• Title/Summary/Keyword: Nuclear engineering

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Analysis of Characteristics of Horizontal Response Spectrum of Velocity Ground Motions from 5 Macro Earthquakes (5개 중규모 지진의 속도 관측자료를 이용한 수평 응답스펙트럼 특성 분석)

  • Kim, Jun-Kyoung
    • Tunnel and Underground Space
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    • v.21 no.6
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    • pp.471-479
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    • 2011
  • The velocity horizontal response spectra using the observed ground motions from the recent 5 macro earthquakes, equal to or larger than 4.8 in magnitude, around Korean Peninsula were analysed and then were compared to the acceleration horizontal response spectra, seismic design response spectra (Reg Guide 1.60), applied to the domestic nuclear power plants, and finally the Korean Standard Design Response Spectrum for general structures and buildings. 102 velocity horizontal ground motions, including NS and EW components, were used for velocity horizontal response spectra and then normalized with respect to the peak velocity value of each ground motion. First, the results showed that velocity horizontal response spectra have larger values at the range of medium natural period, but acceleration horizontal response spectra have larger values at the range of short natural periods. Secondly, the results also showed that velocity horizontal response spectra exceed Reg. Guide 1.60 for longer natural periods bands less than 6-7 Hz. Finally, the results were also compared to the Korean Standard Response Spectrum for the 3 different soil types(SC, SD, and SE soil type) and showed that velocity horizontal response spectra revealed much higher values for the frequency bands below 1.5(SC), 2.0(SD), and 3.0(SE) seconds, respectively, than the Korean Standard Response Spectrum. The results suggest that the fact that acceleration, velocity, and displacement horizontal response spectra have larger values at the range of short, medium, and long natural periods, respectively, can be applied consistently to those form domestic ground motion, especially, the velocity ground motion. Information on response spectrum at such medium range periods can be very important since the domestic design of buildings and structures emphasizes recently medium and long natural periods than short one due to increased super high-rise buildings.

A Study on Dose Assessment by 18F-FDG injected into Patients (환자에게 주입된 18F-FDG 의한 선량 평가에 대한 연구)

  • Kim, Chang-Ju;Kim, Jang-Oh;Jeong, Geun-Woo;Shin, Ji-Hey;Lee, Ji-Eun;Jeon, Chan-Hee;Min, Byung-In
    • Journal of the Korean Society of Radiology
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    • v.14 no.4
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    • pp.467-475
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    • 2020
  • The purpose of this study is to assess doses to 18F-FDG, a radioactive drug, during PET examinations, to alleviate anxiety about radiation in patients and carers, to minimize the indiscriminate examination progress caused by medical institution personnel and space clearance problems, and health examination. The dose assessment was measured using a thermo-fluorescent dosimeter (TLD) and an electronic personal dosimeter (EPD) at the location of the cervical (hypothyroid), thorax (heart), and lower abdomen (breeding line) which are the three highest tissue areas of the radiation tissue weighting. In addition, spatial dose rates and radioactivity in urine were measured using GM counters and ion boxes. The results are as follows: First, the personal dosimeter TLD was measured 0.0425±0.0277 mSv in the cervical region, 0.0440±0.0386 mSv in the thorax and 0.0485±0.0436 mSv in the lower abdomen, with little difference in the heart dose depending on radiation sensitivity. The EPD was measured at 0.942±0.141 mSv/h immediately after the cervical position, and 0.192±0.031 mSv/h after 120 minutes. Immediately after the thorax position, 0.516±0.085 mSv/h, 120 minutes later 0.128±0.040 mSv/h. Immediately after the lower abdomen position, 0.468±0.091 mSv/h, and after 120 minutes 0.105±0.021 mSv/h were measured. The spatial dose rate at the GM counter was measured immediately at 0.041±0.005 mSv/h, 120 minutes later at 0.014±0.002 mSv/h. The radioactivity in urine using ion chamber was measured at 0.113±0.24 MBq/cc after 60 minutes and 0.063±0.13 MBq/cc after 120 minutes. As a result, 18F-FDG should be administered, dose re-evaluated two hours after the PET test is completed, and caregivers should be avoided. In addition, it is deemed necessary to provide patients and carers with sufficient explanations and expected values of exposure dose to avoid reckless testing. It is hoped that the data tested in this study will help patients and families relieve anxiety about radiation, and that the radiation workers' exposure management system and institutional improvements will contribute to the development of medical radiation.

