2,592 research outputs found
Advanced Fenton processing of aqueous phenol solutions:a continuous system study including sonication effects
Our previous report based on a batch reactor system for the Advanced Fenton Process (AFP) showed that pH, hydrogen peroxide and the organic substances treated are among the most important factors affecting the oxidation efficiency. As an extended study towards its commercialisation, this paper reports the effects of the main process parameters including those relating to a new AFP flow-through system. In order to systemise and correlate the results, the Taguchi experimental design method was used. Total organic carbon (TOC) removal was utilised as the measure of the oxidation efficiency and it was found that the removal of phenol from aqueous solution at pH 2.0 and 2.5 was very similar but hydrogen peroxide supply significantly affected the TOC removal with the change of flow rate from 14.4 mL/hr to 60 mL/hr. Also, the initial concentration of phenol was a highly significant factor, with higher concentrations resulting in a lower TOC removal rate. The temperature effects in the range of 14 °C to 42 °C were investigated and it was found that there was accelerated oxidation of phenol in the early stages but after 90 minutes there was no significant difference between the results. Sonication with a bath type sonicator resulted in relatively small enhancements of TOC removal but further studies with cup-horn and probe type sonicators showed that TOC removal increased with higher intensity of sonication on additional input of hydrogen peroxide
Constructions of diagonal quartic and sextic surfaces with infinitely many rational points
In this note we construct several infinite families of diagonal quartic
surfaces \begin{equation*} ax^4+by^4+cz^4+dw^4=0, \end{equation*} where
with infinitely many rational points and
satisfying the condition . In particular, we present an
infinite family of diagonal quartic surfaces defined over \Q with Picard
number equal to one and possessing infinitely many rational points. Further, we
present some sextic surfaces of type , , , or
, with infinitely many rational points.Comment: revised version will appear in International Journal of Number Theor
Non-adaptive Measurement-based Quantum Computation and Multi-party Bell Inequalities
Quantum correlations exhibit behaviour that cannot be resolved with a local
hidden variable picture of the world. In quantum information, they are also
used as resources for information processing tasks, such as Measurement-based
Quantum Computation (MQC). In MQC, universal quantum computation can be
achieved via adaptive measurements on a suitable entangled resource state. In
this paper, we look at a version of MQC in which we remove the adaptivity of
measurements and aim to understand what computational abilities still remain in
the resource. We show that there are explicit connections between this model of
computation and the question of non-classicality in quantum correlations. We
demonstrate this by focussing on deterministic computation of Boolean
functions, in which natural generalisations of the Greenberger-Horne-Zeilinger
(GHZ) paradox emerge; we then explore probabilistic computation, via which
multipartite Bell Inequalities can be defined. We use this correspondence to
define families of multi-party Bell inequalities, which we show to have a
number of interesting contrasting properties.Comment: 13 pages, 4 figures, final version accepted for publicatio
Surface-acoustic-wave-driven luminescence from a lateral p-n junction
The authors report surface-acoustic-wave-driven luminescence from a lateral
p-n junction formed by molecular beam epitaxy regrowth of a modulation doped
GaAs/AlGaAs quantum well on a patterned GaAs substrate.
