• 한국식품과학회지
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• 제31권3호
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• pp.631-637
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• 1999

떡국용 흰떡의 품질특성 시험의 일환으로 다양한 건조방법별로 흰떡을 제조하여 이화학적 특성을 조사하였다. 숙성시간은 흰떡의 수분함량, 수분흡수율과 고형분 용출량에 크게 영향을 미쳤지만, 국물의 혼탁도는 유의적인 차이가 나타나지 않았다. 저장온도에 따라서는 냉장저장시 수분흡수율과 고형분용출량이 가장 높았으며 냉동저장과 상온저장간에는 유의차가 나타나지 않았다. 마이크로파 처리한 시료가 고형분 용출량 및 국물의 혼탁도에서 가장 낮은 값을 보였으나 수분함량은 가장 높았다. 냉장저장한 시료가 가장 밝은 색도를 나타냈고 냉동저장 시료와 상온저장 시료간에는 유의차가 없었다. 숙성시간이나 건조방법에 따른 명암도의 차이는 없었다. 건조후 조리된 흰떡의 조직감은 숙성시간, 저장온도, 건조방법에 따라 차이를 보였으며, 숙성시간이 긴 것이 조직이 단단하였고 냉장저장 시료가 냉동저장이나 상온에 방치한 것보다 경도가 높았다. 마이크로파와 진공을 병행처리한 시료가 마이크로파 및 마이크로파에 열풍을 병행처리한 시료보다 경도가 높았다. 숙성시간은 흰떡의 관능적 특성에 크게 영향을 미쳤지만, 저장온도에 따라서는 경도, 쫀득성, 기호도에서 유의성이 나타나지 않았다. 건조방법에 따라서는 씹힘성을 제외한 모든 특성치에서 유의적인 차이가 나타났다. 미세구조에서는 마이크로파와 진공을 병행한 건조 방법이 표면을 매끄럽게 하면서 기공이 균일한 다공성 구조를 형성시켰다. 물성학적 특성 및 관능적 기호도 등 종합적인 견지에서 볼 때 진공 및 마이크로파를 병행한 건조 방법이 가장 우수함을 나타내었다.

• 한국세라믹학회지
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• 제45권11호
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• pp.662-666
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• 2008

Electrochemical properties of carbon cryogel electrode for the application of composite electrode materials mixed with metal oxide in supercapacitor have been studied. Carbon cryogels were synthesized by sol-gel polycondensation of resorcinol with form aldehyde, followed by a freeze drying, and then pyrolysis in an inert atmosphere. Physical properties of carbon cryogel were characterized by BET, X-ray diffraction (XRD) and scanning electron microscopy (SEM). It is found that carbon cryogel is amorphous material. The electrochemical properties of carbon cryogel were measured by cyclic voltammetry as a function of concentration of liquid electrolyte, galvanostatic charge-discharge with different scan rates and electrochemical impedance measurements. The result of cyclic voltammetry indicated that the specific capacitance value of a carbon cryogel electrode was approximately 150.2 F/g (at 5 mV/s in 6M KOH electrolyte).

• 한국지하수토양환경학회지:지하수토양환경
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• 제20권5호
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• pp.41-46
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• 2015

Three types of experiments, based on the physical properties of oily sludge landfilled soil, were conducted to recover total petroleum hydrocarbons (TPH) from the soil. These experiments included gravity separation, solvent extraction using water, and air floatation. The oil portion was not easily separated from the wet (raw) soil because water molecules aggregate the soil particles, despite the fact that the soil was sandy. However, the drying and grinding processes destroyed the aggregates, causing the TPH recovery to increase to approximately 60% when air floatation was used. The drying process decreased the specific gravity of the soil sample, thereby enhancing the overall recovery of TPH from the soil. Although thermal desorption and/or incineration are common choices for heavily dumped sites, physical separation can recover the oil portion instead of simply removing it.

