• Journal of Conservation Science
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• v.7 no.1
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• pp.23-30
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• 1998

The examination of scientific analysis could give many information on the object of ancient glass. It would be allowed to understand the cultural situation and a course of inflow that the data of glass composition was classified by raw materials, technique of making, period and regional groups. Quantitative analysis conditions for SEM-EDS were set for glass and glaze on the pottery and 62 samples of glass beads excavated from Yangdong-ri remains at Kimhae were analyzed and classified. It was found that the glass beads were made of all alkali-glass. In addition, it was postulated that the potash glass was appeared from the 1st century A.D. and soda glass was appeared from the late second or early 3rd century A.D. in this region. The colors of glass were closely related to the concentration of metallic elements such as copper, iron and manganese. It was confirmed that the composition of glass beads could be classified and characterized by raw materials, color, period and regional groups.

• The Journal of Advanced Prosthodontics
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• v.4 no.3
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• pp.127-133
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• 2012

PURPOSE. Many dentists use desensitizing agents to prevent hypersensitivity. This study compared and evaluated the effect of two desensitizing agents on the retention of cast crowns when cemented with various luting agents. MATERIALS AND METHODS. Ninety freshly extracted human molars were prepared with flat occlusal surface, 6 degree taper and approximately 4 mm axial length. The prepared specimens were divided into 3 groups and each group is further divided into 3 subgroups. Desensitizing agents used were GC Tooth Mousse and $GLUMA^{(R)}$ desensitizer. Cementing agents used were zinc phosphate, glass ionomer and resin modified glass ionomer cement. Individual crowns with loop were made from base metal alloy. Desensitizing agents were applied before cementation of crowns except for control group. Under tensional force the crowns were removed using an automated universal testing machine. Statistical analysis included one-way ANOVA followed by Turkey-Kramer post hoc test at a preset alpha of 0.05. RESULTS. Resin modified glass ionomer cement exhibited the highest retentive strength and all dentin treatments resulted in significantly different retentive values (In Kg.): GLUMA ($49.02{\pm}3.32$) > Control ($48.61{\pm}3.54$) > Tooth mousse ($48.34{\pm}2.94$). Retentive strength for glass ionomer cement were GLUMA ($41.14{\pm}2.42$) > Tooth mousse ($40.32{\pm}3.89$) > Control ($39.09{\pm}2.80$). For zinc phosphate cement the retentive strength were lowest GLUMA ($27.92{\pm}3.20$) > Control ($27.69{\pm}3.39$) > Tooth mousse ($25.27{\pm}4.60$). CONCLUSION. The use of $GLUMA^{(R)}$ desensitizer has no effect on crown retention. GC Tooth Mousse does not affect the retentive ability of glass ionomer and resin modified glass ionomer cement, but it decreases the retentive ability of zinc phosphate cement.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08a
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• pp.706-709
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• 2007

Different from the LCD that have two glass substrates on the top and the bottom, EPD have an advantage that is using the bottom glass substrate and the top e-ink sheet. So, it is impossible to apply R or C type TSP that need bottom and top glass plane. We successfully implemented the TSP (Touch Screen Panel) based on the light over the EPD (Electro Phoretic Display).

• Journal of rehabilitation welfare engineering & assistive technology
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• v.10 no.4
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• pp.259-265
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• 2016

In this paper, new method was proposed to classify lung tissues such as Broncho vascular, Emphysema, Ground Glass Reticular, Ground Glass, Honeycomb, Normal for early lung disease detection. 459 Statistical features was extraced from joint histogram matrix based on multi resolution analysis, volumetric LBP, and CT intensity, then dominant features was selected by using adaboost learning. Accuracy of proposed features and 3D AMFM was 90.1% and 85.3%, respectively. Proposed joint histogram based features shows better classification result than 3D AMFM in terms of accuracy, sensitivity, and specificity.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.28 no.1
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• pp.55-62
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• 2004

Although the previous researches evaluated the fatigue behavior of glass fiber/epoxy laminates using the traditional fracture mechanism, their researches were not sufficient to do it: the damage zone of glass fiber/epoxy laminates was occurred at the delamination zone instead of the crack-metallic damages. Thus, previous researches were not applicable to the fatigue behavior of glass fiber/epoxy laminates. The major purpose of this study was to evaluate delamination behavior using the relationship between crack length and delamination width in hybrid composite material such as Al/GFRP laminate. The details of investigation were as follows : 1) Relationship between crack length and delamination width, 2) Relationship between delamination aspect ratio and delamination area rate, 3) Variation of delamination growth rate is attendant on delamination shape factors. The test results indicated that the delamination growth rate depends on delamination width delamination aspect ratio and delamination shape factors.

