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Salt Effects on the Critical Micelle Concentration and Counterion Binding of Cetylpyridinium Bromide Micelles

  • Jong Jae Chung;Sang Wook Lee;Joon Ho Choi
    • Bulletin of the Korean Chemical Society
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    • v.12 no.4
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    • pp.411-413
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    • 1991
  • The effects of electrolyte on the critical micelle concentration (cmc) and bromide counterion binding in the micelles of cetylpyridinium bromide (CPB) have been investigated by UV spectroscopy and conductance measurements. Salts used in this study decreased cmc in the order $Cl^-\;<\;Br^-\;<\;NO3^-$ (which parallels the lyotropic series for the inorganic anions) and the effects on cmc followed the equation proposed by Shinoda: log cmc = A - B log (cmc + [NaX]). In the equation, constant B represents the counterion binding to the micelles at cmc and for the micelle of CPB at $25^{\circ}C$, B=80.76%. The association constant for the binding of counterions to long chain cations within micelles was also derived from the cmc values and counterion binding constant to the micelles.

A Study on Diesel Spray Combustion Modeling by Eulerian and Lagrangian Conditional Moment Closure Models (Eulerian 및 Lagrangian CMC 모델을 사용한 디젤분무연소 모델링에 관한 연구)

  • Kim, Woo Tae;Cho, Hyun Su;Huh, Kang Y.
    • 한국연소학회:학술대회논문집
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    • 2012.11a
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    • pp.195-198
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    • 2012
  • Numerical simulation is performed to evaluate the conditional moment closure (CMC) models for spray development, ignition, and turbulent combustion for the Engine Combustion Network (ECN) test cases. The CMC model is implemented in the open source code, OpenFOAM, to provide conditional flame structures through the solution of Eulerian as well as Lagrangian conditional transport equations. In spite of more accurate treatment of the convective term, Eulerian CMC provides similar ignition delays and lift-off lengths with Lagrangian CMC.

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CMC SURFACES FOLIATED BY ELLIPSES IN EUCLIDEAN SPACE E3

  • Ali, Ahmad Tawfik
    • Honam Mathematical Journal
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    • v.40 no.4
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    • pp.701-718
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    • 2018
  • In this paper, we will study the constant mean curvature (CMC) surfaces foliated by ellipses in three dimensional Euclidean space $E^3$. We prove that: (1): Surfaces foliated by ellipses are CMC surfaces if and only if it is a part of generalized cylinder. (2): All surfaces foliated by ellipses are not minimal surfaces. (3): CMC surfaces foliated by ellipses are developable surfaces. (4): CMC surfaces foliated by ellipses are translation surfaces generated by a straight line and plane curve.

Effect of carboxymethyl chitosan on postoperative intraperitoneal adhesion formation in the rat (Rat에서 carboxymethyl chitosan의 복강수술후 유착형성에 미치는 효과)

  • Jang, Kwang-ho;Kwon, Yong-sam;Kim, Jung-eun;Kwon, Eun-ju;Oh, Tae-ho;Lee, Keun-woo;Jang, In-ho
    • Korean Journal of Veterinary Research
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    • v.40 no.3
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    • pp.635-643
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    • 2000
  • The aim of this study was to determine the effectiveness of carboxymethyl chitosan(CMC) solution on preventing intraperitoneal adhesions. In this study, 44 rats were divided into four groups ; an untreated control group and three experimental groups that were treated with 3 ml of 1, 2 or 3% CMC solution, respectively. The anti-mesenteric serosa of the ileum was exteriorized and then abraded in a standard manner by scraping with a scalpel blade to create homogenous petechial hemorrhagic surface over a $0.5{\times}1cm$ area. The adhesions were blindly assessed 2 weeks later by using a computerized tensiometer. The mean tensile strength(Newton) of formed adhesions was $2.48{\pm}0.88$ in control group, $1.86{\pm}0.56$ in the 1% CMC-treated group, $1.75{\pm}0.71$ in the 2% CMC-treated group and $1.55{\pm}0.60$ in the 3% CMC-treated group. The most favorable prevention against adhesion was achieved in the 3% CMC-treated group(p<0.01). We could conclude that CMC was effective on preventing the formation of postoperative small intestinal adhesions in the rat.

