Preparation and properties of nanocrystalline Yb2O3

Nanocrystalline Yb2O3 of various particle sizes was prepared using sol-gel method. XRD analysis shows that the prepared nanocrystalline Yb2O3 is cubic in structure with space group Ia3. TEM photographs indicate that Yb2O3 nanoparticles are basically spherical in shape. Calculation of crystallite size indicates that the average crystallite size of Yb2O3 increases with increasing calcination temperature, but the average crystal lattice distortion rate decreases with increasing calcination temperature and crystallite size. This result shows that the smaller the crystallite size, the bigger the crystal lattice distortion, and the worse crystal growth. Solubility test of Yb2O3 in nitric acid shows that the surface activity of Yb2O3 increases with decreasing crystallite size. Fourier Transform Infrared Spectrometer (FTIR) spectra reveal that nanocrystalline Yb2O3 has higher surface activity; than that of ordinary Yb2O3. Absorbance intensity of Yb-O bond of nanocrystalline Yb2O3 is weaker than that of ordinary Yb2O3, and the absorbance of Yb-O bond of nanocrystalline Yb2O3 is small blue-shifted.

Effective interface of a composite membrane serving as an ideally ultrathin barrier layer

A novel idea relating to the selective barrier layer of a composite membrane is described. The effective interface of the composite membrane could act as a barrier layer which could be controlled to an ideally ultrathin thickness. A new type of polyamide composite membrane was prepared according to this idea, which possessed permeability and chemical resistance more than one magnitude greater than those of ordinary polyamide composite membranes. Copyright (C) 1996 Elsevier Science Ltd.

Getting Constitutional Theory into Proportion: A Matter of Interpretation?

Gibbs, N., Getting Constitutional Theory into Proportion: A Matter of Interpretation?, Oxford Journal of Legal Studies, 27 (1), 175-191. RAE2008

Christology in the Epistle to the Hebrews: Martin Luther's Reception of John Chrysostom

Throughout the history of the Church, the Epistle to the Hebrews has been one of the most puzzling letters in the Canon, particularly regarding the implications of understanding the person of Jesus Christ. John Chrysostom, an important patristic writer, is acknowledged to have made significant contributions to the exegesis of this letter. Chrysostom's thought became the norm for traditional thinking and interpretation of this letter in the Middle Ages. Martin Luther's reception of Chrysostom's Homilies on Hebrews presents a unique interpretation that some scholars may describe as the "Reformation Discovery" on Hebrews. In tracing Luther's reception and appropriation of Chrysostom's exegesis of the letter to the Hebrews, there is a noticeable and significant shift in Christological interpretation. Whether or not these modifications were necessary is a matter of debate; however, they do reflect Luther's contextual and existential questions regarding faith, Christ and knowledge of God, which is evident in his Lectures on Hebrews.

The Construction of Arbitrary Stable Dynamics in Non-Linear Neural Networks

In this paper, two methods for constructing systems of ordinary differential equations realizing any fixed finite set of equilibria in any fixed finite dimension are introduced; no spurious equilibria are possible for either method. By using the first method, one can construct a system with the fewest number of equilibria, given a fixed set of attractors. Using a strict Lyapunov function for each of these differential equations, a large class of systems with the same set of equilibria is constructed. A method of fitting these nonlinear systems to trajectories is proposed. In addition, a general method which will produce an arbitrary number of periodic orbits of shapes of arbitrary complexity is also discussed. A more general second method is given to construct a differential equation which converges to a fixed given finite set of equilibria. This technique is much more general in that it allows this set of equilibria to have any of a large class of indices which are consistent with the Morse Inequalities. It is clear that this class is not universal, because there is a large class of additional vector fields with convergent dynamics which cannot be constructed by the above method. The easiest way to see this is to enumerate the set of Morse indices which can be obtained by the above method and compare this class with the class of Morse indices of arbitrary differential equations with convergent dynamics. The former set of indices are a proper subclass of the latter, therefore, the above construction cannot be universal. In general, it is a difficult open problem to construct a specific example of a differential equation with a given fixed set of equilibria, permissible Morse indices, and permissible connections between stable and unstable manifolds. A strict Lyapunov function is given for this second case as well. This strict Lyapunov function as above enables construction of a large class of examples consistent with these more complicated dynamics and indices. The determination of all the basins of attraction in the general case for these systems is also difficult and open.

Keeping their heads down: Shame and pride in the stories of Protestants in the Irish Republic

This study draws on a number of in-depth interviews to explore the ethnic aspect of Protestantism in the Republic of Ireland. We explore themes of shame and pride around issues of identity, together with a sense of loss of a minority rapidly losing cultural distinctiveness. Following Ireland‘s division, the ordinary Protestants of the south, comprising a range of religious denominations bound by history, intermarriage and culture, found themselves in a society in which their story was rarely told. The dominant narrative was one of a Catholic people, long oppressed by a wealthy Protestant minority. The story of ordinary Protestants, including those in rural and urban poverty, went largely unheard. Today, ordinary Protestants – small farmers, shop keepers, housewives – tell the story of Ireland as seen through their family‘s narratives. Themes of pride and shame, often intertwined, form a thread that binds their testimony, drawing on family, personal and local history, folklore and statements of identity.

