• Bulletin of the Korean Chemical Society
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• v.22 no.7
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• pp.732-738
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• 2001

The cross second-derivative of the activation energy,${\theta}$G${\neq}$ , with respect to the two component thermodynamic barriers, ${\theta}$G˚X and ${\theta}$G$^{\circ}C$Y, can be given in terms of a cross-interaction constant (CIC), $\betaXY(\rhoXY)$, and also in terms of the intrinsic barrier,${\theta}$G${\neq}$ , with a simple relationship between the two: $\betaXY$ = $-1}(6${\theta}$G${\neq}$).$ This equation shows that the distance between the two reactants in the adduct (TS, intermediate, or product) is inversely related to the intrinsic barrier. An important corollary is that the Ritchie N+ equation holds (for which $\betaXY$ = 0) for the reactions with high intrinsic barrier. Various experimental and theoretical examples are presented to show the validity of the relationship, and the mechanistic implications are discussed.

• Journal of Advanced Marine Engineering and Technology
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• v.28 no.6
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• pp.938-945
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• 2004

Intrinsic safety is generally considered the safest method of operating electrical instrumention in potentially explosive atmospheres. The method of intrinsic safety limits the energy passing into the hazardus area. The energy limitation is provided by the use of safety barriers which are mounted in the safe area. Because of the energy limitation, regardless of the fault in the hazardous area, sufficient energy cannot be released to ignite the explosive atmosphere. The following industries are known to have hazardous locations: chemical. munitions, petrochemical, auto(paint spray booths), grain, waste water, printing, distillers, pharmaceutical. breweries, cosmetics, and utilities. In this paper, a isolator type barrier for ship(LNG, LPG, etc,) and test equipment confidence are proposed. The test equipments are designed for mechanical electrical life time test and vibration. All of test results satisfy the goal and the studied barrier shows the improved confidence.

• Bulletin of the Korean Chemical Society
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• v.9 no.1
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• pp.10-12
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• 1988

The intrinsic barrier in the methyl transfer reaction $X^- + CH_3X \rightleftharpoons XCH_3 + X^-$ has been shown to vary quadratically with the C-X distance d; linear dependence of the intrinsic barrier on the deformation energies or methyl cation affinities of the substrate, $CH_3X$, should therefore hold only approximately in a narrow range of structural variations in X.

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

• Journal of the Semiconductor & Display Technology
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• v.21 no.2
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• pp.123-126
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• 2022

We investigated deep levels in n-type 4H-SiC epitaxy layer of the Positive-Intrinsic-Negative diode and Schottky barrier diodes by using deep level transient spectroscopy. Despite the excellent performance of 4H-SiC, research on various deep level defects still requires a lot of research to improve device performance. In Positive-Intrinsic-Negative diode, two defects of 196K and 628K are observed more than Schottky barrier diode. This is related to the action of impurity atoms infiltrating or occupying the 4H-SiC lattice in the ion implantation process. The I-V characteristics of the Positive-Intrinsic-Negative diode shows about ~100 times lower the leakage current level than Schottky barrier diode due to the grid structures in Positive-Intrinsic-Negative. As a result of comparing the capacitance of devices diode and Schottky barrier diode devices, it can be seen that the capacitance value lowered if it exists the P implantation regions from C-V characteristics.

• Journal of the Korean Dietetic Association
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• v.11 no.2
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• pp.137-146
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• 2005

This study was carried out to investigate the relationship between diabetic control and related factors of the practice of diet therapy which affects mostly diabetic patients’ dietary compliance. A questionnaire survey was conducted on 128 diabetic patients who had visited Internal medicine endocrinology clinic at University Medical Center of Daegu area. The questionnaires including clinical characteristics, meal regularity and food intake which shows dietary compliance, intrinsic barriers to the practice of diet therapy and knowledge of diet therapy were asked and analyzed. The factor which affects HbA1c was intrinsic barriers and HbA1c became higher as the level of intrinsic barriers was increasing. The education on diet therapy had no influence on the intrinsic barriers, but the level of knowledge on diet therapy was shown higher in the educated patients. The above results suggest that the practice of diet therapy should be leaded to develop behavioral aspects through resonable motivation on dietary compliance along with removing intrinsic barriers rather than simply providing information.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2000.11a
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• pp.248-251
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• 2000

본 논문에서는 SIEMENS사의 BAS125 소자의 I-V curve에서 RF신호를 고려하여 파라미터를 추출하였으며, 바이어스에 독립적인 외부소자를 추출하고, 바이어스에 종속적인 접합캐패시터를 S-parameter를 fitting하여 추출하였다.

