• Title/Summary/Keyword: 열분석적 특성

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Adsorption of Cd on Carbonaceous Adsorbent Developed from Automotive Waste Tire (자동차 폐타이어로부터 발달된 탄소질 흡착제에 의한 Cd의 흡착)

  • Kim, Younjung;Uh, Eun Jeong;Choi, Jong Ha;Hong, Yong Pyo;Kim, Daeik;Ryoo, Keon Sang
    • Journal of the Korean Chemical Society
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    • v.61 no.6
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    • pp.339-345
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    • 2017
  • Carbonaceous adsorbent (CA-WTP) was prepared by heat treatment at $400^{\circ}C$ for 2 h in N2 atmosphere using waste tire powder (WTP). WTP and CA-WTP were first characterized by thermo-gravimetric analysis (TGA), energy dispersive X-ray spectrometer (EDS), scanning electron microscopy (SEM), specific surface area analysis (BET) and FT-IR spectroscopy. Then, they were tested as adsorbents for removal of Cd in water. CA-WTP exhibited much higher specific surface area and total pore volume than WTP itself and showed higher adsorption capacity for Cd. Equilibrium data of adsorption were analyzed using Freundlich and Langmuir isotherm models. It was seen that both Freundlich and Langmuir isotherms have correlation coefficient $R^2$ value larger than 0.95. The results of studies indicate that CA-WTP developed from WTP by heat treatment could be used as efficient adsorbent for the removal Cd from water.

The Temperature Distribution and the Smoke Flow Behaviour During Road Tunnel Fire (도로터널내 화재시 온도분포 및 연기 유동 분석 연구)

  • Choi, Tae-Hee;Yeun, Young-Pyo;Yun, Chul-Uk;Kim, Myung-Bae;Choi, Jun-Seok;Lee, Seung-Ho;Kim, Nag-Young
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.4 no.1
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    • pp.37-43
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    • 2002
  • Recently, the construction of tunnels longer than one kilometer has increased rapidly. Considering characteristic of limiting structure of longer tunnel, if fires inside tunnel broke out because of vehicle incidents, the catastroph would have high possibility to take place due to toxic smoke and heat of fire. In case of highway tunnel, safety facilities which can cope with tunnel fire are installed in the tunnel but according to rapid increase of heavy good traffic, dangerous goods and enlargement of tunnel magnitude, the research has to carry out about heat fluxes and smoke behaviour during tunnel fire. Therefore, through full-sized fire experiment the paper analyzed temperature distribution, wind velocity, smoke behaviour during tunnel fire.

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Trend of heat wave events in South Korea using daily minimum air temperature (일 최저 기온을 이용한 한국의 폭염사상 추세)

  • Kim, Ryoungeun;Won, Jeongeun;Lee, Jungmin;Choi, Jeonghyeon;Kim, Sangdan
    • Journal of Wetlands Research
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    • v.21 no.4
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    • pp.344-353
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    • 2019
  • Heat waves are a global phenomenon that exacerbate the risks associated with heat exposure and cause fatal human injury. The subject of this study was tropical night, one of the forms of heat waves. In this study, we investigated how the trend of tropical night in Korea is changing. From 1973 to 2018, we analyzed the temporal changes of the six tropical nights using daily minimum air temperature at 60 ASOS stations in Korea Meteorological Administration. From these analyzes, 10 sites were selected as attention sites for tropical nights: Incheon, Gangneung, Cheongju, Jeonju, Gwangju, Jangheung, Yeosu, Geoje, Gumi, Yeongdeok. The severe sites for tropical nights were identified as 14 sites including Hongcheon, Yangpyeong, Suwon, Wonju, Boryeong, Daejeon, Buan, Jeongeup, Mokpo, Geochang, Miryang, Pohang, Jeju, and Seogwipo. At the severe sites identified, special tropical night measures will need to be established.

