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Experimental Validation of Topology Design Optimization (밀도법 기반 위상 최적설계의 실험적 검증)

  • Cha, Song-Hyun;Lee, Seung-Wook;Cho, Seonho
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.26 no.4
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    • pp.241-246
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    • 2013
  • From the numerical results of density-based topology design optimization, a CAD geometric model is constructed and fabricated using 3D printer to experimentally validate the optimal design. In the process of topology design optimization, we often experience checkerboard phenomenon and complicated branches, which could result in the manufacturing difficulty of the obtained optimal design. Sensitivity filtering and morphology methods are used to resolve the aforementioned issues. Identical volume fraction is used in both numerical and experimental models for precise validation. Through the experimental comparison of stiffness in various designs including the optimal design, it turns out that the optimal design has the highest stiffness and the experimental result of compliance matches very well with the numerical one.

Corrosion Behavior of High Pressure Die Cast Al-Ni and Al-Ni-Ca Alloys in 3.5% NaCl Solution

  • Arthanari, Srinivasan;Jang, Jae Cheol;Shin, Kwang Seon
    • Corrosion Science and Technology
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    • v.16 no.3
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    • pp.100-108
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    • 2017
  • In this investigation corrosion behavior of newly developed high-pressure die cast Al-Ni (N15) and Al-Ni-Ca (NX1503) alloys was studied in 3.5% NaCl solution. The electrochemical corrosion behavior was evaluated using open circuit potential (OCP) measurement, potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS) techniques. Potentiodynamic polarization results validated that NX1503 alloy exhibited lower corrosion current density ($i_{corr}$) value ($5.969{\mu}A/cm^2$) compared to N15 ($7.387{\mu}A/cm^2$). EIS-Bode plots revealed a higher impedance (${\mid}Z{\mid}$) value and maximum phase angle value for NX1503 than N15 alloy. Equivalent circuit curve fitting analysis revealed that surface layer ($R_1$) and charge transfer resistance ($R_{ct}$) values of NX1503 alloy was higher compared to N15 alloy. Immersion corrosion studies were also conducted for alloys using fishing line specimen arrangement to simultaneously measure corrosion rates from weight loss ($P_W$) and hydrogen volume ($P_H$) after 72 hours and NX1503 alloy had lower corrosion rate compared to N15 alloy. The addition of Ca to N15 alloy significantly reduced the Al3Ni intermetallic phase and further grain refinement may be attributed for reduction in the corrosion rate.

Changes of the Textural Properties of the Sweet Potato Starch Gels using Maltogenic Amylase (Maltogenic amylase를 이용한 고구마 전분겔의 텍스쳐 특성 변화)

  • Kweon, Mee-Ra;Jung, Dong-Sun;Park, Kwan-Hwa
    • Korean Journal of Food Science and Technology
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    • v.25 no.6
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    • pp.649-654
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    • 1993
  • We investigated the texture of the sweet potato starch gels treated with maltogenic amylase. Effects of branched gluco-oligosaccharides and acorn starch on the texture of the sweet potato starch gel were also investigated. Hardness and cohesiveness of gels were measured by using Instron and sensory evaluation on the gel properties was performed. From the results of the instrumental analysis, it was found that the overall textural properties as Mook could be improved by adding branched glucooligosaccharides, maltogenic amylase or acorn starch to the sweet potato starch gel. As a result, there was a decrease in the cohesiveness of gels while the hardness of gels increased. The sensory evaluation study indicated that the sweet potato starch gels treated with 0.02% maltogenic amylase, or added with 12.5% branched gluco-oligosaccharides, or mixed with 50% acorn starch had preferable quality as Mook.

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Insecticidal and Acaricidal Activities of African Plant Extracts against the Brown Planthopper and Two-Spotted Spider Mite (아프리카산 식물체 추출물의 벼멸구 및 점박이응애에 대한 살충 및 살비활성)

  • I. G. Hiremath;Young Joon Ahn;Soon Il Kim;Byung Ryul Choi;Jum Rae Cho
    • Korean journal of applied entomology
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    • v.34 no.3
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    • pp.200-205
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    • 1995
  • Total 31 samples from 21 African plant species in 13 families were tested for their insecticidal and acaricidal activities against Nilaparvata lugens (Stal) and Tetranychus urticae (Koch) adults through topical application an leaf-dipping methods, respectively. The insecticidal and acaricidal activities were both plant parts and species dependent. The methanol extracts from whole plants of Casia occidental is and Cassia tora (Caesalpinaceae), an stem of Prosopis chinensis (Mimosaceae) revealed potent insecticidal activity against N. lugens. Potnet acaricidal activity against T. urticae was obtained from the methanol extracts from whole plants of Celosia trigyna (Amaranthaceae) and Combretum micronthum (Combretaceeae), leaves of Combretm glutinotum, and leaves and fruits of prosopis chinensis.

