• Korean Journal of Materials Research
• /
• v.15 no.12
• /
• pp.780-785
• /
• 2005

To investigate the microcrack healing behavior of $Si_3N_4-20wt\%SiC-8wt\%Y_2O_3$ composite ceramics(SNCY8), we observe the crack length evolution a! the time of 20, 40, 60 minutes with in-situ optical microscopy by varying healing temperature of $800\~1200^{\circ}C$. Crack healing obviously occurred as heating temperature and time increased. We proposed a simple model of effective diffusion based on the crack length evolution with healing condition, and determined the effective diffusion coefficient as Our result implies that we may predict the healing ability quantitatively with temperature and time in structural ceramics through the effective diffusion coefficient model.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.8 no.7
• /
• pp.1093-1101
• /
• 2013

This paper demonstrates that 'Qi Energy Healing' effects on elevation of capabilities in regards with the autonomic nervous system which prevents from the stress. Nineteen participants were assigned into 'Qi Energy Healing' and the 'Ordinary Relaxation' condition. Participants were examined to see the difference of frequency domain analysis, heart rate tachogram, physical resistance through the heart rate variability. The 'Qi Energy Healing' is significantly more likely to influence on reducing and diminishing the stress. 'Qi Energy Healing' treatment showed clear distinction on 6 fact. Our findings established the link between effectiveness of 'Qi Energy Healing' and the autonomic nervous system.

• Proceedings of the KIEE Conference
• /
• 2000.07c
• /
• pp.2110-2112
• /
• 2000

This paper describes the self healing characteristics of a metalized polypropylene film(MPPF) used for energy storage capacitors. In the experiment, a d.c. voltage was applied to the MPPF, and the partial discharge inception voltages(PDIVs), the applied voltages at self healing, the burn out area and the current in the grounding conductor were measured and recorded. As a result, it was found that no PDs were found till the first pre-self healing occurred, and the applied voltage at self healing was increased with PPF thickness. Self healing was much more dependant on the shape of the air void than its diameter and the burn out area and the current in the grounding conductor at self healing was also increased with the applied voltage at self healing.

• International Journal of Highway Engineering
• /
• v.7 no.2 s.24
• /
• pp.69-76
• /
• 2005

While the repeated traffic loading accumulates the damage of asphalt pavement, the damage has being healed during rest periods. And then, this healing enhances the fatigue life of asphalt pavement. A method was developed to determine the healing rate of asphalt mixture in terms of recovered dissipated creep strain energy (DCSE) per unit time, and the healing properties of four different asphalt mixtures were evaluated. The test procedure consists of repeated loading test and periodical resilient modulus tests. A normalized healing rate in terms of $DCSE/DCSE_{applied}$ was defined to evaluate the healing properties independently of the amount of damage incurred in the mixture. From the test results, it was concluded that the healing rates of asphalt mixtures were increased exponentially as the temperature was increased and more affected by the structural characteristics of mixture such as asphalt content than the binder characteristics such as the polymer modification.

• KEPCO Journal on Electric Power and Energy
• /
• v.7 no.2
• /
• pp.295-299
• /
• 2021

Recently, interest in maintenance has been increasing due to the enlargement and aging of infra structures. Therefore, a new paradigm is required to secure and improve the durability of structures differentiated from the past. Accordingly, research on smart concrete incorporating the concept of self-healing into concrete is being actively conducted. In this study, the crack healing performance and durability performance of self-healing concrete applied with a hydrogel containing biomineral-forming microorganisms were evaluated. As a result of evaluating the dispersion of the hydrogel in concrete, it was confirmed that the hydrogel was well distributed in concrete matrix with a dispersion coefficient of 0.35 to 0.46. The crack healing performance evaluation was verified by a water permeability test, and showed a recovery rate of 95% or more at the age of 28 days, confirming the applicability of self-healing concrete. The durability performance of self-healing concrete was evaluated in terms of resistance to penetration of chloride ion and freezing and thawing. Regardless of the mixing of the hydrogel, the same level of durability performance was shown for various compressive strength level. Therefore, it was confirmed that the microbial admixture did not affect concrete durability. In the future, long-term crack healing performance and durability verification studies should be supplemented.

