• The Korean Journal of Rehabilitation Nursing
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• v.10 no.2
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• pp.108-115
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• 2007

Purpose: This study was to investigate the effects of respiratory rehabilitation training on the respiratory functions of hospitalized cervical spinal cord injury patients. Methods: One group pre and post test design was used. Subjects were 20 cervical spinal cord injury inpatients of the national rehabilitation center. Training program consisted of air cumulation training, manual assisted coughing training, and abdominal breathing. Trained rehabilitation nurse implemented 20 minutes program twice a day for 4 weeks. Respiratory function was measured as peak coughing flow rate, and perceived respiratory difficulty after activity on wheel chair for 30 minutes and during speaking and singing. Perceived respiratory difficulty was measured with modified Borg scale. Also content analysis was done with the result of open ended question about subjective feeling about training. All variables were measured 3 times before, 2weeks and 4 weeks after the program. Results: Peak coughing flow rate significantly improved after compared to before training. Also all three perceived respiratory difficulty variables decreased significantly after training. In the content analysis, 'it's easier to cough up phlegm' was the most frequent answered subjective feeling. 'Sound at speaking and coughing became louder', 'respiratory volume increased', and 'comfortable chest feeling' were frequent answered subjective feeling, in order. Conclusion: Although it is preliminary since no control group, respiratory rehabilitation training was found to be effective to improve respiratory function in terms of peak coughing flow rate, perceived respiratory difficulty, and subjective feeling. It is necessary further systemic research to investigate the effects of respiratory rehabilitation training.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.717-722
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• 2010

Supersonic/Hypersonic wind tunnel is a facility which is intended to test and to observe the physical phenomena around a model by creating supersonic flow in the test section. In designing an airplane, the wind tunnel test is demanded to analyzing aerodynamic characteristics of the model without making a prototype. In this research, the model aerodynamic facility(MAF) is modified for the purpose of increasing running time and its functionality. New pneumatic valves for remote control was installed for safety requirement, and new air tanks was installed on MAF as well. A pipe system is also modified to use those new valves and tanks, and the ceiling and side glasses of the test section are switched to ones with the larger surface area. After the MAF modification, a test is performed at Mach 2, 3 and 4. In this test, shadow graph technique, one of the flow visualization methods, is used to visualize supersonic flow field. The pressure in the settling chamber and working section at Mach 2, 3 and 4 was measured in each case. As a result, the possible model size and running time are obtained.

• Journal of Bio-Environment Control
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• v.27 no.3
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• pp.206-212
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• 2018

As many consumers prefer good quality food, farms have used various facilities to cultivate products for satisfying their desires. Among them, the most representative facilities are plastic and glass multi-span greenhouse. The height of both plastic greenhouse and glass greenhouse is around three meters high in Korea. As a result, the crop productivity is limited. The solution is to increase the height of the greenhouses to improve the greenhouses' environment. The device for raising columns consists of a stop device, a pneumatic cylinder, and a vertical member. Pneumatic cylinders were designed with a diameter of 160 mm and a stroke length of 50 mm, taking into consideration the safety factor of 1.5. In addition, the air flow was controlled by nozzle to achieve a time of less than 30 seconds per stroke. It was calculated that $21.5L{\cdot}min^{-1}$ of air was needed to complete in less than 30 seconds. Accordingly, the diameter of the nozzle is designed to be 0.5 mm. When the pressure was 0.9 MPa, the average raising force was 13,805N, which was close to the calculated value of 15,612N. The field test results show that any inconsistency in the row columns was not generated. and that it is considered applicable to the actual glass and plastic greenhouses.

• Fire Science and Engineering
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• v.27 no.2
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• pp.6-10
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• 2013

This study aims to construct the performance data for smoke-control zone and realize the safety of injection and pressurization room which is composed of supply air pressure zone, vestibule, smoke-control zone and stairwell. To obtain this, smoke-control system and the device of the opening-closing force of fire door are manufactured. This subject is the analysis of the closing force, angular velocity and fire door size in the case of fixed volume flow rate. Based on the results, closing force increased as fire door size and closing angular velocity increases. Also, it is remark that there exists a critical angular velocity, which maintains constant maximum closing force even though the angular velocity increases more.

