• Restorative Dentistry and Endodontics
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• 제44권2호
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• pp.18.1-18.9
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• 2019

Objective: This study evaluated the presence of residual root canal filling material after retreatment using micro-computed tomography (micro-CT). Materials and Methods: Extracted human teeth (single- and double-rooted, n = 21/each; C-shaped, n = 15) were prepared with ProFile and randomly assigned to three subgroups for obturation with gutta-percha and three different sealers (EndoSeal MTA, EndoSequence BC sealer, and AH Plus). After 10 days, the filling material was removed and the root canals were instrumented one size up from the previous master apical file size. The teeth were scanned using micro-CT before and after retreatment. The percentage of remaining filling material after retreatment was calculated at the coronal, middle, and apical thirds. Data were analyzed using the Kruskal-Wallis test and Mann-Whitney U test with Bonferroni post hoc correction. Results: The tested sealers showed no significant differences in the percentage of remaining filling material in single- and double-rooted teeth, although EndoSeal MTA showed the highest value in C-shaped roots (p < 0.05). The percentage of remaining filling material of AH Plus and EndoSeal MTA was significantly higher in C-shaped roots than in single- or double-roots (p < 0.05), while that of BC sealer was similar across all root types. EndoSeal MTA showed the highest values at the apical thirds of single- and double-roots (p < 0.05); otherwise, no significant differences were observed among the coronal, middle, and apical thirds. Conclusions: Within the limitations of this study, a large amount of EndoSeal MTA remained after retreatment, especially in C-shaped root canals.

• Asian-Australasian Journal of Animal Sciences
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• 제24권4호
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• pp.532-539
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• 2011

The objective of this study was to determine age-related changes in the percentage content of edible and non-edible components in broiler chickens. The experimental materials comprised 240 Ross 308 chicks (sex ratio 1:1) raised to 10 weeks of age and fed standard diets ad libitum. Starting from the first week of rearing, every 7 days 10 males and 10 females were selected randomly for slaughter and post-slaughter analysis. The data obtained were verified statistically. The percentage content of edible components increased and the percentage content of non-edible parts decreased as the chicks grew older. In broilers aged 1 week and 10 weeks, edible components accounted for 47.0% and 66.4% total body weight, respectively. The share of muscle tissue increased considerably over this period, from 30.9% total body weight in week 1 to 52.4% in week 10. An increase in the percentage of skin and subcutaneous fat was observed for the first three weeks only, while the percentage content of giblets (in contrast to the remaining edible parts) decreased with age. For non-edible parts, the share of bones diminished by 2.5% and the proportion of slaughter offal reduced by 13.8%. A rising tendency was noted with respect to feathers and abdominal fat, while the content of the remaining offal decreased.

• 대한치과교정학회지
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• 제21권3호
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• pp.563-580
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• 1991

The purpose of this study was to investigate and compare the biomechanical properties of orthodontic rubber elastic materials. Latex bands, nylon-covered elastic threads and polyurethane-based elastic modules, delivering $205{\pm}10$ grams force at 30mm stretching state were selected and stored separately in 3 environments-air ($22{\pm}3^{\circ}C$), distilled water ($37{\pm}1^{\circ}C$), or natural saliva ($37{\pm}1^{\circ}C$). And, the amount of remaining force and permanent elongation of each sample were measured on Instron at interval of 1 hour, 6 hours, 12 hours, 24 hours, 1 week, and 2 weeks. So the data derived were analyzed statistically. The results were as follows: 1. Force decay and permanent elongation of all materials increased with time lapsed; elastic module, latex band and nylon-covered elastic thread in that order of the amount of force decay; elastic module, elastic thread, latex band in that order of the amount of permanent elongation. 2. Among environmental conditions, force decay and permanent elongation in natural saliva, most increased, and those in air, least increased. 3. There was a negative correlation between force decay and permanent elongation. 4. Force decay and permanent elongation were most affected by the material itself, time and environments in that order. 5. After 24 hours in saliva, the percentage of remaining force in elastic module was 51.9% (107.37grams); in latex band, 83.2%(172.62grams); in elastic thread, 85.0%(179.25grams). After 2 weeks in saliva, the percentage of remaining force in elastic module was 42.9%(88.75grams); in latex band, 74.5%(154.50grams); in elastic thread, 77.6%(163.75grams).

• International Journal of Industrial Entomology and Biomaterials
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• 제6권1호
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• pp.75-79
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• 2003

Oral supplementation of zinc chloride to silkworm larvae in different concentrations (30, 60 and 90 ${\mu}g$/ml) to the fourth and fifth instar resulted in a significant increase in commercial traits, like larval weight, silk gland weight, cocooning percentage in lower concentrartion (30 ${\mu}g$) treated group. The female cocoon weight, shell weight and its ratio were significantly increased in 30 and 60 ${\mu}g$ treated groups, male cocoon weight, and shell weight in 30 ${\mu}g$ treated group and its ratio in 60 and 90 ${\mu}g$ treated groups, filament length, weight and moth emergence percentage in all the treated groups and egg productivity in 90 ${\mu}g$ treated group were increased significantly. The remaining groups did not show any significant changes compared with that of carrier control.

• 한국연소학회:학술대회논문집
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• 한국연소학회 1999년도 제19회 KOSCO SYMPOSIUM 논문집
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• pp.81-91
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• 1999

Fuel characteristics of sewage sludge as required for the fluidized bed incinerators have been evaluated. Sewage sludge is basically a solid fuel with high percentage of moisture. Moisture content of the fuel directly affects the heating value of the fuel and the exhaust gas composition. When the sludge of transported into the incinerator, sludge cake is subject to the mixing, break-up and heat-up. Fluidization process would enhance these physical processes. The sludge fuel could then undergo the moisture evaporation and devolatilization process. Subsequent oxidation of volatiles as well as the remaining char would then follow. Sludge samples are characterized with high percentage of volatiles out of total combustibles. Quantitative understanding of above listed subprocesses would certainly help in the utilization of fluidized bed incinerators. A limited set of fuel characterization tests including calorimetric analysis, proximate analysis, elemental analysis and thermogravimetric analysis were conducted for the selected sludge samples. The measurement reasults of sludge samples were reported along with some published data. Limited experience in the actual incinerator plant is also presented.

