Measurement of representative landfill gas migration samples at landfill perimeters: a case study

This paper describes the development of a fully integrated autonomous system based on existing infrared sensing technology capable of monitoring landfill gas migration (specifically carbon dioxide and methane) at landfill sites. Sampling using the described system was validated against the industry standard, GA2000 Plus hand held device, manufactured by Geotechnical Instruments Inc. As a consequence of repeated sampling during validation experiments, fluctuations in the gas mixtures became apparent. This initiated a parallel study into what constitutes a representative sample of landfill gas migration as reported to the Environmental Protection Agency. The work described in this paper shows that gas mixture concentrations change with depth of extraction from the borehole well, but with evidence of a steady state after a time

Monitoring of gas emissions at landfill sites using autonomous gas sensors

Executive Summary This report details the work carried out during the Smart Plant project (2005-AIC-MS-43-M4). As part of this research, an autonomous platform for monitoring greenhouse gases (methane (CH4), carbon dioxide (CO2)) has been developed, prototyped and field validated. The modular design employed means that the platform can be readily adapted for a variety of applications involving these and other target gases such as hydrogen sulfide (H2S), ammonia (NH3) and carbon monoxide (CO) and the authors are in the process of completing several short demonstrator projects to illustrate the potential of the platform for some of these applications. The field validation for the greenhouse gas monitoring platform was carried out at two landfill sites in Ireland. The unit was used to monitor the concentration of CO2 and CH4 gas at perimeter borehole wells. The final prototype was deployed for over 4 months and successfully extracted samples from the assigned perimeter borehole well headspace, measured them and sent the data to a database via a global system for mobile (GSM) communications. The data were represented via an updating graph in a web interface. Sampling was carried out twice per day, giving a 60-fold increase on current monitoring procedures which provide one gas concentration measurement per month. From additional work described in this report, a number of conclusions were drawn regarding lateral landfill gas migration on a landfill site and the management of this migration to the site’s perimeter. To provide frequent, reliable monitoring of landfill gas migration to perimeter borehole wells, the unit needs to: • Be fully autonomous; • Be capable of extracting a gas sample from a borehole well independently of personnel; • Be able to relay the data in near real time to a base station; and • Have sensors with a range capable of adequately monitoring gas events accurately at all times. The authors believe that a unit capable of such monitoring has been developed and validated. This unit provides a powerful tool for effective management of landfill site gases. The effectiveness of this unit has been recognised by the site management team at the long-term deployment trial site, and the data gathered have been used to improve the day-to-day operations and gas management system on-site. The authors make the following recommendations: 1. The dynamics of the landfill gas management system cannot be captured by taking measurements once per month; thus, a minimum sampling rate of once per day is advised. 2. The sampling protocol should be changed: (i) Borehole well samples should not be taken from the top of the well but should be extracted at a depth within the headspace (0.5–1.0 m). The measurement depth will be dependent on the water table and headspace depth within the borehole well. (ii) The sampling time should be increased to 3 min to obtain a steady-state measurement from the headspace and to take a representative sample; and (iii) For continuous monitoring on-site, the extracted sample should be recycled back into the borehole well. However, for compliance monitoring, the sample should not be returned to the borehole well. 3. Devices should be placed at all borehole wells so the balance on the site can be maintained through the gas management system and extraction issues can be quickly recognised and addressed before there are events of high gas migration to the perimeter. 4. A pilot study should be carried out by the EPA using 10 of these autonomous devices over three to five sites to show the need and value for this type of sampling on Irish landfill sites

“Disarmament” Under the NPT: Article VI in the 21st Century

Article published in the Michigan State International Law Review

Calculating the Cost of Pilot Turnover

Controlling costs is a critical ingredient in achieving profitability in the airline industry. Typically, labor costs are the first or second highest cost category for airlines. Some components of labor costs, such as pay and benefits, are easy to calculate. Turnover costs, however, are not easy to calculate, and are often underestimated. This paper builds a model for examining turnover costs for pilots in Part 135 carriers, and tests the model empirically in a Part 135 carrier. The model provides a framework to assist airlines in estimating turnover costs for pilots. The case study of a Part 135 cargo operator showed that the turnover rate for pilots was 46%, compared to the average across all jobs and all industries of 15%. Pilot turnover costs for the carrier were shown to be $17,405, compared to the average across all jobs and all industries of$13,996. Per capita turnover costs for the carrier represent 43% of the average pilot’s salary of $40,000. This information can be used by airlines to make cost benefit judgments about retention efforts

