• Electrical & Electronic Materials
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• v.10 no.2
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• pp.150-155
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• 1997

Powder type electroluminescent device(P-ELD) in this study was prepared by printing method. P-ELDs were basically composed of phosphor, insulator and transparent conducting layer. The phosphor powder was prepared by sintering the mixture of ZnS as a host, Cu as an activator, and NaCl as a flux for co-activator and enhancement of growth of the phosphor particles. The phosphor layer was made by printing the paste of the cyanoethylpullan as a binder and the ZnS system phosphor powder. In order to evaluate the luminescence characteristics of ZnS P-ELD, applied voltage - luminance(V-L), frequency-luminance(f-L), and relative luminance spectra(L- .lambda.) characteristics were measured. The experimental results show that luminance increased with increasing the applied voltage and frequency. It can be explained in terms of the potential barrier formed between ZnS and CuS. Two emission peaks in luminance-wavelength spectra measured at applied voltage of 100 $V_{rms}$ were observed at 500nm as a primary peak and 460nm as a secondary peak, respectively.y.

• Journal of Microbiology and Biotechnology
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• v.22 no.2
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• pp.234-238
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• 2012

Recombinant Escherichia coli displaying organophosphorus hydrolase (OPH) was used to overcome the diffusion barrier limitation of organophosphorus pesticides. A new anchor system derived from the N-terminal domain of ice-nucleation protein from Pseudomonas syringae InaV (InaV-N) was used to display OPH onto the surface. The designed sequence was cloned in the vector pET-28a(+) and then was expressed in E. coli. Tracing of the expression location of the recombinant protein using SDS-PAGE showed the presentation of OPH by InaV-N on the outer membrane, and the ability of recombinant E. coli to utilize diazinon as the sole source of energy, without growth inhibition, indicated its significant activity. The location of OPH was detected by comparing the activity of the outer membrane fraction with the inner membrane and cytoplasm fractions. Studies revealed that recombinant E. coli can degrade 50% of 2 mM chlorpyrifos in 2 min. It can be concluded that InaV-N can be used efficiently to display foreign functional protein, and these results highlight the high potential of an engineered bacterium to be used in bioremediation of pesticide-contaminated sources in the environment.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.04a
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• pp.60-61
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• 2006

In this paper, the inorganic-organic thin film encapsulation layer was newly adopted to protect the organic layer from moisture and oxygen. Using the electron beam, Sputter and Spin-Coater system, the various kinds of inorganic and organic thin-films were deposited onto the Ethylene Terephthalate(PET) and their interface properties between organic and inorganic layer were investigated. Results indicates that the SiON/PI/SiON/PI/PET barrier coatings have high potential for flexible organic light-emitting diode(OLEO) applications.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.76.1-76.1
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• 2013

Atomic Layer Deposition (ALD) has remarkably developed in semiconductor and nano-structure applications since early 1990. Now, the advantages of ALD process are well-known as controlling atomic-level-thickness, manipulating atomic-level-composition control, and depositing impurity-free films uniformly. These unique properties may accelerate ALD related industries and applications in various functional thin film markets. On the other hand, one of big markets, Display industry, just starts to look at the potential to adopt ALD functional films in emerging display applications, such as transparent and flexible displays. Unlike conventional ALD process strategies (good quality films and stable precursors at high deposition processes), recently major display industries have suggested the following requirements: large area equipment, reasonable throughput, low temperature process, and cost-effective functional precursors. In this talk, it will be mentioned some demands of display industries for applying ALD processes and/or functional films, in terms of emerging display technologies. In fact, the AMOLED (active matrix organic light emitting diode) Television markets are just starting at early 2013. There are a few possibilities and needs to be developing for AMOLED, Flexible and transparent Display markets. Moreover, some basic results will be shown to specify ALD display applications, including transparent conduction oxide, oxide semiconductor, passivation and barrier films.

• 한국신재생에너지학회:학술대회논문집
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• 2006.06a
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• pp.158-161
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• 2006

Superstrate pin amorphous silicon thin-film (a-Si:H) solar cells are prepared on $SnO_2:F$ and ZnO:Al transparent conducting oxides (TCO) In order to see the effect of TCO/P-layers on a-Si:H solar cell operation. The solar cells prepared on textured ZnO:Al have higher open circuit voltage $V_{oc}$ than cells prepared on $SnO_2:F$. Presence of thin microcrystalline p-type silicon layer $({\mu}c-Si:H)$ between ZnO:Al and p a-SiC:H plays a major role by causing improvement in fill factor as well as $V_{oc}$, of a-Si:H solar cells prepared on ZnO:Al TCO. Without any treatment of pi interface, we could obtain high $V_{oc}$, of 994mv while keeping fill factor (72.7%) and short circuit current density $J_{sc}$ at the same level as for the cells on $SnO_2:F$ TCO. This high $V_{oc}$ value can be attributed to modification in the current transport in this region due to creation of a potential barrier.

