• Title/Summary/Keyword: SEM study

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A Study on Failure Analysis of Low Pressure Trubine Blade Using AFM and FEM (AFM과 FEH을 이용한 저압 터빈 블레이드의 파손해석에 관한 연구)

  • Hong, Soon-Hyeok;Cho, Seok-Swoo;Joo, Won-Sik
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.25 no.11
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    • pp.1705-1712
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    • 2001
  • Mechanical component has striation with constant width and SEM can estimate fracture type and loading condition. SEM has benefit to fatigue fracture analysis but striation can be observed according to the kind of material and range of crack growth rate and can't. In this case, it needs AFM that can measure 3-dimensional surface profile with resolution of atomic size. In this study. to find fracture reason of torsion-mounted blade in nuclear plant, we estimate the relation between stress intensity factor range and root mean square roughness in 12% Cr steel by AFM and predict in-service loading condition of turbine blade. failure analysis is performed by finite element method and Goodman diagram on torsion-mounted blade.

Characterizations of Airborne Fiber Particle Concentrations in Public Facilities and Schools (다중이용시설 및 학교 교사내 실내공기중 섬유상 입자의 농도 특성)

  • Park, Jeong-Ho;Suh, Jeong-Min
    • Journal of Environmental Science International
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    • v.19 no.4
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    • pp.509-516
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    • 2010
  • This study was investigated the characteristics of indoor air concentration of fiber particles in 30 public facilities and 245 schools by PCM (phase contrast microscopy). Also SEM/EDX (scanning electron microscope / energy dispersive using X-ray analysis) was used to obtain physicochemical information of asbestos fiber and to classify asbestos and non-asbestos of fiber particles. The airborne concentrations of fiber particles were $0.0009\pm0.0009$ counts/mL in public facilities and $0.0012\pm0.0006$ counts/mL in schools by PCM. All the samples were satisfied with the IAQ (indoor air quality) level of 0.01 counts/mL. In classification of 4 type shapes, over 80% of the fiber particles were identified as single fiber type. And this study analysed airborne fiber particles in 4 sites for identifying asbestos of by SEM/EDX. The asbestos fibers in most samples could not be found.

Structural Equation Model(SEM) for Constituent Characteristics, Texture, Sensibility and Preference of Fabric (Part 1) - Weight of F/W Women's Jacket Fabrics - (구조방정식을 이용한 소재의 구성특성, 질감 및 감성과 선호도간의 관계모형 (제1보) - 추동 여성 자켓용 소재의 무게 중심으로 -)

  • Roh, Eui-Kyung;Ryu, Hyo-Seon
    • Journal of the Korean Society of Clothing and Textiles
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    • v.31 no.8
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    • pp.1240-1251
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    • 2007
  • The purpose of this study was to examine the relationship between weight of fabrics and texture and sensibility and preference of consumers for F/W women's jacket fabrics. Structural Equation Model(SEM) using AMOS program was conducted to analyze the relationships. Then, this study aimed to provide useful information in planning designing fabrics through predicting the subjective characteristics analyzed. The main survey was developed the 7-point semantic differential scale of subjective texture, sensibility and preference. Fifty trained female panelists of 20-30 years old were participated and questionnaire method was used with 20 kind of fabric. The evaluation methods such as by the sense of sight & touch were used when fabrics were estimated subjectively. When evaluated by the sense of sight & touch, fabric's weight did not have effect directly on preference, but had effect indirectly on preference through the texture and the sensibility..

A Study on Analyzing of Carbonized Fibers in Excavated Cloths (출토복식에 나타난 탄화직물의 분석적 연구)

