• Title/Summary/Keyword: central series

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Liquid Crystalline Properties of Dimers Having o-, m- and p- Positional Molecular Structures

  • Park, Joo-Hoon;Choi, Ok-Byung;Lee, Hwan-Myung;Lee, Jin-Young;Kim, Sung-Jo;Cha, Eun-Hee;Kim, Dong-Hyun;Ramaraj, B.;So, Bong-Keun;Kim, Kyung-Hwan;Lee, Soo-Min;Yoon, Kuk-Ro
    • Bulletin of the Korean Chemical Society
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    • v.33 no.5
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    • pp.1647-1652
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    • 2012
  • With the objective to design and synthesis of Schiff's base symmetrical liquid crystal dimmers and to study the effect of molecular structure variation ($o-ortho$, $m-meta$, $p-para$) and change in alkoxy terminal chain length on mesomorphic properties of liquid crystals, We have synthesized Schiff base dimers from dialdehyde derivative containing 2-hydroxy-1,3-dioxypropylene as short spacer with aniline derivatives having different lengths of terminal alkoxy chains ($n$ = 5, 7, 9). The chemical structure of the final products was characterized by proton nuclear magnetic resonance ($^1H$ NMR) spectroscopy and fourier transform infrared (FT-IR) spectroscopy. The mesomorphic properties and optical textures of the resultant dimers were characterized by differential scanning calorimetry (DSC) and polarized optical microscopy (POM). The existence of smectic A phase transition was confirmed by the observation of batonnets and fan shaped textures in optical microscopy when compound were heated from crystalline phase. All of the dimers of this series, with the exception of $\mathbf{2S_5}$ -ortho, -meta, -para, were thermotropic liquid crystal. The compound $\mathbf{2S_9}$ -meta was monotropic, while the rest were enantiotropic. It was found that the change in terminal alkoxy chain length has pronounced effect on the mesomorphic properties. The temperature range of smectic A phase window widens with increasing alkoxy chain length.

Buffeting response control of a long span cable-stayed bridge during construction using semi-active tuned liquid column dampers

  • Shum, K.M.;Xu, Y.L.;Guo, W.H.
    • Wind and Structures
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    • v.9 no.4
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    • pp.271-296
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    • 2006
  • The frequency of a traditional tuned liquid column damper (TLCD) depends solely on the length of liquid column, which imposes certain restrictions on its application to long span cable-stayed bridges during construction. The configuration of a cable-stayed bridge varies from different construction stages and so do its natural frequencies. It is thus difficult to apply TLCD with a fixed configuration to the bridge during construction or it is not economical to design a series of TLCD with different liquid lengths to suit for various construction stages. Semi-active tuned liquid column damper (SATLCD) with adaptive frequency tuning capacity is studied in this paper for buffeting response control of a long span cable-stayed bridge during construction. The frequency of SATLCD can be adjusted by active control of air pressures inside the air chamber at the two ends of the container. The performance of SATLCD for suppressing combined lateral and torsional vibration of a real long span cable-stayed bridge during construction stage is numerically investigated using a finite element-based approach. The finite element model of SATLCD is also developed and incorporated into the finite element model of the bridge for predicting buffeting response of the coupled SATLCD-bridge system in the time domain. The investigations show that with a fixed container configuration, the SATLCD with adaptive frequency tuning can effectively reduce buffeting response of the bridge during various construction stages.

Study on Development of Crafts Cultural Industry - Central Region of South Korea Craft Industrial as center - (공예문화산업의 발전방안 연구 - 중부권 공예문화산업 중심으로 -)

  • Kim, Sung-Min
    • Journal of Digital Convergence
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    • v.14 no.5
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    • pp.385-390
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    • 2016
  • Cultural industry consists of a national own value and life style known as the cultural characteristics, and it has decorative and practical features so it covers necessaries and items of personal preference that the public use. Craft Culture Industry means the craft industry where goods with cultural features of traditional art are made based on specific region and surroundings, which is a series of process in which inherent traditional and cultural elements are produced, representing cultural industry. With the review on issues and solutions in each section of Craft Culture Industry, it would help solve the problem when developing Craft Culture Industry. This study examines the popularity and status of the craft cultural products and figures out the current situation of the domestic cultural industry and the development plan.

