38 research outputs found

    Sensorless Load Torque Estimation and Passivity Based Control of Buck Converter Fed DC Motor

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    Passivity based control of DC motor in sensorless configuration is proposed in this paper. Exact tracking error dynamics passive output feedback control is used for stabilizing the speed of Buck converter fed DC motor under various load torques such as constant type, fan type, propeller type, and unknown load torques. Under load conditions, sensorless online algebraic approach is proposed, and it is compared with sensorless reduced order observer approach. The former produces better response in estimating the load torque. Sensitivity analysis is also performed to select the appropriate control variables. Simulation and experimental results fully confirm the superiority of the proposed approach suggested in this paper

    Benign intermuscular lipoma in a bitch

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    A case of intermuscular lipoma located between the external abdominal oblique and internal abdominal oblique muscles in a fourteen- year -old dog is described. Presenting signs, radiographic findings, surgical treatments and the follow-up treatment are discussed

    Wound dressings for a proteolytic-rich environment

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    Wound dressings have experienced continuous and significant changes over the years based on the knowledge of the biochemical events associated with chronic wounds. The development goes from natural materials used to just cover and conceal the wound to interactive materials that can facilitate the healing process, addressing specific issues in non-healing wounds. These new types of dressings often relate with the proteolytic wound environment and the bacteria load to enhance the healing. Recently, the wound dressing research is focusing on the replacement of synthetic polymers by natural protein materials to delivery bioactive agents to the wounds. This article provides an overview on the novel protein-based wound dressings such as silk fibroin keratin and elastin. The improved properties of these dressings, like the release of antibiotics and growth factors, are discussed. The different types of wounds and the effective parameters of healing process will be reviewed

    Renaissance of Organic Triboluminescent Materials

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    Solid-state luminescence of organic dyes is an elusive frontier, and understanding and designing solid-state stimuli-responsive materials is not trivial. �Mechanoluminescence� (ML) or �triboluminescence� (TL), which is associated with fracture or force-initiated luminescence from a material, is currently attracting new interest. Fracturing the surfaces of organic crystals ordered in noncentrosymmetric space groups can electronically excite the surface and neighboring molecules through piezo- or pyroelectric effects, and this can result in luminescence when the molecules relax back to their ground states. The combined duration of these two consecutive phenomena leads to force-generated luminescence or TL. Although TL has been known for a very long time, examples of TL-active materials are scarce, but are increasing as synthetic and characterization procedures develop. The question is now whether the relatively rare phenomenon of TL needs to be reevaluated to obtain a broader understanding of the subject. © 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinhei

    Design, Simulation and Analysis of Cantilever Sensor for in-Vitro LDL Detection

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    This work is focused on the design, simulation and analysis of microcantilever integrated with piezoresistors in Wheatstone bridge arrangement to detect low density lipoprotein (LDL) in blood, which is responsible for cholesterol accumulation in arteries. This paper uses Finite Element Method (FEM) to obtain the performance of piezoresistive microcantilever sensor to measure surface stress corresponding to the adsorption of LDL molecules. The FEM results are compared with the analytical solutions. The results suggest that the designed sensor can effectively sense LDL molecules as in-Vitro with few micro-litre of blood sample
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