• Korean Chemical Engineering Research
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• 제57권2호
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• pp.164-171
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• 2019

The protonation parameters, dissociation constants ($pK_{BH^+}$) of conjugate acid, slope values (m, ${\phi}$ and $m^*$) and correlation coefficients (r) of hydroxamic acids were determined by Hammett acidity function method, Bunnett-Olsen method and excess acidity method in hydrochloric and perchloric acid solutions. Effect of acid concentration on partition and percentage protonation was also studied. $pK_{BH^+}$ values show that hydroxamic acids do not behave as Hammett bases, but hydroxamic acids behave as weak bases in strong acidic solutions. The values of $pK_{BH^+}$ obtained through Bunnett-Olsen method and excess acidity method were compared with the Hammett acidity function. ChemAxon's MarvinSketch 6.1.5 software was also used for determining $pK_a$, pI and microspecies distribution (%) of hydroxamic acids with pH. Hydrogen donor and acceptor values and logD were also obtained. The results show that N-p-chlorophenyl-4-bromobenzohydroxamic acid has the highest $pK_a$ and lowest logD values. On the contrary, N-phenyl-3,5-dinitrobenzohydroxamic acid has lowest the $pK_a$ and highest logD values.

• Environmental Analysis Health and Toxicology
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• 제29권
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• pp.13.1-13.11
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• 2014

Objectives This study examined variations in the perceptions of dioxin risk among social groups defined by geographical living location, environmental education, and occupation. Dioxin risk perceptions were analyzed according to values, risk awareness, knowledge, and behavioral preferences. Methods A quasi-experimental survey was designed and conducted on individuals from seven experimental groups in Jeonju city, South Korea, including: people living near incineration facilities; people living far from incineration facilities; governmental experts; non-governmental organization members; office workers in developmental institutes or banks; students who were enrolled in environmental-related classes; and students who were enrolled in business-related classes. Results The results show variations among groups in values, awareness and behavioral preferences. Particular attention should be given to the result that groups with higher connectedness-to-nature values show higher willingness-to-act (WTA) for risk reduction. Result s can be summarized as follows. First, awareness is associated with one's geographical setting. Second, values and WTA behaviors are related to one's environmental-related education and occupation. Third, values are significantly related to WTA behaviors. Conclusions Different cultures, in terms of values or worldview, among groups influence their perceptions of dioxin risk and choices of risk reduction behaviors. It is important to consider values in communicating complicated long-term risk management involving public participation. Further research should be continuously conducted on the effects of multiple dimensions of values on one's WTA for risk reduction behaviors.

• Food Quality and Culture
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• 제3권2호
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• pp.89-93
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• 2009

This study was conducted to investigate the effects of herbs (dill weed, fennel seed and rosemary) on color stability and lipid oxidation of ground pork patties during storage at $2^{\circ}C$ and $-20^{\circ}C$. Lipid oxidation was determined by the thiobarbituric acid reactive substances (TBARS) method. Fennel seed was identified as being the most effective ingredient in terms of meat redness (Hunter a-values) during storage at $2^{\circ}C$ (p<0.05). Patties treated with rosemary had lower Hunter a-values than control, and dill weed was the least beneficial in influencing meat redness, having significantly lower a-values than control patties. During frozen storage at $-20^{\circ}C$, no significant differences in a-values were observed between the control patties and those treated with fennel seed. Patties treated with rosemary had lower a-values than control and patties with dill weed had negative a-values throughout storage. The cooking process increased Hunter L-values and decreased a-values in all patty samples. TBARS values increased during storage. Rosemary displayed excellent antioxidative activity as evidenced by the completely inhibition of TBARS formation of cooked pork patties. Dill weed and fennel seed also exerted an intermediate but significant antioxidant effect during storage (p<0.05).

• Journal of the Korean Data and Information Science Society
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• 제24권1호
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• pp.179-187
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• 2013

Bates and Watts (1981) have discussed the problems of reparameterizing nonlinear models in obtaining accurate linear approximation confidence regions for the parameters. A similar problem exists with computing confidence curves for fitted values or predictions. The statistical behavior of fitted values does not depend on the parameterization. Thus, as long as the intrinsic curvature is small, standard Wald intervals for fitted values are likely to be sufficient. Accuracy of linear approximation for fitted values is investigated using confidence curves.

