• Title/Summary/Keyword: Air volume

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Assessment of Clothing Ventilation through Openings (개구부를 통한 의복의 환기 양상 평가)

  • 추미선
    • The Research Journal of the Costume Culture
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    • v.8 no.5
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    • pp.660-667
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    • 2000
  • Clothing ventilation was investigated using a manikin wearing an impermeable overall under an isothermal condition, in which the ventilation occurred only through the openings. The ventilation volume was estimated by both microenvironment volume and ventilation rate, where, the microenvironment volume was measured by an air subsitution method and the ventilation rate by a trace gas method. Microenvironment volume of the experimental garment was about 21.0 liters. Even though it was certainly affected by the distance from the opening, the ventilation rate was more significantly influenced by the opening area and the shape of air layer in the clothing. The volume of air exchange in the clothing microenvironment was affected greatly by the microenvironment volume and the opening area, and it was different for each part of the body with bigger air exchange volume in the microenvironment of the leg as compared to that of the arm.

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Effects of Leaf Loading Quantity and Circulating Air Volume on the Physical and Chemical Characteristics during Curing in Flue-cured Tobacco Leaves. (열풍건조시 적입 및 송풍량에 따른 황색종 연초엽의 이화학성 변화)

  • 석영선;노재영
    • Journal of the Korean Society of Tobacco Science
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    • v.14 no.1
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    • pp.48-56
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    • 1992
  • This studies were carried out to investigate the effects of leaf loading quantity and circulating air volume during bulk curing on the variation of physical and chemical characteristics in flue-cured tobacco. The results are as follows : 1. The content of sugar in cured leaves was decreased with more circulating air volume and leaf loading quantity at bulk curing. 2. Total nitrogen and protein nitrogen were decreased with less circulating air volume and more leaf loading quantity, while amino nitrogen was increased. 3. The contents of linolenic acid and linoleic acid were increased with more leaf loading quantity and oxalic acid and citric acid had a tendency of being increased in case of high circulating air volume. 4. In general, major aromatic compounds were increased through flue-curing. Relatively high content of solanone in case of lower air volume and less leaf loading were observed, while megastig matrienone was increased when leaf loading was small. 5. The more circulation air volume with leaf loading quantity caused lowering equilibrium moisture content and higher shatter index, which resulted in poor quality of cured leaves based on quality index, nitrogen number, taste index phillips index, and sugar-nicotine ratio.

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Effect of Non-thermal Dielectric Barrier Discharge Plasma by Air Volume against Mycobacterium Tuberculosis (비열 유전체장벽방전 플라즈마 발생기의 풍량에 따른 결핵균 성장억제 효능)

  • Son, Eun-Soon;Kim, Yonghee;Paik, Namwon;Lee, Ilyong;Kim, Eunhwa;Park, Hae-Ryoung;Lee, Jongseok
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.29 no.3
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    • pp.414-419
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    • 2019
  • Objectives: The objective of this study was to evaluate the inhibitory effect of non-thermal dielectric barrier discharge (DBD) plasma by air volume against Mycobacterium tuberculosis (MTB). Methods: Plasma generators (TB-300, Shinyoung Airtec, Seongnam-si, Korea) were operated in a 2A type biosafety cabinet. The plasma generator was set to a wind flow rate of 14 ($80m^3/h$), 18 ($110m^3/h$), and 22 ($150m^3/h$), and exposure times were set to 0 hours, 3 hours, 6 hours, 9 hours, and 24 hours. Results: The inhibitory effects of plasma at air volume 14 with prolonged exposure time of three hours was 20%, 64% at six hours, 82.3% at nine hours, and 100% after 24 hours exposure. With air volume of 18, the inhibitory effects upon plasma exposure were 36% for three hours, and 100% from 24 hours. Greater air volume resulted in greater inhibition of tuberculosis bacterial growth. In particular, the maximum inhibitory effect (100%) was shown in air volume of 22 ($150m^3/h$) after three hours of plasma exposure. Conclusions: The results showed the correlating inhibitory effects of plasma on the growth of MTB in combination with increasing plasma exposure time and air volume.

Air Pollution prediction at Highway Tollgate by Using Real Time Traffic Volume (실시간 교통량을 이용한 고속도로 요금소 대기요염도 예측)

  • 박성규;김신도;이정주
    • Journal of Environmental Health Sciences
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    • v.26 no.4
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    • pp.134-140
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    • 2000
  • The increase in traffic is a worldwide phenomenon. In Korea, it has been increased by 20% per annual in recent 1990’s and approximately 10 millions cars had been registered until 1997. This traffic could easily affect and contribute the local outdoor air quality(QAQ) concerned. The QAQ in highway in one of the examples and the subject in this study. The seoul tollgate located at the north-end of Keypngbu Highway was selected for the study. In case of highway tollgate, the local air pollution could be directly affected by the traffic to approach, wait and start the tollgate. Nitrogen dioxide (NO$_2$) concentration exceeded the EAQS(Environmental Air Quality Standards), but overall indoor air quality was a little better than the outdoor air quality. The measured TSP concentration was much higher than that of the EAQS. To apply a management to a air quality problem of Seoul tollgate, it was predicted air quality with traffic volume and weather condition. It was calculated NO$_2$ emission with traffic volume and predicted in and out of booth by CALINE3 at the Seoul tollgate. To make a comparison between measured and predicted concentration, the prediction was good. It was shown that NO$_2$ concentration was high in the morning at the from Seoul direction and in the evening at the to Seoul direction. it was thought that NO$_2$ concentration variation was reflected according to the traffic volume.

