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Contribution: This article defines "curricular hackathons" and describes the features, challenges, and opportunities of adopting the hackathon format into engineering curricula. It is based on experience implementing a series of curricular hackathons which provide students with formative design experiences as they address ill-structured and integrative design problems. Background: Design is an essential part of engineering practice. However, undergraduate engineering students are provided few opportunities to develop the skills necessary for solving ill-structured and complex design problems prior to their final year capstone projects. Cornerstone projects and other summative activities are common attempts to introduce students to design, but often carry significant academic weight in the host course. Adapting the hackathon format into curricular elements could provide a useful pedagogy for formative design practice. Research Question: How can the hackathon format be effectively adapted into curricular activities? Methodology: The study uses a multiple case study research design to extract insight from 12 implementations of curricular hackathons in engineering at the University of Waterloo. The twelve cases were analyzed through two methods: 1) a synthesis of eight previous publications and 2) an interview study of 12 instructors involved in their design and implementation. Findings: Adapting the popular hackathon format to a curricular setting requires several adaptations to maximize the impact on students. Curricular hackathons: are a short, high intensity social experience; that guide students through the design-build-test cycle of a design problem, include opportunities for reflection; and achieve some level of integration and/or embedding in a program's curriculum.

Contribution: A first-year programming course was redesigned with a large, open-ended robotics project. The course design aligns with best practices for promoting development of students' self-efficacy in solving ill-structured software design problems. Background: From Jonassen's theory, problem-solving outcomes are dependent on the problem structure, complexity, and representation; and the characteristics of the solver. These characteristics are diverse, including knowledge, familiarity, and psychometric qualities of the solver (e.g., self-efficacy and motivation). Thus, better problem-solving outcomes are dependent on the development of these traits, and on the problem characteristics. Intended Outcomes: Pre-2010, course learning activities and assessments overly focused on syntax. The course was redesigned with a focus on ill-structured problem solving and design in high-fidelity problem domains. Application Design: Complex and ill-structured lecture examples, assignments, and exams were redesigned to reinforce the importance of software design and problem solving. An open-ended cornerstone project using robotics was added as a structured means of providing students practice with solving ill-structured and open-ended problems. The assignment and exam questions, with the course cornerstone project, achieve instructional alignment in the course. Findings: The results show that students' self-efficacy improved from start to end of term. The course design achieves several objectives: 1) students learned the requisite programming skills; 2) students developed their self-efficacy in programming and design; and 3) students demonstrated strong problem-solving outcomes.

Contribution: A semester-long, open-ended design project was implemented to promote intellectual development of first-year students while reinforcing event-driven/procedural programming principles. This paper describes this approach, and an evaluation strategy using Perry's model for intellectual development. The results show that students can reach the relativism stage of Perry's model in their first year of studies. Background: Students must move beyond a dualistic worldview to be engineers. Felder and Brent provided a list of recommendations to promote this type of intellectual development in students; active learning strategies strongly align with these recommendations. While active learning is common in programming courses (sometimes taking the form of project-based learning), they are typically tightly controlled by the instructor, and limited in scope (both in time and complexity), potentially reducing their impact on students. Intended Outcomes: This course and term-long project provided students a supportive environment in which to develop their decision-making skills, and promoted their intellectual development through Perry's stages related to software design. Application Design: Aligned with Felder and Brent's recommendations and Kuh's High Impact Practices, a course was built to: 1) teach students procedural programming, with 2) a focus on software design and open-ended problem solving, while maintaining 3) a supportive environment for skill acquisition. Findings: A mixed methods study showed the majority of students align themselves with the relativism stage of intellectual development at the end of the course. This study also illuminated the decision-making processes of teams of students in a first-year software design course.

Generating a controllable and pure source of molecular free-radicals or open-shell atoms has been one of the primary barriers hindering the detailed study of radical processes in the laboratory. Here, we introduce a novel magnetic guide for the generation of a pure beam of velocity-selected radicals—a tuneable source that will enable the study of radical interactions with exceptional control over the properties of the radical species. Only radicals with a selected velocity are transmitted through the guide; all other components of the incoming beam (radical species traveling at other velocities, precursor molecules, and seed gas) are removed. The guide is composed of four Halbach arrays—hexapolar focusing elements—and two skimming blades. The relative positions of these components can be adjusted to tune the properties of the resulting beam and to optimise transmission for a given velocity. Experimental measurements of Zeeman-decelerated H atoms transmitted through the guide, combined with extensive simulations, show that the magnetic guide removes 99% of H-atoms traveling outside the narrow target velocity range. [ABSTRACT FROM AUTHOR]

