• Polymer(Korea)
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• v.38 no.3
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• pp.358-363
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• 2014

Adhesion forces between acrylate imprinting resin and a surface treated atomic force microscope (AFM) tip were investigated. Compared to the untreated silicon tip, 38% of the adhesion force is reduced for the hydrophobic tip treated with $CH_4$ plasma whereas 1.6 time increases is found for the hydrophilic tip with $O_2$ plasma treatment. Such a measurement of the adhesion force using AFM provides very quantitative results on adhesion comparing to the crosscut adhesion test which gives qualitative results. Since the adhesion area becomes larger as the imprinting pattern size gets smaller, the surface treatment issue becomes more important in the nano-imprinting process.

• Journal of the Semiconductor & Display Technology
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• v.10 no.2
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• pp.115-119
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• 2011

A tip-type carbon nanotube(CNT)-based field emitter was studied to consider it as electron source for micro-focused x-ray tube. The CNT was grown directly on a metal (tungsten) substrate by using an inductively coupled plasma-chemical vapor deposition (ICP-CVD) method. Prior to CNT growth, the metal substrate was etched to have various tip angles from $10^{\circ}$ to $180^{\circ}C$ (flat-type). The morphologies and microstructures of all the grown CNTs were analyzed via field-emission SEM. Furthermore, the effects of substrate tip-angles on the emission properties of CNT-based field emitters were characterized to estimate the maximum current density, the turn-on voltage, and the spatial distribution of electron beams. Prolonged long-term stability testing of the CNT emitters was also performed. All the experiment results obtained from this study indicated why a tip-type CNT emitter, compared with a flat-type CNT emitter, would be more desirable for a micro-focused x-ray system, in terms of the emission current level, the focused beam area, and the emission stability.

• Journal of Periodontal and Implant Science
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• v.31 no.3
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• pp.531-542
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• 2001

Periodontal debridement is most important procedure in periodontal treatment, because periodontal disease is the biofilm infection. The use of ultrasonic instrument has many clinical advantages compared to classical hand instrument. The introduction of newly developed ultrasonic scaler tips made the use of ultrasonic scaler popular. However the study of tooth substance removal according to the working parameters of ultrasonic scaler with newly developed tips is not sufficient. The purpose of this study is to evaluate the effects of working parameters of piezoelectric ultrasonic scaler with curette tip on casting gold removal. The working parameters was standardized by the sledge device which controls lateral force(0.5 N, 1.0 N, 2.0 N) and power setting was adjusted 2, 4, 8 in P mode and S mode and instrumentation time was 5 seconds. The defect depth and width were measured with profile meter and defect surface was examined by SME. The depth of defect was significantly large in S mode( $39.58{\pm}19.35{\mu}m$) compared to P mode( $8.37{\pm}6.98{\mu}m$). There was significant decrease of depth of defect between 1.0N($32.87{\pm}27.18{\mu}m$) and 2.0N( $14.86{\pm}15.04{\mu}m$). The area of defect was also significantly large in S mode($4482.42{\pm}3551.71{\mu}m^2$) compared to P mode( $922.06{\pm}960.32{\mu}m^2$). There was significant decrease of area of defect between 1.0N($3889.12{\pm}3936.00{\mu}m$) and 2.0N( $974.66{\pm}986.01{\mu}m$). The change of mode did not effect on the width of the defect. The change of power setting did not effect on the depth, width, and area of defect. In spite of limitation of this study it could be concluded that the use of piezoelectric ultrasonic scaler with curette tip on S mode could make significant tooth substance loss.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.37 no.6
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• pp.457-463
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• 2011

