• 한국동물위생학회지
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• 제21권4호
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• pp.401-405
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• 1998

A male badger which showed depression and bloody diarrhea was submitted to Iksan Branch of Chonbuk Veterinary Service Laboratory for necropsy on May 1998. Grossly, paleness of the mucous membranes was observed and the small intestinal contents were hamorrhagic. The numerous tiny hookworms, sized in 5-10 mm and greyish-white in color, attached to the intestinal mucosa. Male bursa was well developed. Histologically, intestinal lumen was filled with hemorrhagic contents, which contained worms. The epithelial cells of the villi were underwent degeneration and lamina propria was infiltrated by lymphocytes and plasma cells, and goblet cells were hyperplastic. There were rounded cutting plates in the funnel-shaped buccal capsule and transverse striation on sheath in hookworm, ultrastructurally, which were consistent with Uncinaria sp. The shape of eggs were ellipsoidal and morula, and some eggs contained a mobile larva. It was concluded that this badger was infected with Uncinaria.

• 한국광학회:학술대회논문집
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• 한국광학회 1995년도 광학 및 양자전자학 워크샵 논문집
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• pp.138-148
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• 1995

A reduced description of the dynamics of carriers in excited semiconductors is presented. Fristly, a time-convolutionless equation of motion for the reduced density operator is derved from the microscopic Liouville wquation operator method. Secondly, the quantum kinetic equations for intercting electron-hole parirs near band-edge in semiconductors under an extermal optical field are obtained from the equation of motion for the reduced density operator. The non-Markovian optical gain of a driven semiconductor is derived including the many-body effects. plasma screening and excitinic effects are taken into account using as effective Hamiltonian in the time-dependent Hartree-Fock approximation. it is shown that the line shape of optical-gain spectra gain is enhanced by the exicitonic effects caused by the attrative electron-hole Coulomb interaction and the interference effects (renormalized memory effects) between the extermal driving filed and the intermal driving Filed and the stochastic reservoir of the system.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2005년도 춘계학술발표대회 개요집
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• pp.97-99
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• 2005

Laser arc hybrid process is actively researched as a new welding method since it has several advantages by the combination of laser beam and electric arc. By the coupling of two different heat sources, laser and arc mutually assist and influence. High power laser can make the deep keyhole and arc plasma can form the large bead shape. In this paper the effect of two different heat sources to weld bead are investigated and as a result of analysis, it is shown that the lower part of keyhole is heated by laser and the upper part of weld pool is dominantly heated by arc.

• Bulletin of the Korean Chemical Society
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• 제23권8호
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• pp.1127-1134
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• 2002

Fine ceramic particles of zirconia toughened alumina (ZTA), titania toughened alumina (TTA), and zirconia-titania toughened alumina (ZTTA) have been synthesized by ultrasonic spray pyrolysis (USP) at various temperatures from starting salt solutio ns of various compositions aiming for the development of catalytic material. These particles were characterized for properties such as shape, size and size distribution, diffraction pattern, and chemical and phase composition of elements by scanning electron microscopy (SEM), particle size analyzer (PSA), x-ray diffraction (XRD), and inductively coupled plasma-atomic emission spectroscopy (ICP-AES). Chemical compositions and sizes of ceramic composites have been controled by the stoichiometry of salt solutions and the flow rate of spraying solutions. The optimum experimental conditions for the various composite particle syntheses have been proposed.

• 한국세라믹학회지
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• 제35권1호
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• pp.41-47
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• 1998

Cutting and planarization of diamond films have been performed using copper vapor laser under air at-mosphere. Diamond films of about 350${\mu}{\textrm}{m}$ and 800 ${\mu}{\textrm}{m}$ thick have been synthesized with DC plasma assisted chemical vapor deposition. The position of a specimen has been controlled by computer-driven stage. With copper vapor laser beam of 7W cutting depth increases rapidly and saturates with increasing scan number and decreasing scan speed. 8 repetitive scans at scan speed 0.5 mm/sec produce the maximum cutting depth without focus shifting Rod-shape copper vapor laser beam can be made and used effectively in planar-ization of rough diamond surface.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 C
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• pp.1818-1820
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• 2000

Due to recent technology advances, needs for flat panel displays, plasma display panels(PDPs) whose advantages are simple structure, high resolution, wide viewing angle is increasingly expected to be the first flat panel of large screen, walt hanging TVs. But the luminance and luminous efficiency of color PDP is net up to the level of a CRT. So, New electrode shape which is different from the conventional electrode has to propose to improve the luminance and luminous efficiency. In this paper, we suggested new shaped electrodes. In new shaped electrode, the discharge current was reduced compared with conventional type by reducing the unnecessary diffusion loss near the barrier rib. However, the luminance was nearly the same as conventional type. So, the luminous efficiency improved about 35%.

• Journal of KIEE
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• 제11권1호
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• pp.46-50
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• 2001

In order to improve the luminous efficiency in ac PDP(Plasma Display Panel), we have suggested the new structures of sustain electrodes with waffle-type barrier ribs and the discharge current for a given pulse voltage has been decreased by eliminating the electrode area which has nothing to do with visible light emission area compared with conventional structure. As a result, the luminous efficiency was improved about 30% compared with the conventional structure.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 G
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• pp.3316-3318
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• 1999

PMMA(poly-methyl methacrylate) microlens array is fabricated using transparent acrylic resin. PMMA is commonly used material for plastic lens due to its excellent visibility larger than 90% and other optical characteristics so much close to those of glass. Orthodontic resin (DENTSPLY International Inc.), commonly used in dentistry, is an transparent acrylic resin kit including MMA liquid and polymerization powder. Their mixture results in PMMA through polymerization. Using the resin PMMA layer is formed on the substrate through spin-coating. Designed pattern of lens structure is transferred to PMMA layer by RIE (Reactive Ion Etching) with oxygen plasma. Final lens shape is formed by thermal treatment that causes PMMA to reflow, The thickness of PMMA spun on the substrate is $17{\mu}m$ that is also final sag of microlens, Designed diameters of the microlenses are $200{\mu}m$, $300{\mu}m$,and $500{\mu}m$, respectively.

• 한국자동차공학회논문집
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• 제23권6호
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• pp.650-655
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• 2015

A high energy ignition system is essential for lean burn or high EGR gasoline engine, which is getting more and more interest to improve fuel economy. The high energy ignition systems comprise plasma jet, laser beam, corona discharge and so on. In this study, a high energy ignition system using corona discharge is developed and tested in a constant volume combustion chamber. The developed system shows extension of lean limit of propane-air mixture and enhencement of combustion speed. Various shape of corona discharge plugs are also tested and compared in this study.

• 한국표면공학회지
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• 제32권3호
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• pp.461-466
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• 1999

Diamond-like carbon(DLC) films were directly deposited onto germanium(Ge) witness pieces and lenses by a capacitively coupled 13.56 MHz RF glow discharge plasma with $CH_4$ gas. The characterizations of DLC films were measured using a Raman and FTIR spectrometer. The configuration of Raman and FTIR spectra had a traditional shape. The IR transmittance was measured using an IR spectrophotometer. The maximum values of the IR transmission of Ge with the DLC/Ge/DLC, DLC/Ge/BBAR (broad band antireflection), DLC/Ge, and BBAR/Ge structures are 98%, 93%, 64%, and 63.5%, respectively, which come up to the theoretical values. The uniform DLC films were obtained by a rotation of the cathode at certain conditions.