• Title/Summary/Keyword: air quality evaluation

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Quality Characteristics of Dried Shredded Radish and Stir-fry Dried Shredded Radish by Different Drying Methods (건조조건이 다른 무채말랭이 및 무채말랭이 볶음의 품질특성)

  • Kim, Ji-Na;Park, Young-Hee;Noh, Yun-Young;Kim, Young;Kang, Min-Sook
    • Korean journal of food and cookery science
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    • v.31 no.5
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    • pp.596-604
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    • 2015
  • This study investigated changes in the chemical properties and antioxidant activity of dried shredded radish (Raphanus sativus L.). Shredded radishes with a thickness of either 3.5 mm or 7.0 mm were dried using hot air at $45^{\circ}C$ or were sun dried. The degree of browning for the 3.5 mm sun dried radish, the 7.0 mm sun dried radish, the 3.5 mm hot air dried radish and the 7.0 mm hot air dried radish was 0.12, 0.14, 0.04 and 0.04, respectively. The DPPH radical scavenging activity (EDA%) of the hot air dried radish had a higher value than the sun dried radish. In contrast, the ABTS values of the sun dried radishes were higher than the hot air dried radishes. The total polyphenol content of the 7.0 mm and 3.5 mm hot air dried radishes reached high values of 15.99 and 11.62 mg/g, respectively. The total polyphenol contents of the 7.0 mm and 3.5 mm sun dried radishes were 9.63 and 6.77 mg/g, respectively. In sensory evaluation of the stir-fry dried shredded radishes, the 7.0 mm hot air dried sample scored the highest in terms of smell, color, gloss and overall preference. In conclusion, hot air drying ($45^{\circ}C$) and a thickness of 7.0 mm were found to be the optimal conditions for dried shredded radish and stir-fried dried shredded radish products.

Evaluation of Image Quality & Absorbed Dose using MCNPX Simulation in the Digital Radiography System (디지털방사선영상시스템에서 MCNPX 시뮬레이션을 이용한 영상 품질 및 선량평가)

  • An, Hyeon;Lee, Dongyeon;Ko, Sungjin;Kim, Changsoo
    • Journal of the Korean Society of Radiology
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    • v.10 no.5
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    • pp.327-335
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    • 2016
  • The study is enforce to study image quality evaluation of condition provide the IEC and combination of clinical conditions each quality of radiation that image quality to assess the conditions provided to IEC in the clinical environment to conduct image quality assessment of the digital radiography system in the detector have environmental limits. First, image quality evaluation was evaluated by measuring the MTF, NPS using four quality of radiation and Using MCNPX simulation lastly DQE make a image quality evaluation after calculating the particle fluence to analyze spectrum quality of radiation. Second, Using MCNPX simulation of four quality of radiation was evaluated absorbed dose rate about electronic 1 per unit air, water, muscle, bone by using Radiation flux density and energy, mass-energy absorption coefficient of matter. Results of evaluation of image quality, MTF of four quality of radiation was satisfied diagnosis frequency domain 1.0 ~ 3.0 lp/mm of general X-ray that indicated 1.13 ~ 2.91 lp/mm spatial frequency. The NPS has added filter, spatial frequency 0.5 lp/mm at standard NPS showed a tendency to decrease after increase. Unused added filter, spatial frequency 0.5 lp/mm at standard NPS showed a certain NPS result value after decrease. DQE in 70 kVp / unuesd added filter(21 mm Al) / SID 150 cm that patial frequency 1.5 lp/mm at standard showed a tendency to decrease after certain value showed. Patial frequency in the rest quality of radiation was showed a tendency to decrease after increase. Results of evaluation of absorbed dose, air < water < muscle < bone in the order showed a tendency to increase. Based on the results of this study provide to basic data that present for the image quality evaluation method of a digital radiation imaging system in various the clinical condition.

