1.A Study on Air Pollution and Thermal Factors in Underground Shopping Center of Pusan Area.
Sung Yong CHOI ; Deog Hwan MOON ; Jong Tae LEE ; In Hyuk SONG ; Cha Eun LEE ; Sung Min LEE
Korean Journal of Preventive Medicine 1994;27(3):505-516
For the purpose of preparing the fundamental data on air pollution in underground shopping center and also contributing to the health improvement of resident, the authors measured the level of SO2, NO2, TSP, CO, CO2 and also some related factors as air temperature, air movement, relative humidity and mean radiation temperature at inside and outside of underground shopping center in Pusan from January to February and from July to August 1994. The results were as follows: 1. The mean concentration of CO within the underground shopping center was 3.1+/-1.3ppm in winter and 2.1+/-0.9 ppm in summer. There was a negative correlation (p<0.01) between inner CO concentration and temperature in summer and no correlation between inner CO concentration and outer CO concentration in underground shopping center 2. The mean concentration of C02 within the underground shopping center was 876+/-353 ppm in winter and 757+/-125 ppm in summer. There was a negative correlation (P<0.01) between inner CO2 concentration and air movement in summer and positive correlation (p<0.05) between inner CO2 oncentration and outer CO2 concentration in underground shopping center. 3. The mean concentration SO2 within a underground shopping center was 0.036+/-0.019ppm in winter and 0.040+/-0.013ppm in summer. There was a positive correlation(p<0.01) between inner SO2 concentration and positive correlation between inner SO2 concentration and outer SO2 concentration in summer and winter in Underground shopping center. 4. The mean concentration of NO2 within a underground shopping center was 0.052+/-0.038ppm in winter and 0.042+/-0.016ppm in summer. There was a no correlation between inner NO2 concentration and thermal factors in summer and winter and low correlation between inner NO2 concentration in underground shopping center. 5. The mean concentration of TSP within a underground shopping center was 430+/-214 microgram/m3 in winter, 366+/-73 microgram/m3 in summer, and very in excess of the atmospheric environmental quality standards of Korea(150 microgram/m3). There was low correlation between inner TSP concentration and temperature in summer and high correlation between inner TSP concentration and outer TSP concentration in underground shopping center.
Air Movements
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Air Pollution*
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Busan*
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Humidity
2.Prediction and analysis model of temperature and its application to a natural ventilation multi-span plastic greenhouse equipped with insect-proof screen.
Shu-zhen LIU ; Yong HE ; Yu-bao ZHANG ; Xiang-wen MIAO
Journal of Zhejiang University. Science. B 2005;6(6):523-529
The natural ventilation widely used in greenhouses has advantages of saving energy and reducing expense. In order to provide information for climate control of greenhouse, a model was developed to predict the variation of air temperature in the naturally ventilated greenhouse equipped with insect-proof screen. Roof ventilation and combined roof and sidewall ventilation were considered in the model. This model was validated against the results of experiments conducted in the greenhouse when the wind was parallel to the gutters. The model parameters were determined by the least squares method. In the used model, effects of wind speed and window opening height on the air temperature variation were analyzed. Comparison between two types of ventilation showed that there existed a necessary ventilation rate which results in air temperature decrease in natural ventilation under special climatic conditions. In our experiments when wind speed was less than 3.2 ms(-1), wind had a more gradual effect on greenhouse temperature for roof ventilation, compared with combined roof and sidewall ventilation, which had greater air temperature decrease than roof ventilation only.
Air Conditioning
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instrumentation
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methods
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Air Movements
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Computer Simulation
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Computer-Aided Design
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Equipment Design
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Equipment Failure Analysis
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methods
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Insect Control
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instrumentation
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methods
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Models, Theoretical
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Plant Development
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Plastics
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Rheology
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instrumentation
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methods
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Temperature
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Wind
3.Aerodynamics study on pressure changes inside pressure-type whole-body plethysmograph produced by flowing air.
