• Title/Summary/Keyword: Solution growth method

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TSSG growth, morphology and properties of potassium lithium niobate (KLN) crystals

  • Chong, Tow-Chong;Xu, Xue-Wu;Li, Lian;Zhang, Guang-Yu;Kumagai, H.;Hirano, M.
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.9 no.4
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    • pp.396-401
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    • 1999
  • In the present paper, potassium lithium niobate(KLN) crystals have been grown along <001>, <100> and <110> directions by the top seeded solution growth (TSSG) method from Li-richer melts with different compositions. The morphologies of KLN crystals grown along different directions have been studied, and the well-developed facets have been unambiguously indexed using X-ray goniometer and stereographic projection analysis. The growth mechanism and defects such as cracks and inclusions were discussed on the basis of observations of facets on the crystal-solution interfaces. The crystal compositions were determined by a chemical analysis method. The structure and lattice constants of KLN crystals were determined and calculated on the basis of XRD data by using TREOR90 and PIRUM programs. The Curie temperature and optical absorption were determined by dielectric constant peak and spectrum measurements. respectively. The blue second harmonic generation (SHG) characteristics of KLN sample were also investigated using a pulsed dye laser.

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Crystallization and high purification of aluminium chloride hexahydrate from kaolin leaching solution (고령토 침출용액으로부터 고순도 염화알루미늄 결정화 분리)

  • 김우식;장희동
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.6 no.4
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    • pp.584-594
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    • 1996
  • For the separation and purification of aluminium chloride hexahydrate crystals from kaolin leaching solution the effects of crystallization conditions, such as crystallization temperature, concentration of aluminium chloride concentration in the leaching solutin and gas flow rate of HCl into the leaching solution, on purity of the aluminium chloride hexahydrate crystals were investigated. The supersaturation level of aluminium chloride in the leaching solution gave great influence on the purity of the crystals. When supersaturated concentration of the aluminium chloride in the leaching solution was generated in low level, the aluminium chloride hexahydrate crystals were produced with high purity ; that is, the crystals hving a low Fe-ion concentration. The supersaturation level of aluminium chloride in the leaching solution was mainly determined by crystallization temperature, concentrations of aluminium chloride and hydrochloric acid in the solution. However, in spite of changes of the above crystallization coditions, a needle shape morphology of aluminium chloride hexahydrate crystals did not modified. To measure hydrochloric acid concentration in the kaolin leaching solution, we applied the oxalate titration method, which was suggested by shank [9] and it was prove that this method could titrate hydrochloroic acid concentration in multi-component ionic solution such as kaolin leaching solution.

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POSITIVE SOLUTION AND GROUND STATE SOLUTION FOR A KIRCHHOFF TYPE EQUATION WITH CRITICAL GROWTH

  • Chen, Caixia;Qian, Aixia
    • Bulletin of the Korean Mathematical Society
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    • v.59 no.4
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    • pp.961-977
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    • 2022
  • In this paper, we consider the following Kirchhoff type equation on the whole space $$\{-(a+b{\displaystyle\smashmargin{2}{\int\nolimits_{{\mathbb{R}}^3}}}\;{\mid}{\nabla}u{\mid}^2dx){\Delta}u=u^5+{\lambda}k(x)g(u),\;x{\in}{\mathbb{R}}^3,\\u{\in}{\mathcal{D}}^{1,2}({\mathbb{R}}^3),$$ where λ > 0 is a real number and k, g satisfy some conditions. We mainly investigate the existence of ground state solution via variational method and concentration-compactness principle.

Closed-form solution for the buckling behavior of the delaminated FRP plates with a rectangular hole using super-elastic SMA stitches

  • Soltanieh, Ghazaleh;Yam, Michael CH.;Zhang, Jing-Zhou;Ke, Ke
    • Structural Engineering and Mechanics
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    • v.81 no.1
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    • pp.39-50
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    • 2022
  • Layer separation (delamination) is an essential threat to fiber-reinforced polymer (FRP) plates under dynamic, static, and fatigue loads. Under compressive load, the growth of delamination will lead to structural instability. The aim of this paper is to present a method using shape memory alloy (SMA) stitches to suppress the delamination growth in a FRP plate and to improve the buckling behavior of the plate with a rectangular hole. The present paper is divided into two parts. Firstly, a closed-form (CF) formulation for evaluating the buckling load of the FRP plate is presented. Secondly, the finite element method (FEM) will be employed to calculate the buckling loads of the plates which serves to validate the results obtained from the closed-form method. The novelty of this work is the development of the closed-form solution using the p-Ritz energy approach regarding the stress-dependent phase transformation of SMA to trace the equilibrium path. For the FEM, the Lagoudas constitutive model of the SMA material is implemented in FORTRAN programming language using a user material subroutines (VUMAT). The model is simulated in ABAQUS/Explicit solver due to the nature of the loading type. The cohesive zone model (CZM) is applied to simulate the delamination growth.