Introduction: This study evaluate the soft tissue changes to the upper lip and nose after Le Fort I maxillary posterosuperior rotational movement. Materials and Methods: Twenty Skeletal class III patients, who had undergone bimaxillary surgery with a maxillary Le Fort I osteotomy and bilateral sagittal split ramus osteotomy, were included in the study. The surgical plan for maxilla was posterosuperior rotational movement, with the rotation center in the anterior nasal spine (ANS) of maxilla. Soft and hard tissue changes were measured by evaluating the lateral cephalograms obtained prior to surgery and at least 6 months after surgery. For cephalometric analysis, four hard tissue landmarks ANS, posterior nasal spine [PNS], A point, U1 tip), and five soft tissue landmarks (pronasale [Pn], subnasale [Sn], A' Point, upper lip [UL], stomion superius [StmS]) were marked. A paired t test, Pearson's correlation analysis and linear regression analysis were used to evaluate the soft and hard tissue changes and assess the correlation. A P value <0.05 was considered significant. Results: The U1 tip moved $2.52{\pm}1.54$ mm posteriorly in the horizontal plane (P<0.05). Among the soft tissue landmarks, Pn moved $0.97{\pm}1.1$ mm downward (P<0.05), UL moved $1.98{\pm}1.58$ mm posteriorly (P<0.05) and $1.18{\pm}1.85$ mm inferiorly (P<0.05), and StmS moved $1.68{\pm}1.48$ mm posteriorly (P<0.05) and $1.06{\pm}1.29$ mm inferiorly (P<0.05). The ratios of horizontal soft tissue movement to the hard tissue were 1:0.47 for the A point and A' point, and 1:0.74 for the U1 tip and UL. Vertically, the movement ratio between the A point and A' point was 1:0.38, between U1 tip and UL was 1:0.83, and between U1 tip and StmS was 1:0.79. Conclusion: Posterosuperior rotational movement of the maxilla in Le Fort I osteotomy results in posterior and inferior movement of UL. In addition, nasolabial angle was increased. Nasal tip and base of the nose showed a tendency to move downward and showed significant horizontal movement. The soft tissue changes in the upper lip and nasal area are believed to be induced by posterior movement at the UL area.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.19 no.1
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• pp.85-107
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• 1993

The cosmetic fine powders were mixed with variation of mixing time(5) in the mixers (ribbon mixer, powder mixer, micropulverizer and fine impact mill). The powders were nixed with small amount of ferric oxide. as tracer. The mixed powders ere measured the particle size distribution, specific surface area and surface color with mixing time (s). The color variation, particle size distribution and specific surface area of the mixed powder exist a relationship with mining time(s) that can be expressed as mathematical equations to show the degree of the mixing of the powder mixture. The linear velocity of the impellar tip is the main factor contributing to he mixing efficiency of the mixers un this study. According to the linear velocity, he mixers used are devieded as convection mixing (ribbon mixer), sclera mixing powder mixer) and diffusion mixing (micropulverizer/fine impact mill).

• Journal of the Korean Society of Marine Environment & Safety
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• v.17 no.1
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• pp.75-82
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• 2011

Marine current energy is one of the most interesting renewable and clean energy resources that have been less exploited. Especially, Korea has worldwide outstanding tidal current energy resources and it is highly required to develop tidal in-stream energy conversion system in coastal area. The objective of study is to investigate harnessing techniques of tidal current energy and to design the a 100 kW horizontal axis tidal turbine using blade element momentum theory with Prandtl's tip loss factor for optimal design procedures. In addition, Influence of Prandtl's tip loss factor at local blade positions as a function of tip speed ratio was studied, and the analysed results showed that power coefficient of designed rotor blade using NACA 63812 was 0.49 at rated tip speed ratio.

• The Korean Journal of Pain
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• v.19 no.2
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• pp.146-151
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• 2006

