Progress 09/01/10 to 08/31/14
Outputs
Target Audience: Demonstration and testing and with Professors of agriculture at New Mexico State University Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided? Exposed one of our researchers to sensor development, design and field testing. How have the results been disseminated to communities of interest? Demonstration and testing at NMSU What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
(1)A compact portable prototype ethylene analyzer that meets the necessary size, weight, power, and ruggedness requirements was designed and built; (2) Low parts-per-billion (ppb) sensitivity and high selectivity of ethylene detection in the presence of high concentrations of interfering gases under laboratory conditions was demonstrated; and (3) Commercial and USDA applications for the emerging technology were explored by testing at New Mexico State University. While the sensitivitycan not differentiateethylene levels in green chile,differentiation in appleswas easily achieved.The overall goal of the project was to develop a compact, rugged, low ppb gaseous ethylene analyzer, ultimately suitable for widespread application in the agricultural industry.
Publications
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Progress 09/01/11 to 08/31/12
Outputs
OUTPUTS: A one-year no-cost extension was granted to this project, so the new termination date is August 31, 2013. The Phase II prototype instrument is currently being designed and built. During this reporting period, the main project activities included selection and testing of the hardware components, optimization of the detection scheme and data analysis. The obtained data indicate that the main goal of building a prototype ethylene sensor with low parts-per-billion (ppb) sensitivity is likely to be achieved. However, by this time, the proposed technology has not yet reached the degree of maturity that allows it to be demonstrated to the interested communities. By the end of Phase II, demonstration and beta-testing of the prototype ethylene sensor at Cornell University (Department of Horticulture, College of Agriculture and Life Sciences), Utah State University (Department of Plants, Soils and Biometeorology), and possibly with other interested parties is planned. PARTICIPANTS: Jeffrey S. Pilgrim (PI), Andrei B. Vakhtin (Principal Research Scientist), Bernardo Farfan (Research Engineer), William R. Wood (Senior Research Engineer). TARGET AUDIENCES: Research plant physiologists at USDA, NASA, and Universities. PROJECT MODIFICATIONS: A one-year no-cost extension was granted to this project. The new termination day is August 31, 2013.
Impacts
During this reporting period, we worked mostly on design of the optical and mechanical layers of the prototype instrument. The development is currently underway. The Phase II prototype sensor comprises the following main parts: the resonance photoacoustic spectroscopy (PAS) cell, laser light source, microphone(s), sample gas pressure and flow control system, auxiliary sensor board to estimate concentrations of potentially interfering gases such as carbon dioxide and methane, laser wavelength locking cell, analog electronic board, digital field-programmable-gate-array (FPGA) based control board, micro controller, and user interface hardware (LCD, buttons, etc). We are considering different types of PAS cells and different signal acquisition schemes in order to maximize the signal-to-noise ratio and hence the sensor sensitivity. The experimental data show that different cells have their advantages and drawbacks and it is still not clear which cell type is the best. Therefore, the sensor is designed to be compatible with different types of PAS cells, which are fully and easily interchangeable. Different laser light sources (laser diode, laser diode coupled to a semiconductor amplifier, and laser diode coupled to a fiber amplifier) are currently being tested. At this time, the configuration of the system that involves the laser diode coupled to a semiconductor amplifier appears the most promising: it is simple, robust and relatively inexpensive and is likely to be capable of providing the required low parts-per-billion (ppb) ethylene detection limit. Different types of microphones will be evaluated in the nearest future. The pressure and flow control system is also under development. It is based on a commercial proportional valve, digitally controlled absolute pressure sensor and FPGA-based digital control board. Different schemes of measurement of potentially interfering gases such as carbon dioxide and methane are being evaluated. To apply the corrections to the measured ethylene concentration only crude estimates of the concentrations of these gases are necessary; therefore, we are considering incorporating inexpensive electrochemical and solid state sensors to measure water vapor, carbon dioxide, methane and ethanol, and infrared LED-based non-dispersed absorption to measure carbon dioxide. The requirements and specifications to the custom analog electronic boards are being finalized (substantial progress in development of the FPGA-based digital electronics has been achieved during the previous reporting period). Overall, the project is going well. It is expected that by the end of Phase II a prototype instrument will be built, calibrated and beta-tested. The competitive advantages of the Vista Photonics ethylene sensor include low cost, high sensitivity, high selectivity, real-time measurement, fast response, compactness, and portability. It possesses a small footprint, low power consumption, low maintenance, and no moving parts. It is ideal for in situ ethylene monitoring.
Publications
- No publications reported this period
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Progress 09/01/10 to 08/31/11
Outputs
OUTPUTS: Since less than 50% of the Phase II work plan is complete, the technology did not yet reach the degree of maturity that allows it to be demonstrated to the interested communities. By the end of Phase II, beta-testing of the laboratory prototype instrument at Cornell University (Department of Horticulture, College of Agriculture and Life Sciences), Utah State University (Department of Plants, Soils and Biometeorology), and possibly by other interested parties is planned. PARTICIPANTS: Jeffrey S. Pilgrim (PI), Andrei B. Vakhtin (Senior Research Scientist), William R. Wood (Senior Research Engineer), Bernardo Farfan (Research Engineer). TARGET AUDIENCES: Research plant physiologists at USDA, NASA, and Universities PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
As Earth's population grows, higher yield is a critical mechanism for insuring adequate food supply. An effective way to increase yield is by reducing waste. Crops react to stressors by releasing ethylene at low levels. If these levels can be detected, stressors may be mitigated before crop viability is compromised. Further, detection of elevated ethylene can also eliminate compounding of post-harvest waste due to rot or senescence. Vista Photonics is developing a compact, rugged, low parts-per-billion (ppb) gaseous ethylene analyzer ultimately suitable for widespread application in the agricultural industry. The proposed high performance ethylene sensor will provide research plant physiologists a tool with which to correlate the causes and effects of ethylene release and the means to quantitatively measure resulting mitigation strategies. During the first half of the Phase II development, we worked mostly on design and construction of the prototype instrument. The hardware that includes a compact, resonant photoacoustic spectroscopy (PAS) cell with an additional capability to measure carbon dioxide (needed for ethylene signal correction in the presence of very high concentration of carbon dioxide) using an infrared LED/photodetector system is in the final stage of design. The carbon dioxide measurement system has been designed and characterized. The development of the analog electronic boards is in its initial stage. A substantial breakthrough has been achieved in the digital electronics development. The digital electronics are implemented using an FPGA (field programmable gate array) development board. The FPGA blocks that are responsible for generating the required waveforms to control the laser, performing raw data acquisition and primary data processing (demodulation) are developed. Development of FPGA blocks responsible for PAS cell acoustic resonance tracking based on a digital tracking clock generator, time multiplexing of different measurement regimes, and various modes of data averaging are underway. Overall, the project is going well. It is expected that by the end of Phase II a prototype instrument will be built, calibrated and beta-tested. The competitive advantages of the Vista Photonics ethylene sensor include low cost, high sensitivity, high selectivity, real-time measurement, fast response, compactness, and portability. It possesses a small footprint, low power consumption, low maintenance, and no moving parts. It is ideal for in situ ethylene monitoring.
Publications
- No publications reported this period
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