• The Journal of Natural Sciences
• /
• v.16 no.1
• /
• pp.129-141
• /
• 2005

The equilibrium geometry, adiabatic electron affinity, harmonic vibrational frequencies, and infrared intensities of 1,4,6,9-Tetra chlorinated dibenzo-$\rho$-dioxin anion have been studied using B3LYP method. The local minimum conformation is found to be twisted form with $D_2$ symmetry. The predicted adiabatic electron affinity is 0.54 eV. The predicted inversion barrier between twisted and planar conformers was 0.9 kcal/mol, thus we expect that experimentally observed structure seems to be planar. the characteristic IR band of 1,4,6,9-TCDD anion appears at 1510 $cm^4$, which is a benzene ring skeleton vibration mode related with CaCb and C2C3 bond. this characteristic band could be sued for identication of 1,4,6,9-TCDD anion.

• Bulletin of the Korean Chemical Society
• /
• v.34 no.12
• /
• pp.3677-3680
• /
• 2013

Novel tri- and tetra-substituted pyrimido[4,5-d]pyridazines-2(1H,3H,7H)-ones have been synthesized via the regiospecific condensation reaction of hydrazine derivatives with 5-acetyl-4-aryloyl-6-methyl-3,4-dihydropyrimidinones in the presence of $SiO_2-Y(NO_3)_3$ as a green and recyclable catalyst under solvent-free conditions. All products were obtained in high yields and short reaction time. Employing this method is in accord with green chemistry principles.

• Progress in Medical Physics
• /
• v.8 no.2
• /
• pp.77-85
• /
• 1997

Verification of patients setup was very important during radiotherapy. Therefore, we have developed an 1-dimensional on-line portal imaging system and measured the differential linearity of the system. Isooctane(2,2,4-TetraMethyl Pentane) was used as liquid ionization material. And the geometry of the system was designed which has 2mm position resolution and 20cm measurable range. And then the differential linearity of the system was 4.7％.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2001.11b
• /
• pp.378-381
• /
• 2001

The electron drift mobility of poly(4,4'-cyclohexylidenediphenyl carbonate) (PC-Z) doped with 3,5-dimethy-3,5-di-t-butylstilbenequinone(MBSQ), 3,5,3,5-tetra-t-butyl stilbenequinone(TBSQ) and 3,5,3,5-tetra-methyl stilbenequinone(TMSQ) was measured by the time-of-flight technique. The electric field and temperature dependences of the electron drift mobility were discussed with Poole-Frenkel, Arrhenius formulations and non-Arrhenius type of temperature dependence. It was assumed that the hopping sites were Gaussian distribution. Mobility and activation energy of MBSQ were increased with increasing dopant. However, mobilities and activation energy of TBSQ and TMSQ were increased and decreased, respectively.

• Proceeding of EDISON Challenge
• /
• 2017.03a
• /
• pp.333-339
• /
• 2017

최근에는 항공기의 임무 형태나 주위 환경에 따라 변할 수 있는 passive morphing airfoil에 대한 연구가 활발히 이루어지고 있다. 하지만 복잡한 모델링, 실험 과정 및 긴 해석 시간 때문에 아직 여러 chiral 구조를 체계적으로 비교하지 못 하고 있다. 본 논문에서는 이러한 chiral meso structure 중 하나인 Anti-Tetra Chiral 구조를 Hooke's law에 기반을 두어 등가 물성치를 구해보고, 사각형 모양의 연속체 요소로 등가 모델링을 하였다. 그 후, airfoil 내부에 연속체 요소를 직접 적용하여 실제 모델링한 경우와 비교해 본 결과 경향성 파악에 충분한 오차 범위를 얻을 수 있었다. 이를 통해 여러종류의 Chiral meso structure과 기하학적 변수를 적용한 에어포일을 효율적으로 해석할 수 있음을 제시할 수 있다.