The Effect of Substituents on the Liquid Crystalline Behavior of New H-Shaped Dimesogenic Conpounds (새로운 H-자형 이메소겐 화합물의 액정특성에 치환기가 미치는 효과)

  • Park, Joo Hoon;Jin, Jung Il
    • Journal of the Korean Chemical Society
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    • v.42 no.3
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    • pp.315-322
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    • 1998
  • A series of new dimesogenic compounds were prepared and their thermotropic and liquid crystalline properties were studied by differential scanning calorimetry and on a hot-stage of a polarizing microscope. These compounds, 1,10-bis[2,5-bis(4-substitutedphenoxycarbonyl)phenoxy]decanes, consist of two bis(ρ-substitutedphenoxy)terephthalate units interconnected through a oxydecamethyleneoxy spacer on the central terephthaloyl units resulting in the structure of "H-shaped" dimeric twin compounds. The terminal substitutent groups were changed; X=-F, -H, -I, -Cl, -Br, $-NO_2,\;-CF_3,\;-OC_4H_9,\;-CN\;and\;-C_6H_5.$ The compounds with X=$-OC_4H_9,\;-CN\;and\;-C_6H_5$ were monotropically nematic. In contrast, the compounds with $X=-F, -H, -I, -Cl, -Br, $-NO_2\;and\;-CF_3$ were non-liquid crystals. The nematic group efficiency of these compounds was in the order of -C_6H_5>-CN>-OC_4H_9.$

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A Study on the Types and Changes of the Urban Houses in the Korean Inland during the Period 1910-1945 (한국(韓國) 근대기(近代期) 내륙지방(內陸地方) 도시주택(都市住宅)의 유형(類型)과 변천(變遷)에 관한 연구(硏究))

  • Kim, Tai-Young
    • Journal of architectural history
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    • v.7 no.3 s.16
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    • pp.53-66
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    • 1998
  • In the meantime, the study of traditional and contemporary house had been produced so many achievements in korea, but modern house is yet to be solved, Accordingly, It is necessary to develop and present the basic research data in order to build up an objective study for urban house in the modern age(1910-1945), Following to a study on the foreigner's house in grid-type settlement of Open Ports, in this research is to investigate and analyze modern houses of urban areas in korean inland, and then clarify types and changes of them. In the first year($1995{\sim}96$), the modern houses of Central Inland Districts(arrounding river Kumgang)-Kunsan kanggyong Puyo Kongju Pugang Chongju were investigated by the layout of room, the construction and materials, the design and style, etc. In the second year($1996{\sim}97$), the modern houses of Open Market(開市場)-Seoul Taegu Kwangju Taejon Chonju were conducted to investigate as above. The traditional house transformed by differentiation and addition of room(kan), the various types were respectively adopted for the korean reforming and western cultural house. In the layout of room, the types of plan were gradually concentrated from the single wings of korean traditional house. The korean traditional house was later improved through the introduction of entrance, corridor, and internal toilet/bathroom. But the korean under-floor heating system(andal) and a series of three rooms had been entirely maintained, composed of master bedroom/living room(daechung)/room. And the traditional town house with shop and storage, being built closely to each other and walled up both sides, it had taken gradually the extensive characteristics in itself. By the displacement of shop/dwelling/ storage. the various types were respectively adopted for the separated, multi-storied, and complex type. The type of them was gradually changed to the narrow and linear form. And so with the stockpile of fundamental datas about modern houses in korean urban areas, we expect these results contribute to the knowledge of the spatial characteristics of urban house at present which are required to the understanding of transition as well as types.

