• The Journal of Advanced Prosthodontics
• /
• v.9 no.4
• /
• pp.257-264
• /
• 2017

PURPOSE. To evaluate the adhesion to CAD/CAM feldspathic blocks by failure analysis and shear bond strength test (SBSt) of different restorative systems and different surface treatments, for purpose of moderate chipping repair. MATERIALS AND METHODS. A self-adhering flowable composite (Vertise Flow, Kerr) containing bi-functional phosphate monomers and a conventional flowable resin composite (Premise Flow, Kerr) applied with and without adhesive system (Optibond Solo Plus, Kerr) were combined with three different surface treatments (Hydrofluoric Acid Etching, Sandblasting, combination of both) for repairing feldspathic ceramics. Two commercial systems for ceramic repairing were tested as controls (Porcelain Repair Kit, Ultradent, and CoJet System, 3M). SBSt was performed and failure mode was evaluated using a digital microscope. A One-Way ANOVA (Tukey test for post hoc) was applied to the SBSt data and the Fisher's Exact Test was applied to the failure analysis data. RESULTS. The use of resin systems containing bi-functional phosphate monomers combined with hydrofluoric acid etching of the ceramic surface gave the highest values in terms of bond strength and of more favorable failure modalities. CONCLUSION. The simplified repairing method based on self-adhering flowable resin combined with the use of hydrofluoric acid etching showed high bond strength values and a favorable failure mode. Repairing of ceramic chipping with a self-adhering flowable resin associated with hydrofluoric acid etching showed high bond strength with a less time consuming and technique-sensitive procedure compared to standard procedure.

• Journal of Families and Better Life
• /
• v.17 no.1
• /
• pp.167-178
• /
• 1999

The purpose of this study were to 1) classify the domain according to the level f housework sociaklization and 2) illuminate the determinants on it. The subjects of this study were 564 married women living in Seoul. A questionnaire was used as survey method. Frequenciaes percentiles mean and regression were employed for data analysis. major findings were as follows; 1) The domain according to the level of housework socialization were purchases of storage food convemience food dining-out clothes repairing services and laundry wervices 2) Of market goods characteristics quality and time-saving characteristics were influencing variables in the level of storage food purchases. The affecting variables in the level of convenience food purchases dining-out and clothes repairing services purchases was quality of market goods. In the level of laundry services time-saving characteristics was significant.

• ETRI Journal
• /
• v.34 no.3
• /
• pp.478-481
• /
• 2012

Testing memory and repairing faults have become increasingly important for improving yield. Redundancy analysis (RA) algorithms have been developed to repair memory faults. However, many RA algorithms have low analysis speeds and occupy memory space within automatic test equipment. A fast RA algorithm using simple calculations is proposed in this letter to minimize both the test and repair time. This analysis uses the grouped addresses in the faulty bitmap. Since the fault groups are independent of each other, the time needed to find solutions can be greatly reduced using these fault groups. Also, the proposed algorithm does not need to store searching trees, thereby minimizing the required memory space. Our experiments show that the proposed RA algorithm is very efficient in terms of speed and memory requirements.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.10 no.1
• /
• pp.115-122
• /
• 2006

Repairing concrete structures depended on only technician' experience without quality test standards would have problems. For solving those problems, this paper has analyzed the relations between injection quantify and crack width, injection time and crack width, injection pressure and crack width, injection pressure/time and crack width, injection quantity and structure size, injection quantify and individual crack Position, injection time and crack width/structure thickness. The data gained from this analysis would be helpful for systematic quality control of repairing concrete structures.

