• Title/Summary/Keyword: 비파괴 실험

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Non-destructive testing of historical masonry using radar tomography (레이더 토모그래피에 의한 석조문화재 비파괴 검사)

  • Cha, Young-Ho;Kang, Jong-Suk;Choi, Yun-Gyeong;Suh, Jung-Hee;Bae, Byeong-Seon
    • 한국지구물리탐사학회:학술대회논문집
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    • 2004.08a
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    • pp.138-156
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    • 2004
  • GPR(Ground Penetrating Radar) was used for imaging the interior of the historical masonry such as stone pagoda in order to provide the basic information of safely inspection. The scope of the imaging was restricted to the foundation part of stone pagoda that transferred the load of the pagoda to the ground. Kirchhoff migration and traveltime tomography was used for imaging the outer stone and the inside of stone pagoda, respectively. From the migrated images, we could measure the thickness and the shape of the boundaries of the outer stone in the foundation part. From the reconstructed tomograms for the physical model, we could get the GPR propagation velocity distribution and exactly find the position of the air in the model and calculate the average velocity with respect to the different filling materials. The properties and the shape of the interior materials of stone pagoda can be basic informations for the safety inspection.

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Studies on the characteristics of stone structures by shape reversal, geotechnical and dynamic structural engineerings (석조구조물의 효율적 유지관리를 위한 형상역공학적, 지반공학적 및 구조동역학적 특성연구 - 첨성대를 중심으로 -)

  • Shon, Bo-Woong;Kim, Seong-Beom
    • 한국지구물리탐사학회:학술대회논문집
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    • 2004.08a
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    • pp.25-48
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    • 2004
  • Structures show the phehomena of deformation and lowering of function with time-lapse by artificial environments and changes of geotechnical conditions or accumulation of initial deformation elements. This study aims the structural assessment of cultural property, Chum-Sung-Dae, located in Kyeongju city, Korea. It was built about 1,300 years ago, and has undergone deformation and ground-subsidence with time-lapse. Non-destructive evaluation techniques were applied to the Chum-Sung-Dae, to protect it from survey Because of this reason, 3D precise laser scanning surveying system was applied to measure the exact size of Chum-Sung-Dae, displacement and declining angles. Geophysical exploration also was applied to study the subsurface distribution of geotechnical parameters or physical properties. Natural frequencies were measured from real and model of Chum-Sung-Dae to study the dynamic characteristics of vibration and/or earthquake load and stiffness of structures.

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Development of Rapid Prediction Model of C3G Content in Black Pigmented Rice (흑자색미의 C3G 색소함량 신속 예측모델 개발)

  • Ryu Su-Noh;Yang Jong-Jin;Park Sun-Zik
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.50 no.spc1
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    • pp.1-3
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    • 2005
  • It has been reported that Cyanidin 3-Glu-coside (C3G) of the black pigmented rice was as the high anti-oxidency and analyzed by high performance liquid chromatography (HPLC). However, the analysis of C3G by HPLC is needed long pre-treated steps, so development of methods with simple pre-treated steps is needed in order to breed vices with high C3G contents. The analysis of components using near infrared reflectance (NIR) was well known as non pre-treated and nondestructive. C3G contents of Bengjinjubyeo$\times$Suwon425 $F_{10}$ 385 lines were used in order to develop C3G content prediction model in pigmented rice using FT-NIR. The results of C3G content of FT-NIR compared with HPLC were showed that the equation was f(x)=0.9427x+34.0430, $R^2$, standard error of calibration was 0.943, 0.116 and those of validation was 0.928, 0.122, respectively. This prediction model will be able to be used for analyzing C3G contents in black pigmented rice.

