• International Journal of Highway Engineering
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• v.15 no.5
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• pp.75-79
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• 2013

PURPOSES : The objective of this study is to evaluate the environmental resistance of bio-polymer concrete for use of pavement materials developed for reducing the carbon-dioxide. METHODS : The compression, tension, and bending strength tests were conducted on the bio-polymer concrete specimens with and without environmental conditioning. The specimens were conditioned using the freezing-thaw and accelerated weathering process for long period of time. To assess the resistance against chloride, the chloride ion penetration resistance tests were carried out on the bio-polymer concrete specimens. RESULTS : Test results show that the maximum difference in strength between specimens with and without conditioning is about 2.6MPa indicating that the effect of environmental conditioning on specimen strength is negligible. Based on the chloride ion penetration resistance test, the penetration quantity of electric charge of the specimens is zero and there is no ion penetration within the bio-polymer concrete. CONCLUSIONS : It is found from this study that there is slight change in strength of bio-polymer concretes before and after environmental conditioning process and no chloride ion penetration observed in these specimens. Therefore, the developed bio-polymer concretes can be applied effectively as pavement materials due to the small change of physical properties with environment change.

• Proceedings of the SAREK Conference
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• 2005.06a
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• pp.7-7
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• 2005

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.402-405
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• 2006

The diffuser noise of HVAC(heating ventilating and air-conditioning) uses dB(A) or NC as a indoor noise criteria that ASHRAE represents, and there is no specific guide line for application. According to the previous study, there are some problems like that even though the sound level of sound source is same, the NC shows different values, which makes the noise rating confused. This problem is caused by the frequency characteristics of sound source and its sound level. Therefore, appropriate evaluation method should be considered based on the subjective responses. This study aims to analyze the physical parameters appropriate for the evaluation of HVAC diffuser noise. To achieve this, recording of sound sources, calculation of physical parameters and psycho-acoustic experiment were carried out and the results were derived from the correlation analysis between physical parameters and subjective evaluatio

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.23 no.6
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• pp.421-429
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• 2011

Experimental and theoretical studies on cooling performance of two-channel thermoelectric air-cooling system in parallel flow are conducted. The effects of operating temperature to physical properties of thermoelectric module (TEM) are experimentally examined and used in the analysis of an air-cooling system considering thermal network and energy balance. The theoretical predicted temperature variation and cooling capacity are in good agreement with measured data, thereby validating analytic model. The heat absorbed rate increases with increasing the voltage input and decreasing thermal resistance of the system. The power consumption of TEM is linearly proportional to mean temperature differences due to variations of the physical properties on operation temperature of TEM. Furthermore thermal resistance of hot side has greater effects on cooling performance than that of cold side.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.20 no.12
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• pp.814-819
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• 2008

The purpose of this study was developing the building materials for creation the comfortable IAQ. By reducing formaldehyde(HCHO) known as the main factors of Sick House Syndrome. This material must be revealed the physical and eco-friendly performance, so this study set up the basic standards for building materials. The source of physical performance evaluation is Korea Industrial Standards and the base of environmental ability is the Eco Label considering certificated system related to an apartment house. Because the developed material was satisfied with the established standards, it was tested in mock-up room for obtaining the real date from indoor air. The mock-up test was conducted according environmental standard method for indoor air Quality of the ministry of environment. The result of this study were as follows; the functional building materials had a effect to reduce the formaldehyde concentration for a initial period without wall paper, so additional development is needed for application with the wall paper and the available period.

• The Journal of Korean Physical Therapy
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• v.12 no.3
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• pp.497-507
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• 2000

This study was performed to understanding on guidelines for using therapeutic modalities according to injury phases of soft tissue. Clinical decisions on how and when therapeutic modalities may be used should be based on recognition of signs and symptoms. as well as some awareness of the time frames associated with the various phases of the Healing process. The physical therapist must have a sound understanding of that process in terms of the sequence of the various process of healing stage. The results of this study are as follows: 1. Once an acute injury has occured, the healing process consists of the imflammatory response phase, the fibroblastic-repair phase, and the maturation-remodeling phase and can impede by various pathologic factors. 2. Modality use in the initial acute injury phase and the inflammatory response phase should be directed toward limiting the amount of swelling and reducing pain. 3. Modality use in the Fibroblastic repair phase may be change from cold to heat. The purpose of heat is to increase circulation to the injured area to promote healing. 4. During the Maturation-Remodeling phase, some type of heating modalities, ultrasound, or short wave and microwave diathermy should be used to increase circulation to the deeper tissue. In this phases, physical therapists must control training and conditioning habits to allow the injury to heal sufficiently.

• Advances in concrete construction
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• v.15 no.1
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• pp.41-46
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• 2023

Sport has no age limit and can be done anywhere and in any condition with minimal equipment. The existence of sports spaces in all parts of the world is considered a citizen's right. One of the activities carried out in this field is installing sports equipment and structures in parks and encouraging citizens to use this equipment for physical health with the least cost and facilities. Installing sports structures in open spaces such as parks is a practical step for developing citizens' sports. Although using devices in parks is acceptable, it is more critical to meet scientific and technical standards. The components of these structures must have high strength and endurance against changes in environmental conditions such as humidity, temperature difference, and corrosion. Among the various causes of material degradation, corrosion has always been one of several fundamental causes of metal equipment failure. Sports structures in open spaces are not safe from corrosion. Uniform corrosion is the most common type of corrosion. This corrosion usually occurs uniformly through a chemical or electrochemical reaction across the surface exposed to the corrosive environment. Rust and corrosion of outdoor sports structures are examples of this corrosion. For this reason, in this research, with the green synthesis of silica nanoparticles and its application in outdoor sports structures, the life span of these structures can be increased for the use of physical exercises as well as their quality.

