• Title/Summary/Keyword: Ventilation condition

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Analysis of Characteristics and Prognostic Factors in Adult Patients Receiving Mechanical Ventilation in the Medical Intensive Care Unit of a University Hospital (한 대학병원 내과계 중환자실의 기계환기 시행 환자의 현황 및 예후인자의 분석)

  • Song, Jin Woo;Choi, Chang-Min;Hong, Sang-Bum;Oh, Yeon-Mok;Shim, Tae Sun;Lim, Chae-Man;Lee, Sang-Do;Kim, Woo Sung;Kim, Dong Soon;Kim, Won Dong;Koh, Younsuck
    • Tuberculosis and Respiratory Diseases
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    • v.65 no.4
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    • pp.292-300
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    • 2008
  • Background: Respiratory failure is a common condition that requires intensive care, and has a high mortality rate despite the recent improvements in respiratory care. Previous reports of patients with respiratory failure focused on the specific disease or included a large proportion of surgical patients. This study evaluated the clinical characteristics, outcomes and prognostic factors of adult patients receiving mechanical ventilation in a medical intensive care unit. Methods: Retrospective chart review was performed on 479 adult patients, who received mechanical ventilation for more than 48 hours in the medical ICU of one tertiary referral hospital. Results: The mean age of the patients was $60.3{\pm}15.6$ years and 34.0% were female. The initial mean APACHE III score was $72.3{\pm}25$. The cause of MV included acute respiratory failure (71.8%), acute exacerbation of chronic pulmonary disease (20.9%), coma (5.6%), and neuromuscular disorders (1.7%). Pressure controlled ventilation was used as the initial ventilator mode in 67.8% of patients, and pressure support ventilation was used as the initial weaning mode in 83.6% of the patients. The overall mortality rate in the ICU and hospital was 49.3% and 55.4%, respectively. The main cause of death in hospital was septic shock (32.5%), respiratory failure (11.7%), and multiorgan failure (10.2%). Males, an APACHE III score >70, the cause of respiratory failure (interstitial lung disease, coma, aspiration, pneumonia, sepsis and hemoptysis), the total ventilation time, and length of stay in hospital were independently associated with mortality. Conclusion: The cause of respiratory failure, severity of the patients, and gender appears to be significantly associated with the outcome of mechanical ventilatory support in patients with respiratory failure.

The Influence of Ventilation and Shade on the Mean Radiant Temperature of Summer Outdoor (통풍과 차양이 하절기 옥외공간의 평균복사온도에 미치는 영향)

  • Lee, Chun-Seok;Ryu, Nam-Hyung
    • Journal of the Korean Institute of Landscape Architecture
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    • v.40 no.5
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    • pp.100-108
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    • 2012
  • The purpose of the study was to evaluate the influence of shading and ventilation on Mean Radiant Temperature(MRT) of the outdoor space at a summer outdoor. The Wind Speed(WS), Air Temperature(AT) and Globe Temperature(GT) were recorded every minute from $1^{st}$ of May to the $30^{th}$ of September 2011 at a height of 1.2m above in four experimental plots with different shading and ventilating conditions, with a measuring system consisting of a vane type anemometer(Barini Design's BDTH), Resistance Temperature Detector(RTD, Pt-100), standard black globe(${\O}$ 150mm) and data acquisition systems(National Instrument's Labview and Compfile Techs' Moacon). To implement four different ventilating and shading conditions, three hexahedral steel frames, and one natural plot were established in the open grass field. Two of the steel frames had a dimension of $3m(W){\times}3m(L){\times}1.5m(H)$ and every vertical side covered with transparent polyethylene film to prevent lateral ventilation(Ventilation Blocking Plot: VP), and an additional shading curtain was applied on the top side of a frame(Shading and Ventilation Blocking Plot: SVP). The third was $1.5m(W){\times}1.5m(L){\times}1.5m(H)$, only the top side of which was covered by the shading curtain without the lateral film(Shading Plot: SP). The last plot was natural condition without any kind of shading and wind blocking material(Natural Open Plot: NP). Based on the 13,262 records of 44 sunny days, the time serial difference of AT and GT for 24 hour were analyzed and compared, and statistical analysis was done based on the 7,172 records of daytime period from 7 A.M. to 8 P.M., while the relation between the MRT and solar radiation and wind speed was analyzed based on the records of the hottest period from 11 A.M. to 4 P.M.. The major findings were as follows: 1. The peak AT was $40.8^{\circ}C$ at VP and $35.6^{\circ}C$ at SP showing the difference about $5^{\circ}C$, but the difference of average AT was very small within${\pm}1^{\circ}C$. 2. The difference of the peak GT was $12^{\circ}C$ showing $52.5^{\circ}C$ at VP and $40.6^{\circ}C$ at SP, while the gap of average GT between the two plots was $6^{\circ}C$. Comparing all four plots including NP and SVP, it can be said that the shading decrease $6^{\circ}C$ GT while the wind blocking increase $3^{\circ}C$ GT. 3. According to the calculated MRT, the shading has a cooling effect in reducing a maximum of $13^{\circ}C$ and average $9^{\circ}C$ MRT, while the wind blocking has heating effect of increasing average $3^{\circ}C$ MRT. In other words, the MRT of the shaded area with natural ventilation could be cooler than the wind blocking the sunny site to about $16^{\circ}C$ MRT maximum. 4. The regression and correlation tests showed that the shading is more important than the ventilation in reducing the MRT, while both of them do an important role in improving the outdoor thermal comfort. In summary, the results of this study showed that the shade is the first and the ventilation is the second important factor in terms of improving outdoor thermal comfort in summer daylight hours. Therefore, it can be apparently said that the more shade by the forest, shading trees etc., the more effective in conditioning the microclimate of an outdoor space reducing the useless or even harmful heat energy for human activities. Furthermore, the delicately designed wind corridor or outdoor ventilation system can improve even the thermal environment of urban area.