Evaluation of Beef Freshness Using Visible-near Infrared Reflectance Spectra (가시광선-근적외선 반사스펙트럼을 이용한 쇠고기의 신선도 평가)

  • Choi, Chang-Hyun;Kim, Jong-Hun;Kim, Yong-Joo
    • Food Science of Animal Resources
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    • v.31 no.1
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    • pp.115-121
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    • 2011
  • The objective of this study was to develop models to predict freshness factors (total viable counts (TVC), pH, volatile basic nitrogen (VBN), trimethylamine (TMA), and thiobarbituric acid (TBA) values) and the storage period in beef using a visible and near-infrared (NIR) spectroscopic technique. A total of 216 beef spectra were collected during the storage period from 0 to 14 d at a $10^{\circ}C$ storage. A spectrophotometer was used to measure reflectance spectra from beef samples, and beef freshness spectra were divided into a calibration set and a validation set. Multi-linear regression (MLR) models using the stepwise method were developed to predict the factors. The MLR results showed that beef freshness had a good correlation between the predicted and measured factors using the selected wavelength. The correlation of determination ($r^2$), standard error of prediction (SEP), and ratio of standard deviation to SEP (RPD) of the prediction set for TVC was 0.74, 0.64, and 2.75 Log CFU/$cm^2$, respectively. The $r^2$, SEP, and RPD values for pH were 0.43, 0.10, and 1.10; those for VBN were 0.73, 1.45, and 2.00 mg%; those for TMA were 0.70, 0.19, and 2.58 mg%; those for TBA values were 0.73, 0.13, and 2.77 mg MA/kg; and those for storage period were 0.77, 1.94, and 2.53 d, respectively. The results indicate that visible and NIR spectroscopy can predict beef freshness during storage.

Analysis of Fission Products on Irradiated Fuels using EPMA (EPMA를 이용한 사용후핵연료의 연소도 측정에 관한 연구)

  • JUNG Yang-Hong;YOO Byung-Ok;OH Wan-Ho;LEE Hong-Gy;CHOO Yong-Sun;HONG Kwon-Pyo
    • Proceedings of the Korean Radioactive Waste Society Conference
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    • 2005.06a
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    • pp.335-343
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    • 2005
  • The Methodology of burnup calculation with EPMA test set up in this study. The spent fuel from PWR nuclear power plant was used as specimen. This $UO_2$ fuel with $3.2\%$ of enrichment had been irradiated up to 35,000 MWd/MTU(reference data). The burnup is very important factor for nuclear fuel to estimate all fuel behaviors in reactor. To measure amounts of fission products and actinides for the burnup calcualation, chemical analysis (destructive method) has been used but it mattes long experimental time and second radio-wastes. In this study, EPMA test was available to measure amount of fission products. Neodymium is able to be detected and quantified. It can be compared with the results from chemical analysis and ORIGEN-2 code calculation. Concentration of Nd from EPMA test showed good agreement with result of ORIGEN-2 code in the same burnup.

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Analysis of Fission Products on Irradiated Fuels using EPMA (EPMA를 이용한 사용후핵연료의 연소도 측정에 관한 연구)

  • Jung, Yang-Hong;Yoo, Byung-Ok;Oh, Wan-Ho;Lee, Hong-Gy;Choo, Yong-Sun;Hong, Kwon-Pyo
    • Applied Microscopy
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    • v.35 no.3
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    • pp.113-119
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    • 2005
  • The Methodology of burnup calculation with EPMA test set up in this study. The spent fuel from PWR nuclear power plant was used as specimen. This $UO_2$ fuel with 3.2% of enrichment had been irradiated up to 35,000 MWd/MTU. The burnup is very important factor for nuclear fuel to estimate all fuel behaviors in reactor. To measure amounts of fission products and actinides for the burnup calcualation, destructive method analysis has been used but it makes long experimental time and second radio-wastes. In this study, EPMA test was available to measure amount of fission products. Neodymium is able to be detected and quantified. It can be compared with the results from chemical analysis and ORIGEN-2 code calculation. Concentration of Nd from EPMA test showed good agreement with result of ORIGEN-2 code in the same burnup.

