• 제목/요약/키워드: Accumulation, Resistance

검색결과 304건 처리시간 0.027초

Polyimide초박막의 전계인가에 따른 전기특성 (Electrical Properties by Applied Electric Field of Polyimide Ultra Thin Films)

  • 최영일;전동규;구할본;김철;권영수;이경섭
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1998년도 추계학술대회 논문집
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    • pp.73-76
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    • 1998
  • We give pressure stimulation into organic thin films and detect the induced displacement current. then manufacture a device under the accumulation condition that the state surface pressure is 15[mN/m]. In processing of a device manufacture. We can see the process is good from the change of a surface pressure for organic thin films and transfer ratio of area per molecule. The structure of manufactured device is Au/organic thin films(polyimide)/Au, the number of accumulated layers are 31,35, and 41. I-V characteristic of the device is measured from 0[V] to +5[V]. The maximum value of measured current is increased as the number of accumulated layers are decreased. The resistance for the number of accumulated layers, the energy density for an input voltage show desired results, and the insulation of a thin film is better as the interval between electrodes is larger.

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Thermal shock behaviors of TiN coatings on Inconel 617 and Silicon wafer substrates with finite element analysis method

  • Lee, Ki-Seuk;Jeon, Seol;Cho, Hyun;Lee, Heesoo
    • 한국결정성장학회지
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    • 제26권2호
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    • pp.67-73
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    • 2016
  • The degradation behaviors of TiN coating layers under thermo-mechanical stress were investigated in terms of comparison of finite element analysis (FEA) and experimental data. The coating specimen was designed to quarter cylinder model, and the pulsed laser ablation was assumed as heat flux condition. The FEA results showed that heat accumulation at the center of the laser-ablated spot occurred and principle stress was concentrated at the lower region of the coating layer. The microstructural observation revealed that surface melting and decrease of the coating thickness occurred in the TiN/Inconel 617 and the interfacial cracks formed in the TiN/Si. The delamination was caused by the mechanical stress from the center to the outside of the ablated spot as the FEA results expected. It was considered that the improvement of the thermal shock resistance was attributed to higher thermal conductivity of Si wafer than that of Inconel 617.

Effect of $TO_3$ and $NO_2$ on Net Photosynthesis, Transpiration and Accumulation of Nitrite in Sunflower Leaves

  • Park, Shin-Young;Lee, Sang-Chul
    • Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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    • 제3권2호
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    • pp.121-129
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    • 1999
  • Photosynthesis and transpiration rates were simultaneously measured in attached sunflower leaves(Helianthus annuusL. cv. Russian Mammoth) during exposure to $NO_2$ and $O_3$ to determine the effect of mixed gan on photosynthesis and the stomatal aperture. The application of $O_3$ alone reduced both the net photosynthetic and transpiration rates. An analysis of the $CO_2$ diffusive resistances indicated that the main cause affecting photosynthesis reduction during $O_3$ exposure was not the internal gas phase of the leaf $(rCO_2^{liq})$ but rather the liquid phase or mesophyll diffusive resistance $(rCO_2^{liq})$, suggesting that there is a very concomitant relation between photosynthetic reduction and $rCO_2^{liq}$. The application of NO2 alone caused a marked reduction of the net photosynthesis yet no significant reduction of transpiration, indicating that NO2 affects the $CO_2$ fixation processes with no inluence on the stomatal aperture. A greter reduction in the photosynthesis of sunflower plants was caused by the application of $NO_2$ alone as compared to a combination of $NO_2$ and $O_3$. $NO_2$ alone reduced the photosynthetic rate by 90%, whereas a mixture of NO2 and O3 reduced it by 50%.

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지질과 phycobiliproteins 고생산성 Arthrospira platensis 변이주 분리 (Isolation of Arthrospira platensis Mutants Producing High Lipid and Phycobiliproteins)

  • 김영화;이재화
    • KSBB Journal
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    • 제27권3호
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    • pp.172-176
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    • 2012
  • In this study, microalgae Arthrospira platensis (A. platensis) mutants induced by ethyl methane sulfonate (EMS) and further selection for resistance of cerulenin, a potent inhibitor of fatty acid synthase, were characterized. The mutants selected by $2{\mu}M$, $5{\mu}M$ and $10{\mu}M$ of cerulenin were designated EC2, EC5 and EC10, respectively. Under normal growth conditions, the mutants and parental strain exhibited similar growth pattern. The mutants of A. platensis showed enhanced lipid accumulation and phycobiliproteins (phycoerythrin, phycocyanin). The lipid content of mutants EC2 and EC5 was about 4.4 and 4.8-fold higher than wild type. The phycoerythrin and phycocyanin content of mutants EC2 and EC5 was increased about 1.5 and 6.9-fold and 1.4 and 3.8-fold, respectively, compared to the wild type. The chlorophyll and carotenoid content of mutants was slightly increased. The high lipid and pigment contents exhibited by A. platensis mutants would make an excellent candidate for the production of commercially interesting biologically active compounds.

