• Title/Summary/Keyword: Volume of pores

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Qualitative Characteristics of Jeung-Pyun Following the Addition of Lotus Leaf Powder (연잎가루 첨가량에 따른 증편의 이화학적, 관능적 특성)

  • Kim, Sung-Hyang;Park, Geum-Soon
    • Journal of the East Asian Society of Dietary Life
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    • v.20 no.1
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    • pp.60-68
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    • 2010
  • This study was conducted to evaluate the effects of lotus leaf powder on the qualitative characteristics of Jeung-Pyun (traditional Korean fermented rice cake). To achieve the highest volume and specific volume, 4% lotus leaf powder was required. However the moisture content dropped as the lotus leaf powder was added to the mixture. In addition, pH of Jeung-Pyun decreased the longer it was allowed to ferment, but the pH increased after steaming. We also evalusted the transparency of Jeung-Pyun as lotus leaf powder was added. As the lotus leaf powder was added, the L-value decreased and the a-value and b-value increased. Additionally, the hardness, chewiness and brittleness of Jeung-Pyun increased as more lotus leaf powder was added (p<0.05), but the springiness and cohesiveness did not change. The Jeung-Pyun also became darker and the cells became less uniform as the level of lotus powder increased. A control group of Jeung-Pyun without lotus leaf powder produced the strongest takju flavor, while the sourness decreased as more lotus leaf powder was added. The addition of 2% and 4% lotus leaf powder resulted in the chewiest and most flexible Jeung-Pyun. The results of this evaluation showed that Jeung-Pyun with 4% lotus leaf powder had the best appearance, flavor, texture, and taste, and was generally the most preferred Jeung-Pyun. Finally, SEM evaluation of the Jeung-Pyun, revealed that, higher levels of lotus leaf powder resulted in larger and less consistent pores and bubbles.

Adsorption Characteristics of Charcoals of Major Korean Wood Species and Wood-based Materials (국산 주요 수종 및 목질재료 탄화물의 흡착 특성)

  • Kong, Seog-Woo;Kim, Byung-Ro
    • Journal of the Korean Wood Science and Technology
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    • v.30 no.4
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    • pp.33-40
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    • 2002
  • This research was to investigate the adsorption characteristics of charcoals of major Korean wood species (thinned trees) and wood-based materials. As carbonization time and temperature increased, methylene-blue adsorption (MBA) of charcoals of thinned trees and wood-based materials increased. Pinus koraiensis charcoal showed the highest MBA. MBA of softwoods was higher than that of hardwoods. There was a negative correlation between air-dried specific gravity before carbonization and MBA of carbonized thinned trees. The MBA of wood-based materials showed similar value, but wood-based materials in MBA was lower than thinned woods. Surface area and total pore volume of thinned trees and wood-based materials increased as carbonization temperature increased. The species showing highest MBA appeared to have the highest surface area at the carbonization temperature of 600℃ as well. There was a positive correlation between surface area, total pore volume and MBA of charcoals. The charcoal of wood-based materials generally exhibited micro pores.

Quality Characteristics of Domestic Wheat White Bread with Substituted Nelumbo nucifera G. Tea Powder (백련차 분말을 대체한 우리밀 식빵의 품질 특성)

  • Kim, Young-Sook;Kim, Mun-Yong;Chun, Soon-Sil
    • The Korean Journal of Food And Nutrition
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    • v.21 no.4
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    • pp.448-456
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    • 2008
  • In this study, domestic wheat white breads were prepared with the substitution of 1.5, 3.0, 4.5, and 6.0% Nelumbo nucifera G. tea powder(NNTP). The samples and a control were then compared with regard to quality characteristics, including pH, total titratable acidity, fermentation power of dough expansion, specific volume, baking loss, moisture content, color, textural characteristics, external and internal surface appearances, and sensory qualities in order to determine the optimal ratio of NNTP in the formulation. As the NNTP contents increased, the pH of dough and bread, baking loss, and lightness decreased, whereas the total titratable acidity of dough and bread increased. The fermentation power of dough expansion increased with increasing incubation time. The NNTP samples evidenced significantly higher specific volume, greenness, yellowness, resilience, and crumb consistency than were observed in the control group. However, hardness and fracturability evidenced the opposite effect. The water content and uniformity of the crumb pores were highest at a substitution level of 1.5%, and were lowest at a level of 4.5%. Crumb color, flavor, and delicious taste decreased with increasing NNTP contents, whereas lotus leaf flavor, astringency, bitterness, and off-flavor increased. Density of the crumb pore and crumb springiness were not significantly different among the samples. Softness, chewiness, and overall acceptability were maximal with the 1.5% substitution, and were minimal in the 6.0% group. In conclusion, our results demonstrate that $1.5{\sim}3.0%$ NNTP may prove quite useful as a substitute for domestic wheat flour in the production of white bread, and may evidence favorable nutritional and functional properties.

