• Title/Summary/Keyword: J-aggregates

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Optical Absorption Spectra of Mixed Merocyanine Dye LB films (혼합 매로시아닌 LB막의 광흡수 스펙트라)

  • 신훈규;권영수
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1996.05a
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    • pp.35-42
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    • 1996
  • In this Paper, optical absorption were performed on LB films of binary mixtures of three kinds of merocranine dyes DO, DS, and 6Me-BS, where DS and 6Me-DS form J-like aggregates but not DO in single component films. The observed optical absorption spectra of mixed films were markedly defendent on the combination of dyes. [6Me-DS]$\sub$1-x/[DOl]$\sub$x/ LB films show a sharp red shifted J-like band peak in the whole concentration range. We found the formation of f aggregates in a mixed merocyanine dyes containing a non J-aggregate forming dye DO, in a single component case. Farther investigations on the present and other mixed-dye films will be needed to clarify these points.

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Lightweight Self-consolidating Concrete with Expanded Shale Aggregates: Modelling and Optimization

  • Lotfy, Abdurrahmaan;Hossain, Khandaker M.A.;Lachemi, Mohamed
    • International Journal of Concrete Structures and Materials
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    • v.9 no.2
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    • pp.185-206
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    • 2015
  • This paper presents statistical models developed to study the influence of key mix design parameters on the properties of lightweight self-consolidating concrete (LWSCC) with expanded shale (ESH) aggregates. Twenty LWSCC mixtures are designed and tested, where responses (properties) are evaluated to analyze influence of mix design parameters and develop the models. Such responses included slump flow diameter, V-funnel flow time, J-ring flow diameter, J-ring height difference, L-box ratio, filling capacity, sieve segregation, unit weight and compressive strength. The developed models are valid for mixes with 0.30-0.40 water-to-binder ratio, high range water reducing admixture of 0.3-1.2 % (by total content of binder) and total binder content of $410-550kg/m^3$. The models are able to identify the influential mix design parameters and their interactions which can be useful to reduce the test protocol needed for proportioning of LWSCCs. Three industrial class ESH-LWSCC mixtures are developed using statistical models and their performance is validated through test results with good agreement. The developed ESH-LWSCC mixtures are able to satisfy the European EFNARC criteria for self-consolidating concrete.

Solution properties of sodium n-dodecyl sulfate in the presence of meso-tetrakis (N-methylpyridinium-4-yl) porphyrin (Meso-tetrakis (N-methylpyridinium-4-yl) porphyrin 존재 하에서 sodium n-dodecyl sulfate 용액 성질)

  • Hassanpour, Azin;Azani, Mohammad-Reza;Bordbar, Abdol-Khalegh
    • Journal of the Korean Chemical Society
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    • v.55 no.3
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    • pp.335-340
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    • 2011
  • The solution properties of sodium n-dodecyl sulfate, as an anionic surfactant in the presence of a cationic watersoluble 5, 10, 15, 20-tetrakis (N-methylpyridinium-4-yl) porphyrin (TMPyP) has been comprehensively studied by means of conductometry, UV-vis and resonance light scattering (RLS) spectroscopies. The results represent the decreasing of critical micelle concentration of SDS solution due to increasing of TMPyP concentration. The stabilization of SDS micelle is due to neutralization of negative charge at the micelle surface. The presence of three different species of TMPyP in SDS solution has been unequivocally demonstrated: free porphyrin monomers, porphyrin monomers or aggregates bound to the micelles, and nonmicellar porphyrin/surfactant aggregates. Our results show SDS induced an aggregation in TMPyP. In fact two kinds of J-aggregations were observed: one of them for porphyrin monomers or aggregates bound to the micelles and the other for nonmicellar porphyrin/surfactant aggregates. However, the results represent the electrostatic interaction of TMPyP with SDS anion below the cmc.

The investigation into Merocyanine Dye J-aggregation of characteristic by STM (STM을 이용한 Merocyanine Dye J-aggregation 특성관찰)

  • Yang, Chang-Heon;Lee, Ji-Yoon;Choi, Won-Suk;Kwon, Young-Soo
    • Proceedings of the KIEE Conference
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    • 2008.05a
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    • pp.165-166
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    • 2008
  • We investigate characteristics of J-aggregation as take advantage of LB technic. In order to confirm the applications possible for the molecular electronic device, the morphological properties of merocyanine dye were investigated by AFM. $\pi$-A curves investigated the surface pressure of the LB film from a liquid to a solid state ranged between 90 and 100 mN/m. We observed aggregation and it's characteristics by using visible reflection spectroscopy. We have observed morphology of merocyanine dye on gold surface by STM. focuses on results obtained in mercocyanide dye of J-aggregation. When LB films of merocyanine dye are mixed with arachidic acid, J-aggregate formation is exhibited. J-aggregate formation has been serving as typical systems in revealing the physical and structural aspects of nano-sized molecular aggregates constructed as muiltilayers.