ENVIROMENTAL CONDITION DURING AIR SHIPMENT OF HORTICULTURAL PRODUCTS FROM OKINAWA TO TOKYO

  • Akinaga, Takayoshi;Kohda, Yoshihiro
    • Proceedings of the Korean Society for Agricultural Machinery Conference
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    • 1993.10a
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    • pp.413-422
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    • 1993
  • Air shipment affords the quickest possible delivery of horticultural products. The price of air shipped horticultural products are relatively high as most of these products are perishable. Usually the temperature in the cargo compartment is not controlled during flight. Thus, special attention should be paid to procooling prior to shipment. The environmental condition during transportation of horticultural products is an essential parameter for maintaining the quality of perishable products. Commonly horticultural products were loaded by ULD(Unit Load Devices) as a container or pallet in the aircraft (except for small aircraft) . Therefore, inside temperature of the container and cargo compartment came into question. Scarce literature on the relationship between environmental condition and quality changes of horticultural products during air shipment can be found. By the stand point of keeping fresh quality, investigations on the actual condition of air shipments were carried out to improve the technique during the distribution process of fresh horticultural products. Temperature, humidity, atmospheric pressure, carbon dioxide, ethylene, impacts, and changes in quality during the air shipment of snapbeans, okras and chrysanthemums were measured. Temperature was measured by recording thermometers, relative humidity by recording hygrometers, atmospheric pressure by a strain -guage type pressure sensor, carbon dioxide by testing tubes, ethylene by sampling bags and a gaschromatograph, impacts and vibrations by impact recorders and a 3D accelerometer. Relationships between environmental conditions and quality changes during air shipments were clarified. It was expected from investigations into actual shipments that the ventilation and insulation properties of air freight containers were related to the quality of agricultural products. Aircraft can no directly load and unload trucks into them. The transshipment is inclined to cause shocks and vibrations, and to invite damages within a short time.

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Effects of Ventilation Condition on the Fire Characteristics in Compartment Fires (Part I: Performance Estimation of FDS) (구획화재에서 환기조건의 변화가 화재특성에 미치는 영향(Part I: FDS의 성능평가))

