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Synthesis, Spectral Characterization, Electron Microscopic Study and Influence on the Thermal Stability of Phosphorus-containing Dendrimer with a 4,4'-Sulphonyldiphenol at the Core

  • Dadapeer, Echchukattula;Rasheed, Syed;Raju, Chamarthi Naga
    • Bulletin of the Korean Chemical Society
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    • v.32 no.2
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    • pp.498-502
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    • 2011
  • The divergent synthesis of novel phosphorus-containing dendrimer with 4,4'-sulphonyldiphenol at the core has been accomplished involving simple condensation reactions using $P(O)Cl_3$, $P(S)Cl_3$, 3-amino-phenol, 3-hydroxy-benzaldehyde, and 2-butyn 1, 4-diol. The final compound was a Schiff's base macromolecule possessing 4 imine bonds, 8 acetylenic bonds and 8 OH groups at the periphery. The structures of intermediate compounds were confirmed by IR, NMR ($^1H$, $^{13}C$ and $^{31}P$), LC-Mass and C, H, N analysis. The structure of the final dendrimer (5) was confirmed by IR, NMR ($^1H$, $^{13}C$ and $^{31}P$), MALDI-TOF-MS, and C, H, N analysis. The surface morphological characteristics of the final dendrimer were understood by Scanning Electronic Microscopic study (SEM). The thermal stability of the final dendrimer was studied by TGA/DTA analysis.

Synthesis of $CA_2$-based Clinker by Hydration-Burning Method (I) : Effects of Temperature on Synthesis (수화-소성법에 의한 $CA_2$클린커의 합성(I) : 합성에 미치는 온도의 영향)

  • 송태웅;한기성
    • Journal of the Korean Ceramic Society
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    • v.27 no.2
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    • pp.211-218
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    • 1990
  • CA2-based clinker with highly activated surface and hydraulic properties was synthesized at a comparatively lowr temperature than that of conventional synthesis by "hydration-burning method". This consists of calcining the mixture of CaCO3 and Al2O3 to obtain a primary clinker, hydrating the primary clinker and reburning the hydrates to obtain final clinker. Burning of primary clinker above 1200℃ was necessary to eliminate free CaO in it and to obtain it's solid hydrate. However, rising the burning temperature above 1300℃ is ineffective due to the decrease in hydraulic properties of the primary clinker with the temperature. Hydration of primary clinker at the elevated temperature(>35℃) was required to obtain the hydrate with more porous structure and final clinker with more active surface. CA2 was formed and increased with temperature at above 1150℃, finally became a primary phase of the final clinker. However, burning at the temperature above 1300℃ resulted in reverse effect on the hydraulic properties of the final clinker due to rapid decrease in it's surface area with the temperature.

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Intraspecific Variation in the Temperature Niche Component of the Diatom Skeletonema costatum from Korean Coastal Waters

  • YIH Wonho;SHIM Jae Hyung
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.28 no.6
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    • pp.805-811
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    • 1995
  • Final biomass yields (peak optical density) and growth rates (divisions/day) of seven clones of Skeletonema costatum from Korean coastal waters were measured to understand their intraspecific variations in the light intensity niche component under $25^{\circ}C$ condition. Daily growth rates of 6 of 7 S. costatum, clones were maximum at 6000 lux while that of YS4, a neritic clone, was maximum at 9000 lux. The final biomass yields of 4 of the 7 S. costatum clones were maximum at the lowest light intensity of 2000 lux. Minimum final biomass yields were found at 9000 lux in all the S. costatum clones other than an estuarine clone, HDC9. The intraspecific variations of the mean growth rate and mean final biomass yield under each of the three different light intensity in terms of the coefficient of variation were not greater than 10% in any of the 7 S. costatum clones.

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Risk Based Decision Support for Final Closing Section of a Sea Dike

  • Jee, Sung Hyun;Kang, Seong Hae;Kim, Jeong Hwan;Seo, Jong Won
    • Journal of Construction Engineering and Project Management
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    • v.3 no.2
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    • pp.49-57
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    • 2013
  • A sea dike construction has been increased in Korea because of the actively deployed reclamation project in basis of efficient application in land. The degree of completion in sea dike construction is affected by final closing construction, which has a lot of uncertainty that often results in higher accidents rate. Therefore, this research identified risk factors of final closing construction and classified them. This research examines the likelihood and its impact for each risk factor and calculates the risk degree as to the risk matrix. Based on this, the impact and the environmental conditions that affect to risk factors are investigated and further responsive methods are established for each risk factor. Ultimately, this research attempts to provide the risk retrenchment method for inspectors by proposing risk estimation model, responsive action list, and risk management process.

Experimental Phonetic Study of the Syllable Duration of Korean with Respect to the Positional Effect

  • Lee Hyunbok;Seong Cheol-jae
    • MALSORI
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    • no.31_32
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    • pp.195-205
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    • 1996
  • The aim of this paper is to describe the prosodic structure of Korean related to the syllable duration varying with its positional difference. An attempt is made in this study to analyze and describe the concrete correlation between the syllable lengthening and its position in the utterance at the initial and final positions. Using the syllable [na] at the final and initial position of a prosodic phrase in the Korean version of 'the North Wind and the Sun', it has found that the ratio of phrase final versus phrase initial syllable lengthening was approximately 1.8:1 for 4 subjects taking part in the test. In the case of nonsense data, we found that the ratio was approximately 1.6:1 for 2 out of 3 subjects. The results of this study might indicate that Korean tends to have a high rate of final lengthening. We can tentatively classify it, therefore, as a stress-timed language. Still, there is no denying that further studies should be done before we can be absolutely certain about the classification of languages along the dichotomy scale.

