• 제목/요약/키워드: BSE image analysis

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전자빔 몬테 카를로 시물레이션 프로그램 개발 및 전자현미경 이미징 특성 분석 (Development of Electron Beam Monte Carlo Simulation and Analysis of SEM Imaging Characteristics)

  • 김흥배
    • 한국정밀공학회지
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    • 제29권5호
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    • pp.554-562
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    • 2012
  • Processing of Scanning electron microscope imaging has been analyzed in both secondary electron (SE) imaging and backscattered electron (BSE) image. Because of unique characteristics of both secondary electron and backscattered electron image, mechanism of imaging process and image quality are quite different each other. For the sake of characterize imaging process, Monte Carlo simulation code have been developed. It simulates electron penetration and depth profile in certain material. In addition, secondary electron and backscattered electron generation process as well as their spatial distribution and energy characteristics can be simulated. Geometries that has fundamental feature have been imaged using the developed Monte Carlo code. Two, SE and BSE images generation process will be discussed. BSE imaging process can be readily used to discriminate in both material and geometry by simply changing position and direction of BSE detector. The developed MC code could be useful to design BSE detector and their position. Furthermore, surface reconstruction technique is possibly developed at the further research efforts. Basics of Monte Carlo simulation method will be discussed as well as characteristics of SE and BSE images.

해남 성산광산의 명반석 내 진동누대구조에 관한 연구 (Oscillatory Zoning in Alunite from the Sungsan Mine, Korea)

  • 조현구;김수진
    • 한국광물학회지
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    • 제5권1호
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    • pp.42-47
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    • 1992
  • 해남 성산광산에서 산출되는 명반석에서 나타나는 진동누대구조를 back-scattered electron(BSE) 상과 전자현미분석기를 이용하여 연구하였다. 이런 누대구조는 편광현미경 하에서는 관찰되지 않자만, BSE상에서는 아주 명확히 관찰된다. 전자현미분석에 의하면 이런 누대구조는 명반석 구조 내 A 자리에서 칼륨을 치환하는 나트륨의 양적인 차이에 의하여 생긴다는 것을 지시한다. BSE상에서 밝기가 증가함에 따라 칼륨의 양은 증가하지만, 나트륨의 양은 감소한다. 섬세한 작은 규모의 누대구조와 인접한 zone사이의 명확한 경계는 이런 진동누대구조가 성장하는 명반석 결정주변의 열수용액의 성분의 변화에 기인하여 형성된 것임을 가리킨다. 이러한 변화를 초래한 요인은 1) 유입되는 유체 성분의 변화 및 2) 보다 안정한, 나트륨이 적은 명반석의 따른 침전에 의한 용액성분의 변화일 것으로 생각된다.

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Psychosocial Predictors of Breast Self-Examination among Female Students in Malaysia: A Study to Assess the Roles of Body Image, Self-efficacy and Perceived Barriers

  • Ahmadian, Maryam;Carmack, Suzie;Samah, Asnarulkhadi Abu;Kreps, Gary;Saidu, Mohammed Bashir
    • Asian Pacific Journal of Cancer Prevention
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    • 제17권3호
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    • pp.1277-1284
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    • 2016
  • Background: Early detection is a critical part of reducing the burden of breast cancer and breast self-examination (BSE) has been found to be an especially important early detection strategy in low and middle income countries such as Malaysia. Although reports indicate that Malaysian women report an increase in BSE activity in recent years, additional research is needed to explore factors that may help to increase this behavior among Southeastern Asian women. Objective: This study is the first of its kind to explore how the predicting variables of self-efficacy, perceived barriers, and body image factors correlate with self-reports of past BSE, and intention to conduct future breast self-exams among female students in Malaysia. Materials and Methods: Through the analysis of data collected from a prior study of female students from nine Malaysian universities (n=842), this study found that self-efficacy, perceived barriers and specific body image sub-constructs (MBSRQ-Appearance Scales) were correlated with, and at times predicted, both the likelihood of past BSE and the intention to conduct breast self-exams in the future. Results: Self-efficacy (SE) positively predicted the likelihood of past self-exam behavior, and intention to conduct future breast self-exams. Perceived barriers (BR) negatively predicted past behavior and future intention of breast self-exams. The body image sub-constructs of appearance evaluation (AE) and overweight preoccupation (OWP) predicted the likelihood of past behavior but did not predict intention for future behavior. Appearance orientation (AO) had a somewhat opposite effect: AO did not correlate with or predict past behavior but did correlate with intention to conduct breast self-exams in the future. The body image sub-constructs of body area satisfaction (BASS) and self-classified weight (SCW) showed no correlation with the subjects' past breast self-exam behavior nor with their intention to conduct breast self-exams in the future. Conclusions: Findings from this study indicate that both self-efficacy and perceived barriers to BSE are significant psychosocial factors that influence BSE behavior. These results suggest that health promotion interventions that help enhance self-efficacy and reduce perceived barriers have the potential to increase the intentions of Malaysian women to perform breast self-exams, which can promote early detection of breast cancers. Future research should evaluate targeted communication interventions for addressing self-efficacy and perceived barriers to breast self-exams with at-risk Malaysian women. and further explore the relationship between BSE and body image.

