• Title/Summary/Keyword: Air change effectiveness

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A Study on the Effectiveness of Skin Care Solution System using Non-Invasive Air Technology

  • Park, Do-Young;Yoon, Dong-Gon;Seo, Jung-Gil
    • Journal of Platform Technology
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    • v.10 no.3
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    • pp.3-10
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    • 2022
  • The effectiveness of an innovative skin treatment system that delivers an anti-aging solution deep into the skin without invasiveness and pain using a non-invasive air technology was investigated. In addition, an effective change using a non-invasive technique for delivering a solution for skin improvement was confirmed. The equipment named Cellre Jet is an effective skin care and drug delivery equipment that instantly opens the skin epidermis by using a maximum output pressure of 6 bars and high-pressure purified oxygen of 75-90% purity to deliver various nano-sized vital substances deep into the skin, and it uses the method of precisely controlling the equipment through an 8-inch digital touch display to accurately dispense the prescribed dosage. In this study, changes in skin condition were analyzed using this equipment and nano ampoules on subjects with actual skin problems through a related comparison and effectiveness judgment program. Through this study, skin care and drug delivery are possible, which will contribute to verifying the effectiveness of this non-invasive drug delivery equipment in the future, and is expected to establish the systematic effect in observing and studying changes in the skin.

Greenhouse Gas Reduction by Air Quality Management Policy in Gyeonggi-do and Its Co-benefit Analysis (경기도 대기질 개선 정책의 온실가스 동시 저감 및 그에 따른 공편익 효과 분석)

  • Kim, Dong Young;Choi, Min-Ae
    • Journal of Korean Society for Atmospheric Environment
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    • v.33 no.6
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    • pp.570-582
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    • 2017
  • In recent years, national and local government's air quality management and climate change adaptation policy has been significantly strengthened. The measures in the two policies may be in a relationship of trade-off or synergy to each other. Greenhouse gases and air pollutants are mostly emitted from the same sources of using considerable amounts of fossil fuels. Co-benefits, in which either measure has a positive effect on the other, may be maximized by reducing the social costs and by consolidating the objectives of the various policies. In this study, the co-benefits were examined by empirically analyzing the effects of air pollutants and greenhouse gas emission reduction, social cost, and cost effectiveness between the two policies. Of the total 80 projects, the next 12 projects generated co-benefits. They are 1) extend restriction area of solid fuel use, 2) expand subsidy of low-$NO_x$ burner, 3) supply hybrid-vehicles, 4) supply electric-vehicles, 5) supply hydrogen fuel cell vehicles, 6) engine retrofit, 7) scrappage of old car, 8) low emission zone, 9) transportation demand management, 10) supply land-based electric of ship, 11) switching anthracite to clean fuel in private sector, 12) expand regional combined-energy supply. The benefits of air pollutants and greenhouse gas-related measures were an annual average of KRW 2,705.4 billion. The social benefits of the transportation demand management were the highest at an annual average of KRW 890.7 billion, and followed by scrappage of old cars and expand regional combined-energy supply. When the social benefits and the annual investment budgets are compared, the cost effectiveness ratio is estimated to be about 3.8. Overall, the reduction of air pollutants caused by the air quality management policy of Gyeonggi-do resulted in an annual average of KRW 4,790.2 billion. In the point sources management sector, the added value of $CO_2$ reduction increased by 4.8% to KRW 1,062.8 billion, while the mobile sources management sector increased by 3.6% to KRW 3,414.1 billion. If social benefits from $CO_2$ reduction are added, the annual average will increase by 7.2% to KRW 5,135.4 billion. The urban and energy management sectors have shown that social benefits increase more than twice as much as the benefits of $CO_2$ reduction. This result implies that more intensive promotion of these measures are needed. This study has significance in that it presents the results of the empirical analysis of the co-benefits generated between the similar policies in the air quality management and the climate change policy which are currently being promoted in Gyeonggi-do. This study suggested that the method of analyzing the policy effect among the main policies in the climate atmospheric policy is established and the effectiveness and priority of the major policies can be evaluated through the policy correlation analysis based on the co-benefits. It is expected that it could be a basis for evaluation the efficiency of the climate change adaptation and air quality management policies implemented by the national and local governments in the future.

