A process chain for integrating microfluidic interconnection elements by micro- overmoulding of thermoplastic elastomers

This paper presents a process chain for in-line integration of microfluidic interconnection elements by a variant of micro-injection moulding (mu IM). A SEBS-based thermoplastic elastomer (TPE) was moulded over polymethylmethacrylate (PMMA) to produce a hybrid microfluidic structure with an aspect ratio of 2. The process chain implemented micro-milling for fabricating micro-structured tool inserts, and mu IM and micro-overmoulding was used for replication. A two-plate mould was used for moulding the substrate, whilst a three-plate mould with a replaceable insert was used for TPE overmoulding. The presented application was an interconnect system for a microfluidic device, which enabled direct fitting of standard tubes into microfluidic substrates. A leakage test showed that the interconnection was leak-proof within a range of flow rates between 0.32 and 0.62 ml min(-1)

A review of information flow diagrammatic models for product-service systems

A product-service system (PSS) is a combination of products and services to create value for both customers and manufacturers. Modelling a PSS based on function orientation offers a useful way to distinguish system inputs and outputs with regards to how data are consumed and information is used, i.e. information flow. This article presents a review of diagrammatic information flow tools, which are designed to describe a system through its functions. The origin, concept and applications of these tools are investigated, followed by an analysis of information flow modelling with regards to key PSS properties. A case study of selection laser melting technology implemented as PSS will then be used to show the application of information flow modelling for PSS design. A discussion based on the usefulness of the tools in modelling the key elements of PSS and possible future research directions are also presented

Evaluation of the state-of-the-art in informatics in glucometers

This review evaluated the level of informatics in glucometers through an assessment of the quantity and types of information and advice provided to users. Manufacturer websites were investigated and the characteristics of glucometers were examined. One hundred glucometers from 27 manufacturers were analysed. Many glucometers contained simple informatics features and five also contained on-device graphing features for users to monitor trends. Some manufacturers have extended informatics via external software. A small number of glucometers provided knowledge for the user by, for example, simple embedded decision support protocols. However, it is suggested that glucometers could better serve as primary care devices through the incorporation of more decision support directly on the device

Design of experiment for the optimisation of deep reactive ion etching of silicon inserts for micro-fabrication

The following paper describes a design of experiments investigation of the deep reactive of pillar structures on a silicon wafer. The etched wafers would subsequently be used as masters for the fabrication of nickel mould inserts for microinjection moulding. Undercuts occur when the pillar base has a smaller cross-section than the apex of the pillar. They therefore affect tolerances of the subsequent nickel mould, its strength and its de-mouldability from the silicon form. The response measured in these experiments was the degree of undercut of micro-scale (10 μm x 10 μm x 40 μm, 5 μm x 5 μm x 40 μm and 2 μm x 2 μm x 40 μm) The literature suggests that gas pressure, platen power, gas flow rate, phase switching times and mask size can all affect the degree of undercut. After examination of this literature, and of manufacturers guidelines, three parameters were selected for experimental testing: platen power, C 4F 8 gas flow rate during the passivation phase and switching times. Switching times was found to be the only statistically significant parameter for both 10x10 μm and 5x5 μm pillars. The 2x2 μm pillars were not successfully replicated and could therefore not undergo statistical evaluation

Interrupting the social amplification of risk process: a case study in collective emissions reduction

One of the main approaches we have for studying the progressive divergence of understandings around a risk issue is that of social risk amplification. This article describes a case study of a particular environmental contaminant, a chemical flame retardant that could be interpreted as having produced a risk amplifying process. It describes in particular how a group of industrial organizations acted collectively to reduce emissions of this contaminant, in an apparent attempt to avert regulation and boycotts—that is, to intercept the social amplification process and avoid its secondary effects. The aim of the study was to investigate the constitutive qualities of this collective action: the qualities that defined it and made it effective in the eyes of those involved. These include institutionalisation and independence, the ability to confer individual as well as collective benefit, the capacity to attract (rather than avoid) criticism, and the ‘branding’ that helps communicate what otherwise appear to be a set of unconnected, local actions. Although the risk amplification framework has been criticised for implying that there is some externally given risk level that is subsequently amplified, it does appear to capture the mentality of actors involved in issues of this kind. They talk and act as though they believe they are participants in a risk amplification process

