Capstone Engineering Design Projects For Community Colleges

Capstone engineering design courses have been a feature at research universities and four-year schools for many years.  Although such classes are less common at two-year colleges, the experience is equally beneficial for this population of students.  With this in mind, Madison College introduced a project-based Engineering Design course in 2007.  This paper explores Madison College’s experience over the past decade offering this class.  Unique challenges and opportunities for engineering design courses at two-year colleges are discussed.  Our findings include several recommended practices to benefit colleges and universities at any level that are creating new engineering design courses. 

International Approaches To Renewable Energy Education – A Faculty Professional Development Case Study With Recommended Practices For STEM Educators

Calls for increased international competency in U.S. college graduates and the global nature of the renewable energy industry require an exploration of how to incorporate a global perspective in STEM curricula, and how to best develop faculty providing them with global knowledge and skills necessary to update and improve existing teaching practices. To expand awareness of the global renewable energy sector, a cohort of renewable energy educators from across the United States participated in two international learning exchanges to Australia/New Zealand and Germany/Denmark. The exchanges provided opportunities for the participants to meet with technical educators, visit teaching labs, review industry partnerships, talk with policy makers and government representatives, and to share knowledge and best teaching practices.  Three years after the initial international exchange, participant data was collected to measure the extended impact of the experience and the perceived value of various learning activities.  The results show that the exchanges expanded participant’s knowledge of renewable energy technologies and issues both in the U.S. and abroad, and also influenced teaching curriculum and instruction, and academic community engagement. This study serves as a model program for providing STEM faculty with rich international experience. The findings in this manuscript highlight the key components to building a successful international professional development program, and illustrate the type of impacts that can result from these activities.  The lessons learned are meaningful to other institutions or organizations planning similar international activities in a variety of disciplines.

Characterization of elemental ratios and oxidative ratio of horticultural peat

peer-reviewedPeatlands occupy 20% of the land area of Ireland and store over half of soil carbon stocks. Over 80% of these peatlands have been disturbed by human activity such as drainage for peat extraction, afforestation and agriculture. In this study, peat samples were collected from 12 horticultural peat extraction sites in the Irish midlands. The carbon (C), nitrogen (N), hydrogen, and sulphur content were determined, and from these the carbon oxidation state (Cox) and oxidative ratio (OR) were calculated. The carbon oxidation ratio reflects organic matter synthesis and degradation, and is thus an important parameter in understanding terrestrial carbon cycling, whilst OR represents the molar ratio of oxygen (O2) and carbon dioxide (CO2) fluxes associated with net ecosystem exchange. Elemental concentrations and ratios were typical for Irish horticultural peat (e.g. carbon concentrations 54 – 57%), though showed site to site variability. Cox and OR values varied between -0.22 and -0.11, and 1.04 and 1.07 respectively and were comparable to United Kingdom peat soils. All values for OR were lower than 1.1, the value commonly used in global CO2 partitioning studies. Further research should investigate OR values in peatland which has not been studied to date. Across all sites, measures of increased decomposition (i.e. C/N ratios) significantly correlated with increasing OR reflecting more reduced organic matter. This study provides data in temperate peat soils that increases the coverage of Cox and OR values and will inform global CO2 partitioning studies

Soil organic carbon stocks by soil group for afforested soils in Ireland

Forest ecosystems are recognised as Natural Climate Solutions because forest soils are such important carbon stores, containing almost half of the total soil organic carbon of terrestrial ecosystems. Here we present the results of a synthesis of soil carbon stocks by World Reference Base soil group, and forest litter carbon stocks for afforested soils in the Republic of Ireland. We report soil carbon stocks of mineral soils separately from organo-mineral soils. We estimated mean soil carbon stocks in a 100 cm deep mineral soil to be between 162 ± 87 t C/ha (Gleysols) and 416 ± 0 t C/ha (Umbrisols, n = 1), and between 173 ± 65 t C/ha (Phaeozems) and 602 ± 226 t C/ha (Regosols) in a 100 cm deep organo-mineral soil; both less than the estimated soil carbon stocks in organic soils (Histosols): 645 ± 222 t C/ha. The entire soil carbon stocks in mineral Leptosols (100 ± 0 t C/ha, n = 1), Stagnosols (144 ± 39 t C/ha), Luvisols (159 ± 52 t C/ha) and Fluvisols (231 ± 0 t C/ha, n = 1) was contained in the upper 50 cm of soil. Based on a 100 cm deep soil, Histosols hold 1.6–4 times the amount of soil C than mineral soils and 1.1–3.7 times the amount in organo-mineral soils for the same profile depth. Certain mineral (e.g. Umbrisols) and organo-mineral soils (e.g Gleysols, Regosols) contain substantial soil carbon stocks relative to Histosols. We found considerable soil carbon stocks below 30 cm depth, which highlights the importance of depth extent for cumulative soil carbon stocks estimates. The upper third of the 100 cm profile contained 33% (Histosols) to 70% (Luvisols) of the soil carbon stocks and the upper half of a 100 cm profile contained the entire soil carbon stocks for Leptosols, Stagnosols, Luvisols and Fluvisols and organo-mineral Leptosols. Unfortunately, there were few samples available for mineral Leptosols, Umbrisols, Luvisols and Fluvisols, and the organo-mineral Stagnosols and Regosols, which precludes the drawing of conclusions for these groups. Relative to the soil carbon stocks, we found low mean forest litter stocks: 4.1 ± 5.5 t C/ha, 4.8 ± 3.3 t C/ha and 2.7 ± 2.9 t C/ha for broadleaf, coniferous and mixed forests respectively. Few exceptions existed for individual sites: 22.7 and 131.3 t C/ha for broadleaf forests. Our results are evidence that soil carbon stocks in mineral, organo-mineral and organic soils need to be protected, appropriately managed, and enhanced to be beneficial for greenhouse gas mitigation. Assessments are needed to identify which soil-site-management practice combinations risk soil carbon stock depletion. The large range observed in soil and litter carbon stocks stresses the importance of adequately accounting for soil group differences when GHG inventories are compiled. The synthesised dataset will contribute to improved SCS estimation for afforested lands in Ireland

