• Journal of the Korean Wood Science and Technology
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• v.48 no.2
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• pp.253-266
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• 2020

This study selected three types of agglomerated wood charcoal (Agglomerated wood charcoal with charcoal powder, Carbonized wood briquette, Ignition-type of perforated charcoal) that are in circulation in Korea among fuel-type wood products and analyzed the fuel characteristics, harmful substance content, and emissions of air pollutants generated by combustion. The first results showed that charcoal-grilled carbon, which is the raw material of charcoal, produced higher CO than saw-billed carbon. The second result is that the emission standards of air pollutants generated by the combustion of molded wood coal are not up to the emission standards of nitrogen oxides and sulfur oxides in the entire product, compared with the emission criteria of the atmospheric environment preservation method (based on 2019, carbon monoxide: 200 ppm, nitrogen oxides, 150 ppm sulfur oxides: 100 ppm), but the carbon dioxide moulding and carbon dioxide levels were not up. Based on the analysis of combustion gas generated during combustion derived from this study, future research is needed for comparing with the emission standards of pellets, which are wood products for fuel, among the existing biomass burning standards and for reducing carbon monoxide generated during incomplete combustion of agglomerated wood charcoal.

• Journal of Advanced Marine Engineering and Technology
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• v.38 no.7
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• pp.868-876
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• 2014

The objective of this study is focused on the analyzing combustion, carbon monoxide and hydrocarbon emission characteristics of marine diesel oil, utilized for naval propulsion engine, with varying pre-post injection timing of an optically accessible single cylinder engine. And also the combustion process is analyzed by means of a high speed camera visualization. On the result of retarding pre-injection timing toward main injection timing, the mean effective pressure and maximum pressure of combustion chamber are increased; however, the heat release rate is decreased. Furthermore, the emission rates of carbon monoxide and hydrocarbon are reduced in this case. In hence, when a post-injection timing is advanced, the mean effective pressure and maximum pressure are increased, because the combustion has been performed under the high temperature and high pressurized environment during main injection time, and the emission rates of carbon monoxide and hydrocarbon are increased. From the experimental results, it considered that retarding of pre-injection timing affects to shorten the ignition delay of main injection clearly, and to raise the flame intensity comparing to the advanced state. The ignition delay during post-injection is not appeared at any post-injection time, but the flame intensity has been weakened gradually according to the retarding of post-injection timing.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.9
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• pp.204-210
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• 2019

In case of a fire inside a tunnel, unlike ordinary roads, it is very difficult for a driver to obtain visibility, and a large accident is highly likely to occur. In this study, the smoke behavior, visible distance, and CO concentration of a jet fan were analyzed using the NIST fire simulation (FDS). All analyses were set to HRRPUA (Heat Release Rate Per Area) 3.6MW/m and all the analysis times were set to 600s. In all analyses by CFD, the results were confirmed at y=30m and y=110m, and smoke behavior analysis, visible range analysis, and carbon monoxide concentration were confirmed according to the diameter and flow rate. As the size and flow rate of the jet fan increased, the visibility distance was high at y=30m, and the concentration of carbon monoxide was also confirmed to be 0 ppm. Therefore, proper setting of the jet fan diameter and flow rate will be an excellent solution for fires in tunnels, and taking refuge at upstream area of a re-ventilated fan can reduce the number of casualties.

• Membrane Journal
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• v.21 no.3
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• pp.290-298
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• 2011

The influence of co-existing gases on the hydrogen permeation was studied through a Pd-coated $V_{53}Ti_{26}Ni_{21}$ alloy membrane. The hydrogen permeation characteristics of Pd-coated $V_{53}Ti_{26}Ni_{21}$ alloy membrane have been investigated in the pressure range 1-3 bar under pure hydrogen and hydrogen mixture gas with carbon dioxide and carbon monoxide at $450^{\circ}C$. Preliminary hydrogen permeation experiments have been confirmed that hydrogen flux was $5.36mL/min/cm^2$ for a Pd-coated $V_{53}Ti_{26}Ni_{21}$ alloy membrane (thick: 0.5 mm) using pure hydrogen as the feed gas. In addition, hydrogen fluxes were 4.46, 5.20, $3.91mL /min/cm^2$ for$V_{53}Ti_{26}Ni_{21}$ alloy membrane using $H_2/CO_2$, $H_2/CO$ and $H_2/CO_2/CO$ as the feed gas respectively. Therefore, the hydrogen permeation flux decreased with decrease of hydrogen partial pressure irrespective of temperature and pressure when $H_2/CO_2$, $H_2/CO$ and $H_2/CO_2/CO$ mixture applied as feed gas respectively and permeation fluxes were satisfied with Sievert's law in different feed conditions. It was found from XRD results after permeation test that the Pd-coated $V_{53}Ti_{26}Ni_{21}$ alloy membrane had good stability and durability for various mixtures feeding condition.