초음파 진동을 이용한 취성재료 가공기술에 관한 연구 (A Study on Micro Ultrasonic machining for Brittle Material Using Ultrasonic vibration)

  • 이석우;최헌종;이봉구
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 1997년도 추계학술대회 논문집
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    • pp.969-972
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    • 1997
  • Ultrasonic machining technology has been developed over recent years for he manufacture of cost-effective and quality-assured precision parts for several industrial application such as optics, semiconductors, aerospace, and automobile application. The past decade has seen a tremendous in the use of ceramic in structural application. The excellent thermal, chemical and wear resistance of these material can be realized because of recent improvement in the overall strength and uniformity of advanced ceramics. Ultrasonic machining, in which abrasive particles in slurry with water are presented to the work surface in the presence of an ultrasonic-vibrating tool, is process which should be of considerable interest, as its potential is not limited by he electrical or chemical characteristics of the work material, making it suitable for application to ceramics. In order to improve the currently used ultrasonic machining using ultrasonic energy, technical accumulation is needed steadily through development of exciting device of ultrasonic machine composed of piezoelectric vibrator and horn. This paper intends to further the understanding of the basic mechanism of ultrasonic machining for brittle material and ultrasonic machining of ceramics based in the fracture-mechanic concept has been analyzed.

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Genomic Tools and Their Implications for Vegetable Breeding

  • Phan, Ngan Thi;Sim, Sung-Chur
    • 원예과학기술지
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    • 제35권2호
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    • pp.149-164
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    • 2017
  • Next generation sequencing (NGS) technologies have led to the rapid accumulation of genome sequences through whole-genome sequencing and re-sequencing of crop species. Genomic resources provide the opportunity for a new revolution in plant breeding by facilitating the dissection of complex traits. Among vegetable crops, reference genomes have been sequenced and assembled for several species in the Solanaceae and Cucurbitaceae families, including tomato, pepper, cucumber, watermelon, and melon. These reference genomes have been leveraged for re-sequencing of diverse germplasm collections to explore genome-wide sequence variations, especially single nucleotide polymorphisms (SNPs). The use of genome-wide SNPs and high-throughput genotyping methods has led to the development of new strategies for dissecting complex quantitative traits, such as genome-wide association study (GWAS). In addition, the use of multi-parent populations, including nested association mapping (NAM) and multiparent advanced generation intercross (MAGIC) populations, has helped increase the accuracy of quantitative trait loci (QTL) detection. Consequently, a number of QTL have been discovered for agronomically important traits, such as disease resistance and fruit traits, with high mapping resolution. The molecular markers for these QTL represent a useful resource for enhancing selection efficiency via marker-assisted selection (MAS) in vegetable breeding programs. In this review, we discuss current genomic resources and marker-trait association analysis to facilitate genome-assisted breeding in vegetable species in the Solanaceae and Cucurbitaceae families.

Increase in Linolenate Contents by Expression of the fad3 Gene in Transgenic Tobacco Plants

  • Kang, Young-Hwi;Min, Bok-Kee;Park, Hee-Sung;Lim, Kyung-Jun;Huh, Tae-Lin;Lee, Se-Yong
    • BMB Reports
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    • 제29권4호
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    • pp.308-313
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    • 1996
  • An 1.4 kb of the fad3 cDNA encoding microsomal linoleic acid desaturase catalyzing the conversion of linoleic acid (18:2, ${\omega}-6$) to linolenic acid (18:2, ${\omega}-3$) was introduced into tobacco plants by the Agrobacterium-mediated plant transformation, Among the transgenic tobacco plants conferring kanamycin resistance, five transformants showing increment in unsaturated fatty acid contents were selected and further analyzed for the transgenecity, In genomic Southern blot analyses, copy numbers of the integrated fad3 DNA in chromosomal DNA of the five transgenic tobacco plants were varied among the transgenic lines. By Northern blot analyses, the abundancy of the fad3 mRNA transcript directed by Cauliflower Mosaic Virus 35S promoter was consistent with the relative copy number of the fad3 DNA integrated in the chromosome of transgenic tobacco plants. When compared with the wild type, accumulation of linolenic acid in transgenic tobacco roots was elevated 3.7- to 4.7-fold showing a corresponding decrease in the linoleic acid contents; however, slight increments for linolenic acid were noticed in transgenic leaf tissues. These results indicated that the elevated level of fad3 expression is achieved in transgenic tobacco plants.