Differential Intracellular Localization of Mitotic Centromere-associated Kinesin (MCAK) During Cell Cycle Progression in Human Jurkat T Cells (인체 Jurkat T 세포에 있어서 세포주기에 따른 MCAK 단백질의 세포 내 위치변화)

  • Jun Do Youn;Rue Seok Woo;Kim Su-Jung;Kim Young Ho
    • Journal of Life Science
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    • v.15 no.2 s.69
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    • pp.253-260
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    • 2005
  • Mitotic centromere-associated kinesin (MCAK), which is a member of the Kin I (internal motor domain) subfamily of kinesin-related proteins, is known to play a role in mitotic segregation of chromosome during M phase of the cell cycle. In the present study, we have produced a rat polyclonal antibody using human MCAK (HsMCAK) expressed in E. coli as the antigen. The antibody specifically recognized the HsMCAK protein (81 kDa), and could detect its nuclear localization in human Jurkat T cells and 293T cells by Western blot analysis. The specific stage of the cell cycle was obtained through blocking by either hydroxyl urea or nocodazole and subsequent releasing from each blocking for 2, 4, and 7 h. While the protein level of HsMCAK reached a maximum level in the S phase with slight decline in the $G_{2}-M$ phase, the electrophoretic mobility shift from $p81^{MCAK}\;to\;p84^{MCAK}$ began to be induced in the late S phase and reached a maximum level in the $G_{2}/M $ phase, and then it disappeared as the cells enter into the $G_{1}$ phase. Immunocytochemical analysis revealed that HsMCAK protein localized to centrosome and nucleus at the interphase, whereas it appeared to localize to the spindle pole, centromere of the condensed mitotic DNA, spindle fiber, or midbody, depending on the specific stage of the M phase. These results demonstrate that a rat polyclonal antibody raised against recombinant HsMCAK expressed in E. coli specifically detects human MCAK, and indicate that the electrophoretic mobility shift from $p81^{MCAK}\;to\;p84^{MCAK}$, which may be associated with its differential intracellular localization during the cell cycle, fluctuates with a maximum level of the shift at the $G_{2}-M$ phase.

Inhibitory Effect of Scopoletin Isolated from Sorbus commixta on TNF-α-Induced Inflammation in Human Vascular Endothelial EA.hy926 Cells through NF-κB Signaling Pathway Suppression (마가목 수피에서 분리한 scopoletin의 EA.hy926 혈관내피세포에서 NF-κB 신호전달을 통한 TNF-α로 유도된 혈관염증 저해 효과)

  • Kang, Hye Ryung;Kim, Hyo Jung;Kim, Bomi;Kim, Sun-Gun;So, Jai-Hyun;Cho, Soo Jeong;Kwon, Hyun Sook
    • Journal of Life Science
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    • v.30 no.4
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    • pp.343-351
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    • 2020
  • Sorbus commixta Hedl. has traditionally been used as a remedy for cough, asthma, and other bronchial disorders. In this study, three major triterpenoids-lupeol, β-sitosterol, and ursolic acid and a coumarin, scopoletin, were isolated from a CHCl3-soluble fragment of the bark of S. commixta. Their structures were identified by spectroscopic analyses, including mass spectrometry (MS), 1D-, and 2D- nuclear magnetic resonance spectroscopy (NMR), as well as by comparing the data with data reported in the literature. Scopoletin was isolated from this plant for the first time. It is a nutraceutical compound contained in many plants that has been reported to exert diverse biological activities, including anti-inflammatory effects. This study examined the inhibitory effect of scopoletin on TNF-α-induced vascular endothelial inflammation. Unlike the marginal impact of other compounds against low-density lipoprotein (LDL) oxidation and vascular endothelial inflammation, scopoletin showed remarkable activity on LDL oxidation (IC50 = 10.2 μM) and exerted vascular anti-inflammatory effects in EA.hy926 human endothelial cells activated by TNF-α. It suppressed the expression of adhesion molecules, such as ICAM-1, VCAM-1, and E-selectin, and blocked the adhesion between THP-1 monocytes and EA. hy926 endothelial cells. It also inhibited TNF-α-induced NF-κB translocation from the cytosol to the nucleus. Moreover, IκBα phosphorylation, which was increased by TNF-α treatment, was reduced after treatment with scopoletin. Thus, scopoletin inhibited TNF-α-induced vascular inflammation in endothelial cells by suppressing the NF-κB signaling pathway. These results demonstrate that owing to its anti-inflammatory activity in the vascular endothelium, scopoletin has the potential to inhibit atherosclerosis development.

