• Journal of the Korean Society of Propulsion Engineers
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• v.22 no.3
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• pp.97-108
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• 2018

It is definitely important to measure thrust during ground test when developing air-breathing engine, and in case of air-breathing engine, gross thrust should be calculated considering not only the measured thrust but also the force induced by the air flow of engine intake. Also, side thrust like yaw and pitch should be measured and analyzed using multi-component thrust measurement system. Engine performance was accurately evaluated by calculating the gross thrust of air breathing engine precisely which is analyzed from below serial procedure: labyrinth seal isolation, 1-axis gross thrust calculation, develop multi-component thrust measurement system, and side thrust analysis.

• Fire Science and Engineering
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• v.18 no.4
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• pp.16-21
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• 2004

This paper has investigated influences of pollutants in air-breathing on the respirators and it by year of disused air respirators that fire fighter is using in domestic cutting done air respirators after collection observed state of cylinder material through instrumental analysis, and cut open pipe to confirm pollution degree of pipe from cylinder of air respirators to airline mask and confirm pollution availability. The metal surface inside the air respirators was corroded by moisture included in the compressed air. The material generated by corrosion is white powder of less then 100㎛, which is analyzed as aluminum hydroxide corroded by moisture. This aluminum hydroxide powder may get into the lung while one breathes in, and it is easy to be attached to the lung so it will cause a serious influences to human health. This study suggests that Korea should set out the standards for components and composition of breathing air as soon as possible.

• Journal of The Korean Society of Integrative Medicine
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• v.7 no.2
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• pp.133-139
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• 2019

Purpose : This study aims to investigate the rating of perceived exertion (RPE) and muscle activity of the inspiratory primary and accessory muscle during breathing exercise with different air hole diameters of the inspiratory muscle trainer (IMT). Methods : The Borg's scale and surface electromyography (EMG) was used to collect data of the RPE and muscle activity of the inspiratory primary the external intercostal (EI) and diaphragm (DIA) and accessory muscles anterior scalene (AS), sternocleidomastoid (SCM), pectoralis major (PM), and upper trapezius (UT) muscles during breathing exercise with different air hole diameters (6 mm, 4 mm, and 2 mm) of the IMT in healthy young male subjects. Results : The RPE and muscle activities of the AS, SCM, and UT are increased significantly in accordance to the decreasing diameter of air hole of air tip in IMT. However, there are no differences in the muscle activities of the PM, EI, and DIA based on differences of diameters of air hole of air tip in IMT. Conclusion : The smaller the diametr of IMT air-hole, RPE and muscle activities of AS, SCM and UT were increased. Therefore, further study would be necessary to investigate the proper intensity and relaxation posture for the exercise protocol to strengthen the inspiratory primary muscles.

• Journal of Korean Academy of Nursing
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• v.29 no.6
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• pp.1304-1313
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• 1999

Breathing is essential for life and at the same time takes a role as a antidote for stress. In the Orient, it was recognized early that respiration, mind, and body have a relation that is inseparable and therefore proper breathing is so important. However, since the mechanism of therapeutic effect by breathing have not been verified, the treatment has been continued till recent years. From that which originated in the Orient, several techniques in the west have been developed to regulate breathing, and have been applying to the clinical situation and to studies, however scientific studies are still lacking. Recently, relaxed breathing has been used as an efficient strategy for breathing therapy as it has an effect on reducing physiological tension and arousal, and, therefore can be used as a basic technique to control or manage stress. In this study, in order to provide basic information and guidelines for clinical application, which will aid in the application of the theoretical basics of breathing therapy and its technique, a review of the literative was conducted. The findings are as follows: 1. Since proper breathing not only has, physically, the important function in supplying oxygen to the body but also gives a good emotional, or pleasant state of mind, it is the first step in controlling physical and mental health. 2. The basic types of breathing can be classified into two types; ‘diaphragmatic breathing(relaxed breathing)’ and ‘chest breathing(stress breathing)’. In yoga type breathing, there are four kinds of breathing, ‘upper breathing’, ‘mid breathing’, ‘down breathing’, and ‘complete breathing’. 3. The theoretical explanation of the positive thera peutic effect of breathing therapy techniques exemplifies good brain function, sufficient air flow through the nasal passages, diaphragmatic movement, light vagal stimulation, CO2 changes and cognitive diversion but in most studies, the hypothesis of CO2 is supported. 4. The technique of breathing is designated with many names according to the muscles and techniques used for breathing, and for control of stress, diaphragmatic breathing(relaxed breathing) is explained as a basic technique best used to manage of stress. 5. The relaxed-breathing includes slow diaphragmatic breathing, breath meditation, nasal breathing, yogic abdominal breathing, Benson's relaxed response, and quiet response.

