• Title/Summary/Keyword: heat fixation

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Improvement of Histopathological Sample Preparation by Employing Microwave Heating Method on Frozen Section Specimens

  • Ahn, Seung-Ju
    • Biomedical Science Letters
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    • v.13 no.4
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    • pp.361-368
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    • 2007
  • Biological samples can be fixed either by chemical method by using chemical solution or physical methods by using heat treatment. The problem in traditional heat fixation is unsatisfactory quality due to uneven heat conduction in specimen and loss of inner cell contents. Chemical fixation method also bears several intrinsic problems like the limit in specimen size, time consumption in fixative impregnation, and loss of low molecular weight cell components. These factors deteriorate the quality of fixed specimen, thus limit the magnification and contrast of tissue pictures. Microwave heat has been reported to be a good alternative to current chemical methods to overcome these problem. In this study, we tried to introduce the microwave energy method to routine fixation work in hospital. We replaced chemical fixative with saline to provide moderate reaction condition, and used frozen section to reduce time for sample preparation. Temperature was measured at each experiment. The fixation of rat kidney tissue with 2.45 GHz electromagnetic wave and saline showed similar result to the control group fixed with traditional chemical method. Human tumor tissue fixed with 2.45 GHz electromagnetic in frozen section was improved in terms of histochemistry of PAS and immunohistochemistry of tumor marker like cytokeratin. Total turnaround time was reduced from $24\sim38$ h to to $2\sim4$ h. In conclusion, the quality of samples prepared by microwave heating method was at least as good as that of traditional method. If the condition for the fixation of different specimens is standardized, this new method could be applied to routine work in hospital, and could save working time as well.

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Fixation of Compression Set of Heat-Compressed Wood by Steaming (수증기 처리에 의한 열압밀화목재의 압축 고정)

  • 이원희;한규성
    • Journal of the Korea Furniture Society
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    • v.11 no.1
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    • pp.85-89
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    • 2000
  • This study investigated the effect of steaming on fixation of compression set and the effect of these treatments on mechanical properties of heat-compressed wood specimens. To determine the effect of steaming after compression set, wood specimens were compressed for 100min at 180f and then steamed for 20-100min at $120^{\circ}C$. Swelling tests were used to evaluate recovery of compression set. Bending, compression, and Brinell hardness tests were carried out for evaluating mechanical properties. Compressed wood steamed for 100 min at $120^{\circ}C$ showed 1.9% recovery of set, increases in bending and compressive properties, and no hardness change. We concluded that almost complete fixation of compression set in wood can be achieved by steaming compressed wood.

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The Effects of Burn-out Printing on the Polyester/Cellulosic Fiber Mixed Fabrics (폴리에스테르/셀룰로오스계 교직물의 탄화날염가고에 관한 연구)

  • Kim, Ho-Jung
    • Fashion & Textile Research Journal
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    • v.3 no.4
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    • pp.373-377
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    • 2001
  • When the polyester/cellulosic fiber mixed fabrics were treated with sodium hydrogensulfate for burn-out printing, it is examined how the effects of process conditions as concentration of acid, fixation temperature and fixation time act onto the properties of the polyester ground fabrics. The print paste, indalca solution, was mixed with sodium hydrogensulfate and glycerine, and then screen-printed on the fabrics. The properties of the polyester ground fabrics after removing away the cellulosic fibers were investigated. The yellowness index and the breaking load of polyester ground fabrics affected by the process conditions, especially dry heat fixation temperature.

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A Study on the Burn-out Printing of Cellulose-blend Velvet (셀룰로오스계 파일직물의 탄화가공)

  • 김호정
    • Journal of the Korean Society of Clothing and Textiles
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    • v.23 no.5
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    • pp.757-763
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    • 1999
  • The burn-out technique is used to result in the velvet cloth being patterned in open and solid areas by carbonize the cellulose fiber. It is examined how to burn out the cellulose part of the velvet without damage of the other part. The print paste indalca solution is mixed with sodium hydrogensulfate and lycerine and then screen-printed on the back side of the velvet. The effects of process conditions such as concentration of sodium hydrogensulfate dry heat fixation temperature and time pull no. and glycerine contents on the properties of ground farics were investigated. The yellowness index and the breaking load of silk ground fabrics afected by the process conditions especially concentration of sodium hydrogensulfate dry heat fixation temperature.

