• Title/Summary/Keyword: sedimentation method

검색결과 263건 처리시간 0.038초

Particle-in-Binder(PIB) 법을 이용한 다결정 $HgI_2$ 필름 제작 및 특성 연구 (Fabrication and Characterization of Polycrystalline Mereuric Iodide Films using Particle-in-Binder Methods)

  • 차병열;조성호;김소영;윤민석;남상희
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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    • pp.330-330
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    • 2007
  • Polycrystalline mercuric iodide $HgI_2$) films are being developed as a new detector technology for digital x-ray imaging. The $HgI_2$ is generally vacuum deposited by physical vapor deposition (PVD) process. But the PVD thick deposition has been caused any instability in the biasing due to any defects or cracks. In this work we present a new particle-in-binder (PIB) methodologies used for the $HgI_2$ thick films. These growth techniques can be easily extended to produce much larger film areas. This paper, for the first time, presents results and comparison of polycrystalline $HgI_2$ films derived by various PIB methods. We investigated the structural and morphological properties of the films using X-ray diffraction (XRD) and scanning electron microscopy (SEM) analysis. The films were characterized with respect to their electrical properties and in response to x-ray photons. Physical and electrical results were also compared between conventional polycrystalline PVD and our detectors. Leakage current as low as $350\;pA/cm^2$ at the bias voltage of ~ 200 V has been observed. And high sensitivity and good linearity in the response to x-rays was obtained in the film derived by PIB sedimentation method. Our future efforts will concentrate on optimization of film growth techniques for uniform large area deposition on image readout arrays.

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경사모세관법에 의한 우의 적혈구침강 속도에 미치는 환경온도의 영향 (Effect of Ambient Temperature on Bovine Erythrocyte Sedimentation Rate as Measured by Angled Capillary Method)

  • 김경진;이방환
    • 한국임상수의학회지
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    • 제4권1호
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    • pp.395-401
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    • 1987
  • In this study, the effect of ambient temperature on the 45$^{\circ}$micro ESR/hr of cattle blood were observed, and a correction chart for correcting observed values at any ambient temperature to standard values at 20$^{\circ}C$ was plotted. Besides, the effect of storage temperature of blood on the 45$^{\circ}$micro ESR/hr was surveyed. The results were as follows: 1. The values of the 45$^{\circ}$micro ESR/hr were increased as the ambient temperature were elevated(P<0.01), and lower the value of PCV, higher the effect of temperature on the 45$^{\circ}$micro ESR/hr was observed(P<0.01). 2. Regression of values of 45$^{\circ}$micro ESR to ambient temperature in all the group of different level of blood PCV showed linear regression with the highly significant coefficient of correlation. With the results, correction chart was drawn as in Fig. 1. 3. In the purpose to verify the reliability of correction chart, observed values of 45$^{\circ}$micro ESR/hr in field(out door) were corrected to values at 20$^{\circ}C$ by the correction chart(Fig. 1), comparing with the observed values at 20$^{\circ}C$ of standard temperature. No significant differences were found between two groups mentioned above. 4. In the study on the effect of storage temperature of the blood on the 45$^{\circ}$micro ESR/hr, group of storage temperature at 5$^{\circ}C$ showed statistically no significant differences untill 24 hours in contrast with standard control group.

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Collection of Clonorchis sinensis adult worms from infected humans after praziquantel treatment

