Effects of Discharge Fan on the Drying Efficiency in Flat-bed type Dryer
— The study of interaction among the grain, moisture, and the surrounding space (air) is key to understanding the grain-drying process. In Iran, rice (mostly Indica type) is dried by flat bed type dryer until the final MC reaches to 6 to 8%. The experiments were conducted to examine the effect of application of discharge fan with different heights of paddy on the drying efficiency. Experiments were designed based on two different configurations of the drying methods; with and without discharge fan with three different heights of paddy including; 5, 10, and 15 cm. The humid heated air will be going out immediately by the suction of discharge fan. The drying time is established upon the average final MC to achieve about 8%. To save energy and reduce the drying time, the distribution of temperature between layers should be fast and uniform with minimum difference; otherwise the difference of MC gradient between layers will be high and will induce grain breakage. The difference of final MC between layers in the two methods was 48-73%. The steady state of temperature between the two methods has saved time in the range of 10-20%, and the efficiency of temperature distribution increased 17-26% by the use of discharge fan.
UTILIZATION OF VISIBLE LIGHT RADIATION TO DETERMINE CRACK PERCENTAGE IN SOME RICE GRAINS VARIETIES
The main objectives of the present study were to develop of an optical instrument to determine grain cracks based on numbering crack grain using a visible light radiation as the light source., and studying the effects of cracks percentage on some mechanical parameters of grains to minimize grain damage and increase rice grain quality. Grains of rice verities were Sakha 103, Yasmein Masry, Giza 101 and Giza 177. Grains with the initial moisture content of about 10.6 % (b.d.), with the husk of rice grain removed by hand. The milled grains were put on screen then exposed to visible light radiation under the screen, then crack grains were counted. The following conclusions were drawn on the basis of results of mechanical testing and light radiation examination: 1) The percentage of cracks for different grains increased with the increase of the deformation of grain, while compression strength, specific work and elasticity modules were decreased, 2) Type of grains effect on the values of mechanical parameters. Sakha 103 grain variety showed higher strength, modulus of elasticity and specific work than Giza 177 which was the lowest one., 3) Rice grain variety of Giza 177 with the moisture content of about 10.6% followed by resulting in a decrease in grain strength, modulus of elasticity and specific work by 44.75, 66.34, and 52.69%50% compared to the Sakha 103 . where the deformation increased by 36.84% , 4) Mechanical parameters showed high correlation with the percentage of cracks. The correlation coefficient for the strength against crack percentage of grain was equal to 0.92, for the modulus of elasticity 0.99, while in the case of specific work it was equal to 0.89., 5) Resistance to cracking of grain to impacts can be advantageous on storage and biological characteristics .
The potential vorticity flux through the Yucatan Channel and the Loop Current in the Gulf of Mexico
Two‐year‐long time series of current and density structure measurements across the Yucatan Channel's main section allow the calculation of the time‐dependent potential vorticity flux between the Gulf of Mexico and the Caribbean Sea, which is characterized by alternating periods of positive (cyclonic) and negative (anti‐cyclonic) vorticity influx. Periods of negative cumulative vorticity influx are related to the Loop Current extending into the Gulf of Mexico, whereas periods of positive cumulative vorticity influx relate to a Loop Current retraction, sometimes coincident with the shedding of an anti‐cyclonic eddy.