• 한국결정성장학회지
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• 제14권3호
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• pp.95-100
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• 2004

This paper reports a potential problem in the electrical performance of the silicide film to silicon contacts with respect to the scaling trend in integrated circuit (IC) devices. The effects of elastic strain on the agglomeration of the coherent silicide film embedded in an infinite matrix are studied employing continuum linear elasticity and finite-difference numerical method. The interface atomic diffusion is taken to be the dominant transport mechanism where both capillarity and elastic strain are considered for the driving forces. Under plane strain condition with elastically homogeneous and anisotropic system with cubic symmetry, the dilatational misfit and the tetragonal misfit in the direction parallel to the film thickness are considered. The numerical results on the shape evolution agree with the known trend that the equilibrium aspect ratio of the film increases with the elastic strain intensity. When the elastic strain intensity is taken to be only a function of the film size, the flat film morphology with a large aspect ratio becomes increasingly unstable since the equilibrium aspect ratio decreases, as the film scales. The shape evolution results in a large decrease in contact to silicon area, and may deteriorate the electrical performances.

• Bulletin of the Korean Chemical Society
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• 제23권2호
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• pp.253-261
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• 2002

Vibrational properties of ferrocyanide complex ion, $[Fe(CN)_6]^{4-}$ , have been studied based on the force constants obtained from the density functional calculations at B3LYP/$6-31G^{\ast\ast}$ level by means of the normal mode analysis using new bond angle and linear angle internal coordinates recently developed. Vibrations of ferrocyanide were manipulated by twenty-three symmetry force constants. The angled bending deformations of C-Fe-C, the linear bending deformations of Fe-C${\equiv}$N and the stretching vibrations of Fe-C have been quantitatively assigned to the calculated frequencies. The force constants in the internal coordinates employed in the modified Urey-Bradley type potential were evaluated on the density functional force field applied, and better interaction force constants in the internal coordinates have been proposed. The valence force constants in the general quadratic valence force field were also given. The stretch-stretch interaction and stretch-bending interaction constants are not sensitive to the geometrical displacement in the valence force field.

• 공업화학
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• 제26권5호
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• pp.624-629
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• 2015

호모게나이저로 파쇄한 쑥 조직을 탄소반죽에 혼입시켜 과산화수소 감응 바이오센서를 제작하고 그것의 전기화학적 특성을 전압전류법으로 살펴보았다. Hanes-Woolf 도시의 좋은 직선성은 기질분해가 쑥 과산화효소에 의하여 촉매화되고 있음을 보여 주었으며, 작은 값의 대칭인자(${\alpha}$, 0.28)는 전극전위의 변화가 반응속도변화에 미치는 영향이 대단히 민감한 것을 말하여 주었다. 이런 실험적 사실들은 과산화수소의 분해가 쑥전극 표면에 있는 과산화효소의 촉매력에 의하여 정성적, 정량적으로 분해되고 있음을 보여 주는 것으로 서양 고추냉이로부터 추출된 고가의 시판 과산화효소를 쑥 조직으로 대치할 수 있음을 확신하게 하는 것이다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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• pp.153-153
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• 2013

Turbomolecular pump (TMP) is widely used to obtain and maintain high vacuum by spinning turbine rotors to migrate gas molecules to the exhaust of the pump. However, performance of the TMP has not been well observed when it is influenced by strong magnetic field. Such study may give useful information about magnetic field tolerance of TMP, development of magnetic shielding technique for key components of TMP, etc. For this purpose, magnetic field induced by a circular current source was firstly designed and investigated. Using spherical coordinates and vector potential, magnetic field throughout the space including axis of rotation was calculated. Due to the rotational symmetry of the circular current source, induced magnetic field is azimuthally symmetric and, thus, is analyzed by radial and polar components of the magnetic fields. In order to enhance the numerical accuracy for the calculation, magnetic field was expressed by complete elliptic integrals of first and second kinds. According to the calculation, when 1 A of DC-current passes through a 1 turned circular wire with 50 cm of diameter, overall magnitude of the inducedmagnetic field was about 0.02 Gauss, which was used to the determination of the current and the number of turns of wires to fabricate the coil for the study on the magnetic field tolerance of TMP.

• Progress in Superconductivity
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• 제2권1호
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• pp.43-46
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• 2000

We report on the tunneling spectroscopy of tunnel junctions using d-wave superconductor in relation to Andreev reflection. The zero bias conductance peak (ZBCP) which has maximum on [110] direction of ab-plane is observed on metal $Au/YBa_2Cu_3O_y$ tunnel junctions while it is suppressed on the ferromagnetic $Co/Au/YBa_2Cu_3O_y$ tunnel junctions. The effects of Andreev reflection on the differential conductance of each junction are dependent on the tunnel direction. For the $Co/Au/YBa_2Cu_3O_y$ junction, the suppression of Andreev reflection takes place by spin-polarized quasiparticles tunneling from a ferromagnetic material to a d-wave superconductor. By comparing these experimental results with recent theoretical works on Andreev reflection, the existence of Andreev bound state due to the d-wave symmetry of the pair potential is verified in high-$T_c$ superconductor.

