680 research outputs found

    Note on a Viscoelastic Convection Flow

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    A mathematical analysis of the free convection flow of an inwmpressibk viscoelastic (Rivlin-Ericksen) fluid from an infinite flat plate under variable suction acted upon by a transverse magnetic field is presented. It is found that the effect of viscoelasticity is to appreciably alter the skin-friction

    Note on a Viscoelastic Convection Flow

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    A mathematical analysis of the free convection flow of an incompressible viscoelastic(Rivlin-Ericksen) fluid from an infinite flat plate under variable suction acted upon by a transverse magnetic field is presented. It is found that the effect of viscoelasticity is to appreciably alter the skin-friction

    Development of an Energy Efficient Stern Flap for Improved EEDI of a Typical High speed Displacement Vessel

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    The surge in maritime trade is leading to large scale deployment of high-speed displacement ships by all nations. Cargo vessels are designed for a voyage in pre-determined routes at consistent speeds. On the other hand, high-speed displacement vessel engines designed with a capability to cater for top speeds are under-utilised during their normal course of operation. This sub-optimal utilisation impacts efficiency and increases emissions. In this study, a most favourable stern flap is designed for reducing the energy efficiency design index of a typical high-speed displacement vessel with a slender hull. CFD simulations and experimental model testing were conducted for 12 different stern flap configurations for determining most favourable flap design in the Froude no of 0.17-0.48. Performance of the most favourable stern flap was established by calculating, energy efficiency design index (EEDI) and fuel consumption based on typical operating profile. NOx, VOC and PM emissions were estimated in with and without flap condition. Studies demonstrated that the stern flap reduced effective power demand, average fuel consumption and emissions by about 8 per cent, which when considered for the ship’s operating life cycle, are significant. The most favourable stern flap reduced EEDI by 3.74 units and 1.98 units as compared to the bare hull condition and the required EEDI respectively, thereby demonstrating that EEDI could be used as an index to indicate stern flap efficiency

    Spin Polarisability of the Nucleon in the Heavy Baryon Effective Field Theory

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    We have constructed a heavy baryon effective field theory with photon as an external field in accordance with the symmetry requirements similar to the heavy quark effective field theory. By treating the heavy baryon and anti-baryon equally on the same footing in the effective field theory, we have calculated the spin polarisabilities γi,i=1...4\gamma_i, i=1...4 of the nucleon at third order and at fourth-order of the spin-dependent Compton scattering. At leading order (LO), our results agree with the corresponding results of the heavy baryon chiral perturbation theory, at the next-to-leading order(NLO) the results show a large correction to the ones in the heavy baryon chiral perturbation theory due to baryon-antibaryon coupling terms. The low energy theorem is satisfied both at LO and at NLO. The contributions arising from the heavy baryon-antibaryon vertex were found to be significant and the results of the polarisabilities obtained from our theory is much closer to the experimental data.Comment: 21pages, title changed, minimal correction

    Hybrid nanostructures for electrochemical potassium storage

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    The wide availability and low cost of potassium resources have made electrochemical potassium storage a promising energy storage solution for sustainable decarbonisation. Research activities have been rapidly increasing in the last few years to investigate various potassium batteries such as K-ion batteries (KIBs), K–S batteries and K–Se batteries. The electrode materials of these battery technologies are being extensively studied to examine their suitability and performance, and the utilisation of hybrid nanostructures has undoubtedly contributed to the advancement of the performance. This review presents a timely summary of utilising hybrid nanostructures as battery electrodes to address the issues currently existing in potassium batteries via taking advantage of the compositional and structural diversity of hybrid nanostructures. The complex challenges in KIBs and K–S and K–Se batteries are outlined and the role of hybrid nanostructures is discussed in detail regarding the characteristics of intercalation, conversion and alloying reactions that take place to electrochemically store K in hybrid nanostructures, highlighting their multifunctionality in addressing the challenges. Finally, outlooks are given to stimulate new ideas and insights into the future development of hybrid nanostructures for electrochemical potassium storage

    LATENTIATED PRODRUG APPROACH OF DRUGS: AN OVERVIEW

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    Prodrugs, with their capability of declining the adverse events and elevating the bioavailability of certain drugs, have captured enormous attention throughout the world since the 20th century. The versatility of the prodrugs that are inert and after administration releasing the parent moiety for the desired effect has become a major criterion for the scientists to incorporate this to alleviate the undesired effects of a conventional drug. About 10% of the prevailing drugs are prodrugs and their usage is being amplified owing to its critical application in cancer therapy, toxicity alleviation, and specificity. The purpose of this review is to understand the prodrugs, strategies incorporated in designing the prodrugs, applications, their crucial benefits in targeted action at a specific site of the body, their advantageous effects in chemotherapy. Also, to be acknowledged with the ongoing clinical trials and researches on prodrugs and some notable marketed prodrugs in a depth manner

    Theoretical Modeling and Experimental Analyses of Laminated Wood Composite Poles

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    Wood laminated composite poles consist of trapezoid-shaped wood strips bonded with synthetic resin. The thick-walled hollow poles had adequate strength and stiffness properties and were a promising substitute for solid wood poles. It was necessary to develop theoretical models to facilitate the manufacture and future installation and maintenance of this novel engineered wood product. A higher-order governing differential equation (GDE) model was developed for this purpose based on the principle of minimum potential energy. Transverse shear and glue-line effects were taken into account in the development of the model. A simplified theoretical model was also derived to further validate the higher-order GDE model. Thirty-six small-scale wood laminated composite poles were made and tested to validate the models developed. Strip thickness and number of strips were chosen as experimental variables. The deflection predicted by the theoretical models agreed well with those measured in experiment. The agreement with the results predicted by the simplified theoretical model was better than that with those predicted by the higher-order GDE model

    Interference Mitigation Methods for Unmanned Aerial Vehicles Served by Cellular Networks

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    A main challenge in providing connectivity to the low altitude unmanned aerial vehicles (UAVs) through existing cellular network arises due to the increased interference in the network. The increased altitude and favourable propagation condition cause UAVs to generate more interference to the neighbouring cells, and at the same time experience more interference from the downlink transmissions of the neighbouring base stations. The uplink interference problem may result in terrestrial UEs having degraded performance, whereas the downlink interference problem may make it challenging for a UAV to maintain connection with the network. In this paper, we propose several uplink and downlink interference mitigation techniques to address these issues. The results indicate that the proposed solutions can reduce the uplink throughput degradation of terrestrial UEs and ensure UAVs to remain in LTE coverage under the worst case scenarios when all the base stations transmit at full power.Comment: Submitted to IEEE 5G Word Forum 201
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