• Title/Summary/Keyword: SPH

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Antidiabetic effect and mechanisms of SPH-2 in db/db mice

  • Kang, Kwi-Man;Cho, Hee-Jae;Chung, Sung-Hyun
    • Proceedings of the PSK Conference
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    • 2002.10a
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    • pp.260.2-260.2
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    • 2002
  • SPH-2 is a herbal medicine composing oriental prescription. We have studied the antidiabetic effect and mechanism of SPH-2 in insulin-resistant diabetic db/db mice. Mice were grouped and treated for 3 weeks as follows: control group was administrated with tap water orally: treated group was administrated with SPH-2 orally at dose of 500 mg/kg. SPH-2 lowered plasma glucose level by 43% as compared to the diabetic control. Total cholesterol. triglyceride and free fatty acid were all reduced in SPH-2 treated group. (omitted)

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Anchor Collision Simulation of Rock-berm using SPH Technique (SPH 기법을 이용한 Rock-berm의 앵커 충돌 수치 시뮬레이션)

  • Woo, Jinho;Na, Won-Bae;Yu, Jeong-Seok
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.26 no.1
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    • pp.9-15
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    • 2014
  • It is not easy to analyze the behavior of a structural body composed of particles such as rocks using the finite element method facilitating typical element meshes because we cannot ignore the interactions among particles. In the study, we investigated the applicability of smooth particle hydrodynamics (SPH) element method for collision analysis of rock-berm by comparison with the conventional Lagrange method. As the result, SPH technique is expected to be capable of realistic simulation under collision analysis of material composed of particles.

A numerical study on rock cutting by a TBM disc cutter using SPH code (SPH 코드를 사용한 TBM 디스크커터의 암석 절삭에 대한 수치해석적 연구)

  • Jeong, Ho-Young;Jeon, Seok-Won;Cho, Jung-Woo
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.15 no.3
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    • pp.345-356
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    • 2013
  • Numerical simulation on rock cutting by a TBM disc cutter was carried out using SPH (Smoothed Particle Hydrodynamics) code. AUTODYN3D, a commercial software program based on finite element method, was used in this study. The three-dimensional geometry of a disc cutter and a rock specimen were modeled by Lagrange and SPH code respectively. The numerical simulation was carried out for Hwangdeung granite for 10 different cutting conditions. The results of the numerical simulation, i.e. the relation between cutter force and failure behavior, had a good agreement with those from LCM test. The cutter forces measured in the numerical simulation had 10% deviation from the LCM test results. Moreover, the optimum cutter spacing was almost identical with the experimental results. These results indicate that SPH code can be successfully used had applicability for simulation on rock cutting by a TBM disc cutter. However, further study on Lagrange-SPH coupled modelling would be necessary to reduce the computation time.

Cytotoxic activity and probable apoptotic effect of Sph2, a sphigomyelinase hemolysin from Leptospira interrogans strain Lai

  • Zhang, Yi-xuan;Geng, Yan;Yang, Jun-wei;Guo, Xiao-kui;Zhao, Guo-ping
    • BMB Reports
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    • v.41 no.2
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    • pp.119-125
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    • 2008
  • Our previous work confirmed that Sph2/LA1029 was a sphigomyelinase-like hemolyisn of Leptospira interrogans serogroup Icterohaemorrhagiae serovar Lai. Characteristics of both hemolytic and cytotoxic activities of Sph2 were reported in this paper. Sph2 was a heat-labile neutral hemolysin and had similar hemolytic behavior as the typical sphingomyelinase C of Staphylococcus aureus upon sheep erythrocytes. The cytotoxic activity of Sph2 was shown in mammalian cells such as BALB/C mouse lymphocytes and macrophages, as well as human L-02 liver cells. Transmission electron microscopic observation showed that the Sph2 treated BALB/C mouse lymphocytes were swollen and ruptured with membrane breakage. They also demonstrated condensed chromatin as a high-density area. Cytoskeleton changes were observed via fluorescence confocal microscope in Sph2 treated BALB/C mouse lymphocytes and macrophages, where both cytokine IL-$1{\beta}$ and IL-6 were induced. In addition, typical apoptotic morphological features were observed in Sph2 treated L-02 cells via transmission electron microscope and the percentage of apoptotic cells did increase after the Sph2 treatment detected by flow cytometry. Therefore, Sph2 was likely an apoptosis-inducing factor of human L-02 liver cells.