Early production of the passive in two Eastern Bantu languages

The passive construction is acquired relatively late by children learning to speak many languages, with verbal passives not fully acquired till age 6 in English. In other languages it appears earlier, around age 3 or before. Use of passive construction in young children was examined in two Eastern Bantu languages spoken in Kenya (Kiswahili and Kigiriama), both with frequent use of passive. The passive was used productively very early (2;1) in these languages, regardless of the method used to measure productivity. In addition non-actional passives, particularly rare in English and some other European languages, were seen at these early ages. The proportion of verbs that were passive varied between individuals, both in children's speech and in the input to children. Pragmatic and grammatical features of the passive in some languages have previously been suggested to drive early passive acquisition, but these features are not found consistently in the two languages studied here. Findings suggest that the relatively high frequency of input found in these languages is the most plausible reason for early productive use of the passive

The inverse problem in microlensing: from the optical depth to the galaxy models parameters

We present in this paper a simple method to obtain informations on galaxy models parameters using the measured value of the microlensing optical depth. Assuming a 100 percent MACHO's dark halo, we ask the predicted optical depth for a given model to be the same as the observed one, in a given direction. Writing the optical depth in terms of the given halo model parameters and inverting this relation with respect to one of them, it is possible to get information on it, fixing under reasonable hypothesis the other parameters. This is what we call the "inverse problem in microlensing. We apply this technique to the class of power-law models with flat rotation curves, determining the range for the core radius R_c compatible with the constraints on the halo flattening q and the measures of the optical depth towards LMC. Next, we apply the same method to a simple triaxial model, evaluating the axial ratios.Comment: 23 LaTex Pages, including 5 Postscript Figures, uses astron.sty, submitted to A&

Categorisation of visualisation methods to support the design of Human-Computer Interaction systems

During the design of Human-Computer Interaction (HCI) systems, the creation of visual artefacts forms an important part of design. On one hand producing a visual artefact has a number of advantages: it helps designers to externalise their thought and acts as a common language between different stakeholders. On the other hand, if an inappropriate visualisation method is employed it could hinder the design process. To support the design of HCI systems, this paper reviews the categorisation of visualisation methods used in HCI. A keyword search is conducted to identify a) current HCI design methods, b) approaches of selecting these methods. The resulting design methods are filtered to create a list of just visualisation methods. These are then categorised using the approaches identified in (b). As a result 23 HCI visualisation methods are identified and categorised in 5 selection approaches (The Recipient, Primary Purpose, Visual Archetype, Interaction Type, and The Design Process).Innovate UK, EPSRC, Airbus Group Innovation

Studies on Holkham salts hole : an isolated salt water community with relict features

There is at Holkham, North Norfolk, a marine pond which supports a fauna thought to be principally a relict from the time when it was part of an estuarine tideway, two hundred and fifty years ago. Studies have been carried out on the hydrology and hydrography of this pond, known locally as the Salts Hole. The nature of the substratum,changes in salinity, temperature and other physical variables have been assessed and from these it has been possible to establish that conditions within the pond are remarkably stable. The fauna is reviewed and its relationship to other brackish water ponds discussed. Experiments designed to produce response surfaces have been carried out for three crustacean species, Idotea chelipes, Gammarus duebeni and Praunus flexuosus. These describe how changes in salinity, temperature and oxygen concentration influence survival of both adults and juveniles. Populations drawn from the surrounding marshes of Holkham Bay have been compared to those of the pond,, The response surface centres of the Salts Hole populations correlate more closely with the conditions prevailing in the pond, than do the Bay populations. Electrophoresis of Malate dehydrogenase and Leucine aminopeptidase isozymes was performed for the same three species of crustaceans. The Salts Hole populations contain fewer alleles and show significantly higher levels of genetic divergence. Several hypotheses relating genetic polymorphism. and environmental conditions have been examined.The findings support Valentine's hypothesis of trophic resource stability and Stenseth's interpretation of the Red Queen hypothesis, predicting that fewer species are found in the pond than in the surrounding salt-marshes. The relative contributions of random genetic drift and selection are discussed and conclusions are drawn that the Salts Hole populations,despite their relatively short period of isolation and small numbers, have been subjected to the effects of selection