• Title/Summary/Keyword: 흡습효과

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Effects of Film Thickness and Moisture Absorbing material on Ginger Quality during MA Storage (필름두께 및 흡습제 처리에 따른 생강의 MA 저장효과)

  • 정문철;남궁배;김동만
    • Food Science and Preservation
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    • v.6 no.3
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    • pp.264-269
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    • 1999
  • The effects of film thickness and moisture absorbing materials(MAM) on the ginger qualities were investigated during MA storage for 150 days. LDPE films of 0.04, 0.06 and 0.08mm thicknesses were applied to select the adequate film in gas permiability. MAMs of sheet and sachet type were applied to 0.06mm-LDPE film bag to prevent moisture condensation during storage. Thickness of film used affected neither weight loss nor firmness of gingers during U storage. But the thinner in thickness showed the less changes in sprouting, spoilage and reducing sugar. Moreover, compared with MAP alone, MAPs with MAM of both sachet and sheet styles led to the weight loss of gingers increasing by more than 3-4 times, but sprouting rate, spoilage rate and reducing sugar decreasing by 3.3, 1.4 and 2.3 times, respectively. These results showed that MAP with UM was significantly effective to prolong the freshness of ginger by longer than 2 times, compared with MAP alone.

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A Study on the Transient Hygrothermal Stresses in an Orthotropic Hollow Cylinder (직교이방성 속빈 원통에서 과도적 흡습열 응력에 관한 연구)

  • 조환기;신근용
    • Journal of the Korea Institute of Military Science and Technology
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    • v.2 no.1
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    • pp.110-120
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    • 1999
  • Transient hygrothermal stresses in an infinitely long hollow cylinder subjected to heating in hygroscopic environments at the surfaces are studied. The equations of hygrothermoelasticity based on the plane strain assumption are formulated by considering the coupling effects between heat and moisture. A closed form solution for the transient hygrothermal stresses is obtained by using decoupling techniques and the method of separation of variables. Numerical results including distributions of temperature and moisture concentration are presented. Effects of transient hygrothermal characteristics are clearly shown in both displacements and stress distributions in the wall of hollow cylinder.

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Effect of Moisture Absorption on the Compressive and the Bending Residual Strength in Fiber-Reinforced Polymeric Composites (흡습효과가 섬유강화 고분자 복합재료의 압축 ${\cdot}$ 굽힘 잔류강도에 미치는 영향)

  • Kim, Hyuk;Han, Gil-Young;Lee, Dong-Gi;Kim, E-Gon;Kim, Ki-Sung
    • Journal of Ocean Engineering and Technology
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    • v.9 no.2
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    • pp.133-140
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    • 1995
  • This paper deals with the residual strength characteristics of composite materials under the environment of high temperature and humidity. Two types of GFRP, one with unidirection and randomly oriented, are used to investigate the features of moisture absorption and the residual strength. The results show that, when exposed longterms in high temperature and humidity, the randomly oriented composites is more stable than the unidirection one.

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Effect of MMT on Anti-Water Absorption of Polyamide/MMT Nanocomposites (MMT 첨가에 따른 Polyamide/MMT 나노복합체의 흡습 특성)

  • Park, Sang-Cheol;Kim, Ho-Gyum;Min, Kyung-Eun
    • Polymer(Korea)
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    • v.37 no.1
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    • pp.113-120
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    • 2013
  • The melt intercalation to commercialize nanocomposites in a pilot scale was applied and the water absorption characteristics for polyamide/MMT nanocomposites manufactured by twin screw extruder was studied. As a result, water absorption decreased with the introduction of MMT and dimensional stability was improved. However, as water absorption increased, flexural strength and modulus were reduced. Therefore, the effect of MMT introduction on mechanical properties of nanocomposites was clearly observed, which may increase the level of strength by maintaining anti-water absorption property of nanocomposite.

