• International Journal of Highway Engineering
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• v.17 no.3
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• pp.77-83
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• 2015

PURPOSES : In this study, a fracture-based finite element (FE) model is proposed to evaluate the fracture behavior of fiber-reinforced asphalt (FRA) concrete under various interface conditions. METHODS : A fracture-based FE model was developed to simulate a double-edge notched tension (DENT) test. A cohesive zone model (CZM) and linear viscoelastic model were implemented to model the fracture behavior and viscous behavior of the FRA concrete, respectively. Three models were developed to characterize the behavior of interfacial bonding between the fiber reinforcement and surrounding materials. In the first model, the fracture property of the asphalt concrete was modified to study the effect of fiber reinforcement. In the second model, spring elements were used to simulated the fiber reinforcement. In the third method, bar and spring elements, based on a nonlinear bond-slip model, were used to simulate the fiber reinforcement and interfacial bonding conditions. The performance of the FRA in resisting crack development under various interfacial conditions was evaluated. RESULTS : The elastic modulus of the fibers was not sensitive to the behavior of the FRA in the DENT test before crack initiation. After crack development, the fracture resistance of the FRA was found to have enhanced considerably as the elastic modulus of the fibers increased from 450 MPa to 900 MPa. When the adhesion between the fibers and asphalt concrete was sufficiently high, the fiber reinforcement was effective. It means that the interfacial bonding conditions affect the fracture resistance of the FRA significantly. CONCLUSIONS : The bar/spring element models were more effective in representing the local behavior of the fibers and interfacial bonding than the fracture energy approach. The reinforcement effect is more significant after crack initiation, as the fibers can be pulled out sufficiently. Both the elastic modulus of the fiber reinforcement and the interfacial bonding were significant in controlling crack development in the FRA.

• The Journal of Advanced Prosthodontics
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• v.6 no.6
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• pp.444-450
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• 2014

PURPOSE. To compare the accuracy of marginal and internal adaptation of zirconia (Zr) copings fabricated on anatomic (A), semi-anatomic (SA) and non-anatomic (NA) occlusal surface preparations. MATERIALS AND METHODS. 45 extracted bicuspid teeth were prepared for receiving zirconia crowns, with different occlusal preparation designs A=15, SA=15 & NA=15. The Zr copings were fabricated by using CAD4DENT, CAD/CAM. The copings were adjusted, cemented and were cross sectioned centrally from buccal cusp tip to lingual cusp tip into mesial and distal halves. The copings were examined under electron microscope at ${\times}200$ magnification and the measurements were recorded at 9 predetermined areas in micrometers. RESULTS. Overall mean gap values for the three groups was found to be $155.93{\pm}33.98{\mu}m$ with Anatomical Occlusal preparation design having the least gap value of $139.23{\pm}30.85{\mu}m$ showing the best adaptation among the groups. Post Hoc Tukey's test showed a statistically significant difference (P=.007) between the means of gap for A & NA preparation designs. Measurements recorded at 9 predetermined points showed variations for the three groups. CONCLUSION. Anatomical occlusal preparation designs resulted in better marginal and internal adaptation of Zr copings. There is a considerable variation between the measured marginal and internal gap values for the Zr copings fabricated by the (CAD4DENT-CAD/CAM). This variation may be associated with the lack of standardization of the preparation of teeth, computerized designing of the coping for each tooth, cement used, uniform pressure application during the cementation of the copings, sectioning of the copings and the microscopic measurements.

• Bulletin of the Society of Naval Architects of Korea
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• v.27 no.1
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• pp.24-34
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• 1990

In this paper, the formulation of a new simplified finite element is made to analyze the ultimate strength of damaged tubular members subjected to combined axial force and end moment. A damaged tubular member that has the bending deformation and the local dent is modeled by beam elements. Tangent elastic stiffness matrix of a beam element which contains the effect of the geometric nonlinearity is derived by using the updated Lagrangian approach. Here the contribution of the stiffness in the dented area is neglected since its resistance against the external loads is considered to be small. A fully plastic interaction curve of the element under combined loads taking account of the local dent effect is selected as a yielding criterion at each nodal point. Also tangent elasto-plastic stiffness matrix of the element is formulated by plastic node method. Comparison with the present solution and the existing experimental results is made showing that the present method gives quite an accurate solution.