• International Journal of Aeronautical and Space Sciences
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• v.18 no.2
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• pp.352-364
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• 2017

A novel 3D mathematical model for water film runback and icing on a rotating surface is established in this work, where both inertial forces caused by the rotation and shear forces due to the air flow are taken into account. The mathematical model of the water film runback and energy conservation of phase transition process is established, with a cyclical average method applied to simulate the unsteady parameters variation at angles of attack. Ice accretion on a conical spinner surface is simulated and the results are compared with the experimental data to validate the presented model. Then Ice accretion on a cowling surface is numerically investigated. Results show that a higher temperature would correspond to a larger runback ice area and thinner ice layer for glaze ice. Rotation would enhance the icing process, while it would not significantly affect the droplet collection efficiency for an axi-symmetric surface. In the case at angle of attack, the effect of rotation on ice shape is appreciable, ice would present a symmetric shape, while in a stationary case the shape is asymmetric.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.2
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• pp.962-969
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• 2013

This study used Computational Fluid Dynamics(CFD) to assess the properties of the air current inflow and the flow velocity distribution in the fume hood. In order to verify the effect of improvement, it was also predicted the characteristics of the flow pattern in case the hood face is structurally improved. The assessment of the capture velocity with the existing fume hood confirmed maximum 23 to 30% difference as compared to the root mean square (RMS). And the hood face showed great difference in flow velocity, with the flow velocity in the upper part is 58 to 68% faster than that in the lower part of the hood. So, as a result of the improvement of the hood designed to maintain a steady exhaust at the hood face (that is, installing a baffle on the inner wall and designing the slot type face), a difference of maximum 7% as compared to RMS appeared while maximum 12% differentiation in flow velocity through sections was predicted, showing mitigation of much of the difference in control velocity as compared to the previous structure.

• Korean Journal of Veterinary Service
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• v.38 no.4
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• pp.241-248
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• 2015

This study was aimed to investigate factors that affected the status of wearing personal protective equipment (PPE) for handling poultry carcasses with potential exposure to virulent avian infectious agents. A large outbreak of high pathogenic avian influenza (HPAI) occurred in South Korea in 2014. Many public officers participated for euthanizing and handling livestock carcass. However, several safety issues with using PPE were revealed. Therefore, a questionnaire survey was conducted for 340 people who participated euthanasia and carcass disposal in the place where HPAI mainly occurred in 2014. It was found that 31.8% of the respondents had ever taken off their protective equipment during operations because of its inconvenience. The most inconvenient PPE was goggles (54.6%), followed by mask (20.2%), latex gloves (11.6%), shoe covers (5.9%) and protective clothing (5.3%). The main complaints about this individual PPE was unclear sight, damp emitted toward eye, sweating, tearing easily and sweating, respectively. Considering such problems of PPE, new possible directions for improvement of gloves and goggles were suggested. With newly developed rubber coating fabric gloves and conventionally using latex and fabric gloves, H3N2 influenza virus transmission experiment was conducted. Rubber coating fabric gloves showed similar efficiency for blocking virus transmission with latex laboratory gloves and were not easily torn by sharp claws of chicken. In addition, air flow control safety eyewear was suggested to minimize moisture formation. The air flow control system efficiently suppressed moisture formation inside the goggles. Therefore our study will provide more specific directions about new PPE development for safety protection of actual wearers.

