562 research outputs found

    An Audit of export services in England: developing business focused support

    Get PDF
    One of the key thresholds in the development of small and medium sized enterprises is exporting and trading internationally. A brief review of the academic and practitioner literature highlights a number of benefits associated with exporting that include exposure to differing ways of ‘how to do’ business and opportunities for the development of joint ventures and strategic alliances. However, several regions within the United Kingdom perceive that they have too few SMEs who trade internationally. Recent estimates suggest that approximately three per cent of the SMEs in the United Kingdom are actively exporting (Bank of England, 1999). Government policy makers have responded to such concerns by providing a range of support programmes to increase the number of SMEs who trade internationally and enhance the skills and capabilities of those SMEs who export, so that they can efficiently and effectively manage the exporting and market development process. Therefore, in the majority of the English regions, there are a range of publicly funded organisations providing advice, consultancy, information and training to SMEs wishing to trade internationally and those businesses already exporting. In addition, SMEs can access a number of export services from private sector organisations such as banks, accountants, freight forwarders and export agents. There has been no overall national ‘stocktake’ or audit of such provision. However, the need for such a stocktake is becoming increasingly important due to the introduction of a number of new support organisations into the institutional landscape and the re-organisation and re-branding of British Trade International as Trade Partners UK and the appointment of a series of Regional International Trade Directors. The introduction of the Small Business Service will have a major impact on the coverage and nature of provision for exporting SMEs within each of the English regions. The introduction of the Small Business Service, however, provides an opportunity to explore and examine alternative configurations of small business support and the types of organisation that are best placed to satisfy the needs of exporting SMEs. This paper presents the key findings to emerge from an audit of export services within each of the English regions. Based on a research and development project undertaken in conjunction with Trade Partners UK, the paper offers insights into: • The coverage of export services available to SMEs within England; • The effectiveness and appropriateness of current configuration of export services; • The ways in which the effectiveness of the current configuration of export services could be enhanced. The audit was based on a series of face-to-face and telephone interviews with local, regional and national providers of export provision. A key argument within the paper is that effective configurations of export and trade development support arise from insights into, and appropriate responses to, the exporting and trade development process as experienced by SMEs. The paper concludes with a number of implications in terms of how business-driven forms of support can be developed.</p

    Controlling the crystal polymorph by exploiting the time dependence of nucleation rates

    Get PDF
    Most substances can crystallise into two or more different crystal lattices, called polymorphs. Despite this, there are no systems in which we can quantitatively predict the probability of one competing polymorph forming, instead of the other. We address this problem using large scale (hundreds of events) studies of the competing nucleation of the alpha and gamma polymorphs of glycine. In situ Raman spectroscopy is used to identify the polymorph of each crystal. We find that the nucleation kinetics of the two polymorphs is very different. Nucleation of the alpha polymorph starts off slowly but accelerates, while nucleation of the gamma polymorph starts off fast but then slows. We exploit this difference to increase the purity with which we obtain the gamma polymorph by a factor of ten. The statistics of the nucleation of crystals is analogous to that of human mortality, and using a result from medical statistics we show that conventional nucleation data can say nothing about what, if any, are the correlations between competing nucleation processes. Thus we can show that, with data of our form, it is impossible to disentangle the competing nucleation processes. We also find that the growth rate and the shape of a crystal depends on when it nucleated. This is new evidence that nucleation and growth are linked.Comment: 8 pages, plus 17 pages of supplementary materia

    Carbon nanomaterials as drug transporter for cancer therapy

    Get PDF
    There is a vigorous and growing research effort developing carbon nanotubes (CNTs) for medical applications. It is now known that nanocomposites of Single Wall Nanotubes (SWNTs) can be used to deliver anti-cancer drugs to cells. Also, SWNTs are efficient at converting near infrared (NIR) light to heat, and can do so in a cell, and so cancer cells can be targeted for destruction by NIR radiation, once the cells have taken up SWNTs. SWNTs are highly insoluble in water, but can be functionalized via physical or covalent attachment of solubilizing molecules and drugs of interest. Once this is done, they are readily taken up by cells. We found evidence that our CNT nanocomposites were found to enter cells via endocytosis (the mechanism cells use to take up nutrients); this agrees with earlier work by Dai and coworkers. Herein, we perform systematic study of the internalization, delivery and subcellular localization and possible adverse effects of SWNTs dispersed in culture media and SWNTs wrapped with different fluorescently labelled peptide (FLP-SWNTs) on Chinese hamster ovary (CHO) cells and SWNTs attached with anti-cancer drug on two common cancerous cell lines, human epithelial carcinoma cell line (HeLa) and colorectal cancer cell lines (WiDr)

    Instabilities in complex mixtures with a large number of components

    Full text link
    Inside living cells are complex mixtures of thousands of components. It is hopeless to try to characterise all the individual interactions in these mixtures. Thus, we develop a statistical approach to approximating them, and examine the conditions under which the mixtures phase separate. The approach approximates the matrix of second virial coefficients of the mixture by a random matrix, and determines the stability of the mixture from the spectrum of such random matrices.Comment: 4 pages, uses RevTeX 4.

