• Title/Summary/Keyword: Ventilation of a Room

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A Study on the Indoor-Outdoor $NO_2$ Levels and Personal Exposures to $NO_2$ with Analysis of factors Affecting the $NO_2$ Concentrations - Centering on Urban Homes and Housewives - (실내외 $NO_2$농도 및 $NO_2$개인폭로량과 이들에 영향을 미치는 요인에 관한 연구 -도시지역 주택 및 주부를 대상으로-)

  • Chun, Jin-Ho;Lee, Chae-Un;Kim, Joon-Youn;Chung, Yo-Han
    • Journal of Preventive Medicine and Public Health
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    • v.21 no.1 s.23
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    • pp.132-151
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    • 1988
  • This study was conducted to establish the control program for preventing unfavorable health effects of nitrogen dioxide($NO_2$) exposure in homes by preparing the fundamental data for evaluation of relation-ships between $NO_2$ levels and influencing factors through measurements of indoor-outdoor $NO_2$ levels and personal $NO_2$ exposures for housewives with questionnaire survey on 172 homes in Pusan area from April to June, 1987 $NO_2$ measurements were made by using diffusion tube samplers(Palmes tube $NO_2$ sampler) for one week at 4 sites in homes ; kitchen(KIT), bedroom(BED), living room(LIV), outdoor(OUT) and near the collar of housewives(personal exposure livel, PNO). The details of questionnaire were number of household members(FAM), number of regular smokers (SMOKER), daily number of meals eaten(MEAL), type of housing units(HOUSE), location of house with distance from the heavy traffic roads as walking time(DIST), and of kitchen(KAREA), kind of cooking fuels(FUEL), cooking time of each meal(CTIME), usage of kitchen fan for cooking(FAN), type of heating facilities(HEAT) and so on of subject homes. The Obtained results were as fellows : 1) The mean $NO_2$ level was significantly higher at indoors than outdoors(p<0.01) and the kitchen $NO_2$ level was the highest with $33.7{\pm}13.6ppb$(9.5-81.5ppb). The mean personal exposure level of $NO_2$ for housewives was $20.6{\pm}8.8ppb$(3.1-46.9ppb). 2) The mean indoor $NO_2$ level was significantly higher in the group of household members above 5 than below 4(p<0.05), in detached dwellings than apartments(p<0.001), within 5 minutes of distance than over 5 minutes(p<0.001), in the group of unusing fan(p<0.001), in the group of longer cooking time(p<0.001), and it was in order of coal briquette, gas, electricity and oil by kind of cooking fuels(p<0.05). 3) Variables showing significant correlation(p<0.001) with indoor $NO_2$ level were kitchen $NO_2$ level(r=0.8677), cooking time(r=0.5921), outdoor $NO_2$ level(r=0.5192), personal $NO_2$ exposure level(r=0.4615), usage of kitchen fan(r=0.3573) and location of house(r=-0.2988) 4) As a result of multiple regression analysis, the most significant influencing variable to the kitchen $NO_2$ level was cooking time[KIT=$-0.378{\pm}11.772$(CTIME)+0.298(OUT)+3.102(FAN)], it was kitchen $NO_2$ level to the indoor $NO_2$ level[IND=6.996+0.458(KIT)+0.230(OUT)-1.127(KAREA)], and it was indoor $NO_2$ level to the personal $NO_2$ exposure level[PNO=15.562+0.729(IND)-4.542(DIST)-0.200(KIT)] 5) It was recognized that aritificial ventilation in the kitchen, suppression of unnecessary combustion and replacement of cooking fuel, as much as possible, were effective means for decreasing indoor $NO_2$ levels in homes.