• Advances in Energy Research
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• v.2 no.2
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• pp.73-84
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• 2014

Fuel cells of proton exchange membrane type (PEMFC) working with hydrogen in the anode and ambient air in the cathode ('air breathing') have been prepared and characterized. The cells have been studied with variable thickness of the cathode catalyst layer ($L_{CL}$), maintaining constant the platinum and ionomer loads. Polarization curves and electrochemical active area measurements have been carried out. The polarization curves are analyzed in terms of a model for a flooded passive air breathing cathode. The analysis shows that $L_{CL}$ affects to electrochemical kinetics and mass transport processes inside the electrode, as reflected by two parameters of the polarization curves: the Tafel slope and the internal resistance. The observed decrease in Tafel slope with decreasing $L_{CL}$ shows improvements in the oxygen reduction kinetics which we attribute to changes in the catalyst layer structure. A decrease in the internal resistance with $L_{CL}$ is attributed to lower protonic resistance of thinner catalyst layers, although the observed decrease is lower than expected probably because the electronic conduction starts to be hindered by more hydrophilic character and thicker ionomer film.

• 한국신재생에너지학회:학술대회논문집
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• 2008.05a
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• pp.45-48
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• 2008

This paper presents a passive air-breathing direct methanol fuel cell (DMFC) which has been designed and tested. The single cell is fuelled by methanol vapor that is supplied through flow channel from a methanol reservoir at the anode, and the oxygen is supplied via natural air-breathing at the cathode. The methods for supplying the methanol vapor to the single cell were parallel channel and chamber. This research investigates various methods to identify the effects of using flow channels for providing the methanol vapor at the anode, and the opening ratio between the inlet and outlet ports for the methanol flow at the anode. The best flow channel condition for passive DMFC was a chamber, and the opening ratio was 0.8. Under these conditions, the peak power was 10.2mW/$cm^2$ at room temperature and ambient pressure. The key issues for the Passive DMFCs for using methanol vapor are that sufficient methanol needs to be supplied using a large as possible opening ratio. However, it is shown that the performance of the passive DMFC, which has a channel at the anode,is low due to the low differential pressure and insufficient methanol supply rate.

• Transactions of the Korean hydrogen and new energy society
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• v.20 no.4
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• pp.300-308
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• 2009

In a pursuit of the development of alternative mobile power sources with a high energy density, a planar and air-breathing PEMFCs with a new type of hydrogen cartridge which uses onsite $H_2$ generated from sodium borohydride ($NaBH_4$) hydrolysis have been investigated for use in advanced power systems. Two types of $H_2$ generation through $NaBH_4$ hydrolysis are available: (1) using organic acids such as sulphuric acid, malic acid, and sodium hydrogen carbonate in aqueous solution with solid $NaBH_4$ and (2) using solid selected catalysts such as Pt, Ru, CoB into the stabilized alkaline $NaBH_4$ solution. It might therefore be relevant at this stage to evaluate the relative competitiveness of the two methods mentioned above. The effects of flow rate of stabilized $NaBH_4$ solution, MEA (Membrane Electrode Assembly) improvement, and type and flow control of the catalytic acidic solution have been studied and the cell performances of the planar, air-breathing PEMFCs using $NaBH_4$ has been measured from aspects of power density, fuel efficiency, energy density, and fast response of cell. In our experiments, planar, air-breathing PEMFCs using $NaBH_4$ achieved to maximum power density of 128mW/$cm^2$ at 0.7V and energy efficiency of 46% and has many advantages such as low operating temperature, sustained operation at a high power density, compactness, the potential for low cost and volume, long stack life, fast star-up and suitability for discontinuous operation.

