• Bulletin of the Korean Chemical Society
• /
• 제4권5호
• /
• pp.208-211
• /
• 1983

Kinetic studies of nucleophilic substitution reactions of para-substituted benzylchlorides with anilines were conducted in a range of MeOH-MeCN mixtures at $55.1^{\circ}C$. Hammett ${\rho}_C$, ${\rho}_N$ values and Bronsted ${\beta}$ values were determined, in other to examine the transition state variations caused by changes in nucleophiles, substituents and solvents properties (${\pi}^{\ast}$ and ${\alpha}$). Applications of potential energy surface (PES) and quantum mechanical (QM) models of transitheion state characterization lead us to conclude that the reaction proceeds via the dissociative $S_N2$ mechanism.

• Educational Technology International
• /
• 제24권1호
• /
• pp.53-80
• /
• 2023

This study investigates faculty support for quality assurance in online education, and offers suggestions for its improvement based on feedback from Instructional Design (ID) staff working at a public university in the U.S. Qualitative research using semi-structured interviews was conducted with seven ID staff in order to examine their perceptions regarding faculty support related to quality assurance in online education. The results of the data analysis indicate that four types of faculty support-quality assurance reviews using Quality Matter (QM) standards, templates, individual consultations with ongoing support, and monitoring-were offered for faculty. Faculty support for quality assurance in online education could be improved by developing specific quality assurance standards, recruiting external experts, examining learning effects, developing a quality assurance management system, and sharing documents among ID staff. This study highlights the necessity of quality assurance in online education and provides cases of faculty support in a real higher education setting.

• 산업경영시스템학회지
• /
• 제40권4호
• /
• pp.78-86
• /
• 2017

The new businesses started by the companies usually results in being unsuccessful. The main reasons for that are either aiming targeting wrong customers, unsatisfaction of customers' requesting quality standards, or taking wrong actions against the competitors in the market. Therefore, companies should aim the targets for the newly developing products based on the fulfilling values for the customers when they start the new businesses, and should take good cares for risk managements at the each step of the new business to prevent the failure in advance. In addition to that, the companies starting new businesses not only need to take the customers attributes (CA) into account, but they also should apply the new technologies as one system to initiate a new business to satisfy the basic wants of the customers. This article suggests the New Product Development Pursuing Model using the Indicative Planning methodology and the Quality Management tools. The New Product Development Pursuing Model would be completed by the following steps as below; 1. Drawing the CTQ (Critical To Quality) for setting up the new product development objectives by : i) using the VOC (Voice Of Customers) obtained by the QFD (Quality Function Deploypment) if the market is mature, ii) applying AHP (Analytic Hierarchy Process) to information in the QIS (Quality Information System) if the market is unmature to get enough need information of the customers. 2. Risk Management in NPD : The NPD pursuing model consisted of the IP (indicative planning) is suggested not by the process of top-down-way mandatory planning process, but by the tools used in the administrative science and economic fields, namely by governance. The companies could apply innovative methodology for new products development processes to fulfil the customers satisfaction in the fields, through the CA (Contingency Approach) of the NPD (New Product Development) process.

• KSBB Journal
• /
• 제17권1호
• /
• pp.100-105
• /
• 2002

중합도 n$\leq$10을 갖는 N-아세틸-D-글루코사민(GlcNAc)을 미생물 Serratia marcesce-ns QM B14f6의 최소배지 회분식 발효를 이용하여 키틴 및 키토산을 분해하는 효소 키티나제(1.5 unit/mL) [키토바이아제(3.48 unit/mL)가 포함됨]를 생성시킨다. 효소 반응에 의한 키토올리고당의 생성 활성을 규명하기 위하여 부분적으로 탈아세틸화된 키토산을 효소적 가수분해 반응시킴으로써 생성된 N-아세틸-D-글루코사민과 D-글루코사민의 키토올리고당의 생성 패턴을 확인 조사한다. 이 혼합 올리고머로부터 CM-Sephadex의 컬럼 크로마토그래피에 의하여 당별로 분획시켜 추출한 헤테로 키토 올리고당들을 각각 N-아세틸화하고 이 최종 생성물을 전기투석 장치로서 정제하여 키토올리고 1-7당을 제조하였다. 부분적으로 탈아세틸화 키토산(환원당으로서 2697 mg/mL)을 효소반응에 의해 생성시킨 키토올리고당은 1당으로서 GlcNAc=4.25%, 2당 $(GlcNAc)_2$=4.49%, 3당 $(GlcNAc)_3$=11.1%, 4당 $(GlcNAc)_4$=2.5%, 5당 $(GlcNAc)_{5}$ =0.64%, 6당$(GlcNAc)_{6}$=2.12%, 7당 $(GlcNAc)_{7}$=1.21%가 각각 제조되었다.

