• Journal of Chest Surgery
• /
• 제29권2호
• /
• pp.227-230
• /
• 1996

Air space disorders are usually considered medical diseases, although some patients with air space disorders can benefit from surgical intervention. Recently we experienced two cases of bullous emphysema. One case is large bilateral apical bullae and the other is infected large bulls of RUL with bullous emphysema. The patient with large bilateral apical bullae underwent simultaneous operation via bilateral thoracotomy and other patient underwent simultaneous bilateral operation via median sternotomy. Postoperatively, the patient with large bilateral apical bullae showed subjective as well as objective improvement and other patient is resulted subjective improvement.

• 항공우주정책ㆍ법학회지
• /
• 제15권
• /
• pp.67-88
• /
• 2002

• 대한설비공학회지:설비저널
• /
• 제27권2호
• /
• pp.115-122
• /
• 1998

• 대한설비공학회지:설비저널
• /
• 제27권2호
• /
• pp.123-133
• /
• 1998

• 대한설비공학회지:설비저널
• /
• 제25권4호
• /
• pp.304-314
• /
• 1996

• 대한설비공학회지:설비저널
• /
• 제22권1호
• /
• pp.17-27
• /
• 1993

• 대한설비공학회지:설비저널
• /
• 제22권4호
• /
• pp.251-256
• /
• 1993

• Journal of Biosystems Engineering
• /
• 제37권2호
• /
• pp.75-81
• /
• 2012

Oyster mushroom farm which could not meet optimum temperature range yields non-uniform sized, low quality products. Thus, this study, utilizing STAR CCM+, one of the computational fluid dynamics (CFD) programs, analyzed the impact of air circulation and temperature distribution. Methods: After we visited numerous mushroom farms, we measured the temperature at the discharge ports of heaters, fan capacity, and the locations of the air circulators in the farms. According to the data, most mushroom growers installed the heaters near the entrance and discharge ports of the heaters at the third growing bed on the same height as the heaters in the entrance. The temperature at the discharge port of heater was $1,26^{\circ}C$, and the fan capacity was 4,500 $m^3$/hr. The air circulator was placed in the center of the mushroom farm 50cm above the ground, and its capacity of inlet port was 1,100 $m^3$/hr and discharge port 1,600 $m^3$/hr. The mushroom farm was insulated. Results: According to the analysis of the temperature distribution in the vertical plane of the entrance side, no air circulation causes the high temperature zone of 296~299K at the discharge port of the heater to take up 34% of area while the operation of air circulators causes it to occupy only 9%. This means that not using air circulators leads to a concentration of high temperature at the discharge port near the entrance. In addition, with the results of the analysis of the temperature distribution in the vertical planes of the center, no air circulation causes the temperature zone of 295~298K at the discharge port of the heater to take up 48% of area while the operation of air circulators causes it to occupy 80%. This shows that the high outlet port temperature disseminated to the center. Conclusions: After ninety minute operation of both heater and air circulator, the interior temperature became stabilized in the mushroom farm. Air circulation made the high temperature at the discharge port disseminate to the center and exit in the farm and equalize the temperature distribution.

• Journal of Electrical Engineering and Technology
• /
• 제2권3호
• /
• pp.408-412
• /
• 2007

It is almost impossible to secure the reproductibility and stability of a commercial Thick-Film Metal Oxide Semiconductor Gas Sensor since it is very difficult to keep the consistency of the manufacturing environment. Thus it is widely known that the general Semiconductor-Oxide Gas Sensors are not appropriate for precise measurement systems. In this paper, the output characteristic analyzer of the various Thick-Film Metal Oxide Semiconductor Gas Sensors that are used to recognize the air quality within an automobile are proposed and examined. The analyzed output characters in a normal air chamber are grouped by sensor ranks and used to fill out the characteristic table of the Thick-Film Metal Oxide Semiconductor Gas Sensors. The characteristic table is used to determine the rank of the sensor that is equipped in the current air cleaner system of an automobile. The proposed air control system can also adapt the on-demand operation that recognizes the history of the passenger's manual-control.

• 한국대기환경학회지
• /
• 제31권4호
• /
• pp.385-395
• /
• 2015

This study evaluated indoor environmental characteristics in an office room equipped both with ventilation window system and central cooling system. Fresh air is supplied only by the central cooling system whereas indoor air is discharged outside through both ceiling diffuser and a ventilation window system. Numerical study is conducted by changing the volumetric flow rates of exhaust ports of each system. For estimating the performance of this coupled system, $CO_2$ concentration and Predicted Mean Vote (PMV) were calculated using Computational Fluid Dynamics (CFD) simulation. The more the ceiling diffuser exhausts indoor air, the more the $CO_2$ concentration decreases. However, when the ventilation window system exhausts more indoor air, thermal comfort level gets improved in the office room with cooling system. Therefore, when the ventilation window system is operated, the coupled operation with central cooling system should be considered for enhancing indoor air quality and thermal comfort, together.