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Identification of troglitazone responsive genes: induction of RTP801 during troglitazone-induced apoptosis in Hep 3B cells

  • Kim, Jin-Oh;Kim, Ji-Young;Kwack, Mi-Hee;Hong, Su-Hyung;Kim, Moon-Kyu;Kim, Jung-Chul;Sung, Young-Kwan
    • BMB Reports
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    • 제43권9호
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    • pp.599-603
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    • 2010
  • Troglitazone is an anti-diabetic agent that improves hyperglycemia by reducing peripheral insulin resistance in type II diabetic patients. Troglitazone has been shown to cause growth inhibition of various normal and cancerous cells. However, the molecular mechanism by which troglitazone affects the growth of these cancer cells remains unclear. Here, we report that troglitazone treatment of Hep 3B human hepatocellular carcinoma cells resulted in dose-dependent growth inhibition. Analysis of cell cycle distribution by flow cytometry showed that the number of apoptotic cells was increased in a dose-dependent manner in response to troglitazone treatment. cDNA microarray analysis showed a number of differentially expressed genes in response to troglitazone. Among the upregulated genes, hypoxia-inducible factor 1 (HIF-1)-responsive RTP801 was induced in a dose-dependent manner. We also observed HIF-1 accumulation by immnocytochemistry after troglitazone treatment. These results strongly suggest that RTP801 might be involved in troglitazone-induced apoptosis in Hep 3B cells.

Screening for Chemosensitizers from Natural Plant Extracts through the Inhibition Mechanism of P-glycoprotein

  • Ahn, Hee-Jeong;Song, Im-Sook
    • Journal of Pharmaceutical Investigation
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    • 제40권5호
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    • pp.269-275
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    • 2010
  • P-gp plays a critical role in drug disposition and represents a mechanism for the development of multidrug resistance. Flavonoids, a major class of natural compounds widely present in foods and herbal products, have been shown to inhibit P-gp. Therefore, the aim of this study was to identify new candidate chemosensitizers by screening various plant extracts. The ability of natural plant extracts to inhibit P-gp activity was assessed by measuring cellular accumulation of calcein AM, daunorubicin and vincristine in P-gp overexpressing MDCKII-MDR1 cells. Among more than 800 plant extracts, eight were found to inhibit P-gp activity. Curcuma aromatica extract produced greatest inhibition, followed by Curcuma longa and Dalbergia odorifera extracts. Extracts of Aloe ferox, Curcuma zedoariae rhizome, Zanthoxylum planispinum, and Ageratum conyzoides showed moderate inhibitory effects. Curcumin and quercetin exhibited similar inhibition of P-gpmediated efflux of daunorubicin and vincristine, and flavones had a lesser effect. When chemosensitizing effect was evaluated by measuring daunorubicin sensitivity to MDCKII-MDR1 cells in the presence of natural plant extracts, Curcuma aromatica showed the most potent chemosensitizing effect based on daunorubicin cytotoxicity. In conclusion, natural plant extracts such as Curcuma aromatica can potently inhibit P-gp activity and may have potential as a novel chemosensitizers.

1990년대(年代) Hair Style과 Head Dress의 키치특성(特性)에 관(關)한 연구(硏究) (A Study on the Kitsch Characteristics of Hair Style and Head Dress in the 1990s)

  • 구인숙
    • 패션비즈니스
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    • 제5권2호
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    • pp.73-86
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    • 2001
  • This study aims at reviewing the Kitsch aesthetics, grasping the relation between the Kitsch and consumption culture, and pursuing the intrincis meanings and expressive characteristics of Kitsch in the hair style and head dress in the 1990s. Kitsch generally implies a vulgarity, and a bad taste, and can be considered to be a kind of vicarious experience, the aesthetic deception and self-deception. In spite of these negative inplications of Kitsch, the aesthetic categories of Kitsch have been spread to public and been accepted by the public, with the help of the powerful promotion of the modern day mass media. 1. The intrincis meanings of Kitsch convey 1) escapism, 2) conformity, 3) amusements, 4) identification. 2. The expressive characteristics of Kitsch represent 1) aesthetic inadequacy: hair style and head dress showing the imperpectness, accumulation(superfluous ornaments), vulgarity, untidines. 2) resistance: hair style and head dress featuring deconstructional and violent forms revealing the uneasiness, and unsatisfaction of the given regularity. 3) humor: hair style and head dress featuring the innocence, humor, and fun for a relaxation and diversion. 4) hedonism: hair style and head dress with the erotic and sexual feelings. 5) retro, romantism: hair style and head dress featuring the elegance, femininity, folklore, ethnic, and nostalgia.

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