• Journal of the korean academy of Pediatric Dentistry
• /
• 제33권2호
• /
• pp.244-252
• /
• 2006

The aims of this study were to determine if flowable composites can be used as pit and fissure sealants without bonding agents. Three flowable composites(Filtek Flow, Tetric Flow, Charmfil Flow) and a filled sealant (Ultraseal XT plus) were used. The pattern of resin tag formation in the four sealant materials were compared using SEM. For the microleakage assessment, 54 extracted human premolar teeth were randomly divided into 3 groups containing 18 premolars each. In each group, a conventional filled sealant and one of the three flowable composites were applied to occlusal fissures. The teeth were thermocycled(1200 cycles between $5^{\circ}{\pm}2^{\circ}C\;and\;55^{\circ}{\pm}2^{\circ}C$ with a dwell time of 30 seconds) and immersed in a 1% methylene blue solution for 48 hours. Each tooth was sectioned and examined to determine the extent of dye penetration. Three flowable composites and a filed sealant showed a similar resin tag formation pattern. The three flowable composites showed significantly more microleakage in each group than the filled sealant. The level of microleakage was similar in the three flowable composites. Flowable composites are not recommended as pit and fissure sealants because more microleakage can occur even when occlural fissures are mechanically widened.

• Korean journal of applied entomology
• /
• 제21권3호
• /
• pp.138-141
• /
• 1982

The insecticides aldicarb$(Temik^{(R)}\;15G)$, carbofuran$(Curaterr^{(R)}\;3G)$, and disulfoton$(Disyston^{(R)}\;5G)$ were evaluated in the field for the control of the pine gall midges(Thecodiplosis joponensis Uchida et Inouye) at rate of 5 a.i.g/cm dbh using the method of circle-furrow treatment(ca. loom in furrow depth), apart 50cm Iron the trunk of the pine trees. In addition, for improving the application method of granular insecticides the effects of conventional circle-furrow treatment were compared with those of pit treatments and radical-furrow treatments. A single root-zone treatment of aldicarb and carbofuran i the pine trees was significanlty effective for the pressure of the gall incidence by the insects. Control effectiveness in three-pit treatment was identical with those in conventional circle-furrow treatment. The pit treatment compared with the circle-furrow and radical furrow treatments would be a further feasible method in saving labor cost.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 한국정밀공학회 2003년도 추계학술대회 논문요약집
• /
• pp.198-198
• /
• 2003

• Superconductivity and Cryogenics
• /
• 제12권1호
• /
• pp.7-16
• /
• 2010

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
• /
• 한국축산식품학회 2000년도 정기총회 및 제25차 춘계학술발표회
• /
• pp.106-106
• /
• 2000

• Korean Journal of Food Science and Technology
• /
• 제32권3호
• /
• pp.668-673
• /
• 2000

The influence of storage atmosphere on ethylene production, quality attributes and storage injury of 'Tsugaru' apples was investigated. Apples were stored in 1% $O_2+1%\;CO_2,\;1%\;O_2+3%\;CO_2,\;3%\;O_2+1%\;CO_2,\;3%\;O_2+3%\;CO_2$ and air at $0^{\circ}C$ for 5 months. Ethylene production was more suppressed by 1% $O_2$ than 3% $O_2$ atmospheres regardless $CO_2$ levels. The loss of flesh firmness and the decrease of titratable acidity were not significantly different among the storage atmospheres until 3 months of storage but more retarded by 1% $O_2$ than 3% $O_2$ atmospheres thereafter. Soluble solid content was unaffected by the storage atmosphere, but the content tended to be increased until 2 months of storage and then not varied. Ethanol content increased up to a peak level followed by a gradual loss during storage in CA but increased continuously in air. In the sensory evaluation after storage for 5 months, hardness, tartness and overall acceptability of apples stored in 1% $O_2$ atmospheres were significantly higher than those stored in the others. There was no fruit injury or off-flavor production resulting from the 1% $O_2$ atmospheres. The incidence of bitter pit was reduced as storage $O_2$ level decreased. The results show that the optimum conditions of CA storage for 'Tsugaru' apples are $0^{\circ}C$ and 1% $O_2+1{\sim}3%\;CO_2$.

• Explosives and Blasting
• /
• 제24권1호
• /
• pp.57-62
• /
• 2006

The typical blasting method adopted in Pasir Coal Mine is a surface blasting technique with a single free face. It means that there is only one free face, which is usually the ground surface. This kind of blasting method is easy to use but inevitably causes enormous ground vibrations, which, in turn, can affect the stability of the slopes comprising the various boundaries of the open pit mine. In addition, the method also has the problem of lowering the blast efficiency compared to other methods such as bench blasting methods or ones with more than two free faces. In this respect, a project was launched to develop a new blasting method that is suitable for controling the ground vibration and enhancing the blast efficiency. As a part of the project, authors investigated the current blasting method as well as the overall pit developing process in the mine, and established some important guidelines that should be observed during the whole development process. This paper presents the details of the typical blasting pattern and the pit developing method in the mine, and suggests the guidelines determined from the results of the observations.

