• Title/Summary/Keyword: thermal indicator

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Community Structure of Macrobenthos around the Thermal Discharge Area of the Uljin Nuclear Power Plant in the East Sea, Korea (동해 울진 원전 온배수배출구 주변 해역에서의 대형저서동물 군집구조)

  • Kwon, Soon Hyun;Yu, Ok Hwan;Lee, Hyung-Gon
    • Ocean and Polar Research
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    • v.39 no.2
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    • pp.125-148
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    • 2017
  • This study analyzed the community structure of macrobenthic organisms in the subtidal area suffering under the influence of thermal discharge from the Uljin nuclear power plant during 2012-2013 and reviewed the temporal change in the faunal composition of the macrobenthic community using data from previous studies since the start of the plant operation in 1989. A total of 319 species were collected in 2012-2013, with a mean density of $3,330ind./m^2$ and a mean biomass of $131.96g/m^2$. These results were similar to those obtained in 2006-2007. The dominant species were not different from each other before and after the power plant operations began, but the faunal density near the power plant drainage port was significantly higher compared to those densities obtained from other stations. Spiophanes bombyx and Polydora sp., which is known as a pollution indicator species, was dominant only in the drainage port area. The study area consisted of two subregions with different macrobenthic communities depending on the water depth, which was similar to the results of the 2006-2007 survey. The macrobenthic community structures before and after the operation of the power plant in the coastal area were not changed, but there were seasonal differences in the long-term macrobenthic community structure which were strongly related to the thermal discharge from the power plant.

Developing a Multi-Functional Smart Down Jacket Utilizing Solar Light and Evaluating the Thermal Properties of the Prototype (태양광을 활용한 스마트 다운재킷 개발 및 보온성능 평가)

  • Yi, Kyonghwa;Kim, Keumwha
    • Journal of Fashion Business
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    • v.19 no.4
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    • pp.92-108
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    • 2015
  • This study aimed at developing a down jacket prototype that utilized sunlight as an alternative energy source with no air pollution. The jacket is filled with flexible solar panels and has a heat-generating function and LED function. In this study, three smart down jacket prototypes were developed, and the jacket's capabilities were demonstrated through the thermal effect on the performance test. The typical output voltage of the flexible solar panels was 6.4V. By connecting the 2 solar cell modules in series, the final output voltage was 12.8V. A battery charge regulator module was used the KA 7809 (TO-220) of 9V. Three heating pads were to be inserted into the belly of the jacket as direct thermal heating elements, and the LED module was configured, separated by a flash and an indicator. The smart down jacket was designed to prevent damage to the down pack without the individual devices' interfering with the human body's motion. Because this study provides insulation from extreme cold with a purpose, the jacket was tested for heat insulation properties of non-heating, heating on the back, heating on the abdomen, and heating on both the back and abdomen in a sitting posture in a static state. Thermal property analysis results from examining the average skin temperature, core temperature, and the temperature and humidity within clothing showed, that placing a heating element in one place was more effective than distributing the heating elements in different locations. Heating on the back was the most effective for maintaining optimal skin temperature, core temperature, and humidity, whereas heating on the abdomen was not effective for maintaining optimal skin temperature, core temperature, or humidity within clothing because of the gap between the jacket and the body.

Thermodynamic Analysis of Re-liquefaction Cycle of LNG Boil-off Gas (LNG 증발기체의 재액화 사이클에 대한 열역학 해석)

  • Chin, Young-Wook;Moon, Jeong-Woo;Lee, Yoon-Pyo;Chang, Ho-Myung
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.19 no.7
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    • pp.485-490
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    • 2007
  • The LNG BOG re-liquefaction system for LNG carriers was designed based on the Claude refrigeration cycle and the thermodynamic analysis was carried out in order to find the design point of the three heat exchangers constituting the system. The thermodynamic analysis revealed that the system state could be defined by the three cold endpoint temperatures of the three-pass heat exchanger. Hence the iso-lines of the specific liquefaction work, taken as the performance indicator, were presented in terms of those three temperatures and discussed. The system was found most economical when those three temperatures approached a single temperature of $-140^{\circ}C$ and thus this system state could be taken as the design point for the heat exchangers.

