• Title/Summary/Keyword: low-tech

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Sophistication of Export Basket: The Case of Petrochemical Industries in Ulsan, Korea (수출산업 고도화전략에 대한 연구: 울산지역 석유화학산업을 중심으로)

  • Lee, Byeong Wan;Kim, Tae-Hyun
    • Korea Trade Review
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    • v.44 no.1
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    • pp.237-251
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    • 2019
  • This paper seeks to recommend strategic policy options geared towards enhancing sophistication level of Ulsan City's major export industries in the Republic of Korea. Ulsan's major export industries, including shipbuilding, automobile and petrochemical industries, turn out to be based mostly on low to medium technology with low R&D intensity suggesting relatively low level of product sophistication. Using a recent Eurostat high-tech industry classification table which suggests 9 high-tech industries, the paper identifies Ulsan's chemical industry as the only RCA industry. Focusing on chemical industry products at HS 6-digit level, specific products are identified at the efficiency frontier for future policy considerations.

Study on Organic Rankine Cycle (ORC) for Maximum Power Extraction from Low-Temperature Energy Source (저온 열원으로부터 최대 동력을 생산하기 위한 유기랭킨사이클(ORC)에 관한 연구)

  • Kim, Kyoung-Hoon;Han, Chul-Ho;Kim, Gi-Man
    • Journal of the Korean Solar Energy Society
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    • v.31 no.3
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    • pp.73-79
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    • 2011
  • ORC(organic Rankine cycle) has potential of reducing consumption of fossil fuels and has many favorable characteristics to exploit low-temperature heat sources. This work analyzes performance of ORC with superheating using low-temperature energy sources in the form of sensible energy. Maximum mass flow rate of a working fluid relative to that of a source fluid is considerd to extract maximum power from the sources. Working fluids of R134a, $iC_4H_{10}$ and $C_6C_6$, and source temperatures of $120^{\circ}C$, $200^{\circ}C$ and $300^{\circ}C$ are considered in this work. Results show that for a fixed source temperature thermal efficiency increases with evaporating temperaure, however net work per unit mass of source fluid has a maximum with respect to the evaporating temperature in the range of low source temperature. Results also show that the maximum power extraction is possible with R134a for the source temperature of $120^{\circ}C$, with $iC_4H_{10}$ for $200^{\circ}C$, and with $C_6C_6$ for $300^{\circ}C$.

Nutrition and health challenges among low-income families of young children in the post COVID-19 era: a qualitative study

  • Hyunjung Lee;Wilna Oldewage-Theron;Conrad Lyford;Stephanie Shine
    • Nutrition Research and Practice
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    • v.17 no.6
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    • pp.1185-1200
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    • 2023
  • BACKGROUND/OBJECTIVES: In the United States, one in every 5 children is obese with greater likelihood in low-income households. The coronavirus disease 2019 (COVID-19) pandemic may have accelerated disparities in child obesity risk factors, such as poor dietary intake and increased sedentary behaviors, among low-income families because of financial difficulties, social isolation and other struggles. This study reveals insights into nutrition and health challenges among low-income families of young children in West Texas to better understand needs and develop interventions. SUBJECTS/METHODS: In-depth individual interviews were performed via Zoom among 11 families of children under the age of 3. A semi-structured interview guide was developed to explore 3 areas: changes in (1) dietary intake and (2) sedentary behaviors and (3) families' preferences regarding a parent nutrition education program. Each interview was audiorecorded, transcribed, and coded using MaxQDA software. RESULTS: Eating together as a family become challenging because of irregular work schedules during the COVID-19 pandemic. Most parents stated that their children's dietary habits shifted with an increased consumption of processed foods. Many parents are unable to afford healthful foods and have utilized food and nutrition assistance programs to help feed their families. All families reported that their children's screen time substantially increased compared to the pre-pandemic times. Moreover, the majority of parents did not associate child screen time with an obesity risk, so this area could be of particular interest for future interventions. Meal preparation ideas, remote modality, and early timing were identified as key intervention strategies. CONCLUSIONS: Online nutrition interventions that emphasize the guidelines for child screen time and regular meal routines will be effective and promising tools to reach low-income parents for early childhood health promotion and obesity prevention.