Background: Spinal cord stimulation is a well-established method for the management of several types of chronic and intractable pain. This form of stimulation elicits a tingling sensation (paresthesia) in the corresponding dermatomes. The goal of this study was to establish a correlation between the spinal levels of the implanted epidural electrodes and the paresthesia elicited due to stimulation of the neural structures. Methods: Thirty five patients, who received trial spinal cord stimulation, were evaluated. After the insertion of the lead to the selected position, the areas of paresthesia evoked by stimulation were evaluated. Results: Seventy-one percent of cases showed paresthesia in the shoulder area when the tip of the electrode was located between the C2⁣-C4 levels. At the upper extremities, paresthesia was evoked in 86⁣-93% of cases, regardless of the location of the electrode tip within the cervical spinal segments. The most common tip placement of the leads eliciting hand stimulation was at the C5 level. The most common level of electrode tip placement eliciting paresthesia of the anterior and posterior thigh and the foot were at the T7-⁣T12, T10⁣-L1 and T11-⁣L1 vertebral segments, respectively. Conclusions: Detailed knowledge of the patterns of stimulation induced paresthesia in relation to the spine level of the implanted electrodes has allowed the more consistent and successful placement of epidural electrodes at the desired spine level.

• Journal of Digital Convergence
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• v.16 no.1
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• pp.125-134
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• 2018

This study focused on the study of the moderating effects of absorptive capacity(AC) of venture firms on the technological innovation performance(TIP). For this purpose, this study analyzed the relationship between entrepreneurship(ENT), innovation competence(INC), external cooperation(EXO) and AC affecting the performance of technological innovation activities in venture companies in the area of Busan. As a result of analysis, the AC showed a role of moderating processes, in which ENT have affected the INC, and ENT, INC, and EXO have affected the TIP. Secondly, several relationships which have positively influenced or mediated, have been presented. ENT has positively influenced INC, EXO, & TIC. INC have done so EXC & TIP. EXC have done so TIP. Each of INC and EXC has been positively mediating the relationship between ENT & TIP.

• Journal of Adhesion and Interface
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• v.19 no.4
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• pp.163-166
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• 2018

Dip-pen nanolithography(DPN) is an atomic force microscope (AFM) based method of generating nano- or micro-patterns. This technique has been used to transfer various ink materials on the substrate through water meniscus formed between AFM tip and the substrate surface. In this study, the heptadecafluoro-1,1,2,2-tetrahydrodecyltrimethoxysilane (HDFDTMS) ink materials were coated on the pre-coated AFM tip surface with the HDFDTMS molecules. When the tip brought into contact with the hydroxyl-functionalized silicon surface, HDFDTMS ink molecules have been successfully transported from the tip onto the surface via water meniscus. The created array and passivation area showed stable structures on the surface, and the transport of ink materials from the AFM tip to the surface followed linear increase in pattern size with contact time.

• The Journal of Korean Academy of Prosthodontics
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• v.46 no.3
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• pp.255-260
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• 2008

STATEMENT OF PROBLEM: Preparation of implant beds with lasers is considered a safe and reliable method, but the accuracy of this technique has not been examined. PURPOSE: The purpose of this study was to evaluate the accuracy and effectiveness of implant bed preparation using an Er,Cr:YSGG laser. MATERIAL AND METHODS: An Er,Cr:YSGG laser was applied to pig rib bone. The laser was employed at a 5.75 W power setting, 30 Hz/sec pulse repetition, and 70 ${\mu}s$ pulse duration with 50 % water and 60% air spray. According to laser tips the groups were divided as follows; Group 1: paralleled - shaped sapphire tip (0.6 mm${\Phi}$), Group 2: paralleled - shaped zirconia tip (0.6 mm${\Phi}$), Group 3: tapered sapphire tip (0.4 mm${\Phi}$). The Er,Cr:YSGG laser tip was separated by 1 mm from the bone and applied for 15 seconds in a non-contact mode. After the application, the bone was sectioned for specimens. Histologic measurements were determined by computerized morphometry. The length of the prepared bone surface was measured and the width of the entrance was measured. The results were analyzed with one-way ANOVA (P<0.05). RESULTS: The prepared length of group 3 was longer than that of group 2. The prepared bone width was larger than the width of the laser tip in every group. Additional bone removal was observed adjacent to the prepared area and displayed an irregular surface. CONCLUSION & DISCUSSION: Different cutting effects were observed according to the laser tip, emphasizing the importance of proper tip selection in the clinical setting. This preliminary study supported the existence of hydrokinetic effects.