• Membrane Journal
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• v.9 no.4
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• pp.230-239
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• 1999

Perchlorate ion-selective electrodes in PVC membranes that respond linearly to concentration 106 M were developed by incorporating the quaternary phosphonium salts as a canier. The effects of the chemical structure, the contents of canier, the kind of plasticizer and the membrane thickness on electrode characteristics such as the electrode slope, the linear respone range and the detection limit were studied. With this results, the detectable pH range, selectivity coefficients and AC impedance characteristics were compared and investigated. The perchlorate ion substituents of the quaternary phosphonium salts like tetraoctylphosphonium perchlorate (TOPP) , tetraphenylphosphonium perchlorate(TPPP), and tetrabutylphosphonium perchlorate(TBPP) as a canier were used. The electrode characteristics were better in the ascending order of TBPP < TPPP < TOPP, with the increase of carbon chain length of the alkyl group. Dioctylsebacate(OOS) was best as a plasticizer, the canier contents were better with 11.76 wt% and the optimum membrane thickness was 0.19 mm. Under the above condition, the electrode slope was 56.58 mV/$^P{ClO}_4$,the linear response range was $10^{-1}$\times$10^{-6}$ M, the detection limit was 9.66 x $10^{-7}$ M. The performance of electrode was better than Orion electrode. The electrode potential was stable within the pH range from 3 to 11. The order of the selectivity coefficients for the perchlorate ion was sol < F < Br < 1. With the result of impedance spectrum, it was found that the equivalent circuit for the electrode could be expressed by a series combination of solution resistance, parallel circuit consisting of the double layer capacitance and bulk resistance and Warburg impedance. And solution resistance was almost not appeared and Warburg impedance was highly appeared by diffusion. Then Warburg coefficient was 1.32$\times$$10^74 $\Omega$ $\cdot$ ${cm}^2/s^{1/2}$.

• Journal of Korean Ophthalmic Optics Society
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• v.20 no.2
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• pp.255-261
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• 2015

Purpose: purchasing status and understanding trends of Functional progressive addtions lenses buyers', Correlation analysis of the Binocular Function value to determine ADD then can be apply sales and prescriptions. Methods: Years 2011 to 2014, 298 patients who were prescribed functional progressive lenses were analysed based on the prescription data and SPSS (Ver. 20.0) was treated using the statistics. Results: Results: The average age of our customers are $27.66{\pm}11.55$ years, average addition power is $+0.73{\pm}0.36D$, customers are using take a prescription of ADD $+0.75{\pm}0.28D$ was the highest 44.33% to 132 people. Near point of convergence of 276 people (92.62%) was mostly less than 10 cm, and near point of accommodation of 134 people (44.97%) was also below 10 cm, within 11~15 cm were 122 people (40.94%). Most of people were within normal range in terms of Near point of convergence and near point of accommodation, near point of accommodation tend to be longer than Near point of convergence. As you can see this result shows most of customers need extra help in their near point of accommodation instead of they are leak at it. FCC (Fused cross cylinder) check Value and ADD (addition power) tests showed that the value of a strong correlation (p=0.00), NPC and NPA were also p=0.001, the correlation of the NPC and ADD is p=0.003, In addition, NPA and ADD also showed a significant correlations (p=0.005). Near Point of Accommodation, negative relative accommodation, and positive relative accommodation are all significantly correlated (p=0.00). The short distance-related variables of the ADD which are NPC, NPA, Age, also appeared to side correlate significantly with each other. Conclusion: Binocular function values of the subjects were highly correlated with each other so precise examination is required. when Age young people are working at short distance, low ADD values was prescribed for solving discomfort. So, in the case of early presbyopia, accommodative insufficiency, or people feel fatigue when they often working at near although their accommodation function is normal, when functional progressive lenses are prescribed, expectation of this should be exactly notified.

