• Restorative Dentistry and Endodontics
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• v.39 no.1
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• pp.51-55
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• 2014

The term "endo-perio" lesion has been proposed to describe the destructive lesion resulting from inflammatory products found in varying degrees in both the periodontium and the pulpal tissues. In most of the cases, clinical symptoms disappear following successful endodontic therapy. However failure after conventional root canal treatment calls for surgical intervention. A 35 year old male patient with endo-perio lesion in right maxillary lateral incisor was treated with platelet rich fibrin (PRF) and alloplastic bone substitute after conventional endodontic therapy. At the end of 6 months there was gain in clinical attachment, increased radiographic bone fill and reduction in probing depth which was maintained till 18 month follow-up. Present case report aims to evaluate the efficacy of PRF and alloplastic bone substitute in the management of intrabony defect associated with endo-perio lesion in maxillary lateral incisor because the healing potential of PRF and bone graft has not been widely studied in endodontics. The use of PRF allows the clinician to optimize tissue remodelling, wound healing and angiogenesis by the local delivery of growth factors and proteins. The novel technique described here enables the clinician to be benefited from the full regenerative capacity of this autologous biologic material.

• Journal of Fashion Business
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• v.17 no.1
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• pp.13-29
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• 2013

The purpose of this study was to analyze eroticism shown in the fashion of Lady Gaga's music video. This study methods taken theoretical consideration and then was classified eroticism based on previous studies and was analyzed costumes from Lady Gaga's music video. The results of this study were as follows: Avant-garde style exaggerates shoulders, hips, a hat or uses metal and glossy material, tape, leather and it was expressed into emphasizing or baldly exposing breast. Primitive style was expressed in ethnic style and animal patterns, lingerie look with drastic, bald exposing fashion. Romantic style was expressed using rococo style costume, frill, pleats, decoration and was produces eroticism with see-through look or costume fitting to the body. Sportive style expresses a healthier and erotic image using tight costume in yellow, blue and black while exposing belly and legs. Janus-faced style was expressed by dressing up like a man or using the method of attachment and exposure in clergy's costume. Humorous style was expressed by emphasizing parts of body or costume itself. As examined in the above, Lady Gaga was expressed various eroticism images in her music video and is builds her own sexually appealing.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.03a
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• pp.492-498
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• 2008

In this paper are described recent studies about variable nozzles, that are a rectangular type nozzle and an axisymmetric type nozzle, of the precooled turbojet engine(S-engine) which are developed for the demonstration of the key technologies for the propulsion system of the hypersonic airplane and the first stage propulsion of the TSTO space plane. For the rectangular nozzle, three types of C-shaped carbon/carbon composite cowls which includes subscale model of the precooled turbojet engine are fabricated and the fine attachment to the ramp is confirmed. For the firing of the S-engine, stainless steel cowl with concrete heat insulator are fabricated and tested for 20 sec. Axisymmetric variable plug nozzle which is made of C/C material is fabricated and pressurized by the cold flow test. The axisymmetric plug nozzle can be operative up to 0.57 MPa of nozzle inlet pressure.

• Korean Journal of Materials Research
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• v.31 no.5
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• pp.278-285
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• 2021

This study produces electroconductive polycaprolactone (PCL)-based film with different amounts of graphene (G) through electrospinning, and the characteristics of the produced G/PCL composites are investigated. The G/PCL results are analyzed by comparing them with those obtained using pure PCL electrospun film as a control. The morphology of electrospun material is analyzed through scanning electron microscopy and transmission electron microscopy. Mechanical and electrical properties are also evaluated. Composites containing 1 % graphene have the highest elongation rate, and 5 % samples have the highest strength and elasticity. Graphene contents > 25 % show electro-conductivity, which level improves with increase of graphene content. Biological characteristics of G/PCL composites are assessed through behavioral analysis of neural cell attachment and proliferation. Cell experiments reveal that compositions < 50 % show slightly reduced cell viability. Moreover, graphene combinations facilitated cell proliferation compared to pure PCL. These results confirm that a 25 % G/PCL composition is best for application to systems that introduce external stimuli such as electric fields and electrodes to lead to synergistic efficiency of tissue regeneration.

• Korean Journal of Materials Research
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• v.33 no.2
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• pp.47-53
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• 2023

When exposed to different types of bacteria in the oral cavity, denture based resins are prone to bacteria attachment. The purpose of this study was to investigate the physical, biological, and antimicrobial properties of denture base resins coated with Peony extract (200, 400, and 600 ㎍/mL). Specifically, the surface properties (microhardness, contact angle, and color change of the coated specimens), cell cytotoxicity (measured using MTT assay), and antimicrobial activity (against S. mutans (Streptococcus mutans) and C. albicans (Candida albicans) using a growth inhibition assay) were evaluated. The polyphenol content was measured using ultraviolet-visible (UV-vis) spectrometry. The experimental groups (specimens coated with Peony extract) and a control group (specimens coated without Peony extract) were statistically compared using a one-way analysis of variance and Tukey's post-hoc tests. No statistically significant differences in surface properties or cell cytotoxicity were observed, which demonstrated their biocompatibility. Conversely, a statistically significant difference in antimicrobial activity was observed between the experimental and control groups after 48 h. This confirms the antimicrobial activity of the denture base resin coated with Peony extract and demonstrates that it is a promising dental material for preventing stomatitis.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.05a
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• pp.41-42
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• 2023

