• Title/Summary/Keyword: center of resistance

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Effects of Elastic Resistance Exercise Using Proprioceptive Neuromuscular Facilitation on Activities of Daily Living of Patient with Incomplete Spinal Cord Injury -Single Subject Design- (PNF에 기초한 탄력저항운동이 불완전 척수 손상 환자의 일상생활동작에 미치는 효과 -단일사례연구-)

  • Kim, Jwa-Jun;Kim, Min-Soo
    • PNF and Movement
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    • v.14 no.3
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    • pp.245-254
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    • 2016
  • Purpose: This study investigates the influence of elastic resistance exercise using proprioceptive neuromuscular facilitation (PNF) on the daily activities of a patient with incomplete spinal cord injury. The result will be proposed as background data for effective intervention in a patient with incomplete spinal cord injury. Methods: The target subject was a patient with incomplete spinal cord injury to the cervical cord (C6). Elastic resistance exercise based on PNF was performed for 30 min daily, five times a week, for eight weeks. The ASIS motor scale was applied to test the muscular strength of the upper limb, and the spinal cord independence measure II (SCIM II) was used to evaluate the capacity of daily activity. Results: By applying elastic resistance exercise based on PNF, the muscular strength of the upper limb increased and the performance of daily activity improved. Conclusion: Because elastic resistance exercise based on PNF positively influences the ASIA motor scale and SCIM II of the patient with incomplete spinal cord injury. It can be used for training programs to improve the capacity of daily activity of the patient.

Effects of Fluorine Addition on Thermal Properties and Plasma Resistance of MgO-Al2O3-SiO2 Glass (MgO-Al2O3-SiO2계 유리 열물성 및 내플라즈마 특성에 대한 Fluorine 첨가의 영향)

  • Yoon, Ji Sob;Choi, Jae Ho;Jung, YoonSung;Min, Kyung Won;Kim, Hyeong-Jun
    • Journal of the Semiconductor & Display Technology
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    • v.21 no.1
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    • pp.119-126
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    • 2022
  • MAS-based glass, which has been studied to replace the ceramic material used in the plasma etching chamber, has problems such as forming and processing due to its high melting temperature. To solve this problem, in this study, fluoride was added to the existing MAS-based glass to increase the workability in the glass manufacturing and to improve the chemical resistance to CF4/Ar/O2 plasma gas. Through RAMAN analysis, the structural change of the glass according to the addition of fluoride was observed. In addition, it was confirmed that high-temperature viscosity and thermal properties decreased as the fluoride content increased and plasma resistance was maintained, it showed an excellent etching rate of up to 11 times compared to quartz glass.

Experimental Study on Improving Thermal Shock Resistance of Cement Composite Incorporating Hollow Glass Microspheres (중공 유리 마이크로스피어 혼입 시멘트 복합체의 내열충격성 향상에 대한 실험적 연구)

  • Yomin, Choi;Hyun‐Gyoo, Shin
    • Journal of Powder Materials
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    • v.29 no.6
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    • pp.505-510
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    • 2022
  • The thermal shock resistance of cement composites with hollow glass microspheres (HGM) is investigated. Cement composites containing various concentrations of HGM are prepared and their properties studied. The density, thermal conductivity, and coefficient of thermal expansion of the composites decrease with increasing HGM concentration. A thermal shock test is performed by cycling between -60 and 50℃. After the thermal shock test, the compressive strength of the cement composite without HGM decreases by 28.4%, whereas the compressive strength of the cement composite with 30 wt% HGM decreases by 5.7%. This confirms that the thermal shock resistance of cement is improved by the incorporation of HGM. This effect is attributed to the reduction of the thermal conductivity and coefficient of thermal expansion of the cement composite because of the incorporation of HGM, thereby reducing the occurrence of defects due to external temperature changes.

Study on EEC and SSC of the Electric Resistance Welded Linepipe Steel

  • Kim, Wan Keun;Koh, Seong Ung;Yang, Boo Young;Kim, Kyoo Young
    • Corrosion Science and Technology
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    • v.6 no.3
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    • pp.96-102
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    • 2007
  • The resistance of the linepipe steel to hydrogen-induced cracking (HIC) and sulfide stress cracking (SSC) is very important for steel to be used in sour oil/gas environments. Welding of steels is necessary to the construction of pipe-line transporting oil/gas. In this study, HIC and SSC resistance of an electric resistance welded (ERW) steel plate which belongs to API X70 grade was evaluated by using NACE TM0284-96A and NACE TM0177-96A methods. HIC and SSC fracturing behavior was investigated by observing fractured surfaces using optical microscopy (OM) and scanning electron microscopy (SEM). It was discussed in terms of metallurgical parameters such as the distribution of primary microstructure, second phases and inclusions. Results showed that the weld joint of ERW steel is more sensitive than base metal to HIC and SSC. This is due to difference in the contribution of metallurgical parameters to HIC and SSC nucleation and propagation.

