2,199 research outputs found

    DBT degradation enhancement by decorating Rhodococcus erythropolis IGST8 with magnetic Fe3O4 nanoparticles

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    Biodesulfurization (BDS) of dibenzothiophene (DBT) was carried out by Rhodococcus erythropolis IGST8 decorated with magnetic Fe3O4 nanoparticles, synthesized in-house by a chemical method, with an average size of 45-50 nm, in order to facilitate the post-reaction separation of the bacteria from the reaction mixture. Scanning electron microscopy (SEM) showed that the magnetic nanoparticles substantially coated the surfaces of the bacteria. It was found that the decorated cells had a 56% higher DBT desulfurization activity in basic salt medium (BSM) compared to the nondecorated cells. We propose that this is due to permeabilization of the bacterial membrane, facilitating the entry and exit of reactant and product, respectively. Model experiments with black lipid membranes (BLM) demonstrated that the nanoparticles indeed enhance membrane permeability

    Electron localisation in static and time-dependent one-dimensional model systems

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    Electron localization is the tendency of an electron in a many-body system to exclude other electrons from its vicinity. Using a new natural measure of localization based on the exact manyelectron wavefunction, we find that localization can vary considerably between different ground-state systems, and can also be strongly disrupted, as a function of time, when a system is driven by an applied electric field. We use our new measure to assess the well-known electron localization function (ELF), both in its approximate single-particle form (often applied within density-functional theory) and its full many-particle form. The full ELF always gives an excellent description of localization, but the approximate ELF fails in time-dependent situations, even when the exact Kohn-Sham orbitals are employed.Comment: 7 pages, 4 figure

    Managing the humanitarian supply chain: developing a generic model to improve collaboration, efficiency and effectiveness

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    Humanitarian disasters are expected to increase 5-fold over the next 50 years. It is suggested that the scale of resource dedicated to logistics provision in response to disasters accounts for upwards of 80% of the total budget, hence humanitarian logistics is very much in the spotlight. Collaborative working has been promoted as a Silver Bullet in many areas of Supply Chain Management and is contended to be a mechanism to prevent organisations optimising solely their own results, rather than integrating their goals and activities with others to benefit overall end user value. Collaborative techniques inherent within commercial supply chains have not been observed in the humanitarian relief chain. This study investigates why this is the case, as this lack of collaboration leads to inefficiency; which at worst results in increased humanitarian suffering and additional loss of life. The findings reveal ways to advance collaborative working within the humanitarian relief supply chain. A conceptual generic model of the supply chain is developed which highlights significant issues which, if addressed will improve collaboration and thereby benefit overall efficiency and effectiveness

    Cochlear reimplantation

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    Since its inception in 1988 the Cochlear Implant Programme in Manchester has successfully implanted 69 adults and 23 children. Of these 92 procedures, three patients have undergone revision surgery with the insertion of either a new implant or re-positioning of the existing device. We examine the circumstances that lead to the need for reimplantation in these patients, discuss the technical aspects of revision surgery together with the functional results of such procedures. Re-operatio

    Managing the humanitarian supply chain: a collaborative approach?

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    Humanitarian disasters are expected to increase 5-fold over the next 50 years. In 2010 a total of 385 separate disasters killed over 297,000 people worldwide, affected more than 217 million others and caused US$ 123.9 billion of economic damages. It is suggested that the scale of resource dedicated to logistics provision in response to disasters accounts for upwards of 80% of the total budget, hence humanitarian logistics both as a practice and a research topic is very much in the spotlight. Consequently, this research addresses what is argued to be the under-representation of humanitarian logistics in the literature and the associated lack of empirical research focussed on the management of the supply chain. Collaborative working has been promoted as a Silver Bullet in many areas of Supply Chain Management and is contended to be a mechanism to prevent organisations optimising solely their own results rather than integrating their goals and activities with others to benefit overall end user value. Collaborative techniques inherent within commercial supply chains have not been observed in the humanitarian relief chain. This study investigates why this is the case, as this lack of collaboration is reported to lead to inefficiency; which at worst results in increased humanitarian suffering and additional loss of life. Hence, the findings reveal ways to advance collaborative working within the humanitarian relief supply chain. Criticism is levelled at the predominance of quantitative methodologies in current research within humanitarian logistics. This study addresses this gap as well as the calls for more cross-organisational case studies within the field, by adopting a multi-case, qualitative approach based on the triangulation of data gathered during a series of in-depth interviews and focus groups across 4 separate humanitarian relief organisations. Data interpretation is through content analysis to identify specific patterns and themes. The research concerns itself with the response immediately following the onset of a disaster. This limited scope helps to address issues surrounding the generalisability of a purely qualitative approach whilst also maintaining control over data volume; however, there are still ample opportunities for significant theoretical and practical contribution. The findings identify specific barriers to collaborative working within the sector; in particular, themes and patterns within management and control, understanding and training, relationships, and military involvement have surfaced. Outcomes also have implications for commercial supply chain managers who are increasingly faced with challenges that no longer obey the traditional rules of forecast driven certainty and predictability, and are therefore, expected to adopt the more event driven, agile and flexible approaches that are already a reality for their humanitarian sector counterparts. The study concludes with the development of a conceptual generic model of the humanitarian supply chain that includes a number of significant issues which, if addressed will improve collaboration and thereby benefit overall efficiency and effectiveness to the general betterment of future relief provision
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