• 제목/요약/키워드: NDT Methods

검색결과 109건 처리시간 0.024초

Validity and Reliability of New Digital Navicular Drop Test Equipment in Young People

  • Park, Jin-Seong;Park, Du-Jin
    • PNF and Movement
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    • 제19권2호
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    • pp.279-285
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    • 2021
  • Purpose: This study aimed to develop new digital navicular drop test (ND-NDT) equipment and to determine its validity and reliability. Methods: A total of 24 healthy male and female adults, who fully understood the purpose of the study and gave consent to participate in the study, were selected as participants. The NDT and ND-NDT were conducted in the dominant foot of the participants in a random order. For the NDT, the position of the navicular bone was marked with a pen first; then, the height of the navicular bone from the ground was measured in both sitting and standing positions. For the ND-NDT, after the sticker-type reflection markers were attached to the position of the navicular bone, the height of the navicular bone from the ground was measured in both sitting and standing positions. To assess the validity of the diagnostic tests, the same examiner measured the height of the medial longitudinal arch (MLA) three times in both the sitting and standing positions. To assess the inter-rater reliability of the ND-NDT, three examiners, in a random order, attached the sticker-type reflection markers to the position of the navicular bone and then measured the height of the MLA in both positions. Results: In the sitting position, the Pearson correlation coefficient (r) between the two diagnostic tests was very high (r = 0.97) and statistically significant. In the standing position, the Pearson correlation coefficient (r) between the two tests was 0.95, which was also statistically significant. The ICC2,1 values in the sitting and standing positions were 0.93 and 0.95, respectively, indicating significantly high inter-rater reliability. Conclusion: The ND-NDT equipment showed very high diagnostic validity, as well as excellent inter-rater reliability, indicating the clinical usefulness of the equipment as a diagnostic system for confirming pes planus.

Shearography를 이용한 비파괴 검사 (Nondestructive Testing with Shearography)

  • 장석원
    • 비파괴검사학회지
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    • 제21권2호
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    • pp.177-181
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    • 2001
  • 광학적 비접촉 비파괴검사 방법인 ESPI, Shearography를 이용한 측정은 자동차나 항공기산업 등에서 최근 폭넓게 이용되고 있다. 빠른 측정 속도와 측정 대상의 전 영역을 한번에 측정할 수 있는 장점을 가진 Shearography를 이용한 비파괴검사 방법을 기존의 광계측법인 ESPI와 비교하였다. 또한 이러한 장점을 살려 산업현장에서 수행한 여러 가지 비파괴검사 사례를 제시하였다.

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뉴로 다이나믹 기법이 만성 뇌졸중 환자의 균형과 보행에 미치는 즉각적 영향 (The Immediate Effect of Neuro-Dynamics Technique on Balance and Gait in Chronic Stroke Patients)

  • 정주리;양영식;박재명
    • 대한정형도수물리치료학회지
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    • 제22권1호
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    • pp.27-34
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    • 2016
  • Background: The purpose of this study was to investigate the immediate effects of neuro-dynamics technique (NDT) to the balance and gait for chronic stroke patients. Methods: This study was composed of the cross-sectional design. Nine patients with chronic stroke applied to NDT. Balance ability function was measured using the Good Balance System device for static balance, timed up and go test (TUG) and functional reach test (FRT) for dynamic balance. The 10 meter walk test (10MWT) and GAITRite device were used for measurement of gait ability for patients. Results: There were significant improvements were observed on dynamic balance ability (p<.05) and gait ability function (p<.05). Conclusions: This research shows that the NDT is immediate effective on dynamic balance and gait ability of the chronic stroke patients. Further studies may be needed to continuously intervention of NDT for more patients.

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Nondestructive tests for defections detection of nanoparticles in cement-based materials: A review

  • Kaloop, Mosbeh R.;Elrahman, Mohamed Abd;Hu, Jong Wan
    • Advances in nano research
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    • 제12권1호
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    • pp.1-23
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    • 2022
  • To date, nondestructive tests (NDT) applications and advances in detecting the dispersion and defections of the nano concrete (NC) materials fields are very limited. The current paper provides a review of the dispersion efficiency of nanomaterials in cement-based materials and how NDT can be efficiently used in detecting and visualizing the defections and dispersions of NC. The review identifies the characteristics of different types of nanoparticles used in NC. Nanomaterials influences on concrete characteristics and their dispersion degree are presented and discussed. The main aim of this article is to present and compare the common NDT that can be used for detecting and visualizing the defections and dispersions of different kinds of nanomaterials utilized in NC. The different microscopy and X-ray methods are explicitly reviewed and compared. Based on the collected data, it can be concluded that the fully detecting and visualizing of NC defections and dispersions have not been fully discovered and that needs further investigations. So, the distinction of this paper lies in defining NDT that can be employed for detecting and/or visualizing NC defections and dispersions.

