Fresnel coefficients of a two-dimensional atomic crystal

In general the experiments on the linear optical properties of a single-layer two-dimensional atomic crystal are interpreted by modeling it as a homogeneous slab with an effective thickness. Here I fit the most remarkable experiments in graphene optics by using the Fresnel coefficients, fixing both the surface susceptibility and the surface conductivity of graphene. It is shown that the Fresnel coefficients and the slab model are not equivalent. Experiments indicate that the Fresnel coefficients are able to simulate the overall experiments here analyzed, while the slab model fails to predict absorption and the phase of the reflected light

Using community interaction theory to understand the effects of group mentoring on adolescents

This paper describes the outcomes for adolescents taking part in a 12-week group behavioural mentoring programme and possible causal mechanisms involved, using Law's (1981) Community Interaction Theory as a theoretical framework. The two-stage qualitative research with four groups of students aged 13–14 showed that there were changes to their understanding of self, their self confidence, their ability to control emotions and behaviour and, importantly, changes in their career aspirations. Interacting with their mentors (adults from outside their previous communities) appeared to have a significant impact on them. The data suggests this was via the creation of a new community which moderated existing beliefs about who they were, and what opportunities were open to them. The mentors provided feedback, support and information, and were perceived as a credible and trusted role model. The study offers an application of Law's theory to the younger students it was developed for and provides evidence suggestive of the importance of interactions with wider communities in career development and widening participation, although future research should consider long-term follow-up of mentees

SCiP Alliance Thriving Lives Toolkit: Implementation and Impact Evaluation

Primary and secondary schools responded positively to the Thriving Lives Toolkit, finding it to be a valuable resource which promoted auditing, action planning and development. All schools made progress on the principles, even when they had only been using it for a short time frame. Senior leadership support was important for facilitating this. The progress made by schools started with appointing a named contact and typically involved making use of local and national support groups and evidence based resources to increase staff awareness and implement a range of interventions. Most often these were focused on making transition more effective but schools also spent time on improving wellbeing and attainment. Schools perceived several outcomes as a consequence of this activity. School staff were more confident in supporting Service children and this had become a key activity in schools. Service children were perceived to have improved wellbeing and to be more engaged in school. Schools had improved relationships with Service families. The findings suggest that the self-assessment process enabled schools to improve their provision - engaging with the Toolkit has facilitated activity, progress and positive outcomes for Service children

Rollup subsolar array Quarterly technical report, 5 Mar. - 30 May 1969

Thermal cycling and environmental tests for solar arra

Compensation of atmospheric CO2 buildup through engineered chemical shrinkage

Retrieval of background carbon dioxide into regional chemical extractors would counter anthropogenic inputs in a manner friendly to established industries. We demonstrate via atmospheric transport/scaling calculations that for idealized flat removal units, global coverage could be less than two hundred thousand square kilometers. The disrupted area drops to a small fraction of this with engineering into the vertical to bypass laminarity. Fence structures and artificial roughness elements can both be conceived. Sink thermodynamics are analyzed by taking calcium hydroxide as a sample reactant. Energy costs could be minimized at near the endothermicity of binding reversal. In the calcium case the value is 25 kcal mole-1, as against a fuel carbon content of 150 in the same units. Aqueous kinetics are less than favorable for the hydroxide, but misting could counteract slow liquid phase transfer. Properties of superior scrubbers are outlined

Chemical transport modeling of potential atmospheric CO2 sinks

The potential for carbon dioxide (CO2) sequestration via engineered chemical sinks is investigated using a three dimensional chemical transport model (CTM). Meteorological and chemical constraints for flat or vertical systems that would absorb CO2 from the atmosphere, as well as an example chemical system of calcium hydroxide (Ca(OH)2) proposed by Elliott et al. [Compensation of atmospheric CO2 buildup through engineered chemical sinkage, Geophys. Res. Lett. 28 (2001) 1235] are reviewed. The CTM examines land based deposition sinks, with 4° × 5° latitude/longitude resolution at various locations, and deposition velocities (v). A maximum uptake of ∼20 Gton (1015 g) Cyr-1 is attainable with v ≥ 5 cms-1 at a mid-latitude site. The atmospheric increase of CO2 (3 Gtonyr-1) can be balanced by an engineered sink with an area of no more than 75, 000 km2 at v of 1 cms-1. By building the sink upwards or splitting this area into narrow elements can reduce the active area by more than an order of magnitude as discussed in Dubey et al. © 2002 Elsevier Science Ltd. All rights reserved

New statistical method identifes cytokines that distinguish stool microbiomes

Regressing an outcome or dependent variable onto a set of input or independent variables allows the analyst to measure associations between the two so that changes in the outcome can be described by and predicted by changes in the inputs. While there are many ways of doing this in classical statistics, where the dependent variable has certain properties (e.g., a scalar, survival time, count), little progress on regression where the dependent variable are microbiome taxa counts has been made that do not impose extremely strict conditions on the data. In this paper, we propose and apply a new regression model combining the Dirichlet-multinomial distribution with recursive partitioning providing a fully non-parametric regression model. This model, called DM-RPart, is applied to cytokine data and microbiome taxa count data and is applicable to any microbiome taxa count/metadata, is automatically fit, and intuitively interpretable. This is a model which can be applied to any microbiome or other compositional data and software (R package HMP) available through the R CRAN website