시멘트계 자기치유 시편에 대한 반사전자현미경 이미지 분석을 위한 함침과 연마의 중요성 (Importance of Impregnation and Polishing for Backscattered Electron Image Analysis for Cementitious Self-Healing Specimen)

  • 김동현;강국희;배승묵;임영진;이승헌
    • 한국건설순환자원학회논문집
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    • 제5권4호
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    • pp.435-441
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    • 2017
  • 자기치유에 관한 연구는 현재 다각화되었으며 연구를 평가하는 방법도 다양해졌다. 그중에서, 스캐닝 전자 현미경(SEM)을 통해 획득된 반사전자(BSE) 이미지는 균열에서의 자기치유 효과를 평가하는 수단으로 시도되었다. BSE 이미지를 평가하기 위해서 정교한 시편 전처리가 대단히 중요하다. 에폭시 함침은 경화체의 입자, 기공과 인공 균열 내부에 투입되어 새롭게 생성된 자기치유 수화물의 구조를 안정화시키고 변형 없이 연삭 및 연마의 응력을 견딜 수 있게 한다. 함침 시편은 표면을 매끄럽게 하고 고해상도의 BSE 영상을 얻기 위해 건조 연마 후 습식 연마용 다이아몬드 서스펜션으로 연마한다. 함침과 연마가 된 자기치유 시편의 자기치유 수화물을 평가한 결과, 생성된 수화물은 인공균열의 표면에 형성되었으며 자기치유 물질은 $Ca(OH)_2$와 C-S-H로 확인되었다.

마이크로웨이브-질산용출과자력/수력선별에의한자연금및자철석의선별효과 (The Selection Effect of Native Gold and Magnetite by Microwave-nitric Acid Leaching and Magnetic/hydro Separation)

  • 이종주;박천영
    • 자원환경지질
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    • 제53권2호
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    • pp.183-196
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    • 2020
  • 본 연구는 마이크로웨이브-질산용출과 자력/수력선별을 이용하여 정광으로부터 자연 금을 회수하는 것을 목표로 하였다. 마이크로웨이브-질산용출실험을 통해 용출용액으로부터 불용성-잔류물을 여과하였다. 용출용액을 원자흡수분광기(AAS)로 분석한 결과 Au는 전혀 용출되지 않은 것을 그리고 불용성-잔류물을 후방산란전자영상(BSE)으로 관찰한 결과 자연 금이 단체분리된 것으로 확인되었다. 불용성-잔류물을 자력/수력선별 하여 자성광물과 비-자성광물로 선별하였다. 자성광물에서 자철석이 회수되었고, 비-자성광물을 다시 수력선별한 결과 자연 금이 회수되었다. 자연 금은 X선 회절 분석(XRD)과 BSE 영상에서 확인되었다.

철근 부식 방식을 위한 굳지 않은/굳은 콘크리트의 전기방식 적용에 관한 연구 (The Inhibitive Effect of Electrochemical Treatment Applied to Fresh/hardened Concrete)

