• Restorative Dentistry and Endodontics
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• v.32 no.1
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• pp.9-18
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• 2007

The purposes of this study were to examine the variability of adhesive thickness on the different site of the cavity wall when used total-etch system without filler and simplified self-etch system with filler and to evaluate the relationship between variable adhesive thickness and microtensile bond strength to the cavity wall. A class I cavity in six human molars was prepared to expose all dentinal walls. Three teeth were bonded with a filled adhesive, $Clearfil^{TM}$ SE bond ana the other three teeth were bonded with unfilled adhesives, $Scotchbond^{TM}$ Multi Purpose. Morphology and thickness of adhesive layer were examined using fluorescence microscope. Bonding agent thickness was measured at three points along the axial cavity wall edge of cavity margin (rim). halfway down each cavity wall (h1f), internal angle of the cavity (ang). After reproducing the adhesive thickness at rim, h1f and ang, micro-tensile bond strength were evaluated. For both bonding agents, adhesive thickness of ang was significantly thicker than that of rim and h1f (P <0.05). As reproduced the adhesive thickness, microtensile bond strength was increased as adhesive thickness was increased in two bonding agents. Adhesive thickness of internal angle of the cavity was significantly thicker than that of the cavity margin and the halfway cavity wall for both bonding agents. Microtensile bond strength of the thick adhesive layer at the internal angle of the cavity was higher than that of the thin adhesive layer at 1,he cavity margin and the halfway cavity in the two bonding systems.

• YAKHAK HOEJI
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• v.42 no.3
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• pp.290-295
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• 1998

To optimize the formulation of acetaminophen liquid suppository, the effect of additives on the physicochemical properties of liquid suppository base was investigated. The physi cochemical properties of P 407/P 188 (15/15%) (abbreviated in 15/15) and P 407/P l88 (15/20%) (abbreviated in 15/20) were measured after the addition of following additives; 2.5% acetaminophen as an active ingredient, vehicle components (5% ethanol, 5% propylene glycol, 5% glycerin), preservatives (0.1% sodium benzoate, 0,1% methylparahydroxybenzoate, 0.1% propylparahydroxybenzoate) and 1% of sodium chloride as an ionic strength controlling agent. Poloxamer gel was prepared with three different buffer solutions (pH 1.2, 4.0 and 6.8) and the physicochemical properties, gelation temperature, gel strength and bioadhesive force, were determined. In the results, the effect of additives on the physicochemical properties was dependent on their bonding capacities including hydrogen bonding and cross-linking bonding. Because the hydrogen-bonding capacities of acetaminophen, ethanol and propylene glycol were smaller than that of poloxamer, the binding force of poloxamer gel became weak by their putting in between poloxamer gel. Therefore, the gelation temperature (15/15, $35.7^{\circ}C$ vs 37.0, 39.4 $38.2^{\circ}C$; 15/20, $29.2^{\circ}C$ vs 31.2, 32.0, $30.3^{\circ}C$) increased, and gel strength (15/15, 4.03 see vs 2.72, 2.08, 3.12sec; 15/20, 300g vs 50, 50, 200g) and bioadhesive force (15/15, $6.8{\times}10^2\;dyne/cm^2$ vs 3.2, 6.0, $6.0{\times}10^2\;dyne/cm^2$; 15/20, $97.3{\times}10^2\;dyne/cm^2$ vs 11.1, 89.5, $92.0{\times}10^2\;dyne/cm^2$) decreased. Furthermore, the binding force of poloxamer gel became strong due to the hydrogen-bonding capacities of glycerin and the cross-liking bonding of sodium salt. Then, the gelation temperature (15/15, 35.0, $32.1^{\circ}C$; 15/20, 26.0, $21.0^{\circ}C$) decreased, and gel strength (15/15, 6.51 see, 300g; 15/20, 500, 650g) and bioadhesive force (15/15, 7.2, $81.6{\times}10^2\;dyne/cm^2$; 15/20, 112.3, $309.2{\times}10^2\;dyne/cm^2$) increased. The effect of pH on the physicochemical properties of poloxamer gel was dependent on the ingredients with which the buffer solutions were prepared. Poloxamer gels prepared with pH 1.2 and 4.0 buffer solutions had the increasing gelation temperature (15/15, 37.5, $38.1^{\circ}C$; 15/20, 33.1, $34.0^{\circ}C$) and the decreasing gel strength (15/15, 2.98, 3.81sec; 15/20, 200, 200g) and bioadhesive force (15/15, $7.0{\times}10^2dyne/cm^2$; 15/20, $74.0{\sim}88.1{\times}10^2dyne/cm^2$) owing to HCl. Poloxamer gel prepared with pH 6.8 buffer solutions had the decreasing gelation temperature (15/15, $27.2^{\circ}C$; 15/20, $22.3^{\circ}C$) and the increasing gel strength (15/15, 400g; 15/20, 550g) and bioadhesive force (15/15, $207.0{\times}10^2dyne/cm^2$; 15/20, $215.0{\times}10^2dyne/cm^2$) due to the cross-linking bonding of $NaH_2PO_4\;and\;K_2HPO_4$.