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Indoor Exposure and Health Risk of Polycyclic Aromatic Hydrocarbons (PAHs) via Public Facilities PM2.5, Korea (II)

  • Kim, Ho-Hyun;Lee, Geon-Woo;Yang, Ji-Yeon;Jeon, Jun-Min;Lee, Woo-Seok;Lim, Jung-Yun;Lee, Han-Seul;Gwak, Yoon-Kyung;Shin, Dong-Chun;Lim, Young-Wook
    • Asian Journal of Atmospheric Environment
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    • v.8 no.1
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    • pp.35-47
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    • 2014
  • The purpose of the study is to evaluate the pollution level (gaseous and particle phase) in the public facilities for the PAHs, non-regulated materials, forecast the risk level by the health risk assessment (HRA) and propose the guideline level. PAH assessments through sampling of particulate matter of diameter < 2.5 ${\mu}m$ ($PM_{2.5}$). The user and worker exposure scenario for the PAHs consists of 24-hour exposure scenario (WIES) assuming the worst case and the normal exposure scenario (MIES) based on the survey. This study investigated 20 PAH substances selected out of 32 substances known to be carcinogenic or potentially carcinogenic. The risk assessment applies major toxic equivalency factor (TEF) proposed from existing studies and estaimates individual Excess Cancer Risk (ECR). The study assesses the fine dusts ($PM_{2.5}$) and the exposure levels of the gaseous and particle PAH materials for 6 spots in each 8 facility, e.g. underground subway stations, child-care facilities, elderly care facilities, super market, indoor parking lot, terminal waiting room, internet caf$\acute{e}$ (PC-rooms), movie theater. For internet caf$\acute{e}$ (PC-rooms) in particular, that marks the highest $PM_{2.5}$ concentration and the average concentration of 10 spots (2 spots for each cafe) is 73.3 ${\mu}g/m^3$ (range: 6.8-185.2 ${\mu}g/m^3$). The high level of $PM_{2.5}$ seen in internet cafes was likely due to indoor smoking in most cases. For the gaseous PAHs, the detection frequency for 4-5 rings shows high and the elements with 6 rings shows low frequency. For the particle PAHs, the detection frequency for 2-3 rings shows low and the elements with 6 rings show high frequency. As a result, it is investigated that the most important PAHs are the naphthalene, acenaphthene and phenanthrene from the study of Kim et al. (2013) and this annual study. The health risk assessment demonstrates that each facility shows the level of $10^{-6}-10^{-4}$. Considering standards and local source of pollution levels, it is judged that the management standard of the benzo (a)pyrene, one of the PAHs, shall be managed with the range of 0.5-1.2 $ng/m^3$. Smoking and ventilation were considered as the most important PAHs exposure associated with public facility $PM_{2.5}$. This study only estimated for inhalation health risk of PAHs and focused on the associated cancer risk, while multiple measurements would be necessary for public health and policy.

A Study on An Integrated GEO/TES with Geothermal Heat Exchanger and Thermal Ice Storage (지중열 교환기와 빙축열조(Thermal Ice Storage)를 연계시킨 통합 지중열-빙축열조 시스템(Integrated GEO/TES))

  • Lohrenz ED.;Hahn Jeongsang;Han Hyuk Sang;Hahn Chan;Kim Hyoung Soo
    • Economic and Environmental Geology
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    • v.38 no.6 s.175
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    • pp.717-729
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    • 2005
  • Peak cooling load of large buildings is generally greater than their peak heating load. Internal and solar heat gains are used fur selection of adquate equipment in large building in cold winter climate like Canada and even Korea. The cost of geothermal heat exchanger to meet the cooling loads can increase the initial cost of ground source heat pump system to the extend less costly conventional system often chosen. Thermal ice storage system has been used for many years in Korea to reduce chiller capacity and shift Peak electrical time and demand. A distribution system designed to take advantage of heat extracted from the ice, and use of geothermal loop (geothermal heat exchanger) to heat as an alternate heat source and sink is well known to provide many benifits. The use of thermal energy storage (TES) reduces the heat pump capacity and peak cooling load needed in large building by as much as 40 to $60\%$ with less mechanical equipment and less space for mechanical room. Additionally TES can reduce the size and cost of the geothermal loop by 1/3 to 1/4 compared to ground coupled heat pump system that is designed to meet the peak heating and cooling load and also can eliminate difficuties of geothermal loop installation such as space requirements and thermal conditions of soil and rock at the urban area.

