• Restorative Dentistry and Endodontics
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• v.24 no.1
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• pp.240-250
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• 1999

The purpose of this study was to evaluate the effect of different etching time on the shear bond strength and adaptibility of composite to enamel and dentin when used one-bottle adhesive Prime & Bond$^{TM}$ 2.0. The proximal and occlusal surfaces of 88 extracted human molars were ground to expose enamel(n=44) and dentin (=44) using diamond wheel saw. Teeth were randomly assigned to four test groups(n=11) and received the following treatments : Control group were conditioned with 36% phosphoric acid for 20 sec. according to the manufacturer's directions. Experimental 10 sec. group, 30 sec. group and 60 sec. group were conditioned with 36% phosphoric acid for 10 sec., 30 sec. and 60 sec., respectively. Teeth were rinsed and dried for 2 sec. Prime & Bond$^{TM}$ 2.0 were applied according to the manufacturer's directions and Spectrum$^{TM}$ TPH composite resins were bonded to enamel and dentin surfaces. All specimens were stored in distilled water for 24 hours. Eighty specimens were sheared in a Universal Testing Machine with a crosshead speed of 5mm/minute. One way ANOVA and LSD test were used for statistical analysis of the data. Failure modes of all specimens after shear bond strength test were examined and listed. Also, representive postfracture modes and eight specimens were examined under scanning electron microscope. The results of this study were as follows: 1. The shear bond strength to enamel was the highest value in 30 sec. group (20.68${\pm}$8.54MPa) and the lowest value in 10 sec. group (14.92${\pm}$6.07MPa), so there was significant difference of shear bond strength between two groups (p<0.05). But there was no significant difference among other groups (p>0.05). With longer etching time to enamel from 10 sec. to 30 sec., higher the shear bond strength was obtained, but the shear bond strength was decreased at 60 sec. etching time. 2. The shear bond strength to dentin was the highest value in control group (13.08${\pm}$6.25MPa) and the lowest value in 60 sec. group (9.47${\pm}$3.35MPa), but there was no significant difference among the all groups (p>0.05). The eching time over 20 sec. decreased the shear bond strength to dentin. 3. In SEM observation, the enamel and resin interfaces were showed close adaptation with no relation to etching time of enamel. And the dentin and resin interfaces were showed close adaptation at 20 sec. and 30 sec. etching time, but showed some gaps at 10 sec. and 60 sec. etching time. Accordingly, these results indicated that a appropriate etching time in Prime & Bond$^{TM}$ 2.0 was required to be 30 sec. in enamel and 20 sec. in dentin for the high shear bond strength and good adaptation between the composite resin and tooth substance.

• The Journal of Engineering Geology
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• v.18 no.3
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• pp.331-338
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• 2008

A new ground water sampler was developed and evaluated for target depth sampling under most rigorous field conditions. This new concept sampler comprises an air-cylinder, a hypodermic needle and a sampling bottle. Pressurized air or nitrogen gas can be used as a mechanical power source to operate the sampler. The air-cylinder is used to jab the hypodermic needle into the rubber cap of the sampling bottle. The hypodermic needle functions as a pathway to inject groundwater into the sampling bottle. Field test was conducted in a seawater intrusion monitoring well located at Handong district of Jeju Island. Water qualities in this well are periodically changed from the effects of sea water. Water sampling fir the same target depth in this well were tried at various times, and variations in electrical conductivity and pressure at the inside and outside of the sampler were measured using CTD divers. We found that the device could collect water samples only when it was actuated, and the pattern and range of variations in electrical conductivities and pressures measured at the inside and outside of the sampler were nearly identical. These results indicate that water samples using the sampler presented in this study represent correctly water qualities in which the samplings were made at a specific target depth in a well.

• Journal of Conservation Science
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• v.38 no.2
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• pp.144-153
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• 2022

This study conducted scientific analysis and preservation treatment for the local 7 relics (depurator bottle, eagle patten button, rank insignia, mess tin, M1 Grand-gun cleaning tool kit, Carbine bullet, cartridge) of the fallen of Korean War excavated through the MND Agency for KIA Recovery & Identification that are possessed in the exhibition hall of the Ground Operations Command. FT-IR analysis results show that remainder of depurator bottle is assumed to play a role of water and food purifier during the war for its spectrum similar to Trisodium phosphate, and inscription carved on the cartridge that is hard to observe with naked eyes was also confirmed through 3D digital shooting method. This study also established directivity of preservation treatment of relics for stable treatment by carrying out a survey of conditions based on the microscope and visual observation. The result is expected to be used as basic data for establishment of future directivity of preservation treatment for a variety of war relics.