Test results for a total of four types of complex waterproofing methods were analyzed. In the case of the A method, the stress generated by high-viscosity compounds adhering to the base test body during the behavior of the test body was transferred to the sheet surface layer. In the case of the B method and the C method, the properties of the waterproof sheet consisting of a non-hardened seal based and a non-hardened seal are well reflected and stress absorption in the non-hardened seal layer acts strongly, rapidly reducing stress transfer to the surface of the waterproof sheet. In the case of the D method, slip occurs due to repeated behavior, and the stress on the attachment surface is reduced, and the stress transfer to the surface is greatly reduced. As a result, four types of composite waterproofing methods resulted in changing the stress transfer mechanism caused by behavior on the concrete surface due to the physical properties of the internal constituent material of the waterproof sheet.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.23 no.8
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• pp.605-610
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• 2010

The devices based on electrically erasable programmable read-only memory (EEPROM) structure are proposed for the detection of external electric charges. A large size charge contact window (CCW) extended from the floating gate is employed to immobilize external charges, and a control gate with stacked metal-insulator-metal (MIM) capacitor is adapted for a standard single polysilicon CMOS process. When positive voltage is applied to the capacitor of CCW of an n-channel EEPROM, the drain current increases due to the negative shift of its threshold voltage. Also when a pre-charged external capacitor is directly connected to the floating gate metal of CCW, the positive charges of the external capacitor make the drain current increase for n-channel, whereas the negative charges cause it to decrease. For an p-channel, however, the opposite behaviors are observed by the external voltage and charges. With the attachment of external charges to the CCW of EEPROM inverter, the characteristic inverter voltage behavior shifts from the reference curve dependent on external charge polarity. Therefore, we have demonstrated that the EEPROM inverter is capable of detecting external immobilized charges on the floating gate. and these devices are applicable to sensing the pH's or biomolecular reactions.

• Journal of Environmental Science International
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• v.23 no.6
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• pp.1175-1182
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• 2014

In this study, we examined the effect of cathode from electrolysis reactor for treating ballast water. We are going to select a suitable cathode for seawater electrolysis after considering the effect on the generation of the oxidant of cathode and the electrode deposition materials adhering to the surface of cathode. Anode is Ru-Ti-Pd electrode and cathode are Ti, Pt, JP520 (Ni-Pt-Ce) electrodes. Using the cathode of the three types, experiments were conducted to examine the effects of TRO (total residual oxidants) generation concentration and RNO (N, N-Dimethyl-4-nitrosoaniline, indicator of the generation of OH radical) degradation concentration (in 1, 35 psu), ohmic drop, FESEM(field emission scanning electron microscope) observation of cathode surface and EDX (energy dispersive X-ray spectroscopy) measurements of attached fouling material. The results showed that TRO generation concentration and RNO degradation concentration in according to each type of cathode are not different. The attached fouling materials were observed on the surface of Ti and the JP520 electrode by the observation of SEM after electrolysis for two hours, but it was not observed on the surface of Pt electrode. When considering the surface ohmic drop of cathode and the attached fouling materials, Pt electrode was judged as the excellent cathode.

• Journal of the Korea Institute of Building Construction
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• v.12 no.4
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• pp.377-385
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• 2012

In this study, the Impact resistance of steel fiber and organic fiber reinforced concrete and mortar was evaluated and the improvement in toughness resulting from an increase in compressive strength and mixing fiber for impact resistance on performance was examined. The types of fiber were steel fiber, PP and PVA, and these were mixed in at 0.1, 0.5 and 1.0 vol.%, respectively. Impact resistance is evaluated with an apparatus for testing impact resistance performance by high-speed projectile crash by gas-pressure. For the experimental conditions, Specimen size was $100{\times}100{\times}20$, 30mm ($width{\times}height{\times}thickness$). Projectile diameter was 7 and 10 mm and impact speed is 350m/s. After impact test, destruction grade, penetration depth, spalling thickness and crater area were evaluated. Through this evaluation, it was found that as compressive strength is increased, penetration is suppressed. In addition, as the mixing ratio of fiber is increased, the spalling thickness and crater area are suppressed. Organic fibers have lower density than the steel fiber, and population number per unit area is bigger. As a result, the improvement of impact resistance is more significant thanks to dispersion and degraded attachment performance.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.8
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• pp.104-109
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• 2020

Recently, vibration and noise have become an important issue in the auto industry. Asphalt vibration damping pads are used to reduce the noise and vibration of automobile bodies, and asphalt is used for many mass-produced parts due to its simple attachment process and low processing costs. In this study, the self-adhesion of asphalt pads using Joule heating was evaluated. To create the asphalt pad for the experiment, the asphalt pad was molded into a specific thickness by using SGACC material and rubber used in the vehicle body as a main component and a modified resin and filler. The SGACC material was 200 mm in length, 200 mm in width, and 0.7 mm in thickness. The asphalt pad was 200 mm in length, 100 mm in width, and 3 mm in thickness. The equipment was composed of a TR (Transformer) DC254kVA and a TC (Time controller) for a current of up to 20,000 A. The current for the Joule heating was set to 7.0 kA and a 3/1 cycle, for which the adhesion of the asphalt pad over the current flow time was evaluated.