• Applied Biological Chemistry
• /
• v.34 no.3
• /
• pp.258-261
• /
• 1991

In order to establish the optimum drying temperature of the heated air blast-grain circulation dryer, a 2 ton scale of paddy was used in this experiment. The temperatures of heated air used were 45, 50, 55, 60, 65 and $70^{\circ}C$. Moisture content of the paddy was reduced to 15% from 24% by drying. The higher air temperature, the shorter drying time and the less fuel consumed. The portion of cracked kernels was found to be low as $3{\sim}10%\;at\;40{\sim}55^{\circ}C$, but was very high to $28{\sim}30%\;at\;60{\sim}70^{\circ}C$. The germination percent was very high as 98 and 93% at 40 and $45^{\circ}C$, but it was decreased to 86 and 30% at 50 and $70^{\circ}C$, respectively. The recovery yield of milled rice from paddy was decreased by 1.76, 2.63 and 7.52% at 60, 65 and $70^{\circ}C$, respectively, compared with 75.86% as drying at $40^{\circ}C$. The higher heated air temperature, the less head rice of milled rice was recovered, and the decreased ratio was increased $60^{\circ}C$. The higher heated air temperature, the less alkali disintergation value and gel consistency of milled rice and the more water up take, expanded vlume, total solid in residual liquid and intensity of starch iodine blue value of residual liquid, and those tendency was found clear from $60^{\circ}C$ temperature of heated air.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.33 no.2
• /
• pp.729-737
• /
• 2013

The environmental load of concrete pavement can be categorized by temperature and moisture loads, which mean temperature distribution, and drying shrinkage and creep in the concrete slab. In this study, a method calculating the environmental load essential to mechanistic design of airport concrete pavement was developed. First, target area and design slab thickness were determined. And, the concrete temperature distribution with slab depth was predicted by a pavement temperature prediction program to calculate equivalent linear temperature difference. The concrete drying shrinkage was predicted by improving an existing model to calculate differential shrinkage equivalent linear temperature difference considering regional relative humidity. In addition, the stress relaxation was considered in the drying shrinkage. Eventually, the equivalent linear temperature difference due to temperature and the differential shrinkage equivalent linear temperature difference due to moisture were combined into the total equivalent linear temperature difference as terminal environmental load. The environmental load of eight civilian and two military airports which represent domestic regional weather conditions were calculated and compared by the method developed in this study to show its application.

• Journal of the Korean Electrochemical Society
• /
• v.27 no.1
• /
• pp.40-46
• /
• 2024

Among the electrode manufacturing processes for lithium-ion batteries, the drying process is crucial for production speed and process cost. Particularly, as the loading level of the electrode increases to enhance the energy density of the battery, optimizing process conditions for electrode drying becomes more critical. In this study, we compared the drying time and electrochemical performance of the positive electrode prepared at different drying temperatures. LiNi_0.6Co_0.2Mn_0.2O₂ (NCM622) was used as the active material and manufactured under various drying temperature conditions ranging from 120 ℃ to 210 ℃ at loading levels of 2.5 and 4.5 mAh cm^-2. The physical and electrochemical properties of the electrodes were compared. As the loading level of the electrode increases, the drying time of the electrode also increases, but this time can be reduced by increasing the drying temperature. The drying temperature used in manufacturing the NCM622 positive electrode does not significantly affect the electrochemical performance but drying above 210 ℃ resulted in an increase in the volume resistivity of the electrode and a decrease in electrochemical performance. Accordingly, in the manufacture of high-loading electrodes, the drying temperature was increased to 190 ℃ to shorten the electrode manufacturing time without a loss of performance.

• Fire Science and Engineering
• /
• v.31 no.3
• /
• pp.73-78
• /
• 2017

In this paper, the fire risk using a bimetal type thermometer for construction installation is presented. Because construction equipment is used widely in the field and the site is exposed to explosions and fire by combustible gas or fume, strong restrictions on the structure and usage are applied. Moreover, the risk of fire increases as precise temperature measurements are poorly conducted via an inner temperature sensor inside construction furnace. Therefore, this paper presents the results of structural analysis of a bimetal temperature sensor which is used widely in construction installation and temperature measurement experiments relative to the material property of the target object. The results revealed the relatively precise temperature of the liquid object, whereas those of the gas and solid object showed a lower temperature compared to the real temperature. This shows that bimetal-type temperature sensor is more suitable for measuring a liquid state object than measuring a gas or solid state object.

• Proceedings of the Korean Society for Bio-Environment Control Conference
• /
• 1999.11a
• /
• pp.204-208
• /
• 1999

농산물의 적정 건조온도는 대상작물에 따라서 다르지만, 건조온도를 적정수준으로 유지하고 건조시간을 단축하기 위하여 기계식 건조가 많이 이용되고 있다. 이것은 건조시간의 단축뿐만 아니라 노동력도 상당히 절약할 수 있는 장점을 가지고 있으나 연료비의 불안정과 자원의 한계성 때문에 태양열을 비롯한 대체 에너지를 이용하는 연구가 꾸준히 이루어지고 있다. (중략)

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
• /
• 2003.10a
• /
• pp.214.1-214
• /
• 2003

