• Title/Summary/Keyword: Phases-difference

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Space-time and The theory of Eumyang-ohaeng -way of thinking in the standpoint of Oriental Medicine- (시공(時空)과 음양오행(陰陽五行) -한의학의 사고체계-)

  • Back, Sang-Ryong
    • Korean Journal of Oriental Medicine
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    • v.9 no.2
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    • pp.17-27
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    • 2003
  • Eumyang-ohaeng[陰陽五行-Eumyang and five phases], as a standing rule that establishes the theory of Oriental medicine and origin of the oriental philosophy, it provides the perspective of the oriental medicine's outlook of the world. Without knowing the Eumyang-ohaeng, we cannot discuss Oriental medicine, nor can we understand the oriental way of thinking. Time and Space is what the human being created in order to explain the existence and change of matters. There is a common denominator between this universal concept of time and space and the theory of Eumyang-ohaeng. Consequently this paper investigates how characteristics of Eumyang-ohaeng and that of time and space matches Eumyang represents all matter and its characteristic, by comparison with each other space, and Ohaeng shows the change of matter with time gradually and sequancely. But this separation is only a separation by words, they really melt into one like two sides of a coin is actually just one coin. After all the theory of Eumyang-ohaeng is a theory that leads us to realize time and space, matter and power are all just one. So consequently, despite the difference in mass or size or longevity of matters, Eumyang-ohaeng pulls all matter into one body. It's why Eumyang-ohaeng is defined as the unified theory of time and space.

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superconducting properties of Bi-2223 tapes with various heat treatment condition (열처리 온도 및 분위기 변화에 따른 Bi-2223 초전도 선재에서의 특성변화)

  • 하동우;이동훈;하홍수;오상수;김홍대;양주생;윤진국;최정규;권영길
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2002.07a
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    • pp.527-530
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    • 2002
  • A lot of efforts have been focused on the optimization of PIT parameters for Bi-2223/Ag wire. In this paper, initial annealing of Bi-2223/Ag wire to transform Bi-2212 orthorhombic from Bi-2212 tetragonal Precursor was investigated. This initial annealing step at low oxygen partial pressure were to transform Bi-2212 orthorhombic structure and to reduce the formation of second phases at superconducting wire. However Bi-2223 Phases were appeared at higher annealing temperature. Critical currents(Je) of Bi-2223/Ag tapes were sintered at low oxygen Partial pressure were higher than that of the wires sintered at atmosphere condition. In order to investigate the effect of rolling reduction ratio, Bi-2223/Ag HTS tapes were rolled with different reduction ratio. There were no clear difference of Je and filaments shape with various rolling reduction ratio.

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Simple and Highly Efficient Droplet Merging Method Using a Microfluidic Device (미세유체소자를 이용한 간단하고 효율적인 액적의 병합)

  • Jin, Byung-Ju;Kim, Young-Won;Yoo, Jung-Yul
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.33 no.3
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    • pp.178-185
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    • 2009
  • Simple and highly efficient droplet merging method is proposed, which enables two nanoliter or picoliter droplets to merge regularly in a straight microchannel. Using a cross channel with inflows of one oil phase through the main channel and two water phases through the side channels, two droplets of different sizes can be generated alternatingly in accordance with flow rate difference of the water phases. It is shown that for a fixed oil phase flow rate, the flow rate of one water phase required for alternating droplet generation increases linearly with the flow rate of another water phase. By this method, the droplets are merged with 100 % efficiency without any additional driving forces.

Stability of High Internal Phase Emulsions

  • Park, C.I.;Cho, W.G.
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.25 no.4 s.34
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    • pp.65-74
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    • 1999
  • We have studied the stability of W/O high internal phase emulsions(HIPE) containing water, cetyl dimethicone copolyol and oils varying magnesium sulfate in the range 0 to 0.5 wt% and oil polarities, respectively. The rheological consistency was mainly destroyed by the coalescence of the deformed water droplets. The greater the increase of complex modulus was, the less coalescence occurred and the more consistent the concentrated emulsions were. The increasing pattern of complex modulus versus volume fraction has been explained with the resistance to coalescence of the deformed interfacial film of water droplets in concentrated W/O emulsion. The stability is dependent on: (i) the choice of the oil is important, the requirements coincide with the requirements for the formation of the rigid liquid crystalline phases; and (ii) addition of salts the aqueous phase opposes the instability due to coalescence. Increasing the salt concentration increases the refractive index of the aqueous phase. It lowers the difference in the refractive index between the oil and aqueous phases. This decreases the attraction between the water domains, thus increasing the stability.

