• Title/Summary/Keyword: Compression and Recovery

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Mechanical Properties and Fabric Handle of Grafted Silk Fabrics (그라프트 가공 견직물의 力學特性과 태의 分析硏究)

  • Kim, Kyu Beom;Chin, Young Gil
    • Textile Coloration and Finishing
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    • v.8 no.3
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    • pp.52-58
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    • 1996
  • In order to study an applicable level for the graft finish of silk filaments and the characteristics of silk fabric, some sample fabrics were woven with grafted weft and the characteristics of sample fabrics were analyzed to evaluate the mechanical properites and the handle values according to the graft yield(%) of MMA and HEMA monomers on silk filaments. 1. The tensile properties were detected in the increase of linearity(LT) and the recovery in time of the increasing resilience(RT). 2. The bending properties were detected to have a lot of effect on the balance of bending rigidity(B) to hysteresis(2HB) according to the elastic relaxation of warp tension and the interlacing stress. 3. The shearing properities were detected to show the softness and the elastics in a case of the decrease in shearing rigidity(G) and hysteresis(2HG, 2HG5) according to the graft yields. 4. The compression properties were detected in the decrease of linearity(LC) and the uniformity of resilience(RC). It explains that the tendancies of compressible variation is not accepted. 5. The surface properities were detected to be affected by the surface forms of grafted silk filaments and the variation in the morphologies of interlacing sections. Considering the interlacing eveness, MMA grafted fabrics were accepted within the level of WOMEN'S THIN DRESS(KN-201-LDY) but HEMA grafted fabrics were not accepted. 6. The variation of handles were detected in the increase of total hand(TAV) within the levels of 65% of KOSHI and 82% of HARI on the average. 7. The handle fashions were detected in the nature of Habuta and Dechine from MAA graft but the nature of Fugi were shaped from HEMA graft in proportion to the graft yields.

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Effect of Muscle Taping and Joint Taping on Static and Dynamic Balance in Normal Adults with Chronic Ankle Instability

  • Kim, Hyun-Sung;Park, Jae-Young
    • Journal of The Korean Society of Integrative Medicine
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    • v.10 no.1
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    • pp.101-108
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    • 2022
  • Purpose : This study was conducted to investigate the effect of muscle taping and joint taping on static and dynamic balance in normal adults with chronic ankle instability. Methods : The subjects of this study were 32 people who met the inclusion criteria. This cross-sectional study was conducted using the Kinesio tape, an elastic tape, was used. Subjects were randomized to exclude the effect of sequence, and no taping, joint taping, and muscle taping were applied as taping interventions. One-leg standing test and a Functional reach test were conducted to measure static balance, and Y-balance test was conducted to measure dynamic balance. One way repeated ANOVA was performed to investigate the difference in balance ability according to the taping intervention. If there was a significant difference, a post-hoc was performed using the Bonferroni method. Results : In the case of static balance, joint taping showed more significant results than did no taping and muscle taping (p<.05), and muscle taping showed more significant results than did no taping (p<.05). In the case of dynamic balance, muscle taping showed significantly larger results than did no taping and joint taping (p<.05) and joint taping showed significantly larger results than did no taping (p<.05). Conclusion : This study found that mechanical stimulation of muscles and joint compression by elastic taping increased ankle stability and improved static and dynamic balance. In particular, for static balance, joint taping was more effective than muscle taping, and for dynamic balance, muscle taping was more effective than joint taping. Applying the appropriate taping method to individual subjects has the advantage of maximizing the therapeutic effect for the recovery of balance ability. Similarly, the application of various tapings to subjects with ankle instability will have a positive effect on functional improvement.

A Study on the Mechanical Properties of Fabrics for Korean Folk Clothes (Part 3) On the core-spun yarn woven fabrics (한복지의 역학적특성에 관한 연구 (제3보) 코어방적계 한복지)