• The Plant Pathology Journal
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• v.15 no.1
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• pp.72-75
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• 1999

A scab disease occurred on watermelon seedlings by the infection of Cladosporium cucumberinum. This is the first report demonstrating the scab disease on watermelon in Korea. The casual agent attacked all plant parts of the seedlings on the ground. Infection sites were initiated with sunken and dark green spots, and then suddenly developed to large lesions softened with gummy substances. When hypocotyl and leaf stalk of seedlings were infected and softened, upper parts of seedlings were brokin down, dried and eventually died. Conidiophores of the fungus were characterized by pale olivaceous brown color, and variable length of about 3-5 mm in width. Conidia were formed I long branched chains, and conidium was ellipsoidal, fusiform or subspherical single cell mostly without septum. Morphological characteristics of the fungus were almost identical to Cladosporium cucumerinum Ellis & Authur. The fungus was also pathogenic to cucumber, squash and oriental melon, suggesting that it is a common pathogen to cucurbits. However, the fungus was not pathogenic to bottle gourd.

• Tuberculosis and Respiratory Diseases
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• v.77 no.3
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• pp.132-135
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• 2014

Rhinovirus infection is typically associated with the common cold and has rarely been reported as a cause of severe pneumonia in immunocompetent adults. A 55-year-old previous healthy woman, who consumed half a bottle of alcohol daily, presented with respiratory failure after one week of upper respiratory infection symptoms. Radiography revealed bilateral, diffuse ground glass opacity with patchy consolidation in the whole lung field; bronchoalveolar lavage fluid analysis indicated that rhinovirus was the causative organism. After five days of conservative support, the symptoms and radiographic findings began to improve. We report this rare case of rhinovirus pneumonia in an otherwise healthy host along with a review of references.

• Journal of the East Asian Society of Dietary Life
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• v.3 no.2
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• pp.1-13
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• 1993

This paper has examined and analyzed the ways of making Jang(Korean soybean sauce), vinegar and liquor in terms of food processes, which are mentioned in sooljip 5 and 6 Food collections of 'Kosa-sibi Jip', an encyclopaedia written in Chinese and published in 1789-the eleventh year of King Jung-jo of Chosun Dynasty. There respestively six items of nine items of and thirty three items of the recipe for making jang, vinegar and liquor, Soybean was a major material for making jang. And wheat flour and ground barley were added. Myun-jang was made from only flour. Dong-kook Jojang Bup(oriental soybean sauce preparation) which is the traditional Korean process for making jang from only soybean is recorded in this book. The cereals used in the nine items of the vinegar making recipe were rice(six times), wheat(twice), barley(three times) and wheat flour(once). And fruits are also used. Rice was most used of all these materials. The cereals used in the thirty three items of the liquor-making recipe were regular rice(50%), sticky rice(42.6%) and wheat flour(7.4%) In particular sticky rice was much used for Yakyee Rhue and Bok-sik Rhue for medications. The ways of processing cereals for liquor-making were Jee-ae-bop : steamed rice(52.9%), Jook:thick gruel with cereal (32.3%), Goo-mung Tuck: doughnut-shaped rice cake(8.8%) and Hin-moo-ree Tuck: shawith peless rice cake(2.9%). The three unique processes are as follows. First, in winter when the process of liquor-making did not go on because the jar was cold, the bottle with hot water in was put in the jar and so the aduquate temperature for liquor-making was maintained. Next, in warming up a small double boiler, they prevented effervescence by hanging down thread. Finally. in warming up in a double boiler, they sealed the mouth-piece of the jar and put a handful of wet rice when the rice was completely cooked, it was thought of as the sign that the process of liquor-making was done.

• Journal of the korean academy of Pediatric Dentistry
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• v.37 no.4
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• pp.422-428
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• 2010

Giomer is fluoride-releasing, resin-based dental materials that comprise PRG(pre-reacted glass ionomer) filler. The purpose of this study was to evaluate the shear bond strength of Giomer using self-etching primer systems to bovine dentin. Bovine incisors were mounted in self-curing orthodontic resin and the facial surfaces were wet ground on SIC paper to expose the dentin. Total 100 samples were made and divided randomly into 4 groups, Giomer group(I), Composite resin group(II) and Compomer group(III), Giomer and single bottle adhesive group(IV). The shear bond strengths of 25 samples per each group were measured using universal testing machine. And data were analyzed statistically with One-way ANOVA and Scheffe test. Giomer group(I) showed the significantly higher bond strength than Compomer group(III)(p<0.05). There was no significant difference between Giomer group(I) and Composite resin group(II)(p>0.05). And there is no significant difference between gourp(I) and group(IV). Based on the results of present study, the use of Giomer as an esthetic restorative material for primary teeth might be justified. It is considered that more study about the fluoride releasing ability is needed to evaluate the anticariogenic effect of giomer.

• Journal of the Korea Concrete Institute
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• v.20 no.5
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• pp.619-626
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• 2008

There have been numerous studies to develop eco-friendly concrete. The attempt to reduce the amount of cement usage is suggested as one of the solutions for eco-friendly concrete. To reduce the amount of cement usage, the pozzolan-reaction materials such as ground granulated blast furnace slag, fly ash, and meta kaolin are widely used as the mineral admixture. Hwangtoh which deposited broadly in Korea is a well known eco-friendly material and the activated Hwangtoh with pozzolan-reaction can be practically used as a mineral admixture of concrete. Meanwhile, PET fiber made of recycled PET bottle is a type of recycled material, which can be used to control micro cracks in concrete. But the study about concrete mixed with recycled PET fiber is insufficient and the research of Hwangtoh concrete mixed with PET fiber is urgently needed presently. In this study, experiment and analysis flexural behavior of Hwangtoh concrete blended with recycled PET fiber are carried out. The results are discussed in detail.