Effects of PLGA/Fibrin Scaffolds on Attachment and Proliferation of Costal Cartilage Cells (PLGA/피브린 지지체가 늑연골 세포의 부착과 성장에 미치는 영향)

  • Song, Jeong Eun;Lee, Yujung;Lee, Yun Me;Cho, Sun Ah;Jang, Ji Eun;Lee, Dongwon;Khang, Gilson
    • Polymer(Korea)
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    • v.37 no.2
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    • pp.141-147
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    • 2013
  • Poly(lactide-co-glycolic acid) (PLGA) has been widely used in the drug delivery and tissue engineering applications because of its good mechanical strength and biodegradation profile. However, cell attachment to the scaffold is low compared with that on fibrin although cells can be attached to the polymer surface. In this study, PLGA scaffolds were soaked in cells-fibrin suspension and polymerized with dropping fibrinogen-thrombin solution. Cellular proliferation activity was observed in PLGA/fibrin-seeded costal cartilage cells (CC) on 1, 3, and 7 days using the MTT assay and SEM. The effects of fibrin on the extracellular matrix (ECM) formation were evaluated using CC cell-seeded PLGA/fibrin scaffolds. The PLGA/fibrin scaffolds elicited more production of glycosaminoglycan (GAG) and collagen than the PLGA scaffold. In this study, fibrin incorporated PLGA scaffolds were prepared to evaluate the effects of fibrin on the cell attachment and proliferation in vitro and in vivo. In this result, we confirmed that proliferation of cells in PLGA/fibrin scaffolds were better than in PLGA scaffolds. The PLGA/fibrin scaffolds provide suitable environment for growth and proliferation of costal cartilage cells.

Preparations of Polymer Dispersed Liquid Crystals Using the Liquid Crystals with negative dielectric anisotropy

  • Hwang, Sung-Ho;Woo, Sung-Ho;Jeon, Chan-Wook;Yang, Kee-Jeong;Choi, Byeong-Dae;Kim, Byung-Kyu;Kim, Eun-Hee
    • 한국정보디스플레이학회:학술대회논문집
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    • 2006.08a
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    • pp.1394-1397
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    • 2006
  • Polymer Dispersed Liquid Crystal (PDLC) films, of which the liquid crystal has negative dielectric anisotropy, were prepared from the phase separation between MJ001317 and a variety of compositions of resins by common polymerization induced phase separation method. In this work, the effects of resin compositions have been systematically investigated and it was found that the morphology and size of droplet, which is closely related to electro-optic properties, mainly depend on the rate of polymerization and cross-linking density for each resin composition. The reverse mode PDLC films from this newly developed formulation containing TPGDA/EHA/HMPPO showed the good off-state transmittance, contrast ratio (19/1), and relatively low driving voltage(10V).

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Enhancement of Protein Separation by Electric Field Applied to Ultrafiltration

  • Shin, Chun-Hwa;Son, Dong-Ho;Lee, Yun-Hee;Koo, Ja-Kyung;Jang, Dong-Il;Cho, Nam-Jun
    • 한국생물공학회:학술대회논문집
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    • 2005.10a
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    • pp.554-557
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    • 2005
  • Ultrafiltration has been performed to separate proteins, which is almost unique method of protein separation in mass production scale. The problems of its low selectivity and decline in permeation flux resulted from gel formation on the membrane surface have been greatly improved by an applied electric field across the membrane. The applied electric field promoted or hindered the permeation of protein through membranes depending on the electric charge of protein molecules in aqueous solution. With the effects of electric field, the permeation flux and the selectivity of the ultrafiltration could be improved significantly.

