• Title/Summary/Keyword: Compression Effect

Search Result 2,014, Processing Time 0.032 seconds

Change of Wood Color of Radiata Pine (Pinus radiata D.Don) by Press Temperature and Time (라디에타 소나무재의 압밀화 온도와 시간에 따른 색상의 변화)

  • Hwang, Sung-Wook;Lee, Won-Hee
    • Journal of the Korean Wood Science and Technology
    • /
    • v.39 no.3
    • /
    • pp.238-243
    • /
    • 2011
  • This study was estimated the change of color of compressed wood by compression temperature and time. Wood color was measured using a colorimeter and evaluated by the NBS (National Bureau of Standards) unit. As a result, the whiteness decreased with increasing compression temperature. In contrast, redness and yellowness was increased with increasing compression temperature. All of the color difference showed the 'Very Much' by NBS unit. The whiteness decreased with increasing compression time. The redness and yellowness were insignificant effect on compression temperature. In other words, the effect of compression temperature was much greater than compression time in the change of wood color.

Effect of Shoulder Stabilization Exercise with Pelvic Compression Belt Application on Muscle Activity, Pain and Function of Muscles around Shoulder Joint in Subjects with Round Shoulders (둥근 어깨가 있는 대상자에게 골반 압박 벨트 적용을 동반한 어깨 안정화 운동의 수행이 어깨관절 주위 근육의 근활성도와 통증 및 기능에 미치는 영향)

  • Kim, Chung-Yoo;Lee, Yeon-Seop;Kim, Hyeon-Su
    • Journal of The Korean Society of Integrative Medicine
    • /
    • v.10 no.4
    • /
    • pp.199-207
    • /
    • 2022
  • Purpose : The purpose of this study is to investigate the effect of shoulder stabilization exercise accompanied by application of a pelvic compression belt on the muscle activity, pain and function of the muscles around the shoulder in subjects with round shoulders. Methods : For the study method, 28 students who were enrolled in K University with a distance of 1 cm or more between the clavicle of the peak and the outer ear path were selected through GPS 400 global postural analysis system measurement. The subjects were randomly assigned to 14 participants in the group wearing a pelvic compression belt and 14 patients in the group not wearing a pelvic compression belt. In all subjects, the muscle activities of the middle trapezius, lower trapezius, and serratus anterior muscles and the shoulder pain disorder index (SPADI) were measured. The intervention was performed 3 times a week for 4 weeks, and the applied intervention was push-up plus and modified prone cobra exercise. The muscle activities of the middle trapezius, lower trapezius, and serratus anterior muscles and SPADI score were compared using dependent t test before and after intervention. Results : In this study, both groups showed that the muscle activity of the middle trapezius, lower trapezius, and serratus anterior significantly increased after the intervention compared to before the intervention. On the other hand, SPADI showed no significant difference. Conclusion : The results of this study showed that muscle activity in the peri-shoulder joint was increased after push-up plus and modified prone cobra exercise in both groups, regardless of whether pelvic compression was applied or not. Therefore, it was found that shoulder stabilization exercise using the pelvic compression belt also contributed to the enhancement of muscle activity in the joints around the shoulder.

Research on hysteretic characteristics of EBIMFCW under different axial compression ratios

  • Li, Sheng-cai;Lin, Qiang
    • Earthquakes and Structures
    • /
    • v.22 no.5
    • /
    • pp.461-473
    • /
    • 2022
  • Energy-saving block and invisible multiribbed frame composite wall (EBIMFCW) is an important shear wall, which is composed of energy-saving blocks, steel bars and concrete. This paper conducted seismic performance tests on six 1/2-scale EBIMFCW specimens, analyzed their failure process under horizontal reciprocating load, and studied the effect of axial compression ratio on the wall's hysteresis curve and skeleton curve, ductility, energy dissipation capacity, stiffness degradation, bearing capacity degradation. A formula for calculating the peak bearing capacity of such walls was proposed. Results showed that the EBIMFCW had experienced a long time deformation from cracking to failure and exhibited signs of failure. The three seismic fortification lines of the energy-saving block, internal multiribbed frame, and outer multiribbed frame sequentially played important roles. With the increase in axial compression ratio, the peak bearing capacity and ductility of the wall increased, whereas the initial stiffness decreased. The change in axial compression ratio had a small effect on the energy dissipation capacity of the wall. In the early stage of loading, the influence of axial compression ratio on wall stiffness and strength degradation was unremarkable. In the later stage of loading, the stiffness and strength degradation of walls with high axial compression ratio were low. The displacement ductility coefficients of the wall under vertical pressure were more than 3.0 indicating that this wall type has good deformation ability. The limit values of elastic displacement angle under weak earthquake and elastic-plastic displacement angle under strong earthquake of the EBIMFCW were1/800 and 1/80, respectively.

