• Title, Summary, Keyword: freeze-thawing effect

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Effect of Repeated Freeze-Thaw Cycles on Beef Quality and Safety

  • Rahman, Mohammad Hafizur;Hossain, Mohammad Mujaffar;Rahman, Syed Mohammad Ehsanur;Hashem, Mohammad Abul;Oh, Deog-Hwan
    • Food Science of Animal Resources
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    • v.34 no.4
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    • pp.482-495
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    • 2014
  • The objectives of this study were to know the effect of repeated freeze-thaw cycles of beef on the sensory, physicochemical quality and microbiological assessment. The effects of three successive freeze-thaw cycles on beef forelimb were investigated comparing with unfrozen fresh beef for 75 d by keeping at $-20{\pm}1^{\circ}C$. The freeze-thaw cycles were subjected to three thawing methods and carried out to know the best one. As the number of freeze-thaw cycles increased color and odor declined significantly before cook within the cycles and tenderness, overall acceptability also declined among the cycles after cook by thawing methods. The thawing loss increased and dripping loss decreased significantly (p<0.05). Water holding capacity (WHC) increased (p<0.05) until two cycles and then decreased. Cooking loss increased in cycle 1 and 3, but decreased in cycle 2. pH decreased significantly (p<0.05) among the cycles. Moreover, drip loss, cooking loss and WHC were affected (p<0.05) by thawing methods within the cycles. 2-Thiobarbituric acid (TBARS) value increased (p<0.05) gradually within the cycles and among the cycles by thawing methods. Total viable bacteria, total coliform and total yeast-mould count decreased significantly (p<0.05) within and among the cycles in comparison to the initial count in repeated freeze-thaw cycles. As a result, repeated freeze-thaw cycles affected the sensory, physicochemical and microbiological quality of beef, causing the deterioration of beef quality, but improved the microbiological quality. Although repeated freeze-thaw cycles did not affect much on beef quality and safety but it may be concluded that repeated freeze and thaw should be minimized in terms of beef color for commercial value and WHC and tenderness/juiciness for eating quality.

Effect of Emulsified Refine Cooking Oil and Expandable Microsphere on Durability of High-Volume Blast Furnace Slag Concrete (정제유지류 및 팽창성 인공 기포 조합이 고로슬래그 다량치환 콘크리트의 내구성 및 미시적 특성에 미치는 영향)

  • Han, Min-Cheol;Han, Dongyeop;Lee, Myung-Ho
    • Journal of the Korea Institute of Building Construction
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    • v.15 no.2
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    • pp.201-207
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    • 2015
  • In this paper, a series of experiments was conducted to evaluate the resistibility of carbonation and freeze-thawing damage of the high-volume blast furnace slag concrete using expancel, the expandable microsphere, and ERCO, emulsified refine cooking oil. The concrete mixture of 0.45 water-to-binder ratio with 60% of blast furnace slag was evaluated for carbonation, freeze-thawing resistibility, SEM, and porosity. According to the previous research, replacing ERCO contributes on improving carbonation resistibility with capillary pore filling effect by soap foaming reaction of ERCO while significantly decreased freeze-thawing resistibility. To improve this decreased freeze-thawing resistibility, expancel was used, and thus freeze-thawing resistibility was improved as the replacement ratio of expancel was increased. It is considered that the selective volume shrunken effect of expancel due to the external pressure and decreased air void spacing factor due to expancel.

Freezing and Thawing Resistance of Hardened Cement Paste Containing Blending Materials (혼합재를 사용한 시멘트경화체의 동결융해 저항성)

  • 이양수;김정환;최상흘;한기성
    • Journal of the Korean Ceramic Society
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    • v.27 no.3
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    • pp.437-443
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    • 1990
  • The resistivity of cement paste and mortar for freezing and thawing was investigated for densifying the structure of cement paste and mortor, slag, diatomaceous earth and fly ash as blending materials and superplasticizer were used, and air entraining agent was added to absorb the volume expansion by freezing and thawing reaction. And then the specimens were subjected to freeze-thaw in water. When both of air entraining agent and superplasticizer as additives were mixed to specimens, their freeze-thaw resistance was enhanced by the air entraining effect and the water reduction effect. When 4% of slag were added to cement, freeze-thaw resistance was especially excellent. In addition, it was found that the specimens with blending materials were more influenced by curing periods than those without admixture. It is assumed that the curing periods contribute to exibit the potential hydraulicity and pozzolanic reactivity of blending materials and to densify their texture.

