Covalently Functionalized Sawdust for the Remediation of Phosphate from Agricultural Wastewater

Phosphate remediation from wastewater is rapidly becoming an ever more attractive process due to a combination of both the economic pressure of increasing phosphate scarcity and the environmental damage caused by untreated agricultural runoff. Ideally, remediated phosphate will be recoverable and would be able to be reused as fertilizer. Many different resins have been investigated, but due to the scale of the challenge, any feasible solution will involve the use of very inexpensive waste products as the solid support. Sawdust, functionalized with iron-binding ligands, is such a potential resin. Sawdust alone binds 0.3 g/kg of phosphate which is insufficient. Iron has a strong affinity for phosphate, making the formation of iron-phosphate bonds a promising avenue for the development of recyclable resins. Previously prepared iron-chitosan complexes bound 8.2 g/kg. However, as the price of chitosan has rapidly increased, alternatives are required. In this current study, the covalent modification of the sawdust using either carboxymethylcellulose-supported ligands, or direct functionalization of the sawdust can increase this to 40 g/kg using ethylene diamine as the iron-binding ligand. Binding decreases over repeated cycles of phosphate exposure and elution, but can be fully restored through regeneration using iron salts. The simple green synthesis of this material, and the iron-binding capability of the investigated ligands is discussed. These sawdust-based resins show promise as potential candidates for industrial-scale phosphate recovery efforts in the future

Implementation and validation of a novel instrument for the grading of unexpected events in paediatric surgery: Clavien–Madadi classification

Background: Inconsistent definitions of complications and unexpected events have limited accurate analysis of surgical outcomes. Perioperative outcome classifications currently used for adult patients have limitations when used for children./ Methods: A multidisciplinary group of experts modified the Clavien–Dindo classification to increase its utility and accuracy in paediatric surgery cohorts. Organizational and management errors were considered in the novel Clavien–Madadi classification, which focuses on procedural invasiveness rather than anaesthetic management. Unexpected events were prospectively documented in a paediatric surgery cohort. Results of the Clavien–Dindo and Clavien–Madadi classifications were compared and correlated with procedure complexity./ Results: Unexpected events were prospectively documented in a cohort of 17 502 children undergoing surgery between 2017 and 2021. The results of both classifications were highly correlated (ρ = 0.95), although the novel Clavien–Madadi classification identified 449 additional events (organizational and management errors) over the Clavien–Dindo classification, increasing the total number of events by 38 per cent (1605 versus 1158 events). The results of the novel system correlated significantly with the complexity of procedures in children (ρ = 0.756). Furthermore, grading of events > grade III according to the Clavien–Madadi classification showed a higher correlation with procedure complexity (ρ = 0.658) than the Clavien–Dindo classification (ρ = 0.198)./ Conclusion: The Clavien–Madadi classification is a tool for the detection of surgical and non-medical errors in paediatric surgery populations. Further validation in paediatric surgery populations is required before widespread use

Oscillatons revisited

In this paper, we study some interesting properties of a spherically symmetric oscillating soliton star made of a real time-dependent scalar field which is called an oscillaton. The known final configuration of an oscillaton consists of a stationary stage in which the scalar field and the metric coefficients oscillate in time if the scalar potential is quadratic. The differential equations that arise in the simplest approximation, that of coherent scalar oscillations, are presented for a quadratic scalar potential. This allows us to take a closer look at the interesting properties of these oscillating objects. The leading terms of the solutions considering a quartic and a cosh scalar potentials are worked in the so called stationary limit procedure. This procedure reveals the form in which oscillatons and boson stars may be related and useful information about oscillatons is obtained from the known results of boson stars. Oscillatons could compete with boson stars as interesting astrophysical objects, since they would be predicted by scalar field dark matter models.Comment: 10 pages REVTeX, 10 eps figures. Updated files to match version published in Classical and Quantum Gravit

Galactic Collapse of Scalar Field Dark Matter

We present a scenario for galaxy formation based on the hypothesis of scalar field dark matter. We interpret galaxy formation through the collapse of a scalar field fluctuation. We find that a cosh potential for the self-interaction of the scalar field provides a reasonable scenario for galactic formation, which is in agreement with cosmological observations and phenomenological studies in galaxies.Comment: 4 pages, 3 figue

High temperature behaviour of a CuO/Al2O3 oxygen carrier for Chemical-Looping Combustion