• Clinical and Experimental Pediatrics
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• v.53 no.3
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• pp.349-357
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• 2010

Purpose : Transient tachypnea of the newborn (TTN) is usually benign and improves within 72 hours. However, it can also progress to prolonged tachypnea over 72 hours, profound hypoxemia, respiratory failure, and even death. The aim of this study is to find predictable risk factors and describe the clinical courses and outcomes of prolonged TTN (PTTN). Methods : The medical records of 107 newborns, >$35^{+0}$ weeks of gestational age with TTN, who were admitted to the NICU at Seoul Asan Medical Center from January 2001 to September 2007 were reviewed. They were divided into 2 groups based on duration of tachypnea. PTTN was defined as tachypnea ${\geq}72$ hours of age, and simple TTN (STTN) as tachypnea <72 hours of age. We randomly selected 126 healthy-term newborns as controls. We evaluated neonatal and maternal demographic findings, and various clinical factors. Results : Fifty-five infants (51%) with total TTN were PTTN. PTTN infants had grunting, tachypnea >90/min, $FiO_2$ >0.4, and required ventilator care more frequently than STTN infants. PTTN had lower level of serum total protein and albumin than STTN. The independent predictable risk factors for PTTN were grunting, maximal respiration rate >90/min, and $FiO_2$ >0.4 within 6 hours of life. Conclusion : When a newborn has grunting, respiration rate >90/min, and oxygen requirement >0.4 of $FiO_2$ within 6 hours of life, the infant is at high risk of having persistent tachypnea ${\geq}72$ hours. We need further study to find the way to reduce PTTN.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.8 no.1
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• pp.9-17
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• 2010

The LCC (Liquid Cadmium Cathode) structure to be developed for inhibiting the formation and growth of the uranium dendrite has been known as a key part in the electrowinning process for the simultaneous recovering of uranium and TRU (TRans Uranium) elements from spent fuels. A zinc-gallium (Zn-Ga) experimental system which is able to be functional in aqueous condition and normal temperature has been set up to observe the formation and growth phenomena of the metal dendrites on liquid cathode. The growth of the zinc dendrites on the gallium cathode and the performance of the existing stirrer type and pounder type cathode structure were observed. Although the mechanical strength of the dendrites appeared to be weak in the electrolyte and easily crashed by the various cathode structures, it was difficult to effectively submerge the dendrite into the bottom of the liquid cathode. Based on the results of the aqueous phase experiments, a lab-scale electrowinning experimental apparatus which are applicable to the development of LCC srtucture for the electrowinning process was established and the performance tests of the different types of LCC structure were conducted to prohibit the uranium dendrite growth on LCC surface. The experimental results of the stirrer type LCC structures have shown that they could not effectively remove the uranium dendrites growing at the inner side of the LCC crucible and the performances of the paddle and harrow type LCC structure were similar. Therefore a mesh type LCC structure was developed to push down the uranium dendrites to the bottom of the LCC crucible growing on the LCC surface and at the inner side of the crucible. From the experimental results for the performance test of the mesh type LCC structure, the uranium was recovered over 5 wt% in cadmium without the growth of uranium dendrites. After completion of the experiments, solid precipitates of the bottom of the LCC crucible were identified as an intermetallic compound (UCd11) by the chemical analysis.

• The Journal of Korean Society for Radiation Therapy
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• v.16 no.1
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• pp.51-56
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• 2004

The aim of this study is to evaluate the effect of skin dose and PDD by using wounds protecting gauzes or Vaselinespread gauzes. And it was studied that the possibility to substitute custom bolus into gauzes. 4MV photon (CL600C, varian, US), Polystyrene Phantom (30(W) X30(L) X 30(H)) with Markus chamber(PTW, US) were used for dose measurement. This study was distinguished natural gauzes and spread over Vaseline gauzes. We gave variety to the gauze thickness at 5, 10 and 15 sheets respectively. For comparison between using bolus and not that, we had used 1.0 cm thickness bolus so that analyzed surface dose and PDD at the same conditions above mentioned. When maximum point was defined as reference point, surface dose was measured as $35\%$ in open beam. When the gauzes were attached to surface as 5, 10 and 15 sheets, surface dose were increased as 69, 80 and $91\%$ respectively according to thickness of gauzes. When spread over Vaseline gauzes were attached to surface as 5, 10 and 15 sheets, surface dose were increased respectively as 98, 100 and $98\%$ according to thickness of gauzes. Also when 0.5 cm bolus and 5 sheets gauzes were composed, surface dose was measured as $98\%$. The gauzes that were attached to skin surface in radiation therapy had been scattering material and contributed increasing surface dose without variation of percentage depth dose. However, if we want to delivery much dose to skin surface then we have to apply many sheets of gauzes to skin surface. Although we get easy that result by bolus or spread over Vaseline gauzes, we have to revise percentage depth dose at calculation. Therefore, if we find pertinent conditions based on measured data that are considered skin dose and patient setup efficiency, to replace custom bolus with gauzes will be helpful to efficient treatment.