Acta Physiologica Sinica 2010;62(1):42-48
When using pressure-type plethysmography to test lung function of rodents, calculation of lung volume is always based on Boyle's law. The precondition of Boyle's law is that perfect air is static. However, air in the chamber is flowing continuously when a rodent breathes inside the chamber. Therefore, Boyle's law, a principle of air statics, may not be appropriate for measuring pressure changes of flowing air. In this study, we deduced equations for pressure changes inside pressure-type plethysmograph and then designed three experiments to testify the theoretic deduction. The results of theoretic deduction indicated that increased pressure was generated from two sources: one was based on Boyle's law, and the other was based on the law of conservation of momentum. In the first experiment, after injecting 0.1 mL, 0.2 mL, 0.4 mL of air into the plethysmograph, the pressure inside the chamber increased sharply to a peak value, then promptly decreased to horizontal pressure. Peak values were significantly higher than the horizontal values (P<0.001). This observation revealed that flowing air made an extra effect on air pressure in the plethysmograph. In the second experiment, the same volume of air was injected into the plethysmograph at different frequencies (0, 0.5, 1, 2, 3 Hz) and pressure changes inside were measured. The results showed that, with increasing frequencies, the pressure changes in the chamber became significantly higher (P<0.001). In the third experiment, small animal ventilator and pipette were used to make two types of airflow with different functions of time. The pressure changes produced by the ventilator were significantly greater than those produced by the pipette (P<0.001). Based on the data obtained, we draw the conclusion that, the flow of air plays a role in pressure changes inside the plethysmograph, and the faster the airflow is, the higher the pressure changes reach. Furthermore, the type of airflow also influences the pressure changes.
Air Movements
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Animals
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Models, Theoretical
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Plethysmography, Whole Body
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instrumentation
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methods
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Pressure
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Rats
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Respiration
4.Orbital Emphysema Causing Eye Movement Restriction Without Orbital Fractures Due to Compressed Air Injury.
Yun JUNG ; Ho Seok MOON ; Jee Woong JUNG ; Mi Jung CHI
Journal of the Korean Ophthalmological Society 2013;54(1):180-183
PURPOSE: The authors experienced a case of orbital emphysema causing eye movement disorder following conjunctival tear without any orbital wall fractures after exposure to compressed air. CASE SUMMARY: A 28-year-old man's left periorbital area was injured while working with compressed air. There was marked lid swelling on the left side with palpable crepitus. The patient had an exotropia and hypertropia of the left eye. In addition, the extraocular movement of the left eye was restricted on upgaze without nausea and vomiting. On slit-lamp examination, conjunctival partial laceration and subconjunctival air bubbles adjacent to the conjunctival laceration could be seen. Orbital computed tomography showed air in the periorbital and retrobulbar region of the left eye and no evidence of orbital fracture. On examination 4 days after the primary repair of the conjunctival laceration, the patient completely recovered without any complication. CONCLUSIONS: Orbital emphysema following a conjunctival laceration caused by compressed air without any orbital wall fractures can cause restriction of eye movement.
Adult
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Compressed Air*
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Emphysema*
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Exotropia
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Eye Movements*
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Humans
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Lacerations
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Nausea
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Ocular Motility Disorders
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Orbit*
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Orbital Fractures*
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Strabismus
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Vomiting
5.Optimization of one-step pelletization technology of Jiuwei Xifeng granules by response surface methodology.
Xiu-hai WANG ; Xu-fang YANG ; Ye-wen FAN ; Yan-jun ZHANG ; Zhong-kun XU ; Lin-yong YANG ; Zhen-zhong WANG ; Wei XIAO
China Journal of Chinese Materia Medica 2014;39(24):4782-4786
Using the qualified rates of particles as the evaluation indexes, the impact tactors of one-step pelletization technology of Jiuwei Xifeng granules were selected from six factors by the Plackett-Burman experimental design and the levels of non-significant factors were identified. According to the Plackett-Burman experimental design, choosing the qualified rates of particles and angle of repose as the evaluation indexes, three levels of the three factors were selected by Box-Behnken of central composite design to optimize the experimental. The best conditions were as follows: the fluid extract was sprayed with frequency of 29 r . min-1, inlet air temperature was 90 °C, the frequency of fan was 34 Hz. Under the response surface methodology optimized scheme, the average experimental results are similar to the predicted values, and surface methodology could be used in the optimization of one-step pelletization for Chinese materia medica.
Air Movements
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Analysis of Variance
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Drug Compounding
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methods
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Drugs, Chinese Herbal
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chemistry
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Hot Temperature
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Models, Theoretical
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Research Design
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Tablets
6.Self-reported Cabin Environment and Work-related Musculoskeletal Disorders (WMSDs) among Female Flight Attendants on Long-haul International Flights.
