• Title/Summary/Keyword: over-potential

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Potential Health Risks from Persistent Organic Pollutants (POPs) in Marine Ecosystem

  • Lee, Youn Ju;Jang, Jae-Seok;Yang, Jae-Ho
    • Journal of Marine Bioscience and Biotechnology
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    • v.8 no.1
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    • pp.10-17
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    • 2016
  • A wide-spread contamination of persistent organic pollutants (POPs) such as dioxins, PCBs, PBDEs in the aquatic ecosystem has generated a great concern over the potential risk for these substances to impact marine biotas and food web. Since a major exposure route of these substances to the humans is through the consumption of food including fish and marine byproducts, the consumption of contaminated products has been a great public health concern. Exposure to POPs has been associated with a wide spectrum of adverse effects including reproductive, developmental, immunologic, carcinogenic, and neurotoxic effects. This review covers the background information of key POPs substances and the recent development of toxicity studies including the mode of action. Because neurotoxic effects of some POPs have been observed in humans at low concentrations, polychlorinated biphenyl (PCB), a representative chemical of POPs, is focused to discuss the possible mode(s) of action for the neurotoxic effects. This review provides the updates of toxicity studies on POPs and paves ways to discuss a possible implication of contaminated marine biota over the human health among the marine biotechnology researchers.

A Reliability Analysis of a Guyed Tower (Guyed Tower의 신뢰성 해석)

  • Tae-B.,Ha;Hang-S.,Choi
    • Bulletin of the Society of Naval Architects of Korea
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    • v.24 no.2
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    • pp.29-35
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    • 1987
  • As offshore activities move into deeper ocean, conventional fixed-base platforms drastically increase in size and cost, One of alternatives available is a guyed tower, in which environmental loads are supported by guylines instead of structural members. The guying system of the guyed tower is designed on one hand to be stiff enough to limit the structural displacement in normal operations, but on the other hand to be soft enough to permit large slow sways during the presence of design-level storms. This compliancy provides an efficient means of withstanding harsh environment so that the disproportionate increase in size of deep water platforms can be kept to a rational limit. Novel configurations contain always some degrees of potential risks mainly due to the lack of experience. The most critical hazard inherent to a guyed tower may be the pullout of anchor piles. Once it happens, the guyline fails to function and it may eventually lead to the total collapse of the system. It is the aim of this paper to discuss and quantify the anchor-pullout risk of a guyed tower. A stochastic analysis is made for evaluating the first-upcrossing probability of the tension acting on anchor piles over the uplift capacity. Nonlinearities involved in the mooring stiffness and hydrodynamics are taken into account by using time-domain analysis. A simplified two dimensional dynamic model is developed to exemplify the underlying concept. Real hurricane data in the Gulf of Mexico spanning over 70 years are incorporated in a numerical example of which result clearly indicates highly potential risk of anchor pullout.

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The Anti-wrinkle Effects and Whitening Effects of Galla Rhois (오배자의 항 주름 효과 및 미백 효과에 미치는 실험적 연구)

  • Park, Jin-Mee;Park, Kyung-Jun
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.23 no.1
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    • pp.135-148
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    • 2010
  • Recently, the demands for the effective and safe depigmentating and anti-aging agents of the skin have increased due to the medical, pharmaceutical and cosmetic reasons. The aim of this study is to search Galla Rhois (GR) inhibitory activity against aging process of skin in vitro. GR was screened for their inhibitory activity against elastase. GR (final concentration 1 mg/ml) appeared over 40% of inhibition of elastase activity. So we investigated anti wrinkle effects of GR look through MMP-1 inhibition activity. Also Extracts of GR showed higher anti-tyrosinase activity than arbutin (final concentration 1 mg/ml). These results suggest that GR could be potential sources of anti-aging and whitening effects for the skin. Objective : Galla Rhois extracts, Elastase (pancreatic from porcine pancreas), N-Succinyl-(Ala)3-p-nitroanilide, Ursolic acid, mushroom tyrosinase, L-tyrosine, arbutin, Amicon Ultra, Hand Hold UV lamp, MMP-1 primary antibody, MMP-1 secondary antibody Result : 1. GR appeared over 40% of elastase inhibitory activity. 2. GR had MMP-1 inhibition activity. 3. GR showed higher anti-tyrosinase activity than arbutin. Conclusion : According to above results, it is supposed that Galla Rhois could be strong potential sources of anti-aging and whitening effects for the skin.

