2,854 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
Coping with Persistent Pain, Effectiveness Research into Self-management (COPERS): statistical analysis plan for a randomised controlled trial
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated
The partially alternating ternary sum in an associative dialgebra
The alternating ternary sum in an associative algebra, , gives rise to the partially alternating ternary sum in an
associative dialgebra with products and by making the
argument the center of each term: . We use computer algebra to determine the polynomial identities in
degree satisfied by this new trilinear operation. In degrees 3 and 5 we
obtain and ; these identities define a new variety of partially alternating ternary
algebras. We show that there is a 49-dimensional space of multilinear
identities in degree 7, and we find equivalent nonlinear identities. We use the
representation theory of the symmetric group to show that there are no new
identities in degree 9.Comment: 14 page
The impact of exhibit type on behaviour of caged and free-ranging tamarins
The lack of appropriate stimuli associated with captive environments has been documented to cause several behavioural and physiological issues in captive species, including loss of natural behaviours, psychopathologies and decreased reproductive success. Providing free-ranging, naturalistic exhibits that replicate elements of a species’ natural environment is advocated as a means of promoting and preserving the natural behavioural repertoire in captive species. Exhibition of natural behaviour is considered beneficial to conservation in terms of animal health and welfare, reintroduction success, education and research. This study assessed differences in behaviour of emperor and pied tamarins housed in free-ranging and caged exhibits at Durrell Wildlife Park to determine the impact of exhibit type. Free-ranging tamarins were expected to exhibit a repertoire of behaviours more similar to that of wild tamarins based on their access to a more naturalistic and complex environment. Data was collected on a variety of behaviours, including activity, substrate use and communication, using instantaneous and one-zero sampling at 30 s intervals. Findings indicated that both free-ranging and caged tamarins exhibited natural behaviours; however, there were significant differences in mean rates of behaviours between conditions. Free-ranging tamarins exhibited significantly higher rates of locomotion (emperors: P < 0.001; pieds: P < 0.001), long calls (pieds: P = 0.019) and alarm calls (emperors: P = 0.012), and displayed competent use of the environment in terms of natural substrate use (emperors: P < 0.001; pieds: P = 0.007) and interspecific interactions. Caged tamarins exhibited significantly higher rates of affiliative (emperors: P = 0.001; pieds: P = 0.026) and agonistic (emperors: P = 0.003) intraspecific interactions and time spent in contact (emperors: P = 0.048; pieds: P = 0.043), which was largely attributed to spatial restrictions imposed by caged exhibits. This study, consistent with existing literature, indicated that the free-ranging exhibit was conducive to the expression of a behavioural repertoire more similar to that of wild tamarins. This was probably a result of the increased behavioural opportunities available in the free-ranging exhibit, highlighting their importance in promoting wild-type behaviours. However, some mean rates of behaviour were still noticeably less than those documented in wild counterparts. Methods to further promote natural behaviours in both exhibits are recommended to facilitate ex situ and in situ conservation efforts
The parameterized complexity of some geometric problems in unbounded dimension
We study the parameterized complexity of the following fundamental geometric
problems with respect to the dimension : i) Given points in \Rd,
compute their minimum enclosing cylinder. ii) Given two -point sets in
\Rd, decide whether they can be separated by two hyperplanes. iii) Given a
system of linear inequalities with variables, find a maximum-size
feasible subsystem. We show that (the decision versions of) all these problems
are W[1]-hard when parameterized by the dimension . %and hence not solvable
in time, for any computable function and constant
%(unless FPT=W[1]). Our reductions also give a -time lower bound
(under the Exponential Time Hypothesis)
Mineralisation of surfactants using ultrasound and the Advanced Fenton Process
The destruction of the surfactants, sodium dodecylbenzene sulfonate (DBS) and dodecyl pyridinium chloride (DPC), using an advanced oxidation process is described. The use of zero valent iron (ZVI) and hydrogen peroxide at pH = 2.5 (the advanced Fenton process), with and without, the application of 20 kHz ultrasound leads to extensive mineralisation of both materials as determined by total organic carbon (TOC)measurements. For DBS, merely stirring with ZVI and H2O2 at 20°C leads to a 51% decrease in TOC, but using 20 kHz ultrasound at 40°C, maintaining the pH at 2.5 throughout and adding extra amounts of ZVI and H2O2 during the degradation, then the extent of mineralisation of DBS is substantially increased to 93%. A similar result is seen for DPC where virtually no degradation occurs at 20°C, but if extra amounts of both ZVI and hydrogen peroxide are introduced during the reaction at 40°C and the pH is maintained at 2.5, then an 87% mineralisation of DPC is obtained. The slow latent remediation of both surfactants and the mechanism of degradation are also discussed
Measuring Controlled-NOT and two-qubit gate operation
Accurate characterisation of two-qubit gates will be critical for any
realisation of quantum computation. We discuss a range of measurements aimed at
characterising a two-qubit gate, specifically the CNOT gate. These measurements
are architecture-independent, and range from simple truth table measurements,
to single figure measures such as the fringe visibility, parity, fidelity, and
entanglement witnesses, through to whole-state and whole-gate measures achieved
respectively via quantum state and process tomography. In doing so, we examine
critical differences between classical and quantum gate operation.Comment: 10 pages (two-column). 1 figur
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