Relationship between Kinesiotaping and compression wear for postural balance in healthy men: a cross-sectional study

  • Choi, Nak-Hoon;Hwang, Sujin
    • Physical Therapy Rehabilitation Science
    • /
    • v.9 no.4
    • /
    • pp.275-280
    • /
    • 2020
  • Objective: Compression wear is an external aid which promotes performance and recovery, diminishes muscular microtrauma, reduces muscle fiber recruitment, improves neuromechanics, enhances coordinative activities, and reduces the perceived exertion. The purpose of this study was to investigate the relationship between athletic taping and compression wear on dynamic postural balance in healthy young men. The hypothesis was that the athletic taping and compression wear would affect dynamic postural balance, with athletic taping having a different effect on dynamic postural balance in healthy young adults. Design: Cross-sectional study. Methods: Thirty-seven healthy young men participated in this study. To examine the association between athletic taping and compression wear, 3 clinical measurement tools, including 5 times sit-to-stand (5xSTS), one-leg standing (OLS) test, and Y-balance test (YBT) in 5 different conditions, namely (1) non-supporting, and support with (2) athletic taping, (3) regular compression wear, (4) silicon compression wear, and (5) double-fiber compression wear were used. Results: The distance of the Y-balance test (YBT) on both the dominant and non-dominant sides showed a statistically difference among the 5 supporting conditions (p<0.05). The distance measured via the YBT in the non-support condition was significantly different than that in the other four supporting conditions (p<0.05). However, 5xSTS and OLS were not significantly different in these supporting conditions. Conclusions: The results of this study suggest that athletic taping, silicon compression wear, and double-fiber compression wear were more effective for dynamic balance than non-supporting and regular compression wear.

Damped Vibrations of Axially-Stressed Laminated Beams using Zig-Zag Finite Element (축방향 하중을 받는 점탄성물질이 심어진 적층보의 지그재그요소를 이용한 진동해석)

  • 이덕규
    • Proceedings of the Korean Society For Composite Materials Conference
    • /
    • 2001.10a
    • /
    • pp.1-4
    • /
    • 2001
  • Dynamic analysis of laminated beams with a embedded damping layer under tension or compression axial load is investigated. Improved Layer-Wise Zig-Zag Beam Theory and Interdependent Kinematic Relation using the governing equations of motion are incorporated to model the laminated beams with a damping layer and a corresponding beam zig-zag finite element is developed. Flexural frequencies and modal loss actors under tension or compression axial load are calculated based on Complex Eigenvalue Method. The effect of the axial tension and compression load on the frequencies and loss factors is discussed.

  • PDF

Lossless/lossy Image Compression based on Non-Separable Two-Dimensional LWT

  • Chokchaitam, Somchart;Iwahashi, Masahiro
    • Proceedings of the IEEK Conference
    • /
    • 2002.07b
    • /
    • pp.912-915
    • /
    • 2002
  • In this report, we propose a non-separable two-dimensional (2D) Lossless Wavelet Transform (LWT) for image compression. Filter characteristics of our proposed LWT are the same as those or conventional 2D LWT based on applying 1D LWT twice but our coding performance is better due to reduction of rounding effects. Simulation results confirm effectiveness of our proposed LWT.