• International Journal of Air-Conditioning and Refrigeration
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• v.6
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• pp.93-103
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• 1998

The nucleate boiling heat transfer experiments are performed using a ternary refrigerant R407C which is a candidate of alternatives of HCFC 22. The boiling phenomena of R-32, R-125 and R-134a which are the constituent refrigerants of R407C are also investigated. The nucleate boiling heat transfer coefficients of R407C are less than those of HCFC 22 which have the similar physical and transport properties. In our experimental pressure range, which is similar to the operational pressure of air conditioning system, the deterioration of boiling heat transfer coefficients of mixture refrigerant R407C does not appear for moderate wall superheat region. Since nucleate boiling heat transfer coefficients cannot be obtained from ideal mixing law of mixture, Thome's method was used to predict. To account for the heat flux effect and system pressure in Thome's method, the correcting factor, a(P.L1T), was introduced and obtained from experiments for ternary refrigerant R407C.

• International Journal of Air-Conditioning and Refrigeration
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• v.11 no.1
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• pp.1-9
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• 2003

The examinations of the operating mechanism of an oscillating capillary tube heat pipe (OCHP) using the visualization method revealed that the working fluid in the OCHP oscillated to the axial direction by the contraction and expansion of vapor plugs. The contraction and expansion were due to the formation and extinction of bubbles in the evaporating and condensing part, respectively The actual physical mechanism, whereby the heat which was transferred in such an OCHP was complex and not well understood. In this study, a theoretical model of the OCHP was developed to model the oscillating motion of working fluid in the OCHP. The differential equations of two-phase flow were applied and simultaneous non-linear partial differential equations were solved. From the analysis of the numerical results, it was found that the oscillating motion Of working fluid in the OCHP was affected by the operation and design conditions such as the heat flux, the charging ratio of working fluid and the hydraulic diameter of flow channel. The simulation results showed that the proposed model and solution could be used for estimating the operating mechanism in the OCHP.

• Journal of Korean Public Health Nursing
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• v.14 no.2
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• pp.191-202
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• 2000

This study was conducted for 39 patients who are recipients of allogeneic hemopoietic stem cell transplantation at BMT ward of St. Mary's hospital affiliated to Catholic University of Korea from April to September 1999. The subjects were devided into two groups; those who received both TEl and chemo therapy as conditioning regimen (TEl group). and those who used chemo agents as singular conditioning regimen (chemo group). The oral intake status of the two groups were compared through physical assessment and blood chemistry exam of the subjects, and factors influencing their nutritional change and oral intake were explored in each stage of the transplantation (six stages: admission, conditional stage, date of transplantation, one week after transplantation, two weeks after transplantation, and three weeks after transplantation). The prior aim of the study was to provide baseline data to minimize delayed treatment from nutritional deficiency of the subjects. The results were as follows: 1. TBI group was significantly decreased of oral calorie intake in two weeks after transplantation compared to admission and conditioning stage while that of chemo group was significantly decreased on the date of transplantation. 2. TBI group was significantly decreased of protein intake in two weeks after transplantation compared to admission and conditioning stage. In chemo group, protein intake was significantly decreased on the date of transplantation compared to admission. It was remarkable that TBI group showed lesser protein intake than chemo group. 3. Both group were significantly decreased of BMI in one week and three weeks after transplantation compared to admission. TBI group showed significantly higher BMI than chemo group. 4. Both group were significantly decreased of Triceps Skinfold Thickness (TST)on the date of transplantation compared to admission stage. 5. TBI group was significantly decreased of mid-arm muscle circumference (MAMC) in two weeks after transplantation compared to admission, conditioning, date of transplantation. 6. TBI group was significantly decreased of albumin level in two weeks after transplantation compared admission stage. In chemo group, it was significantly decreased on the date of transplantation compared to admission, three weeks after the transplantation. 7. TBI group was significantly decreased of transferrin level in two weeks after transplantation compared admission, conditioning, date of transplantation and one week after transplantation. In chemo group, it was decreased of transferrin level in 3 weeks after transplantation. 8. Oral intake of TEl group was impacted by vomiting before transplantation and gingivitis after transplantation. In chemo group, it was impacted by vomiting before transplantation and by two factors, gingivitis and nausea, after transplantation. The results showed oral calorie intake was not different between the two groups while protein intake was significantly lower in TBI group than chemo group. Oral intake was significantly impacted by vomiting before transplantation in both groups, but affected by oral gingivitis in TBI group and gingivitis and nausea in chemo group after transplantation. This findings present that standardized strategies to manage nutrition and gingivitis more effectively are desperately needed to enhance oral intake and protein intake of patients who receive TBI as conditioning regimen.