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Development of an Automated System for Predicting Shape and Volume of Air Pocket on the Draw Die (드로우 금형의 에어 포켓 형상 및 체적예측 자동화 시스템 개발)

  • Jung, Sung-Yuen;Hwang, Se-Joon;Park, Warn-Gyu;Kim, Chul
    • Journal of the Korean Society for Precision Engineering
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    • v.25 no.1
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    • pp.72-78
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    • 2008
  • Metal stamping is widely used in the mass-production process of the automobile. During the stamping process, air may be trapped between the draw die and the panel and/or between the punch and the panel. Air pocket rapidly not only increases forming load in the final stage, but also deforms the product just formed by compressive air inside the air pocket in knockout process. To prevent these problems air bent holes are drilled in the die to exhaust the trapped air but all processes associated with air bent holes are performed by empirical know-how of workers in the field due to lack of researches. Therefore this study developed an automated design system for predicting the shape and position, and volume of air pocket on the draw die by using the AutoLISP language under AutoCAD circumstance. The system is able to display the shape of air pocket occurred in the draw die and to calculate automatically its volume by strokes. So it makes a stepping stone to calculate theoretical size of an air bent hole and numbers according to it by predicting and analyzing the position and volume of air pocket. Results obtained from the system enable the designers or manufacturers of the stamping die to be more efficient in this field.

Performance Evaluation of Multidrop Chamber Ventilation System in Apartment (공동주택내 다분기챔버형 환기시스템 적용을 통한 풍량분배 개선효과에 관한 연구)

  • Kim, Sung-Soo;Son, Jang-Yeul
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.21 no.10
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    • pp.545-552
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    • 2009
  • It is common to design the duct branches where to supply the required air flow for individual room in residential apartment house. And TAB process is applied to control the designed air volume with adjusting volume dampers and/or supply diffusers after fully installing the ventilation system. This process has been resulted increasing the initial cost for the residential ventilation system because of man-hour and accessories such as volume control damper or diffuser. However it is difficult to adjust the air volume adequately in small air duct branches in residential ventilation system. The purpose of this study is to figure out the performance of Multidrop chamber coupling system for the residential ventilation system.

Characteristics of the Emissions and Concentrations of Air Pollutants with Change in Traffic Volume during the Beach Opening Period in Busan (부산지역 해수욕장 개장시 교통량 변화에 따른 대기오염물질 배출량 및 농도 특성 분석)

  • Seo, Woo-Mi;Shon, Zang-Ho;Song, Sang-Keun
    • Journal of Environmental Science International
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    • v.21 no.9
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    • pp.1149-1162
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    • 2012
  • The impact of a considerable increase in traffic volume on the emission and concentrations of air pollutants was investigated at three beaches (Haeundae (HB), Gwanganri (GB), and Songjeong (SB)) in Busan during beach opening period (BOP) in 2011. During the BOP, passenger car was the major vehicle type, followed by taxi, and van. CO was the major contributor of total air pollutant emissions followed by NOx, VOC, and $PM_{10}$. For the temporal variation of the emission of air pollutants during the BOP, it was generally the highest in the afternoon followed by the evening and morning, except for SB. For the spatial variation of their emission, it was the highest at GB followed by SB and HB. The emissions of air pollutants during the BOP were generally higher than those during the Non-BOP, except for HB. In contrast, the significant impact of the traffic volume increase on the concentrations of air pollutants at monitoring sites near the three beaches during the BOP were not found compared to the Non-BOP due to the significant distances between monitoring sites of air pollutants and monitoring sites of traffic volume at the beaches.

Control Method to Ensure Uniform Exhaust Function by Household of Apartment House (공동주택의 세대별 균등 배기량을 확보 하는 제어방법에 관한 연구)

  • Kwon, Yong-Il
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.29 no.12
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    • pp.628-637
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    • 2017
  • This study was conducted to present an effective control method for the common duct system to uniformly discharge volume flow rate exhausted from the kitchen and bathroom of each household in an apartment regardless of the position of household. Since the common duct system is installed vertically and the ventilator is installed in the terminal, the static pressure of each household decreases when vertical height increases. Therefore, the volume flow rate exhausted from each household is different. In order to improve such a phenomenon, a constant air volume damper shall be installed in a branch duct coupled with a common vertical duct system. The selected ventilator should also be able to handle the maximum volume flow rate considering diversity factor. Therefore, a uniform volume flow rate must be exhausted from all households where the hood is operated. This paper mainly focuses on suggestion of an optimum exhaust control method by comparing exhaust performance of each household according to the presence or absence of a constant air volume damper.

A Measurement and Evaluation on the Cabins' Thermal Conditions of Large Cruiser in the Winter (대형 크루저 선실의 동절기 온열환경 측정평가)

  • Hwang, Kwang-Il;Moon, Tae-Il;Park, Min-Kang;Shim, Jae-Gun
    • Proceedings of the Korean Society of Marine Engineers Conference
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    • 2006.06a
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    • pp.231-232
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    • 2006
  • The purpose of this study is to measure and evaluate the thermal conditions of large cruiser's cabin. As the result of this study, followings are cleared. The air volume supplied to the 2 types of cabins is quite diffenrent. Temperature differences in the Room A which is located A deck and supplied enough air volume is stable all around the cabin. But Room B which is located B deck and supplied comparatively small air volume has temperature distribution problems, like time-dependent differences, vertical differences. To serve more comfort and productivity of Room B, it is strongly recommended to do a T.A.B.(Testing, Adjusting and Balancing) for more air volume and/or to design new air flow path to make air stay longer.

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