• 제목/요약/키워드: Reduced viscosity

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The physico-chemical nature of prepared dextran sulfates

  • Kim, Young-Choong
    • Archives of Pharmacal Research
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    • v.4 no.1
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    • pp.33-41
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    • 1981
  • The prepared dextran sulfates were characterized by measuring the reduced viscosisty at five different concentrations to obtain an intrinsic viscosity in both phosphate and tris buffers, pH 7.4, ionic strength of 0.1 Dextran sulfates having 0.81, 1.06 sulfate groups per hexose unit have reduced viscosity value below 40 ml/g whereas dextran sulfates having 1.21, 1.43, 1.69 sulfate groups per hexose unit have reduced viscosity value over 40 ml/g. Dextran sulfate having 1.21 sulfate groups per hexose unit had highest value of reduced viscosity. The reduced viscosity of dextran sulfate in tris buffer was always higher than that in phosphate buffer regardless of the sulfate content of dextran sulfate. The influence of the sulfation of the dextran sulfate. The influence of the sulfation of the dextran sulfate molecule on the dextran sulfate-LDL interaction was studied with three different dextran sulfate molecules. Dextran sulfate molecules having more than one sulfate group per hexose unit. The dextran sulfate having 0.81 sulfate groups per hexose unit showed considerably different precipitation curves in phosphate and tris buffers. This peculiar behavior of dextran sulfate having 0.81 sulfate groups per hexose unit in the two buffer systems was not noticed with dextran sulfate having more than one noticed with dextran sulfate having more than one sulfate group per hexose unit.

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The Helium-Xenon Interaction Potential

  • Elaheh K. Goharshadi;Majid Moinssadati
    • Bulletin of the Korean Chemical Society
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    • v.22 no.9
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    • pp.945-947
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    • 2001
  • The He-Xe interaction potential has been determined using a direct inversion of the experimentally reduced-viscosity collision integrals obtained from the corresponding states correlation. The potential is in a good agreement with the previously determined potential. The potential predicts viscosity and diffusion coefficients and they are found to be in a good agreement with experiment.

Quality Characteristics of Dried Noodle Made with Lotus Root Powder (연근분말을 첨가한 국수의 품질특성)

  • Park, Bock-Hee;Cho, Hee-Sook;Bae, Kyoung-Yun
    • Korean journal of food and cookery science
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    • v.24 no.5
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    • pp.593-600
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    • 2008
  • The principal objective of this study was to evaluate the quality characteristics of dried noodles when different concentrations of Lotus root powder were added to the wheat flour. The cooking quality, mechanical textural properties, and viscosity were measured, and a sensory evaluation was conducted with the prepared noodles. The gelatinization points of the composite Lotus root powder-wheat flours were shown to have increased and the viscosity at $95^{\circ}C$, viscosity at $95^{\circ}C$ after 15 minutes, and maximum viscosity values of those samples were reduced, as the Lotus root powder content was increased as measured via amylography. As increasing amounts of Lotus root powder were added, the L and b values were reduced, and the color values, weight, and volume of the cooked noodles increased, as did the turbidity of the soup. With regard to the textural characteristics, the Lotus root powder additive increased hardness and reduced adhesiveness, cohesiveness, and springiness. Overall, the noodles prepared with 15% Lotus root powder were preferred more than the other noodles, according to the results of our sensory evaluation.

Effects of Bangpoongsan on the Cardiovascular System in the Experimental Animals (방풍산(防風散)이 실험동물(實驗動物)의 심혈관계(心血管系)에 미치는 영향(影響))

