• Title/Summary/Keyword: GHA

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A Study of Radioactive Contamination in Hospital Toilet (병원 화장실의 방사성 오염에 관한 연구)

  • Kim, Ki-Jin;Kim, Gha-Jung
    • Journal of the Korea Safety Management & Science
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    • v.17 no.4
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    • pp.241-246
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    • 2015
  • Generally a patient who was injected radiopharmaceuticals for nuclear medicine examination is not an object of isolation. Therefore, when the patient uses toilet, we expect surface contamination of a toilet by radioisotope. The measured value is $25.69Bq/cm^2$(a restroom near admission and administration), $19.39Bq/cm^2$(a toilet near department of radiology). The study shows that 9 of 24 locations in controlled area exceed over surface contamination limit. From now on, we should find source of contamination through measurement radioactive nuclide to apply radiation safety management.

Adequacy Assessment to Abdomen Shield of Pregnant X-ray Chest PA (임산부 흉부촬영 시 복부차폐의 적정성 평가)

  • Kim, Ki-Jin;Kim, Gha-Jung
    • Journal of the Korea Safety Management & Science
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    • v.17 no.4
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    • pp.207-212
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    • 2015
  • When performing Chest x-ray examination to pregnant woman, normally we shield back side of abdomen. In this situation, scattered rays made by equipment and surrounding structure can enter front side of abdomen. Therefore, in this study, we evaluate suitability of abdomen shield especially to pregnant woman. In case of One shielding material placed back of abdomen, the measured value is $0.676{\pm}0.19uSv/hr$. Two shielding material is $0.764{\pm}0.04uSv/hr$. Three is $0.685{\pm}0.16uSv/hr$. The exposure dose inferred in this study does not excess annual effective dose limit. But It is not mean absolute safety. So we have to minimize occurrence of stochastic effect of radiosensitivity by shielding front side of abdomen of pregnant woman in clinic.

A Study on the Design of Microwave Low Noise Amplifier Using GaAs FET (GaAs FET를 이용한 저잡음증폭기 설계에 관한 연구)

  • 전광일;주창복;박정기
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.11 no.2
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    • pp.101-107
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    • 1986
  • Analysis and design procedure for the low noise amplifier design are presented. A Microwave low noise amplifier is designed and fabricated using packaged GaAs FET at the center frequency of 12GHa. The experimental results with respect to the noise figure and power gain are quite agreeable with the design specifications except that the input and output VSWR are slightly higher than the desingned.

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U/RE Recovery Using Large-Scale LCC Electrowinning System

  • Kim, Si Hyung;Shim, Joon-Bo;Jang, Junhyuk;Kwon, Sang-Woon;Lee, Young Sang;Kwon, Youngwoo;Kim, Gha-Young;Lee, Sung-Jai
    • Proceedings of the Korean Radioactive Waste Society Conference
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    • 2018.05a
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    • pp.53-54
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    • 2018
  • U/RE was electrochemically recovered to LCC at $50mA/cm^2$ from LiCl-KCl salt containing $0.5wt%UCl_3$, $0.22wt%NdCl_3$, 0.15wt%$CeCl_3$ and $0.07wt%LaCl_3$. The Cd in the LCC deposit was removed during the distillation using Cd distiller. U/RE product of 107g obtained from the distiller was installed to TG and then heated to $1200^{\circ}C$ to be consolidated. Dense U/RE metal ingot was not acquired through the consolidation process because U/RE product had been partially already oxidized during the distillation process.

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Cyclic Voltammetry Depending on the Electrode Connection Mode in Small-scale LCC Electrowinning System

  • Kim, Si Hyung;Kim, Taek-Jin;Kim, Gha-Young;Lee, Seul Gi;Jang, Junhyuk;Paek, Seungwoo;Lee, Hansoo;Eun, Hee-Chul;Lee, Sung-Jai;Ahn, Do-Hee
    • Proceedings of the Korean Radioactive Waste Society Conference
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    • 2017.05a
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    • pp.92-93
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    • 2017
  • In this paper, CV behavior of electrowinning system was studied depending on the electrode connection mode of potentiostat. In this system, currents can be flown from electrodes to SUS parts because the LCC assembly was electrically connected between the SUS parts and electrolytic salt. Standard mode without ground line of multi tab or CE to ground mode is considered to be more reasonable than standard mode when using multi tab having ground line.

