• Title/Summary/Keyword: drying index

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A study on the Shrinkage Properties of precast concrete using Calcium hardening accelerator (칼슘계 경화촉진제를 사용한 프리캐스트 콘크리트의 수축특성에 관한 연구)

  • Min, Tae-Beom;Jo, In-Seong;Lee, Han-Seung
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2014.11a
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    • pp.44-45
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    • 2014
  • On this study, initial crack index was evaluated by performing FEM analysis to crack propagation from hydration heat for development of precast concrete. On the result, as increased the usage of hardening accelerator, initial compressive strength were improved and setting time also was shortened. Additionally, central temperature of concrete was increased, the reaching time for the highest temperature could be shortened. By the result to assess crack index, there was no problem about crack despite of growth of initial high hydration heating. This result guessed because of small size element when analyzed trough FEM, realization for mass concrete's crack index should be performed.

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Slaking Characteristics of shale in the Gyoungsang Super-group, Korea (경상누층군 셰일의 내구성 특성)

  • Park, Sung-Sik;Ye, Sung-Ryol;Kim, Gyo-Won
    • The Journal of Engineering Geology
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    • v.26 no.3
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    • pp.315-324
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    • 2016
  • Because of a fissility characteristics of shale in the Gyoungsang super-group, it breaks down to debris when daylighted by construction work and causes a slope unstability. To assess the durability property of shale, a series of slake durability tests was conducted by controlling test conditions such as shape of specimen, number of specimen, revolution speed, revolution number, drying temperature and pH of submerging liquid. For the specimen shape, cube one showed relatively lower durability index than cuboid and/or fan shape one. The test with the more number of specimens showed the less durability index because of a higher friction among specimens in the drum. The durability index is linearly decreased by increasing the total number of revolution, while the revolution velocity could not affect the index. And the durability index is also decreased by increasing the drying temperature of specimen and by decreasing the pH of submerging liquid. Because the durability index of shale is almost similar to that of crystalline rocks, the disintegration characteristics of shale could not be assessed by the slake durability test recommended by ISRM, and thus a new test method by changing the total revolution number may be required for the shale having fissility characteristics.

Evaluation of the tributaries by influence index on the mid-lower portion of the Nakdong River basin

  • Lee, Shun-Hwa;Jung, Seung-Gyu;Park, Seoung-Muk;Lee, Byung-Dae
    • Environmental Engineering Research
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    • v.23 no.2
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    • pp.150-158
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    • 2018
  • The deteriorating role of Nakdong River due to the Four Major Rivers Project has caused a series of problems, including water pollution, drying streams, aggravation of the hydroecology. Geumho River and Gyeongseong-cheon had a higher concentration index and is believed to impact the water quality of the main stream. The influence index of Geumho River and Nam River between 2015 and 2016, which have a large amount of discharge, was the highest among the tributaries in terms of the load material balance. Showing the highest average concentration and average load in the index assessment, Geumho River is believed to require an intensive management for improving the water quality of the main stream. Furthermore, when the cumulative percentage of the average concentration and average load was compared based on the water quality improvement of the tributaries mixed to Nakdong River, which was set to 60%, Geumho River, Nam River, Topyeong-cheon, and Cha-cheon, which showed the highest ratio in that order, were determined to require a water quality management program as a priority.

Reological Studies on Cocoon Filament III. Stretching Strength and Elasticity Index of Cocoon Filament in Stretching Transformation (견사의 탄성적 성질에 관한 연구 III. 신장변형과정에 있어서의 인장강도 및 Elasticity Index에 대하여)

  • 남중희
    • Journal of Sericultural and Entomological Science
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    • v.15 no.1
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    • pp.31-35
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    • 1973
  • Strength, elongation and elasticity are essential properties with regard to the tensile properties of raw silk thread. The reasonable harmony of the above three physical characters appears to be the specific nature of the raw silk thread and the dynamical functions are determined by the cocoon filament forming the raw silk. From such viewpoint, the author has studied the tensile property of the thread when the cocoon filament is stretched and transformed. The results obtained are as follows: 1) The stretching strength of the inner layer filament is stronger than that of the outer and medium layer ones. 2) The stretching strength of the filaments is influenced by the moisture-heat denaturalization of cocoon layer sericin in the drying process. 3) The more transformed functions by the stretching become, the lower the elasticity index of the cocoon filament was shown. 4) When cocoon layer sericin is denatured by moisture and heat, elasticity index of the filament is decreased.

