• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.25 no.11
• /
• pp.606-611
• /
• 2013

In responding to the recent framework convention on climate change, and the rise of the need for energy efficient buildings, such as Zero Energy Buildings (ZEB), domestic insulation standards and energy conservation regulations are being reinforced, to prevent heat loss. Accordingly, the Ministry of Land, Infrastructure and Transport have made amendments in Chapter 21 "Enforcement regulations for building facilities standards etc.", and Chapter 22 "Energy conservation standard", to reflect these changes. To effectively implement these regulations, it is required to propose air-tightness test methods, and establish air-tightness standards, based on the air leakage characteristics of domestic apartment housings. This research has been done primarily to collect basic technical data, to provide guidance for the establishment of domestic air-tightness standards for new apartment housing, through studying air-tightness test methods, field measurement on air-tightness of new apartment housings, and air leakage characteristics of major developed countries.

• Journal of the Korean Society for Heat Treatment
• /
• v.18 no.3
• /
• pp.164-171
• /
• 2005

Iodine-Induced Stress Corrosion Cracking (ISCC) properties of Zircaloy-4 and HANA4 developed in KAERI for the high burn-up nuclear fuel cladding were evaluated. To confirm the effect of final heat treatment on ISCC resistance of Zr-alloy, stress relieved and recrystallized specimens were prepared and tested. With the pre-cracked specimen at internal surface, ISCC crack propagation rates and threshold stress intensity factor ($K_{ISCC}$) based on the fracture mechanics were measured by internal pressurization test at $350^{\circ}C$ in iodine environment. $K_{ISCC}$ of Zircaloy-4 and HANA4 cladding were $3.3MPa{\cdot}m^{1/2}$ and $4.4MPa{\cdot}m^{1/2}$, respectively. Pitting corrosion at the crack surface was observed and it seemed that TG crack propagation was derived from the pitting.

• Journal of Energy Engineering
• /
• v.12 no.2
• /
• pp.74-83
• /
• 2003

In the advanced nuclear power plants including APR1400, the SDVS (Safety Depressurization and Vent System) is adopted to increase the plant safety using the concept of feed-and-bleed operation. In the case of the TLOFW (Total Loss of Feedwater), the POSRV (Power Operated Safety Relief Value) located at the top of the pressurizer is expected to open due to the pressurization of the reactor coolant system and discharges steam and/or water mixture into the water pool, where the mixture is condensed. During the condensation of the mixture, thermal-hydraulic loads such as pressure and temperature variations are induced to the pool structure. For the pool structure design, such thermal-hydraulic aspects should be considered. Understanding the phenomena of the submerged steam jet condensation in a water pool is helpful for system designers to design proper pool structure, sparger, and supports etc. This paper reviews and evaluates the steam jet condensation in a water pool on the physical phenomena of the steam condensation including condensation regime map, heat transfer coefficient, steam plume, steam jet condensation load, and steam jet induced flow.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.16 no.9 s.114
• /
• pp.919-925
• /
• 2006

An accurate mathematical model for complex stiffness of the pneumatic spring would be necessary for an efficient design of a pneumatic spring used in vibration isolation tables for precision instruments such as optical devices or nano-scale equipments. A diaphragm, often employed for prevention of air leakage, plays a significant role of complex stiffness element as well as the pressurized air itself Therefore, effects of the diaphragm need to be included in the dynamic model for a more faithful description of dynamic behavior of pneumatic spring. But the complex stiffness of diaphragm is difficult to predict In an analytical way, since it is a rubber membrane of complicated shape in itself. Moreover, the diaphragm should be expandable in response to pressurization inside a chamber, which makes direct measurement of complex stiffness of diaphragm extremely difficult. In our earlier research, the complex stiffness of diaphragm was indirectly measured, which was just to eliminate the theoretical stiffness of pressurized air from the measured complex stiffness of the pneumatic spring. In order to reflect complex stiffness of inflated diaphragm on the total stiffness at the initial design or design improvement stage, however. it is required to be able to predict beforehand. In this paper, how to predict the complex stiffness of inflated rubber diaphragm by commercial FE codes (e.g. ABAQUS) will be discussed and the results will be compared with the indirectly measured values.

