• Title/Summary/Keyword: Freezing hardness

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The Properties of Concrete with Permeability Liners("CON-SILK") on the Formwork (탈수섬유시트 거푸집을 사용한 콘크리트의 특성에 관한 연구)

  • Koo, Bong-Kuen;Seo, Chee-Ho;Yoo, Taek-Dong;Park, Jae-Seong
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.7 no.2
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    • pp.141-148
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    • 2003
  • Concrete surface is a part that resists chiefly to carbonation by carbonic acid gas, affluence of rainwater and air, deterioration by freezing thawing, salt damage by seawater, and other chemical erosion etc. Therefore, this research analyzed physical characteristic and durable characteristic of concrete eliminated glut water and bubble of concrete surface using CON-SILK that is permeated with dehydration. As a research result, concrete using CON-SILK was improved, in comparison with concrete using general formwork, in physical performance and durability of concrete, as surface hardness, carbonation resistivity, and salt content permeation resistivity etc. Therefore, we could know that it is effective to use CON-SILK in performance elevation of concrete surface.

Effects of Freezing and Reheating on the Textural Characteristics of Mungbean Flour Gels and Mungbean Cake(Bindaedduk) (동결 및 재가열이 녹두가루겔 및 빈대떡의 조직 특성에 미치는 영향)

  • 고하영;우자원
    • Korean journal of food and cookery science
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    • v.15 no.4
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    • pp.353-357
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    • 1999
  • The textural characteristics of mungbean flour gels and mungbean cake(Bindaedduk) were investigated in steam and microwave reheating condition after 20$^{\circ}C$, 5$^{\circ}C$ and -18$^{\circ}C$ storage. The hardness of mungbean flour gels were 2.36 kg in microwave reheating and 3.59 kg in steam reheating after 6 days frozen storage, respectively and its gumminess were increased after reheating. The hardness of mungbean flour gels did not significantly change with the storage temperature. The textural characteristics of mungbean cake made with 2 parts of mungbean flour and 1/2∼1/8 parts of nonwaxy rice flour had the similar values in spite of the different compositions. Microwave reheated mungbean flour gels had the different hardness values of 4.13 kg in non package and 1.70 kg in polyethylene film wrap after 24 hours storage at 20$^{\circ}C$. In sensory evaluation mungbean flour gels showed the high scores in hardness and the unpleasant flavor after reheating but mungbean cake of different compositions showed the good sensory qualities.

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Effects of Freezing Period and Chilling Process after Thawing on Physicochemical Properties and Palatability of Loin from Jeju Island Reared Crossbred Black Pigs (동결 기간 및 해동 후 냉장이 제주 흑돼지고기의 물리화학적, 기호적 품질에 미치는 영향)

  • Moon, Yoon-Hee
    • Journal of the East Asian Society of Dietary Life
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    • v.20 no.4
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    • pp.560-566
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    • 2010
  • In this study, the effects of the chilling process after thawing on pork quality were investigated by comparing the physiochemical properties and palatability of the samples just after thawing(0-TP) and the other chilled at $2^{\circ}C$ for two days after thawing (2-TP). The samples used for this study were obtained from vacuum packaged frozen loin from crossbred black pigs reared on Jeju island, and frozen at $-20^{\circ}C$ for 1 month and 12 months, and then thawing them at $4^{\circ}C$ for 20 hours. In the case of loin that was thawed after freezing for 1 month, 2-TP showed a higher water holding capacity and myofibril fragmentation index, lower hardness and chewiness, as well as better juiciness and palatability than 0-TP. However, effects of chilling after thawing were not significant in the case of loin that had been frozen for 12 months.

Quality Characteristics of Sulgidduk Prepared with Added Freeze Dried-eggplant Powder (동결 건조한 가지 분말을 첨가한 설기떡의 품질특성)