• Journal of The Korean Society of Grassland and Forage Science
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• v.14 no.1
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• pp.57-63
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• 1994

We use a variety of methods to determine the optimum time for havesting corn for silage. In addition, adequate dry matter for silage must be considered along with maturity stage. The objective of this study was to evaluate using the kernel milk line to determine when to harvest com for silage in 1992 on the Livestock Experimental F m , Keiymung Junior College at Keongsan, Keongsangbukdo. Four hybrids were field grown and com plants were harvested at various stages of kernel development so that kemel milk line movement could be analyzed whilc the corn was in the premature stages. As the plants approached maturity, the ears were collected from each of the hybrids and the position of the milk line wa5 noted. Then the whole plants were chopped and the content of DM was determined. The milk line was a readily identifiable feature of maturing com kemels. We focused on the five development \tage\. The fint was "soft dough". The second was "dent". The third wa, "75% milk". and the fourth wa5 "half milk". The half milk occurs when the milk line is positioned falf way down the kemel face. and the final stages win "no milk", milk disappearance as indicators of physiological maturity in maix. Milk free stage of the kemel occurred from I to 3 days prior to black layer having developed. The range for harvesting com for silage occurs a kemels mature from 75% milk to no milk. Position of milk line was easy to see. and can be used as a visible indicator to determine com matunty stage\ and whole plant dry matter. Whole plant dry matter increased with advancing maturity. averaged over hybrids it was 24.1, 25.6. 28.5. 34.6 and 39.0% at soft dough, dent, 75% milk. half milk and no milk. Milk line was more usehl indicator in monitoring corn maturity prior to physiological maturity.ing corn maturity prior to physiological maturity.

• The Journal of Advanced Prosthodontics
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• v.15 no.4
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• pp.189-201
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• 2023

PURPOSE. The aim of this study was to investigate the mechanical properties of three-dimensional (3D) printed denture base resin incorporating microcapsules containing plant essential oils. MATERIALS AND METHODS. Denture base specimens containing up to 3% w/v essential oil microcapsule powders (MCPs), i.e., eucalyptus, geranium, lavender, menthol, and tea tree, in two resins (Detax and NextDent 3D+) were 3D printed using two printers (Asiga and NextDent 5100). The dispersion and interaction of the MCPs in the resin were assessed by SEM while the mechanical properties of the incorporated denture base including flexural strength (MPa), flexural modulus (MPa), Vickers hardness (VHN), and surface roughness (Ra) were also subsequently evaluated. Statistical analysis of any differences in mean values was determined using a two-way ANOVA with Tukey's post hoc testing (α = .05). RESULTS. The spherical shape of the MCPs was maintained during the mixing and polymerization/printing process. However, the Detax-Asiga group showed significant agglomeration of the MCPs even at the lowest MCP concentration levels (0.5% w/v). Overall, as the microcapsule concentration increased, the mean flexural strength decreased, though the menthol MCP groups remained compliant with the ISO standard. The flexural modulus and harness remained relatively unchanged, and the flexural modulus complied with the ISO standard regardless of the MCP concentration. Surface roughness increased with the addition of the MCPs but also remained below that required for clinical acceptance. CONCLUSION. Incorporation of microencapsulated plant essential oils into 3D printed denture base resin was successfully achieved. While incorporation negatively influenced flexural strength and surface roughness, little effect on flexural modulus and Vickers hardness was demonstrated.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.48 no.3
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• pp.267-275
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• 2003

To observe the effects of seed matriconditioning on the emergence, plumule growth, and seed physiological properties of normal and aged seeds of three corn(Zea mays L.) genotypes (dent, sugary, and shrunken-2), normal and artificially aged seeds were matriconditioned at 50, 75, 100, and 125% moisture contents of vermiculite at $25^{\circ}C$ for 24 hours and the germinability was examined at $25^{\circ}C$ and in cold test (7 days at 1$0^{\circ}C$followed by $25^{\circ}C$). Emergence rate, emergence speed, and plumule growth were smaller in the order of dent＞sugary＞shrunken-2. Matriconditioning did not affect the emergence rate of normal dent and sugary seeds, while it enhanced emergence speed and plumule growth. In contrast, the emergence rate, emergence speed, and plumule growth of normal shrunken-2 and aged seeds of all genotypes were enhanced as the moisture content of vermiculite increased up to 125% both at $25^{\circ}C$ and in cold test. Matriconditioning promoted $\alpha$-amylase activity and DNA and soluble protein contents, while it reduced the leakage of total sugars and electrolytes from the seeds when soaked in water.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.14
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• pp.123-131
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• 1973

