1,551 research outputs found

    The year in cardiology: arrhythmias and pacing.

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    During this last year, there has been much progress with regard to anticoagulant and ablation therapy for atrial fibrillation (AF). Apart from recently issued European Society of Cardiology Guidelines for the management of patients with supraventricular arrhythmias, there has been little progress in research in this field. Ventricular arrhythmias and device therapy have seen modest progress

    A thermodynamic framework to predict thermophysical properties that control pMDI aerosol generation

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    Activity coefficient models are introduced to provide a thermodynamic framework for simultaneously predicting multiple thermophysical properties of relevance to pressurized metered dose inhaler (pMDI) aerosol formation. The UNIFAC and UNIQUAC models are discussed in the context of calculation of saturated vapor pressure, surface tension and liquid viscosity using molecule and functional group interaction parameters. New interaction parameters are generated and presented for HFA134a/ethanol mixtures using experimental data for saturated vapor pressure, surface tension and viscosity. The UNIFAC model is shown to give adequate predictivity and can be used when no experimental data is available. Better predictions were obtained with the UNIQUAC model, which is most useful when high-quality measurement data are obtained. The use of these models for flexible thermophysical property prediction of low-global warming potential (GWP) formulations is discussed, with potential developments to improve model fits and better utilize the experimental data

    Validity in market research Practice: `New' is not always `improved'

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    Market research suppliers want to provide a differentiated product or service offering to their clients. However, the frequent need to appear 'new' results in adaptation of research to different contexts. This has consequences for validity. In this paper we make the case for tempering the existing enthusiasm for constant 'innovation' in market research methodologies. In particular, we argue that unfettered adaptation can lead to the generation of invalid findings. We demonstrate some methods of how invalid results can develop. Finally we explain current concepts of 'validity' and provide an innovative way of showing the relationship between the dozen or more varieties of validity that are commonly used in the literature(s). This paper aims to remind practitioners and academics alike, that concepts of validity are important and that there is no point in having a perfectly reliable, but completely invalid, measurement tool

    Building a full-size glider

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    The building and flying of a glider is possible for anyone who can use a few basic tools. This report presents some plans and techniques for building your own glider

    Managing Engineering Talent: Unique Challenges to Optimize the Best and Brightest

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    Most engineers are bright, hard-working, reliable, and prefer to avoid conflict. An engineering curriculum tends to self-select these characteristics. By most standards, you would expect workers exhibiting these traits to require minimal supervision. But is this true? Is this how most current engineering managers lead? Looking at some current theories on leadership combined with personal anecdotes, this presentation will look at some common misconceptions about leading engineers

    Near to One's Heart: The Intimate Relationship Between the Placenta and Fetal Heart.

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    The development of the fetal heart is exquisitely controlled by a multitude of factors, ranging from humoral to mechanical forces. The gatekeeper regulating many of these factors is the placenta, an external fetal organ. As such, resistance within the placental vascular bed has a direct influence on the fetal circulation and therefore, the developing heart. In addition, the placenta serves as the interface between the mother and fetus, controlling substrate exchange and release of hormones into both circulations. The intricate relationship between the placenta and fetal heart is appreciated in instances of clinical placental pathology. Abnormal umbilical cord insertion is associated with congenital heart defects. Likewise, twin-to-twin transfusion syndrome, where monochorionic twins have unequal sharing of their placenta due to inter-twin vascular anastomoses, can result in cardiac remodeling and dysfunction in both fetuses. Moreover, epidemiological studies have suggested a link between placental phenotypic traits and increased risk of cardiovascular disease in adult life. To date, the mechanistic basis of the relationships between the placenta, fetal heart development and later risk of cardiac dysfunction have not been fully elucidated. However, studies using environmental exposures and gene manipulations in experimental animals are providing insights into the pathways involved. Likewise, surgical instrumentation of the maternal and fetal circulations in large animal species has enabled the manipulation of specific humoral and mechanical factors to investigate their roles in fetal cardiac development. This review will focus on such studies and what is known to date about the link between the placenta and heart development

    Long-range gravitational-like interaction in a neutral atomic cold gas

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    A quasi-resonant laser induces a long-range attractive force within a cloud of cold atoms. We take advantage of this force to build in the laboratory a system of particles with a one-dimensional gravitational-like interaction, at a fluid level of modeling. We give experimental evidences of such an interaction in a cold Strontium gas, studying the density profile of the cloud, its size as a function of the number of atoms, and its breathing oscillations.Comment: 4 pages, 4 figures. Published in PRA 87, 013401 (2013

    Leveraging BIM and big data to deliver well maintained highways

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    The Highway infrastructure is one of the most valuable assets for any state or national Government. Efficient operations of Highways lead to success of national and local economies as well as improve the quality of life of the general public dependent on it.  In order to ensure aging road networks continues to move with its ever increasing number of users, requires maintenance and improvements to the road network at the highest standard. Increasing scrutiny over the cost of maintenance along with increasing pressure from Government and the public for transparency over road network spending, has made a strong case for more efficient management of the Highway road asset and traffic management data. Better management of information could allow for life cycle management of asset data and predictive analytics. This paper focuses on proposing a platform that integrates various technologies and systems of Highways Authority and its supply chain, to allow for continuous flow of data throughout an assets life-cycle, leading to seamless, collaborative and effecting working. The integration takes into account developments in the area of BIM and big data; BIM provides a platform to better integrate information whereas big data can provide analytical platform to draw insights
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