• Title/Summary/Keyword: Root gap

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Effects of Bogijetong-Tang on Diabetic-peripheral Neuropathy Induced by Streptozotocin in the Mouse (보기제통탕(補氣除痛湯)이 Streptozotocin으로 유발된 당뇨병성 말초신경병증 동물 모델에 미치는 영향)

  • Lee, Jong Bin;Kim, Chul Jung;Cho, Chung Sik
    • The Journal of Korean Medicine
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    • v.34 no.3
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    • pp.126-142
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    • 2013
  • Objectives: Previous reports have shown that Bogijetong-Tang (BJT) is effective in peripheral neuropathy induced by taxol and crush injury. In this study, we researched the effects of BJT on diabetic neuropathy induced by STZ in the mouse. Methods: We performed both in vitro and in vivo experiments to verify the effects of BJT on diabetic neuropathy induced by STZ in mice. Changes in axonal recovery were observed with immunofluorescence staining using NF-200, Hoechst33258, $S100{\beta}$, caspase 3 and anti-cdc2. Proliferation and degeneration of Schwann cells were investigated by immunofluorescence staining and western blot analyses. Results: BJT showed considerable effects on neurite outgrowth and axonal regeneration in diabetic neuropathy. BJT contributed to the creation of NF-200, GAP-43, Cdc2, phospho-vimentin, ${\beta}1$, active ${\beta}1$, ${\beta}3$ integrin, phospho-Erk1/2 protein. Conclusions: Through this study, we found that BJT is effective for enhanced axonal regeneration via dynamic regulation of regeneration-associated proteins. Therefore, BJT had a pharmaceutical property enhancing recovery of peripheral nerves induced by diabetic neuropathy and could be a candidate for drug development after more research.

A Study on System for Real-time Measurement of Welding Distortion (실시간 용접변형 계측을 위한 시스템에 관한 연구)

  • Jeong, Jae-Won;Kim, Ill-Soo;Kim, In-Ju;Son, Sung-Woo;Shim, Ji-Yeon
    • Journal of Welding and Joining
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    • v.27 no.5
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    • pp.62-67
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    • 2009
  • Welding deformation during the assembly process is affected by not only local shrinkage due to rapid heating and cooling, but also root gap and misalignment between parts to be welded. Therefore, the prediction and control of welding deformation have become of critical importance. In this study, it was focused on the development of the 3-axis apparatus for real-time measurement of the welded deformation. To achieve the objective, a D-H algorithm has been carried out to check the behavioral and performance evaluation for the developed robot. The sequence experiments were taken the base materials of $400{\times}200{\times}4.5mm$ plate for butt welding. The real-time experimental measurements are in good agreement with the measured results.

Evaluation for Moisture Susceptibility of Asphalt Mixtures using Non-Destructive Impact Wave (비파괴 충격파를 이용한 아스팔트 공시체의 수분민감도 평가)

  • Jang, Byung Kwan;Kim, Do Wan;Mun, Sung Ho;Jang, Yeong Sun
    • International Journal of Highway Engineering
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    • v.15 no.3
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    • pp.53-63
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    • 2013
  • PURPOSES : This study is to evaluate moisture susceptibility of asphalt mixtures by using non-destructive impact wave and to determine durability so as to decrease the gap between before and after freezing in the future. METHODS : Using non-destructive impact wave, this study is to determine the dynamic modulus of asphalt specimen. Furthermore, the results obtained from two experiment accelerometers are used for the dynamic modulus determination. The dynamic moduli of specimens are compared with those of the freezing-thawing specimens. RESULTS : Test results showed that the dynamic modulus before freezing and thawing environment loads at each temperature dropped about 3.7% after the environmental loads. Furthermore, correlation analysis indicates that transition of dynamic modulus at each point is about 89.59%. CONCLUSIONS: Evaluation of asphalt mixtures using non-destructive impact wave has excellent repeatability and simple equipment for the test. Consequently, the method in the study will be useful for evaluating the characteristics of a various asphalt mixtures.