• Korean Parent-Child Health Journal
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• v.6 no.1
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• pp.70-81
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• 2003

The otitis media has the highest rate of occurrence in 6-36 month after birth, and relatively high rate of occurrence to six years old. It is one of major cause for hearing loss problem because of its high rate of recurrence. The researcher observed at bed that feeding posture and feeding habit at night have some relationship with occurrence of otitis media. I found that medical research in this area was very weak, and it caused her to concentrate her research on the topic. This paper was undertook a retrospective case-control study to find out the relationship between the mode of feeding and the occurrence of otitis media among the otitis media patients and the healthy persons. As the controling groups, the researcher chose fifty eight mothers whose children received the treatment of otitis media(6-36 months after birth) from the pediatrics clinic of two general hospitals in Seoul, as the patient group, and forty five mothers who consulted with their child to well baby clinic at the general hospital and kindergarten in Seoul as the control group. The results of the survey can be summarized as followed : 1. "Otitis media patient group may have more lying posture mothers while feeding than the healthy control group". The first hypothesis is supported by the fact that the children who have lying posture feeding habit mothers are more easily exposed to otitis media than those who have sitting posture feeding habit mothers as the analysis show : $X^2=8.142$, p = .017 2. "Otitis media patient group may have higher rate of sleeping habit with milk bottle on the month at night than the healthy control group does". The second hypothesis was supported by the fact that the patients group has higher rate of expected sleeping habit than the healthy group dose as the analysis show : $X^2=4.35$, p = .037 3. "Otitis media can be found more in the artificial feeding group than in the healthy children group". The hypothesis is rejected by the analysis, $X^2=1.550$, p = .416. Though the hypothesis is not supported by this research, we need to encourage mothers to feed mother's breast milk on the ground that healthy group has mother's milk feeding tendency, and the best food for infants is their mother's milk, and psychological-sociological effects of breast feeding os quite good for children. It will improve the health of infants. It can be summarized as follows : Otitis media is more concerned with posture of feeding and night feeding habits than feeding modes. On the basis of this survey, feeding education problem for mothers of infants need to be developed. In the education, sitting-embracing posture of feeding, mother's breast feeding, and prohibition of children's lying posture feeding at night need to be emphasized.

• Journal of Environmental Health Sciences
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• v.39 no.1
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• pp.56-70
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• 2013

Objectives: This paper aims to investigate the seasonal deposition characteristics of water-soluble ion species by comparing the deposition amount of two samples taken according to different sampling methods of deposition for ambient aerosol such as gases and particulate matters. Methods: Deposition samples were collected using two deposition gauges in the downtown area of Iksan City over approximately two weeks of each season in 2004. The type of deposition gauges consisted of two different sampling methods known as dry gauge and a wet gauge. The dry gauge was empty and used a dry PE bottle with an inlet diameter of 9.6 cm. Before the beginning of each deposition sampling, a volume of 30-50 ml distilled ionized water was added to the wet gauge to wet the bottom during the sampling period. Deposition samples were measured twice per day and analyzed for inorganic water-soluble ion species using ion chromatography. Results: The daily deposition amounts of all measured ions in the dry gauge and the wet gauge showed a significant increase when precipitation occurred, having no difference of deposition amount between in the wet gauge and in the dry gauge. By excluding two samples from rainy days during the sampling period, the mean daily deposition of all ions in dry gauge and wet gauge were $6.58mg/m^2/day$ and $18.16mg/m^2/day$, respectively. The mean deposition amounts of each ion species were higher in the wet gauge than in the dry gauge because of the surface difference of the sampling gauge, especially for $NH_4{^+}$ and ${SO_4}^{2-}$. The mean deposition amounts of $NH_4{^+}$ and ${SO_4}^{2-}$ in the wet gauge were found to be about 15.4 times and 5.2 times higher than that in dry gauge, with a pronounced difference between spring and summer, while the remaining ion species were 1.1-2.0 times higher in the wet gauge than in the dry gauge. Dominant species in the dry gauge were $Ca^{2+}$ and $NO_3{^-}$, accounting for 36.4% and 18.1% of the total ion deposition, whereas those in the wet gauge were $NH_4{^+}$ and ${SO_4}^{2-}$, accounting for 32.5% and 25.0% of the total ion deposition, respectively. Conclusion: The seasonal differences in deposition amounts of water-soluble ion species in ambient aerosol depending on the two types of different sampling methods were identified. This suggests that the removal of ambient aerosol is strongly influenced by the weather conditions of each season as well as the condition of earth's surface, such as dry ground and water.