• Title/Summary/Keyword: mechanical quality

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EFFECT OF CONTINUOUS AND STEPWISE CHANGE IN DRYING TEMPERATURE ON DRYING CHARACTERISTICS AND PRODUCT QUALITY

  • Chua, K.J.;Mujumdar, A.S.;A Hawlader, M.N.;Chou, S.K.;Ho, J.C.
    • Proceedings of the Korean Society for Agricultural Machinery Conference
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    • 2000.11b
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    • pp.413-422
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    • 2000
  • Samples of banana were dried in a two-stage heat pump dryer capable of producing stepwise control of the inlet drying air temperature while keeping absolute humidity constant. Two stepwise air temperature profiles were tested. The incremental temperature step change in temperature of the drying air about the mean air temperature of 30 $^{\circ}C$ was 5 $^{\circ}C$. The total drying time for each temperature-time profile was about 300 minutes. The drying kinetics and color change of the products dried under these stepwise variation of the inlet air temperature were measured and compared with constant air temperature drying. The stepwise air temperature variation was found to yield better quality product in terms of color of the dried product. Further, it was found that by employing a step-down temperature profile, it was possible to reduce the drying time to reach the desired moisture content.

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An Experimental Study on Mathematical Model to Predict Bead Width in GMA Weldment (GMA 용접부의 비드폭 예측을 위한 수학적 모델에 관한 실험적 연구)

  • Kim, Ill Soo;Park, Min Ho;Kim, Hak Hyoung;Lee, Jong Pyo;Park, Cheol Kyun;Shim, Ji Yeon
    • Journal of the Korean Society for Precision Engineering
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    • v.32 no.2
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    • pp.209-217
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    • 2015
  • Generally welding is one of the most important processes to have a strong influence on the quality and productivity from a manufacture-based industry such as shipbuilding, automotive and machinery. The GMA(Gas Metal Arc) welding process involves large number of interdependent welding parameters which may affect product quality, productivity and cost effectiveness. To solve such problems, mathematical models are required to select the welding parameters for GMA welding process. In this study, the GMA welding process was studied using the information generated during the welding. The statistical analysis of a generalized regression approach was conducted by the following three methods: Firstly using the mathematical model (linear regression, 2nd regression); Secondly GA(Genetic Algorithm) with intelligent models; And finally using response surface analysis of models to develop the relationships between welding parameters and bead width as welding quality.

Evaluation and solution of noise making weldment in automotive body (차체 이음 유발 용접 불량에 대한 분석과 해결 방안)

  • Cho, Jungho;Lee, Jungjae;Bae, Seunghwan;Lee, Yongki;Park, Kyungbae;Kim, Yongjun;Moon, Semin
    • Journal of Welding and Joining
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    • v.33 no.2
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    • pp.18-22
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    • 2015
  • The importance of emotional quality of car is getting higher in these days. Noise takes great portion in emotional quality because it is detectable problem with just a few rides. The sources of car noise during operation are various and the related technical issues are vast. Sometimes weldments of auto body are referred as the source of noise and the suspicious weldment shows unsatisfactory welding quality in most cases. In this research, cases of noise making weldments are investigated to figure out the solution for welding quality improvement. They are categorized into several groups in according to the inferred types of the error source then appropriate solutions are suggested. Auto body has weldments of resistance spot welding and gas metal arc welding in general. Therefore the solutions are suggested as adjustment of welding process variables and related machineries. Inevitable error source is also referred which is originated from thermal expansion rate difference between ultra high strength steel and mild steel. This new approach is validated through simple calculation then more concrete investigation with numerical analysis is remained as further works to be done.