  • Huh, Jae-Hyeok;Kim, Seh-Gil
    • The Journal of Internal Korean Medicine
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    • v.16 no.1
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    • pp.181-196
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    • 1995
  • The present experiments were designed to investigate the effects of BangPoongSan on the cardiovascular system in the experimental Animals. And thus the change of blood pressure, auricular blood flow, artery contraction, death rate, platelet aggregation repression, plasma coagulation factor activity, plasma antithrombin activity, whole blood viscosity and plasma viscosity were studied. The result were summarized as the followings: 1. BangPoongSan dropped the blood pressure in the spontaneous hypertensive rat. 2. The drug increased the auricular blood flow in rabbit. 3. The drug relaxed the artery contraction by pretreated norepinephrine in white rat. 4. The drug inhibited the death rate of mouse which was led to thromboembolism by serotonin and collagen. 5. The drug inhibited the platelet aggregation in rat. 6. The drug prolonged the prothrombin time and activated partial thromboplastin time on the test of plasma coagulation factor activity in rat, but was not valuable. 7. The drug presented the antithrombin activity in rat. 8. The drug reduced the whole blood viscosity and plasma viscosity in rat, but the latter was not valuable. According to the results, Bangpoongsan increased the blood flow and dropped the blood pressure by dilatation of blood vessel smooth muscle. And the drug presented the antithrombin acivity, inhibited the platelet aggregation and reduced blood viscosity. Therefore these effects are assumed to improve the cardiovascular circulation disorder and prevent thrombosis.

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Synthesis and Solution Properties of Zwitterionic Copolymer of Acrylamide with 3-[(2-Acrylamido)dimethylammonio]propanesulfonate

  • Xiao, Hui;Hu, Jing;Jin, Shuailin;Li, Rui Hai
    • Bulletin of the Korean Chemical Society
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    • v.34 no.9
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    • pp.2616-2622
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    • 2013
  • A novel zwitterionic monomer 3-[(2-acrylamido)dimethylammonio]propanesulfonate (DMADAS) was designed and synthesized in this study. Then it was polymerized with acrylamide (AM) by free radical polymerization in 0.5 mol/L NaCl solution with ammonium persulfate ($(NH_4)_2S_2O_8$) and sodium sulfate ($NaHSO_3$) as initiator. The structure and composition of DMADAS and acrylamide-3-[(2-acrylamido)-dimethylammonio]propanesulfonate copolymer (P-AM-DMADAS) were characterized by FT-IR spectroscopy, $^1H$ NMR and elemental analyses. Isoelectric point (IEP) of P-AM-DMADAS was tested by nanoparticle size and potential analyzer. Solution properties of copolymer were studied by reduced viscosity. Antipolyelectrolyte behavior was observed and was found to be enhanced with increasing DMADAS content in copolymer. The results showed that the viscosity of P-AM-DMADAS is 5.472 dl/g in pure water. Electrolyte was added, which weakened the mutual attraction between sulfonic acid group and quaternary ammonium group. The conformation became loose, which led to the increase of reduced viscosity. The ability of monovalent and divalent cation influencing the viscosity of zwitterionic copolymer obeyed the following sequence: $Li^+$ < $Na^+$ < $K^+$, $Mg^{2+}$ < $Ca^{2+}$ < $Ba^{2+}$, and that of anion is in the order: $Cl^-$ < $Br^-$ < $I^-$, $CO{_3}^{2-}$ > $SO{_3}^{2-}{\approx}SO{_4}^{2-}$.

Flow behavior of high internal phase emulsions and preparation to microcellular foam

  • Lee, Seong Jae
    • Korea-Australia Rheology Journal
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    • v.16 no.3
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    • pp.153-160
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    • 2004
  • Open microcellular foams having small-sized cell and good mechanical properties are desirable for many practical applications. As an effort to reduce the cell size, the microcellular foams combining viscosity improvers into the conventional formulation of styrene and water system were prepared via high internal phase emulsion polymerization. Since the material properties of foam are closely related to the solution properties of emulsion state before polymerization, the flow behavior of emulsions was investigated using a controlled stress rheometer. The yield stress and the storage modulus increased as viscosity improver concentration and agitation speed increased, due to the reduced cell size reflecting both a competition between the continuous phase viscosity and the viscosity ratio and an increase of shear force. Appreciable tendency was found between the rheological data of emulsions and the cell sizes of polymerized foams. Cell size reduction with the concentration of viscosity improver could be explained by the relation between capillary number and viscosity ratio. A correlative study for the cell size reduction with agitation speed was also attempted and the result was in a good accordance with the hydrodynamic theory.

