• Title/Summary/Keyword: Pull-in

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Hydrophobicity and Adhesion Evaluation of MWCNT/Teflon-polyurethane Topcoat for Aircraft with Different MWCNT Coating Times (탄소나노튜브 코팅횟수에 따른 항공기용 탄소나노튜브/테프론-폴리우레탄 탑코트의 표면소수성 및 부착력 평가)

  • Lee, Jae-Hyuk;Kim, Jong-Hyun;Park, Joung-Man
    • Composites Research
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    • v.35 no.2
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    • pp.80-85
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    • 2022
  • This work presents an experiment study to evaluate the nanoparticle adhesion and surface hydrophobicity characteristics of Teflon-polyurethane top coat depending on the number of multi-wall carbon nanotube (MWCNT) coatings, which is a carbon-based hydrophobic particle. In order to measure the adhesion between the nanoparticles and the top coat, adhesion pull-off test was performed with different MWCNT oxidation times. Static contact angle and roughness measurements were carried out to characterize the surface hydrophobic behavior. Through the roughness evaluation, it was confirmed that the carbon nanotubes were wetted in the Teflon-polyurethane top coat, and the degree carbon nanotube wetting was confirmed through a USB-microscope. As a result, it was found that the larger the degree of wetting, the better the adhesion. From the experimental results, as the hydrophobicity of Teflon-polyurethane increased, the adhesive propertydecreased with the number of coatings. It was possible to improve the adhesive force and determine the number of coatings of carbon nanotubes with optimized hydrophobicity.

Transcutaneous medial fixation sutures for free flap inset after robot-assisted nipple-sparing mastectomy

  • Kim, Bong-Sung;Kuo, Wen-Ling;Cheong, David Chon-Fok;Lindenblatt, Nicole;Huang, Jung-Ju
    • Archives of Plastic Surgery
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    • v.49 no.1
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    • pp.29-33
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    • 2022
  • The application of minimal invasive mastectomy has allowed surgeons to perform nipples-paring mastectomy via a shorter, inconspicuous incision under clear vision and with more precise hemostasis. However, it poses new challenges in microsurgical breast reconstruction, such as vascular anastomosis and flap insetting, which are considerably more difficult to perform through the shorter incision on the lateral breast border. We propose an innovative technique of transcutaneous medial fixation sutures to help in flap insetting and creating and maintaining the medial breast border. The sutures are placed after mastectomy and before flap transfer. Three 4-0 nylon suture loops are placed transcutaneously and into the pocket at the markings of the preferred lower medial border of the reconstructed breast. After microvascular anastomosis and temporary shaping of the flap on top of the mastectomy skin, the three corresponding points for the sutures are identified. The three nylon loops are then sutured to the dermis of the corresponding medial point of the flap. The flap is placed into the pocket by a simultaneous gentle pull on the three sutures and a combined lateral push. The stitches are then tied and buried after completion of flap inset.

Nonlinear Analysis of Cyclically Loaded Concrete-Steel Structures Using an Anchor Bond-Slip Model (앵커 부착-미끄러짐 모형을 이용한 콘크리트-강재 구조물의 비선형 반복하중 해석)

  • Lim, Ju Eun;Lee, Jee Ho
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.29 no.5A
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    • pp.495-501
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    • 2009
  • In this paper, a numerical anchor bond-slip model is proposed to improve the numerical simulation of concrete-steel structures connected with steel anchor bolts and subjected to extreme cyclic loading. The suggested bond-slip model is composed of a group of nonlinear uniaxial connector elements and its parameters can be determined by calibrating the model with pull-out test data. Numerical analysis results from simulating a concrete foundation-steel column structure using the proposed bond-slip anchor model, which is implemented based on Abaqus elements, and the perfect-bond anchor model are compared with the experimental results. It is concluded that a reasonable anchor bond-slip model is required to realistically simulate concrete-steel structures subjected to extreme cyclic loading, and the proposed anchor bond-slip model shows acceptable performance in the present numerical analysis.

