377 research outputs found

    Modelling of methanol synthesis in a network of forced unsteady-state ring reactors by artificial neural networks for control purposes

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    A numerical model based on artificial neural networks (ANN) was developed to simulate the dynamic behaviour of a three reactors network (or ring reactor), with periodic change of the feed position, when low-pressure methanol synthesis is carried out. A multilayer, feedforward, fully connected ANN was designed and the history stack adaptation algorithm was implemented and tested with quite good results both in terms of model identification and learning rates. The influence of the ANN parameters was addressed, leading to simple guidelines for the selection of their values. A detailed model was used to generate the patterns adopted for the learning and testing phases. The simplified model was finalised to develop a model predictive control scheme in order to maximise methanol yield and to fulfil process constraints

    Lanthanide grafted phenanthroline-polymer for physiological temperature range sensing

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    Accurate measurement of the temperature is crucial as it determines the dynamics of almost any system. Conventional contact thermometers are not well suited for small scale measurements. Temperature dependent luminescent materials, i.e. materials that emit light of different color at different temperature, are therefore of particular interest in the development of noncontact thermometers. Luminescent materials consisting of lanthanide ions feature high thermal sensitivity, high photostability and high quantum yields. These ions possess very interesting light emitting properties. By anchoring them onto different backbone materials, their light absorption is increased. The search for a backbone that allows the sensor to be active in a defined temperature range, with a high detection sensitivity is ongoing. This work reports the first insoluble phenanthroline-polymer (phen-polymer) backbone on which europium (Eu3+) and terbium (Tb3+) trifluoroacetylacetone (tfac) complexes are easily grafted in a 1 : 1 metal ratio in order to create a noncontact temperature sensor. Two clear, discriminable emission peaks were observed during the photoluminescence study at room temperature, demonstrating that this material can be used as a ratiometric thermometer. The characteristic emission peak correlated to Eu3+ transition is slightly stronger than the emission peak of Tb3+ transition, resulting in a yellow emission color. The maximum value of the relative temperature sensitivity was calculated to be 2.3404% K-1 (340 K), which indicated good thermometric behavior. The emission color of the designed phen-polymer@Eu,Tb_tfac changed from light green (260 K) to orange-red (460 K). The thermometer can therefore be used as a ratiometric noncontact temperature sensor in the broad physiological temperature range

    Social disparities in patient safety in primary care : a systematic review

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    Background: Patient safety is a quality indicator for primary care and it should be based on individual needs, and not differ among different social groups. Nevertheless, the attention on social disparities in patient safety has been mainly directed towards the hospital care, often overlooking the primary care setting. Therefore, this paper aims to synthesise social disparities in patient safety in the primary care setting. Methods: The Databases PubMed and Web of Science were searched for relevant studies published between January 1st 2006 and January 31st 2017. Papers investigating racial, gender and socioeconomic disparities in regards to administrative errors, diagnostic errors, medication errors and transition of care errors in primary care were included. No distinction in terms of participants' age was made. Results: Women and black patients are more likely to experience patient safety events in primary care, although it depends on the type of disease, treatment, and healthcare service. The available literature largely describes gender and ethnic disparities in the different patient safety domains whilst income and educational level are studied to a lesser extent. Conclusions: The results of this systematic review suggest that vulnerable social groups are likely to experience adverse patient safety events in primary care. Enhancing family doctors' awareness of these inequities is a necessary first step to tackle them and improve patient safety for all patients. Future research should focus on social disparities in patient safety using socioeconomic indicators, such as income and education
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