Current Issue : January - March Volume : 2014 Issue Number : 1 Articles : 6 Articles
Development of real time and continuous sensing systems for soil physical and mechanical properties provides a\r\nvaluable tool to obtain inexpensive and rapid information of soil current status and future management in the context of\r\nprecision agriculture. This study aimed to design, fabricate and evaluate a mechanical transducer to measure aggregate sizes\r\nin real time by determining dynamic strain behavior of commercially available spring tines in field experiments. Dynamic\r\nstrain was measured with strain gauges mounted on the spring tines and respective circuits. Signals acquired from strain\r\ngauges were received and saved by a data-acquisition system and then analyzed. The results of field experiment data was\r\ncorrelated to standard sieve data. The results show that the transducer�s output voltage increases with increasing aggregates\r\nmean diameters and estimated liner equation was D=13. 827V-33.536 with a correlation coefficient of R2=0. 93. Mean\r\nweight diameter (MWD) was obtained with putting the average of the output signals in the equation. Calculated diameter of\r\nthe mechanical transducer was approximately 25% higher than standard sieve analyses....
The objective of this study was to theoretically investigate the factors affecting kernels during picking up and\r\ntransporting stage using a pneumatic precision metering device designed especially for wheat precision seeding and correlates\r\nfindings with the results from practical testing under laboratory conditions using a test stand with camera system. The results\r\nfrom dynamic analysis were found to be corresponding with that of the laboratory testing. The findings revealed that the\r\nperformance indices, such as quality of feed index (QFI), multiple index (MULI) and miss index (MISI), were obviously\r\ninfluenced by changing the negative pressure force FQ and rotating speed . The result from test stand highlighted that when\r\nthe negative pressure increased the QFI increased, MULI increased and MISI decreased, however, the QFI decreased and MISI\r\nincreased with increasing the rotating speed. The dynamic analysis likewise revealed that increasing the friction index tang\r\nby choosing a suitable material with high friction angle g for seed plate as well as enlarging the seed hole diameter could\r\nimprove the efficiency of the negative pressure force FQ....
Urea Super Granule (USG) placement in 6-10 cm depth in wet land rice field can save 30% of nitrogen than\r\nbroadcasted prilled urea. But, deep placement by hand is more time consuming, labor expensive and also hazardous to health.\r\nTo solve the problems of USG placement, a manually operated push type two-row fertilizer applicator for puddled rice field has\r\nbeen developed in Farm Machinery and Postharvest Process Engineering (FMPE) Division of Bangladesh Agricultural\r\nResearch Institute (BARI) in 2009. The applicator was modified for variable row spacing (17-25 cm) reducing weight from 9\r\nto 6 kg by changing the construction material of skid and drive wheel from steel to plastic. To reduce the moving resistance,\r\nthe length of the skid was reduced from 760 to 610 mm. Based on farmers'' demand; the hoppers were modified to hold 1 kg\r\nof USG in each hopper instead of 0.5 kg. Field performance of BARI USG applicator was evaluated in four different location\r\nof the country during the boro season (January-April) of 2011-12. Average field capacity and efficiency of the applicator were\r\nfound to be 0.139 hah???? and 81% respectively. Considering custom hiring, the net income per year was US$ 915 (Tk 75??000)\r\nand the payback period was 3 days. The price of the applicator is US$ 43 (Tk 3,500). Use of the applicator ensured similar\r\nyield of rice to hand application of USG in all locations. Higher yield of rice was obtained from USG applied plot than\r\ngranular urea. This improved USG applicator may be used for application of USG in puddled rice field in the rice growing\r\ncountries....
In this paper, a low-cost dynamometer for undriven, steered wheels is described. The dynamometer was produced\r\nto determine whether such an instrumented mechanism is practical. Four S-beam load cells and two opto-counters were used\r\nto obtain all moments, forces, and points of their application. Overturning, aligning, and rolling resistance moments besides\r\nvertical force are directly measured by the load cells. The opto-counters detect wheel angular velocity and steering angle.\r\nThe dynamometer evaluation results showed significant correlation between expected values and measured data with high\r\naccuracy. Wheel dynamic behavior can be defined according to dynamic and kinematic analysis in which relative calculations\r\nhave minimum simplifying assumptions....
Agriculture mechanization plays a significant economic role by increasing agriculture production and reducing cost\r\nof cultivation. There is a dire need to develop more processing machinery for value addition of agricultural produce with a\r\nreduction in time and labour. The planting operation is one of the most important tasks that sugarcane growers undertake. It\r\nshould result in a plant stand at the desired density that emerges quickly and uniformly. Austoft sugarcane planter was studied\r\nand the CAD model for metering device was simulated with Catia software. Main components of this machine are hopper,\r\nmetering device, and basis. Multiple regression and Response Surface Methodology (RSM) were applied to data for\r\ninvestigating the effect of angle and speed of sugarcane billet metering device on discharging and precision indices. The\r\nspeed of metering device had more effect than angle on both performance indices. Analytical hierarchy process (AHP) used to\r\nmatch the best operation condition for discharging billets from hopper. The angle of 80�° and speed of 1 m s-1 was the best\r\nsuited condition for sugarcane billet metering device with 98.64% for precision index and 4.2 billets in per second for\r\ndischarging index. A consistency ratio evaluation value of 0.1 confirmed the results....
Design, construction and evaluation of a mechanical transducer to measure aggregate sizes in real time were\r\nconducted by the same authors. The spring tines were instrumented using the strain gauges and tested in field conditions.\r\nThe main conclusion is that the spring tine transducers could be used as sensors to estimate the mean weight diameter of a given\r\nclod size distribution. In order to evaluate the influence of working speed and depth on performance of the tine transducer,\r\nfactorial experiments were conducted based on randomized complete block design with three replications. Working speed and\r\ndepth were investigated each at three levels. The results of the variance analysis showed that sensing speed and depth affect\r\ntine transducer performance independently. Sensing speed has a very little impact on performance of tine transducer but\r\nsensing depth has a significant impact on performance of tine transducer. Results also showed that the higher sensing depth\r\nand speed the higher horizontal force on the spring tines. Optimal sensing speed of 5 km h-1 was chosen in order to reduce the\r\neffect of inertia forces due to higher speeds than the critical speed and avoid of plastic deformation and failure of the tine.\r\nMechanical transducer was calibrated with sensing depth of 70 mm in order to avoid getting into excessive force to the tines\r\nand considering the root depth of the various products in the soil....
Loading....