  • Baek, Young-Mee;Kwon, Young-Suk
    • 한국문화재보존과학회:학술대회논문집
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    • 2004.10a
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    • pp.109-114
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    • 2004
  • The purpose of this study lies in analyzing the characteristics of the carbonized textile fabrics and to know the carbonizing mechanism. Samples were Jiyo excavated from the grave of Mrs. Hansan Lee as the wife of Jinju Kang at Daeduk-gu, Daejon, and black fragements assumed as of the outside material of cotton skirt and black dusts collected out of Jikryung for official dress. The composition and status of the fiber were clarified by means of Microscopic FT-IR and both cross sectioanl and side parts of the fiber were observed using the technique of scanning electron microscopy(SEM). Finally EDS analysis was carried out to qualitatively analyze inorganic ingredients contained in the carbonized fiber. As a result of FT-IR measurement, characteristic peak was very strong around $1625cm^{-1}$ and could be found even between 2500 and $2300cm^{-1}$ because of a high-molecule pigmental substance, melanine. When SEM photography was applied to the fractions, the tissues were identified as silk fiborine through the observation of their side and cross sectional parts. SEM-EDS measurement indicated that both the cotton skirt and Jikryung for official dress contained a high proportion of inorganic substances such as Si, Ca suggesting the existence of silicide and calcium carbonate.

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A Study on SEM Observations of Low Temperature Degradation in Zirconia Dental Ceramics (저온열화에 따른 치과용 지르코니아의 전자현미경 관찰 연구)

  • Lee, Jung-Hwan;Joo, Kyu-Ji;Ahn, Jae-Seok
    • Journal of Technologic Dentistry
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    • v.33 no.1
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    • pp.15-23
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    • 2011
  • Purpose: Thy yttria tetragonal zirconia polycrystalline(Y-TZP) is a good structural ceramic for dental restoration. But it have a problem that delamination of veneering ceramic from the Y-TZP core materials. The problem generally occur at the interface, thus this study was conducted to evaluate the interface of Y-TZP using scanning electron microscopy(SEM). Methods: To investigate this aspect, high-resolution SEM observations were made of polished and etched (HF content gel) cross-sections of the interface area. Dry and moist veneering porcelain powders were built up on the zirconia base. Results: The extent of this surface faceting is dependent upon the moisture content of the porcelain powder and the firing temperature. More moisture and higher final heating temperature accelerates the observed faceting of the Y-TZP grains at the interface to the veneering ceramic. Conclusion: These changes of the Y-TZP grains indicate that destabilization of the tetragonal phase of zirconia occurs at the interface during veneering with ceramic. It may result in a reduction of the stability of the zirconia and interface.

Development of a Usability Evaluation Structural Model on Car Driver (승용차 운전자에 대한 사용성 평가 구조 모형 개발)

  • Park, Jun-Soo;Park, Sung-Joon;Lim, Young-Jae;Jung, Eui-S.
    • Journal of the Ergonomics Society of Korea
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    • v.29 no.6
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    • pp.843-851
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    • 2010
  • This study aims to systematically develop a usability evaluation model using the Structural Equation Model (SEM) from experiment of usability on using vehicle. Vehicle developers have been adding many functions for enhance the user satisfaction. But it will be made the trade-off problem of usability and design elements of vehicle interior from attempt to make best usability satisfaction in a restricted space. To solve the trade-off problem, we set a new solution criterion from usability evaluation model. The usability experiment is based on major activity pool from derived user's acts pattern in vehicle for make more accurate usability evaluation model. And this model was built with twenty-nine measurement variables for the evaluation of usability of vehicle user. As a result, the proposed SEM model showed statistical significance as well as a high level of R Square (0.7144). This model shows the relationships of detailed usability and design elements. According to the result, this study introduces the criterion to secure the best satisfaction of usability and design elements.

PLS-SEM to Predict the Relationship between Procedural Justice, Organizational Commitment, OCB, and Job Satisfaction

  • MARIA, Siti;DARMA, Dio;SETYAWAN, Hery
    • Journal of Wellbeing Management and Applied Psychology
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    • v.3 no.3
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    • pp.1-13
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    • 2020
  • Human resource management has always been the most important part of any organization (corporate and government-owned). Until whenever improvement in human resource management is always the background of every problem that occurs in the organization. This study aims to examine the relationship of procedural justice and organizational commitment to OCB satisfaction and job satisfaction in the Public Works Office of Kutai Kartanegara Regency. Sampling involved the entire population, i.e. 109 informants. They are employees who have goods and services certificates. Hypothesis test carried out with the SEM-PLS model in two stages (outer model and inner model). After that, the survey data was used SMART PLS 3.0. Based on empirical findings, we find that procedural justice has a positive and significant effect on OCB, while organizational commitment does not. Procedural justice, organizational commitment, and OCB have had a positive and significant effect on job satisfaction. The novelty of the study lies in the originality value that describes the conditions in a government agency with different benchmarks (variables and indicators) from previous studies, so it is very interesting and varied.