Effect of NaCl, Gum Arabic and Microbial Transglutaminase on the Gel and Emulsion Characteristics of Porcine Myofibrillar Proteins

  • Davaatseren, Munkhtugs;Hong, Geun-Pyo
    • Food Science of Animal Resources
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    • v.34 no.6
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    • pp.808-814
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    • 2014
  • This study investigated the effect of gum arabic (GA) combined with microbial transglutaminase (TG) on the functional properties of porcine myofibrillar protein (MP). As an indicator of functional property, heat-set gel and emulsion characteristics of MP treated with GA and/or TG were explored under varying NaCl concentrations (0.1-0.6 M). The GA improved thermal gelling ability of MP during thermal processing and after cooling, and concomitantly added TG assisted the formation of viscoelastic MP gel formation. Meanwhile, the addition of GA decreased cooking yield of MP gel at 0.6 M NaCl concentration, and the yield was further decreased by TG addition, mainly attributed by enhancement of protein-protein interactions. Emulsion characteristics indicated that GA had emulsifying ability and the addition of GA increased the emulsification activity index (EAI) of MP-stabilized emulsion. However, GA showed a negative effect on emulsion stability, particularly great drop in the emulsion stability index (ESI) was found in GA treatment at 0.6 M NaCl. Consequently, the results indicated that GA had a potential advantage to form a viscoelastic MP gel. For the practical aspect, the application of GA in meat processing had to be limited to the purposes of texture enhancer such as restructured products, but not low-salt products and emulsion-type meat products.

Development of a Drought Detection Indicator using MODIS Thermal Infrared Data

  • Park, Sun-Yurp
    • Korean Journal of Remote Sensing
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    • v.20 no.1
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    • pp.1-11
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    • 2004
  • Based on surface energy balance climatology, surface temperatures should respond to drying conditions well before plant response. To test this hypothesis, land surface temperatures (LST) derived from MODIS data were analyzed to determine how the data were correlated with climatic water balance variables and NDVI anomalies during a growing season in Western and Central Kansas. Daily MODIS data were integrated into weekly composites so that each composite data set included the maximum temperature recorded at each pixel during each composite period. Time-integrated, or cumulative values of the LST deviation standardized with mean air temperatures had significantly high correlation coefficients with SM, AE/PE, and MD/PE, ranging from 0.65 to 0.89. The Standardized Thermal Index (STI) is proposed in this study to accomplish the objective. The STI, based on surface temperatures standardized with observed mean air temperatures, had significant temporal relationships with the hydroclimatological factors. STI classes in all the composite periods also had a strong correlation with NDVI declines during a drought episode. Results showed that, based on LST, air temperature observations, and water budget analysis, NDVI declines below normal could be predicted as early as 8 weeks in advance in this study area.

Analysis of Reflux Cooling in the SG U-Tubes Under Loss of RHRS During Midloop Operation with Primary System Partly Open

  • Son, Young-Seok;Kim, Won-Seok;Kim, Kyung-Doo;Chung, Young-Jong;Chang, Won-Pyo
    • Nuclear Engineering and Technology
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    • v.30 no.2
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    • pp.112-127
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    • 1998
  • The present study is to assess the applicability of the best-estimate thermal-hydraulic codes, RELAP5/MOD3.2 and CATHARE2V1.3U, to the analysis of thermal-hydraulic behavior in PWRs during midloop operation following the loss of RHRS. The codes simulate an integral test, BETHSY 6.94, which was conducted in the large scale test facility of BETHSY in France. The test represents the accident where the loss of RHRS occurs during midloop operation with the pressurizer and upper head vents open and the sight level indicator broken. Besides, the hot legs are half filled with water and the upper parts of the primary cooling system are filled with nitrogen, with a letdown line open and only one SG available. The purposes of this study are to understand the physical phenomena associated with reflux cooling in the 5G U-tubes when noncondensable gas is present under low pressure and to assess the applicability of the codes to simulate the loss of RHRS event by comparing the predictions with the test results. The results of the study may contribute to actual applications for plant safety evaluation and description of the emergency operating procedure.

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Tropical red alga Compsopogon caeruleus: an indicator of thermally polluted waters of Europe in the context of temperature and oxygen requirements

  • Andrzej S., Rybak;Andrzej M., Woyda-Ploszczyca
    • ALGAE
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    • v.37 no.4
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    • pp.301-316
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    • 2022
  • The red alga Compsopogon caeruleus can generally be found in tropical and subtropical waters worldwide. In addition to its natural habitats, this species may be found in waters that receive abnormally hot water, e.g., from powerhouses. To date, the presence of C. caeruleus has not been observed in thermally polluted lacustrine ecosystems in Poland, which has a moderate climate. The thalli of this red alga were found growing on Vallisneria spiralis in Lichenskie Lake. Importantly, this paper presents a previously unknown relationship between the temperature (20, 25, 30, 35, and 40℃) and oxygen requirements of C. caeruleus (based on ex situ measurements of O2 consumption by thalli). Surprisingly, 35℃ can be the optimum temperature for C. caeruleus, and this temperature is higher than the values reported by some previous thermal analyses by approximately 10℃. Additionally, we reviewed and mapped the distribution of this nonnative and mesophilic red alga in natural / seminatural water ecosystems in Europe. Finally, we propose that the occurrence of C. caeruleus mature thalli can be a novel, simple and easy-to-recognize bioindicator of artificially and permanently heated waters in moderate climate zones by a regular discharge of postindustrial water.

