• Title/Summary/Keyword: 박정현

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Fusion of Aerosol Optical Depth from the GOCI and the AHI Observations (GOCI와 AHI 자료를 활용한 에어로졸 광학두께 합성장 산출 연구)

  • Kang, Hyeongwoo;Choi, Wonei;Park, Jeonghyun;Kim, Serin;Lee, Hanlim
    • Korean Journal of Remote Sensing
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    • v.37 no.5_1
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    • pp.861-870
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    • 2021
  • In this study, fused Aerosol Optical Depth (AOD) data were produced using AOD products from the Geostationary Ocean Color Imager (GOCI) onboard Communication, Oceanography and Meteorology Satellite (COMS)satellite and the Advanced Himawari Imager (AHI) onboard Himawari-8. Since the spatial resolution and the coordinate system between the satellite sensors are different, a preprocessing was first preceded. After that, using the level 1.5 AOD dataset of AErosol RObotic NETwork (AERONET), which is ground-based observation, correlations and trends between each satellite AOD and AERONET AOD were utilized to produce more accurate satellite AOD data than the originalsatellite AODs. The fused AOD were found to be more accurate than the originalsatellite AODs. Root Mean Square Error (RMSE) and mean bias of the fused AODs were calculated to be 0.13 and 0.05, respectively. We also compared errors of the fused AODs against those of the original GOCI AOD (RMSE: 0.15, mean bias: 0.11) and the original AHI AOD (RMSE: 0.15, mean bias: 0.05). It was confirmed that the fused AODs have betterspatial coverage than the original AODsin areas where there are no observations due to the presence of cloud from a single satellite.

Facilitation of cisplatin-induced acute kidney injury by high salt intake through increased inflammatory response (염분 섭취에 의한 시스플라틴 유도 급성 신장 손상의 촉진과 염증 반응과의 연관성)

  • Ji, Seon Yeong;Hwangbo, Hyun;Kim, Min Yeong;Kim, Da Hye;Park, Beom Su;Park, Joung-Hyun;Lee, Bae-Jin;Lee, Hyesook;Choi, Yung Hyun
    • Journal of Marine Bioscience and Biotechnology
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    • v.13 no.2
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    • pp.86-93
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    • 2021
  • A high salt diet contributes to kidney damage by causing hypoxia and oxidative stress. Recently, an increase in dietary salt has been reported to induce an inflammatory phenotype in immune cells, further contributing to kidney damage. However, studies on the exact mechanism and role of a high salt diet on the inflammatory response in the kidneys are still insufficient. In this study, a cisplatin-induced acute kidney injury model using C57BL/6 mice was used to analyze the effect of salt intake on kidney injury. Results showed that high salt administration aggravated kidney edema in mice induced by treatment with cisplatin. Moreover, the indicators of kidney and liver function impairment were significantly increased in the group cotreated with high salt compared with that treated with cisplatin alone. Furthermore, the exacerbation of kidney damage by high salt administration was also associated with a decrease in the number of cells in the immune regulatory system. Additionally, high salt administration further decreased renal perfusion functions along with increased cisplatin-induced damage to proximal tubules. This was accompanied by increased expression of T cell immunoglobulin, mucin domain 1 (a biomarker of kidney injury), and Bax (a pro-apoptotic factor). Moreover, cisplatin-induced expression of proinflammatory mediators and cytokines, including cyclooxygenase-2 and tumor necrosis factor-α in kidney tissue, was further increased by high salt intake. Therefore, these results indicate that the kidney's inflammatory response by high salt treatment can further promote kidney damage caused by various pathological factors.