Surface-acoustic-wave-driven transport is demonstrated by peaks in the
electrical current and light emission from the GaAs quantum well at the
resonant frequency of the transducer. This type of junction offers high carrier
mobility and scalability. The demonstration of surface-acoustic-wave
luminescence is a significant step towards single-photon applications in
quantum computation and quantum cryptography.Comment: 4 pages, 3 figure
Outcome Independence of Entanglement in One-Way Computation
We show that the various intermediate states appearing in the process of
one-way computation at a given step of measurement are all equivalent modulo
local unitary transformations. This implies, in particular, that all those
intermediate states share the same entanglement irrespective of the measurement
outcomes, indicating that the process of one-way computation is essentially
unique with respect to local quantum operations.Comment: 6 pages, 4 figure
Large Deviation Bounds for k-designs
We present a technique for derandomising large deviation bounds of functions
on the unitary group. We replace the Haar distribution with a pseudo-random
distribution, a k-design. k-designs have the first k moments equal to those of
the Haar distribution. The advantage of this is that (approximate) k-designs
can be implemented efficiently, whereas Haar random unitaries cannot. We find
large deviation bounds for unitaries chosen from a k-design and then illustrate
this general technique with three applications. We first show that the von
Neumann entropy of a pseudo-random state is almost maximal. Then we show that,
if the dynamics of the universe produces a k-design, then suitably sized
subsystems will be in the canonical state, as predicted by statistical
mechanics. Finally we show that pseudo-random states are useless for
measurement based quantum computation.Comment: 20 page
Use of serum lactate levels to predict survival for patients with out-of-hospital cardiac arrest: A cohort study
Objectives: We examined the association of serum lactate levels and early lactate clearance with survival to hospital discharge for patients suffering an out-of-hospital cardiac arrest (OHCA). Methods: A retrospective cohort analysis was performed of patients with OHCA transported by ambulance to two adult tertiary hospitals in Perth, Western Australia. Exclusion criteria were traumatic cardiac arrest, return of spontaneous circulation prior to the arrival of the ambulance, age less than 18 years and no serum lactate levels recorded. Serum lactate levels recorded for up to 48h post-arrest were obtained from the hospital clinical information system, and lactate clearance over 48h was calculated. Descriptive and logistic regression analyses were conducted. Results: There were 518 patients with lactate values, of whom 126 (24.3%) survived to hospital discharge. Survivors and non-survivors had different mean initial lactate levels (mean±SD 6.9±4.7 and 12.2±5.5mmol/L, respectively; P<0.001). Lactate clearance was higher in survivors. Lactate levels for non-survivors did not decrease below 2mmol/L until at least 30h after the ambulance call. Conclusion: In OHCA patients who had serum lactate levels measured, both lower initial serum lactate and early lactate clearance in the first 48h following OHCA were associated with increased likelihood of survival. However, the use of lactate in isolation as a predictor of survival or neurological outcome is not recommended. Prospective studies that minimise selection bias are required to determine the clinical utility of serum lactate levels in OHCA patients. © 2016 Australasian College for Emergency Medicine and Australasian Society for Emergency Medicine
Critical Language and Discourse Awareness in Management Education
Communication and, through it, language have become key elements of business and organizational life. How organizations interact within their walls and with the outside world fundamentally affects business processes, creating organizational culture, shaping public perceptions, and influencing consumer choices. This essay calls for a greater acknowledgment of language and communication and suggests that management educators may want to review how they are incorporated in management education curricula. Expanding on the skill-based approach typically adopted in business school classes, the essay points to the utility of exposing business students to the dual function of language as a means of doing work and as a social action that constitutes social reality. Drawing on examples from scholarship in linguistics and discourse analysis, the essay demonstrates that the ability to notice, identify, and reflect on linguistic and discourse practices is a crucial managerial skill. Nurturing such analytical and thinking skills enables people to become not only better communicators but also critical thinkers able to understand and challenge when social control, power, or injustice is enacted in organizations
A practical scheme for quantum computation with any two-qubit entangling gate
Which gates are universal for quantum computation? Although it is well known
that certain gates on two-level quantum systems (qubits), such as the
controlled-not (CNOT), are universal when assisted by arbitrary one-qubit
gates, it has only recently become clear precisely what class of two-qubit
gates is universal in this sense. Here we present an elementary proof that any
entangling two-qubit gate is universal for quantum computation, when assisted
by one-qubit gates. A proof of this important result for systems of arbitrary
finite dimension has been provided by J. L. and R. Brylinski
[arXiv:quant-ph/0108062, 2001]; however, their proof relies upon a long
argument using advanced mathematics. In contrast, our proof provides a simple
constructive procedure which is close to optimal and experimentally practical
[C. M. Dawson and A. Gilchrist, online implementation of the procedure
described herein (2002), http://www.physics.uq.edu.au/gqc/].Comment: 3 pages, online implementation of procedure described can be found at
http://www.physics.uq.edu.au/gqc
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