• Title/Summary/Keyword: aging process

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An ultrasonic study on Gelation Process in Egg White Protein (초음파에 의한 egg white의 gel 화의 연구)

  • 배종림
    • The Journal of the Acoustical Society of Korea
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    • v.9 no.6
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    • pp.74-80
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    • 1990
  • 천연 단백질인 egg white의 gel화의 과정을 초음파 측정에 의하여 연구하였다. Egg white는 6 0℃ 이상의 어떤 온도에서 aging 측정을 하면 gel화의 진행에 따라 흡수는 증가, 음속은 감소하였다. Egg white의 gel 화는 60℃와 75℃에서 크게 진행하였고, egg white gel의 비가역성을 반영해서 음속과 흡수 모두 이력현상이 관측되었다.

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A Study on the Design Guide of Fee Charging Residential Facility for the Elderly reflected in Color Perception Characteristic (노인의 색지각적 특성을 고려한 유료 노인주거 실내공간의 설계지침에 관한 연구)

  • Song, Choon-Eui;Kim, Moon-Duck
    • Archives of design research
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    • v.20 no.3 s.71
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    • pp.247-256
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    • 2007
  • Aging brings color-weakness to the eye due to yellowed eye sight. The 87% of information required for human behavioral decisions are visually perceived. Therefore, the color-weakness will affect behavior in many ways. Most of previous research regarding color planning for the aged focuses on discovering their preferred colors and reflecting the colors on facility color planning. But such research failed to identify the confused range of color cognitions due to the color weakness of the aged. The purpose of this study is to propose a design guide for fee-charging residential facilities for the elderly, reflecting upon color perception characteristics. An experimental simulation on aged vision using the UV filter and Y-2 filter, YA-3 filter alternating for general eyesight, 70 year-old and late 80 year-old was conducted. The results of this study are as follow : color perception is changed by crystalline lens aging process and yellowed eye sight. The recognition arrangement of colors was preferred to contrast harmony rather than similarity harmony and the dominant color is a warm color rather than a cool color.

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Spatial Characteristics of Longevity Degree in Korea (한국 장수도(長壽度) 변화의 공간적 특성)

  • Park, Sam-Ock;Jeong, Eun-Jin;Song, Kyung-Un
    • Journal of the Korean association of regional geographers
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    • v.11 no.2
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    • pp.187-210
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    • 2005
  • The purpose of this study is to examine the spatial characteristics of the longevity phenomenon and long-live areas in Korea where a rapid aging process is undergoing. Population data from 1966 to 2000 at the county level are analyzed to understand aging process and changes of longevity degree by regions. The relationship between the degree of longevity and a region's natural environments and distance to a metropolis has been analyzed to understand regional factors of longevity. The findings from the study are summarized as follows. Firstly, the rural regions in Honam show the highest degree of longevity in the nation. Secondly, the areas of the high degree of longevity has recently shifted and/or expanded from the islands and seashore areas of southwestern region to inland mountainous areas around Soback Mountain. Southern islands and seashore regions used to show the nation's highest degree of longevity in the 1970s. Thirdly, the analysis of regional environment factors indicated that longevity has more related to a precipitation and an average altitude than temperature. Fourthly, in order to identify the longevity factors in urban areas, social and economic factors should be considered beyond the natural environmental factors.

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Manufacture of $BaTiO_3$ Powders by Gel-hydrothermal Method (겔의 수열합성법에 의한 다공성 구형 $BaTiO_3$ 미분체의 제조)

  • Kim, Yong-Ryul
    • Journal of the Korean Applied Science and Technology
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    • v.22 no.4
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    • pp.306-314
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    • 2005
  • In this study, spherical $pre-BaTiO_3$ particles are prepared by gelation and aging process in autoclave without catalysts. The (Ba-Ti) gel used as a starting material was prepared by aging mixtures of titanyl acylate with barium acetate aqueous solution([glacial acetic acid (AcOH)]/[titanium isopropoxide (TIP)] 4, [barium acetate]/[TIP] 1) at $45^{\circ}C$ for 48hrs. XRD and SEM results for the (Ba-Ti) gel sample at aging process showed that the gel was formed via aggregation of the fine particles. It seems to be the primary particles of bulk (Ba-Ti) gel amorphous, but the spatial arrangement of barium and titanium in the (Ba-Ti) gel is similar to that in crystalline $BaTiO_3$ particles. From XRD and FT-IR. spectroscopy analysis it was found that the crystal structure of the prepared particles continuously transformed from amorphous to tetragonal as the calcination temperature increased, and crystallized spherical cubic and tetragonal $BaTiO_3$ powder obtained at the very low calcination temperature between $500^{\circ}C$ and $900^{\circ}C$ after 1hrs of heat treatment respectively. According to BET analysis result, final particle have pore structure of ink bottle shape which is produced by aggregation of fine spherical particles with surface area of $280m^2/g$ and average pore size of 130nm.