A study on the impact of smartphone addiction on adolescents' school adaptation - Focusing on students attending middle schools in Gwangju Metropolitan City

  • Gull Lim
    • Journal of the Korea Society of Computer and Information
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    • v.29 no.1
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    • pp.231-239
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    • 2024
  • This study was conducted with the purpose of understanding the factors that influence smartphone addiction on adolescents' school adaptation. The subjects were examined with a focus on students currently attending middle schools in Gwangju Metropolitan City, and data analysis was conducted using SPSS 26.0 to examine the factors influencing school adaptation, focusing on the inducements and forced inducements that lead teenagers to fall into smartphone addiction. As a result of the analysis, it was found that anonymity and desire satisfaction among the attractive factors leading to smartphone addiction have a negative impact on school adaptation, and the forcing factors that cause adolescents to become overly dependent on smartphones include online games, online chatting, online addiction, and social interaction. It was analyzed that both action and information search had a negative impact on adolescents' school adaptation. Based on the above results, policy recommendations were presented by considering the points pointed out by the two discovered factors.

Application of Virtual Studio Technology and Digital Human Monocular Motion Capture Technology -Based on <Beast Town> as an Example-

  • YuanZi Sang;KiHong Kim;JuneSok Lee;JiChu Tang;GaoHe Zhang;ZhengRan Liu;QianRu Liu;ShiJie Sun;YuTing Wang;KaiXing Wang
    • International Journal of Internet, Broadcasting and Communication
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    • v.16 no.1
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    • pp.106-123
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    • 2024
  • This article takes the talk show "Beast Town" as an example to introduce the overall technical solution, technical difficulties and countermeasures for the combination of cartoon virtual characters and virtual studio technology, providing reference and experience for the multi-scenario application of digital humans. Compared with the live broadcast that combines reality and reality, we have further upgraded our virtual production technology and digital human-driven technology, adopted industry-leading real-time virtual production technology and monocular camera driving technology, and launched a virtual cartoon character talk show - "Beast Town" to achieve real Perfectly combined with virtuality, it further enhances program immersion and audio-visual experience, and expands infinite boundaries for virtual manufacturing. In the talk show, motion capture shooting technology is used for final picture synthesis. The virtual scene needs to present dynamic effects, and at the same time realize the driving of the digital human and the movement with the push, pull and pan of the overall picture. This puts forward very high requirements for multi-party data synchronization, real-time driving of digital people, and synthetic picture rendering. We focus on issues such as virtual and real data docking and monocular camera motion capture effects. We combine camera outward tracking, multi-scene picture perspective, multi-machine rendering and other solutions to effectively solve picture linkage and rendering quality problems in a deeply immersive space environment. , presenting users with visual effects of linkage between digital people and live guests.

Experimental and numerical study on mechanical behaviour of grouted splices with light-weight sleeves

  • Quanwei Liu;Tao Wu;Zhengyi Kong;Xi Liu;Ran Chen;Kangxiang Hu;Tengfei Xiang;Yingkang Zhou
    • Steel and Composite Structures
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    • v.52 no.2
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    • pp.165-182
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    • 2024
  • Grouted sleeve splice (GSS) is an effective type of connection applied in the precast concrete structures as it has the advantages of rapidly assembly and reliable strength. To decrease the weight and cost of vertical rebar connection in precast shear walls, a light-weight sleeve is designed according to the thick-cylinder theory. Mechanical behaviour of the light-weighted GSS is investigated through experimental analysis. Two failure modes, such as rebar fracture failure and rebar pull-out failure, are found. The load-displacement curves exhibit four different stages: elastic stage, yield stage, strengthening stage, and necking stage. The bond strength between the rebar and the grout increases gradually from outer position to inner position of the sleeve, and it reaches the maximum value at the centre of the anchorage length. A finite element model predicting the mechanical properties of the light-weighted GSS is developed based on the Concrete Damage Plasticity (CDP) model and the Brittle Cracking (BC) model. The effect of the rebar anchorage length is significant, while the increase of the thickness of sleeve and the grout strength are not very effective. A model for estimating ultimate load, including factors of inner diameter of sleeves, anchorage length, and rebar diameter, is proposed. The proposed model shows good agreement with various test data.