Combined Effects of Antibacterial Film and Storage Temperature on Shelf-life and Microbiological Safety of Mackerel (항균 필름과 저장 온도의 고등어 저장성 및 미생물학적 안정성에 대한 병행 효과)

  • Ha, Ji-Hyoung;Lee, Yu-Si;Heo, Sun-Kyung;Bae, Dong-Ho;Park, Sang-Kyu;Hwang, Sun-Soon;Ha, Sang-Do
    • Journal of Food Hygiene and Safety
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    • v.22 no.4
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    • pp.317-322
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    • 2007
  • The purpose of this study was to investigate the antibacterial effect of films on shelf-life and microbiological safety of mackerel. Effects of antimicrobial films against total aerobic bacteria, Escherichia coli O157:H7, Listeria monocytogenes, Vibrio parahaemolyticus in mackerel were evaluated during storage of 5-14 days at $5^{\circ}C,\;10^{\circ}C\;and\;15^{\circ}C$. Antimicrobial films were developed with addition of a natural substance, wasabi extracts (Wasabia japonica). At $5^{\circ}C$ storage, growth of total aerobic bacteria, Escherichia coli O157:H7, Listeria monocytogenes were inhibited higher than at 10 and $15^{\circ}C$. Especially, the numbers of V. parahaemolyticus were decreased gradually at $5^{\circ}C$ even in the control sample, and about $1\;log_{10}cfu/g\;and\;1.8\;log_{10}cfu/g$ reductions were observed at 1 and 4 days, respectively. After 7 days, V. parahaemolyticus in all samples were not detected. There is a limit of a single treatment of antimicrobial film to prolong shelf-life of mackerel. The synergistic effect of antimicrobial film were shown by addition of $5^{\circ}C$ refrigeration.

Effect of Edible Coating on Hygroscopicity and Quality Characteristics of Freeze-Dried Korean Traditional Actinidia (Actinidia arguta) Cultivars Snack (가식성 코팅처리가 토종다래(Actinidia arguta) 동결건조 스낵의 흡습과 품질에 미치는 영향)

  • Kim, Ah-Na;So, Seul-Ah;Park, Chan-Yang;Lee, Kyo-Yeon;Rahman, M. Shafiur;Choi, Sung-Gil
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.45 no.9
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    • pp.1344-1350
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    • 2016
  • The purpose of this study was to evaluate the effect of edible coating on hygroscopicity and quality characteristics of a freeze-dried Actinidia arguta snack. Freeze-dried A. arguta snacks were coated with various edible coating materials such as albumin, dextrin, and whole soy flour. There were no significant effects of coating on major quality properties such as moisture content, water activity, yield, water soluble index, water absorption index, and rehydration properties of all samples. Compared with non-coated samples, edible coated samples effectively inhibited hygroscopicity as a function of hygroscopic time. The samples coated with dextrin showed lower hygroscopicity than the other coated samples. In addition, the effects of edible coating treatment on hardness, total phenolic content, and antioxidant activity measured by 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity were investigated. Edible coated samples had higher hardness, total phenolic content, and antioxidant activity than the non-coated samples as a function of hygroscopic time. Among edible coating materials, dextrin was the most effective coating material. Dextrin as an edible coating material for freeze-dried A. arguta snack may help to prevent hygroscopicity and extend market quality and shelf-life during storage.

A Study of Conservation and Desalination Methods for an Iron Stele of the Joseon Dynasty (조선시대 철비(鐵碑)의 보존처리와 탈염방법 비교 연구)

  • Lee, Hye-Youn;Cho, Nam-Chul
    • Journal of Conservation Science
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    • v.25 no.4
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    • pp.399-409
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    • 2009
  • Outdoor iron artefacts are easily corroded by affection of environmental pollutants directly. Especially they need to be removed $Cl^-$ ions, but outdoor iron artefacts are excluded for desalination owing to their special features. Therefore this study contains the conservation processes of an iron stele of the Joseon Dynasty as the sample as well as desalination experiments that were carried out the desalting method using spill pads and the immersion desalting method together in order to compare. Desalting methods were compared by analyses such as an optical and metallurgical microscope, SEM-EDS, pH meter, Ion Chromatography and X-ray diffraction. As a result of the analysis, the optical and metallurgical microscopy show that the corrosion products are constituted by the layers and the metallurgical microstructure is a white cast iron. The SEM-EDS results of corrosion products detected mainly Fe, O, and especially Cl upto 2.48wt%. The results of pH and anion analysis for the washing solution, the desalting method using spill pads shows the similar effect to the immersion desalting method. As a result of XRD analysis before and after desalting corrosion products, goethite, magnetite, lepidocrocite and akaganeite are detected before desalting, but akaganeite is not detected after desalting at the desalting methode using spill pads, which indicates to have an effect on desalination. Therefore the results show that the desalting method using spill pads has an effect on desalination similar to the immersing desalting method.