Quality Characteristics of Bread with Added Angelica plant (Bakluncho) and Angelica Gigas (Senggumcho) Powders (백련초분말과 승검초분말 첨가에 따른 식빵의 품질 특성)

  • Jeon, Eun-Raye;Park, In-Duck
    • Journal of the Korean Home Economics Association
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    • v.44 no.3 s.217
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    • pp.163-169
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    • 2006
  • The effects of adding Angelica plant (Bakluncho) and Angelica gigas (Senggumcho) powders on the quality characteristics of bread were investigated. The moisture, crude protein, ash, reducing sugar and vitamin C contents of Angelica plant (Bakluncho) powder were 7.78%, 6.07%, 7.37%, 6.13% and 50.10mg%, respectively, and of Angelica gigas (Senggumcho) powder were 8.69%, 12.28%, 5.15%, 2.21% and 108.00mg%, respectively. The lightness value decreased but the redness and yellowness values increased with the addition of Angelica plant (Bakluncho) and Angelica gigas (Senggumcho) powders. The mechanical hardness of bread decreased with the addition of 3% of Angelica plant (Bakluncho) powder, but increased with the addition of 1% and 5% of Angelica plant (Bakluncho) powder. The mechanical hardness of bread decreased with the addition of 1%, 3% and 5% of Angelica gigas (Senggumcho) powder. In sensory characteristics, the crust color, crumb color, moistness and springiness decreased, but aroma and hardness increased with the addition of Angelica plant (Bakluncho) and Angelica gigas (Senggumcho) powders. The savory taste and overall quality of breads with 1% Angelica plant (Bakluncho) and 1% Angelica gigas (Senggumcho) powders were higher than without either powder. A negative correlation was observed between mechanical hardness and overall bread quality with the addition of Angelica plant (Bakluncho) powder, while a positive correlation (p<0.01) was observed with the addition of Angelica gigas (Senggumcho) powder.

A Generative Research Methodology for Implementing TQM in Small and Medium-sized Manufacturing Enterprises

  • Lewis, W.G.;Pun, K.F.;Lalla, T.R.M.
    • International Journal of Quality Innovation
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    • v.5 no.2
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    • pp.89-105
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    • 2004
  • Many researchers and practitioners have acknowledged the need to investigate the relationships amongst various criteria of implementing total quality management (TQM) in small and medium-sized manufacturing enterprises (SMMEs). There is a need to have practical research methodologies that take cognisance of the peculiarities of SMMEs and impact on their quality management practices in developing countries. This paper presents the theoretical foundation of a proposed Generative Research Methodology and configures the specification of a TQM implementation framework in SMMEs. The methodology combines rigorous research approaches, builds theory based on the dynamics of the environment and the firms' characteristics and incorporates various TQM criteria into the design of the framework. It synchronises inductive and deductive research methods in three phases and uses various means to acquire empirical evidence and examine the dependent and independent variables of TQM implementation. It is anticipated that the methodology could help SMMEs to develop, analyse and evaluate the framework for attaining quality performance goals.

Manufacture of High Quality Musical Steel Drums in Trinidad and Tobago

  • Lewis Winston G.;Ameerali Aaron O.;Pun Kit-Fai
    • International Journal of Quality Innovation
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    • v.6 no.3
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    • pp.204-215
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    • 2005
  • This paper explores innovative manufacturing processes, which can be used to manufacture the national musical instrument of Trinidad and Tobago, the Musical Steel Drum or Steel Pan. The main manufacturing process used today is the manual hand-forming technique. In order to achieve more consistent and deeper formed components while maintaining the high quality of the instrument, it is proposed that the Marforming process and the Flow-forming process, an adaptation of the Spinforming process, be used more frequently in the future to replace the traditional Hand-forming method. In the traditional Spinforming technique material is pushed from the outer circumference of the metal disc to the center in progressive passes of the former. This results in a thinning of the outer region of the formed component with thickening of the center, however the opposite is required for the musical steel drum and by adapting the process the required strain distributions were achieved. Evaluation took the form of strain analyses of pre-formed steel drums and visual inspection of the quality of the surface finish. It was found that the Marformed components had the smallest range of strain values while the Spinformed components had the largest range.