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Fixation of Reactive Dyes on Ink-jet Dyeing

  • Urakawa, Hiroshi;Tamura, Kyoko;Yasukawa, Ryoko;Ueda, Mitsuo;Kajiwara, Kanji
    • Proceedings of the Korean Fiber Society Conference
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    • 2003.10a
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    • pp.31-32
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    • 2003
  • The fixation of reactive dyes onto cotton fabrics by means of dry heat treatment was examined in terms of water regain in fabrics. Dye liquors were applied to fabrics by ink-jet printer. The fixation strongly depended on water regain. At certain level of water regain the fixation showed stepwise increase. After this point the fixation reached to saturated value. The observed results were interpreted by the aggregation behavior of dyes and reactivity of hydroxyl group of cellulose depending on the amount of the surrounding water molecules. Urea molecules played a role of water at low water regain to increase the fixation.

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Surface Electrochemical Study on the Fixation Properties of New Water-borne Preservatives in Red Pine (새로운 수용성(水溶性) 방부방충제(防腐防蟲劑)의 재중(材中) 정착성(定着性)에 관한 계면전기화학적(界面電氣化學的) 특성(特性))

  • Kim, Yeong-Suk
    • Journal of the Korean Wood Science and Technology
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    • v.24 no.4
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    • pp.93-99
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    • 1996
  • In order to investigate the extent of fixation of new water-borne preservatives in blocks of pinus densiflora sapwoods the streaming potential through the column with preservative treated wood was measured at various conditions. The rates of leachability of ingredients in the treated wood were estimated by the measurement of electric conductivity of the solution with the leached components. The solution was also analyzed by Atomic absorption spectrophotometer (AA). As a results, the experimental data indicated that the fixation of CCB, CCFZ and ACQ in wood were relatively unstable. The fixation rates of CCB, CCFZ were improved by increasing heat and drying time. The amounts of the leached ingredients were apparently higher in CCB and CCFZ than in CCA, while the rate of leaching of ACQ was not changed at various drying temperature.

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Protective Role of Light in Heat-Induced Inhibition of Photosynthesis in Isolated Chloroplasts

  • Jun, Sung-Soo;Kim, Chang-Hoon;Hong, Young-Nam
    • Journal of Photoscience
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    • v.5 no.4
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    • pp.157-162
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    • 1998
  • The effect of heat treatment in the light on the subsequent CO2 fixation was studied with isolated spinach chloroplasts to define the role of light during heat stress. The degree of inhibition in CO2 fixation after heat treatment at 35$^{\circ}C$ under full light intensity (600W/$m^2$) was same as that in the dark. However, heat treatment of isolated chloroplasts in the light manifested thylakoidal damage, which did not occur in the dark. Under weak light (10~30 W/$m^2$ ) where no thylakoidal damage occurred, the inhibition was substantially alleviated , showing protective effect of light . The inhibition caused by heat treatment in the dark or light is prevented by the addition of a few combined compounds to the medium prior to treatment. Fructose-1-6- bisphosphate(with aldolase)and ribose-5-phosphate, known to be effective combined with oxaloacetate in preventing inhibition after heat treatment in the dark were equally effective in the light even without oxaloacetate. Addition of sugar phosphate reduced the Mehler reaction, which may occur in fast rae under high light. However, the addition of bicarbnate and catalase that would remove Mehler reaction did not provide any protection, indicating that protective role of sugar phosphate is elsewhere. Furghermore, in whole plants rapid recovery from heat stress was observed in the light. The apparently lesser or equal inhibition in spite of additional thylakoidal damage under heat stres in the light and less requirement for the protection against heat treatment suggest that the inhibitory effect of heat stress is alleviated by light treatment.