  • Shen, Chenghua;Kim, Jae-Hwan;Lee, Jeong-Keun;Bae, Young-Mee;Choi, Min-Ho;Oh, Jin-Kyoung;Lim, Min-Kyung;Shin, Hai-Rim;Hong, Sung-Tae
    • Parasites, Hosts and Diseases
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    • 제45권2호
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    • pp.149-152
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    • 2007
  • A cohort was established for evaluation of cancer risk factors in Sancheong-gun, Gyeongsangnam-do, Korea. As one of the cohort studies, stools of 947 residents (403 males and 544 females, age range: 29-86 years) were screened for Clonorchis sinensis eggs using both Kato-Katz method and formalin-ether sedimentation technique. The overall egg positive rate of C. sinensis was 37.7% and individual EPG (eggs per gram of feces) counts ranged from 24 to 28,800. Eight egg positive residents voluntarily joined a process of collection of the passed worms after praziquantel treatment. A total of 158 worms were recovered from 5 of the 8 treated persons, ranged from 3 to 108 in each individual. The worms were $15-20 mm{\times}2-3 mm$ in size, and showed brown-pigmented, red, or white body colors. This is the first collection record of C. sinensis adult worms from humans through anthelmintic treatment and purgation. The adult worms of C. sinensis may be paralyzed by praziquantel and then discharged passively through bile flow in the bile duct and by peristaltic movement of the bowel.

고창 장호리 해안사구의 수직 발달 과정 연구 (Vertically Development Processes of Jangho-ri Coastal Dune, West Coast of Korea)

  • 한민;김진철;양동윤;김종연
    • 한국지형학회지
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    • 제23권3호
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    • pp.79-92
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    • 2016
  • Samples from two boreholes of coastal dune field at Jangho-ri coast, Gochang was studied. These were analyzed by grain size analysis geochemical analysis, and the application of OSL dating method to understand the development during the Holocene. The boreholes SB8 and SB9 were classified into three different sedimentary layers by their mean grain size and geochemical characteristics. The results revealed that the upper sand layer is equivalent to the present coastal dune layer, which developed since 1,200 years ago; the silt layer in the middle to the dune slack or lagoon sedimentation layer, which developed between 1,200 and 6,000 years ago; and the sand layer at the bottom to the paleo coastal dune that developed between 6,000 and 7,000 years ago. It was proposed that the forming material of current coastal dune was supplied from the sandy flat in coastal area, while the middle silt layer was supplied from the weathered soil of a bed rock by the comparison with material of surrounding area. In the case of coastal dune, concentrated layer of sands were identified which were buried about 300 and 1,200 years ago, which is identified as the little ice age. This study confirmed the development of Jangho-ri coastal dunes after Holocene Climate Optimum period, and it is likely to assist in the understanding of coastal dunes development.

Water Resources Management Challenge in the Citarum River Basin, Indonesia

  • Wicaksono, Albert;Yudianto, Doddi;Jeong, Gimoon;Kang, Doosun
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2016년도 학술발표회
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    • pp.198-198
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    • 2016
  • The Citarum River Basin is the biggest river basin in West Java Province, Indonesia and it plays strategic roles in providing water for irrigation, domestic and industrial uses, and power generation, besides controlling the flood during rainy season. Flowing through seven major cities makes the river flow and water demand are vulnerable to land use change around the river. The present water resources management has involved the regulator, operator, and users in deciding an appropriate water management plan for the entire basin. The plan includes an operation plan for three reservoirs, construction or maintenance of the river channel, and water allocation for all users along the river. Following this plan, a smaller operation group will execute and evaluates the plan based on the actual flow condition. Recently, a deforestation, environment degradation, river sedimentation, a rapid growth of population and industry, also public health become new issues that should be considered in water basin planning. Facing these arising issues, a new development program named ICWRMIP was established to advance the existing management system. This program includes actions to strengthen institutional collaboration, do the restoration and conservation of the river environment, improve water quality and public health, also advance the water allocation system. At present, the water allocation plan is created annually based on a forecasted flow data and water usage prediction report. Sometimes this method causes a difficulty for the operator when the actual flow condition is not the same as the prediction. Improving existing system, a lot of water allocation studies, including a development of the database and water allocation simulation model have been placed to help stakeholders decide the suitable planning schemes. In the future, this study also tries to contribute in advancing water allocation planning by creating an optimization model which ease stakeholders discover a suitable water allocation plan for individual users.