• Bulletin of the Korean Chemical Society
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• v.4 no.1
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• pp.28-36
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• 1983

We considered the tunneling effect on the rate constants calculated from transition-state theory for the H + $D_2$ and D + $H_2$ reactions. A method for evaluating the important parameter Ec (potential barrier height) was proposed. A tunnel-effect correlation factor (TECF) ${\Gamma}_{t}exp{\theta}_t$ was estimated from experimental data, and compared with the corresponding values obtained from many theoretical methods. According to our results, the tunneling effect cannot be negligible around $800^{\circ}$K where the TECF value is ca. 0.8 whereas the factor approaches to unity at T > $2400^{\circ}$K where the tunneling completely disappears. In addition to the above fact, we also found that the TECF for the D + $H_2$ reaction is greater than that of the H + $D_2$ reaction in agreement with Garrett and Truhlar's result. In contrast to our result, however, Shavitt found that the order is reversed, i.e., TECF for (D + $H_2$) is greater than that for (H + $D_2$). We discussed about the Shavitt's result.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.47 no.3
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• pp.185-191
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• 2021

Environmental pollution is defined as contamination of the earth's environment with materials which interfere with human health, quality of life, or the natural functioning of the ecosystem. Whenever a prolonged and repetitive exposure to environmental stressors exceeds the skin's normal defensive potential, there is a disturbance in the skin barrier function leading to the development of various skin diseases. Major air pollutants which affect the skin are polycyclic aromatic hydrocarbons, volatile organic compounds, nitrogen oxides, particulate matter, cigarette smoke, heavy metals and arsenic. Dermal uptake depends on the deposition of air pollutants on the skin surface, the composition of epidermal lipids, and the diffusion through the epidermis to the blood vessels.

• Journal of the Society of Naval Architects of Korea
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• v.56 no.3
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• pp.251-262
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• 2019

This paper is about design concept and simplified analysis method against dropped object events. The ships and offshore structures are exposed to various types of dropped object accidents such as laydown area struck by drill collar and topside deck hit by food container during their lifetime. Mitigation can be accomplished by proper facility layout and designing structures to safely absorb energy from accidental loads. It shall be designed to avoid loss of life, environmental pollution and loss of assets. Impact loads can lead to structural global collapse of the main structure or punching of a local barrier type structure with potential to escalate directly or indirectly to a global collapse of the structure. This study provides the background information on the issue of dropped object of the shipyard and also focuses on structural assessment of the local individual component such as deck plate, stiffener and web/girder by using simplified analysis method. The results of the simplified analysis method were compared with numerical results using non-linear finite element simulation.

• Nuclear Engineering and Technology
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• v.53 no.3
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• pp.741-751
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• 2021

There has been a deep interest in trying to find better-performing fuel clad motivated by the desire to decrease the likelihood of the reactor barrier failure like what happened in Fukushima in recent years. In this study, the effect of move towards accident tolerant fuel (ATF) cladding as the most attracting concept for improving reactor safety is investigated for SMART modular reactor. These reactors have less production cost, short construction time, better safety and higher power density. The SiC and FeCrAl materials are considered as the most potential candidate for ATF cladding, and the results are compared with Zircaloy cladding material from reactor physics point of view. In this paper, the calculations are performed by generating PMAX library by DRAGON lattice physics code to be used for further reactor core analysis by PARCS code. The differential and integral worth of control and safety rods, reactivity coefficient, power and temperature distributions, and boric acid concentration during the cycle are analyzed and compared from the conventional fuel cladding. The rod ejection accident (REA) is also performed to study how the power changed in response to presence of the ATF cladding in the reactor core. The key quantitative finding can be summarized as: 20 ℃ (3%) decrease in average fuel temperature, 33 pcm (3%) increase in integral rod worth and cycle length, 1.26 pcm/℃ (50%) and 1.05 pcm/℃ (16%) increase in reactivity coefficient of fuel and moderator, respectively.

• Bulletin of the Korean Chemical Society
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• v.6 no.6
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• pp.362-366
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• 1985

The hydrogen atom transfer reaction between substituted methane, $CH_3X,$ and its radical, $CH_2X(X=H,F,CH_3,CN,OH\;and\;NH_2$ was studied by MINDO/3 method. The transition state(TS) structure and energy barriers were determined and variation of the transition state and of the reactivity due to the change of X were analyzed based on the potential energy surface characteristics. It was found that the greater the radical stabilization energy. the looser the TS becomes; the TS occurs at about 15% stretch of the C-H bond, which becomes longer as the radical stabilization energy of $CH_2X$ increasers. The intrinsic barrier, ${\Delta}E*_{x.x},$ of the reaction with X was found to increase in the order $H The degree of bond stretch of the C-H bond stretch of the C-H bond at the TS also had the same order indicating that the homolytic bond cleavage of the C-H bond is rate-determining. Orbital interactions at the TS between LUMO of the fragment $C{\ldots}H{\ldots}C$ and the symmetry adapted pair of nonbonding, $n{\pm}(=n_1{\pm}n_2),$ or pi orbitals of the two X atoms were shown to be the dominant contribution in determining tightness or looseness of the TS. The Marcus equation was shown to apply to the MINDO/3 barriers and energy changes of the reaction.