• Title/Summary/Keyword: Curing method

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Studies on the Horizontal Hanging Method in Burley Tobacco Stalk-curing (버어리종 잎담배 대말림시 수평대걸기에 관한 연구)

  • 배성국;김요태;임해건;조천준
    • Journal of the Korean Society of Tobacco Science
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    • v.19 no.1
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    • pp.29-32
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    • 1997
  • This study was carried out to develop a new stalk curing of the horizontal hanging method that would reduce the harvesting and curing labor, and improve its quality of cured leaf than the conventional stalk curing method in burley tobacco. The horizontal hanging stalk-curing method designed from 1988 was compared with the conventional method. The horizontal method shortened the curing Period for 7 days and reduced to 0.3%, while it occurred 9.4% in the vertical method. In the horizontal method, the quality of cured leaf improved 9%, but the contents of chemical components and physical properties were similar to those of vertical method. The labor of stalk-cut and loading in curing facility reduced 28% by the horizontal method. In harvesting and curing process, the horizontal method resulted 12% of labor saving as compared with the vertical method. Key words : horizontal hanging stalk-curing method, vertical method, stalk-curing.

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A Study on the Curing Method to Improve Bonding Strength of Aluminum/CFRP Composites (알루미늄/CFRP 복합재의 접착강도 향상을 위한 경화방법에 관한 연구)

  • 이경엽;양준호;최낙삼
    • Transactions of the Korean Society of Automotive Engineers
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    • v.10 no.3
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    • pp.130-135
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    • 2002
  • This study investigates the effect of curing method on the bonding strength of aluminum/CFRP composites. The surface of aluminum panel was treated by DC plasma. Lap shear tests and T-peel tests were performed based on the procedure of ASTM 906-94a and ASTMD1876-95, respectively. Test samples were fabricated by using the co-curing method and the secondary curing method. The results showed that the shear strength of test samples made by the co-curing method was 2.5 times greater than that of test samples made by the secondary curing method. The T-peel strength of the co-curing method case was almost 2 times greater than that of the secondary curing method case.

The Experimental Study of Characteristics of Concrete Strength according to the pattern of curing (양생방법에 따른 콘크리트의 역학적 특성에 관한 실험적 연구)

  • 이준구;윤상대;박광수;최광선;김명원
    • Proceedings of the Korea Concrete Institute Conference
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    • 1998.04b
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    • pp.695-702
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    • 1998
  • The purpose of this study is to investigate the mechanical properties of precast concrete cured by accelerated curing methods such as, steam curing method and warm water curing method varing maximum temperature of curing along to the period of curing. Some specimens are cured by accelerated curing method(warm water curing method) and then deposited in the storehouse. The others are deposited in the storehouse directly. All of these are cured until being tested to compare these two group's mechanical characteristics for each period 3days, 7days, 28days. The goal of this comparison is to estimate the efficiency of accelerated curing method in the case of precast concrete stocked in the field or warehouse for a long term and to make guide line for factory manager to make a economical products of concrete of a good quality. We can conclude some guide lines 1) It is not efficient to cure concrete with accelerated method at higher than 80℃. 2) The continuing of curing period more than 36hr makes damage to concrete in using accelerated curing method. 3) The strength revelation of concrete cured by accelerated curing methods, added rice husk ash more delayed than OPC concrete done but the strength of maximum value is higher than OPC concrete. 4) It is not efficient to use accelerated curing method in the case of storing the products for more than 7days in the aspect of mechanical properties.

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Early Estimation of Compressive Strength of Concrete Using Mineral Admixture by Refrigeration Curing Method (냉동양생에 의한 광물질 혼합 콘크리트의 압축강도 추정)

  • Sung , Chan-Yong;Cho , Il-Ho
    • Journal of The Korean Society of Agricultural Engineers
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    • v.46 no.5
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    • pp.55-60
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    • 2004
  • This study was performed to evaluate the early estimation of compressive strength of concrete using mineral admixture by refrigeration curing method. It was a method of early decision for the property of concrete after the curing age 28days through the refrigeration curing at $-18{\pm}3^{\circ}$ for five hours. The test result was fixed connection between the curing age 28days and 31hours by the compressive strength test through the standard curing and refrigeration curing. Accordingly, it can be reduced the mistake of construction work by forecasting the property of concrete through the refrigeration curing.

Strength Properties of the Mortar According to the Curing Condition of the Modified Sulfur Mortar (개질유황 모르타르의 양생조건에 따른 모르타르의 강도특성)

  • Jung, Byeong-Yeol;Lee, Sang-Soo;Song, Ha-Young
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2013.05a
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    • pp.332-333
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    • 2013
  • This research utilizes the modified sulfur having the low melting point which 65℃ is tries to study the strength property of the mortar according to the cure method of the modified sulfur mortar. And we try to use as basic data for investigating the curing condition of the light panel optimum utilizing the modified sulfur. We experimented by five kinds; 20℃ water curing method and 20, 40, 60, 80(℃) air dry curing method. In 3 day curing, the compressive strength was improved caused by high curing temperature. But the compressive strength was degraded caused by enhanced temperature in 7day curing and 28day curing. Therefore, the curing temperature of the modified sulfur mortar is determined that it comes 20 time case curing and the water curing is the most recommendable.

