• Journal of Mechanical Science and Technology
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• 제17권8호
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• pp.1211-1218
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• 2003

The present study investigated two-phase flow distribution and phase separation of R-22 refrigerant through various types of branch tubes. The key experimental parameters were the orientation of inlet and branch tubes (horizontal and vertical), diameter ratio of branch tube to inlet tube (1 and 0.61), mass flux (200-500 kg/㎡s), and inlet quality (0.1-0.4). The predicted local pressure profile in the tube with junction was compared and generally agreed with the measured data. The local pressure profile within the pressure recovery region after the junction has to be carefully investigated for modeling the pressure drop through the branch. The equal flow distribution case can be found by adjusting the orientation of the inlet and branch tubes and the diameter ratio of the branch tube to the inlet tube. The T-junction with horizontal inlet and branch tubes showed the nearly equal phase distribution ratio. The quality at the branch tube varied from 0 to 1 as the orientation of the branch tube changed, while it varied within${\pm}$50% as the orientation of the inlet tube changed.

• 한국표면공학회지
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• 제22권4호
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• pp.207-214
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• 1989

The surface morphology and the proferred orientation of the Pb-Sn alloy electrodeposite were investated by the change of electrolysis conditions in pulse current electroplating. The preferred orientation of Pb-phase in alloy deposits was changed in the sequence of (110)longrightarrow(100)or(100)+(111)longrightarrow(111) with increasing peak current density, while that of $\beta$-Sn phase changed from (321)+(301)to(301)+(111) mixed orientation. The surface morphology was closely related to the preferred orientation of alloy electrodeposits. The alloy deposits, which had (100)or(111) for pb-phase and (321)or(100)(301)for $\beta$-Sn sespectively, showed the surface structure of granular crystallites. The alloy deposits whih mixed orientations for both phases had microstructure of closely the closely stacked crysrallites, which was inclined to the surface.

• Interaction and multiscale mechanics
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• 제4권2호
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• pp.155-164
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• 2011

The lattice strain evolution within polycrystalline solids is influenced by the crystal orientation and grain interaction. For multi-phase polycrystals, due to potential large differences in properties of each phase, lattice strains are even more strongly influenced by grain interaction compared with single phase polycrystals. In this research, the effects of the grain interaction and crystal orientation on the lattice strain evolution in a two-phase polycrystals are investigated. Duplex steel of austenite and ferrite phases with equal volume fraction is selected for the analysis, of which grain arrangement sensitivity is confirmed in the literature through both experiment and simulation (Hedstr$\ddot{o}$m et al. 2010). Analysis on the grain interaction is performed using the results obtained from the finite element calculation based on the model of restricted slip within crystallographic planes. The dependence of lattice strain on grain interactions as well as crystal orientation is confirmed and motivated the need for more in-depth analysis.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2000년도 제1회 학술대회 논문집
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• pp.61-62
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• 2000

We have studied the molecular orientation by the phase transitions of the chiral smectic liquid crystals, 4-(1-Trifluoromethyl-6-ethoxy-hexyloxycarbonlphenyl)-4-nonyloxybiphenyl-4-carbo-xylate (R-TFMEOHPNBC) to seek the original solution of the zig-zag defect using two different experimental techniques; optical system and x-ray scattering. The phase sequence is gamma ferroelectric $(SmC{\gamma}\;^*)$ ${\rightarrow}$ smectic A (SmA) ${\rightarrow}$ isotropic (I). Existence of two layer spacing at chiral smectic phase gives a possibility of the molecular orientation in two different tilt angles, ${\theta}\;_1$ and ${\theta}\;_2$, which are separated each other to the layer normal at a given temperature. The gamma ferroelectric-like phase is, first, discovered in the single compound.

• Journal of Electrical Engineering and Technology
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• 제13권1호
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• pp.315-325
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• 2018

This paper investigates optimum air-gap flux distribution with third harmonic rotor flux orientation adjustment for five-phase induction motor. The technique of objective is to generate a nearly rectangular air-gap flux, and it improves iron utilization under variation loading conditions. The proportional relations between third harmonic and fundamental plane currents is usually adopted in the conventional method. However, misalignment between fundamental and third harmonic component occurs with variation loading. The iron of stator teeth is saturated due to this misalignment. This problem is solved by third harmonic rotor flux orientation adjustment simultaneously, and direction and amplitude are changed with mechanical load variation. The proposed method ensures that the air-gap flux density is near rectangular for a maximum value from no load to rated load. It is confirmed that the proposed method guarantees complete both planes decoupling with third harmonic flux orientation adjustment. The effectiveness of the proposed technique is validated experimentally.

