Results from the arable crop rotation study at Oak Park 2000 - 2007

An organic rotation trial was established at Oak Park in 2000. The crop sequence in the seven year rotation was: two years grass-clover, winter wheat, potatoes, winter oats, lupins and spring barley. The grass-clover, which supplies nitrogen to the system, also provides vegetation which of late is cut and mixed with cereal straw to produce compost. The compost replaced sheep manure which was available up to 2007. Manure was applied to potato plots prior to cultivation for the period 2002 to 2007 and to barley plots from 2005 to 2007. The average yield of crops over the period of the rotation was: winter wheat 5.9 t/ha, potatoes 32.7 t/ha, winter oats 5.8 t/ha, lupins 2.4 t/ha and spring barley 4.5 t/ha. Triticale, which was grown in one of the plots designated for winter wheat, had an average yield of 7.5 t/ha. Lupins have been unsatisfactory due to uncompetitiveness with weeds and lateness of maturity

Analysis of nitrogen tetroxide samples Final report

Chemical analysis of nitrogen tetroxide trace impuritie

Analysis and Comparison of the Scope, Impacts, and Responses to the COVID-19 Pandemic and Climate Change as Major Crises in the United States

The COVID-19 pandemic has become the global crisis of 2020 and the focal point of much public attention. Climate change is the ongoing crisis of the industrial and post-industrial ages. The United States and the rest of the world are attempting to navigate both crises. This study researched and analyzed the COVID-19 pandemic and climate change as the major crises affecting the United States of America in terms of the scope of both crises, their impacts, and national responses. This project draws on the knowledge learned throughout the Energy Policy and Climate Change program such as the principles of climate change, its effects, and challenges with regards to implementing effective adaptation and mitigation measures. To the best of this researcher’s knowledge, this project is the first attempt to analyze both COVID-19 and climate change as contemporaneous crises occurring within the United States. As the pandemic continues to evolve, every passing month has offered new information relevant to this project, highlighting both this project’s novelty and the dynamism of the crisis. The research needed to complete this project drew initially from over two-hundred resources, from the Intergovernmental Panel on Climate Change Assessment Reports to newspaper articles. Additionally, it forced “deep-dives” into the impacts of climate change, challenging preconceived notions, and brought to light the reality that the people most likely to suffer from one crisis are most likely to suffer both. Looking beyond this project, a next step beyond comparing and contrasting will be to splice the two crises to learn their independent effects and how overlapping impacts interact with each other. This would allow a cumulative analysis of the impacts on shared, vulnerable demographics in order to understand how crises in the U.S. continue the oppression of certain demographics of American society. This project should be considered a first step toward better understanding COVID-19, climate change, and the way in which crises are processed in 21st century American society

Using Pre-Lecture Activities to Enhance Learner Engagement in a Large Group Setting

The disadvantage to students of beginning a module with no prior knowledge or inaccurate knowledge is well documented. For learners, the development of the necessary prior knowledge to facilitate their learning is essential. The use of screencasts, whether prior to or during class, is becoming more widespread. There is a need, however, to better understand how these are used and whether or not there is any impact on overall learner engagement and academic achievement when a component with instantaneous feedback (such as a multiple choice quiz) is embedded into the pre-lecture screencast activity. In this study, pre-learning activities consisting of screencasts and multiple choice quizzes were introduced to improve student engagement with the topic, gauge common misconceptions and give timely feedback to the students. An examination of screencast usage indicated that students did not predominantly nor exclusively employ the resources as originally intended, that is, in advance of lectures. Rather, students continued to access the activities across the module and often after the associated lecture. Implications are discussed with an acknowledgement of the importance of taking into account how learners prefer to use resources when designing and introducing new activities to modules. Keywords large group teaching, learner engagement, multiple choice quizzes, prior knowledge, screencasts Identifying and enhancing learner prior knowledge – what do learners know already and how can this help them?[AQ1] To find ways to support student learning, educators are increasingly turning their attention to the very roots of the learning experience, that is, to the knowledge, skills, environments and processes already possessed and encountered by the learner before the new, to-be-learned material is introduced (Coppola and Krajcik, 2014). Although such awareness of the importance of prior knowledge is not a recent emergence (Ausubel, 1968), interest in what learners know in advance

Observations of Shadow Bands at the Total Solar Eclipse of 16 February 1980

Photoelectric observations of short term light variations (shadow bands) at the 16 Feb. 1980 total solar eclipse have been made using a set of spatially separated PIN diodes. Light variations in a bandpass of 1-500 Hz were detected during the half-minutes preceding and following the total phase. Fourier analysis of the noise spectrum of the variations reveals a sharp drop-off for frequencies about 50 Hz and an overall spectrum quite similar to previously reported power spectra of stellar scintillation. This is consistent with an atmospheric origin for the shadow bands. Cross-correlations between the detector outputs are low, suggesting a short persistence time for the turbulent elements causing the patterns