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Cesium and strontium recovery from LiCl-KCl eutectic salt using electrolysis with liquid cathode

  • Jang, Junhyuk;Lee, Minsoo;Kim, Gha-Young;Jeon, Sang-Chae
    • Nuclear Engineering and Technology
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    • v.54 no.10
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    • pp.3957-3961
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    • 2022
  • Deposition behaviors of Sr and Cs in various liquid cathodes, such as Zn, Bi, Cd, and Pb, were examined to evaluate their recovery from LiCl-KCl eutectic salt. Cations in the salt were deposited on the liquid cathode, exhibiting potential of -1.8 to -2.1 V (vs. Ag/AgCl). Zn cathode had successful deposition of Sr and exhibited the highest recovery efficiency, up to 55%. Meanwhile, the other liquid cathodes showed low current efficiencies, below 18%, indicating LiCl-KCl salt decomposition. Sr was recovered from the Zn cathode as irregular rectangular SrZn13 particles. A negligible amount of Cs was deposited on the entire liquid cathode, indicating that Cs was hardly deposited on liquid cathodes. Based on these results, we propose that liquid Zn cathode can be used for cleaning Sr in LiCl-KCl salt.

Advances in Optical Tools to Study Taste Sensation

  • Gha Yeon, Park;Hyeyeong, Hwang;Myunghwan, Choi
    • Molecules and Cells
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    • v.45 no.12
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    • pp.877-882
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    • 2022
  • Taste sensation is the process of converting chemical identities in food into a neural code of the brain. Taste information is initially formed in the taste buds on the tongue, travels through the afferent gustatory nerves to the sensory ganglion neurons, and finally reaches the multiple taste centers of the brain. In the taste field, optical tools to observe cellularlevel functions play a pivotal role in understanding how taste information is processed along a pathway. In this review, we introduce recent advances in the optical tools used to study the taste transduction pathways.

Electrochemical corrosion behavior of atmospheric-plasma-sprayed copper as a coating material for deep geological disposal canisters

  • Sung-Wook Kim;Gha-Young Kim;Young-Ho Lee;Jun-Hyuk Jang;Chung-Won Lee;Jeong-Hyun Woo;Seok Yoon
    • Nuclear Engineering and Technology
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    • v.55 no.11
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    • pp.4032-4038
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    • 2023
  • Cu, which exhibits excellent corrosion resistance in underground environments, has been investigated as a canister material for use in the deep geological disposal of spent nuclear fuels. In this study, the technical viability of atmospheric plasma spraying for producing Cu-coated canisters was investigated. A high-purity Cu film (millimeter scale) was deposited onto a stainless-steel substrate using a plasma gun with a shroud structure. Potentiodynamic polarization studies revealed that the Cu film exhibited a sufficiently low corrosion rate in the groundwater electrolyte. In addition, no pitting corrosion was observed on the Cu film surface after accelerated corrosion studies. A prototype cylindrical Cu film was fabricated on a 1/20 scale on a stainless-steel tube to demonstrate the scalability of atmospheric plasma spraying in producing Cu-coated canisters.

A Study on Utilization Plan and Assessment of Ecological Carrying Capacity of Asan City - Focused on the Ecological Footprint Survey - (아산시 생태환경용량 평가를 통한 도시계획 활용방안 연구 - 생태발자국을 중심으로 -)

  • Joo, YongJoon;Sagong, Hee;Lee, SangYoon
    • Journal of Wetlands Research
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    • v.19 no.4
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    • pp.523-532
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    • 2017
  • Environmental problems in urban spaces tend to result from excessive use of resources faster than the ecosystem can recover itself. In order to address this problem, city or municipal governments tend to devise plans and policies to lead development within their ecological carrying capacity. This study computes ecological capacity of Asan city, Province Chung Nam, South Korea through applying the concept of ecological footprint. This study finds ecological footprint and deficit of Asan city in 2015 were 5.12 and -4.99, respectively. From 2001 to 2015, Asan city experienced not only an 81% increase of ecological footprint, but also a 190% increase of ecological deficit. Such results suggest that Asan city has experienced a steady increase of resource consumption due to population increase and urban growth, indicating that loss of ecological spaces such as green space, farmland, wetland and so on restoring the ecosystem has been accelerated. Therefore, in order to promote sustainable development, Asan city should not only protect green space, farmland, wetland, and so on but also create urban growth plans and policies taking into account its environmental capacity of the city. This study provides suggestions for Asan city to lead urban growth within its environmental capacity by applying ecological deficit.

A Study of Display Sampling and Visual Momentum (디스플레이 표집과 시각타성에 관한 연구)

  • Yang, Lee-Gha
    • Archives of design research
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    • v.20 no.3 s.71
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    • pp.39-48
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    • 2007
  • This study explored the Eye Movement, the horizontal and vertical flow of vision, and genetic, cultural and empirical schema, and the differentiation of the visual system of the cerebrum through the engineering psychological or the cognitive neuroscientific experiments measuring Eye Movement to maximize the efficiency of the Public Sign System in the urban environment. Accordingly, the study derived an algorithm that can bring out the most efficient visual design measurement by using EMR test and bitmap counting method. The scientific test data in this study will show the existence of the momentum of differentiation and visual sampling by the Schema and Sensory Qualia of the human.

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