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A cost-effective method to prepare size-controlled nanoscale zero-valent iron for nitrate reduction

  • Ruiz-Torres, Claudio Adrian;Araujo-Martinez, Rene Fernando;Martinez-Castanon, Gabriel Alejandro;Morales-Sanchez, J. Elpidio;Lee, Tae-Jin;Shin, Hyun-Sang;Hwang, Yuhoon;Hurtado-Macias, Abel;Ruiz, Facundo
    • Environmental Engineering Research
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    • 제24권3호
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    • pp.463-473
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    • 2019
  • Nanoscale zero-valent iron (nZVI) has proved to be an effective tool in applied environmental nanotechnology, where the decreased particle diameter provides a drastic change in the properties and efficiency of nanomaterials used in water purification. However, the agglomeration and colloidal instability represent a problematic and a remarkable reduction in nZVI reactivity. In view of that, this study reports a simple and cost-effective new strategy for ultra-small (< 7.5%) distributed functionalized nZVI-EG (1-9 nm), with high colloidal stability and reduction capacity. These were obtained without inert conditions, using a simple, economical synthesis methodology employing two stabilization mechanisms based on the use of non-aqueous solvent (methanol) and ethylene glycol (EG) as a stabilizer. The information from UV-Vis absorption spectroscopy and Fourier transform infrared spectroscopy suggests iron ion coordination by interaction with methanol molecules. Subsequently, after nZVI formation, particle-surface modification occurs by the addition of the EG. Size distribution analysis shows an average diameter of 4.23 nm and the predominance (> 90%) of particles with sizes < 6.10 nm. Evaluation of the stability of functionalized nZVI by sedimentation test and a dynamic light-scattering technique, demonstrated very high colloidal stability. The ultra-small particles displayed a rapid and high nitrate removal capacity from water.

연자성 금속 분말의 분산에 분산제와 실란이 미치는 영향 (Effect of Dispersant and Silane on Dispersion of Magnetic Powder Paste)

  • 이창현;신효순;여동훈;남산
    • 한국전기전자재료학회논문지
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    • 제32권1호
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    • pp.25-29
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    • 2019
  • Various process technologies for manufacturing power inductors are under development. The core goal is to increase the mixing ratio of the soft magnetic powder in the epoxy, and to uniformly disperse it in a molding-type power inductor, manufactured by the injection molding method. In this study, we investigated the effect of dispersant and silane on the dispersion of soft magnetic metal powders in epoxy. We added 0.6 wt% of dispersant and 2.0 wt% of silane, and an excellent dispersibility resulted. Under the conditions of 0.3 wt% of dispersant and 0.5 wt% of silane, we added both dispersant and silane together to observe the effect of their interaction on dispersibility. Similarly, the addition of 0.3 wt% of dispersant and 0.1 wt% of silane resulted in a sharp increase in viscosity, considered to be due to the interaction of the dispersant and silane. The addition of 0.1 wt% of dispersant with 0.5 wt% of silane resulted in a sharp rise in viscosity, and sedimentation-height decreased sharply due to the dispersion optimization.

Comparison of seaweed pack and mudpack as treatment for knee osteoarthritis: a prospective randomized controlled study

