• Journal of the Korean Chemical Society
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• v.37 no.11
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• pp.923-928
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• 1993

The series of solid solutions in the $Sr_{1+x}Ho_{1-x}FeO_{4-y}$ (x = 0.00, 0.25, 0.50, 0.75 and 1.00) systems with $K_2NiF_4$ type structure have been prepared at 1550$^{\circ}$C under an atmospheric air pressure. The X-ray powder diffraction spectra of these samples assign that the crystallographic phases are tetragonal system over the whole x range. The lattice volume was increased with increasing the substitution amount of the $Sr^{2+}$ ion. The mole ratio of the $Fe^{4+}$ ion to total iron ions or ${\tau}$ value has been determined by Mohr salt titration of the sample and then the y value was calculated from x and ${\tau}$ values. The ${\tau}$ and y values have been increased with x values. The nonstoichiometric chemical formula are formulated from the general formula of $Sr_{1+x}Ho_{1-x}Fe^3_{1-}\;^+_{\tau}Fe_{\tau}^{4+}O_{4-y}$ replaced by x,${\tau}$ and y values. Mossbauer spectra show the mixed valence state and coordination state of $Fe^{3+}\;and\;Fe^{4+}$ ions. It is found out that the magnetic property of the samples is paramagnetic at room temperature. Electrical conductivity varied within the semiconductivity range of 1.0 to 1 ${\times}\;10^{-9}{\Omega}^{-1}cm^{-1}$. Activation energy of the electrical conductivity was decreased with the $\tau$ value. The conduction mechanism should be explained by the hopping model of the conduction electrons between the valence states of $Fe^{3+}\;and\;Fe^{4+}$ ions.

• Journal of dental hygiene science
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• v.15 no.4
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• pp.509-517
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• 2015

This study attempted to identify the entrance exam stress levels in high school students and analyze the relationship this entrance exam stress and perceived oral health status. Self-administered survey was conducted in total 304 students attending in academic high schools in Bucheon. For analysis, SPSS was used to perform t-test and one-way ANOVA. As a result of the study, the entrance exam stress level of academic high school students was 2.71. The level of sub-factors were that tension for exam/poor result was highest by 3.08 and the next were future uncertainty (2.81), parents pressure (2.56), and insufficient free time (2.52). The group with high entrance exam stress showed significantly high perceived degrees of temporomandibular disorder, oral mucosal disease and xerostama. Among sub-factors of stress, the group with high tension for exam/poor result stress had significantly high perceived degrees of dental caries, teporomandibular disorder, oral mucosal disease and xerostama. Because perception on oral health issues increased with high entrance exam stress in high school students, it is necessary to seek some ways to decrease oral health problems even though entrance exam stress is intensified. To do so, it is inferred that it will be very important to promote oral health education to develop ability of high school students to practice correct oral management method.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.249-249
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• 2017

This study was carried out to compare the antioxidant components and antioxidant activity of brown rice according to addition rate (0, 10, 20, 30, 50, and 100%) and cooker. Brown rice was cooked using general and high pressure cookers with and without fermented alcohol. Pasting characteristics with addition rate of brown rice decreased with increasing amounts of brown rice. Total polyphenol and flavonoid contents increased with increasing amounts of brown rice. DPPH and ABTS radical scavenging activities increased with increasing amounts of brown rice. Moreover, brown rice cooked by the general cooking method with fermented alcohol showed higher antioxidant effects compared to other cooking methods. In this study, antioxidant components and antioxidant activity of cooking brown rice with addition rate and cooking method can be used as basic data on processed manufactured products.

• Korean Journal of Food Science and Technology
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• v.49 no.3
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• pp.311-317
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• 2017

In this study, the phenolic content and antioxidant activity of rice cooked using different methods with different amounts of germinated brown rice (10, 20, 30, and 50%) were compared. Germinated brown rice was cooked using general and high-pressure cooking methods with and without fermented alcohol. Pasting characteristics decreased, and total polyphenol and flavonoid contents, and DPPH and ABTS radical scavenging activities increased with increasing amounts of germinated brown rice. Moreover, germinated brown rice cooked by general cooking method with fermented alcohol showed higher antioxidant activity than that showed by rice cooked by other cooking methods. The results obtained in this study are expected to serve as basic data for manufacturing of processed products.

