• 제목/요약/키워드: moisture property

검색결과 515건 처리시간 0.031초

불투명 외피의 열관류에서 단열재의 습도영향 (Effects of the Moisture on the Overall Heat Transfer Through Heat Insulators Opaque Envelopes)

  • 이성
    • 태양에너지
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    • 제18권3호
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    • pp.63-69
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    • 1998
  • 일반적으로 건물 단열재는 건조된 것이 사용되며 이 상태에서 열전도율을 측정하여 열 손실을 산정할 때 기초자료로 이용될 수 있다. 그러나 이러한 단열재가 흡습성 재료인 경우에는 습도평형 혹은 다른 작용에 의해 습도가 높아지기에 이에 따라 열전도율도 상승하게된다. 이처럼 재료 열전도율의 상승효과는 건축물에 흡습성 재료가 사용될 경우 그 사이에 비흡습성 단열재료가 시공됐을 때도 양쪽재료의 흡습성으로 인하여 단열재의 열전도율이 상승하게 되며 이에 따른 열손실 또한 높아진다. 본 논문에서는 이러한 열전도율의 상승을 간단하게 계획단계에서 적용할 수 있도록 실측에 의해 검증된 약산식을 통해 산출될 수 있도록 하였다.

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포장담배의 저장수명에 관한 연구 (Study on shelf life packaged cigarettes.)

  • 이영택;김성한;이근회;양광규
    • 한국연초학회지
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    • 제8권1호
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    • pp.23-31
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    • 1986
  • The water content, physical property and sensory of cigarette brands lave been studied from the view point of the individual and inner packages. It was found that the cigarettes had absorbed the moisture from alto more than 56% of a relative humidity (RH) and lost it under RH, 56%. The critical moisture contents for the optimum quality of cigarette maintenance were 7.7% through 14.595 in the range of equilibrium relative humidity (ERH) 52.2%-63.5%. The ERH at the initial moisture content of 12.1% showed 58.8% When cigarettes were storaged in 9095 of RH and 4$0^{\circ}C$, the shelf life of the Inner package was respectively shown 18.8 days In cellophane, 33.3 days In PET(25u), 69.8 days in OPP and 73.5 days in OPP film coated with PVDC. As shown above, the longest life time was found in the OPP film coated with PVDC. In the individual packages, the shelf life of packaging materials used above was significantly short in the same conditions as of the inner packages. Each shelf life of the individual packages was same In order comparing with that of the inner Packages.

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식물성 활성탄을 활용한 시멘트 경화체의 특성 (Properties of Cement Matrix Using Vegetable Activated Carbon)

  • 이재훈;박채울;이상수
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2020년도 봄 학술논문 발표대회
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    • pp.138-139
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    • 2020
  • With the rapid progress of industrialization, indoor air quality is a very important factor for modern people who spend most of their day indoors. The recent issue of fine dust and radon on the portal site's popularity search shows that interest in indoor air quality has increased. Fine dust causes respiratory diseases, and radon causes severe lung cancer. The new material was tested using plant activated carbon, palm activated carbon and bamboo activated carbon. Both palm activated carbon and bamboo activated carbon are porous materials and generate smooth physical adsorption. As a result of the experiment, both the activated carbon tends to gradually decrease in strength and fluidity as the replacement ratio increases. The reason for this is that both activated carbons have the property of absorbing moisture, so it is judged that the strength is lowered by absorbing moisture necessary for curing. In the case of fluidity, it is judged that the fluidity is reduced by absorbing the moisture required for the flow. In the future, if the problem of the color of the finished cured body is compensated, it will be possible to manufacture a functional finishing board to replace the existing interior finishing material.

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Improving Accuracy of Soil Property Measurements by NIR Spectroscopy

  • Ryu, Kwan Shig;Cho, Rae Kwang;Park, Woo Churl;Kim, Bok Jin
    • Journal of Applied Biological Chemistry
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    • 제44권4호
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    • pp.177-179
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    • 2001
  • Traditional wet chemical methods for testing of soil properties require extensive time and labor, and cause the discharge of pollutants, making them undesirable for routine soil analyses. This research was conducted to improve the accuracy of soil properties in soil fertility assessments. A total of 140 finely ground soil samples were used to obtain accurate calibrations and validation for estimating soil moisture, OM, and T-N. Finely ground soil samples satisfied the improved accuracy for routine NIR measuring of the field soils. The results indicated that NIR spectroscopy could be used as a routine method for quantitatively determining OM, moisture, and T-N of field soil, although this technique requires many combinations of sample pretreatments and data manipulations to obtain optimal predictions.

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Synthesis and Characterization of Acrylic Polymer Containing Silk Protein

  • Zhongmin Chen;Kim, Mutsumi ura;Masahiro Suzuki;Yoshiyuki Kondo;Kenji Hanabusa;Hirofusa Shirai
    • 한국섬유공학회:학술대회논문집
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    • 한국섬유공학회 2003년도 The Korea-Japan Joint Symposium
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    • pp.87-87
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    • 2003
  • Three kinds of acrylic polymers containing silk protein were synthesized, which are (1) blending of silk fibroin (SF) fiber and polyacrylonitrile (PAN); (2) graft-copolymer of PAN onto SFs; (3) random-copolymer synthesized by copolymerization of acrylonitrile (AN) and silk fibroin peptide (SFP) with vinyl groups, and their solubility, thermal property, and moisture absorption was investigated, respectively. These polymers have difference solubility and attributable to their structure. Their excellent thermal stabilities and better moisture absorptions were indicated.