Variable Emission Factor Prediction Model for An Air Quality Assessment of Transportation Projects (교통사업의 대기질 평가를 위한 가변적 배출계수 예측모형)

  • Lee, Gyu-Jin;Choe, Gi-Ju;Yu, Jeong-Hun;O, Se-Chang
    • Journal of Korean Society of Transportation
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    • v.29 no.6
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    • pp.117-128
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    • 2011
  • In this study, a model is developed to predict emission factors, which aims to objectively evaluate the impact of transport projects on air quality. Two emission prediction models for the years of 2015 and 2030 are developed using the historical trends in vehicle aging and vehicle deterioration factors. The analysis results show that the emission factors under the operating speed of 30km/h for the year 2030 are 5~37% and 2~83% less than those used in the current studies for passenger cars and bus/trucks, respectively. The statistically validated experiment results demonstrate the applicability of the proposed model to evaluation of the impact of transport policies on air quality.

Heat and Mass Transfer Characteristics and Performance Evaluation of a Double-Tube Condenser for an Alternative Refrigerant (대체냉매의 2중관 응축기 열 및 물질전달과 성능평가)

  • 이상무;박병덕;소산번
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.14 no.6
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    • pp.468-476
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    • 2002
  • This paper deals with heat and mass transfer characteristics and performance evaluation of a counter flow double-tube condenser for a multi-component refrigerant mixture. The local heat and mass transfer characteristics of ternary zeotropic refrigerant mixtures composed of HFC32/HFC125/HFC134a are evaluated for a counter flow double-tube condenser cooled by water. Then, the local values of vapor quality, thermodynamic states at bulk vapor, vapor-liquid interface and bulk liquid, heat flux and condensation mass flux are obtained. The heat exchange performance for ternary zeotropic refrigerant mixtures composed of HFC32/HFC125/HFC134a on the total pressure drop and the heat transfer characteristics are also compared with those for R404A, R410A, R502, R22, R32, Rl23 and R134a.

Evaluation of Condensation Heat Transfer Correlations for Microfin Tubes

  • Han, Dong-Hyouck;Lee, Kyu-Jung
    • International Journal of Air-Conditioning and Refrigeration
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    • v.15 no.4
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    • pp.163-168
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    • 2007
  • The feature of six existing condensation heat transfer correlations for microfin tubes were evaluated with the consideration of vapor quality, mass flux, geometries, and various refrigerants. The Kosky and Staub [15] and the Jaster and Kosky [16] correlations for smooth tube were used for the evaluation of the heat transfer enhancement factor (EF). For the prediction of zeotropic mixtures, most correlations show discrepancy with previous measurements. The Yu and Koyama [4] and the Shikazono et al. [8] correlations do not consider spiral angle effect. The Han and Lee [10] correlation shows fin height growth deteriorates heat transfer. Experimental verification to develop reliable condensation heat transfer correlation for microfin tubes is still needed with the consideration of geometrical effects and working conditions.

A Study on Cold-Weather Curing Quality Management Based on Using Energy Saving Electronic Heater (에너지 절감형 전기히터를 활용한 동절기 양생품질 관리방안)

  • Jo, Man-Ki;Hong, Sung-Min;Park, Jong-Hun;Kim, Jin-Sik;Lee, Dong-Hyun;Cho, Seong-Jun
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2020.11a
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    • pp.109-110
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    • 2020
  • In This study, we tried to review an efficient curing method in consideration of safety and constructability among the problems of winter construction. In other words, as a result of the mock-up test, the measured value of carbon monoxide was 0 ppm in the case of an electric hot air fan. Since there is no carbon monoxide, problems such as suffocation are expected to be solved. In terms of temperature characteristics, electric hot air fans exhibited high thermal efficiency performance with a slight difference in upper/lower temperatures compared to the existing ones. In the future, we plan to conduct thermal efficiency evaluation through actual site performance verification. We will propose an efficient curing method through applicability evaluation.

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Evaluation of Lighting Performance of Mixed Type Light-shelf in Residential Space According to Angular Variations (주거공간의 혼합형 광선반 각도 변화에 따른 채광성능 평가)

  • Chae, Woori;Lee, Heangwoo;Seo, Janghoo;Kim, Yongseong
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.26 no.9
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    • pp.424-433
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    • 2014
  • The purpose of this study is to evaluate the effectiveness in the lighting performance of mixed type light-shelf, by comparing and analyzing the internal light-shelf, external light-shelf, and mixed-type light-shelf. The performance of light-shelf was evaluated according to the angle of light-shelf at summer solstice, winter solstice, vernal equinox, and autumn equinox. The comparative analysis between the internal light-shelf, external light-shelf, and mixed-type light-shelf was carried out using the performance evaluation and analysis method. The result of performance evaluation is shown as follows. The mixed type light-shelf showed the highest lighting performance all at summer solstice, winter solstice, vernal equinox, and autumn equinox, followed by the external light-shelf and the internal light-shelf in the same order. The mixed type light-shelf was the most favorable for bringing daylight to indoors by adjusting the angle of light-shelf, and it also showed the highest lighting performance in terms of uniformity ratio of illumination which indicates the quality of light.