1. In order to evaluate the performance of the $F_2$ and $F_3$ generations of $F_1$ varietal crosses which in past trials yielded better than or as high as the recommended double-cross hybrids, eleven yellow and five white-endosperm $F_1$ varietal crosses, their $F_2$ and $F_3$ generations, and the parental open-pollinated varieties together with the standard double-cross hybrids were tested in performance trials in the 1963 wet and 1963-64 dry seasons. The former trials, however, failed due to a strong typhoon that damaged the crop. 2. Net hybrid vigor was highly manifested in grain yield in the $F_1$ varietal crosses, which on the average was 39.9 per cent of the mid-parent yields. Reduction in heterosis was 27.2 per cent in the $F_2$and 30.3 per cent in the $F_3$ generation, respectively. 3. A fairly high degree of reduction in yield occurred in the $F_2$ and $F_3$ generation. On the average, the $F_2$ generation decreased by 17.6 per cent and the $F_3$ by 20.7 per cent. The losses in two generations were exhibited in two levels; four crosses decreased by 10.9 per cent and twelve combinations by 22.0 per cent. The advanced generations of one yellow cross, Cuban Yellow Flint ${\times}$ Hawaiian Flinty Dent, and three white flint crosses, Bicol White Flint ${\times}$ Eto Blanco, College White Flint ${\times}$ Eto Blanco and Bicol White Flint ${\times}$ Nariono 330b, yielded as high as Philippine Hybrid No.1 and Philippine Hybrid No.4, respectively. 4. No significant differences in yield were obtained between the $F_2$ and $F_3$ populations, showing that genetic equilibrium was reached in $F_2$, as may be expected in view of the Hardy-Weinberg law on panmixis. 5. As in past trials, Hawaiian Flinty Dent, a variety, yielded as high as Philippine Hybrid No. 1.

• Restorative Dentistry and Endodontics
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• v.32 no.6
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• pp.550-558
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• 2007

The purpose of this study was to evaluate the insertion depth of several brands of master gutta percha cones after shaping by various Ni-Ti rotary files in simulated canals. Fifty resin simulated J-shape canals were instrumented with ProFile, ProTaper and HEROShaper. Simulated canals were prepared with ProFile .04 taper #25(n=10), .06 taper #25(n=10), ProTaper F2(n=10), HEROShaper .04 taper #25(n=10) and .06 taper #25(n=10). Size #25 gutta percha cones with a .04 & .06 taper from three different brands were used: DiaDent; META; Sure-endo. The gutta percha cones were selected and inserted into the prepared simulated canals. The distance from the apex of the prepared canal to the gutta percha cone tip was measured by image analysis program. Within limited data of this study, the results were as follows 1. When the simulated root canals were prepared with HEROShaper, gutta-percha cones were closely adapted to the root canal. 2. All brands of gutta percha cones fail to go to the prepared length in canal which was instrumented with ProFile, the cones extend beyond the prepared length in canal which was prepared with ProTaper. 3. In canal which was instrumented with HEROShaper .04 taper #25, Sure-endo .04 taper master gutta percha cone was well fitted(p < 0.05). 4. In canal which was instrumented with HEROShaper .06 taper #25, META .06 taper master gutta percha cone was well fitted(p < 0.05). As a result, we concluded that the insertion depth of all brands of master gutta percha cone do not match the rotary instrument, even though it was prepared by crown-down technique, as recommended by the manufacturer. Therefore, the master cone should be carefully selected to match the depth of the prepared canal for adequate obturation.

• Restorative Dentistry and Endodontics
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• v.33 no.5
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• pp.463-471
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• 2008

This study investigated the clinical effectiveness and safety of sealed bleaching compared to conventional in-office bleaching using a randomized clinical trial of split arch design. Ten participants received a chairside bleaching treatment on the upper anterior teeth, and each side was randomly designated as sealed or control side. A mixture of Brite powder (PacDent, Walnut, USA), 3% hydrogen peroxide and carbamide peroxide (KoolWhite, PacDent, Walnut, USA) were used as bleaching agent. The control side was unwrapped and the experimental side was covered with a linear low density polyethylene (LLDPE) wrap for sealed bleaching. The bleaching gel was light activated for 1 hour. The tooth shades were evaluated before treatment, after treatment, and at one week check up by means of a visual shade (VS) assessment using a value oriented shade guide and a computer assisted shade assessment using a spectrophotometer (SP). The data were analyzed by paired t-test. In the control and sealed groups, the visual shade scores after bleaching treatment and at check up showed statistically significant difference from the preoperative shade scores (p<.05). The shade scores of the sealed group were significantly lighter than the control immediately after bleaching and at the check-up appointment (p<0.05). Compared to prebleaching status, the ${\Delta}E$ values at post bleaching condition were $4.35{\pm}1.38\;and\;5.08{\pm}1.34$ for the control and sealed groups, respectively. The ${\Delta}E$ values at check up were $3.73{\pm}1.95\;and\;4.38{\pm}2.08$ for the control and sealed groups. ${\Delta}E$ values were greater for the sealed group both after bleaching (p<.05) and at check up (p<.05). In conclusion, both ${\Delta}E$ and shade score changes were greater for the sealed bleaching group than the conventional bleaching group, effectively demonstrating the improvement of effectiveness through sealing.