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소프트 닙 캘린더링 변수가 도공지의 물성에 미치는 영향 (The Effect of Soft Nip Calendering Variables on the Property of Coated Papers)

  • 이사용;이학래
    • 펄프종이기술
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    • 제34권1호
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    • pp.37-45
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    • 2002
  • The effect of soft nip calendering variables including pressure, temperature, nip residence time and sheet moisture on the properties of coated papers was investigated. The change of gloss, opacity, bulk and brightness were determined after calendering. Increase of calendering pressure and temperature increased gloss, but it decreased opacity, bulk and brightness of coated papers. Nip residence time and sheet moisture content showed similar effects on these properties. Calendering conditions of 16$0^{\circ}C$ of temperature, 146kg$_{f}$/cm of line load or less were found to provide optimum conditions to obtain reasonable gloss and smoothness while minimizing the loss of bulk and opacity for coated papers.

Karl Fischer를 통한 전력케이블용 반도전 Composite 특성 연구 (A Study on the Property of Semiconductive Shield Composite through Karl Fischer Method in Power Cable)

  • 양훈;박대희
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2008년도 Techno-Fair 및 합동춘계학술대회 논문집 전기물성,응용부문
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    • pp.187-188
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    • 2008
  • In this paper, we have investigated water content of semiconductive shield materials for power cables, EEA(Ethylene Ethyl Acrylate) is used polymer matrix. And filler is used CNT(Carbon Nanotube) and CB(Carbon Black). EEA, CNT and CB is favor moisture. In case of EEA, it has polyolefin resin that strong polarity combination. To research water content, experimental method used KF(Karl Fischer). KF method is Electrochemical titration based on chemical reaction. As a result, specification by KEPCO(Korea Electric Power Corporation) is lower than 800ppm. CNT and CB ratio of 80 versus 20 is best specimen that had lowest moisture content. It seem likely to increase crosslinking rate, CNT between CB.

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Gamma-Irradiation Sensitivity of Aspergillus flavus Contaminated in Semi-Dried Beef Jerky

  • Lee, Ju-Woon;Lee, You-Seok;Kim, Jang-Ho;Byun, Myung-Woo
    • 한국축산식품학회:학술대회논문집
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    • 한국축산식품학회 2004년도 정기총회 및 제33차 춘계 학술대회
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    • pp.181-184
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    • 2004
  • This study was conducted to investigate the adequate irradiation dose to eliminate harmful fungi inoculated if beef jerky with a 10% higher moisture content and improved textural property. Aspergillus flavus (approximately $10^6\;CFU/cm^2$) was tested in broth, spore suspension, and inoculated jerky. $D_{10}$ values of A. flavus were 0.36 kGy in the broth and suspension, and 0.47 kGy in the jerky. The results indicate that gamma irradiation can be effectively used to control the fungus growth in beef jerky with an improved quality and higher moisture content.

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Physicochemical Properties and Consumer Acceptance of Tofu Incorporated with Yakong

  • Lee, Jun Ho;Han, Ji Yoon
    • 산업식품공학
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    • 제13권2호
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    • pp.99-104
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    • 2009
  • Tofu has been playing an important role in people's daily diet in most of Asia and recently in North America due to several health-promoting functions, preventing and treating a number of chronic diseases such as cancer, coronary heart disease and osteoporosis. The objective of this study was to investigate the effect of different levels of yakong incorporation (0, 5, 10, and 15%, w/w) in preparation of firm tofu. Quality parameters such as pH, titratable, moisture content, color, and consumer preference were determined, and their correlations were analysed. There were no significant differences in pH, titratable acidity, and moisture content due to different levels of yakong incorporation studied (p>0.05). A significant decrease in L$^{*}$ and b$^{*}$-values whereas significant increase in a$^{*}$-value was observed (p<0.05). Five percent yakong tofu received the most favorable mean scores with respect to color, texture, and overall acceptability. Correlation analysis revealed that yakong incorporation was well correlated with some of physicochemical properties as well as consumer preference.

곶감의 지방산 및 아미노산 조성과 저장성 (The Compositions of Fatty Acid and Amino Acid and Storage Property in Dried Persimmons)

  • 문광덕;김종국;김준한
    • 한국식품저장유통학회지
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    • 제4권1호
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    • pp.1-10
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    • 1997
  • This study was performed to determine chemical compositions of dried persimmons stored with plastic film at low temperature and the effect of film packaging on dried persimmons during storage. The moisture contents of dried persimmons were 30 to 36% and alcohol contents were 264 to 318 mg/100g and acetaldehyde contents were 25 to 40mg/100g. Total lipid contents of dried persimmon were 626 to 869mg/100g and oleic, palmitic, linolenic, and palmitoleic acid were major fatty acids in total lipids. Major amino acids were glutamic acid, arginine, cystine and aspartic acid. From the result of storage experiment, non-packed group was that hardness was high as decreased in moisture content. In case of film packed groups stored at 5$^{\circ}C$, self life was longer than non-packed and packed groups stored at room temperature. But, it need to develop available packing material and storage method.

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