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Intergeneric Transfer of Nitrogen Fixation Genes from Rhizobium leguminosarum by RP4::Mu cts (RP4::Mu cts에 의한 Rhizobium leguminosarum 질소고정 유전자의 속간전달에 관한 연구)

  • 허연주;이영록
    • Korean Journal of Microbiology
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    • v.24 no.3
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    • pp.211-220
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    • 1986
  • Nitrogen fixation (nif) genes of Rhizobium leguminosarum were transferred to nif Klebsiella pneumoniae and E. coli by conjugation after partial heat induction of $RP_4$ :: Mu cts in Rhizobium $R^+$ transconjugant, and the hybrid plasmids in the transconjugant strains were isolated and characterized. In order to transfer the nif genes from Rhizobium, the hybrid plasmid $RP_4$ :: Mu cts was transferred by conjugation from E. coil to the symbiotic nitrogen fixer, R. leguminosarum. After stabillity test, the $RP_4$ :: Mu cts in Rhixobium $R^+$ transconjugant was subjected to partial heat induction by culturing it statically at $38^{\circ}C$ for 16 hours, and then conjugated with the nif defective mutant strains of K. pneumoniae or nif mutant strains of E. coli having whole nif gene plasmid. Recombinant strains of K. pneumoniae, which could grow in a N-free medium and exhibit the nitrogenase activity were selected. However, in the case of E. coli, they could grow well in a NA medium containing antibiotices, but hardly frow in a N-free medium. The hybrid plasmids in these transconjugal strains were isolated by gel electrophoresis and compared their molecular sizes.

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Feasibility study of LFG-MGT power generation system with $CO_2$ fixation development (농작물의 $CO_2$ 고정화 연계 LFG-MGT 시스템의 타당성 연구)

  • Park, Jung-Keuk;Hur, Kwang-Beom;Rhim, Sang-Gyu
    • 한국신재생에너지학회:학술대회논문집
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    • 2009.06a
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    • pp.821-824
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    • 2009
  • LFG-MGT CHP system development project with $CO_2$ enrichment in greenhouses was introduced. LFG is produced from the anaerobic digestion of landfilled waste and it has been utilized for power/heat generation since it contains around 50% of $CH_4$. Utilization of LFG from small scale landfill is also needed as well as large scale landfill. However, due to economy of scale, it is very difficult to develop business model. In this context, combining CHP system with greenhouses is considered as feasible option for LFG utilization. LFG-MGT CHP system with $CO_2$ fixation in greenhouses has been derived as an active greenhouse gas reduction strategy, The focus of the system is beyond carbon neutral LFG utilization to neutral carbon absorption. The system is feasible in terms of direct and indirect $CO_2$ emission reduction with more economical way.

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Hardness and Dimensional Stability of Radiata Pine (Pinus radiata D.Don) Heat-Compressed Wood - Effect of Press Temperature & Time - (라디에타소나무 열압밀화 목재의 경도와 치수안정성 - 압체 온도와 시간의 영향 -)

  • Hwang, Sung-Wook;Lee, Won-Hee
    • Journal of the Korean Wood Science and Technology
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    • v.39 no.3
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    • pp.206-212
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    • 2011
  • It was investigated the hardness and dimensional stability of heat-compressed wood by compression temperature and time. The surface hardness of heat-compressed wood increased with increasing compression temperature. The lowest hardness value (5.0 N/$mm^2$) was observed in the temperature $70^{\circ}C$ while the highest value (15.6 N/$mm^2$) was obtained in compression temperature $220^{\circ}C$. Dimensional recovery test results showed that fixation of compression set improved with increasing compression temperature. However, the fixation effects were negligible by press time. Contact angle increased with increasing press temperature and time.