Tom Sawyer and the construction of value

This paper challenges the common assumption that economic agents know their tastes. After reviewing previous research showing that valuation of ordinary products and experiences can be manipulated by non-normative cues, we present three studies showing that in some cases people do not have a pre-existing sense of whether an experience is good or bad-even when they have experienced a sample of it. © 2005 Elsevier B.V. All rights reserved.

A population model of folate-mediated one-carbon metabolism.

BACKGROUND: Previous mathematical models for hepatic and tissue one-carbon metabolism have been combined and extended to include a blood plasma compartment. We use this model to study how the concentrations of metabolites that can be measured in the plasma are related to their respective intracellular concentrations. METHODS: The model consists of a set of ordinary differential equations, one for each metabolite in each compartment, and kinetic equations for metabolism and for transport between compartments. The model was validated by comparison to a variety of experimental data such as the methionine load test and variation in folate intake. We further extended this model by introducing random and systematic variation in enzyme activity. OUTCOMES AND CONCLUSIONS: A database of 10,000 virtual individuals was generated, each with a quantitatively different one-carbon metabolism. Our population has distributions of folate and homocysteine in the plasma and tissues that are similar to those found in the NHANES data. The model reproduces many other sets of clinical data. We show that tissue and plasma folate is highly correlated, but liver and plasma folate much less so. Oxidative stress increases the plasma S-adenosylmethionine/S-adenosylhomocysteine (SAM/SAH) ratio. We show that many relationships among variables are nonlinear and in many cases we provide explanations. Sampling of subpopulations produces dramatically different apparent associations among variables. The model can be used to simulate populations with polymorphisms in genes for folate metabolism and variations in dietary input.

An analysis of masculine and feminine writings in postings within a series of health and social care online undergraduate courses

This study aims to extend understanding of pedagogic dialogue by analysing the effect that the gender of the student has on interaction within a selection of ordinary health and social care on line courses.

Simplified theory of wideband spectra of liquid H2O and D2O (from 0 to 1000 cm(-1)) due to reorienting polar and vibrating H-bonded water molecules

A semi-phenomenological molecular model is presented, which is capable of describing with the use of analytical formulae, the wideband dielectric(1) and far-infrared spectra of ordinary and heavy water. In the model the vector of a dipole moment is presented as a sum of two components. The absolute value of the first one is constant; the second one changes harmonically with time. The key aspect of this work is consideration of FIR spectra due to the second component. In the context of the modified hybrid model presented in the work, reorientation of the dipoles in the rectangular potential well is considered, as a result of which the librational (near 700 cm (-1)) and translational (near 200 cm (-1)) absorption bands and the microwave Debye relaxation spectrum arise. It is shown that the time-dependent part of a dipole moment contributes most to the translational band, the relevant mechanism is taken to be stretching vibration of the H-bonded molecules. Previous linear-response molecular models were unsuccessful in describing this band (in heavy water) in terms of the complex dielectric permittivity. The spatial and time scales characteristic of water are estimated. (C) 2002 Elsevier Science B.V. All rights reserved.

Atomistic studies of interactions between the dominant lattice dislocations and γ/γ-lamellar boundaries in lamellar γ-TiAl

This paper reports on atomistic simulations of the interactions between the dominant lattice dislocations in ?-TiAl (<1 0 1] superdislocations) with all three kinds of ?/?-lamellar boundaries in polysynthetically twinned (PST) TiAl. The purpose of this study is to clarify the early stage of lamellar boundary controlled plastic deformation in PST TiAl. The interatomic interactions in our simulations are described by a bond order potential for L10-TiAl which provides a proper quantum mechanical description of the bonding. We are interested in the dislocation core geometries that the lattice produces in proximity to lamellar boundaries and the way in which these cores are affected by the elastic and atomistic effects of dislocation-lamellar boundary interaction. We study the way in which the interfaces affect the activation of ordinary dislocation and superdislocation slip inside the ?-lamellae and transfer of plastic deformation across lamellar boundaries. We find three new phenomena in the atomic-scale plasticity of PST TiAl, particularly due to elastic and atomic mismatch associated with the 60° and 120° ?/?-interfaces: (i) two new roles of the ?/?-interfaces, i.e. decomposition of superdislocations within 120° and 60° interfaces and subsequent detachment of a single ordinary dislocation and (ii) blocking of ordinary dislocations by 60° and 120° interfaces resulting in the emission of a twinning dislocation.

