• 한국자기학회지
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• 제18권3호
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• pp.89-93
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• 2008

준강자성체 구리-철-크롬 산화물 $CuFe_{0.9}Cr_{1.1}O_4$을 제조하여 액체질소 온도에서부터 닐 온도까지의 범위에 대한 뫼스바우어 분광실험을 하였다. 닐 온도는 355 K로 측정되었으며, 닐 온도 이상에서의 전기사중극자 상호작용의 크기인 사중극자 분열값은 0.50 mm/s인 반면, 닐 온도 이하에서의 사중극자 이동값은 실험오차 범위 내에서 0.00 mm/s이었다. 이러한 전기사중극자 상호작용에 대한 겉보기 불일치 현상은 자기적 초미세 자기장이 전기장 기울기 텐서의 주축에 대하여 무작위로 배열된다는 모델을 이용하면 설명될 수 있다.

• Earthquakes and Structures
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• 제22권6호
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• pp.597-608
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• 2022

One of the most important parameters affecting nonlinearsoil-structure interaction, especially rocking foundation, is the vertical factor of safety (F.S_v). In this research, the effect of F.S_v on the behavior of rocking foundations was experimentally investigated. A set of slow, cyclic, horizontal loading tests was conducted on elastic SDOF structures with different shallow foundations. Vertical bearing capacity tests also were conducted to determine the F.S_v more precisely. Furthermore, 10% silt was mixed with the dry sand at a 5% moisture content to reach the minimum apparent cohesion. The results of the vertical bearing capacity tests showed that the bearing capacity coefficients (N_c and N_γ) were influenced by the scaling effect. The results of horizontal cyclic loading tests showed that the trend of increase in capacity was substantially related to the source of nonlinearity and it varied by changing F.S_v. Stiffness degradation was found to occur in the final cycles of loading. The results indicated that the moment capacity and damping ratio of the system in models with lower F.S_v values depended on soil specifications such cohesiveness or non-cohesiveness and were not just a function of F.S_v.

• Nuclear Engineering and Technology
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• 제55권10호
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• pp.3808-3814
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• 2023

The thermal stability of nitric acid solutions after contact with non-irradiated and irradiated tributyl phosphate (TBP) and its solution in Isopar-M has been studied. It has been established that exothermic processes occur during heating due to the interaction of soluble radiolysis products and the decomposition of the extractant with nitric acid. Such processes can occur at temperatures below 100 ℃, but unlike a thermal explosion that occurs in seconds, they are longer in time and are accompanied by weak heat evolution. Their intensity depends on the composition of the extractant, the concentration of HNO₃, and the volume ratio of the organic and aqueous phases. The presence of extractant degradation products in raffinates does not pose a risk of a rapid evolution of gaseous products during evaporation, however, the presence of reducing agents can significantly increase the intensity of the exothermic decomposition of raffinates.

• Steel and Composite Structures
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• 제3권6호
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• pp.383-401
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• 2003

Two new formulae for the design of beam-columns at room temperature have been proposed into Eurocode 3, prEN 1993-1-1 (2002), and are the result of great efforts made by two working groups that followed different approaches, a French-Belgian team and an Austrian-German one. Under fire conditions the prEN 1993-1-2 (structural fire design) presents formulae, for the design of beam-columns based on the prENV 1993-1-1 (1992). In order to study the possibility of having, in part 1-1 and part 1-2 of the Eurocode 3, the same approach, a numerical research was made using the finite element program SAFIR, developed at the University of Liege for the study of structures subjected to fire.

• Bulletin of the Korean Chemical Society
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• 제16권5호
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• pp.454-458
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• 1995

Inhibiting action of semicarbazide, thiosemicarbazide, sym. diphenylcarbazide towards corrosion of zinc in hydrochloric acid has been investigated. The rate of corrosion depends on the nature of the inhibitor and its concentration. The values of inhibition efficiency from, weight loss, thermometric measurements are in good agreement with those obtained from polarization studies. From the polarization studies, the inhibitors used act as mixed absorption type inhibitors, increased adsorption resulting from an increase in the electron density at the reactive C=S and C=O groups and N-atoms. The thermodynamic parameters of adsorption obtained using Bockris-Swinkels adsorption isotherm reveal a strong interaction of these carbazides on zinc surface.

• Bulletin of the Korean Chemical Society
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• 제27권3호
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• pp.399-402
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• 2006

Porous organic-inorganic hybrids have been prepared from tetraethylorthosilicate (TEOS) and organosilane precursors by sol-gel method. Two organosilanes, 3-(2,4-dinitrophenylamino)propyltriethoxysilane (DNPTES) and N-[[(2-nitrophenyl)methoxy]carbonyl]-3-triethoxysilylpropylamine (NPTES) were used to incorporate electron-accepting (di)nitrophenyl groups into the hybrids. The hybrids were characterized by FT-IR spectroscopy and elemental analysis, and their pore characteristics were studied by nitrogen sorption porosimetry. Surface area of the hybrids ranged from 563 to 770 $m^2$/g, pore volume, 0.23-0.30 $cm^3$/g, and porosity, 35-41%. It was demonstrated by UV-vis spectroscopy that aniline, ethylenediamine, and 1-aminonaphthalene could be removed from their hexane solutions in the presence of the hybrid powders. The removal of amines is attributable to donor-acceptor interaction between the electron-donating amines and electron-accepting (di)nitrophenyl moiety.

