• Restorative Dentistry and Endodontics
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• v.19 no.1
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• pp.1-26
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• 1994

The purpose of this study was to investigate the dissolution components during corrosion of amalgams and to identify surface corrosion products in the modified Fusayama artificial saliva. Four type of amalgam alloys were used: low copper lathe cut amalgam alloy (Cavex 68), low copper spherical amalgam alloy (Caulk Spherical Alloy), high copper admixed amalgam alloy (Dispersalloy) and high copper single composition amalgam alloy (Tytin). Each amalgam alloy and Hg were triturated according to the manufacturer's direction by means of mechanical amalgamator (Capmaster, S.S.White), and then the triturated mass was inserted into the cylindrical metal mold which was 10mm in diameter and 2.0mm in height and condensed with compression of 150kg/$cm^2$ using oil pressor. The specimens were removed from the mold and stored at room temperature for 7 days and cleansed with distiled water for 30 minutes in an ultrasonic cleaner. The specimens were immersed in the modified Fusayama artificial saliva for the periods of 1 month, 3 months and 6 months. The amounts of Hg, Cu, Sn and Zn dissolved from each amalgam specimen immersed in the artificial saliva for the periods of 1 month, 3 months and 6 months were measured using Inductivity Coupled Plasma Atomic Emission Spectrometry (ICPQ-1000, Shimadzu, Japan) and amount of Ag dissolved from amalgam specimen was measured using Atomic Absorption Spectrophotometry (Atomic Absorption/Flame emission spectrophotometer M-670, Shimadzu, Japan). A surface corrosion products of specimens were analysed using Electron Spectroscopy Chemical Analyser (ESCA PHI-558, PERKIN ELMER, U.S.A.). The secondary image and back scattered image of corroded surface of specimens was observed under the SEM, and the corroded surface of specimens was analysed with the EDX. The following results were obtained. 1. The dissolution amount of Cu was the most in high copper admixed amalgam(Dispersalloy) and the least in high copper single composition amalgam(Tytin). 2. Sn and Zn were dissolved during all the experiment periods, and dissolution amounts were decreased as the time elapsed. 3. Initial surface corrosion products were ZnO and SnO. 4. Corrosion of ${\gamma}$ and ${\gamma}_2$ phase in low copper amalgams was observed and Ag-Cu eutectic alloy phase was corroded in low copper spherical amalgam(Caulk Sperical Alloy). 5. Corrosion of ${\gamma}$ and $\eta$' phase in high copper amalgams was observed and Ag-Cu eutectic alloy phase was corroded in high copper admixed amalgam(Dispersalloy). 6. Sn-Cl was produced in the subsurface of low copper amalgams and high copper admixed amalgam.

• Asian Journal of Turfgrass Science
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• v.21 no.2
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• pp.147-154
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• 2007

In March of 2004, gray snow mold (Typhula blight) caused by Typhula spp. occurred on perennial ryegrass (Lolium perenne L.) and Kentucky bluegrass (Poo pratensis L.) at MuJu golf courses in Jeonbuk Province. Leaves in the affected areas were matted together and frequently covered with white to grayish mycelia. Sclerotia were formed on the leaf blade, leaf sheath, or crown regions. The fungus isolated from the diseased leaf formed whitish mycelium, clamp connections, and light pink to brown, irregular-shaped small sclerotia of less than 1.4 mm in diameter, which are characteristic to Typhula incarnata. Optimum temperature ranges for mycelial growth were $5^{\circ}C$ to $15^{\circ}C$. The causal organism was confirmed to be T. incarnata as the partial sequence of its ribosomal RNA ITS1 (internal transcribed spacer) region was 91% homologous to those of T. incarnata in GenBank database. Out of the 14 fungicides tested fur antifungal activity in vitro, 10 fungicides including iprodione, tebuconazole, polyoxin D, flutolanil, hexaconazole, tolclofos-methyl, fosetyl-Al, mepronil, pencycuron+tebuconazole, and fenarimol completely inhibited fungal growth at their recommended concentrations. In the field test, these fungicides and others such as thifluzamide and thiram effectively controlled the gray snow mold of turfgrass with some variable degrees of control efficacies.

• Composites Research
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• v.31 no.6
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• pp.421-428
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• 2018

In order to optimize the prepreg compression molding (PCM) process, the forming simulation is required to cope with any problems that may be raised during the process. For the improvement of simulation accuracy, the input data of material property should be measured accurately. However, most studies assume that the compressive properties of the prepreg are identical to the tensile properties without quantifying them separately. Therefore, in this study, the in - plane compressive properties of the prepreg are presented to improve the accuracy of the forming simulation. As a result, the compressive modulus of the fibers was measured to be about $10^{-2}$ times lower than the tensile modulus. Also we designed a square-cup mold with a tilting angle of $110^{\circ}$ to simulate the prepreg formability during the high temperature compression mold process. Shear angles were measured at each corner, which were compared with the simulation results. It was observed that the simulation results using the accurate compressive properties of the prepreg showed a similar trend with the experimental results. It was confirmed that the measured data of the in-plane compression property improved the accuracy of the forming simulation results.