A Case Study on Cause Analysis for Longitudinal Crack of Duct Slab in Tunnel (터널 덕트슬래브의 종방향 균열에 대한 원인 분석 사례 연구)

  • Park, Sung Woo;Park, Seung Su;Hwang, In Baek;Cha, Chul Joon
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.16 no.5
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    • pp.19-28
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    • 2012
  • In this study, cause of longitudinal crack which is found on duct slab of road tunnel is studied. In-depth investigation, such as visual inspection, non-destructive testing and geometrical surveying of duct slab, is carried out. In order to perform cause analysis, the investigated results are compared to the results of numerical analysis. Many factors, which cause longitudinal crack, are classified as constrained condition of the duct slab, location of the rebar, temperature, shrinkage and so on. According to the classified causes of longitudinal crack, numerical analysis is performed considering construction stage of the tunnel lining. Especially, in order to predict shrinkage stain due to discrepancy of curing date, ACI-209 model, KCI structural design code and other researcher's shrinkage test results are compared. The results show that shrinkage strain is one of the main factors causing longitudinal crack. Other investigated tunnels are classified along with the construction method of duct slab and patterns of cracks. As a result, improving ways to construct duct slab are suggested.

Utilization of Near Infrared Spectroscopy for Analysis of Proximate Composition and Starch in Alaska Pollack Surimi (명태 수리미의 일반성분 및 전분의 분석을 위한 근적외선 분광분석법의 이용)

  • Song Ho Su;Lee Keun Tai;Park Seong Min;Hwang Sun Young
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.35 no.4
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    • pp.321-326
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    • 2002
  • Near infrared spectroscopy (NIR), is recently applied to analysis of food, and it gives non-destructive and highly reproducible results. The objectives of this study were to assay protein, lipid and starch content in Alaska pollack surimi and to investigate application in seafood. NIR spectra showed the absorbance signal at 1,510 nm, 2,050 nm, 2,170 nm and 2,180 nm for protein, and signal were increased with protein content. Standard error of equation (SEE) was 0,296 and standard error of prediction (SEP) was 0.327. In analysis of lipid in Alaska pollack surimi by NIR, near infrared spectra of lyophilized Alaska pollack surimi were scanned and the signals of absorbance from C-H functional groups in lipid were identified at 1,730 nm, 1,740 nm and 2,300 nm and these signals were risen as Increasing lipid contents of Alaska pollack surimi as samely protein. SEE and SEP were 0.319, 0,353, respectively. In starch analysis using NIR the signals of starch distinctly changed at wavelength of 1,450 nm and 1,950 nm. Collected values of SEE and SEP were 0.304 and 0.318, respectively and the range of errors was $0.0186\~0.6470$ in starch contents.

A Study on the Thermo-Mechanical Fatigue Loading for Time Reduction in Fabricating an Artificial Cracked Specimen (열-기계적 피로하중을 받는 균열시편 제작시간 단축에 관한 연구)

  • Lee, Gyu-Beom;Choi, Joo-Ho;An, Dae-Hwan;Lee, Bo-Young
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.21 no.1
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    • pp.35-42
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    • 2008
  • In the nuclear power plant, early detection of fatigue crack by non-destructive test (NDT) equipment due to the thermal cyclic load is very important in terms of strict safety regulation. To this end, many efforts are exerted to the fabrication of artificial cracked specimen for practicing engineers in the NDT company. The crack of this kind, however, cannot be made by conventional machining, but should be made under thermal cyclic load that is close to the in-situ condition, which takes tremendous time due to the repetition. In this study, thermal loading condition is investigated to minimize the time for fabricating the cracked specimen using simulation technique which predicts the crack initiation and propagation behavior. Simulation and experiment are conducted under an initial assumed condition for validation purpose. A number of simulations are conducted next under a variety of heating and cooling conditions, from which the best solution to achieve minimum time for crack with wanted size is found. In the simulation, general purpose software ANSYS is used for the stress analysis, MATLAB is used to compute crack initiation life, and ZENCRACK, which is special purpose software for crack growth prediction, is used to compute crack propagation life. As a result of the study, the time for the crack to reach the size of 1mm is predicted from the 418 hours at the initial condition to the 319 hours at the optimum condition, which is about 24% reduction.

