• Title/Summary/Keyword: Effective temperature

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Effect of Temperature, Pressure, and Air Flow Rate on VOCs Desorption for Gasoline Vapor Recovery (유증기 회수를 위한 VOCs 탈착에 미치는 온도, 압력 및 공기유량의 영향)

  • Lee, Song-Woo;Na, Young-Soo;Kam, Sang-Kyu;Lee, Min-Gyu
    • Journal of Environmental Science International
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    • v.22 no.9
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    • pp.1131-1139
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    • 2013
  • Desorption characteristics of VOCs were investigated for the effective recovery of gasoline vapor. The adsorption capacity and desorption capacity were excellent at relatively low temperatures. The differences in the desorption capacity were not large in the condition; desorption temperature $25^{\circ}C$, desorption pressure 760 mmHg, inlet air flow rate 0.5 L/min, but were relatively great in the condition; desorption temperature $0^{\circ}C$, desorption pressure 60 mmHg, inlet air flow rate 1.0 L/min. The desorption ability of pentane was increased to about 81.4%, and the desorption ability of hexane was increased to about 102%, also the desorption ability of toluene was increased to about 156.7% by changes of temperature, pressure, inlet air flow rate in the experimental conditions. The optimum desorption condition for the effective recovery of VOCs was in the conditions; desorption temperature $0^{\circ}C$, desorption pressure 60 mmHg, inlet air flow rate 1.0 L/min.

Characteristics of Thermal Environments and Evaluation of Thermal Comfort in Office Building in Summer (여름철 사무실내 온열환경 특성 및 쾌적성 평가)

  • Lee, C.H.;Bae, G.N.;Choi, H.C.;Lee, C.S.
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.6 no.3
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    • pp.206-217
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    • 1994
  • In this study, indoor thermal parameters were measured to investigate the characteristics of thermal environments and 212 occupants were questioned to evaluate Korean thermal comfort in office building in summer. Thermal and comfort sensations were estimated using PMV(Predicted Mean Vote) and ET* (New Effective Temperature) which are most widely used nowadays. Comparing this experimental result with international standards and that of other research, Korean thermal responses were discussed. It was found that TSV(Thermal Sensation Vote) is more sensitive than PMV to the variation of temperature and that the measured percentage of dissatisfied is higher than PPD(Predicted Percentage of Dissatisfied) in real office building environments. By regression analysis, the following regression equation has been obtained: TSV=0.461ET*-11.808 and neutral temperature is $25.6^{\circ}C$ in this case. Thermal comfort range based on 80% satisfaction is also $24.0{\sim}26.8^{\circ}C$, which is about $1^{\circ}C$ higher than that of ANSI/ASHRAE Standard.

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Comparison of Thermal Comfort Performance Indices for Cooling Loads in the Lecture Room - An Correlation of PMV Bnd EDT - (강의실에서의 냉방부하에 따른 열쾌적성 평가지표 비교 - PMV와 EDT의 연관성 -)

  • Noh Kwang-Chul;Oh Myung-Do
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.29 no.7 s.238
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    • pp.868-877
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    • 2005
  • We performed the experimental and the numerical study on the comparison of thermal comfort performance indices for cooling loads in the lecture room for 4 cases: Fan coil unit(FCU) or 4-way cassette air-conditioner is respectively operated with the ventilation system or without. We measured the velocity, the temperature distribution and predicted mean vote(PMV) value in the lecture room for 4 different air-conditioning methods. Effective draft temperature(EDT) and PMV were investigated to analyze the characteristics of two thermal comfort indices in the lecture room and to compare their values each other. From the results we knew that there is the similarity between PMV values and EDTs when the room is air-conditioned for cooling loads. It turned out that definition of the control temperature is very important when the EDT is calculated. Finally EDT should not be used to predict the accurate thermal comfort in case that the temperature and humidity are suddenly varied and the zone affected by the solar and inner wall radiation.