Maximizing sustainable ground-water withdrawals: comparing accuracy and computational requirements for steady-state and transient digital modeling approaches

Rigorous models for maximizing sustainable groundwater withdrawals may require more computer memory for their constraint set than is available. In some situations, alternative constraint formulations yield similar or identical answers resulting in great saving in computer memory requirements. In order to evaluate the efficiency of using alternative constraints1 maximum ground-water withdrawal pumping strategies were computed by three digital models for a hypothetical area for a five-decade period. Model A maximized steady ground-water withdrawal. Model B maximized unsteady ground-water mining. Model C maximized unsteady ground-water mining subject to a constraint that final pumping be sustainable after the end of the 50-year period. Change in pumping with time was forced to be monotonic (variably increasing or decreasing but not oscillating) in time. The models were tested by assuming constant transmissivity and by using a range of recharge constraints for four scenarios with stressed and unstressed initial potentiometric surfaces and with constant and changing upper limits on pumping. In situations where upper limits on pumping changed with time, Model A was run repetitively, by using monotonicity constraints. In -those situations, optimality of solution is not assured in all cells. Models A and C computed pumping strategies sustainable after the end of the 50-year period. Model C was the most detailed in that it allowed pumping to vary in time and recharge constraints were based both on unsteady-state flow at 50 years and on steady flow after that time. Model A considered only steady pumping and recharge constraints. Pumping strategies from Model B were not necessarily sustainable because it considered only recharge constraints at 50 years. Results indicate that, when recharge through the study area periphery is unconstrained, all models compute identical pumping. For an initially undeveloped aquifer, or for a developed aquifer if steady pumping is assumed, Model A computes strategies very similar to those computed with Model C and requires only 28 percent of the computer memory and 38 percent of the execution time. For an initially overdeveloped aquifer, Model B computes identical pumping strategies to those computed with Model C and requires 73 percent of the computer memory and 78 percent of the computation time. For that situation, Model A is more conservative and computes less pumping than Model C if pumping in Model C is permitted to vary. Although Model A may compute lower pumping rates during the first 50 years, the sustainable pumping rate thereafter may be greater for Model A than for Model C

Reducing the nitrate content of protected lettuce.

End of Project ReportA research project was carried out jointly between Teagasc, Kinsealy Research Centre and University College Dublin, Department of Crop Science, Horticulture and Forestry which studied the effects of cultivar, nitrogen fertilisation and light intensity on the nitrate content of protected butterhead lettuce. In a series of cultivar trials of winter and summer butterhead lettuce, significant differences in the nitrate content of the lettuce between cultivars were found only in one experiment. In this instance, the differences were not consistent between successive harvests. It was concluded that screening lettuce cultivars for tissue nitrate level is unlikely to contribute to an overall reduction of nitrate levels. The application of N in a liquid feed throughout the cropping period resulted in higher nitrate levels in lettuce plants grown in soil filled containers compared with a similar amount of N applied to the soil before planting. Withdrawing N for the final 10 days of the cropping period did not affect the nitrate content of the lettuce. In an experiment studying nitrogen source and rate on lettuce grown in containers, the use of calcium cyanamide as a N source resulted in lower nitrate levels in the lettuce and gave a reduced head weight compared with calcium ammonium nitrate (CAN) or ammonium sulphate. Increasing the rate of CAN or ammonium sulphate gave higher lettuce nitrate levels. A nitrification inhibitor reduced the soil nitrate levels especially with sulphate of ammonia as the N source but did not affect the plant nitrate levels significantly. The addition of chloride to the soil reduced nitrate levels in the lettuce. In a further fertilisation study using containers, calcium cyanamide again resulted in lower plant nitrate levels than CAN. Increasing the rate of CAN increased soil nitrate levels, lettuce head weight and plant nitrate levels. The relationship between soil nitrate levels, lettuce head weight and plant nitrate level indicates that the level of 100-150 mg·L-1 of nitrate N in the soil, advocated in the Code of Good Practice, is a compromise between maximising plant growth and minimising lettuce nitrate content. A comparison between CAN and calcium cyanamide in a border soil experiment again showed that the latter N source resulted in lower lettuce nitrate levels. In this experiment the addition of chloride to the soil did not affect plant nitrate levels. Lettuce was grown, in late summer, in small tunnels using a range of polyethylene cladding materials. Head weight correlated well with the overall light transmission of the materials. In one of the materials that had a low light transmission, lettuce nitrate content was doubled compared with those grown under the materials with high light transmission. Under both winter and summer conditions, the nitrate content of lettuce heads was not influenced by the time of day at which harvest took place. In experiments in which multiple harvests were carried out there was no consistent trend in nitrate content as the heads developed and matured. Within individual heads of lettuce there was a steep concentration gradient with the older outer leaves having much higher concentrations of nitrate than the younger inner leaves. Herbicides commonly used in protected lettuce production did not influence the nitrate content of the lettuce