• 한국임상약학회지
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• 제9권1호
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• pp.19-26
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• 1999

Adequate nutrition is important in maintaining optimal health. Malnutrition can expose individual to increased risks of morbidity and mortality. The purposes of this study were to determine the basal energy expenditure (BEE) of Korean healthy subjects and TPN patients using Bioelectrical Impedance Analysis (BIA) method and to compare these values with those predicted by Harris-Benedict equation (H-B). BEE values measured by BIA were compared with predicted BEE values by the H-B formula in 59 clinically stable TPN patients and 65 healthy volunteers. In healthy volunteers and TPN patients, statistically significant differences were not shown between the BEE values measured by BIA (1392.5 Kcal and 1325.9 Kcal) and those predicted by H-B formula (1384.1 Kcal and 1270.1 Kcal). In male volunteers, statistically significant differences were not shown between BEE values measured by BIA (1670.7 Kcal) and the H-B formula (1550.9 Kcal), but in female volunteers, statistically significant differences were shown between BEE values measured by BIA (1194.8 Kcal) and the H-B formula (1265.6 Kcal). In male TPN patients, statistically significant differences were shown between BEE values measured by BIA (1453.5 Kcal) and the H-B formula (1335.9 Kcal), but in female TPN patients, statistically significant differences were not shown between BEE values measured by BIA (1126.4 Kcal) and the H-B formula (1167.2 Kcal). In normal healthy volunteers, $90.8\%$ of BEE values measured by BIA and in TPN patients $89.8\%$ of BEE values measured by BIA were within $15\%$ of BEE values predicted by the H-B formula in non-obese subjects. In conclusion, BEE values predicted by H-B formula or measured by BIA can be applied to non-obese Koreans. However, these values should be confirmed with Indirect calorimetry for Koreans.

• 한국지역사회생활과학회지
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• 제17권4호
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• pp.39-48
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• 2006

This study was carried out to make a search for the usefulness of marigold plants (Tagetes erecta) as a natural dye. And we have also examined into the dyeability and antifungal activity of silk and cotton fabrics dyed with 2% powdered colorant and 1% liquid colorant. Almost surface colors of silk and cotton fabrics dyed with 2% powdered colorant and that dyed with 1% liquid colorant except for that treated Cu and Fe with mordants were shown by Y-level. $L^*$ values of silk fabrics dyed with 2% powdered colorant were 66.2 to 86.39, those $a^*$ values were -1.97 to 6.09, and those $b^*$ values were 13.69 to 35.97. And $L^*$ values of cotton fabrics dyed with 2% powdered colorant were 78.97 to 89.62, those a values were -3.39 to 0.38, and those $b^*$ values were 5.63 to 15.61 $L^*$ values of silk fabrics dyed with 1% liquid colorant were 34.37 to 85.57, those a values were -7.79 to 12.33, and those $b^*$ values were 15.13 to 82.91, And $L^*$ values of cotton fabrics dyed with 1% liquid colorant were 44.12 to 87.90, those $a^*$ values were -8.37 to 6.18, and those $b^*$ values were 11.65 to 78.87. Colorfastness of silk fabrics against light treated nothing with mordants and that dyed with 1% liquid colorant decreased for a little by second grade, however, that against washing, rubbing, perspiration and dry cleaning were increased over fourth grade. Colorfastness of cotton fabrics in terms of rubbing, light, and dry cleaning, except for washing and perspiration, were shown by over third grade, when that was treated nothing with mordants. Antifungal activities of silk fabrics treated nothing with mordants and dyed with 1% liquid colorant of marigold extracts were shown by 28.9% against Staphylococcus aureus. However, those of Al, Ca, Cu and tartaric acid mordanting were more than 25.5% against Staphylococcus aureus and Klebsiella pneumoniae.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.I
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• pp.85-88
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• 2005

A low-cost and high-speed PDP color inspection system can be constructed by using a CCD camera against a colorimeter. Though the inspection can be done using RGB signals obtained by a camera, it has some difficulty to introduce human color sensitivity. Thus, it is quite desirable to convert the RGB values into the XYZ values that can be compared to the values of a colorimeter. Accordingly, the current study proposes a color conversion method that can analytically calculate the RGB-to-XYZ conversion matrix by utilizing the RGB primaries and the reference white. Experiments on Macbeth colorchecker colors showed that the average color difference between the converted XYZ values of the proposed method and the measured XYZ values of a colorimeter is much below the threshold of distinguishing two adjacent color patches.