Study of thermal stability on PVC using mixed metal soap and stabilizer (복합금속비누와 안정화조제를 이용한 PVC의 열안정화에 대한 연구)

  • Jeon, In-Ki;Ahn, Sung-Hwan;Chung, Kwang-Bo
    • Journal of the Korean Applied Science and Technology
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    • v.27 no.4
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    • pp.552-558
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    • 2010
  • Zinc soap and Zn/Ba mixed metal soap were synthesized and PVC plastisol with mixed metal soap and various costabilizers were also synthesized with good structures and characterized by IR and $^1H$-NMR. The IR spectrums and $^1H$-NMR spectrums of the synthesized soaps were in very good accordance with the structures proposed by earlier workers. In using phosphite as a costabilizer, TIDP phosphite was shown to be the excellent thermal stabilization effect at the low temperature and TNPP phosphite was shown to be the excellent thermal stabilization effect at the high temperature. In case of antioxidant, it was revealed that antioxidant was not effective in the low temperature thermal stabilization effect while highly effective in the high temperature thermal stability. $NaClO_4$ solution with sorbitol solvent had the best thermal stabilization effect among $NaClO_4$ solution series at low and high temperature.

Characteristics of Thermal Comfort in Environment Chamber for Winter

  • Kim, Kyung-Hoon;Park, Jong-Il;Song, Yong-Gil
    • International Journal of Air-Conditioning and Refrigeration
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    • v.8 no.1
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    • pp.73-83
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    • 2000
  • The purpose of this study is to analyze and characterize the correlation of the thermal comfort sensation with physiological responses for men in winter indoor environment. A number of experiments were conducted under twenty different environmental conditions with college male students. Clinical information on each participant was reported in terms of electrocardiogram (ECG), electroencephalogram (EEG) and self-centered evaluation. The comfort zone in winter is found, throughout the study, at Standard New Effective Temperature (SET$T^+$) of 25.2$^{\circ}C$, Predicted Mean Vote (PMV) between 0.27 and 0.62, and Thermal Sensation Vote (TSV) in the range of -0.76 and 0.36. The largest difference in skin temperature is measured at the calf area with respect to air temperature changes. Skin sensitivity to environment temperature is explained as calf, head, chest and abdomen in descending order. Change in heat rate is analyzed to be in parallel with that of SET$T^+$.

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A Field Measuring Study on the Thermal Environment of Human Surrounding in the Classroom Equipped with Ceiling Unit (천장형 유닛을 설치한 교실 내의 인체 주변 온열환경에 관한 실측연구)

  • Cho Sung-Woo;Im Young-Bin;Lee Kyung-Hee
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.18 no.3
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    • pp.240-246
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    • 2006
  • This paper performed to investigate on vertical temperature distribution, effective draft temperature (ETD) and PMV (Predicted Mean Vote) in the classroom, which is located YangSan city (Kyungsangnam-Do), Korea, is equipped with ceiling unit. The vertical temperature difference between F.L+10 cm (ankle) and F.L+120 cm (neck) of a measuring point which is adjacent corridor in the classroom showed about $1^{\circ}C$ but of measuring point which is adjacent outdoor expressed up to $4^{\circ}C$, The effective draft temperature (ETD) is -2.3 and -0.52 and 0.67 at near ceiling unit but is 1.2 and 3.3 at far from ceiling unit. The PMV of total classroom showed the range of 'Cold' and 'Slightly Cold.' Therefore, to achieve comfort condition in the classroom is equipped with ceiling unit, the location of ceiling unit and discharge angle and discharge distance from ceiling unit are very important elements.