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Breast Auto-Augmentation: A Versatile Method of Breast Rehabilitation-A Retrospective Series of 107 Procedures

  • Kirwan, Laurence;Wazir, Umar;Mokbel, Kefah
    • Archives of Plastic Surgery
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    • v.42 no.4
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    • pp.438-445
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    • 2015
  • Background Breast auto-augmentation (BAA) using an inferior pedicle dermoglandular flap aims to redistribute the breast tissue in order to increase the fullness in the upper pole and enhance the central projection of the breast at the time of mastopexy in women who want to avoid implants. The procedure achieves mastopexy and an increase in breast volume. Methods Between 2003 and 2014, 107 BAA procedures were performed in 53 patients (51 bilateral, 2 unilateral and 3 reoperations) with primary or secondary ptosis of the breast associated with loss of fullness in the upper pole (n=45) or undergoing explantation combined with capsulectomy (n=8). Six patients (11.3%) had prior mastopexy and 2 (3.7%) patients had prior reduction mammoplasty. The mean patients' age was 41 years (range, 19-66 years). All patients had preoperative and postoperative photographs and careful preoperative markings. Follow-up ranged from 6 months to 9 years (mean, 6.6 months). Results The range of elevation of the nipple was from 6 to 12 cm (mean, 8 cm). The wounds healed completely with no complications in 50 (94.3%) patients. Three patients had complications including 2 (3.7%) hematomas and 1 (1.9%) partial necrosis of the nipple-areola complex. Three (5.7%) patients were dissatisfied with the level of mastopexy achieved underwent a further procedure. No patient complained of scar hypertrophy. Conclusions BAA is a versatile technique for women with small breasts associated with primary or secondary ptosis. It is also an effective technique for the salvage of breasts after capsulectomy and explantation.

Endogenous Development Strategy of Technopolis in Korea: Case of Daedeok INNOPOLIS

  • Lee, Eung-Hyun;Oh, Deog-Seong
    • World Technopolis Review
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    • v.5 no.1
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    • pp.2-18
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    • 2016
  • The development of Technopolis and the establishment of innovative ecosystem have made an important contribution in South Korea's latest industrial development and economic growth. Particularly, Daedeok INNOPOLIS which is responsible for the central role in the national science technology advancement was founded as the Science Town in the 1970s. Since then, it has undergone three-phases of development: Science Park, Technopolis and Innovation cluster. As the result of the transition, Daedeok INNOPOLIS currently serve as the leading role for achieving sustainable economic growth, employment promotion, national and regional innovation. In order to accelerate the progress for success, Daedeok INNOPOLIS have arranged an opportunity for 21st century new industry development, improved growth of technology-intensive SMEs, reinforced academic-industrial cooperation, and established innovative ecosystem. Daedeok INNOPOLIS is considered as an outstanding case of endogenous development strategy of Technopolis. This study attempts to consider the endogenous development strategy of Technopolis in Korea through the analysis of development characteristics of Daedeok INNOPOLIS in two different perspectives: changes of spatial structure and establishment of innovation ecosystem. Daedeok INNOPOLIS have experienced a series of endogenous growth that is consisted of advancement strategy and structural changes, which allowed Daedeok research town to grow into an innovative cluster. A sign of growth of Daedeok INNOPOLIS became apparent when its strategy to reinforce the academic-industry cooperation system by promoting participation from universities helped to overcome a functional limitation as a research institute integrated for the establishment of innovative ecosystem. Since then, the center for creative economy and innovation established in cooperation with large enterprise, has a role to build a startup ecosystem and to promote next level of development such as proactive fostering of venture companies for sustainable technopolis development.

An Approach for a Substitution Matrix Based on Protein Blocks and Physicochemical Properties of Amino Acids through PCA

  • You, Youngki;Jang, Inhwan;Lee, Kyungro;Kim, Heonjoo;Lee, Kwanhee
    • Interdisciplinary Bio Central
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    • v.6 no.4
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    • pp.3.1-3.10
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    • 2014
  • Amino acid substitution matrices are essential tools for protein sequence analysis, homology sequence search in protein databases and multiple sequence alignment. The PAM matrix was the first widely used amino acid substitution matrix. The BLOSUM series then succeeded the PAM matrix. Most substitution matrixes were developed by using the statistical frequency of substitution between each amino acid at blocks representing groups of protein families or related proteins. However, substitution of amino acids is based on the similarity of physiochemical properties of each amino acid. In this study, a new approach was used to obtain major physiochemical properties in multiple sequence alignment. Frequency of amino acid substitution in multiple sequence alignment database and selected attributes of amino acids in physiochemical properties database were merged. This merged data showed the major physiochemical properties through principle components analysis. Using factor analysis, these four principle components were interpreted as flexibility of electronic movement, polarity, negative charge and structural flexibility. Applying these four components, BAPS was constructed and validated for accuracy. When comparing receiver operated characteristic ($ROC_{50}$) values, BAPS scored slightly lower than BLOSUM and PAM. However, when evaluating for accuracy by comparing results from multiple sequence alignment with the structural alignment results of two test data sets with known three-dimensional structure in the homologous structure alignment database, the result of the test for BAPS was comparatively equivalent or better than results for prior matrices including PAM, Gonnet, Identity and Genetic code matrix.

