• Proceedings of the KIEE Conference
• /
• 2007.07a
• /
• pp.1305-1306
• /
• 2007

To lower the fabrication cost of silicon solar cells, a surface treatment using a dielectric barrier discharge instead of a wet cleaning technique was examined on electrode surfaces on silicon solar cells. The fill factor obtained through measuring current-voltage characteristics was evaluated, and the treated surface state was characterized by energy-dispersive X-ray. It was found that the dielectric barrier discharge effectively activated the electrode surface and the surface treatment on finger electrodes contributed greatly to improve the fill factor.

• Bulletin of the Korean Chemical Society
• /
• v.7 no.6
• /
• pp.448-453
• /
• 1986

Two contributions to the activation barrier of the $S_N2$ reaction, intrinsic and thermodynamic, are discussed in connection with the predictive power of various rate-equilibrium relationships. It has been shown that the PES models can only give correct predictions of changes in structure and energy of the transition state if the activation barrier is dictated by the thermodynamic factor. We concluded that the identity and dissociative $S_N2$ reactions are dominated by the intrinsic component while associative $S_N2$ reactions are predominantly of thermodynamic controlled. Thus in the former cases, the PES models fail, whereas in the latter cases predictions based on the intrinsic factor, the quantum mechanical models, fail. Finally in a general case of equal contributions by thermodynamic and intrinsic factors, the $SN_2$ reaction proceeds by a synchronous process with zero net charge on the reaction center, for which predictions of substituent effects will be the same as for the intrinsic control case.

• Proceedings of the PSK Conference
• /
• 2003.10b
• /
• pp.69.2-69.2
• /
• 2003

The purpose of this study is to examine whether the efflux system for taurine from brain to blood is present on the blood-brain barrier (BBB) using the brain efflux index (BEl) method and taurine transport system is regulated by CNS cell damage with oxidative stress agent such as diethyl maleate (DEM) or tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) in vivo. ［$^3$H]Taurine was microinjected into parietal cortex area 2 (Par2) of the rat brain, and was eliminated from the brain with efflux transport rate of 1.22 10$\^$-2//min, and the process is saturable with a $K_{m}$ of 43.5 ${\mu}$M. (omitted)

• Journal of the Korean housing association
• /
• v.22 no.4
• /
• pp.43-50
• /
• 2011

In an aging society, as the number of people with disabilities increases concerns are raised about the quality of life of these people and their access to a safe environment becomes important. The purpose of this study is to find out the value of accessibility as an attribute of housing. To estimate the value of accessible, barrier-free housing, this study uses the Contingent Valuation Method (CVM) and analyzes the factors which affect the Willingness To Pay (WTP) of survey respondents by using Survival Analysis. In addition, the importance and satisfaction of barrier-free facilities in the dwellings of survey respondents was investigated. Since aging could be an important factor in influencing the need for accessibility, this study surveyed two age groups, one group (212 respondents) of people below the age of 65 and the other (162 respondents) of people above 65. The results of this study show that respondents would pay on average 2.67% more for being barrier-free when answering an open-ended question and 3.87% more for barrier-free housing when using the double referendum model. This is the increase in value that the respondents perceive as a consequence of removing all the architectural barriers from a dwelling. On average, elderly respondents would pay 2.99% of housing price for accessible features compared to 4.40% of the younger group. However, if the elderly who have willingness to pay for accessibility, the value the older group put on barrier-free housing was higher than the value perceived by the younger group. Factors that influence the WTP are importance of barrier-free facilities, education level and housing type. The value of dwellings without barriers estimated in this study shows the potential size and value of this kind of housing market to the housing development sector.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2010.08a
• /
• pp.178-178
• /
• 2010

With the scaling down of ULSI(Ultra Large Scale Integration) circuit of CMOS(Complementary Metal Oxide Semiconductor)based electronic devices, the electronic devices become more faster and smaller size that are promising field of semiconductor market. However, very narrow line width has some disadvantages. For example, because of narrow line width, deposition of conformal and thin barrier is difficult. Besides, proportion of barrier width is large, thus resistance is high. Conventional PVD(Physical Vapor Deposition) thin films are not able to gain a good quality and conformal layer. Hence, in order to get over these side effects, deposition of thin layer used of ALD(Atomic Layer Deposition) is important factor. Furthermore, it is essential that copper atomic diffusion into dielectric layer such as silicon oxide and hafnium oxide. If copper line is not surrounded by diffusion barrier, it cause the leakage current and devices degradation. There are some possible methods for improving the these secondary effects. In this study, TaNx, is used of Tertiarybutylimido tris (ethylamethlamino) tantalum (TBITEMAT), was deposited on the 24nm sized trench silicon oxide/silicon bi-layer substrate with good step coverage and high quality film using plasma enhanced atomic layer deposition (PEALD). And then copper was deposited on TaNx barrier using same deposition method. The thickness of TaNx was 4~5 nm. TaNx film was deposited the condition of under $300^{\circ}C$ and copper deposition temperature was under $120^{\circ}C$, and feeding time of TaNx and copper were 5 seconds and 5 seconds, relatively. Purge time of TaNx and copper films were 10 seconds and 6 seconds, relatively. XRD, TEM, AFM, I-V measurement(for testing leakage current and stability) were used to analyze this work. With this work, thin barrier layer(4~5nm) with deposited PEALD has good step coverage and good thermal stability. So the barrier properties of PEALD TaNx film are desirable for copper interconnection.