A direct simulation Monte Carlo (DSMC) method is applied to model collisions between He buffer gas atoms and ammonia molecules within a buffer gas cell. State-to-state cross sections, calculated as a function of the collision energy, enable the inelastic collisions between He and NH3 to be considered explicitly. The inclusion of rotational-state-changing collisions affects the translational temperature of the beam, indicating that elastic and inelastic processes should not be considered in isolation. The properties of the cold molecular beam exiting the cell are examined as a function of the cell parameters and operating conditions; the rotational and translational energy distributions are in accord with experimental measurements. The DSMC calculations show that thermalisation occurs well within the typical 10-20 mm length of many buffer gas cells, suggesting that shorter cells could be employed in many instances--yielding a higher flux of cold molecules. [ABSTRACT FROM AUTHOR]

This paper describes the development and implementation of a survey instrument, based on Jonassen's design theory of problem solving, which characterizes educational design activities. The motivation behind this work is to determine the effectiveness of authentic problem solving activities - called Engineering Design Days - implemented in the University of Waterloo's 14 engineering programs. The instrument is a guided survey given to instructors which captures an activity's problem variation and representation. The survey was developed through a number of iterations. with refinements addressing observed shortcomings in the collected data. Its application is demonstrated with a case study of one design activity that was offered to first year software engineering students. The survey captures many of the elements of Jonassen's design theory of problem solving as they pertain to educational design activities. Future work will focus on applying the instrument to additional educational design activities, which may inform future evolutions to the survey. [ABSTRACT FROM AUTHOR]

The Canadian Design Workshop (CDW) is a new biennial workshop - held in partnership with the Clive L. Dym Mudd Design Workshop - that aims to investigate and share information on design education and research unique to Canadian institutions, focusing on elevating engineering design education and research within the Canadian context. The Canadian engineering education and research landscapes presently share commonalities and important differences from the landscape typically explored during the Clive L. Dym Mudd Design Workshops. This paper discusses the logistics of running the inaugural workshop (CDW 1), including challenges and opportunities afforded by the virtual offering. A thematic analysis of the presentations and ensuing discussions during the workshop reveals a number of recurring themes across all sessions, including transdisciplinarity, sustainability, the design studio pedagogy, teaching of design in the "middle years" of engineering programs, and challenges in design education. The paper concludes with a reflection on the first offering of the workshop and implications for the future of CDW. [ABSTRACT FROM AUTHOR]

This paper describes the implementation of a short duration, design-build-test project for first and second year students where teams were tasked with creating a functioning scanning tunneling microscope. The activity was scaffolded to ensure students could handle the demands of such a complex activity, while making sure that all students could experience some measure of success through specific tasks. This "Engineering Design Day" activity sought to provide experience in engineering design early in students' academic careers as a means to improve their design self-efficacy, show them connections with their classroom learning, and provide an authentic opportunity to work in teams. To evaluate the activity, the Engineering Design Self-Efficacy Instrument was given to students before taking part in the activity, and again at the end of the semester to assess whether there was any growth in student self-efficacy in conducting engineering design. The results showed a statistically significant increase iii student confidence and motivation in conducting design, and in their expectations of success at design, while there was no change in their anxiety regarding design. Through examining responses, students enjoyed the activity, they were able to practice working in a team and they were engaged with the design process throughout. These results show that design activities of shorter duration than a typical course project may lead to positive change in students engineering design self-efficacy beliefs. [ABSTRACT FROM AUTHOR]

The laser-induced blackbody-assisted rotational cooling of a linear polyatomic ion, C2H+2 , in its 2Π ground electronic state in the presence of the blackbody radiation field at 300 K and 77 K is investigated theoretically using a rate-equations model. Although pure rotational transitions are forbidden in this non-polar species, the v5 cis-bending mode is infrared active and the (1-0) band of this mode strongly overlaps the 300 K blackbody spectrum. Hence the lifetimes of state-selected rotational levels are found to be short compared to the typical timescale of ion trapping experiments. The v5 (1-0) transition is split by the Renner-Teller coupling of vibrational and electronic angular momentum, and by the spin-orbit coupling, into six principal components and these effects are included in the calculations. In this paper, a rotational-cooling scheme is proposed that involves simultaneous pumping of a set of closely spaced Q-branch transitions on the 2Δ5/2 -2Π3/2 band together with two Q-branch lines in the 2Σ+- 2Π½ band. It is shown that this should lead to >70% of total population in the lowest rotational level at 300 K and over 99% at 77 K. In principle, the multiple Q-branch lines could be pumped with just two broad-band (~Δv = 0.4-3 cm-1) infrared lasers. [ABSTRACT FROM AUTHOR]