A Study on the Fracture Toughness Characteristics of FCAW Weldment of Steel for Offshore Structures (해양 구조물용 강재 FCAW 용접부의 파괴인성 특성에 관한 연구)

  • Kang Sung-Won;Kim Myung-Hyun;Kim Yong-Bin;Shin Yong-Taek;Lee Hae-Woo
    • Journal of Welding and Joining
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    • v.22 no.6
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    • pp.57-63
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    • 2004
  • Fracture toughness is an important parameter in designing offshore structures to ensure resistance to fracture at various temperatures. In this study, a series of experiments is carried out to obtain fracture toughness values (CTOD) of API 2W Gr.50B, welded using FCAW(Flux Cored Arc Weld). In particular, a comparison of absorbed impact energy and CTOD values are made with respect to two different welding groove shapes; double-V-groove and double-bevel-groove. Charpy impact tests are performed for specimens sampled near the root gap, and CTOD tests are carried out for three point bending specimens having the notch at weld zone. While Charpy impact test result is determined to be a good qualitative measure of fracture toughness, no quantitative correspondence between impact absorbed energy and CTOD values was found. Based on the experiment, it is observed that double-V-groove welds give lower transition temperature than those of double-bevel-groove.

Analysis of Turbine-Generator Shaft System Mechanical Torque Response based on Turbine Blade Modeling (터빈 블레이드 모델링을 통한 터빈 발전기 축 시스템의 기계적 토크 응답 분석)

  • Park, Ji-Kyung;Chung, Se-Jin;Kim, Chul-Hwan
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.64 no.9
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    • pp.1269-1275
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    • 2015
  • Turbine-generator torsional response is caused by interaction between electrical transient air-gap torque and mechanical characteristics of turbine-generator shafts. There are various factors that affects torsional interaction such as fault, circuit breaker switching and generator mal-synchronizing, etc. Fortunately, we can easily simulate above torsional interaction phenomena by using ElectroMagnetic Transient Program (EMTP). However, conventional EMTP shows the incomplete response of super- synchronous torsional mode since it does not consider turbine blade section. Therefore, in this paper, we introduced mechanical-electrical analogy for detailed modeling of turbine-generator shaft system including low pressure turbine blade section. In addition, we derived the natural frequencies of modeled turbine-generator shaft system including turbine blade section and analyzed the characteristics of mechanical torque response at shaft coupling and turbine blade root area according to power system balanced/unbalanced faults.

EXPERIMENTAL STUDIES ON THE TISSUE RESPONSE OF HA COATED, TPS AND $Al_2O_3$ ARTIFICIAL ROOT IMPLANTS (HA, TPS 및 $Al_2O_3$ 인공치근 매식체의 조직반응에 관한 실험적 연구)

  • Kim, Sun-Young;Kim, Yung-Soo
    • The Journal of Korean Academy of Prosthodontics
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    • v.29 no.2
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    • pp.267-284
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    • 1991
  • Since the concept of a direct contact between bone and implants, without interposed soft- tissue layers, was reported by Dr. $Br{\aa}nemark$, there has been increasing necessity for correct under-standing of bone-implant interface and surrounding tissue response. Beside quality of bone, surgical technique, load applied to implants, one must consider implant materials, design and surface characteristics to obtain osseointegration. In this study HA plasma-sprayed implants, TPS implants and $Al_2O_3$ implants were inserted into the alveolar bone of dog and tissue response was observed with radiograph, stereoscope, light microscope, and scanning electron microscope. Results were as follows : 1. There was rapid and active bone formation in the region adjacent to HA plasma-sprayed implants but in the deep supporting bone only slight bone formation was seen. 2. There was considerable lamella bone formation in the region adjacent to TPS implants and the deep supporting bone became more compact. 3. There was some gap and sclerosing bone formation in the adjacent region of $Al_2O_3$ implants, but there was irregular new bone formation in the deep supporting bone. Therefore, it seems that $Al_2O_3$ is not adequate for osseointegrated implants.

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The Fundamental Study on the Parameter Identification of Station Storm Model (지점 호우 모형의 매개상수 동정의 관한 기초 연구)

  • Lee, Jae Hyoung;Ceon, Ir Kweon;Cho, Dae Hyun
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.12 no.2
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    • pp.123-130
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    • 1992
  • We check up on whether the one-dimensional station precipitation model of Geogakakos and Bras is suitable to the storm model for Chonju station or not. The fundamental variables of the physically based model consists of the pressure at the cloud top, the hight-averaged updraft velocity(HAUV), and the inverse of the average diameter of the hydrometeors(ADH) at cloud base. And they are parameterized by input variables. The parameters are eastimated by the direct search algorithm of Hooke and Jeeves in this paper. The results show that HAUV and ADH are dominant factors to minimize root mean square error between the calculated and the observed rainfall. In this numerical analysis, the deviation between the calculated and the total observed rainfall is small, otherwise the gap for the time distribution is quite big.

