• 제목/요약/키워드: formation and stabilization

검색결과 204건 처리시간 0.026초

유기물 처리가 간척지 토양의 입단형성에 끼치는 영향 (Effect of Organic Material Treatments on Soil Aggregate Formation in Reclaimed Tidelands)

  • 손재권;조재영
    • 한국토양비료학회지
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    • 제42권3호
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    • pp.201-206
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    • 2009
  • 신선유기물 (이탈리안 라이그라스), 신선유기물 + 부산물비료 그리고 부산물비료 처리 후 3년 동안 토양입단 발달상태를 조사한 결과, 토양별로는 모래 함량이 상대적으로 높은 새만금 간척지 토양 보다는 미사와 점토함량이 높은 고흥 간척지 토양에서의 입단형성이 더 양호한 것으로 나타났다. 유기물 자원 처리별로는 고흥 간척지 토양에서는 유의성 있는 차이가 나타나지 않았으나 (P<0.05), 새만금 간척지 토양에서는 녹비 형태의 신선 유기물 즉, 이탈리안 라이그라스를 처리한 시험구에서 가장 입단화도가 높게 나타났다. 유기물 종류별로는 이탈리안 라이그라스와 같은 신선 유기물을 단독 처리한 시험구에서 토양 입단의 중량평균직경이 가장 크게 나타났다. 간척지 토양의 물리성 및 토양구조 개선을 위한 유기물 처리시 신선유기물의 처리가 바람직하며, 불가피할 경우 일반 유기질/부산물비료의 단독처리보다는 신선유기물과 혼합하여 처리하는 것이 타당한 것으로 조사되었다.

수종의 골이식재를 이용한 유도재생골의 조직학적 평가 (Histologic evaluation of the regenerated bone using bone graft materials)

  • 유호철;박준봉;권영혁;허익;정종혁;주성숙
    • Journal of Periodontal and Implant Science
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    • 제36권2호
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    • pp.289-303
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    • 2006
  • This study was performed to evaluate the effect of bone graft materials including demineralized freeze-dried bone, freeze-dried bone, deproteinized bovine bone on space-making capacity and bone formation in guided bone regeneration with titanium reinforced ePTFE membrane(TR-ePTFE). Adult male rabbits(mean BW 2kg) were used in this study. Intramarrow penetration defects were surgically created with round bur on calvaria of rabbits. TR-ePTFE membrane was adapted to calvarial defect and bone graft materials were placed. Animals were sacrificed at 2, 8, 12 weeks after surgery. Non-decalcified specimens were processed for histologic analysis and prepared with Villaneuva bone stain. The results of this study were as follows: 1. TR-ePTFE membrane was biocompatible and capable of maintaining the space-making. 2. Tissue integration was not good at TR-ePTFE membrane. Fixation was not enough. so, wound stabilization was not good. 3. In animals using deproteinized bovine bone, demineralized freeze-dried bone, bone formation was little. 4. In animals using freeze-dried bone, bone formation was better. Within the above results, bone formation may be inhibited when wound stabilizafion was not good.

RCM을 이용한 디젤 분무 거동 및 자발화 특성에 관한 실험적 연구 (An Experimental Study on Diesel Spray Dynamics and Auto-Ignition Characteristics to use Rapid Comperssion Machine)

  • 안재현;김형모;신명철;김세원
    • 한국분무공학회지
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    • 제8권3호
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    • pp.33-40
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    • 2003
  • The low-emission and high-performance diesel combustion is an important issue in the combustion research community, In order to understand the detailed diesel flame involving the complex physical processes, it is quite desirable to diesel spray dynamics, auto-ignition and spray flame propagation. Dynamics of fuel spray is a crucial element for air-fuel mixture formation, flame stabilization and pollutant formation, In the present study, the diesel RCM (Rapid Compression Machine) and the Electric Control injection system have been designed and developed to investigate the effects of injection pressure, injection timing, and intake air temperature on spray dynamics and diesel combustion processes, In terms of the macroscopic spray combustion characteristics, it is observed that the fuel jet atomization and the droplet breakup processes become much faster by increasing the injection pressure and the spray angle, With increasing the cylinder pressure, there is a tendency that the of spray pattern in the downstream region tends to be spherical due to the increase of air density and the corresponding drag force, Effects of intake temperature and injection pressure on auto-ignition is experimently analysed and discussed in detail.