Under the UK focused Greenhouse gAs and Uk and Global Emissions (GAUGE) project, two new tall tower greenhouse gas (GHG) observation sites were established in the 2013/2014 Northern Hemispheric winter. These sites were located at two existing telecommunications towers, Heathfield (HFD) and Bilsdale (BSD), utilised a combination of cavity ring-down spectroscopy (CRDS) and gas chromatography (GC) to measure key GHGs (CO2, CH4, CO, N2O and SF6). Measurements were made at multiple intake heights on each tower. The inclusion of the two additional tower stations within the existing UK Deriving Emissions linked to Climate Change (DECC) network of four stations was found to reduce the uncertainty of CH4 UK emission estimates by between 10-20 %. CO2 and CH4 dry mole fractions were calculated from either CRDS measurements of wet air which were post corrected with an instrument specific empirical correction or samples dried to between 0.05 and 0.3 % H2O using a Nafion dryer, with a smaller correction applied for the residual H2O. The impact of these two drying strategies was examined. Drying with a Nafion drier was not found to have a significant effect on the observed CH4 mole fraction; however, Nafion drying did cause a 0.02 μmol mol-1 CO2 bias. This bias was stable with sample CO2 mole fractions between 373 and 514 μmol mol-1 and for sample H2O up to 3.5 %. As the calibration and standard gases are treated in the same manner, this error is mostly calibrated out with the residual error below the World Meteorological Organization's (WMO) reproducibility requirements. Of more concern was the error associated with both default factory and empirical instrument specific water correction algorithms. These corrections are relatively stable and reproducible for samples with H2O between 0.2 and 2.5 %, CO2 between 345 and 449 μmol mol-1 and CH4 between 1743 and 2145 nmol mol-1. However, the residual errors in these corrections increase to > 0.05 μmol mol-1 for CO2 and > 1 nmol mol-1 for CH4 (greater than the WMO internal reproducibility guidelines) at higher humidities and for samples with very low (< 0.5 %) water content. These errors were also found to scale with the absolute magnitude of the CO2 and CH4 mole fraction. As such, water corrections calculated in this manner are not suitable for samples with low (< 0.5 %) or high (> 2.5 %) water contents and either alternative correction methods should be used or partial drying or humidification considered prior to sample analysis. [ABSTRACT FROM AUTHOR]

A chopper wheel construct is used to shorten the duration of a molecular beam to 13 µs. Molecular beams seeded with NO or with Br2 and an initial pulse width of ≥200 µs were passed through a spinning chopper wheel, which was driven by a brushless DC in vacuo motor at a range of speeds, from 3000 rpm to 80 000 rpm. The resulting duration of the molecular-beam pulses measured at the laser detection volume ranged from 80 µs to 13 µs and was the same for both NO and Br2. The duration is consistent with a simple analytical model, and the minimum pulse width measured is limited by the spreading of the beam between the chopper and the detection point as a consequence of the longitudinal velocity distribution of the beam. The setup adopted here effectively eliminates buildup of background gas without the use of a differential pumping stage, and a clean narrow pulse is obtained with low rotational temperature. [ABSTRACT FROM AUTHOR]

Carbon nitride (CNx) film growth by 193 nm pulsed laser ablation of graphite in a low pressure of N2 has been investigated both by studying optical emission from the plume and by analyses of the composition, structure and bonding of material deposited at a range of substrate temperatures. Spectral analysis of the emission reveals the presence of C+ ions, C atoms, C2 and CN radicals and N2+ molecular ions within the ablation plume travelling towards the substrate. Films deposited at low substrate temperature (Tsub) are amorphous, with an N/C ratio of ∼20 at.%. Raman analysis shows CNx films grown at higher Tsub to be increasingly nanocrystalline, but thinner, and suggests that N inclusion encourages nanocrystallite formation. X-ray photoelectron spectroscopy reveals that CNx films grown at higher Tsub also have a reduced overall N content. The observations have been rationalised by assuming an increased propensity for sputtering or desorption of more labile CN species from the growing film surface at higher Tsub, resulting in a higher fraction of C&z.sbnd;C bonding—most probably in the form of graphitic nanocrystallites embedded in an amorphous matrix. [Copyright &y& Elsevier]

The laser-induced blackbody-assisted rotational cooling of a linear polyatomic ion, C2H+2 , in its 2Π ground electronic state in the presence of the blackbody radiation field at 300 K and 77 K is investigated theoretically using a rate-equations model. Although pure rotational transitions are forbidden in this non-polar species, the v5 cis-bending mode is infrared active and the (1-0) band of this mode strongly overlaps the 300 K blackbody spectrum. Hence the lifetimes of state-selected rotational levels are found to be short compared to the typical timescale of ion trapping experiments. The v5 (1-0) transition is split by the Renner-Teller coupling of vibrational and electronic angular momentum, and by the spin-orbit coupling, into six principal components and these effects are included in the calculations. In this paper, a rotational-cooling scheme is proposed that involves simultaneous pumping of a set of closely spaced Q-branch transitions on the 2Δ5/2 -2Π3/2 band together with two Q-branch lines in the 2Σ+- 2Π½ band. It is shown that this should lead to >70% of total population in the lowest rotational level at 300 K and over 99% at 77 K. In principle, the multiple Q-branch lines could be pumped with just two broad-band (~Δv = 0.4-3 cm-1) infrared lasers. [ABSTRACT FROM AUTHOR]