• 한국지반환경공학회 논문집
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• 제18권12호
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• pp.37-45
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• 2017

구조물은 영하의 온도가 유지되는 겨울철에 동상으로 인해 크고 작은 피해가 발생한다. 동상은 동토지반의 가장 대표적인 공학적 특성으로 다양한 동상민감성 판정법이 존재한다. 동상민감성 판정법은 크게 3가지로 분류할 수 있다. 첫 번째 동상민감성은 입도분포를 이용하여 결정된다. 많은 국가들이 지반의 입도분포를 이용해 비교적 간편한 동상민감성 판정법을 현장에 적용하고 있다. 그러나 본 논문에서 몇 가지 시료의 입도분포를 이용해 동상민감성 판정 기준에 적용한 결과에 따르면 입도분포로 토질의 동상민감성을 판정하기에는 다소 무리가 있다. 두 번째로는 동상시험에 의한 동상민감성 판정법이다. 새롭게 개발된 온도제어형 삼축셀을 이용한 동상 실내시험을 통해 동상민감성 기준 신뢰성을 분석하였다. 새롭게 개발된 장비와 시험방법은 기존에 제시하고 있는 동상민감성 판정 기준을 충족하는 것으로 판단되었다. 세 번째로는 복합적인 동상민감성 판정법으로 흙의 입도분포, 분류, 그리고 동상시험을 고려한 복합적인 동상민감성 판정 기준 그래프를 제시하고 있다. 본 논문에서 몇 가지 시료에 대해 복합적인 동상민감성 판정 기준에 적용한 결과 다양한 토질에 대한 추가적인 데이터를 바탕으로 복합적인 동상민감성 판정 그래프를 보완해야 할 것으로 판단되었다.

• 한국자기학회지
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• 제4권1호
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• pp.1-6
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• 1994

본 연구에서는 초 연자성(ultra-soft magnetic) 비정질 박막에서 관찰되는 감쇄가 큰(overdamped) 고주파 자기특성의 원인을 이해함으로써 자기 스핀의 동적 자화거동을 확인하고자한다. 고주파에서의 자화율(susceptibility) 특성곡선에 대한 실험결과와 Gilbert의 운동방정식으로 부터의 계산 결과를 비교하여 초 연자성 박막의 겨우 $\alpha=20$ 정도의 큰 감쇄상수와 무시할 정도로 작은 $D_{x}{\approx}D_{y}{\approx}D_{z}{\approx}0$의 반자장 계수를 구하였다. 이 결과로 부터 불균일 박막의 자화율 특성곡선과 자기 스핀의 동적 자화거동을 설 명하기 위해 vortex 형상의 자화분포를 제안하였다. Vortex형 자화분포는 초 연자성 박막 내의 미세한 자성입자들에서의 안정된 스핀 분포로 형성되며, vortex의 불균일한 스핀운동은 스핀파로 부터의 에너지와 박막내 결함구조와의 상호작용에 의해 큰 감쇄를 갖는 것으로 설명되었다.

• Nuclear Engineering and Technology
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• 제41권3호
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• pp.347-354
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• 2009

Welding is required for a connection between two different components in the nuclear fuel of a pressurized water reactor. This work relies on a mechanical experiment and analytic results to investigate the structural integrity of nuclear fuel in a situation where some components are not welded to each other. A series of lateral vibration tests are performed in a test facility, and the test structures are examined in terms of dynamic behavior. In the tests, the displacement signal at every grid structure that sustains fuel rods is measured and processed to identify the dynamic properties. The fluid-elastic stability of the structure is also analyzed to evaluate susceptibility to a cross flow with an assumed conservative cross flow distribution. The test and analysis results confirm that the structural integrity can be maintained even in the absence of some welding connections.

• Progress in Superconductivity
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• 제11권1호
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• pp.67-71
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• 2009

The effect of Cu substitution on the structural and superconducting properties of the $(Ru_{1-x}Cu_x)Sr_2(Eu_{1.34{\cdot}}Ce_{0.66})Cu_2O_z$ system with x = 0, 0.25 and 0.5 prepared under ambient pressure have been investigated. The X-ray diffraction patterns indicated that the Ru ions are replaced by the Cu ions. It is found that the Cu substitution for Ru significantly reduces the ferromagnetic component of field-cooled magnetic susceptibility, but results in a small change in diamagnetic onset transition temperature of zero-field-cooled magnetic susceptibility. In contrast to the Ru $Sr_2(Eu_{1.34{\cdot}}Ce_{0.66})Cu_2O_z$, bulk Meissner effect is observed in the field-cooled magnetization measurements of the Cu doped samples. The experimental results are discussed in connection with the spontaneous vortex phase interpretation.

• Macromolecular Research
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• 제15권7호
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• pp.671-675
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• 2007

Soybean proteins appear to harbor a great deal of potential as functional ingredients due to the fact that they are composed of highly bioavailable peptides and amino acids. To develop drink- or gel-type foods formulated with soybean protein, the physicochemical properties of intact and chemically modified soy glycinin were assessed. Maleylation to soy glycinin altered the surface charges of glycinin via the modification of lysine residues, and subsequently generated the dissociation of glycinin subunits owing to the increase in charge repulsion. This modification thus improved the solubility of glycinin, particularly under acidic pH conditions. It is worthy of note that maleylation increased the susceptibility of the basic subunits of mTGase and the formation of a substantial quantity of molecules at a low protein solution concentration. The results of dynamic rheological studies indicated that the 5% intact glycinin progressively formed the gel with mTGase treatment in a concentration-dependent manner, but maleylated-glycinin did not.

