The oxidative degradation of organic contaminants using a manganese oxide-containing mine waste

Manganese oxide tailings material, a waste product generated during Mn ore extraction processes in South Africa, has been assessed in terms of its potential to oxidatively breakdown organic contaminants. Azo dyes and polycyclic aromatic hydrocarbons (anthracene) show oxidative interactions with the tailings, resulting in the formation of products which are more environmentally favourable than the parent compound. Tailings samples from five mines were characterised to establish the redox reactivity of the material. Based on chemical and mineralogical data the tailings were grouped into the carbonate-rich Mamatwan type (MT) tailings (Mamatwan and Gloria mines), the Mn oxide- enriched Wessels type (WT) tailings (Wessels and Nchwaning mines) and the Mn oxide enriched Hotazel type (HT) tailings (Hotazel mine). The tailings are net-alkaline and non acid generating with a point of zero charge below pH 4. The average Mn oxidation state of the three tailings types ranges from 1.2 to 1.5 in the order HT>WT>MT. Despite a low surface area (1.5 to 6.4 m(^2) .g(^-1)) the tailings show a substantial (0.5 to 3.0%) 'easily' reducible, reactive Mn phase as well as a large pool of more recalcitrant dithionite-extractable Mn. Thus the tailings material displays both 'quick and slow release' oxidative capacity. The oxidative decolorisation of acid azo dyes acid orange 7 (AO 7) and acid yellow 36 (AY 36) by the Mn tailings is highly pH dependent, with increased oxidation occurring at lower pH. The reaction mechanism for the oxidation of AO 7 by the tailings has many similarities to enzymatic degradation of the dye observed with white rot fungi. The reaction, initiated on the phenolic group, occurs via successive one electron transfers from the dye molecule to the Mn oxide. A series of radical reactions occur resulting m the asymmetrical cleavage of the azo bond and the generation of terminal reaction products 1,2 naphthoquinone and 4- hydroxybenzenesulfonate. Attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) demonstrated that initial sorption of AO 7 is pH dependent and outer-sphere. A pronounced lag phase exists between the initial sorption of the dye to a Mn oxide surface and the initiation of oxidation. This lag phase can indicate that either the transfer of the initial electron is rate limiting or that correct orientation followed by inner- sphere complexation is necessary before oxidation can take place. The reaction mechanism proposed for the oxidation of AY 36 is initiated at the amino moiety and proceeds via successive, one electron transfers from the dye to the Mn tailings. The reaction pathway involves the formation of a number of colourless intermediate products, some of which hydrolyse in a Mn oxide-independent step. The terminal oxidation products were observed to bep-benzoquinone and 3-hydroxybenzenesulfonate.Light, both UV and ambient, and auxiliary compounds such as acetate buffer and salts did not reduce the decolorisation capacity of the tailings. Increased buffer strength enhanced decolorisation and addition of Na(_2)S0(_4) in the presence of buffer increased the initial oxidation of AO 7. The decolorisation capacity of the Mn tailings showed durability with 90% colour removal observed 60 days after daily dye replenishment. Drying anthracene-spiked Mn tailings, synthetic Mn oxide and calcite water slurries resulted in anthracene oxidation to anthraquinone (6-30% oxidation). Small but significant (4%) anthracene oxidation was also observed when anthracene spiked water was evaporated from quartz and a clean glass surface. No anthracene oxidation was apparent without the evaporation of water at pH > 5. The HT tailings oxidised up to 30% anthracene when dried, the most substantial oxidation took place below 5% gravimetric water content. Evaporation of anthracene-spiked cyclohexane slurries resulted in the same observed oxidation from both Mn tailings and calcite. It could not be established whether elecfron transfer was occurring between the Mn oxide phase of the tailings and the anthracene or whether the transformation was solely a surface mediated phenomenon with oxygen being used as the elecfron acceptor. Under fully hydrated conditions the Mn oxide tailings oxidised 75% of anthracene to anthraquinone at pH values less than 4.5. This would suggest that the Mn tailings can oxidise anthracene and sufficient mineral-contaminant contact can be achieved despite the low water solubility of the compound