Development and verification of PWR core transient coupling calculation software

  • Li, Zhigang;An, Ping;Zhao, Wenbo;Liu, Wei;He, Tao;Lu, Wei;Li, Qing
    • Nuclear Engineering and Technology
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    • v.53 no.11
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    • pp.3653-3664
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    • 2021
  • In PWR three-dimensional transient coupling calculation software CORCA-K, the nodal Green's function method and diagonal implicit Runge Kutta method are used to solve the spatiotemporal neutron dynamic diffusion equation, and the single-phase closed channel model and one-dimensional cylindrical heat conduction transient model are used to calculate the coolant temperature and fuel temperature. The LMW, NEACRP and PWR MOX/UO2 benchmarks and FangJiaShan (FJS) nuclear power plant (NPP) transient control rod move cases are used to verify the CORCA-K. The effects of burnup, fuel effective temperature and ejection rate on the control rod ejection process of PWR are analyzed. The conclusions are as follows: (1) core relative power and fuel Doppler temperature are in good agreement with the results of benchmark and ADPRES, and the deviation between with the reference results is within 3.0% in LMW and NEACRP benchmarks; 2) the variation trend of FJS NPP core transient parameters is consistent with the results of SMART and ADPRES. And the core relative power is in better agreement with the SMART when weighting coefficient is 0.7. Compared with SMART, the maximum deviation is -5.08% in the rod ejection condition and while -5.09% in the control rod complex movement condition.

Seed Dormancy and Germination Characteristics of Endemic Elder Species (Sambucus racemosa subsp. pendula) and Common Elder Species (S. williamsii) in Korea

  • Hyo-In, Lim
    • Journal of Forest and Environmental Science
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    • v.38 no.4
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    • pp.284-289
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    • 2022
  • This study was conducted to determine the seed dormancy types of Sambucus racemosa subsp. pendula Nakai and S. williamsii Hance. Low temperature stratification (1, 2, 3, 4 months) and GA3 treatment (1,000 mg/L) were performed on seeds to determine the type of seed dormancy. After the treatment, seeds were placed on a petri dish at 25℃ under light conditions. The germination rate and mean germination time were investigated. Results showed that cold stratification was effective in breaking the dormant state of the seed in both species. In the low temperature stratification treatment, the seed germination performance was improved as the treatment period was prolonged. Gibberellin treatment was effective in breaking the dormant state of S. racemosa subsp. pendula without low temperature stratification. However, S. williamsii did not break the dormant state of the seed by gibberellin treatment without low temperature stratification treatment. In the gibberellin treatment, germination performance was improved according to the low temperature stratification treatment period. As a result of this study, the seeds of S. williamsii have both an intermediate complex and a deep complex morphophysiological dormancy (MPD). In comparison, it was found that the S. racemosa subsp. pendula had intermediate composite MPD.

A Study on the Fundamental Properties of High Strength Concrete Using Silica Fume (실리카흄 사용 고강도콘크리트의 기초적 성질에 대한 연구)

  • 문한영;김기형;문대중
    • Proceedings of the Korea Concrete Institute Conference
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    • 1993.10a
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    • pp.11-17
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    • 1993
  • In this study, the fundamental properties of High-Strength Concrete(HSC), such as the slump loss, the temperature increment, the strength development, are considered by experiment. In reducing the temperature and the slump loss, and developing the strength of HSC, the application of silica fume as an admixtures is very effective. And when gypsum is added, the slump loss is reduced and the strength of HSC is improved remarkably, but the temperature of concrete is increased, thus a more study to reduce the temperature increment is required

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Characteristics of Efficient Radius of Meteorological Observation Data to Estimate Regional Wind Energy (국지규모 풍력에너지 평가를 위한 기상 관측 자료의 영향 반경 특성)

  • Lee, Soon-Hwan;Kim, Min-Jung;Lee, Hwa-Woon
    • Journal of Korean Society for Atmospheric Environment
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    • v.23 no.5
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    • pp.585-595
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    • 2007
  • Representative impacts and effectiveness of surface meteorological observation data assimilation were examined in order to use wind resources estimation around southern coastal area of the Korean Peninsula. The data used in study are observational wind and temperature data at 5 and 41 sites of Regional Meteorological Offices and Automatical Weather Systems, respectively. Observation wind speed data tends to show small effective radius with limited area. Especially assimilation impacts of data observed at peninsula type sites like Yeosu play only around the inside of the peninsula. This limited effective radius for wind speed is caused by the strong correlation between topography and wind speed. And the efficient radius for surface air temperature is larger than that of wind. Data assimilation for observational air temperature is useful to increase the accuracy of wind energy estimation. However assimilation of wind data requires special care in its application due to high sensitivity of topographical complexity.