  • 김성욱;문재흠;안기용
    • 한국구조물진단유지관리공학회 논문집
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    • 제17권5호
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    • pp.67-76
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    • 2013
  • 본 연구에서는 전기방식 종류에 따른 문헌 고찰 및 굳지 않은/굳은 상태의 콘크리트에 대해 전기방식 적용 시 방식 효과와 관련하여 연구를 실시하였다. 굳은 콘크리트의 경우 우선적으로 철근의 부동태피막 파괴를 유도하기 위하여 NaCl을 혼입한 후, 2주일동안 250, 500, $750mA/m^2$의 방식전류를 통전하였다. 그 후 부동태피막 복원화와 염소 이온 추출에 대해서 정량화를 실시하였다. 동시에, 굳지 않는 상태의 콘크리트에 대해서는 굳은 상태와 동일한 양의 방식전류를 타설 직후부터 동일한 기간동안 통전하여 전기방식을 실시하였다. 후광산란(Backscattered electron; BSE) 이미지를 이용하여 철근-콘크리트 계면을 관찰하였으며, 염소이온 확산에 대해서 염소이온 이동 속도와 철근 부식 저항성에 대한 콘크리트의 성질 변화에 대해 측정하였다. 결과적으로 보면, 전기 방식은 부동태피막 복원화에 매우 효육적이며, 콘크리트 내의 염소이온 중 63-73% 정도가 추출되는 것으로 확인 되었다. 굳지 않는 상태의 콘크리트에 전기방식을 적용할 경우, 철근 표면에서 $Ca(OH)_2$ 층이 조밀하게 되어 철근 부식 저항성이 향상되었다. 다만, 방식 전류에 따라 콘크리트 표면 염화물량이 증가하는 경향이 나타나는 것을 확인 할 수 있다.

Realistic pore structure of Portland cement paste: experimental study and numerical simulation

  • Ma, Hongyan;Li, Zongjin
    • Computers and Concrete
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    • 제11권4호
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    • pp.317-336
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    • 2013
  • In this study, the pore structure of Portland cement paste is experimentally characterized by MIP (mercury intrusion porosimetry) and nitrogen adsorption, and simulated by a newly developed status-oriented computer model. Cement pastes with w/c=0.3, 0.4 and 0.5 at ages from 1 day to 120 days are comprehensively investigated. It is found that MIP cannot generate valid pore size distribution curves for cement paste. Nevertheless, nitrogen adsorption can give much more realistic pore size distribution curves of small capillary pores, and these curves follow the same distribution mode. While, large capillary pores can be effectively characterized by the newly developed computer model, and the validity of this model has been proved by BSE imaging plus image analysis. Based on the experimental findings and numerical simulation, a hypothesis is proposed to explain the formation mechanism of the capillary pore system, and the realistic representation of the pore structure of hydrated cement paste is established.

Cu-Ni 첨가형 열연강판의 열간균열현상에 관한 연구 (A Study on the Hot Cracking Phenomena of Cu-Ni Bearing Hot Rolled Steels)

  • 윤인택;조열래;김순호;김인배
    • 한국재료학회지
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    • 제9권4호
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    • pp.335-340
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    • 1999
  • The hot cracking phenomena and phase behaviors during hot working process of Cu-Ni bearing hot rolled steels were investigated by a $90^{\circ}$bending tests, BSE image analysis and EDS analysis. For aNi-free 1.2% Cu bearing steel, the surface hot cracking occurred about $1100^{\circ}C$ due to a liquid state Cu-enriched phase formed continuously at the interface between oxide scale and matrix. The liquid Cu-enriched phase penetrated into austenite grain boundaries and caused surface cracking during the hot working. In case of 0.6% Ni containing 1.2% Cu-Ni bearing steel, solid state Cu-Ni-riched phase existed at the scale/matrix interface as a discontinuous type. But the higher addition of 1.2% Ni, solid state Ni-Cu-riched phase was formed dominantly in the oxide scale. It was found that the addition of Ni suppressed the surface cracking of 1.2% Cu bearing steel by eliminating the liquid state Cu-enriched phase.

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A TWO-STAGE SOURCE EXTRACTION ALGORITHM FOR TEMPORALLY CORRELATED SIGNALS BASED ON ICA-R

  • Zhang, Hongjuan;Shi, Zhenwei;Guo, Chonghui;Feng, Enmin
    • Journal of applied mathematics & informatics
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    • 제26권5_6호
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    • pp.1149-1159
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    • 2008
  • Blind source extraction (BSE) is a special class of blind source separation (BSS) methods, which only extracts one or a subset of the sources at a time. Based on the time delay of the desired signal, a simple but important extraction algorithm (simplified " BC algorithm")was presented by Barros and Cichocki. However, the performance of this method is not satisfying in some cases for which it only carries out the constrained minimization of the mean squared error. To overcome these drawbacks, ICA with reference (ICA-R) based approach, which considers the higher-order statistics of sources, is added as the second stage for further source extraction. Specifically, BC algorithm is exploited to roughly extract the desired signal. Then the extracted signal in the first stage, as the reference signal of ICA-R method, is further used to extract the desired sources as cleanly as possible. Simulations on synthetic data and real-world data show its validity and usefulness.

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