A Machine for Pasture Interseeding

A pasture interseeding machine that interseeds legumes and grasses in established grasslands has been developed by the Agricultural Engineering Department of South Dakota State University. The pasture interseeding machine cuts four furrows approximately 4 inches wide, 2 inches deep and 30 inches apart. Seeds are placed in a seedbed prepared in these furrows. The furrows eliminate some competition from the existing sod and minimize runoff and erosion if placed on the contour. SDSU agricultural engineers designed the machine so the spring-loaded coulters and inclined disks cut slices of sod and soil. These slices are displaced to the sides of the cut furrows. Seeds are planted with furrow openers operating in the cut furrows. The results of interseeding legumes and grasses in grassland during 1969, 1970 and 1971 were favorable when adequate moisture and weather conditions prevailed. Most furrows and sod slices produced while interseeding will weather (see Figures 1 and 2), thus, maintenance of the grassland will not be severely handicapped. Results show much promise of increasing production and quality of grasslands

Ablation debris control by means of closed thick film filtered water immersion

The performance of laser ablation generated debris control by means of open immersion techniques have been shown to be limited by flow surface ripple effects on the beam and the action of ablation plume pressure loss by splashing of the immersion fluid. To eradicate these issues a closed technique has been developed which ensured a controlled geometry for both the optical interfaces of the flowing liquid film. This had the action of preventing splashing, ensuring repeatable machining conditions and allowed for control of liquid flow velocity. To investigate the performance benefits of this closed immersion technique bisphenol A polycarbonate samples have been machined using filtered water at a number of flow velocities. The results demonstrate the efficacy of the closed immersion technique: a 93% decrease in debris is produced when machining under closed filtered water immersion; the average debris particle size becomes larger, with an equal proportion of small and medium sized debris being produced when laser machining under closed flowing filtered water immersion; large debris is shown to be displaced further by a given flow velocity than smaller debris, showing that the action of flow turbulence in the duct has more impact on smaller debris. Low flow velocities were found to be less effective at controlling the positional trend of deposition of laser ablation generated debris than high flow velocities; but, use of excessive flow velocities resulted in turbulence motivated deposition. This work is of interest to the laser micromachining community and may aide in the manufacture of 2.5D laser etched patterns covering large area wafers and could be applied to a range of wavelengths and laser types

User-centered design and reference services in international librarianship: a case study of Nazarbayev University Library

Major changes over the past decade have moved Kazakhstan and its university students out of the old Soviet model of education and into the realm of international scholarship. While students from this region are being prepared in new and innovative ways, their research needs are still unique and require a firm understanding on the part of academic librarians. With an eye to better serving students at Nazarbayev University, librarians undertook a usability of the library’s web resources in February 2013. This article presents findings from the study, which address the distinct needs of university students from post-Soviet nations

Developing a pressure ulcer risk factor minimum data set and risk assessment framework

AIM: To agree a draft pressure ulcer risk factor Minimum Data Set to underpin the development of a new evidenced-based Risk Assessment Framework.BACKGROUND: A recent systematic review identified the need for a pressure ulcer risk factor Minimum Data Set and development and validation of an evidenced-based pressure ulcer Risk Assessment Framework. This was undertaken through the Pressure UlceR Programme Of reSEarch (RP-PG-0407-10056), funded by the National Institute for Health Research and incorporates five phases. This article reports phase two, a consensus study.DESIGN: Consensus study.METHOD: A modified nominal group technique based on the Research and Development/University of California at Los Angeles appropriateness method. This incorporated an expert group, review of the evidence and the views of a Patient and Public Involvement service user group. Data were collected December 2010-December 2011.FINDINGS: The risk factors and assessment items of the Minimum Data Set (including immobility, pressure ulcer and skin status, perfusion, diabetes, skin moisture, sensory perception and nutrition) were agreed. In addition, a draft Risk Assessment Framework incorporating all Minimum Data Set items was developed, comprising a two stage assessment process (screening and detailed full assessment) and decision pathways.CONCLUSION: The draft Risk Assessment Framework will undergo further design and pre-testing with clinical nurses to assess and improve its usability. It will then be evaluated in clinical practice to assess its validity and reliability. The Minimum Data Set could be used in future for large scale risk factor studies informing refinement of the Risk Assessment Framework

