• Title/Summary/Keyword: degradation stabilization

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Beam Stabilization Beamforming Technique for Hull-Mounted Sonar Performance Enhancement (선저고정형 소나의 탐지성능 향상을 위한 빔 안정화 빔형성 기법)

  • Ryu, Young-Woo
    • Journal of the Korea Institute of Military Science and Technology
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    • v.11 no.3
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    • pp.129-137
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    • 2008
  • Hull-Mounted Sonar(HMS) has been the main equipment to detect and track underwater threats like torpedoes and enemy submarines. The HMS has short warming-up time and is employable independently with sea-state and weather condition. But these bad environmental condition and ship maneuvering make ship's roll and pitch. Ship's roll and pitch make unstability of sensor position, then cause degradation of the HMS performance. In this paper, we will show how the unstability influences the HMS performance, propose the 'Beam Stabilization Beamforming Technique' to overcome these phenomenon. And present the effectiveness of proposed technique by comparing with conventional beamforming result.

Stabilization of Modified Deceleration Mode for Improvement of Low-energy Ion Implantation Process (저 에너지 이온 주입의 개선을 위한 변형된 감속모드 이온 주입의 안정화 특성)

  • 서용진;박창준;김상용
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.16 no.3
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    • pp.175-180
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    • 2003
  • As the integrated circuit device shrinks to the deep submicron regime, the ion implantation process with high ion dose has been attracted beyond the conventional ion implantation technology. In particular, for the case of boron ion implantation with low energy and high dose, the stabilization and throughput of semiconductor chip manufacturing are decreasing because of trouble due to the machine conditions and beam turning of ion implanter system. In this paper, we focused to the improved characteristics of processing conditions of ion implantation equipment through the modified deceleration mode. Thus, our modified recipe with low energy and high ion dose can be directly apply in the semiconductor manufacturing process without any degradation of stability and throughput.

시멘트/슬래그/Fe(II) 시스템에 의한 NAPL TCE의 분해 특성

  • 박정현;강완협;황인성;박주양
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2004.04a
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    • pp.218-222
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    • 2004
  • Batch slurry experiments were conducted to develop cement/slag/Fe(II) system that could treat hazardous liquid wastes containing halogenated organic solvents. Portland cement in combination with Fe(II) was reported to reductively dechlorinate chlorinated organics in a modified solidification/stabilization process. TCE (trichloroethylene) was used a model halogenated organic solvent. The objectives of this study were to assess the feasibility of using cement and steel converter slag amended with Fe(II) as a low cost abiotic reductive dechlorination and to investigate the kinetics of TCE dechlorination over a wide range of TCE concentration. From the result of screening experiments, cement/slag/Fe(II) system was identified as a potentially effective system to treat halogenated organic solvent. Kinetic studies were carried out to further investigate degradation reaction of TCE NAPL (Non Aqueous Phase Liquids) in cement/slag/Fe(II) systems by using batch slurry reactors. Degradation rate of TCE solution in this system can be explained by pseudo-first-order rate law because the prediction with the rate law is in good agreement with the observed data.

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Conservation of Biodiversity and Forest Resources in Nepal -Degradation and Threats-

  • Ghimire, Bimal Kumar;Islam, Mohammad Saiful;Chun, Su-Kyoung
    • Journal of the Korea Furniture Society
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    • v.19 no.4
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    • pp.300-306
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    • 2008
  • Nepal is rich country in terms of its vast array of biological diversity. The relationship between local communities and the biological diversity in Nepal is a very entangle one, whereby two-thirds of our population are heavily dependent upon the biodiversity for their survival. The destruction of biodiversity signifies the destruction of people's livelihoods and survival. Biodiversity and genetic resources conservation has been a most significant part of the Nepalese society due to its socio-economic and cultural importance and provides the human race trees for timber, fuel, food, industrial raw materials, pharmaceuticals, beverages and environmental stabilization. Threats to biodiversity at global level is of greater concern, specially, human activities are the greatest factor currently affecting biodiversity, through the use of natural resources by industry, agriculture, hunting, and energy generation.

