tailieunhanh - Advanced Microwave Circuits and Systems P15

Các bản vẽ kỹ thuật để chế tạo là sản phẩm cuối cùng của khâu thiết kế. Chúng phải thỏa mãn hai mục đích: bao gồm đầy đủ tất cả các thông tin cần thiết để chế tạo và cũng còn là một tiêu chí kiểm soát kỹ thuật đối với các mức độ sửa chữa. Trước cuối thế kỷ 20, rất nhiều bản vẽ kỹ thuật được thực hiện bằng tay với sự trợ giúp của bảng vẽ cơ khí. Sự ra đời của máy tính với giao diện người dùng đồ họa đã có thể giúp thực hiện. | 484 Advanced Microwave Circuits and Systems exciting monopole antenna is positioned at the top of the silo s lid below the microwave source. a b Fig. 11. Design and simulation of the silo structure using CST software a defined structure b simulated E-field Mofidian et al. 2007 2007 IEEE The simulation of the structure has been done using GHz normalized microwave source. The resulted E-field in the simulated silo is illustrated in b . It is obvious that the power density is concentrated in the center part of the system approximately ten times higher than near the wall. Therefore we expect that the wheats located in the center of the bulk absorb much more power in comparison to the other areas. Fig. 12 presents the constructed system of the silo and the exciting circuit including 220 2000 volt transformer voltage rectifier antenna and the 600 watt magnetron with its feeding circuit. Electromagnetic Solutions for the Agricultural Problems 485 Fig. 12. The constructed scaled Silo using a GHz source Mofidian et al. 2007 2007 IEEE Regarding the comparison of mortality rate between larvae and adults it is evident that larvae are more susceptible than adults to high temperatures as larvae s mortality is more than adult s which can be seen in in terms of different exposed times. The susceptibilities of both insects are depicted in . having similar behavior although Sitophilus granarius is quite more outstanding than Tribolium. The low mortality rate for 10minute and 20-minute tests caused by the none-uniform distribution of the field. In the high intensity part the pests are burnt while they are still alive in the low intensity parts. To improve the performance the system antenna can be restructured using an array antenna. Obviously we can reach a complete mortality of insects by increasing the exposure time or the power magnitude as well. Fig. 13. Comparison between larvae and adults mortality rate of Tribolium and Sitophilus Granarius exposed