• Microbiology and Biotechnology Letters
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• v.42 no.4
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• pp.361-366
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• 2014

In this study, Glycyrrhiza uralensis and Glycyrrhiza glabra extracts, with their countries of origin as Korea (Jecheon), Uzbekistan and China, were prepared under various extraction conditions. There were 8 extraction conditions which the licorice were subjected to, and all conditions had different extraction solvents, temperatures and times. Antimicrobial activity on skin flora was evaluated comparatively by a disc diffusion assay, broth macrodilution assay, and kill time curve assay. Based on the antimicrobial activity of their extract confirmed by disc diffusion assay, we established optimal extraction conditions. The Korean licorice extract (85% ethanol, $40^{\circ}C$, 12 h) showed the best activity amongst the samples examined. In particular, its antimicrobial activity against Propionibacterium acnes was the highest. Minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) of the licorice extracts revealed that the Korean licorice ($156{\mu}g/ml$ and $1,250{\mu}g/ml$) had better antimicrobial activity than that of the Uzbekistani licorice ($625{\mu}g/ml$ and $2,500{\mu}g/ml$) and the Chinese licorice ($625{\mu}g/ml$ and $5,000{\mu}g/ml$). Taken together, it was shown that Korean licorice extracted in group F (85% ethanol, $40^{\circ}C$, 12 h) had the highest antimicrobial activity amongst the licorices from the other countries of origin. These results also suggest that the optimal extraction conditions are 85% ethanol, $40^{\circ}C$, 12 h, and that licorice has a potential application as a natural preservative in cosmetics products, thereby replacing synthetic preservatives.

• Microbiology and Biotechnology Letters
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• v.42 no.4
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• pp.317-323
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• 2014

Violacein has received much attention due to its various important biological activities, including broad-spectrum antibacterial and antifungal activity, anti-malarial, anti-tumoral, anti-oxidant, and anti-diarrheal activities. EP15224 strain isolated from forest soils in Korea was found to be a new species belonged to the genus Massilia based on its 16S ribosomal DNA sequences. The 16S ribosomal DNA of strain EP15224 displayed 97% homology with Massilia sp. BS-1, the nearest violacein-producing bacterium. Strain EP15224 produced bluish-purple pigment well in a synthetic MM2 medium containing glucose, $(NH_4)_2SO_4$, $Na_2HPO_4{\cdot}7H_2O$, $KH_2PO_4$, $MgSO_4{\cdot}7H_2O$, and 1 mM $\small{L}$-tryptophan. The chemical analysis of the pigment by LC/MS/MS showed that it is violacein with molecular weight of 343.34. This is the second report on the production of violacein by a Massilia species. In this study, the optimal culture conditions for violacein production were established under which 280 mg/l crude violacein was produced : glucose 2 g/l, $(NH_4)_2SO_4$ 1 g/l, $Na_2HPO_4{\cdot}7H_2O$ 2 g/l, $KH_2PO_4$ 1 g/l, $MgSO_4{\cdot}7H_2O$ 0.1 g/l, L-tryptophan 0.24 g/l, 25 ml medium in a 250 ml flask, with an inoculumn size of 10% (v/v), 72 h of cultivation with 250 rpm at $25^{\circ}C$.

• Journal of the Korean Applied Science and Technology
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• v.37 no.3
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• pp.463-472
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• 2020