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A Study on the Effect of Entrained Air Contents of Marine Concrete on the Properties of Freeze-Thawing Resistance and Chloride Migration (해양콘크리트의 연행공기량이 동결융해 저항성 및 염화물 확산특성에 미치는 영향에 관한 연구)

  • Park Sang Joon;Yoo Jae Kang;Shin Hong Chul;Kim Young Jin;Park Hyung Keun;Lim Hyun Chil
    • Proceedings of the Korea Concrete Institute Conference
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    • pp.483-486
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    • 2005
  • This study investigates the effect of air contents on concrete properties, compressive strength, chloride migration coefficient and freeze-thaw resistance. Chloride migration and freeze-thawing test conducted in accordance with NT-BUILD 492 and pr-EN 12390-9, respectively. As a result, compressive strength reduced with air contents increase, but chloride migration coefficient more influenced by the water-binder ratios than air contents. Air contents of hardened concrete measured half times that of fresh concrete after mixing. Also, concrete scaling decreased with air contents increased.

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Effect of Freezing and Thawing on the Histology and Ultrastructure of Buffalo Muscle

  • Sen, A.R.;Sharma, N.
    • Asian-Australasian Journal of Animal Sciences
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    • v.17 no.9
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    • pp.1291-1295
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    • 2004
  • Histology and transmission electron microscopy studies were carried out on buffalo muscles that were subjected to repeated freeze-thaw cycles at -10 and $-18^{\circ}C$. In the first freeze thaw cycle ($-10^{\circ}C$) structures of muscle showed slight change and closely resembled to those of normal muscle. There were frequent gaps in the half way across the fibres and some cracks in individual fibre were also noticed in second freeze thaw cycle. In the muscle frozen at $-18^{\circ}C$, more pronounced shrinkage with extensive damage of fibres with tearing was observed. The interfibrillar gaps were wider, shrinkage and tearing of the fibres were more distinct after second freeze-thaw cycle. After the second cycle, the interior portion showed large scale degradation of the ultrastructure. Our studies of buffalo muscle showed that under the proper condition, little structural damage takes place in the meat histology and ultrastructure under repeated freeze-thaw conditions. This study adds continued weight to the evidence that limited freeze-thaw cycles will not deteriorate the quality of meat.

Effect of Blending Materials on the Durability of Concrete II. Freezing and Thawing Resistance of Concrete (염분환경하 콘크리트 경화체의 내구성에 미치는 혼합재의 영향 II. 콘크리트의 동결융해저항성)

  • Jaung, J.d.;Kim, W.K.;Jeong, Y.;Han, K.S.;Choi, S.H.
    • Proceedings of the Korea Concrete Institute Conference
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    • pp.34-39
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    • 1991
  • It is well-known that concretes under sea water environment show remarkably degrading phenomena physically by repeatable freeze-thawing action and chemically by penetration of soluted ions in sea water. In this study the influences of type of blending materials, their dosage and W/C ratio on freeze-thawing resistances of hardened cement concrete using foy ash, ground blast furnace slag, silica fume, EVA and SBR under sea-water environment were investigated.

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The effects of different cement dosages, slumps and pumice aggregate ratios on the freezing and thawing of concrete

