34,309 research outputs found

    The influence of bulk particulate properties on pneumatic conveying performance

    Get PDF
    Interest in the use of dense phase conveying has grown considerably in recent years. However, not all products are capable of being conveyed in dense phase and it is often difficult to predict which products have dense phase capability without carrying out pilot conveying trials. The main objective of this work was to investigate the effect of bulk particular properties on pneumatic conveying performance. To achieve this, an extensive programme of conveying trials was carried out and each product tested was subjected to a series of bench scale tests to evaluate the bulk properties of the material. A phase diagram is proposed, based on the aeration properties of a material, which groups together products of similar conveying potential. The phase diagram gives a first indication on the basis of a small sample of material whether or not a product is capable of dense phase conveying. Further, it will predict the most appropriate mode of flow. For products capable of dense phase in a moving bed type flow regime, a further correlation is proposed which predicts the likely conveying performance in the pipeline in terms of mass throughput of product for given conditions based on the air retention characteristics of a product. The correlation has been generalised to extend its applicability to a range of pipeline configurations. The combination of the phase diagram and the correlation for dense phase moving bed type flow (the most commonly used form of dense phase conveying) provides a powerful design tool which will reduce the need for full conveying trials. In addition, the effect of material bulk properties on blow tank performance has also been investigated and a correlation between aeration properties and blow tank discharge characteristics is proposed

    Parameterized Algorithms for Load Coloring Problem

    Full text link
    One way to state the Load Coloring Problem (LCP) is as follows. Let G=(V,E)G=(V,E) be graph and let f:V{red,blue}f:V\rightarrow \{{\rm red}, {\rm blue}\} be a 2-coloring. An edge eEe\in E is called red (blue) if both end-vertices of ee are red (blue). For a 2-coloring ff, let rfr'_f and bfb'_f be the number of red and blue edges and let μf(G)=min{rf,bf}\mu_f(G)=\min\{r'_f,b'_f\}. Let μ(G)\mu(G) be the maximum of μf(G)\mu_f(G) over all 2-colorings. We introduce the parameterized problem kk-LCP of deciding whether μ(G)k\mu(G)\ge k, where kk is the parameter. We prove that this problem admits a kernel with at most 7k7k. Ahuja et al. (2007) proved that one can find an optimal 2-coloring on trees in polynomial time. We generalize this by showing that an optimal 2-coloring on graphs with tree decomposition of width tt can be found in time O(2t)O^*(2^t). We also show that either GG is a Yes-instance of kk-LCP or the treewidth of GG is at most 2k2k. Thus, kk-LCP can be solved in time $O^*(4^k).

    Scaling of Electrode-Electrolyte Interface Model Parameters In Phosphate Buffered Saline

    Get PDF
    We report how the impedance presented by a platinum electrode scales with the concentration of phosphate buffered saline (PBS). We find that the constant phase element of the model scales with approximately the log of concentration, whereas the resistivity is inversely proportional. Using a novel DC measurement technique we show that the Faradaic response of a platinum electrode, and thus the safe exposure limit, does not scale with concentration below 900mV overpotential across a pair of electrodes. We compare objective measurements made in saline to those made in the spinal cavity of live sheep. We comment upon the appropriateness of using PBS as a substitute for living sheep

    An exploration into aesthetic association of product form

    Get PDF
    Creating a relevant and pleasing design aesthetic is a fundamental aim designers endeavour to achieve. Perception of aesthetics takes place both during the design process when the designer creates a form, and later, through the users’ interpretation of the form. Within the perception process, association plays a significant role. This paper addresses the stage research results of our exploration into the associative meanings of a product. By analysing the evaluation of a series of top award winning designs, it was found that some associative meanings (represented by descriptive words) are correlated, such as ‘pure-architecturalgeometrical’, ‘delicate-curvaceous-organic’ etc. By conducting a series of workshops, both in the UK and China, we have been able to explore the extent to which young designers are able to manipulate form, style and create an overall perception of a positive aesthetic. One of the main outputs during the workshops was to design a MP3 player with speaker units, styled in line with three topics of aesthetic association: topic 1 – pure, architectural, geometrical and technical; topic 2 – curvaceous, organic, and fun; topic 3 – graceful, cheerful, and powerful. Three non-correlated associative descriptors were deliberately used in topic 3. Results suggest that young designers tend to differ in their ability and success of manipulating form to match different aesthetic targets. When the descriptive words in one aesthetic topic are correlated, student designers seem to find it easier to manipulate the form matching the topic. Comparative analysis between the results from the workshops in the UK (Southampton Solent University) and in China (Tsinghua University) is also presented in the paper

    Feasibility of Harvesting Power To Run A Domestic Water Meter Using Streaming Cell Technology

    Get PDF
    We investigate the possibility of using streaming cells as a means of harvesting energy from the town water supply. We measure the electrical power developed from streaming cells using tap water as a working fluid. We estimate the amount of energy available from a typical domestic household based on water usage data. We estimate the amount of energy required to operate a simple data logger and transmitter. From these estimates we calculate the required efficiency and physical form of a streaming cell energy converter. We comment on the feasibility of using streaming cell technology as a means of harvesting energy from a domestic water supply

    A Home-Start peer support scheme for women with low mood following childbirth

    Get PDF
    Perinatal mental health problems vary in impact and severity, and can have long-lasting effects on maternal health and child psychological health and development. The evidence to support the effectiveness of postnatal peer and volunteer support schemes to improve the long-term health of women is mixed, with some studies highlighting positive effects in terms of reducing symptoms of depression. Using data from a peer support scheme designed to support women with low mood following childbirth, this paper provides insight into the initial support needs of women, alongside the challenges of using volunteer and peer support services. This paper provides health visitors and others working in community settings with an understanding of how volunteer befriending services may, or may not work in community settings. The data suggests that Home-Start does have a positive impact on the lives of some women, however more work is required in order to understand which aspects of the Home-Start intervention women find effective and why

    Modeling Graph Languages with Grammars Extracted via Tree Decompositions

    Get PDF
    Work on probabilistic models of natural language tends to focus on strings and trees, but there is increasing interest in more general graph-shaped structures since they seem to be better suited for representing natural language semantics, ontologies, or other varieties of knowledge structures. However, while there are relatively simple approaches to defining generative models over strings and trees, it has proven more challenging for more general graphs. This paper describes a natural generalization of the n-gram to graphs, making use of Hyperedge Replacement Grammars to define generative models of graph languages.9 page(s
    corecore