8 pages, 10 figures, 2 tables.- Available online April 13, 2011.Chemical-Looping Combustion (CLC) is a combustion technology with inherent CO2 separation and, therefore, without energy losses. CLC is based on the transfer of oxygen from the air to the fuel by means of an oxygen carrier (OC) in the form of a metal oxide. The OC circulates between two interconnected reactors, the fuel (FR) and the air reactor (AR). To scale up the CLC process for industrial application OCs materials suitable to work at high temperatures are needed. So far, Cu-based OCs had been proved to fulfil the requirements for an OC material, although operating temperatures lower than 1073 K are recommended. In this work, the behaviour of an impregnated Cu-based oxygen carrier (CuO-Al2O3) was studied in a continuous CLC unit of 500 Wth during long-term tests using methane as fuel gas and FR temperatures up to 1173 K and AR temperatures up to 1223 K. The behaviour of the oxygen carrier on the process performance was evaluated taking into account important aspects such as combustion efficiency, resistance to attrition, fluidization behaviour and preservation of the oxygen transport capacity and reactivity. It was found that both TFR and TAR had a great influence on the resistance to attrition of the particles. Stable operation for more than 60 h was only feasible at TFR =1073 K and TAR = 1173 K. However agglomeration or deactivation of the particles was never detected in any of the temperatures used. This is the first time that a CuO-Al2O3 OC, prepared by a commercial manufacturing method, and used at 1073K in the FR and 1173 K in the AR exhibits such a good properties: high reactivity together with high mechanical durability and absence of agglomeration. This result opens new possibilities for the application of Cu-based materials in industrial-scale CLC processes.This research was conducted with financial support from the Spanish Ministry of Science and Innovation (MICINN, Project CTQ2007-64400) and C.S.I.C. (200480E619).Peer reviewe

Multi-scale investigation of uranium attenuation by arsenic at an abandoned uranium mine, South Terras

Detailed mineralogical analysis of soils from the UK’s historical key uranium mine, South Terras, was performed to elucidate the mechanisms of uranium degradation and migration in the 86 years since abandonment. Soils were sampled from the surface (0 – 2 cm) and near-surface (25 cm) in two distinct areas of ore processing activities. Bulk soil analysis revealed the presence of high concentrations of uranium (<1690 ppm), arsenic (1830 ppm) and beryllium (~250 ppm), suggesting pedogenic weathering of the country rock and ore extraction processes to be the mechanisms of uranium ore degradation. Micro-focus XRF analysis indicated the association of uranium with arsenic, phosphate and copper; µ-XRD data confirmed the presence of the uranyl-arsenate minerals metazeunerite (Cu(UO2)2(AsO4)2·8H2O) and metatorbernite (Cu(UO2)2(PO4)2·8H2O) to be ubiquitous. Our data are consistent with the solid solution of these two uranyl-mica minerals, not previously observed at uranium-contaminated sites. Crystallites of uranyl-mica minerals were observed to coat particles of jarosite and muscovite, suggesting that the mobility of uranium from degraded ores is attenuated by co-precipitation with arsenic and phosphate, which was not previously considered at this site

The institutional shaping of management: in the tracks of English individualism

Globalisation raises important questions about the shaping of economic action by cultural factors. This article explores the formation of what is seen by some as a prime influence on the formation of British management: individualism. Drawing on a range of historical sources, it argues for a comparative approach. In this case, the primary comparison drawn is between England and Scotland. The contention is that there is a systemic approach to authority in Scotland that can be contrasted to a personal approach in England. An examination of the careers of a number of Scottish pioneers of management suggests the roots of this systemic approach in practices of church governance. Ultimately this systemic approach was to take a secondary role to the personal approach engendered by institutions like the universities of Oxford and Cambridge, but it found more success in the different institutional context of the USA. The complexities of dealing with historical evidence are stressed, as is the value of taking a comparative approach. In this case this indicates a need to take religious practice as seriously as religious belief as a source of transferable practice. The article suggests that management should not be seen as a simple response to economic imperatives, but as shaped by the social and cultural context from which it emerges

‘A priori’ external contextual factors and relationships with process indicators: a mixed methods study of the pre-implementation phase of ‘Communities in Charge of Alcohol’

Background It is widely recognised that complex public health interventions roll out in distinct phases, within which external contextual factors influence implementation. Less is known about relationships with external contextual factors identified a priori in the pre-implementation phase. We investigated which external contextual factors, prior to the implementation of a community-centred approach to reducing alcohol harm called ‘Communities in Charge of Alcohol’ (CICA), were related to one of the process indicators: numbers of Alcohol Health Champions (AHCs) trained. Methods A mixed methods design was used in the pre-implementation phase of CICA. We studied ten geographic communities experiencing both high levels of deprivation and alcohol-related harm in the North West of England. Qualitative secondary data were extracted from pre-implementation meeting notes, recorded two to three months before roll-out. Items were coded into 12 content categories using content analysis. To create a baseline ‘infrastructure score’, the number of external contextual factors documented was counted per area to a maximum score of 12. Descriptive data were collected from training registers detailing training numbers in the first 12 months. The relationship between the baseline infrastructure score, external contextual factors, and the number of AHCs trained was assessed using non-parametric univariable statistics. Results There was a positive correlation between baseline infrastructure score and total numbers of AHCs trained (Rs = 0.77, p = 0.01). Four external contextual factors were associated with significantly higher numbers of lay people recruited and trained: having a health care provider to coordinate the intervention (p = 0.02); a pool of other volunteers to recruit from (p = 0.02); a contract in place with a commissioned service (p = 0.02), and; formal volunteer arrangements (p = 0.03). Conclusions Data suggest that there were four key components that significantly influenced establishing an Alcohol Health Champion programme in areas experiencing both high levels of deprivation and alcohol-related harm. There is added value of capturing external contextual factors a priori and then testing relationships with process indicators to inform the effective roll-out of complex interventions. Future research could explore a wider range of process indicators and outcomes, incorporating methods to rate individual factors to derive a mean score. Trial registration ISRCTN81942890, date of registration 12/09/2017