• Journal of Biosystems Engineering
• /
• v.12 no.3
• /
• pp.50-56
• /
• 1987

중규모 벼농가에서의 벼건조 및 저장을 위하여, 한국형 개량곳간(크기: $1.8{\times}2.4m$, 높이 : 3.2m, 규모 : 2-4 M/T)을 개발하였다. 송풍기(0.5마력) 및 공기유도닥트를 부착하여 건조 및 aeration이 가능하도록 하였으며, 저장중 양곡손실을 최소한 줄이기 위해 방서용철망, 환풍창 및 구판들을 설치하였다. 그리고 양곡의 입출고가 용이하도록 내리닫이쪽문을 설치하였다. 개발된 개량곳간을 이용하여 1981년, 1982년, 1983년 가을에 각각 수확한 물벼를 수확즉시 건조하였을 때, 기후조건, 수확시기, 수확시의 수분함량, 풍량, 송풍시간, 곳간내에서의 벼의 높이 등에 따라서 차이는 있으나 상온 통풍에 의하여 벼를 잘 건조할 수 있었다. 그리고 건조조건에 따라서 건조양상은 달랐으나 180~352시간의 건조시간이 소요되었으며, 연속 상온통풍에 의하여 건조된 벼의 품질은 비교적 양호하였다.

• Proceedings of the Korean Society of Marine Engineers Conference
• /
• 2011.06a
• /
• pp.298-298
• /
• 2011

• Proceedings of the Korean Society of Marine Engineers Conference
• /
• 2011.06a
• /
• pp.299-299
• /
• 2011

• Horticultural Science & Technology
• /
• v.28 no.3
• /
• pp.492-496
• /
• 2010

This experiment was carried out to obtain the maximum quantity of essential oil on the basis of harvesting time, cultivation regions & types, and drying methods. We have selected 6 native and introduced herbs viz. $Thymus$ $quinquecostatus$, $Agastache$ $rugosa$, $Chrysanthemum$ $indicum$, $Rosmarinus$ $officinalis$, $Chamaemelum$ $nobile$, and $Lavandula$ $stoechas$. The quantity of essential oil ranged from 0.06% to 3.46% in all six herbs. Native herbs produce 30.5% higher quantity of oil in comparison to introduced herbs. The quantity of essential oil obtained from $Lavandula$ $stoechas$ was 3.46%, followed by $Rosmarinus$ $officinalis$ 2.89%, while minimum in $Agastache$ $rugosa$ 0.60%. Higher quantity of essential oil obtained if they are cultivated under rain shelter culture (PE film) in comparison to open field conditions. Recovery of essential oil is always high if herbs flower in July. Semi-alpine region was found better than the plain region for herbs production. Quantity of oil is high if oil is extracted from fresh herbs followed by freezed herbs, shade dry and hot wind dry herbs. As far as plant part is concern flower produced maximum oil than any other part.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.43 no.6
• /
• pp.884-892
• /
• 2014

The purpose of this study was to investigate the drying characteristics and drying models of Ainsliaea acerifolia Sch. Bip. using far-infrared thin layer drying. Far-infrared thin layer drying test on Ainsliaea acerifolia Sch. Bip. was conducted at two air velocities of 0.6 and 0.8 m/sec, as well as three drying temperatures of 40, 45, and $50^{\circ}C$ respectively. The drying models were estimated using coefficient of determination and root mean square error. Drying characteristics were analyzed based on factors such as drying rate, leaf color changes, antioxidant activity, and contents of polyphenolics and flavonoids. The results revealed that increases in drying temperature and air velocity caused a reduction in drying time. The Thompson model was considered suitable for thin layer drying using far-infrared radiation for Ainsliaea accerifolia Sch. Bip. Greenness and yellowness values decreased and lightness values increased after far-infrared thin layer drying, and the color difference (${\Delta}E$) values at $40^{\circ}C$ were higher than those at $45^{\circ}C$ and $50^{\circ}C$. The antioxidant properties of Ainsliaea acerifolia Sch. Bip. decreased under all far-infrared thin layer drying conditions, and the highest polyphenolic content (37.9 mg/g), flavonoid content (22.7 mg/g), DPPH radical scavenging activity (32.5), and ABTS radical scavenging activity (31.1) were observed at a drying temperature of $40^{\circ}C$ with an air velocity of 0.8 m/sec.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.22 no.2
• /
• pp.401-408
• /
• 2021

Supplies of wood chips for fuel tend to increase owing to energy decentralization and new renewable energy policies. This study suggests a technical method that is necessary in order to supply heating energy to rural regions by using wood chips for fuel. Therefore, this study investigates the effects of natural drying methods for eight months by installing a drying facility with natural ventilation capable of loading 10 tons of wood chips, and which derive a natural drying method based on this to meet the quality standards of wood chips for fuel. The study results confirm that it is possible to produce wood chips for high-quality fuel with water content at 20% or less after around 90 days of drying, provided that a drying facility with natural ventilation is equipped with materials that can be procured easily in rural regions. It is also possible to block the proliferation and fermentation of molds that affect the quality of wood chips, provided that intake and exhaust systems adhering to standards are equipped.

