• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1999.11a
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• pp.114-120
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• 1999

It is possible for a volume of fluid to become trapped in the space between two adjoining teeth and the tips of the teeth engage in Gear Pumu with involute teeth. This trapped fluid leads to several harmful results, for example fluctuating pressure and aeration of pump. In this study, hence, theoretical and experimental analyses on this 'Trapping' were accomplished as using relief port, one of the means for avoiding it. Also, the grasp and analysis on variational type of the internal pressure in parallel with above experiments are achieved so that hydrodynamic behaviors in pump were contemplated.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.44 no.3
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• pp.56-62
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• 2012

Recycled pulp therefore play a very important role in the paper industry today as a substitute for virgin pulp. In many countries of the world, the paper industry could not exist as it does without recycled pulp. Because, this is mainly due to economic reasons. Particularly in our country, the additional reason is the scarcity of native pulpwood resources. Therefore, the use of recycled pulp is very important. This study was aimed to apply recycled pulp to textbook paper. So we made a paper containing 30% recycled pulp and investigated about print quality, such as color reproduction, trapping, contrast, dot gain, gloss and print through. The results showed that is similar to existing textbook papers.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.594-594
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• 2012

Al doped ZnO (AZO) thin films were deposited on textured glass substrate by magnetron sputtering method. Also, AZO films on textured glass were etched by hydrochloric acid (HCl). Average thickness of etched AZO films are 90 nm. We observed morphology of AZO film by AFM with various etchant concentration and etching time. Etched AZO films have low resistivity and high haze. The surface RMS roughness of AZO film was increased from 53.8 nm to 84.5 nm. The haze ratio was also enhanced in above 700 nm of wavelength due to light trapping effect was increased by rough AZO surface. The etched AZO films on textured glass are applicable to fabricate solar cell.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.245-246
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• 2011

Emission lines ratios were used for diagnostics of and excited level densities in low-temperature plasmas. In this work, an optical emission spectroscopy (OES) was used to determine the electron temperature and metastable level densities in low-pressure inductively coupled plasma. The emission spectroscopy method was based on a simple collisional-radiative model. The selected lines of the Ar(4p to 4s) were influenced by the radiation trapping at relatively high pressures where the plasma become optically thick. To quantify this effect, a pressure dependence factor ${\alpha}$(P) was derived by using corrections for the measured intensities. It was found that the lower metastable level densities were obtained when ${\alpha}$(P) increased with the increasing discharge pressure. The effect of non-Maxwellian electron energy distribution functions (EEDFs) on the metastables was also presented and discussed.

• Current Photovoltaic Research
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• v.5 no.3
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• pp.75-82
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• 2017

High efficiency thin film solar cells require an absorber layer with high absorption and low defect, a transparent conductive oxide (TCO) film with high transmittance of over 80% and a high conductivity. Furthermore, light can be captured through the glass substrate and sent to the light absorbing layer to improve the efficiency. In this paper, morphology formation on the surface of glass substrate was investigated by using HF, mainly classified as random etching and periodic etching. We discussed about the etch mechanism, etch rate and hard mask materials, and periodic light trapping structure.

• Transactions of the Korean Society of Automotive Engineers
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• v.3 no.2
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• pp.130-135
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• 1995

In this paper, the numerical simulation of the method of characteristics for a two-stroke SI engine was carried out, and the scavenging efficiency and the performance of single engine with two types of exhaust system, that is, a pipe exhaust system and a tuned exhaust system, were predicted and compared. The conculusions are obtained as follows. (1) The method of characteristics of hometropic flow considering the friction and the variation of area is useful to predict the scavenging efficiency and the performance of the two-stroke engine. (2) The shape of exhaust system effects directly on the scavenging and the trapping efficiency. (3) A tuned exhaust system consisted of the diffuser and the convergent nozzle makes the plugging pulse and therefore enhances the scavenging and the trapping efficiency. (4) It may be possible to design the optimum exhaust system by using the plugging pulse.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07a
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• pp.361-363
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• 2005

The transient current of STN-LCD cells was measured and simulated to characterize ionic behavior in LCD cells. An experiment was performed to investigate the contribution of LC material and PI trapping effect to mobile ions in the LC layer. We observed that most of ions are trapped on the PI surface rather than stay in the LC layer in case of normal STN-LCD, and PI surface favors larger ions in general. A linear correlation of ion density and $V_50$ shift of the Transmission-Voltage (TV) curve between 30Hz and 1kHz at typical ion mobility was found.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.48 no.9
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• pp.634-640
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• 1999

Resonance radiation trapping has a great influence on the characteristics of vacuum ultraviolet(VUV) photon emissions in AC PDP cell. We calculate the spatial andspectral distributions of VUV photons, which are radiated by excited Xe in AC PDP cell by Monte Carlo method. Especially a dip in the spectrum at center frequency is discovered both in simulation and in experiment. We give a physical explanation of this phenomenon by the concept of frequency-dependent mean free path of VUV photons.

• Transactions on Electrical and Electronic Materials
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• v.6 no.3
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• pp.91-96
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• 2005

We report the efficient red light-emitting diodes based on the fluorescent dye 4-(dicyanomethylene)-2-i-propyl-6-(1,1,7,7-tetramethyljulolidyl-9-enyl)-4H-pyran (DCJTI) and 5,6,11,12-tetraphenyl naphthacene (rubrene) codoped in the tris(8-hydroxyquinoline)aluminum $(Alq_3)$. Luminance efficiency of 2.2 cd/A with a Commission International De L'Eclairage (CIE) chromaticity coordinate of x, y = (0.640, 0:350) are achieved at the driving current density of $20\;mA/cm^2$. Adding the rubrene to the DCJTI in tris(8-hydroxyquinoline)aluminum $(Alq_3)$, the red color purity and luminance efficiency improved comparing to the DCJTI only doped devices because the rubrene molecules assist the polarization effect of DCJTI by molecular interaction and enhance the energy transfer from $(Alq_3)$ to DCJTI.

• Journal of the Korean Chemical Society
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• v.23 no.6
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• pp.396-401
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• 1979

Measuring the reaction rate of bilirubin and oxodipyrromethenes with singlet oxygen, we have found oxodipyrromethenes to be better singlet oxygen trapping agents than diphenyl-isobenzofuran, the best such agent known so far. The photooxygenation rates of bilirubin and the model compounds, oxodipyrromethenes approached the diffusion control threshold. A new oxodipyrromethene is synthesized.