• Journal of The Korean Society of Integrative Medicine
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• v.9 no.3
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• pp.203-211
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• 2021

Purpose : It was to compare changes in respiratory function (pulmonary function, inspiratory function) after four weeks of inspiratory muscle strengthening training (diaphragmatic breathing with upper arm exercise, Power-Breathe breathing) for 36 healthy people. Methods : Subjects were randomly assigned to diaphragmatic breathing with upper arm exercise (Group I) and Power-breathe breathing (Group II) was conducted by the protocol for four weeks five times per week. As the main measurement method for comparison between groups For pulmonary function, Forced Vital Capacity (FVC) and Forced Expiratory Volume at One second (FEV1) were used, and for inspiratory function, Maximum Inspiratory Capacity (MIC), Maximum Inspiratory Pressure (MIP), and Maximum Inspiratory Flow Rate (MIFR) were used. Results : In changes in pulmonary function between groups, FVC and FEV₁ showed no significant difference, and in inspiratory function changes, MIC showed no significant difference, but in MIP and MIFR, Group B significantly improved over Group A. Conclusion : The progressive resistance training using the Power-breath device applied to the inspiratory muscle did not show a significant difference in the increase in the amount of air in the lungs and chest cage compared to the diaphragmatic breathing training accompanied by the upper arm exercise. However, by increasing the air inflow rate and pressure, it showed a more excellent effect on improving respiratory function.

• International Journal of Advanced Culture Technology
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• v.8 no.4
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• pp.95-100
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• 2020

Recently, the problem of hypoxia caused by jogging is attracting attention. To solve this problem, this paper proposed a new solution. This paper proved that as a vocalization method of reading aloud, it is possible to increase air intake and activate lung function to exchange more air and obtain more oxygen. Then, blood oxygen saturation was used as an evaluation index for the body's oxygen content level to prove its effectiveness. A photoelectric pulse oximeter developed on the basis of different light absorption principles in blood was used to test blood oxygen saturation. Experimental results show that a certain degree of hypoxia is induced when a lot of oxygen is required due to jogging. Therefore, it was proved that the new vocal breathing method by reading books can increase the blood oxygen saturation of the body and improve the hypoxia of the body. Reading vocal breathing is a simple and efficient oxygen saturation recovery breathing method.

• Journal of Environmental Science International
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• v.4 no.5
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• pp.61-61
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• 1995

Volatile organic compounds(VOCs) are of concern for their potential chronic toxicity, their suspected role in the formation of smog, and their suspected role in destruction of stratospheric ozone. Present study evaluated the exposures to selected VOCs in three microenvironments: 2 chlorinated and 5 aromatic VOCs in the indoor and outdoor air, and 5 aromatic VOCs in the breathing zone air of gas-service station attendants. With permissible Quality Assurance and Quality Control performances VOC concentrations were measured 1) to be higher in indoor air than in outdoor air, 2) to be higher in two Taegu residential areas than in a residential area of Hayang, and 3) to be higher in the nighttime than in the daytime. Among five aromatics, Benzene and Toluene were two most highly measured VOCs in breathing zone air of service station attendants. Based on the sum of VOC concentrations, the VOC exposure during refueling was estimated to be about 10% of indoor and outdoor exposures. For Benzene only, the exposure during refueling was estimated to cause about 52% of indoor and outdoor exposure. The time used to calculate the exposures was 2 minutes for refueling and 24 hours for indoor and outdoor exposures.