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Effects of Processing Parameters of Twin Screw Extruder and Dry Methods on the Resistant Starch Formation from Normal Maize Starch (압출성형공정과 건조조건이 옥수수전분의 저항전분 수율에 미치는 영향)

  • Shin, Mal-Shick;Mun, Sae-Hun;Bae, Chun-Ho
    • Korean Journal of Human Ecology
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    • v.5 no.1
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    • pp.62-70
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    • 2002
  • The objective of this study was to evaluate the effects of processing parameters of co-rotating twin screw extruder and dry methods on the level of resistant starch (RS) and the properties of extrudate prepared from normal maize starch. The processing parameters were used 90, 110, 130$^{\circ}C$ in temperature, 25.0~30.0% in moisture content, 150, 200, 250 rpm in screw speed and hot and cool air drying and drying after refrigerating in drying methods. The barrel temperature and drying methods had affected the level of resistant starch of extrudate. RS levels of extrudates were ranged from 2.4 to 15.5% by AOAC method. The extrudates, extruded at 110$^{\circ}C$ and then stored at 4$^{\circ}C$, showed the highest level of RS level (15.5%). Water absorption index increased with increasing moisture content and peak temperatures and viscosities of extudates decreased compare to that of raw starch from 94$^{\circ}C$ to 50~65$^{\circ}C$ and from 220 to 46~98 RVU, respectively. Extudates treated in 90$^{\circ}C$ and 110$^{\circ}C$ showed strong peak at $2{\theta}=6.7{\sim}17.0^{\circ}$ by X-ray diffractometry and had ~150$^{\circ}C$ endotherm like as that of RS3 starch by differential scanning calorimetry. In case of 130$^{\circ}C$, extrudates showed strong peak at $2{\theta}=20.0^{\circ}$ and had 106$^{\circ}C$ endotherm.

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Preparation and Sensory Properties of Semi-dried Israeli Carp Cyprinus carpio (향어(Cyprinus carpio)를 활용한 반건제품의 제조 및 관능 특성)

  • Lee, Chang Yong;Park, Si Hyeong;Park, Ye Eun;Choe, Yu Ri;Lee, Seok Min;Oh, Seon Hwa;Kim, Jin-Soo
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.55 no.2
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    • pp.121-128
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    • 2022
  • The aims of this study were to optimize the processing procedure of high-quality semi-alternating temperature dried Israeli carp Cyprinus carpio (SAD-IC) and to investigate the sensory properties of the product. Based on the differences in moisture content of the dorsal and ventral muscles, high quality SAD-IC was prepared by alternating the drying temperature between 4 h at 35℃, and 2 h at 5℃, three times before final drying for 2 h at 35℃. The surface in SAD-IC produced under the optimal alternating-temperature drying process had a markedly superior browning index value and softer texture compared to products produced using constant-temperature drying. SAD-IC produced from dorsal and ventral muscle had significantly superior taste values than the raw material. These results suggest that SAD-IC has the potential to be industrialized.

The Comparative Study of Quality by Processing Methods of Liriope platyphylla (한국산(韓國産) 맥문동(麥門冬)의 포제방법(炮製方法)에 따른 품질(品質) 비교(比較) 연구(硏究))

  • Cho, Eun-Hwan;Roh, Seong-Soo;Seo, Young-Bae;Jeong, Gi-Hoon
    • The Korea Journal of Herbology
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    • v.25 no.4
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    • pp.95-102
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    • 2010
  • Objectives : Specifications by Processing Methods of Liriope platyphylla (LP) was not established in korea. We carried out method study for manufacture of LP. Above all, LP were purchased and were processed at four kinds. First group had hearts of swelling roots, not cut bodies(LP-A). Second group had not hearts of swelling roots, not cut bodies(LP-B). Third group had hearts of swelling roots, cut bodies(LP-C). Forth group had an aggregate of hearts of swelling roots(LP-D). Methods : We has gained losses on drying, contents of ethanol-soluble extracts, contents of water-soluble extracts and contents of spicatoside A. Results : 1. Losses on drying of all group were less than 18% that is a standard of chinese pharmacopoeia. 2. Contents of ethanol-soluble extracts at LP-C, LP-D were included more than contents of those in the other groups in significance levels. 3. Contents of water-soluble extracts at LP-A, LP-C were included more than contents of those in the other groups in significance levels. 4. Contents of spicatoside A in LP-B were included more than content of spicatoside A in the other groups in significance levels. Resultingly, standards of LP in korea were proposed compatible proposals suggested as below. 1. Losses on drying of LP were less than 15% that is less than that of chinese pharmacopoeia. 2. Form to boil in water must be cutting body with heart of swelling root. 3. Because there is no content of spicatoside A in heart of swelling root, it is not suited to purpose a index component. Conclusions : The subjects of loss on drying and form of LP to boil in water must be contained in korean pharmacopoeia. Moreover, because of much valuable LP in food and medicine, it is urgently required aspect of index component such as spicatoside B, spicatoside C, flavonoid, polysaccharide having medical actions and so on.