Removal of Manganese and Copper from Aqueous Solution by Yeast Papiliotrema huenov

  • Van, Phu Nguyen;Truong, Hai Thi Hong;Pham, Tuan Anh;Cong, Tuan Le;Le, Tien;Nguyen, Kim Cuc Thi
    • Mycobiology
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    • v.49 no.5
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    • pp.507-520
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    • 2021
  • Papiliotrema huenov was previously reported to be highly tolerant of a range of extremely toxic heavy metals. This study aimed to identify the potential of P. huenov to remove manganese and copper from aqueous solution. Physical conditions which affect removal of Mn(II) and Cu(II) were determined. Optimal temperature for adsorption of both metal ions was 30 ℃, and optimal pH for maximum uptake of Mn(II) and Cu(II) were 5 and 6, respectively. Under these conditions, living cells of P. huenov accumulated up to 75.58% of 110 mg/L Mn(II) and 70.5% of 128 mg/L Cu(II) over 120 h, whereas, the removal efficiency of metal ions by dead cells over 1 h was 60.3% and 56.5%, respectively. These results indicate that living cells are more effective than dead biomass for bioremediation, but that greater time is required. The experimental data extends the potential use of P. huenov in biosorption and bioaccumulation of toxic heavy metals to copper and manganese, two of the most common industrial contaminants.

Energy Use Coordinator for Multiple Personal Sensor Devices

  • Rhee, Yunseok
    • Journal of the Korea Society of Computer and Information
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    • v.22 no.2
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    • pp.9-19
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    • 2017
  • Useful continuous sensing applications are increasingly emerging as a new class of mobile applications. Meanwhile, open, multi-use sensor devices are newly adopted beyond smartphones, and provide huge opportunities to expand potential application categories. In this upcoming environment, uncoordinated use of sensor devices would cause severe imbalance in power consumption of devices, and thus result in early shutdown of some sensing applications depending on power-hungry devices. In this paper, we propose EnergyCordy, a novel inter-device energy use coordination system; with a system-wide holistic view, it coordinates the energy use of concurrent sensing applications over multiple sensor devices. As its key approach, we propose a relaxed sensor association; it decouples the energy use of an application from specific sensor devices leveraging multiple context inference alternatives, allowing flexible energy coordination at runtime. We demonstrated the effectiveness of EnergyCordy by developing multiple example applications over custom-designed wearable senor devices. We show that EnergyCordy effectively coordinates the power usage of concurrent sensing applications over multiple devices and prevent undesired early shutdown of applications.

Uncertainties estimation of AOGCM-based climate scenarios for impact assessment on water resources (수자원 영향평가를 위한 기후변화 시나리오의 불확실성 평가)

  • Park E-Hyung;Im Eun-Soon;Kwon Won-Tae;Lee Eun-Jeong
    • Proceedings of the Korea Water Resources Association Conference
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    • 2005.05b
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    • pp.138-142
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    • 2005
  • The change of precipitation and temperature due to the global. warming eventually caused the variation of water availability in terms of potential evapotranspiration, soil moisture, and runoff. In this reason national long-term water resource planning should be considered the effect of climate change. Study of AOGCM-based scenario to proposed the plausible future states of the climate system has become increasingly important for hydrological impact assessment. Future climate changes over East Asia are projected from the coupled atmosphere-ocean general circulation model (AOGCM) simulations based on Intergovernmental Panel on Climate Change (IPCC) Special Report on Emissions Scenarios (SRES) A2 and B2 scenarios using multi-model ensembles (MMEs) method (Min et al. 2004). MME method is used to reduce the uncertainty of individual models. However, the uncertainty increases are larger over the small area than the large area. It is demonstrated that the temperature increases is larger over continental area than oceanic area in the 21st century.