본 연구는 4~6개월의 유아들을 위하여 재수화시킨 후 숟가락으로 떠먹일 수 있도록 쌀을 기본으로 하고 당근, 쇠고기 및 계란을 각각 주재료로 한 냉동건조 이유식 제조의 최적조건을 결정하기 위하여 수행되었다. 본 연구에서 얻어진 결과를 요약하면 다음과 같다. 당근, 쇠고기 및 계란이유식에서 모두 냉동건조시간은 수분함량이 높고 가열판 온도가 낮을수록 증가하였다. 파쇄성은 수분함량이 감소하고 가열판온도가 증가함에 따라 증가하였다. 관능적 특성 중 수화속도, 균질성 및 매끄러운 정도는 수분함량이 증가하고 가열판 온도가 감소할수록 증가였고, 뜨기 쉬운 정도는 수분함량이 증가할수록 증가하였으나, 가열판온도의 영향은 거의 받지 않았다. 또한 피막형성성은 수분함량과 가열판온도가 증가할수록 증가하였다. 이유식 제조치 최적조건은 당근이유식의 경우 수분함량 88.5%와 가열한 온도 34$^{\circ}C$로, 쇠고기이유식에서는 수된함량 88.5% 와 가열판온도 28$^{\circ}C$로, 그리고 계란이유식에서는 수분함량 87.5%와 가열판 온도 39$^{\circ}C$로 결정되었다.

• Korean Journal of Food Science and Technology
• /
• v.43 no.6
• /
• pp.696-701
• /
• 2011

To evaluate the processing adaptability of taro flours, the physicochemical properties of taro flour with different drying, roasting and steaming conditions were investigated. The moisture content and total dietary fiber were decreased as temperature increased with hot-air drying. Freeze-dried taro flours showed the highest vitamin C contents. Taro flours made by freeze-drying and hot-air drying showed significantly higher total dietary fiber content than those with roasting and steaming process. Steamed taro flours had the highest water absorption index, while hot-air dried and freeze dried taro flours had the highest water solubility index. No differences were displayed in the differential scanning calorimetry (DSC) thermal characteristics among hot-air dried and freeze dried taro flours. Roasted taro displayed decreased onset temperature and peak temperature as roasting temperature increased. Using a rapid visco-analyzer, the peak viscosity, through viscosity, and final viscosity of dried and steamed taro flours were higher than roasted taro flours, whereas the set back value, which is a prediction of retrogradation, decreased with steaming processing. From those results, it could be concluded that hotair dried taro flours, which have high gelatinization viscosity, are beneficial in imparting viscosity to dough products and hot-air drying after steaming taro flours, which retard retrogradation, is good for porridge and flake base products.

• Korean Journal of Food Science and Technology
• /
• v.21 no.5
• /
• pp.655-661
• /
• 1989

Optimal drying conditions consisting of air temperature and relative humidity were searched by the simulation-optimization technique for minimizing quality changes in red pepper drying. Optimized drying conditions were analysed in the viewpoint of quality change kinetics and effects of control variables on the state variables. Optimal drying conditions were nearly same in both cases for carotenoid maximization and browning minimization. In two staged optimized drying, relative humidity took a lower search limit of about 10%, and air temperature in the first stage was near the lower limit of $50^{\circ}C$ and in second stage increased to a higher temperature varying with total drying time and stage changing time. Response surface analysis of time invariable drying confirmed the location of the optimal point lying on the vertex of lower limit humidity and a lowest drying temperature which ensures to attain target moisture of 0.2g water/g dry solid. Two stage drying can attain the higher objective function of quality by 3-5% than time invariable drying for shorter total drying times.

• Food Science and Preservation
• /
• v.22 no.4
• /
• pp.505-511
• /
• 2015

This study was performed to investigate the effect of drying temperature on the quality characteristics and antioxidant activity of blueberry. Blueberries were dried at different times and temperatures, including A ($40^{\circ}C$, 72 hr), B ($40^{\circ}C$, 48 h and $50^{\circ}C$, 24 hr), C ($50^{\circ}C$, 72 hr), and D ($60^{\circ}C$, 72 hr). The yield and pH ranges of blueberry were determined to be 17.73~31.17% and 3.20~3.25, respectively. The yield rate of A treatments, soluble solid of D treatments, was the highest. The yield rate and soluble content was the highest in the treatment of A and D, respectively. The moisture content and water activity were significantly decreased with the increase in drying temperature (p<0.05). The L value of A treatment, and a and b values of D treatment were the greatest. In the analysis of texture analyzer, hardness, springiness, cohesiveness, gummiess and chewiness were significantly increased with the increase in drying temperature (p<0.05). In the sensory evaluation of blueberry, the appearance and color were the highest in the A treatment. The moisture, texture and taste was highest in the B treatment. The overall acceptability was in the order of B > A > C >D. The total polyphenol content and DPPH radical-scavenging activity were 9.21~13.05 mg/GAEg and 61.90~81.42%, respectively, which were significantly decreased with the increase in drying temperature (p<0.05). Therefore, the optimum time and temperature for blueberry drying was founded to be B treatment ($40^{\circ}C$, 48 hr and $50^{\circ}C$, 24 hr) among other treatments.

• Applied Biological Chemistry
• /
• v.38 no.1
• /
• pp.78-82
• /
• 1995

A microcomputer drying system, which could be designed to be operated easily and economically, was developed. The optimum drying conditions with this system for onion and ginger were obtained. The temperature, relative humidity, and weight of material were measured and controlled successfully, and the better quality of products was obtained. Optimum drying condition for onion was $65^{\circ}C$ and 25% RH, and for ginger was $50^{\circ}C$ and 25%, respectively.