90,942 research outputs found
The evolution of ideas and practice concerning the provision of children's playspace (with a special reference to New Zealand and Palmerston North) : a thesis presented in partial fulfilment of the requirements for the degree of Master of Philosophy in Social Science at Massey University
This thesis seeks to explore the historical processes underlying the allocation and use of public space for children's play in nineteenth and twentieth century industrial society and examine how the processes have influenced the New Zealand situation.
The form of publicly provided playspace in New Zealand borrows extensively from overseas ideas and practices. The origins of playspace were a response to the conditions existing as a result of industrialisation in the late nineteenth century. The convergence of two streams of thought; the first the use of play as a tool for social integration of migrant children in the United States; and secondly the development of an urban parks system to alleviate the industrial blight of the cityscape in the United Kingdom; led to the establishment of recreation standards for the provision of children's playspace. The transportable nature of these ideas and practices resulted in children's playgrounds developing in New Zealand between 1920 and 1970 in a largely similar way. During this same period ideas concerning child constructed playgrounds and safety were evolving overseas. Such ideas when adopted in New Zealand have influenced the appearance and internal design of New Zealand playgrounds. However, in terms of function and form these changes have only been superficial.
Within New Zealand the social mechanisms for determining the allocation and design of playgrounds has constrained the use of playgrounds often to the disadvantage of different societal groups. The thesis concludes with a review of this issue
Influence of temperature on the performance of a full-scale activated sludge process operated at varying solids retention times whilst treating municipal sewage
In this study, the solid retention time (SRT) was varied with the ambient temperature for a full-scale municipal activated sludge plant with capacity of 200,000 PE (Population Equivalent) located in a humid sub-tropical environment. The effects of ambient temperature on treatment performance were investigated. Off-line samples were collected and analyzed from the treatment plant. The actual temperature variation during the study period was divided into three overlapping ranges and the SRT was adjusted accordingly with temperature in order to achieve the desired effluent quality. The plant’s observed effluent quality and thereby its overall removal efficiency was evaluated in terms of measuring standard biochemical parameters. The results indicate that significant improvement in effluent quality can be obtained by applying the variable SRT (5–7 days) dependent on temperature variation
Beyond the Spectral Theorem: Spectrally Decomposing Arbitrary Functions of Nondiagonalizable Operators
Nonlinearities in finite dimensions can be linearized by projecting them into
infinite dimensions. Unfortunately, often the linear operator techniques that
one would then use simply fail since the operators cannot be diagonalized. This
curse is well known. It also occurs for finite-dimensional linear operators. We
circumvent it by developing a meromorphic functional calculus that can
decompose arbitrary functions of nondiagonalizable linear operators in terms of
their eigenvalues and projection operators. It extends the spectral theorem of
normal operators to a much wider class, including circumstances in which poles
and zeros of the function coincide with the operator spectrum. By allowing the
direct manipulation of individual eigenspaces of nonnormal and
nondiagonalizable operators, the new theory avoids spurious divergences. As
such, it yields novel insights and closed-form expressions across several areas
of physics in which nondiagonalizable dynamics are relevant, including
memoryful stochastic processes, open non unitary quantum systems, and
far-from-equilibrium thermodynamics.
The technical contributions include the first full treatment of arbitrary
powers of an operator. In particular, we show that the Drazin inverse,
previously only defined axiomatically, can be derived as the negative-one power
of singular operators within the meromorphic functional calculus and we give a
general method to construct it. We provide new formulae for constructing
projection operators and delineate the relations between projection operators,
eigenvectors, and generalized eigenvectors.
