Alien Registration- Crichton, James A. (Gorham, Cumberland County)

https://digitalmaine.com/alien_docs/31956/thumbnail.jp

High-pressure x-ray diffraction study of bulk and nanocrystalline PbMoO4

We studied the effects of high-pressure on the crystalline structure of bulk and nanocrystalline scheelite-type PbMoO4. We found that in both cases the compressibility of the materials is highly non-isotropic, being the c-axis the most compressible one. We also observed that the volume compressibility of nanocrystals becomes higher that the bulk one at 5 GPa. In addition, at 10.7(8) GPa we observed the onset of an structural phase transition in bulk PbMoO4. The high-pressure phase has a monoclinic structure similar to M-fergusonite. The transition is reversible and not volume change is detected between the low- and high-pressure phases. No additional structural changes or evidence of decomposition are found up to 21.1 GPa. In contrast nanocrystalline PbMoO4 remains in the scheelite structure at least up to 16.1 GPa. Finally, the equation of state for bulk and nanocrystalline PbMoO4 are also determined.Comment: 18 pages, 4 figure

Learner Requirements and Geospatial Literacy Challenges for Making Meaning with Google Earth

This research contributes an educational research perspective to teaching and learning with geospatial technologies. This work considers the literacy of a geospatial text that is readily accessible to students, but often assumed to be intuitive to read– dynamic scalable satellite imagery, which often serves as base maps for common navigation, GIS, and virtual globe applications. Within the context of a STEM project, Grades 5 and 6 students were observed and interviewed to identify knowledge and skills that were required to make meaning of Google Earth imagery. A qualitative methodological approach incorporating a thinkaloud data collection protocol was followed to stay true to the breadth, depth and nuances of the student voice and experience. When engaged with Google Earth, the students were observed to employ a range of image interpretation skills, demonstrated various expertise in navigation, and also drew upon their knowledge of the technology. Challenges to understanding the imagery included dominant alignment effect, dimensional translation, and interpreting the nadir view. Students who had an understanding of the underlying technology of the application were better able to overcome these challenges. These results suggest that ensuring students have knowledge about the technology itself, and basic literacy of satellite imagery, is valuable in order to make meaning of the data, critical at this age when students are developing their mental constructs of the world with such geospatial data

Data-constrained assessment of ocean circulation changes since the middle Miocene in an Earth system model

Since the middle Miocene (15 Ma, million years ago), the Earth's climate has undergone a long-term cooling trend, characterised by a reduction in ocean temperatures of up to 7–8 ∘C. The causes of this cooling are primarily thought to be due to tectonic plate movements driving changes in large-scale ocean circulation patterns, and hence heat redistribution, in conjunction with a drop in atmospheric greenhouse gas forcing (and attendant ice-sheet growth and feedback). In this study, we assess the potential to constrain the evolving patterns of global ocean circulation and cooling over the last 15 Ma by assimilating a variety of marine sediment proxy data in an Earth system model. We do this by first compiling surface and benthic ocean temperature and benthic carbon-13 (δ13C) data in a series of seven time slices spaced at approximately 2.5 Myr intervals. We then pair this with a corresponding series of tectonic and climate boundary condition reconstructions in the cGENIE (“muffin” release) Earth system model, including alternative possibilities for an open vs. closed Central American Seaway (CAS) from 10 Ma onwards. In the cGENIE model, we explore uncertainty in greenhouse gas forcing and the magnitude of North Pacific to North Atlantic salinity flux adjustment required in the model to create an Atlantic Meridional Overturning Circulation (AMOC) of a specific strength, via a series of 12 (one for each tectonic reconstruction) 2D parameter ensembles. Each ensemble member is then tested against the observed global temperature and benthic δ13C patterns. We identify that a relatively high CO2 equivalent forcing of 1120 ppm is required at 15 Ma in cGENIE to reproduce proxy temperature estimates in the model, noting that this CO2 forcing is dependent on the cGENIE model's climate sensitivity and that it incorporates the effects of all greenhouse gases. We find that reproducing the observed long-term cooling trend requires a progressively declining greenhouse gas forcing in the model. In parallel to this, the strength of the AMOC increases with time despite a reduction in the salinity of the surface North Atlantic over the cooling period, attributable to falling intensity of the hydrological cycle and to lowering polar temperatures, both caused by CO2-driven global cooling. We also find that a closed CAS from 10 Ma to present shows better agreement between benthic δ13C patterns and our particular series of model configurations and data. A final outcome of our analysis is a pronounced ca. 1.5 ‰ decline occurring in atmospheric (and ca. 1 ‰ ocean surface) δ13C that could be used to inform future δ13C-based proxy reconstructions.</p

Evaluation of a rehabilitation support service after acute stroke: Feasibility and patient/carer benefit

Background: Stroke survivors returning home after discharge from hospital and their carers require support to meet their rehabilitation needs (independence in Activities of Daily Living, exercise, psychosocial support). Voluntary or charitable care providers may be able to address some of these needs. Objective: To explore the feasibility of delivering and evaluating enhanced support to stroke survivors and their carers, with a Rehabilitation Support Worker (RSW). Methods: 16 consecutive stroke survivors and their carers were included. All participants received usual hospital care. Seven of these patients and their carers were also allocated an RSW from a charitable care provider. The RSW accompanied therapy training sessions with the patient, carer and therapist in hospital. On discharge, the RSW visited the patient and carer at home over the initial 6 week post-discharge period to support them in practising rehabilitation skills. Patient function (Barthel Index) and patient/carer confidence were independently assessed at discharge (Week 0). The above assessments and patient/carer mood (GHQ-12) and Carer Giver Strain were also assessed at Weeks 1, 6 and 12. RSWs were interviewed for their views about the service. Results: Participants’ functional ability at Week 1 post-discharge was significantly higher in the RSW group. At 6 and 12 weeks post-discharge, functional ability was not significantly different between groups. Carers in the intervention group were less confident at all time points, however, this was not significant. There was no significant effect on carer strain or well-being. Interviews with RSWs highlighted areas of their training that could be enhanced and the need for greater clarity as to their role. Conclusions: The results showed that a definitive trial of rehabilitation support is feasible. A number of obstacles however would need to be overcome including: difficulty in identifying suitable patients, clarity of the RSW role, and appropriate training content