  • PDF

Analysis of Elastic Local Buckling of an Orthotropic Compression Member with Asymmetric Edge Stiffeners (비대칭연단보강재가 설치된 직교이방성 압축재의 탄성 국부좌굴해석)

  • 최원창;정상균;윤순종
    • Proceedings of the Korean Society For Composite Materials Conference
    • /
    • 2000.11a
    • /
    • pp.5-8
    • /
    • 2000
  • This paper presents the analytical investigation pertaining to the local buckling behavior of orthotropic open section thin-walled compression members with asymmetric edge stiffeners. In the analysis, 3 different cases of the second moment of inertia are considered to find the asymmetric edge stiffener effect on the local buckling strength. The analytical study results are presented in the graphical form so that the edge stiffener effects on the local buckling strength can be easily found.

  • PDF

Effect of Mold Temperature on the Separation and the Orientation during Compression Molding of Fiber-Reinforced Polymeric Composites (섬유강화 고분자 복합재료의 압축성형에 있어서 분리 ${\cdot}$ 배향에 미치는 금형온도의 영향)

  • Lee, Dong-Gi;Han, Gil-Young;Kim, E-Gon
    • Journal of Ocean Engineering and Technology
    • /
    • v.9 no.2
    • /
    • pp.123-132
    • /
    • 1995
  • During compression molding of fiber-reinforced polymeric composites, microstructural changes such as the fiber-matrix separation and the fiber orientation are occurred by the flow of composite materials. Since the nonhomogeneity and anisotropy of composites are caused by the separation and orientation of fibers. On the other hand, the separation and the orientation of fibers are inseparably related to each other. In this paper the degree of nonhomogeneity which is a measure of the separation is obtained using one-dimensional rectangular shaped part compression molding. And the orientation function is measured by the image processing using soft X-rayed photograph and image scanner. We study effects of the mold temperature on the degree of nonhomogeneity and the orientation function.

  • PDF

The Analysis of Inground LNG Storage Tank Compression Ring Behavior during Concrete Pouring (콘크리트 타설에 따른 지하식 LNG 저장탱크 컴프레션 링 거동 분석)

  • Kim Y.K.;Kim J.H.;Yoon I.S.;Oh B.T.;Yang Y.M.
    • 한국가스학회:학술대회논문집
    • /
    • 2004.11a
    • /
    • pp.82-87
    • /
    • 2004
  • Compression ring is a part of LNG storage tank. The main function of the compression ring is connected the roof plate with concrete side wall. End of its one side is embedded in the side concrete wall and the other's connected with the roof plate by welding. It is designed to support stably for all the loads such as self weight of steel roof, inner pressure and concrete weight. We fulfill the FEM analysis to analysis the compression ring behavior during construction. Also we studied the effect of the change of design variables. On the basis of the results, we could introduce a more reasonable design method for compression ring.

  • PDF

Performance Analysis of Two-stage Compression and Two-stage Expansion Refrigeration System using Freon Refrigerants (친환경 프레온 냉매를 이용하는 단압축 단팽창 냉동시스템의 성능예측)

  • Roh, Geun-Sang;Kim, Jong-Ryeol
    • Journal of Fisheries and Marine Sciences Education
    • /
    • v.25 no.2
    • /
    • pp.301-306
    • /
    • 2013
  • In this paper, cycle performance analysis of two-stage compression and two-stage expansion refrigeration system using alternative freon refrigerants is presented to offer the basic design data for the operating parameters of the system. Alternative freon refrigerant for freon refrigerant R22 were used as working fluids in this study. The operating parameters considered in this study included evaporation temperature, condensation temperature, subcooling degree, superheating degree, and mass flow rate ratio of inter-cooler. The main results were summarized as follows : The COP of two-stage compression and two-stage expansion refrigeration system increases with the increasing subcooling degree and mass flow rate ratio of inter-cooler, but decreases with the increasing evaporating temperature, condensing temperature and superheating degree. Therefore, subcooling degree, mass flow rate ratio of inter-cooler of two-stage compression and two-stage expansion refrigeration system using alternative freon refrigerants have an effect on COP of this system.