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Studies on Practical Methods to Control Seed Vigour in Several Food Crops (주요식량작물 종자세 개선에 관한 연구)

  • 김진기
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.39 no.2
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    • pp.128-138
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    • 1994
  • To improve seed vigour in rice, barley and soybean, several methods of presowing treatment, using chemicals and priming in polyethylene glycol solution, were investigated. Gibberellic acid($GA_3$) slightly improved germination of rice, but other chemical treatments showed no beneficial effect on seed vigour. Aged seeds were primed in polyethylene glycol solution then rinsed and germinated with drying back. In general mean germination time increased and percentage germination decreased with in- creasing water potential of the priming solution, but there were no significant effects on spread of germination times. Priming also showed no marked improvement in germination under cold, wet, or osmotic conditions. None of the treatments used was successful in practically improving the seed germination and vigour of the tested crops. However, seed treated with GA$_3$ gave the best overall germination response.

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Effects of various concentrations of skullcap extract in the diets on disease resistance of olive flounder, Paralichthys olivaceus (생약재 황금 뿌리 열수추출물의 넙치 투여시 질병저항성에 미치는 영향)

  • Jee, Bo-Young;Seo, Jung-Soo;Jeon, Eun-Ji;Lee, Eun-Hye;Choi, Hee-Jung;Kim, Jin-Do;Jung, Sung-Hee;Park, Myoung-Ae
    • Journal of fish pathology
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    • v.25 no.1
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    • pp.21-30
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    • 2012
  • Effects of various concentration of skullcap Scutellaria baicalensis in the diets on a nonspecific immunity and a disease resistance of olive flounder were investigated. After feeding trial, weight gain of fish fed 0.05% skullcap immersed group was higher than that of fish fed 0, 0.1 and 1% skullcap diet but no significant differences were observed among the experimental groups. Furthermore, no significant differences in hematological indices of olive flounder were found among the experimental groups. Lysozyme activity in the serum and kidney of the administrated group(0.05% skullcap immersed group) was significantly higher than the control group. In addition, the chemiluminescent(CL) responses of head kidney leucocytes from the 0.05% skullcap immersed group was significantly higher(P<0.05) than the control group. In the histological results, the 1% skullcap immersed group appeared to have the detrimental effects for fish health. In a challenge experiment with Edwardsiella tarda(GY-01) and Streptococcus iniae(FT5228), relative percent survival (RPS) in the 0.05% skullcap immersed group was higher than the control group injected with E. tarda(GY-01) at $4^{th}$ and $8^{th}$ weeks. The results suggest that the skullcap extract (0.05%) would be effective to enhance the nonspecific immunity and protective ability of olive flounder against fish pathogen such as E. tarda.

Effect of Disease Resistance on Oral Administration of Lightyellow Sophora Extract in Olive Flounder (생약제 고삼 뿌리 열수추출물의 넙치 투여시 질병 저항성에 미치는 영향)

  • SEO, Jung-Soo;JEON, Eun-Ji;KWON, Mun-Gyeong;HWANG, Jee-Youn;KIM, Jin-Do;JUNG, Sung-Hee;KIM, Na-Young;JEE, Bo-Young;PARK, Myoung-Ae
    • Journal of Fisheries and Marine Sciences Education
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    • v.27 no.6
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    • pp.1656-1664
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    • 2015
  • The effects of lightyellow sophora, Sophora flavescens extract were tested on non-specific immune response and a disease resistance of olive flounder, Paralichthys olivaceus. For feeding trial, weight gain of fish fed different treated groups were not significant differences. Serum analysis of treated and control group did not demonstrated any differences. Lysozyme activity in the kidney and spleen of the 0.05% treated group on $4^{th}$ and $8^{th}$ week showed significant increase, respectively. In addition, phagocytic activity of the 0.05% treated group on $4^{th}$ and 8th week showed significant increase compared to the control group. Histopathology of the liver and kidney tissue of the administrated group for $4^{th}$, $8^{th}$ and $12^{th}$ week showed no particular signs of tissue degeneration. The treated group was higher than control group by analyzing the relative percent survival (RPS) of the experimental challenge of Edwardsiella tarda. Therefore, the lightyellow sophora showed effective in preventing fish-pathogenic edwardsiellosis for a certain period of time.