• Bulletin of the Korean Chemical Society
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• 제30권4호
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• pp.882-886
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• 2009

The electrode contact poling is one of the efficient tools to induce a stable polar order of nonlinear optical (NLO) chromophores in the solid film. Self-assembled NLO chromophores with high electro-optic (E-O) activities were utilized for quantitative determination of the chromophore order induced under contact poling by spectroscopic changes. We found that NLO chromophores rarely decompose under the high electric field during contact poling. The absorption spectra were de-convoluted into a sum of Gaussian components to separate energy transitions for a binary composite system which contains a secondary guest chromophore AJC146 in the self-assembled chromophore HDFD. Poling efficiency was significantly improved in the binary system compared to the individual components.

• Bulletin of the Korean Chemical Society
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• 제30권8호
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• pp.1755-1759
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• 2009

Surface structure and molecular orientation of self-assembled monolayers (SAMs) formed by the spontaneous adsorption of tetrahydrothiophene (THT) and thiophene (TP) on Au(111) were investigated by means of scanning tunneling microscopy (STM) and carbon K-edge near edge X-ray absorption fine structure (NEXAFS) spectroscopy. STM imaging revealed that THT SAMs have a commensurate (3 ${\times}\;2\sqrt[]{3}$) structure containing structural defects in ordered domains, whereas TP SAMs are composed of randomly adsorbed domains and paired molecular row domains that can be described as an incommensurate packing structure. The NEXAFS spectroscopy study showed that the average tilt angle of the aliphatic THT ring and $\pi$-conjugated TP ring in the SAMs were calculated to be about $30^o\;and\;40^o$, respectively, from the surface normal. It was also observed that the $\pi$* transition peak in the NEXAFS spectrum of the TP SAMs is very weak, suggesting that a strong interaction between $\pi$-electrons and the Au surface arises during the self-assembly of TP molecules. In this study, we have clearly demonstrated that the surface structure and adsorption orientation of organic SAMs on Au(111) are strongly influenced by whether the cyclic ring is saturated or unsaturated.

• 분석과학
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• 제7권4호
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• pp.427-434
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• 1994

GFAAS(graphite furnace atomic absorption spectrophotometer)를 이용하여 혈액 중 납을 분석할 때, 납은 비교적 휘발성 원소인 관계로 바탕선이 높아지므로 희화 온도를 일정 온도 이상으로 높일 수 없었다. 그래서 종래에는 매트릭스 변형제를 사용하여 희화 온도를 $700^{\circ}C$까지 올려서 희화시켜야 바탕선이 안정되었다. 본 연구에서는 광온도 및 전류 제어 장치가 부착된 기기(Shimadzu, AA-6501S)를 사용하여 온도조절을 단시간에 정확히 함으로써 매트릭스 변형제를 사용하지 않고 Triton X-100으로만 희석하여 분석해도 희화 온도 $550^{\circ}C$ 부근에서 바탕선이 안정됨을 알았다. 또한 자동 바탕 보정 장치인 $D_2$ arc형과 SR(self reversal)법을 비교해 본 결과, 같은 농도에서의 흡광도는 $D_2$ arc형이 높았으나 BGC(background correction)값은 SR법이 높음을 알았다.

• Computers and Concrete
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• 제21권2호
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• pp.149-156
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• 2018

This paper investigated the influence of binary and ternary blends of mineral admixtures in self-compacted mortar (SCM) on the fresh, mechanical and durability properties. For this purpose, 25 mortar mixtures were prepared having a total binder content of $640kg/cm^3$ and water/binder ratio between 0.41 and 0.50. All the mixtures consisted of Portland cement (PC), fly ash (FA) and silica fume (SF) as binary and ternary blends and air-entrained admixture wasn't used while control mixture contained only PC. The compressive and tensile strength tests were conducted for 28 and 91 days as well as slump-flow and V-funnel time tests whilst freeze-thaw (F-T) resistance and capillary water absorption tests were made for 91-day. Finally, in general, the use of SF with FA as ternary blends improved the tensile strength of mortars at 28- and 91-day while the use of SF15 with FA increased the compressive strength of the mortars compared to binary blends of FA. SCM mixtures with ternary blends had lower the sorptivity values than that of the mortars with binary blends of FA and the control mixture due to the beneficial properties of SF while the use of FA with SF as ternary blends induced the F-T resistance enhancement.

• Bulletin of the Korean Chemical Society
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• 제25권2호
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• pp.298-300
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• 2004

An alternative molecular porphyrin-phthalocyanine aggregate was prepared and characterized with UV-visible and X-ray absorption spectroscopies. UV-visible experiments evidence 1-dimensional porphyrin-phthalo-cyanine array formed by mixing $SnTPPCl_2 ({\lambda}_{max}=429,\;{\varepsilon}=2.4{\times10^ 5 /M{\cdot}cm)\;and\;NiPc(OBu)_8({\lambda}_{max}=744 nm,\;{\varepsilon}= 2.0{\times}10^ 5 /M{\cdot}cm)$ in solution. In the UV-visible spectrum of the porphyrin-phthalocyanine array, $(SnPNiPc)_n$, a new Q-band appeared at 844 nm with decrease of the Q-band peak of $NiPc(OBu)_8$ at 744 nm. The red-shift of Q-band evidences an alternative porphyrin-phthalocyanine array formed in solution through metal-halide interaction rather than ${\pi}-{\pi}$ facial interaction, in which nickel of $NiPc(OBu)_8$ coordinates with chloride of $SnTPPCl_2$ through self assembly. Ni K-edge XANES (X-ray absorption near edge structure) spectra also support the axial ligation of nickel to chloride. The square planar structure of $NiPc(OBu)_8$ turns to an octahedral structure in (SnPNiPcSnP) by axial ligation. A higher energy-shift (0.2 eV) of the preedge peak of (SnPNiPcSnP) indicaties partial oxidation of nickel by charge transfer from NiPc$(OBu)_8$ to SnTPPCl$_2$.