Mineralogical Studies of the Tourmaline for Medicinal Applications by Production Localities (본초 광물로서의 활용을 위한 산지별 전기석의 광물학적 연구)

  • Jie, Yan;Kim, Seon-ok;Park, Hee Yul;Park, Maeng-Eon
    • Economic and Environmental Geology
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    • v.51 no.4
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    • pp.345-358
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    • 2018
  • In this study, we have performed electron probe micro analyzer (EPMA), X-ray differaction (XRD), inductively coupled plasma spectroscopy (ICP), Fourier transform Raman spectroscopy (FT-Raman), far-infrared (FIR), nuclear magnetic resonance (NMR), and pH-DO Analyses for characterizing medicinal mineralogy aspect of the black tourmaline (Shantung, china), black and pink tourmaline (Minas Geraris, Brazil), black touemaline (Daeyu mine, Korea). In addition, heating effects of the tourmaline sauna as well as the effects of tourmaline powder-added soap on skin troubles have been investigated. It has been revealed that chemical composition of the tourmaline is either high in Fe-, Al-, B-rich types. Ratio of the K-Ca, Na-K, and Fe-B reflects the component change property of solid solution. $CaO/CaO+Na_2O$ and MgO/FeO+MgO ratio show high positive correlation. When tourmaline reacts with distilled water, extended reaction time DO values approximately decrease and it stabilizes at DO = 10. Otherwise, pH values increase until 6 hours and it stabilizes at pH = 8 after 24 hours. Distilled water changes to alkaline when it reacts with tourmaline powder and particles. Tourmaline showed lower absorption spectrum strength and transmittance at short wave, where absorption spectrum wavelength and strength were determined by the content of the composition elements and characteristics of crystallography. Increase of the Fe content has been confirmed to be the cause for the reduction of irradiation. For the chemical composition and spectral property of the tourmaline particle samples, it has been found that Si and Fe contents show positive correlation with Far-Infrared irradiation, while Al and Mg contents show negative correlation. For tourmaline powder, it has been confirmed that $^{17}O-NMR$ FWHM (full width at half maximum) decreases when reacts with distilled water. Tourmaline sauna (approximately $100^{\circ}C$) was found to increase $0.5-1.5^{\circ}C$ of body temperature, average of 12 heartbeat, and 10mg Hg of blood pressure. Tourmaline soap had very good aesthetic effect to skin and was confirmed to have above the average improvements to skin troubles (e.g., allergy or atopy).