    A coil-globule transition of a semiflexible polymer driven by the addition of spherical particles

    Full text link
    The phase behaviour of a single large semiflexible polymer immersed in a suspension of spherical particles is studied. All interactions are simple excluded volume interactions and the diameter of the spherical particles is an order of magnitude larger than the diameter of the polymer. The spherical particles induce a quite long ranged depletion attraction between the segments of the polymer and this induces a continuous coil-globule transition in the polymer. This behaviour gives an indication of the condensing effect of macromolecular crowding on DNA.Comment: 12 pages, 4 figure

    Heterogeneous nucleation near a metastable vapour-liquid transition: the effect of wetting transitions

    Full text link
    Phase transformations such as freezing typically start with heterogeneous nucleation. Heterogeneous nucleation near a wetting transition, of a crystalline phase is studied. The wetting transition occurs at or near a vapour-liquid transition which occurs in a metastable fluid. The fluid is metastable with respect to crystallisation, and it is the crystallisation of this fluid phase that we are interested in. At a wetting transition a thick layer of a liquid phase forms at a surface in contact with the vapour phase. The crystalline nucleus is then immersed in this liquid layer, which reduces the free energy barrier to nucleation and so dramatically increases the nucleation rate. The variation in the rate of heterogeneous nucleation close to wetting transitions is calculated for systems in which the longest-range forces are dispersion forces.Comment: 11 pages including 3 figure

    The sedimentology of gravel beds in groundwater-dominated chalk streams: Implications for sediment modelling and management

    Get PDF
    Elevated fine sediment accumulation in a river system's gravel bed is known to cause detrimental ecological impacts. Current sediment targets and approaches to mitigation have failed due to the oversimplification of geomorphological processes controlling fine sediment accumulation and the lack of relevant scientific knowledge underpinning them. This is particularly apparent in chalk streams (groundwater-dominated systems) which regularly exhibit high rates of sediment accumulation despite low suspended sediment yields. A necessary first step is to better characterise their sedimentology; thus, the novelty of this study was to determine the sedimentological characteristics of chalk stream gravel beds, specifically the quantity and distribution of fine sediment with depth. We collated published and unpublished freeze-core data, encompassing 90 sites across 11 UK chalk streams. Results showed average quantities of fine sediment (75% of beds exceeding thresholds for ecological degradation. Quantities of fine sediment increased with increasing depth into the bed, with an average increase between surface and subsurface layers of 54%, and 89% of the gravel bed over-saturated with fine sediment. Regional differences were attributed to differences in stream power and local sediment sources, including surficial geology and catchment land use. Additionally, a major contrast was identified between experimental conditions in flume studies used to establish models describing interactions/mechanisms of fine sediment infiltration into immobile gravel beds and the natural conditions observed in chalk streams. As such, the use of such models as a basis to explore sediment management scenarios is unlikely to predict the outcome of such management techniques correctly in a real-world situation

    Phase behaviour of a model of colloidal particles with a fluctuating internal state

    Get PDF
    Colloidal particles are not simple rigid particles, in general an isolated particle is a system with many degrees of freedom in its own right, e.g., the counterions around a charged colloidal particle.The behaviour of model colloidal particles, with a simple phenomenological model to account for these degrees of freedom, is studied. It is found that the interaction between the particles is not pairwise additive. It is even possible that the interaction between a triplet of particles is attractive while the pair interaction is repulsive. When this is so the liquid phase is either stable only in a small region of the phase diagram or absent altogether.Comment: 12 pages including 4 figure

    Effects of polymer polydispersity on the phase behaviour of colloid-polymer mixtures

    Full text link
    We study the equilibrium behaviour of a mixture of monodisperse hard sphere colloids and polydisperse non-adsorbing polymers at their θ\theta-point, using the Asakura-Oosawa model treated within the free-volume approximation. Our focus is the experimentally relevant scenario where the distribution of polymer chain lengths across the system is fixed. Phase diagrams are calculated using the moment free energy method, and we show that the mean polymer size ξc\xi_{\rm c} at which gas-liquid phase separation first occurs decreases with increasing polymer polydispersity δ\delta. Correspondingly, at fixed mean polymer size, polydispersity favours gas-liquid coexistence but delays the onset of fluid-solid separation. On the other hand, we find that systems with different δ\delta but the same {\em mass-averaged} polymer chain length have nearly polydispersity-independent phase diagrams. We conclude with a comparison to previous calculations for a semi-grandcanonical scenario, where the polymer chemical potentials are imposed, which predicted that fluid-solid coexistence was over gas-liquid in some areas of the phase diagram. Our results show that this somewhat counter-intuitive result arose because the actual polymer size distribution in the system is shifted to smaller sizes relative to the polymer reservoir distribution.Comment: Changes in v2: sketch in Figure 1 corrected, other figures improved; added references to experimental work and discussion of mapping from polymer chain length to effective radiu
    corecore