A Numerical Study on the Performance Analysis of Plume Abatement Cooling Tower with Dry Type Heat Exchanger (건식 열교환기를 이용한 백연방지 냉각탑 성능의 수치해석적 연구)

  • 김병조;최영기
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.15 no.12
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    • pp.1018-1027
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    • 2003
  • This study treats the analysis of the performance and the design of plume abatement wet/dry cooling tower with dry type heat exchanger using a numerical method. A two-dimensional analysis is performed using the finite volume method for mechanical draft counterflow and crossflow tower. For a coupling problem between water and air system, a turbulent two phase flow is considered. Effectiveness-NTU method is used for modeling of the dry type heat exchanger. The parameter change simulations of the outer wall shape, the relative flowrate of air, and attachment of an air mixer are performed to examine the effect on plume abatement. It is found that if the relative air flowrate ratio and the adequate air mixer type are chosen well in addition to the ratio of water to air flowrate, the loss of the cooling capacity and the additional cost are reduced and the plume is abated.

An Experimental Analysis of Ventilation Effectiveness using Tracer Gas (환기방식별 실내 환기효율 분석에 관한 실험적 연구)

  • Kang, Tae-Wook
    • Journal of Advanced Marine Engineering and Technology
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    • v.30 no.2
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    • pp.260-266
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    • 2006
  • A tracer gas technique based on ASTM Standard E741-83 was used to measure ventilation performances in a model chamber ($0.84m{\times}0.68m{\times}0.7m$) with an exhaust fan and a supply fan. Experiments were performed for the ventilation effectiveness on three types of mechanical ventilation systems. For all cases. higher ventilation effectiveness was found in the type to ventilation system due to shorter residual time of air compared to type 1 and type 3.

An Analysis of the Impact of China's Pollution Reduction Policy on Sulfur Dioxide Emissions (중국의 오염저감 정책이 이산화황 배출에 미치는 영향 분석)

  • Kim, Ka Young;Lee, Jae Seung
    • Journal of Climate Change Research
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    • v.6 no.4
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    • pp.367-377
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    • 2015
  • This study analyzed the effectiveness of China's policy to reduce of sulfur dioxide. China's $12^{th}$ Five-year plan on national economic and social development emphasized environmental protection and low-carbon economic development. Sulfur dioxide was one of the major gases to affect air pollution and climate change and its control became a key policy agenda in the environment and energy sector. As the absolute amount of sulfur dioxide emissions in China came from the industrial sector, the control of the coal-based energy was especially urgent. This study analyzed the factors that influenced the sulfur dioxide emissions and the policy effects to reduce sulfur dioxide in China from 2003 to 2012 based on regional data. The air pollution treatment investments showed the biggest impact together with energy conservation policy in reducing sulfur dioxide emissions. However, pollutant emissions charge did not show a relevant policy effectiveness in all regions as the amount of charge would be smaller than economic benefit from non-compliance. Rationalizing pollutant emissions charge is, therefore, a key policy task for further reduction of sulfur dioxide emissions.

Compressor Control of a Multi-type AIr Conditioning System (멀티형 냉방시스템의 압축기 제어)

  • 한도영;권형진
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.13 no.8
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    • pp.780-786
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    • 2001
  • For the compressor speed control of a multi-type air conditioning system, a fuzzy control algorithm was developed. The sum of zone temperature errors and its derivative were used as input variables, and the compressor speed was selected as the output variable. To test the effectiveness of the control algorithm, one outdoor environmental chamber and four indoor environmental chambers were used. In the chambers the zone temperature step change test and the indoor unit change over test were performed. Test results showed that, for the control of compressor speed, the fuzzy control algorithm was more effective than the conventional proportional control algorithm for the energy conservation.

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Computation of Compact Heat Exchanger Performance by the Heat Exchangelet Method : Effect of Tube-to-tube Conduction along the Fin (미소열교환기법에 의한 밀집형 열교환기의 성능 계산 : 핀을 통한 튜브간 전도의 영향)

  • 성시경;송태호;최영철
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.12 no.5
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    • pp.494-501
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    • 2000
  • Effectiveness of a 3-pass plate finned-tube heat exchanger is calculated using heat exchangelet method by changing the shape of fin and the arrangement of tubes. The alternative refrigerant R134a is taken in this study. Conduction between neighboring tubes along the fin is taken into account in addition to convection between the fin and the surrounding air. Governing equations are obtained by using energy balance in a small control volume containing a tube and fins. They are numerically solved following the tube. Effect of tube-to-tube conduction is investigated in single-phase and two-phase flows with various fin shapes and arrangements of tubes. Improvement of effectiveness by fin perforation is studied too. The results shows that perforating fins, increasing the number of tubes, and increasing the distance between neighboring tubes at the same fin area enhance the effectiveness.