The Oogenesis of Kribensis, Pelvicachromis pulcher, Cichlidae, Teleostei (경골어류 시클리드과 크리벤시스(Pelvicachromis pulcher)의 난자형성과정)

  • Kim, Dong-Heui;Chang, Byung-Soo;Teng, Yung-Chien;Kwon, Jung-Kyun;Lee, Myeong-Seon;Lee, Gui-Young;Lee, Kyu-Jae
    • Applied Microscopy
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    • v.40 no.2
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    • pp.65-71
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    • 2010
  • Kribensis, Pelvicachromis pulcher is a teleost belonging to Cichlidae. The oogenesis was investigated by light microscope. The ovary was located between intestine and air bladder, a yellowish and ellipsoidal shape with the major axis 20mm and the minor axis 5 mm. Cytoplasm of oogonia in early stage was basophilic and many nucleoli were located at inside of nuclear membrane. In primary oocytes, yolk vesicles were distributed only in the marginal area and egg envelope was not formed on the outside of an egg. In secondary oocytes, the egg envelope was formed and yolk vesicles in the cytoplasm were increased than the earlier stage. The basophilic substance of cytoplasm was changed to acidic. Some yolk vesicles started forming small yolk mass except the surrounding nucleus. In case of matured egg, size of egg were increased. The yolk vesicles were changed to yolk mass in accordance with development. The yolk mass contained crystal-like structures. In conclusion, the oogenesis of Pelvicachromis pulcher was summarized by the increase in cell size, the formation and the accumulation of yolk, and the decrease of basophilic substance in the cytoplasm. The oogenesis of Coreoleuciscus splendidus is similar with other teleost. But there were differences in distribution of yolk vesicle and yolk mass containing cristal-like structures.

Derivation of rock parameters from Televiewer data (텔레뷰어에 의한 토목설계 매개변수의 산출)

  • Kim Jung-Yul;Kim Yoo-Sung
    • 한국지구물리탐사학회:학술대회논문집
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    • 1999.08a
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    • pp.137-155
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    • 1999
  • Recently, Televiewer(Borehole Acoustic Scanner(Televiewer)) has come to be widely used specially for the general engineering construction design. The Televiewer tool using a focussed acoustic beam is to detect the amplitude and traveltime of each reflected acoustic signal at the wall, resulting in the amplitude- and traveltime image respectively. Fractures can be well detected, because they easily scatter the acoustic energy due to the highly narrow beam. In addition, the drilling work will rough the borehole wall so that the acoustic energy can be scattered simply due to the roughness of the wall. Thus, the amplitude level can be directed associated with the elastic properties(impedance) and the hardness of the rock as well. Meanwhile, the traveltime image provides an information about the borehole shape and can be converted to a high precision 3D caliper log(max. 288 arms). In this paper, based on the high resolution of Televiewer images, general evaluation methods are illustrated to derive very reliable rock parameters.

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An historical analysis on the carbon lock-in of Korean electricity industry (한국 전력산업의 탄소고착에 대한 역사적 분석)

  • Chae, Yeoungjin;Roh, Keonki;Park, Jung-Gu
    • Journal of Energy Engineering
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    • v.23 no.2
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    • pp.125-148
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    • 2014
  • This paper performs a historical analysis on the various factors contributing to the current carbon lock-in of Korean electricity industry by using techo-institutional complex. The possibilities of the industry's carbon lock-out toward more sustainable development are also investigated. It turns out that market, firm, consumer, and government factors are all responsible for the development of the carbon lock-in of Korean power industry; the Korean government consistently favoring large power plants based on the economy of scale; below-cost electricity tariff; inflation policy to suppress increases in power price; rapid demand growth in summer and winter seasons; rigidities of electricity tariff; and expansion of gas-fired and imported coal-fired large power plants. On the other hand, except for nuclear power generation and smart grid, environment laws and new and renewable energy laws are the other remaining factors contributing to the carbon lock-out. Considering three key points that Korea is an export-oriented economy, the generation mix is the most critical factor to decide the amounts of carbon emission in the power industry, and the share of industry and commercial power consumption is over 85%, it is unlikely that Korea will achieve the carbon lock-out of power industry in the near future. Therefore, there are needs for more integrated approaches from market, firm, consumer, and government all together in order to achieve the carbon lock-out in the electricity industry. Firstly, from the market perspective, it is necessary to persue more active new and renewable energy penetration and to guarantee consumer choices by mitigating the incumbent's monopoly power as in the OECD countries. Secondly, from the firm perspective, the promotion of distributed energy system is urgent, which includes new and renewable resources and demand resources. Thirdly, from the consumer perspective, more green choices in the power tariff and customer awareness on the carbon lock-out are needed. Lastly, the government shall urgently improve power planning frameworks to include the various externalities that were not properly reflected in the past such as environmental and social conflict costs.