The purpose of this study is to identify the BMI, diet perception and diet behavior of female university students. A descriptive survey design was used 165 students from October 29 to November 9, 2018. Data were analyzed using mean, t-test, ANOVA, cross analysis with SPSS 21.0. Total diet perception was 3.44 points, highest sub category was 'practice' with 4.00 points, followed by 'information and education' with 3.58 points, 'necessity' with 3.32 points and lowest category was 'self-recognition' with 2.84. 65 students(43.0%) were 'less than three times' in 'Number of diets' and diet methods was 65(43.0%) for 'food control' and 62(41.1%) for 'exercise'. During in a week, 98 students(84.9%) exercised within three hours, followed by 33(21.9%) who did not exercised at all. 22 students(14.6%) said they experienced damage from dieting, while the types included gastrointestinal disease, menstrual irregularity and hair loss. The total score of diet perception according to BMI was lower in the underweight group than in the normal and overweight groups(p<.001). In diet 'practice' category, low weight group scored lower than normal weight and overweight groups(p<.05). In 'information and education' category, overweight group scored the highest, followed by normal and underweight groups(p<.001). In diet 'necessity' and 'self-recognition' categories, low weight group scored lower than normal weight and overweight groups(p<.001). Diet behavior by diet perception was different in number and method of diet(p<.001). Based on the results, it is thought that attention and education are needed to form a proper diet perception and maintain healthy living for female university students.

• Journal of Distribution Science
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• v.10 no.4
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• pp.21-28
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• 2012

While recent economic stagnation has left consumers dispirited, rapid growth has been seen in the domestic coffee industry recently. With the growth in coffee consumption, a tremendous increase in the number of specialty coffee shops has been seen in the domestic coffee market. The expectation that markets specializing in coffee will continue to grow for a long time will cause existing enterprises to expand their shops and increase the rate of entry of new shops. Intense competition in the domestic coffee market will force companies to create a competitive advantage through differentiated marketing strategies. This paper focuses on how the shopping value and repatronage intention of customers using coffee shops is affected by service quality. Moreover, this paper intends to examine the service quality that is critical for the successful management of relationships and the values that are important to consumers. For these purposes, the discriminative effect of service quality on shopping value was analyzed and the effect of utilitarian and hedonic value on repatronage intention was reviewed. The results of this study are detailed below. First, interaction and outcome quality can positively affect the hedonic value, whereas environment quality is not meaningful for utilitarian value. Considering the relative effect on utilitarian value outcome, the effect of outcome quality is greater than that of interaction. This result shows that the role of outcome quality is most important for improving utilitarian value. Second, outcome and environment quality positively affect hedonic value; however, interaction quality does not meaningfully increase hedonic value. These results indicate that customers recognize hedonic value on the basis of their evaluation of the service outcomes and the background to delivery service. In particular, it was revealed that the relative effect of outcome quality on hedonic value is greater than that of environment quality. Third, both utilitarian value and hedonic value had a positive effect on repatronage intention. The relative influence of the hedonic value is that the shopping value affects the repatronage intention more than the utilitarian value. These results mean that customers recognize coffee shops as spaces for satisfying utilitarian and hedonic values, and they place more importance on the benefits of the emotional experience than functional needs. Finally, this study suggests that output quality is more important than other service factors, and the results of this paper give some implications to the coffee shop industry that customers seek utilitarian needs based on economic value and place more weight on hedonic value, such as that offered by relationship media.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.6
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• pp.643-651
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• 2001

Paddlewheel-driven circulation in a culture pond has been simulated based on the depth integrated 2 dimensional hydrodynamic model. Acceleration by paddlewheel is expressed as shaft force divided by water mass discharged by paddlewheel blades. The model has been calibrated and applied to culture ponds as following steps:- i) The model predicted velocities at every 10 m along longitudinal direction from the paddlewheel. The model was calibrated comparing the results with the measured values at mass correction factor $\alpha$ and dimensionless eddy viscosity constant $\gamma$, respectively, in a range $15\~20$ and 6. ii) Wind shear stress was simulated under conditions of direction $0^{\circ}C,\;90^{\circ}C\;and\;180^{\circ}C$ and speed 0.0, 2.5, 5.0 and 7.5 m/s. Change rate of current speed was <$1\%$ at wind in parallel or opposite direction to the paddlewheel-driven jet flow, while $4\%$ at orthogonal angle. iii) The model was then applied to 2 culture ponds located at the Western coast of Korea. The measured and predicted currents for the ponds were compared using the regression analysis. Analysis of flow direction and speed showed correlation coefficients 0.8928 and 0.6782 in pond A, 0.8539 and 0.7071 in pond B, respectively. Hence, the model is concluded to accurately predict circulation driven by paddlewheel such that it can be a useful tool to provide pond management strategy relating to paddlewheel operation and water quality.