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A Study on Nano-emulsion for Enhanced Transdermal Delivery of Hippophae rhamnoides Leaf Extract (비타민나무 잎 추출물의 피부 흡수 증진을 위한 나노에멀젼 연구)

  • Chae, Kyo Young;Kwon, Soon Sik;Park, Soo Nam
    • Applied Chemistry for Engineering
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    • v.24 no.3
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    • pp.260-265
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    • 2013
  • In this study, nano-emulsions containing 0.01, 0.03, 0.05, and 0.10% ethyl acetate fraction of Hippophae rhamnoides (H. rhamnoides) leaf extracts were prepared. The particle size, particle size distribution and skin permeability of the nano-emulsions were evaluated for five weeks. Nano-emulsion was prepared by the sequential use of homogenizer and microfluidizer. Nano-emulsion containing the ethyl acetate fraction exhibited a monodispersed form. Nano-emulsion containing 0.03% ethyl acetate fraction was the most stable for five weeks. The in vitro skin permeation study of nano-emulsion containing 0.03% ethyl acetate fraction was carried out using Franz diffusion cell. The nano-emulsion showed a better skin permeability than that of O/W emulsion. These results indicate that the nano-emulsion containing the ethyl acetate fraction of H. rhamnoides leaf extract showed a remarkable stability and skin permeability than that of O/W emulsion.

A Posterior Annuloplasty, Papillary Muscle Plication and Left Ventricle Reduction Through Left Ventriculotomy in Severe Ischemic Cardiomyopathy with Mitral Regurgitation (승모판 폐쇄 부전을 동반한 허혈성 심근병증에서 좌심실 절개를 통한 승모판 성형술 및 유두근 단축술과 좌심실 용적 축소술)

  • Jung Jong-Pil;Cho Won-Chul;Kim Joon-Bum;Lee Jae-Won
    • Journal of Chest Surgery
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    • v.39 no.7 s.264
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    • pp.549-552
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    • 2006
  • In the mitral regurgitation (MR) accompanied with a serious ischemic cardiomyopathy (ICMP), coronary revascularization to viable myocardium, LV reduction and mitral reconstruction become the main surgery under the bad conditions that the cardiac transplantation is not so easy. The MR in ischemic cardiomyopathy appears as various pathologic factors, among them, the papillary muscle displacement in addition to the annular dilatation is pointed out as the important cause. Our hospital would like to report the experience of the surgery about coronary revascularization to the left main with 3-vessel coronary disease, severe ICMP patients accompanied with the MR, posterior mitral annuloplasty and papillary muscle plication through the LVtomy.

Status of meat alternatives and their potential role in the future meat market - A review

  • Lee, Hyun Jung;Yong, Hae In;Kim, Minsu;Choi, Yun-Sang;Jo, Cheorun
    • Asian-Australasian Journal of Animal Sciences
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    • v.33 no.10
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    • pp.1533-1543
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    • 2020
  • Plant-based meat analogues, edible insects, and cultured meat are promising major meat alternatives that can be used as protein sources in the future. It is also believed that the importance of meat alternatives will continue to increase because of concerns on limited sustainability of the traditional meat production system. The meat alternatives are expected to have different roles based on their different benefits and limitations. Plant-based meat analogues and edible insects can replace traditional meat as a good protein source from the perspective of nutritional value. Furthermore, plant-based meat can be made available to a wide range of consumers (e.g., as vegetarian or halal food products). However, despite ongoing technical developments, their palatability, including appearance, flavor, and texture, is still different from the consumers' standard established from livestock-based traditional meat. Meanwhile, cultured meat is the only method to produce actual animal muscle-based meat; therefore, the final product is more meat-like compared to other meat analogues. However, technical difficulties, especially in mass production and cost, remain before it can be commercialized. Nevertheless, these meat alternatives can be a part of our future protein sources while maintaining a complementary relationship with traditional meat.

