• Title/Summary/Keyword: Morphological properties

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Effects of Morphology on the Electrical and Mechanical Properties of the Polycarbonate/Multi-Walled Carbon Nanotube Composites

  • Kum Chong-Ku;Sung Yu-Taek;Han Mi-Sun;Lee Heon-Sang;Lee Sun-Jeong;Joo Jin-Soo;Kim Woo-Nyon
    • Macromolecular Research
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    • v.14 no.4
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    • pp.456-460
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    • 2006
  • The electrical, morphological, and mechanical properties of poly carbonate (PC)/multi-walled carbon nan-otube (MWNT) composites were studied by electrical conductivity, electromagnetic interference shielding efficiency (EMI SE), scanning electron microscopy, and tensile strength measurements. In the electrical property analysis of the PC/MWNT composites, the percolation threshold of the PC/MWNT composites was observed between 1.5 and 2.5 wt% MWNT content. From the electrical conductivity and EMI SE studies, the theoretical values of the EMI SE were in good agreement with the experimental values of the EMI SE. From the morphology of the PC/MWNT composites, it was observed that MWNT is dispersed homogenously in the PC matrix. From the electrical conductivity and morphological studies, it was suggested that the percolation threshold of the PC/MWNT composites is related with the morphological results in that MWNT is apparently interconnected to form an electrical pathway. The mechanical properties of the PC/MWNT composites peaked at the MWNT content of 2.5 wt%.

Influence of Carbide Formation on Tensile and Fatigue Properties of Carburized Steels

  • Yu, Eunji;Jung, Heejong;Kim, Kun-Su;Kim, Eui-Jun;Kim, Jongryoul
    • Applied Microscopy
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    • v.43 no.2
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    • pp.81-87
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    • 2013
  • The influence of carbide formation on mechanical properties has been investigated in carburized steels. Through controlled diffusion and precipitation processes, the morphologies of carbides could be changed and then fine, networked, and spherical shapes at carburized layers were obtained. These morphological changes affected tensile and bending fatigue properties of the steel. The fine and the spherical carbides acted as resistance sites against crack propagation, which improved the mechanical properties. However, the networked carbides deteriorated the properties because the cracks propagated along the boundaries of them. These results indicate that the morphological control of carbides is one of important keys to improve the mechanical properties.

Electrical and morphological properties of titanium silicide fabricated by high temperature sputtering method (고온스퍼터링법으로 제작된 티타늄실리사이드의 구조적 전기적 특성 연구)

  • Lee, S.J.;Kim, D.S.;Seong, K.S.;Kang, Y.M.;Cha, J.H.;Song, M.K.;Jung, W.;Kim, D.Y.;Lee, Y.H.;Cho, H.Y.;Hong, J.S.
    • Proceedings of the IEEK Conference
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    • 2000.06b
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    • pp.60-63
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    • 2000
  • We have investigated the relationship between electrical and morphological properties of titanium silicide films. In this study, the C54 titanium silicides were formed by using high temperature sputtering and one-step annealing. From the measurement of electrical and morphological properties, a smooth surface and a relaxed roughness were observed for the titanium silicide film fabricated by high temperature sputtering. And it seems that the previous effect could improve electrical properties.

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Morphological Properties of Lintnerized Maize Starches with Different Amylose Content (아밀로오스 함량이 다른 산처리 옥수수전분의 형태학적 특성)

  • 신말식;이신경
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.26 no.6
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    • pp.1086-1090
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    • 1997
  • Morphological properties on lintnerized maize starches with different amylose content were investigated. With increasing the lintnerization periods and decreasing the amylose content, hydrolysis rate was increased. As amylose content of starch was increased, the degree of damage with acid treatment was decreased by SEM. With increasing hydrolysis, iodine affinity, apparent amylose content and ${\lambda}_{max}$ of lintnerized starches were decreased. Water binding capacities of lintnerized starches were higher than those of native starches.

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The approach of properties-flavours theory and the study of morphological standard in ARTEMISIAE HERBA (인진호(茵陳蒿)의 기미론(氣味論)적 해석과 내외부형태연구)

  • Lee, Hwa-Jung;Choi, Mun-Il;Kim, Ja-Young;Kang, Kyoung-Sik;Shin, Chol-Gyun;Jul, Young-Sung;Yun, Ju-Bong
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.19 no.2
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    • pp.130-145
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    • 2006
  • Objectives : The aim of this work is the approaching of properties-flavours theory and the making of morphological standard in Artemisiae herba. Methods : The properties-flavours theory were attempted with bibliographic method and various climate-information. The external-internal morphological standards were determined by using stereoscope and butanol series. Conclusions : The following is a list the conclusion of the approaching of properties-flavours theory and how to make the standard of morphological standard in artemisiae herba. 1. The significant analysis for the artemisiae herba as the properties-flavours theory, is a follow-up survey of the effect written in the official oriental medicine book 2. The other analytic methods according to the gathering time, processing or storing system or especially nature or growth environment(altitude, temperature,. the mean moisture, and the agronomical survey) by way of the explanation of properties-flavours theory appears so many insufficiency at the many cases. 3. In the case of artemisiae herba., there are 2 cases(Artemisia capillaris $T_{HUNB}$ and A. iwayomogi $K_{ITAMURA}$) in current and recently A. aruwa L. is substituted for artemisiae herba in circulation. 4. The external and internal characteristics according to the shape of original plant or herbal states, entirely correspond to all the official oriental medicine boo 5. According to the place of productiot the difference appeals. (1) A. capillatis $T_{HUNB}$. has leaves like a fine thread, and A. iwayomogi $K_{ITAMURA}$ has big and wide leaves, and shows some reddish color, and A. aruwa L. has narrow leaves, its section lines long vertically. (2) In the internal shapes, as the A. capillatis $T_{HUNB}$. leaves', upper epidermal cell wall shows relatively straight form, its all upper- lower epidemical cell wall has a stoma, and calcium rosette crystal is relatively few. As iwayomogi $K_{ITAMURA}$, all upper- lower epidermal cell wall is wavelike concave, and hypodermics has many stoma and many calcium rosette crystal. (3) In the internal shapes of A. aruwa L. the shape of leaves' epidermal cell is irregular and has so many non-glandular hair nad glandular hair on its surface.

