• Title/Summary/Keyword: Potential source

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A study on the elimination of static electricity by use of beta radiation source (Beta 방사선원을 이용한 정전기 제거법에 대한 고찰)

  • 임용규
    • 전기의세계
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    • v.14 no.3
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    • pp.28-33
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    • 1965
  • This experiment is based on "the feasible improvement studies for an eliminating device of the static electricity which applies the ionizing effect of beta radiation." In order to accomplish this object, the following problems were necessarily considered to investigate and to determine. The efficiency of the elimination of static electricity was determined by means of measuring the ion current between electrically charged plates with micro-ammeter. The effects of various factors, i.e., the distance between charged plate and radiation source, the activity of radiation source, the electric otential and the area of the charged plate, the shape of the source housing, the lining of backscattering material (Pb) on the source housing surface and blowing of ionized air, on the static electricity eliminating efficiency were studied. The beta radiation sources used in this experiment were S$^{35}$ and Sr$^{90}$ -Y$^{90}$ . It was revealed that ion current increased with source activity, the electric potential and area of the plates, the lead (Pb) lining on the surface of the source housing and the velocity of the ionized air blowing. As one could expect the S$^{35}$ was more effective to increase the ion current since it is known to be a higher specific ionization source than Sr$^{90}$ -Y$^{90}$ . The detailed result and performance of the eliminating device of the static electricity are described here.ibed here.

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The Distribution of the Torso Surface Potentials based on electrical cardiac dipole source (심장의 전기쌍극자 소스에 의한 토르소 표면 전위의 분포)

  • Lee, K.J.;Lee, S.J.;Park, K.L.;Song, G.K.
    • Proceedings of the KOSOMBE Conference
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    • v.1996 no.05
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    • pp.188-191
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    • 1996
  • This study is to find the distribution of the torso surface potential based on electrical cardiac dipole source. In order to find the torso surface potential, the governing equation was developed based on the Green's second theorem. The boundary element method(BEM) which has a good computing capability in case of homogeneous and isotropic medium was applied to solve the equation. To validate the BEM, we considered a homogeneous sphere model which has an electric dipole source inside. The results showed the good agreement between the analytic solution and the computed solution. In normal heart, the simulated torso surface isopotential maps are good agreement with that obtained from the ventricular excitation. The validity of the simulated results were verified by comparing with other results.

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Antimicrobial Effect of Natural Medicines on Bacterial Species from Soybean Curd Residue

  • Kim, Seong-Sun;Jin, Yu-Mi;Jeon, Yong-Deok;Jin, Jong-Sik
    • Proceedings of the Plant Resources Society of Korea Conference
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    • 2019.10a
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    • pp.102-102
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    • 2019
  • Soybean curd residue (SCR), known as a major waste product of soybean processing, is the water-insoluble fraction which is removed by filtration during soymilk production. For these reasons, SCR was usually considered as food waste. SCR might have a good potential as a functional food material, value-added processing and utilization. SCR contains high-quality protein and consists of a good source of nutrients, including protein, oil, dietary fiber, minerals, along with un-specified monosaccharides and oligosaccharides. Also, SCR might be a potential source of low cost protein for human consumption. However, SCR could be a source of bacterial contamination when during food processing. This study was aimed to investigate antibacterial capacity of natural product through detecting relationship between SCR and microbial. We isolated five bacterial strains from SCR and elucidated antibacterial activity of nature medicines to extend storage capacity of food made with SCR. Thus, the extract which showed antibacterial effects in Corynebacterium calloonae and Raoultella amithinolytica is a combination of seven kinds of extracts: Glycyrrhiza uralensis, Cudrania tricuspidata, Salvia miltiorrhiza Bunge, blueberry, Acorus gramineus, Ginkgo biloba L., Camellia sinensis. This study suggested that antibacterial activities of natural medicines could be used for extension of storage capacity in SCR-contained food.

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Rockfall Source Identification Using a Hybrid Gaussian Mixture-Ensemble Machine Learning Model and LiDAR Data

  • Fanos, Ali Mutar;Pradhan, Biswajeet;Mansor, Shattri;Yusoff, Zainuddin Md;Abdullah, Ahmad Fikri bin;Jung, Hyung-Sup
    • Korean Journal of Remote Sensing
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    • v.35 no.1
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    • pp.93-115
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    • 2019
  • The availability of high-resolution laser scanning data and advanced machine learning algorithms has enabled an accurate potential rockfall source identification. However, the presence of other mass movements, such as landslides within the same region of interest, poses additional challenges to this task. Thus, this research presents a method based on an integration of Gaussian mixture model (GMM) and ensemble artificial neural network (bagging ANN [BANN]) for automatic detection of potential rockfall sources at Kinta Valley area, Malaysia. The GMM was utilised to determine slope angle thresholds of various geomorphological units. Different algorithms(ANN, support vector machine [SVM] and k nearest neighbour [kNN]) were individually tested with various ensemble models (bagging, voting and boosting). Grid search method was adopted to optimise the hyperparameters of the investigated base models. The proposed model achieves excellent results with success and prediction accuracies at 95% and 94%, respectively. In addition, this technique has achieved excellent accuracies (ROC = 95%) over other methods used. Moreover, the proposed model has achieved the optimal prediction accuracies (92%) on the basis of testing data, thereby indicating that the model can be generalised and replicated in different regions, and the proposed method can be applied to various landslide studies.