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A Study on the Effectiveness of the Instructional Design for Further Interaction on English Learning in a CMC Based Language Learning Environment: Focusing on University General English Education (CMC기반의 영어학습 환경에서 상호작용 촉진을 위한 교수설계가 영어학습에 미치는 효과 : 교양 영작문 과목을 중심으로)

  • 정양수
    • Korean Journal of English Language and Linguistics
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    • v.3 no.2
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    • pp.281-308
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    • 2003
  • The purpose of this study is to determine the effects of CMC-based English learning. In this study, CMC components were found to provide circumstances of facilitating interactions between student-student and student-student-teacher, which enabled students to accomplish language learning tasks. Findings of this study are as follows: First, CMC based language learning experience helps students have positive attitudes toward their English language learning. Second, student-student-instructor interaction group outperformed other groups in academic achievement and class activity participation. Third, cooperative learning groups more actively participated in the class activity than the individual learning group resulting in better academic performances. These findings supported the fact that cooperative learning with CMC components are useful in bringing more class participation and positive attitude that were believed to foster language learning than other groups in traditional language learning environments. This study suggests that the instructor needs to use instructional design strategies helpful to facilitate active interactions between instructors and students in order to achieve better effectiveness of English learning in a CMC based learning environment.

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A Statistical-Mechanical Model on the Temperature Dependence of Critical Micelle Concentration (임계 마이셀 농도의 온도 의존성에 대한 통계 역학적 모델)

  • Lim, Kyung-Hee;Kang, Kye-Hong;Lee, Mi-Jin
    • Applied Chemistry for Engineering
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    • v.17 no.6
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    • pp.625-632
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    • 2006
  • Dependence of the critical micelle concentration (CMC) on temperature is examined from a statistical-mechanical point of view. A simple and primitive model examined in this article yields ln CMC= A+BT+C/T+D ln T with T being temperature and A, B, C, D being constants depending on the properties of the surfactant molecules which comprise the micelles. The resulting equation combines Muller's and Lim's equations, which have already been proven to fit well measured CMC data with temperature. The statistical-mechanical model on micellization discussed in this article provides a theoretical basis on these equations.

Improvement of Rheological Properties of Silica Composites Employing Response Surface Methodology (반응표면분석법을 이용한 실리카복합재료의 레올로지 속성 개선)

  • Yim, Gie-Hong;Yang, Seung-Nam;Kim, Nam-Ki
    • Polymer(Korea)
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    • v.32 no.1
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    • pp.19-25
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    • 2008
  • The purpose of this study was improving the rheology properties of dentifrice by finding optimum binders polymer system which consists of carboxymethylcellulose (CMC), carbomer, and Mg/Al silicate. Response surface methodology (RSM) was employed to investigate the correlation between polymers and rheological properties of dentifrice and to optimize responses. Rheological properties were measured with oscillatory rheometer. As a result, it was identified that gel strength and yield stress were dependent on contents of CMC and carbomer and CMC caused long stringiness of dentifrice. And springness of dentifrice was dependent on contents of CMC and Mg/Al silicate. Optimum components proportion of polymers and silicate were obtained by responses optimization process. According to determined optimum components proportion, it was possible to observe a dentifrice with improved rheological properties.

Carboxymethyl Chitosan Promotes Migration and Inhibits Lipopolysaccharide-Induced Inflammatory Response in Canine Bone Marrow-Derived Mesenchymal Stem Cells

