• Restorative Dentistry and Endodontics
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• v.5 no.1
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• pp.7-12
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• 1979

After applying three types of composite resins - Hi-Pol composite with Enamel bond, Hi-Pol composite without Enamel bond, Restodent - to the intact and the ground surface of tooth that had been acid etched for one or two minutes, the author observed the penetration of these resins into the acid etched enamel surface with scanning electron microscope. The results were as follows. 1. All the experimented materials showed the penetration into the acid etched enamel surface, and the average depth of penetration was 7 microns. 2. There was no significant difference in the penetration of these three resins despite different etching, time. 3. The grinding of the Enamel surface before acid - etching was not effective in altering the depth of penetration of these materials.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.11a
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• pp.166-167
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• 2019

In this study, to test the performance of concrete used as a concrete admixture as a recycling method of CGS, gypsum was mixed and the chloride ion penetration resistance test of CGS and BFS substituted concrete was conducted. As a result, it was found that without gypsum type test specimen, the CGS sustituted test specimens had lower chloride ion penetration resistance than the BFS substituted specimens. When gypsum was added, it was confirmed that the chloride ion penetration resistance was poor regardless of the type of admixture. In addition, it was confirmed that both admixtures were less resistant to chloride ion penetration than OPC, regardless of the presence of gypsum. However, considering the uneven quality variation of coal, which greatly affects the quality of CGS, further research is needed.

• Structural Engineering and Mechanics
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• v.13 no.2
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• pp.171-186
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• 2002

Static and dynamic penetration tests of reinforced concrete (RC) slab specimens are described and discussed. The experimental study was aimed at a better understanding of mechanisms that are involved in dynamic penetration, through their identification in static tests, and by establishing their relative influence in similar dynamic cases. The RC specimens were $80{\times}80-cm$ square plates, and they were made of 30 MPa concrete. The non-deforming steel penetrator was a 50-mm diameter steel rod with a conical nose of 1.5 aspect ratio. Impact penetration tests were carried out with an air gun, which launched the projectiles at velocities of up to 300 m/sec. The static tests were conducted using a closed loop displacement control actuator, where the penetrator was pushed at a constant rate of displacement into the specimen. The static tests reveal important mechanisms that govern the penetration process and therefore contribute to a better understanding of RC barriers resistance to non-deforming projectiles impact.

• Journal of Distribution Science
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• v.19 no.5
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• pp.35-48
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• 2021

Purpose: This research aims to analyze the influence of relational penetration capability on salesperson performance and the influence of customer orientation, customer knowledge accessibility, and salesperson-customer relationship quality on the relational penetration capability of the insurance service industry in Central Java. Research design, data, and methodology: This explanatory research involved 211 respondents. Path analysis was used to analyze the primary data obtained. Results: The customer orientation positively influences relational penetration capability and customer knowledge accessibility which can improve salesperson performance. The salesperson-customer relationship quality shows a positive impact on the salesperson's relational penetration capability, salesperson performance, and relational penetration capability which will lead to an improved salesperson-customer relationship. Higher knowledge levels of customer necessity have important implications for a salesperson's capability of finding potential customers and of fulfilling customers' requirements through careful analysis of necessity. Conclusions: The salespeople should be capable of building and maintaining a good relationship with their customers as an indication that salespeople of Insurance Service Company Distribution in Central Java have good performance.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.25 no.1
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• pp.82-88
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• 2015

Objectives: This study is designed to analyze the penetration performance into ceiling materials containing asbestos of scattering prevention agents and investigate the change in penetration depth and viscosity according to the dilution rate of anti-scattering agents diluted with distilled water. Methods: Five different types of scattering prevention agents were spread on plate-type asbestos ceiling materials. The penetration depth of each coated ceiling material was measured by energy dispersive spectroscopy (EDS) analysis, based on X-ray fluorescence (XRF) results of the non-coated ceiling materials. Test equipment installed the ceiling materials and 60 minutes were collected at a flow rate of $10{\ell}/min$ at a filter of 25 mm. Results: An EDS analysis of the cross-section of ceiling materials constructed with a scattering prevention agent revealed that potassium is detected in the process of penetrating hardener solidification and this element could be an indicator for infiltration. When anti-scattering agents with different viscosities were constructed and the penetration depth was analyzed by potassium detection assessment using EDS, the depth results with viscosities of 5.0, 2.5, and 1.9 cP were 98.5, 103, and $147{\mu}m$, respectively. Penetration performance improved with decrease in viscosity. Conclusions: For asbestos ceiling materials, it is concluded that a higher dilution rate of the scattering prevention agent leads to lower viscosity, and hence a deeper penetration depth from $156{\mu}m$ to 3 mm. The asbestos anti-scattering properties according to the penetration depth will be confirmed through further study.