Effects of anti-inflammatory on Perilla frutescens var. crispa Induced by mutants with γ-Ray (감마선을 이용한 육종 차조기의 항염증 효과)

  • Sim, Boo-Yong;Park, Jung-Hyun;Kim, Sung-Kyu;Ji, Joong-Gu
    • Journal of the Korean Applied Science and Technology
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    • v.36 no.2
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    • pp.488-497
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    • 2019
  • The purpose of this study was to confirmed anti-inflammatory effect the apple Induced by mutants with ${\gamma}-Ray$ extract. Cell viability was assessed by MTT assay using RAW 264.7 cells. The extracts measured through changes in the levels of reactive oxygen species (ROS), nitric oxide (NO), inflammatory cytokines, NF-kB, and COX-2 on LPS-induced RAW 264.7 cells. All test results were analyzed by ELISA reader, Luminex and RT-PCR. In result, the extracts was not toxic below in 25 ug/ml, and extracts was inhibited the productions nitric oxide, ROS, cytokines (IL-1b, IL-6, TNF-a), NF-kB and COX-2 in LPS-induced RAW 264.7 cells. Also, the expression levels were decreased on mRNA of $NF-{\kappa}B$ and COX-2. In other words, Perilla frutescens var. crispa Induced by mutants with ${\gamma}-Ray$ extracts showed significant anti-inflammatory effect. These results may be developed as a raw material for new health food and therapeutics to ease the related to the above mediators.

Hexagonal shape Si crystal grown by mixed-source HVPE method (혼합소스 HVPE 방법에 의해 성장된 육각형 Si 결정)

  • Lee, Gang Seok;Kim, Kyoung Hwa;Park, Jung Hyun;Kim, So Yoon;Lee, Ha Young;Ahn, Hyung Soo;Lee, Jae Hak;Chun, Young Tea;Yang, Min;Yi, Sam Nyung;Jeon, Injun;Cho, Chae Ryong;Kim, Suck-Whan
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.31 no.3
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    • pp.103-111
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    • 2021
  • Hexagonal shape Si crystals were grown by the mixed-source hydride vapor phase epitaxy (HVPE) method of mixing solid materials such as Si, Al and Ga. In the newly designed atmospheric pressure mixed-source HVPE method, nuclei are formed by the interaction between GaCln, AlCln and SiCln gases at a high temperature of 1200℃. In addition, it is designed to generate a precursor gas with a high partial pressure due to the rapid reaction of Si and HCl gas. The properties of hexagonal Si crystals were investigated through scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDS), high-resolution X-ray diffraction (HR-XRD), and Raman spectrum. From these results, it is expected to be applied as a new material in the Si industry.

Operational Characteristics of a Cam-type Vegetable Transplanter and Mechanism of a Transplanting Device (캠방식 채소 정식기의 작동 특성 및 식부장치 작동 메커니즘 분석)

  • Park, Jeong-Hyeon;Hwang, Seok-Joon;Nam, Ju-Seok
    • Journal of agriculture & life science
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    • v.53 no.4
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    • pp.113-124
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    • 2019
  • In this study, the operational characteristics of a cam-type vegetable transplanter which usually used in domestic was analyzed and operating mechanism of a transplanting device was analyzed. The main components and power path of the transplanter were analyzed. The maximum and minimum control cycles according to the moving speed and the plant spacing were analyzed. 3D modeling and simulation were performed to derive the trajectory of the bottom end of the transplanting hopper and the plant spacing at the each operating condition. The simulation results were verified by the field tests. As main findings of this study, the transplanting device has one degree of freedom (DOF) which consist of 13 links, 17 rotating joints and 1 half joint, and each part has composite structure with cam and links. By continuous and repetitive motion of the structures of transplanting device, the transplanting hopper plants the seedling in the ground with a vertical direction, and the seedling was planted stably. The power is transmitted to the driving part and transplanting device from the engine, and the maximum and minimum plant spacing of the transplanting device were about 900 mm and 350 mm, respectively.