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Brassinosteroids Accelerate the Rate of Cell Division in Isolated Petal Protoplasts of Petunia hybrida

  • Oh, Man-Ho
    • Journal of Plant Biotechnology
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    • v.5 no.1
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    • pp.69-77
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    • 2003
  • Brassinosteroids are known to promote cell elongation in a wide range of plant species but their effect on cell division has not been extensively studied. The effect of brassinolide on the kinetics and final division frequencies of regenerating petal protoplasts of Petunia hybrida Vilm v. Comanche was examined. Under optimal auxin and cytokinin conditions, 10-100 nM brassinolide not only reduced the time of first cell division by 4.5 days but also altered the final division frequencies after 10 days of culture. One micromolar brassinolide showed the same acceleration of first cell division but inhibited the final division frequency by approximately 9%. Under sub-optimal auxin conditions, 10-100 nM brassinolide accelerated the first cell division, but no significant increase in the 8-10 days final division frequencies. Isolated protoplasts may provide a useful model system for the investigation of the molecular mechanisms of brassinosteroid action on cell division and proliferation in higher plants.

Brassinosteroids Accelerate the Rate of Cell Division in Isolated Petal Protoplasts of Petunia hybrida

  • Oh, Man-Ho
    • Journal of Plant Biotechnology
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    • v.5 no.1
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    • pp.63-67
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    • 2003
  • Brassinosteroids are known to promote cell elongation in a wide range of plant species but their effect on cell division has not been extensively studied. The effect of brassinolide on the kinetics and final division frequencies of regenerating petal protoplasts of Petunia hybrida Vilm v. Comanche was examined. Under optimal auxin and cytokinin conditions, 10-100 nM brassinolide not only reduced the time of first cell division by 4.5 days but also altered the final division frequencies after 10 days of culture. One micromolar brassinolide showed the same acceleration of first cell division but inhibited the final division frequency by approximately 9%. Under sub-optimal auxin conditions, 10-100 nM brassinolide accelerated the first cell division, but no significant increase in the 8-10 days final division frequencies. Isolated protoplasts may provide a useful model system for the investigation of the molecular mechanisms of brassinosteroid action on cell division and proliferation in higher plants.

Predicting Final Moisture Contents of Kiln-dried Western Hemlock Boards I: Distribution of Moisture Contents along the Length

  • Kang, Ho-Yang
    • Journal of the Korean Wood Science and Technology
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    • v.37 no.5
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    • pp.459-464
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    • 2009
  • This study was conducted to find the relationship between the moisture content and basic density of green lumber and the final moisture content of kiln dried lumber. The possibility of using a ultrasonic nondestructive testing technology was investigated. Four matched 2-foot long boards were kiln-dried for 12, 24, 36 and 48 hours. Twenty three slices were cut to examine the distribution of moisture content along the length. It was revealed that the green weight was a better estimator of the final moisture content of the kiln-dried board than the green moisture content. The standard deviations of the moisture contents of the slices were not correlated with the final moisture contents of the kiln-dried boards. The two ultrasonic devices used for this study were apparently good tools for NDT.

Initialness of Sentence-final Particles in Mandarin Chinese

  • Huang, Xiao You Kevin
    • Proceedings of the Korean Society for Language and Information Conference
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    • 2007.11a
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    • pp.182-191
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    • 2007
  • This paper gives a thorough investigation into Mandarin sentence-final particles (henceforth SFPs). First I induce core grammatical functions and semantic interpretations of SFPs. Based on Rizzi's (1997) Split CP hypothesis, I make some modifications to accommodate Mandarin SFPs and map them onto separate functional heads within a proper hierarchy. I also examine some empirical evidence of head directionality and tentatively assume Mandarin C is head-initial. To explain the surface head-final order, in light of Chomsky's (2001) Phase Theory and Hsieh's (2005) revised Spell-out hypothesis, I pose a CP complement to Spec movement. Following Moro's (2000) idea, I further claim the motivation behind is to seek for antisymetry.

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Crystallization and In-plane Alignment Behavior of Pb(Zr, Ti)$O_3$ Films

  • Hwang, Kyu-Seog;Kim, Byung-Hoon
    • The Korean Journal of Ceramics
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    • v.3 no.3
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    • pp.191-194
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    • 1997
  • Epitaxial Pb(Zr, Ti)O3(PZT) thin films were prepared on MgO(100) substrates by dipping-pyrolysis (DP) process using metal naphthenates as starting materials, and effects of pyrolysis and final heat-treatment conditions on the film's orientation were investigated. Solid-state epitaxial growth of PZT proceeds at lower temperature around 650℃ from the precursor pyrolyzed at 350 and 500℃. The in-plane alignment of the PZT films depends not only on the final heat-treatment temperature but on the pyrolysis conditions; the films, pyrolyzed at a higher temperature for a short time, i.e., at 500℃ for 10 min, exhibited stronger orientation after the same final heat treatment at 650°∼750℃. The PZT films with the strongest orientation were prepared by pyrolysis under the above conditions followed by final heat treatment at 750℃.

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