• Journal of the Korean Ceramic Society
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• v.40 no.6
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• pp.547-552
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• 2003

ZnO thin films on glass substrate were deposited by RF magnetron reactive sputtering at 100 W, 1.33 Pa, Ar/O2=50 : 50, 200$^{\circ}C$, and a target/substrate distance of 4 cm. Crystallinities, surface morphologies, chemical compositions, and electrical properties of the films were investigated by XRD, SEM, AFM, RBS, and electrometer. All films showed a strong preferred c-axis orientation and the chemical stoichiometry. The propagation velocity of ZnO/IDT/glass of single electrode and double electrode types SAW filter was about 2,589 m/sec, 2,533 m/sec and insertion loss was a minimum value of about -11 dB and -21 dB, respectively.

• Elastomers and Composites
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• v.54 no.4
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• pp.308-312
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• 2019

Polyphenylene sulfide (PPS) is a well-known super engineering plastic with a high melting temperature (above 290℃). It is generally insoluble under regular conditions. Therefore, it can be used for replacing metallic materials. Many researchers are looking at the possibility of replacing aluminum in the engine compartment of an automobile. However, studies on PPS are not common as compared to conventional engineering plastics because only a few companies produce super engineering plastics. In this research, the material properties of PPS composites containing two different kinds of glass fibers and produced under different processing temperatures were investigated. The tensile strength of the PPS composites increased as the processing temperature increased. Although glass fibers with similar aspect ratios were compounded under the same processing condition, one of them yielded a higher mechanical strength.

• Journal of the Korean Ceramic Society
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• v.53 no.2
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• pp.258-262
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• 2016

The effect of zirconium dioxide ($ZrO_2$) on the properties of color conversion glasses was examined in the $BaO-ZnO-B_2O_3-SiO_2$ system. The difference in refractive index between glass and phosphor affect the optical properties of the color conversion glass because of light scattering. Reducing the difference in refractive index is a method to improve the luminous efficacy of color conversion glasses. As a reference, a type of glass that contains 25 mol% of each component was used. To increase the refractive index of the glass samples, the BaO content was increased from 25 to 40 mol%, and $ZrO_2$ was added at levels of 1, 3, and 5 mol%. Color conversion glasses were prepared by sintering a mixture of glass and 5 wt% $YAG:Ce^{3+}$ phosphor. As a result, the refractive index of the glass was found to be dependent on the BaO and $ZrO_2$ contents in the BaO-ZnO-$B_2O_3-SiO_2$ system. As the BaO and $ZrO_2$ contents were increased, the luminous efficacy of the color conversion glass was improved because the refractive index difference between the glass and the $YAG:Ce^{3+}$ phosphor decreased.

• Fibers and Polymers
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• v.4 no.2
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• pp.77-83
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• 2003

The cell modeling homogenization method to derive the constitutive equation considering the microstructures of the fiber reinforced composites has been previously developed for composites with simple microstructures such as 2D plane composites and 3D rectangular shaped composites. Here, the method has been further extended for 3D circular braided com-posites, utilizing B-spline curves to properly describe the more complex geometry of 3D braided composites. For verification purposes, the method has been applied for orthotropic elastic properties of the 3D circular braided glass fiber reinforced com-posite, in particular for the tensile property. Prepregs of the specimen have been fabricated using the 3D braiding machine through RTM (resin transfer molding) with epoxy as a matrix. Experimentally measured uniaxial tensile properties agreed well with predicted values obtained for two volume fractions.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2005.11a
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• pp.31-34
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• 2005

For the damage tolerance improvement of conventional laminated composites, stitching process has been utilized for providing through-thickness reinforcements. 2D prefonl1S were stacked with S-2 glass plain weave, and 3D preforms were fabricated using the stitching process. For the matrix system, epoxy and phenol resins were considered. To examine the damage resistance performance the low velocity drop weight impact test has been carried out, and the impact damage was examined by scanning image. CAI (Compressive After Ih1paet) tests were also conducted to evaluate residual compressive strength. Compared with 2D epoxy composites, 2D phenol composites showed drastic reduction in the compressive strength prior to impact because of the higher contents of voids. The damage area of 2D phenol composites were also larger than that of 2D epoxy composites. However, by introducing the stitching, the damage area of 3D phenol composites was reduced by 60%, while the CAI strength improvement was negligible.