  • Hwang, Cheol-Hong;Park, Chung-Hwa;Ko, Gwon-Hyun;Lock, Andrew
    • Fire Science and Engineering
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    • v.24 no.3
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    • pp.131-138
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    • 2010
  • Experimental and numerical studies were conducted to investigate the thermal and chemical characteristics of heptane fires in a full-scale ISO 9705 room. Representative fire conditions were considered for over-ventilated fire (OVF) and under-ventilated fire (UVF). Fuel flow rate and doorway width were changed to create OVF and UVF conditions. Detailed comparisons of temperature and species concentrations between experimental and numerical data were presented in order to validate the predictive performance of FDS (Fire Dynamic Simulator). The OVF and UVF were explicitly characterized with distributions of temperature and product formation measured in the upper layer, as well as combustion efficiency and global equivalence ratio. It was shown that the numerical results provided a quantitatively realistic prediction of the experimental results observed in the OVF conditions. For the UVF, the numerically predicted temperature showed reasonable agreement with the measured temperature. The predicted steady-state volume fractions of $O_2$, $CO_2$, CO and THC also agreed quantitatively with the experimental data. Although there were some limitations to predict accurately the transient behavior in terms of CO production/consumption in the UVF condition, it was concluded that the current FDS was very useful tool to predict the fire characteristics inside the compartment for the OVF and UVF.

A subjective symptom on indoor air quality in dental hygienist (치과위생사의 실내공기질에 의한 자각증상 특성)

  • Choi, Mi-Suk;Son, Bu-Soon
    • Journal of environmental and Sanitary engineering
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    • v.21 no.4 s.62
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    • pp.1-10
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    • 2006
  • This research is based on self-filling survey which 220 dental hygienists who work in seoul participated on July 2006 through August 2006. This survey was analyzed the experience item and occurred time of the symptoms and the time of acute and vanish of the symptoms that dental office's working environment effects on physical subjective symptom. We suggest a plan to minimizing physical subjective symptom for health manage of dental hygienist. We found out the fact that dental hygienists were unsatisfied with hospital air condition and this polluted air condition cause them physical subjective symptom in work place. As follows analyzed results ventilation time is below the 3-times a day, this may be have some trouble in indoor air quality. The experience the symptoms level is higher then non-experience level in "Fatigue and sleepiness", "Dorsalgia, omarthralgia, cervicodynia", "Hypersensitivity", "Dry eye, itch, smarting", "Headaches" and a subjective symptom is occurred at after 11:00(am) more then 60%, 50% of the dental hygienist. This experience the symptom' pain is vanished after the work and reduced when go out the office and building, respectively. The ratio of the experience the symptoms and starting time the symptoms is anywhere from 12 noon to 4 pm (73.2%) in a day. The time of acute pain the symptoms is anywhere from 12 noon to 4 pm (78.7%) refer to the individual characteristics and work environment.

An active system for unnecessary noise reduction in kitchen range hoods

  • Kim, Eunhee;Jang, Jaechun;Lim, Changmok
    • Journal of the Korea Society of Computer and Information
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    • v.21 no.3
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    • pp.91-96
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    • 2016
  • We have surrounded undesired living noises in our life. One of biggest noises coming out of range hood during cooking in the kitchen. A range hood is one of the most important appliances in the kitchen because it ventilates polluted air out during cooking, and maintains air quality in the kitchen. But current kitchen range hoods bring up some issues; First, the range hoods consume massive amount of standby power not in use condition. Second, current models have designed manual fan operating system with sudden onset of noise with starting. In this paper, we propose an auto control system entire processes from air ventilation to noise reduction. Our system is consist of three parts (Eco-sensors pack, Main Controller and Active Noise Controller); Eco-sensors pack detects air pollution of kitchen areas and sends the detection values to Main Controller. Main Controller determines operation of range hood by detected values. Active Noise Controller is located inside of the range hood. It received starting signals from Main Controller which elicits degrees of polluted air condition and fan operating speed from 1 to 3. Once Active Noise Controller detected the signals, it runs a ventilating fan until new value from Main Controller becomes 0. while the range hood works, A noise cancellation algorithm inside of Active Noise Controller become activated to reduce levels of noise. As a result, the proposed system clearly shows reduction in power consumption include standby power and decreases in levels of noise.