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A Study on the Characteristics of ALC Material with Melamine Resin (멜라민 수지를 혼합한 ALC 소재의 특성에 관한 연구)

  • Seo, Sung-Kwan;Chu, Yong-Sik;Song, Hun;Lee, Jong-Kyu;Im, Du-Hyuk
    • Journal of the Korean Ceramic Society
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    • v.48 no.6
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    • pp.595-599
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    • 2011
  • ALC(Autoclaved Lightweight Concrete) is produced using quartz sand, lime and cement and water. And aluminum powder is used for blowing agent. ALC is manufactured by autoclave chamber under high-temperature and high-pressure. Generally, ALC is 1/4 levels lighter than concrete and mortar, because it has a lot of pores. So density of ALC is about 0.45~0.65 g/$cm^3$. But, ALC has a weakness, typically low strength, with its porous structure. So, it is necessary to excellent strength properties for extensive apply of ALC materials in high porosity. In this study, melamine resin was used to improve the strength characteristics of ALC materials. We performed compressive and bending strength measurements. Compressive strength of ALC with 2% melamine resin increased 26.88% than 'melamine-free' ALC. Also we performed functionality evaluation such as thermal conductivity, sound absorption, and flame-resistance.

Enzyme Activities Related to the Methanol Oxidation of Mycobacterium sp. strain JCl DSM 3803

  • Youngtae Ro;김응빈;김영민
    • Korean Journal of Microbiology
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    • v.38 no.4
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    • pp.209-209
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    • 2002
  • Mycobacterium sp. strain JCl DSM 3803 grown in methanol showed no methanol dehydrogenase or oxidase activities found in mast methylotrophic bacteria and yeasts, respectively. Even though the methanol-grown cells exhibited a little methanol-dependent oxidation by cytochrome c-dependent methanol dehydrogenase and alcohol dehydrogenase, they were not the key enzymes responsible for the methanol oxidation of the cells, in that the cells contained no c-type cytochrome and the methanol oxidizing activity from the partially purified alcohol dehydrogenase was too low, respectively. In substrate switching experiments, we found that only a catalase-peroxidase among the three types of catalase found in glucose-grown cells was highly expressed, in the methanol-grown cells and that its activity was relatively high during the exponential growth phase in Mycobacterium sp. JCl. Therefore, we propose that catalase-peroxidase is an essential enzyme responsible for the methanol metabolism directly Of indirectly in Mycobacterium sp. JCl.

Compaction and Sintering Behavior of $Al_2O_3$-modified Ziroconium Titanate $(ZrTiO_4)$

  • Chun, Myoung-Pyo;Geun, Hur;Myoung, Seung-Jae;Cho, Jung-Ho;Kim, Byung-Ik
    • Proceedings of the Korean Powder Metallurgy Institute Conference
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    • 2006.09b
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    • pp.822-823
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    • 2006
  • The compaction and sintering behavior of zirconium titanate $(ZrTiO_4)$ was investigated by means of the measurement of sintering density and shrinkage, and the observation of microstructure. With increasing the content of $Al_2O_3$ additive, $Al_2O_3$-modified zirconium titanate samples fired at $1300^{\circ}C$ showed the anisotropic shrinkage behavior that the upper region of sintered body has higher sintering shrinkage than the low region. This difference of sintering shrinkage decreased with increasing firing temperature from 1300 to $1400^{\circ}C$. The SEM micrographs of powder compation show that the anisotropic shrinkage behavior is related with non-uniform density in a uniaxial compaction.

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Ads Impact of Communication Convergence Platform's Creative Strategy and Personal Attributes (커뮤니케이션 융합플랫폼의 크리에이티브 전략과 개인적 성향에 따른 광고효과)

  • Kim, Jea-Young
    • Journal of the Korea Convergence Society
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    • v.11 no.9
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    • pp.99-107
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    • 2020
  • The new characteristic of Millennial High-Tech Media is breaking the existing standardized creative grammar. The destructive form of high-tech media is differently accommodated according to the consumer's tendency or characteristics. The purpose of this study is to explore guidelines for effective creative strategy creation of high-tech media. In consumer psychology, consumer innovation is a key factor in evaluating the creativeness of high-tech media. The results of finding out the effect of persuasive communication on consumer innovation and advertising creative type are as follows. Informative(image) creative type showed higher attitude toward advertisement, brand attitude, purchase intention, and prior intention to consumers with high innovation than consumers with low innovation.