• Korean Journal of Food Science and Technology
• /
• v.27 no.3
• /
• pp.387-393
• /
• 1995

Diffusion coefficients of moisture and solid, reaction rate constants of carotene destruction, and the fitness of drying models for moisture transfer were determined to study the characteristics of mass transfer during osmotic dehydration. Moisture loss and solid gain were increased with increase of temperature and concentration; temperature had higher osmotic effect than concentration. Diffusion coefficient showed similar trend with osmotic effect. Diffusion coefficients of solids were larger than those of moisture because the movement of solid was faster than that of moisture at the high temperature. Reaction rate constants were affected to the greater extent by concentration changes than by temperature changes. Arrhenius equation was applied to determine the effect of temperature on diffusion coefficients and reaction rate constants. Moisture diffusion required high activation energy in $20^{\circ}Brix$, while relatively low in $60^{\circ}Brix$. To predict the diffusion coefficients and reaction rate constants, a model was established by using the optimum functions of temperature and concentration. The model had high $R^2$ value when applied to diffusion coefficients, but low when applied to reaction rate constants. Quadratic drying model was most fittable to express moisture transfer during drying. In conclusion, moisture content of carrots could be predictable during the osmotic dehydration process, and thereby mass transfer characteristics could be determined by predicted moisture content and diffusion coefficient.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.10 no.4
• /
• pp.112-117
• /
• 2002

This study was conducted to induce the optimal composting conditions of pig manure mixed with sawdust and dried paper-mill sludge in the composting for production of high quality compost. Pig manure contains high water content and How C/N ratio because of comparatively high nitrogen content than sawdust and dried paper-mill sludge. Therefore the addition of dried paper-mill sludge and sawdust to the raw materials helps controlling the C/N and the water content of compost pile. The composting system used in the experiment was agitated static bed system. The physical properties of the mixed raw materials was not good at the working conditions in the early stage of composting. The temperature of compost heap reaches at $60^{\circ}C$within 5 day after starting composting in P-2 treatment mixed with pig manure and sawdust(56.6 : 43.4). Then the water content of P-2 was 58%. The pH in all treatments were slowly decreased as the composting was proceeded. Although the changes of T-C and T-N were not extended because of the short composting experiment period. Reduction rates of T-C in treatments were 5-12% without special difference. By considering the efficiency of composting in each of five treatments with pig manure the optimal water contents was about 57% level. Mixing a sawdust as a bulking agent was more positive than dried paper-mill sludge from a viewpoint of compost quality.

• Food Science and Preservation
• /
• v.22 no.1
• /
• pp.1-11
• /
• 2015

Raspberries are a good resource of polyphenols and have a powerful antioxidant activity, but shelf life for raspberries is short which brings a lot of economic losses. In this study, we try to use cool-air ($20{\sim}40^{\circ}C$) or hot-air ($60{\sim}100^{\circ}C$) to produce semi-dried raspberries with extended shelf life, and to determine the best method for improving fruit quality by minimizing nutrient losses during drying processes. The effects of process variables (drying temperature and processing time) on the quality of final dried raspberries were investigated. Response surface methodology was employed to establish statistical models for simulating the drying processes, and the moisture residue content and the loss ratios of total phenolic content (TPC), vitamin C (VC), and ellagic acid (EA) that result from the drying processes of raspberries using either hot or cool-air were predicted. Superimposed contour plots have been successfully used in the determination of the optimum zone within the experimental region. Optimal conditions determined for achieving minimal losses of TPC, VC, and EA, and a final moisture residue of 45% using the hot-air drying process were a drying temperature of $65.75^{\circ}C$ and a processing time of 4.3 hr. While for the cool-air process, the optimal conditions predicted were $21.3^{\circ}C$ and 28.2 hr. Successful application of response surface methodology provided scientific reference for optimal conditions of semi-drying raspberries, minimizing nutrient losses and improving product quality.

• Proceedings of the Korean Society for Agricultural Machinery Conference
• /
• 2002.07a
• /
• pp.233-240
• /
• 2002

표고버섯의 재배는 농촌 부업뿐만 아니라 농한기의 노동력 이용면에서 유리하고, 영양학적으로 혈압강하물질, 빈혈치료물질, 제암물질 등이 함유되어 있음이 밝혀져 영양식품, 또는 건강식품으로 그 진가를 더욱 평가받게 되었으며 주로 동양에서 많이 소비되었으나 서양에서도 소비가 증가하여 수요는 날로 증가하고 있어 표고재배 사업의 전망은 매우 밝다(이, 1982). 그러나 아직까지 고품질 버섯의 생산이나 버섯의 상품성을 높이기 위한 연구들은 미흡한 실정이다. 국내의 표고버섯은 생산량의 50% 이상이 건조되어 유통되므로 표고버섯의 건조특성에 관한 연구는 필수적이며 특히 건조 뿐 아니라 가공 및 저장의 가장 기초적인 자료로 이용되는 평형함수율에 관한 명확한 구명이 요구된다. (중략)