Microstructure and Mechanical Properties of Strip Casted Ag-27%Cu-25%Zn-3%Sn Brazing Alloy (브레이징용 Ag-27%Cu-25%Zn-3%Sn 박판 주조 스트립의 미세조직 및 기계적 특성 연구)

  • Kim, S.J.;Kim, M.C.;Lee, K.A.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2008.10a
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    • pp.313-316
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    • 2008
  • This work sought to examine the suitability of twin roll strip casting for Ag-27%Cu-25%Zn-3%Sn brazing alloy (BAg-7A) and to investigate the mechanical properties and microstructure of the strip. The effect of aging heat treatment on the properties was also studied,. This new manufacturing process has applications in the production of the brazing alloy. XRD and microstructural analysis of the Ag-27%Cu-25%Zn-3%Sn strip represented eutectic microstructure of a Cu-rich phase and a Ag-rich matrix regardless of heat treatment. The results of mechanical tests showed tensile strength of 470MPa, a significant enhancement, and an 18% elongation of the twin roll casted strip, due mainly to the solid solution strengthening of Zn atoms (${\sim}20%$) in the Cu-rich phases. Tensile results showed gradually decreasing strengths and increasing elongation with aging heat treatment. Microstructural evolution and fractography were also investigated and related to the mechanical properties.

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IDENTIFICATION AND ASSESSMENT OF AGING-RELATED DEGRADATION OCCURRENCES IN NUCLEAR POWER PLANTS

  • Choi, In-Kil;Choun, Young-Sun;Kim, Min-Kyu;Nie, Jinsuo;Braverman, Joseph I.;Hofmayer, Charles H.
    • Nuclear Engineering and Technology
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    • v.44 no.3
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    • pp.297-310
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    • 2012
  • Aging-related degradation of nuclear power plant components is an important aspect to consider in securing the long term safety of the plant, especially the seismic safety, since the degradation of the components affects not only their seismic capacity but their response. This can cause a change in the seismic margin of a component and the overall seismic safety of a system. To better understand the status and characteristics of degradation of components in Nuclear Power Plants (NPPs), the degradation occurrences of components in the U.S. NPPs were identified by reviewing recent publicly available information sources and the characteristics of these occurrences were evaluated and compared to observations from the past. Ten categories of components that are of high risk significance in Korean NPPs were identified, comprising anchorage, concrete, containment, exchanger, filter, piping systems, reactor pressure vessels, structural steel, tanks, and vessels. Software tools were developed to expedite the review process. Results from this review effort were compared to previous data in the literature to characterize the overall degradation trends.

Effects of Aging Additives in Preparation of Barium Titanate by Oxalate Process (Oxalate법에 의한 $BaTiO_3$분체제조에서 시효시 첨가제의 영향)

  • 노준형;신효순;이대희;이석기;이병교
    • Journal of the Korean Ceramic Society
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    • v.34 no.3
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    • pp.323-329
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    • 1997
  • Particle growth of BT-oxalate was investigated in aging with various additives such as glycerine, chloro-form and NaCl. Their effects on size and morphlogy of particle was examined. It can be known that particle size distributions of BT-oxalate precipitate varied with amounts of these additivies. With small amounts of these additives, particle growth of nonuniform distribution was occurred, but above 1 mole percent of those additives, uniform size distributions of about 0.4 ${\mu}{\textrm}{m}$ could be obtain. There was little difference among the effects by the kinds of additives. From the decomposition of uniform BT-oxalate, BaTiO3 powders of about 0.3${\mu}{\textrm}{m}$ could be obtained.

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The Dry-aging and Heating Effects on Protein Characteristics of Beef Longissiumus Dorsi

  • Kim, Ji-Han;Lee, Ha-Jung;Shin, Dong-Min;Kim, Tae-Kyung;Kim, Young-Boong;Choi, Yun-Sang
    • Food Science of Animal Resources
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    • v.38 no.5
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    • pp.1101-1108
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    • 2018
  • The aim of this study was to investigate the effects of dry-aging (DA) and the cooking process on the myofibril protein functionalities and in vitro digestibility of proteins in beef loin. Six sirloins from beef were dry-aged for 28 d, and the control group (n=6) was analyzed 2 d postmortem for this study. Dimensional changes (reduction of thickness and surface shrinkage) after cooking were significantly greater in the control group than the DA group, whereas the shear force of the DA group was significantly lower than that of the control. Effect of cooking on aggregation, hydrophobicity, and in vitro digestibility were significantly higher in the DA group than in the control. After cooking, the protein in DA sirloins was more oxidized than in the control samples. According to the sodium dodecyl sulfate-polyacrylamide gel electrophoresis result, the low molecular weight bands (below 17 kDa) increased in the DA group, finding that the protein characteristics of dry-aged beef was affected by cooking.