• Korean Journal of Veterinary Research
• /
• v.37 no.3
• /
• pp.629-637
• /
• 1997

This study was performed to determine the optimal dose of laser energy for wound healing. The skin wound with 8mm diameter was induced over the lumbar vertebrae of the rats, and wound squares, scab hardness, hematologic findings and histopathlogic findings according to irradiation of laser energy were studied. 1. Wound square was significantly reduced at Day 1 (p<0.01), 2 (p<0.01), 3 (p<0.05), 7 (p<0.01) and 8 (p<0.05), respectively in experimental groups, especially group II, compared with control group. 2. Scab hardness was significantly increased at Day 1 (p<0.01), 2 (p<0.01), 3 (p<0.05), 5 (p<0.01) and 7 (p<0.01), respectively in experimental groups, especially group II, compared with control group. 3. In hematological findings, red blood cells and white blood cells in experimental group were increased according to the lapse of days, but they were not significant. 4. In histopathologic findings, experimental groups, especially group II, revealed early scab formation, early appearance of phagocytes and fibroblast, rapid growth of granulation tissue and collagen, and promotion of wound healing in the result.

• Tunnel and Underground Space
• /
• v.33 no.1
• /
• pp.42-56
• /
• 2023

In deep geological disposal of high-level radioactive waste (HLW), the natural barrier must physically support the disposal facility and delay the movement of radionuclides for at least hundreds of thousands of years. To evaluate the long-term geological evolution of the natural barriers, it is essential to analyze the long-term behavior of rock joints, including the frictional healing behavior. This study aimed to experimentally analyze the frictional healing behavior of rock joints under hydro-mechanical (H-M) conditions through the slide-hold-slide (SHS) test. The SHS tests were performed under mechanical and H-M conditions for joint specimens of different roughness. In the H-M conditions, the frictional healing rate tended to increase, which was more evident in the specimens with large roughness. In addition, it was confirmed that the effect of the hydro-mechanical conditions was more significant when the effective normal stress acting on the joint surface was small. These results are expected to be used as fundamental data to understand the frictional healing behavior of rock joints in the natural barriers.

• Journal of the Korean Society for Precision Engineering
• /
• v.20 no.12
• /
• pp.198-204
• /
• 2003

The bone fracture healing is simulated by using one of the complex system rules, named cellular automata method. It is assumed that each cell has property of Bone, Cartilage or Fibrous connective tissue. Nine local rules are adopted to change the property of each cell against the mechanical stimulus, which consists of the strain energy density, and the existence of bone in the surroundings. Two dimensional sheep metatarsal model is considered and the bone fracture healing is simulated. The simulation results agree well with those obtained by using fuzzy logic model and experimental data. The cellular automata method found to be one of the simulation methods to express the bone fracture healing. The cellular automata method is expected to be effective in representing biological phenomenon.

• Journal of The Korea Institute of Healthcare Architecture
• /
• v.18 no.3
• /
• pp.29-39
• /
• 2012

Window and shading designs have a great influence on energy consumption and daylighting in buildings. As far as energy is concerned, small window area is advantageous. But it is not good to the patient healing in hospital. So it is important to find out the optimum window shape which is favorable for both energy consumption and patient healing. In this study, annual energy consumption and daylight illumination levels were analyzed according to the window shapes and shading devices for a multi-beded patient room in hospitals. The simulations were conducted for 19 different cases by COMFEN 4.0 computer simulation program. The results of this paper are as follows. First, window to wall area ratio and shading devices have great influences on annual energy consumption. But it is a problem in that they decrease significantly daylight level in bed room. Second, considering the same energy consumption, reducing the width of window rather than the hight of window is desirable for the secure of daylight level. Third, increase of the number of horizontal shade is not desirable in south face of the building for the energy consumption and daylight level. Fourth, sun shade is not necessary in north face of the building for the energy consumption and daylight level.

• Journal of the Korean Recycled Construction Resources Institute
• /
• v.10 no.4
• /
• pp.531-538
• /
• 2022

In this study, the self-healing hybrid capsules were prepared, were mixed with 3 %, 5 %, and 7 % based on cement mass. The healing performance were evaluated according to mixing ratio self-healing hybrid capsule. As a result of the experiment, it was found that the crack healing performance improved as the mixing rate of the self-healing hybrid capsule increased, but the quality performance tended to decrease. Therefore, it is judged that using the mixing ratio of the hybrid capsule within 5 % reduces the quality performance to within about 10 % and secures about 90 % or more of the healing performance.