• 대한치과보철학회지
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• 제43권5호
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• pp.662-670
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• 2005

Statement of problem: Little is known about the effect of abutment preparation procedure on do-torque values in different implant platform and the relationship of final do-torque values with different implant platform size. Purpose: This study evaluated the effect of abutment preparation procedure on do-torque values in different implant platform and the relationship of final do-torque values with different implant platform size. Material and method: Six ITI implants (2 narrow-neck implants, 2 regular-neck implants, 2 wide-neck implants) and six Branemark implants (2 narrow platforms, 2 regular platforms, 2 wide platforms) were embedded in each acrylic resin block with epoxy resin. Eighteen $synOcta^(R)$ abutments (6 narrow-neck implant-abutments, 6 regular-neck implant-abutments, 6 wide-neck implant-abutments) and eighteen esthetic abutments (6 narrow platform-abutments, 6 regular platform-abutments, 6 wide platform-abutments) were tightened to each implant with digital torque gauge. Initial do-torque values were measured using digital torque gauge. After preparation of abutments, Final do-torque values were measured with digital torque gauge. Results and conclusion: 1. Screws loosening or abutments motion were not detected in all experimental group, but some scratches of implant-abutment joints were detected in all group 2. Reduction ratios of final do-torque values were greater than initial do-torque values in all measured group, except in narrow-neck implant-abutment group (p<0.05). 3. Reduction ratios of final do-torque values in wide-neck implant-abutment group were greater than regular-neck implant-abutment group (p<0.01). 4. The greatest standard deviation value was detected in wide platform group in both implant systems.

• 한국수산과학회지
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• 제49권6호
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• pp.838-844
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• 2016

In this study, epidemiological cut-off values were estimated for 44 Photobacterium damselae isolates, since clinical breakpoints have not been established for this pathogenic bacterium. The susceptibility of the isolates to 10 antibiotics was evaluated using internationally standardized disc diffusion protocols. Normalized resistance interpretation was used to generate statistically valid epidemiological cut-off values for the susceptibility data. There were not enough strains exhibiting full sensitivity to ampicillin and amoxicillin to allow analysis of these antibiotics. Because there were only a marginally sufficient number of strains exhibiting full sensitivity to oxytetracycline, the cut-off value generated provided only a provisional estimate. The valid wild-type cut-off values were <13, 13, 9, 22, 25, 27, and 28 mm for gentamicin, cephalexin, erythromycin, oxolinic acid, flumequine, florfenicol, and sulfamethoxazole/trimethoprim, respectively. The application of these cut-off values should greatly facilitate the rational selection of antibiotics for use in commercial fish farms.

• Bulletin of the Korean Chemical Society
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• 제16권12호
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• pp.1218-1222
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• 1995

The pKa values of benzyltetrahydrothiophenium halides 1a-f in water have been estimated by measuring the absorbances of the solution in aqueous hydroxide ion solution. Assuming that the ratios of the activity coefficients remains close to unity, the absorbance of the solution can be expressed as A/[SH]o=(εSH+εS-K[OH-])/(1+K[OH-]), where A, [SH]o, K, εSH, and εS- are the absorbance of solution, the initial concentration of 1a-f, the equilibrium constant, and the extinction coefficients for SH and S-, respectively. The εS- and K values that best fit with this equation were calculated by a nonlinear regression analysis with a large number of absorbance data determined at different [OH-] and [SH]o. The pKa values of the SH were then calculated with the relationship Ka=-log K+14. The validity of this method has been demonstrated by the excellent agreements between the experimental and literature pKa values of three organic acids. The pKa values of 1a-f estimated by this method are in the range of 12.5-15.3 and correlate well with the Hammett equation. The large negative deviation for the pKa values of 1e and 1f from the Hammett plot has been attributed to the extra hydrogen bonding between the phenyl group and water molecules attracted by the hydrophilic substituents.