41 research outputs found

    Ceramic Waste Powder as a Partial Substitute of Fly Ash for Geopolymer Concrete Cured at Ambient Temperature

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    The growth of the construction industry has expanded the demand for ceramic building products such as ceramic tiles, which constitute essential building materials. Nonetheless, a huge quantity of waste powder is produced during the polishing of ceramic tiles. The disposal of ceramic waste powder is a key environmental concern that needs to be properly addressed. The purpose of this research is to evaluate the potential of recycling ceramic waste powder as a geopolymer binder. The main objective consists of exploring the impacts of two types of ceramic waste powder (vitrified tiles and wall tiles) on the partial substitution of fly ash in geopolymer concrete. For this, concrete was prepared under ambient conditions without oven curing. Slump, compressive strength, split tensile strength, and modulus of elasticity tests were performed to measure the workability and the mechanical properties of the geopolymer concrete. Its durability was evaluated through water absorption and sorptivity tests. The microstructural behavior was investigated using scanning electron microscopy and X-ray diffraction measurements. The investigation revealed that a 15% partial replacement of fly ash by wall-tile ceramic waste powder in geopolymer concrete gave similar compressive strength, a 3% increase in tensile strength, and a 7% improvement in the modulus of elasticity. Partial replacement of fly ash with 15% vitrified ceramic waste powder reduced sorptivity and improved the microstructure of geopolymer concrete. The findings revealed that ceramic waste powder can be used to replace 10‚Äď15% of the fly ash in M35 grade structural geopolymer concrete, which can be cured under ambient conditions.¬†Doi: 10.28991/CEJ-2022-08-07-05 Full Text: PD

    3 Dimensional Electromagnetic Analysis of an Axial Active Magnetic Bearing

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    In the rotating electrical machines, active magnetic bearing are basically performing the same role like mechanical bearings to support rotor. The function is based on the principle of magnetic levitation. The idea behind this involves creation of a magnetic field by supplying controlled currents in the bearing coil through amplifiers and complex power electronics. The accurate design of a magnetic bearing system incorporates many parameters before its implementation. The current work of the thesis encircles only the three dimensional (3D) modeling of axial active magnetic bearing (AMB). The static and dynamic models are analyzed for the bearing with a consideration of nonlinear material. In the study, the major emphasis is on the magnetic field, eddy current behavior and exerted magnetic forces in the magnetic bearing. The required input parameters for simulation are considered from the available two dimensional (2D) analysis for the same axial actuator. Elmer open source finite element tool is used in the entire work for making 3D simulations. Finally, the computed results are compared with the 2D case. As a part of the thesis work, a modified geometry is simulated to analyze eddy currents. The hypothesis in later task is the reduction of eddy current losses by providing a radial cut in the bearing ferromagnetic path. The radial cut brings asymmetry in the bearing and the three dimensional analysis provides the possibility to analyze the complete model. The results obtained in the above work provide a good understanding of 3D fields in axial AMB and the computed magnetic forces are in good agreement with the 2D results

    Community-based interventions for the prevention and control of Cutaneous Leishmaniasis: A systematic review

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    We reviewed the evidence on community-based interventions for the prevention and control of cutaneous leishmaniasis (CL). Community initiatives tailored towards awareness and mobilisation are regarded as a priority area in the Neglected Tropical Disease Roadmap 2021‚Äď2030 by the World Health Organization. We searched nine electronic databases for intervention-based studies. Two independent reviewers screened and assessed the articles for methodological quality using predefined criteria. We conducted a meta-analysis using a random effects model, along with narrative synthesis. Thirteen articles were eligible for inclusion, of which 12 were quantitative studies (quasi-experimental with control group and pre-post interventions) and one qualitative study. All articles reported on health education interventions aimed at changing people‚Äôs knowledge, attitudes, and practices (KAP) in relation to CL. Participant groups included students, mothers, housewives, volunteer health workers, and residents in general. An increased score was recorded for all outcomes across all interventions: knowledge (SMD: 1.85, 95% CI: 1.23, 2.47), attitudes (SMD: 1.36, 95% CI: 0.56, 2.15), and practices (SMD: 1.73, 95% CI: 0.99, 2.47). Whilst our findings show that educational interventions improved people‚Äôs knowledge, attitudes, and practices about CL, we argue that this approach is not sufficient for the prevention and control of this disease. Knowledge does not always translate into action, particularly where other structural barriers exist. Therefore, we recommend the design of more innovative community-based interventions with a broader focus (e.g., stigma, financial barriers, and healthcare access

    Community based interventions for the prevention and control of Cutaneous Leishmaniasis : a systematic review