• Food Science and Preservation
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• v.11 no.2
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• pp.250-256
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• 2004

The objectives of this study were to develop a new commercial grain cooler suited to domestic weather and post-harvesting conditions for paddy, and to evaluate the performance. A prototype grain cooler capable of cooling paddy of 200 tons within 24 hours was developed. The grain cooler was designed to control the refrigeration capacity from 0 to 100% by controlling the capacity of compressor with unloading solenoid valve and by changing the flow rates of hot refrigerant gas flowing into reheater and evaporator from compressor. And a controller with one chip microprocessor was developed to control temperature and relative humidity of cooling air. The maximum cooling capacity of the grain cooler was 35,284㎉/hr at condensing/evaporating pressure of 16.5/3.6 kgf/$\textrm{cm}^2$. Maximum flow rate of cooling air was 120 ㎥/min at static pressure of 279 mmAq. The total maximum required power was 22.8㎾, and total required energy was saved from 26.7 to 33.3% of maximum power depending on operating conditions. The coefficient of performance of refrigeration devices and total coefficient of performance of the grain cooler were 4.71 and 1.8, respectively.

• Journal of Bio-Environment Control
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• v.11 no.3
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• pp.101-107
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• 2002

This study was carried out to improve the performance of heat recovery device attached to exhaust gas flue connected to combustion chamber of greenhouse heating system. Three different units were prepared far the comparison of heat recovery performance; A-type is exactly the same with the typical one fabricated for previous study of analyzing heat recovery performance in greenhouse heating system, other two types (B-type and C-type) modified from the control unit are different in the aspects of airflow direction (U-turn airflow) and pipe arrangement. The results are summarized as follows ; 1. In the case of Type-A, when considering the initial cost and current electricity fee required for system operation, it was expected that one or two years at most would be enough to return the whole cost invested. 2. Type-B and Type-C, basically different with Type-A in the aspect of airflow pattern, are not sensitive to the change of blower capacity with higher than 25m$^3$.min$^{-1}$ . Therefore, heat recovery performance was not improved so significantly with the increment of blower capacity. This was assumed to be that air flow resistance in high air capacity reduced the heat exchange rate as well. Never the less, compared with control unit, resultant heat recovery rate of Type-B and Type-C was improved by about 5％ and 13％, respectively 3. Desirable blower capacity of these heat recovery units experimented were expected to be about 25m$^3$.min$^{-1}$ , and at the proper blower capacity, U-turn airflow units showed better heat recovery performance than control unit. But, without regard to the type of heat recovery unit, it was recommended that comprehensive consideration of system's physical factors such as pipe arrangement density, unit pipe length and pipe thickness, etc., was required for the optimization of heat recovery system in the aspects of not only energy conservation but economic system design.

• Tuberculosis and Respiratory Diseases
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• v.82 no.1
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• pp.81-85
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• 2019

Background: Bronchoscopy is a useful diagnostic and therapeutic tool. However, the clinical use of high-flow nasal cannula (HFNC) in adults with acute respiratory failure for diagnostic and invasive procedures has not been well evaluated. We present our experiences of well-tolerated diagnostic bronchoscopy as well as cases of improved saturation in hypoxaemic patients after a therapeutic bronchoscopic procedure. Methods: We retrospectively reviewed data of hypoxaemic patients who had undergone bronchoscopy for diagnostic or therapeutic purposes from October 2015 to February 2017. Results: Ten patients (44-75 years of age) were enrolled. The clinical purposes of bronchoscopy were for diagnosis in seven patients and for intervention in three patients. For the diagnoses, we performed bronchoalveolar lavage in six patients. One patient underwent endobronchial ultrasonography with transbronchial needle aspiration of a lymph node to investigate tumour involvement. Patients who underwent bronchoscopy for therapeutic interventions had endobronchial mass or blood clot removal with cryotherapy for bleeding control. The mean saturation ($SpO_2$) of pre-bronchoscopy in room air was 84.1%. The lowest and highest mean saturation with HFNC during the procedure was 95% and 99.4, respectively. The mean saturation in room air post-bronchoscopy was 87.4%, which was 3.3% higher than the mean room air $SpO_2$ pre-bronchoscopy. Seven patients with diagnostic bronchoscopy had no hypoxic event. Three patients with interventional bronchoscopy showed improvement in saturation after the procedure. Bronchoscopy was well tolerated in all 10 cases. Conclusion: This study suggests that the use of HFNC in hypoxaemic patients during diagnostic and therapeutic bronchoscopy procedures has clinical effectiveness.