• Asian Pacific Journal of Cancer Prevention
• /
• 제16권8호
• /
• pp.3473-3477
• /
• 2015

Plants and their by-products offer a diverse mixture of chemical constituents like natural antioxidants. Date-pits are rich in phenolic compounds that have antioxidant potential. The main objective of this study was to investigate the protective effect of a date-pit extract (DPE) against AOM-induced colonic carcinogenicity and oxidative stress. Thirty-two weanling male Sprauge-Dawley rats were randomly divided into four groups (eight rats in each group). All rats were fed basic diet and water ad libitum, and randomly distributed per treatment groups as follows: negative controls injected with normal saline once a week for two weeks, a cancer group injected intra-peritoneally with azoxymethane (15mg/kg body weight) for two consecutive weeks, and DPE treated groups receiving the extract via the oral route (1.5ml/day) for the entire experiment in the presence or absence of AOM injection. Results showed that DPE contained phytonutrients that were capable of inhibiting chemically-induced oxidative stress in the rat colonic cells. In those animals that consumed DPE, a protective effect was observed against AOM-induced oxidative stress in rat colonic cells as evident by a significant decrease in MDA and oxidized DCF formation in AOM injected and DPE fed groups. It is concluded that DPE has potential antioxidant and anticarcinogenic properties.

• Journal of Korean society of Dental Hygiene
• /
• 제18권5호
• /
• pp.843-852
• /
• 2018

Objectives: The study aimed to isolate the abundant bacteria in dental caries in children and to investigate the bacterial species involved in addition to those that have been previously reported. Methods: The specimens were collected from the supragingival plaques of each dental caries area, pit and fissure caries, deep dentinal caries, smooth surface caries, and dental caries, and from healthy subjects in the control group. Bacteria were cultured from these specimens, DNA was extracted from the isolated bacteria, and the 16S rRNA gene sequences were analyzed and identified. Results: Based on the results of the 16S rRNA gene sequence analysis for the 90 strains of dominant bacteria from the 45 specimens, 5, 7, 8, 7, and 13 species were identified from the supragingival plaques from healthy teeth, pit and fissure caries, deep dentinal caries, smooth surface caries, and dental caries, respectively. In healthy teeth, Actinomyces naeslundii dominated. Corynebacterium durum, Ralstonia pickettii, and Streptococcus intermedius showed equal distribution. The dominant bacterial species in dental caries, S. sanguinis, showed the greatest difference in prevalence in pit and fissure caries. In deep dentinal caries, S. mutans and Lactobacillus rhamnosus were dominant; in smooth surface caries, S. mutans and S. sanguinis were dominant; and in the supragingival plaques of dental caries, S. sanguinis and S. mutans were dominant. Conclusions: The bacterial species isolated from dental caries encompassed four phyla, eight genera, and 22 species. In addition, the SS1-2 strain, belonging to the genus Neisseria, was identified as a new species from among the isolated strains.

• Journal of Animal Environmental Science
• /
• 제6권2호
• /
• pp.73-81
• /
• 2000

A two-phase anaerobic digestion system for the treatment of swine waste was constructed in a commercial hog farm. The digester system was composed of 4 major units; slurry storage pit, acidogenic digester, methanogenic digester and sedimentation pit. A biogas boiler unit was also attached to maintain the digester temperature of 37$^{\circ}C$. Substrate lading was made with 2hr-interval by pumping about 2.1$m^3$ of slurry type swine waste from the slurry pit into the acidogenic digester, which corresponds to hydraulic retention time of 4 days for the acidogenic digester and of 11 days for the methanogenic digester. Digester temperature were well maintained as the set temperature of 37$^{\circ}C$ in the methanogenic digester, while the temperature in the acidogenic digester showed around 34$^{\circ}C$. pH also showed a steady-state results of 7.3 in the acidogenic digester and of 7.6 in the methanogenic digester during the operation period. Average biogas production rate was 0.66$m^3$/$m^3$ digester volume. Reduction rate of total solid and volatile solid were 42.8% and 5.8%, respectively. Total nitrogen and ammonia nitrogen were not reduced during the anaerobic fermentation, however, most of VFAs seemed to be converted to the biogas,. These fermentation performance data may suggest that he newly developed a two-phase anaerobic digester for the swine waste treatment worked so successfully.