Variation during IR and heated-air drying process and effect on milling quality with moisture differenoe of paddy floe were investigated. The results indicate that the moisture SD （Standard Deviation） decreases duri...Variation during IR and heated-air drying process and effect on milling quality with moisture differenoe of paddy floe were investigated. The results indicate that the moisture SD （Standard Deviation） decreases during IR （Infrared RadiationS） and heated-alr （HA） drying process, and moisture uniform level for the paddy rice dried by IR treatment is higher than that by heated-air treatment. No matter IR or HA, the higher initial SD of MCs is, the bigger of the variable of the SDR value will be at the beginning stage of dried paddy storage.展开更多
Colour and moisture content are two most important attributes of the commercial food product.Estimation of moisture content is very important to know the storability of the food product.It also relates to the process ...Colour and moisture content are two most important attributes of the commercial food product.Estimation of moisture content is very important to know the storability of the food product.It also relates to the process of drying in a fruit or vegetable.Extra drying and shrinkage deteriorates the quality of food product.The goal of the experiment was to examine the changes in RGB values of an apple during drying at different temperatures.In this study,emphasis was given on how the colour changes when there is a significant change in the moisture content of the apple.Three randomly chosen varieties of apples were sliced to 8 mm thickness and dried in vacuum oven at 60°C,70°C,and 80°C.The loss of moisture was recorded for every 30 min interval and corresponding digital images were taken to determine the change in RGB value.The images that were captured during the study was analysed in MATLAB image analysis computer software.The analysis of moisture content and average colour share with respect to time showed that average colour share value decreases with time at all three temperatures.More than 50 per cent of variation in moisture content was explained by average colour share.There is a significant linear relationship between moisture content and colour changes in RGB and can be used to predict the moisture content of apple during drying process.展开更多
The moisture contents (MC) of popular veneers were tested in Composition Board Laboratory of Northeast Forestry University by contact drying with flexible screen. The influence factors considered included temperature,...The moisture contents (MC) of popular veneers were tested in Composition Board Laboratory of Northeast Forestry University by contact drying with flexible screen. The influence factors considered included temperature, initial moisture contents (IMC), and veneer thickness. Veneer-drying laws under different hot press conditions were analyzed. The results showed that the drying rate increased with temperature rising. 160°C was considered to be more efficient than 140°C and 180°C because excessive high temperature has no significant contribution to drying rate. IMC had significant effect on drying rate. The veneer with high IMC had a higher drying rate at above fiber saturation point (FSP) and a lower drying rate at below FSP, compared to the veneer with low IMC. Average drying rate also varied with thickness in power law.展开更多
This study was undertaken to investigate the drying characteristics of red and white varieties of onion (Allium cepa) in a convective dryer. The drying characteristics of onion slices were examined at air temperatures...This study was undertaken to investigate the drying characteristics of red and white varieties of onion (Allium cepa) in a convective dryer. The drying characteristics of onion slices were examined at air temperatures of 50℃, 60℃ and 70℃ and sample thicknesses of 2 mm. During the drying experiments, air velocity was held stable at 0.9 m/s. The effects of air temperature on the drying characteristics and quality parameters such as vitamins C and D, macro minerals (Mg, Na, P, Ca and K), non-enzymatic browning and thiolsulphinate of the