• 제목/요약/키워드: drying index

검색결과 163건 처리시간 0.021초

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

  • 민태범;조인성;이한승
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2014년도 추계 학술논문 발표대회
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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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경상누층군 셰일의 내구성 특성 (Slaking Characteristics of shale in the Gyoungsang Super-group, Korea)

  • 박성식;예성렬;김교원
    • 지질공학
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    • 제26권3호
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    • pp.315-324
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    • 2016
  • 본 연구에서는 경상누층군 셰일에 대한 슬레이크 내구성 특성을 조사하기 위하여 다양한 인자 즉, 시료형태, 시료개수, 회전속도, 총 회전수, 건조온도 및 수침용액의 산도 등을 제어하면서 실험을 수행하였다. 실험 결과, 시료형태가 정육면체인 경우 가장 낮은 내구성 지수를 보였으며 부채꼴 시료가 가장 큰 내구성 지수를 보였고, 시료개수는 증가할수록 시료들 사이의 마찰이 증가하여 내구성지수가 감소하는 경향을 보였다. 회전속도는 영향이 거의 없는 것으로 나타났으나, 총 회전수가 증가할수록 내구성 지수는 직선적으로 감소하는 경향을 보였다. 또 시료 건조온도가 증가할수록, 수침용액의 산성도가 증가할수록 내구성 지수는 감소하였다. 대기 중에 노출되어 쉽게 풍화하는 특성 때문에 낮을 것으로 예상하였던 셰일의 내구성지수가 결정질 암석과 뚜렷한 차이가 없어서 기존의 실험법은 셰일의 장기적인 안정성을 평가하는데 부적합하다고 판단되어 교결도가 양호한 경상누층군 셰일의 장기적인 내구성 특성을 확인하기 위한 새로운 내구성 실험방법이 필요할 것으로 보인다.

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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    • 제23권2호
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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.

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

  • 남중희
    • 한국잠사곤충학회지
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    • 제15권1호
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    • pp.31-35
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    • 1973
  • 생사의 항장성에 관여하는 기본적인 성질은 강력 신도 및 탄성이다. 그리고 이들 3자간의 적당한 조화가 생사의 특성을 발현한다. 또 생사의 이러한 역학적 거동은 이를 구성하고 있는 견사가 지배하는 것이다. 이러한 견지에서 저자는 견사의 신장변형과정에서의 항장성에 관하여 연구하고 다음과 같은 결과를 얻었다. 1. 견층별견사의 인장강력은 내층견사가 외층 및 중층견사보다 높았다. 2. 견건조과정에 있어서 견층 sericin의 습열변성은 견사의 인장강력을 변화시킨다. 3. 신장과정에 있어서 견사의 변형량이 증가하면 elasticity index가 감소한다. 4. 다습열에 의한 견층 sericin의 변성은 견사의 elasticity 를 감소시킨다.

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

  • 신말식;문세훈;배천호
    • 한국가정과학회지
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    • 제5권1호
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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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향어(Cyprinus carpio)를 활용한 반건제품의 제조 및 관능 특성 (Preparation and Sensory Properties of Semi-dried Israeli Carp Cyprinus carpio)

  • 이창영;박시형;박예은;최유리;이석민;오선화;김진수
    • 한국수산과학회지
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    • 제55권2호
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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.

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) (The Comparative Study of Quality by Processing Methods of Liriope platyphylla)

  • 조은환;노성수;서영배;정기훈
    • 대한본초학회지
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    • 제25권4호
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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.

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

  • 김아라;강수태;정은;이재준
    • 한국식품영양과학회지
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    • 제43권5호
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    • pp.682-689
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    • 2014
  • 본 연구는 모시잎의 건조방법에 따른 항산화 및 암세포 증식억제효과를 비교 분석하였다. 80% 에탄올로 추출한 열풍건조 및 동결건조 모시잎의 총 폴리페놀 함량은 건조방법에 따른 유의적 차이를 보이지 않았다. 반면 총 플라보노이드 함량은 열풍건조 모시잎이 동결건조 모시잎에 비하여 유의하게 높게 나타났다. 1,000 ppm에서 열풍건조 및 동결건조 모시잎의 DPPH 라디칼 소거능은 각각 77.74%와 77.29%의 비슷한 라디칼 소거능을 보였으며, Rancimat으로 측정한 열풍건조 및 동결건조 모시잎의 항산화지수는 각각 1.38과 1.32로 BHT, BHA 및 비타민 C에 비해서는 낮았으나 시료를 미첨가한 음성대조군보다는 높은 항산화력을 보였다. 위암(AGS), 간암(Hep G2) 및 폐암(A549) 세포에 대한 모시잎 에탄올 추출물의 암세포 증식 억제효과를 알아본 결과, 열풍건조 및 동결건조 모시잎 에탄올 추출물의 농도가 증가할수록 암세포의 증식 억제 활성은 농도 의존적으로 증가되었다. 건조방법에 따른 항암활성은 비슷한 경향이었으며 가장 높은 농도인 $800{\mu}g/mL$에서 80% 이상의 간암 및 폐암세포의 증식 억제 활성을 보였고, 위암세포에서는 75%이상의 증식 억제 활성을 보였다. 이상의 결과 열풍건조 및 동결건조 모시잎 에탄올 추출물은 in vitro에서 항산화효과와 암세포의 증식 억제효과를 보였고, 건조방법에 따른 모시잎 에탄올 추출물의 항산화 활성 및 암세포 증식 억제 활성은 비슷한 경향으로 나타났다.

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

  • Haluk, Ergezer;Yeliz, Kara;Orhan, Ozunlu
    • 한국축산식품학회지
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    • 제38권6호
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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.

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

  • 정정림;김희은
    • 한국의류산업학회지
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    • 제11권6호
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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.