Influence of Bacterial Attachment on Arsenic Bioleaching from Mine Tailings: Dependency on the Ratio of Bacteria-Solid Substrate (광물찌꺼기 내 비소의 미생물 침출 시 박테리아 흡착 영향: 박테리아와 고체 기질 비율에 관한 연구)

  • Park, Jeonghyun;Silva, Rene A.;Choi, Sowon;Ilyas, Sadia;Kim, Hyunjung
    • Resources Recycling
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    • v.30 no.3
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    • pp.30-40
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    • 2021
  • The present study investigates the bioleaching efficiencies of arsenic via contact and non-contact mechanisms. The attachment of Acidithiobacillus ferrooxidans was restricted by a partition system comprising a semi-permeable membrane with a molecular weight cutoff of 12-14 kDa. The results were compared for two arsenic concentrations in the system (1.0% and 0.5% w/v) to maintain a homogeneous system. The overall bacterial performance was monitored by comparing total arsenic and iron concentrations, Fe ion speciation, pH, and solution redox potentials in flask bioleaching experiments over a period of 10 d. Our results indicated that bacterial attachment could increase arsenic extraction efficiency from 20.0% to 44.9% at 1.0 % solid concentrations. These findings suggest that the bacterial contact mechanism greatly influences arsenic bioleaching from mine tailings. Therefore, systems involving two-step or non-contact bioleaching are less effective than those involving one-step or contact bioleaching for the efficient extraction of arsenic from mine tailings.

Effects of Fermented Oyster Extract Supplementation on Body Composition, Muscular Strengths and Blood Muscle Growth Fact ors in Elderly Women (발효굴 섭취가 중년 여성의 신체조성, 근력 및 혈중 근성장 인자에 미치는 영향)

  • Park, Joung-Hyun;Kim, Dong-Seok;Lee, Bae-Jin;Her, Jung-Soo;Jeon, Byeong Hwan
    • Journal of Marine Bioscience and Biotechnology
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    • v.13 no.2
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    • pp.76-85
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    • 2021
  • Crassostrea gigas were fermented using L. brevis BJ20 to prepare fermented oyster extract (FO). The participants of this study were randomly assigned to FO and placebo (CON) groups. The FO group was given 1.0 g of FO supplementation and the CON group was given sucrose each day for eight weeks. The effects of FO supplementation on body composition, muscula r strength, and blood factors associated with muscle growth were assessed. The FO supplement was enriched with arginine (6,183.3 mg), phenylalanine (217.9 mg), leucine (122.6 mg), isoleucine (59.8 mg), valine (16.4 mg), and γ-amino butyric acid (GABA, 1,053.7 mg). The total fat was significantly decreased in the FO group compared with the CON group (p < 0.05). 60D/S Ext.T/Wo rk and 60D/S Flex.T/Work concomitantly with 60D/S Flex.PeakTQ/BW were significantly increase d by FO treatment compared to CON group (p < 0.05). However, posture stability was not significa ntly different between the groups. The levels of angiotensin-converting enzyme were significantly decreased within the FO group (p < 0.05). The FO group showed significantly decreased levels of tumor necrosis factor-α and increased levels of human growth hormone compared with the CON group (p < 0.01). The levels of insulin-like growth factor-1 increased (p < 0.01) in the FO group while that of creatine kinase and triglyceride decreased significantly compared with the CON group (p < 0.05). These results demonstrated that FO supplementation is effective in preventing sarcopenic obesity and maintaining and strengthening muscular function in elderly wom en. Hence, FO supplements can be used as functional ingredients for these benefits.

Low Temperature CO Oxidation over Cu-Mn Mixed Oxides (Cu-Mn 혼합산화물 상에서 일산화탄소의 저온산화반응)

