• Title/Summary/Keyword: Compositions

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Studies on Computer Optimization Techniques for Hydrophilic Vehicle Compositions

  • Lee, Chi-Ho;Shin, Young-Hee
    • Archives of Pharmacal Research
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    • v.11 no.3
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    • pp.185-196
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    • 1988
  • The inflence of hydrophilic vehicles on percutaneous absorption rate of griseofulvin was studied using intact skin of full thickness of hairless rat. The in vitro absorption rates were used as the characteristics for deciding the optimum formula of ointment vehicles. The optimum formula of vehicle compositions for maximum absorption rate was obtained from the polynomial regression equation and the two graphical techniques, contour graph and partial derivative graph. It was composed of sodium lauryl sulfate (1.65 W /W%), white petrolatum (16.5 W /W%), propylene glycol (12.0 W /W%), and stearyl alcohol (19.6W /W%). The experimental value obtained from the optimum formula and the prediction value were 33.99 and 33.87 ${\mu}g/\sqrt{min}$, respectively. From these results, it was believed that optimum formula for semisolid dosage forms could be obtained from the application of the optimization technique used in this study.

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Experimental Study on the Material Properties of Unreinforced Masonry (비보강 조적조의 재료특성 평가에 관한 실험연구)

  • 박진호
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2000.04a
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    • pp.178-185
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    • 2000
  • A set of tests were accomplished in order to get better insight of the basic material properties of masonry made of normal concrete brick and different type of mortar compositions. Three different types of test were performed. Masonry unit and prism were tested by compressive strength test, Masonry wallets were tested by compressive strength test. Masonry wallets were tested in diagonally under tension. A significant influence of different mortar compositions on compression strength of masonry prism was observed, The tests have shown that for diagonal compression three different mode of failure were possible : tension crack along the loaded diagonal sliding along a mortar joint and combined sliding and diagonal crack according to the adhesive strength of a mortar.

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Study on Combustion Characteristics of the Opposed Flames for Different Mixing Rates of Carbon Dioxide and Water Vapor (이산화탄소 및 수중기의 혼합율에 따른 대향류 화염의 연소특성 연구)

  • Park, Won-Hee;Jo, Bum-Jin;Kim, Tae-Kuk
    • 한국연소학회:학술대회논문집
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    • 2004.11a
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    • pp.49-54
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    • 2004
  • Detailed flame structures of the opposed flames formed for different oxidant compositions are studied numerically. The detailed chemical reactions are modeled by using the CHEMKIN code. Only the $CO_2$ and $H_2O$ are assumed to participate by absorbing the radiative energy while all other gases are assumed to be transparent. The discrete ordinates method and the narrow band based WSGGM with a gray gas regrouping technique are applied for modeling the radiative transfer through non-homogeneous and non-isothermal combustion gas mixtures generated by the opposed flow flames. The results show that the different radiation model can cause different results for flame structures and the WSGGM with gray gas regrouping is successful in modeling the opposed flames with non-gray gas mixture. The numerical results show that the increases in $CO_2$ and $H_2O$ compositions cause to reduce the flame temperature and the NO formation.

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Effects of Microstructure on Ductility of Medium Carbon Spring Steels (중탄소 스프링강의 연성에 미치는 미세조직의 영향)

  • Lee, Hyun-Kwuon;Lee, Sang-Woo
    • Journal of the Korean Society for Heat Treatment
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    • v.22 no.2
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    • pp.80-87
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    • 2009
  • Effects of retained austenite contents on ductility of medium carbon spring steels according to steel alloy compositions and heat treatment conditions were studied. Contents of retained austenite varied with steel compositions and heat treatment conditions, and some retained austenite were found to transform to martensite on stress. Reduction of area (RA) increased with contents of retained austenite, then saturated through its maximum, and subsequently decreased. Increase in RA with retained austenite contents could be due to crack blunting effect by retained austenite on stress, however, more contents of martensite transformed from retained austenite in its higher contents could cause decrease in RA.

Redundancy Analysis Demonstration of the Relevance of Temperature to Ammonia-Oxidizing Bacterial Community Compositions in a Full-Scale Nitrifying Bioreactor Treating Saline Wastewater

  • Park, Hee-Deung;Lee, Seung-Yong;Hwang, Seok-Hwan
    • Journal of Microbiology and Biotechnology
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    • v.19 no.4
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    • pp.346-350
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    • 2009
  • Although salt is known to influence the performance of nitrification significantly, it has not been well reported on how salt affects ammonia-oxidizing bacterial(AOB) community compositions and dynamics in wastewater treatment bioreactors. In this study, these questions were evaluated in a full-scale bioreactor treating saline wastewater. Clone library analysis for the ammonia monooxygenase subunit A gene revealed that AOB belonging to the Nitrosomonas europaea and the N. oligotropha lineages inhabited in the bioreactor. Terminal restriction fragment length polymorphism analysis for monthly samples demonstrated a fluctuation pattern among AOB populations, although AOB within the N. europaea lineage were dominant during the test period. Correlation analysis between patterns of terminal restriction fragments and environmental variables suggested that sodium, chloride, and sulfate were less important; rather, temperature was the most significant factor affecting the AOB community in the bioreactor.