Manufacturing Techniques and Provenance of Gilt-bronze Seated Bhaisajyaguru (Medicine Buddha) Statue of Cheongyang Janggoksa Temple, Korea (보물 제337호 청양 장곡사 금동약사여래좌상의 제작기법 및 납 원료 산지연구)

  • Bae, Go Woon;Lee, Sang Ok;Beom, Dae Geon;Chung, Kwang Yong
    • Journal of Conservation Science
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    • v.34 no.1
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    • pp.59-67
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    • 2018
  • This study investigated manufacturing technique and provenance of the Gilt-bronze Seated Bhaisajyaguru (Medicine Buddha) Statue of Janggoksa Temple. The statue had the following : Cu(68.8%)-Sn(10.4%)-Pb(17.1%), it is similar to other medium or large Buddha statue. As results of comparison lead isotope ratio of sample with the provenance data were plotted in zone 3 of the South Korean galena map. According to this result of Bronze Buddha could be made into galena of the located in same area the temple. The results of this study were compared with the Bronze Bodhisattva statue of Goseongsa Temple. The manufacturing techniques were different based on the characteristics of Buddha statues and thus could be made into galena of the located in same area the temple.

A Combustion Analysis of Surface Fuel Burning Experiment According to Density Variation (밀도에 따른 지표 연료의 연소실험 분석)

  • Kim, Eung-Sik;Kim, Jang-Hwan;Kim, Dong-Hyun;Park, Hyung-Ju;Kim, Jeong-Hun
    • Fire Science and Engineering
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    • v.24 no.1
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    • pp.1-7
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    • 2010
  • This paper shows combustion characteristics of fallen leaves of Quercus variabilis and Pinus densiflora according to variation of mass densities. Combustion temperature, mass loss rate, flame height, duration of combustion and velocity of hot gas are measured and analyzed. For the experiment 10cm heighted baskets with varying diameters of 20, 30, 40 and 50cm are used for the combustion and the pilot ignition is carried on the top of the fuel. In case of Pinus densiflora mass loss rate, duration of flame, flame height and combustion time become larger as the mass density and diameter of basket increase, on the other hand Quercus variabilis shows saturation characteristics in mass loss rate and flame height. Velocity of hot gas is proportional to flame height.

Effects of the Changes in Flow Pattern on Convective Heat Transfer in the Vicinity of Pipe Elbow (유동형태 변화가 배관 곡관부 대류열전달에 미치는 영향)

  • Song, Seung-Hyun;Yoo, Hoseon
    • Plant Journal
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    • v.15 no.1
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    • pp.25-30
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    • 2019
  • In this study, by varying flow patterns, which is one of the hydraulic factors of FAC, a strategy to reduce pipe wall thinning by mass transfer has been investigated. A similarity between heat transfer and mass transfer was verified via theoretical analysis, and local convective heat transfer coefficients were analyzed using a commercial numerical analysis program. When ribs were installed inside and outside of the internal surface in the straight section of the pipe, the maximum local heat transfer coefficient was shown to decrease substantially by up to 24.9% compared to the basic flow depending on the position and shape of ribs. If a guide vein was inserted in the pipe elbow, the maximum local heat transfer coefficient decreased by up to 26.7% compared to the basic flow depending on the internal surface area of the pipe by the guide vein.

Feasibility Study of a Corrugated Steel Protective Structure for Ammunition Test Facility (탄약시험장의 강재 방호구조물 적용성 분석 연구)

  • Han, Jae Duk;Kim, Donghee;Kim, Sungkon
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.42 no.5
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    • pp.671-679
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    • 2022
  • Harmful factors such as shock waves and fragments are generated at domestic ammunition testing sites and military shell shooting training sites due to frequent shooting and explosion tests. As a result, complaints from local residents are rapidly increasing, and there is a high risk of damage to facilities and human life. The recently constructed ammunition test site built a test facility for firing artillery and rocket propulsion in a narrow area with a radius of 300 m due to site restrictions, but damage to the facility is accumulating because there is no adequate protective structure. Therefore, in this study, quantitative data on harmful factors such as noise, vibration, shock wave, and thermal effect generated between artillery firing and rocket propulsion tests were measured, and explosion pressure characteristics were analyzed to design a protective structure, and use Autodyn to protect performance. to perform verification.