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Glial Mechanisms of Neuropathic Pain and Emerging Interventions

  • Jo, Daehyun;Chapman, C. Richard;Light, Alan R.
    • The Korean Journal of Pain
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    • v.22 no.1
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    • pp.1-15
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    • 2009
  • Neuropathic pain is often refractory to intervention because of the complex etiology and an incomplete understanding of the mechanisms behind this type of pain. Glial cells, specifically microglia and astrocytes, are powerful modulators of pain and new targets of drug development for neuropathic pain. Glial activation could be the driving force behind chronic pain, maintaining the noxious signal transmission even after the original injury has healed. Glia express chemokine, purinergic, toll-like, glutaminergic and other receptors that enable them to respond to neural signals, and they can modulate neuronal synaptic function and neuronal excitability. Nerve injury upregulates multiple receptors in spinal microglia and astrocytes. Microglia influence neuronal communication by producing inflammatory products at the synapse, as do astrocytes because they completely encapsulate synapses and are in close contact with neuronal somas through gap junctions. Glia are the main source of inflammatory mediators in the central nervous system. New therapeutic strategies for neuropathic pain are emerging such as targeting the glial cells, novel pharmacologic approaches and gene therapy. Drugs targeting microglia and astrocytes, cytokine production, and neural structures including dorsal root ganglion are now under study, as is gene therapy. Isoform-specific inhibition will minimize the side effects produced by blocking all glia with a general inhibitor. Enhancing the anti-inflammatory cytokines could prove more beneficial than administering proinflammatory cytokine antagonists that block glial activation systemically. Research on therapeutic gene transfer to the central nervous system is underway, although obstacles prevent immediate clinical application.

Dental Occlusion and Relationship to TMD and Systemic Symptoms (III) -Chirodontics, Dental Distress Syndrome(DDS), Quadrant Theorem- (교합이 악구강계 및 전신에 미치는 영향 (III) -카이로돈틱과 치아 스트레스 원인 증후군 및 Quadrant Theorem을 중심으로-)

  • Park, Eun-Jin;Choi, Byeong-Gap;Bae, Hanna Eun-Kyong
    • Journal of Dental Rehabilitation and Applied Science
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    • v.26 no.2
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    • pp.89-95
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    • 2010
  • This is the third series of article on dental occlusion and relationship to TMD and systemic symptoms. In this part of the series, it will overview the theory, treatment methods, criteria, their limitation of Chirodontics, Dental Distress Syndrome (DDS) and quadrant theorem(QT). Chirodontics has its root on Chiropractic and to maintain the 'healthy status' of TMJ with stable occlusion via dental treatment. Dental distress syndrome on the other hand believes that all the TMD has originated from reduced or collapse of posterior support and incorrect posterior vertical support had caused imbalance of the head and neck structure which eventually affect the whole body symptoms. The analysis and treatment is planned using quadrant theorem where the position of head, rotatory pivot point and occlusal plane is analyzed.

Etching Characteristics of Polyctystalline 3C-SiC Thin Films by Magnetron Reactive Ion Etching (마그네트론 RIE를 이용한 다결정 3C-SiC의 식각 특성)

  • Ohn, Chang-Min;Kim, Gwiy-Yeal;Chung, Gwiy-Sang
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2007.06a
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    • pp.331-332
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    • 2007
  • Surface micromachined SiC devices have readily been fabricated from the polycrystalline (poly) 3C-SiC thin film which has an advantage of being deposited onto $SiO_2$ or $Si_3N_4$ as a sacrificial layer. Therefore, in this work, magnetron reactive ion etching process which can stably etch poly 3C-SiC thin films grown on $SiO_2$/Si substrate at a lower energy (70 W) with $CHF_3$ based gas mixtures has been studied. We have investigated the etching properties of the poly 3C-SiC thin film using PR/Al mask, according to $O_2$ flow rate, pressure, RF power, and electrode gap. The etched RMS (root mean square), etch rate, and etch profile of the poly 3C-SiC thin films were analyzed by SEM, AFM, and $\alpha$-step.

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