• The Journal of Internal Korean Medicine
• /
• v.40 no.6
• /
• pp.1152-1168
• /
• 2019

Objectives: The aim of this study was to present several proposals for future pulse diagnosis practice and research by investigating the trend of pulse diagnosis studies in Korea. Methods: We searched online medical databases, including National Discovery for Science Leaders (NDSL), the Oriental Medicine Advanced Searching Integrated System (OASIS), the Research Information Sharing Service (RISS), and the Korean Traditional Knowledge Portal (KTKP), for pulse diagnosis articles in Korea. We selected articles on pulse diagnosis but excluded duplicate articles, articles irrelevant to pulse diagnosis, and articles published in foreign countries. Results: In the first screening, 801 articles were selected. We found 251 articles and classified them according to category. The medical engineering field had 148 articles. A total of 24 articles were related to algorithms for pulse wave detection, 34 to sensors, five to pressurization technology, 16 to systems, 11 to remote medical service, five to mobiles, nine to trends, and 44 to basic research. The Korean medicine field had 103 articles. A total of 41 articles were devoted to literature reviews, 20 to case reports, 11 to constitutional medicine, six to experimental studies, and 25 to relevant research. Conclusion: More efforts to practice pulse diagnosis for various diseases should be made and the results actively published.

• 한국초전도학회:학술대회논문집
• /
• v.10
• /
• pp.125-127
• /
• 2000

We report high pressure synthesis of Sr$_{0.9}$Sm$_{0.1}$CuO$_2$. Powder x-ray diffraction showed that the synthesized compounds have infinite layer structure as a major component. Slow heating at the first stage of heating processes after pressurization resulted in several larger grains. The largest grain was found to have the longest edge length of about 100 micrometer. Through magnetic property measurement in superconducting state, we found that pinning in this compound has substantial difference from that of La doped infinite layer, which has no unpaired spin at Sr site.

• Steel and Composite Structures
• /
• v.26 no.1
• /
• pp.55-66
• /
• 2018

In this paper, the response of an underground fibreglass reinforced plastic (FRP) composite pipe system subjected to realistic loading scenarios that may be experienced by an actual buried pipeline is investigated. The model replicates an arbitrary site with a length of buried pipeline, passing through a $90^{\circ}$ bend and into a valve pit. Various loading conditions, which include effects of pipe pressurization, differences in response between stainless steel and fibreglass composite pipes and severe loss of bed-soil support are studied. In addition to pipe response, the resulting soil stresses and ground settlement are also analysed. Furthermore, the locations of potential leakage and burst have also been identified by evaluating the contact pressures at the joints and by comparing stresses to the pipe hoop and axial failure strengths.

• Proceedings of the Korea Contents Association Conference
• /
• 2005.11a
• /
• pp.115-118
• /
• 2005

Leakage of waterworks pipe line net cause loss of water resources, additional foundation of pressurization facilities from pressure loss and soil weakening near leaked pipe line, etc. This is difficult to maintain and manage waterworks pipe line net and to cause serious economic loss. Rate of accounted water is better by monitoring always water pressure and flux, etc. from isolated region, positively dealing with leakage accident and preventing leakage from occurring. Actually after isolating region, average rate of accounted water in this region is 88.94% by continuously monitering control of water pressure and inflow rate. It is about 9.44% more than that of Busan metropolitan city in 2003, 79.5%.

• Journal of the Korean Applied Science and Technology
• /
• v.14 no.2
• /
• pp.115-122
• /
• 1997

The field of printing use to pressurization ink using screen gassamer that is called screen printing. Existing cleaning solvent using screen printing are the organic solvents including aromatic compounds carried with poisonous and stench. Besides, cleaning method of current screen printing are for the most part mixed cleaning method of dipping and polish. Using 1,1,1-TCE, CFC-113 alternative system cleaning solvent be substituted for existing cleaning solvent against screen printing ink measured the cleaning efficiency according to gravimetric analysis method and property change of gassamer according to Image Analyzer. Also, Cleaning process system carry with excellent cleaning efficiency studied which was proposed new cleaning process including ultrasonic and vibration cleaning process be substituted for existing mixed cleaning method of dipping and polish.

• Journal of the Korean Society for Precision Engineering
• /
• v.25 no.11
• /
• pp.119-125
• /
• 2008

The objective of this study was to compare micro-scale friction coefficients with and without synovial fluid, and micro-scale measurements were performed using atomic force microscopy (AFM) with a $5{\mu}m$ spherical probe. Four cylindrical cartilage specimens were harvested from two fresh bovine humeral heads (4-6 months old). $Average{\pm}standard$ deviation values of the micro-scale AFM frictional coefficients calculated from the liner fit of friction versus normal force was $0.177{\pm}0.012$ and $0.130{\pm}0.010$ with and without synovial fluid coating on AFM probe respectively, showing its reduction by ${\sim}27%$ with synovial fluid. To the best of our knowledge, this experimental study investigates the first such comparisons of frictional response of articular cartilage with and without synovial fluid coating on AFM probe, and provides significant insights into the role of synovial fluid in the articular cartilage friction and lubrication independently of the confounding effect of fluid pressurization in the articular cartilage.