Systems to prevent the load resistance loss of pallet racks exposed to cyclic external force

  • Heo, Gwanghee;Kim, Chunggil;Baek, Eunrim;Jeon, Seunggon
    • Structural Engineering and Mechanics
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    • v.83 no.6
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    • pp.745-756
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    • 2022
  • This study aims to determine the cause of the load resistance loss in storage racks that can be attributed to external forces such as earthquakes and to improve safety by developing reinforcement systems that can prevent load resistance loss. To this end, a static cyclic loading test was performed on pallet racks commonly used in logistics warehouses. The test results indicated that a pallet rack exposed to an external force loses more than 50% of its load resistance owing to the damage caused to column-beam joints. Three reinforcement systems were developed for preventing load resistance loss in storage racks exposed to an external force and for performing differentiated target functions: column reinforcement device, seismic damper, and viscoelastic damper. Shake table testing was performed to evaluate the earthquake response and verify the performance of these reinforcement systems. The results confirmed that, the maximum displacement, which causes the loss of load resistance and the permanent deformation of racks under external force, is reduced using the developed reinforcement devices. Thus, the appropriate selection of the developed reinforcement devices by users can help secure the safety of the storage racks.

Electrical Characterization of Electronic Materials Using FIB-assisted Nanomanipulators

  • Roh, Jae-Hong;You, Yil-Hwan;Ahn, Jae-Pyeong;Hwang, Jinha
    • Applied Microscopy
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    • v.42 no.4
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    • pp.223-227
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    • 2012
  • Focused Ion Beam (FIB) systems have incorporated versatile nanomanipulators with inherent sophisticated machining capability to characterize the electrical properties of highly miniature components of electronic devices. Carbon fibers were chosen as a model system to test the applicability of nanomanipulators to microscale electronic materials, with special emphasis on the direct current current-voltage characterizations in terms of electrode configuration. The presence of contact resistance affects the electrical characterization. This resistance originates from either i) the so-called "spreading resistance" due to the geometrical constriction near the electrode - material interface or ii) resistive surface layers. An appropriate electrode strategy is proposed herein for the use of FIB-based manipulators.

Adiponectin induced AMP-activated protein kinase impairment mediates insulin resistance in Bama mini-pig fed high-fat and high-sucrose diet

  • Niu, Miaomiao;Xiang, Lei;Liu, Yaqian;Zhao, Yuqiong;Yuan, Jifang;Dai, Xin;Chen, Hua
    • Asian-Australasian Journal of Animal Sciences
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    • v.30 no.8
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    • pp.1190-1197
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    • 2017
  • Objective: Adipose tissue is no longer considered as an inert storage organ for lipid, but instead is thought to play an active role in regulating insulin effects via secretion adipokines. However, conflicting reports have emerged regarding the effects of adipokines. In this study, we investigated the role of adipokines in glucose metabolism and insulin sensitivity in obese Bama mini-pigs. Methods: An obesity model was established in Bama mini-pigs, by feeding with high-fat and high-sucrose diet for 30 weeks. Plasma glucose and blood biochemistry levels were measured, and intravenous glucose tolerance test was performed. Adipokines, including adiponectin, interleukin-6 (IL-6), resistin and tumor necrosis factor alpha ($TNF-{\alpha}$), and glucose-induced insulin secretion were also examined by radioimmunoassay. AMP-activated protein kinase (AMPK) phosphorylation in skeletal muscle, which is a useful insulin resistance marker, was examined by immunoblotting. Additionally, associations of AMPK phosphorylation with plasma adipokines and homeostasis model assessment of insulin resistance (HOMA-IR) index were assessed by Pearce's correlation analysis. Results: Obese pigs showed hyperglycemia, high triglycerides, and insulin resistance. Adiponectin levels were significantly decreased (p<0.05) and IL-6 amounts dramatically increased (p<0.05) in obese pigs both in serum and adipose tissue, corroborating data from obese mice and humans. However, circulating resistin and $TNF-{\alpha}$ showed no difference, while the values of $TNF-{\alpha}$ in adipose tissue were significantly higher in obese pigs, also in agreement with data from obese humans but not rodent models. Moreover, strong associations of skeletal muscle AMPK phosphorylation with plasma adiponectin and HOMA-IR index were obtained. Conclusion: AMPK impairment induced by adiponectin decrease mediates insulin resistance in high-fat and high-sucrose diet induction. In addition, Bama mini-pig has the possibility of a conformable model for human metabolic diseases.