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The PTCR Effect of Semiconducting Zn-Ti-Ni-O Ceramics (Zn-Ti-Ni-O 반도성 세라믹스의 PTCR 현상)

  • Ko, Il-Young;Choi, Seung-Chul;Kim, Hwan
    • Journal of the Korean Ceramic Society
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    • v.30 no.8
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    • pp.609-614
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    • 1993
  • Semiconducting Zn-Ti-Ni-O and Zn-Ti-O system were investigated. The specimens sintered at the temperature between 125$0^{\circ}C$ and 145$0^{\circ}C$ exhibited PTCR effect between -5$0^{\circ}C$ and 35$0^{\circ}C$ with resistivity ration exceeding three decades. Semiconducting Zn-Ti-Ni-O is consisted of two phases, one is n-type ZnO and the other is p-type spinel structure. The mechanism of PTCR effect was explained in relation to the piezoelectric property of ZnO and the residual stress caused by thermal expansion difference between two phases during cooling process.

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Stability of High Internal Phase Emulsions

  • Park, C-I.;W-G. Cho
    • Proceedings of the SCSK Conference
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    • 1999.10a
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    • pp.65-74
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    • 1999
  • We have studied the stability of W/O high internal phase emulsions(HIPE) containing water, cetyl dimethicone copolyol and oils varying magnesium sulfate in the range 0 to 0.5wt% and oil polarities, respectively. The rheological consistency was mainly destroyed by the coalescence of the deformed water droplets. The greater the increase of concentrated modulus was, the less coalescence occurred and the more consistent the concentrated emulsions were. The increasing pattern of complex modulus versus volume fraction has been explained with the resistance to coalescence of the deformed interfacial film of water droplets in concentrated W/O emulsion. The stability is dependent on: (i) the choice of the oil is important, the requirements coincide with the requirements for the formation of the rigid liquid crystalline phases :5; and (ii) addition of salts the aqueous phase opposes the instability due to coalescence:. Increasing the salt concentration increases the refractive index of the aqueous phase. It lowers the difference in the refractive index between the oil and aqueous phases. This decreases the attraction between the water domains, thus increasing the stability.

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Influence of W Additions on the Corrosion Characteristics and Hardness of Super Duplex Stainless Steel (슈퍼 듀플렉스 내식강의 부식특성 및 경도에 미치는 텅스텐 첨가의 영향)

  • Yun-Gi Han;Jeong-Min Kim
    • Journal of the Korean Society for Heat Treatment
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    • v.36 no.5
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    • pp.261-269
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    • 2023
  • This study aims to investigate the effects of tungsten additions on the microstructure, corrosion characteristics, and hardness of super duplex stainless steel heat-treated at two different annealing temperatures. Under the annealing temperature of 1100℃, the microstructure of the stainless steels consisted mainly of ferrite, while under the annealing temperature of 1000℃, significant amounts of austenite and secondary phases were also observed. In terms of corrosion characteristics in 3.5 wt%NaCl solution, there was not a significant difference due to W addition at the 1100℃ conditions. However, at the 1000℃, a tendency of decreased corrosion resistance was observed with increasing the tungsten content. On the other hand, the micro-hardness of the stainless steel heat-treated 1000℃ showed an increasing trend with tungsten addition. This increase can be mainly attributed to the higher fraction of secondary phases, primarily sigma, known for their high hardness.

A Study on the Recovery of Li2CO3 from Cathode Active Material NCM(LiNiCoMnO2) of Spent Lithium Ion Batteries