• 한국신재생에너지학회:학술대회논문집
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• 2006.06a
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• pp.214-217
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• 2006

p-type 비정질 실리콘 에미터와 n-type 실리콘 기판의 계면에 intrinsic 비정질 실리콘을 증착함으로써 계면의 재결합을 억제하여 20%가 넘는 효율을 보이는 이종접합 태양전지가 Sanyo에 의해 처음 제시된 후 intrinsic layer에 대한 연구가 많이 진행되어 왔다. 하지만 p-type wafer의 경우는 n-type에 비해 intrinsic buffer의 효과가 미미하거나 오히려 특성을 저하시킨다는 보고가 있으며 그 이유로는 minority carrier에 대한 barrier가 상대적으로 낮다는 것과 partial epitaxy가 발생하기 때문으로 알려져 있다. 본 연구에서는 partial epitaxy를 억제하기 위한 방법으로 증착 온도를 낮추고 QSSPC를 사용하여 minority carrier lifetime을 측정함으로써 각 온도에 따른 passivation 특성을 평가하였다. 또한 SiH4에 H2를 섞어서 증착하였을 경우 각 dilution ratio(H2 flow/SiH4 flow)에서의 passivation 특성 또한 평가하였다. 기판 온도 $100^{\circ}C$에서 증착된 샘플의 lifetime이 가장 길었으며 그 이하와 이상에서는 lifetime이 감소하는 경향을 보였다 낮은 온도에서는 박막 자체의 결함이 증가하였기 때문이며 높은 온도에서는 partial epitaxy의 영향으로 추정된다. H2 dilution을 하여 증착한 샘플의 경우 SiH4만 가지고 증착한 샘플보다 훨씬 높은 lifetime을 가졌다 이 또한 박막 FT-IR결과로부터 H2 dilution을 한 경우 compact한 박막이 형성되는 것을 확인할 수 있었는데 radical mobility 증가에 의한 박막 특성 향상이 원인으로 생각된다.

• Membrane Journal
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• v.27 no.2
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• pp.154-166
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• 2017

Polymeric films for gas barrier applications such as food packaging and electronic devices have attracted great interest due to their cheap, light and easy processability among gas barrier materials. Especially in electronic devices, extremely low gas permeance is necessary for maintaining the device performance. However, current polymeric barrier films still suffer from relatively high gas permeance than other materials. Therefore, there have been strong needs to enhance the gas barrier performance of polymeric barrier films while keep their own advantages. Recently, graphene is highlighted as a 2D-layered material for gas barrier applications. However, owing to the poor workability and difficulty to produce in engineering scale, graphene oxide (GO) is on the rise. GO consists of oxygen-containing functional groups on surface with intrinsic 2D-layered structure and high aspect ratio, and it can be well-dispersed in aqueous polar solvents like water, resulting in scalable mass production. Here, we prepared GO incorporated polyimide (PI) nanocomposites. PI is widely used barrier polymer with high mechanical strength and thermal and chemical stability. We demonstrated that PI/GO nanocomposites could perform as a gas barrier. Furthermore, surfactants (Triton X-100 (TX) and Sodium deoxycholate (SDC)) are introduced to enhance the gas barrier performance by improving the degree of dispersion of GO in PI matrix. As a result, TX enhanced the gas barrier performance of PI/GO nanocomposites which is similar to predicted value. This finding will provide new insight to polymer nanocomposites for gas barrier applications.

• Proceedings of the IEEK Conference
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• 2001.06b
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• pp.205-208
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• 2001

Schottky barrier diodes are fabricated on a intrinsic GaN(4${\mu}{\textrm}{m}$) epitaxial structure grown by rf plasma molecular beam epitaxy (MBE) on sapphire substrates. First, We make Ohmic electrodes (Ti/Al/Ti/Au) by evaporator. Next, we contact RuO$_2$ by dipping in the solution (RuCl$_3$.HClO$_4$), and then we deposit Ni/Au on the surface of RuO$_2$ by evaporator. We study the electrical characteristics of GaN Schottky barrier diodes made by these methods. Measurements are C-V, I-V, SEM, EDX, and XRD for the characteristics of devices. Thickness of RuO$_2$ layer depends on supplied voltage and dipping time. Device of thinner RuO$_2$ layer have a good Schottky characteristics compare with device of thicker RuO$_2$ layer