Demonstration of a positron beam-driven hollow channel plasma wakefield accelerator

International audiencePlasma wakefield accelerators have been used to accelerate electron and positron particle beams with gradients that are orders of magnitude larger than those achieved in conventional accelerators. In addition to being accelerated by the plasma wakefield, the beam particles also experience strong transverse forces that may disrupt the beam quality. Hollow plasma channels have been proposed as a technique for generating accelerating fields without transverse forces. Here we demonstrate a method for creating an extended hollow plasma channel and measure the wakefields created by an ultrarelativistic positron beam as it propagates through the channel. The plasma channel is created by directing a high-intensity laser pulse with a spatially modulated profile into lithium vapour, which results in an annular region of ionization. A peak decelerating field of 230 MeV/m is inferred from changes in the beam energy spectrum, in good agreement with theory and particle-in-cell simulations

Emittance Measurements of Trapped Electrons from a Plasma Wakefield Accelerator

Recent electron beam driven plasma wakefield accelerator experiments carried out at SLAC showed trapping of plasma electrons. These trapped electrons appeared on an energy spectrometer with smaller transverse size than the beam driving the wake. A connection is made between transverse size and emittance; due to the spectrometer's resolution, this connection allows for placing an upper limit on the trapped electron emittance. The upper limit for the lowest normalized emittance measured in the experiment is 1 mm {center_dot} mrad

Lifetime measurement of the 2₁⁺ state in ⁷⁴Rb and isospin properties of quadrupole transition strengths at N = Z

Self-conjugate nuclei in the A ≈ 70–80 region have attracted a great deal of attention due to phenomena such as shape coexistence and increasing collectivity along the N=Zline. We investigate the structure of nuclei in this region through lifetime measurements using the GRETINA array. The first implementation of the Differential Recoil Distance Doppler Shift technique with fast radioactive beams is demonstrated and verified through a measurement of the well-known B(E2; 2₁⁺→ 0₁⁺)transition strength in ⁷⁴Kr. The method is then applied to determine the B(E2; 2₁⁺→ 0₁⁺) transition strength in ⁷⁴Rb, the heaviest odd–odd N=Z nucleus for which this quantity has been determined. This result and extended systematics along N=Z suggest the dominance of the isoscalar part of the quadrupole transition strengths in self-conjugate nuclei, as well as the possible presence of shape coexistence in ⁷⁴Rb

Brf1 loss and not overexpression disrupts tissues homeostasis in the intestine, liver and pancreas

RNA polymerase III (Pol-III) transcribes tRNAs and other small RNAs essential for protein synthesis and cell growth. Pol-III is deregulated during carcinogenesis; however, its role in vivo has not been studied. To address this issue, we manipulated levels of Brf1, a Pol-III transcription factor that is essential for recruitment of Pol-III holoenzyme at tRNA genes in vivo. Knockout of Brf1 led to embryonic lethality at blastocyst stage. In contrast, heterozygous Brf1 mice were viable, fertile and of a normal size. Conditional deletion of Brf1 in gastrointestinal epithelial tissues, intestine, liver and pancreas, was incompatible with organ homeostasis. Deletion of Brf1 in adult intestine and liver induced apoptosis. However, Brf1 heterozygosity neither had gross effects in these epithelia nor did it modify tumorigenesis in the intestine or pancreas. Overexpression of BRF1 rescued the phenotypes of Brf1 deletion in intestine and liver but was unable to initiate tumorigenesis. Thus, Brf1 and Pol-III activity are absolutely essential for normal homeostasis during development and in adult epithelia. However, Brf1 overexpression or heterozygosity are unable to modify tumorigenesis, suggesting a permissive, but not driving role for Brf1 in the development of epithelial cancers of the pancreas and gut

Creating a Solar Roadmap for your School

This presentation, provided by Madison Area Technical College, was given at the Midwest Renewable Energy Fair on June 21, 2019. This presentation provides a brief overview of historical clean energy efforts at Madison College, the Solar Photovoltaic Roadmap, Madison College's rooftop solar project, and steps to a solar roadmap for educational institutions. The steps include: Assemble Roadmap Team, Motivating Objectives, Identifying Stakeholders, Energy Usage and Costs, Document Energy Management Practices, Assess Site for Solar, Economic Modeling, Prioritize Projects, Disseminate the Plan, and Implement Projects.Â