• Applied Chemistry for Engineering
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• v.10 no.4
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• pp.523-530
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• 1999

Acrylic pressure-sensitive adhesive has been made utilizing organic solvents, but nowadays it is made by solvent-free system due to environmental problems. In this study, emulsion polymerization were carried out at $40^{\circ}C$ with methacrylic acid(MAA), n-butyl acrylate(n-BA) and 2-ethylhexyl acrylate(2-EHA) as monomers in the presence of anionic(sodium dodecyl sulfate, SDS) and nonionic(ethylene oxide types) surfactant mixtures. The overall conversion of the polymerization reaction in a mixed surfactant system was found to be higher than that in a single surfactant system. Emulsion stability in mixed or anionic surfactant systems was found to be over 12 week, which was better than that in nonionic surfactant system. Emulsion particle size decreased as surfactant content increased. The Tg and molecular weight of emulsion polymer were inependent of the type, the amount and the mixing ratio of surfactant. Based on the results of stability and peel strength, the optimum nonionic surfactant ratio in total 4 g of surfactant mixture systems is found to be 40~60% by weight where the nonionic surfactant has 50 ethylene oxide groups and 16~18 carbon atoms in hydrophobic alkyl chain.

• Research in Plant Disease
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• v.16 no.1
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• pp.66-73
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• 2010

Field trials were conducted in Suwon, Andong, Bongwha and Taean to evaluate an anthracnose forecaster in the integrated pest management system (IPM) including anthracnose, Phytophthora blight and tobacco budworm for hot pepper in 2008-2009. Percentage of diseased fruits by pepper anthracnose and yield were compared among three treatments, no-fungicide, forecaster and conventional. The incidence and yield of the forecaster at Bongwha on two varieties were 3.1-3.5% and 30-33 kg/40 plants. These were little less than those of the conventional's 0.3-0.8% and 35-36 kg/40 plants and much higher than those of the no-fungicide's 23-27% and 18-24 kg/40 plants. The number of spray at the forecaster was 5 times, whereas those at the conventional was 11-19 times depending on the farmers. In addition, the results of an anthracnose forecaster at the other three field trials allowed in protecting hot pepper from anthracnose while reducing the amount of pesticides used and the total cost of the pathogen control. However, it is needed to improve for anthracnose forecaster when anthracnose pressure was high such as Taean where 60-80% of the incidence. Because the control values of the forecaster at Taean were between those of no-pesticide and conventional treatment at best. If anthracnose is severe early in the season, additional preventive control should be considered when the fruits were fully grown yet.

• Archives of Plastic Surgery
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• v.39 no.5
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• pp.540-545
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• 2012

Background Patients have anxiety and fear of complications due to general anesthesia. Through new instruments and local anesthetic drugs, a variety of anesthetic methods have been introduced. These methods keep hospital costs down and save time for patients. In particular, the target-controlled infusion (TCI) system maintains a relatively accurate level of plasma concentration, so the depth of anesthesia can be adjusted more easily. We conducted this study to examine whether intravenous anesthesia using the TCI system with propofol and remifentanil would be an effective method of anesthesia in breast augmentation. Methods This study recruited 100 patients who underwent breast augmentation surgery from February to August 2011. Intravenous anesthesia was performed with 10 mg/mL propofol and 50 ${\mu}g/mL$ remifentanil simultaneously administered using two separate modules of a continuous computer-assisted TCI system. The average target concentration was set at 2 ${\mu}g/mL$ and 2 ng/mL for propofol and remifentanil, respectively, and titrated against clinical effect and vital signs. Oxygen saturation, electrocardiography, and respiratory status were continuously measured during surgery. Blood pressure was measured at 5-minute intervals. Information collected includes total duration of surgery, dose of drugs administered during surgery, memory about surgery, and side effects. Results Intraoperatively, there was transient hypotension in two cases and hypoxia in three cases. However, there were no serious complications due to anesthesia such as respiratory difficulty, deep vein thrombosis, or malignant hypertension, for which an endotracheal intubation or reversal agent would have been needed. All the patients were discharged on the day of surgery and able to ambulate normally. Conclusions Our results indicate that anesthetic methods, where the TCI of propofol and remifentanil is used, might replace general anesthesia with endotracheal intubation in breast augmentation surgery.