Development of Tenderness Measurement System of Beef Carcass Using Ultrasound (초음파를 이용한 한우도체 연도 측정 시스템 개발)

  • 조성인;남기찬;임용우
    • Proceedings of the Korean Society for Agricultural Machinery Conference
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    • 2002.02a
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    • pp.479-485
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    • 2002
  • 본 연구는 초음파를 이용하여 한우도체의 연도를 비파괴적이며 객관적으로 측정할 수 있는 시스템을 개발하기 위해서 수행되었다. 한우도체 연도 측정 시스템은 크게 초음파 측정장치, 자동 탐촉자 수직이동장치, 데이터 획득 및 분석장치로 구성되었는데 초음파 측정장치는 초음파 pulser/receiver 및 탐촉자, 자동 탐촉자 이동장치는 상하운동부, 구동부, 제어부, 데이터 획득 및 분석장치는 digitizer, Labview 5.1을 사용하여 구성되었다. 통합된 시스템을 이용하여 획득된 도체의 초음파 신호를 분석하기 위해 1.0~1.1 MHz의 bandpass filtering을 거쳐 hilbert 변환을 이용, envelope를 구할 수 있었으며 탐촉자와 도체의 최적 접촉 위치를 결정하기 위하여 3단계로 나누어 신호분석을 실시하였다. 시료의 개수는 40개였으며 획득된 envelope를 FFT 변환 후 PLS, PCR 분석을 수행한 결과 7단계의 PCR 분석에서 $R^2$= 0.6474의 유의성 있는 결과를 나타내었으므로 최적 접촉 위치로 결정하였다. 최적 접촉 위치를 통해 시료 80개의 추가 실험을 실시한 결과 PCR 분석에서 $R^2$= 0.4304의 결과를 나타내었으며 이를 이용, 도체의 연도를 측정하는 프로그램을 개발하고 최종 통합 시스템을 구축하였다. 본 한우도체 연도 측정 시스템의 개발을 통해 한우도체의 전단력을 예측하여 연도를 객관적으로 판정 가능할 것으로 생각되며 또한 사이즈의 확대로 도축장에 설치하는 설비로서 가능할 것이라 사료된다. 그러나 추후 좀 더 세밀한 측정과 결과의 보완을 위한 분석방법의 개선에 관한 연구가 진행되어야 할 것이다. 사용해 설계된 장치를 사용자가 쉽게 제작할 수 있도록 하였다. 공정설계프로그램을 통해 설계된 공정은 데이터베이스에 저장이 되며 장치설계프로그램에서 쉽게 이전에 설계했던 공정을 이용할 수 있도록 하여 공정 설계와 장치설계를 연계하도록 하였다.동투하시간과 비용 -종자준비부터 통마늘선별까지의 일관기계화로 투입된 주요작업의 노력은 75∼76%가 절감되고, 재배규모 3ha기준시 비용은 44-53%절감되었음. the annealing texture. Observations by TEM and EBSD revealed the formation of very fine grains of ∼1.0$\mu\textrm{m}$ after CCSS.he dislocations form local defect arrangements at the grooves permitting the substantial reduction in defect density over the remainder of the interfacial area.한 최대의 감자 재배지역을 형성하였다. 제주도는 산지지형과 따뜻한 기온으로 2기작이 가능하고, 감자가공 공장설립과 교통발달에 따른 육지 시장과의 접근이 용이해졌기 때문에 남한에서 2번째로 큰 감자재배지역이 되었다.(요약 및 결론에서 발췌)그람양성균에서 효과적이었으며, 농도별 항균력시험 결과 농도가 증가할수록 비례하여 저해율도 증가함을 알 수 있었다. 첨가농도를 달리하여 미생물의 생육도를 측정한 결과, fraction II磎꼭\ulcorner경우 그람양성균에 대해 500 ppm 이상에서 뚜렷한 증식억제효과를 나타내었다.서 뚜렷한 증식억제효과를 나타내었다.min/+}$계

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