Measurement of carbonation depth of concrete in old buildings and experimental evaluation of carbonation degree and CO2 absorption using differential thermal gravimetric analysis (노후 건축물의 콘크리트 탄산화 깊이 측정과 시차열 중량분석을 통한 탄산화도 및 CO2 흡수량 실험적 평가)

  • Lee, Sang-Hyun;Ki, Jun-Do;Cho, Hong-Bum;Park, Chang-Gun;Kim, Young-Sun;Moon, Hyung-Jae
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2022.11a
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    • pp.197-198
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    • 2022
  • Based on the carbonation depth measurement by the indicator for concrete collected from old structures and the quantitative analysis of Ca(OH)2 and CO2 in the carbonation section before and after the carbonation depth and in the non-carbonation section, the absorbable CO2 amount and carbonation degree measurement result is as follows 1) The carbonation depth of the 40-year-old reinforced concrete structure was measured to be about 22 mm. (basement interior wall, marble finish, strength 30MPa) 2) The amount of CO2 absorbed by the concrete was about 4.3% of the sample weight, and the carbonation degree was estimated to be about 53%.

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Antioxidant Defenses and Physiological Changes in Olive Flounder (Paralichthys olivaceus) in Response to Oxidative Stress Induced by Elevated Water Temperature (고수온 환경에 의해 유도된 산화 스트레스에 대한 넙치의 항산화 작용과 생리적 변화)

  • Shin, Hyun-Suk;An, Kwang-Wook;Kim, Na-Na;Choi, Cheol-Young
    • Korean Journal of Ichthyology
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    • v.22 no.1
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    • pp.1-8
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    • 2010
  • We determined oxidative stress caused by thermal stress in olive flounder Paralichthys olivaceus based on the altered-mRNA expression and enzymatic activity of two key antioxidant enzymes, superoxide dismutase (SOD) and catalase (CAT), along with monitoring of several other biomarkers. When the fish were exposed to acute thermal change (from $20^{\circ}C$ to $25^{\circ}C$ and $30^{\circ}C$), the expression and activity of both enzymes were significantly higher at elevated temperatures ($25^{\circ}C$ and $30^{\circ}C$) than at $20^{\circ}C$. Lipid peroxidation (LPO) was also higher at $25^{\circ}C$ and $30^{\circ}C$ than at $20^{\circ}C$. In addition, the plasma $H_2O_2$ concentration was significantly increased by thermal stress. Furthermore, we investigated changes due to thermal stress by measuring levels of plasma alanine aminotransferase (AlaAT) and aspartate aminotrasferase (AspAT). Both were significantly increased by thermal stress. As an immune indicator, the lysozyme concentration was lower at $30^{\circ}C$ than at $20^{\circ}C$, indicating that thermal stress decreases immune function. Therefore, thermal stress could induce oxidative stress and suppress immune function and can cause physiological stress.

Evaluation of Permeability Performance by Cryogenic Thermal Shock in Composite Propellant Tank for Space Launch Vehicles (우주 발사체용 복합재 산화제 탱크 구조물의 극저온 열충격에 따른 투과도 성능 평가)

  • Kim, Jung-Myung;Hong, Seung-Chul;Choi, Soo-Young;Jeong, Sang-Won;Ahn, Hyon-Su
    • Composites Research
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    • v.33 no.5
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    • pp.309-314
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    • 2020
  • Polymer composites were used to reduce the weight of the spacecraft's cryogenic propellant tank. Since these materials were directional, the permeability performance of the gas permeated or delivered in the stacking direction was an indicator directly related to performance such as tank stability and onboard fuel quantity estimation. In addition, the results of permeation measurements and optical analysis of the surface to verify the effect of the number of cycles exposed to the cryogenic-room temperature environment are included. As a result, the permeability was inversely proportional to the thickness and was proportional to the number of thermal shocks, and it was verified that the permeability performance was suitable for the cryogenic propellant tank material for the space launch vehicle.