• 한국지역사회생활과학회지
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• 제25권3호
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• pp.383-388
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• 2014

This study was examined the physical characteristics (geometry, yield strength, thousand-seeds weight, true density, and moisture content) required for mechanization-related technologies such as (harvesting, washing, transport, and drying). Large differences in the size and shape of boxthorn berries(Jangmyeong, Bullo, Chungmyeong, and Hokwang) are used to analyze these physical properties. The average diameter, volume, surface area, and sphericity rate are calculated using long and short diameters of the boxthorn berry according to its variety. Hokwang has the largest measured surface area, and Bullo, the smallest. Average yield strength is 1.78 kPa and the mechanical pressure of soft boxthorn berries is not more than 1 kPa. Bullo has the highest true density. The optimum drying time for the measurement of moisture content is 4 hours at the drying temperature of $100^{\circ}C$.

• 설비공학논문집
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• 제27권12호
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• pp.645-651
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• 2015

This paper presents an experimental study on the freeze drying process for poly ${\gamma}$ glutamic acid. The physical properties of poly ${\gamma}$ glutamic acid are measured during the freeze-drying process. The moisture contents of poly ${\gamma}$ glutamic acid according to the glass transient temperature are obtained by DSC (Differential Scanning Calorimetry) analysis. The end point of primary drying for the poly ${\gamma}$ glutamic acid with a thickness of 3 mm is obtained by measuring the thickness of the dried layer, the amount of moisture evaporation, the moisture content, and the pressure in the drying vacuum chamber during the freeze-drying process. By considering the variation in the glass transient temperature with respect to the moisture content of the material, a control schedule for the heating plate temperature is suggested during the secondary drying process.

• 한국식품과학회지
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• 제32권4호
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• pp.881-888
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• 2000

본 연구에서는 냉동건조에 의한 생균수 감소를 줄이기 위하여 첨가된 냉동건조보호제(Freeze Drying Protectant : FDP)가 우유 또는 난백분말로 만든 젖산균 발효식품의 품질(관능적 특성, 휘발성 향기 성분, 물성)에 미치는 영향을 조사하였다. 우유시료에는 0.2%의 Tween 80과 1%의 ascorbate를 각각 첨가하고, 난백분말시료에는 3%의 raffinose와 1%의 ascorbate를 각각 첨가하여 다음과 같은 결과를 얻었다. (1) 냉동건조시키지 않은 시료의 관능적 특성은 표준시료(우유시료)와 비교하여 ascorbate 첨가 우유시료는 관능적 특성이 다소 우수하였으나, 난백분말시료 또는 FDP 첨가 난백분말시료는 관능적 특성이 다소 저조하였다. (2) 냉동건조 후 복원시킨 시료의 관능성은 표준시료(우유시료)와 다른 5종의 시료 사이에 차이가 없었다. (3) Ascorbate 첨가 우유시료는 냉동건조/복원에 의하여 관능적 특성이 저하되었고, ascorbate 첨가 난백분말시료는 냉동건조/복원에 의하여 관능적 특성이 변화하지 않았다. (4) 휘발성 향기 성분의 분석 결과를 보면, 냉동건조에 의하여 모든 휘발성 향기 성분 함량이 감소하였으며, 우유시료군과 난백분말시료군 사이에는 회수율이 다소 다른 pattern을 보였다. (5) 휘발성 향기성분의 종류에 따라 다르지만 우유시료군과 난백분말 시료군의 휘발성 향기 성분 함량은 냉동건조 전에는 차이가 비교적 컸으나, 냉동건조/복원한 후에는 차이가 비교적 작았다. (6) 냉동건조에 의하여 우유시료군의 물성은 크게 변화하였으나, 난백분말시료군의 물성변화는 비교적 작았다.