• 복식문화연구
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• 제23권1호
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• pp.145-160
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• 2015

The purpose of this study is to review the concept and thinking structure of deconstruction theoretically and thereupon, analyze the visual beauty and wearable comfort of the clothing and further, discuss the aesthetic characteristics and values of the decentering phenomenon in the 21st century fashion. Deconstruction provides for an cognitive framework whereby we could comprehensively review the difficult-to-understand and imprudent creativity unravelling in the name of the post-modernism as well as the ambiguous visual beauty and wearable comfort of our contemporary fashion. In particular, deconstruction refuses such concepts involving the relationship between the conventional clothing and its components as order, symmetry, balance, harmony, perfection and simplicity and instead, attaches some sense of value to such relatively inferior concepts as disorder, asymmetry, unbalance, disharmony, imperfection and complexity, and thus, reflects them in the modes of aesthetic representations to create new aesthetics and expand the expressive potential.

• 한국세라믹학회지
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• 제54권5호
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• pp.422-428
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• 2017

Single-phase yellow phosphor, $CaGd_{2-x}ZrSc(AlO_4)_3:xCe^{3+}$ ($CGZSA:Ce^{3+}$), possessing cubic symmetry with varied $Ce^{3+}$ concentrations, was synthesized using the solid-state reaction method. The samples were characterized using X-ray diffraction (XRD), excitation spectra, emission spectra, thermal quenching, and decay curves. The cubic phase of $CGZSA:Ce^{3+}$ phosphor was confirmed via XRD analysis. The photoluminescence spectra of $CGZSA:Ce^{3+}$ phosphor demonstrated that the phosphor could be excited at the wavelength of 440 nm; a broad yellow emission band was centered at 541 nm. These results indicate that the phosphors are adequately excited by blue light and have the potential to function as yellow-emitting phosphors for applications in white light-emitting diodes.

• 대한조선학회지
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• 제21권3호
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• pp.43-50
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• 1984

A body form, which experiences minimum vertical wave-exciting forces in the vicinity of a prescribed wave frequency in water of finite depth, is obtained by an approximate method. Its configuration has the symmetry with respect to the vertical axis, expressed in terms of exponential functions. By distributing three-dimensional pulsating sources and dipoles on the immersed surface of the body, a velocity potential is determined and subsequently hydrodynamic forces including the 2nd-order time-mean drift forces are calculated. The dynamic behavior of the body moored in irregular waves is investigated numerically by using central difference method. Hereby irregular wave trains are simulated with examining its repeatability by comparing the resulting spectrum with original one. Numerical results indicated that the body form obtained from the present analysis possesses in general a favorable hydrodynamic characteristics in comparison with a spherical buoy and that the maximum excursion of the body can be significantly reduced by setting pre-tension of an appropriate amount in the mooring cable.

• 한국자기학회지
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• 제17권4호
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• pp.152-155
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• 2007

다중강전자 상태의 $YMnO_3,\;ScMnO_3$의 전자구조와 자기구조를 국소스핀밀도근사(LSDA)를 이용하여 계산하였다. 강자성 상태이며 강유전 상태의 전자구조는 육방정계 구조로 인하여 Mn 3d 에너지띠가 분리되어 띠틈을 나타내었다. 이러한 에너지 띠틈과 작은 Y, Sc 이온의 반경으로 인하여 $YMnO_3,\;ScMnO_3$는 반강자성 강유전적 성질을 가지는 다중강전자 구조를 가지고 있음을 보았다. 또한 총에너지 계산을 통하여 반강자성, 강유전 상태가 가장 안정됨이 실험과 일치하였다.

• 전기화학회지
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• 제7권1호
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• pp.9-15
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• 2004

Cyclic voltammetry and chronocoulometry have been used for characterization of catechol violet (CV) at the hanging mercury drop electrode in acetic acid-sodium acetate buffer solution. At pH 2.94 a nearly symmetric cyclic voltammetric wave due to an irreversible weak adsorption of CV on mercury was obtained at concentration of $0.53{\mu}mol\;dm ^{-3}$. Under these conditions, CV adsorbes in a monolayer. Upon increasing the concentration, the symmetry of the wave decreases; it can be attributed to a mixed diffusion adsorption process. The amount of the adsorbed catechol violet on the HMDE expressed as surface concentration as well as the surface areaf occupied by one molecule$(\sigma)$ were calculated. It was found that the values obtained for f and o utilizing cyclic voltammetric and chrono-coulometry are almost identical. A 1:1 and 1:2 Th (IV)-CV complexes are formed on addition of thorium (IV) to catechol violet. These complexes are adsorbed and reduced on the HMDE at more negative potentials than the peak potential of free CV, Using the square-wave (SW) technique, the adsorptive cathodic stripping voltammetry, ACSV, of these complexes was studied. It was found that the SW-ACSV of Th(IV)-CV can be applied to the determination of thorium at the nanomole level. Optimum conditions and the analytical method of determination were presented and discussed.