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A Study on Phenomena of Watertree and Dielectric Breakdown in XLPE (XLPE의 수트리와 절연파괴 현상에 관한 연구)

  • 이성일
    • Journal of the Korea Safety Management & Science
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    • v.3 no.4
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    • pp.45-52
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    • 2001
  • In order to Investigate water tree degradation behavior on XLPE cable, direct voltage of 200 to 800V has been applied to the material at 5$0^{\circ}C$~10$0^{\circ}C$, and the water tree property has been correlated with voltage and temperature. The leakage current was increase as temperature increased and the Ohm's law was generally satisfied in this experiment though some experimental errors were found. The leakage current was decreased and reached to the stable state with time. It was also shown that the time for the stabilization of leakage current was lessened as voltage increased

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STAT3 Potentiates SIAH-1 Mediated Proteasomal Degradation of β-Catenin in Human Embryonic Kidney Cells

  • Shin, Minkyung;Yi, Eun Hee;Kim, Byung-Hak;Shin, Jae-Cheon;Park, Jung Youl;Cho, Chung-Hyun;Park, Jong-Wan;Choi, Kang-Yell;Ye, Sang-Kyu
    • Molecules and Cells
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    • v.39 no.11
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    • pp.821-826
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    • 2016
  • The ${\beta}$-catenin functions as an adhesion molecule and a component of the Wnt signaling pathway. In the absence of the Wnt ligand, ${\beta}$-catenin is constantly phosphorylated, which designates it for degradation by the APC complex. This process is one of the key regulatory mechanisms of ${\beta}$-catenin. The level of ${\beta}$-catenin is also controlled by the E3 ubiquitin protein ligase SIAH-1 via a phosphorylation-independent degradation pathway. Similar to ${\beta}$-catenin, STAT3 is responsible for various cellular processes, such as survival, proliferation, and differentiation. However, little is known about how these molecules work together to regulate diverse cellular processes. In this study, we investigated the regulatory relationship between STAT3 and ${\beta}$-catenin in HEK293T cells. To our knowledge, this is the first study to report that ${\beta}$-catenin-TCF-4 transcriptional activity was suppressed by phosphorylated STAT3; furthermore, STAT3 inactivation abolished this effect and elevated activated ${\beta}$-catenin levels. STAT3 also showed a strong interaction with SIAH-1, a regulator of active ${\beta}$-catenin via degradation, which stabilized SIAH-1 and increased its interaction with ${\beta}$-catenin. These results suggest that activated STAT3 regulates active ${\beta}$-catenin protein levels via stabilization of SIAH-1 and the subsequent ubiquitin-dependent proteasomal degradation of ${\beta}$-catenin in HEK293T cells.

DNA Damage-inducible Phosphorylation of p53 at Ser20 is Required for p53 Stabilization

  • Yang, Dong-Hwa;Rhee, Byung-Kirl;Yim, Tae-Hee;Lee, Hye-Jin;Kim, Jungho
    • Animal cells and systems
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    • v.6 no.3
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    • pp.263-269
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    • 2002
  • The p53 tumor suppressor gene is among the most frequently mutated and studied genes in human cancer, but the mechanisms by which it sur presses tumor formation remain unclear. DNA damage regulates both the protein levels of p53 and its affinity for specific DNA sequences. Stabilization of p53 in response to DNA damage is caused by its dissociation from Mdm2, a downstream target gene of p53 and a protein that targets p53 for degradation in the proteosome. Recent studies have suggested that phosphorylation of human p53 at Ser20 is important for stabilizing p53 in response to DNA damage through disruption of the interaction between Mdm2 and p53. We generated mice with an allele encoding changes at Ser20, known to be essential for p53 accumulation following DNA damage, to enable analyses of p53 stabilization in vivo. Our data showed that the mutant p53 was clearly defective for full stabilization of p53 in response to DNA damage. We concluded that Ser20 phosphorylation is critical for modulating the negative regulation of p53 by Mdm2, probably through phosphorylation-dependent inhibition of p53-Mdm2 interaction in the physiological context.

