• Journal of Ginseng Research
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• 제9권2호
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• pp.248-255
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• 1985

In order to investigate the optimal drying condition of white ginseng by using bulk air drier(130 x 62 x 65cm), drying curves, diffusion coefficient at various drying temperature, the energy of activation, variation of color intensity and chemical components during drying of white ginseng were studied. Fick's second low of diffusion for diffusion out of spheres was successfully applied to describe the drying of white ginseng. It was found that the diffusion coefficient of water was 2.2x107, 9.0x107 cm2/sec at drying temperature 4$0^{\circ}C$, 55$^{\circ}C$, respectively. An Arrhenius type temperature dependency of moisture diffusivity was found, the energy of activation being 18.8 Kcal/g mol. Color intensity of white ginseng dried at various drying temperature was increased with an increase in drying temperature. The contents of crude protein, reducing sugar and crude saponin during drying of white ginseng were gradually decreased as increasing of drying time. And with the sensory evaluation by multiple comparison difference analysis, the optimal drying temperature of white ginseng was between 45$^{\circ}C$ and 5$0^{\circ}C$.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2009년도 춘계 학술대회 제21권1호
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• pp.407-408
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• 2009

건조수축은 콘크리트 구조물의 내구성에 큰 영향을 미친다. 이러한 건조수축을 예측하기 위하여 여러 가지 모델들이 실험적으로 제시되고 있다. 본 연구에서는 콘크리트 강도와 양생조건에 따른 건조수축을 측정하여 대표적인 모델코드와 그 특성을 비교하였다. 실험결과 물-시멘트비가 작아질수록 건조수축량은 감소하였고, 4주간 습윤 양생한 경우 전체수축이 크게 저하하였다. 예측 모델과 실험결과를 비교할 때 EC2 모델과 가장 잘 일치하였다.

• 한국식품저장유통학회지
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• 제10권4호
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• pp.476-481
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• 2003

아가리쿠스 버섯에 있어 각 온도별 건조 품질을 살펴보았다. 우선 갓과 대의 건조시간은 5$0^{\circ}C$에서 모두 29시간이었으며 10$0^{\circ}C$의 경우 갓과 대 모두 10시간 소요되었으며 실온에서 음건할 때에는 갓과 대가 모두 3일 정도 소요되었다. 수분감소율은 온도가 높을수록 켰으며, 부위별로는 5$0^{\circ}C$에서 초기감소율이 갓보다 대가 크게 나타났으며 최종수분함량은 갓이 대보다 적었다. 반면에 10$0^{\circ}C$와 실온에서 갓의 수분감소율이 켰으며, 최종수분함량은 갓이 적었다. 수분활성도는 갓과 대가 모두 실온에서 음건, 5$0^{\circ}C$, 10$0^{\circ}C$의 순으로 낮았다. 수화복원력은 갓과 대 모두가 건조온도와는 관계없었으며, 실온에서 침지 120분까지 급격히 증가하여 이때에 최대치를 나타내었다. 색도는 갓에서의 전체적으로 건조 온도가 상승함에 따라 백색도를 나타내는 L 값이 낮아지는 것으로 조사되었다. 세부적으로는 L 값이 5$0^{\circ}C$에서의 시료가 가장 높았고 생것이 가장 낮았다. a 값은 생시료가 가장 높았고, 10$0^{\circ}C$ 건조시료가 가장 낮았다. b 값은 10$0^{\circ}C$에서 건조시료가 가장 높았고 생것이 가장 낮았다. 갈변도는 건조온도가 높을수록 높았으며 갓이 대보다 켰다. 이는 온도 상승이 건조 아가리쿠스의 품질을 저하한다는 것을 보여주었다. 관능검사결과 건조온도가 상승함에 따라 색과 외관품질이 떨어지는 것으로 조사되었다. 하지만 향에 있어서 건조 온도가 5$0^{\circ}C$이상에서 전체적으로 좋은 향이 나오는 것으로 확인되었다 결과적으로 5$0^{\circ}C$의 건조온도에서 아가리쿠스를 열풍 건조하는 것이 경제적 뿐만 아니라 품질면에서 가장 좋은 조건이라 조사되었다. 뿐만 아니라 아가리쿠스의 약리성분들은 열에 강한 특성이 있으므로 5$0^{\circ}C$에서 건조하여도 충분히 기능성 및 약리성에 영향이 없을 것으로 사료되었다. 하지만 앞으로 아가리쿠스의 약리성분을 중심으로 조에 온도에 따른 영향을 조사하여 적정온도를 결정할 수 있는 연구가 필요하리라 생각된다.

