• 제목/요약/키워드: physical and mechanical methods

검색결과 452건 처리시간 0.032초

Development and Application of Porous Superelastic TiNi Materials for Medical Implants

  • Gjunter, V.E.
    • 한국분말야금학회:학술대회논문집
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    • 한국분말야금학회 1998년도 추계학술대회 및 발표대회 강연 및 발표논문 초록집
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    • pp.7-7
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    • 1998
  • Research activities of Russian Medical Engineering Center and Institute of Medical Materials of Shape Memory Alloys and Implants are presented as follows: ${\bullet}$ The direction of elaboration of porous shape memory alloys for medicine. ${\bullet}$ Medical and technical requirements and physical and mechanical criteria of porous shape memory implants elaboration. ${\bullet}$ Basic laws of heat-, stress- and strain-induced changes of mechanical properties, shape memory effect and superelasticity in porous TiNi-based alloys. ${\bullet}$ Methods of regulation of shape memory effect parameters in porous alloys and methods for controlling the regulation-induced changes of physical and mechanical properties. ${\bullet}$ Original technologies of elaboration of porous alloys In various fields of medicine. ${\bullet}$ Arrangement of serial production of shape memory porous implants and examples of their medical use.

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물리적 인간-기계 상호작용을 위한 표면 근전도 신호 기반의 어깨 굴곡 토크 및 각도 추정 (Estimation of Shoulder Flexion Torque and Angle from Surface Electromyography for Physical Human-Machine Interaction)

  • 박기한;이동주;김정
    • 한국정밀공학회지
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    • 제28권6호
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    • pp.663-669
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    • 2011
  • This paper examines methods to estimate torque and angle in shoulder flexion from surface electromyography(sEMG) signals for intuitive and delicate control of robotic assistance device. Five muscles on the upper arm, three for shoulder flexion and two for shoulder extension, were used to offer favorable sEMG recording conditions in the estimation. The methods tested were the mean absolute value (MAV) with linear regression and the artificial neural network (ANN) method. An optimal condition was sought by varying combination of muscles used and the parameters in each method. The estimation performance was evaluated using the correlation values and normalized root mean square error values. In addition, we discussed their possible use as an estimation of motion intent of a user or as a command input in a physical human-machine interaction system.

솔크 생물학 연구소에 적용된 건물시스템 통합기법 분석에 관한 연구 (Analysis on the Building System Integration Methods of the Salk Institute for Biological Studies)

  • 최준성
    • 대한건축학회논문집:계획계
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    • 제34권7호
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    • pp.59-68
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    • 2018
  • Salk Institute for Biological studies is widely considered as architectural masterpiece of Louis Kahn's. Its iconic plaza with symmetrical concrete structures, overlooking the Pacific ocean in La Jolla, has been acclaimed as a facade to the sky. Little has been written on Kahn's achievements in the building system integration in order to bridge the gap between technology and design. This paper explores the technical issues, the design intents, and the major building systems to identify the Kahn's integration methods between building systems. The project is analysed into four major systems; structure, mechanical, envelope, and interior system. The integration methods of building systems are investigated in physical, visual, and functional aspects. The most distinguished cases of building system integration are the introduction of the interstitial floors between the laboratories and the creation of the smooth and warm materiality of exposed concrete walls. Kahn proposed open floor plans for the laboratories which are capable of easily adapting to changing needs. He also introduced the interstitial floors which are framed of the vierendeel truss systems and deliberately overlapped the structure systems with the mechanical systems such as ducts, water pipes, and electric conduits. The exposed concrete walls mixed with pozzolan ashes look very much like granite or limestone as the result of the physical and visual integration between structure, envelope, and interior systems.

Effect of Phenol Formaldehyde Impregnation on The Physical and Mechanical Properties of Soft-Inner Part of Oil Palm Trunk

  • Hartono, Rudi;Hidayat, Wahyu;Wahyudi, Imam;Febrianto, Fauzi;Dwianto, Wahyu;Jang, Jae-Hyuk;Kim, Nam-Hun
    • Journal of the Korean Wood Science and Technology
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    • 제44권6호
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    • pp.842-851
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    • 2016
  • The objective of this study was to improve physical and mechanical properties of soft-inner part of oil palm trunk (S-OPT) after impregnation with phenol formaldehyde (PF) resin and densification by close system compression (CSC) method. Effect of different methods of PF resin impregnation (i.e., no vacuum-pressure, vacuum, and vacuum-pressure) was evaluated. The results showed that PF resin impregnation and CSC significantly improved the physical and mechanical properties of S-OPT up to: (1) 176% in density; (2) 309% in modulus of rupture (MOR); (3) 287% modulus of elasticity (MOE); and (4) 191% in the compressive strength. Physical and mechanical properties of S-OPT showed their best performances when PF resin impregnated with vacuum-pressure method as shown by higher weight gain, density, MOR, MOE, compressive strength, and lower recovery of set due to better penetration of PF resin into S-OPT. Combining PF resin impregnation and densification by CSC method could be a good method to improve physical and mechanical properties of S-OPT.