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The Statistical Analysis of Morphological Filters for a Continuous Stationary lst-Order Gauss-Markov Source (연속정상 1차 Gauss-Markov 신호원에 대한 형태론적 여파기의 통계적 분석)

  • 김한균;윤정민;나상신;최태영
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.32B no.6
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    • pp.899-908
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    • 1995
  • In this paper, the probabilistic relations of dual morphological operations, such as dilation and erosion, closing and opening, and close- open and open-close, and the statistical properties for a continuous stationary lst order Gauss-Markov source are analyzed. The result is that the dual filters have symmetrical means and skews, and equal variances. Also, the statistics of morphological filters are very similar with those of input source, as correlation coefficient increases.

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Relationship between morphology and viscosity of the main culture broth of Cephalosporium acremonium M25

  • Kim Jong Chae;Lim Jung Soo;Kim Jung Mo;Kim Chongyoup;Kim Seung Wook
    • Korea-Australia Rheology Journal
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    • v.17 no.1
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    • pp.15-20
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    • 2005
  • In this study, the relationship between morphology and viscosity of the main culture broth of Cephalosporium acremonium M25 was investigated in a 2.5 L bioreactor. The differentiation of C. acremonium M25 showed a complex pattern during the main culture. The morphological changes of C. acremonium M25 were related to the rheological properties of the culture broth and it was well agreed with the power law model. As a result of rheology study, it was found that rheological properties of the main culture broths of C. acremonium M25 in bioreactor were closely related to morphological changes. Also, fractal dimension fairly predicted morphological and rheological changes in the main culture broth.

Rheological, Morphological and Electrical Properties of Polycarbonate/Multi-walled Carbon Nanotube Composites

  • Han, Mi-Sun;Sung, Yu-Taek;Chung, Ji-Woong;Kim, Woo-Nyon;Lee, Heon-Sang;Kum, Chong-Ku
    • Proceedings of the Polymer Society of Korea Conference
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    • 2006.10a
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    • pp.220-220
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    • 2006
  • Rheological and electrical properties of the polycarbonate (PC) / multi-walled carbon nanotube (MWNT) were studied. The MWNT was funtoinalized by treating with the hydrogen peroxide ($H_{2}O_{2}$). The electrical conductivity showed higher value for the PC/MWNT ($H_{2}O_{2}$ treated, freeze drying) composites compared that of the PC/MWNT ($H_{2}O_{2}$ treated, thermal drying) composites. From the results of the morphological, rheological, and electrical properties of the PC/MWNT composites, it is suggested that the electrical and rheological properties of the PC/MWNT composites are affected by the MWNT-MWNT network structure which is related with the MWNT morphologies such as the degree of aggregation and aspect ratio of the MWNT.

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Dynamic Mechanical and Morphological Properties of Natural Rubber Vulcanizates Containing Fillers

  • Lee, Hae Gil;Park, Chan Young
    • Elastomers and Composites
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    • v.51 no.3
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    • pp.218-225
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    • 2016
  • In order to examine correlation between silane coupling agent and activator which affects the physical properties of silica filled natural rubber compound, such as heat buildup, rebound property, dynamic mechanical and morphological properties were measured. With incorporation of silane coupling agent, $tan{\delta}$ at $0^{\circ}C$ was increased and at $60^{\circ}C$ was decreased, which resulted in improving of wet grip and rolling resistance. When silane coupling agent which is corresponding to 8~10% of silica was used, most favorable heat build up and $tan{\delta}$ was obtained. And also when activator was used, dispersibility of silica was improved as a result of reduction of reaggregation of silica.

Studies on the Risk Class and Morphological Characteristics of Injured Microorganisms in Wooden Cultural Properties (목조문화재 가해 미생물의 형태학적 특성 및 가해위험도 연구)

  • Lee, Min-Young;Jeong, Seon-Hye;Kim, Eun-Song;Kim, Dae-Woon;Chung, Yong-Jae
    • 보존과학연구
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    • s.30
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    • pp.31-46
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    • 2009
  • In the study, we confirmed morphological traits and calculated the Risk Class of 25 mould species, including Tyromyces palustris, through decomposition rate of substrate for characteristic confirmation of injured microorganisms. We received the injured microorganisms in wood and it was pure cultivated. We observed growth traits and decomposition rate of substrate. Also, it allows the calculation of Risk Class to be worried in the case of growth in wooden cultural properties. As a result, Tyromyces palustris, representative of brown-rot, has the characteristics about decomposition rate of substrate - Cellulose ; more active(+++), Lignin ; more active(+++), Xylan ; more active(+++), Starch ; active(++). We classified Tyromcyes palustris as a first Risk Class and as a second Risk Class about Schizophyllum commune et al(9 species, See table 1. We look forward to offering standard data base for evaluating Risk Class as a matter of applying preventive conservation in wooden cultural properties through our study.

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