• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.97-97
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• 2015

전 세계적으로 화석연료의 고갈 및 환경오염 문제를 해결하기 위해 신재생에너지에 대한 관심이 급증하고 있다. 이러한 신재생에너지에는 수소 에너지, 자연 에너지(태양열, 지열 등), 바이오 매스 에너지 등이 포함된다. 이 중 수소 에너지는 지구상에 풍부하게 존재하고 있는 물과 탄화수소로부터 얻어지며, 연소 시에도 다시 물을 형성하여 오염 물질을 배출하지 않는 차세대 무공해 에너지원으로써 주목을 받고 있다. 수소 제조를 위한 공정에는 수증기 개질 공정(steam reforming), 부분 산화(partial oxidation) 및 자열개질(autothermal reforming) 등이 있으며 실제로 생산되는 대부분의 수소는 탄소/수소비(1:4)가 높은 메탄($CH_4$) 가스를 이용한 메탄 수증기 개질 공정(steam methane reforming)을 통하여 제조된다. 이 때 수소 제조의 고효율화 및 저비용화를 위해서는 반응물에 대한 높은 선택도, 고활성도 및 높은 안정성을 갖는 촉매가 반드시 필요하며, 대표적으로 Ni, Pt, Ru 등이 보고되고 있다. 이러한 촉매들은 대부분 세라믹 pellet 형태로 제작되어 왔으나 열전도도가 낮고 물리적 충격에 취약하다는 단점이 존재한다. 따라서 우리는 이러한 단점을 극복하고, 촉매의 활성을 높이기 위하여 다공성 금속 합금 폼을 촉매 지지체로 도입하였다. 또한, 다공성 금속 합금 폼 표면에 촉매의 분산 및 안정성을 향상시키기 위해 지지체와 촉매 사이에 원자층 증착법을 이용하여 inter-layer를 도입하였다. 이들의 구조, 형태, 및 표면의 화학적 상태는 주사전자현미경, EDS (energy dispersive spectroscopy)가 탑재된 주사전자현미경, X-선 회절, 및 X-선 광전자 분광법을 이용하여 규명하였다. 더하여 정전압-전류 측정법 및 유도 결합 플라즈마 분광 분석기을 이용하여 전기 화학 반응을 유도하고, 반응 후 전해질의 성분분석을 통해 촉매와 지지체 간의 안정성을 평가하였다. 따라서 본 결과들은 한국진공학회 하계정기학술대회를 통해 좀 더 자세히 논의될 것이다.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1972.03a
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• pp.6-7
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• 1972

The air pollutants can be classified into the irritant gas and the asphixation gas, and the irritant gas is closely related to the otorhinolaryngological diseases. The common irritant gases are nitrogen oxides, sulfur oxides, hydrogen carbon compounds, and the potent and irritating PAN (peroxy acyl nitrate) which is secondarily liberated from photosynthesis. Those gases adhers to the mucous membrane to result in ulceration and secondary infection due to their potent oxidizing power. 1. Sulfur dioxide gas Sulfur dioxide gas has the typical characteristics of the air pollutants. Because of its high solubility it gets easily absorbed in the respiratory tract, when the symptoms and signs by irritation become manifested initially and later the resistance in the respiratory tract brings central about pulmonary edema and respiratory paralysis of origin. Chronic exposure to the gas leads to rhinitis, pharyngitis, laryngitis, and olfactory or gustatory disturbances. 2. Carbon monoxide Toxicity of carbon monoxide is due to its deprivation of the oxygen carrying capacity of the hemoglobin. The degree of the carbon monoxide intoxication varies according to its concentration and the duration of inhalation. It starts with headache, vertigo, nausea, vomiting and tinnitus, which can progress to respiratory difficulty, muscular laxity, syncope, and coma leading to death. 3. Nitrogen dioxide Nitrogen dioxide causes respiratory disturbances by formation of methemoglobin. In acute poisoning, it can cause pulmonary congestion, pulmonary edema, bronchitis, and pneumonia due to its strong irritation on the eyes and the nose. In chronic poisoning, it causes chronic pulmonary fibrosis and pulmonary edema. 4. Ozone It has offending irritating odor, and causes dryness of na sopharyngolaryngeal mucosa, headache and depressed pulmonary function which may eventually lead to pulmonary congestion or edema. 5. Smog The most outstanding incident of the smog occurred in London from December 5 through 8, 1952, because of which the mortality of the respiratory diseases increased fourfold. The smog was thought to be due to the smoke produced by incomplete combustion and its byproduct the sulfur oxides, and the dust was thought to play the secondary role. In new sense, hazardous is the photochemical smog which is produced by combination of light energy and the hydrocarbons and oxidant in the air. The Yonsei University Institute for Environmental :pollution Research launched a project to determine the relationship between the pollution and the medical, ophthalmological and rhinopharyngological disorders. The students (469) of the "S" Technical School in the most heavily polluted area in Pusan (Uham Dong district) were compared with those (345) of "K" High School in the less polluted area. The investigated group had those with subjective symptoms twice as much as the control group, 22.6% (106) in investigated group and 11.3% (39) in the control group. Among those symptomatic students of the investigated group. There were 29 with respiratory symptoms (29%), 22 with eye symptoms (21%), 50 with stuffy nose and rhinorrhea (47%), and 5 with sore thorat (5%), which revealed that more than half the students (52%) had subjective symptoms of the rhinopharyngological aspects. Physical examination revealed that the investigated group had more number of students with signs than those of the control group by 10%, 180 (38.4%) versus 99 (28.8%). Among the preceding 180 students of the investigated group, there were 8 with eye diseases (44%), 1 with respiratory disease (0.6%), 97 with rhinitis (54%), and 74 with pharyngotonsillitis (41%) which means that 95% of them had rharygoical diseases. The preceding data revealed that the otolaryngological diseases are conspicuously outnumbered in the heavily polluted area, and that there must be very close relationship between the air pollution and the otolaryngological diseases, and the anti-pollution measure is urgently needed.