A Study on the Strategy of Securing the Archival Budget through Qualitative Research Method (기록전문직의 기록관리 사업예산 확보 전략 연구)

  • Suh, Hwayul;Yim, Jinhee
    • Journal of Korean Society of Archives and Records Management
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    • v.22 no.3
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    • pp.55-81
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    • 2022
  • The purpose of this study is to explore a budget-securing strategy to enable archival professionals in public institutions to continuously secure the budget for records management projects. This study is an analysis of the results of in-depth interviews with 14 archival professionals who have worked for public institutions and secured budgets for records management projects. As a result of the analysis, 4 upper categories and 10 categories are extracted as factors influencing budget securement. The top four categories are the job environment of archival professionals, umbrella organization and organizational culture, business and budget characteristics, and system and social environment. As the budget-securing strategy for archival professionals, a total of 3 categories and 13 strategic codes are derived. The three categories are utilizing individual-centered competencies, establishing organization-centered relationships, and finding external environment-centered triggers. This study emphasized the perspective of archival professionals and suggested implications such as the role of archival professionals and the direction of improvement in securing budgets.

Climatological Characteristics in the Variation of Soil temperature in Korea (우리나라 지중온도 변동의 기후학적 특성)

  • Kim Seoung-Ok;Suh Myoung-Seok;Kwak Chong-Heum
    • Journal of the Korean earth science society
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    • v.26 no.1
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    • pp.93-105
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    • 2005
  • Climatological characteristics in the variation of soil temperatures in Korea were investigated using Korea Meterological Administration's observation data. And the impacts of soil moisture on the variation of soil temperature were examined using observed precipitation data. The climatological averages of soil temperatures are ranged from 14.4 to $15.0^{\circ}C$ regardless of depths. And they showed an latitudinal gradient with a warm temperature at the southern region and 'U' shape as in the air temperature with a high value along the coastal region. The relatively higher heat capacity and low conductivity of soil compared to those of the air resulted in the significant delay of the maximum and minimum date with depth. As a results, soil acts as a heat source during winter while a heat sink during summer. Global warming and urban heat island have increased the soil temperatures with an average rate $0.3\~0.5^{\circ}C/10-year$ as in the air temperature during last 30 years $(1973\~2002)$. However, the warming rate is maximized during spring contrary to the winter in the air temperature. The temporal variation of soil temperatures is strongly affected by that of soil moisture through an modification of the heat capacity and heat convection. In general, the increased soil moisture clearly decreased the temporal variations and increased the deep layer soil temperatures during cold season.

Effect of Package Size and Pasteurization Temperature on the Quality of Sous Vide Processed Spinach (Sous Vide 가공 시금치의 품질에 미치는 포장단위 및 살균온도의 영향)

  • 장재덕;김기태;이동선
    • Food Science and Preservation
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    • v.11 no.2
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    • pp.195-200
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    • 2004
  • Microbial lethal value and nutrient retention of sous vide processed spinach were evaluated with mathematical model prediction and experimental trial for different package sizes and pasteurization temperatures. The package size covers 500 g, 1 kg and 2 kg, while the pasteurization temperature includes 80, 90 and 97$^{\circ}C$. The basic process scheme consists of filling blanched spinach into barrier plastic film pouch, sealing under vacuum, pasteurization in hot water with over pressure and final cooling to 3$^{\circ}C$. Pasteurization condition was designed based on attainment of 6 decimal inactivation of Listeria monocytogenes at geometric center of the pouch package by heating cycle, which was determined by general method. Heat penetration property of the package and thermal destruction kinetics were combined to estimate the retention of ascorbic acid and chlorophyll. Smaller packages with shorter pasteurization time gave better nutrient retention, physical and chemical qualities. Larger package size was estimated and confirmed experimentally to give higher pasteurization value at center, lower ascorbic acid and chlorophyll contents caused by longer heat process time. Lower pasteurization temperature with longer process time was predicted to give lower pasteurization value at center and lower ascorbic acid, while chlorophyll content was affected little by the temperature. Experimental trial showed better retention of ascorbic acid and chlorophyll for smaller package and higher pasteurization temperature with shorter heating time. The beneficial effect of smaller package and higher pasteurization temperature was also observed in texture, color retention and drip production.