  • Choi, Sang-Ho;Moon, Sook-Jeong;Lee, Mi-Kyung;Ahn, Jong-Sung
    • The Korean Journal of Food And Nutrition
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    • v.26 no.3
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    • pp.421-427
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    • 2013
  • The results of testing general components, physical property and physical function after having made steamed rice cake by adding eggplant, which caters to consumers' tastes are as follows. It showed that when eggplant powder content increased, the moisture content of steamed rice cake with eggplant was decreased. It also showed that the lightness value (L) of steamed rice cake with eggplant powder was the highest as 82.75 in the control group. When eggplant powder content increased, the redness (a) and yellowness (b) were increased. From the results of having measured the antioxidant potential over the steamed rice cake with freezing-drying eggplant powder by DPPH radical elimination, we figured out that it was the lowest as 48.30% in the control group. As more eggplant powder was added, its elimination increased accordingly. As per hardness of steamed rice cake with eggplant, the added group with 7% was revealed as the highest at 0.757. It showed that adhesiveness was the lowest as 30.233 in the control group, and springiness and cohesiveness were on the rise as freezing-drying eggplant powder was increased. Furthermore, softness and chewiness were shown to be high in the added group with eggplant powder of 3, 5%. The evaluation over the overall preference was the highest in 5% added group. Judging from this, adding 3~5% eggplant powder against non-glutinous rice powder is considered an optimal quantity in making steamed rice cake with eggplant.

Weathering of Rock Specimens Exposed to Recurrent Freezing and Thawing Cycles (동결-융해 풍화에 의한 암석 물성 변화 양상과 추정에 관한 연구)

  • Ryu, Sung-Hoon;Song, Jae-Joon
    • Tunnel and Underground Space
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    • v.22 no.4
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    • pp.276-283
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    • 2012
  • Changes in rock properties due to freezing and thawing cycles ranging from $-20^{\circ}C$ to $10^{\circ}C$ were checked for the typical Korean rocks: granite (weathered), limestone, sandstone, tuff, shale and basalt. The porosity, seismic velocity, shore hardness and specific gravity were measured every 10 cycles for each type of rock up to 40 cycles. The specific gravity was rarely changed. Granite (w), shale and basalt decreased gradually in their shore hardness and seismic velocity values, these values for limestone, sandstone and tuff changed only a very little. The porosity increased in the granite (w), shale and basalt, whereas in the others it did not change. Due to the low tensile strength with high porosity, granite (w), shale and basalt were susceptible to the F-T cycles. A linear regression equation was calculated based on the experiment results according to properties and types of rock. The relationship between the freeze-thaw sensitivity (=initial porosity/initial tensile strength) and the coefficients of the regression equation was examined. With additional experimental data, the coefficients of the regression equation can be estimated using the F-T sensitivity. This makes it possible to predict the properties of rock as affected by freeze-thaw weathering by only measuring the initial properties without knowledge of the regression equation coefficients for each type of rock.

Freeze Drying of Lactic Acid Bacteria Fermented Food Prepared from Egg White Powder and Casein Supplemented with Growth Stimulating Agent (생육촉진물질이 첨가된 난백분말과 카제인으로 만든 젖산균 발효식품의 동결건조)

  • Ko, Young-Tae;Lee, Eun-Ju
    • Korean Journal of Food Science and Technology
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    • v.31 no.5
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    • pp.1337-1344
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    • 1999
  • Lactic acid bacteria fermented foods were prepared from egg white powder, casein and growth stimulating agent. pH change and growth of Lactbacillus acidophilus(KCTC 2182) during freeze drying were studied. The effects of freeze drying on sensory evaluation. hardness and volatile aroma compounds in freeze dried sample or reconstituted sample were also studied. Freezing and freeze drying did not affect pH of fermented samples. Number of viable cells in original fermented samples was markedly reduced during freezing or freeze drying. When number of viable cells in original fermented sampler was considered at 100%. survival ratio of viable cells after freezing was $72.0{\sim}82.4%$ and that after freeze dying $10.0{\sim}20.4%$. When sensory properties of original fermented samples were compared with those of freeze dried/reconstituted samples, sensory properties of original samples were generally better than those of freeze dried/reconstitute samples. However, the reconstitution property and the acceptability of freeze dried samples were good. Volatile aroma compounds in original fermented samples were reduced during freeze drying. The reduction degree of volatile aroma compounds varied with sample.

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Material Characteristics and Application Efficiency of Treatments for Usuki Stone Buddha Statues in Japan (일본 우스키 석불군의 재질특성과 보존처리제 적용 효과)

  • Lee, Myeong Seong;Lee, Jae Man;Lee, Sun Myung;Kim, Sa Dug;Morii, Masayuki
    • Korean Journal of Heritage: History & Science
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    • v.44 no.3
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    • pp.78-91
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    • 2011
  • The Usuki Stone Buddha Statues in Japan are carved on mainly dark gray welded lapilli tuff accompanied by lenticular fiamme. This rock is composed of matrix which contains feldspar and opaque minerals with some phenocrysts of quartz and feldspar. The matrix is slight to highly welded. The statues have been weathered and weakened by salt and freezing of water. To enhance the mechanical properties of the rock, consolidants and water repellents were applied. The absorption ratio of the rock was highly decreased after the treatment of the water repellents, the consolidant OH 100, as well. Ultrasonic velocity revealed similarly higher values in the treated rock by KSE 300 and OH 100, compared to non-treated rock. KSE 300, especially, highly increased the Equotip surface hardness. All studied consolidants and water repellents were found to change the original color of the stone. SNL, specifically, resulted the significant change in color. In addition, KSE 300 were observed to improve resistance to weathering such as microcrack and fracture through freezing-thawing test after treatment.