Security governance and networks: New theoretical perspectives in transatlantic security

The end of the Cold War has not only witnessed the rise of new transnational threats such as terrorism, crime, proliferation and civil war; it has also seen the growing role of non-state actors in the provision of security in Europe and North America. Two concepts in particular have been used to describe these transformations: security governance and networks. However, the differences and potential theoretical utility of these two concepts for the study of contemporary security have so far been under-examined. This article seeks to address this gap. It proposes that security governance can help to explain the transformation of Cold War security structures, whereas network analysis is particularly useful for understanding the relations and interactions between public and private actors in the making and implementation of national and international security policies

The determinants of election to the United Nations Security Council

This is the author's accepted manuscript. The final publication is available at Springer via http://dx.doi.org/10.1007/s11127-013-0096-4.The United Nations Security Council (UNSC) is the foremost international body responsible for the maintenance of international peace and security. Members vote on issues of global importance and consequently receive perks—election to the UNSC predicts, for instance, World Bank and IMF loans. But who gets elected to the UNSC? Addressing this question empirically is not straightforward as it requires a model that allows for discrete choices at the regional and international levels; the former nominates candidates while the latter ratifies them. Using an original multiple discrete choice model to analyze a dataset of 180 elections from 1970 to 2005, we find that UNSC election appears to derive from a compromise between the demands of populous countries to win election more frequently and a norm of giving each country its turn. We also find evidence that richer countries from the developing world win election more often, while involvement in warfare lowers election probability. By contrast, development aid does not predict election

Towards improved decision support in the assessment and management of pain for people with dementia in hospital: a systematic meta-review and observational study

This is the final version. Available from NIHR Journals Library via the DOI in this record.Background Pain and dementia are common in older people, and impaired cognitive abilities make it difficult for them to communicate their pain. Pain, if poorly managed, impairs health and well-being. Accurate pain assessment in this vulnerable group is challenging for hospital staff, but essential for appropriate management. Robust methods for identifying, assessing and managing pain are needed. Aims and objectives Two studies were undertaken to inform the development of a decision support tool to aid hospital staff in the recognition, assessment and management of pain. The first was a meta-review of systematic reviews of observational pain assessment instruments with three objectives: (1) to identify the tools available to assess pain in adults with dementia; (2) to identify in which settings they were used and with what patient populations; and (3) to assess their reliability, validity and clinical utility. The second was a multisite observational study in hospitals with four objectives: (1) to identify information currently used by clinicians when detecting and managing pain in patients with dementia; (2) to explore existing processes for detecting and managing pain in these patients; (3) to identify the role (actual/potential) of carers in this process; and (4) to explore the organisational context in which health professionals operate. Findings also informed development of health economics data collection forms to evaluate the implementation of a new decision support intervention in hospitals. Methods For the meta-review of systematic reviews, 12 databases were searched. Reviews of observational pain assessment instruments that provided psychometric data were included. Papers were quality assessed and data combined using narrative synthesis. The observational study used an ethnographic approach in 11 wards in four UK hospitals. This included non-participant observation of 31 patients, audits of patient records, semistructured interviews with 52 staff and four carers, informal conversations with staff and carers and analysis of ward documents and policies. Thematic analysis of the data was undertaken by the project team. Results Data from eight systematic reviews including 28 tools were included in the meta-review. Most tools showed moderate to good reliability, but information about validity, feasibility and clinical utility was scarce. The observational study showed complex ward cultures and routines, with variations in time spent with patients, communication patterns and management practices. Carer involvement was rare. No pain decision support tools were observed in practice. Information about pain was elicited in different ways, at different times, by different health-care staff and recorded in separate documents. Individual staff made sense of patients’ pain by creating their own ‘overall picture’ from available information. Limitations Grey literature and non-English-language papers were excluded from the meta-review. Sample sizes in the observational study were smaller than planned owing to poor documentation of patients’ dementia diagnoses, gatekeeping by staff and difficulties in gaining consent/assent. Many patients had no or geographically distant carers, or a spouse who was too unwell and/or reluctant to participate. Conclusions No single observational pain scale was clearly superior to any other. The traditional linear concept of pain being assessed, treated and reassessed by single individuals did not ‘fit’ with clinical reality. A new approach enabling effective communication among patients, carers and staff, centralised recording of pain-related information, and an extended range of pain management interventions is proposed [Pain And Dementia Decision Support (PADDS)]. This was not tested with users, but a follow-on study aims to codesign PADDS with carers and clinicians, then introduce education on staff/patient/carer communications and use of PADDS within a structured implementation plan. PADDS will need to be tested in differing ward contexts.National Institute for Health Research Health Services and Delivery Research programm