Same sex attraction, homophobic bullying and mental health of young people in Northern Ireland

This article reports on the relationship between same-sex attraction, experience of bullying in school and mental health measured using the 12-item version of the General Health Questionnaire (GHQ12). A random sample of 16 year olds, drawn from the Child Benefit Register, was invited to take part in the 2005 Young Life and Times survey, which is a postal survey carried out in Northern Ireland every year. Eight hundred and nineteen 16 year olds responded, which represented a return rate of 40%. The results of the survey showed that respondents who said they had been attracted to a person of the same sex at least once were significantly more likely to report experiences of school bullying. Same-sex-attracted 16 year olds were significantly less likely than those attracted to persons of the opposite sex only to say that their school provided real help to those who are being bullied. The 2005 Young Life and Times data also indicated that same-sex-attracted respondents were more than twice as likely as respondents who were only attracted to people of the opposite sex to have higher levels of psychiatric disorder. (Contains 5 tables.)

Alasdair MacIntyre and the Hope for a Politics of Virtuous Interdependence

Rebellion, philosophic and political, impels the work of Alasdair MacIntyre. Neither of the left nor the right, he treads a borderline path between conservatism and radicalism in holding to a socialist Thomistic Aristotelianism underpinned by a deliberative ‘ethic of care’ that is implacably opposed to modernity and the advanced capitalist nation-state. The depth of this opposition arouses strong opinions in friend and foe alike. To some he is an eminently dispensable reactionary whose sole consistent feature is an inexplicable ‘hatred of liberal individualism’ (Lessnoff 1999: 4). To others he appears a revolutionary enunciating a departure capable of legitimating the activities of ordinary persons so ‘that previously isolated struggles might be transformed into a new class war of attrition’ (Knight 1996: 896). However, neither interpretation rings true. MacIntyre does develop a cogent critique of the present, but this critique points in directions towards which no politics could hope to move.

Dynamical instability in surface permeability characteristics of building sandstones in response to salt accumulation over time

This paper explores how the surface permeability of sandstone blocks changes over time in response to repeated salt weathering cycles. Surface permeability controls the amount of moisture and dissolved salt that can penetrate in and facilitate decay. Connected pores permit the movement of moisture (and hence soluble salts) into the stone interior, and where areas are more or less permeable soluble salts may migrate along preferred pathways at differential rates. Previous research has shown that salts can accumulate in the near-surface zone and lead to partial pore blocking which influences subsequent moisture ingress and causes rapid salt accumulation in the near-surface zone.

Two parallel salt weathering simulations were carried out on blocks of Peakmoor Sandstone of different volumes. Blocks were removed from simulations after 2, 5, 10, 20 and 60 cycles. Permeability measurements were taken for these blocks at a resolution of 20 mm, providing a grid of 100 permeability values for each surface. The geostatistical technique of ordinary kriging was applied to the data to produce a smoothed interpolation of permeability for these surfaces, and hence improve understanding of the evolution of permeability over time in response to repeated salt weathering cycles.

Results illustrate the different responses of the sandstone blocks of different volumes to repeated salt weathering cycles. In both cases, after an initial subtle decline in the permeability (reflecting pore blocking), the permeability starts to increase — reflected in a rise in mean, maximum and minimum values. However, between 10 and 20 cycles, there is a jump in the mean and range permeability of the group A block surfaces coinciding with the onset of meaningful debris release. After 60 cycles, the range of permeability in the group A block surface had increased markedly, suggesting the development of a secondary permeability. The concept of dynamic instability and divergent behaviour is applied at the scale of a single block surface, with initial small-scale differences across a surface having larger scale consequences as weathering progresses.

After cycle 10, group B blocks show a much smaller increase in mean permeability, and the range stays relatively steady — this may be explained by the capillary conditions set up by the smaller volume of the stone, allowing salts to migrate to the ‘back’ of the blocks and effectively relieving stress at the ‘front’ face.

Knowledge, innovation and emulation in the evolutionary thought of Bernard Mandeville

Of the early modern writers on the division of labour, Bernard Mandeville alone extended it to all aspects of human activity and emphasised its role in a cumulative process of evolution in which each generation modified and built on what had been achieved by earlier generations. This required exploration of the mechanisms through which new knowledge was developed as well as the means by which knowledge was transmitted between the generations. The present article examines Mandeville’s treatment of these mechanisms and explores their theoretical origins. It examines Mandeville’s understanding of the role of the division of labour in facilitating discovery and learning and the role of education and imitation in transmitting social knowledge. It shows that, for Mandeville, innovators were people of ordinary capacity who were alert to the opportunities and challenges of their environment. As a result of specialisation, they possessed tacit knowledge which was actualised in what they did rather than in theoretical propositions. Mandeville’s evolutionary thought influenced subsequent writers on political economy and evolutionary social thinkers. It may also have had some influence on Charles Darwin, though it is not, in itself, Darwinian. © The Author 2013. Published by Oxford University Press on behalf of the Cambridge Political Economy Society. All rights reserved.