The Influence of Engine Operating Conditions and Lubricants on Oil Film Thickness of Engine Connecting Rod Bearing (커넥팅로드 베어링의 유막두께에 미치는 기관 운전조건 및 윤활유의 영향)

  • Lee, D.H.;Chang, B.J.
    • Transactions of the Korean Society of Automotive Engineers
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    • v.2 no.5
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    • pp.1-10
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    • 1994
  • By applying of total electric capacitance method on engine connecting rod bearing during engine operating, the influence of engine operating conditions and lubricants on bearing oil film thickness was investigated. Minimum oil film thickness increases with kinematic viscosity, but as increasing of viscosity, the increasing ratio of film thickness is reduced. Also minimum oil film thickness increases with engine speed but there is a limit. Above this limit, film thickness decreases in opposition because of crankshaft inertia. As increasing of engine torque and oil temperature, munimum oil film thickness decreases linearly. For non-Newtonian oils, the correlation between $100{\circ}C$ kinematic viscosity and munimum oil film thickness is very poor.

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Effects of boundary layer and liquid viscosity and compressible air on sloshing characteristics

  • Zou, Chang-Fang;Wang, De-Yu;Cai, Zhong-Hua
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.7 no.4
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    • pp.670-690
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    • 2015
  • In this paper, numerical investigations for tank sloshing, based on commercial CFD package FLUENT, are performed to study effects of boundary layer grid, liquid viscosity and compressible air on sloshing pressure, wave height and rising time of impact pressure. Also, sloshing experiments for liquids of different viscosity are carried out to validate the numerical results. Through comparison of numerical and experimental results, a computational model including boundary layer grid can predict the sloshing pressure more accurately. Energy dissipation due to viscous friction leads to reduction of sloshing pressure and wave elevation. Sloshing pressure is also reduced because of cushion effect of compressible air. Due to high viscosity damping effect and compressible air effect, the rising time of impact pressure becomes longer. It is also found that liquid viscosity and compressible air influence distribution of dynamic pressure along the vertical tank wall.

Rheological Properties of Dried Noodles with Added Enteromorpha intenstinalis Powder (파래 분말을 이용한 국수의 이화학적 물성에 관한 연구)

  • Cho, Hee-Sook
    • Journal of the East Asian Society of Dietary Life
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    • v.20 no.4
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    • pp.567-574
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    • 2010
  • This study was performed to evaluate the physicochemical and quality characteristics of dried noodles when different concentrations of Enteromorpha intenstinalis powder (EIP) were added to the wheat flour, thereby determining which noodle recipe was preferred. The cooking quality, mechanical texture properties, and viscosity of the prepared with noodles were measured, and then a sensory evaluation was conducted on them. The gelatinization points of the composite Enteromorpha intenstinalis powder-wheat flour were shown to have an increased viscosity at $95^{\circ}C$ after 15 minutes. As measured via amylograph, the maximum viscosity values of those samples decreased with increasing EIP content. Also, when increased amounts of EIP were added, both the L and b values were reduced, whereas the a value was increased. The color values, weight and volume of the cooked noodles increased, as did the turbidity of the soup. With regard to the textural characteristics, the EIP additive increased hardness and reduced adhesiveness, cohesiveness and springiness. Overall, according to the results of our sensory evaluations, the noodles prepared with 5% EIP were preferred over other noodles.

A Fundamental Study on the Development of AE Water Reducing Agent for Reduction of Bleeding (블리딩 저감용 AE감수제 개발에 관한 기초적 연구)

  • 문학용;김한준;김규용;신동인;한천구
    • Proceedings of the Korea Concrete Institute Conference
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    • 2003.05a
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    • pp.75-78
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    • 2003
  • This study is to investigate the probability to develop the AE Water-reducing agent which can decrease the bleeding by mixing melamine type super-plasticizer(SP) and methyl cellulose(MC) viscosity agent. According to the result, as the mixing ratio of melamine type SP and MC viscosity agent increases, the bleeding is reduced due to a increase of the air content. When the mixing ratio of melamine type SP and MC viscosity agent is 1:2 and 1;3 at the water content of 165kg/$m^3$ and 175kg/$m^3$ respectively, slump and air content are satisfied and bleeding is reduced to some extent, so this is determined as the mixing ratio of AE water reducing agent for reduction of bleeding. It is prove that the developed AE water reducing agent for reduction of bleeding can reduce the amount of bleeding and prohibit the plastic shrinkage crack by slowing down the bleeding speed. Compressive strength of hardened concrete does not make any difference in comparison with plain concrete.

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