• 한국농공학회지
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• 제17권1호
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• pp.3677-3684
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• 1975

A newly devised dryer with heated air for the farm products, especially suited for high water content materials such as red pepper, Beer ground, each Vegetables, and Low water content materials such as Rough rice was tested for its thermal efficiency and drying mechanism, and the optimum conditions for each sample were established. In order to improve the present rural situation of drying farm products which entirely dependent upon natural solar radiation, a study upon an economic multi-parpose dryer was conducted. A series of drying tests were run first with red pepper which is one of the important cash crop in Korean farm. And successive series of tests were also run with such proaucts as garlic, sweet potatoes, green onion, radish, Beer ground and Rough rice. The results from the above experiment in drying system with heat dryer can be summarized as follows. 1. Drying duration could be shortened by the tempering effect in high water content crop such as red pepper and beer ground. 2. The color changes occured in around 20% water content in red pepper. The degree of color change was heavily affected by high temperature and short drying duration. 3. The drying condition of red pepper was most favourable at the temperature of 85$^{\circ}C$ in early stage and 80$^{\circ}C$ in middle stage and 75$^{\circ}C$ at the final stage, and with the air rate of 0.81㎥/sec and with sample amount of 200kg. 4. The drying condition of Rough rice(I.R.667) was most favourable at the templature of 40$^{\circ}C$ in early stage and 35$^{\circ}C$ in middle stage and final stage and with the air rate of 0.2㎥/sec and with sample amount of 75kg. 5. In order to prevent the color change of red pepper and to assure high efficiency in drying mechanism, it was necessary to lower the temperature as the time passes in drying process. 6. For vege tables, the drying rate were short in early stage and there was also tempering effect. However, for garlics, Constant drying rates through the early and final stages were observed and there were no tempering effects. 7. The drying condition or capability were as follows; Sample drying temp($^{\circ}C$) amount of material(kg) drying time(hr) Red pepper 85 200 9 Garlic 85 150 7 Sweet potato 85 200 6 Green Onion 85 200 4 Carrot 85 200 4 Radish 90 250 4 Rough rice(I.R.667) 35 75 4 Beer ground 90 320 3 Considering the above result of experiments, if this kind of dryers were distributed Korean farm and the optimun process were practiced in rural area, it would certainly help them improving the qualites of their product preventing their undue losses, and thus assuring an increase of Korean farm income and promotion of their living standards.

• Journal of Advanced Marine Engineering and Technology
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• 제24권4호
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• pp.427-434
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• 2000

In tradition, there have been two kinds of drying methods, which are sun drying and artificial drying. The sun drying method which has been adopted traditionally has been replaced by the hot-air drying method which is one of the most general methods of artificial drying, with its simple drying system, low initial cost of drying plant, and easy operating method. But the hot-air drying method has some defects; (1) much energy loss happens due to the discharge of hot air during the drying process, (2) control of drying rate is not easy on account of changing relative humidity of inlet air for uniform hot air temperature, (3) high temperature of foods in drying process brings about the production of low-grade drying products. Vacuum drying takes advantage of energy saving and mass production because it reduces the drying time by increasing the drying rate under low temperature condition. The aim of this paper is to develop the low temperature vacum dryer, with low initial investments and operating costs, easy operating method and trouble-free operation.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2009년도 춘계학술대회 논문집
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• pp.53-56
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• 2009

과산화수소를 일원 추진제로 사용하는 추력기용 촉매의 건조 조건에 따른 성능 변화에 대한 실험을 수행하였다. 사용한 촉매는 백금이며 촉매 지지체는 펠렛 타입의 알루미나이다. 일반적인 촉매 제작 방법인 증발건조법을 사용하였으며, 이 때 건조 조건에 따른 촉매의 성능을 평가하였다. 촉매 제작 조건 중 pH 값이 낮은 경우 촉매 제작이 유리하였기 때문에 다양한 산성 용액에서 촉매를 담지 해 실험을 수행하였다. 건조 온도는 각각 25, 50, 70, $90^{\circ}C$이며 실험 결과 $90^{\circ}C$에서 건조한 경우 높은 성능을 보임을 알 수 있었다. 이는 빠른 증발속도로 인해서 백금이 결정화를 이루지 못하고 고르게 분산되었기 때문으로 판단된다.