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J-aggregation Property of Merocyanine Dye LB Thin Film by UV Irradiation (UV 조사에 의한 메로시아닌 색소 LB박막의 J-aggregation 특성)

  • Yang, Chang-Heon;Lee, Ji-Yoon;Kwon, Young-Soo
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2008.04c
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    • pp.123-124
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    • 2008
  • We investigate characteristics of J-aggregation as take advantage of LB technic. In order to confirm the applications possible for the molecular electronic device, the morphological properties of merocyanine dye were investigated by AFM. $\pi$-A curves investigated the surface pressure of the LB film from a liquid to a solid state ranged between 90 and 100 mN/m. We observed aggregation and it's characteristics by using visible reflection spectroscopy. This paper focuses on results obtained in mercocyanide dye. When LB films of merocyanine dye are mixed with arachidic acid, J-aggregate formation is exhibited. J-aggregate formation has been serving as typical systems in revealing the physical and structural aspects of nano-sized molecular aggregates constructed as muiltilayers.

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Callus Formation from Suspension Culture-Derived Protoplasts of Sweet Potato(Ipomoea batatas) (고구마(Ipomoea batatas)의 현탁배양 세포의 원형질체 배양에 의한 캘러스 형성)

  • Liu, Jang R.;Cantliffe, Daniel J.
    • Journal of Plant Biology
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    • v.32 no.4
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    • pp.247-253
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    • 1989
  • Protoplasts were enzymatically isolated from suspension culture of sweet potato. High yields of single protoplasts were produced from nonembryogenic cell aggregates. However, most protoplasts obtained from embryogenic cell clumps were spontaneously fused during enzyme treatment; a small portion of them remained single. Upon transfer to Murashige and Skoog's(MS) liquid medium supplemented with 0.1 mg/1 6-benzyladenine(BA) and 1 mg/12,4-dichlorophenoxyacetic acid(2,4-D), protoplasts from nonembryogenic cell aggregates sustained cell divisions to form cellus. Upon subculture onto MS media with 0.2 mg/12,4-D or without growth regulators, the callus did not give rise to any organs. On the other hand, first cell division of single protoplasts from embryogenic cell clumps was sporadically observed.

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Red ginseng extract inhibits lipopolysaccharide-induced platelet-leukocyte aggregates in mice

  • Yuan Yee Lee;Sung Dae Kim;Jin-Kyu Park;Won-Jae Lee;Jee Eun Han;Min-Soo Seo;Min-Goo Seo;Seulgi Bae;Dongmi Kwak;Evelyn Saba;Man Hee Rhee
    • Journal of Ginseng Research
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    • v.48 no.4
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    • pp.428-434
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    • 2024
  • Background: Platelet-leukocyte aggregates (PLAs) play important roles in cardiovascular disease and sepsis. Red ginseng extract (RGE) has been well-studied for its antiplatelet and anti-inflammatory activities. However, the potential inhibitory effects of RGE on PLA have not been investigated. Methods: Six-week-old ICR mice were given oral gavage of RGE for 7 days, followed by an intraperitoneal injection of 15 mg/kg of lipopolysaccharide. Mice were euthanized 24 h later, and blood samples were collected for further analysis. Flow cytometry was utilized to sort populations of PLAs and platelet-neutrophil aggregates (PNAs). By using confocal microscopy, PNAs were validated. Morphological changes in platelets and leukocytes were visualized with scanning electron microscopy. Expressions of tissue factor (TF) and platelet factor 4 (PF4) were investigated using enzyme-linked immunosorbent assay. Results: Populations of activated platelets, PLAs and PNAs, were significantly increased with LPS-induction. Treatment with 200 and 400 mg/kg of RGE decreased platelet activation. Moreover, the populations of PLAs and PNAs were reduced. PNAs were visible in the blood of septic mice, and this was attenuated by treatment with 400 mg/kg of RGE. Morphologically, sepsisinduced platelet activation and fibrin formation in the blood. This was reduced with RGE treatment. Sepsis-induced increase in the plasma levels of TF and PF4 was also reduced with RGE treatment. Conclusion: This study shows that RGE is a potential therapeutic that reduces the activation of platelets and targets PLA and PNA formation. Detailed inhibitory mechanisms of RGE should be studied.

The measurement into Merocyanine Dye J-aggregaion of characteristic as various temperature by STM (STM을 이용한 온도 변화에 따른 Merocyanine Dye J-aggregation 특성측정)

  • Yang, Chang-Heon;Lee, Ji-Yoon;Kim, Gyong-Chol;Kwon, Young-Soo
    • Proceedings of the KIEE Conference
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    • 2008.10a
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    • pp.165-166
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    • 2008
  • We investigate characteristics of J-aggregation as take advantage of LB technic. In order to confirm the applications possible for the molecular electronic device, the morphological properties of merocyanine dye were investigated by AFM. ${\pi}-A$ curves investigated the surface pressure of the LB film from a liquid to a solid state ranged between 90 and 100 mN/m. We observed aggregation and it's characteristics by using visible reflection spectroscopy. We have observed morphology of merocyanine dye on gold surface by STM. focuses on results obtained in mercocyanide dye of J-aggregation. When LB films of merocyanine dye are mixed with arachidic acid, J-aggregate formation is exhibited. J-aggregate formation has been serving as typical systems in revealing the physical and structural aspects of nano-sized molecular aggregates constructed as muiltilayers.

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