Development of resistance welding technology for producing Ir-192 industrial radiation sources (Ir-192 산업용 방사선원의 생산을 위한 저항용접기술 개발)

  • Han, In-Su;Son, Kwang-Jae;Lee, Jun-Sig;Jang, Kyung-Duk;Park, Ul-Jae
    • Proceedings of the KWS Conference
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    • 2007.11a
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    • pp.288-290
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    • 2007
  • Ir-192 source is one of the most widely used radioisotopes in the field of non-destructive testing applications. To obtain radiation safety it is necessary to take into consideration integrity of welded joint in the production of sealed radiation source. Generally, the quality of a resistance welded joint is strongly influenced by process parameters during the welding process such as current, welding time and applied force. In this study, resistance welding technology and system were developed for sealing of Ir-192 industrial radiation source capsules. In order to evaluate the weld quality in real time, quantitative relationships between process parameters and electrode displacement were also established.

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Damage Detection in Fiber Reinforced Composites Containing Electrically Conductive Phases

  • Shin, Soon-Gi;Hideaki Matsubara
    • The Korean Journal of Ceramics
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    • v.6 no.3
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    • pp.201-205
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    • 2000
  • Fiber reinforced plastic (FRP) composites and ceramic matrix composites (CMC) which contain electrically conductive phases have been designed and fabricated to introduce the detection capability of damage/fracture detection into these materials. The composites were made electrically conductive by adding carbon and TiN particles into FRP and CMC, respectively. The resistance of the conductive FRP containing carbon particles showed almost linear response to strain and high sensitivity over a wide range of strains. After each load-unload cycle the FRP retained a residual resistance, which increased with applied maximum stress or strain. The FRP with carbon particles embedded in cement (mortar) specimens enabled micro-crack formation and propagation in the mortar to be detected in situ. The CMC materials exhibited not only sensitive response to the applied strain but also an increase in resistance with increasing number of load-unload cycles during cyclic load testing. These results show that it is possible to use these composites to detect and/or fracture in structural materials, which are required to monitor the healthiness or safety in industrial applications and public constructions.

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A Long Non-Coding RNA snaR Contributes to 5-Fluorouracil Resistance in Human Colon Cancer Cells

  • Lee, Heejin;Kim, Chongtae;Ku, Ja-Lok;Kim, Wook;Kim Yoon, Sungjoo;Kuh, Hyo-Jeong;Lee, Jeong-Hwa;Nam, Suk Woo;Lee, Eun Kyung
    • Molecules and Cells
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    • v.37 no.7
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    • pp.540-546
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    • 2014
  • Several types of genetic and epigenetic regulation have been implicated in the development of drug resistance, one significant challenge for cancer therapy. Although changes in the expression of non-coding RNA are also responsible for drug resistance, the specific identities and roles of them remain to be elucidated. Long non-coding RNAs (lncRNAs) are a type of ncRNA (> 200 nt) that influence the regulation of gene expression in various ways. In this study, we aimed to identify differentially expressed lncRNAs in 5-fluorouracil-resistant colon cancer cells. Using two pairs of 5-FU-resistant cells derived from the human colon cancer cell lines SNU-C4 and SNU-C5, we analyzed the expression of 90 lncRNAs by qPCR-based profiling and found that 19 and 23 lncRNAs were differentially expressed in SNU-C4R and SNU-C5R cells, respectively. We confirmed that snaR and BACE1AS were down-regulated in resistant cells. To further investigate the effects of snaR on cell growth, cell viability and cell cycle were analyzed after transfection of siRNAs targeting snaR. Down-regulation of snaR decreased cell death after 5-FU treatment, which indicates that snaR loss decreases in vitro sensitivity to 5-FU. Our results provide an important insight into the involvement of lncRNAs in 5-FU resistance in colon cancer cells.