Korean Journal of Aerospace and Environmental Medicine 2006;16(1):2-8
Physical environmental factors have been found to increase the risk for work-related musculoskeletal disorders (WMSDs) in a variety of occupations. To date little is known about the influence of physical environmental factors in the cabin of an airplane on WMSDs among flight attendants. The purpose of this study was to examine the relationship between self-reported physical environment factors in the cabin and WMSDs in the neck, shoulder, upper back, and lower back among U.S. female flight attendants on long-haul international flights. A cross-sectional mailed survey was conducted with 185 female fight attendants working on long-haul international flights. The physical environment measure included 12 items regarding cabin-air quality, noise, lighting, and whole-body vibration. WMSDs were measured by the Nordic Musculoskeletal Questionnaire and the National Institute for Occupational Safety and Health Symptom Survey. The percentage of flight attendants who had WMSDs for each body region varied from 31% to 54%. The majority (>80%) of the flight attendants often or always experienced low humidity, stuffy air, and little air movement while working in the cabin. Being frequently exposed to unfavorable cabin environmental factors increased the risk of neck (OR=2.89), shoulder (OR=2.96), and upper-back WMSDs (OR=2.14). Cabin environmental factors should be taken into account when examining the risk factors for WMSDs.
Air Movements
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Aircraft
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Body Regions
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Female*
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Humans
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Humidity
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National Institute for Occupational Safety and Health (U.S.)
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Neck
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Noise
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Occupations
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Postal Service
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Risk Factors
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Shoulder
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Vibration
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Surveys and Questionnaires
7.Sick Building Syndrome in Office Workers.
Korean Journal of Occupational and Environmental Medicine 1996;8(3):519-525
A cross-sectional study was conducted to evaluate the relationship between sick building syndrome (SBS) and the factors affecting SBS among 90 office workers. The study consisted of 1) a review of previous environmental investigations, 2) measurements of COy temperature, and relative humidity (RH), 3) a questionnaire survey of symptom prevalence and perception of environmental conditions using the National Institute for Occupational Safety and Health Indoor Air Quality (NIOSH IAQ) questionnaire, and 4) confidential interview and a review of medical records of employees having respiratory symptoms. COy temperature, and RH measured on the day of questionnaire survey were within the recommended range by American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE). Sixty-six percent of respondents were women and 60% considered their job description either "managerial (28%) "or "professional (32%)". Respondents had worked in the building for an average of 5.8 years. Forty-four percent reported having SBS defined as "having one or more symptoms that had occurred at work one or more days a week and tended to get better when away from work". Sex(p=0.001), duration of computer use(p=0.02), use of laser printer (p=0.02), use of cleanser or other office chemicals (p=0.004), feeling too little air movement (p=0.001), feeling air too dry(p=0.001), and unsatisfied with the current job(p=0.02) were related to an increased prevalence of SBS. Use of cleanser or other office chemicals (pO. 01), feeling too little air movement (p=0.01), and feeling air too dry (p=0.02) remained significant predictors of SBS when adjusting other variables by logistic regression analysis. The results of medical record review revealed a discrepancy in the number of diagnosed asthma cases by personal physician and an independent physician. Although this study contains several .limitations (e. g., cross-sectional study, small numbers of study, subjects, etc.), these results indicated that SBS is related to personal, environmental, and psychosocial factors and the precision of diagnosis is critical when evaluating environment-relatedness during disease cluster investigation.
Air Movements
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Air Pollution, Indoor
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Asthma
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Cross-Sectional Studies
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Data Collection
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Diagnosis
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Female
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Heating
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Hot Temperature
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Humans
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Humidity
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Job Description
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Logistic Models
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Medical Records
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National Institute for Occupational Safety and Health (U.S.)
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Prevalence
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Psychology
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Questionnaires
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Sick Building Syndrome*
8.Gone with the Wind
Osong Public Health and Research Perspectives 2019;10(2):49-50
No abstract available.
Wind
9.The Wind of Change: Uncomplicated Diverticulitis.
Annals of Coloproctology 2015;31(2):43-44
No abstract available.
Diverticulitis*
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Wind*
10.Development of Transcutaneous Energy Transmission System for Implantable Devices.
Dong Soo YOO ; Joon Ha LEE ; Hee Don SEO ; Sang Hag LEE
Korean Journal of Medical Physics 2005;16(3):155-159
As a part of implantable device in body, a transcutaneous energy transmission system has been developed. It would be desirable to tansfer electrical energy to implantable devices transcutaneously. The distance between transcutaneous transformer windings are approximately equal to the thickness of the human's skin, nominally between 10~20 mm. Class-E resonant amplifier is used to drive a primary coil for high efficiency. Maximum current is above 50 mA at any frequency. The developed system shows that the circuit operates correctly at each frequency; 500 kHz, 1 MHz and 4 MHz.
Skin
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Wind