• Biomolecules & Therapeutics
• /
• v.29 no.2
• /
• pp.175-183
• /
• 2021

The mitogen-activated protein kinase (MAPK) pathway controls intestinal epithelial barrier permeability by regulating tight junctions (TJs) and epithelial cells damage. Heme oxygenase-1 (HO-1) and carbon monoxide (CO) protect the intestinal epithelial barrier function, but the molecular mechanism is not yet clarified. MAPK activation and barrier permeability were studied using monolayers of Caco-2 cells treated with tissue necrosis factor α (TNF-α) transfected with FUGW-HO-1 or pLKO.1-sh-HO-1 plasmid. Intestinal mucosal barrier permeability and MAPK activation were also investigated using carbon tetrachloride (CCl4) administration with CoPP (a HO-1 inducer), ZnPP (a HO-1 inhibitor), CO releasing molecule 2 (CORM-2), or inactived-CORM-2-treated wild-type mice and mice with HO-1 deficiency in intestinal epithelial cells. TNF-α increased epithelial TJ disruption and cleaved caspase-3 expression, induced ERK, p38, and JNK phosphorylation. In addition, HO-1 blocked TNF-α-induced increase in epithelial TJs disruption, cleaved caspase-3 expression, as well as ERK, p38, and JNK phosphorylation in an HO-1-dependent manner. CoPP and CORM-2 directly ameliorated intestinal mucosal injury, attenuated TJ disruption and cleaved caspase-3 expression, and inhibited epithelial ERK, p38, and JNK phosphorylation after chronic CCl4 injection. Conversely, ZnPP completely reversed these effects. Furthermore, mice with intestinal epithelial HO-1 deficient exhibited a robust increase in mucosal TJs disruption, cleaved caspase-3 expression, and MAPKs activation as compared to the control group mice. These data demonstrated that HO-1-dependent MAPK signaling inhibition preserves the intestinal mucosal barrier integrity by abrogating TJ dysregulation and epithelial cell damage. The differential targeting of gut HO-1-MAPK axis leads to improved intestinal disease therapy.

• The Korean Journal of Physiology and Pharmacology
• /
• v.19 no.1
• /
• pp.1-7
• /
• 2015

Our previous study has shown berberine prevents damage to the intestinal mucosal barrier during early phase of sepsis in rat through mechanisms independent of the NOD-like receptors signaling pathway. In this study, we explored the regulatory effects of berberine on Toll-like receptors during the intestinal mucosal damaging process in rats. Male Sprague-Dawlay (SD) rats were treated with berberine for 5 d before undergoing cecal ligation and puncture (CLP) to induce polymicrobial sepsis. The expression of Toll-like receptor 2 (TLR 2), TLR 4, TLR 9, the activity of nuclear factor-kappa B ($NF-{\kappa}B$), the levels of selected cytokines and chemokines, percentage of cell death in intestinal epithelial cells, and mucosal permeability were investigated at 0, 2, 6, 12 and 24 h after CLP. Results showed that the tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) and interleukin-6 (IL-6) level were significantly lower in berberine-treated rats compared to the control animals. Conversely, the expression level of tight junction proteins, percentage of cell death in intestinal epithelial cells and the mucosal permeability were significantly higher in berberine-treated rats. The mRNA expression of TLR 2, TLR 4, and TLR 9 were significantly affected by berberine treatment. Our results indicate that pretreatment with berberine attenuates tissue injury and protects the intestinal mucosal barrier in early phase of sepsis and this may possibly have been mediated through the TLRs pathway.

• Journal of the military operations research society of Korea
• /
• v.11 no.2
• /
• pp.6-14
• /
• 1985

The layered multi-barrier defense situation against penetrating enemy threat is analytically modeled towards minimizing the penetration probability. Each layer is characterized by probability of detection and probability of kill given detection. The two capabilities are assumed independent. Detection in a layer, however, affects detection performance in subsequent layers. The following three models were formulated and investigated: (1) 'Model A' permits increase of detection performance in only the next barrier, (2) 'Model B' permits the increase in all subsequent barriers linearly, and (3) 'Model C' expresses the increase in an asymptotic exponential way. The best and the worst barrier combinations are determined through model exercise and model performances are compared through sensitivity analysis for the 'intensification factor.'

• Korean Journal of Materials Research
• /
• v.26 no.10
• /
• pp.556-560
• /
• 2016

Using current-voltage (I-V) and capacitance-voltage (C-V) measurements, the electrical properties of Au and Cu Schottky contacts to n-Ge were comparatively investigated. Lower values of barrier height, ideality factor and series resistance were obtained for the Au contact as compared to the Cu contact. The values of capacitance showed strong dependence on the bias voltage and the frequency. The presence of an inversion layer at the interface might reduce the intercept voltage at the voltage axis, lowering the barrier height for C-V measurements, especially at lower frequencies. In addition, a higher interface state density was observed for the Au contact. The generation of sputter deposition-induced defects might occur more severely for the Au contact; these defects affected both the I-V and C-V characteristics.

• Current Optics and Photonics
• /
• v.1 no.2
• /
• pp.95-100
• /
• 2017

The transmittance of the three dimensional (3D) transparent display is an important factor and can be enhanced by adding a see-through area to the displayed 3D image in order to transmit an ambient light with maximum transparency. However, there is a side effect that the perceived 3D resolution can be degraded due to the see-through area. In this paper, we propose an advanced method to resolve the above trade-off relation between the transparency and the 3D resolution by using an active parallax barrier (PB) with a see-through area. The experimental results are also presented to prove the proposed principle.