Application of the Convolution Method on the Fast Prediction of the Wind-Driven Current in a Samll Bay (소규모 만에서 취송류의 신속예측을 위한 convolution 기법의 적용)

  • 최석원;조규대;윤홍주
    • Journal of Environmental Science International
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    • v.8 no.3
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    • pp.299-307
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    • 1999
  • In order to fast predict the wind-driven current in a small bay, a convolution method in which the wind-driven current can be generated only with the local wind is developed and applied in the idealized bay and the idealized Sachon Bay. The accuracy of the convlution method is assessed through a series of the numerical experiements carried out in the jidealized bay and the idealized Sachon Bay. The optimum response function for the convolution method is obtained by minimizing the root man square (rms) difference between the current given by the numerical model and the current given by the convolution method. The north-south component of the response function shows simultaneous fluctuations in the wind and wind-driven current at marginal region while it shows "sea-saw" fluctuations (in which the wind and wind-driven current have opposite direction) at the central region in the idealized Sachon Bay. The present wind is strong enough to influence on the wind-driven current especially in the idealized Sachon Bay. The spatial average of the rms ratio defined as the ratio of the rms error to the rms speed is 0.05 in the idealized bay and 0.26 in the idealized Sachon Bay. The recover rate of kinetic energy(rrke) is 99% in the idealized bay and 94% in the idealized Sachon Bay. Thus, the predicted wind-driven current by the convolution model is in a good agreement with the computed one by the numerical model in the idealized bay and the idealized Sachon Bay.achon Bay.

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The study on the Igneous Activity in the Southeastern Zone of the Ogcheon Geosynclinal Belt, Korea(I) with the Igneous Activity in Namweon-Geochang-Sangju Area (옥천지향사대(沃川地向斜帶) 동남대(東南帶)에서의 화성활동(火成活動)(I): 남원(南原)-거창(居昌)-상주(尙州) 지역(地域)을 중심(中心)으로)

  • Kim, Yong Jun;Park, Yong Seog;Choo, Seung Hwan;Oh, Mihn Soo
    • Economic and Environmental Geology
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    • v.22 no.4
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    • pp.355-370
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    • 1989
  • Igneous rocks of study area consist of Pre-Cambrian orthogneiss, Devonian granite, Triassic foliated granites and Jurassic granites distributed along the southeast margin of Ogcheon Geosynclinal belt(SE-zone), and irregular shaped granitic stocks in the central part of the belt(C-zone). Anorthosite and gaabbro are also present in southern part of the SE-zone in the belt and intruded into gneiss complex of Ryongnam massif. Distribuition of foliated granites shows three linear arrangements which are composed of hornblende-biotite foliated granodiorite, porphyritic foliated granodiorite, biotite foliated granodiorite, leuco foliated granite and two mica foliated granite. Foliated granites generated by dextral strike slip movement at deep level. Jurassic granites composed of several rock facies are considered to be formed by differentiation of magma during Daebo Orogeny. A general trend of the chemical composition of these igneous rocks in study area suggests that most of them corresponding to calc-alkaline rock series was affected under orogeny and I-type granite except for two mica foliated granite. In chondrite normalised REE pattern of these igneous rocks, LREE shows more variable range and strong (-)Eu anomaly than HREE. Geochronological episodes of igneous activity from early Proterozoic to Cretaceous in SE-zone of Ogcheon Geosynclinal belt are two more Pre-Cambrian Orogeny, Devonian Orogeny(Variscan), Songrim Disturbance, Daebo Orogeny and Bulkuksa Disturbance.

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