  • Ryu, Ho-Sung;Ryou, Seong-Hwan;Jang, Min;Ku, Sae-Kwang;Kwon, Young-Sam;Seo, Min-Soo
    • Journal of Veterinary Clinics
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    • v.38 no.6
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    • pp.261-268
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    • 2021
  • The study was conducted to evaluate the effects of carboxymethyl chitosan (CMC) on proliferation, migration, and lipopolysaccharide (LPS)-induced inflammatory response in canine bone marrow-derived mesenchymal stem cells (BMSCs). The proliferation and migration of BMSCs were examined after treatment with CMC. The effect of CMC on the mRNA expression of inflammatory cytokines, such as interleukin (IL)-1β, IL-6, tumor necrosis factor (TNF)-α, IL-10, and transforming growth factor (TGF)-β, was also evaluated by reverse transcription polymerase chain reaction (RT-PCR). In the proliferation assay, no significant changes were found at all CMC concentrations compared with controls. The migration assay showed that CMC dose-dependently stimulated the migration of BMSCs in normal and LPS-treated conditions. RT-PCR showed that TNF-α and IL-10 expressions were suppressed in the BMSCs after CMC treatment. However, other genes were not affected. Taken together, CMC promoted BMSC migration and inhibited TNF-α and IL-10. Therefore, CMC may be possible to regulate wound healing when mesenchymal stem cells are applied in inflammatory diseases.

Identifying the Effect of Service Quality Attributes on an Overall Customer Satisfaction by the Foodservice Type and the Contract Management Company(CMC) Scale (급식 대상 유형과 위탁급식전문업체 규모별 고객 만족도에 영향을 미치는 서비스 품질 속성의 규명)

  • Park, Mun-Gyeong
    • Journal of the Korean Dietetic Association
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    • v.13 no.2
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    • pp.138-156
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    • 2007
  • The purposes of this study were to a) measure the service quality attributes of foodservice type such as school foodservice, hospital foodservice and business & industry(B&I) foodservice, managed by contract management company(CMC), b) compare with service quality attributes by CMC scale, c) analyze overall customer satisfaction(CS) by the foodservice type and the CMC scale, and d) identify the effect of service quality attributes on an overall CS by the foodservice type and the CMC scale. The questionnaires were handed out to 6,620 customers of 207 school, 38 hospital, and 86 B&I foodservices in 108 CMCs. The statistical data analysis was completed using SPSS Win(ver 12.0) for descriptive analysis, t-test, reliability analysis, and multiple linear regression analysis. From an analysis on service quality attributes, 'proper arrangement of table and chair at hall distribution(3.53)', 'operation of nutrition education(3.50)' were highly perceived to student, 'correctable serving(4.08)', 'serve at fixed distribution time(4.08)', 'kindness of serving employee(4.04)' were highly perceived to patient, 'employee's kindness(3.84)' were highly perceived to customer of B&I. In comparison of service quality attributes by CMC scale, most scores of large enterprise(LE) were significantly higher than small and medium sized enterprise(SME) in school foodservice, hospital foodservice and B&I foodservice. Overall CS levels were 3.53 out of a maximum 5 on B&I, 3.46 on school, and 3.44 on hospital and were evaluated differently CS score by CMC scale. Finally, regression results for the effects of service quality attributes on overall CS by each of foodservice type were identified significantly different service quality attributes by foodservice type such as school, hospital, B&I(p<.001) and by CMC scale. For considering the goal of enterprise on profit-making through CS and the needs of customer on CS at moment of truth(MOT), the findings should be applied to the CMC and the foodservice industry.

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A Empirical Study about the Impact of the Calibration and Measurement Capability(CMC) on Korean Trade (교정 및 측정능력(CMC)이 한국의 무역에 미치는 영향에 관한 실증분석)

  • Park, Jookeun;Han, Seong;Park, Jongseon
    • Journal of Technology Innovation
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    • v.25 no.2
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    • pp.127-152
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    • 2017
  • With the advent of the WTO system in 1995, non-tariff barriers including technical barriers to trade(TBT) has become one of the important issues in world trade order. The purpose of this study is to analyse an impact of the calibration and measurement capabilities(CMC), the degree of equivalence of national measurement standards which is maintained by NMIs to provide governments with a technical foundation for wider agreements related to international trade. The results of the analysis using the gravity model with the proxy of the CMC shows that the CMC has a positive impact on Korean trade. Particularly, it was estimated that the CMC registered by high-income economies has more impact on Korean trade than those by low income economies. This implies that the countries highly dependent upon foreign trade like Korea need to have much more interest in the investment into measurement standards and science which is generally considered to be a public goods.