비파괴시험에 의한 GFRP Pipe의 평가 (The Evaluation of GFRP Pipe by NDT Methods)

  • 이주석;조경식;장홍근;이승희
    • 비파괴검사학회지
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    • 제9권1호
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    • pp.48-55
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    • 1989
  • It is desirable to develop the effective NDT techniques to evaluate the strength of composite structures. In this study several of acoustic NDT techniques were applied to investigate useful parameters for evaluating the filament wound GFRP structures and following results were obtained. 1. Propagation velocity of stress wave to axial direction in the filament wound GFRP pipe depends on the effective modulus along the propagation direction and source location was parcticable from the a measured velocities. 2. By the application of acoustic emission techniques to GFRP pipe during hydraulic test, it was proven to be possible to detect the damage initiating pressure which could be evaluated nondestructively through the measuring of stress wave energy factor(SWEF). 3. The final failure pressure of GFRP was greatly influenced in the presence of pass through defects, and void-like defects were more dangerous than the laminar type defects.

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가압열충격을 고려한 원자로 압력용기의 파괴역학적 해석 (Fracture Mechanics Analysis of a Reactor Pressure Vessel Considering Pressurized Thermal Shock)

  • 박재학;박상윤
    • 한국안전학회지
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    • 제16권4호
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    • pp.29-38
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    • 2001
  • The purpose of this paper is to evaluate the structural integrity of a reactor pressure vessel subjected to the pressurized thermal shock(PTS) during the transient events, such as main steam line break(MSLB) and small break loss of coolant accident(SBLOCA). For postulated surface or subsurface cracks, variation curves of stress intensity factor are obtained by using the three different methods, including ASME section XI code anlysis, the finite element alternating method and the finite element method. From the stress intensity factor curves, the maximum allowable nil-ductility transition temperatures(RT/NDT/) are determined by the tangent criterion and the maximum criterion for various crack configurations and two initial transient events. As a result of the analysis, it is noted that axial cracks have smaller maximum allowable RT$_{NDT}$ values than same-sized circumferential cracks for both the transient events in the case of the tangent criterion. Axial cracks have smaller RT$_{NDT}$ values than same-sized circumferential cracks for MSLB and circumferential cracks have smaller values than axial cracks for SBLOCA in the case of the maximum criterion.

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The Relationship Between the Range of Hip Rotation and the Quadriceps Angle in Subjects With and Without Flat Foot

  • Lee, Keun-hyo;Chon, Seung-chul
    • 한국전문물리치료학회지
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    • 제25권4호
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    • pp.19-26
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    • 2018
  • Background: Alignment of the lower limb is an important factor, influencing balance and gait in kinematics and kinetics, in patients with and without a flat arched foot. Flat arched foot are associated with the range of motion (ROM) of the hip and alignments of the knee joints, is strongly influenced. Objects: The purpose of this research was to investigate the relationship between hip joint ROM and quadriceps angle (Q-angle), by dividing them into two groups according to the presence or absence of flat feet, using a navicular drop test (NDT) and resting calcaneal stance position (RCSP). Methods: Forty elderly patients were allocated to the experimental group (flat foot group, n1=20) or the control group (non-flat group, n2=20). Universal and digital goniometer, tractograph and tape measure were used to determine the related changes in the hip ROM, Q-angle, NDT and RCSP. Results: Data were analyzed using the Pearson correlation coefficients. Active internal ROM of the hip joint (right, r=.803, p<.001), (left, r=.951, p<.001) were highly correlated with NDT, and also, was moderately correlated with Q-angle (right, r=.562, p=.019), (left, r=.757, p<.001). Passive internal ROM of the hip joint (right, r=.742, p=.001), (left, r=.922, p<.001) were highly correlated with NDT, and also, was moderately correlated with RCSP (right, r=-.530, p=.029) and with Q-angle (right, r=.710, p=.001), (left, r=.698, p=.002) in the flat foot group. However, no strong correlation among the hip ROM, NDT, RCSP and Q-angle were found in the non-flat foot group. Conclusion: This research may provide evidence of the correlations between hip internal ROM and flat foot.

