• Title/Summary/Keyword: Foaming

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Wear Behaviors of Plasma-Sprayed Coating Layers in Mo and Co-based Alloy (몰리브덴늄 및 코발트 합금을 플라즈마 용사한 피막 층의 마모거동)

  • Lee, S.W.;Kim, B.K.;Ha, G.H.;Nam, T.H.
    • Journal of the Korean institute of surface engineering
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    • v.29 no.1
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    • pp.15-25
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    • 1996
  • 자동차엔진의 피스톤-링에 응용할 목적으로 플라즈마 용사 기술로 피막한 몰리부덴늄 및 코발트 합금 피막 층의 마모성질을 비교 조사하였다. Ball-on-disc 형태의 마모기를 사용하여 상온 및 대기 중에서의 마모 및 마찰거동에 대하여 조사하였다. 용사 층의 미세경도 시험도 행하였으며, 용사층의 결정구조를 알기 위해 용사층을 x-선 회절 방법으로 분석하였다. 주사전자현미경을 사용하여 마모면의 표면 형상을 관찰하였다. 여러 용사조건으로 만든 용사층의 미세경도치와 마모거동과의 상관관계를 이해하려고 시도하였다. 주사전자현미경과 EDX를 사용하여 마모시 화학반응층과 마모기구를 규명하고자 하였다. 모리부덴늄 및 코발트 합금 분말을 각각 플라즈마 용사층의 단면을 관찰하여 마모기구을 비교하였다.

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Influence of sugar alcohol and enzyme treatment on the quality characteristics of soy ice cream (당알콜과 효소의 종류가 대두아이스크림의 품질특성에 미치는 영향)

  • 구선희;이숙영
    • Korean journal of food and cookery science
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    • v.16 no.2
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    • pp.151-159
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    • 2000
  • The effects of bromelain and $\alpha$-chymotrypsin treatments on the functional properties(foaming capacity, foaming stability, emulsifying capacity, and emulsifying stability) of soy protein isolate(SPI) and the addition of various sweeteners(sucrose, sorbitol, xylitol) on the quality attributes(viscosity, overrun ratio, melt-down property, and sensory characteristic) of soy ice cream were studied. SPI was more effectively hydrolyzed with $\alpha$-chymotrypsin than bromelain, resulting in a better foaming and emulsifying capacity. Adding xylitol could significantly improve the viscosity, overrun and melt-down property of soy ice creams while the effect was the lowest in the sucrose addition. Bromelain treatment caused a lower apparent viscosity of SPI suspension compared with $\alpha$-chymotrypsin treatment and untreated. The overrun ratios of the soy ice cream prepared with bromelain and $\alpha$-chymotrypsin treated SPI were 18.9∼25.9% and 24.9∼40.3%, respectively as a result of freezing with agitation for 20 min in an ice cream maker. Comparatively, untreated SPI could bring only 15.8∼21.4% overrun ratios after operating for 15 min. The bromelain treatment caused high melt-down tendency of the product while soy ice cream with untreated SPI showed an opposite trend. In sensory characteristics, no significant differences in the strength of beany flavor were noted among the samples. Sweetness, bitter taste, icy feel, and mouthfeel of the product were greatly affected by the enzyme-treatment of SPI. Soy ice cream added with xylitol after $\alpha$-chymotrypsin treatment was the most acceptable among all samples.

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Comparison of Toluene Diisocyanate Concentrations Collected with Different Sampling Methods by Work Process (시료채취 방법에 따른 작업 공정별 Toluene diisocyanates 포집농도 비교)

  • Kim, Sung Ho;Won, Jong Uk;Kim, Chi Nyon;Jung, Woo Jin;Roh, Jaehoon
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.23 no.2
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    • pp.95-102
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    • 2013
  • Objectives: The aim of this study is to present an appropriate sampling method for individual exposure assessment based on a comparison of toluene diisocyanate (TDI) concentrations collected through different sampling methods by work process type. Methods: Two plants handling TDIs in the Incheon area were selected. The samplings were taken during respective processes of spray painting, drying, grinding, and foaming, in which the production of TDIs took on different forms. For the sampling methods for airborne TDIs, open-face cassette holder, modified 2-piece cassette holder, and impinger were used, and the sampling was performed simultaneously at the same locations. Results: The comparison of TDI collection concentrations by each process depending on the sampling method showed high concentrations in the order of the impinger, modified 2-piece cassette holder, and open-face cassette holder for spray painting and foaming. In all processes with the exception of drying, TDI collection concentrations were higher for sampling done with the modified 2-piece cassette holder than with the open-face cassette holder. Conclusions: Based on these results, the modified 2-piece cassette holder was found to be a more appropriate sampling method than the open-face cassette holder when taking individual samples of TDIs from spray painting, grinding, and foaming processes. In particular, for individual exposure assessment of the spray painting process, which features comparatively high collection concentrations compared to the other processes, the use of a modified 2-piece cassette holder is considered appropriate.