Bond Characteristics and Splitting Bond Stress on Steel Fiber Reinforced Reactive Powder Concrete (강섬유로 보강된 반응성 분체 콘크리트의 부착특성과 쪼갬인장강도)

  • Choi, Hyun-Ki;Bae, Baek-Il;Choi, Chang-Sik
    • Journal of the Korea Concrete Institute
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    • v.26 no.5
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    • pp.651-660
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    • 2014
  • Structural members using ultra high strength concrete which usually used with steel fiber is designed with guidelines based on several investigation of SF-RPC(steel fiber reinforced reactive powder concrete). However, there are not clear design method yet. Especially, SF-RPC member should be casted with steam(90 degree delicious) and members with SF-RPC usually used with precast members. Although the most important design parameter is development method between SF-RPC and steel reinforcement(rebar), there are no clear design method in the SF-RPC member design guidelines. There are many controversial problems on safety and economy. Therefore, in order to make design more optimum safe design, in this study, we investigated bond stress between steel rebar and SF-RPC according to test. Test results were compared with previously suggested analysis method. Test was carried out with direct pull out test using variables of compressive strength of concrete, concrete cover and inclusion ratio of steel fiber. According to test results, bond stress between steel rebar and SF-RPC increased with increase of compressive strength of concrete and concrete cover. Increasing rate of bond stress were decrease with increase of compressive strength of SF-RPC and concrete cover significantly. 1% volume fraction inclusion of steel fiber increase the bond stress between steel rebar and SF-RPC with two times but 2% volume fraction cannot affect the bond stress significantly. There are no exact or empirical equations for evaluation of SF-RPC bond stress. In order to make safe bond design of SF-RPC precast members, previously suggested analysis method for bond stress by Tepfers were evaluated. This method have shown good agreement with test results, especially for steel fiber reinforced RPC.

JSAP1 Interacts with Kinesin Light Chain 1 through Conserved Binding Segments (JSAP1과 Kinesin Light Chain 1의 결합 및 결합부위 규명)

  • Kim, Sang-Jin;Lee, Chul-Hee;Park, Hye-Young;Yea, Sung-Su;Jang, Won-Hee;Lee, Sang-Kyeong;Park, Yeong-Hong;Cha, Ok-Soo;Moon, Il-Soo;Seog, Dae-Hyun
    • Journal of Life Science
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    • v.17 no.7 s.87
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    • pp.889-895
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    • 2007
  • A conventional kinesin, KIF5/kinesin-I, is composed of two kinesin heavy chains (KHCs) and two kinesin light chains (KLCs) and binds directly to microtubules. KIF5 motor mediates the transport of various membranous organelles, but the mechanism how they recognize and bind to a specific cargo has not yet been completely elucidated. Here, we used the yeast two-hybrid system to identify the neuronal protein(s) that interacts with the tetratricopeptide repeats (TRP) of KLCI and found a specific interaction with JNK/stress-activated protein kinase-associated protein 1 (JSAP1/JIPP3). The yeast two-hybrid assay demonstrated that the TRP 1,2 domain-containing region of KLCI mediated binding to the leucine zipper domain of JSAP1. JSAP1 also bound to the TRP region of lac2 but not to neuronal KIF5A, KIF5C and ubiquitous KIF5B in the yeast two-hybrid assay. In addition, these proteins showed specific interactions in the GST pull-down assay and by co-immunoprecipitation. KLCI and KIF5B interacted with GST-ISAP1 fusion proteins, but not with GST alone. An antibody to JSAPI specifically co-immunoprecipitated KIF5s associated with JSAP1 from mouse brain extracts. These results suggest that JSAP1, as KLC1 receptor, is involved in the KIF5 mediated transport.