dried onion slices were determined. For each of the plots of the drying curves from the mechanical drying tests, there was an absence of or just a very brief appearance of a constant rate period because onions are hygroscopic and hygroscopic foods tending to quickly enter the falling rate period;drying time decreased considerably with increased temperature. The time required to reduce the moisture content to any given value was dependent on the drying conditions, being the longest at an air temperature of 50℃, 0.9 m/s and the shortest at an air temperature of 70℃ and air velocity of 0.9 m/s. The loss of vitamin C, which is a thermo-sensitive compound, was the least at an air temperature of 50℃.展开更多
The characteristics of radiation and drying properties of TiO2 bulb in the fixed bed with infrared radiation have been studied in this paper, and the experiments on drying dynamics has been analysed also. The optimiz...The characteristics of radiation and drying properties of TiO2 bulb in the fixed bed with infrared radiation have been studied in this paper, and the experiments on drying dynamics has been analysed also. The optimization of heat and mass transfer data has been determined, which could provide the scientific basis for engineering design.展开更多
为使热红外遥感诊断土壤含水率更加准确、高效,以不同水分处理的大田玉米为研究对象,借助无人机可见光图像,对热红外图像进行植土分离,并提取玉米冠层温度和地表土壤温度。通过剔除温度直方图两端1%的温度像元对温度信息进行优化,进而...为使热红外遥感诊断土壤含水率更加准确、高效,以不同水分处理的大田玉米为研究对象,借助无人机可见光图像,对热红外图像进行植土分离,并提取玉米冠层温度和地表土壤温度。通过剔除温度直方图两端1%的温度像元对温度信息进行优化,进而计算作物水分胁迫指数(Crop water stress index,CWSI)、冠层相对温差(Canopy relative temperature difference,CRTD)、地表相对温差(Surface relative temperature difference,SRTD),利用三者之和求得水分温度综合指数(Water-temperature composite index,WTCI),并用于诊断不同深度的土壤含水率。结果表明,剔除温度直方图两端1%温度像元的玉米冠层温度与实测冠层温度的相关性更高(4次试验的R2由0.823、0.886、0.899、0.876提高至0.906、0.938、0.944、0.922),剔除温度直方图前端1%温度像元的地表土壤温度与实测地表温度的相关性也更高(2次试验的R2由0.841、0.875提高至0.908、0.925),即通过直方图法优化的温度更接近实测温度;在拔节前期,CWSI、WTCI诊断0~20 cm土壤含水率效果较优,而拔节后期、抽雄吐丝期、乳熟期诊断0~40 cm土壤含水率效果较优;在半覆盖条件下,包含冠层温度信息(CWSI、CRTD)和土壤温度信息(SRTD)的WTCI1与土壤含水率的相关性更高(0~40cm:决定系数为0.500、0.821,高于0.463、0.748);在全覆盖状态下,包含冠层相对温差(CRTD)的WTCI2与土壤含水率的相关性更高(0~40 cm:决定系数为0.809、0.729,高于0.721、0.656),表明WTCI是诊断土壤含水率效果较优的指标。展开更多
基金Young Cadreman Teachers of Education Ministry of Heilongjiang Province(2004)
文摘Variation during IR and heated-air drying process and effect on milling quality with moisture differenoe of paddy floe were investigated. The results indicate that the moisture SD （Standard Deviation） decreases during IR （Infrared RadiationS） and heated-alr （HA） drying process, and moisture uniform level for the paddy rice dried by IR treatment is higher than that by heated-air treatment. No matter IR or HA, the higher initial SD of MCs is, the bigger of the variable of the SDR value will be at the beginning stage of dried paddy storage.
文摘Colour and moisture content are two most important attributes of the commercial food product.Estimation of moisture content is very important to know the storability of the food product.It also relates to the process of drying in a fruit or vegetable.Extra drying and shrinkage deteriorates the quality of food product.The goal of the experiment was to examine the changes in RGB values of an apple during drying at different temperatures.In this study,emphasis was given on how the colour changes when there is a significant change in the moisture content of the apple.Three randomly chosen varieties of apples were sliced to 8 mm thickness and dried in vacuum oven at 60°C,70°C,and 80°C.The loss of moisture was recorded for every 30 min interval and corresponding digital images were taken to determine the change in RGB value.The images that were captured during the study was analysed in MATLAB image analysis computer software.The analysis of moisture content and average colour share with respect to time showed that average colour share value decreases with time at all three temperatures.More than 50 per cent of variation in moisture content was explained by average colour share.There is a significant linear relationship between moisture content and colour changes in RGB and can be used to predict the moisture content of apple during drying process.