• Bulletin of the Korean Chemical Society
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• 제32권8호
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• pp.2722-2726
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• 2011

Plasticized poly(vinyl chloride), PVCs, with different membrane compositions tested for use in the construction of an ion-selective sensor for the determination dibucaine. A prepared membrane with dioctyl phthalate-PVC and ion-pair of N-(1-naphthyl)ethylenediamine dihydrochloride-tetraphenyl borate had a good potential to acts as a potentiometric sensor for the analysis of dibucaine. A linear relationship was obtained between potential and logC varying between $1.0{\times}10^{-6}$ and $1.0{\times}10^{-2}$ M dibucaine with a good repeatability and reproducibility. The sensor was applied for the determination of the drug in pharmaceuticals and biological fluids such as plasma and urine samples with satisfactory results. The drug electrode has also been used to study the interaction of bovine serum albumin (BSA) with dibucaine. The saturated quantities of dibucaine binding were 13.04, 5.30 and 9.70 mol/mol in 0.01, 0.02 and 0.1% of protein, respectively.

• Molecules and Cells
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• 제26권1호
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• pp.87-92
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• 2008

We employed dual color Fluorescence Cross Correlation Spectroscopy (FCCS) to measure the interaction between PKA regulatory (RII) and catalytic subunits (CAT) in living cells. Elevation of intracellular cAMP with forskolin decreased the cross-correlation amplitude between RFP-fused RII (RII -mRFP) and GFP-fused CAT (CAT-EGFP) by 50%, indicating that cAMP elevation leads to dissociation of RII-CAT complexes. Moreover, diffusion coefficient analysis showed that the diffusion rate of CAT-EGFP was significantly increased, suggesting that the decreased RII-CAT association caused by cAMP generated free CAT subunits. Our study demonstrates that in vivo FCCS measurements and their quantitative analysis permit one not only to directly quantify protein-protein interactions but also to estimate changes in the intracellular cAMP concentration.

• 전기전자학회논문지
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• 제20권2호
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• pp.177-180
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• 2016

본 연구에서는 4H-SiC(0001)기판 위에서 형성되는 나노구조화를 제어하기 위해 상지층과 하지층으로 구성된 이중층 금속을 증착하고 두께, 열처리 시간을 변화하였다. 또한 표면에너지와 응집현상의 상관관계를 분석하기 위해 SiC와는 다른 표면에너지를 갖는 Glass와 Si기판에도 같은 조건으로 실험하였다. FE-SEM을 통하여 금속이 나노구조화를 형성하는 두께가 Ag=20nm, Ti=2nm임을 확인 했으며 두께가 두꺼울 수록 나노 입자가 형성되지 않았다. 세기판의 표면에너지를 구하기 위해 접촉각 측정기를 통해 정접촉각법으로 측정하였다. 그 결과 표면에너지 값이 가장 높은 Glass(53.89 mN/m) 기판에서 나노 입자가 가장 고르게 분포된 형태를 보였으며 SiC(41.13 mN/m)에서 나노구조화 되는 양상을 보였고, Si(32.96 mN/m)에서는 NPs 형성이 되지 않았다. 표면에너지가 작을수록 나노 입자형성이 고르게 분포되는 현상을 Young equation으로 분석하였다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 하계학술대회 논문집 Vol.3 No.2
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• pp.585-588
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• 2002

The USM uses friction between a mobile part (rotor) and a vibration part(stator), which is different from the principle of the conventional motor based on the interaction of electric and magnetic fields. In this thesis, a flat-type $L_1-B_8$ mode USM was designed and fabricated the characteristics of an ultrasonic vibration. The results of fabricated USM are as follows: (1) In case of ultrasonic motor with elastic-body of stainless, when applied voltage, frequency, pressing force of rotor were 50 [V], 27.9 [kHz], 1.5 [N], 5.0[mN m] respectively, the speed of revolution could be presented up to 0 [cm/s]. (2) In case of ultrasonic motor with elastic-body of brass, when applied voltage, frequency, pressing force of rotor were 50 [V], 21.4 [kHz], 1.5 [N], 1.4[mN m]respectively, the speed of rotor revolution was presented up to 0 [cm/s]. (3) The USM of elastic-body of stainless showing 1.17[%], somewhat low, in the maximum efficiency according to torque was superior to the USM of elastic-body of brass showing 0.34 [%]. The Flat-type $L_1-B_8$ mode USM had characteristics of typical drooping torque-speed, large torque and high speed, and operating in both directions by phase reversal.