Measurement of Specific Radioactivity for Clearance of Waste Contaminated with Re-186 for Medical Application (의료용 Re-186 오염폐기물의 규제해제를 위한 방사능측정)

  • Kim, Chang-Bum;Lee, Sang-Kyung;Jang, Seong-Joo;Kim, Jung-Min
    • Journal of radiological science and technology
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    • v.40 no.4
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    • pp.633-638
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    • 2017
  • The amount of radioactive waste has been rapidly increased with development of radiation treatment in medical field. Recently, it has been a common practice to use I-131 for thyroid cancer, F-18 for PET/CT and Tc-99m for diagnosis of nuclear medicine. All the wastes concerned have been disposed of by means of the self-disposal method, for example incineration, after storage enough to decay less than clearance level. IAEA proposed criteria for clearance level of waste which depends on the individual ($10{\mu}Sv/y$) and collective dose (1 man-Sv/y), and concentration of each nuclide (IAEA Safety Series No 111-P-1.1, 1992 and IAEA RS-G-1.7, 2004). In this study, specific radioactivity of radioactive waste contaminated with Re-186 was measured to confirm whether it meets the clearance level. Re-186 has long half life of 3.8 days relatively and emits beta and gamma radiation, therefore it can be applied in treatment and imaging purposes. The specific radioactivity of contaminated gloves weared by radiation workers was measured by MCA(Multi-channel Analyzer) which was calibrated by reference materials in accordance with the measuring procedure. As a result, comparison evaluation of decay storage period between the half-life which was calculated by attenuation curve based on real measurement and physical half-life was considered, and it is showed that the physical half-life is longer than induced half-life. Therefore, the storage period of radioactive waste for self-disposal may be curtailed in case of application of induced half-life. The result of this study will be proposed as ISO standard.

Ethanol Extract of Glycyrrhiza uralensis Protects Against Oxidative Stress-induced DNA Damage and Apoptosis in Retinal Pigment Epithelial Cells (망막색소상피세포에서 감초 추출물의 산화적 스트레스에 의한 DNA 손상 및 apoptosis 유발의 차단 효과)

  • Kim, So Young;Kim, Jeong-Hwan;Kim, Sung Ok;Park, Seh-Kwang;Jeong, Ji-Won;Kim, Mi-Young;Lee, Hyesook;Cheong, JaeHun;Choi, Yung Hyun
    • Journal of Life Science
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    • v.29 no.11
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    • pp.1273-1280
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    • 2019
  • Age-related macular degeneration (AMD) is one of the leading causes of blindness in the elderly population, and damage to retinal pigment epithelial (RPE) cells due to oxidative stress contributes to the development of AMD. Glycyrrhiza uralensis Fischer is one of the most widely used herbal medicines for the treatment of various diseases in Asian countries. Although recent studies indicated that treatment with G. uralensis can protect cells from oxidative stress, its mechanisms in RPE cells remain unknown. We evaluated the effect of a G. uralensis ethanol extract (GU) on $H_2O_2$-induced oxidative injury in ARPE-19 RPE cells. The GU pretreatment attenuated reactive oxygen species (ROS) generation induced by $H_2O_2$, which was associated with induced expression of nuclear factor erythroid-derived-2-like 2 (Nrf2) and heme oxygenase-1 (HO-1). GU also suppressed $H_2O_2$-induced DNA damage and mitochondrial dysfunction. The inhibitory effect of GU on $H_2O_2$-induced apoptosis was associated with the protection of caspase-3 activation. Overall, GU appeared to protect RPE cells from oxidative injury by inhibiting DNA damage and reducing apoptosis. Further studies are needed to determine the regulation of Nrf2-mediated HO-1 expression, but our results suggest the possibility of using GU to reduce the risk of AMD.