• Fire Science and Engineering
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• v.18 no.4
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• pp.93-102
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• 2004

The function of fire barrier penetration sealing is highly important to confine a fire propagation a fire severity within a fire area where the fire started. Especially for the penetration seals at the nuclear power plants with the long-term operated history, it is needed to make it clear that the conformance to the sealing requirements has been proven to guarantee the fire-resistive performance of fire barrier penetration parts. If there are any parts of fire barrier penetration sealing which can not meet the required rating for the fire endurance performance, the relevant parts must be modified to meet regulatory requirements. At this paper, the engineering analysis methodology was established to approximate the fire endurance rating for the fire barrier penetration seals. With this study, the method of engineering analysis to decide fire endurance rating for the fire barrier penetration seals was established and this way can be utilized to check the performance of the fire rating for the penetration seal at the domestic nuclear power plants.

• Restorative Dentistry and Endodontics
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• v.20 no.1
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• pp.261-274
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• 1995

This study aimed to evaluate the marginal microleakage of Class V cavities of All-bond 2 (Wet - bonding system), Gluma (Adhesion of resin to exposed collagen fibers), and Scotchbond Multi-purpose(Mild Etching System). Hundred extracted human teeth divided into a control and three experimental groups consisting of eight teeth. The experimental group was further subdivided into All- bond2, Gluma and Scotchbond MP groups, Vitrebond served as the control. The positive control group consisted of specimens filled with resin and with no etching, primer and bonding procesure. Polished specimens underwent temperature changed from $5^{\circ}C$ to $55^{\circ}C$ a thousand times. After thermocycling, speciemens were placed in 2 % methylene blue dye solution for 24 hours in an incubator set at $37^{\circ}C$. The teeth were sectioned buccolingually and the degree of dye penetration was observed with a stereomicroscoped(*20). The following results were obtained. 1. Both the control and the experimental group showed a lower degree of dye penetration on enamel than on dentin margins(p<0.05) 2. Gluma exhibited a statistically significant lower degree of dye penetration than All-bond 2 on enamel margins(p<0.05) Scotchbond MP also exhibited a lower degree of dye penetration than All-bone 2 but was no statistically significant. Gluma and Scotchbond MP exhibited a similar degree of dye penetration. 3. The degree of dye penetration of All-bond 2, Gluma and Scotch bond MP showed no statistically singnificance on enamel margins but was significantly lower than in the control using Vitrebond. 4. All-bond 2 exhibited a statistically significant lower degree of dye penetration than Gluma on dentin margins. All- bond 2 and Scotchbond MP showed a similar degree of dye penetration. 5. The degree of dye penetration of All-bond 2, Gluma and Scotchbond MP showed no statistically significance on dentin margins. There was neither a statistical significance with the control.

• Korean Journal of Veterinary Service
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• v.26 no.4
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• pp.329-337
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• 2003