• Journal of the Korean Society for Marine Environment & Energy
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• v.12 no.4
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• pp.307-319
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• 2009

Carbon dioxide capture and storage (CCS) technology has been regarded as one of the most possible and practical option to reduce the emission of carbon dioxide ($CO_2$) and consequently to mitigate the climate change. Korean government also have started a 10-year R&D project on $CO_2$ storage in sea-bed geological structure including gas field and deep saline aquifer since 2005. Various relevant researches are carried out to cover the initial survey of suitable geological structure storage site, monitoring of the stored $CO_2$ behavior, basic design of $CO_2$ transport and storage process and the risk assessment and management related to $CO_2$ leakage from engineered and geological processes. Leakage of $CO_2$ to the marine environment can change the chemistry of seawater including the pH and carbonate composition and also influence adversely on the diverse living organisms in ecosystems. Recently, IMO (International Maritime Organization) have developed the risk assessment and management framework for the $CO_2$ sequestration in sub-seabed geological structures (CS-SSGS) and considered the sequestration as a waste management option to mitigate greenhouse gas emissions. This framework for CS-SSGS aims to provide generic guidance to the Contracting Parties to the London Convention and Protocol, in order to characterize the risks to the marine environment from CS-SSGS on a site-specific basis and also to collect the necessary information to develop a management strategy to address uncertainties and any residual risks. The environmental risk assessment (ERA) plan for $CO_2$ storage work should include site selection and characterization, exposure assessment with probable leak scenario, risk assessment from direct and in-direct impact to the living organisms and risk management strategy. Domestic trial of the $CO_2$ capture and sequestration in to the marine geologic formation also should be accomplished through risk management with specified ERA approaches based on the IMO framework. The risk assessment procedure for $CO_2$ marine storage should contain the following components; 1) prediction of leakage probabilities with the reliable leakage scenarios from both engineered and geological part, 2) understanding on physio-chemical fate of $CO_2$ in marine environment especially for the candidate sites, 3) exposure assessment methods for various receptors in marine environments, 4) database production on the toxic effect of $CO_2$ to the ecologically and economically important species, and finally 5) development of surveillance procedures on the environmental changes with adequate monitoring techniques.

• Korean Journal of Remote Sensing
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• v.39 no.6_2
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• pp.1651-1669
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• 2023

Sea ice currently covers approximately 7% of the world's ocean area, primarily concentrated in polar and high-altitude regions, subject to seasonal and annual variations. It is very important to analyze the area and type classification of sea ice through time series monitoring because sea ice is formed in various types on a large spatial scale, and oil and gas exploration and other marine activities are rapidly increasing. Currently, research on the type and area of sea ice is being conducted based on high-resolution satellite images and field measurement data, but there is a limit to sea ice monitoring by acquiring field measurement data. High-resolution optical satellite images can visually detect and identify types of sea ice in a wide range and can compensate for gaps in sea ice monitoring using Geostationary Ocean Color Imager-II (GOCI-II), an ocean satellite with short time resolution. This study tried to find out the possibility of utilizing sea ice monitoring by training a rule-based machine learning model based on learning data produced using high-resolution optical satellite images and performing detection on GOCI-II images. Learning materials were extracted from Liaodong Bay in the Bohai Sea from 2021 to 2022, and a Random Forest (RF) model using GOCI-II was constructed to compare qualitative and quantitative with sea ice areas obtained from existing normalized difference snow index (NDSI) based and high-resolution satellite images. Unlike NDSI index-based results, which underestimated the sea ice area, this study detected relatively detailed sea ice areas and confirmed that sea ice can be classified by type, enabling sea ice monitoring. If the accuracy of the detection model is improved through the construction of continuous learning materials and influencing factors on sea ice formation in the future, it is expected that it can be used in the field of sea ice monitoring in high-altitude ocean areas.