CFD Analysis for Microclimate of Venlo Type Glasshouse with the Screen Height and Air-inflow Quantity (스크린설치높이·공기유입량 차이에 따른 벤로형 유리온실 미기상 CFD 유동해석)

  • Yang, Won Mo
    • Journal of Bio-Environment Control
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    • v.29 no.1
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    • pp.52-61
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    • 2020
  • The natural change of winter night temperature from 00:00 to 04:30 O'clock with the different height of thermal screen in a venlo type glasshouse (W59×L68×H5.9 m) was studied using computational fluid dynamics (CFD). At the early stage of CFD analysis, the room temperature decrease of glasshouse with the 5.9 m height of thermal screen were faster than it with the 4.1m height of thermal screen, but at 2 hr after analysis it was slower than in it with the 4,1m, the temperature difference was 0.6℃ after 4 hr. If we consider that turn on the heater when the temperature were decrease below 13℃ at 1hr after CFD analysis, it is good for energy saving in the glasshouse with the 4.1 m height of thermal screen rather than in it with the 5.9 m height, because of the temperature decrease were slow during 2 hrs after analysis. The airflow at the height of 2 m which were grown tomato were fast and wide in the glasshouse with the 5.9 m height thermal screen rather than in it with the 4.1 m, the speed difference was 0.034m·s-1 at 1hr after CFD analysis. The effect of temperature decrease in summer season were compared with the different height of shading screen from 12:00 to 14:30 O'clock. The height of shading screen were 5.7, 3.9 m, the gap of it were 30%. The air-inflow quantity by the fan with duct at lower part of venlo glasshouse was 0.67 ㎥·s-1 until 1hr and to increase 3 times of it from 1hr after analysis. The roof window were open 100%. Until 1hr of CFD analysis, the temperature in the 30% open of shading screen was 0.9℃ higher than in the none shading screen. From 13:00 O'clock when the air-inlet quantity to increase 3 times, the temperature in case 30% gap of shading screen were decreased compare with the none shading screen, the temperature difference was 0.5℃ at 14:30 O'clock. The temperature on the floor surface in case 30% gap of shading screen were lower with it's height increase, the temperature difference was 8℃ compare with none shading screen. The relative humidity difference were insignificant by the height and gap of shading screen.

Maximum Value Calculation of High Dose Radioiodine Therapy Room (고용량 방사성옥소 치료 병실의 최대치 산출)

  • Lee, Kyung-Jae;Cho, Hyun-Duck;Ko, Kil-Man;Park, Young-Jae;Lee, In-Won
    • The Korean Journal of Nuclear Medicine Technology
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    • v.14 no.1
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    • pp.28-34
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    • 2010
  • Purpose: According to increment of thyroid cancer recently, patients of high dose radioiodine therapy were accumulated. Taking into consideration the acceptance capability in the current facility, this study is to calculate the maximum value of high dose radioiodine therapy in patients for treatment. Materials and Methods: The amount and radioactivity of waste water discharged from high dose radioiodine therapy in patients admitted at present hospital as well as the radiation density of the air released into the atmosphere from the high dose radioiodine therapy ward were measured. When the calculated waste water's radiation and its density in the released air satisfies the standard (management standard for discharge into water supply 30 Bq/L, management standard for release into air 3 $Bq/m^3$) set by the Ministry of Education, Science and Technology, the maximum value of treatable high dose radioiodine therapy in patients was calculated. Results: When we calculated in a conservative view, the average density of radiation of waste water discharged from treating high dose radioiodine therapy one patient was 8 MBq/L and after 117 days of diminution in the water-purifier tank, it was 29.5 Bq/L. Also, the average density of radiation of waste water discharged from treating high dose radioiodine therapy two patients was 16 MBq/L and after 70 days of diminution in the water-purifier tank, it was 29.7 Bq/L. Under the same conditions, the density of radiation released into air through RI Ventilation Filter from the radioiodine therapy ward was 0.38 $Bq/m^3$. Conclusion: The maximum value of high dose radioiodine therapy in patients that can be treated within the acceptance capability was calculated and applied to the current facility, and if double rooms are managed by improving the ward structure, it would be possible to reduce the accumulated treatment waiting period for radioiodine therapy in patients.