A Study on the Durability of PCM Mixed Concrete for the Reduction of Cold and Hot Damage (혹한·혹서 피해 저감용 PCM 혼입콘크리트의 내구성에 관한 연구)

  • Hoyeol Kim;Il Young Jang
    • Journal of the Society of Disaster Information
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    • v.20 no.2
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    • pp.390-397
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    • 2024
  • Purpose: In this study, PCM was used to give thermal performance to concrete and analyze its effect on durability to prevent disasters that may occur in concrete when exposed to hot and cold environments. Method: After preparing concrete specimens containing 10, 30, and 50% of the two types of PCMs compared to the cement volume, the pore volume, freeze melting resistance, and scaling resistance were evaluated. Result: Regardless of the type, when PCM powder was mixed with concrete, the amount of pores decreased, and when 10% and 30% were mixed, the freeze-melting resistance was also improved. It was also confirmed that the higher the mixing amount, the better the scaling resistance. Conclusion: When mixing powdered PCM into concrete, it is believed that durability can be improved to a certain level by the filling effect, and additional various studies should be supported for actual field application.

Characteristics of Pore Structures and Compressive Strength in Calcium Leached Concrete Specimens (칼슘이 용출된 콘크리트의 공극 구조 및 강도 특성)

  • Yang, Eun-Ik;Choi, Yoon-Suk
    • Journal of the Korea Concrete Institute
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    • v.23 no.5
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    • pp.647-656
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    • 2011
  • In radioactive waste repositories constructed in underground, concrete member could be in contact with groundwater for a long time. However, this pure water creates concentration gradients which lead to the diffusion of Ca ions from the pore water and the degradation of underground concrete. Therefore, this study is aimed at investigating the alteration of pore structure and loss of compressive strength associated with dissolution. The results showed that as the leaching period became longer, the pore volume within 50 nm to 500 nm in diameter is greatly increased. Also, the volume of pores larger than 200 nm rapidly increased during initial leaching time and those below 200 nm gradually increased. Furthermore, the compressive strength gradually decreased with increase of degraded thickness. The residual strength of the degraded concrete with OPC was in the range of 33% to 58%.

Variation of the Physical-microstructural Properties of Sandstone and Shale Caused by CO2 Reaction in High Pressure Condition (고압 이산화탄소 반응에 의한 사암과 셰일의 물리적-미세구조적 변화)

  • Park, Jihwan;Son, Jin;Park, Hyeong-Dong
    • Tunnel and Underground Space
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    • v.26 no.4
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    • pp.293-303
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    • 2016
  • Underground $CO_2$ storage technology is one of the most effective methods to reduce atmospheric $CO_2$. In this study, $CO_2$ storage condition was simulated in the laboratory. Sandstone and shale specimens were saturated in 1M NaCl and were reacted at $45^{\circ}C$, 10 atm for 4 weeks. The physical and microstructural properties of rock specimens were measured. Variations on physical properties of shale specimens were bigger than those of sandstone specimens, such as volume, density, elastic wave velocity, Poisson's ratio and Young's modulus. Microstructure were analyzed using X-ray computed tomography. Total number of pores were decreased, and average volume, average area and average equivalent diameter of each pore were changed after $CO_2$ reaction. Swelling and leakage of clay mineral caused by $CO_2$-mineral reaction were the reason of changes. The results of this study can be applied to predict the physical and microstructural changes in underground $CO_2$ storage condition.