  • Lee, Sang Hee;Han, Ji Hoon;Lee, Sung Jae;Cho, Hwi Young;Baek, Jung Heum;Kim, Jae Gyoon
    • Physical Therapy Rehabilitation Science
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    • 제8권1호
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    • pp.22-31
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    • 2019
  • Objective: For knee osteoarthritis (OA), there is a demand for alternative modalities in order to delay surgery and to avoid the side effects of medications. This study compared the effects of applying seaweed pack and mudpack for the treatment of knee OA. Design: Randomized controlled trial. Methods: Twenty-five patients with knee OA who satisfied the criteria were included. The patients were divided into two groups according to the treatment method: mudpack (n=12) and seaweed pack (n=13). The two groups were treated for 20 minutes, twice a day for five continuous days at the Ocean Healing Center at Wando Island, South Korea. Participants were assessed by clinical scores (Western Ontario and McMaster Universities Osteoarthritis Index, Hospital for Special Surgery Knee Score, Knee injury and Osteoarthritis Outcome Score and 36-Item Short Form Health Survey) and lab results (erythrocyte sedimentation rate, C-reactive protein, insulin-like growth factor-1 [IGF-1], tumor necrosis $factor-{\alpha}$ [$TNF-{\alpha}$]) during the follow-up period. Results: For the most part, clinical scores improved after therapy and maintained improvements for four weeks in both groups (p<0.05). In the seaweed group, $TNF-{\alpha}$ was significantly decreased at two weeks post-therapy (p<0.05). In both groups, IGF-1 was significantly increased immediately post-therapy (p<0.05). There were no statistically significant differences after therapy between the groups in clinical scores and labs. Conclusions: Seaweed packs and mudpacks had similar positive effects for knee OA. Additionally, the seaweed pack group showed decreased levels of $TNF-{\alpha}$ at two weeks post-treatment, which may explain the reduced inflammatory reaction. For rehabilitation therapy, use of seaweed packs may serve as an alternative modality for the treatment of knee OA.

국내 연약지반의 심도별 과압밀비 산정에 관한 사례연구 (Assessment of Overconsolidation Ratio by Depth of Soft Ground: A Case Study in South Korea)

  • 이종영;한중근
    • 한국지반신소재학회논문집
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    • 제20권4호
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    • pp.9-18
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    • 2021
  • 본 연구에서는 국내 연약점토지반을 대상으로 현장에서 불교란 상태로 채취된 흙을 이용해 실내 물리실험 및 역학시험을 실시하여 OCR을 산정하였으며, 실험 결과를 이용해 기존의 경험식과 심도별로 OCR을 예측하였다. 액성지수와 NAVFAC의 경험식을 실제 측정값과 비교·검토한 결과 액성지수를 이용한 방법이 지반의 개략적인 OCR을 추정하기에 적절한 것으로 나타났으나 지하수위 상부 지반의 경우에는 건조로 인한 영향을 고려하지 못한 것으로 나타났다. 따라서 지하수위 상부지반을 포함한 각 지역별 심도-OCR간의 상관관계식을 제안하였으며, 제안된 식을 인접지역의 OCR 예측에 적용한 결과 점토(CL, CH)로 구성된 지역에서의 예측값은 실측값과 상당부분 일치하는 경향을 보였다. 그러나 실트(ML)로 구성된 지역에서는 예측값이 실제값과 불일치한 결과를 보여 흙의 공학적 특성보다는 퇴적 및 구성 특성이 OCR예측에 중요한 영향인자임을 확인할 수 있었다.

함평만 갯벌의 모래 퇴적물로 인한 염습지 식물의 공간적 변이 (Spatial Variations of Salt Marsh Plants Induced by Sandy Sediment in Hampyeong Tidal Flat)

  • 홍민기;이재연;박정수;이효혜미
    • Ecology and Resilient Infrastructure
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    • 제9권4호
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    • pp.247-258
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    • 2022
  • 함평만은 좁은 만 입구와 복잡한 지형 구조로 인하여 비대칭적인 퇴적물 이동이 일어나기 때문에, 갯벌의 저질에는 모래 함량이 증가하는 것으로 연구되었다. 모래화 갯벌은 염습지 식생 분포를 변화시키는 것으로 현존식생도와 식생단면도 조사를 통해 분석되었다. 2016년과 2022년의 식생면적 비교에서 절대염생식물인 해홍나물군락은 74% 감소하였다. 반면 임의염생식물인 갯잔디군락은 75% 증가하였다. 특히 갯잔디는 지하경과 줄기의 밀도가 높게 발달하여, 군락 내 모래와 같은 퇴적물을 가둬서 견고한 사구환경을 조성하는 것으로 보인다. 함평만 갯벌의 효과적인 자연보전 관리 계획 수립을 위하여, 갯벌 토성 변화와 식생 군집의 상호작용이 향후 갯벌생태계에 미치는 영향에 대해 통합적 접근이 필요하다.