Log-based petrophysical analysis of Khatatba Formation in Shoushan Basin, North Western Desert, Egypt

  • Osli, Liyana Nadiah;Yakub, Nur Yusrina;Shalaby, Mohamed Ragab;Islam, Md. Aminul
    • Geosciences Journal
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    • v.22 no.6
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    • pp.1015-1026
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    • 2018
  • This paper aims to investigate the good reservoir quality and hydrocarbon potentiality of the Khatatba Formation, Qasr Field in the Shoushan Basin of the North Western Desert, Egypt by combining results from log-based petrophysical analysis, petrographic description and images from scanning electron microscope (SEM). Promising reservoir units are initially identified and evaluated through well log analysis of three wells in the field of study. Petrophysical results are then compared with petrographic and SEM images from rock samples to identify features that characterize the reservoir quality. Well log results show that Khatatba Formation in the study area has good sandstone reservoir intervals from depths ranging from 12848 ft to 13900 ft, with good effective porosity records of 13-15% and hydrocarbon saturations of greater than 83%. Petrographic analysis of these sandstone reservoir units indicate high concentrations of vacant pore spaces with good permeability that can be easily occupied by hydrocarbon. The availability of these pore spaces are attributed to pore-enhancing diagenetic features, mainly in the form of good primary porosity and dissolution. SEM images and EDX analysis confirmed the presence of hydrocarbon, therefore indicating a good hydrocarbon-storing potential for the Khatatba Formation sandstones.

The Effect of Job Satisfaction on the Major Satisfaction of Science and Engineering College Students According to Gender Differences (성별에 따른 이공계 전공교육만족이 일자리 만족에 미치는 영향)

  • Yoon, Jiyoung;Lim, Jungyeon
    • Journal of Engineering Education Research
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    • v.22 no.4
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    • pp.32-42
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    • 2019
  • This study is aim to the effects of job satisfaction on the major satisfaction of science and engineering college students and also analyzed the mediating effects of future outlook of job and major relevance in career choice. To do this, structural equation modeling(SEM) and multi-group SEM were applied to data from 2016 Graduate Occupational Mobility Survey(GOMS). In the results of this study, the major satisfaction, future outlook of job and major relevance were positive effects on job satisfaction and the mediating effects of future outlook of job and major relevance were verified. And results of analysis according to gender difference, the coefficient of woman was smaller than man. Among major satisfaction had a positive effect on job satisfaction, job satisfaction fell for women who value their relevance to the major when choosing a job. Based on such results, universities need to further strengthen their role in helping them enhance their expertise through skills and learning about their majors.

Analysis of Human Error Influencing Factor Using SEM (Structural Equation Modeling) (구조방정식모형을 이용한 휴먼에러 영향요인 분석)

  • Joo, Youngjong;Oh, Jun;Jung, TaeHoi;Kim, Byungjik;Park, Kyoshik
    • Journal of the Korean Society of Safety
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    • v.36 no.3
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    • pp.60-65
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    • 2021
  • Human error is often in part in the cause of accidents and the result of various factors in an organization. Accidents should be investigated to elucidate all causes. Therefore, to reduce accidents, it is necessary to identify which factors affect human error within the organization. In this study, five groups of influencing factors on human error were selected using previousresearch, and operational definitions were made based on them. In addition, a questionnaire for measuring latent variables by operational definition was developed as an observation variable, and responses were received from employees of chemical companies in Ulsan. Based on SEM (structural equation modeling) analysis, 1) confirmatory factor analysis of variables in the human error model, 2) reliability and validity of latent variables, 3) correlations among latent variables, 4) influencing coefficients among influence factors, and 5) the verification results of the paths that these influencing factors have on human error are introduced in this study.