Preparation of Lightweight Aggregate Using Glass Abrasive Sludge and Effects of Pores on the Aggregate Properties (유리연마슬러지를 사용한 경량골재 제조 및 골재의 내부기공이 물성에 미치는 영향에 관한 연구)

  • Chu, Yong-Sik;Lee, Jong-Kyu;Shim, Kwang-Bo
    • Journal of the Korean Ceramic Society
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    • v.42 no.1
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    • pp.37-42
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    • 2005
  • Lightweight aggregate was made using glass abrasive sludge and graphite in this study. This study tried to draw the correlation between lightweight aggregate's properties and internal pore. The precursor was made by added different graphite contents and was burned for 20 min. at $700^{circ}C$ and $800^{circ}C$. The volume change of aggregate was checked at before and after homing, and confirmed that the homing temperature effected more than expanding agent on volume change. The size and area of pore in aggregate increased according to the amount of expanding agent and homing temperature but it didn't bring about big effect above $1\%$ of expanding agent. The absorbtion ratio, thermal conductivity and porosity have a high correlation, so each coefficient of correlation showed above $0.8\pm$.

NAPL Removal from Contaminated Soil Using Steam Injection (스팀주입에 의한 토양내 NAPL 제거 실험)

  • Lee, Sang-Il;Jang, Yeon-Su;Kim, Seon-Gi
    • Journal of Korea Water Resources Association
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    • v.30 no.5
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    • pp.459-465
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    • 1997
  • The possibility of NAPL removal from contaminated soil was studied using the steam injection technique. Both single (octane, toluene and xylene) and composite NAPL (gasoline) were used as contaminant. Soils used in this study were Chumunjin fine sand and weathered granitic soil, both of which are commonly found in Korea. Experimental results showed that with 1 pore volume steam injection, the NAPL removal rate was in the range of 66∼78% for sand and 45∼73% for weathered granitic soil. The steam injection technique seems to have high potential for soil remediation with advantages of relatively short operating time and no side-effect. Rise in the background temperature led to the delay of steam condensation and the increase of NAPL mobility, which resulted in the improvement of removal efficiency. In addition, water flooding after steam injection turned out to be a very efficient way of removing NAPL residual in the soil pores.

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Studies on the Pore of Coating Layer and Printability(III) -Effects of Properties of Latices on Pore of Coating Layer- (도공층의 공극과 인쇄적성에 관한 연구(제3보) -라텍스의 특성이 미치는 영향-)

  • 이용규;김창근
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.33 no.2
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    • pp.41-48
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    • 2001
  • This paper was made to evaluate the effect of the type of latex for coating on the printability by investigating the structure of pore such as the pore fraction, the number of pores, pore size and distribution of coated paper. The coated structure is mainly depend on the results of interaction between pigment and binder. It means that the structure of pore formed is chiefly affected by the type of latex. This physical properties of pore have a close relation with ink set-off associated with the drying rate, the speed of penetration of ink into base paper and printing gloss. Therefore it was necessary to find out the relationship between pore structure and the performance of printability by modifying the type of latex to vary the pore structure of coated paper. Acrylic latex was superior to S/B latex in the sedimentation volume, compressibility, smoothness, pore fraction and its number, the weight of transferred ink onto the coated paper and ink repellance. In contrast, water retention and ink setting were not good. in the comparison of anionic and amphoteric latex, amphoteric latex showed better performance in the thickness, smoothness, pore fraction and its number, pore size, the weight of ink transmitted and K&N ink receptivity, etc.

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Preparation, characterization of activated carbon fiber from luffa and its application in CVFCW for rainwater treatment

  • Ahmed, Sanjrani Manzoor;Zhou, Boxun;Zhao, Heng;Zheng, You Ping;Wang, Yue;Xia, Shibin
    • Membrane and Water Treatment
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    • v.11 no.2
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    • pp.151-158
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    • 2020
  • ACF preparation from different materials has been attached with great attention during these years. This study was conducted to prepare activated carbon fiber (ACF) from luffa through the processes i.e pre-treatment, pre-oxidation and carbonization activation. Besides, this study also characterizes the ACF and its effect, i.e effect of pre-oxidation time and temperature also activation time and temperature on the compressive strength of ACF were investigated. The results from SEM, BET, FTIR and XRD show that the ACF is very efficient. The products under the optimum conditions had a specific surface area of 478.441 m2 /g with an average pore diameter of 3.783nm, and a pore volume of 0.193 cm3 /g. The surface of the luffa fiber is degummed and exposed, which is beneficial to the subsequent process and the increase of product properties. The compressive strength of HP-ACF was prepared under the optimum conditions, which can reach 0.2461 MPa. ACF is rich in micro-pores and has a good application prospect in the field of environmental protection.