A Study of Normalized Smoothed Particle Hydrodynamics (정규 완화입자유동법의 고찰)

  • 박정수;이진성;박희덕;김용석;이재민
    • Journal of the Korea Institute of Military Science and Technology
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    • v.6 no.4
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    • pp.89-99
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    • 2003
  • Smoothed particle hydrodynamics, SPH, is a gridless Lagrangian technique which is a useful alternative numerical analysis method to simulate high velocity deformation problems as well as astrophysical and cosmological problems. The SPH method brings about some difficulties such as tensile Instability and stress oscillation. A new SPH method, so called normalized algorithm, was introduced to overcome these difficulties. In this paper we aimed to estimate this method and have developed an one-dimensional normalized SPH program. The high velocity impact model of an aluminum bar has been analysed by using the developed program and a commercial hydrocode, LS-DYNA. The obtained numerical results showed good agreement with the results of the same model in reference. The program also showed more stable results than those of LS-DYNA in stress oscillation. We hopefully expect that the developed one-dimensional normalized SPH program can be used to solve hydrodynamic problems especially for explosive detonation analysis.

Antidiabetic effect and mechanisms of SPH-1 in db/db mice

  • Kang, Kwi-Man;Cho, Hee-Jae;Chung, Sung-Hyun
    • Proceedings of the PSK Conference
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    • 2002.10a
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    • pp.263.2-264
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    • 2002
  • SPH-l is a herbal medicine composing oriental prescription. We have studied the antidiabetic effect and mechanism of SPH-l in insulin-resistant diabetic db/db mice. Mice were grouped and treated for 3 weeks as follows: control group was administrated with tap water orally: treated group was administrated with SPH-l orally at dose of 500 mg/kg. SPH-l lowered plasma glucose level by 67% as compared to the diabetic control (omitted)

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Change master cast by hardening method to position of tray after impression taking (인상채득 후 경화시 트레이의 위치에 따른 주모형의 변화)

  • Lee, Jung Ae
    • Journal of Korean society of Dental Hygiene
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    • v.8 no.2
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    • pp.53-66
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    • 2008
  • There was to purpose of this study improves analyzing cause that prosthesis brings bite engaging that is inaccurate in patient's mouth, when supposed that all conducts that do in operatory and dental laboratory are perfect. Impression did check bite by alginate impression material and polymerization style silicon impression material that use usually in presence at a sickbed Irreversibility, hydrocolloid, alginate impression material washed in flowing water and poured anhydrite after wait about 8 minutes so that region that charge interest after impression check bite may become undoing. And hydrophile property addition polymerization style impression material poured anhydrite after blow 30 considering impression material dwell time and H2 gas occurrence time (5~15 minute) after have washed in flowing water. I got each 7 models, result that manufactures total 28 and measures by third dimension measuring instrument (Meteo, Korea) following sequence curing in tray holder and floor 1, By Alginate impression when is hardened in tray holder and when is hardened in the floor after do check bite, SPH 4, SPH5 all as there is synonymy appeared(P<0.05). By in case do not use average 0.1741 in case use tray holder in 0.0447 SPH5s in case do not use average 0.2838 pastas in case use tray holder in SPH4 0.0309, When did not use both SPH4 and SPH5 tray holder, when used tray holder, 1 appeared more greatly. 2. By amity sex addition polymerization style silicon impression when is hardened in tray holder after do check bite and when is hardened in the floor SPH 4, a11 of the SPH5s very big synonymy be(P>0.05). And in case use tray holder in 0.000657 pasta SPH5s in case do not use average 0.000129 pastas in case use tray holder in SPH4 average 0.000114 pastas, by in case do not use 0.000757, I appeared more greatly when used tray when did not use both SPH4 and SPH5 tray holder, but 1 appeared is not level to keep in mind(Table 8~9). 3 SPH4 was looked very big mindfulness in model that manufacture doing impression check bite by Alginate and model that do impression check bite by amity sex accessory penalty silicon without using tray holder(P< 0.001). I use tray holder and SPH4 did not appear synonymy in model that manufacture doing impression check bite by Alginate and model that do impression check bite by amity sex accessory penalty silicon(P>0.05). Study finding of above when see synthesis Alginate certainly tray holder use must and I could know that hardening method does not exert big influence on volume stability if remove impression sieve of excess because amity sex accessory penalty silicon passes over tray, Also, Alginate impression material previewed can get heading a conspiracy style that volume stability of accessory penalty silicon impression material degree is if use tray holder.