• Journal of the Korean Society of Food Science and Nutrition
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• v.16 no.4
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• pp.350-363
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• 1987

This study dealt with the comparison of the individual lipid component and fatty acid composition in the six varieties of dent corn, Zea mays Indentata. The fatty acid and sterol compositions of the total lipid were analyzed by gas liquid chromatography. The total lipid was also fractionated into three lipid classes namely neutral, glyco and phospolipid by the methods of silicic acid column chromatography. The lipid componets of lipid-classes were estimated by thin layer chromatography and TLC-scanner. The contents of total lipid in six varieties of Cdent corn were $3.7{\sim}5.3%$. Total lipid were mainly Composed of triglyceride$(69.8{\sim}75.7%)$ free fatty acid$(13.0{\sim}17.9%)$, lanosterol$(4.8{\sim}6.0%)$. hydrocarbon & esterified sterol$(3.5{\sim}6.0%)$, and polar lipid & pigment$(2.7{\sim}5.9%)$. The contents of triglycerde in $Chech'{\breve{o}}nok$ and Hwangok No.3 were slightly higher then other varieties. The major fatty acid In total lipid from six varieties of dent corn were chiefly consisted of linoleic$(46.0{\sim}61.4%)$, oleic$(21.9{\sim}29.9%)$ and palmitic acid$(10.9{\sim}16.7%)$. Particularly the content of linoleic acid in $Chech'{\breve{o}}nok$ was higher but oleic and palmitic acid in $Chech'{\breve{o}}nok$ were less than other varieties. The compositions of 4-desmethylsterol were mainly composed of siterol $(44.0{\sim}63.2%)$, campestetel$(11.6{\sim}15.5%)$ and stigmasterol$(5.6{\sim}9.1%)$. The content of sitosterol in Chinjuok was higher than other varieties and isofucosterol was detected only in Chinjuok. The compositions of 4-monomethlysterol were mainly composed of obtusifoliol$(17.7{\sim}37.6%)$, gramisterol$(15.0{\sim}27.0%)$ and citrostadienol$(9.1{\sim}17.3%)$. The contents of obtusifoliol and citrostadienol in Kwangok and Chinjuok were less than other varieties. The contents of fractionated neural lipid in Suwon No.19. Kwangok, $Hoengs{\breve{o}}ngok$ and Chinjuok$(90.3{\sim}97.1%)$ were higher than those of $Chech'{\breve{o}}nok$ and Hwangok No.3$(85.5{\sim}86.1%)$. Neutral lipid were mainly composed of triglyceride$(24.7{\sim}80.0%)$, lanosterol$(6.2{\sim}20.2%)$, Cholesterol$(1.0{\sim}50.6%)$, free fatty acid$(4.4{\sim}8.9%)$ and esterified sterol$(1.5{\sim}15.9%)$. The major fatty acid in neutral lipid from six varieties of dent corn were chiefly consisted of linoleic$(26.2{\sim}55.4%)$ oleic$(22.7{\sim}39.1%)$ and palmitic acid$(11.4{\sim}41.6%)$. Particularly the contents of linoleic acid Suwon No.19 and $Chech'{\breve{o}}nok$ were higher but palmtic acid in Suwon No.19 and $Chech'{\breve{o}}nok$ were less tan other varieties. Glycolipd were mainly composed of nlonoglycosflsterol $(17.5{\sim}56.4%)$, monoglycosylce-ramide $(8.2{\sim}25.9%)$ and monoglycoslydiacylglycerol$(12.4{\sim}22.2%)$. The contents of mono-g1ycosrlceramide and monoglycosrlsterol in Chinjuok. Were higher than other varieties. The major fatty acid in glycolipid from six varieties of dent corn were chiefly consisted$(14.6{\sim}39.3%)$, palmitic$(20.0{\sim}26.1%)$, linoleic$(3.6{\sim}26.9%)$ and heptadecanoic acid $(3.3{\sim}24.7%)$. Particutarly the cantents of oleic acid in Chinjuok and heptadecanoic acid in $Chech'{\breve{o}}nok$ were higher than other varieties. Phospholipid were mainly composed of phosphatidyllnositol$(30.9{\sim}86.4%)$ and phosphatidylcholine$(4.5{\sim}22.0%)$. The contents of phosphatidrlinositol in $Hoengs{\breve{o}}ngok$ and Hwanngok No. 3 were less than other varieties. The major fatty acid in phospolipid from six varieties of dent corn chiefly consisted of patmitic$(37.2{\sim}61.6%)$ heptadecanoic$(9.2{\sim}31.8%)$ and oleic acid$(4.3{\sim}17.2%)$. Particuiarlr the content of oleic acid in $Hoengs{\breve{o}}ngok$ was higher but heptadccanoic acid in $Hoengs{\breve{o}}ngok$ was less than othcr varieties.