• Food Science and Biotechnology
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• 제14권6호
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• pp.747-751
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• 2005

Microencapsulation of pine flavors was investigated to determine the optimum wall material and spray drying condition. ${\beta}$-Cyclodextrin, maltodextrin, and a 3:1 mixture of maltodextrin and gum arabic were evaluated as wall materials. The latter mixture was determined to be the best wall material based on dispersion capacity and flavor yield. Spray drying effectiveness was evaluated using a $3^3$ fraction factorial design and statistical analysis. The optimum operation condition was an inlet air temperature of $175^{\circ}C$, inlet airflow rate of $0.65\;m^3/min$ and atomizing pressure of 180 kPa, which resulted in a 93% flavor yield. The best particle shape observed by SEM was a round globular shape obtained under the above spray drying condition, whereas lower temperatures and higher inlet airflow rates resulted in initial and full collapses, respectively. The round globular shapes remained stable for at least one month.

• 농업과학연구
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• 제42권4호
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• pp.439-446
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• 2015

Kimbugak is one of Korea's traditional snacks made of laver. This study was conducted to investigate the physical drying and frying characteristics of kimbugaks made by a pasting & garnishing machine. The drying and frying characteristics should be analyzed to develop a continuous operation system for manufacturing kimbugak because kimbugak has a high moisture content after pasting process. Materials for pasting and garnishing on laver were rice gruel and sesame. The aluminum shelf with square hole was selected as a drying shelf. The recommended size of the square hole type was $1.5mm{\times}1.5mm$ because characteristics of deformation and easy separation from the shelf were excellent at the hole size. The drying time of 2 hours was also recommended with the drying temperature of $70^{\circ}C$ based on the test results such as dried condition (good), moisture conten t (3.7%), deformation (12.1 mm), and shrinkage rate (19.8%). As the frying conditions for dried kimbugaks, recommended oil temperature and frying time were $170^{\circ}C$, 15 seconds, respectively when corn oil was used. In the case of frying for undried kimbugaks, recommended oil temperature and frying time were $210^{\circ}C$, 2 - 3 minutes, respectively for improvement of work efficiency.

• 한국수산과학회지
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• 제15권3호
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• pp.207-210
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• 1982

갑오징어 우리나라에서 비교적 맏이 어획되어 대부분 천연건조에 의해 가공되고 있다. 갑오징어의 고정층 건조를 실시하여 건조 속도 및 Shirai식에 의한 건조 속도 상수 (k) 를 구하고, Arrhenius' plot에 의해 온도 의존성을 관찰하여 다음과 같은 결론을 얻었다. 1. 갑오징어의 수분 함량을 $40\%$이하로 낮추는데 본 실험의 경구 4시간이내가 소요되어 고정층 건조방법이 배등의 열풍건조법보다 효과적인 방법으로 판단된다. 2. 시료의 세분화, 껍질 제거, 열풍의 온도 상승 및 방향 조정 등으로 건조시간을 2시간으로 단축할 수 있었다. 3. 본 실험의 결과는 Shirai식과 Arrhenius' law에 잘 적용되었다.

• 한국염색가공학회지
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• 제7권4호
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• pp.33-38
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• 1995

In resist-discharge printing of cotton fabrics with reactive/reactive dyes the effects of intermediate drying on the white and the colored resist-dischargeabilities were studied. From the results of resist-discharge printing in case of 75% pick up, it was found that the most effective condition of intermediate drying which could at once prevent bleeding and improve the resist-dischargeability was 11$0^{\circ}C$ x 1min. The drying condition of 10$0^{\circ}C$ x 2min or 12$0^{\circ}C$ x 1min can be also recommended. It is important to pay close attention to the intermediate drying temperature and time. Because in case of 75% pick up when drying was carried on at 11$0^{\circ}C$ or 12$0^{\circ}C$ for more than 1 minute the resist-dischargeability was greatly lowerd by the fast fixation of ground color caused by high temperature, and in case of 100 % pick up the insufficient drying of ground color caused the resist-dischargeability to lower with giving rise to various troubles such as bleeding and smearing.