• 폴리머
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• 제24권1호
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• pp.72-81
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• 2000

벤조산 폴리에스테르/락톤 폴리올의 합성은 디올로서 폴리카프로락톤 0201, 트리올로서 트리메틸올프로판, 2염기산으로서 아디프산 및 1염기산으로 벤조산을 사용하였다. 폴리이소시아네이트 프리폴리머는 HDI-biuret형인 Desmodur N-100을 사용하였다. 벤조산 폴리에스테르/락톤 폴리올, 폴리이소시아네이트, 안료, 습윤분산제 및 플로우개량제 등을 블렌드하여 2성분계 폴리우레탄 도료를 제조하였다. 제조된 폴리우레탄 도료로서 도막시편을 제작하여 각종 도막 물성시험을 행한 결과 KS 규격에서 제시한 기준치와 비교하여 내마모성, 촉진내후성, 황변도는 우수하게, 굴곡성, 내충격성, 60$^{\circ}$ 경민광택도, 접착력, 내유성, 명도지수차는 양호하게, 경도는 다소 나쁘게 나타났다. 따라서 디올로서 폴리카프로락톤 0201을 도입한 후 내유성, 굴곡성, 내충격성의 장점이 나타남을 확인하였다. 또한 벤조산 함량변화에 따른 고화 및 경화거동을 살펴 본 결과, 고화에 따른 건조시간은 2~4시간으로, 경화에 따른 가사시간은 20~37시간으로 각각 나타나, 도막표면의 고화 및 경화상태가 양호함을 보여주었다.

• 한국응용과학기술학회지
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• 제28권1호
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• pp.35-47
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• 2011

For the synthesis of water soluble acrylic modified epoxyester resin, fatty acid/epoxy ratio of 50/50 was used, and introduced maleic anhydride. Ratio of styrene/acrylic acid of acrylic monomers was fixed 85/15 and ratio of epoxyester/acrylic monomer was controlled 80/20, 75/25, 70/30, 65/35, and degree of neutralization were changed 65%, 80%, to 100%. As a result, 40% solids acrylic modified epoxyester resins were synthesized. Resins were evaluated water soluble stability, drying time, water resistant, storage stability and physical properties. And the white paints were prepared, and were evaluated viscosity, drying time, water resistance, adhesion, sagging, spray workability, gloss, salt spray resistance, skinning, whiteness and flash rust. As a result, the degree of neutralization of 100% and the ratio of epoxyester/acrylic monomer of 75/25 showed the best properties.

• 센서학회지
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• 제15권3호
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• pp.173-178
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• 2006

Silica aerogel with ultra low density and high porosity has been focused on versatile application due to its fascinating properties. Ambient drying process of waterglass, in this study was researched to fabricate a crack-free monolith body in the point view of cost effective way. Wet gel was obtained by removing of $Na^{+}$ ions in waterglass, which contains 8 wt% of $SiO_{2}$. Xylene, which has a low vapor pressure, was used as a solution substitutor to prevent the formation a cracks during drying. Various surface modifiers like as hexamethyldisilazane (HMDSZ), trimethylchlorosilane (TMCS), methyltriethoxylsilane (MTES), methyltrimethoxysilane (MTMS) and phenyltriethoxysilane (PTES) were used in order to improve hydrophobicity of the waterglass Silica aerogel. Some physical properties of the surface modified aerogels were investigated by FT-IR, TGA, BET and SEM. Hydrophobicity and hydrophilicity of Silica aerogel is attributed to the Si-OH bond and the non-polar C-H bond groups on the surface of aerogel. Crack-free waterglass aerogel with >90 % of porosity, 17 nm of pore size and <0.15 $g/cm^{3}$ of density was prepared. HMDSZ and TMCS are effective as a surface modifier

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2003년도 가을 학술발표회 논문집
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• pp.481-484
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• 2003

This study is intended to investigate application of mica waste(MS) to fine aggregate for mortar by comparing it with cement mortar in which crushed sand(CS) and river sand(NS) are used. According to the results, as the physical properties of aggregate, specific gravity is large in order of MS, NS and CS, absorption ratio in order of MS, CS and NS, and unit weight and solid volume percentage in order of NS, CS and MS. In the case of MS mortar, mechanical properties, drying shrinkage and heat conduction ratio are reduced, but the radiative amount of infrared light is excellent compared with NS mortar. Fluidity and unit weight of MS mortar is larger than those of CS mortar, and strength does not make differences. Length change by drying shrinkage is larger, but heat conduction ratio and radiative amount of infrared light are smaller than CS mortar. Thus, it proves that MS can be used in place of NS and CS, but its quality is deteriorated slightly.