Comparison of X-ray computed tomography and magnetic resonance imaging to detect pest-infested fruits: A pilot study

  • Kim, Taeyun;Lee, Jaegi;Sun, Gwang-Min;Park, Byung-Gun;Park, Hae-Jun;Choi, Deuk-Soo;Ye, Sung-Joon
    • Nuclear Engineering and Technology
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    • 제54권2호
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    • pp.514-522
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    • 2022
  • Non-destructive testing (NDT) technology is a widely used inspection method for agricultural products. Compared with the conventional inspection method, there is no extensive sample preparation for NDT technology, and the sample is not damaged. In particular, NDT technology is used to inspect the internal structure of agricultural products infested by pests. The introduction and spread of pests during the import and export process can cause significant damage to the agricultural environment. Until now, pest detection in agricultural products and quarantine processes have been challenging because they used external inspection methods. However, NDT technology is advantageous in these inspection situations. In this pilot study, we investigated the feasibility of X-ray computed tomography (X-ray CT) and magnetic resonance imaging (MRI) to identify pest infestation in agricultural products. Three kinds of artificially pest-infested fruits (mango, tangerine, and chestnut) were non-destructively inspected using X-ray CT and MRI. X-ray CT was able to identify all pest infestations in fruits, while MRI could not detect the pest-infested chestnut. In addition, X-ray CT was superior to the quarantine process than MRI based on the contrast-to-noise ratio (CNR), image acquisition time, and cost. Therefore, X-ray CT is more appropriate for the pest quarantine process of fruits than MRI.

초음파 탐상법을 이용한 접착이음에 대한 계면균열의 검출 (Detection of Interface Crack Using Ultrasonic Method in Adhesively Bonded Joints)

  • 정남용;이명대;박성일
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2000년도 춘계학술대회논문집A
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    • pp.97-102
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    • 2000
  • It is well recognized that the ultrasonic methods is one of the most common and reliable nondestructive testing(NDT) methods for the quantitative estimation of defects in welded structures. However, NDT techniques applying for adhesively bonded joints have not been clearly established yet. In this paper, the detection of interface crack by the ultrasonic method was applied for the measurement of interfacial crack length in the adhesively bonded joints of double-cantilever beam(DCB). The optimum condition of transmission coefficients in the adhesively bonded joints and it's experimental accuracy by the ultrasonic method have been investigated. The experimental values are in good agreement with the computed results by boundary element method(BEM) and Ripling's equation.

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비파괴시험을 이용한 현장타설말뚝의 건전도 평가에 관한 연구 (Application of Non-Destructive Testing Techniques to the Evaluation of Integrity of Drilled Shaft)

  • 채종훈;유재명;김대규;이우진
    • 한국지반환경공학회 논문집
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    • 제2권4호
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    • pp.5-14
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    • 2001
  • 최근 구조물기초에 큰 변형 및 손상을 가하지 않고 안정성에 대한 정보를 비교적 쉽게 얻을 수 있는 비파괴시험(NDT, Non-Destructive Testing)기법이 큰 관심을 얻고 있다. 본 연구에서는 비파괴시험 중 검측공 기법(CSL, CT, PS)과 표면파 기법(SE, IR)을 현장타설말뚝의 건전도 평가에 이용하기 위한 적용성의 문제를 현장시험을 통하여 고찰하였다. 이를 위하여 결함이 없는 한 본의 정상말뚝과 연약선단, 단면축소 확대, 불량콘크리트 타설 등 현장에서 발생하기 쉬운 결함의 종류, 크기, 위치 등을 변화 조합한 9본의 현장타설말뚝(직경 0.4m, 길이 7.0m)을 시공하여 다양한 비파괴시험을 수행하였다. 시험을 통하여 각 기법을 현장타설말뚝의 건전도 평가에 적용할 때의 문제점과 각 기법의 합리적인 조합에 대하여 고찰하였다.

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