  • Turkmen, Ibrahim;Demirboga, Ramazan;Gul, Rustem
    • Computers and Concrete
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    • v.3 no.2_3
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    • pp.163-175
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    • 2006
  • This research was conducted to determine effect of pumice aggregate ratio, cement dosage and slumps on freeze-thaw resistance, density, water absorption and elasticity of concrete. In the first batch, $300kg/m^3$ cement dosage were kept constant and pumice ratios were changed as 25%, 50%, 75% and 100% of replacement for normal aggregate by volume for $3{\pm}1cm$, $5{\pm}1cm$ and $7{\pm}1cm$ slumps. Other batches were prepared with $200kg/m^3$, $250kg/m^3$, $350kg/m^3$, $400kg/m^3$ and $500kg/m^3$ cement dosages and 25% pumice aggregate +75% normal aggregate at a constant slump. Test results showed that when pumice-aggregate ratio decreased the density and freeze-thaw resistance of concretes increased. With increasing of cement dosage in the mixtures, density of the concretes increased, however, freeze-thaw resistance of concretes decreased. Water absorption of the concrete decreased with increasing cement dosage but increased with the pumice ratio. Water absorption of the concrete also decreased after freeze-thaw cycles. Freeze-thaw resistance of concretes was decreased with increasing the slumps.

Effect of Polymers on the Freezing and Thawing Resistance of Hardened Cement Mortar (시멘트 경화체의 동결융저항성에 미치는 Polymer의 영향)

  • 이선우;김정환;최상흘;한기성
    • Journal of the Korean Ceramic Society
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    • v.28 no.7
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    • pp.509-516
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    • 1991
  • The effect of various polymers on the freeze-thaw resistance of hardened cement mortar was investigated. For this study, styrene butadiene rubber (SBR), ethylene vinyl acetate (EVA), polyvinyl alcohol (PVA) were used to prepare cement mortar specimen, and then freeze-thaw experiment was carried out. By adding SBR adn EVA to the specimen, the freeze-thaw resistance of specimens was improved, but when PVA was added to the specimen, its freeze-thaw resistance was lowered. Particularly, the specimens which were added 5, 10% of SBR and 5% of EVA showed excellent freeze-thaw resistance in the salt environment.

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Strengthening Performance of RC Beams Exposed to Freezing and Thawing Cycles after Strengthening in Shear with CFRP Sheet (CFRP 쉬트로 전단보강후 동결융해에 노출된 철근콘크리트 보의 보강성능)

  • Yun, Hyun-Do;Kim, Sun-Woo;Kim, Yun-Su;Lee, Min-Jung;Seo, Soo-Yeon;Choi, Ki-Bong
    • Proceedings of the Korea Concrete Institute Conference
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    • pp.161-164
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    • 2008
  • In recent years, carbon fiber-reinforced polymer (CFRP) has been widely used for repairing and/or strengthening structural elements in concrete. Not enough test data, however, are available to predict the long-term performance of the repaired and improved structures exposed to weathering. The objective of this research is to study the effect of freeze-thaw cycling on the behavior of reinforced concrete (RC) beams strengthened in shear with carbon fiber sheet. Six small-scale RC beams (100mm${\times]$100mm${\times]$400mm) were strengthened with CFRP in shear, subjected to up to 400 cycles freeze-thawing from -17${\sim}4^{\circ}C$, and tested to failure in four-point bending. Test result, there was no significant damage to carbon fiber sheet strengthened concrete beams had been suffered 30 cycles of freeze-thawing, and more over 60 cycles of freezing-thawing brought about a reduction in resistance of only 25% of the initial level.

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Strength Development and Freeze-Thaw Resistance of Concrete Incorporating High Volume Blast-Furnace Slag Subjected to Initial Frost Damage (초기동해를 받은 고로슬래그 다량 혼입 콘크리트의 강도발현 및 동결융해 저항성)

  • Koh, Kyung-Taek;Ryu, Gum-Sung
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.6 no.3
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    • pp.79-87
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    • 2011
  • Concrete incorporating high volume blast-furnace slag placed in cold weather regions might be in danger of initial frost damage because dependently on the mix proportions, the setting and the hardening would be remarkably delayed. Therefore, this study investigated to effect of the degree of frost on the strength development and the resistance to freezing and thawing of the concrete incorporating blast-furnace slag when being subjected to freeze at early age. As the experimental results, the concrete incorporating blast-furnace slag attacked by initial frost damage showed the remarkable reduction of both the compressive strength development and the resistance to freezing and thawing. Especially, the resistance to freezing-thawing of the concrete incorporating high volume blast-furnace slag became much lower than that of the normal concrete.

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