The Actual Wearing and Purchase Conditions of Bicycle Wear focused on the Active Senior Women (액티브 시니어 여성의 자전거의류 착용 및 구매실태)

  • Jung, Hee-Kyeong;Lee, Jeong-Ran
    • Fashion & Textile Research Journal
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    • v.17 no.3
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    • pp.440-446
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    • 2015
  • This study identified active senior women's wearing and the purchase situation of bicycle wear to develop functional bicycle wear that can satisfy active senior consumers. The survey was conducted for women in their fifties and sixties who ride bicycles on a regular basis. A total of 119 questionnaires were used for data analysis excluding incompletely replied questionnaires. Data was analyzed by descriptive analysis, frequency analysis and cross analysis. The results are as follows. First, 50's individuals represented 60% of this survey who continuously rodebicycles for 5 years or more. The purpose of riding bicycle was exercise, leisure and club activities. Second, they wore bicycle wear while riding due to activity, functionality and safety. There is also a requirement to manufacture comfortable bicycle wear easy to put on and take off and for old people. Third, considering the purchase situation of bicycle wear, the respondents had difficulties buying bicycle wear due to price. It is necessary to have bicycle wear at a reasonable price. Fourth, the most necessary functionsforbicycle wear materials were ventilation and durability. A major function needed for future developmentwill bethermoregulation.

A study on the Development of Vertical Air Temperature Distribution Model in Atrium (아트리움의 수직온도 분포해석 프로그램의 개발에 관한 연구)

  • Kim, Y.I.;Cho, K.H.;Kim, K.W.
    • Solar Energy
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    • v.17 no.3
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    • pp.3-11
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    • 1997
  • Recently the construction of atrium buildings has increased but along with it many problems in thermal environment have arised. since the exterior wall of glass, indoor temperature is greatly influenced by weather conditions and since the space volume is very large, the vertical air temperature is not uniform. So, in this study, a Vertical Temperature Distribution Model was developed to predict the vertical air temperature of an atrium and evaluate the effects of the design parameters on the air temperature distribution of an atrium. To consider the characteristics of the vertical air temperature distribution in an atrium, the Satosh Togari's Macroscopic Model was used basically for the calculation of the vertical air temperature distribution in large space and the solar radiation analysis model and natural ventilation analysis model in atrium. And to calculate the unsteady-state inside wall surface temperature(boundary condition), the finite difference method was used. For the verification of the developed temperature distribution program, numerical evaluation of air flow by the ${\kappa}-{\varepsilon}$ turbulence model and in-situ test was conducted in parallel. The results of this study, the developed temperature distribution program was seen to predict the thermal condition of the atrium very accurately.

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Study on Characteristics of Heat Release Rate in Compartment of Building for Scenario of Smoke Management (건축물 제배연시나리오 작성을 위한 구획실 발열특성 연구)

  • Kim, Jung-Yup;Shin, Hyun-Joon
    • Proceedings of the SAREK Conference
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    • 2009.06a
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    • pp.398-403
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    • 2009
  • The theoretical bases on characteristics of heat release rate in compartment of building for scenario of smoke management are introduced and the numerical applications to simple compartment model are carried out. The growth stage which is important for smoke management design is modelled as t-squared fire curve including fire growth coefficient with related to growth rate. The conditions for the happening of flashover is presented such as $600^{\circ}C$ of temperature or $20kW/m^2$ of radiation heat flux. After the flashover happen, the fire in compartment changes to fully developed fire having the characteristics of ventilation-controlled fire. As the result of numerical analysis to simple compartment model, the time to reach 900K under ceiling for condition of medium growth is twice for condition of fast growth.

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Study on Air Washer using Underground Water in the Subway Stations (지하철 역사 지하수를 이용한 에어와셔에 관한 연구)

  • Kim, Dong-Gyu;Kim, Hoe-Youl;Chung, Yong-Hyun;Kim, Jong-Ryul;Kum, Jong-Soo
    • Journal of Fisheries and Marine Sciences Education
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    • v.22 no.4
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    • pp.604-610
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    • 2010
  • Busan subway transportation system has been established a key role in the society last 20 years. However many people are suffering from hot and humid environment at subway station and platform due to deteriorated ventilation system as well as insufficient air conditioning system in existing stations and platforms. As a result, these systems require revitalization. There is about 5400tons of low temperature underground water is generated from subway stations every day. By using this method and air washer we are trying to lower the temperature. Air washer is commonly used for removing humidity but in this experiment it will be used as air precooling. This research offers result of experiment using air washer system to lower the temperature in large spaces like subway station. The experiment result has shown when L/G was the same, at condition which water spray temperature at $18^{\circ}C$ resulting inlet and outlet temperature difference larger. Also, in the same water spray temperature conditions, larger L/G condition showed a greater temperature difference. LCC evaluation of both system were shown that air washer system of using underground water will save 53% of the initial cost than refrigeration system, and save 75% of operating cost.