Effects of Ramie Leaf according to Drying Methods on Antioxidant Activity and Growth Inhibitory Effects of Cancer Cells (건조방법에 따른 모시잎의 항산화 활성 및 암세포 증식 억제효과)

  • Kim, Ah-Ra;Kang, Su-Tae;Jeong, Eun;Lee, Jae-Joon
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.43 no.5
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    • pp.682-689
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    • 2014
  • This study was carried out to discriminate the effects of the ramie leaf according to the drying methods (hot air drying and freeze drying) on antioxidative activity in vitro and antiproliferation in human cancer cells. There were no significant differences in total polyphenol content of ramie leaf ethanol extracts depending on the drying methods, but total flavonoid content was significantly higher in hot air dried ramie leaf (HR) than in freeze dried ramie leaf (FR). The DPPH radical scavenging activity of HR and FR ethanol extracts were found to be 77.74%, and 77.29% in 1000 ppm, respectively. Antioxidative index of HR and FR ethanol extracts measured by Rancimat were lower than those in BHT, BHA, and ascorbic acid, but were higher than that in control. The antiproliferation effect of 80% ethanol extracts of HR and FR on liver cancer cell line (H460), stomach cancer cell line (AGS), and lung cancer cell line (A549) were increased with a dose-dependent manner. The cancer cell growth inhibition activities of HR and FR ethanol extracts at the concentration of $800{\mu}g/mL$ showed greater than 80% on Hep G2 and A549 cell line, and greater than 75% on AGS cell line. These results suggest that HR and FR ethanol extracts possess potential antioxidative effect and antiproliferation in human cancer cells, and those activities of ramie leaf ethanol extracts depending on the drying methods were similar.

Production of Bone Broth Powder with Spray Drying Using Three Different Carrier Agents

  • Haluk, Ergezer;Yeliz, Kara;Orhan, Ozunlu
    • Food Science of Animal Resources
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    • v.38 no.6
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    • pp.1273-1285
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    • 2018
  • The aim of this study is to determine the some physicochemical (proximate composition, pH and $a_w$ values) and reconstitution (wettability, dispersibility and solubility index (SI)) properties of spray-dried bone broth powder (BBP) along with the effects of the addition of different carrier agents. Subsequently, the powdered products were stored to determine the storage stability (pH, lipid oxidation, color, browning index) for 3 mon at $-18^{\circ}C$. For this purpose, firstly marrow-containing bones (Os femur and Os humerus) have been boiled to get the bone broth. Three different emulsions were respectively prepared (1) 20% maltodextrin (MD) added BBP, (2) 20% whey powder isolate (WPI) added BBP and (3) 10% MD and 10% WPI added BBP and the emulsions were dried using a spray-dryer with $185^{\circ}C$ inlet and $95^{\circ}C$ outlet temperature. The proximate composition and reconstitution properties of BBP were found statistically different (p<0.05) depending on the use of different carrier agents. MD added BBP showed uniform and smooth morphology. The color, browning index, thiobarbituric acid reactive substances (TBARS) and pH values of BBP significantly changed (p<0.05) during storage. In conclusion, both the results of physicochemical and storage period analyses showed that the most suitable encapsulation material in the production of the bone broth powder is MD.

Evaluation of the Wear Comfort of Outdoorwear by Skin Wettedness Analyses (Skin Wettedness 분석을 통한 아웃도어웨어의 착용 쾌적성 평가)

  • Jeong, Jeong-Rim;Kim, Hee-Eun
    • Fashion & Textile Research Journal
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    • v.11 no.6
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    • pp.947-952
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    • 2009
  • The purpose of this study is to analyze skin wettedness($w$) used as the rate index of thermal comfort, and to evaluate the wear comfort of outdoorwear. Skin wettedness is widely used to express the degree of thermal comfort. If skin wettedness exceeds a certain threshold, the body feels damp and discomfort. An experiment which consisted of rest(30 min), exercise(30 min) and recovery(20 min) periods was administered in a climate chamber with 10 healthy male participants. Two kinds of outdoorwears made of 100% cotton fabrics (Control) and specially engineered fabrics having feature of quick sweat absorbency and high speed drying fabric (Functional) were evaluated in the experiment. The condition of climate chamber was controlled according to the thermal insulation of 4 kinds of experimental ensembles(E1~E4). Total sweat loss, sweat loss absorbed into clothing and skin temperature were measured. Skin wettedness was calculated from the ratio of evaporative rate to the maximal evaporative capacity. Skin wettedness of 'Functional' was lower than 'Control' in the 3 kinds of ensembles(E1, E2, E4) because the materials of 'Functional' were composed of quick sweat absorbency and high speed drying fabrics, water vapour permeability and waterproof fabrics.