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Effectiveness of droplet protective screens and portable air purifiers against droplet and airborne transmission during conversation (비말 가림막과 휴대형 공기청정기 사용에 의한 대화 중 비말 및 공기전파 저감 효과)

  • Jieun, Heo;Dongho, Shin;Hee-Joo, Cho;Hyun-Seol, Park;Yun-Haeng, Joe
    • Particle and aerosol research
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    • v.18 no.4
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    • pp.87-95
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    • 2022
  • Currently, droplet protective screens (DPSs) are used to prevent the spread of respiratory diseases. As virus particles can maintain their infective in indoor environments, recent studies have investigated the risk of airborne transmission. However, the ability of DPSs to block airborne transmission has not been verified yet. In this study, the preventive ability of DPSs against droplet and airborne transmission was evaluated. Moreover, the effectiveness of a Portable air purifier (PAP) was investigated. According to results, in a simulated room where an infectious person spoke, the DPS blocked more than 90% of the micron-sized droplets (with a diameter larger than 1 ㎛) transmitted to the front of the infectious person. However, sub-micron droplets (with a diameter smaller than 1 ㎛) passed through the DPS and spread in a room. However, the PAP reduced the amount of both micron and sub-micron droplets transmitted to the front of the infectious person. When the PAP airflow direction was set from the DPS surface to the free space near the infectious person, improved prevention against droplet and airborne transmission was recorded. However, airborne transmission was accelerated when the PAP airflow direction was set from the free space to the DPS surface.

The Impact of Climate Change on the Trends of Precipitation Effectiveness Ratio and Runoff Data in South Korea (기후변화에 따른 우리나라 강수효율 및 유출량의 변화특성 분석)

  • Kim, Jong-Pil;Kim, Gwang-Seob
    • Journal of Korea Water Resources Association
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    • v.44 no.8
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    • pp.683-694
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    • 2011
  • To analyze the regional impact of air temperature increase and precipitation variation on water resources, the variability of precipitation-effectiveness (P-E) ratio which is estimated using precipitation and air temperature data of 59 weather stations operated by the Korean Meteorological Administration (KMA) during 1973~2009 was analyzed. Also runoff data resulting from the Precipitation-Runoff Modelling System (PRMS) modelling were analyzed during 1966~2007. The overall spatio-temporal variability of P-E ratio and runoff data in South Korea is corresponding to the variability of precipitation amount. However some region shows that the P-E ratio decreases even though the trend of precipitation amount increases which may be caused by the air temperature increase. Runoff trend is similar to that of P-E ratio. Precipitation and P-E ratio have decreased all seasons except summer season and it means the reduction of available water resources during those seasons. These variability should be reflected in the spring, fall, and winter water supply strategy.

A Study on the Control Method of Ventilating System for High Speed Train in a Tunnel (터널주행 고속전철의 환기시스템 제어 방법에 관한 연구)

  • 최영석
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.13 no.3
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    • pp.184-193
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    • 2001
  • The present study develops programs simulating the internal pressure change of cars due to the change of external pressure when trains run into or passing each other in a tunnel. A new continuous ventilating system control method has been developed in order to alleviate the aural discomfort of passengers riding a high speed train. This method is based on the change of the charged and discharged flow rate by detecting the air pressures generated outside and inside of the train. When the outside and inside pressure are detected, the speed of the charge or exhaust fans and also the valve opening ratios are changed. The elementary performance of the system is checked using dta of the TGV-K high speed train at a speed of 300km/h. Moreover, applicability of the system to the Koran high speed train at a speed of 350 km/h is ascertained by simulation and its effectiveness as a means to alleviate the ear pains is confirmed. This application of the system to the Korean high speed vehicles running in the speed range of 350km/h is considered to have good prospect.

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