2,657 research outputs found
The Value of Literacy Practices
The concepts of literacy events and practices have received considerable attention in educational research and policy. In comparison, the question of value, that is, ‘which literacy practices do people most value?’ has been neglected. With the current trend of cross-cultural adult literacy assessment, it is increasingly important to recognise locally valued literacy practices. In this paper we argue that measuring preferences and weighting of literacy practices provides an empirical and democratic basis for decisions in literacy assessment and curriculum development and could inform rapid educational adaptation to changes in the literacy environment. The paper examines the methodological basis for investigating literacy values and its potential to inform cross-cultural literacy assessments. The argument is illustrated with primary data from Mozambique. The correlation between individual values and respondents’ socio-economic and demographic characteristics is explored
Lunar base CELSS: A bioregenerative approach
During the twenty-first century, human habitation of a self-sustaining lunar base could become a reality. To achieve this goal, the occupants will have to have food, water, and an adequate atmosphere within a carefully designed environment. Advanced technology will be employed to support terrestrial life-sustaining processes on the Moon. One approach to a life support system based on food production, waste management and utilization, and product synthesis is outlined. Inputs include an atmosphere, water, plants, biodegradable substrates, and manufacutured materials such as fiberglass containment vessels from lunar resources. Outputs include purification of air and water, food, and hydrogen (H2) generated from methane (CH4). Important criteria are as follows: (1) minimize resupply from Earth; and (2) recycle as efficiently as possible
Intrinsic hole mobility and trapping in a regio-regular poly(thiophene)
The transport properties of high-performance thin-film transistors (TFT) made
with a regio-regular poly(thiophene) semiconductor (PQT-12) are reported. The
room-temperature field-effect mobility of the devices varied between 0.004
cm2/V s and 0.1 cm2/V s and was controlled through thermal processing of the
material, which modified the structural order. The transport properties of TFTs
were studied as a function of temperature. The field-effect mobility is
thermally activated in all films at T<200 K and the activation energy depends
on the charge density in the channel. The experimental data is compared to
theoretical models for transport, and we argue that a model based on the
existence of a mobility edge and an exponential distribution of traps provides
the best interpretation of the data. The differences in room-temperature
mobility are attributed to different widths of the shallow localized state
distribution at the edge of the valence band due to structural disorder in the
film. The free carrier mobility of the mobile states in the ordered regions of
the film is the same in all structural modifications and is estimated to be
between 1 and 4 cm2/V s.Comment: 20 pages, 8 figure
Characterization of Lubricants on Ball Bearings by FT-IR Using an Integrating Sphere
Fourier Transform-Infrared reflectance microspectroscopy has been used extensively for the examination of coatings on nonplanar surfaces such as ball bearings. While this technique offers considerable advantages, practical application has many drawbacks, some of which are easily overcome by the use of integrating sphere technology. This paper describes the use of an integrating sphere for the quantification of thin layers of lubricant on the surface of ball bearings and the parameters which require optimization in order to obtain reliable data. Several applications of the technique are discussed including determination of lubricant load on 12.7 mm steel ball bearings and the examination of degraded lubricant on post mortem specimens
Test of mode coupling theory for a supercooled liquid of diatomic molecules.I. Translational degrees of freedom
A molecular dynamics simulation is performed for a supercooled liquid of
rigid diatomic molecules. The time-dependent self and collective density
correlators of the molecular centers of mass are determined and compared with
the predictions of the ideal mode coupling theory (MCT) for simple liquids.
This is done in real as well as in momentum space. One of the main results is
the existence of a unique transition temperature T_c, where the dynamics
crosses over from an ergodic to a quasi-nonergodic behavior. The value for T_c
agrees with that found earlier for the orientational dynamics within the error
bars. In the beta- regime of MCT the factorization of space- and time
dependence is satisfactorily fulfilled for both types of correlations. The
first scaling law of ideal MCT holds in the von Schweidler regime, only, since
the validity of the critical law can not be confirmed, due to a strong
interference with the microscopic dynamics. In this first scaling regime a
consistent description within ideal MCT emerges only, if the next order
correction to the asymptotic law is taken into account. This correction is
almost negligible for q=q_max, the position of the main peak in the static
structure factor S(q), but becomes important for q=q_min, the position of its
first minimum. The second scaling law, i.e. the time-temperature superposition
principle, holds reasonably well for the self and collective density
correlators and different values for q. The alpha-relaxation times tau_q^(s)
and tau_q follow a power law in T-T_c over 2 -- 3 decades. The corresponding
exponent gamma is weakly q-dependent and is around 2.55. This value is in
agreement with the one predicted by MCT from the value of the von Schweidler
exponent but at variance with the corresponding exponent gammaComment: 14 pages of RevTex, 19 figure
Three qubit entanglement within graphical Z/X-calculus
The compositional techniques of categorical quantum mechanics are applied to
analyse 3-qubit quantum entanglement. In particular the graphical calculus of
complementary observables and corresponding phases due to Duncan and one of the
authors is used to construct representative members of the two genuinely
tripartite SLOCC classes of 3-qubit entangled states, GHZ and W. This nicely
illustrates the respectively pairwise and global tripartite entanglement found
in the W- and GHZ-class states. A new concept of supplementarity allows us to
characterise inhabitants of the W class within the abstract diagrammatic
calculus; these method extends to more general multipartite qubit states.Comment: In Proceedings HPC 2010, arXiv:1103.226
Oxidative phosphorylation. Halide-dependent and halide-independent effects of triorganotin and trioganolead compounds on mitochondrial functions
Involutive Categories and Monoids, with a GNS-correspondence
This paper develops the basics of the theory of involutive categories and
shows that such categories provide the natural setting in which to describe
involutive monoids. It is shown how categories of Eilenberg-Moore algebras of
involutive monads are involutive, with conjugation for modules and vector
spaces as special case. The core of the so-called Gelfand-Naimark-Segal (GNS)
construction is identified as a bijective correspondence between states on
involutive monoids and inner products. This correspondence exists in arbritrary
involutive categories
SuperWASP: Wide Angle Search for Planets
SuperWASP is a fully robotic, ultra-wide angle survey for planetary transits.
Currently under construction, it will consist of 5 cameras, each monitoring a
9.5 x 9.5 deg field of view. The Torus mount and enclosure will be fully
automated and linked to a built-in weather station. We aim to begin
observations at the beginning of 2003.Comment: 4 pages, 1 figure, to be published in proceedings of "Scientific
Frontiers in Research on Extrasolar Planets
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