• 한국연초학회지
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• 제23권1호
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• pp.77-81
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• 2001

This study was conducted to determine menthol migration from the tobacco to the filter and the change in percentage of menthol in pack for different mentholated cigarettes. Methanol was used to extract menthol from tobacco, filter and foil. A known weight of internal standard was added to each extract and then the extracts were analyzed by gas chromatography. After 4 days, 95% of the menthol applied to the foil was delivered into the tobacco and filter, but in case of menthol applied to the tobacco, the percentage of menthol that migrated from the tobacco to the filter was below 10%. After 100 days, 30-45% of the menthol in the tobacco had migrated into the filter. The amount of menthol in the pack decreased after 20 days of storage, however, the remaining menthol in cigarette treated with 0.30% propylene glycol was higher in amount than that with 0.12% propylene glycol In analysis on menthol transfer to mainstream smoke, the most efficient sample was the cigarette with menthol applied to the foil rather than to the tobacco.

• 한국표면공학회지
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• 제32권2호
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• pp.93-99
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• 1999

Surface polymer layer formed on the silicon wafer during the oxide overetching using $C_4F_8$/ helicon wave plasmas and their characteristics were investigated using spectroscopic elipsometry, X-ray photoelectron spectroscopy, and secondary ion mass spectrometry. Overetch percentage and dc-self bias voltage were varied to investigate the effects on the characteristics of the polymers remaining on the overetched silicon surface. The increase of bias voltage from -80 volts to -120 volts increased the C/F ratio and carbon bondings such as C-C, $C-CF_x$/, and C-Si in the polymer while reducing the thickness of the polymer layer. However, the increase of the overetch percentage from 50% to 100% did not change the composition of the polymer layer and the carbon bondings in the polymer layer remained same even though it increased the polymer thickness. The polymer layer formed at the higher dc-self bias voltage was more difficult to be removed by the following various post-etch treatments compared to that formed at the longer overetch percentage.

• Journal of Yeungnam Medical Science
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• 제21권1호
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• pp.51-59
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• 2004

Background: The objective of this study is to evaluate the relationship between chewing ability and health status in order to provide basic information for the development of program which may lead to an improvement of a the elderly health status in urban areas. Materials and methods: The subjects of this study were 128 elderly urban female over the age of 65 who reside at house. The data were collected from May 21 to August 20, 2001, through questionnaires about nutrient intake status, direct measurement of anthropometrics, and oral examinations. Results: In terms of remaining teeth, there was significant negative relationship between age and number of remained teeth. The average number of remained teeth our subjects was $13.1{\pm}10.6$. About sixty five percent of the subjects were denture users (partial or full dentures) and there was positive relationship between age and the percentage of denture user. There was a significant negative correlation between age and chewing ability. The group that was able to chew had more remained teeth than the other group. Conclusion: This study suggests that there is strong positive relationship between chewing ability (remaining teeth) and elderly health status in urban areas, and the importance of preserving original teeth to improve the elderly health status in the public health program.

• 대한소아치과학회지
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• 제2권1호
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• pp.13-17
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• 1975

The purpose of this investigation was to make a comprohensive study and evaluation of the oral health of a group of orthopedically handicapped children by considering the DMF rate, occlusion, and oral hygiene status of 194 orthopedic children. The obtained results were as follows. 1. The DMF rate of over all examined children was 59.85%, and when the four orthopedic groups were compared among themselves, it was found that Cerebral Palsy group had a significant higher DMF rate than that occuring in any of the remaining groups. 2. Total prevalence of malocclusion was 50. 10%, and it was found that Cerebral Palsied children had a significantly higher incidence of malocclusion ($67.90{\pm}4.12$), and that Cerebral Palsy group showed a significantly different distribution of higher percentage of Class II occlusions from that observed in the remaining groups. 3. In dental plaque index, Average plaque index per tooth was 2.09. Plaque index of each group was as follows A) Cerebral palsy: 2.35 B) Poliomyelitis: 2.24 C) Tb Group: 1.65 D) miscellaneous Group: 1.72.

• Asian-Australasian Journal of Animal Sciences
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• 제16권12호
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• pp.1755-1762
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• 2003

Two experiments were conducted to determine effects of particle size in total mixed ration (TMR) on performance of lactating cows. Three rumen cannulated Holstein cows were used in a $3{\times}3$ Latin square design for the metabolic experiment. The particle size of the diets was determined using the Penn State Particle Size Separator (PSPSS) and weighing the proportion of sample remaining on the top screen (19 mm diameter). The 3 treatments were short, medium or long diets (4.9, 24.2 and 27.8% of sample remaining on the top screen of the PSPSS, respectively). Nine farms in the Edmonton area were surveyed and the farms were placed into groups based on the particle size of the ration fed. The groups were short ${\leq}6%$, medium 7-12% and long ${\geq}13%$ of sample weight remaining on the top screen of the PSPSS. Dry matter intake was greater (p=0.07) for the medium diet than the long diet in the metabolic study and resulted in a higher (p=0.07) efficiency of milk production. On the commercial farms, a significantly (p=0.002) lower milk fat percentage was observed for the long diet compared to the short diet. The results of these studies confirm that forage particle size influences milk composition and milk fat was negatively correlated to TMR particle size.