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RCM을 이용한 디젤 분무거동 및 자발화 특성에 관한 연구 (An Experimental Study on Diesel Spray Dynamics and Auto-Ignition Characteristics in the Rapid Compression Machine)

  • 강필중;김형모;김용모;김세원
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2000년도 춘계학술대회논문집B
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    • pp.447-452
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    • 2000
  • The low-emission and high-performance diesel combustion is an important issue in the combustion research community. In order to understand the detailed diesel flame field involving the complex Physical Processes, It Is quite desirable to study diesel spray dynamics, auto-ignition and spray flame propagation. Dynamics of fuel spray is a crucial element for air-fuel mixture formation flame stabilization and pollutant formation. In the present study, the diesel RCM (Rapid Compression Machine) and the Electric Control injection system have been designed and developed to investigate the effects of injection Pressure, injection timing, and intake air temperature on spray dynamics and diesel combustion processes. In terms of the macroscopic spray combustion characteristics it is observed that the fuel jet atomization and the droplet breakup processes become much faster by increasing the injection pressure and the spray angle. With increasing the cylinder pressure there is a tendency that the shape of spray pattern in the downstream region tends to be spherical due to the increase of air density and the corresponding drag force. Effects of intake temperature and injection pressure on auto-ignition is experimently analysed and discussed in detail.

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Trypsin 반응에 대한 용매의 유전상수 및 압력의 영향 (Effect of Pressure and Solvent Dielectric Constant on the Kinetic Constants of Trypsin-Catalyzed Reaction.)

  • 박현;지영민
    • 한국미생물·생명공학회지
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    • 제28권1호
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    • pp.26-32
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    • 2000
  • Electrostatic forces contribute to the high degree of enzyme transition state complementarity in enzyme catalyzed reaction and such forces are modified by the solvent through its dielectric constant and polar properties. The contributions of electrostatic interaction to the formation of ES complex and the stabilization of transition state of the trypsin catalyzed reaction were probed by kinetic studied with high pressure and solvent dielectric constant. A good correlation has been observed between the increase of catalytic efficiency of trypsin and the decrease of solvent dielectric constant. Activation volume linearly decreased as the dielectric constant of solvent decreased, which means the increase in the reaction rae. Moreover, the decrease of activation volume by lowering the solvent dielectric constant implies a solvent penetration of the active with and a reduction of electrostatic energy for the formation of dipole of the active site oxyanion hole. When the 야electric constant of the solvents was lowered to 4.7 unit, the loss of activation energy and that of free energy of activation were 2.262 KJ/mol and 3.169 KJ/mol, respectively. The results of this study indicate that the high pressure kinetics combined with solvent effects can provide unique information on enzyme reaction mechanisms, and the controlling the solvent dielectric constant can stabilize the transition state of the trypsin-catalyzed reaction.

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오메프라졸과 베타-시클로덱스트린과의 포접화합물 형성에 따른 특성 (Studies on the Formation of Inclusion Complex between Omeprazole and $\beta$-cyclodextrin)

  • 소재일;이창현;이계주
    • 약학회지
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    • 제35권5호
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    • pp.372-378
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    • 1991
  • To increase the stability and bioavailability of Omeprazole(OMP), which is used newly as a proton-pump inhibitor, inclusion complex of OMP with $\beta$-cyclodextrin($\beta$-CD) was prepared by coprecipitation method and its characteristics were ascertained by means of solubility test, DSC, IR, and the accelerated stability analysis. The type of OMP inclusion complex is classified as Bs-type on phase solubility diagram, and the stoichiometric ratio of OMP: $\beta$-CD complex is 1:2 and formation constant is 80.82/mole. The solubility of the complex could be increased remarkably by complexation compare with OMP. Degradation process of both OMP and OMP complex followed apparent first-order kinetics, of which degradation rate constants and activation energies are k$_{25}$=8.1$\times$10$^{-4}$/day, E$_{a}$=22 Kcal/mole (OMP), and k$_{25}$=4.65$\times$10$^{-6}$/day, E$_{a}$=35 Kcal/mole (complex), respectively. These results show the increase of the stability and solubility of OMP markedly, therefore it is believed that the improvement of stabilization for OMP by inclusion complexation might be practically available.