Principals\u27 Beliefs Regarding the Use of Corporal Punishment in Tennessee\u27s First District Public Schools

There were two major purposes of this study. The first purpose was to obtain information from all principals in Tennessee\u27s First District concerning their beliefs about the use of corporal punishment in public schools in Tennessee. Generalizations could be made in areas of similar geographic and cultural makeup. The second purpose of this study was to generate reflective thought in Tennessee\u27s First District to clarify administrators\u27 beliefs as to the use of corporal punishment as a deterrent. Demographic findings of the study revealed a predominately male population of principals. The majority of the population surveyed was male Caucasian. There was a normal distribution among education levels for principals in the First District, ranging from Bachelor degrees to Doctoral degrees. Subgroups that were tested using the Mann-Whitney U test for significance were: principals with 0-10 years experience and those with more than 10 years experience, principals who used corporal punishment in their schools and those who did not, and principals who experienced corporal punishment as children and those who did not. The review of literature in regard to corporal punishment revealed four constructs that proponents used when explaining why it was used: religious beliefs, legal perspectives, cultural beliefs, and effectual beliefs as a disciplinary measure. Principals in the First District of Tennessee had similar religious beliefs regarding the use of corporal punishment. In comparison, principals who used corporal punishment had significantly different belief scores relative to legal perspectives, culture, and effectiveness than those who did not use corporal punishment. Principals who experienced corporal punishment as children scored significantly higher in beliefs of its effectiveness than those who had never experienced it

The Wright Brothers vs. the World: Understanding the Wright Patent Wars

The Wright brothers\u27 long and expensive legal defense of their patent was understandable, but damaging to both the brothers and the fledgling American aviation industry. Orville and Wilbur Wright believed that, as the inventors of the airplane, they were owed recognition and financial reward. The Wrights\u27 attempts to enforce this through legal means prevented them from making further advances in aeronautics, and frustrated the normal course of invention and improvement promoted by the patent system

Understanding Generation: Implications for Flight Training, Hiring, and Retention

Generation is a much discussed topic in the literature on workforce training and education. The simultaneous presence of numerous generations in the workforce has created tensions, challenges, and opportunities. In collegiate flight training, the Millennial generation is giving way to the post-Millennial generation, which will bring its own learning style and priorities to the cockpit. This presentation reviews the scientific literature on generational differences, identifying which differences are actually supported by data. Demographic and economic trends, including data from the National Science Foundation’s Scientists and Engineers Statistical Data System, will be combined with demonstrated generational differences in work-related attitudes and choices to discuss the implications for flight training. Future ideas for research will be explored

Comparison of Fixed-Wing Unmanned Aircraft Systems (UAS) for Agriculture Monitoring

Florida citrus growers need inexpensive methods to observe citrus plants to detect disease and stress consistently. Health vegetation indices, such as the Normalized Difference Vegetation Index (NDVI) collected from Unmanned Aircraft Systems (UAS), can be used to identify variation in plant health. Simple-to-operate UAS may enable growers to determine within-field variation more frequently than with inspections from scouts, providing more frequent knowledge about the crop condition. This research compared two low-cost fixed-wing UAS, a $5,000 Parrot Disco Pro Ag and a$16,690 senseFly eBee, each equipped with a Parrot Sequoia multispectral camera, to determine if there were differences in the NDVI data results and ease of operation. There were no statistical differences between NDVI reflectance values obtained using the Disco Pro Ag (M = 0.62, SD = 0.15) and the eBee (M = 0.60, SD = 0.15), t(45) = -1.45; p = 0.15. There was a significant positive correlation between the datasets (Pearson correlation = 0.963, p = 0.00). These results suggest that both the Disco Pro Ag and eBee were equally capable of producing the same data from the Parrot Sequoia multispectral camera. Differences in mobility and methods of waypoint planning between these two low-cost UAS may provide remote pilots with different styles of operation. As growers continue to adopt UAS technology to understand their fields better, the characteristics of each system will be important for quick setup time and ease of use