• 한국가금학회지
• /
• 제50권4호
• /
• pp.261-266
• /
• 2023

가축의 골격근은 동물성 단백질 식품으로서 중요한 역할을 하며, 가금육의 소비는 전세계적으로 꾸준히 증가하고 있다. 근육의 형성과 발달에는 근형성조절인자를 포함한 많은 유전자들이 관여하며, 발달 단계에 따라 유전자 발현의 정확한 조절이 필요하다. 본 연구에서는 근육에서 특이적으로 발현하는 유전자를 선발하고, 해당 유전자의 프로모터를 클로닝하고 기능을 분석하였다. 동물의 조직별 유전자 발현을 분석한 결과, 다수의 유전자들이 골격근 특이적인 발현양상을 보였는데, 특히 TNNT3와 TNNC2, MYF6 유전자들은 가금에서도 유사한 양상을 나타냈다. TNNT3, TNNC2, MYF6 유전자의 프로모터 부위를 중합효소연쇄반응을 통해 각각 1.2 kb, 1.03 kb, 1.43 kb씩 증폭하여, 녹색형광단백질 유전자를 포함한 벡터의 앞부분에 삽입하였다. 염기서열 분석 결과, 세 프로모터는 기존에 밝혀진 유전체 서열과 거의 일치함을 확인하였다. QM7 메추리 근육세포주에서 각각의 프로모터를 포함한 벡터를 도입한 결과, 세 프로모터 모두녹색형광단백질을 성공적으로 발현시켰다. 녹색 형광의 밝기는 대조군으로 사용한 CMV-IE 프로모터와 비교 시, 약 7배 정도 어두웠다. 클로닝한 프로모터들에는 230개 이상의 전사인자들이 결합할 수 있을 것으로 예측되었으며, 특히 MYF5나 MYOD, MYOG와 같은 근형성조절인자를 포함한 근육에서 발현하는 다양한 전사인자들이 결합할 수 있을 것으로 예측되었다. 이 프로모터들은 가금의 근육세포에서 유전자 발현을 유도하는 연구에 활용이 가능할 것이며, 추후연구를 통해 프로모터 부위별 발현 조절 기능 연구가 필요할 것으로 사료된다.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2004년도 하계학술대회 논문집 C
• /
• pp.1624-1626
• /
• 2004

This study was to measure the minuteness structure, piezoelectric properties of (0.3-x)PMN- xPSS -0.7PZT+0.5[wt%]NiO+0.5(wt%)$MnO_2$ (x=0.05, 0.10, 0.15, 0.20, 0.25)ceramics according to sintering temp- erature and PSS(mol%) after manufacturing the specimens with a general method. the results of this study were gotten such as follows. The crystal structure of ceramic has the rombohedral structure in XRD. It appeared that addition of Ni, Mn additive was helpful to the formation of stable structure. The electrome- chanical coupling coefficient(kp) showed good properites on the whole, showed its maximum value 25.94[%] in specimens sintered at 1100[$^{\circ}C$], x=0.25mol. The mechanical quality coefficient(Qm) showed its maximum value 272.42 in specimens sintered at 1150[$^{\circ}C$], x=0.05mol. and was decreased by increasing PSS[mol%] The temperature coefficient of the resonant frequency(TCFr) showed stable properties in all sintering temperature with x=0.05mol. Especially good stability of 0.0054[%/$^{\circ}C$] showed in specimens sintered at 1100$^{\circ}C$, x=0.05mol.