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A Study on the Properties of Cement Mortar with the Content of Expansive Additives Under Various Curing Method (팽창재량 및 양생방법에 따른 시멘트 모르터의 특성에 관한 연구)

  • 한성수;김정진;김효구;홍상희;한천구
    • Proceedings of the Korea Concrete Institute Conference
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    • 1999.04a
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    • pp.181-186
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    • 1999
  • When the expansive additives are used in concrete to reduce the shrinkage cracking, it shows variable properties with the curing method and curing temperature. Therefore, in this study, the experiments are perfomed to present the expansion of cement mortar by varying the unit additions of expansive additives and the curing method. According to the test results, the order of expansion by curing method, which is caused by hydration heat of cement, is follows ; curing at water > curing at air after curing at water for 7 days > curing at air. Cement mortar using expansive additives shows that high expansion is place with rise of temperature.

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A Study on Curing Methods for Concrete Pavement on Early Strength Development in Cool Weather Condition (저온 환경에서 콘크리트 포장의 강도발현 촉진을 위한 양생방법 연구)

  • Ryu, SungWoo;Kim, JinHwan;Hong, SeungHo;Park, JeJin
    • International Journal of Highway Engineering
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    • v.19 no.3
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    • pp.11-18
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    • 2017
  • PURPOSES : This study investigates the effect on concrete pavement accordance with the curing methods in cool weather and supports the best method in the field. METHODS : Two field tests evaluated the curing methods of concrete pavement in cool weather. Firstly, five curing methods were tested, including normal curing compound, black curing compound, bubble sheet, curing mat, and curing mat covered with vinyl. Concrete maturity was compared from temperature data. Secondly, normal curing compound and curing mat with vinyl, which showed the best performance, were compared in terms of maturity and join condition index. RESULTS:From the field tests, it is an evident that curing mat with vinyl accelerated the concrete strength. Therefore, it is possible to conduct saw-cut works in cool weather, which minimizes damage on concrete at joint. CONCLUSIONS : For concrete pavement in cool weather, using curing mat with vinyl as the curing method could overcome the strength delay. Therefore, strength and durability problems on concrete at joint due to cool weather would be fewer in the future.

Changes of Nitrogeneous Compounds Depending upon the Curing Methods in Burley Tobacco (버어리종 건조방법에 따른 질소화합물의 변화)

  • 백순옥;한상빈;배성국
    • Journal of the Korean Society of Tobacco Science
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    • v.25 no.1
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    • pp.27-33
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    • 2003
  • This study was conducted to determine the changes of nitrogen compounds in lamina and midrib during the curing process with the different curing methods, such as priming and stalk-cut curing. After KB 108 burley tobacco was cultivated by the different fetilization levels such as standard and 20% higher, only the tips and leaf were harvested. Though the contents of total alkaloid and total nitrogen were similar in lamina, midrib showed a very low contents of those components by the different curing method and fertilization levels. The content of nitrate-nitrogen in lamina increased during a middle of curing process, and then these compound was decreased during an end of curing process by stalk-cut curing method. Nitrate-nitrogen contents in the lamina by the priming curing showed a high level caused by rapid drying process during an end of curing process. That component in midrib was 5-6 times higher than that of lamina. The contents of ammonia-nitrogen in the lamina and midrib were increased during a curing process. Though those amount in tips showed a similar by a different fetilization and curing method, midrib of stalk-cut curing showed a slow increasing during a curing process.

Effect of Air Flow During Curing Process on Physical Properties of Bulk Cured Leaves (황색종 Bulk건조시 송풍량 조절에 따른 건조엽의 물리성 변화)

  • 이철환;진정의;한철수
    • Journal of the Korean Society of Tobacco Science
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    • v.21 no.1
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    • pp.5-9
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    • 1999
  • In recent years, the line of increase in policy on tobacco production triggered a rise in the loading volume per bulk curing barn, and manufacturers boosted the output of their blowers in order to prevent dirty leaves in the process of curing. for this reason, we studied the effect of the reducing air flow in bulk curing chamber from the color fixing stage to the stem drying stage of flue curing process on physical properties of cured leaves. The control of air flow was composed of the reducing air velocity of blower by means of a voltage regulator (slidac), and condition before color fixing stage was all the same with the conventional curing method. As a result, an effectiveness of improvement in the physical properties of cured leaves were observed. The leaves cured by this method were somewhat orange in color of upper stalk position, better bodied, and less brittle compared with the leaves produced by conventional curing. However, the leaves cured by this method had a little sharpness and harshness. As to the physical properties, there was decreased in occurrence of flat leaves than that of conventional ones. On the other hand, in case of reducing air flow during the curing process, increase of price per kg reached to about 5 % compared with those of conventional curing method.

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A Study on the Curing Bladder Shaping of Tire by Finite Element Method Using Contact Element (접촉요소를 이용한 유한요소법에 의한 타이어 가류브레더 팽창거동에 관한 연구)

  • Kim, Hang-Woo;Hwang, Gab-Woon;Cho, Kyu-Zong
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.21 no.3
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    • pp.378-384
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    • 1997
  • In curing process of tire, contact and slip occurs between green tire and curing bladder. The curing process is a critical step in the manufacture of tires. In this investigation, curing bladder shaping is examined using a finite element method. Specifically, a finite element model between the inner part of green tire and the outer part of curing bladder is generated using contact element and curing bladder is generated using incompressible element. Numerical analysis are performed on two different bladder types, different overall outer diameters of curing bladder and different heights of curing bladder. Numerical results show that contact pressure is increased by using toroidal type of curing bladder, increasing overall diameter and increasing height of curing bladder. To obtain natural equilibrium carcass line, there is a requirement in increasing contact pressure of the section between side and bead.