129 research outputs found

    Dynamics on Multiple Potential Energy Surfaces: Quantitative Studies of Elementary Processes Relevant to Hypersonics

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    The determination of thermal and vibrational relaxation rates of triatomic systems suitable for application in hypersonic model calculations is discussed. For this, potential energy surfaces for ground and electronically excited state species need to be computed and represented with high accuracy and quasiclassical or quantum nuclear dynamics simulations provide the basis for determining the relevant rates. These include thermal reaction rates, state-to-state cross-sections, or vibrational relaxation rates. For exemplary systems - [NNO], [NOO], and [CNO] - all individual steps are described and a literature overview for them is provided. Finally, as some of these quantities involve considerable computational expense, for the example of state-to-state cross sections the construction of an efficient model based on neural networks is discussed. All such data is required and being used in more coarse-grained computational fluid dynamics simulations.Comment: Review article, 46 pages, 8 figure

    Current opinions and recommendations of paediatric healthcare professionals - The importance of tablets:Emerging orally disintegrating versus traditional tablets

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    The appropriate prescribing of paediatric dosage forms is paramount in providing the desired therapeutic effect alongside successful medication adherence with the paediatric population. Often it is the opinion of the healthcare practitioner that dictates which type of dosage form would be most appropriate for the paediatric patient, with liquids being both the most commonly available and most commonly used. Orally disintegrating tablets (ODTs) are an emerging dosage form which provide many benefits over traditional dosage forms for paediatric patients, such as rapid disintegration within the oral cavity, and the reduction in the risk of choking. However the opinion and professional use of healthcare practitioners regarding ODT's is not known. This study was designed to assess the opinions of several types of healthcare professionals (n = 41) regarding ODTs, using a survey across two hospital sites. Results reaffirmed the popularity of liquids for prescribing in paediatrics, with 58.0% of participants preferring this dosage form. ODTs emerged as the second most popular dosage form (30.0%), with healthcare practitioners indicating an increasing popularity amongst patients in the hospital setting, belief with 63.0% of practitioners agreeing that many liquid formulations could be substituted with a suitable ODT. The desired properties of an ideal ODT were also identified by healthcare practitioners preferring a small, fast disintegrating tablet (90.2% and 95.1% respectively), with the taste, disintegration time and flavour being the three most important attributes identified (29.5%, 28.7% and 21.7% respectively). This study provided a pragmatic approach in assessing healthcare professional's opinions on ODTs, highlighting the ideas and thoughts of practitioners who are on the frontline of paediatric prescribing and treatment and gave an indication to their preference for ODT properties

    Analysis of optimum matching of a DC series motor driven centrifugal pump to a photovoltaic generator

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    Direct coupling between a photovoltaic (PV) generator and a monoblock DC series motor connected with ventilator load torque centrifugal pump has been analyzed theoretically as a function of the no flow motor-pump speed (w0) and the water head of the pump. The value of w0 is directly related with motor terminal voltage which has been derived. The condition of the maximum motor-pump efficiency has been deduced mathematically in terms of the speed-torque constant K1 at a given w0 for different water heads. The variation of w0 and perfectly matched motor constant (M0) have been calculated at various solar insolation and different water heads. From these theoretical studies, the optimum matching condition has been suggested according to the requirements. One optimally matched monoblock DC series motor and centrifugal pump, of 125 W, was chosen for study. The calculated coupling efficiencies such as electrical energy, mechanical energy, and hydraulic energy of the pump, have been discussed. Some of these results are also compared to information available in the literature

    Arterial switch operations for single coronary artery ostium or intramural coronary artery

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    Background Successful transfer of the coronary arteries is the most critical step during arterial switch operations for patients with transposition of the great arteries with a single coronary artery ostium and/or intramural coronary arteries. Various techniques have been reported and the present study was an evaluation of them in 10 neonatal patients
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