Application of Ion Cyclotron Resonance to the Study of Inelastic Excitation by Low-Energy Electrons

The geometry of the resonance cell employed for ion cyclotron resonance spectroscopy (1-3) is ideally suited for studying inelastic excitation by low-energy electrons. It has been shown that the electron beam traverses a parabolic potential well between the trapping electrodes, the depth of which is approximately half the applied trapping voltage (3,4). Low-energy electrons generated by impact excitation of an atomic or molecular energy level can be trapped in the resonance cell if their final translational energy is insufficient to escape the preset depth of the potential well. These electrons can be drifted from the source of the resonance region by applying the usual static drift field E normal to the primary magnetic field H (4). The electron drift velocity in this crossed field geometry, given by cE/H, is independent of both charge and mass. For typical values of E and H the drift velocity is in the range of 10^1-10^3 cm/sec. In the lower range of accessible drift velocities, the residence time of electrons in the resonance cell approaches 0.1 sec

Molecular Gas Around Young Stellar Clusters

We have begun a survey of the molecular gas surrounding 31 young clusters in order to investigate the link between environment and the resulting cluster. We present here a preliminary comparison of two clusters in our sample: GGD12-15 and Mon R2. Since both clusters are located in the MonR2 molecular cloud at a distance of 830 pc, observational biases due to differing sensitivities and angular resolutions are avoided.Comment: 2 pages, 2 figures, uses newpasp.sty. To appear in "Hot Star Workshop III: The Earliest Phases of Massive Star Birth" (ed. P.A. Crowther

Peer-to-Peer Feedback: An Instructional Strategy in Teacher Evaluation

Over the last several decades there have been federal movements in education which place more accountability on schools and consequently their principals. Principals have many responsibilities which vary from administrative duties to improving teaching in their schools. As a result, principals are often asked to do more than they believe they have time to accomplish. Peer-to-peer feedback is a practice that principals can use to help evaluate, and more importantly, help teachers improve their teachers’ teaching. This multi-case or multi-school qualitative study researched the practice of peer-to-peer feedback at two elementary schools. The purpose was to understand how peer-to-peer feedback informs teacher efficacy, or a teachers’ self-beliefs to be successful, and the factors which are contributing to those self-beliefs. Interviews, focus groups, and journal responses were used to gather data from participating teachers and the principals. In Case 1 there were three participants, and in Case 2 there were six participants. Both cases or schools have evidence to suggest that teacher efficacy is informed positively by peer-to-peer feedback. The shared factors between the two schools were support, improved teaching, and more joy. This provides more data that peer-to-peer feedback can be used in the future to inform teacher efficacy positively, and also highlights the need to do more research in this field

The Near-Infrared Extinction Law in Regions of High Av

We present a spectroscopic study of the shape of the dust-extinction law between 1.0 and 2.2um towards a set of nine ultracompact HII regions with Av > 15 mag. We find some evidence that the reddening curve may tend to flatten at higher extinctions, but just over half of the sample has extinction consistent with or close to the average for the interstellar medium. There is no evidence of extinction curves significantly steeper than the standard law, even where water ice is present. Comparing the results to the predictions of a simple extinction model, we suggest that a standard extinction law implies a robust upper limit to the grain-size distribution at around 0.1 - 0.3um. Flatter curves are most likely due to changes in this upper limit, although the effects of flattening due to unresolved clumpy extinction cannot be ruled out.Comment: 9 pages, 7 figure

Improving Instructional Practice through Peer Observation and Feedback

The Every Student Succeeds Act provides an opportunity for policymakers and researchers to revisit what is known about effective teacher evaluation practices to make better-informed decisions moving forward. Principals—responsible for implementing new teacher evaluation reforms and accommodating the demands to spend more time observing and providing feedback to teachers—are overworked. They have little time to provide high-quality feedback, and may lack important content-based expertise. With these considerations in mind, we explore the role of peer observation and feedback as a vehicle to move beyond high-stakes evaluation and re-center efforts on instructional improvement. Our systematic review of extant literature (n = 38 documents, 92% peer-reviewed empirical articles) indicates that peer observation and feedback is a promising practice for instructional improvement, but one that lacks sufficient evidence. Policy, thus, can encourage innovation and research around this practice so that peer observation and feedback models can be piloted and the most effective established, as well as strategies to tackle the biggest barriers schools, particularly U.S. schools face in implementing such a practice—time

The interaction of ions with nonpolar neutrals: The collision broadening of ion cyclotron resonance lines of ions in hydrogen and methane

The motion of ions in an ion cyclotron resonance cell is considered, and measurements of ion cyclotron resonance linewidths are described. The connection between cyclotron resonance linewidths and kinetic parameters is developed. Mobilities and collision frequencies of CH5 + , C2H5 + , C3H7 + , C4H9 + , and Na + in methane and H + , H3 + , H30 + , CH5 + , C2H5 + , C3H7 + , and Na + in hydrogen are determined from the linewidth measurements. Resulting mobilities of H + , H3 + , and Na + in H2 are found to agree well with drift tube measurements, in contrast to previous cyclotron resonance linewidth determinations. The mobilities are interpreted in terms of three model ion molecule interaction potentials. The mobilities are found to be in general consistent with both a three term 12–6–4 potential and an acentric potential but not with the simple polarization potential. Potential parameters consistent with binding energies from the literature and the present mobility measurements are reported for H3 + –H2, CH5 + –CH4, and C2H5 + –CH4