    Get PDF
    We reviewed the evidence on community-based interventions for the prevention and control of cutaneous leishmaniasis (CL). Community initiatives tailored towards awareness and mobilisation are regarded as a priority area in the Neglected Tropical Disease Roadmap 2021‚Äď2030 by the World Health Organization. We searched nine electronic databases for intervention-based studies. Two independent reviewers screened and assessed the articles for methodological quality using predefined criteria. We conducted a meta-analysis using a random effects model, along with narrative synthesis. Thirteen articles were eligible for inclusion, of which 12 were quantitative studies (quasi-experimental with control group and pre-post interventions) and one qualitative study. All articles reported on health education interventions aimed at changing people‚Äôs knowledge, attitudes, and practices (KAP) in relation to CL. Participant groups included students, mothers, housewives, volunteer health workers, and residents in general. An increased score was recorded for all outcomes across all interventions: knowledge (SMD: 1.85, 95% CI: 1.23, 2.47), attitudes (SMD: 1.36, 95% CI: 0.56, 2.15), and practices (SMD: 1.73, 95% CI: 0.99, 2.47). Whilst our findings show that educational interventions improved people‚Äôs knowledge, attitudes, and practices about CL, we argue that this approach is not sufficient for the prevention and control of this disease. Knowledge does not always translate into action, particularly where other structural barriers exist. Therefore, we recommend the design of more innovative community-based interventions with a broader focus (e.g., stigma, financial barriers, and healthcare access).peer-reviewe

    Home is where the future is: The BrightFocus Foundation consensus panel on dementia care

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    IntroductionA national consensus panel was convened to develop recommendations on future directions for home‚Äźbased dementia care (HBDC).MethodsThe panel summarized advantages and challenges of shifting to HBDC as the nexus of care and developed consensus‚Äźbased recommendations.ResultsThe panel developed five core recommendations: (1) HBDC should be considered the nexus of new dementia models, from diagnosis to end of life in dementia; (2) new payment models are needed to support HBDC and reward integration of care; (3) a diverse new workforce that spans the care continuum should be prepared urgently; (4) new technologies to promote communication, monitoring/safety, and symptoms management must be tested, integrated, and deployed; and (5) targeted dissemination efforts for HBDC must be employed.DiscussionHBDC represents a promising paradigm shift to improve care for those living with dementia and their family caregivers: these recommendations provide a framework to chart a course forward for HBDC.HighlightsFive core BrightFocus Foundation panel recommendations:Home‚Äźbased dementia care should be considered the nexus of new long‚Äźterm care models.New payment models are needed to stimulate, reward, and support home care practices.A skilled new workforce spanning long‚Äźterm care needs to be developed and equipped.New technologies to promote best practices must be tested, integrated, and deployed.Value propositions and improved public health communication are needed.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/152597/1/alzjjalz201710006.pd

    Flow around a rotating circular cylinder with an end plate near a plane wall boundary

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    The objective of the present study is to investigate the characteristics of a flow around a rotating circular cylinder with and without an end plate near a wall boundary. The different cases which are taken into consideration in the current investigations were with gap ratios of 0.1d, 0.5d, 1.0d, 1.5d and 2.0d. A symmetric end plate is attached behind the rotating circular cylinder at a distance of 0.1d from the cylinder and a gap ratio of 1.5d. We performed Computational Fluid Dynamics (CFD) simulation of the flow around a rotating circular cylinder near a plane wall boundary using a CFD solver, STAR-CCM+. Free-stream velocity is kept constant at 5 m/s and the Reynolds number calculated is 3.24X104. We then studied the flow characteristics such as lift and drag generated on the circular cylinder with and without an end plate and the wake structure. We observed that the vortex suppression is increased when the gap ratio is reduced, i.e., when the circular cylinder is nearer to the plane wall boundary. As the gap ratio increases the drag force generated decreases and the lift force increases considerably. In the case of rotating circular cylinder with an end plate, the wake area has moved upwards and the lift generated has increased manifold

    Efficient Finite Element Modelling of Litz Wires in Toroidal Inductors

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    Accurate understanding of losses and frequency-dependent winding parameters have been an important aspect for selecting the right configuration of stranded conductors in power-electronic inductors. This paper presents an approach for modelling frequency-dependent parameters of a winding with twisted wire bundles in toroidal inductors using a multi-axial sliced finite element (FE) modelling approach. A 2-D magnetodynamic FE problem is solved in several axial and radial slices of the inductor, accounting for the twisted conductor bundles by varying the conductor positions in the slices. Case studies are presented for different levels and pitch lengths of twisting. The approach is validated against 3-D FE simulations in the case of 3-4 parallel strands and against measurements in the case of 75, 105 and 125 strands, which would be impossibly heavy for conventional 3-D FE tools. The results provide insight into the effect of strand grouping, twisting levels and twisting pitch on the frequency-dependent resistance of windings.publishedVersionPeer reviewe

    Multi-Axial Sliced Finite Element Model for Toroidal Inductors

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    This paper demonstrates a novel approach for analyzing 3-D electromagnetic fields in toroidal inductors with minimal computational time and resources. A 2-D magnetodynamic finite element (FE) problem is solved in several axial and radial slices of the 3-D inductor geometry using the AVI-formulation. A procedure to couple the slices with each other through circuit equations and suitable interface conditions is proposed. The obtained results are validated with a 3-D FE model in a time-harmonic case. The modelling shows massive reduction in computation time compared to traditional 3-D FE analysis.acceptedVersionPeer reviewe
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