• Journal of the Korean Applied Science and Technology
• /
• v.28 no.2
• /
• pp.178-184
• /
• 2011

The analysis of reaction kinetics provided that the reaction order was the $1^{st}$ of triglyceride and the rate constant was 0.067 $min^{-1}$. The transesterification of camelina oil using 0.6 wt% mixed catalyst which consists of 40 v/v% of potassium hydroxide (1 wt%) and 60 v/v% of tetra methyl ammonium hydroxide (0.8 wt%), was carried out at $65^{\circ}C$ on the tubular reactor packed with static mixer. The conversion was shown to be 95.5% at the 6:1 molar ratio of methanol to oil, flow rate of feed of 3.0 mL/min and 24 of element of static mixer. The volume of washing water emitted by 0.6 wt% mixed catalyst was the half of the volume emitted by 1 wt% potassium hydroxide.

• Journal of the Korean Institute of Telematics and Electronics
• /
• v.12 no.5
• /
• pp.6-11
• /
• 1975

반복형 그래이 부호 중 14진 및 16진 부호용 디지트 절차(digit sequence 또는 DS)의 여러가지 특성에 관하여 논하였으며 그것들을 통일적으로 기적할 수 있는 PDS는 각각 31종 및 11종이 있다는 것을 명백히 하였다. 그리고 이 PDS들에 회전변환과 순렬변환을 실시하여 얻을 수 있는 DS의 총수와 각종 특수 DS의 성질에 관하여도 논하였으며 대칭형 DS를 이용한 14진 및 16진 GC Counter를 설계하여 그것들의 동작을 실험에 의하여 확인하였다. Investigations on some characteristics of Tetra-Decimal and Hexa-Decimal recycling Gray co de (GC)-digit sequence(DS) are carried out, and, 31 and 11 kinds of prime digit sequence(PDS) are proposed respectively. From these PDS, by means of rotational conversion and permutational conversion, the numbers of all DS are obtained, and also the characteristics of some special DS are studied. Tetra Decimal and Hexa-decimal GC counters are designed using symmetrical DS, and, their operations are experimentally verified.

• International Journal of High-Rise Buildings
• /
• v.2 no.2
• /
• pp.93-96
• /
• 2013

Greenhouse gas emissions and excessive energy consumption have been an on-going world issue nowadays. We can find that the majority portion is caused by high-rise office buildings. In order to resolve these problems, it is extremely important to implement various active or passive strategies in a building design. To successfully meet these design goals and energy reduction approaches, a project building must utilize an efficient design process from the early start. One of the most effective project delivery process called Integrated Project Delivery (IPD) will be implemented in a case study project building (KEPCO) during design phase and show how important it is to plan a project's green environmental performance goal together through an early collaboration from all key project participants, which helps to construct an successful green building design without any critical construction pitfalls.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2013.11a
• /
• pp.200-201
• /
• 2013

This study is interested in manufacturing the concrete surface impregnants including tetra ethyl ortho silicate, alkali silicate for the repair of the exposed concrete and the color concrete requiring the advanced function in view of the concrete appearance. The surface layer change and porosity properties was tested for the review of application. The result of this study show that the effective silicate are tetra ethyl ortho silicate and alkali silicate t. The adhesion in tension is slightly increased but the reinforcement of concrete substrate is slight. So, the concrete impregnant of this study is more desirable for the improvement of durability rather than the reinforcement.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2001.11a
• /
• pp.378-381
• /
• 2001

The electron drift mobility of poly(4,4'-cyclohexylidenediphenyl carbonate)(PC-Z) doped with 3,5-dimethy-3,5-di-t-butylstilbenequinone(MBSQ), 3,5,3,5-tetra-t-butyl stilbenequinone(TMSQ) and 3,5,3,5-tetra-methyl stilbenequinone(TMSQ) was measured by the time-of-flight technique. The electric field and temperature dependences of the electron drift mobility were discussed with Poole-Frenkel, Arrhenius formulations and non-Arrhenius type of temperature dependence. It was assumed that the hopping sites were Gaussian distribution. Mobility and activation energy of MBSQ were increased with increasing dopant. However, mobilities and activation energy of TBSQ and TMSQ were increased and decreased, respectively.