Determining the Proportions of Bone and Cartilage Growth in the Crucian Carp (carassius auratus) Using the Modified Simultaneous Differential Staining Technique

  • Lee, Jin-Heon
    • Journal of Environmental Health Sciences
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    • v.36 no.4
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    • pp.337-341
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    • 2010
  • The modified simultaneous differential staining technique, which enables double staining of cartilage and bones, needs to be improved to prevent soft tissues from being damaged during the staining process. Key factors influencing the extent to which soft tissues are damaged include the fixative used, macerating time, potassium hydroxide concentration, incubation temperature and the removal of skin from specimens. Here we describe a protocol that enables the hardening of tissues during bleaching and maceration. We also describe a method for objectively measuring rates of cartilage and bone growth. The use of formalin as a fixative rendered soft tissues more rigid due to the resulting chemical bonds formed between proteins. Blotted specimens were immersed in 1% potassium hydroxide (KOH) and incubated at $37^{\circ}C$ for 1 day (smaller specimens) or 2-3 days (larger specimens). The 1% KOH solution was also used as the diluent solution for the subsequent immersion in a graded series of 30%, 50%, 70%, 90%, 100% glycerol solutions, a procedure that made soft tissues even more transparent and hardened. It was not necessary to remove the skin of specimens shorter than 2 cm, since the macerating solution could easily penetrate their thin skin layer and continuously remove those pigments hindering visibility. Since excessive osmosis is another factor that can damage soft tissues in the macerating process by causing the rupture of those cells not able to withstand the osmotic pressure, here it was minimized by balancing the salt concentration between the interior and exterior of cells with the addition of 0.9% sodium chloride (NaCl) in the macerating solution. Finally, to determine the proportions of cartilage and bone growth, photographs of the stained specimens were taken with a dissecting microscope and sections corresponding to the cartilage and bones were cut out from the printed pictures and weighed. Our results show that this method is suitable for the objective evaluation of bone and cartilage growth.

MULTIPLE SOLUTIONS RESULT FOR THE MIXED TYPE NONLINEAR ELLIPTIC PROBLEM

  • Jung, Tacksun;Choi, Q-Heung
    • Korean Journal of Mathematics
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    • v.19 no.4
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    • pp.423-436
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    • 2011
  • We obtain a theorem that shows the existence of multiple solutions for the mixed type nonlinear elliptic equation with Dirichlet boundary condition. Here the nonlinear part contain the jumping nonlinearity and the subcritical growth nonlinearity. We first show the existence of a positive solution and next find the second nontrivial solution by applying the variational method and the mountain pass method in the critical point theory. By investigating that the functional I satisfies the mountain pass geometry we show the existence of at least two nontrivial solutions for the equation.

Morphology Control of NTO Crystals with Various Recrystallization Techniques

  • Lee, H.Y.;K.K. Koo;Kim, K.J.;G.B. Lim;W.B. Jeong;Kim, S.H.;Kim, H.S.;Park, B.S.
    • Proceedings of the Korea Association of Crystal Growth Conference
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    • 1997.10a
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    • pp.123-127
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    • 1997
  • Various recrystallization techniques has been applied to control morphology and size of NTO(3-nitro-1, 2, 4-triazole-5-one) crystals. With cooling method, it was found that the size of NTO at aqueous solution was controlled in the range of 5 to 500 $\mu\textrm{m}$. The spherical or cubic shapes of particles were obtained by adjusting operating conditions. Hexagonal and cubic shaped crystals of NTO were also obtained by sonication and evaporative method using aqueous solution of NTO. Their particle sizes were ranged 20 to 30 $\mu\textrm{m}$. In gas anti-solvent method with NTO/DMF and NTO/DMSO solutions, cubic type of NTO was obtained and the range of their sizes was 0.5-2$\mu\textrm{m}$.

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Process design for solution growth of SiC single crystal based on multiphysics modeling (다중물리 유한요소해석에 의한 SiC 단결정의 용액성장 공정 설계)

  • Yoon, Ji-Young;Lee, Myung-Hyun;Seo, Won-Seon;Shul, Yong-Gun;Jeong, Seong-Min
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.26 no.1
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    • pp.8-13
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    • 2016
  • A top-seeded solution growth (TSSG) is a method of growing SiC single crystal from the Si melt dissolved the carbon. In this study, multiphysics modeling was conducted using COMSOL Multiphysics, a commercialized finite element analysis package, to get analytic results about electromagnetic analysis, heat transfer and fluid flow in the Si melt. Experimental results showed good agreements with simulation data, which supports the validity of the simulation model. Based on the understanding about solution growth of SiC and our set-up, crystal growth was conducted on off-axis 4H-SiC seed crystal in the temperature range of $1600{\sim}1800^{\circ}C$. The grown layer showed good crystal quality confirmed with optical microscopy and high resolution X-ray diffraction, which also demonstrates the effectiveness of the multiphysics model to find a process condition of solution growth of SiC single crystal.

Low temperature solution growth of silicon on foreign substrates (이종기판을 사용한 저온에서의 실리콘 박막 용액 성장법)

  • Soo Hong Lee;Martin A. Green
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.4 no.1
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    • pp.42-45
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    • 1994
  • Deposition of silicon on pretreated sapphire and glass substrates has been investigated by the solution growth method at low temperatures. An average 14 $\mu\textrm{m}$ thickness of silicon was grown over a large area on sapphire substrate originally coated with a much thinner silicon layer [0.5 $\mu\textrm{m}$ (100) Si/(1102) sapphire)] at low temperatures from $380~460^{\cire}C$. Successful results were obtained from surface treated glass substrates in the temperatures range from $420~520^{\circ}C$.

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Properties and Hair Growth Effect of Eugenol-Aspirin Derivative (유제놀의 아스피린 유도체에 관한 물성 및 육모효과)

  • Shin, Joon-Su;Kim, Jong-Ho;Kim, Kyoung-Soon;Youm, Jeong-Rok;Kim, Bak-Kwang
    • YAKHAK HOEJI
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    • v.41 no.5
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    • pp.571-574
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    • 1997
  • We have synthesized acetylsalicylic acid derivative of eugenol. And also, physico-chemical properties and analysis on this compound were examined. The correlation coefficient of the calibration curve in methanol solution was 0.9998. The hair growth stimulation of eugenol derivative on the hair of black mouse (C57BL/6), was also carried out using Implant method. When its ethanol solution was administered to the black mouse by route of skin, eugenol derivative promoted the growth of hair.

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