• 대한기계학회논문집
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• 제19권9호
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• pp.2181-2193
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• 1995

The effective elasticity and conduction of composite materials containing arbitrarily oriented multiple phases has been analyzed using the concept of orientation-dependent average fields and concentration factors. The analysis provided closed form expressions for the effective stiffnesses and conductivities. Under the prescribed boundary conditions, the concentration factors were evaluated by the equivalent inclusion principle, through which the interaction between various phases is approximated by the Mori-Tanaka mean-field approximation. SiC particulate(SiC$_{p}$) reinforce aluminum(Al) matrix composites were fabricated and their elastic constants and electrical conductivities were measured together with a careful study of their microstructure. The measured properties showed a systematic anisotropy and this behavior could be attributed to the preferred orientation of SiC$_{p}$. The theoretical model developed was applied to the computation of the anisotropic properties of these composites. Both two-phase and three-phase composites were considered based on the microstructural information. The SiC$_{p}$ was modeled as an ellipsoid with planar random orientation distribution in the extruded Al/SiC$_{p}$ composites. The effect of extraneous phase such as intermetallic compounds was also investigated.tigated.

• 설비공학논문집
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• 제14권9호
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• pp.741-748
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• 2002

The present study investigated the two-phase flow characteristics of refrigerant R-22 in T-branch with horizontal and vertical inlet tube The key experimental parameters were the orientation of inlet and branch tubes (horizontal and vertical), diameter ratio of branch tube to inlet tube (1 and 0.61), inlet mass flux (200~500 kg/$m^2$s) and inlet quality (0.1~0.4). Predicted pressure profile agreed with the measured data within 25.4%. The flow distribution ratio decreased as the mass flux increased. The flow distribution ratio decreased by 12~25% as the tube diameter ratio decreased from 1 to 0.61, and decreased by 38~47% as the orientation of branch changed from horizontal to vertical upward for horizontal inlet tubes. As the orientation of inlet tube changed from horizontal to vertical upward for horizontal branch, the flow distribution ratio increased by 15~68%, but the quality in the branch tube decreased by 28~92% due to phase separation.

• 한국초전도저온공학회:학술대회논문집
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• 한국초전도저온공학회 1999년도 제1회 학술대회논문집(KIASC 1st conference 99)
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• pp.47-50
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• 1999

The orientation mechanism of an amorphous $Bi_{2}$$Sr_{2}$$Ca_{2 x}$$Cd_{x}$$Cu_{3}$$O_{y}$ phase were studied by using the dilatometry. The amorphous $Bi_{2}$$Sr_{2}$$Ca_{2 x}$$Cd_{x}$$Cu_{3}$$O_{y}$ samples brought about a volume shrinkage at the onset of the crystallization of a $Bi_{2}$$Sr_{2}$$CaCu_{2}$$O_{6}$phase around $400^{\circ}C$. The random crystal growth of $Bi_{2}$$Sr_{2}$$CaCu_{2}$$O_{8}$ phase around $800^{\circ}C$. yielded a rapid volume expansion and after then samples shrinmed, accompanied with the crystal orientation. The$Bi_{2}$$Sr_{2}$$Ca_{2 x}$$Cd_{x}$$Cu_{3}$$O_{y}$ (x=0.4) sample exhibited the best-oriented structure because the liquid phase formed seemed to have the lowest viscosity which would contributed to the easy collapse of the card-house structure.

• 산업기술연구
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• 제11권
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• pp.65-72
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• 1991

In this paper, a control algorithm is discussed when the quadruped walking robot walks over the unknown soft ground. Firstly, it estimated the relationship between the foot force and the ground sinkage at the leg-placing phase. Secondly, the generated soil property is applied to the leg-supporting phase. If the attitude angle is changed by incorrect ground sinkage compensation, the control algorithm adjusts the attitude angle using simplified orientation orientation matrix.

• 암석학회지
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• 제9권4호
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• pp.205-210
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• 2000

암석중에 미립(직경 0.3mm내외)으로 존재하는 조암광물의 동정 및 결정학적인 배향도를 미소부 X선 회절분석기를 이용하여 측정하였다. 실험에 사용된 표품들은 $A1_{2}SiO_{5}$ 3상디형(규선석, 남정석, 홍주석)으로서 모든 표품들은 박편상의 것을 측정대상으로 하였다 측정에 이용된 X선 회절분석기는 3(${\omega}\;{\chi}\;{\phi}$)축 회전 측각기 및 위치민감형 검출기로 구성되어 있으며 X선원으로는 $CuK_{\alpha}$를 사용하였으며 직경 $50\;\mu\textrm{m}$의 시준기를 사용하였다. 광물 동정은 3(${\omega}\;{\chi}\;{\phi}$)축 회전 측정법에 의해 시행되었으며, 박편표면에 우세하게 나타나는 광물상의 격자면을 알아보기 위해 2(${\omega}\;{\phi}$)축 회전 측정을 실시하였고 2축 회전 측정법에 의해 우세하게 나타난 회절선에 대한 격자방향의 배향도와 극분포를 확인하기 위하여 X-선 극점도 측정을 시행하였다. 3축 회전 측정결과 측정대상 광물상에 대해 동정이 가능하였으며 2축 회전 측정과 X-선 극점도 측정결과 규선석(310), 남성석(200), 홍주석(122)극이 절단면, 즉 박편표면의 법선방향으로 잘 발달하고 있음을 확인할 수 있었다. 본 측정법은 편광현미경을 사용하여 식별이 용이하지 않은 미립조암광물의 동정과 배향도를 알아보는데 유용하게 사용될 수 있는 분석기법이다.