Allogeneic clonal mesenchymal stem cell therapy for refractory graft-versus-host disease to standard treatment: a phase I study

  • Yi, Hyeon Gyu;Yahng, Seung-Ah;Kim, Inho;Lee, Je-Hwan;Min, Chang-Ki;Kim, Jun Hyung;Kim, Chul Soo;Song, Sun U.
    • The Korean Journal of Physiology and Pharmacology
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    • v.20 no.1
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    • pp.63-67
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    • 2016
  • Severe graft-versus-host disease (GVHD) is an often lethal complication of allogeneic hematopoietic stem cell transplantation (HSCT). The safety of clinical-grade mesenchymal stem cells (MSCs) has been validated, but mixed results have been obtained due to heterogeneity of the MSCs. In this phase I study, the safety of bone marrow-derived homogeneous clonal MSCs (cMSCs) isolated by a new subfractionation culturing method was evaluated. cMSCs were produced in a GMP facility and intravenously administered to patients who had refractory GVHD to standard treatment resulting after allogeneic HSCT for hematologic malignancies. After administration of a single dose ($1{\times}10^6cells/kg$), 11 patients were evaluated for cMSC treatment safety and efficacy. During the trial, nine patients had 85 total adverse events and the rate of serious adverse events was 27.3% (3/11 patients). The only one adverse drug reaction related to cMSC administration was grade 2 myalgia in one patient. Treatment response was observed in four patients: one with acute GVHD (partial response) and three with chronic GVHD. The other chronic patients maintained stable disease during the observation period. This study demonstrates single cMSC infusion to have an acceptable safety profile and promising efficacy, suggesting that we can proceed with the next stage of the clinical trial.

Component Analysis of Persicaria hydropiper L. Extracts (여뀌 추출물의 성분 분석)

  • Kim, Jung-Eun;Kim, Eun-Hee;Park, Soo-Nam
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.36 no.1
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    • pp.89-92
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    • 2010
  • In the previous study, we reported the antioxidative activity, antiaging activity, antibacterial activity and moisturizing effect of cream containing Persicaria hydropiper L. extract. In this study, the components of Persicaria hydropiper L. extract were analyzed by TLC and HPLC. Aglycone fractions obtained from the deglycosylation reaction of ethyl acetate fraction among the Persicaria hydropiper L. extract, showed 2 bands and 2 peaks in TLC and HPLC experiments, respectively. Two components were identified as quercetin and kaempferol. TLC chromatogram of ethyl acetate fraction of Persicaria hydropiper L. extract revealed 6 bands and HPLC chromatogram showed 7 peaks, which were identified as quercetin, hyperin, isoquercitrin, quercitrin, kaempferol. In conclusion, with the antioxidative activity, antiaging activity, antibacterial activity and moisturizing effect reported previously, component analysis of Persicaria hydropiper L. extracts could be applicable to new cosmeceuticals.

A Study on the character of Urban Entertainment Center in multi-anchor and exposure time - Focusing on Cheongryanri station and Yongsan station - (집객시설과 노출시간에 따른 도심 엔터테인먼트형 복합상업시 설(UEC)의 특징에 관한 연구 - 청량리역과 용산역을 중심으로 -)

  • Kim, Hyeongjung
    • Korean Institute of Interior Design Journal
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    • v.22 no.1
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    • pp.283-290
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    • 2013
  • The change of shopping environment created new emerging type of shopping center after 1990's, Urban Entertainment Center(UEC) in northen America. One hand traditional shopping center was retail-centered, the other hand UEC is entertainment-centered and offers the trinity of synergy. Each components, that are retail, dining and entertainment, play a role of drawing people, extending duration of visiting and making people revisit then the synergy makes commercial profit in shopping center. As northen America many of shopping centers with complex have been built in Korea since 2000 and some projects is planning by the change of shopping environment and regenerating urban. Although the term of "UEC" is used in Korea, it seems to be added entertainment facilities to shopping center without considering on commercial strategy. This study will take a look at mix and duration of visit which ULI stresses in UEC development and comparing with those of Yongsan Station and Chyeongrangri Station which are built recently in seoul, it will get characters and situation of these UECs. Finally, the analysis is to be used as a planning data in UEC development.