Petrology and Petrochemistry of the Cretaceous Granites in the Southern Mungyeong Area (문경(聞慶) 남부일대(南部一帶)에 분포(分布)하는 백악기(白惡紀) 화남암류(花南岩類)의 암석학(岩石學) 및 암석화학(岩石化學))

  • Yun, Hyun Soo;Kim, Seon Eok
    • Economic and Environmental Geology
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    • v.23 no.3
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    • pp.343-352
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    • 1990
  • The Cretaceous granites are widely distributed in the studied area, Mungyeong-Sangju, which belongs to the southwestern part of the Ogcheon Folded Belt. The granites are characterized by medium-coarse grained, spotted miaroles, partly flow textures of biotite, aplitic dykes and pegmatitic pockets with druse. From the major compositions, the granites indicate peraluminous, calc-alkaline, salic and late stage products of differentiation. In the view of normative compositions of Qz-Ab-Or and perthitic alkali feldspar, they were formed under 1-4kb and $426^{\circ}-456^{\circ}C$ in acqueous conditions. The K/ Ar biotite age shows $72{\pm}1$ Ma for this grante, corresponding to the igneous activity of the Bulgugsa Disturbance periods in the area. The above results represent that these granite bodies are differentiated from a single magma.

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Estimation of product compositions for multicomponent distillation columns

  • Shin, Joonho;Lee, Moonyong;Park, Sunwon
    • 제어로봇시스템학회:학술대회논문집
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    • 1996.10a
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    • pp.295-298
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    • 1996
  • In distillation column control, secondary measurements such as temperatures and flows are widely used in order to infer product composition. This paper addresses the design of static estimators using the secondary measurements for estimating the product compositions of the multicomponent distillation columns. Based on the unified framework for the estimator problems, the relationships among several typical static estimators are discussed including the effect of the measured inputs. Design guidelines for the composition estimator using PLS regression are also presented. The estimator based on the guidelines is robust to sensor noise and has a good predictive power.

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Flame Stability of Dual Swirl Combustor with variable SNG composition using the Chemiluminescence Measurement (자발광 계측을 통한 모사 SNG 수소함량에 따른 이중선회 버너의 화염 안정화 특성)

  • Choi, Inchan;Oh, Kwangchul;Lee, Keeman
    • 한국연소학회:학술대회논문집
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    • 2014.11a
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    • pp.147-148
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    • 2014
  • This article describes an investigation of flame stability characteristics with various compositions of synthetic natural gas (SNG) in dual swirl combustor. The objective of this study is to investigate the flame stabilization, flame structure, fuel compatibility using chemiluminescence measurement in SNG with varying fuel compositions. As experimental conditions, hydrogen content was adjusted from 0 to 11%. Experimental results show that the addition of hydrogen has a major effect on flame behavior due to the higher burning rates associated with hydrogen consequently, The higher reaction activity of hydrogen has extended lean blow-off limit. Especially, DI flame limit has improved more 12.1%.

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Effect of $Mg^{2+}$ co-doping on luminescent properties of $ZnGa_2O_4:Mn^{2+}$

  • Singh, Binod Kumar;Bartwal, Kunwar Singh;Ryu, Ho-Jin
    • Journal of the Semiconductor & Display Technology
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    • v.6 no.4
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    • pp.29-32
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    • 2007
  • Zinc gallate, $ZnGa_2O_4:Mn^{2+}$ co-doped with different concentrations of $Mg^{2+}$ (0.001- 0.5 mol%) was prepared by solid state synthesis method. These compositions were investigated for their photoluminescence and cathodoluminescence properties. The optimized composition $Zn_{0.990}Mg_{0.005}Ga_2O_4:Mn_{0.005}$ shows higher luminescence intensity compared to the parent phosphor. The intense green emission peak was found at 504 nm. The $Mg^{2+}$ doping does not affect much the decay time. It remains <10 ms for these compositions which make them potential candidate for application in TV screens.

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곤충병원성 선충과 공생박테리아의 지방산 함량 분석

  • Park, Seon-Ho;Kim, Hyo-Hyeon;Kim, Ji-Yeon
    • 한국생물공학회:학술대회논문집
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    • 2001.11a
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    • pp.910-913
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    • 2001
  • The fatty acid compositions of entomopathogenic nematodes Steinernema carpocapsae strain produced in vitro and in vivo were examined. Nematodes cultured both in vitro and in vivo revealed similar fatty acids compositions with respect to 16, 18, 20 carbons. However, the contents of lipids were varied by culture methods. Furthermore, it was distinctive that nematodes cultured in vitro contained fatty acids with 19 carbon. In the case of symbiotic bacterium Xenorhabdus nematophilus isolated from Steinernema carpocapsae, the major lipid component was palmitic (c16:0) fatty acids.

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