, causing the stagnation of the air flow. In the recent trend of climate change can not but consider the temperature rise of the urbanization. This study was aimed to analyze the thermal comfort of planetary boundary layer in different artificial constructions areas which has a direct impact on urban climate, and estimating the warming phenomena. Envi-met model was used to consider the urban structure associated with urban growth in order to precisely determine the impact of the building on the city weather condition. The analyzed values of thermal comfort index were temperature, wind speed, horizontal and vertical turbulent diffusivity. In particular, analysis of the PPD(Predicted Percentage of Dissatisfied) represents the human thermal comfort. In this study, by adjusting the arrangement and proportion of the top floor building in the urban it was found that the inflow of the fresh air and cooling can be derived low PPD. Vertical heat flux amount of the city caused by climate change was a factor to form a high potential temperature in the city and the accumulation of cold air does not appear near the surface. Based on this, to make the city effectively respond to climate change may require a long-term restructuring of urban spatial structure and density management.

Photodynamic Diagnosis and Therapy for Peritoneal Carcinomatosis from Gastrointestinal Cancers: Status, Opportunities, and Challenges

  • Kim, Hyoung-Il;Wilson, Brian C.
    • Journal of Gastric Cancer
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    • v.20 no.4
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    • pp.355-375
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    • 2020
  • Selective accumulation of a photosensitizer and the subsequent response in only the light-irradiated target are advantages of photodynamic diagnosis and therapy. The limited depth of the therapeutic effect is a positive characteristic when treating surface malignancies, such as peritoneal carcinomatosis. For photodynamic diagnosis (PDD), adjunctive use of aminolevulinic acid- protoporphyrin IX-guided fluorescence imaging detects cancer nodules, which would have been missed during assessment using white light visualization only. Furthermore, since few side effects have been reported, this has the potential to become a vital component of diagnostic laparoscopy. A variety of photosensitizers have been examined for photodynamic therapy (PDT), and treatment protocols are heterogeneous in terms of photosensitizer type and dose, photosensitizer-light time interval, and light source wavelength, dose, and dose rate. Although several studies have suggested that PDT has favorable effects in peritoneal carcinomatosis, clinical trials in more homogenous patient groups are required to identify the true benefits. In addition, major complications, such as bowel perforation and capillary leak syndrome, need to be reduced. In the long term, PDD and PDT are likely to be successful therapeutic options for patients with peritoneal carcinomatosis, with several options to optimize the photosensitizer and light delivery parameters to improve safety and efficacy.