• KDI북한경제리뷰
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• v.22 no.4
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• pp.41-58
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• 2020

1998~2017년 북한의 교역을 관측한 결과, 북한의 대중 교역 비중은 꾸준히 증가하여 2017년에는 그 비중이 94.8%까지 높아진 것으로 관찰됐다. 즉, 동기간의 북한의 대중국 교역 의존도가 급증한 것을 확인 할 수 있다. 이러한 북한의 대중국 교역 의존도가 북한만의 특이한 교역 구조인지 확인하기 위해 본고는 ① 전세계, ② 아시아, ③ 중국 접경 국가를 비교군으로 설정하여 시계열 및 횡단면 비교를 각각 실시하였다. 먼저 시계열로 비교한 결과 1998~2017년 전 기간 동안 북한은 전세계, 아시아, 중국 접경 국가 보다 대중국 교역의존도가 현저히 높았던 것으로 나타났다. 또한 북한은 대중국 교역의존도 증가 추세 역시 가장 가파른 국가로 확인됐다. 예를 들어, 1998년 북한의 대중국 교역 의존도는 24.8%, 아시아 지역의 대중국 교역 의존도는 6.5%로 북한이 아시아 지역에 비해 약 3.8배 높았으나, 2017년의 경우 북한 94.8%, 아시아 19.4%로 약 4.9배 더 높은 것으로 나타나 지난 20년 동안 북한의 대중국 교역 의존도가 다른 전세계 국가들에 비해 가파르게 증가한 것으로 나타났다. 구체적으로 중국 접경 국가군에 소속된 개별 국가와 비교한 결과, 북한 다음으로 대중국 교역 의존도가 높고, 가파르게 증가한 국가는 몽골과 미얀마인 것으로 관찰된다. 그러나 몽골, 미얀마는 북한에 비해서 대중국 교역 의존도 증가 추세는 상대적으로 완만하다. 다음으로, 본고에서 설정한 최종 관측연도인 2017년 한해에 대해 횡단면 비교를 실시하였다. 횡단면 비교에서는 대중국 교역 의존도를 수출입 의존도로 세분화하여 비교하고, 대중국 GDP 의존도를 추가하여 비교했다. 그 결과 2017년 북한의 대중국 수출입 의존도 모두 전세계, 아시아, 중국 접경 국가들 중 가장 높은 순위를 기록했다. 특이한 점은 북한의 대중국 교역의존도는 수출보다 수입에서 높게 나타난 반면, 북한 다음으로 대중국 교역 의존도가 높은 몽골과 미얀마의 경우 수입보다 수출의 대중국 의존도가 높게 나타났다는 점이다. 대중국 GDP 의존도의 경우 북한은 중국 접경 국가들 중 몽골과 베트남 다음으로 의존도가 높은 국가로 확인된다. 추가적으로 2017년의 북한, 몽골 및 미얀마의 교역 특징을 알아보았다. 먼저 북한, 몽골, 미얀마의 대중 교역 품목을 비교한 결과 이들 3개국 모두 공통적으로 주로 석탄, 천연가스 등의 천연자원을 중국에 수출한다는 특징을 가진다. 그러나 수입의 경우 북한은 대두유와 같은 식량류와 합성 직물, 무선 전화기 등을 주로 수입하는 반면, 몽골과 미얀마는 산업 생산에 필요한 에너지 및 부속품을 주로 수입한다는 차이점이 있었다. 다음으로, 2017년 북한과 몽골, 미얀마가 가장 많이 교역한 중국의 성(省)을 비교해본 결과, 북한은 요녕성, 몽골은 내몽고자치구, 미얀마는 운남성과의 교역이 가장 많았다는 것을 확인 할 수 있었다. 이를 통해 대중 교역 의존도가 높은 3개 국가들이 중국과 국경을 접한 성(省)과 가장 교역을 많이 한다는 특징을 확인할 수 있었다.

• Journal of Animal Environmental Science
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• v.9 no.2
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• pp.103-112
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• 2003

In this study, the distributions of internal climates such as air temperature, humidity, dust, ammonia gas, and air velocity were systematically measured at a mechanically ventilated broiler houses during summer season, with local weather data. The analysis was focused on the suitability, stability, and uniformity of internal climate, resulting in serious stress on chickens and decrease of productivity In the mechanically ventilated broiler house, the difference between measured and recommended air temperatures(suitability) was 10.4C in maximum during the summer time. The difference of air temperature in the house between day and night was $8.7^{\circ}C$ in maximum. And maximal hourly range of internal air temperature at 0.4m height from the floor was $3.7^{\circ}C$ suggesting it maintained thermal uniformity in the broiler house. The $NH_3$ and dust concentrations were pretty low because ventilation was fully performed. The air speed at chicken location was measured 2.2m/s and 1.7m/s, respectively without and with chicken existence.