• Bulletin of the Korean Chemical Society
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• 제13권4호
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• pp.381-384
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• 1992

The hydrolytic susceptibility of large unilamellar vesicle (LUV) toward cabbage phospholipase D (PLD) was studied. The activity of PLD was determined by pH stat titration method. Using phosphatidylcholine LUV as substrate a pH optimum of 6.96 was observed. For maximal activity the optimal temperature of $31^{\circ}C$ and 10 mM of Ca2+ were required. The apparent Km value estimated was 2.5 mM. The hydrolytic activity of PLD toward PC LUV was somewhat high despite the absence of activator in assay system and this high susceptibility of PC LUV may be attributed to the structural properties of LUV. The effect of amphiphatic substances such as dicetyl phosphate and phosphatidic acid on the enzyme activity were also examined in mixed LUVs.

• 한국지반공학회논문집
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• 제26권7호
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• pp.71-80
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• 2010

지리학적 특성으로 국내는 계절 동토지역으로 겨울철에는 동상현상이 발생하고 봄철에는 지반이 해빙된다. 도로는 다양한 재료와 단면으로 구성된 구조물이기 때문에 환경성과 재료 물성뿐만 아니라 포장체 각 층의 구조적 적정성 또는 지지력을 파악하는 것이 무엇보다 중요하다. 현재 기존 동상방지층 설계법에 따르면, 동상방지층은 포장체의 구조적 적정성과는 무관하게 온도조건에 따른 동결깊이에 따라 일률적으로 결정되고 있다. 이러한 동결깊이를 포장구조설계에 적용함으로써 포장의 과다설계 우려가 있다. 따라서 본 논문에서는 노상층, 동상방지층, 보조기층의 역학적 실험을 실시하여 동상민감성을 판단하고 실규모 현장도로 모형축소 실험을 실시하였다. 동상민감성을 판단하기 위하여 토층별 온도, 동결팽창량, 부동수분 및 동결깊이를 측정하였다.

• Journal of Magnetics
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• 제1권2호
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• pp.57-59
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• 1996

The YBa$_2$Cu$_3$O6+xstructures have been fluorinated by a gas phase exchange technique, and 19F NMR was used to identify the structural fluorine. Magnetic susceptibility measurements showed that the fluorination turned a marginally nonsuperconducting sample into a 40 K superconductor, as well as that it raised the onset of the superconducting transition of the 60 K superconductor YBa$_2$Cu$_3$O6.7 to about 100 K.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집A
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• pp.322-327
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• 2001

The internal leaks of RCS pressure boundary valves may cause thermal fatigue crack because of the TASCS in RCS branch line. After experienced unisolable piping failures in several PWR plants, many studies have peformed to understand these phenomena and various methods were applied to ensure the structural integrity of piping. In this paper, the cause of unisolable piping failures and the alternatives to prevent recurrence of failure were reviewed. Also, the severity of piping failure including susceptibility of valve leaks was evaluated for the Westinghouse 2-loop plant. The length of turbulent penetration on RHR inlet piping was measured and, thermal fluid analysis and fatigue analysis was performed for this piping. As a means of ensuring the structural integrity, temperature monitoring and specialized UT and other alternatives were compared for the further application.

• Bulletin of the Korean Chemical Society
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• 제34권12호
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• pp.3615-3620
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• 2013

Two novel copper(II) bromide complexes with pyridine containing Schiff base ligands, $Cu(pmed)Br_2$ and $Cu(pmed)Br_2$ where pmed = N'-((pyridin-2-yl)methylene)ethane-1,2-diamine (pmed) and dpmed = N,N-diethyl-N'-((pyridin-2-yl)methylene)ethane-1,2-diamine (dpmed) were synthesized and characterized using X-ray single crystal structure analysis, optical and magnetic susceptibility measurements. Crystal structural analysis of $Cu(pmed)Br_2$ showed that the copper(II) ion has a distorted square-pyramidal geometry with the trigonality index of ${\tau}=0.35$ and two intermolecular hydrogen bonds, which result in the formation of two dimensional networks in the ab plane. On the other hand, $Cu(pmed)Br_2$ displayed a near square-pyramidal geometry with the value of ${\tau}=0.06$. In both compounds, the NNN Schiff base and one Br atom occupy the basal plane, whereas the fifth apical position is occupied by the other Br atom at a greater Cu-Br apical distance. The reported complexes show $g_{\mid}$ > $g_{\perp}$ > 2.0023 with a $d_{x2-y2}$ ground state and a penta-coordinated square pyramidal geometry. Variable temperature magnetic susceptibility measurements showed that the developed copper(II) complexes follow the Curie-Weiss law, that is there are no magnetic interactions between the copper(II) ions since the Cu--Cu distance is too far for magnetic contact.