Evaluation of Herbicides as Desiccants for Lentil (Lens culinaris Medik) Production

The indeterminate nature of lentil (Lens culinaris Medik), in conjunction with adverse field conditions, can lead to varying degrees of maturity among plants at harvest. This variable maturity may have a negative influence on lentil production and can delay harvest. Desiccants are currently used to improve lentil crop dry-down. However, applying desiccants too early may result in reduced crop yield and quality, and also leave unacceptable herbicide residues in lentil seeds. In addition, only four herbicides (glyphosate, diquat, saflufenacil, and glufosinate) are registered as desiccants for lentil desiccation in Canada, which limits options for growers. Therefore, the objectives of this thesis were i) to determine the importance of desiccant application timing in affecting crop yield and quality, as well as herbicide residues and ii) to determine whether additional desiccants applied alone or tank-mixed with glyphosate provide better crop desiccation. Field trials were conducted at Saskatoon and Scott, Saskatchewan, from 2012 to 2014. In the application timing trial, glyphosate or saflufenacil alone, or glyphosate+saflufenacil generally decreased seed yield, thousand seed weight, and crop dry-down, and increased herbicide residue levels at earlier application timings. For example, when applied at 60% seed moisture, saflufenacil reduced yield and thousand seed weight by 22% and 10%, respectively, and resulted in glyphosate and saflufenacil residues greater than 2.0 and 0.03 ppm, respectively. Although there were no reductions in yield and thousand seed weight when desiccants were applied at 50% or 40% seed moisture, glyphosate residue exceeded 2.0 ppm. Application of desiccants at 20 or 30% seed moisture content had no effect on yield, thousand seed weight, or herbicide residues. These results indicate that desiccant application timing is critical, and should not be made before 30% seed moisture. In a second study, glufosinate and diquat tank mixed with glyphosate were the most consistent desiccants and provided optimal crop dry-down without reducing yield and thousand seed weight, and effectively reduced glyphosate residue. The other herbicides tested (pyraflufen-ethyl and flumioxazin) were found to be poor options for growers as they had sub-optimal crop desiccation and did not affect glyphosate residue

A compact 6-bit phase shifter with high-power capacity based on composite right/left-handed transmission line

The EuMC 2010 Conference was one of the 4 conferences held during the 13th European Microwave Week (EuMW2010): "Connecting the World", Paris, France, 26 September-1 October 2010A compact 6-bit phase shifter with high power-handling capacity is designed based on the use of metamaterial, composite right/left-handed transmission line (CRLH-TL). Eight PIN diodes mounted on the fingers of the CRLH-TL are used as switches to control the phase incursion of the input signal. Different phase shifts are achieved by using different states of the switches (PIN diodes) determined by 6 controlling bits. Since the surface current flowing through each of the switches is only a fraction of the total current through the device, the power handled by each of the PIN diodes is much smaller than the total power through the device; thus the power-handling capacity of the phase shifter can be greatly improved. The phase shifter is designed to provide a phase-shift range from 0° to 360° at a step of 5.625° and operate in the frequency band from 9.2 to 9.8 GHz. Simulation results and measurement results of the prototype agree closely and show that the phase shifter has a much higher power-handling capacity than that of the PIN diode and low insertion losses across the operating frequency band. © 2010 EuMA.published_or_final_versionThe 40th European Microwave Conference (EuMC 2010), Pairs, France, 28-30 September 2010. In Proceedings of EuMC 2010, 2010, p. 437-44

A rectangular-shaped time-delay line inspired by CRLH TL unit cell for UWB operation

This paper presents the design of a rectangular-shaped ultra-wideband (UWB) time-delay line inspired by the use of composite right/left-handed transmission line (CRLH TL) unit cells. A rotated version of a conventional CRLH TL unit cell is used as the basic elements to achieve UWB operation. For comparison, time-delay lines using the right-handed transmission line (RH TL) and CRLH TL unit cells are also studied, fabricated and tested. Simulation and measurement results show that our proposed time-delay lines have high return loss, low insertion loss, UWB operation and much longer time delays than that of the time-delay line based on RH TL. © 2010 IEEE.published_or_final_versionThe 12th IEEE International Conference on Communication Systems (ICCS 2010), Singapore, 17-19 November 2010. In Proceedings of 12th ICCS, 2010, p. 27-3

A compact and UWB time-delay line inspired by CRLH TL unit cell

This paper presents the design of compact and ultra-wideband (UWB) time-delay lines inspired by the use of composite right/left-handed transmission line (CRLH TL) unit cell. A conventional CRLH TL unit cell is used as the basic elements for the design of time-delay lines and a rotated version of the unit cell is used to achieve ultrawide bandwidth operation. Time-delay lines for large time delays are designed by cascading the proposed unit cells, optimized using computer simulation and then fabricated on PCBs. A compact UWB time-delay line is designed by bending the time-delay line in a meander. For comparison, the time-delay line using the right-handed transmission line (RH TL) is also fabricated. Simulation and measurement results show that our proposed time-delay lines have ultrawide bandwidth operation and much longer time delays than that of the time-delay line based on RH TL. They also have the advantages of high return losses and low insertion losses. © 2010 IEEE.published_or_final_versionThe 2010 IEEE Region 10 International Conference (TENCON 2010), Fukuoka, Japan, 21-24 November 2010. In TENCON (IEEE Region 10 Conference) Proceedings, 2010, p. 868-87

Ultra-wideband time-delay line inspired by composite right/left-handed transmission line unit cell

Proceedings of the IEEE International Conference on Ultra-Wideband, 2010, v. 2, p. 607-610This paper presents a design of ultra-wideband time-delay line inspired by the composite right/left-handed transmission line (CRLH TL) unit cell. A rotated version of the conventional CRLH TL unit cell is used to increase the operating bandwidth. The time-delay line is optimized using computer simulation and then fabricated on a PCB for measurement. For comparison, the time-delay lines using the right-handed transmission line (RH TL) and periodic microstrip line (PML) are also designed, optimized and fabricated. Simulation and measurement results show that, for the same length of 60 mm, our proposed time-delay line has a much longer time delay of 2000 ps with high return loss and low insertion loss. © 2010 IEEE.published_or_final_versio