• Korean Journal of Medicinal Crop Science
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• v.22 no.3
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• pp.210-216
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• 2014

The average and maximum temperature were $29.5^{\circ}C$ and $33.2^{\circ}C$ at 2:00 p.m. respectively, in the plastic-film house covered with shade net, and both of temperature were lower $0.6^{\circ}C$ and $1.3^{\circ}C$ than those of conventional shade. Light transmittance was 14% in the plastic-film house, while 9.9% in conventional shade during growing season from May to October. Withering time of aboveground part was on October 3rd in conventional shade with 60% of withering leaf, while it was on November 10th with 3.7% of withering leaf in the plastic-film house, about 40 days longer survival. The main disease incidence were 15% of anthracnose, 17% of leaf spot, 5% of phytophthora blight and 3% of gray mold in the conventional shade, while 0 ~ 0.1% disease incidence and 95% of emergence rate in the plastic-film house. The growth in the aboveground and underground part of ginseng was totally better, particularly characteristics affecting yield such as root length, main root length and diameter in the plastic-film house. The fresh weight was increased by 128% compared to the conventional shade and harvested roots per $3.3m^2$ were 36 roots in the conventional shade and 58 roots in the plastic-film house and futhermore yield per $3.3m^2$ was increased by 216% compared to the conventional shade. As covering materials, the rice straw in the plastic-film house was excellent. The ginsenoside contents affecting the quality of ginseng were higher in the plastic-film house indicating 0.333% of Rg1, 0.672% of Rb1, 0.730% of Rc and rate of red rusty root was less than 4.0 ~ 6.1%. Above the results, the quality of ginseng grown in the plastic-film house covered with shade net was improved than that of the conventional shade.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.11
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• pp.5247-5253
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• 2012

The purpose of this study was to apply in the HACCP(Hazard Analysis Critical control) system of liquefied coffee and sikhe. The establishment of Critical limit during sterilization processing was measured by sterilization temperature and sterilization time for 30 days from April 1~30, 2012, and it was conducted at P company in Jincheon (Chungcheongbuk-do), korea. As a result, microbial(coliform, bacillus cereus, Clostridium perfringens and yeast & mold) of sikhe and liquefied coffee were detected before sterilization. In contrat, all microbial was not detected to Sikhe(238mL Can, 500mL and 300mL PP, 1.8L PP) after sterilization ($15{\pm}1$, $35{\pm}1$ and $45{\pm}1$ mins at $121{\pm}1^{\circ}C$, respectively) and Liquefied coffee was not detected after sterilization($121{\pm}1^{\circ}C$, $20{\pm}1$ mins). The sterilizer condition for deciding the most temperature and time were $121{\pm}1^{\circ}C$, $20{\pm}1$ mins. In conclusion, the sterilization process would be a great alternative to prevention, decreasing and removing of harmful microorganism, such as general bacteria, coliform and pathogenic bacteria etc. Therefore, the critical limit of sterilization temperature and time for quality control and biosafety was established at $121{\pm}1^{\circ}C$, $20{\pm}1$ mins. And it suggests that HACCP plan is necessary for monitoring method, monitoring cycle, solving method, education, training and record management during sterilization processing.

• Composites Research
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• v.27 no.4
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• pp.146-151
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• 2014

In this study, the experimental study has been performed by varying the polarization of the electric field and impact force to check the piezoelectric characteristics of piezoelectric paint sensor. Piezoelectric paint sensor used in this study is composed of epoxy resin with a hardener and PNN-PZT powder in 1:1 weight ratio. The dimensions of the paint sensor specimen are $40{\times}40{\times}1mm^3$ and regular specimens were made using a mold. The voids are removed from the specimen in the vacuum desiccator. Both upper side and bottom side of the paint sensor were coated with silver paste for making an electrode and then dried at room temperature for a day. The poling treatment has been carried out under controlled conditions of the electric field in order to check the effect of piezoelectric sensitivities, while the poling temperature was fixed at room temperature and the poling time was set to 30 min. The piezoelectric sensitivities have been measured by comparing output voltage from paint sensor with output force from impact hammer when the impact hammer hits the paint sensor. In result, the effect of the electric field has been evaluated for the sensitivity and describe the result.