Choice in the context of informal care-giving

Extending choice and control for social care service users is a central feature of current English policies. However, these have comparatively little to say about choice in relation to the informal carers of relatives, friends or older people who are disabled or sick. To explore the realities of choice as experienced by carers, the present paper reviews research published in English since 1985 about three situations in which carers are likely to face choices: receiving social services; the entry of an older person to long-term care; and combining paid work and care. Thirteen electronic databases were searched, covering both the health and social care fields. Databases included: ASSIA; IBSS; Social Care Online; ISI Web of Knowledge; Medline; HMIC Sociological Abstracts; INGENTA; ZETOC; and the National Research Register. The search strategy combined terms that: (1) identified individuals with care-giving responsibilities; (2) identified people receiving help and support; and (3) described the process of interest (e.g. choice, decision-making and self-determination). The search identified comparatively few relevant studies, and so was supplemented by the findings from another recent review of empirical research on carers' choices about combining work and care. The research evidence suggests that carers' choices are shaped by two sets of factors: one relates to the nature of the care-giving relationship; and the second consists of wider organisational factors. A number of reasons may explain the invisibility of choice for carers in current policy proposals for increasing choice. In particular, it is suggested that underpinning conceptual models of the relationship between carers and formal service providers shape the extent to which carers can be offered choice and control on similar terms to service users. In particular, the exercise of choice by carers is likely to be highly problematic if it involves relinquishing some unpaid care-giving activities

X-ray Absorption Spectroscopy as Process Analytical Technology: Reaction Studies for the Manufacture of Sulfonate-Stabilized Calcium Carbonate Particles

Process analytical technologies are widely used to inform process control by identifying relationships between reagents and products. Here, we present a novel process analytical technology system for operando XAS on multiphase multicomponent synthesis processes based on the combination of a conventional lab-scale agitated reactor with a liquid-jet cell. The preparation of sulfonate-stabilized CaCO3 particles from polyphasic Ca(OH)2 dispersions was monitored in real time by Ca K-edge XAS to identify changes in Ca speciation in the bulk solution/dispersion as a function of time and process conditions. Linear combination fitting of the spectra quantitatively resolved composition changes from the initial conversion of Ca(OH)2 to the Ca(R–SO3)2 surfactant to the ultimate formation of nCaCO3·mCa(R− SO3)2 particles. The system provides a novel tool with strong chemical specificity for probing multiphase synthesis processes at a molecular level, providing an avenue to establishing the relationships between critical quality attributes of a process and the quality and performance of the product