The Effects of the Ash Content in Flour on the Rheological Properties of Frozen Dough (밀가루의 회분 함량이 냉동 생지 반죽의 물성에 미치는 영향)

  • Kim, Seok-Young;Han, Jae-Heung;Song, Young;Lee, Si-Kyung
    • Applied Biological Chemistry
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    • v.46 no.1
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    • pp.39-45
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    • 2003
  • This study was conducted to investigate the effect of ash contents of bread flour on the rheology of frozen dough In making frozen dough by measuring amylograph, flrinograph and extensograph. The quality of frozen-stored dough under freezing condition ($-20^{\circ}C$, 12 weeks) was evaluated by measuring final proof time, moisture content, baking loss, loaf volume and hardness of bread with storage time. In bread flour with high ash content farinogram showed that water absorption, degree of softening increased but valorimeter value decreased. In bread flour with low ash content amylogram showed that gelatinization temperature and maximum viscosity increased and extensogram showed that the area and resistance of the bread flour increased. As the proof time increased the extensibility decreased. Final proof time of frozen dough was shortened at the bread flour with low ash content with storage time. In bread using the flour with high ash content, moisture content, increased but baking loss rate decreased while the hardness of product increased slowly with time. But in bread using the flour with low ash content, the loaf volume of baking increased but the hardness of product decreased. As the frozen storage time was shortened, the product was more stable and better in quality.

Novel Porous Materials Prepared by Repeated Directional Crystallization of Solvent (용매의 반복 방향성 결정화를 통해 제작된 새로운 다공성재료)

  • Kim, Hyun Jin;Lee, Jonghwi
    • Polymer(Korea)
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    • v.39 no.1
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    • pp.151-156
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    • 2015
  • Herein, novel porous structures were fabricated from monomer solutions of dimethylsiloxane and benzene by directional crystallization in twice. First, a honeycomb-like structure was fabricated by $1^{st}$ directional crystallization of solvent. By infiltration of the solution and subsequent $2^{nd}$ directional crystallization, novel structures of different pores in the honeycomb-like structure were fabricated. The porous materials prepared by the repeated directional crystallization have higher indentation modulus and hardness than those of the samples prepared by single directional crystallization. When a higher solution concentration was used in $2^{nd}$ directional crystallization, the maximum increase (indentation modulus: 2140% increase, indentation hardness: 2330% increase) was obtained. On the other hand, porosity and contact angle were lower in the samples from $2^{nd}$ directional crystallization than those from $1^{st}$ directional crystallization. A large decreases was observed, when a relatively high concentration was used in $2^{nd}$ directional crystallization (porosity: 21% decrease, contact angle: 36% decrease).

The Effect of Vitamin C on Properties of the Breads Made by Dough Frozen after 1st Fermentation (1차 발효 후 냉동생지를 이용한 빵의 특성에 미치는 비타민 C의 영향)

  • Lee, Jeong-Hoon;Choi, Doo-Ri;Lee, Si-Kyung;Min, Sang-Gi
    • Korean Journal of Food Science and Technology
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    • v.35 no.1
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    • pp.92-96
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    • 2003
  • Effects of vitamin C on the properties of bread including number of yeast cells, volume of bread, specific loaf volume, and hardness and sensory characteristics were evaluated. Vitamin C was added at various amounts to frozen doughs made through sponge &dough method using sweet dough formula and quickly frozen at $-40^{\circ}C$. Doughs were stored for 4 weeks at $-20^{\circ}C$. Evaluations were done after frozen dough was thawed, fermented, and baked every week. The bread with 150 ppm vitamin C revealed higher yeast cell survival rate during freezing storage, and higher specific and bread volumes than other doughs. Hardness of bread increased with increasing amount of vitamin C added. Bread with 100 ppm vitamin C revealed the highest sensory score. Consequently, addition of 100 ppm vitamin C to bread dough resulted in the highest overall evaluation.