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The Study of Effectiveness of MERS on the Law and Remaining Task (국내 메르스(MERS) 사태가 남긴 과제와 법률에 미친 영향에 대한 소고(小考))

  • Yoon, Jong Tae
    • The Korean Society of Law and Medicine
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    • v.16 no.2
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    • pp.263-291
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    • 2015
  • In May, 2015, a 68 years old man, who has been Middle East Saudi Arabia and the United Arab Emirates, had high fever, muscle aches, cough and shortness of breath. he went two local hospital near his house and the S Medical Center emergency center. He was diagnosed MERS(Middle East respiratory syndrome) and the diseases had put South Korea the fear of epidemics for three months. Especially, this disease has firstly reported in Middle East Asia in September 2012 and spreaded to twenty-six countries. In 21, July, 2015, European Center for disease prevention and control reported 533 people were died and in South Korea, 186 people were infected, 36 people were died and 16,693 people were isolated from MERS. South Korea government were faced into epidemic control and blamed from public. Especially, hospital acquired infection, disease control chain, opening of information, ventilation, lack of isolation bed, the problem of function of local health center, the issue of reparation for hospital and insurance cover rate, the classification of disease, the role of Korea Centers for disease control and prevention, the culture of visiting hospital to see sick people, the issue of hospital multiple room and other related social support policy. it is time to study and discuss to solve these problems. South Korea citizens felt fear and fright from MERS. What is wore, they thought the dieses were out of their government control. It was unusual case for word except Middle East Asia. numerous tourists canceled visiting korea. South korea economic were severly damaged especially, tourism industry. South korea government should admit that they had failed initial action against MERS and take full reasonability from any damages. The government have to open information to public in terms of epidemic diseases and try to prevent any other epidemic diseases and try to work with local governments.

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The Effect of Common Features on Consumer Preference for a No-Choice Option: The Moderating Role of Regulatory Focus (재몰유선택적정황하공동특성대우고객희호적영향(在没有选择的情况下共同特性对于顾客喜好的影响): 조절초점적조절작용(调节焦点的调节作用))