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Immunoglobulin G(IgG)를 함유한 DOPE 리포솜의 제조와 담즙산염에 의한 용해 특성 (The Solubilization Behavior of DOPE-Immunoliposomes with Immunoglobulin G(IgG) by Added Bile Salts)

  • 이은옥;김진구;김종득
    • Journal of Pharmaceutical Investigation
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    • 제20권3호
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    • pp.135-144
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    • 1990
  • The effects of bile salts (BS) on the stability of dioleoylphosphatidylethanolamine (DOPE) liposomes were investigated, observing apparent absorbance of vacant liposomes and calcein release from entrapped liposomes. Unilamellar liposomes were prepared by using a small quantity of palmitoly-immunoglobulin G(IgG) ($2.5{\times}10^{-4}$ mo1/lipid mol) to stabilize the bilayer phase of the unsaturated DOPE which by itself does not form stable liposomes. The destabilization of PE immunoliposomes by papain, clearly demonstrates that the IgG is essential for stabilization of PE bilayer. Approximately 4% of the entrapped calcein was released from the PE liposomes after 1 hr from liposome formation. Calcein release and absorbance of liposomes depended on the BS/lipid ratio because of the solubilization of lipid molecule in bilayer and the formation of mixed micelles. At very low BS concentrations, the incorporation of BS induced BS/lipid aggregates in the outer vesicles monolayer, while high BS concentrations, mixed micelles were formed. Chelate and its conjugates as $3{\alpha},\;7{\alpha},\;12{\alpha}-trihydroxy$ BS induce the concentration of the $3{\alpha}$, $12{\alpha}-dihydroxy$ BS at half-maximal solubilization of immunoliposomes to approximately 2.5-, or 5-fold. Conjugation of BS with glycine or taurine slightly enhanced their capacities to perturb membranes.

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BK Channel Deficiency in Osteoblasts Reduces Bone Formation via the Wnt/β-Catenin Pathway

  • Jiang, Lan;Yang, Qianhong;Gao, Jianjun;Yang, Jiahong;He, Jiaqi;Xin, Hong;Zhang, Xuemei
    • Molecules and Cells
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    • 제44권8호
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    • pp.557-568
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    • 2021
  • Global knockout of the BK channel has been proven to affect bone formation; however, whether it directly affects osteoblast differentiation and the mechanism are elusive. In the current study, we further investigated the role of BK channels in bone development and explored whether BK channels impacted the differentiation and proliferation of osteoblasts via the canonical Wnt signaling pathway. Our findings demonstrated that knockout of Kcnma1 disrupted the osteogenesis of osteoblasts and inhibited the stabilization of β-catenin. Western blot analysis showed that the protein levels of Axin1 and USP7 increased when Kcnma1 was deficient. Together, this study confirmed that BK ablation decreased bone mass via the Wnt/β-catenin signaling pathway. Our findings also showed that USP7 might have the ability to stabilize the activity of Axin1, which would increase the degradation of β-catenin in osteoblasts.

Beeswax와 실리콘계 계면활성제를 사용한 W/O유화계에서 액정의 형성 및 안정도에 관한 연구 (Studies on the Formation of Liquid Crystal and the Stability in W/O Emulsion Systems using Beeswax and Silicone Surfactant)

  • 최문재;이영무;진병석
    • 한국응용과학기술학회지
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    • 제21권4호
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    • pp.279-288
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    • 2004
  • Liquid crystal (LC) system was introduced into W/O emulsion in order to enhance the stability and moisturizing effect. The LC system, composed of beeswax, surfactant, and water was formed on the surface of emulsion droplet, which was investigated through a polarized microscope. The phenomenon that the viscosity in W/O emulsion system is decreased with time, was reduced by the formation of LC with the addition of beeswax. Centrifugal separation test showed that the stability of emulsion system was increased with the addition of beeswax to 3%. The color change of vitamin C was delayed in LC emulsion systems, which indicates stabilization effect against the oxidation of vitamin C. Evaporation rate in W/O emulsion was retarded by LC, so that high moisturizing effect is expected in W/O LC system.

Streptococcus mutans의 Plaque 형성에 미치는 Dextranase와 Glucose-oxidase 의 영향 (Effect of dextranase and glucose-oxidase on the formation of plaque by Streptococcus mutans)

  • 김윤석;안재현;정광례;이기붕
    • 미생물학회지
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    • 제27권4호
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    • pp.430-435
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    • 1989
  • Dextranase와 glucose←oxidase의 향치아우식 인자로서의 효괴와 dentifrice 앙분으로서의 이용 가능성융,경토하였다. W Water-insoluble glucan에 의한 plaque의 형성은 dextranase와 glucose-oxida앤플 사용함으호써 억제할 수 9.]였다. D Dextranase의 경우 낮은 농도에서도 plaque의 형생억저l와 분해에 매우 효과적이였다. Glucose-oxidase의 경우 얄균작용 에 의해 생균수를 줄임으로써 plaque의 형성억제에는 효과적이었으나 분해작용은 미약하였다. Dentifrice의 각 성분에 대한 compatibility test 를 통해 효소의 안쟁화를 위한 Mode] Dentifrice 플 구생하였고. Model Dentifrice 에서의 activity 변 화플 관창한 결과 안정성이 오랫동안 유지될을 확인할 수 있었다.

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