  • Sung Su-Kwang;Kwon Oh-Kyung
    • Journal of the Korean Society of Clothing and Textiles
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    • v.13 no.1 s.29
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    • pp.79-87
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    • 1989
  • In the part 1 and 2, relations were found between fundmental mechanical properties and primary hand values, performance of Korean women's summer and fall & winter fabrics. In this paper, in order to investigate the hand values and mechanical properties such as tensile, shearing, bending, compression, surface and thickness & weight of the core-spun yarn woven fabrics for Korean folk clothes were measured by KES-F system. The experimental results are statistically analyzed in the aspects of the mechanical properties, their effects on the hand values, formation of weared clothes and transformation behavior. The correlation in the hand values are analyzed, too. Furthermore, there mechanical properties are discussed in comparison with those values for kimono fabrics. The main results are summarized as follows: 1. The core-spun yarn woven fabrics for Korean folk clothes have box-shaped silhouette based on higher bending rigidity and shear elasticity. 2. The core-spun yarn woven fabrics for Korean folk clothes are inferior to silk fabrics, superior to polyester fabrics in formation. 3. A drapability and wrinkle recovery of core-spun yarn woven fabrics for Korean folk clothes formation for weared clothes are inferior to polyester fabrics, superior to silk fabrics. 4. A primary factor of mechanical properties contribute to the hand values of core-spun yarn woven fabrics for Korean folk clothes are same as the Korean women's winter fabrics, except for flexibility with soft feeling. 5. As for the hand values of core-spun yarn woven fabrics for Korean folk clothes, stiffness, anti-drape stiffness are superior to those of polyester fabrics. And also, flexibility with soft feeling, scrooping feeling of core-spun yarn woven fabrics have greater values as compared with silk fabrics for Korean folk clothes.

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Analysis of Surface Displacement of Oil Sands Region in Alberta, Canada Using Sentinel-1 SAR Time Series Images (Sentinel-1 SAR 시계열 영상을 이용한 캐나다 앨버타 오일샌드 지역의 지표변위 분석)

  • Kim, Taewook;Han, Hyangsun
    • Korean Journal of Remote Sensing
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    • v.38 no.2
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    • pp.139-151
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    • 2022
  • SAGD (Steam-Assisted Gravity Drainage) method is widely used for oil recovery in oil sands regions. The SAGD operation causes surface displacement, which can affect the stability of oil recovery plants and trigger various geological disasters. Therefore, it isimportant to monitor the surface displacement due to SAGD in the oil sands region. In this study, the surface displacement due to SAGD operations of the Athabasca oil sands region in Alberta, Canada, was observed by applying Permanent Scatterer Interferometric Synthetic Aperture Radar (PSInSAR) technique to the Sentinel-1 time series SAR data acquired from 2016 to 2021. We also investigated the construction and expansion of SAGD facilitiesfrom Landsat-7/8 time seriesimages, from which the characteristics of the surface displacement according to the oil production activity of SAGD were analyzed. Uplift rates of 0.3-2.5 cm/yr in the direction of line of sight were observed over the SAGDs and their vicinity, whereas subsidence rates of -0.3--0.6 cm/yr were observed in areas more than several kilometers away from the SAGDs and not affected by oil recovery activities. Through the analysis of Landsat-7/8 images, we could confirm that the SAGDs operating after 2012 and showing high oil production activity caused uplift rates greater than 1.6 cm/yr due to the subsurface steam injection. Meanwhile, very small uplift rates of several mm per year occurred over SAGDs which have been operated for a longer period of time and show relatively low oil production activity. This was probably due to the compression of reservoir sandstone due to continuous oil recovery. The subsidence observed in areas except for the SAGDs and their vicinity estimated to be a gradual land subsidence caused by melting of the permafrost. Considering the subsidence, it was expected that the uplift due to SAGD operation would be greater than that observed by the PSInSAR. The results of this study confirm that the PSInSAR can be used as an effective means for evaluating productivity and stability of SAGD in the extreme cold regions.

Studies on the Physical and Mechanical Properties of Imported and Domestic Corks (수입(輸入)코르크와 국산(國産)코르크의 물리(物理)·기계적(機械的) 성질(性質)에 관(關)한 연구(硏究))

  • Kim, Byung-Ro
    • Journal of the Korean Wood Science and Technology
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    • v.21 no.4
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    • pp.45-54
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    • 1993
  • This study examines the differences in structures, physical and mechanical properties between domestic(Quercus variabilis Blume) and foreign(Quercus suber L.) corks. The results obtained are as follows: 1. The cork tissue consists of cork cells, lenticels, sclereids and dark-brown zone. There was a significant difference in ratio of cork cells between foreign cork(93 %) and domestic cork(87 %). The ring width and width of late cork of the foreign cork were wider than those of domestic cork. But the percentage of late cork of domestic cork was richer than that of foreign cork. The size of cork cell of foreign cork was larger by about two times than that of domestic cork. 2. The density was slightly higher in domestic cork(0.22 g/$cm^3$) than in foreign cork(0.19 g/$cm^3$). During first 24 hours, the amount of water absorption of the foreign cork was greater than that of domestic cork. However, after 24 hours, the tendency was reversed. The level of EMC was higher in domestic cork than in foreign cork. Total shrinkage in the radial and tangential directions was larger in domestic cork than tn foreign cork. In the longitudinal direction, the tendency was reversed. There was no difference in total swelling in three woody directions between the two corks. 3. The modulus of elasticity in compression in the logitudinal and tangential direction was higher in domestic cork than in foreign cork, but the tendency was reversed in the radial direction. Both corks showed 95% of recovery rate after 24 hours when they were compressed by 0.5. There were no differences in tension strength and Brinell,s hardness bet ween domestic and foreign corks.