• Journal of Preventive Medicine and Public Health
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• v.16 no.1
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• pp.153-156
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• 1983

1950년(年) 이후(以後) 무연탄(無煙炭)으로 만든 연탄(煉炭)을 취사(炊事), 난방용(煖房用)으로 가정(家庭)에서 광범위(廣範圍)하게 사용(使用)하게 되면서 연탄(煉炭)가스내(內)의 일산화탄소(一酸化炭素)로 인(因)한 중독사고(中毒事故)가 빈발(頻發)하여 심각(深刻)한 국민보건(國民保健)의 문제(問題)가 되어왔다. 저자(著者)들의 실태조사(實態調査)(1975년도(年度))에 의(依)하면 서울특별시일원(特別市一圓)에 있어 일산화탄소중독(一酸化炭素中毒)의 년간발생(年間發生)은 인구(人口), 10만당(萬當) 경증(輕症) 260명(名), 혼수상태(昏睡狀態)의 중증중독(重症中毒) 45명(名), 사망(死亡) 1명(名)으로 위험인구(危險人口)를 3,000만명(萬名)으로 하였을 때 전국적(全國的)으로 일산화탄소중독(一酸化炭素中毒)의 추정발생수(推定發生數)는 년간(年間) 경증(輕症) 78만명(萬名), 중증(重症) 13만(萬) 5천명(千名), 사망(死亡) 3,000명(名)으로 그 피해(被害)의 규모(規模)가 100만을 육박(肉薄)하는 가공(可恐)할 수자(數字)를 보여주고 있다. 저자(著者)들은 이러한 심각(深刻)한 국민보건(國民保健)의 문제(問題)를 우선(于先) 실천가능(實踐可能)한 제이차예방(第二次豫防)에 역점(力點)을 두어 고압산소요법(高壓酸素療法)을 보급(普及)할 목적(目的)으로 일인용고압산소장치(一人用高壓酸素裝置)를 개발(開發)하고 1969년(年) 1월(月)에 서울대학교병원(大學校病院)에 고압산소치료실(高壓酸素治療室)을 개설(開設)하여 급성일산화탄소(急性一酸化炭素) 중독환자(中毒患者)에 대(對)한 응급치료(應急治療)를 실시(實施)하여 1978년(年)까지 10년간(年間)의 치료결과(治療結果)를 요약(要約)한바 다음과 같다. 1. 총치료환자수(總治療患者數)는 2,242명(名)이고 회복(回復)된 수(數)는 2,202명(名)으로 98.2%의 회복률(回復率)을 보였다. 2. 계절적(季節的)으로 10월(月)에서 4월(月)까지가 연중최성기(年中最盛期)이나 5월(月)에서 9월(月)까지도 적지않은 환자(患者)의 발생(發生)을 볼 수 있었다. 3. 연령별분포(年齡別分布)를 보면 15세(歲)${\sim}29$세군(歲群)이 전체환자(全體患者)의 반이상(半以上)인 52.7%를 차지하고 있고 $0{\sim}14$세군(歲群)은 인구비(人口比)에 대해 발생(發生)이 훨씬 적은 결과(結果)를 보이고 있다. 4. 도착시간별(到着時間別) 입원율(入院率)은 오전(午前) 10시이후(時以後) 도착군(到着群)서부터는 입원율(入院率)이 급증(急增)하는데 이는 병원도착(病院到着)이 늦일수록 당일회복(當日回復)이 되지못하고 입원가료(入院加療)하게 됨을 나타내주는 결과(結果)라 할 수 있다. 5. 병발증(倂發症)으로는 급성욕창, 폐렴(肺炎) 및 신경학적(神經學的) 이상등(異常等)의 소견(所見)을 많이 볼 수 있었다.

• Journal of the Korean Geographical Society
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• v.32 no.2
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• pp.245-263
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• 1997

Housing market is segmented through 1) housing supply classified by housing characteristics and 2) housing demand classified by different housing opportunity of household. Moreover, neighborhood plays a role in intensifying housing market segmentation as a factor affecting on decision making relevant to housing supply and demand. while segmented housing markets have different mechanism, existing studies on residential differentiation and housing market have overlooked the characteristic differences among housing submarkets as the studies presume metropolitan housing market to be a single housing market. while the concept of 'residential differentiation' pays much attention on spatial pattern after the ecological approach appeared, the concept of ‘housing submarkets' is explanatory of the process of urban space structure formation. Analysis on housing submarkets makes up for the weak points of the behavioral approach inquiring into socio-economic constraint and different housing opportunity of household.