On the Wave Drift Forces Acting on the Fixed 2-Dimensional Cylinder (고정 2차원 주상분에 작용하는 파랑표류력)

  • Hong, Seok-Won;Lee, Sang-Mu;Yang, Seung-Il
    • 한국기계연구소 소보
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    • s.14
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    • pp.135-144
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    • 1985
  • A method is described to obtain the first order force and second order steady force on the fixed two dimensional submerged or semisubmerged cylinders at infinite depth of water due to regular waves. The first order diffraction wave velocity potential which describes the flow diffracted by a body is obtained numerically using source distribution method on the mean wetted surface. And a technique to remove the irregular frequency phenomena of the source distribution method is also applied. The second order steady force is calculates by means of direct integration of the pressures on the body as derived from the first order velocity potential and is also computed by means of reflection wave height derives from momentum conservation theory. The results are compared with those of published works, and show good agreement.

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Isolation and Structure Determination of a Proteasome Inhibitory Metabolite from a Culture of Scytonema hofmanni

  • Shim, Sang-Hee;Chlipala, George;Orjala, Jimmy
    • Journal of Microbiology and Biotechnology
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    • v.18 no.10
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    • pp.1655-1658
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    • 2008
  • Cyanobacteria, blue-green algae, are a rich source of bioactive secondary metabolites with many potential applications. The ubiquitin-proteasome proteolytic system plays an important role in selective protein degradation and regulates cellular events including apoptosis. Cancer cells are more sensitive to the proapoptotic effects of proteasome inhibition than normal cells. Thus, proteasome inhibitors can be potential anticancer agents. Cyanobacteria have been shown to be a rich source of highly effective inhibitors of proteases. A proteasome inhibitor was screened from an extract of the culture of Scytonema hofmanni on the basis of its inhibitory activity, which led to the isolation of nostodione A with an $IC_{50}$ value of 50${\mu}M$. Its structure was determined by spectroscopic methods such as $^{1}H$-NMR and ESI-MS spectral analyses.

The Anti-Inflammatory and Anti-Oxidant Activity of Ethanol Extract from Red Rose Petals

  • Kim, Hyun-Kyoung
    • International Journal of Internet, Broadcasting and Communication
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    • v.12 no.3
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    • pp.139-148
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    • 2020
  • Red rose petals are usually disposed but they are an abundant source of phenolics and traditionally used as food supplement and as herbal medicine. Of the Various phenolics, they are known to have anticancer, antioxidant, and anti-inflammatory properties. In this study, we investigated the anti-inflammatory effects of red rose ethanolic extracts (GRP) on lipopolysaccharide (LPS)-activated RAW 264.7 cells. The results demonstrated that pretreatment of GRP (500㎍/mL) significantly reduced NO production by suppressing iNOS protein expression in LPS-stimulated cells. Anti-inflammatory effects by red rose petals were observed in the following. Red rose petals inhibited the translocation of NF-κB from the cytosol to the nucleus via the suppression of IκB-α phosphorylation and also inhibited LPS-stimulated NF-κB transcriptional activity. These findings suggest that red rose petals exert anti-inflammatory actions and help to elucidate the mechanisms underlying the potential therapeutic values of red rose petals. Therefore, red rose petals could be regarded as a potential source of natural anti-inflammatory agents.

The Practical Use of the Productive Aquifer Systems as a Source of a Renewable Thermal Energy and Local Water Works (지방상수도의 신규 수원과 재생에너지원으로서 고산출성 대수층의 활용)

  • Hahn, Jeongsang
    • Journal of Soil and Groundwater Environment
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    • v.23 no.4
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    • pp.16-25
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    • 2018
  • The Quaternary volcanic rocks, clastic sedimentary rocks of Kyongsang System, and carbonate rocks of Joseon and Pyongan System are known as good productive and potential aquifer systems in South Korea. National Groundwater Informaton Mangement and Service System (GIMS) indicates that the exploitable, sustainable, and current use of groundwater are about 18.8, 12.9, and $3.73billion\;m^3/a$, respectively. The rest amount ($9.1billion\;m^3/a$) can still be used for an additional water supply source. Therefore. comprehensive groundwater survey work comprising hydrogeological mapping, subsurface investigation and quantitative aquifer test etc. are highly required to establish rational groundwater management strategy.

Evaluation of BSR Noise Properties of Instrument Panel in a Vehicle (자동차 계기판 BSR 소음특성 평가)

  • Shin, Su-Hyun;Cheong, Cheol-Ung;Kim, Duck-Whan;Jung, Sung-Soo
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2010.05a
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    • pp.330-331
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    • 2010
  • In this paper, BSR noise from an instrument panel of a vehicle are investigated with integrated experimental methods. First, potential source regions of the instrument panel for BSR are localized by using the module-excitor and near-acoustic field visualization system. Then, subjective evaluation of BSR nosie from the detected potential noise source regions is made with the Zwicker's loudness and time-varying loudness methods.

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Transient Voltage Analysis of Low-Voltage Source Circuit inn Thermal Power Plant due to Grounding Potential Rise by Lightening (낙뢰침입에 의한 대지전위상승이 발전소 저압전원회로에 미치는 과전압 해석)

  • Yang, Byeong-Mo;Jeong, Jae-Kee;Min, Byeong-Wook;Lee, Jong-Seok
    • Proceedings of the KIEE Conference
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    • 1998.07e
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    • pp.1644-1646
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    • 1998
  • High-Smokestacks have been the symbol of the thermal power plant. Those cause the thermal power plant to be damaged by lightening for reaching several hundreds meter. In this paper, we investigated the accident of low-voltage source circuit due to grounding potential rise by lightening via high-smokestack in practically driving power plant, described examination into the cause and the impulse analysis. We analysed the transient voltage by EMTP(ElectroMagnetic Transient Program) via modeling the grounding system of power plant. This theoretical results coincided with practical accidental state. Therefore, it was verified that we could apply the grounding system of power plant and substation with the distribution-circuit analysis(EMTP).

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