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Evaluation of Cryogenic Compressive Strength of Divinycell of NO 96-type LNG Insulation System (NO96타입 LNG 방열시스템 Divinycell의 극저온 압축 강도 평가)

  • Choe, Yeong-Rak;Kim, Jeong-Hyeon;Kim, Jong-Min;Park, Sungkyun;Park, Kang Hyun;Lee, Jae-Myung
    • Journal of Ocean Engineering and Technology
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    • v.30 no.5
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    • pp.349-355
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    • 2016
  • Divinycell, which functions as both insulation and a supporting structure, is generally applied in the NO96-type liquefied natural gas (LNG) insulation system. Polymer-material-based Divinycell, which has a high strength and low weight, has been widely used in the offshore, transportation, wind power generation, and civil engineering fields. In particular, this type of material receives attention as an insulation material because its thermal conductivity can be lowered depending on the ambient temperature. However, it is difficult to obtain research results for Divinycell, even though the component materials of the NO96-type LNG cargo containment system, such as 36% nickel steel (invar steel), plywood, perlite, and glass wool, have been extensively studied and reported. In the present study, temperature and strain-rate dependent compressive tests on Divinycell were performed. Both the quantitative experimental data and elastic recovery are discussed. Finally, the mechanical characteristics of Divinycell were compared to the results of polyurethane foam insulation material.

The Experience of Using Current Perception Threshold in Bilateral Thoracic Outlet Syndrome (TOS) Patient -A case report- (흉곽출구증후군 환자에서 Current Perception Threshold (CPT) 사용 경험)

  • Choi, Jeong-Hwan;Choi, Jin-Hwan;Sung, Choon-Ho;Park, Jong-Wook
    • The Korean Journal of Pain
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    • v.13 no.1
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    • pp.97-100
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    • 2000
  • Thoracic outlet syndrome (TOS) is a combination of signs and symptoms caused by the compression of the vital neurovascular structure at the thoracic outlet region. It may stem from a number of abnormalities, including degenerative or bony disorders, trauma to cervical spine, fibromuscular bands, vascular abnormalities and spasm of the anterior scalene muscle. CPT (current perception threshold) is defined as the minimum amount of current applied transcutaneously that an individual consciously perceives. It enables quantification of the hyperesthesia that precedes progressive nerve impairment, as well as hypoesthetic conditions. We experienced a case of thoracic outlet syndrome caused by fibrosis of anterior scalene muscle. The patient was a 30 years old woman with a 3 years history of numbness on the ulnar side, progressive weakness and coldness of both hand, tiredness in the left arm, nocturnal pain in the left forearm, and pain in the left elbow, shoulder and neck. Conservative treatment, stellate ganglion block, cervical epidural block, anterior scalene block and previous operation, including both carpal tunnel release, provided no remarkable relief to the patient. A left scalenectomy and first rib resection were performed by transaxillary approach and left cervical root neurolysis was done. After surgery, we measured CPT using neurometer and found conditions worsening in the opposite arm. We performed the same procedure on right side, and followed by CPT measurement. This case suggests that CPT is a useful measurement of recovery and progression of TOS.

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Osteoplasty in Acute Vertebral Burst Fractures