• Science of Emotion and Sensibility
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• v.13 no.2
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• pp.309-316
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• 2010

This paper proposes healthcare bathing system for improving the multisensory function and not washing. We designed various types of bathtub for developing bathing system. This system consists of whirlpool bathtub for multisensory stimulation, a cover of bathtub with visual-auditory stimulation function, a small size PC for main control, touch panel, digital multimedia broadcasting (DMB), color-changeable LED mood lighting system for improving visual sensibility and speaker. We investigate the effects on autonomic nervous system during bathing with healthcare bathing system for improving the multisensory functions. To analysis physiological parameter, body temperature, blood pressure, intraocular pressure and heart rate variability (HRV) were measured before, during and after bath using healthcare bathing system. Experiments were performed on partial immersion bath and the water temperature was kept $39{\pm}0.5^{\circ}C$. The body temperature and the heart rate variability of the subject were measured every 5 minutes before, during, and after the bath. In analysis of HRV, the parasympathetic nerve increased from starting bath and decreased after 15 minutes. So the subjects felt comfortable at 15 minutes after starting bath. Blood pressure decreased to 16mmHg maximumly however pulse increased. Bath using healthcare bathing system for improving the multisensory functions affects positively the circulation of the blood. From this results, it leaves something to be desired in evaluation of serviceability and physiological analysis using the healthcare bathing system, however, we expect to analyze more clearly the relationship between the serviceability of product, physiological change and sensibility by various physiological parameters.

• Applied Biological Chemistry
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• v.38 no.1
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• pp.83-89
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• 1995

Changes in physical, chemical and microbiological characteristics of rice-doenjang prepared with two different methods with or without soak treatment were investigated during 60 days of aging at $32^{\circ}C$ and $15^{\circ}C$. The pH of soak-treated rice-doenjang decreased slowly, but that of nonsoak-treated rice-doenjang decreased rapidly at the initial aging stage with the aging temperature of $32^{\circ}C$, resulting in pH 5.1 after the 60 days of aging time. Reducing sugar contents increased up to the $30{\sim}50$ days of aging time and decreased thereafter. The contents of soluble nitrogen, formol nitrogen, ammoniacal nitrogen and amino nitrogen were more affected by preparation methods than by aging temperatures. Color values depended not only on preparation methods but also on aging temperatures. There were no significant differences in the bacterial counts of rice-doenjang, while apparent differences in the yeast and mold counts by aging temperatures were observed. These results suggested that the properties of soak-treated rice-doenjang were less changed than those of nonsoak-treated rice-doenjang by aging time and temperature. And, with a view point of nitrogen compounds, aging time could be reduced by soak treatment.

• Journal of Conservation Science
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• v.29 no.4
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• pp.333-343
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• 2013

The exhibition hall of museum has been damaged by abundant dust and mold of the air in the room. Occurrence of microorganisms on the surface of the cultural heritage will cause damages such as coloration, materials degradation, deterioration, etc. In this study, we investigated the temperature/humidity and microbes distribution in exhibition hall, display showcase, and on surface of wall paintings in the Muwisa museum. From some samples collected in exhibition hall and display showcase, we identified so many varieties of micro-organisms such as Aspergillus sp., Penicillium sp., Cladosporium sp.. In particular, we could see a large number of microorganisms in the number 1, 2 exhibition hall compared with the number 3 exhibition hall. The results examining the distribution of the temperature and humidity were showed as $28{\pm}4^{\circ}C$ and 70~80%, respectively. The number 1 exhibition showcase was higher humidity environment than the number 2, 3 exhibition hall compared to the distribution ratio, which considered as correlation with the distribution of microorganism concentration. As these results, we understood that high temperature and humidity in the exhibition hall and display showcase of the Muwisa museum were characteristics caused by environmental management and hermetically-sealed rooms.

• Applied Microscopy
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• v.42 no.1
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• pp.43-48
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• 2012

This study shows that ceresin wax, candellila wax and microcrystalline wax mixed together with liquid paraffin oil to produce lipsticks (LS-1, LS-2) and capric/caprylic triglyceride oil added to produce lipsticks (LS-3, LS-4). After each type of lipsticks were molded, LS-1 and LS-3 was put into a cooling chamber ($5^{\circ}C$). LS-2 and LS-4 was put into a cooling chamber ($5^{\circ}C$) for 18 hours and kept in an incubator ($45^{\circ}C$) for 5 hours and put again into a cool chamber ($5^{\circ}C$). After that, the wax's three dimensional network structure was observed under scanning electron microscopy. Regardless of the kind of oil, the LS-1 and LS-3 wax structure had more distinct shape than the lipstick wax structure of LS-2 and LS-4. Also, regardless of the kind of wax, the three dimensional network structure was modified as the storage temperature increased. As a result, the lipstick's molding temperature increased, the wax's structure size also increased and the shape irregularly modified. This modification causes sweating phenomenon which affected lipstick's surface rheological property.