A Study on the Improvement of Defense Specification Affairs to Improve the Production Quality of Military Supplies (군수품 생산품질 향상을 위한 규격업무 개선 연구)

  • Baek, Il-Ho;Bong, Ju-Sung;Hur, Jang-Wok
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.20 no.5
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    • pp.47-54
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    • 2021
  • In this study, systems and procedures for improving the research and development and purchasing projects for defense specifications were investigated, and the current situation was analyzed in terms of the disclosure and establishment of defense specifications. I would like to discuss the measures that need to be taken to improve the specification affairs of our defense sector in order to improve the production quality of military supplies. It should be noted that it is necessary to establish specifications and procedures for improving the quality of domestically purchased military supplies. Therefore, it is highly imperative to systematically establish detailed performance, and miscellaneous specifications in order to actively respond to the rapid development of superior private technologies. In addition, the barriers in the entry of the defense industry should be removed through active disclosure of the specification data, and the opportunities for participation should be expanded to promote a smooth follow-up logistics support and to improve the quality of military supplies

Mechanical splice Using Self lighting (Self lighting 조사를 이용한 광기계식 접속자)

  • Choe, Yeong-Bok;Park, Su-Jin
    • Proceedings of the Optical Society of Korea Conference
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    • 2008.07a
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    • pp.179-180
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    • 2008
  • Optical Mechanical splice is essential component to construct for FTTH. Optical Mechanical splice is executed many countries' FTTH including Korea. In this paper, we have designed Optical Mechanical splice using UV and completed a series of mechanical and environmental tests on the optical Mechanical splice. And the results of tests and Bellcore-requirements for optical Mechanical splice will be presented. Accordingly, evaluation method of optical Mechanical splice has gained power to improve the quality and stability of it.

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Physicochemical and Texture of Bread added Paecilomyces japonica according to Storage Period (동충하초 첨가식빵의 저장기간에 따른 이화학적. 텍스쳐 특성)

  • 박금순;김수진;박어진
    • Journal of the East Asian Society of Dietary Life
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    • v.11 no.6
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    • pp.485-497
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    • 2001
  • For a period of 5 days, the quality of breads with Paecilomyces japonica powder were investigated using chemical, sensory, and mechanical evaluations at $25^{\circ}C$. The result of analysis of chemical properties revealed that the pH value of dough was increased as the amount of Paecilomyces japonica powder increased, but volume of dough and baking loss rate were decreased. Breads with 1% and 2% Paecilomyces japonica powder showed a good overall preference in sensory evaluation. As storing time passed. moisture content, lightness, and redness were decreased in all breads, but yellowness increased. Hardness and gumminess of texture analysis were increased as storing time passed, but springiness decreased. Springiness of the mechanical properties was negatively correlated with pH value of dough and volume of bread, while was positively correlated with volume of dough and baking loss rate. In the analysis of correlation between sensory and mechanical properties showed that hardness of mechanical properties had negative correlation with softness, moistness, and springiness. Cohesiveness of mechanical properties had positive correlation with acceptability.

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Realation of Injection Temperature and Weld-quality in Injection Molding (사출 성형 시 수지온도와 웰드품질과의 관계)

  • Noh, Keon-Cheol;Lee, Gyu-Ho;Jang, Min-Kyu;Jeong, Yeong-Deug
    • Design & Manufacturing
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    • v.9 no.1
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    • pp.27-30
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    • 2015
  • The injection molding is used in more than 70% of total production of plastic products. Weld line in injection molded part is one of the defects in injection molding process. Weld line deteriorates not only appearance quality but also mechanical property. In this study, tensile strength about material such as ABS, PP, PA and PS was tested. as the results, the first result appears that weld's strength retention ratio's are 0.90, 0.84, 0.85, 0.76 and the second result apeears that weld depth decrease as processing temperature increased.

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