38 research outputs found
For the Good of the Empire: The Basis of Decisional Thought at The Council of Niceae
As the Christian Church began to gain power in Late Antiquity the church needed to have an agreed upon set of beliefs. At the Council of Nicaea many of the early church Canons and creeds were created. This Thesis looks at the political reasons for why such decisions were made
A case study of the impact of credit bearing programmes relating to teachers from one institution of higher education
A key component of school improvement initiatives has been the professional development of teachers. However, relatively little work has been undertaken to explore the contribution made by programmes in higher education in the professional development of teachers and their institutions. This is despite some considerable doubt raised by some writers and official policies. This research focuses upon the evidence for impact, the conditions that contribute to that impact and an analysis of the role of HE in the professional development of teachers in the context of school improvement. The research is a case study of one institution. A naturalistic and interpretative approach is adopted, portraying the views of participants on the APU programme. Data is collected through semi structured interviews and supported by observation, documentary analysis and Ofsted reports. The research concludes that impact is widespread and ubiquitous, and that conditions are found in individual motivations, within schools and within the HEI provider. This leads to a conclusion that care for the whole system of education, including the university sector is essential for developing continuous improvement. In particular, the way the profession values academic awards, and the inherent qualities of critical reflection, research, and analysis that the awards represent are shown to be an important factor or condition in assessing 'impact'
Developing engagement in Ultralab’s online communities of enquiry
This paper provides an account of the development of online communities at Ultralab for students engaged on masters‐level programmes, doctoral research and continuing professional learning. It considers the ways in which the engagement of learners, and their consequent participation, is seen to be dependent on several factors—the learners’ perception of purpose, their sense of identity and trust, framing of learning activities, interventions from learning facilitators and tutors, and the information architecture of the learning space. The notion of engagement in this online community in higher education (HE) is explored. The term ‘community of enquiry’ is used to indicate the key purpose of the community—that of practitioner‐based enquiry, or research
Pyrochlore formation, phase relations, and properties in the CaO-TiO2-(Nb,Ta)(2)O-5 systems
International audiencePhase equilibria studies of the CaO:TiO2:Nb2O5 system confirmed the formation of six ternary phases: pyrochlore (A2B2O6O′), and five members of the (110) perovskite-slab series Can(Ti,Nb)nO3n+2, with n=4.5, 5, 6, 7, and 8. Relations in the quasibinary Ca2Nb2O7−CaTiO3 system, which contains the Can(Ti,Nb)nO3n+2 phases, were determined in detail. CaTiO3 forms solid solutions with Ca2Nb2O7 as well as CaNb2O6, resulting in a triangular single-phase perovskite region with corners CaTiO3–70Ca2Ti2O6:30Ca2Nb2O7–80CaTiO3:20CaNb2O6. A pyrochlore solid solution forms approximately along a line from 42.7:42.7:14.6 to 42.2:40.8:17.0 CaO:TiO2:Nb2O5, suggesting formulas ranging from Ca1.48Ti1.48Nb1.02O7 to Ca1.41Ti1.37Nb1.14O7 (assuming filled oxygen sites), respectively. Several compositions in the CaO:TiO2:Ta2O5 system were equilibrated to check its similarity to the niobia system in the pyrochlore region, which was confirmed. Structural refinements of the pyrochlores Ca1.46Ti1.38Nb1.11O7 and Ca1.51Ti1.32V0.04Ta1.10O7 using single-crystal X-ray diffraction data are reported (Fd3m (#227), a=10.2301(2) Å (Nb), a=10.2383(2) Å (Ta)), with Ti mixing on the A-type Ca sites as well as the octahedral B-type sites. Identical displacive disorder was found for the niobate and tantalate pyrochlores: Ca occupies the ideal 16d position, but Ti is displaced 0.7 Å to partially occupy a ring of six 96g sites, thereby reducing its coordination number from eight to five (distorted trigonal bipyramidal). The O′ oxygens in both pyrochlores were displaced 0.48 Å from the ideal 8b position to a tetrahedral cluster of 32e sites. The refinement results also suggested that some of the Ti in the A-type positions may occupy distorted tetrahedra, as observed in some zirconolite-type phases. The Ca–Ti–(Nb,Ta)–O pyrochlores both exhibited dielectric relaxation similar to that observed for some Bi-containing pyrochlores, which also exhibit displacively disordered crystal structures. Observation of dielectric relaxation in the Ca–Ti–(Nb,Ta)–O pyrochlores suggests that it arises from the displacive disorder and not from the presence of polarizable lone-pair cations such as Bi3+
High-Frequency/High-Field Electron Paramagnetic Resonance and Theoretical Studies of Tryptophan-Based Radicals
Tryptophan-based
free radicals have been implicated in a myriad
of catalytic and electron transfer reactions in biology. However,
very few of them have been trapped so that biophysical characterizations
can be performed in a high-precision context. In this work, tryptophan
derivative-based radicals were studied by high-frequency/high-field
electron paramagnetic resonance (HFEPR) and quantum chemical calculations.
Radicals were generated at liquid nitrogen temperature with a photocatalyst,
sacrificial oxidant, and violet laser. The precise <i>g</i>-anisotropies of l- and d-tryptophan, 5-hydroxytryptophan,
5-methoxytryptophan, 5-fluorotryptophan, and 7-hydroxytryptophan were
measured directly by HFEPR. Quantum chemical calculations were conducted
to predict both neutral and cationic radical spectra for comparison
with the experimental data. The results indicate that under the experimental
conditions, all radicals formed were cationic. Spin densities of the
radicals were also calculated. The various line patterns and <i>g</i>-anisotropies observed by HFEPR can be understood in terms
of spin-density populations and the positioning of oxygen atom substitution
on the tryptophan ring. The results are considered in the light of
the tryptophan and 7-hydroxytryptophan diradical found in the biosynthesis
of the tryptophan tryptophylquinone cofactor of methylamine dehydrogenase