• Bulletin of the Korean Chemical Society
• /
• 제28권12호
• /
• pp.2219-2225
• /
• 2007

The reaction mechanisms for the cyclizations of N-methyl-2-(2-chloropyridin-3-yloxy)acetamide to 1-methylpyrido[ 3,2-b][1,4]oxazin-2-one and 1-methyl-pyrido[2,3-b][1,4]oxazin-2-one were investigated using ab initio Hartree-Fock, second-order Moller-Plesset perturbation, single point coupled cluster with both single and double substitution, and density functional theory methods. The 5-membered spiro intermediate (2) is optimized from the cyclization of the acyclic reactants through the proton-transfer reaction, and this intermediate proceeds continuously to the 6-membered intermediate through either a stepwise or a concerted reaction. In the stepwise reaction, an N-bridge-type intermediate as a stable structure is optimized, whereas, in the concerted reaction, the O-bridge-type intermediate is not optimized.

• 대한화학회지
• /
• 제47권3호
• /
• pp.229-236
• /
• 2003

Cyclobutenedions을 lithium trimethylsilylacetylene과 반응시키고 물로 반응을 정지시키면 butenolides가 생성된다. 이 색다른 반응을 위해 allene을 intermediate로 하는 기전을 제안하였다. 이는 trimethylsilyl group이 너무 크기 때문에 보통의 diradical intermediate는 형성이 어렵고, allene이 ${\alpha}$-silyl group에 의해 안정화되기 때문이라고 사료된다.

• 한국전산구조공학회:학술대회논문집
• /
• 한국전산구조공학회 2006년도 정기 학술대회 논문집
• /
• pp.520-527
• /
• 2006

The structural design process of the buildings consists of several design phases, which perform the simple calculation and the decision mailing to be with designers judgement, recursively. In this paper, the information that created during the design phases and used for generating the rational design result is called intermediate information. The intermediate information as well as the structural design results must be managed together in order to develop an integrated system for computer aided structural design. This paper presents the research for the object modeling concepts and the formal object model according to them for the systematic management of not only structural design results but also intermediate information.

• 한국소성가공학회:학술대회논문집
• /
• 한국소성가공학회 1999년도 춘계학술대회논문집
• /
• pp.95-98
• /
• 1999

In this study, a method to find the optimal intermediate die geometry for the multi-stage drawing process for the rectangular rod from a round bar is proposed and a program using the proposed method is developed. On the stage of the design of the intermediate die geometry, the virtual die was constructed using the initial billet as a inlet of the drawing die and the final product as a exit of that and the virtual die was divided by the number of pass. Divided die was transformed into the rectangular one which is the intermediate die geometry for the multi-stage rectangular drawing process. In order to verify the application of the proposed method on the real industrial product, the drawing of the rectangular rod from a round which composed two stage has been performed and simulated by the three dimensional rigid plastic finite element method.

• 대한음성학회지:말소리
• /
• 제47호
• /
• pp.15-29
• /
• 2003

When intonation in French is analysed in terms of a multi-dimentional and hierarchical structure, each of the prosodic units such as accent phrases(having different combinations of the basic tonemes L and H), pre-sentencial and post-sentencial long pauses, intonation phrases(containing boundary intonation), as well as intermediate phrases can be considered being realized on a separate tier. Unlike on the tiers where accent phrases and intonation phrases occur, an intonation rhythm consisting of plateaus is realised on that of intermediate phrases. This intonation rhythm consisting of plateaus is one of the significant factors that lead a basic French metrical rhythm. This paper first shows the types of combinations of the basic tonemes L and H found in French accent phrases. Secondly, this paper examines the roles intermediate phrases and plateaus play in French. Finally, this paper argues that intermediate phrases are the metrical units actually adopted as real utterance units in French.