중성화 처리 시점 및 양생방법에 따른 에코 콘크리트의 물리.역학적 특성 (Physical and Mechanical Properties of ECO-concrete for Neutralization Treatment Point and Curing Methods)

  • 임상혁;김영익;성찬용
    • 한국농공학회:학술대회논문집
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    • 한국농공학회 2002년도 학술발표회 발표논문집
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    • pp.193-196
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    • 2002
  • This study is performed to examine physical and mechanical properties or neutralization treatment point and curing methods of ECO-cencrete using rice straw ash. Tests for void ratio, compressive and bending strength with neutralization treatment point and curing methods are performed. The test result shows that the void ratio is decreased with increasing content of rice straw ash. But, the compressive and bending strength is increased with increasing content of rice straw ash. The greatest strength is appeared when neutralization is treated at the curing age of 6 days.

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고전압맥동전류가 통각과민 백서의 통각역치 및 유해성 굴곡반사에 미치는 영향 (Change of Pain Threshold and Nociceptive Flexion Reflex of Hyperalgesia Rat by High Voltage Pulsed Current)

  • 김수현;문달주;최석주;정대인;이정우;정진규;김태열
    • The Journal of Korean Physical Therapy
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    • 제18권2호
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    • pp.25-34
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    • 2006
  • Purpose: This study conducted quantitative sensory test and nociceptive flexion reflex(NFR) measurement to examine degree of pain depending on polarity of high voltage pulsed current(HVPC) of hyperalgesia site in hyperalgesia rat by local thermal injury. mechanical pain threshold, thermal pain threshold and root mean square of NFR were measured. Methods: This study was conducted with control group I of hyperalgesia rat at hind paw by thermal injury and experimental groups divided into cathodal HVPC group II, anodal HVPC group III and alternate HVPC group IV. It measured pain threshold and root mean square(RMS) of NFR and obtained the following results. Results: Mechanical pain threshold of hyperalgeisa site was significantly increased at groups II, III and IV applying HVPC group compared to control group, but there was no difference among HVPC groups. Thermal pain threshold of hyperalgesia site showed a significant increase in group II. Group III showed significant difference after 4 days of hyperalgesia. RMS of NFR at hyperalgeisa site was significantly reduced in group II after 2 days of hyperalgesia. Group III showed significant decrease after 5 and 6 days of hyperalgesia. Conclusion: Consequently it was found that application of HVPC of hyperalgesia site increased pain threshold at hyperalgesia site by mechanical stimuli and thermal stimuli. NFR by electrical stimuli was similar to pain threshold by mechanical stimuli. Effects by polarity of HVPC showed the greatest reduction of hyperalgesia when cathodal electrode was used.

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맥스웰 응력텐서의 물리적 의미의 고찰 (On the Physical Meaning of Maxwell Stress Tensor)

  • 최홍순;박일한;문원규
    • 전기학회논문지
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    • 제58권4호
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    • pp.725-734
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    • 2009
  • Maxwell stress tensor is one of the methods which are generally used for electromagnetic force calculation. In this paper, it is presented that Maxwell stress tensor T and n${\cdot}$T have no physical meaning and therefore should not be used as sources of mechanical force for deformations or dynamics. The divergence of Maxwell stress tensor ${\nabla}{\cdot}T$ is the one which can acquire a physical identity and is electromagnetic body force density by an action at a distance like a gravity. This result can be derived from the principle of power balance, and also verified by some thought experiments. The virtual air-gap approach is proposed as a valid solution for the calculation of the body force.