By way of illustrating its application, we explore several, rather distinct
examples.Comment: 29 pages, 4 figures, expanded historical citations;
http://csc.ucdavis.edu/~cmg/compmech/pubs/bst.ht
Quantitative sum rule analysis of low-temperature spectral functions
We analyze QCD and Weinberg-type sum rules in a low-temperature pion gas
using vector and axial-vector spectral functions following from the
model-independent chiral-mixing scheme. Toward this end we employ recently
constructed vacuum spectral functions with ground and first-excited states in
both channels and a universal perturbative continuum; they quantitatively
describe hadronic tau-decay data and satisfy vacuum sum rules. These features
facilitate the implementation of chiral mixing without further assumptions, and
lead to in-medium spectral functions which exhibit a mutual tendency of
compensating resonance and dip structures, suggestive for an approach toward
structureless distributions. In the sum rule analysis, we account for pion mass
corrections, which turn out to be significant. While the Weinberg sum rules
remain satisfied even at high temperatures, the numerical evaluation of the QCD
sum rules for vector and axial-vector channels reveals significant deviations
setting in for temperatures beyond ~140 MeV, suggestive of additional physics
beyond low-energy chiral pion dynamics.Comment: 8 pages, 3 figure
Rayleigh-Benard Convection with a Radial Ramp in Plate Separation
Pattern formation in Rayleigh-Benard convection in a large-aspect-ratio
cylinder with a radial ramp in the plate separation is studied analytically and
numerically by performing numerical simulations of the Boussinesq equations. A
horizontal mean flow and a vertical large scale counterflow are quantified and
used to understand the pattern wavenumber. Our results suggest that the mean
flow, generated by amplitude gradients, plays an important role in the roll
compression observed as the control parameter is increased. Near threshold the
mean flow has a quadrupole dependence with a single vortex in each quadrant
while away from threshold the mean flow exhibits an octupole dependence with a
counter-rotating pair of vortices in each quadrant. This is confirmed
analytically using the amplitude equation and Cross-Newell mean flow equation.
By performing numerical experiments the large scale counterflow is also found
to aid in the roll compression away from threshold but to a much lesser degree.
Our results yield an understanding of the pattern wavenumbers observed in
experiment away from threshold and suggest that near threshold the mean flow
and large scale counterflow are not responsible for the observed shift to
smaller than critical wavenumbers.Comment: 10 pages, 13 figure
Quantum bicriticality in the heavy-fermion metamagnet YbAgGe
Bicritical points, at which two distinct symmetry-broken phases become
simultaneously unstable, are typical for spin-flop metamagnetism.
Interestingly, the heavy-fermion compound YbAgGe also possesses such a
bicritical point (BCP) with a low temperature T_BCP ~ 0.3 K at a magnetic field
of mu_0 H_BCP ~ 4.5 T. In its vicinity, YbAgGe exhibits anomalous behavior that
we attribute to the influence of a quantum bicritical point (QBCP), that is
close in parameter space yet can be reached by tuning T_BCP further to zero.
Using high-resolution measurements of the magnetocaloric effect, we demonstrate
that the magnetic Grueneisen parameter Gamma_H indeed both changes sign and
diverges as required for quantum criticality. Moreover, Gamma_H displays a
characteristic scaling behavior but only on the low-field side, H < H_BCP,
indicating a pronounced asymmetry with respect to the critical field. We
speculate that the small value of T_BCP is related to the geometric frustration
of the Kondo-lattice of YbAgGe.Comment: submitted to PR
Accurate nine-decade temperature-compensated logarithmic amplifier
Transistor-driven temperature-stable amplifier with logarithmic operating characteristics permits presentation of the entire range of the reactor without range switching. This circuit is capable of monitoring ion chamber currents over spans of 8 or 9 decades and is used in nuclear reactor instrumentation. Application is found in materials under ultrahigh vacuum
Public perceptions of recycled water: a survey of visitors to the London 2012 Olympic Park
The Old Ford Water Recycling Plant, operated by Thames Water, was used to supply non-potable recycled blackwater to some of the venues at the London 2012 Games. In an effort to learn from this experience, Thames Water commissioned a survey of visitors to the Olympic Park during the Games to explore public responses to the water recycling project. Results show a very high level of support for using non-potable recycled blackwater, both in public venues and in homes. Such findings may indicate a growing receptivity towards this technology, and show that Thames Water (and other private water companies) are well placed to encourage and even lead public discussion around the role of water reuse in the future of urban water supplies
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