Is the UU Stitch Really Alternative to Modified MA (Mason-Allen) Stitch for Rotator Cuff Repair? - Biomechanical Comparative Study of UU to Modified MA Stitch - (회전근 개 파열의 봉합에서 UU 봉합법은 변형된 MA(Mason-Allen) 봉합법을 대치할 수 있는가? - UU 봉합법과 변형된 MA 봉합법의 생역학적 비교-)

  • Friedman, Darren J;Ko, Sang-Hun;Park, Ki-Bong;Jun, Hyung-Min;Kim, Tae-Won;Lim, Hyun-Woo;Yum, Young-Jin
    • Clinics in Shoulder and Elbow
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    • v.12 no.2
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    • pp.207-214
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    • 2009
  • Purpose: In arthroscopic rotator cuff repairs there are generally weak link in tendon suture interface, arthroscopic rotator cuff repairs can have higher retear rates than open repairs. The purpose of this study was to compare the strength of UU (Ulsan University) suture than open modified MA (Mason-Allen) suture when suture anchored into bone. Materials and Methods: The human supraspinatus tendons were harvested from the shoulder of the cadaver and split in 2 times, producing four tendons per one shoulder, for a total of 24 specimens. Two suture configurations (UU, MA) were randomized and checked on each set of tendons. Specimens were cyclically loaded under force control between 5 and 30 N at 0.25 Hz for fifty cycles. Each specimen was loaded to failure under displacement control at 1 mm/sec. Cyclic elongation, peak to peak displacement, stiffness, ultimate tensile load, mode of failure were checked. Results: No significant difference was found between two suture configuration with respect to peak to peak displacement, cyclic elongation, and stiffness. With regard to ultimate failure load, there were no significant difference statistically between the UU suture and modified MA suture (109.4 N, 110.6 N). The most common mode of failure between both sutures was suture pull-out through the tendon. Conclusion: The UU suture and modified MA suture produced similar biomechanical properties.

Cenozoic Geological Structures and Tectonic Evolution of the Southern Ulleung Basin, East Sea(Sea of Japan) (동해 울릉분지 남부해역의 신생대 지질구조 및 지구조 진화)

  • Choi Dong-Lim;Oh Jae-Kyung;Mikio SATOH
    • The Korean Journal of Petroleum Geology
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    • v.2 no.2 s.3
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    • pp.59-70
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    • 1994
  • The Cenozoic geological structures and the tectonic evolution of the southern Ulleung Basin were studied with seismic profiles and exploration well data. Basement structure of the Korea Strait is distinctly characterized by normal faults trending northeast to southwest. The normal faults of the basement are most likely related to the initial liking and extensional tectonics of Ulleung Basin. Tsushima fault along the west coast of Tsushima islands runs northeastward to the central Ulleung Basin. The Middle Miocene and older sequences in the Tsushima Strait show folds and faults mostly trending northeast to southwest. These folds and faults may be interpreted as a result of compressional tectonics. The Late Miocene to Qauternary sequences are not much deformed, but numerous faults mostly N-S trending are dominated in the Tsushima Strait. The Ulleung Basin was in intial rifting during Oligocene, and then active extension and subsidence from Early to early Middle Miocene. Therefore SW Japan separated from Korea Peninsula and drifted toward southeast, and Ulleung Basin was formed as a pull-apart basin under dextral transtensional tectonic regime. During rifting and extensional stage, Tsushima fault as a main tectonic line separating SW Japan block from the Korean Peninsula acted as a normal faulting with right-lateral strike-slip motion as SW Japan drifted southeastward. During middle Middle Miocene to early Late Miocene, the opening of Ulleung basin stopped and uplifted due to compressional tectonics. The southwest Japan block converging on the Korean Peninsula caused compressional stress to the southern margin of Ulleung Basin, resulting in strong deformation under sinistral transpressional tectonic regime. Tsushima fault acted as thrust fault with left-lateral strike-slip motion. From middle Late Miocene to Quaternary, the southern margin of Ulleung Basin has been controlled by compressional motion. Thus the Tsushima fault still appears to be an active thrust fault by compressional tectonic regime.

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