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ANALYSIS OF TROPOSPHERIC $NO_2$ BASED ON SATELLITE MEASUREMENTS

  • Kwon Eun-Han;Lim Hyo-Suk
    • Proceedings of the KSRS Conference
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    • 2005.10a
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    • pp.374-377
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    • 2005
  • The distribution and changes of tropospheric nitrogen dioxide ($NO_2$) are analyzed using the satellite measurements data from GOME (Global Ozone Monitoring Experiment) and SCIMACHY (SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY). We produced global maps of tropospheric $NO_2$ for 4 seasons using GOME measurements from January 1997 to June 2003. The global distribution shows high values in regions with dense population and high industrialization. Tropospheric $NO_2$ shows obvious seasonal changes depending on its emission and lifetime. Based on the good agreement between two instruments in the time period of overlapping measurements (January 2003-June2003), we linked SClAMACHY data to the GOME time series. The combined time series over the past decade indicate that $NO_2$ 1evels over China are rapidly increasing while those over Europe are decreasing. We also discussed potential application of spaceborne instruments in detecting and characterizing long-distance transport of $NO_2$.

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Prediction of the number of Tropical Cyclones over Western North Pacific in TC season (여름철 북서태평양 태풍발생 예측을 위한 통계적 모형 개발)

  • Sohn, Keon-Tae;Hong, Chang-Kon;Kwon, H.-Joe;Park, Jung-Kyu
    • 한국데이터정보과학회:학술대회논문집
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    • 2002.06a
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    • pp.9-15
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    • 2002
  • This paper presents the seasonal forecasting of the occurrence of tropical cyclone (TC) over Western North Pacific (WNP) using the generalized linear model (GLM) and dynamic linear model (DLM) based on 51-year-data (1951-2001) in TC season (June to November). The numbers of TC and TY are predictands and 16 indices (the E1 Nino/Southern Oscillation, the synoptic factors over East asia and WNP) are considered as potential predictors. With 30-year moving windowing, the estimation and prediction of TC and TY are performed using GLM. If GLM forecasts have some systematic error like a bias, DLM is applied to remove the systematic error in order to improve the accuracy of prediction.

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A Study of High Efficiency Electrodeless lamp Properties (고효율 신광원 시스템의 특성에 관한 연구)

  • Kim, H.S.;Lee, S.H.;Shin, S.W.;Lim, J.M.;Huh, S.K.;Hwang, M.K.
    • Proceedings of the KIEE Conference
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    • 2002.07c
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    • pp.1717-1720
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    • 2002
  • Electrodeless discharge lamps have been objects of interest and research for several decades, mainly because of their potential for extremely long life, high lamp efficacies and smaller than standard fluorescent lamps size. A series of measurements and observations concerning variables has yielded optical and electrical characteristics for electrodeless discharge lamp like incandescent lamp and circular lamp feature. Last experiment were carried out to determine the lamp temperature at several surface points during operation. Light output levels in excess over 60,000 cd/$m^2$ have been measured in electrodeless discharge lamp for a general of conditions. At lamp surface temperatures have been measured over $80^{\circ}C$, and starting current have been measured over ${\sim}A$.

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A Study on the Improvement of Stress Field Analysis in a Domain Composed of Dissimilar Materials

  • Song, Kee-Nam;Lee, Jin-Seok
    • Nuclear Engineering and Technology
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    • v.30 no.3
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    • pp.202-211
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    • 1998
  • Interfacial stresses at two-material interfaces and initial displacement field over the entire domain are obtained by modifying the potential energy functional with a penalty function, which enforces continuity of the stresses at the interface of two materials. Based on the initial displacement field and interfacial stresses, a new methodology to generate a continuous stress field over the entire domain has been proposed by combining the modified projection method of stress-smoothing and Loubignac's iterative method of improving the displacement field. Stress analysis is carried out on two examples made of dissimilar materials : one is a two-material cantilever composed of highly dissimilar materials and the other is a zirconium-lined cladding tube made of slightly dissimilar materials. Results of the analysis show that the proposed method provides an improved continuous stress field over the entire domain, and accurately predicts the nodal stresses at the interface, while the conventional displacement-based finite element method produces significant stress discontinuities at the interface. In addition, the total strain energy evaluated from the improved continuous stress field converges to the exact value in a few iterations.

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