  • Wang, Jei-Pil;Pyo, Jae-Jung;Ahn, Se-Ho;Choi, Dong-Hyeon;Lee, Byeong-Woo;Lee, Dong-Won
    • Journal of Powder Materials
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    • v.25 no.4
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    • pp.296-301
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    • 2018
  • In this study, an experiment is performed to recover the Li in $Li_2CO_3$ phase from the cathode active material NMC ($LiNiCoMnO_2$) in waste lithium ion batteries. Firstly, carbonation is performed to convert the LiNiO, LiCoO, and $Li_2MnO_3$ phases within the powder to $Li_2CO_3$ and NiO, CoO, and MnO. The carbonation for phase separation proceeds at a temperature range of $600^{\circ}C{\sim}800^{\circ}C$ in a $CO_2$ gas (300 cc/min) atmosphere. At $600{\sim}700^{\circ}C$, $Li_2CO_3$ and NiO, CoO, and MnO are not completely separated, while Li and other metallic compounds remain. At $800^{\circ}C$, we can confirm that LiNiO, LiCoO, and $Li_2MnO_3$ phases are separated into $Li_2CO_3$ and NiO, CoO, and MnO phases. After completing the phase separation, by using the solubility difference of $Li_2CO_3$ and NiO, CoO, and MnO, we set the ratio of solution (distilled water) to powder after carbonation as 30:1. Subsequently, water leaching is carried out. Then, the $Li_2CO_3$ within the solution melts and concentrates, while NiO, MnO, and CoO phases remain after filtering. Thus, $Li_2CO_3$ can be recovered.

TEM analysis of IBAD/RABiTS substrates prepared by Tripod polishing (Tripod polishing을 이용한 IBAD/RABiTS 기판의 TEM 분석)

  • Choi, Soon-Mee;Chung, Jun-Ki;Yoo, Sang-Im;Park, Chan;Oh, Sang-Soo;Kim, Cheol-Jin
    • Progress in Superconductivity and Cryogenics
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    • v.8 no.1
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    • pp.9-14
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    • 2006
  • Sample preparation plays a critical role in microstructure analysis using TEM. Although TEM specimen has been usually prepared by jet-polishing or Ar-ion beam milling technique. these methods could not be applied to YBCO CC which is composed of IBAD or RABiTS substrates, several buffet layers, and YBCO superconducting layer because of big difference in mechanical strengths between the metallic phase and oxide phases. To obtain useful cross-sectional information such as interface between the phases or second phases in YBCO CC, it is prerequisite to secure the large area of thin section in the cross-sectional direction. The superconducting layer or the buffer layers are relatively weak and fragile compared to the metallic substrate such as Ni-5wt%W RABiTS of Hastelloy-based IBAD, and preferential removal of weak ceramic phases during polishing steps makes specimen preparation almost impossible. Tripod polisher and small jig were home-made and employed to sample preparation. The polishing angle was maintained <$1^{\circ}$ throughout the polishing steps using 2 micrometers attached to the tripod plate. TEM specimens with large and thin area could be secured and used for RABiTS/IBAD substrate analyses. In some cases, additional Ar-beam ion milling with low beam current and impinging angle was used for less than 30 sec. to remove debris or polishing media attacked to the specimens.

Comparison of Foot Pressure Distribution During Single-leg Squat in Individuals With and Without Pronated Foot

  • Il-kyu Ahn;Gyeong-tae Gwak;Ui-jae Hwang;Hwa-ik Yoo;Oh-yun Kwon
    • Physical Therapy Korea
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    • v.31 no.1
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    • pp.40-47
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    • 2024
  • Background: Single-leg squat (SLS)s are commonly used as assessment tool and closed kinetic exercises are useful for assessing performance of the lower extremities. Pronated feet are associated with foot pressure distribution (FPD) during daily activities. Objects: To compare the FPD during SLSs between groups with pronated and normal feet. Methods: This cross-sectional study included 30 participants (15 each in the pronated foot and control groups) are recruited in this study. The foot posture index was used to distinguish between the pronated foot and control groups. The Zebris FDM (Zebris Medical GmbH) stance analysis system was used to measure the FPD on the dominant side during a SLS, which was divided into three phases. A two-way mixed-model ANOVA was used to identify significant differences in FPD between and within the two groups. Results: In the hallux, the results of the two-way mixed-model ANOVAs revealed a significant difference between the group and across different phases (p < 0.05). The hallux, and central forefoot were significantly different between the group (p < 0.05). Moreover, significant differences across different phases were observed in the hallux, medial forefoot, central forefoot, lateral forefoot, and rearfoot (p < 0.05). The post hoc t-tests were conducted for the hallux and forefoot central regions. In participants with pronated foot, the mean pressure was significantly greater in hallux and significantly lower, in the central forefoot during the descent and holding phases. Conclusion: SLSs are widely used as screening tests and exercises. These findings suggest that individuals with pronated feet should be cautious to avoid excessive pressure on the hallux during the descent-to-hold phase of a SLS.