Evaluation of the Ventilation Efficiency in an Underground Sewage Disposal Plant (지하 수처리시설 유지관리층 환기설비의 성능평가)

  • Kang, Han-Gi;Lee, Jae-Heon
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.19 no.10
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    • pp.695-702
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    • 2007
  • In this paper, the ventilation efficiencies of an underground sewage disposal plant were investigated for ventilating system without fan, ventilating system with eleven cross flow fans and ventilating system with sixteen cross flow fans by numerical method. It has been found that the air change effectiveness of the system without fan was predicted 0.44. It means that an additional ventilating equipment is needed to maintain good indoor air quality. For the ventilating system with sixteen cross flow fans, the air change effectiveness was predicted 0.55. The air change effectiveness of the ventilating system with eleven cross flow fans was predicted 0.51. It is known that the air change effectiveness above 0.5 is enough to eliminate pollutant and bad smell in the indoor. Therefore, it is recommended to select the ventilating system with eleven cross flow fans for the underground sewage disposal plant in an economic point of view.

Comparative Efficiency Evaluation of Air Cleaners for Improving Indoor Air Quality (실내용 공기청정기 유형별 실내환경개선 성능에 대한 비교평가)

  • Na, Kyung-Ho;Son, Jin-Seok;Sung, Kijune;Jang, Young-Kee
    • Journal of Environmental Impact Assessment
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    • v.14 no.3
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    • pp.109-115
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    • 2005
  • This study was conducted to evaluate the efficiency of indoor air cleaners and to inform how to select them correctly to the users. The efficiencies of removing suspended bacteria per hour were $64.3{\pm}13.1%$ for filter, wet, and complex type, respectively, which showed the complex type was the most efficient. The removal efficiencies of formaldehyde (HCHO) after two hours operation of air cleaners showed 88.3% and 81.1% for filter and wet type, respectively. The efficiency of complex type, with removal rate of 55.5~58.4%, was decreased after 30 minutes operation. Therefore, it is recommended to perform over 60 minutes when doing air cleaner certification test for HCHO removal efficiency. Generally, air cleaners having low wind volume showed higher efficiency. All tested air cleaners had no potential for removing of volatile organic compounds (VOCs), which is toxic substances, and it is desirable to develop a device which can control these substances. The results also confirmed that there was no ozone production from all tested air cleaners. And it is recommended to ventilate for 20 minutes every four hours to maintain 50% ventilation status.

Analysis of the Possibility of Rapid Quality Appraisal of Water-Reducing Agents Using the Liquid Densimeter and pH Meter (액체 밀도계 및 pH meter기를 이용한 감수제의 신속품질평가 가능성 분석)

  • Kim, Min-Sang;Hyun, Seong-Yong;Baek, Cheol;Jo, Man-Ki;Han, Min-Cheol;Han, Cheon-Goo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2017.05a
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    • pp.210-211
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    • 2017
  • According to KS F 2560, water-reducing agents used when mixing concrete are to undergo quality evaluation testing slump, air contents, setting time, etc., when delivered from the admixture factory to the ready mixed concrete site. Yet in actual acceptance testing this could be substituted by the score report of the admixture company, in which a possibility of low reliability lies. Therefore this study sought to analyze whether by artificially changing the solid content rate of lignin- and naphthalene-based water-reducing agents and using a liquid densimeter evaluate the quality of the admixture. The results showed that the Type B liquid densimeter was most appropriate and 50cc the most appropriate capacity for the mass cylinder. Also, judging from the changes in density and pH according to the changes in solid content rate, it concludes that a rapid appraisal of the quality of lignin- and naphthalene-based water-reducing agents would be possible using a Type B liquid densimeter.

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