• Bulletin of the Korean Chemical Society
• /
• 제29권8호
• /
• pp.1499-1504
• /
• 2008

Pyrazine derivatives bind to b-RAF receptor which is important in cancer therapy. The ligand-receptor interactions have been studied by comparative molecular field analysis (CoMFA) and molecular docking methods. Applying conventional ligand-based alignment schemes for the whole set was not successful. However, QM and DFT results suggested that some ligands have electrostatic interaction while others have steric interactions. On the basis of these results, we divided the dataset into two subsets. Electrostatic effect was found to be important in one set while steric effect for the other. Best docking modes were obtained for each subset based on the available crystal structure. These receptor-guided CoMFA models propose an interesting possibility which is difficult to obtain otherwise. i.e., in one binding mode the electrostatic interaction plays a key role for one subset ($q^2$ = 0.46, $r^2$ = 0.98), while in another binding mode steric effect is important with another subset ($q^2$ = 0.43, $r^2$ = 0.74).

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2004년도 학술대회지
• /
• pp.482-485
• /
• 2004

We fabricated a hybrid bulk/fully depleted silicon on insulator (FDSOI) complementary metal oxide semiconductor (CMOS) active pixel image sensor. The active pixel is comprised of reset and source follower transistors on the SOI seed wafer, while the pinned photodiode and readout gate and floating diffusion are fabricated on the SOI handle wafer after the removal of the buried oxide. The source of dark current is eliminated by hybrid bulk/FDSOI pixel structure between localized oxidation of silicon (LOCOS) and photodiode(PD). By using the low noise hybrid pixel structure, dark currents qm be suppressed significantly. The pinned photodiode can also be optimized for quantum efficiency and reduce the noise of dark current. The spectral response of the pinned photodiode on the SOI handle wafer is very flat between 400 nm and 700 nm and the dark current that is higher than desired is about 10 nA/cm2 at a $V_{DD}$ of 2 V.

• 대한화학회지
• /
• 제41권1호
• /
• pp.22-46
• /
• 1997

25℃와 35℃에서 메탄올-아세토니트릴 혼합용매계에 대한 할로겐화 펜아실과 피리딘 치환체와의 친핵성치환반응을 속도론적으로 연구하였다. 전이상태 파라미터인 ΔH≠와 ΔS≠ 및 Brosted β값으로 보아 $S_N2$반응 메카니즘을 예상할 수 있었고, 이탈기 변화에 따른 QM모형의 적용으로 이들 반응의 전이상태 역시 생성물 닮은 구조임을 알 수 있었다.

• 한국세라믹학회지
• /
• 제36권10호
• /
• pp.1108-1114
• /
• 1999

Microstructure and electrical properties of ZnO-doped (0-5 mol%) 0.05 Pb(Mn1/3Sb2/3)O3-0.95 PZT ceramics were investigated. Sintering temperature was decreased to 100$0^{\circ}C$ due to eutetic reaction between PbO and ZnO. Grain-size increased up to adding 1mol% ZnO and then decreased. Compositions of grain and grain-boundary were investigated by WDS. Lattice parameter was decreased with ZnO addition. Density increased with ZnO addition and reached to the maximum of 7.84(g/cm2) at 2 mol% ZnO. The effect of ZnO on electrical properties of PMS-PZT was investigated. At 3mol% ZnO addition electromechanical coupling factor(kp) was about 50% and relative dielectric constant($\varepsilon$33/$\varepsilon$0) was 997 Mechanical quality factor(Qm) decreased with ZnO addition. Lattice parameters and tetragonality(c/a) were measured to investigate relationship between the electric properties and substitution of Zn2+. At 3 mol% ZnO tetragonality was maximiged at c/a=1.0035 Curie temperature (Tc) decreased slightly with ZnO addition.