• 한국토양비료학회지
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• 제9권3호
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• pp.133-147
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• 1976

1. The purpose of this study is to provide a series of statistical "bench marks" from which one can begin to think systematically about the required development of the Korean food and fertilizer needs over the next quarter-century. 2. The Korean population has been estimated by the characteristics of the population and its social and political situations today. Because fertility and mortality rates are relatively stable and are under control of politics concerned, the estimation rates were established with 1.6% over 1975-1980, 1.3% over 1981-1990, and 1.0% over 1991-2000. 3. Annual per capita absorption of milled rice has fluctuated rather closely around 140kg, since 1968, with no evidence of declining trend. Per capita absorption of barley and wheat around 120 kg, and legumes around 10.6kg, However because the case of wheat and corn productions are rather difficult the self-sufficiency in the future, the rice is considered to be accelerate its yield growth surplus the level of self-sufficiency to export. 4. The fertilizer demand in each element has been calculated by mechanical multiplication of "the recommend index of fetilizer application" to yield a unit production over the need of national food supply by crop year. 5. As a results refer to Table (8), the estimated quantities of total fertilizer demand to meet the national food supply of the years of 1974, 1980, 1985, 1.990, 1995, and 2000 are reached around 871500, 1138150, 1375480, 1515030, 1652090 and 1799850 metric tons in each year.

• 패션비즈니스
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• 제12권2호
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• pp.12-27
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• 2008

The purpose of this study is to study main characters' (Roxie Hart, Velma Kelly) costumes and color images in the movie "Chicago". First, regarding the costumes and color images in characters, Roxie's straight silhouette slip in skin tone reflected her frailty and monotonous routines in reality. On the other hand, a white beaded dress showed her fame-hungry and self-absorption in fantasy. Also, a low waistline blue dress and a see-through black dress with a white collar were to disguise her guilt and draw sympathy to win a suitcase. Black and contrasting colors of red and blue body-suit style dresses expressed Velma's sensual attraction, aggressiveness, and desperation. Second, these images were reinforced by color images in the backgrounds in the film. On the scene of Velma's 'cell block tango', black and red showed her strong character. Contrasting colors of the red and blue expressed Velma's desire and despair in her act of 'the desperation'. As for images of black color on Roxie's stages, they represented her self-absorption and frustration of failing to attract public attention. On the ending of duet performance of Roxie and Velma, the yellow of the background expressed success and joy in life.

• Bulletin of the Korean Chemical Society
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• 제24권5호
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• pp.593-599
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• 2003

The nanoparticle magnetite of which diameter was about 3 nm was synthesized in a homogeneous aqueous solution without a template. The synthesized magnetite nanoparticle was easily oxidized to maghemite in an ambient condition. The magnetic properties of the ferrite nanoparticle show superparamagnetism at room temperature and its blocking temperature is around 93 K. Modifying the sequential adsorption method of metal bisphosphonate, we have prepared a multilayer thin film of the ferrite nanoparticle on planar substrates such as glass, quartz and Si wafer. In this multilayer the ferrite nanoparticle layer and an alkylbisphosphonate layer are alternately placed on the substrates by simple immersion in the solutions of the ferrite nanoparticle and 1, 10-decanediylbis (phosphonic acid) (DBPA), alternately. This is the first example, as far as we know, of nanoparticle/alkyl-bisphosphonate multilayer which is an analogy of metal bisphosphonate multilayer. UV-visible absorption and infrared reflection-absorption studies show that the growth of each layer is very systematic and the film is considerably optically transparent to visible light of 400-700 nm. Atomic force microscopic images of the film show that the surface morphology of the film follows that of the substrate in μm-scale image and the nanoparticle-terminated surface is differentiated from the DBPA-terminated one in nm-scale image. The magnetic properties of this ferrite/DBPA thin film are almost the same as those of the ferrite nanoparticle powder only.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 춘계학술대회 논문집 센서 박막재료 반도체재료 기술교육
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• pp.24-26
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• 2002

In this paper, we discuss the electrical properties of self-assembled (2'-amino-4,4-di(ethynylphenyl)-5'-nitro-l-(thioacetyl)benzene), which has been well known as a conducting molecule having possible application to molecular level NDR device. The phenomenon of negative differential resistance (NDR) is characterized by decreasing current through a junction at increasing voltage. also fabrication of MIM-type molecular electronic and the Molecular Level Using Scanning Tunneling Microscopy

• 한국식품조리과학회지
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• 제20권2호
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• pp.133-137
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• 2004

This study was investigated the effects of condensed phosphates (pyrophosphate, metaphosphate and polyphosphate) on the quality and self-life of wet noodle. The initial pasting temperatures were increased by the addition of pyrophosphate and metaphosphate, respectively, whereas those of propylene glycol and polyphosphate were decreased. Pyrophosphate showed the highest final viscosity, whereas metaphosphate showed the lowest. Setback of PG, polyphosphate, pyrophosphate and metaphosphate were all lower than the control. The water absorption ratios of PG and polyphosphate were increased compared to the control, whereas those of pyrophosphate and metaphosphate were decreased. The volume expansion ratios of PG and polyphosphate were slightly increased. Turbidities of PG and polyphosphate were lower than those of the control, whereas those of pyrophosphate and metaphosphate were increased in cooked noodles. The bacterial counts of wet noodles made with PG, polyphosphate, metaphosphate and pyrophosphate were all lower than those of the control after storage at 5$^{\circ}C$.