요통 환자를 위한 멕켄지의 역학적 증후군 진단 : 역학적 부하 전략을 중심으로 (Diagnosis of McKenzie Mechanical Syndromes for Patient with Low Back Pain : Focused on mechanical loading strategies)

  • 김민희
    • 정형스포츠물리치료학회지
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    • 제14권2호
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    • pp.109-115
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    • 2018
  • Purpose: McKenzie is a widely-used and conventional clinical therapeutic exercise for patients with mechanical lower back pain. It is a well-designed assessment and classification system for the spine. Main issue: Patients with mechanical lower back pain are classified into one of three mechanical syndromes (posture, dysfunction, or derangement syndrome) by mechanical loading strategies. These methods evaluate symptomatic and mechanical responses during repeated end-range movement and sustained postures. The goal of McKenzie mechanical syndrome diagnosis is to determine directional preferences. Directional preference is a phenomenon of preference for posture or movement in one direction, which reduces or centralizes pain. However, in Korea, there is a lack of awareness of basic McKenzie mechanical syndromes diagnostic concepts. Koreans tend to think of the McKenzie method as a simple lumbar extension exercise. However, an accurate diagnosis of a mechanical syndrome must precede the application of McKenzie exercise. Conclusions: Thus, in this study, I present a classification method of McKenzie mechanical syndrome diagnosis and clinical characteristics of each mechanical syndrome.

비파괴시험과 관입시험에 의한 노상토의 물리·역학적 특성 (Physical and Mechanical Characteristics of Subgrade Soil using Nondestructive and Penetration Tests)

  • 김규선;김동휘;프라타 단테;이우진
    • 대한토목학회논문집
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    • 제31권1C호
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    • pp.19-27
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    • 2011
  • 본 연구에서는 도로 성토현장에서 파 기반의 비파괴시험법과 관입시험의 현장 다짐품질 측정에 대한 적용성을 평가하였다. 현장에서 다짐 노상토의 물리 역학적 특성을 평가하기 위해 흙강성 측정기(SSG), 시간영역 반사측정기(TDR), 소형 전기-기계 시스템(MEMS) 가속도계 등의 비파괴시험을 이용하여 다짐 전후 흙의 응답을 평가하였고, 동적 콘관입시험기(DCP)를 이용하여 다짐 후 전단특성을 평가하였다. 현장시험은 두 가지 흙의 종류에 대해 네 가지의 다짐장비 및 다짐에너지로 조성된 성토지반에서 수행되었다. 시험결과, 조사 매커니즘이 다른 시험법인 SSG, TDR, MEMS 가속도계 및 DCP로 측정된 흙의 파라메터들은 상호 연관성이 있는 것으로 분석되었으며, 다짐지반의 전체적인 품질 및 공학적인 응답을 고려하여 시험 방법들을 현장에 적용할 경우, 기존의 다짐도 평가 방법들을 대체 또는 보완하여 현장에서 신속한 다짐품질 평가를 수행할 수 있는 것으로 나타났다.

Feasibility Study on Styrofoam Layer Cushioning for Banana Bulk Transport in a Local Distribution System

  • Wasala, W.M.C.B.;Dharmasena, D.A.N.;Dissanayake, C.A.K.;Tilakarathne, B.M.K.S.
    • Journal of Biosystems Engineering
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    • 제40권4호
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    • pp.409-416
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    • 2015
  • Purpose: This study evaluates a new banana bulk packaging method under the real transport conditions of Sri Lanka. Methods: A field evaluation of optimized 8-mm thick Styrofoam sheets used as the cushioning material was applied. A trial transport was conducted from Thambuttegama to Colombo using a medium-sized open truck, with banana leaves as the control material. Data were recorded at the farmer, transporter, retailer, and consumer stages of the supply chain. Mechanical damage, physiological loss in weight, fruit firmness, total soluble solids, ripeness index, visual quality ratings, and the physical damage index of the bananas were measured at each stage. A cost-benefit analysis was also conducted for both packaging methods. Results: The 8-mm styrofoam sheets significantly reduced (p < 0.05) the mechanical damage from 26.3% to 12.9% compared to the conventional method for long-distance transport, and the physiological loss in weight showed a decrease of 2.88%. The loss of firmness of the fruits followed a simmilar pattern for both methods until reaching the retailer, but at the consumer was significantly higher (p < 0.05) for the control. However, the physical damage index at the retail stage for the control showed symptoms of physical injury, whereas the bananas transported using the cushioning materials exhibited only minor symptoms. Further, the visual quality of the fruits after transport from the farmer to the consumer was preserved, which is one of the main factors affecting consumer preference and retail price. The proposed method increases the profit margin by 51.2% for Embul bananas owing to the reduced postharvest losses. Conclusion: The 8-mm thick Styrofoam sheets reduced the physical damage to the bananas, with the quality parameters maintained at the prefered level. Moreover, profits may be increased.