• Korean Journal of Organic Agriculture
• /
• v.3 no.1
• /
• pp.11-22
• /
• 1994

Exposing plant organs to high doses of ionizing irradiation, penetrating into the plant tis-sues and cells, along the track structure of particles, lesions, and sublesions are formed on the molecules and organelles. As a result, disorders in the growth and development as well as chlorophyll-deficiency symptoms occur. The time scale of their reparation, recovery and over compensation during ontogenesis, constitutes a question of high theoretical and practical importanced, with special regard to nuclear fallout. With an aim to model the “ut supra”stated phenomena, the seeds of bean, Echo elit licensed variety, were irradiated by 300 Gy dose of X-ray-irradiation (120 kV:4.5 mA). According to the data obtained, the biosynthesis of photosynthetic pigments, will have been completed by the beginning of flowering. In consequence of the overcompensation of the repairing processes, the organs of plants developed from irradiated seeds, showed a partly differing correlative growth, compared to those of control plants. In order to characterize the vivo response of radiation-injured plants, a new method and approach were used. The changes of the electric capacitance of the plants during their ontogenesis, were continously monitored and recorede via a computer-aided and controlled measurement. In view of the data collected in such a way, the repairing plants may respond more quickly and intensively to the changes of environmental factors.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2006.05b
• /
• pp.325-328
• /
• 2006

Recently, repair mortars have been mainly used for repairing old concrete structures. In this study, a new repair mortar including shotcrete admixture, slag, silica fume, sulphate and calcium carbonate, was developed for repairing shotcrete layer and the fresh properties and mechanical characteristics of the repair mortar was measured, Test results showed that the shortcrete admixture and other additives reduce the final setting time from about 7 hours to within 20 minutes and increase very early strength and stiffness (within 5 hours after cast).

• Proceedings of the KIEE Conference
• /
• 1999.07c
• /
• pp.1205-1207
• /
• 1999

All the submarine cable lines have been repaired restored and newly installed since 1970' s they were installed by the foreign technician around the islands off the southern and western coast of Korean peninsula. But April, 10th, 1998, for the first time in Korea, we Korean team of technicains succeeded in repairing and restoring the troubled cable lines from HEUGIL island to MASAG island, WANDO county, CHUN-NAM province. This job was done only by applying our newly researched and developed technology. The troubled cable lines were connected again by this technology.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2018.11a
• /
• pp.193-194
• /
• 2018

In this study, various materials such as epoxy material, urethane material, cement material, and acrylic material are used to solve the water leakage occurring in underground structures. However, in the reality that the durability is insufficient and the effect is insufficient, it is aimed to improve the repairing effect by using acrylics. As a second study, it is confirmed that leachate can be used as a repair material by considering long time under water stability, elongation range test, fatigue resistance test, tube stability test, damage recovery performance ana temperature stability considering leakage environment for polyacrylate. In addition, this material is applied to Expansion Joint to perform leakage repair, and to verify the effect of repairing leakage by monitoring and visual observation of concrete humidification.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2003.03a
• /
• pp.241-248
• /
• 2003

In August 2002, side wall of OO tunnel, at the Bonghwa, Kungbuk province, Korea, was collapsed by abruptly applied heavy soil and water pressure to side wall from a inclined shaft when there was a heavy rain. These days, Inclined shaft is used for the purpose of reducing construction time, using ventilation system, using the out of carrying equipment and mucking when we construct tunnel in the world. Recently constructed tunnel has the source of inclined shafts, but the more time elapse, we lose the source of the inclined shaft such as exact position, condition, and the fact that whether inclined shaft is exist or not. Therefore, this study inspected the interior's appearance, analyzed structure to evaluate the reason of collapsing side wall and this study also performed the repairing work. Finally, we show improving maintenance method to prevent that similar accident that might be happened.

• Journal of the Korean Recycled Construction Resources Institute
• /
• v.2 no.1
• /
• pp.1-9
• /
• 2014

In this paper, $CO_2$ amount is evaluated considering repairing timing and unit $CO_2$ amount per repair method including various stage of material manufacturing, moving, and construction. Four mix proportions with mineral admixture are considered and repairing timing/numbers are simulated based on the results from Life 365 which can handle chloride penetration. Furthermore two repair methods (simple cover concrete replacement and replacement with electro-chemical method for removing chloride content) are considered and the related $CO_2$ emissions are evaluated. From the study, the case with high W/B (water to binder ratio) ratio shows smaller $CO_2$ emission in construction stage but it increases more rapidly with increasing number of repair. $CO_2$ emission considering electro-chemical method greatly increases with the increasing unit $CO_2$ for the repairing method. The numbers of jumping step (repairing number) are evaluated to be 9 for WB37-OPC, 18 for WB50-OPC, 4 for WB40-SG, and 7 for WB47-SG respectively. RC structures with the longer maintenance free period are evaluated to be advantageous for saving $CO_2$ emission.