Helium and Hydrogen Line Ratios and The Stellar Content of Compact HII Regions

We present observations and models of the behaviour of the HI and HeI lines between 1.6 and 2.2um in a small sample of compact HII regions. As in our previous papers on planetary nebulae, we find that the `pure' 1.7007um 4^3D-3^3P and 2.16475um 7^(3,1)G-4^(3,1)F HeI recombination lines behave approximately as expected as the effective temperature of the central exciting star(s) increases. However, the 2.058um 2^1P-2^1S HeI line does not behave as the model predicts, or as seen in planetary nebulae. Both models and planetary nebulae showed a decrease in the HeI 2^1P-2^1S/HI Br gamma ratio above an effective temperature of 40000K. The compact HII regions do not show any such decrease. The problem with this line ratio is probably due to the fact that the photoionisation model does not account correctly for the high densities seen in these HII regions, and that we are therefore seeing more collisional excitation of the 2^1P level than the model predicts. It may also reflect some deeper problem in the assumed model stellar atmospheres. In any event, although the normal HeI recombination lines can be used to place constraints on the temperature of the hottest star present, the HeI 2^1P-2^1S/HI Br gamma ratio should not be used for this purpose in either Galactic HII regions or in starburst galaxies, and conclusions from previous work using this ratio should be regarded with extreme caution. We also show that the combination of the near infrared `pure' recombination line ratios with mid-infrared forbidden line data provides a good discriminant of the form of the far ultraviolet spectral energy distribution of the exciting star(s). From this we conclude that CoStar models are a poor match to the available data for our sources, though the more recent WM-basic models are a better fit.Comment: Accepted for publication in MNRA

Comparative Environmental Benefits of Lightweight Design in the Automotive Sector: The Case Study of Recycled Magnesium Against Cfrp and Steel

A LCA feasibility study was undertaken to determine the environmental impact of an Eco-magnesium process route by recycled chips to manufacture panel for the automotive sector to be compared with comparative scenarios, a non-recycled carbon fiber reinforced polymer (CFRP) and a baseline steel-made component scenario. The objective of this LCA study was to assess the actual benefits of a lightweight solution considering the whole life cycle, including the dirty-phase (i.e. the “cradle-to-exit gate” stage) that impacts differently for the different materials. For this reason the analysis has regarded the net “cradle-to-grave” scenario. Different automotive floor pans were then compared considering the rate of fuel consumption during vehicle operation - i.e. the fuel-mass correlation factor - and the different material substitution factors allowed by the different materials selected

Care, control and the electroconvulsive therapy (ECT) ritual: Making sense of polarised patient narratives

Despite evidence of short-term effectiveness of ECT (electroconvulsive therapy), both positive and negative patient reports are common. However, research examining these polarized accounts has not adequately elucidated why such divergences occur. We thus sought to examine opposing patient narratives to better understand underlying meanings. Eighteen interviews were conducted with UK-based people who had experienced the treatment. Our analysis revealed that the quality of relations with staff, ECT artefacts (e.g. the ECT suite), and perceived outcomes all play a role in divergent accounts. Positive reflections on ECT emerged alongside narratives of trust in staff, comfort with ECT, and perception of sufficient personal control. Conversely, where negative evaluations of ECT predominated, there was anger associated with a lack of control, and a belief that ECT made little sense, and was linked to past abuses and/or the unacceptability of side effects. We discuss the implications of our findings for professionals

Functional Comparison of Six-Minute Walk Tests Between Shod and Minimalist Footwear Individuals in Mid-Life: A Preliminary Pilot Study Analysis

Research has shown that wearing minimalistic footwear can increase intrinsic and extrinsic foot muscle size and strength,although the effect of transitioning from shod to minimalist footwear on gait functionality–such as performance on a six-minute walk test–is not well documented. PURPOSE: We observed the differences in a six-minute functional walk test between mid-life (45yrs-65yrs) individuals who transitioned to minimalist footwear (MF) over a fourteen month period compared to habitually shod (HS) individuals. METHODS: Twenty mid-life individuals participated in this study. Participants were randomly assigned to either the MF (n=8, age= 56.5 ± 5.18 yrs, height= 162.71 ± 7.69 cm, weight= 82.71 ± 16.24 kg,) or HS (n=12, age= 57.36 ± 5.43 yrs, height= 162.91 ± 7.44 cm, weight= 73.48 ± 15.65 kg) group. MF participants were coached through a nine-week training to safely transition to MF. Participants assigned to the HS group were instructed to continue normal activity. Each participant underwent a data collection at 1 week, 9 weeks, 8 months, and 14 months. At each data collection, the individual was instructed to walk as far as possible around a set track for 6 minutes. Every lap around the track was 208 feet and partial laps were measured to the distance completed. RESULTS: A repeated measures ANOVA indicated a significant increase in distance walked at 8 months (1703.5 ± 190.2 ft, p=0.009) and 14 months (1708.1 ± 181.1 ft, p=0.025) compared to week 1 (1634.6 ± 194.7 ft). There was no significant difference between groups in the increase in walking distance (p=0.950). Significant covariates were biological sex (p=0.007) and height (p=0.034). CONCLUSION: Overall, participants in the study increased walking distance in the six-minute walk test regardless of group. Therefore, minimalist shoes do not appear to affect gait functionality in mid-life adults during the six-minute walk test