  • Park, Sang-Kyu;Bak, Koang-Hum;Cheong, Jin-Hwan;Kim, Jae-Min;Kim, Choong-Hyun
    • Journal of Korean Neurosurgical Society
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    • v.40 no.2
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    • pp.90-94
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    • 2006
  • Objective : Acute vertebral burst fractures warrant extensive fixation and fusion on the spine. Osteoplasty [vertebroplasty with high density resin without vertebral expansion] has been used to treat osteoporotic vertebral compression fractures. We report our experiences with osteoplasty in acute vertebral burst fractures. Methods : Twenty-eight cases of acute vertebral burst fracture were operated with osteoplasty. Eighteen patients had osteoporosis concurrently. Preoperative MRI was performed in all cases to find fracture level and to evaluate the severity of injury. Preoperative CT revealed burst fracture in the series. The patients with severe ligament injury or spinal canal compromise were excluded from indication. Osteoplasty was performed under local anesthesia and high density polymethylmethacrylate[PMMA] was injected carefully avoiding cement leakage into spinal canal. The procedure was performed unilaterally in 21 cases and bilaterally in 7 cases. The patients were allowed to ambulate right after surgery. Most patients discharged within 5 days and followed up at least 6 months. Results : There were 12 men and 16 women with average age of 45.3[28-82]. Five patients had 2 level fractures and 2 patients had 3 level fractures. The average injection volume was 5.6cc per level Average VAS [Visual Analogue Scale] improved 26mm after surgery. The immediate postoperative X-ray showed 2 cases of filler spillage into spinal canal and 4 cases of leakage into the retroperitoneal space. One patient with intraspinal leakage was underwent the laminectomy to remove the resin. Conclusion : Osteoplasty is a safe and new treatment option in the burst fractures. Osteoplasty with minimally invasive technique reduced the hospital stay and recovery time in vertebral fracture patients.

A Study on Blended Inlet Body Design for a High Supersonic Unmanned Aerial Vehicle

  • You, Lianxing;Yu, Xiongqing;Li, Hongmei
    • International Journal of Aeronautical and Space Sciences
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    • v.17 no.2
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    • pp.260-267
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    • 2016
  • The design process of blended inlet body (BIB) for the preliminary design of a near-space high supersonic unmanned aerial vehicle (HSUAV) is presented. The mass flow rate and cowl area of inlet at a design point are obtained according to the cruise condition of the HSUAV. A mixed-compression axisymmetric supersonic inlet section with a fixed geometry reasonably matching the high supersonic cruise state is created by using the inviscid theory of aerodynamics. The inlet section is optimized and used as a baseline section for the BIB design. Three BIB concepts for the HSUAV are proposed, and their internal aerodynamic characteristics of inlet are evaluated using Euler computational fluid dynamics (Euler CFD) solver. The preferred concept is identified, in which the straight leading edge of the baseline HSUAV configuration is modified into the convex leading edge to accommodate the inlet and meet the requirements of the cowl area to capture the sufficient air flow. The total recovery of inlet for the preferred BIB concept and the aerodynamic characteristics of the modified HSUAV configuration are verified using Navier-Stokes computational fluid dynamics (NS CFD) solver. The validation indicates that the preferred BIB concept can meet both the requirements of the inlet and aerodynamic performance of the HSUAV.

A Physiotherapy Program for Secondary School Teachers with Forward Head Posture Accompanied by Moderate to Severe Neck Pain: Comparison of the effects of cranio-cervical flexor training and general training (중등도 이상의 목 통증을 동반한 앞쪽 머리 자세를 가진 중·고등학교 교사들을 위한 물리치료적 프로그램: 머리-목뼈 굽힘근 훈련과 일반적 훈련의 효과 비교)

  • Hyeon-Su Kim;Yeon-Ki Choo
    • Journal of The Korean Society of Integrative Medicine
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    • v.11 no.3
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    • pp.195-204
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    • 2023
  • Purpose : This study applied general training (control group) or cranio-cervical flexor training (experimental group) using a pressure biofeedback unit along with general training for 4 weeks to secondary school teachers with moderate to severe neck pain and forward head posture. After that, we tried to compare the effects through differences in neck pain intensity (using numberical rating scale), functional performance (using neck disability index), and cranio-vertebral angle change. Methods : All 50 subjects were randomly assigned to either the "experimental group (n= 25)" or the "control group (n= 25)", and the measurements were evaluated in the same way before the intervention (baseline) and after the intervention (4 weeks). During the intervention period, the subject visited the physiotherapy center and made a reservation three times a week at a fixed time as much as possible, and each training session was thoroughly conducted under the 1:1 guidance of the therapist in charge so that the correct movement and number of times could be performed without compensatory action. Results : As a result of the homogeneity analysis on the general characteristics of the subjects, there were no significant differences between the groups in all variables (p>.05). Compared to the "control group", the "experimental group" showed significant improvement after intervention in all measured variables of neck pain intensity, functional performance, and cranial-vertebral angle (p<.05). Conclusion : For secondary school teachers with forward head accompanied by neck pain, cranio-cervical flexor training using a compression biofeedback unit is an excellent method to show superior pain reduction and functional performance improvement compared to general training alone. In addition, it can be presented as a more effective intervention method that can promote recovery of forward head posture, which is an essential element of the solution.