• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.240-240
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• 2009

We developed the low level laser therapy(LLLT) apparatus for external injury cure using a GaAsP Diode. This equipment was fabricated by using GaAsP diode and a microcontroller, and designed to enable us to control light irradiation timer, and frequency. In this paper, the designed device was used to find out how GaAsP diode light source affects the skin wound of RAT. In the experiment, $1cm^2$ wounds on the External injury of RAT were made. Light irradiation RAT and none light irradiation RAT divided, each RAT was irradiated 20 min a day for 9 days. In result, compared with none light irradiation RAT, the lower incidence of inflammation and faster recovery was shown in light irradiation RAT.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.12
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• pp.1209-1215
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• 2012

Experiments with premixed flames in a tube have been conducted to investigate the transition phenomenon from a laminar flat flame to turbulent motions. To induce this phenomenon, a flat flame is formed in a tube. Then, the local velocity at the center of the flat flame surface is increased using $CO_2$ laser irradiation. The deformed flame front propagates with an increase in the total flame surface and oscillating instability. Eventually, the flame front accelerates explosively, and it shows turbulent flame motions with a strong noise. The dynamic behaviors of the flame front prior to the turbulent motions are analyzed in this study to elucidate this process. The physical model of the process is presented according to observations.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.407-408
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• 2011

Natural boron consists of two stable isotopes 10B and 11B with natural abundance of 18.8 atom percent of 10B and 81.2 atom percent of 11B. The thermal neutron absorption cross-section for 10B and 11B are 3837 barn and 0.005 barn respectively. 10B enriched specific compounds are used for control rods and as a reactor coolant additives. In this work 2 methods for boron enrichment were analysed: 1) Gas irradiation in static conditions. Dissociation occurs due to multiphoton absorption by specific isotopes in appropriately tuned laser field. IR shifted laser pulses are usually used in combination with increasing the laser intensity also improves selectivity up to some degree. In order to prevent recombination of dissociated molecules BCl3 is mixed with H2S 2) SILARC method. Advantages of this method: a) Gas cooling is helpful to split and shrink boron isotopes absorption bands. In order to achieve better selectivity BCl3 gas has to be substantially rarefied (~0.01%-5%) in mixture with carrier gas. b) Laser intensity is lower than in the first method. Some preliminary calculations of dissociation and recombination with carrier gas molecules energetics for both methods will be demonstrated Boron separation in SILARC method can be represented as multistage process: 1) Mixture of BCl3 with carrier gas is putted in reservoir 2) Gas overcooling due to expansion through Laval nozzle 3) IR multiphoton absorption by gas irradiated by specifically tuned laser field with subsequent gradual gas condensation in outlet chamber It is planned to develop software which includes these stages. This software will rely on the following available software based on quantum molecular dynamics in external quantized field: 1) WavePacket: Each particle is treated semiclassicaly based on Wigner transform method 2) Turbomole: It is based on local density methods like density of functional methods (DFT) and its improvement- coupled clusters approach (CC) to take into account quantum correlation. These models will be used to extract information concerning kinetic coefficients, and their dependence on applied external field. Information on radiative corrections to equation of state induced by laser field which take into account possible phase transition (or crossover?) can be also revealed. This mixed phase equation of state with quantum corrections will be further used in hydrodynamical simulations. Moreover results of these hydrodynamical simulations can be compared with results of CFD calculations. The first reasonable question to ask before starting the CFD simulations is whether turbulent effects are significant or not, and how to model turbulence? The questions of laser beam parameters and outlet chamber geometry which are most optimal to make all gas volume irradiated is also discussed. Relationship between enrichment factor and stagnation pressure and temperature based on experimental data is also reported.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.34 no.4
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• pp.311-316
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• 2008

In this study, we have investigated the effects of ultraviolet (UV) irradiation on the external and internal structure of human hair. For changes in morphological and chemical structure of UV-exposed hair, we utilized several microscopic techniques such as scanning electron microscope (SEM), transmission electron microscope (TEM), confocal laser scanning microscope (CLSM), and etc. The SEM showed the scales of UV-exposed hair appeared to be rough and bulkier because of chemical oxidation during UV irradiation. Small bulgy area of UV_exposed hair surface was appeared as a result of the decomposition in cysteic acid. In the TEM picture the UV-exposed hair showed the cleaved aperture of hair and destruction of melanin granules. Three dimensional topographical images were obtained by using CLSM. In the optical single section, high fluorescent intensity appeared in virgin hair. In the case of UV-exposed hair, low fluorescence intensity appeared. This means the aromatic amino acids in virgin hair were more abundant than UV-exposed hair.