  • Park, Jong-Chul;Kim, Kyung-Jin
    • Journal of Global Scholars of Marketing Science
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    • v.20 no.1
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    • pp.89-97
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    • 2010
  • This study researches the effects of common features on a no-choice option with respect to regulatory focus theory. The primary interest is in three factors and their interrelationship: common features, no-choice option, and regulatory focus. Prior studies have compiled vast body of research in these areas. First, the "common features effect" has been observed bymany noted marketing researchers. Tversky (1972) proposed the seminal theory, the EBA model: elimination by aspect. According to this theory, consumers are prone to focus only on unique features during comparison processing, thereby dismissing any common features as redundant information. Recently, however, more provocative ideas have attacked the EBA model by asserting that common features really do affect consumer judgment. Chernev (1997) first reported that adding common features mitigates the choice gap because of the increasing perception of similarity among alternatives. Later, however, Chernev (2001) published a critically developed study against his prior perspective with the proposition that common features may be a cognitive load to consumers, and thus consumers are possible that they are prone to prefer the heuristic processing to the systematic processing. This tends to bring one question to the forefront: Do "common features" affect consumer choice? If so, what are the concrete effects? This study tries to answer the question with respect to the "no-choice" option and regulatory focus. Second, some researchers hold that the no-choice option is another best alternative of consumers, who are likely to avoid having to choose in the context of knotty trade-off settings or mental conflicts. Hope for the future also may increase the no-choice option in the context of optimism or the expectancy of a more satisfactory alternative appearing later. Other issues reported in this domain are time pressure, consumer confidence, and alternative numbers (Dhar and Nowlis 1999; Lin and Wu 2005; Zakay and Tsal 1993). This study casts the no-choice option in yet another perspective: the interactive effects between common features and regulatory focus. Third, "regulatory focus theory" is a very popular theme in recent marketing research. It suggests that consumers have two focal goals facing each other: promotion vs. prevention. A promotion focus deals with the concepts of hope, inspiration, achievement, or gain, whereas prevention focus involves duty, responsibility, safety, or loss-aversion. Thus, while consumers with a promotion focus tend to take risks for gain, the same does not hold true for a prevention focus. Regulatory focus theory predicts consumers' emotions, creativity, attitudes, memory, performance, and judgment, as documented in a vast field of marketing and psychology articles. The perspective of the current study in exploring consumer choice and common features is a somewhat creative viewpoint in the area of regulatory focus. These reviews inspire this study of the interaction possibility between regulatory focus and common features with a no-choice option. Specifically, adding common features rather than omitting them may increase the no-choice option ratio in the choice setting only to prevention-focused consumers, but vice versa to promotion-focused consumers. The reasoning is that when prevention-focused consumers come in contact with common features, they may perceive higher similarity among the alternatives. This conflict among similar options would increase the no-choice ratio. Promotion-focused consumers, however, are possible that they perceive common features as a cue of confirmation bias. And thus their confirmation processing would make their prior preference more robust, then the no-choice ratio may shrink. This logic is verified in two experiments. The first is a $2{\times}2$ between-subject design (whether common features or not X regulatory focus) using a digital cameras as the relevant stimulus-a product very familiar to young subjects. Specifically, the regulatory focus variable is median split through a measure of eleven items. Common features included zoom, weight, memory, and battery, whereas the other two attributes (pixel and price) were unique features. Results supported our hypothesis that adding common features enhanced the no-choice ratio only to prevention-focus consumers, not to those with a promotion focus. These results confirm our hypothesis - the interactive effects between a regulatory focus and the common features. Prior research had suggested that including common features had a effect on consumer choice, but this study shows that common features affect choice by consumer segmentation. The second experiment was used to replicate the results of the first experiment. This experimental study is equal to the prior except only two - priming manipulation and another stimulus. For the promotion focus condition, subjects had to write an essay using words such as profit, inspiration, pleasure, achievement, development, hedonic, change, pursuit, etc. For prevention, however, they had to use the words persistence, safety, protection, aversion, loss, responsibility, stability etc. The room for rent had common features (sunshine, facility, ventilation) and unique features (distance time and building state). These attributes implied various levels and valence for replication of the prior experiment. Our hypothesis was supported repeatedly in the results, and the interaction effects were significant between regulatory focus and common features. Thus, these studies showed the dual effects of common features on consumer choice for a no-choice option. Adding common features may enhance or mitigate no-choice, contradictory as it may sound. Under a prevention focus, adding common features is likely to enhance the no-choice ratio because of increasing mental conflict; under the promotion focus, it is prone to shrink the ratio perhaps because of a "confirmation bias." The research has practical and theoretical implications for marketers, who may need to consider common features carefully in a practical display context according to consumer segmentation (i.e., promotion vs. prevention focus.) Theoretically, the results suggest some meaningful moderator variable between common features and no-choice in that the effect on no-choice option is partly dependent on a regulatory focus. This variable corresponds not only to a chronic perspective but also a situational perspective in our hypothesis domain. Finally, in light of some shortcomings in the research, such as overlooked attribute importance, low ratio of no-choice, or the external validity issue, we hope it influences future studies to explore the little-known world of the "no-choice option."