• Bulletin of the Korean Chemical Society
• /
• 제32권3호
• /
• pp.909-914
• /
• 2011

An improved convergent and economical method has been developed for the synthesis of erlotinib, a 4-anilinoquinazoline and an EGFR-tyrosine kinase inhibitor for treatment of non-small-cell lung cancer. The final two steps for the formation of this 4-anilinoquinazoline from suitable 2-aminobenzonitrile intermediate and 3-ethynylaniline were modified and were performed in a simple one-pot reaction. The ring-closing mechanism for the formation of erlotinib from the suitable formamidine intermediate and 3-ethynylaniline was investigated and determined to proceed via the formation of phenyl benzamidine intermediate rather than involving Dimroth rearrangement reported earlier. The new benzamidine intermediate was isolated for the first time and characterized.

• Bulletin of the Korean Chemical Society
• /
• 제15권12호
• /
• pp.1054-1058
• /
• 1994

Different behavior on the formation of soluble intermediate was observed depending on the substrate employed during the nucleation of lead dioxide from plumbous ion using a rotating ring-disk electrode. It was found that no soluble intermediate was formed at glassy carbon electrode, while the presence of soluble intermediate could be detected at platinum substrate. From the different anodic behavior of two substrates, the formation of a probable Pb(Ⅲ) soluble intermediate was suggested. A most probable nucleation mechanism at the platinum substrate involving a second order chemical reaction was derived on the basis of rotating disk electrode experiments.

• International Journal of Naval Architecture and Ocean Engineering
• /
• 제12권1호
• /
• pp.157-167
• /
• 2020

The purpose of this study is to analyze the relationship between the occurrence of intermediate peak and time duration, and to conduct a review for the causes of the intermediate peak. In this test, ice impact tests were conducted using a bow side shell frame and ice specimen. A total of 70 samples were manufactured. Two types of ice specimen with relatively different surface conditions were used. The criterion for dividing the two types of ice specimen was the different exposure times to room temperature after freezing. This experiment was conducted for each parameter in order to reproduce the actual icebreaking situation. As a result of the analysis, the intermediate peak in the ice load signal have been found to be caused by mechanisms by which the inner surface of broken ice contact with hull immediately after the initial hitting point of ice has been broken.

• 시스템엔지니어링학술지
• /
• 제16권2호
• /
• pp.141-147
• /
• 2020

Due to the nature of the long-term project of a Railway business, Many problems have been arisen in the process of delivering products or systems verified by suppliers to the customer's operation site. Unexpectedly, it is often necessary for the verified products to store intermediately at the supplier's site for a variety of reasons, such as delays in business and delays in civil engineering, at the time of sending them to the customer's operation site. In this study, the intermediate storage process for finding and solving problems related to intermediate storage was presented focusing on the Rolling Stock of Railway System by reference to ISO/IEC/IEEE 15288:2015. A suitable intermediate storage process based on the developed product or system's characteristics will allow the verified products or systems to be placed on the customer's operation site and to meet the customer's product or system requirements.

• Archives of Plastic Surgery
• /
• 제36권3호
• /
• pp.344-347
• /
• 2009

Purpose: Malignant soft tissue tumors, known as sarcomas, are well known to be locally aggressive, frequently metastatic, and highly recurrent. In other hands, intermediate soft tissue tumors often recur locally with adjacent tissue infiltration so the clinical management is difficult as sarcoma. In the present study, we evaluate the clinical course of the intermediate soft tissue tumors and consider the management plan for those. Methods: From March, 1998 to April 2008, total 3 patients of intermediate soft tissue tumors underwent operations. A patient with fibrohistiocytic neoplasm, a free flap reconstruction was performed, and he underwent several more operations because of recurrences. Other patients with desmoids - type fibromatosis showed local invasion and adhesion, and one of them underwent reoperation due to local recurrence. Results: 2 of 3 patients underwent recurrences of tumors and reoperations were performed. In another patient with no recurrence, follow-up period was just 5 months, so there may be recurrence of tumor in long term follow-up. Conclusion: The clinical course of intermediate soft tissue tumors shows high recurrence rate. So clinically, intermediate soft tissue tumors should be considered as sarcomas. The successful management requires wide resection, carefully planned reconstruction, and close follow up with radiologic evaluation.