• The Journal of Internal Korean Medicine
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• v.43 no.4
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• pp.779-793
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• 2022

Objectives: The purpose of this study was to report on the cases and prescriptions of non-face-to-face care performed to alleviate COVID-19 symptoms and to present their results. Methods: This study was conducted on 63 COVID-19 patients who visited the Ilsan Hamsoa Korean Medicine Clinic from January 24 to June 11, 2022. We retrospectively analyzed all 63 patient charts and amassed COVID-19-related symptoms and their changes according to clinical characteristics and outcomes. Results: All 63 COVID-19 patients complained of symptoms, such as coughing, sore throat, sputum, fever, headache, myalgia, rhinorrhea, nasal obstruction, postnasal drip, and voice change. In total, 30 patients were administered Eunma-san, 6 patients were administered Eungyo-san plus Mahaenggamseok-tang, 10 patients were administered Galgeunhaegi-tang, 7 patients were administered Eungyo-san, 6 patients were administered Maekmundong-tang, and 4 patients were administered Jugyeopseoggo-tang. Improvements in symptoms due to herbal medicine included the disappearance of COVID-19 fever (22 cases) within 3.59±4.2 days, sore throat (32 cases) within 4.37±2.98 days, and cough (36 cases) within 4.86±3.1 days. Conclusion: Various herbal medicine prescriptions were effective COVID-19 treatments, indicating that herbal medicines may be alternative treatment options for COVID-19. However, the evidence should be supplemented with better designed prospective research on individual prescriptions.

• Korean Journal of Psychosomatic Medicine
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• v.24 no.2
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• pp.133-139
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• 2016

Objectives : As the prevalence of elderly depression increases, it becomes urgent problem to provide preventive and management measures. But in practice, it is difficult to detect depression in early stage. The purpose of this study is to evaluate the association between sociodemographic factors and depression in elderly welfare facility users in a city. Methods : In this research, the severity of depression and sociodemographic factors(gender, age, education, co-morbid disease, housing type, number of children, number of family members living with the subjects) was evaluated through PHQ-9 and interview. Using the data, the associations of depression and sociodemographic factors were analyzed. Based on PHQ-9 depression cut-off value(10 points), the subjects were divided into two groups, and the difference of the variables between groups were analyzed statistically. Results : 'Own house'(YES/NO), education(less than elementary school graduation/more than elementary school graduation) were sociodemographic factors which showed significance difference in mean PHQ-9 scores. Group with Over PHQ-9 10 points showed less 'having their own house' and less education level than group with less PHQ-9 10 points. Conclusions : With this research, it is expected that the risk factors for the elderly depression can be understood and the measures for early detection and invention of elderly depression would be provided.

• Journal of the Korean Society for Railway
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• v.11 no.3
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• pp.216-224
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• 2008

In general, based on criteria of subway law, radius 500m from subway station is defined as SIA(Subway Station Influence Area). Therefore, in this paper, selection models of SIA are developed to identify appropriate SIA for recently developed 4 new towns based based on CART analysis. As a result, following outputs are obtained; (1) walking distance from subway station is the most influential factor to define SIA (2) SIAs vary with new towns (i.e., bundang city: 856m, ilsan sanbon city 508m, pyungchon city 495m), and (3) walking distance from subway station is influential to land price of SIA. In addition, bundang and pyungchon new town are more affected in land price and walking distance. Therefore, it is desirable for current definition of SIA (radius 500m from subway station) to reflect characteristics of land use and walking distance in the new towns.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.34 no.3
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• pp.269-274
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• 2010

As a preliminary study on a SOFC-GT hybrid system integrated a with coal-gasification system, the influence of the concentrations of $H_2$ and CO in syngas on the performance characteristics of the hybrid system is investigated. It is expected that the differences in the heating values of fuels with different compositions trigger the off-design operation of the gas turbine and result in different performance characteristics of the overall hybrid system. Syngas compositions are found to affect the SOFC performance. Performance of hybrid system with carbon monoxide is poorer than the case with hydrogen. In the case of part-load performance with syngas, performance degradation at part-load operating conditions with hydrogen is more dominant than the case with carbon monoxide.