文摘The moisture contents (MC) of popular veneers were tested in Composition Board Laboratory of Northeast Forestry University by contact drying with flexible screen. The influence factors considered included temperature, initial moisture contents (IMC), and veneer thickness. Veneer-drying laws under different hot press conditions were analyzed. The results showed that the drying rate increased with temperature rising. 160°C was considered to be more efficient than 140°C and 180°C because excessive high temperature has no significant contribution to drying rate. IMC had significant effect on drying rate. The veneer with high IMC had a higher drying rate at above fiber saturation point (FSP) and a lower drying rate at below FSP, compared to the veneer with low IMC. Average drying rate also varied with thickness in power law.
文摘This study was undertaken to investigate the drying characteristics of red and white varieties of onion (Allium cepa) in a convective dryer. The drying characteristics of onion slices were examined at air temperatures of 50℃, 60℃ and 70℃ and sample thicknesses of 2 mm. During the drying experiments, air velocity was held stable at 0.9 m/s. The effects of air temperature on the drying characteristics and quality parameters such as vitamins C and D, macro minerals (Mg, Na, P, Ca and K), non-enzymatic browning and thiolsulphinate of the dried onion slices were determined. For each of the plots of the drying curves from the mechanical drying tests, there was an absence of or just a very brief appearance of a constant rate period because onions are hygroscopic and hygroscopic foods tending to quickly enter the falling rate period;drying time decreased considerably with increased temperature. The time required to reduce the moisture content to any given value was dependent on the drying conditions, being the longest at an air temperature of 50℃, 0.9 m/s and the shortest at an air temperature of 70℃ and air velocity of 0.9 m/s. The loss of vitamin C, which is a thermo-sensitive compound, was the least at an air temperature of 50℃.
文摘The characteristics of radiation and drying properties of TiO2 bulb in the fixed bed with infrared radiation have been studied in this paper, and the experiments on drying dynamics has been analysed also. The optimization of heat and mass transfer data has been determined, which could provide the scientific basis for engineering design.
文摘为使热红外遥感诊断土壤含水率更加准确、高效,以不同水分处理的大田玉米为研究对象,借助无人机可见光图像,对热红外图像进行植土分离,并提取玉米冠层温度和地表土壤温度。通过剔除温度直方图两端1%的温度像元对温度信息进行优化,进而计算作物水分胁迫指数(Crop water stress index,CWSI)、冠层相对温差(Canopy relative temperature difference,CRTD)、地表相对温差(Surface relative temperature difference,SRTD),利用三者之和求得水分温度综合指数(Water-temperature composite index,WTCI),并用于诊断不同深度的土壤含水率。结果表明,剔除温度直方图两端1%温度像元的玉米冠层温度与实测冠层温度的相关性更高(4次试验的R2由0.823、0.886、0.899、0.876提高至0.906、0.938、0.944、0.922),剔除温度直方图前端1%温度像元的地表土壤温度与实测地表温度的相关性也更高(2次试验的R2由0.841、0.875提高至0.908、0.925),即通过直方图法优化的温度更接近实测温度;在拔节前期,CWSI、WTCI诊断0~20 cm土壤含水率效果较优,而拔节后期、抽雄吐丝期、乳熟期诊断0~40 cm土壤含水率效果较优;在半覆盖条件下,包含冠层温度信息(CWSI、CRTD)和土壤温度信息(SRTD)的WTCI1与土壤含水率的相关性更高(0~40cm:决定系数为0.500、0.821,高于0.463、0.748);在全覆盖状态下,包含冠层相对温差(CRTD)的WTCI2与土壤含水率的相关性更高(0~40 cm:决定系数为0.809、0.729,高于0.721、0.656),表明WTCI是诊断土壤含水率效果较优的指标。