• Journal of Global Scholars of Marketing Science
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• v.19 no.2
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• pp.40-52
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• 2009

Franchising is one of the fastest growing types of business. It is already popular and well-known in the U.S., and has been growing in many other countries including Korea. Furthermore, many Korean franchising companies have expanded their business overseas actively. According to the data by the Ministry of Industry and Resource, 82 companies out of a sample of 500 franchising companies are already operating in many foreign countries and 48% of them have started their foreign business since 2006. This clearly indicates the fast growing current trend of foreign operation by Korean franchising companies. In spite of the fast growing trend of foreign expansion in the industry, academic research on internationalization of franchising companies is extremely difficult to find. Accordingly, academic research on the issue is necessary and urgent in Korea. Among the various research questions on internationalization of franchising business, this study intends to investigate the difference in organizational factors between the franchising companies doing foreign operation and those doing business only domestically. More specifically, this research has the following purposes. First, considering the lack of theoretical basis of previous studies, resource-based theory and agency theory are employed as the theoretical bases. Second, this study explains the difference in internationalization based on organizational factors such as company size, history and growth rate. Third, the five hypotheses regarding the difference in organizational factors are presented and tested empirically, which is the first attempt in the area of this topic. Finally, the study attempts to clarify the conflicting implications among theories regarding some organizational factos such as growth rate. As the theoretical background, resource-based theory and agency theory are discussed. According to resource-based theory, a firm can grow continuously when it has competence and resource, and also the ability to develop them. The competence and resource can include capital, human resource, management skill, market information, ability to manage risk, etc. Meanwhile, agency theory views the relationship between franchisor and franchisee as an agency relationship. In agency theory, bonding capability and monitoring capability are the two key factors which promote internationalization of franchising companies. Based on the two theories, a conceptual model is designed. The model consists of two groups of variables. One is organizational factors including size, history, growth rate, price bonding and geographic dispersion. The other is whether a franchising company is operating overseas or not. We developed the following five research hypotheses basically describing the relationship between organizational factors and internationalization of franchising companies. H1: The size of franchising companies operating overseas is larger than that of franchising companies operating domestically. H2: The history of franchising companies operating overseas is longer than that of franchising companies operating domestically. H3: The growth rate of franchising companies operating overseas is higher than that of franchising companies operating domestically. H4: The price bonding of franchising companies operating overseas is higher than that of franchising companies operating domestically. H5: The geographic dispersion of franchising companies operating overseas is wider than that of franchising companies operating domestically. Data for the analyses are obtained from 2005 Korea Franchise Survey data co-generated by Ministry of Industry and Resource, GS1 Korea, and Korea Franchise Association. Out of 2,804 population companies, 2,489 companies are excluded for various reasons and 315 companies are selected as the final sample. Prior to hypotheses tests, validity and reliability of the measures of size, history, growth rate and price bonding are examined for further analyses. Geographic dispersion is not validated since it is measured using nominal data. A series of independent sample T-tests is used to find out whether there exists any significant difference between the companies internationalized and those operating only domestically for each organizational factor. Among the five factors, size and geographic dispersion show significant difference, growth rate and price bonding do not reveal any difference and, finally, history factor shows conflicting results in the difference depending on how to measure it.