  • Cho, Kyong-Ho;Park, Jung-Hyun;Shin, Chae-Ho
    • Clean Technology
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    • v.16 no.2
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    • pp.132-139
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    • 2010
  • The Cu-Mn mixed oxide catalysts with different molar ratios of Cu/(Cu+Mn) prepared by co-precipitation method have been investigated in CO oxidation at $30^{\circ}C$. The catalysts used in this study were characterized by X-ray Diffraction (XRD), $N_2$ sorption, X-ray photoelectron spectroscopy (XPS), and $H_2$-temperature programmed reduction $(H_2-TPR)$ to correlate with catalytic activities in CO oxidation. The $N_2$ adsorption-desorption isotherms of Cu-Mn mixed oxide catalysts showed a type 4 having pore range of 7-20 nm and BET surface area was increased from 17 to $205\;m^2{\cdot}g^{-1}$ with increasing of Mn content. The XPS analysis showed the surface oxidation state of Cu and Mn represented $Cu^{2+}$and the mixture of $Mn^{3+}$ and $Mn^{4+}$, respectively. Among the catalysts studied here, Cu/(Cu+Mn) = 0.5 catalyst showed the highest activity at $30^{\circ}C$ in CO oxidation and the catalytic activity showed a typical volcano-shape curve with respect to Cu/(Cu+Mn) molar ratios. The water vapor showed a prohibiting effect on the efficiency of the catalyst which is due to the competitive adsorption of carbon monoxide on the active sites of catalyst surface and finally the formation of hydroxyl group with active metals.

A Study to Increase Methane Ratio of Landfill Gas by Capturing Carbon Dioxide (매립지가스의 메탄 비율 증가를 위한 이산화탄소 포집 연구)

  • Bada Kim;Junghyun Park;Sungwoon Choi;Youngchul An;Daeyup Lee
    • Journal of the Korean Institute of Gas
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    • v.27 no.2
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    • pp.25-31
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    • 2023
  • The purpose of this study is to increase the thermal efficiency of a landfill gas (LFG) power generation engine by capturing carbon dioxide (CO2) from landfill gas (LFG) using monoethanolamine (MEA), which is widely used in the chemical CO2 absorption process. Since the use of LFG as an energy source can be a means of reducing greenhouse gas emissions, MEA can be used to reduce CO2 in LFG and increase the concentration of CH4 to improve the efficiency of power generation. In this study, experiments were conducted to measure the solubility of CO2 and CH4 in MEA solution, increase the solubility under different conditions, and analyse the dissolution characteristics. It was found that the CO2 absorption rate increased as the ratio of MEA to reaction gas increased. There is an optimum MEA concentration to maximise CO2 solubility, and even if the concentration is increased above this concentration, the solubility does not improve significantly. This study provided fundamental work to develop a more practical fuel by capturing CO2 from LFG and increasing the concentration of CH4 while reducing greenhouse gas emissions.

Removal of NAPL TCE using Cement/Slag contained Fe(II) (Fe(II)로 개질된 시멘트/슬래그를 이용한 NAPL TCE의 제거)

  • Lee, Seung-Hyoung;Park, Jung-Hyun;Choi, Won-Ho;Park, Joo-Yang
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.29 no.1B
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    • pp.97-103
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    • 2009
  • The decompostion characteristics of NAPL TCE in cement/slag/Fe(II) system were studied with various TCE concentration and amounts of binders (cement/slag) For analyses of the TCE degradation by cement/slag/Fe(II), TCE solution injected using gas-tight syringe after TCE solution dissolved a methanol. Initial concentrations of TCE are 0.42 mM, NAPL condition 11.7 mM and saturated condition 16.8 mM respectively. The result showed that the cases of 8.4 mM and 4.2 mM are decreased 88% of total TCE concentration within 18 days. NAPL condition 11.7 mM was decreased 84% within 50 days and saturated condition 16.8 mM was decreased 60% of total TCE concentration within 60 days respectively. This showed that degradations of TCE in various concentrations were in one kind reaction as pseudo-first-order. TCE was dissolved as aqueous solution before degraded. The reaction rate was increased $0.12day^{-1}$, $0.24day^{-1}$, $0.31day^{-1}$ when the mass of media 0.1, 0.2, 0.3 S/L rate was increased. TCE reaction speed is affected by cement/slag surface ares in this system. When HDTMA, experimental facter, was added, TCE decomposition rate was high despite the high concentration of NAPL. and The decompostion characteristics of NAPL TCE in cement/slag/Fe(II) system were studied by using modeling.