1,040 research outputs found

    Solution heat treatment, forming and in-die quenching of a commercial sheet magnesium alloy into a complex-shaped component: experimentation and FE analysis

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    Interest in lightweight materials, particularly magnesium alloys, has increased significantly with rising efficiency requirements in the automotive sector. Magnesium is the lightest available structural metal, with a density approximately 35% lower than that of aluminium. The potential is great for magnesium to become a primary material used in future low carbon vehicle structures; however, there are significant obstacles, namely low ductility and formability, particularly at room temperature. The aim of this work is to present the feasibility of using the solution Heat treatment, Forming, and in-die Quenching (HFQ) process to produce complex shapes from a sheet magnesium alloy, and to use the results to verify a simulation of the process developed using commercial FE software. Uniaxial tensile tests were initially conducted to establish the optimum parameters for forming the part. Stamping trials were then carried out using these parameters, and a simulation set up modelling the forming operation. It was shown that the HFQ process could be used to form a successful component from this alloy, and that a good match was achieved between the results of the forming experiments and the simulation.The authors gratefully acknowledge the support from the EPSRC (Grant Ref: EP/I038616/1) for TARF-LCV: Towards Affordable, Closed-Loop Recyclable Future Low Carbon Vehicle Structures

    Scattering solutions of the spinless Salpeter equation

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    A method to compute the scattering solutions of a spinless Salpeter equation (or a Schrodinger equation) with a central interaction is presented. This method relies on the 3-dimensional Fourier grid Hamiltonian method used to compute bound states. It requires only the evaluation of the potential at equally spaced grid points and yields the radial part of the scattering solution at the same grid points. It can be easily extended to the case of coupled channel equations and to the case of non-local interactions.Comment: 7 page

    Indicators for the measurement of institutional performance concerning water managment - The case of Uzbekistan and Ghana.

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    The indicators are furthermore applied on the irrigation sectors of Ghana e Uzbekistan.Editor: C. Wolln

    Preparation and characterization of lapatinib-loaded PVP nanofiber amorphous solid dispersion by electrospinning

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    Lapatinib-loaded polyvinylpyrrolidone-based nanofibrous solid dispersions were prepared by electrospinning in order to enhance the aqueous solubility and dissolution rate of the anticancer drug. The prepared nanofibers were characterized by smooth-surfaced, homogenous filaments with average diameters of 462±160 nm determined by scanning electron microscopy. The crystalline to amorphous transition of the active ingredient was confirmed by differential scanning calorimetry, while Raman spectroscopy showed that amorphous lapatinib was uniformly distributed in the fibrous structures. Gas chromatographic analyses revealed that residual solvents in the nanofiber mats were below the ICH Guideline Q3C recommended limits, namely ethanol 10.9±2.3 ppm (recommended limit 5000 ppm) and dimethyl formamide 780±56 ppm (recommended limit 880 ppm). Determination of drug content and in vitro dissolution studies were performed in order to observe the influence of electrospinning on the drug release characteristics of the product obtained. The lapatinib content in the nanofibers were measured to be 16.76±0.11 w/w%, whereas the dissolution study at pH 6.8 indicated a rapid disintegration of the nanofibrous mats, releasing ~70% of the drug loading under 5 minutes compared to the ~0.05% dissolution of the neat lapatinib ditosylate. The results confirm the applicability of electrospinning for the improvement of physicochemical characteristics of the poorly bioavailable anticancer agent
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