Bioremediation of Polycyclic aromatic hydrocarbons (PAHs) and Heavy metals in contaminated marine sediments at filed scale study using biostimulant ball (오염연안저질에 함유된 PAH와 중금속의 생물정화를 위한 생물활성촉진제의 현장적용)

  • Woo, Jung-Hui;Subha, Bakthavachallam;Song, Young-chae
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2016.05a
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    • pp.132-134
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    • 2016
  • The Study mainly focused on bioremediation of 16 types PAHs and heavy metals in contaminated marine sediments at filed scale study using slow release biostimulant ball (BSB) was investigated. In our experiment, filed scale study ($1m{\times}1m$) was performed and the effect of BSB on PAHs and heavy metals were analysed. BSB size and distance were determined and optimum size and distance were 3cm and 5.5cm respectively. BSB containing nutrients of acetate, nitrate and sulphate which can enhance the activity of microorganism to increase degrading capacity of PAHs and enhance the heavy metals stabilization also to decrease bioavailability. PAHs containing 16 types of 2, 3, 4, 5 and 6 rings compound PAHs were found and to degrade upto 100% in 2, 3 rings, upto 90 to 94% in 4 and 5 rings and 6 ring compound was degrade up to 70%. For heavy metals stabilization percentage was increased using BSB sediment and exchangeable portion was decreased and residual portion was increased in all analysed heavy metals. BSB enhance the PAHs degradation and stabilization of heavy metals percentages. BSB is a promising method for remediation of PAHs and heavy metals in contaminated marine sediments.

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Stabilization of Solid Waste in Lysimeter by Air Injection Mode (공기주입 방식을 이용한 매립모형조내 폐기물 안정화)

  • Kim, Kyung;Park, Joon-Seok;Lee, Hwan;Lee, Cheol-Hyo;Kim, Joung-Dae
    • Journal of Environmental Health Sciences
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    • v.31 no.1
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    • pp.15-22
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    • 2005
  • This study was conducted to evaluate air injection mode on stabilization of solid waste in lysimeter. For three lysimeters, one was maintained under anaerobic condition as control, and air was injected into two lysimeters in continuous mode (atmospheric pressure) and intermittent mode (high pressure of 2 bar). Distilled water was sprayed over solid waste in 1.4 l/$m^3$(solid waste)/day, supposing rainfall intensity of 1,200 mm/yr and 30% infiltration. Oxygen in landfill gas was not detected in control lysimeter during operational days. After 30 day-aeration, oxygen concentrations of continuous and intermittent modes were maintained in 14% and 6%, respectively. $COD_{Cr}$ removal efficiencies of continuous and intermittent modes were about 70% and 50%, and BOD5 removal efficiencies were about 80% and 20%, respectively. In view of oxygen supply, and $COD_{Cr}$ and $BOD_5$ removal, continuous air injection mode of atmospheric pressure was more effective than intermittent mode of 2 bar. Settling degree of solid waste in case of two air injection modes was 3 times higher than that of anaerobic condition as control. Considering the above results, it was thought that air injection (especially continuous atmospheric pressure) could improve degradation of solid waste and induce preliminary stabilization in landfill site.

A Study on Stabilization of Landfill by Air Ventilation in Field (공기주입방식을 통한 쓰레기 안정화의 현장적용에 관한 연구)

  • Lee, Hwan;Lee, Chae-young;Jeon, Yeon-ho;Kim, Kyung;Kim, Doo-il;Lee, Cheol-hyo
    • Journal of the Korea Organic Resources Recycling Association
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    • v.8 no.4
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    • pp.121-128
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    • 2000
  • Landfill and lysimeter experiments were conducted to estimate the optimum air injection method for the degradation of waste in landfill and the pre-stabilization. Continuous injection with low pressure and quantity can be effective for pre-stabilization of old landfill due to the lower contents of volatile solids in landfill. Air injection and landfill gas (LFG)extraction showed that the SVE (Soil Vapor Extraction) effect by air ventilation was more significant than the biodegradation of organics. Theses results suggested that they could accelerate the biological stabilization of organic waste in landfills. It is also expected that they would reduce the problems including gas emission during the landfill mining, separation and/or transportation to such levels that might be discharged directly to the atmosphere or with minimal treatment, if required.

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