The functional role of the cumulus cells on sperm penetration and polyspermy during in vitro fertilization was examined. The penetration rate was significantly higher(p<0.01) in oocytes with(61%) than without(25%) cumulus cells. No significant differences, however, was observed in polyspermy. When the hyaluronidase was supplemented to the fertilization medium with different concentrations, penetration rates in oocytes with cumulus cells were higher than oocytes without cumulus cells at 0(61 vs 34% ; p<0.05), 0.01(56 vs 35% ; p<0.05), 0.1(66 vs 30% ; p<0.05) and 1.0 mg/$m\ell$(39 vs 27%). On the other hand, the polyspermy rates were lower oocytes without than with cumulus cells, and had a tendency to decrease with high concentrations of hyaluronidase. In another experiment, the penetration and polyspermy rates had a tendency to increase as time of sperm-oocytes culture was prolonged. At 16 and 20hrs after insemination, the penetration rates were significantly higher(p<0.05) in oocytes with(48 and 62% for 16 and 20hrs) than without(25 and 31% for 16 and 20hrs) cumulus cells in medium with hyaluronidase. However, the polyspermy rates were significantly(p<0.05) lower in oocytes without(3 and 16%) than with(37 and 48%) cumulus cells at 16 and 20hrs after insemination. In cumulus-free oocytes inseminated in medium with or without hyaluronidase at different concentrations of cumulus cells, the penetration rates were significantly(p<0.05) higher in medium with than without hyaluronidase at different concentrations of cumulus cells. The proportions of polyspermy were lower in medium without than with hyaluronidase at 0 (10 vs 0%), 10$^2$(25 vs 0%), 10$^4$(24 vs 14%) and 10$\^$6/(29 vs 10% ; p<0.05) cumulus cells/ml. These results suggest the advantage of culture in medium with cumulus cells and denuded oocytes to inhibit polyspermy with no decrease in the penetration rates during the fertilization in vitro in the porcine.

• Transactions of the Korean Society of Automotive Engineers
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• v.14 no.1
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• pp.79-85
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• 2006

CFRP(Carbon Fiber Reinforced Plastics) of the advanced composite materials as structural materials for vehicle, has a wide application in light-weigh structural materials of airplanes, ships and automobiles because of high strength and stiffness, However, there is a design variable to be considered in practical application of the laminate composite materials, these materials are vulnerable to transverse impact. This paper is to study the effects of stacking sequence and curvature on the penetration characteristics of composite laminate shell. They are stacked to $[0_3/90_3]S,\;[90_3/0_3]s\;and\;[0_2/90_3/0]s,\;[90_2/0_3/90]s$ and their interlaminar number two and four. They are manufactured to various curvature radius (R=100, 150, 200mm and $\infty$), When the specimen is subjected to transverse impact by a steel ball, the velocity of the steel ball was measured both before and after impact by determing the time for it to pass two ballistics-screen sensors located a known distance apart. The critical penetration energy of specimen A and B with less interfaces were a little higher than those of C and D. As the curvature increases, the critical penetration energy increases linearly because the resistance to the in-plane deformation as well as bending deformation increases, which need higher critical penetration energy. The specimen A and C have higher critical penetration energy than B and D because of different stacking sequences. We examined crack length through a penetration test. For the specimen A with 2interfaces, the longest circumferential direction crack length were observed on the first interface from the impact point. For the specimen B 4-interface, the longest circumferential direction crack length were observed on the second interface from the impact point.

• Restorative Dentistry and Endodontics
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• v.41 no.2
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• pp.114-120
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• 2016

Objectives: The aim of this study was to compare the push-out bond strength and dentinal tubule penetration of root canal sealers used with coated core materials and conventional gutta-percha. Materials and Methods: A total of 72 single-rooted human mandibular incisors were instrumented with NiTi rotary files with irrigation of 2.5% NaOCl. The smear layer was removed with 17% ethylenediaminetetraacetic acid (EDTA). Specimens were assigned into four groups according to the obturation system: Group 1, EndoRez (Ultradent Product Inc.); Group 2, Activ GP (Brasseler); Group 3, SmartSeal (DFRP Ltd. Villa Farm); Group 4, AH 26 (Dentsply de Trey)/gutta-percha (GP). For push-out bond strength measurement, two horizontal slices were obtained from each specimen (n = 20). To compare dentinal tubule penetration, remaining 32 roots assigned to 4 groups as above were obturated with 0.1% Rhodamine B labeled sealers. One horizontal slice was obtained from the middle third of each specimen (n = 8) and scanned under confocal laser scanning electron microscope. Tubule penetration area, depth, and percentage were measured. Kruskall-Wallis test was used for statistical analysis. Results: EndoRez showed significantly lower push-out bond strength than the others (p < 0.05). No significant difference was found amongst the groups in terms of percentage of sealer penetration. SmartSeal showed the least penetration than the others (p < 0.05). Conclusions: The bond strength and sealer penetration of resin-and glass ionomer-based sealers used with coated core was not superior to resin-based sealer used with conventional GP. Dentinal tubule penetration has limited effect on bond strength. The use of conventional GP with sealer seems to be sufficient in terms of push-out bond strength.