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Two-component Signal Transduction in Synechocystis sp. PCC 6803 under Phosphate Limitation: Role of Acetyl Phosphate

  • Juntarajumnong, Waraporn;Eaton-Rye, Julian J.;Incharoensakdi, Aran
    • BMB Reports
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    • v.40 no.5
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    • pp.708-714
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    • 2007
  • The two-component signal transduction, which typically consists of a histidine kinase and a response regulator, is used by bacterial cells to sense changes in their environment. Previously, the SphS-SphR histidine kinase and response regulator pair of phosphate sensing signal transduction has been identified in Synechocystis sp. PCC 6803. In addition, some response regulators in bacteria have been shown to be cross regulated by low molecular weight phosphorylated compounds in the absence of the cognate histidine kinase. The ability of an endogenous acetyl phosphate to phosphorylate the response regulator, SphR in the absence of the cognate histidine kinase, SphS was therefore tested in Synechocystis sp. PCC 6803. The mutant lacking functional SphS and acetate kinase showed no detectable alkaline phosphatase activity under phosphate-limiting growth conditions. The results suggested that the endogenous acetyl phosphate accumulated inside the mutants could not activate the SphR via phosphorylation. On the other hand, exogenous acetyl phosphate could allow the mutant lacking functional acetate kinase and phosphotransacetylase to grow under phosphate-limiting conditions suggesting the role of acetyl phosphate as an energy source. Reverse transcription PCR demonstrated that the transcripts of acetate kinase and phospho-transacetylase genes in Synechocystis sp. PCC 6803 is up-regulated in response to phosphate limitation suggesting the importance of these two enzymes for energy metabolism in Synechocystis cells

Elasto-Plastic Dynamic Analysis of Solids by Using SPH without Tensile Instability (인장 불안정이 제거된 SPH을 이용한 고체의 동적 탄소성해석)

  • Lee, Kyoung Soo;Shin, Sang Shup;Park, Taehyo
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.31 no.2A
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    • pp.71-77
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    • 2011
  • In this paper elasto-plastic dynamic behavior of solid is analyzed by using smoothed particle hydrodynamics (SPH) without tensile instability which caused by a clustering of SPH particles. In solid body computations, the instability may corrupt physical behavior by numerical fragmentation which, in some cases of elastic or brittle solids, is so severe that the dynamics of the system is completely wrong. The instability removed by using an artificial stress which introduces negligible errors in long-wavelength modes. Applications to several test problems show that the artificial stress works effectively. These problems include the collision of rubber cylinders, fracture and crack of plate.

SPH Code Development and Validation for Numerical Simulation of Liquid-Liquid Swirl Coaxial Injector (액체-액체 동축형 스월 인젝터의 수치적 모사를 위한 SPH 코드 개발 및 검증)

  • Kim, You-Cheon;Sirotkin, Fedir V.;Yoh, Jai-Ick
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.43 no.1
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    • pp.8-22
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    • 2015
  • Most jet spray and atomization simulations are done with the Eulerian method which has inherent disadvantage in representing jet breakups and droplets. Full Lagrangian particles method called Smoothed Particle Hydrodynamics(SPH) is used in this work. We develop the SPH code and perform validations that confirm the suitability of our SPH method for simulating liquid jet atomization problem. Then, we conduct the simulation of liquid-liquid swirl coaxial injector for comparison against the experimental data.