• Tunnel and Underground Space
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• v.27 no.1
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• pp.12-25
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• 2017

In local underground mines heavily depending on the natural ventilation, ducted fan auxiliary ventilation system is strongly recommended instead of the total mine ventilation system requiring large capital and operating costs. Optimizing the installation of ducted fans in series in long large-opening mines is required to assure the economy and efficiency of the ventilation system. The two most critical design parameters for optimization are the wall separation distance and gap length between adjoining ducts. This study aims at deriving the optimal values for those two parameters concerning the economic and environmental aspects through the extensive CFD analysis, which minimizes pressure loss, leakage and entrainment of the contaminated air in the gap space. The ranges of the wall separation distance and gap length for study are selected by taking into consideration the existing recommendations and guidelines. The ultimate goal is to optimize the auxiliary ventilation system using ducted fans in series to provide a reliable and efficient solution to maintain clean and safe workplace environment in local long underground mines.

• Journal of Trauma and Injury
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• v.30 no.4
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• pp.113-119
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• 2017

Purpose: Despite the numerous protocols and evidence-based guidelines that have been published, application of the therapeutics to eligible patients is limited in clinical settings. Therefore, a rounding checklist was developed to reduce errors of omission and the implementation results were evaluated. Methods: A checklist consisting of 12 components (feeding, analgesia, sedation, thromboembolic prophylaxis, head elevation, stress ulcer prevention, glucose control, pressure sore prevention, removal of catheter, endotracheal tube and respiration, delirium monitoring, and infection control) was recorded by assigned nurses and then scored by the staff for traumatized, critically ill patients who were admitted in the trauma intensive care unit (ICU) of Dankook University Hospital for more than 2 days. A total of 170 patients (950 sheets) between April and October 2016 were divided into 3 periods (period 1, April to June; period 2, July to August; and period 3, September to October) for the analysis. Questionnaires regarding the satisfaction of the nurses were conducted twice during this implementation period. Results: Record omission rates decreased across periods 1, 2, and 3 (19.9%, 12.7%, and 4.2%, respectively). The overall clinical application rate of the checklist increased from 90.1% in period 1 to 93.8% in period 3. Among 776 (81.7%) scored sheets, the rates of full compliance were 30.2%, 46.2%, and 45.1% for periods 1, 2, and 3, respectively. The overall mean score of the questionnaire regarding satisfaction also increased from 61.7 to 67.6 points out of 100 points from period 1 to 3. Conclusions: An ICU rounding checklist could be an effective tool for minimizing the omission of preventative measures and evidence-based therapy for traumatized, critically-ill patients without overburdening nurses. The clinical outcomes of the ICU checklist will be evaluated and reported at an early date.

• Korean Journal of Soil Science and Fertilizer
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• v.16 no.4
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• pp.343-346
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• 1983

This paper was prepared to characterize a physico-chemical and mineralogical examination on blast furnace slag as a source of silicate fertilizer, which was quenched with high pressure water stream in process of iron refinery at Pohang Iron and Steel Manufacturing Inc. Quenched slag was more coarse in particle size compared to present commercial silicate fertilizer milled from air-cooled slag and mostly generated in size of 1 to 2 mm. The total chemical composition of quenched and air-cooled slags was same but mineralogical composition was quite different. The former was composed of amorphous materials resulting in more soluble silica content, however, the latter contained dominantly crystalline minerals such as akermanite, gehlenite and wollastonite which meant less soluble ones. Latent cementing property and angular surface of gain of the slag made it difficult to apply the slag directly, however, it could be used as a source of silicate fertilizer and soil ammendment.